diff options
Diffstat (limited to 'mDNSResponder/mDNSCore/uDNS.c')
| -rwxr-xr-x | mDNSResponder/mDNSCore/uDNS.c | 5995 |
1 files changed, 5995 insertions, 0 deletions
diff --git a/mDNSResponder/mDNSCore/uDNS.c b/mDNSResponder/mDNSCore/uDNS.c new file mode 100755 index 00000000..be7a5a32 --- /dev/null +++ b/mDNSResponder/mDNSCore/uDNS.c @@ -0,0 +1,5995 @@ +/* -*- Mode: C; tab-width: 4 -*- + * + * Copyright (c) 2002-2013 Apple Computer, Inc. All rights reserved. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + + * To Do: + * Elimate all mDNSPlatformMemAllocate/mDNSPlatformMemFree from this code -- the core code + * is supposed to be malloc-free so that it runs in constant memory determined at compile-time. + * Any dynamic run-time requirements should be handled by the platform layer below or client layer above + */ + +#if APPLE_OSX_mDNSResponder +#include <TargetConditionals.h> +#endif +#include "uDNS.h" + +#if (defined(_MSC_VER)) +// Disable "assignment within conditional expression". +// Other compilers understand the convention that if you place the assignment expression within an extra pair +// of parentheses, this signals to the compiler that you really intended an assignment and no warning is necessary. +// The Microsoft compiler doesn't understand this convention, so in the absense of any other way to signal +// to the compiler that the assignment is intentional, we have to just turn this warning off completely. + #pragma warning(disable:4706) +#endif + +// For domain enumeration and automatic browsing +// This is the user's DNS search list. +// In each of these domains we search for our special pointer records (lb._dns-sd._udp.<domain>, etc.) +// to discover recommended domains for domain enumeration (browse, default browse, registration, +// default registration) and possibly one or more recommended automatic browsing domains. +mDNSexport SearchListElem *SearchList = mDNSNULL; + +// The value can be set to true by the Platform code e.g., MacOSX uses the plist mechanism +mDNSBool StrictUnicastOrdering = mDNSfalse; + +// We keep track of the number of unicast DNS servers and log a message when we exceed 64. +// Currently the unicast queries maintain a 64 bit map to track the valid DNS servers for that +// question. Bit position is the index into the DNS server list. This is done so to try all +// the servers exactly once before giving up. If we could allocate memory in the core, then +// arbitrary limitation of 64 DNSServers can be removed. +mDNSu8 NumUnicastDNSServers = 0; +#define MAX_UNICAST_DNS_SERVERS 64 + +#define SetNextuDNSEvent(m, rr) { \ + if ((m)->NextuDNSEvent - ((rr)->LastAPTime + (rr)->ThisAPInterval) >= 0) \ + (m)->NextuDNSEvent = ((rr)->LastAPTime + (rr)->ThisAPInterval); \ +} + +#ifndef UNICAST_DISABLED + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - General Utility Functions +#endif + +// set retry timestamp for record with exponential backoff +mDNSlocal void SetRecordRetry(mDNS *const m, AuthRecord *rr, mDNSu32 random) +{ + rr->LastAPTime = m->timenow; + + if (rr->expire && rr->refreshCount < MAX_UPDATE_REFRESH_COUNT) + { + mDNSs32 remaining = rr->expire - m->timenow; + rr->refreshCount++; + if (remaining > MIN_UPDATE_REFRESH_TIME) + { + // Refresh at 70% + random (currently it is 0 to 10%) + rr->ThisAPInterval = 7 * (remaining/10) + (random ? random : mDNSRandom(remaining/10)); + // Don't update more often than 5 minutes + if (rr->ThisAPInterval < MIN_UPDATE_REFRESH_TIME) + rr->ThisAPInterval = MIN_UPDATE_REFRESH_TIME; + LogInfo("SetRecordRetry refresh in %d of %d for %s", + rr->ThisAPInterval/mDNSPlatformOneSecond, (rr->expire - m->timenow)/mDNSPlatformOneSecond, ARDisplayString(m, rr)); + } + else + { + rr->ThisAPInterval = MIN_UPDATE_REFRESH_TIME; + LogInfo("SetRecordRetry clamping to min refresh in %d of %d for %s", + rr->ThisAPInterval/mDNSPlatformOneSecond, (rr->expire - m->timenow)/mDNSPlatformOneSecond, ARDisplayString(m, rr)); + } + return; + } + + rr->expire = 0; + + rr->ThisAPInterval = rr->ThisAPInterval * QuestionIntervalStep; // Same Retry logic as Unicast Queries + if (rr->ThisAPInterval < INIT_RECORD_REG_INTERVAL) + rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; + if (rr->ThisAPInterval > MAX_RECORD_REG_INTERVAL) + rr->ThisAPInterval = MAX_RECORD_REG_INTERVAL; + + LogInfo("SetRecordRetry retry in %d ms for %s", rr->ThisAPInterval, ARDisplayString(m, rr)); +} + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - Name Server List Management +#endif + +mDNSexport DNSServer *mDNS_AddDNSServer(mDNS *const m, const domainname *d, const mDNSInterfaceID interface, const mDNSs32 serviceID, const mDNSAddr *addr, + const mDNSIPPort port, mDNSu32 scoped, mDNSu32 timeout, mDNSBool cellIntf, mDNSu16 resGroupID, mDNSBool reqA, + mDNSBool reqAAAA, mDNSBool reqDO) +{ + DNSServer **p = &m->DNSServers; + DNSServer *tmp = mDNSNULL; + + if ((NumUnicastDNSServers + 1) > MAX_UNICAST_DNS_SERVERS) + { + LogMsg("mDNS_AddDNSServer: DNS server limit of %d reached, not adding this server", MAX_UNICAST_DNS_SERVERS); + return mDNSNULL; + } + + if (!d) + d = (const domainname *)""; + + LogInfo("mDNS_AddDNSServer(%d): Adding %#a for %##s, InterfaceID %p, serviceID %u, scoped %d, resGroupID %d req_A is %s req_AAAA is %s cell %s req_DO is %s", + NumUnicastDNSServers, addr, d->c, interface, serviceID, scoped, resGroupID, reqA ? "True" : "False", reqAAAA ? "True" : "False", + cellIntf ? "True" : "False", reqDO ? "True" : "False"); + + mDNS_CheckLock(m); + + while (*p) // Check if we already have this {interface,address,port,domain} tuple registered + reqA/reqAAAA bits + { + if ((*p)->scoped == scoped && (*p)->interface == interface && (*p)->serviceID == serviceID && (*p)->teststate != DNSServer_Disabled && + mDNSSameAddress(&(*p)->addr, addr) && mDNSSameIPPort((*p)->port, port) && SameDomainName(&(*p)->domain, d) && + (*p)->req_A == reqA && (*p)->req_AAAA == reqAAAA) + { + if (!((*p)->flags & DNSServer_FlagDelete)) + debugf("Note: DNS Server %#a:%d for domain %##s (%p) registered more than once", addr, mDNSVal16(port), d->c, interface); + tmp = *p; + *p = tmp->next; + tmp->next = mDNSNULL; + } + else + { + p=&(*p)->next; + } + } + + // NumUnicastDNSServers is the count of active DNS servers i.e., ones that are not marked + // with DNSServer_FlagDelete. We should increment it: + // + // 1) When we add a new DNS server + // 2) When we resurrect a old DNS server that is marked with DNSServer_FlagDelete + // + // Don't increment when we resurrect a DNS server that is not marked with DNSServer_FlagDelete. + // We have already accounted for it when it was added for the first time. This case happens when + // we add DNS servers with the same address multiple times (mis-configuration). + + if (!tmp || (tmp->flags & DNSServer_FlagDelete)) + NumUnicastDNSServers++; + + + if (tmp) + { + tmp->flags &= ~DNSServer_FlagDelete; + *p = tmp; // move to end of list, to ensure ordering from platform layer + } + else + { + // allocate, add to list + *p = mDNSPlatformMemAllocate(sizeof(**p)); + if (!*p) + { + LogMsg("Error: mDNS_AddDNSServer - malloc"); + } + else + { + (*p)->scoped = scoped; + (*p)->interface = interface; + (*p)->serviceID = serviceID; + (*p)->addr = *addr; + (*p)->port = port; + (*p)->flags = DNSServer_FlagNew; + (*p)->teststate = /* DNSServer_Untested */ DNSServer_Passed; + (*p)->lasttest = m->timenow - INIT_UCAST_POLL_INTERVAL; + (*p)->timeout = timeout; + (*p)->cellIntf = cellIntf; + (*p)->req_A = reqA; + (*p)->req_AAAA = reqAAAA; + (*p)->req_DO = reqDO; + // We start off assuming that the DNS server is not DNSSEC aware and + // when we receive the first response to a DNSSEC question, we set + // it to true. + (*p)->DNSSECAware = mDNSfalse; + (*p)->retransDO = 0; + AssignDomainName(&(*p)->domain, d); + (*p)->next = mDNSNULL; + } + } + (*p)->penaltyTime = 0; + // We always update the ID (not just when we allocate a new instance) because we could + // be adding a new non-scoped resolver with a new ID and we want all the non-scoped + // resolvers belong to the same group. + (*p)->resGroupID = resGroupID; + return(*p); +} + +// PenalizeDNSServer is called when the number of queries to the unicast +// DNS server exceeds MAX_UCAST_UNANSWERED_QUERIES or when we receive an +// error e.g., SERV_FAIL from DNS server. +mDNSexport void PenalizeDNSServer(mDNS *const m, DNSQuestion *q, mDNSOpaque16 responseFlags) +{ + DNSServer *new; + DNSServer *orig = q->qDNSServer; + + mDNS_CheckLock(m); + + LogInfo("PenalizeDNSServer: Penalizing DNS server %#a question for question %p %##s (%s) SuppressUnusable %d", + (q->qDNSServer ? &q->qDNSServer->addr : mDNSNULL), q, q->qname.c, DNSTypeName(q->qtype), q->SuppressUnusable); + + // If we get error from any DNS server, remember the error. If all of the servers, + // return the error, then return the first error. + if (mDNSOpaque16IsZero(q->responseFlags)) + q->responseFlags = responseFlags; + + // After we reset the qDNSServer to NULL, we could get more SERV_FAILS that might end up + // peanlizing again. + if (!q->qDNSServer) goto end; + + // If strict ordering of unicast servers needs to be preserved, we just lookup + // the next best match server below + // + // If strict ordering is not required which is the default behavior, we penalize the server + // for DNSSERVER_PENALTY_TIME. We may also use additional logic e.g., don't penalize for PTR + // in the future. + + if (!StrictUnicastOrdering) + { + LogInfo("PenalizeDNSServer: Strict Unicast Ordering is FALSE"); + // We penalize the server so that new queries don't pick this server for DNSSERVER_PENALTY_TIME + // XXX Include other logic here to see if this server should really be penalized + // + if (q->qtype == kDNSType_PTR) + { + LogInfo("PenalizeDNSServer: Not Penalizing PTR question"); + } + else + { + LogInfo("PenalizeDNSServer: Penalizing question type %d", q->qtype); + q->qDNSServer->penaltyTime = NonZeroTime(m->timenow + DNSSERVER_PENALTY_TIME); + } + } + else + { + LogInfo("PenalizeDNSServer: Strict Unicast Ordering is TRUE"); + } + +end: + new = GetServerForQuestion(m, q); + + if (new == orig) + { + if (new) + { + LogMsg("PenalizeDNSServer: ERROR!! GetServerForQuestion returned the same server %#a:%d", &new->addr, + mDNSVal16(new->port)); + q->ThisQInterval = 0; // Inactivate this question so that we dont bombard the network + } + else + { + // When we have no more DNS servers, we might end up calling PenalizeDNSServer multiple + // times when we receive SERVFAIL from delayed packets in the network e.g., DNS server + // is slow in responding and we have sent three queries. When we repeatedly call, it is + // okay to receive the same NULL DNS server. Next time we try to send the query, we will + // realize and re-initialize the DNS servers. + LogInfo("PenalizeDNSServer: GetServerForQuestion returned the same server NULL"); + } + } + else + { + // The new DNSServer is set in DNSServerChangeForQuestion + DNSServerChangeForQuestion(m, q, new); + + if (new) + { + LogInfo("PenalizeDNSServer: Server for %##s (%s) changed to %#a:%d (%##s)", + q->qname.c, DNSTypeName(q->qtype), &q->qDNSServer->addr, mDNSVal16(q->qDNSServer->port), q->qDNSServer->domain.c); + // We want to try the next server immediately. As the question may already have backed off, reset + // the interval. We do this only the first time when we try all the DNS servers. Once we reached the end of + // list and retrying all the servers again e.g., at least one server failed to respond in the previous try, we + // use the normal backoff which is done in uDNS_CheckCurrentQuestion when we send the packet out. + if (!q->triedAllServersOnce) + { + q->ThisQInterval = InitialQuestionInterval; + q->LastQTime = m->timenow - q->ThisQInterval; + SetNextQueryTime(m, q); + } + } + else + { + // We don't have any more DNS servers for this question. If some server in the list did not return + // any response, we need to keep retrying till we get a response. uDNS_CheckCurrentQuestion handles + // this case. + // + // If all servers responded with a negative response, We need to do two things. First, generate a + // negative response so that applications get a reply. We also need to reinitialize the DNS servers + // so that when the cache expires, we can restart the query. We defer this up until we generate + // a negative cache response in uDNS_CheckCurrentQuestion. + // + // Be careful not to touch the ThisQInterval here. For a normal question, when we answer the question + // in AnswerCurrentQuestionWithResourceRecord will set ThisQInterval to MaxQuestionInterval and hence + // the next query will not happen until cache expiry. If it is a long lived question, + // AnswerCurrentQuestionWithResourceRecord will not set it to MaxQuestionInterval. In that case, + // we want the normal backoff to work. + LogInfo("PenalizeDNSServer: Server for %p, %##s (%s) changed to NULL, Interval %d", q, q->qname.c, DNSTypeName(q->qtype), q->ThisQInterval); + } + q->unansweredQueries = 0; + + } +} + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - authorization management +#endif + +mDNSlocal DomainAuthInfo *GetAuthInfoForName_direct(mDNS *m, const domainname *const name) +{ + const domainname *n = name; + while (n->c[0]) + { + DomainAuthInfo *ptr; + for (ptr = m->AuthInfoList; ptr; ptr = ptr->next) + if (SameDomainName(&ptr->domain, n)) + { + debugf("GetAuthInfoForName %##s Matched %##s Key name %##s", name->c, ptr->domain.c, ptr->keyname.c); + return(ptr); + } + n = (const domainname *)(n->c + 1 + n->c[0]); + } + //LogInfo("GetAuthInfoForName none found for %##s", name->c); + return mDNSNULL; +} + +// MUST be called with lock held +mDNSexport DomainAuthInfo *GetAuthInfoForName_internal(mDNS *m, const domainname *const name) +{ + DomainAuthInfo **p = &m->AuthInfoList; + + mDNS_CheckLock(m); + + // First purge any dead keys from the list + while (*p) + { + if ((*p)->deltime && m->timenow - (*p)->deltime >= 0 && AutoTunnelUnregistered(*p)) + { + DNSQuestion *q; + DomainAuthInfo *info = *p; + LogInfo("GetAuthInfoForName_internal deleting expired key %##s %##s", info->domain.c, info->keyname.c); + *p = info->next; // Cut DomainAuthInfo from list *before* scanning our question list updating AuthInfo pointers + for (q = m->Questions; q; q=q->next) + if (q->AuthInfo == info) + { + q->AuthInfo = GetAuthInfoForName_direct(m, &q->qname); + debugf("GetAuthInfoForName_internal updated q->AuthInfo from %##s to %##s for %##s (%s)", + info->domain.c, q->AuthInfo ? q->AuthInfo->domain.c : mDNSNULL, q->qname.c, DNSTypeName(q->qtype)); + } + + // Probably not essential, but just to be safe, zero out the secret key data + // so we don't leave it hanging around in memory + // (where it could potentially get exposed via some other bug) + mDNSPlatformMemZero(info, sizeof(*info)); + mDNSPlatformMemFree(info); + } + else + p = &(*p)->next; + } + + return(GetAuthInfoForName_direct(m, name)); +} + +mDNSexport DomainAuthInfo *GetAuthInfoForName(mDNS *m, const domainname *const name) +{ + DomainAuthInfo *d; + mDNS_Lock(m); + d = GetAuthInfoForName_internal(m, name); + mDNS_Unlock(m); + return(d); +} + +// MUST be called with the lock held +mDNSexport mStatus mDNS_SetSecretForDomain(mDNS *m, DomainAuthInfo *info, + const domainname *domain, const domainname *keyname, const char *b64keydata, const domainname *hostname, mDNSIPPort *port, mDNSBool autoTunnel) +{ + DNSQuestion *q; + DomainAuthInfo **p = &m->AuthInfoList; + if (!info || !b64keydata) { LogMsg("mDNS_SetSecretForDomain: ERROR: info %p b64keydata %p", info, b64keydata); return(mStatus_BadParamErr); } + + LogInfo("mDNS_SetSecretForDomain: domain %##s key %##s%s", domain->c, keyname->c, autoTunnel ? " AutoTunnel" : ""); + + info->AutoTunnel = autoTunnel; + AssignDomainName(&info->domain, domain); + AssignDomainName(&info->keyname, keyname); + if (hostname) + AssignDomainName(&info->hostname, hostname); + else + info->hostname.c[0] = 0; + if (port) + info->port = *port; + else + info->port = zeroIPPort; + mDNS_snprintf(info->b64keydata, sizeof(info->b64keydata), "%s", b64keydata); + + if (DNSDigest_ConstructHMACKeyfromBase64(info, b64keydata) < 0) + { + LogMsg("mDNS_SetSecretForDomain: ERROR: Could not convert shared secret from base64: domain %##s key %##s %s", domain->c, keyname->c, mDNS_LoggingEnabled ? b64keydata : ""); + return(mStatus_BadParamErr); + } + + // Don't clear deltime until after we've ascertained that b64keydata is valid + info->deltime = 0; + + while (*p && (*p) != info) p=&(*p)->next; + if (*p) {LogInfo("mDNS_SetSecretForDomain: Domain %##s Already in list", (*p)->domain.c); return(mStatus_AlreadyRegistered);} + + // Caution: Only zero AutoTunnelHostRecord.namestorage AFTER we've determined that this is a NEW DomainAuthInfo + // being added to the list. Otherwise we risk smashing our AutoTunnel host records that are already active and in use. + info->AutoTunnelHostRecord.resrec.RecordType = kDNSRecordTypeUnregistered; + info->AutoTunnelHostRecord.namestorage.c[0] = 0; + info->AutoTunnelTarget.resrec.RecordType = kDNSRecordTypeUnregistered; + info->AutoTunnelDeviceInfo.resrec.RecordType = kDNSRecordTypeUnregistered; + info->AutoTunnelService.resrec.RecordType = kDNSRecordTypeUnregistered; + info->AutoTunnel6Record.resrec.RecordType = kDNSRecordTypeUnregistered; + info->AutoTunnelServiceStarted = mDNSfalse; + info->AutoTunnelInnerAddress = zerov6Addr; + info->next = mDNSNULL; + *p = info; + + // Check to see if adding this new DomainAuthInfo has changed the credentials for any of our questions + for (q = m->Questions; q; q=q->next) + { + DomainAuthInfo *newinfo = GetAuthInfoForQuestion(m, q); + if (q->AuthInfo != newinfo) + { + debugf("mDNS_SetSecretForDomain updating q->AuthInfo from %##s to %##s for %##s (%s)", + q->AuthInfo ? q->AuthInfo->domain.c : mDNSNULL, + newinfo ? newinfo->domain.c : mDNSNULL, q->qname.c, DNSTypeName(q->qtype)); + q->AuthInfo = newinfo; + } + } + + return(mStatus_NoError); +} + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - +#pragma mark - NAT Traversal +#endif + +// Keep track of when to request/refresh the external address using NAT-PMP or UPnP/IGD, +// and do so when necessary +mDNSlocal mStatus uDNS_RequestAddress(mDNS *m) +{ + mStatus err = mStatus_NoError; + + if (!m->NATTraversals) + { + m->retryGetAddr = NonZeroTime(m->timenow + 0x78000000); + LogInfo("uDNS_RequestAddress: Setting retryGetAddr to future"); + } + else if (m->timenow - m->retryGetAddr >= 0) + { + if (mDNSv4AddrIsRFC1918(&m->Router.ip.v4)) + { + static NATAddrRequest req = {NATMAP_VERS, NATOp_AddrRequest}; + static mDNSu8* start = (mDNSu8*)&req; + mDNSu8* end = start + sizeof(NATAddrRequest); + err = mDNSPlatformSendUDP(m, start, end, 0, mDNSNULL, &m->Router, NATPMPPort, mDNSfalse); + debugf("uDNS_RequestAddress: Sent NAT-PMP external address request %d", err); + +#ifdef _LEGACY_NAT_TRAVERSAL_ + if (mDNSIPPortIsZero(m->UPnPRouterPort) || mDNSIPPortIsZero(m->UPnPSOAPPort)) + { + LNT_SendDiscoveryMsg(m); + debugf("uDNS_RequestAddress: LNT_SendDiscoveryMsg"); + } + else + { + mStatus lnterr = LNT_GetExternalAddress(m); + if (lnterr) + LogMsg("uDNS_RequestAddress: LNT_GetExternalAddress returned error %d", lnterr); + + err = err ? err : lnterr; // NAT-PMP error takes precedence + } +#endif // _LEGACY_NAT_TRAVERSAL_ + } + + // Always update the interval and retry time, so that even if we fail to send the + // packet, we won't spin in an infinite loop repeatedly failing to send the packet + if (m->retryIntervalGetAddr < NATMAP_INIT_RETRY) + { + m->retryIntervalGetAddr = NATMAP_INIT_RETRY; + } + else if (m->retryIntervalGetAddr < NATMAP_MAX_RETRY_INTERVAL / 2) + { + m->retryIntervalGetAddr *= 2; + } + else + { + m->retryIntervalGetAddr = NATMAP_MAX_RETRY_INTERVAL; + } + + m->retryGetAddr = NonZeroTime(m->timenow + m->retryIntervalGetAddr); + } + else + { + debugf("uDNS_RequestAddress: Not time to send address request"); + } + + // Always update NextScheduledNATOp, even if we didn't change retryGetAddr, so we'll + // be called when we need to send the request(s) + if (m->NextScheduledNATOp - m->retryGetAddr > 0) + m->NextScheduledNATOp = m->retryGetAddr; + + return err; +} + +mDNSlocal mStatus uDNS_SendNATMsg(mDNS *m, NATTraversalInfo *info, mDNSBool usePCP) +{ + mStatus err = mStatus_NoError; + + if (!info) + { + LogMsg("uDNS_SendNATMsg called unexpectedly with NULL info"); + return mStatus_BadParamErr; + } + + // send msg if the router's address is private (which means it's non-zero) + if (mDNSv4AddrIsRFC1918(&m->Router.ip.v4)) + { + if (!usePCP) + { + if (!info->sentNATPMP) + { + if (info->Protocol) + { + static NATPortMapRequest NATPortReq; + static const mDNSu8* end = (mDNSu8 *)&NATPortReq + sizeof(NATPortMapRequest); + mDNSu8 *p = (mDNSu8 *)&NATPortReq.NATReq_lease; + + NATPortReq.vers = NATMAP_VERS; + NATPortReq.opcode = info->Protocol; + NATPortReq.unused = zeroID; + NATPortReq.intport = info->IntPort; + NATPortReq.extport = info->RequestedPort; + p[0] = (mDNSu8)((info->NATLease >> 24) & 0xFF); + p[1] = (mDNSu8)((info->NATLease >> 16) & 0xFF); + p[2] = (mDNSu8)((info->NATLease >> 8) & 0xFF); + p[3] = (mDNSu8)( info->NATLease & 0xFF); + + err = mDNSPlatformSendUDP(m, (mDNSu8 *)&NATPortReq, end, 0, mDNSNULL, &m->Router, NATPMPPort, mDNSfalse); + debugf("uDNS_SendNATMsg: Sent NAT-PMP mapping request %d", err); + } + + // In case the address request already went out for another NAT-T, + // set the NewAddress to the currently known global external address, so + // Address-only operations will get the callback immediately + info->NewAddress = m->ExtAddress; + + // Remember that we just sent a NAT-PMP packet, so we won't resend one later. + // We do this because the NAT-PMP "Unsupported Version" response has no + // information about the (PCP) request that triggered it, so we must send + // NAT-PMP requests for all operations. Without this, we'll send n PCP + // requests for n operations, receive n NAT-PMP "Unsupported Version" + // responses, and send n NAT-PMP requests for each of those responses, + // resulting in (n + n^2) packets sent. We only want to send 2n packets: + // n PCP requests followed by n NAT-PMP requests. + info->sentNATPMP = mDNStrue; + } + } + else + { + PCPMapRequest req; + mDNSu8* start = (mDNSu8*)&req; + mDNSu8* end = start + sizeof(req); + mDNSu8* p = (mDNSu8*)&req.lifetime; + + req.version = PCP_VERS; + req.opCode = PCPOp_Map; + req.reserved = zeroID; + + p[0] = (mDNSu8)((info->NATLease >> 24) & 0xFF); + p[1] = (mDNSu8)((info->NATLease >> 16) & 0xFF); + p[2] = (mDNSu8)((info->NATLease >> 8) & 0xFF); + p[3] = (mDNSu8)( info->NATLease & 0xFF); + + mDNSAddrMapIPv4toIPv6(&m->AdvertisedV4.ip.v4, &req.clientAddr); + + req.nonce[0] = m->PCPNonce[0]; + req.nonce[1] = m->PCPNonce[1]; + req.nonce[2] = m->PCPNonce[2]; + + req.protocol = (info->Protocol == NATOp_MapUDP ? PCPProto_UDP : PCPProto_TCP); + + req.reservedMapOp[0] = 0; + req.reservedMapOp[1] = 0; + req.reservedMapOp[2] = 0; + + req.intPort = info->Protocol ? info->IntPort : DiscardPort; + req.extPort = info->RequestedPort; + + // Since we only support IPv4, even if using the all-zeros address, map it, so + // the PCP gateway will give us an IPv4 address & not an IPv6 address. + mDNSAddrMapIPv4toIPv6(&info->NewAddress, &req.extAddress); + + err = mDNSPlatformSendUDP(m, start, end, 0, mDNSNULL, &m->Router, NATPMPPort, mDNSfalse); + debugf("uDNS_SendNATMsg: Sent PCP Mapping request %d", err); + + // Unset the sentNATPMP flag, so that we'll send a NAT-PMP packet if we + // receive a NAT-PMP "Unsupported Version" packet. This will result in every + // renewal, retransmission, etc. being tried first as PCP, then if a NAT-PMP + // "Unsupported Version" response is received, fall-back & send the request + // using NAT-PMP. + info->sentNATPMP = mDNSfalse; + +#ifdef _LEGACY_NAT_TRAVERSAL_ + if (mDNSIPPortIsZero(m->UPnPRouterPort) || mDNSIPPortIsZero(m->UPnPSOAPPort)) + { + LNT_SendDiscoveryMsg(m); + debugf("uDNS_SendNATMsg: LNT_SendDiscoveryMsg"); + } + else + { + mStatus lnterr = LNT_MapPort(m, info); + if (lnterr) + LogMsg("uDNS_SendNATMsg: LNT_MapPort returned error %d", lnterr); + + err = err ? err : lnterr; // PCP error takes precedence + } +#endif // _LEGACY_NAT_TRAVERSAL_ + } + } + + return(err); +} + +mDNSexport void RecreateNATMappings(mDNS *const m, const mDNSu32 waitTicks) +{ + mDNSu32 when = NonZeroTime(m->timenow + waitTicks); + NATTraversalInfo *n; + for (n = m->NATTraversals; n; n=n->next) + { + n->ExpiryTime = 0; // Mark this mapping as expired + n->retryInterval = NATMAP_INIT_RETRY; + n->retryPortMap = when; + n->lastSuccessfulProtocol = NATTProtocolNone; + if (!n->Protocol) n->NewResult = mStatus_NoError; +#ifdef _LEGACY_NAT_TRAVERSAL_ + if (n->tcpInfo.sock) { mDNSPlatformTCPCloseConnection(n->tcpInfo.sock); n->tcpInfo.sock = mDNSNULL; } +#endif // _LEGACY_NAT_TRAVERSAL_ + } + + m->PCPNonce[0] = mDNSRandom(-1); + m->PCPNonce[1] = mDNSRandom(-1); + m->PCPNonce[2] = mDNSRandom(-1); + m->retryIntervalGetAddr = 0; + m->retryGetAddr = when; + +#ifdef _LEGACY_NAT_TRAVERSAL_ + LNT_ClearState(m); +#endif // _LEGACY_NAT_TRAVERSAL_ + + m->NextScheduledNATOp = m->timenow; // Need to send packets immediately +} + +mDNSexport void natTraversalHandleAddressReply(mDNS *const m, mDNSu16 err, mDNSv4Addr ExtAddr) +{ + static mDNSu16 last_err = 0; + NATTraversalInfo *n; + + if (err) + { + if (err != last_err) LogMsg("Error getting external address %d", err); + ExtAddr = zerov4Addr; + } + else + { + LogInfo("Received external IP address %.4a from NAT", &ExtAddr); + if (mDNSv4AddrIsRFC1918(&ExtAddr)) + LogMsg("Double NAT (external NAT gateway address %.4a is also a private RFC 1918 address)", &ExtAddr); + if (mDNSIPv4AddressIsZero(ExtAddr)) + err = NATErr_NetFail; // fake error to handle routers that pathologically report success with the zero address + } + + // Globally remember the most recently discovered address, so it can be used in each + // new NATTraversal structure + m->ExtAddress = ExtAddr; + + if (!err) // Success, back-off to maximum interval + m->retryIntervalGetAddr = NATMAP_MAX_RETRY_INTERVAL; + else if (!last_err) // Failure after success, retry quickly (then back-off exponentially) + m->retryIntervalGetAddr = NATMAP_INIT_RETRY; + // else back-off normally in case of pathological failures + + m->retryGetAddr = m->timenow + m->retryIntervalGetAddr; + if (m->NextScheduledNATOp - m->retryGetAddr > 0) + m->NextScheduledNATOp = m->retryGetAddr; + + last_err = err; + + for (n = m->NATTraversals; n; n=n->next) + { + // We should change n->NewAddress only when n is one of: + // 1) a mapping operation that most recently succeeded using NAT-PMP or UPnP/IGD, + // because such an operation needs the update now. If the lastSuccessfulProtocol + // is currently none, then natTraversalHandlePortMapReplyWithAddress() will be + // called should NAT-PMP or UPnP/IGD succeed in the future. + // 2) an address-only operation that did not succeed via PCP, because when such an + // operation succeeds via PCP, it's for the TCP discard port just to learn the + // address. And that address may be different than the external address + // discovered via NAT-PMP or UPnP/IGD. If the lastSuccessfulProtocol + // is currently none, we must update the NewAddress as PCP may not succeed. + if (!mDNSSameIPv4Address(n->NewAddress, ExtAddr) && + (n->Protocol ? + (n->lastSuccessfulProtocol == NATTProtocolNATPMP || n->lastSuccessfulProtocol == NATTProtocolUPNPIGD) : + (n->lastSuccessfulProtocol != NATTProtocolPCP))) + { + // Needs an update immediately + n->NewAddress = ExtAddr; + n->ExpiryTime = 0; + n->retryInterval = NATMAP_INIT_RETRY; + n->retryPortMap = m->timenow; +#ifdef _LEGACY_NAT_TRAVERSAL_ + if (n->tcpInfo.sock) { mDNSPlatformTCPCloseConnection(n->tcpInfo.sock); n->tcpInfo.sock = mDNSNULL; } +#endif // _LEGACY_NAT_TRAVERSAL_ + + m->NextScheduledNATOp = m->timenow; // Need to send packets immediately + } + } +} + +// Both places that call NATSetNextRenewalTime() update m->NextScheduledNATOp correctly afterwards +mDNSlocal void NATSetNextRenewalTime(mDNS *const m, NATTraversalInfo *n) +{ + n->retryInterval = (n->ExpiryTime - m->timenow)/2; + if (n->retryInterval < NATMAP_MIN_RETRY_INTERVAL) // Min retry interval is 2 seconds + n->retryInterval = NATMAP_MIN_RETRY_INTERVAL; + n->retryPortMap = m->timenow + n->retryInterval; +} + +mDNSlocal void natTraversalHandlePortMapReplyWithAddress(mDNS *const m, NATTraversalInfo *n, const mDNSInterfaceID InterfaceID, mDNSu16 err, mDNSv4Addr extaddr, mDNSIPPort extport, mDNSu32 lease, NATTProtocol protocol) +{ + const char *prot = n->Protocol == 0 ? "Add" : n->Protocol == NATOp_MapUDP ? "UDP" : n->Protocol == NATOp_MapTCP ? "TCP" : "???"; + (void)prot; + n->NewResult = err; + if (err || lease == 0 || mDNSIPPortIsZero(extport)) + { + LogInfo("natTraversalHandlePortMapReplyWithAddress: %p Response %s Port %5d External %.4a:%d lease %d error %d", + n, prot, mDNSVal16(n->IntPort), &extaddr, mDNSVal16(extport), lease, err); + n->retryInterval = NATMAP_MAX_RETRY_INTERVAL; + n->retryPortMap = m->timenow + NATMAP_MAX_RETRY_INTERVAL; + // No need to set m->NextScheduledNATOp here, since we're only ever extending the m->retryPortMap time + if (err == NATErr_Refused) n->NewResult = mStatus_NATPortMappingDisabled; + else if (err > NATErr_None && err <= NATErr_Opcode) n->NewResult = mStatus_NATPortMappingUnsupported; + } + else + { + if (lease > 999999999UL / mDNSPlatformOneSecond) + lease = 999999999UL / mDNSPlatformOneSecond; + n->ExpiryTime = NonZeroTime(m->timenow + lease * mDNSPlatformOneSecond); + + if (!mDNSSameIPv4Address(n->NewAddress, extaddr) || !mDNSSameIPPort(n->RequestedPort, extport)) + LogInfo("natTraversalHandlePortMapReplyWithAddress: %p %s Response %s Port %5d External %.4a:%d changed to %.4a:%d lease %d", + n, + (n->lastSuccessfulProtocol == NATTProtocolNone ? "None " : + n->lastSuccessfulProtocol == NATTProtocolNATPMP ? "NAT-PMP " : + n->lastSuccessfulProtocol == NATTProtocolUPNPIGD ? "UPnP/IGD" : + n->lastSuccessfulProtocol == NATTProtocolPCP ? "PCP " : + /* else */ "Unknown " ), + prot, mDNSVal16(n->IntPort), &n->NewAddress, mDNSVal16(n->RequestedPort), + &extaddr, mDNSVal16(extport), lease); + + n->InterfaceID = InterfaceID; + n->NewAddress = extaddr; + if (n->Protocol) n->RequestedPort = extport; // Don't report the (PCP) external port to address-only operations + n->lastSuccessfulProtocol = protocol; + + NATSetNextRenewalTime(m, n); // Got our port mapping; now set timer to renew it at halfway point + m->NextScheduledNATOp = m->timenow; // May need to invoke client callback immediately + } +} + +// To be called for NAT-PMP or UPnP/IGD mappings, to use currently discovered (global) address +mDNSexport void natTraversalHandlePortMapReply(mDNS *const m, NATTraversalInfo *n, const mDNSInterfaceID InterfaceID, mDNSu16 err, mDNSIPPort extport, mDNSu32 lease, NATTProtocol protocol) +{ + natTraversalHandlePortMapReplyWithAddress(m, n, InterfaceID, err, m->ExtAddress, extport, lease, protocol); +} + +// Must be called with the mDNS_Lock held +mDNSexport mStatus mDNS_StartNATOperation_internal(mDNS *const m, NATTraversalInfo *traversal) +{ + NATTraversalInfo **n; + + LogInfo("mDNS_StartNATOperation_internal %p Protocol %d IntPort %d RequestedPort %d NATLease %d", traversal, + traversal->Protocol, mDNSVal16(traversal->IntPort), mDNSVal16(traversal->RequestedPort), traversal->NATLease); + + // Note: It important that new traversal requests are appended at the *end* of the list, not prepended at the start + for (n = &m->NATTraversals; *n; n=&(*n)->next) + { + if (traversal == *n) + { + LogMsg("Error! Tried to add a NAT traversal that's already in the active list: request %p Prot %d Int %d TTL %d", + traversal, traversal->Protocol, mDNSVal16(traversal->IntPort), traversal->NATLease); + #if ForceAlerts + *(long*)0 = 0; + #endif + return(mStatus_AlreadyRegistered); + } + if (traversal->Protocol && traversal->Protocol == (*n)->Protocol && mDNSSameIPPort(traversal->IntPort, (*n)->IntPort) && + !mDNSSameIPPort(traversal->IntPort, SSHPort)) + LogMsg("Warning: Created port mapping request %p Prot %d Int %d TTL %d " + "duplicates existing port mapping request %p Prot %d Int %d TTL %d", + traversal, traversal->Protocol, mDNSVal16(traversal->IntPort), traversal->NATLease, + *n, (*n)->Protocol, mDNSVal16((*n)->IntPort), (*n)->NATLease); + } + + // Initialize necessary fields + traversal->next = mDNSNULL; + traversal->ExpiryTime = 0; + traversal->retryInterval = NATMAP_INIT_RETRY; + traversal->retryPortMap = m->timenow; + traversal->NewResult = mStatus_NoError; + traversal->lastSuccessfulProtocol = NATTProtocolNone; + traversal->sentNATPMP = mDNSfalse; + traversal->ExternalAddress = onesIPv4Addr; + traversal->NewAddress = zerov4Addr; + traversal->ExternalPort = zeroIPPort; + traversal->Lifetime = 0; + traversal->Result = mStatus_NoError; + + // set default lease if necessary + if (!traversal->NATLease) traversal->NATLease = NATMAP_DEFAULT_LEASE; + +#ifdef _LEGACY_NAT_TRAVERSAL_ + mDNSPlatformMemZero(&traversal->tcpInfo, sizeof(traversal->tcpInfo)); +#endif // _LEGACY_NAT_TRAVERSAL_ + + if (!m->NATTraversals) // If this is our first NAT request, kick off an address request too + { + m->retryGetAddr = m->timenow; + m->retryIntervalGetAddr = NATMAP_INIT_RETRY; + } + + // If this is an address-only operation, initialize to the current global address, + // or (in non-PCP environments) we won't know the address until the next external + // address request/response. + if (!traversal->Protocol) + { + traversal->NewAddress = m->ExtAddress; + } + + m->NextScheduledNATOp = m->timenow; // This will always trigger sending the packet ASAP, and generate client callback if necessary + + *n = traversal; // Append new NATTraversalInfo to the end of our list + + return(mStatus_NoError); +} + +// Must be called with the mDNS_Lock held +mDNSexport mStatus mDNS_StopNATOperation_internal(mDNS *m, NATTraversalInfo *traversal) +{ + mDNSBool unmap = mDNStrue; + NATTraversalInfo *p; + NATTraversalInfo **ptr = &m->NATTraversals; + + while (*ptr && *ptr != traversal) ptr=&(*ptr)->next; + if (*ptr) *ptr = (*ptr)->next; // If we found it, cut this NATTraversalInfo struct from our list + else + { + LogMsg("mDNS_StopNATOperation_internal: NATTraversalInfo %p not found in list", traversal); + return(mStatus_BadReferenceErr); + } + + LogInfo("mDNS_StopNATOperation_internal %p %d %d %d %d", traversal, + traversal->Protocol, mDNSVal16(traversal->IntPort), mDNSVal16(traversal->RequestedPort), traversal->NATLease); + + if (m->CurrentNATTraversal == traversal) + m->CurrentNATTraversal = m->CurrentNATTraversal->next; + + // If there is a match for the operation being stopped, don't send a deletion request (unmap) + for (p = m->NATTraversals; p; p=p->next) + { + if (traversal->Protocol ? + ((traversal->Protocol == p->Protocol && mDNSSameIPPort(traversal->IntPort, p->IntPort)) || + (!p->Protocol && traversal->Protocol == NATOp_MapTCP && mDNSSameIPPort(traversal->IntPort, DiscardPort))) : + (!p->Protocol || (p->Protocol == NATOp_MapTCP && mDNSSameIPPort(p->IntPort, DiscardPort)))) + { + LogInfo("Warning: Removed port mapping request %p Prot %d Int %d TTL %d " + "duplicates existing port mapping request %p Prot %d Int %d TTL %d", + traversal, traversal->Protocol, mDNSVal16(traversal->IntPort), traversal->NATLease, + p, p->Protocol, mDNSVal16( p->IntPort), p->NATLease); + unmap = mDNSfalse; + } + } + + if (traversal->ExpiryTime && unmap) + { + traversal->NATLease = 0; + traversal->retryInterval = 0; + + // In case we most recently sent NAT-PMP, we need to set sentNATPMP to false so + // that we'll send a NAT-PMP request to destroy the mapping. We do this because + // the NATTraversal struct has already been cut from the list, and the client + // layer will destroy the memory upon returning from this function, so we can't + // try PCP first and then fall-back to NAT-PMP. That is, if we most recently + // created/renewed the mapping using NAT-PMP, we need to destroy it using NAT-PMP + // now, because we won't get a chance later. + traversal->sentNATPMP = mDNSfalse; + + // Both NAT-PMP & PCP RFCs state that the suggested port in deletion requests + // should be zero. And for PCP, the suggested external address should also be + // zero, specifically, the all-zeros IPv4-mapped address, since we would only + // would have requested an IPv4 address. + traversal->RequestedPort = zeroIPPort; + traversal->NewAddress = zerov4Addr; + + uDNS_SendNATMsg(m, traversal, traversal->lastSuccessfulProtocol != NATTProtocolNATPMP); + } + + // Even if we DIDN'T make a successful UPnP mapping yet, we might still have a partially-open TCP connection we need to clean up + #ifdef _LEGACY_NAT_TRAVERSAL_ + { + mStatus err = LNT_UnmapPort(m, traversal); + if (err) LogMsg("Legacy NAT Traversal - unmap request failed with error %d", err); + } + #endif // _LEGACY_NAT_TRAVERSAL_ + + return(mStatus_NoError); +} + +mDNSexport mStatus mDNS_StartNATOperation(mDNS *const m, NATTraversalInfo *traversal) +{ + mStatus status; + mDNS_Lock(m); + status = mDNS_StartNATOperation_internal(m, traversal); + mDNS_Unlock(m); + return(status); +} + +mDNSexport mStatus mDNS_StopNATOperation(mDNS *const m, NATTraversalInfo *traversal) +{ + mStatus status; + mDNS_Lock(m); + status = mDNS_StopNATOperation_internal(m, traversal); + mDNS_Unlock(m); + return(status); +} + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - +#pragma mark - Long-Lived Queries +#endif + +// Lock must be held -- otherwise m->timenow is undefined +mDNSlocal void StartLLQPolling(mDNS *const m, DNSQuestion *q) +{ + debugf("StartLLQPolling: %##s", q->qname.c); + q->state = LLQ_Poll; + q->ThisQInterval = INIT_UCAST_POLL_INTERVAL; + // We want to send our poll query ASAP, but the "+ 1" is because if we set the time to now, + // we risk causing spurious "SendQueries didn't send all its queries" log messages + q->LastQTime = m->timenow - q->ThisQInterval + 1; + SetNextQueryTime(m, q); +#if APPLE_OSX_mDNSResponder + UpdateAutoTunnelDomainStatuses(m); +#endif +} + +mDNSlocal mDNSu8 *putLLQ(DNSMessage *const msg, mDNSu8 *ptr, const DNSQuestion *const question, const LLQOptData *const data) +{ + AuthRecord rr; + ResourceRecord *opt = &rr.resrec; + rdataOPT *optRD; + + //!!!KRS when we implement multiple llqs per message, we'll need to memmove anything past the question section + ptr = putQuestion(msg, ptr, msg->data + AbsoluteMaxDNSMessageData, &question->qname, question->qtype, question->qclass); + if (!ptr) { LogMsg("ERROR: putLLQ - putQuestion"); return mDNSNULL; } + + // locate OptRR if it exists, set pointer to end + // !!!KRS implement me + + // format opt rr (fields not specified are zero-valued) + mDNS_SetupResourceRecord(&rr, mDNSNULL, mDNSInterface_Any, kDNSType_OPT, kStandardTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, mDNSNULL, mDNSNULL); + opt->rrclass = NormalMaxDNSMessageData; + opt->rdlength = sizeof(rdataOPT); // One option in this OPT record + opt->rdestimate = sizeof(rdataOPT); + + optRD = &rr.resrec.rdata->u.opt[0]; + optRD->opt = kDNSOpt_LLQ; + optRD->u.llq = *data; + ptr = PutResourceRecordTTLJumbo(msg, ptr, &msg->h.numAdditionals, opt, 0); + if (!ptr) { LogMsg("ERROR: putLLQ - PutResourceRecordTTLJumbo"); return mDNSNULL; } + + return ptr; +} + +// Normally we'd just request event packets be sent directly to m->LLQNAT.ExternalPort, except... +// with LLQs over TLS/TCP we're doing a weird thing where instead of requesting packets be sent to ExternalAddress:ExternalPort +// we're requesting that packets be sent to ExternalPort, but at the source address of our outgoing TCP connection. +// Normally, after going through the NAT gateway, the source address of our outgoing TCP connection is the same as ExternalAddress, +// so this is fine, except when the TCP connection ends up going over a VPN tunnel instead. +// To work around this, if we find that the source address for our TCP connection is not a private address, we tell the Dot Mac +// LLQ server to send events to us directly at port 5353 on that address, instead of at our mapped external NAT port. + +mDNSlocal mDNSu16 GetLLQEventPort(const mDNS *const m, const mDNSAddr *const dst) +{ + mDNSAddr src; + mDNSPlatformSourceAddrForDest(&src, dst); + //LogMsg("GetLLQEventPort: src %#a for dst %#a (%d)", &src, dst, mDNSv4AddrIsRFC1918(&src.ip.v4) ? mDNSVal16(m->LLQNAT.ExternalPort) : 0); + return(mDNSv4AddrIsRFC1918(&src.ip.v4) ? mDNSVal16(m->LLQNAT.ExternalPort) : mDNSVal16(MulticastDNSPort)); +} + +// Normally called with llq set. +// May be called with llq NULL, when retransmitting a lost Challenge Response +mDNSlocal void sendChallengeResponse(mDNS *const m, DNSQuestion *const q, const LLQOptData *llq) +{ + mDNSu8 *responsePtr = m->omsg.data; + LLQOptData llqBuf; + + if (q->tcp) { LogMsg("sendChallengeResponse: ERROR!!: question %##s (%s) tcp non-NULL", q->qname.c, DNSTypeName(q->qtype)); return; } + + if (PrivateQuery(q)) { LogMsg("sendChallengeResponse: ERROR!!: Private Query %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); return; } + + if (q->ntries++ == kLLQ_MAX_TRIES) + { + LogMsg("sendChallengeResponse: %d failed attempts for LLQ %##s", kLLQ_MAX_TRIES, q->qname.c); + StartLLQPolling(m,q); + return; + } + + if (!llq) // Retransmission: need to make a new LLQOptData + { + llqBuf.vers = kLLQ_Vers; + llqBuf.llqOp = kLLQOp_Setup; + llqBuf.err = LLQErr_NoError; // Don't need to tell server UDP notification port when sending over UDP + llqBuf.id = q->id; + llqBuf.llqlease = q->ReqLease; + llq = &llqBuf; + } + + q->LastQTime = m->timenow; + q->ThisQInterval = q->tcp ? 0 : (kLLQ_INIT_RESEND * q->ntries * mDNSPlatformOneSecond); // If using TCP, don't need to retransmit + SetNextQueryTime(m, q); + + // To simulate loss of challenge response packet, uncomment line below + //if (q->ntries == 1) return; + + InitializeDNSMessage(&m->omsg.h, q->TargetQID, uQueryFlags); + responsePtr = putLLQ(&m->omsg, responsePtr, q, llq); + if (responsePtr) + { + mStatus err = mDNSSendDNSMessage(m, &m->omsg, responsePtr, mDNSInterface_Any, q->LocalSocket, &q->servAddr, q->servPort, mDNSNULL, mDNSNULL, mDNSfalse); + if (err) { LogMsg("sendChallengeResponse: mDNSSendDNSMessage%s failed: %d", q->tcp ? " (TCP)" : "", err); } + } + else StartLLQPolling(m,q); +} + +mDNSlocal void SetLLQTimer(mDNS *const m, DNSQuestion *const q, const LLQOptData *const llq) +{ + mDNSs32 lease = (mDNSs32)llq->llqlease * mDNSPlatformOneSecond; + q->ReqLease = llq->llqlease; + q->LastQTime = m->timenow; + q->expire = m->timenow + lease; + q->ThisQInterval = lease/2 + mDNSRandom(lease/10); + debugf("SetLLQTimer setting %##s (%s) to %d %d", q->qname.c, DNSTypeName(q->qtype), lease/mDNSPlatformOneSecond, q->ThisQInterval/mDNSPlatformOneSecond); + SetNextQueryTime(m, q); +} + +mDNSlocal void recvSetupResponse(mDNS *const m, mDNSu8 rcode, DNSQuestion *const q, const LLQOptData *const llq) +{ + if (rcode && rcode != kDNSFlag1_RC_NXDomain) + { LogMsg("ERROR: recvSetupResponse %##s (%s) - rcode && rcode != kDNSFlag1_RC_NXDomain", q->qname.c, DNSTypeName(q->qtype)); return; } + + if (llq->llqOp != kLLQOp_Setup) + { LogMsg("ERROR: recvSetupResponse %##s (%s) - bad op %d", q->qname.c, DNSTypeName(q->qtype), llq->llqOp); return; } + + if (llq->vers != kLLQ_Vers) + { LogMsg("ERROR: recvSetupResponse %##s (%s) - bad vers %d", q->qname.c, DNSTypeName(q->qtype), llq->vers); return; } + + if (q->state == LLQ_InitialRequest) + { + //LogInfo("Got LLQ_InitialRequest"); + + if (llq->err) { LogMsg("recvSetupResponse - received llq->err %d from server", llq->err); StartLLQPolling(m,q); return; } + + if (q->ReqLease != llq->llqlease) + debugf("recvSetupResponse: requested lease %lu, granted lease %lu", q->ReqLease, llq->llqlease); + + // cache expiration in case we go to sleep before finishing setup + q->ReqLease = llq->llqlease; + q->expire = m->timenow + ((mDNSs32)llq->llqlease * mDNSPlatformOneSecond); + + // update state + q->state = LLQ_SecondaryRequest; + q->id = llq->id; + q->ntries = 0; // first attempt to send response + sendChallengeResponse(m, q, llq); + } + else if (q->state == LLQ_SecondaryRequest) + { + //LogInfo("Got LLQ_SecondaryRequest"); + + // Fix this immediately if not sooner. Copy the id from the LLQOptData into our DNSQuestion struct. This is only + // an issue for private LLQs, because we skip parts 2 and 3 of the handshake. This is related to a bigger + // problem of the current implementation of TCP LLQ setup: we're not handling state transitions correctly + // if the server sends back SERVFULL or STATIC. + if (PrivateQuery(q)) + { + LogInfo("Private LLQ_SecondaryRequest; copying id %08X%08X", llq->id.l[0], llq->id.l[1]); + q->id = llq->id; + } + + if (llq->err) { LogMsg("ERROR: recvSetupResponse %##s (%s) code %d from server", q->qname.c, DNSTypeName(q->qtype), llq->err); StartLLQPolling(m,q); return; } + if (!mDNSSameOpaque64(&q->id, &llq->id)) + { LogMsg("recvSetupResponse - ID changed. discarding"); return; } // this can happen rarely (on packet loss + reordering) + q->state = LLQ_Established; + q->ntries = 0; + SetLLQTimer(m, q, llq); +#if APPLE_OSX_mDNSResponder + UpdateAutoTunnelDomainStatuses(m); +#endif + } +} + +mDNSexport uDNS_LLQType uDNS_recvLLQResponse(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, + const mDNSAddr *const srcaddr, const mDNSIPPort srcport, DNSQuestion **matchQuestion) +{ + DNSQuestion pktQ, *q; + if (msg->h.numQuestions && getQuestion(msg, msg->data, end, 0, &pktQ)) + { + const rdataOPT *opt = GetLLQOptData(m, msg, end); + + for (q = m->Questions; q; q = q->next) + { + if (!mDNSOpaque16IsZero(q->TargetQID) && q->LongLived && q->qtype == pktQ.qtype && q->qnamehash == pktQ.qnamehash && SameDomainName(&q->qname, &pktQ.qname)) + { + debugf("uDNS_recvLLQResponse found %##s (%s) %d %#a %#a %X %X %X %X %d", + q->qname.c, DNSTypeName(q->qtype), q->state, srcaddr, &q->servAddr, + opt ? opt->u.llq.id.l[0] : 0, opt ? opt->u.llq.id.l[1] : 0, q->id.l[0], q->id.l[1], opt ? opt->u.llq.llqOp : 0); + if (q->state == LLQ_Poll) debugf("uDNS_LLQ_Events: q->state == LLQ_Poll msg->h.id %d q->TargetQID %d", mDNSVal16(msg->h.id), mDNSVal16(q->TargetQID)); + if (q->state == LLQ_Poll && mDNSSameOpaque16(msg->h.id, q->TargetQID)) + { + m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it + + // Don't reset the state to IntialRequest as we may write that to the dynamic store + // and PrefPane might wrongly think that we are "Starting" instead of "Polling". If + // we are in polling state because of PCP/NAT-PMP disabled or DoubleNAT, next LLQNATCallback + // would kick us back to LLQInitialRequest. So, resetting the state here may not be useful. + // + // If we have a good NAT (neither PCP/NAT-PMP disabled nor Double-NAT), then we should not be + // possibly in polling state. To be safe, we want to retry from the start in that case + // as there may not be another LLQNATCallback + // + // NOTE: We can be in polling state if we cannot resolve the SOA record i.e, servAddr is set to + // all ones. In that case, we would set it in LLQ_InitialRequest as it overrides the PCP/NAT-PMP or + // Double-NAT state. + if (!mDNSAddressIsOnes(&q->servAddr) && !mDNSIPPortIsZero(m->LLQNAT.ExternalPort) && + !m->LLQNAT.Result) + { + debugf("uDNS_recvLLQResponse got poll response; moving to LLQ_InitialRequest for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); + q->state = LLQ_InitialRequest; + } + q->servPort = zeroIPPort; // Clear servPort so that startLLQHandshake will retry the GetZoneData processing + q->ThisQInterval = LLQ_POLL_INTERVAL + mDNSRandom(LLQ_POLL_INTERVAL/10); // Retry LLQ setup in approx 15 minutes + q->LastQTime = m->timenow; + SetNextQueryTime(m, q); + *matchQuestion = q; + return uDNS_LLQ_Entire; // uDNS_LLQ_Entire means flush stale records; assume a large effective TTL + } + // Note: In LLQ Event packets, the msg->h.id does not match our q->TargetQID, because in that case the msg->h.id nonce is selected by the server + else if (opt && q->state == LLQ_Established && opt->u.llq.llqOp == kLLQOp_Event && mDNSSameOpaque64(&opt->u.llq.id, &q->id)) + { + mDNSu8 *ackEnd; + //debugf("Sending LLQ ack for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); + InitializeDNSMessage(&m->omsg.h, msg->h.id, ResponseFlags); + ackEnd = putLLQ(&m->omsg, m->omsg.data, q, &opt->u.llq); + if (ackEnd) mDNSSendDNSMessage(m, &m->omsg, ackEnd, mDNSInterface_Any, q->LocalSocket, srcaddr, srcport, mDNSNULL, mDNSNULL, mDNSfalse); + m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it + debugf("uDNS_LLQ_Events: q->state == LLQ_Established msg->h.id %d q->TargetQID %d", mDNSVal16(msg->h.id), mDNSVal16(q->TargetQID)); + *matchQuestion = q; + return uDNS_LLQ_Events; + } + if (opt && mDNSSameOpaque16(msg->h.id, q->TargetQID)) + { + if (q->state == LLQ_Established && opt->u.llq.llqOp == kLLQOp_Refresh && mDNSSameOpaque64(&opt->u.llq.id, &q->id) && msg->h.numAdditionals && !msg->h.numAnswers) + { + if (opt->u.llq.err != LLQErr_NoError) LogMsg("recvRefreshReply: received error %d from server", opt->u.llq.err); + else + { + //LogInfo("Received refresh confirmation ntries %d for %##s (%s)", q->ntries, q->qname.c, DNSTypeName(q->qtype)); + // If we're waiting to go to sleep, then this LLQ deletion may have been the thing + // we were waiting for, so schedule another check to see if we can sleep now. + if (opt->u.llq.llqlease == 0 && m->SleepLimit) m->NextScheduledSPRetry = m->timenow; + GrantCacheExtensions(m, q, opt->u.llq.llqlease); + SetLLQTimer(m, q, &opt->u.llq); + q->ntries = 0; + } + m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it + *matchQuestion = q; + return uDNS_LLQ_Ignore; + } + if (q->state < LLQ_Established && mDNSSameAddress(srcaddr, &q->servAddr)) + { + LLQ_State oldstate = q->state; + recvSetupResponse(m, msg->h.flags.b[1] & kDNSFlag1_RC_Mask, q, &opt->u.llq); + m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it + // We have a protocol anomaly here in the LLQ definition. + // Both the challenge packet from the server and the ack+answers packet have opt->u.llq.llqOp == kLLQOp_Setup. + // However, we need to treat them differently: + // The challenge packet has no answers in it, and tells us nothing about whether our cache entries + // are still valid, so this packet should not cause us to do anything that messes with our cache. + // The ack+answers packet gives us the whole truth, so we should handle it by updating our cache + // to match the answers in the packet, and only the answers in the packet. + *matchQuestion = q; + return (oldstate == LLQ_SecondaryRequest ? uDNS_LLQ_Entire : uDNS_LLQ_Ignore); + } + } + } + } + m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it + } + *matchQuestion = mDNSNULL; + return uDNS_LLQ_Not; +} + +// Stub definition of TCPSocket_struct so we can access flags field. (Rest of TCPSocket_struct is platform-dependent.) +struct TCPSocket_struct { TCPSocketFlags flags; /* ... */ }; + +// tcpCallback is called to handle events (e.g. connection opening and data reception) on TCP connections for +// Private DNS operations -- private queries, private LLQs, private record updates and private service updates +mDNSlocal void tcpCallback(TCPSocket *sock, void *context, mDNSBool ConnectionEstablished, mStatus err) +{ + tcpInfo_t *tcpInfo = (tcpInfo_t *)context; + mDNSBool closed = mDNSfalse; + mDNS *m = tcpInfo->m; + DNSQuestion *const q = tcpInfo->question; + tcpInfo_t **backpointer = + q ? &q->tcp : + tcpInfo->rr ? &tcpInfo->rr->tcp : mDNSNULL; + if (backpointer && *backpointer != tcpInfo) + LogMsg("tcpCallback: %d backpointer %p incorrect tcpInfo %p question %p rr %p", + mDNSPlatformTCPGetFD(tcpInfo->sock), *backpointer, tcpInfo, q, tcpInfo->rr); + + if (err) goto exit; + + if (ConnectionEstablished) + { + mDNSu8 *end = ((mDNSu8*) &tcpInfo->request) + tcpInfo->requestLen; + DomainAuthInfo *AuthInfo; + + // Defensive coding for <rdar://problem/5546824> Crash in mDNSResponder at GetAuthInfoForName_internal + 366 + // Don't know yet what's causing this, but at least we can be cautious and try to avoid crashing if we find our pointers in an unexpected state + if (tcpInfo->rr && tcpInfo->rr->resrec.name != &tcpInfo->rr->namestorage) + LogMsg("tcpCallback: ERROR: tcpInfo->rr->resrec.name %p != &tcpInfo->rr->namestorage %p", + tcpInfo->rr->resrec.name, &tcpInfo->rr->namestorage); + if (tcpInfo->rr && tcpInfo->rr->resrec.name != &tcpInfo->rr->namestorage) return; + + AuthInfo = tcpInfo->rr ? GetAuthInfoForName(m, tcpInfo->rr->resrec.name) : mDNSNULL; + + // connection is established - send the message + if (q && q->LongLived && q->state == LLQ_Established) + { + // Lease renewal over TCP, resulting from opening a TCP connection in sendLLQRefresh + end = ((mDNSu8*) &tcpInfo->request) + tcpInfo->requestLen; + } + else if (q && q->LongLived && q->state != LLQ_Poll && !mDNSIPPortIsZero(m->LLQNAT.ExternalPort) && !mDNSIPPortIsZero(q->servPort)) + { + // Notes: + // If we have a NAT port mapping, ExternalPort is the external port + // If we have a routable address so we don't need a port mapping, ExternalPort is the same as our own internal port + // If we need a NAT port mapping but can't get one, then ExternalPort is zero + LLQOptData llqData; // set llq rdata + llqData.vers = kLLQ_Vers; + llqData.llqOp = kLLQOp_Setup; + llqData.err = GetLLQEventPort(m, &tcpInfo->Addr); // We're using TCP; tell server what UDP port to send notifications to + LogInfo("tcpCallback: eventPort %d", llqData.err); + llqData.id = zeroOpaque64; + llqData.llqlease = kLLQ_DefLease; + InitializeDNSMessage(&tcpInfo->request.h, q->TargetQID, uQueryFlags); + end = putLLQ(&tcpInfo->request, tcpInfo->request.data, q, &llqData); + if (!end) { LogMsg("ERROR: tcpCallback - putLLQ"); err = mStatus_UnknownErr; goto exit; } + AuthInfo = q->AuthInfo; // Need to add TSIG to this message + q->ntries = 0; // Reset ntries so that tcp/tls connection failures don't affect sendChallengeResponse failures + } + else if (q) + { + // LLQ Polling mode or non-LLQ uDNS over TCP + InitializeDNSMessage(&tcpInfo->request.h, q->TargetQID, (DNSSECQuestion(q) ? DNSSecQFlags : uQueryFlags)); + end = putQuestion(&tcpInfo->request, tcpInfo->request.data, tcpInfo->request.data + AbsoluteMaxDNSMessageData, &q->qname, q->qtype, q->qclass); + if (DNSSECQuestion(q) && q->qDNSServer && !q->qDNSServer->cellIntf) + { + if (q->ProxyQuestion) + end = DNSProxySetAttributes(q, &tcpInfo->request.h, &tcpInfo->request, end, tcpInfo->request.data + AbsoluteMaxDNSMessageData); + else + end = putDNSSECOption(&tcpInfo->request, end, tcpInfo->request.data + AbsoluteMaxDNSMessageData); + } + + AuthInfo = q->AuthInfo; // Need to add TSIG to this message + } + + err = mDNSSendDNSMessage(m, &tcpInfo->request, end, mDNSInterface_Any, mDNSNULL, &tcpInfo->Addr, tcpInfo->Port, sock, AuthInfo, mDNSfalse); + if (err) { debugf("ERROR: tcpCallback: mDNSSendDNSMessage - %d", err); err = mStatus_UnknownErr; goto exit; } + + // Record time we sent this question + if (q) + { + mDNS_Lock(m); + q->LastQTime = m->timenow; + if (q->ThisQInterval < (256 * mDNSPlatformOneSecond)) // Now we have a TCP connection open, make sure we wait at least 256 seconds before retrying + q->ThisQInterval = (256 * mDNSPlatformOneSecond); + SetNextQueryTime(m, q); + mDNS_Unlock(m); + } + } + else + { + long n; + if (tcpInfo->nread < 2) // First read the two-byte length preceeding the DNS message + { + mDNSu8 *lenptr = (mDNSu8 *)&tcpInfo->replylen; + n = mDNSPlatformReadTCP(sock, lenptr + tcpInfo->nread, 2 - tcpInfo->nread, &closed); + if (n < 0) + { + LogMsg("ERROR: tcpCallback - attempt to read message length failed (%d)", n); + err = mStatus_ConnFailed; + goto exit; + } + else if (closed) + { + // It's perfectly fine for this socket to close after the first reply. The server might + // be sending gratuitous replies using UDP and doesn't have a need to leave the TCP socket open. + // We'll only log this event if we've never received a reply before. + // BIND 9 appears to close an idle connection after 30 seconds. + if (tcpInfo->numReplies == 0) + { + LogMsg("ERROR: socket closed prematurely tcpInfo->nread = %d", tcpInfo->nread); + err = mStatus_ConnFailed; + goto exit; + } + else + { + // Note that we may not be doing the best thing if an error occurs after we've sent a second request + // over this tcp connection. That is, we only track whether we've received at least one response + // which may have been to a previous request sent over this tcp connection. + if (backpointer) *backpointer = mDNSNULL; // Clear client backpointer FIRST so we don't risk double-disposing our tcpInfo_t + DisposeTCPConn(tcpInfo); + return; + } + } + + tcpInfo->nread += n; + if (tcpInfo->nread < 2) goto exit; + + tcpInfo->replylen = (mDNSu16)((mDNSu16)lenptr[0] << 8 | lenptr[1]); + if (tcpInfo->replylen < sizeof(DNSMessageHeader)) + { LogMsg("ERROR: tcpCallback - length too short (%d bytes)", tcpInfo->replylen); err = mStatus_UnknownErr; goto exit; } + + tcpInfo->reply = mDNSPlatformMemAllocate(tcpInfo->replylen); + if (!tcpInfo->reply) { LogMsg("ERROR: tcpCallback - malloc failed"); err = mStatus_NoMemoryErr; goto exit; } + } + + n = mDNSPlatformReadTCP(sock, ((char *)tcpInfo->reply) + (tcpInfo->nread - 2), tcpInfo->replylen - (tcpInfo->nread - 2), &closed); + + if (n < 0) + { + LogMsg("ERROR: tcpCallback - read returned %d", n); + err = mStatus_ConnFailed; + goto exit; + } + else if (closed) + { + if (tcpInfo->numReplies == 0) + { + LogMsg("ERROR: socket closed prematurely tcpInfo->nread = %d", tcpInfo->nread); + err = mStatus_ConnFailed; + goto exit; + } + else + { + // Note that we may not be doing the best thing if an error occurs after we've sent a second request + // over this tcp connection. That is, we only track whether we've received at least one response + // which may have been to a previous request sent over this tcp connection. + if (backpointer) *backpointer = mDNSNULL; // Clear client backpointer FIRST so we don't risk double-disposing our tcpInfo_t + DisposeTCPConn(tcpInfo); + return; + } + } + + tcpInfo->nread += n; + + if ((tcpInfo->nread - 2) == tcpInfo->replylen) + { + mDNSBool tls; + DNSMessage *reply = tcpInfo->reply; + mDNSu8 *end = (mDNSu8 *)tcpInfo->reply + tcpInfo->replylen; + mDNSAddr Addr = tcpInfo->Addr; + mDNSIPPort Port = tcpInfo->Port; + mDNSIPPort srcPort = zeroIPPort; + tcpInfo->numReplies++; + tcpInfo->reply = mDNSNULL; // Detach reply buffer from tcpInfo_t, to make sure client callback can't cause it to be disposed + tcpInfo->nread = 0; + tcpInfo->replylen = 0; + + // If we're going to dispose this connection, do it FIRST, before calling client callback + // Note: Sleep code depends on us clearing *backpointer here -- it uses the clearing of rr->tcp + // as the signal that the DNS deregistration operation with the server has completed, and the machine may now sleep + // If we clear the tcp pointer in the question, mDNSCoreReceiveResponse cannot find a matching question. Hence + // we store the minimal information i.e., the source port of the connection in the question itself. + // Dereference sock before it is disposed in DisposeTCPConn below. + + if (sock->flags & kTCPSocketFlags_UseTLS) tls = mDNStrue; + else tls = mDNSfalse; + + if (q && q->tcp) {srcPort = q->tcp->SrcPort; q->tcpSrcPort = srcPort;} + + if (backpointer) + if (!q || !q->LongLived || m->SleepState) + { *backpointer = mDNSNULL; DisposeTCPConn(tcpInfo); } + + mDNSCoreReceive(m, reply, end, &Addr, Port, tls ? (mDNSAddr *)1 : mDNSNULL, srcPort, 0); + // USE CAUTION HERE: Invoking mDNSCoreReceive may have caused the environment to change, including canceling this operation itself + + mDNSPlatformMemFree(reply); + return; + } + } + +exit: + + if (err) + { + // Clear client backpointer FIRST -- that way if one of the callbacks cancels its operation + // we won't end up double-disposing our tcpInfo_t + if (backpointer) *backpointer = mDNSNULL; + + mDNS_Lock(m); // Need to grab the lock to get m->timenow + + if (q) + { + if (q->ThisQInterval == 0) + { + // We get here when we fail to establish a new TCP/TLS connection that would have been used for a new LLQ request or an LLQ renewal. + // Note that ThisQInterval is also zero when sendChallengeResponse resends the LLQ request on an extant TCP/TLS connection. + q->LastQTime = m->timenow; + if (q->LongLived) + { + // We didn't get the chance to send our request packet before the TCP/TLS connection failed. + // We want to retry quickly, but want to back off exponentially in case the server is having issues. + // Since ThisQInterval was 0, we can't just multiply by QuestionIntervalStep, we must track the number + // of TCP/TLS connection failures using ntries. + mDNSu32 count = q->ntries + 1; // want to wait at least 1 second before retrying + + q->ThisQInterval = InitialQuestionInterval; + + for (; count; count--) + q->ThisQInterval *= QuestionIntervalStep; + + if (q->ThisQInterval > LLQ_POLL_INTERVAL) + q->ThisQInterval = LLQ_POLL_INTERVAL; + else + q->ntries++; + + LogMsg("tcpCallback: stream connection for LLQ %##s (%s) failed %d times, retrying in %d ms", q->qname.c, DNSTypeName(q->qtype), q->ntries, q->ThisQInterval); + } + else + { + q->ThisQInterval = MAX_UCAST_POLL_INTERVAL; + LogMsg("tcpCallback: stream connection for %##s (%s) failed, retrying in %d ms", q->qname.c, DNSTypeName(q->qtype), q->ThisQInterval); + } + SetNextQueryTime(m, q); + } + else if (NextQSendTime(q) - m->timenow > (q->LongLived ? LLQ_POLL_INTERVAL : MAX_UCAST_POLL_INTERVAL)) + { + // If we get an error and our next scheduled query for this question is more than the max interval from now, + // reset the next query to ensure we wait no longer the maximum interval from now before trying again. + q->LastQTime = m->timenow; + q->ThisQInterval = q->LongLived ? LLQ_POLL_INTERVAL : MAX_UCAST_POLL_INTERVAL; + SetNextQueryTime(m, q); + LogMsg("tcpCallback: stream connection for %##s (%s) failed, retrying in %d ms", q->qname.c, DNSTypeName(q->qtype), q->ThisQInterval); + } + + // We're about to dispose of the TCP connection, so we must reset the state to retry over TCP/TLS + // because sendChallengeResponse will send the query via UDP if we don't have a tcp pointer. + // Resetting to LLQ_InitialRequest will cause uDNS_CheckCurrentQuestion to call startLLQHandshake, which + // will attempt to establish a new tcp connection. + if (q->LongLived && q->state == LLQ_SecondaryRequest) + q->state = LLQ_InitialRequest; + + // ConnFailed may happen if the server sends a TCP reset or TLS fails, in which case we want to retry establishing the LLQ + // quickly rather than switching to polling mode. This case is handled by the above code to set q->ThisQInterval just above. + // If the error isn't ConnFailed, then the LLQ is in bad shape, so we switch to polling mode. + if (err != mStatus_ConnFailed) + { + if (q->LongLived && q->state != LLQ_Poll) StartLLQPolling(m, q); + } + } + + mDNS_Unlock(m); + + DisposeTCPConn(tcpInfo); + } +} + +mDNSlocal tcpInfo_t *MakeTCPConn(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, + TCPSocketFlags flags, const mDNSAddr *const Addr, const mDNSIPPort Port, domainname *hostname, + DNSQuestion *const question, AuthRecord *const rr) +{ + mStatus err; + mDNSIPPort srcport = zeroIPPort; + tcpInfo_t *info; + mDNSBool useBackgroundTrafficClass; + + useBackgroundTrafficClass = question ? question->UseBackgroundTrafficClass : mDNSfalse; + + if ((flags & kTCPSocketFlags_UseTLS) && (!hostname || !hostname->c[0])) + { LogMsg("MakeTCPConn: TLS connection being setup with NULL hostname"); return mDNSNULL; } + + info = (tcpInfo_t *)mDNSPlatformMemAllocate(sizeof(tcpInfo_t)); + if (!info) { LogMsg("ERROR: MakeTCP - memallocate failed"); return(mDNSNULL); } + mDNSPlatformMemZero(info, sizeof(tcpInfo_t)); + + info->m = m; + info->sock = mDNSPlatformTCPSocket(m, flags, &srcport, useBackgroundTrafficClass); + info->requestLen = 0; + info->question = question; + info->rr = rr; + info->Addr = *Addr; + info->Port = Port; + info->reply = mDNSNULL; + info->replylen = 0; + info->nread = 0; + info->numReplies = 0; + info->SrcPort = srcport; + + if (msg) + { + info->requestLen = (int) (end - ((mDNSu8*)msg)); + mDNSPlatformMemCopy(&info->request, msg, info->requestLen); + } + + if (!info->sock) { LogMsg("MakeTCPConn: unable to create TCP socket"); mDNSPlatformMemFree(info); return(mDNSNULL); } + err = mDNSPlatformTCPConnect(info->sock, Addr, Port, hostname, (question ? question->InterfaceID : mDNSNULL), tcpCallback, info); + + // Probably suboptimal here. + // Instead of returning mDNSNULL here on failure, we should probably invoke the callback with an error code. + // That way clients can put all the error handling and retry/recovery code in one place, + // instead of having to handle immediate errors in one place and async errors in another. + // Also: "err == mStatus_ConnEstablished" probably never happens. + + // Don't need to log "connection failed" in customer builds -- it happens quite often during sleep, wake, configuration changes, etc. + if (err == mStatus_ConnEstablished) { tcpCallback(info->sock, info, mDNStrue, mStatus_NoError); } + else if (err != mStatus_ConnPending ) { LogInfo("MakeTCPConn: connection failed"); DisposeTCPConn(info); return(mDNSNULL); } + return(info); +} + +mDNSexport void DisposeTCPConn(struct tcpInfo_t *tcp) +{ + mDNSPlatformTCPCloseConnection(tcp->sock); + if (tcp->reply) mDNSPlatformMemFree(tcp->reply); + mDNSPlatformMemFree(tcp); +} + +// Lock must be held +mDNSexport void startLLQHandshake(mDNS *m, DNSQuestion *q) +{ + if (m->LLQNAT.clientContext != mDNSNULL) // LLQNAT just started, give it some time + { + LogInfo("startLLQHandshake: waiting for NAT status for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); + q->ThisQInterval = LLQ_POLL_INTERVAL + mDNSRandom(LLQ_POLL_INTERVAL/10); // Retry in approx 15 minutes + q->LastQTime = m->timenow; + SetNextQueryTime(m, q); + return; + } + + // Either we don't have {PCP, NAT-PMP, UPnP/IGD} support (ExternalPort is zero) or behind a Double NAT that may or + // may not have {PCP, NAT-PMP, UPnP/IGD} support (NATResult is non-zero) + if (mDNSIPPortIsZero(m->LLQNAT.ExternalPort) || m->LLQNAT.Result) + { + LogInfo("startLLQHandshake: Cannot receive inbound packets; will poll for %##s (%s) External Port %d, NAT Result %d", + q->qname.c, DNSTypeName(q->qtype), mDNSVal16(m->LLQNAT.ExternalPort), m->LLQNAT.Result); + StartLLQPolling(m, q); + return; + } + + if (mDNSIPPortIsZero(q->servPort)) + { + debugf("startLLQHandshake: StartGetZoneData for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); + q->ThisQInterval = LLQ_POLL_INTERVAL + mDNSRandom(LLQ_POLL_INTERVAL/10); // Retry in approx 15 minutes + q->LastQTime = m->timenow; + SetNextQueryTime(m, q); + q->servAddr = zeroAddr; + // We know q->servPort is zero because of check above + if (q->nta) CancelGetZoneData(m, q->nta); + q->nta = StartGetZoneData(m, &q->qname, ZoneServiceLLQ, LLQGotZoneData, q); + return; + } + + if (PrivateQuery(q)) + { + if (q->tcp) LogInfo("startLLQHandshake: Disposing existing TCP connection for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); + if (q->tcp) { DisposeTCPConn(q->tcp); q->tcp = mDNSNULL; } + if (!q->nta) + { + // Normally we lookup the zone data and then call this function. And we never free the zone data + // for "PrivateQuery". But sometimes this can happen due to some race conditions. When we + // switch networks, we might end up "Polling" the network e.g., we are behind a Double NAT. + // When we poll, we free the zone information as we send the query to the server (See + // PrivateQueryGotZoneData). The NAT callback (LLQNATCallback) may happen soon after that. If we + // are still behind Double NAT, we would have returned early in this function. But we could + // have switched to a network with no NATs and we should get the zone data again. + LogInfo("startLLQHandshake: nta is NULL for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); + q->nta = StartGetZoneData(m, &q->qname, ZoneServiceLLQ, LLQGotZoneData, q); + return; + } + else if (!q->nta->Host.c[0]) + { + // This should not happen. If it happens, we print a log and MakeTCPConn will fail if it can't find a hostname + LogMsg("startLLQHandshake: ERROR!!: nta non NULL for %##s (%s) but HostName %d NULL, LongLived %d", q->qname.c, DNSTypeName(q->qtype), q->nta->Host.c[0], q->LongLived); + } + q->tcp = MakeTCPConn(m, mDNSNULL, mDNSNULL, kTCPSocketFlags_UseTLS, &q->servAddr, q->servPort, &q->nta->Host, q, mDNSNULL); + if (!q->tcp) + q->ThisQInterval = mDNSPlatformOneSecond * 5; // If TCP failed (transient networking glitch) try again in five seconds + else + { + q->state = LLQ_SecondaryRequest; // Right now, for private DNS, we skip the four-way LLQ handshake + q->ReqLease = kLLQ_DefLease; + q->ThisQInterval = 0; + } + q->LastQTime = m->timenow; + SetNextQueryTime(m, q); + } + else + { + debugf("startLLQHandshake: m->AdvertisedV4 %#a%s Server %#a:%d%s %##s (%s)", + &m->AdvertisedV4, mDNSv4AddrIsRFC1918(&m->AdvertisedV4.ip.v4) ? " (RFC 1918)" : "", + &q->servAddr, mDNSVal16(q->servPort), mDNSAddrIsRFC1918(&q->servAddr) ? " (RFC 1918)" : "", + q->qname.c, DNSTypeName(q->qtype)); + + if (q->ntries++ >= kLLQ_MAX_TRIES) + { + LogMsg("startLLQHandshake: %d failed attempts for LLQ %##s Polling.", kLLQ_MAX_TRIES, q->qname.c); + StartLLQPolling(m, q); + } + else + { + mDNSu8 *end; + LLQOptData llqData; + + // set llq rdata + llqData.vers = kLLQ_Vers; + llqData.llqOp = kLLQOp_Setup; + llqData.err = LLQErr_NoError; // Don't need to tell server UDP notification port when sending over UDP + llqData.id = zeroOpaque64; + llqData.llqlease = kLLQ_DefLease; + + InitializeDNSMessage(&m->omsg.h, q->TargetQID, uQueryFlags); + end = putLLQ(&m->omsg, m->omsg.data, q, &llqData); + if (!end) { LogMsg("ERROR: startLLQHandshake - putLLQ"); StartLLQPolling(m,q); return; } + + mDNSSendDNSMessage(m, &m->omsg, end, mDNSInterface_Any, q->LocalSocket, &q->servAddr, q->servPort, mDNSNULL, mDNSNULL, mDNSfalse); + + // update question state + q->state = LLQ_InitialRequest; + q->ReqLease = kLLQ_DefLease; + q->ThisQInterval = (kLLQ_INIT_RESEND * mDNSPlatformOneSecond); + q->LastQTime = m->timenow; + SetNextQueryTime(m, q); + } + } +} + +// forward declaration so GetServiceTarget can do reverse lookup if needed +mDNSlocal void GetStaticHostname(mDNS *m); + +mDNSexport const domainname *GetServiceTarget(mDNS *m, AuthRecord *const rr) +{ + debugf("GetServiceTarget %##s", rr->resrec.name->c); + + if (!rr->AutoTarget) // If not automatically tracking this host's current name, just return the existing target + return(&rr->resrec.rdata->u.srv.target); + else + { +#if APPLE_OSX_mDNSResponder + DomainAuthInfo *AuthInfo = GetAuthInfoForName_internal(m, rr->resrec.name); + if (AuthInfo && AuthInfo->AutoTunnel) + { + StartServerTunnel(m, AuthInfo); + if (AuthInfo->AutoTunnelHostRecord.namestorage.c[0] == 0) return(mDNSNULL); + debugf("GetServiceTarget: Returning %##s", AuthInfo->AutoTunnelHostRecord.namestorage.c); + return(&AuthInfo->AutoTunnelHostRecord.namestorage); + } + else +#endif // APPLE_OSX_mDNSResponder + { + const int srvcount = CountLabels(rr->resrec.name); + HostnameInfo *besthi = mDNSNULL, *hi; + int best = 0; + for (hi = m->Hostnames; hi; hi = hi->next) + if (hi->arv4.state == regState_Registered || hi->arv4.state == regState_Refresh || + hi->arv6.state == regState_Registered || hi->arv6.state == regState_Refresh) + { + int x, hostcount = CountLabels(&hi->fqdn); + for (x = hostcount < srvcount ? hostcount : srvcount; x > 0 && x > best; x--) + if (SameDomainName(SkipLeadingLabels(rr->resrec.name, srvcount - x), SkipLeadingLabels(&hi->fqdn, hostcount - x))) + { best = x; besthi = hi; } + } + + if (besthi) return(&besthi->fqdn); + } + if (m->StaticHostname.c[0]) return(&m->StaticHostname); + else GetStaticHostname(m); // asynchronously do reverse lookup for primary IPv4 address + LogInfo("GetServiceTarget: Returning NULL for %s", ARDisplayString(m, rr)); + return(mDNSNULL); + } +} + +mDNSlocal const domainname *PUBLIC_UPDATE_SERVICE_TYPE = (const domainname*)"\x0B_dns-update" "\x04_udp"; +mDNSlocal const domainname *PUBLIC_LLQ_SERVICE_TYPE = (const domainname*)"\x08_dns-llq" "\x04_udp"; + +mDNSlocal const domainname *PRIVATE_UPDATE_SERVICE_TYPE = (const domainname*)"\x0F_dns-update-tls" "\x04_tcp"; +mDNSlocal const domainname *PRIVATE_QUERY_SERVICE_TYPE = (const domainname*)"\x0E_dns-query-tls" "\x04_tcp"; +mDNSlocal const domainname *PRIVATE_LLQ_SERVICE_TYPE = (const domainname*)"\x0C_dns-llq-tls" "\x04_tcp"; + +#define ZoneDataSRV(X) ( \ + (X)->ZoneService == ZoneServiceUpdate ? ((X)->ZonePrivate ? PRIVATE_UPDATE_SERVICE_TYPE : PUBLIC_UPDATE_SERVICE_TYPE) : \ + (X)->ZoneService == ZoneServiceQuery ? ((X)->ZonePrivate ? PRIVATE_QUERY_SERVICE_TYPE : (const domainname*)"" ) : \ + (X)->ZoneService == ZoneServiceLLQ ? ((X)->ZonePrivate ? PRIVATE_LLQ_SERVICE_TYPE : PUBLIC_LLQ_SERVICE_TYPE ) : (const domainname*)"") + +// Forward reference: GetZoneData_StartQuery references GetZoneData_QuestionCallback, and +// GetZoneData_QuestionCallback calls GetZoneData_StartQuery +mDNSlocal mStatus GetZoneData_StartQuery(mDNS *const m, ZoneData *zd, mDNSu16 qtype); + +// GetZoneData_QuestionCallback is called from normal client callback context (core API calls allowed) +mDNSlocal void GetZoneData_QuestionCallback(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord) +{ + ZoneData *zd = (ZoneData*)question->QuestionContext; + + debugf("GetZoneData_QuestionCallback: %s %s", AddRecord ? "Add" : "Rmv", RRDisplayString(m, answer)); + + if (!AddRecord) return; // Don't care about REMOVE events + if (AddRecord == QC_addnocache && answer->rdlength == 0) return; // Don't care about transient failure indications + if (answer->rrtype != question->qtype) return; // Don't care about CNAMEs + + if (answer->rrtype == kDNSType_SOA) + { + debugf("GetZoneData GOT SOA %s", RRDisplayString(m, answer)); + mDNS_StopQuery(m, question); + if (question->ThisQInterval != -1) + LogMsg("GetZoneData_QuestionCallback: Question %##s (%s) ThisQInterval %d not -1", question->qname.c, DNSTypeName(question->qtype), question->ThisQInterval); + if (answer->rdlength) + { + AssignDomainName(&zd->ZoneName, answer->name); + zd->ZoneClass = answer->rrclass; + AssignDomainName(&zd->question.qname, &zd->ZoneName); + GetZoneData_StartQuery(m, zd, kDNSType_SRV); + } + else if (zd->CurrentSOA->c[0]) + { + DomainAuthInfo *AuthInfo = GetAuthInfoForName(m, zd->CurrentSOA); + if (AuthInfo && AuthInfo->AutoTunnel) + { + // To keep the load on the server down, we don't chop down on + // SOA lookups for AutoTunnels + LogInfo("GetZoneData_QuestionCallback: not chopping labels for %##s", zd->CurrentSOA->c); + zd->ZoneDataCallback(m, mStatus_NoSuchNameErr, zd); + } + else + { + zd->CurrentSOA = (domainname *)(zd->CurrentSOA->c + zd->CurrentSOA->c[0]+1); + AssignDomainName(&zd->question.qname, zd->CurrentSOA); + GetZoneData_StartQuery(m, zd, kDNSType_SOA); + } + } + else + { + LogInfo("GetZoneData recursed to root label of %##s without finding SOA", zd->ChildName.c); + zd->ZoneDataCallback(m, mStatus_NoSuchNameErr, zd); + } + } + else if (answer->rrtype == kDNSType_SRV) + { + debugf("GetZoneData GOT SRV %s", RRDisplayString(m, answer)); + mDNS_StopQuery(m, question); + if (question->ThisQInterval != -1) + LogMsg("GetZoneData_QuestionCallback: Question %##s (%s) ThisQInterval %d not -1", question->qname.c, DNSTypeName(question->qtype), question->ThisQInterval); +// Right now we don't want to fail back to non-encrypted operations +// If the AuthInfo has the AutoTunnel field set, then we want private or nothing +// <rdar://problem/5687667> BTMM: Don't fallback to unencrypted operations when SRV lookup fails +#if 0 + if (!answer->rdlength && zd->ZonePrivate && zd->ZoneService != ZoneServiceQuery) + { + zd->ZonePrivate = mDNSfalse; // Causes ZoneDataSRV() to yield a different SRV name when building the query + GetZoneData_StartQuery(m, zd, kDNSType_SRV); // Try again, non-private this time + } + else +#endif + { + if (answer->rdlength) + { + AssignDomainName(&zd->Host, &answer->rdata->u.srv.target); + zd->Port = answer->rdata->u.srv.port; + AssignDomainName(&zd->question.qname, &zd->Host); + GetZoneData_StartQuery(m, zd, kDNSType_A); + } + else + { + zd->ZonePrivate = mDNSfalse; + zd->Host.c[0] = 0; + zd->Port = zeroIPPort; + zd->Addr = zeroAddr; + zd->ZoneDataCallback(m, mStatus_NoError, zd); + } + } + } + else if (answer->rrtype == kDNSType_A) + { + debugf("GetZoneData GOT A %s", RRDisplayString(m, answer)); + mDNS_StopQuery(m, question); + if (question->ThisQInterval != -1) + LogMsg("GetZoneData_QuestionCallback: Question %##s (%s) ThisQInterval %d not -1", question->qname.c, DNSTypeName(question->qtype), question->ThisQInterval); + zd->Addr.type = mDNSAddrType_IPv4; + zd->Addr.ip.v4 = (answer->rdlength == 4) ? answer->rdata->u.ipv4 : zerov4Addr; + // In order to simulate firewalls blocking our outgoing TCP connections, returning immediate ICMP errors or TCP resets, + // the code below will make us try to connect to loopback, resulting in an immediate "port unreachable" failure. + // This helps us test to make sure we handle this case gracefully + // <rdar://problem/5607082> BTMM: mDNSResponder taking 100 percent CPU after upgrading to 10.5.1 +#if 0 + zd->Addr.ip.v4.b[0] = 127; + zd->Addr.ip.v4.b[1] = 0; + zd->Addr.ip.v4.b[2] = 0; + zd->Addr.ip.v4.b[3] = 1; +#endif + // The caller needs to free the memory when done with zone data + zd->ZoneDataCallback(m, mStatus_NoError, zd); + } +} + +// GetZoneData_StartQuery is called from normal client context (lock not held, or client callback) +mDNSlocal mStatus GetZoneData_StartQuery(mDNS *const m, ZoneData *zd, mDNSu16 qtype) +{ + if (qtype == kDNSType_SRV) + { + AssignDomainName(&zd->question.qname, ZoneDataSRV(zd)); + AppendDomainName(&zd->question.qname, &zd->ZoneName); + debugf("lookupDNSPort %##s", zd->question.qname.c); + } + + // CancelGetZoneData can get called at any time. We should stop the question if it has not been + // stopped already. A value of -1 for ThisQInterval indicates that the question is not active + // yet. + zd->question.ThisQInterval = -1; + zd->question.InterfaceID = mDNSInterface_Any; + zd->question.flags = 0; + zd->question.Target = zeroAddr; + //zd->question.qname.c[0] = 0; // Already set + zd->question.qtype = qtype; + zd->question.qclass = kDNSClass_IN; + zd->question.LongLived = mDNSfalse; + zd->question.ExpectUnique = mDNStrue; + zd->question.ForceMCast = mDNSfalse; + zd->question.ReturnIntermed = mDNStrue; + zd->question.SuppressUnusable = mDNSfalse; + zd->question.SearchListIndex = 0; + zd->question.AppendSearchDomains = 0; + zd->question.RetryWithSearchDomains = mDNSfalse; + zd->question.TimeoutQuestion = 0; + zd->question.WakeOnResolve = 0; + zd->question.UseBackgroundTrafficClass = mDNSfalse; + zd->question.ValidationRequired = 0; + zd->question.ValidatingResponse = 0; + zd->question.ProxyQuestion = 0; + zd->question.qnameOrig = mDNSNULL; + zd->question.AnonInfo = mDNSNULL; + zd->question.pid = mDNSPlatformGetPID(); + zd->question.QuestionCallback = GetZoneData_QuestionCallback; + zd->question.QuestionContext = zd; + + //LogMsg("GetZoneData_StartQuery %##s (%s) %p", zd->question.qname.c, DNSTypeName(zd->question.qtype), zd->question.Private); + return(mDNS_StartQuery(m, &zd->question)); +} + +// StartGetZoneData is an internal routine (i.e. must be called with the lock already held) +mDNSexport ZoneData *StartGetZoneData(mDNS *const m, const domainname *const name, const ZoneService target, ZoneDataCallback callback, void *ZoneDataContext) +{ + DomainAuthInfo *AuthInfo = GetAuthInfoForName_internal(m, name); + int initialskip = (AuthInfo && AuthInfo->AutoTunnel) ? DomainNameLength(name) - DomainNameLength(&AuthInfo->domain) : 0; + ZoneData *zd = (ZoneData*)mDNSPlatformMemAllocate(sizeof(ZoneData)); + if (!zd) { LogMsg("ERROR: StartGetZoneData - mDNSPlatformMemAllocate failed"); return mDNSNULL; } + mDNSPlatformMemZero(zd, sizeof(ZoneData)); + AssignDomainName(&zd->ChildName, name); + zd->ZoneService = target; + zd->CurrentSOA = (domainname *)(&zd->ChildName.c[initialskip]); + zd->ZoneName.c[0] = 0; + zd->ZoneClass = 0; + zd->Host.c[0] = 0; + zd->Port = zeroIPPort; + zd->Addr = zeroAddr; + zd->ZonePrivate = AuthInfo && AuthInfo->AutoTunnel ? mDNStrue : mDNSfalse; + zd->ZoneDataCallback = callback; + zd->ZoneDataContext = ZoneDataContext; + + zd->question.QuestionContext = zd; + + mDNS_DropLockBeforeCallback(); // GetZoneData_StartQuery expects to be called from a normal callback, so we emulate that here + if (AuthInfo && AuthInfo->AutoTunnel && !mDNSIPPortIsZero(AuthInfo->port)) + { + LogInfo("StartGetZoneData: Bypassing SOA, SRV query for %##s", AuthInfo->domain.c); + // We bypass SOA and SRV queries if we know the hostname and port already from the configuration. + // Today this is only true for AutoTunnel. As we bypass, we need to infer a few things: + // + // 1. Zone name is the same as the AuthInfo domain + // 2. ZoneClass is kDNSClass_IN which should be a safe assumption + // + // If we want to make this bypass mechanism work for non-AutoTunnels also, (1) has to hold + // good. Otherwise, it has to be configured also. + + AssignDomainName(&zd->ZoneName, &AuthInfo->domain); + zd->ZoneClass = kDNSClass_IN; + AssignDomainName(&zd->Host, &AuthInfo->hostname); + zd->Port = AuthInfo->port; + AssignDomainName(&zd->question.qname, &zd->Host); + GetZoneData_StartQuery(m, zd, kDNSType_A); + } + else + { + if (AuthInfo && AuthInfo->AutoTunnel) LogInfo("StartGetZoneData: Not Bypassing SOA, SRV query for %##s", AuthInfo->domain.c); + AssignDomainName(&zd->question.qname, zd->CurrentSOA); + GetZoneData_StartQuery(m, zd, kDNSType_SOA); + } + mDNS_ReclaimLockAfterCallback(); + + return zd; +} + +// Returns if the question is a GetZoneData question. These questions are special in +// that they are created internally while resolving a private query or LLQs. +mDNSexport mDNSBool IsGetZoneDataQuestion(DNSQuestion *q) +{ + if (q->QuestionCallback == GetZoneData_QuestionCallback) return(mDNStrue); + else return(mDNSfalse); +} + +// GetZoneData queries are a special case -- even if we have a key for them, we don't do them privately, +// because that would result in an infinite loop (i.e. to do a private query we first need to get +// the _dns-query-tls SRV record for the zone, and we can't do *that* privately because to do so +// we'd need to already know the _dns-query-tls SRV record. +// Also, as a general rule, we never do SOA queries privately +mDNSexport DomainAuthInfo *GetAuthInfoForQuestion(mDNS *m, const DNSQuestion *const q) // Must be called with lock held +{ + if (q->QuestionCallback == GetZoneData_QuestionCallback) return(mDNSNULL); + if (q->qtype == kDNSType_SOA ) return(mDNSNULL); + return(GetAuthInfoForName_internal(m, &q->qname)); +} + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - host name and interface management +#endif + +mDNSlocal void SendRecordRegistration(mDNS *const m, AuthRecord *rr); +mDNSlocal void SendRecordDeregistration(mDNS *m, AuthRecord *rr); +mDNSlocal mDNSBool IsRecordMergeable(mDNS *const m, AuthRecord *rr, mDNSs32 time); + +// When this function is called, service record is already deregistered. We just +// have to deregister the PTR and TXT records. +mDNSlocal void UpdateAllServiceRecords(mDNS *const m, AuthRecord *rr, mDNSBool reg) +{ + AuthRecord *r, *srvRR; + + if (rr->resrec.rrtype != kDNSType_SRV) { LogMsg("UpdateAllServiceRecords:ERROR!! ResourceRecord not a service record %s", ARDisplayString(m, rr)); return; } + + if (reg && rr->state == regState_NoTarget) { LogMsg("UpdateAllServiceRecords:ERROR!! SRV record %s in noTarget state during registration", ARDisplayString(m, rr)); return; } + + LogInfo("UpdateAllServiceRecords: ResourceRecord %s", ARDisplayString(m, rr)); + + for (r = m->ResourceRecords; r; r=r->next) + { + if (!AuthRecord_uDNS(r)) continue; + srvRR = mDNSNULL; + if (r->resrec.rrtype == kDNSType_PTR) + srvRR = r->Additional1; + else if (r->resrec.rrtype == kDNSType_TXT) + srvRR = r->DependentOn; + if (srvRR && srvRR->resrec.rrtype != kDNSType_SRV) + LogMsg("UpdateAllServiceRecords: ERROR!! Resource record %s wrong, expecting SRV type", ARDisplayString(m, srvRR)); + if (srvRR == rr) + { + if (!reg) + { + LogInfo("UpdateAllServiceRecords: deregistering %s", ARDisplayString(m, r)); + r->SRVChanged = mDNStrue; + r->ThisAPInterval = INIT_RECORD_REG_INTERVAL; + r->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; + r->state = regState_DeregPending; + } + else + { + // Clearing SRVchanged is a safety measure. If our pevious dereg never + // came back and we had a target change, we are starting fresh + r->SRVChanged = mDNSfalse; + // if it is already registered or in the process of registering, then don't + // bother re-registering. This happens today for non-BTMM domains where the + // TXT and PTR get registered before SRV records because of the delay in + // getting the port mapping. There is no point in re-registering the TXT + // and PTR records. + if ((r->state == regState_Registered) || + (r->state == regState_Pending && r->nta && !mDNSIPv4AddressIsZero(r->nta->Addr.ip.v4))) + LogInfo("UpdateAllServiceRecords: not registering %s, state %d", ARDisplayString(m, r), r->state); + else + { + LogInfo("UpdateAllServiceRecords: registering %s, state %d", ARDisplayString(m, r), r->state); + ActivateUnicastRegistration(m, r); + } + } + } + } +} + +// Called in normal client context (lock not held) +// Currently only supports SRV records for nat mapping +mDNSlocal void CompleteRecordNatMap(mDNS *m, NATTraversalInfo *n) +{ + const domainname *target; + domainname *srvt; + AuthRecord *rr = (AuthRecord *)n->clientContext; + debugf("SRVNatMap complete %.4a IntPort %u ExternalPort %u NATLease %u", &n->ExternalAddress, mDNSVal16(n->IntPort), mDNSVal16(n->ExternalPort), n->NATLease); + + if (!rr) { LogMsg("CompleteRecordNatMap called with unknown AuthRecord object"); return; } + if (!n->NATLease) { LogMsg("CompleteRecordNatMap No NATLease for %s", ARDisplayString(m, rr)); return; } + + if (rr->resrec.rrtype != kDNSType_SRV) {LogMsg("CompleteRecordNatMap: Not a service record %s", ARDisplayString(m, rr)); return; } + + if (rr->resrec.RecordType == kDNSRecordTypeDeregistering) { LogInfo("CompleteRecordNatMap called for %s, Service deregistering", ARDisplayString(m, rr)); return; } + + if (rr->state == regState_DeregPending) { LogInfo("CompleteRecordNatMap called for %s, record in DeregPending", ARDisplayString(m, rr)); return; } + + // As we free the zone info after registering/deregistering with the server (See hndlRecordUpdateReply), + // we need to restart the get zone data and nat mapping request to get the latest mapping result as we can't handle it + // at this moment. Restart from the beginning. + if (!rr->nta || mDNSIPv4AddressIsZero(rr->nta->Addr.ip.v4)) + { + LogInfo("CompleteRecordNatMap called for %s but no zone information!", ARDisplayString(m, rr)); + // We need to clear out the NATinfo state so that it will result in re-acquiring the mapping + // and hence this callback called again. + if (rr->NATinfo.clientContext) + { + mDNS_StopNATOperation_internal(m, &rr->NATinfo); + rr->NATinfo.clientContext = mDNSNULL; + } + rr->state = regState_Pending; + rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; + rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; + return; + } + + mDNS_Lock(m); + // Reevaluate the target always as Target could have changed while + // we were getting the port mapping (See UpdateOneSRVRecord) + target = GetServiceTarget(m, rr); + srvt = GetRRDomainNameTarget(&rr->resrec); + if (!target || target->c[0] == 0 || mDNSIPPortIsZero(n->ExternalPort)) + { + if (target && target->c[0]) + LogInfo("CompleteRecordNatMap - Target %##s for ResourceRecord %##s, ExternalPort %d", target->c, rr->resrec.name->c, mDNSVal16(n->ExternalPort)); + else + LogInfo("CompleteRecordNatMap - no target for %##s, ExternalPort %d", rr->resrec.name->c, mDNSVal16(n->ExternalPort)); + if (srvt) srvt->c[0] = 0; + rr->state = regState_NoTarget; + rr->resrec.rdlength = rr->resrec.rdestimate = 0; + mDNS_Unlock(m); + UpdateAllServiceRecords(m, rr, mDNSfalse); + return; + } + LogInfo("CompleteRecordNatMap - Target %##s for ResourceRecord %##s, ExternalPort %d", target->c, rr->resrec.name->c, mDNSVal16(n->ExternalPort)); + // This function might get called multiple times during a network transition event. Previosuly, we could + // have put the SRV record in NoTarget state above and deregistered all the other records. When this + // function gets called again with a non-zero ExternalPort, we need to set the target and register the + // other records again. + if (srvt && !SameDomainName(srvt, target)) + { + AssignDomainName(srvt, target); + SetNewRData(&rr->resrec, mDNSNULL, 0); // Update rdlength, rdestimate, rdatahash + } + + // SRVChanged is set when when the target of the SRV record changes (See UpdateOneSRVRecord). + // As a result of the target change, we might register just that SRV Record if it was + // previously registered and we have a new target OR deregister SRV (and the associated + // PTR/TXT records) if we don't have a target anymore. When we get a response from the server, + // SRVChanged state tells that we registered/deregistered because of a target change + // and hence handle accordingly e.g., if we deregistered, put the records in NoTarget state OR + // if we registered then put it in Registered state. + // + // Here, we are registering all the records again from the beginning. Treat this as first time + // registration rather than a temporary target change. + rr->SRVChanged = mDNSfalse; + + // We want IsRecordMergeable to check whether it is a record whose update can be + // sent with others. We set the time before we call IsRecordMergeable, so that + // it does not fail this record based on time. We are interested in other checks + // at this time + rr->state = regState_Pending; + rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; + rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; + if (IsRecordMergeable(m, rr, m->timenow + MERGE_DELAY_TIME)) + // Delay the record registration by MERGE_DELAY_TIME so that we can merge them + // into one update + rr->LastAPTime += MERGE_DELAY_TIME; + mDNS_Unlock(m); + // We call this always even though it may not be necessary always e.g., normal registration + // process where TXT and PTR gets registered followed by the SRV record after it gets + // the port mapping. In that case, UpdateAllServiceRecords handles the optimization. The + // update of TXT and PTR record is required if we entered noTargetState before as explained + // above. + UpdateAllServiceRecords(m, rr, mDNStrue); +} + +mDNSlocal void StartRecordNatMap(mDNS *m, AuthRecord *rr) +{ + const mDNSu8 *p; + mDNSu8 protocol; + + if (rr->resrec.rrtype != kDNSType_SRV) + { + LogInfo("StartRecordNatMap: Resource Record %##s type %d, not supported", rr->resrec.name->c, rr->resrec.rrtype); + return; + } + p = rr->resrec.name->c; + //Assume <Service Instance>.<App Protocol>.<Transport protocol>.<Name> + // Skip the first two labels to get to the transport protocol + if (p[0]) p += 1 + p[0]; + if (p[0]) p += 1 + p[0]; + if (SameDomainLabel(p, (mDNSu8 *)"\x4" "_tcp")) protocol = NATOp_MapTCP; + else if (SameDomainLabel(p, (mDNSu8 *)"\x4" "_udp")) protocol = NATOp_MapUDP; + else { LogMsg("StartRecordNatMap: could not determine transport protocol of service %##s", rr->resrec.name->c); return; } + + //LogMsg("StartRecordNatMap: clientContext %p IntPort %d srv.port %d %s", + // rr->NATinfo.clientContext, mDNSVal16(rr->NATinfo.IntPort), mDNSVal16(rr->resrec.rdata->u.srv.port), ARDisplayString(m, rr)); + if (rr->NATinfo.clientContext) mDNS_StopNATOperation_internal(m, &rr->NATinfo); + rr->NATinfo.Protocol = protocol; + + // Shouldn't be trying to set IntPort here -- + // BuildUpdateMessage overwrites srs->RR_SRV.resrec.rdata->u.srv.port with external (mapped) port number + rr->NATinfo.IntPort = rr->resrec.rdata->u.srv.port; + rr->NATinfo.RequestedPort = rr->resrec.rdata->u.srv.port; + rr->NATinfo.NATLease = 0; // Request default lease + rr->NATinfo.clientCallback = CompleteRecordNatMap; + rr->NATinfo.clientContext = rr; + mDNS_StartNATOperation_internal(m, &rr->NATinfo); +} + +// Unlink an Auth Record from the m->ResourceRecords list. +// When a resource record enters regState_NoTarget initially, mDNS_Register_internal +// does not initialize completely e.g., it cannot check for duplicates etc. The resource +// record is temporarily left in the ResourceRecords list so that we can initialize later +// when the target is resolvable. Similarly, when host name changes, we enter regState_NoTarget +// and we do the same. + +// This UnlinkResourceRecord routine is very worrying. It bypasses all the normal cleanup performed +// by mDNS_Deregister_internal and just unceremoniously cuts the record from the active list. +// This is why re-regsitering this record was producing syslog messages like this: +// "Error! Tried to add a NAT traversal that's already in the active list" +// Right now UnlinkResourceRecord is fortunately only called by RegisterAllServiceRecords, +// which then immediately calls mDNS_Register_internal to re-register the record, which probably +// masked more serious problems. Any other use of UnlinkResourceRecord is likely to lead to crashes. +// For now we'll workaround that specific problem by explicitly calling mDNS_StopNATOperation_internal, +// but long-term we should either stop cancelling the record registration and then re-registering it, +// or if we really do need to do this for some reason it should be done via the usual +// mDNS_Deregister_internal path instead of just cutting the record from the list. + +mDNSlocal mStatus UnlinkResourceRecord(mDNS *const m, AuthRecord *const rr) +{ + AuthRecord **list = &m->ResourceRecords; + while (*list && *list != rr) list = &(*list)->next; + if (*list) + { + *list = rr->next; + rr->next = mDNSNULL; + + // Temporary workaround to cancel any active NAT mapping operation + if (rr->NATinfo.clientContext) + { + mDNS_StopNATOperation_internal(m, &rr->NATinfo); + rr->NATinfo.clientContext = mDNSNULL; + if (rr->resrec.rrtype == kDNSType_SRV) rr->resrec.rdata->u.srv.port = rr->NATinfo.IntPort; + } + + return(mStatus_NoError); + } + LogMsg("UnlinkResourceRecord:ERROR!! - no such active record %##s", rr->resrec.name->c); + return(mStatus_NoSuchRecord); +} + +// We need to go through mDNS_Register again as we did not complete the +// full initialization last time e.g., duplicate checks. +// After we register, we will be in regState_GetZoneData. +mDNSlocal void RegisterAllServiceRecords(mDNS *const m, AuthRecord *rr) +{ + LogInfo("RegisterAllServiceRecords: Service Record %##s", rr->resrec.name->c); + // First Register the service record, we do this differently from other records because + // when it entered NoTarget state, it did not go through complete initialization + rr->SRVChanged = mDNSfalse; + UnlinkResourceRecord(m, rr); + mDNS_Register_internal(m, rr); + // Register the other records + UpdateAllServiceRecords(m, rr, mDNStrue); +} + +// Called with lock held +mDNSlocal void UpdateOneSRVRecord(mDNS *m, AuthRecord *rr) +{ + // Target change if: + // We have a target and were previously waiting for one, or + // We had a target and no longer do, or + // The target has changed + + domainname *curtarget = &rr->resrec.rdata->u.srv.target; + const domainname *const nt = GetServiceTarget(m, rr); + const domainname *const newtarget = nt ? nt : (domainname*)""; + mDNSBool TargetChanged = (newtarget->c[0] && rr->state == regState_NoTarget) || !SameDomainName(curtarget, newtarget); + mDNSBool HaveZoneData = rr->nta && !mDNSIPv4AddressIsZero(rr->nta->Addr.ip.v4); + + // Nat state change if: + // We were behind a NAT, and now we are behind a new NAT, or + // We're not behind a NAT but our port was previously mapped to a different external port + // We were not behind a NAT and now we are + + mDNSIPPort port = rr->resrec.rdata->u.srv.port; + mDNSBool NowNeedNATMAP = (rr->AutoTarget == Target_AutoHostAndNATMAP && !mDNSIPPortIsZero(port) && mDNSv4AddrIsRFC1918(&m->AdvertisedV4.ip.v4) && rr->nta && !mDNSAddrIsRFC1918(&rr->nta->Addr)); + mDNSBool WereBehindNAT = (rr->NATinfo.clientContext != mDNSNULL); + mDNSBool PortWasMapped = (rr->NATinfo.clientContext && !mDNSSameIPPort(rr->NATinfo.RequestedPort, port)); // I think this is always false -- SC Sept 07 + mDNSBool NATChanged = (!WereBehindNAT && NowNeedNATMAP) || (!NowNeedNATMAP && PortWasMapped); + + (void)HaveZoneData; //unused + + LogInfo("UpdateOneSRVRecord: Resource Record %s TargetChanged %d, NewTarget %##s", ARDisplayString(m, rr), TargetChanged, nt->c); + + debugf("UpdateOneSRVRecord: %##s newtarget %##s TargetChanged %d HaveZoneData %d port %d NowNeedNATMAP %d WereBehindNAT %d PortWasMapped %d NATChanged %d", + rr->resrec.name->c, newtarget, + TargetChanged, HaveZoneData, mDNSVal16(port), NowNeedNATMAP, WereBehindNAT, PortWasMapped, NATChanged); + + mDNS_CheckLock(m); + + if (!TargetChanged && !NATChanged) return; + + // If we are deregistering the record, then ignore any NAT/Target change. + if (rr->resrec.RecordType == kDNSRecordTypeDeregistering) + { + LogInfo("UpdateOneSRVRecord: Deregistering record, Ignoring TargetChanged %d, NATChanged %d for %##s, state %d", TargetChanged, NATChanged, + rr->resrec.name->c, rr->state); + return; + } + + if (newtarget) + LogInfo("UpdateOneSRVRecord: TargetChanged %d, NATChanged %d for %##s, state %d, newtarget %##s", TargetChanged, NATChanged, rr->resrec.name->c, rr->state, newtarget->c); + else + LogInfo("UpdateOneSRVRecord: TargetChanged %d, NATChanged %d for %##s, state %d, null newtarget", TargetChanged, NATChanged, rr->resrec.name->c, rr->state); + switch(rr->state) + { + case regState_NATMap: + // In these states, the SRV has either not yet been registered (it will get up-to-date information when it is) + // or is in the process of, or has already been, deregistered. This assumes that whenever we transition out + // of this state, we need to look at the target again. + return; + + case regState_UpdatePending: + // We are getting a Target change/NAT change while the SRV record is being updated ? + // let us not do anything for now. + return; + + case regState_NATError: + if (!NATChanged) return; + // if nat changed, register if we have a target (below) + + case regState_NoTarget: + if (!newtarget->c[0]) + { + LogInfo("UpdateOneSRVRecord: No target yet for Resource Record %s", ARDisplayString(m, rr)); + return; + } + RegisterAllServiceRecords(m, rr); + return; + case regState_DeregPending: + // We are in DeregPending either because the service was deregistered from above or we handled + // a NAT/Target change before and sent the deregistration below. There are a few race conditions + // possible + // + // 1. We are handling a second NAT/Target change while the first dereg is in progress. It is possible + // that first dereg never made it through because there was no network connectivity e.g., disconnecting + // from network triggers this function due to a target change and later connecting to the network + // retriggers this function but the deregistration never made it through yet. Just fall through. + // If there is a target register otherwise deregister. + // + // 2. While we sent the dereg during a previous NAT/Target change, uDNS_DeregisterRecord gets + // called as part of service deregistration. When the response comes back, we call + // CompleteDeregistration rather than handle NAT/Target change because the record is in + // kDNSRecordTypeDeregistering state. + // + // 3. If the upper layer deregisters the service, we check for kDNSRecordTypeDeregistering both + // here in this function to avoid handling NAT/Target change and in hndlRecordUpdateReply to call + // CompleteDeregistration instead of handling NAT/Target change. Hence, we are not concerned + // about that case here. + // + // We just handle case (1) by falling through + case regState_Pending: + case regState_Refresh: + case regState_Registered: + // target or nat changed. deregister service. upon completion, we'll look for a new target + rr->SRVChanged = mDNStrue; + rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; + rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; + if (newtarget->c[0]) + { + LogInfo("UpdateOneSRVRecord: SRV record changed for service %##s, registering with new target %##s", + rr->resrec.name->c, newtarget->c); + rr->state = regState_Pending; + } + else + { + LogInfo("UpdateOneSRVRecord: SRV record changed for service %##s de-registering", rr->resrec.name->c); + rr->state = regState_DeregPending; + UpdateAllServiceRecords(m, rr, mDNSfalse); + } + return; + case regState_Unregistered: + default: LogMsg("UpdateOneSRVRecord: Unknown state %d for %##s", rr->state, rr->resrec.name->c); + } +} + +mDNSexport void UpdateAllSRVRecords(mDNS *m) +{ + m->NextSRVUpdate = 0; + LogInfo("UpdateAllSRVRecords %d", m->SleepState); + + if (m->CurrentRecord) + LogMsg("UpdateAllSRVRecords ERROR m->CurrentRecord already set %s", ARDisplayString(m, m->CurrentRecord)); + m->CurrentRecord = m->ResourceRecords; + while (m->CurrentRecord) + { + AuthRecord *rptr = m->CurrentRecord; + m->CurrentRecord = m->CurrentRecord->next; + if (AuthRecord_uDNS(rptr) && rptr->resrec.rrtype == kDNSType_SRV) + UpdateOneSRVRecord(m, rptr); + } +} + +// Forward reference: AdvertiseHostname references HostnameCallback, and HostnameCallback calls AdvertiseHostname +mDNSlocal void HostnameCallback(mDNS *const m, AuthRecord *const rr, mStatus result); + +// Called in normal client context (lock not held) +mDNSlocal void hostnameGetPublicAddressCallback(mDNS *m, NATTraversalInfo *n) +{ + HostnameInfo *h = (HostnameInfo *)n->clientContext; + + if (!h) { LogMsg("RegisterHostnameRecord: registration cancelled"); return; } + + if (!n->Result) + { + if (mDNSIPv4AddressIsZero(n->ExternalAddress) || mDNSv4AddrIsRFC1918(&n->ExternalAddress)) return; + + if (h->arv4.resrec.RecordType) + { + if (mDNSSameIPv4Address(h->arv4.resrec.rdata->u.ipv4, n->ExternalAddress)) return; // If address unchanged, do nothing + LogInfo("Updating hostname %p %##s IPv4 from %.4a to %.4a (NAT gateway's external address)",n, + h->arv4.resrec.name->c, &h->arv4.resrec.rdata->u.ipv4, &n->ExternalAddress); + mDNS_Deregister(m, &h->arv4); // mStatus_MemFree callback will re-register with new address + } + else + { + LogInfo("Advertising hostname %##s IPv4 %.4a (NAT gateway's external address)", h->arv4.resrec.name->c, &n->ExternalAddress); + h->arv4.resrec.RecordType = kDNSRecordTypeKnownUnique; + h->arv4.resrec.rdata->u.ipv4 = n->ExternalAddress; + mDNS_Register(m, &h->arv4); + } + } +} + +// register record or begin NAT traversal +mDNSlocal void AdvertiseHostname(mDNS *m, HostnameInfo *h) +{ + if (!mDNSIPv4AddressIsZero(m->AdvertisedV4.ip.v4) && h->arv4.resrec.RecordType == kDNSRecordTypeUnregistered) + { + mDNS_SetupResourceRecord(&h->arv4, mDNSNULL, mDNSInterface_Any, kDNSType_A, kHostNameTTL, kDNSRecordTypeUnregistered, AuthRecordAny, HostnameCallback, h); + AssignDomainName(&h->arv4.namestorage, &h->fqdn); + h->arv4.resrec.rdata->u.ipv4 = m->AdvertisedV4.ip.v4; + h->arv4.state = regState_Unregistered; + if (mDNSv4AddrIsRFC1918(&m->AdvertisedV4.ip.v4)) + { + // If we already have a NAT query active, stop it and restart it to make sure we get another callback + if (h->natinfo.clientContext) mDNS_StopNATOperation_internal(m, &h->natinfo); + h->natinfo.Protocol = 0; + h->natinfo.IntPort = zeroIPPort; + h->natinfo.RequestedPort = zeroIPPort; + h->natinfo.NATLease = 0; + h->natinfo.clientCallback = hostnameGetPublicAddressCallback; + h->natinfo.clientContext = h; + mDNS_StartNATOperation_internal(m, &h->natinfo); + } + else + { + LogInfo("Advertising hostname %##s IPv4 %.4a", h->arv4.resrec.name->c, &m->AdvertisedV4.ip.v4); + h->arv4.resrec.RecordType = kDNSRecordTypeKnownUnique; + mDNS_Register_internal(m, &h->arv4); + } + } + + if (!mDNSIPv6AddressIsZero(m->AdvertisedV6.ip.v6) && h->arv6.resrec.RecordType == kDNSRecordTypeUnregistered) + { + mDNS_SetupResourceRecord(&h->arv6, mDNSNULL, mDNSInterface_Any, kDNSType_AAAA, kHostNameTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, HostnameCallback, h); + AssignDomainName(&h->arv6.namestorage, &h->fqdn); + h->arv6.resrec.rdata->u.ipv6 = m->AdvertisedV6.ip.v6; + h->arv6.state = regState_Unregistered; + LogInfo("Advertising hostname %##s IPv6 %.16a", h->arv6.resrec.name->c, &m->AdvertisedV6.ip.v6); + mDNS_Register_internal(m, &h->arv6); + } +} + +mDNSlocal void HostnameCallback(mDNS *const m, AuthRecord *const rr, mStatus result) +{ + HostnameInfo *hi = (HostnameInfo *)rr->RecordContext; + + if (result == mStatus_MemFree) + { + if (hi) + { + // If we're still in the Hostnames list, update to new address + HostnameInfo *i; + LogInfo("HostnameCallback: Got mStatus_MemFree for %p %p %s", hi, rr, ARDisplayString(m, rr)); + for (i = m->Hostnames; i; i = i->next) + if (rr == &i->arv4 || rr == &i->arv6) + { mDNS_Lock(m); AdvertiseHostname(m, i); mDNS_Unlock(m); return; } + + // Else, we're not still in the Hostnames list, so free the memory + if (hi->arv4.resrec.RecordType == kDNSRecordTypeUnregistered && + hi->arv6.resrec.RecordType == kDNSRecordTypeUnregistered) + { + if (hi->natinfo.clientContext) mDNS_StopNATOperation_internal(m, &hi->natinfo); + hi->natinfo.clientContext = mDNSNULL; + mDNSPlatformMemFree(hi); // free hi when both v4 and v6 AuthRecs deallocated + } + } + return; + } + + if (result) + { + // don't unlink or free - we can retry when we get a new address/router + if (rr->resrec.rrtype == kDNSType_A) + LogMsg("HostnameCallback: Error %d for registration of %##s IP %.4a", result, rr->resrec.name->c, &rr->resrec.rdata->u.ipv4); + else + LogMsg("HostnameCallback: Error %d for registration of %##s IP %.16a", result, rr->resrec.name->c, &rr->resrec.rdata->u.ipv6); + if (!hi) { mDNSPlatformMemFree(rr); return; } + if (rr->state != regState_Unregistered) LogMsg("Error: HostnameCallback invoked with error code for record not in regState_Unregistered!"); + + if (hi->arv4.state == regState_Unregistered && + hi->arv6.state == regState_Unregistered) + { + // only deliver status if both v4 and v6 fail + rr->RecordContext = (void *)hi->StatusContext; + if (hi->StatusCallback) + hi->StatusCallback(m, rr, result); // client may NOT make API calls here + rr->RecordContext = (void *)hi; + } + return; + } + + // register any pending services that require a target + mDNS_Lock(m); + m->NextSRVUpdate = NonZeroTime(m->timenow); + mDNS_Unlock(m); + + // Deliver success to client + if (!hi) { LogMsg("HostnameCallback invoked with orphaned address record"); return; } + if (rr->resrec.rrtype == kDNSType_A) + LogInfo("Registered hostname %##s IP %.4a", rr->resrec.name->c, &rr->resrec.rdata->u.ipv4); + else + LogInfo("Registered hostname %##s IP %.16a", rr->resrec.name->c, &rr->resrec.rdata->u.ipv6); + + rr->RecordContext = (void *)hi->StatusContext; + if (hi->StatusCallback) + hi->StatusCallback(m, rr, result); // client may NOT make API calls here + rr->RecordContext = (void *)hi; +} + +mDNSlocal void FoundStaticHostname(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord) +{ + const domainname *pktname = &answer->rdata->u.name; + domainname *storedname = &m->StaticHostname; + HostnameInfo *h = m->Hostnames; + + (void)question; + + if (answer->rdlength != 0) + LogInfo("FoundStaticHostname: question %##s -> answer %##s (%s)", question->qname.c, answer->rdata->u.name.c, AddRecord ? "ADD" : "RMV"); + else + LogInfo("FoundStaticHostname: question %##s -> answer NULL (%s)", question->qname.c, AddRecord ? "ADD" : "RMV"); + + if (AddRecord && answer->rdlength != 0 && !SameDomainName(pktname, storedname)) + { + AssignDomainName(storedname, pktname); + while (h) + { + if (h->arv4.state == regState_Pending || h->arv4.state == regState_NATMap || h->arv6.state == regState_Pending) + { + // if we're in the process of registering a dynamic hostname, delay SRV update so we don't have to reregister services if the dynamic name succeeds + m->NextSRVUpdate = NonZeroTime(m->timenow + 5 * mDNSPlatformOneSecond); + debugf("FoundStaticHostname: NextSRVUpdate in %d %d", m->NextSRVUpdate - m->timenow, m->timenow); + return; + } + h = h->next; + } + mDNS_Lock(m); + m->NextSRVUpdate = NonZeroTime(m->timenow); + mDNS_Unlock(m); + } + else if (!AddRecord && SameDomainName(pktname, storedname)) + { + mDNS_Lock(m); + storedname->c[0] = 0; + m->NextSRVUpdate = NonZeroTime(m->timenow); + mDNS_Unlock(m); + } +} + +// Called with lock held +mDNSlocal void GetStaticHostname(mDNS *m) +{ + char buf[MAX_REVERSE_MAPPING_NAME_V4]; + DNSQuestion *q = &m->ReverseMap; + mDNSu8 *ip = m->AdvertisedV4.ip.v4.b; + mStatus err; + + if (m->ReverseMap.ThisQInterval != -1) return; // already running + if (mDNSIPv4AddressIsZero(m->AdvertisedV4.ip.v4)) return; + + mDNSPlatformMemZero(q, sizeof(*q)); + // Note: This is reverse order compared to a normal dotted-decimal IP address, so we can't use our customary "%.4a" format code + mDNS_snprintf(buf, sizeof(buf), "%d.%d.%d.%d.in-addr.arpa.", ip[3], ip[2], ip[1], ip[0]); + if (!MakeDomainNameFromDNSNameString(&q->qname, buf)) { LogMsg("Error: GetStaticHostname - bad name %s", buf); return; } + + q->InterfaceID = mDNSInterface_Any; + q->flags = 0; + q->Target = zeroAddr; + q->qtype = kDNSType_PTR; + q->qclass = kDNSClass_IN; + q->LongLived = mDNSfalse; + q->ExpectUnique = mDNSfalse; + q->ForceMCast = mDNSfalse; + q->ReturnIntermed = mDNStrue; + q->SuppressUnusable = mDNSfalse; + q->SearchListIndex = 0; + q->AppendSearchDomains = 0; + q->RetryWithSearchDomains = mDNSfalse; + q->TimeoutQuestion = 0; + q->WakeOnResolve = 0; + q->UseBackgroundTrafficClass = mDNSfalse; + q->ValidationRequired = 0; + q->ValidatingResponse = 0; + q->ProxyQuestion = 0; + q->qnameOrig = mDNSNULL; + q->AnonInfo = mDNSNULL; + q->pid = mDNSPlatformGetPID(); + q->QuestionCallback = FoundStaticHostname; + q->QuestionContext = mDNSNULL; + + LogInfo("GetStaticHostname: %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); + err = mDNS_StartQuery_internal(m, q); + if (err) LogMsg("Error: GetStaticHostname - StartQuery returned error %d", err); +} + +mDNSexport void mDNS_AddDynDNSHostName(mDNS *m, const domainname *fqdn, mDNSRecordCallback *StatusCallback, const void *StatusContext) +{ + HostnameInfo **ptr = &m->Hostnames; + + LogInfo("mDNS_AddDynDNSHostName %##s", fqdn); + + while (*ptr && !SameDomainName(fqdn, &(*ptr)->fqdn)) ptr = &(*ptr)->next; + if (*ptr) { LogMsg("DynDNSHostName %##s already in list", fqdn->c); return; } + + // allocate and format new address record + *ptr = mDNSPlatformMemAllocate(sizeof(**ptr)); + if (!*ptr) { LogMsg("ERROR: mDNS_AddDynDNSHostName - malloc"); return; } + + mDNSPlatformMemZero(*ptr, sizeof(**ptr)); + AssignDomainName(&(*ptr)->fqdn, fqdn); + (*ptr)->arv4.state = regState_Unregistered; + (*ptr)->arv6.state = regState_Unregistered; + (*ptr)->StatusCallback = StatusCallback; + (*ptr)->StatusContext = StatusContext; + + AdvertiseHostname(m, *ptr); +} + +mDNSexport void mDNS_RemoveDynDNSHostName(mDNS *m, const domainname *fqdn) +{ + HostnameInfo **ptr = &m->Hostnames; + + LogInfo("mDNS_RemoveDynDNSHostName %##s", fqdn); + + while (*ptr && !SameDomainName(fqdn, &(*ptr)->fqdn)) ptr = &(*ptr)->next; + if (!*ptr) LogMsg("mDNS_RemoveDynDNSHostName: no such domainname %##s", fqdn->c); + else + { + HostnameInfo *hi = *ptr; + // We do it this way because, if we have no active v6 record, the "mDNS_Deregister_internal(m, &hi->arv4);" + // below could free the memory, and we have to make sure we don't touch hi fields after that. + mDNSBool f4 = hi->arv4.resrec.RecordType != kDNSRecordTypeUnregistered && hi->arv4.state != regState_Unregistered; + mDNSBool f6 = hi->arv6.resrec.RecordType != kDNSRecordTypeUnregistered && hi->arv6.state != regState_Unregistered; + if (f4) LogInfo("mDNS_RemoveDynDNSHostName removing v4 %##s", fqdn); + if (f6) LogInfo("mDNS_RemoveDynDNSHostName removing v6 %##s", fqdn); + *ptr = (*ptr)->next; // unlink + if (f4) mDNS_Deregister_internal(m, &hi->arv4, mDNS_Dereg_normal); + if (f6) mDNS_Deregister_internal(m, &hi->arv6, mDNS_Dereg_normal); + // When both deregistrations complete we'll free the memory in the mStatus_MemFree callback + } + mDNS_CheckLock(m); + m->NextSRVUpdate = NonZeroTime(m->timenow); +} + +// Currently called without holding the lock +// Maybe we should change that? +mDNSexport void mDNS_SetPrimaryInterfaceInfo(mDNS *m, const mDNSAddr *v4addr, const mDNSAddr *v6addr, const mDNSAddr *router) +{ + mDNSBool v4Changed, v6Changed, RouterChanged; + + if (m->mDNS_busy != m->mDNS_reentrancy) + LogMsg("mDNS_SetPrimaryInterfaceInfo: mDNS_busy (%ld) != mDNS_reentrancy (%ld)", m->mDNS_busy, m->mDNS_reentrancy); + + if (v4addr && v4addr->type != mDNSAddrType_IPv4) { LogMsg("mDNS_SetPrimaryInterfaceInfo v4 address - incorrect type. Discarding. %#a", v4addr); return; } + if (v6addr && v6addr->type != mDNSAddrType_IPv6) { LogMsg("mDNS_SetPrimaryInterfaceInfo v6 address - incorrect type. Discarding. %#a", v6addr); return; } + if (router && router->type != mDNSAddrType_IPv4) { LogMsg("mDNS_SetPrimaryInterfaceInfo passed non-v4 router. Discarding. %#a", router); return; } + + mDNS_Lock(m); + + v4Changed = !mDNSSameIPv4Address(m->AdvertisedV4.ip.v4, v4addr ? v4addr->ip.v4 : zerov4Addr); + v6Changed = !mDNSSameIPv6Address(m->AdvertisedV6.ip.v6, v6addr ? v6addr->ip.v6 : zerov6Addr); + RouterChanged = !mDNSSameIPv4Address(m->Router.ip.v4, router ? router->ip.v4 : zerov4Addr); + + if (v4addr && (v4Changed || RouterChanged)) + debugf("mDNS_SetPrimaryInterfaceInfo: address changed from %#a to %#a", &m->AdvertisedV4, v4addr); + + if (v4addr) m->AdvertisedV4 = *v4addr;else m->AdvertisedV4.ip.v4 = zerov4Addr; + if (v6addr) m->AdvertisedV6 = *v6addr;else m->AdvertisedV6.ip.v6 = zerov6Addr; + if (router) m->Router = *router;else m->Router.ip.v4 = zerov4Addr; + // setting router to zero indicates that nat mappings must be reestablished when router is reset + + if (v4Changed || RouterChanged || v6Changed) + { + HostnameInfo *i; + LogInfo("mDNS_SetPrimaryInterfaceInfo: %s%s%s%#a %#a %#a", + v4Changed ? "v4Changed " : "", + RouterChanged ? "RouterChanged " : "", + v6Changed ? "v6Changed " : "", v4addr, v6addr, router); + + for (i = m->Hostnames; i; i = i->next) + { + LogInfo("mDNS_SetPrimaryInterfaceInfo updating host name registrations for %##s", i->fqdn.c); + + if (i->arv4.resrec.RecordType > kDNSRecordTypeDeregistering && + !mDNSSameIPv4Address(i->arv4.resrec.rdata->u.ipv4, m->AdvertisedV4.ip.v4)) + { + LogInfo("mDNS_SetPrimaryInterfaceInfo deregistering %s", ARDisplayString(m, &i->arv4)); + mDNS_Deregister_internal(m, &i->arv4, mDNS_Dereg_normal); + } + + if (i->arv6.resrec.RecordType > kDNSRecordTypeDeregistering && + !mDNSSameIPv6Address(i->arv6.resrec.rdata->u.ipv6, m->AdvertisedV6.ip.v6)) + { + LogInfo("mDNS_SetPrimaryInterfaceInfo deregistering %s", ARDisplayString(m, &i->arv6)); + mDNS_Deregister_internal(m, &i->arv6, mDNS_Dereg_normal); + } + + // AdvertiseHostname will only register new address records. + // For records still in the process of deregistering it will ignore them, and let the mStatus_MemFree callback handle them. + AdvertiseHostname(m, i); + } + + if (v4Changed || RouterChanged) + { + // If we have a non-zero IPv4 address, we should try immediately to see if we have a NAT gateway + // If we have no IPv4 address, we don't want to be in quite such a hurry to report failures to our clients + // <rdar://problem/6935929> Sleeping server sometimes briefly disappears over Back to My Mac after it wakes up + mDNSu32 waitSeconds = v4addr ? 0 : 5; + NATTraversalInfo *n; + m->ExtAddress = zerov4Addr; + m->LastNATMapResultCode = NATErr_None; + + RecreateNATMappings(m, mDNSPlatformOneSecond * waitSeconds); + + for (n = m->NATTraversals; n; n=n->next) + n->NewAddress = zerov4Addr; + + LogInfo("mDNS_SetPrimaryInterfaceInfo:%s%s: recreating NAT mappings in %d seconds", + v4Changed ? " v4Changed" : "", + RouterChanged ? " RouterChanged" : "", + waitSeconds); + } + + if (m->ReverseMap.ThisQInterval != -1) mDNS_StopQuery_internal(m, &m->ReverseMap); + m->StaticHostname.c[0] = 0; + + m->NextSRVUpdate = NonZeroTime(m->timenow); + +#if APPLE_OSX_mDNSResponder + if (RouterChanged) uuid_generate(m->asl_uuid); + UpdateAutoTunnelDomainStatuses(m); +#endif + } + + mDNS_Unlock(m); +} + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - Incoming Message Processing +#endif + +mDNSlocal mStatus ParseTSIGError(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, const domainname *const displayname) +{ + const mDNSu8 *ptr; + mStatus err = mStatus_NoError; + int i; + + ptr = LocateAdditionals(msg, end); + if (!ptr) goto finish; + + for (i = 0; i < msg->h.numAdditionals; i++) + { + ptr = GetLargeResourceRecord(m, msg, ptr, end, 0, kDNSRecordTypePacketAdd, &m->rec); + if (!ptr) goto finish; + if (m->rec.r.resrec.RecordType != kDNSRecordTypePacketNegative && m->rec.r.resrec.rrtype == kDNSType_TSIG) + { + mDNSu32 macsize; + mDNSu8 *rd = m->rec.r.resrec.rdata->u.data; + mDNSu8 *rdend = rd + m->rec.r.resrec.rdlength; + int alglen = DomainNameLengthLimit(&m->rec.r.resrec.rdata->u.name, rdend); + if (alglen > MAX_DOMAIN_NAME) goto finish; + rd += alglen; // algorithm name + if (rd + 6 > rdend) goto finish; + rd += 6; // 48-bit timestamp + if (rd + sizeof(mDNSOpaque16) > rdend) goto finish; + rd += sizeof(mDNSOpaque16); // fudge + if (rd + sizeof(mDNSOpaque16) > rdend) goto finish; + macsize = mDNSVal16(*(mDNSOpaque16 *)rd); + rd += sizeof(mDNSOpaque16); // MAC size + if (rd + macsize > rdend) goto finish; + rd += macsize; + if (rd + sizeof(mDNSOpaque16) > rdend) goto finish; + rd += sizeof(mDNSOpaque16); // orig id + if (rd + sizeof(mDNSOpaque16) > rdend) goto finish; + err = mDNSVal16(*(mDNSOpaque16 *)rd); // error code + + if (err == TSIG_ErrBadSig) { LogMsg("%##s: bad signature", displayname->c); err = mStatus_BadSig; } + else if (err == TSIG_ErrBadKey) { LogMsg("%##s: bad key", displayname->c); err = mStatus_BadKey; } + else if (err == TSIG_ErrBadTime) { LogMsg("%##s: bad time", displayname->c); err = mStatus_BadTime; } + else if (err) { LogMsg("%##s: unknown tsig error %d", displayname->c, err); err = mStatus_UnknownErr; } + goto finish; + } + m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it + } + +finish: + m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it + return err; +} + +mDNSlocal mStatus checkUpdateResult(mDNS *const m, const domainname *const displayname, const mDNSu8 rcode, const DNSMessage *const msg, const mDNSu8 *const end) +{ + (void)msg; // currently unused, needed for TSIG errors + if (!rcode) return mStatus_NoError; + else if (rcode == kDNSFlag1_RC_YXDomain) + { + debugf("name in use: %##s", displayname->c); + return mStatus_NameConflict; + } + else if (rcode == kDNSFlag1_RC_Refused) + { + LogMsg("Update %##s refused", displayname->c); + return mStatus_Refused; + } + else if (rcode == kDNSFlag1_RC_NXRRSet) + { + LogMsg("Reregister refused (NXRRSET): %##s", displayname->c); + return mStatus_NoSuchRecord; + } + else if (rcode == kDNSFlag1_RC_NotAuth) + { + // TSIG errors should come with FormErr as per RFC 2845, but BIND 9 sends them with NotAuth so we look here too + mStatus tsigerr = ParseTSIGError(m, msg, end, displayname); + if (!tsigerr) + { + LogMsg("Permission denied (NOAUTH): %##s", displayname->c); + return mStatus_UnknownErr; + } + else return tsigerr; + } + else if (rcode == kDNSFlag1_RC_FormErr) + { + mStatus tsigerr = ParseTSIGError(m, msg, end, displayname); + if (!tsigerr) + { + LogMsg("Format Error: %##s", displayname->c); + return mStatus_UnknownErr; + } + else return tsigerr; + } + else + { + LogMsg("Update %##s failed with rcode %d", displayname->c, rcode); + return mStatus_UnknownErr; + } +} + +// We add three Additional Records for unicast resource record registrations +// which is a function of AuthInfo and AutoTunnel properties +mDNSlocal mDNSu32 RRAdditionalSize(mDNS *const m, DomainAuthInfo *AuthInfo) +{ + mDNSu32 leaseSize, hinfoSize, tsigSize; + mDNSu32 rr_base_size = 10; // type (2) class (2) TTL (4) rdlength (2) + + // OPT RR : Emptyname(.) + base size + rdataOPT + leaseSize = 1 + rr_base_size + sizeof(rdataOPT); + + // HINFO: Resource Record Name + base size + RDATA + // HINFO is added only for autotunnels + hinfoSize = 0; + if (AuthInfo && AuthInfo->AutoTunnel) + hinfoSize = (m->hostlabel.c[0] + 1) + DomainNameLength(&AuthInfo->domain) + + rr_base_size + (2 + m->HIHardware.c[0] + m->HISoftware.c[0]); + + //TSIG: Resource Record Name + base size + RDATA + // RDATA: + // Algorithm name: hmac-md5.sig-alg.reg.int (8+7+3+3 + 5 bytes for length = 26 bytes) + // Time: 6 bytes + // Fudge: 2 bytes + // Mac Size: 2 bytes + // Mac: 16 bytes + // ID: 2 bytes + // Error: 2 bytes + // Len: 2 bytes + // Total: 58 bytes + tsigSize = 0; + if (AuthInfo) tsigSize = DomainNameLength(&AuthInfo->keyname) + rr_base_size + 58; + + return (leaseSize + hinfoSize + tsigSize); +} + +//Note: Make sure that RREstimatedSize is updated accordingly if anything that is done here +//would modify rdlength/rdestimate +mDNSlocal mDNSu8* BuildUpdateMessage(mDNS *const m, mDNSu8 *ptr, AuthRecord *rr, mDNSu8 *limit) +{ + //If this record is deregistering, then just send the deletion record + if (rr->state == regState_DeregPending) + { + rr->expire = 0; // Indicate that we have no active registration any more + ptr = putDeletionRecordWithLimit(&m->omsg, ptr, &rr->resrec, limit); + if (!ptr) goto exit; + return ptr; + } + + // This is a common function to both sending an update in a group or individual + // records separately. Hence, we change the state here. + if (rr->state == regState_Registered) rr->state = regState_Refresh; + if (rr->state != regState_Refresh && rr->state != regState_UpdatePending) + rr->state = regState_Pending; + + // For Advisory records like e.g., _services._dns-sd, which is shared, don't send goodbyes as multiple + // host might be registering records and deregistering from one does not make sense + if (rr->resrec.RecordType != kDNSRecordTypeAdvisory) rr->RequireGoodbye = mDNStrue; + + if ((rr->resrec.rrtype == kDNSType_SRV) && (rr->AutoTarget == Target_AutoHostAndNATMAP) && + !mDNSIPPortIsZero(rr->NATinfo.ExternalPort)) + { + rr->resrec.rdata->u.srv.port = rr->NATinfo.ExternalPort; + } + + if (rr->state == regState_UpdatePending) + { + // delete old RData + SetNewRData(&rr->resrec, rr->OrigRData, rr->OrigRDLen); + if (!(ptr = putDeletionRecordWithLimit(&m->omsg, ptr, &rr->resrec, limit))) goto exit; // delete old rdata + + // add new RData + SetNewRData(&rr->resrec, rr->InFlightRData, rr->InFlightRDLen); + if (!(ptr = PutResourceRecordTTLWithLimit(&m->omsg, ptr, &m->omsg.h.mDNS_numUpdates, &rr->resrec, rr->resrec.rroriginalttl, limit))) goto exit; + } + else + { + if (rr->resrec.RecordType == kDNSRecordTypeKnownUnique || rr->resrec.RecordType == kDNSRecordTypeVerified) + { + // KnownUnique : Delete any previous value + // For Unicast registrations, we don't verify that it is unique, but set to verified and hence we want to + // delete any previous value + ptr = putDeleteRRSetWithLimit(&m->omsg, ptr, rr->resrec.name, rr->resrec.rrtype, limit); + if (!ptr) goto exit; + } + else if (rr->resrec.RecordType != kDNSRecordTypeShared) + { + // For now don't do this, until we have the logic for intelligent grouping of individual records into logical service record sets + //ptr = putPrereqNameNotInUse(rr->resrec.name, &m->omsg, ptr, end); + if (!ptr) goto exit; + } + + ptr = PutResourceRecordTTLWithLimit(&m->omsg, ptr, &m->omsg.h.mDNS_numUpdates, &rr->resrec, rr->resrec.rroriginalttl, limit); + if (!ptr) goto exit; + } + + return ptr; +exit: + LogMsg("BuildUpdateMessage: Error formatting message for %s", ARDisplayString(m, rr)); + return mDNSNULL; +} + +// Called with lock held +mDNSlocal void SendRecordRegistration(mDNS *const m, AuthRecord *rr) +{ + mDNSu8 *ptr = m->omsg.data; + mStatus err = mStatus_UnknownErr; + mDNSu8 *limit; + DomainAuthInfo *AuthInfo; + + // For the ability to register large TXT records, we limit the single record registrations + // to AbsoluteMaxDNSMessageData + limit = ptr + AbsoluteMaxDNSMessageData; + + AuthInfo = GetAuthInfoForName_internal(m, rr->resrec.name); + limit -= RRAdditionalSize(m, AuthInfo); + + mDNS_CheckLock(m); + + if (!rr->nta || mDNSIPv4AddressIsZero(rr->nta->Addr.ip.v4)) + { + // We never call this function when there is no zone information . Log a message if it ever happens. + LogMsg("SendRecordRegistration: No Zone information, should not happen %s", ARDisplayString(m, rr)); + return; + } + + rr->updateid = mDNS_NewMessageID(m); + InitializeDNSMessage(&m->omsg.h, rr->updateid, UpdateReqFlags); + + // set zone + ptr = putZone(&m->omsg, ptr, limit, rr->zone, mDNSOpaque16fromIntVal(rr->resrec.rrclass)); + if (!ptr) goto exit; + + if (!(ptr = BuildUpdateMessage(m, ptr, rr, limit))) goto exit; + + if (rr->uselease) + { + ptr = putUpdateLeaseWithLimit(&m->omsg, ptr, DEFAULT_UPDATE_LEASE, limit); + if (!ptr) goto exit; + } + if (rr->Private) + { + LogInfo("SendRecordRegistration TCP %p %s", rr->tcp, ARDisplayString(m, rr)); + if (rr->tcp) LogInfo("SendRecordRegistration: Disposing existing TCP connection for %s", ARDisplayString(m, rr)); + if (rr->tcp) { DisposeTCPConn(rr->tcp); rr->tcp = mDNSNULL; } + if (!rr->nta) { LogMsg("SendRecordRegistration:Private:ERROR!! nta is NULL for %s", ARDisplayString(m, rr)); return; } + rr->tcp = MakeTCPConn(m, &m->omsg, ptr, kTCPSocketFlags_UseTLS, &rr->nta->Addr, rr->nta->Port, &rr->nta->Host, mDNSNULL, rr); + } + else + { + LogInfo("SendRecordRegistration UDP %s", ARDisplayString(m, rr)); + if (!rr->nta) { LogMsg("SendRecordRegistration:ERROR!! nta is NULL for %s", ARDisplayString(m, rr)); return; } + err = mDNSSendDNSMessage(m, &m->omsg, ptr, mDNSInterface_Any, mDNSNULL, &rr->nta->Addr, rr->nta->Port, mDNSNULL, GetAuthInfoForName_internal(m, rr->resrec.name), mDNSfalse); + if (err) debugf("ERROR: SendRecordRegistration - mDNSSendDNSMessage - %d", err); + } + + SetRecordRetry(m, rr, 0); + return; +exit: + LogMsg("SendRecordRegistration: Error formatting message for %s, disabling further updates", ARDisplayString(m, rr)); + // Disable this record from future updates + rr->state = regState_NoTarget; +} + +// Is the given record "rr" eligible for merging ? +mDNSlocal mDNSBool IsRecordMergeable(mDNS *const m, AuthRecord *rr, mDNSs32 time) +{ + DomainAuthInfo *info; + (void) m; //unused + // A record is eligible for merge, if the following properties are met. + // + // 1. uDNS Resource Record + // 2. It is time to send them now + // 3. It is in proper state + // 4. Update zone has been resolved + // 5. if DomainAuthInfo exists for the zone, it should not be soon deleted + // 6. Zone information is present + // 7. Update server is not zero + // 8. It has a non-null zone + // 9. It uses a lease option + // 10. DontMerge is not set + // + // Following code is implemented as separate "if" statements instead of one "if" statement + // is for better debugging purposes e.g., we know exactly what failed if debugging turned on. + + if (!AuthRecord_uDNS(rr)) return mDNSfalse; + + if (rr->LastAPTime + rr->ThisAPInterval - time > 0) + { debugf("IsRecordMergeable: Time %d not reached for %s", rr->LastAPTime + rr->ThisAPInterval - m->timenow, ARDisplayString(m, rr)); return mDNSfalse; } + + if (!rr->zone) return mDNSfalse; + + info = GetAuthInfoForName_internal(m, rr->zone); + + if (info && info->deltime && m->timenow - info->deltime >= 0) {debugf("IsRecordMergeable: Domain %##s will be deleted soon", info->domain.c); return mDNSfalse;} + + if (rr->state != regState_DeregPending && rr->state != regState_Pending && rr->state != regState_Registered && rr->state != regState_Refresh && rr->state != regState_UpdatePending) + { debugf("IsRecordMergeable: state %d not right %s", rr->state, ARDisplayString(m, rr)); return mDNSfalse; } + + if (!rr->nta || mDNSIPv4AddressIsZero(rr->nta->Addr.ip.v4)) return mDNSfalse; + + if (!rr->uselease) return mDNSfalse; + + if (rr->mState == mergeState_DontMerge) {debugf("IsRecordMergeable Dontmerge true %s", ARDisplayString(m, rr)); return mDNSfalse;} + debugf("IsRecordMergeable: Returning true for %s", ARDisplayString(m, rr)); + return mDNStrue; +} + +// Is the resource record "rr" eligible to merge to with "currentRR" ? +mDNSlocal mDNSBool AreRecordsMergeable(mDNS *const m, AuthRecord *currentRR, AuthRecord *rr, mDNSs32 time) +{ + // A record is eligible to merge with another record as long it is eligible for merge in itself + // and it has the same zone information as the other record + if (!IsRecordMergeable(m, rr, time)) return mDNSfalse; + + if (!SameDomainName(currentRR->zone, rr->zone)) + { debugf("AreRecordMergeable zone mismatch current rr Zone %##s, rr zone %##s", currentRR->zone->c, rr->zone->c); return mDNSfalse; } + + if (!mDNSSameIPv4Address(currentRR->nta->Addr.ip.v4, rr->nta->Addr.ip.v4)) return mDNSfalse; + + if (!mDNSSameIPPort(currentRR->nta->Port, rr->nta->Port)) return mDNSfalse; + + debugf("AreRecordsMergeable: Returning true for %s", ARDisplayString(m, rr)); + return mDNStrue; +} + +// If we can't build the message successfully because of problems in pre-computing +// the space, we disable merging for all the current records +mDNSlocal void RRMergeFailure(mDNS *const m) +{ + AuthRecord *rr; + for (rr = m->ResourceRecords; rr; rr = rr->next) + { + rr->mState = mergeState_DontMerge; + rr->SendRNow = mDNSNULL; + // Restarting the registration is much simpler than saving and restoring + // the exact time + ActivateUnicastRegistration(m, rr); + } +} + +mDNSlocal void SendGroupRRMessage(mDNS *const m, AuthRecord *anchorRR, mDNSu8 *ptr, DomainAuthInfo *info) +{ + mDNSu8 *limit; + if (!anchorRR) {debugf("SendGroupRRMessage: Could not merge records"); return;} + + if (info && info->AutoTunnel) limit = m->omsg.data + AbsoluteMaxDNSMessageData; + else limit = m->omsg.data + NormalMaxDNSMessageData; + + // This has to go in the additional section and hence need to be done last + ptr = putUpdateLeaseWithLimit(&m->omsg, ptr, DEFAULT_UPDATE_LEASE, limit); + if (!ptr) + { + LogMsg("SendGroupRRMessage: ERROR: Could not put lease option, failing the group registration"); + // if we can't put the lease, we need to undo the merge + RRMergeFailure(m); + return; + } + if (anchorRR->Private) + { + if (anchorRR->tcp) debugf("SendGroupRRMessage: Disposing existing TCP connection for %s", ARDisplayString(m, anchorRR)); + if (anchorRR->tcp) { DisposeTCPConn(anchorRR->tcp); anchorRR->tcp = mDNSNULL; } + if (!anchorRR->nta) { LogMsg("SendGroupRRMessage:ERROR!! nta is NULL for %s", ARDisplayString(m, anchorRR)); return; } + anchorRR->tcp = MakeTCPConn(m, &m->omsg, ptr, kTCPSocketFlags_UseTLS, &anchorRR->nta->Addr, anchorRR->nta->Port, &anchorRR->nta->Host, mDNSNULL, anchorRR); + if (!anchorRR->tcp) LogInfo("SendGroupRRMessage: Cannot establish TCP connection for %s", ARDisplayString(m, anchorRR)); + else LogInfo("SendGroupRRMessage: Sent a group update ID: %d start %p, end %p, limit %p", mDNSVal16(m->omsg.h.id), m->omsg.data, ptr, limit); + } + else + { + mStatus err = mDNSSendDNSMessage(m, &m->omsg, ptr, mDNSInterface_Any, mDNSNULL, &anchorRR->nta->Addr, anchorRR->nta->Port, mDNSNULL, info, mDNSfalse); + if (err) LogInfo("SendGroupRRMessage: Cannot send UDP message for %s", ARDisplayString(m, anchorRR)); + else LogInfo("SendGroupRRMessage: Sent a group UDP update ID: %d start %p, end %p, limit %p", mDNSVal16(m->omsg.h.id), m->omsg.data, ptr, limit); + } + return; +} + +// As we always include the zone information and the resource records contain zone name +// at the end, it will get compressed. Hence, we subtract zoneSize and add two bytes for +// the compression pointer +mDNSlocal mDNSu32 RREstimatedSize(AuthRecord *rr, int zoneSize) +{ + int rdlength; + + // Note: Estimation of the record size has to mirror the logic in BuildUpdateMessage, otherwise estimation + // would be wrong. Currently BuildUpdateMessage calls SetNewRData in UpdatePending case. Hence, we need + // to account for that here. Otherwise, we might under estimate the size. + if (rr->state == regState_UpdatePending) + // old RData that will be deleted + // new RData that will be added + rdlength = rr->OrigRDLen + rr->InFlightRDLen; + else + rdlength = rr->resrec.rdestimate; + + if (rr->state == regState_DeregPending) + { + debugf("RREstimatedSize: ResourceRecord %##s (%s), DomainNameLength %d, zoneSize %d, rdestimate %d", + rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype), DomainNameLength(rr->resrec.name), zoneSize, rdlength); + return DomainNameLength(rr->resrec.name) - zoneSize + 2 + 10 + rdlength; + } + + // For SRV, TXT, AAAA etc. that are Unique/Verified, we also send a Deletion Record + if (rr->resrec.RecordType == kDNSRecordTypeKnownUnique || rr->resrec.RecordType == kDNSRecordTypeVerified) + { + // Deletion Record: Resource Record Name + Base size (10) + 0 + // Record: Resource Record Name (Compressed = 2) + Base size (10) + rdestimate + + debugf("RREstimatedSize: ResourceRecord %##s (%s), DomainNameLength %d, zoneSize %d, rdestimate %d", + rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype), DomainNameLength(rr->resrec.name), zoneSize, rdlength); + return DomainNameLength(rr->resrec.name) - zoneSize + 2 + 10 + 2 + 10 + rdlength; + } + else + { + return DomainNameLength(rr->resrec.name) - zoneSize + 2 + 10 + rdlength; + } +} + +mDNSlocal AuthRecord *MarkRRForSending(mDNS *const m) +{ + AuthRecord *rr; + AuthRecord *firstRR = mDNSNULL; + + // Look for records that needs to be sent in the next two seconds (MERGE_DELAY_TIME is set to 1 second). + // The logic is as follows. + // + // 1. Record 1 finishes getting zone data and its registration gets delayed by 1 second + // 2. Record 2 comes 0.1 second later, finishes getting its zone data and its registration is also delayed by + // 1 second which is now scheduled at 1.1 second + // + // By looking for 1 second into the future (m->timenow + MERGE_DELAY_TIME below does that) we have merged both + // of the above records. Note that we can't look for records too much into the future as this will affect the + // retry logic. The first retry is scheduled at 3 seconds. Hence, we should always look smaller than that. + // Anything more than one second will affect the first retry to happen sooner. + // + // Note: As a side effect of looking one second into the future to facilitate merging, the retries happen + // one second sooner. + for (rr = m->ResourceRecords; rr; rr = rr->next) + { + if (!firstRR) + { + if (!IsRecordMergeable(m, rr, m->timenow + MERGE_DELAY_TIME)) continue; + firstRR = rr; + } + else if (!AreRecordsMergeable(m, firstRR, rr, m->timenow + MERGE_DELAY_TIME)) continue; + + if (rr->SendRNow) LogMsg("MarkRRForSending: Resourcerecord %s already marked for sending", ARDisplayString(m, rr)); + rr->SendRNow = uDNSInterfaceMark; + } + + // We parsed through all records and found something to send. The services/records might + // get registered at different times but we want the refreshes to be all merged and sent + // as one update. Hence, we accelerate some of the records so that they will sync up in + // the future. Look at the records excluding the ones that we have already sent in the + // previous pass. If it half way through its scheduled refresh/retransmit, merge them + // into this packet. + // + // Note that we only look at Registered/Refresh state to keep it simple. As we don't know + // whether the current update will fit into one or more packets, merging a resource record + // (which is in a different state) that has been scheduled for retransmit would trigger + // sending more packets. + if (firstRR) + { + int acc = 0; + for (rr = m->ResourceRecords; rr; rr = rr->next) + { + if ((rr->state != regState_Registered && rr->state != regState_Refresh) || + (rr->SendRNow == uDNSInterfaceMark) || + (!AreRecordsMergeable(m, firstRR, rr, m->timenow + rr->ThisAPInterval/2))) + continue; + rr->SendRNow = uDNSInterfaceMark; + acc++; + } + if (acc) LogInfo("MarkRRForSending: Accelereated %d records", acc); + } + return firstRR; +} + +mDNSlocal mDNSBool SendGroupUpdates(mDNS *const m) +{ + mDNSOpaque16 msgid; + mDNSs32 spaceleft = 0; + mDNSs32 zoneSize, rrSize; + mDNSu8 *oldnext; // for debugging + mDNSu8 *next = m->omsg.data; + AuthRecord *rr; + AuthRecord *anchorRR = mDNSNULL; + int nrecords = 0; + AuthRecord *startRR = m->ResourceRecords; + mDNSu8 *limit = mDNSNULL; + DomainAuthInfo *AuthInfo = mDNSNULL; + mDNSBool sentallRecords = mDNStrue; + + + // We try to fit as many ResourceRecords as possible in AbsoluteNormal/MaxDNSMessageData. Before we start + // putting in resource records, we need to reserve space for a few things. Every group/packet should + // have the following. + // + // 1) Needs space for the Zone information (which needs to be at the beginning) + // 2) Additional section MUST have space for lease option, HINFO and TSIG option (which needs to + // to be at the end) + // + // In future we need to reserve space for the pre-requisites which also goes at the beginning. + // To accomodate pre-requisites in the future, first we walk the whole list marking records + // that can be sent in this packet and computing the space needed for these records. + // For TXT and SRV records, we delete the previous record if any by sending the same + // resource record with ANY RDATA and zero rdlen. Hence, we need to have space for both of them. + + while (startRR) + { + AuthInfo = mDNSNULL; + anchorRR = mDNSNULL; + nrecords = 0; + zoneSize = 0; + for (rr = startRR; rr; rr = rr->next) + { + if (rr->SendRNow != uDNSInterfaceMark) continue; + + rr->SendRNow = mDNSNULL; + + if (!anchorRR) + { + AuthInfo = GetAuthInfoForName_internal(m, rr->zone); + + // Though we allow single record registrations for UDP to be AbsoluteMaxDNSMessageData (See + // SendRecordRegistration) to handle large TXT records, to avoid fragmentation we limit UDP + // message to NormalMaxDNSMessageData + if (AuthInfo && AuthInfo->AutoTunnel) spaceleft = AbsoluteMaxDNSMessageData; + else spaceleft = NormalMaxDNSMessageData; + + next = m->omsg.data; + spaceleft -= RRAdditionalSize(m, AuthInfo); + if (spaceleft <= 0) + { + LogMsg("SendGroupUpdates: ERROR!!: spaceleft is zero at the beginning"); + RRMergeFailure(m); + return mDNSfalse; + } + limit = next + spaceleft; + + // Build the initial part of message before putting in the other records + msgid = mDNS_NewMessageID(m); + InitializeDNSMessage(&m->omsg.h, msgid, UpdateReqFlags); + + // We need zone information at the beginning of the packet. Length: ZNAME, ZTYPE(2), ZCLASS(2) + // zone has to be non-NULL for a record to be mergeable, hence it is safe to set/ examine zone + //without checking for NULL. + zoneSize = DomainNameLength(rr->zone) + 4; + spaceleft -= zoneSize; + if (spaceleft <= 0) + { + LogMsg("SendGroupUpdates: ERROR no space for zone information, disabling merge"); + RRMergeFailure(m); + return mDNSfalse; + } + next = putZone(&m->omsg, next, limit, rr->zone, mDNSOpaque16fromIntVal(rr->resrec.rrclass)); + if (!next) + { + LogMsg("SendGroupUpdates: ERROR! Cannot put zone, disabling merge"); + RRMergeFailure(m); + return mDNSfalse; + } + anchorRR = rr; + } + + rrSize = RREstimatedSize(rr, zoneSize - 4); + + if ((spaceleft - rrSize) < 0) + { + // If we can't fit even a single message, skip it, it will be sent separately + // in CheckRecordUpdates + if (!nrecords) + { + LogInfo("SendGroupUpdates: Skipping message %s, spaceleft %d, rrSize %d", ARDisplayString(m, rr), spaceleft, rrSize); + // Mark this as not sent so that the caller knows about it + rr->SendRNow = uDNSInterfaceMark; + // We need to remove the merge delay so that we can send it immediately + rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; + rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; + rr = rr->next; + anchorRR = mDNSNULL; + sentallRecords = mDNSfalse; + } + else + { + LogInfo("SendGroupUpdates:1: Parsed %d records and sending using %s, spaceleft %d, rrSize %d", nrecords, ARDisplayString(m, anchorRR), spaceleft, rrSize); + SendGroupRRMessage(m, anchorRR, next, AuthInfo); + } + break; // breaks out of for loop + } + spaceleft -= rrSize; + oldnext = next; + LogInfo("SendGroupUpdates: Building a message with resource record %s, next %p, state %d, ttl %d", ARDisplayString(m, rr), next, rr->state, rr->resrec.rroriginalttl); + if (!(next = BuildUpdateMessage(m, next, rr, limit))) + { + // We calculated the space and if we can't fit in, we had some bug in the calculation, + // disable merge completely. + LogMsg("SendGroupUpdates: ptr NULL while building message with %s", ARDisplayString(m, rr)); + RRMergeFailure(m); + return mDNSfalse; + } + // If our estimate was higher, adjust to the actual size + if ((next - oldnext) > rrSize) + LogMsg("SendGroupUpdates: ERROR!! Record size estimation is wrong for %s, Estimate %d, Actual %d, state %d", ARDisplayString(m, rr), rrSize, next - oldnext, rr->state); + else { spaceleft += rrSize; spaceleft -= (next - oldnext); } + + nrecords++; + // We could have sent an update earlier with this "rr" as anchorRR for which we never got a response. + // To preserve ordering, we blow away the previous connection before sending this. + if (rr->tcp) { DisposeTCPConn(rr->tcp); rr->tcp = mDNSNULL;} + rr->updateid = msgid; + + // By setting the retry time interval here, we will not be looking at these records + // again when we return to CheckGroupRecordUpdates. + SetRecordRetry(m, rr, 0); + } + // Either we have parsed all the records or stopped at "rr" above due to lack of space + startRR = rr; + } + + if (anchorRR) + { + LogInfo("SendGroupUpdates: Parsed %d records and sending using %s", nrecords, ARDisplayString(m, anchorRR)); + SendGroupRRMessage(m, anchorRR, next, AuthInfo); + } + return sentallRecords; +} + +// Merge the record registrations and send them as a group only if they +// have same DomainAuthInfo and hence the same key to put the TSIG +mDNSlocal void CheckGroupRecordUpdates(mDNS *const m) +{ + AuthRecord *rr, *nextRR; + // Keep sending as long as there is at least one record to be sent + while (MarkRRForSending(m)) + { + if (!SendGroupUpdates(m)) + { + // if everything that was marked was not sent, send them out individually + for (rr = m->ResourceRecords; rr; rr = nextRR) + { + // SendRecordRegistrtion might delete the rr from list, hence + // dereference nextRR before calling the function + nextRR = rr->next; + if (rr->SendRNow == uDNSInterfaceMark) + { + // Any records marked for sending should be eligible to be sent out + // immediately. Just being cautious + if (rr->LastAPTime + rr->ThisAPInterval - m->timenow > 0) + { LogMsg("CheckGroupRecordUpdates: ERROR!! Resourcerecord %s not ready", ARDisplayString(m, rr)); continue; } + rr->SendRNow = mDNSNULL; + SendRecordRegistration(m, rr); + } + } + } + } + + debugf("CheckGroupRecordUpdates: No work, returning"); + return; +} + +mDNSlocal void hndlSRVChanged(mDNS *const m, AuthRecord *rr) +{ + // Reevaluate the target always as NAT/Target could have changed while + // we were registering/deeregistering + domainname *dt; + const domainname *target = GetServiceTarget(m, rr); + if (!target || target->c[0] == 0) + { + // we don't have a target, if we just derregistered, then we don't have to do anything + if (rr->state == regState_DeregPending) + { + LogInfo("hndlSRVChanged: SRVChanged, No Target, SRV Deregistered for %##s, state %d", rr->resrec.name->c, + rr->state); + rr->SRVChanged = mDNSfalse; + dt = GetRRDomainNameTarget(&rr->resrec); + if (dt) dt->c[0] = 0; + rr->state = regState_NoTarget; // Wait for the next target change + rr->resrec.rdlength = rr->resrec.rdestimate = 0; + return; + } + + // we don't have a target, if we just registered, we need to deregister + if (rr->state == regState_Pending) + { + LogInfo("hndlSRVChanged: SRVChanged, No Target, Deregistering again %##s, state %d", rr->resrec.name->c, rr->state); + rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; + rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; + rr->state = regState_DeregPending; + return; + } + LogInfo("hndlSRVChanged: Not in DeregPending or RegPending state %##s, state %d", rr->resrec.name->c, rr->state); + } + else + { + // If we were in registered state and SRV changed to NULL, we deregister and come back here + // if we have a target, we need to register again. + // + // if we just registered check to see if it is same. If it is different just re-register the + // SRV and its assoicated records + // + // UpdateOneSRVRecord takes care of re-registering all service records + if ((rr->state == regState_DeregPending) || + (rr->state == regState_Pending && !SameDomainName(target, &rr->resrec.rdata->u.srv.target))) + { + dt = GetRRDomainNameTarget(&rr->resrec); + if (dt) dt->c[0] = 0; + rr->state = regState_NoTarget; // NoTarget will allow us to pick up new target OR nat traversal state + rr->resrec.rdlength = rr->resrec.rdestimate = 0; + LogInfo("hndlSRVChanged: SRVChanged, Valid Target %##s, Registering all records for %##s, state %d", + target->c, rr->resrec.name->c, rr->state); + rr->SRVChanged = mDNSfalse; + UpdateOneSRVRecord(m, rr); + return; + } + // Target did not change while this record was registering. Hence, we go to + // Registered state - the state we started from. + if (rr->state == regState_Pending) rr->state = regState_Registered; + } + + rr->SRVChanged = mDNSfalse; +} + +// Called with lock held +mDNSlocal void hndlRecordUpdateReply(mDNS *m, AuthRecord *rr, mStatus err, mDNSu32 random) +{ + mDNSBool InvokeCallback = mDNStrue; + mDNSIPPort UpdatePort = zeroIPPort; + + mDNS_CheckLock(m); + + LogInfo("hndlRecordUpdateReply: err %d ID %d state %d %s(%p)", err, mDNSVal16(rr->updateid), rr->state, ARDisplayString(m, rr), rr); + + rr->updateError = err; +#if APPLE_OSX_mDNSResponder + if (err == mStatus_BadSig || err == mStatus_BadKey || err == mStatus_BadTime) UpdateAutoTunnelDomainStatuses(m); +#endif + + SetRecordRetry(m, rr, random); + + rr->updateid = zeroID; // Make sure that this is not considered as part of a group anymore + // Later when need to send an update, we will get the zone data again. Thus we avoid + // using stale information. + // + // Note: By clearing out the zone info here, it also helps better merging of records + // in some cases. For example, when we get out regState_NoTarget state e.g., move out + // of Double NAT, we want all the records to be in one update. Some BTMM records like + // _autotunnel6 and host records are registered/deregistered when NAT state changes. + // As they are re-registered the zone information is cleared out. To merge with other + // records that might be possibly going out, clearing out the information here helps + // as all of them try to get the zone data. + if (rr->nta) + { + // We always expect the question to be stopped when we get a valid response from the server. + // If the zone info tries to change during this time, updateid would be different and hence + // this response should not have been accepted. + if (rr->nta->question.ThisQInterval != -1) + LogMsg("hndlRecordUpdateReply: ResourceRecord %s, zone info question %##s (%s) interval %d not -1", + ARDisplayString(m, rr), rr->nta->question.qname.c, DNSTypeName(rr->nta->question.qtype), rr->nta->question.ThisQInterval); + UpdatePort = rr->nta->Port; + CancelGetZoneData(m, rr->nta); + rr->nta = mDNSNULL; + } + + // If we are deregistering the record, then complete the deregistration. Ignore any NAT/SRV change + // that could have happened during that time. + if (rr->resrec.RecordType == kDNSRecordTypeDeregistering && rr->state == regState_DeregPending) + { + debugf("hndlRecordUpdateReply: Received reply for deregister record %##s type %d", rr->resrec.name->c, rr->resrec.rrtype); + if (err) LogMsg("ERROR: Deregistration of record %##s type %d failed with error %d", + rr->resrec.name->c, rr->resrec.rrtype, err); + rr->state = regState_Unregistered; + CompleteDeregistration(m, rr); + return; + } + + // We are returning early without updating the state. When we come back from sleep we will re-register after + // re-initializing all the state as though it is a first registration. If the record can't be registered e.g., + // no target, it will be deregistered. Hence, the updating to the right state should not matter when going + // to sleep. + if (m->SleepState) + { + // Need to set it to NoTarget state so that RecordReadyForSleep knows that + // we are done + if (rr->resrec.rrtype == kDNSType_SRV && rr->state == regState_DeregPending) + rr->state = regState_NoTarget; + return; + } + + if (rr->state == regState_UpdatePending) + { + if (err) LogMsg("Update record failed for %##s (err %d)", rr->resrec.name->c, err); + rr->state = regState_Registered; + // deallocate old RData + if (rr->UpdateCallback) rr->UpdateCallback(m, rr, rr->OrigRData, rr->OrigRDLen); + SetNewRData(&rr->resrec, rr->InFlightRData, rr->InFlightRDLen); + rr->OrigRData = mDNSNULL; + rr->InFlightRData = mDNSNULL; + } + + if (rr->SRVChanged) + { + if (rr->resrec.rrtype == kDNSType_SRV) + hndlSRVChanged(m, rr); + else + { + LogInfo("hndlRecordUpdateReply: Deregistered %##s (%s), state %d", rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype), rr->state); + rr->SRVChanged = mDNSfalse; + if (rr->state != regState_DeregPending) LogMsg("hndlRecordUpdateReply: ResourceRecord %s not in DeregPending state %d", ARDisplayString(m, rr), rr->state); + rr->state = regState_NoTarget; // Wait for the next target change + } + return; + } + + if (rr->state == regState_Pending || rr->state == regState_Refresh) + { + if (!err) + { + if (rr->state == regState_Refresh) InvokeCallback = mDNSfalse; + rr->state = regState_Registered; + } + else + { + // Retry without lease only for non-Private domains + LogMsg("hndlRecordUpdateReply: Registration of record %##s type %d failed with error %d", rr->resrec.name->c, rr->resrec.rrtype, err); + if (!rr->Private && rr->uselease && err == mStatus_UnknownErr && mDNSSameIPPort(UpdatePort, UnicastDNSPort)) + { + LogMsg("hndlRecordUpdateReply: Will retry update of record %##s without lease option", rr->resrec.name->c); + rr->uselease = mDNSfalse; + rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; + rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; + SetNextuDNSEvent(m, rr); + return; + } + // Communicate the error to the application in the callback below + } + } + + if (rr->QueuedRData && rr->state == regState_Registered) + { + rr->state = regState_UpdatePending; + rr->InFlightRData = rr->QueuedRData; + rr->InFlightRDLen = rr->QueuedRDLen; + rr->OrigRData = rr->resrec.rdata; + rr->OrigRDLen = rr->resrec.rdlength; + rr->QueuedRData = mDNSNULL; + rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; + rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; + SetNextuDNSEvent(m, rr); + return; + } + + // Don't invoke the callback on error as this may not be useful to the client. + // The client may potentially delete the resource record on error which we normally + // delete during deregistration + if (!err && InvokeCallback && rr->RecordCallback) + { + LogInfo("hndlRecordUpdateReply: Calling record callback on %##s", rr->resrec.name->c); + mDNS_DropLockBeforeCallback(); + rr->RecordCallback(m, rr, err); + mDNS_ReclaimLockAfterCallback(); + } + // CAUTION: MUST NOT do anything more with rr after calling rr->Callback(), because the client's callback function + // is allowed to do anything, including starting/stopping queries, registering/deregistering records, etc. +} + +mDNSlocal void uDNS_ReceiveNATPMPPacket(mDNS *m, const mDNSInterfaceID InterfaceID, mDNSu8 *pkt, mDNSu16 len) +{ + NATTraversalInfo *ptr; + NATAddrReply *AddrReply = (NATAddrReply *)pkt; + NATPortMapReply *PortMapReply = (NATPortMapReply *)pkt; + mDNSu32 nat_elapsed, our_elapsed; + + // Minimum NAT-PMP packet is vers (1) opcode (1) + err (2) = 4 bytes + if (len < 4) { LogMsg("NAT-PMP message too short (%d bytes)", len); return; } + + // Read multi-byte error value (field is identical in a NATPortMapReply) + AddrReply->err = (mDNSu16) ((mDNSu16)pkt[2] << 8 | pkt[3]); + + if (AddrReply->err == NATErr_Vers) + { + NATTraversalInfo *n; + LogInfo("NAT-PMP version unsupported message received"); + for (n = m->NATTraversals; n; n=n->next) + { + // Send a NAT-PMP request for this operation as needed + // and update the state variables + uDNS_SendNATMsg(m, n, mDNSfalse); + } + + m->NextScheduledNATOp = m->timenow; + + return; + } + + // The minimum reasonable NAT-PMP packet length is vers (1) + opcode (1) + err (2) + upseconds (4) = 8 bytes + // If it's not at least this long, bail before we byte-swap the upseconds field & overrun our buffer. + // The retry timer will ensure we converge to correctness. + if (len < 8) + { + LogMsg("NAT-PMP message too short (%d bytes) 0x%X 0x%X", len, AddrReply->opcode, AddrReply->err); + return; + } + + // Read multi-byte upseconds value (field is identical in a NATPortMapReply) + AddrReply->upseconds = (mDNSs32) ((mDNSs32)pkt[4] << 24 | (mDNSs32)pkt[5] << 16 | (mDNSs32)pkt[6] << 8 | pkt[7]); + + nat_elapsed = AddrReply->upseconds - m->LastNATupseconds; + our_elapsed = (m->timenow - m->LastNATReplyLocalTime) / mDNSPlatformOneSecond; + debugf("uDNS_ReceiveNATPMPPacket %X upseconds %u nat_elapsed %d our_elapsed %d", AddrReply->opcode, AddrReply->upseconds, nat_elapsed, our_elapsed); + + // We compute a conservative estimate of how much the NAT gateways's clock should have advanced + // 1. We subtract 12.5% from our own measured elapsed time, to allow for NAT gateways that have an inacurate clock that runs slowly + // 2. We add a two-second safety margin to allow for rounding errors: e.g. + // -- if NAT gateway sends a packet at t=2.000 seconds, then one at t=7.999, that's approximately 6 real seconds, + // but based on the values in the packet (2,7) the apparent difference according to the packet is only 5 seconds + // -- if we're slow handling packets and/or we have coarse clock granularity, + // we could receive the t=2 packet at our t=1.999 seconds, which we round down to 1 + // and the t=7.999 packet at our t=8.000 seconds, which we record as 8, + // giving an apparent local time difference of 7 seconds + // The two-second safety margin coves this possible calculation discrepancy + if (AddrReply->upseconds < m->LastNATupseconds || nat_elapsed + 2 < our_elapsed - our_elapsed/8) + { LogMsg("NAT-PMP epoch time check failed: assuming NAT gateway %#a rebooted", &m->Router); RecreateNATMappings(m, 0); } + + m->LastNATupseconds = AddrReply->upseconds; + m->LastNATReplyLocalTime = m->timenow; +#ifdef _LEGACY_NAT_TRAVERSAL_ + LNT_ClearState(m); +#endif // _LEGACY_NAT_TRAVERSAL_ + + if (AddrReply->opcode == NATOp_AddrResponse) + { +#if APPLE_OSX_mDNSResponder + static char msgbuf[16]; + mDNS_snprintf(msgbuf, sizeof(msgbuf), "%d", AddrReply->err); + mDNSASLLog((uuid_t *)&m->asl_uuid, "natt.natpmp.AddressRequest", AddrReply->err ? "failure" : "success", msgbuf, ""); +#endif + if (!AddrReply->err && len < sizeof(NATAddrReply)) { LogMsg("NAT-PMP AddrResponse message too short (%d bytes)", len); return; } + natTraversalHandleAddressReply(m, AddrReply->err, AddrReply->ExtAddr); + } + else if (AddrReply->opcode == NATOp_MapUDPResponse || AddrReply->opcode == NATOp_MapTCPResponse) + { + mDNSu8 Protocol = AddrReply->opcode & 0x7F; +#if APPLE_OSX_mDNSResponder + static char msgbuf[16]; + mDNS_snprintf(msgbuf, sizeof(msgbuf), "%s - %d", AddrReply->opcode == NATOp_MapUDPResponse ? "UDP" : "TCP", PortMapReply->err); + mDNSASLLog((uuid_t *)&m->asl_uuid, "natt.natpmp.PortMapRequest", PortMapReply->err ? "failure" : "success", msgbuf, ""); +#endif + if (!PortMapReply->err) + { + if (len < sizeof(NATPortMapReply)) { LogMsg("NAT-PMP PortMapReply message too short (%d bytes)", len); return; } + PortMapReply->NATRep_lease = (mDNSu32) ((mDNSu32)pkt[12] << 24 | (mDNSu32)pkt[13] << 16 | (mDNSu32)pkt[14] << 8 | pkt[15]); + } + + // Since some NAT-PMP server implementations don't return the requested internal port in + // the reply, we can't associate this reply with a particular NATTraversalInfo structure. + // We globally keep track of the most recent error code for mappings. + m->LastNATMapResultCode = PortMapReply->err; + + for (ptr = m->NATTraversals; ptr; ptr=ptr->next) + if (ptr->Protocol == Protocol && mDNSSameIPPort(ptr->IntPort, PortMapReply->intport)) + natTraversalHandlePortMapReply(m, ptr, InterfaceID, PortMapReply->err, PortMapReply->extport, PortMapReply->NATRep_lease, NATTProtocolNATPMP); + } + else { LogMsg("Received NAT-PMP response with unknown opcode 0x%X", AddrReply->opcode); return; } + + // Don't need an SSDP socket if we get a NAT-PMP packet + if (m->SSDPSocket) { debugf("uDNS_ReceiveNATPMPPacket destroying SSDPSocket %p", &m->SSDPSocket); mDNSPlatformUDPClose(m->SSDPSocket); m->SSDPSocket = mDNSNULL; } +} + +mDNSlocal void uDNS_ReceivePCPPacket(mDNS *m, const mDNSInterfaceID InterfaceID, mDNSu8 *pkt, mDNSu16 len) +{ + NATTraversalInfo *ptr; + PCPMapReply *reply = (PCPMapReply*)pkt; + mDNSu32 client_delta, server_delta; + mDNSBool checkEpochValidity = m->LastNATupseconds != 0; + mDNSu8 strippedOpCode; + mDNSv4Addr mappedAddress = zerov4Addr; + mDNSu8 protocol = 0; + mDNSIPPort intport = zeroIPPort; + mDNSIPPort extport = zeroIPPort; + + // Minimum PCP packet is 24 bytes + if (len < 24) + { + LogMsg("uDNS_ReceivePCPPacket: message too short (%d bytes)", len); + return; + } + + strippedOpCode = reply->opCode & 0x7f; + + if ((reply->opCode & 0x80) == 0x00 || (strippedOpCode != PCPOp_Announce && strippedOpCode != PCPOp_Map)) + { + LogMsg("uDNS_ReceivePCPPacket: unhandled opCode %u", reply->opCode); + return; + } + + // Read multi-byte values + reply->lifetime = (mDNSs32)((mDNSs32)pkt[4] << 24 | (mDNSs32)pkt[5] << 16 | (mDNSs32)pkt[ 6] << 8 | pkt[ 7]); + reply->epoch = (mDNSs32)((mDNSs32)pkt[8] << 24 | (mDNSs32)pkt[9] << 16 | (mDNSs32)pkt[10] << 8 | pkt[11]); + + client_delta = (m->timenow - m->LastNATReplyLocalTime) / mDNSPlatformOneSecond; + server_delta = reply->epoch - m->LastNATupseconds; + debugf("uDNS_ReceivePCPPacket: %X %X upseconds %u client_delta %d server_delta %d", reply->opCode, reply->result, reply->epoch, client_delta, server_delta); + + // If seconds since the epoch is 0, use 1 so we'll check epoch validity next time + m->LastNATupseconds = reply->epoch ? reply->epoch : 1; + m->LastNATReplyLocalTime = m->timenow; + +#ifdef _LEGACY_NAT_TRAVERSAL_ + LNT_ClearState(m); +#endif // _LEGACY_NAT_TRAVERSAL_ + + // Don't need an SSDP socket if we get a PCP packet + if (m->SSDPSocket) { debugf("uDNS_ReceivePCPPacket: destroying SSDPSocket %p", &m->SSDPSocket); mDNSPlatformUDPClose(m->SSDPSocket); m->SSDPSocket = mDNSNULL; } + + if (checkEpochValidity && (client_delta + 2 < server_delta - server_delta / 16 || server_delta + 2 < client_delta - client_delta / 16)) + { + // If this is an ANNOUNCE packet, wait a random interval up to 5 seconds + // otherwise, refresh immediately + mDNSu32 waitTicks = strippedOpCode ? 0 : mDNSRandom(PCP_WAITSECS_AFTER_EPOCH_INVALID * mDNSPlatformOneSecond); + LogMsg("uDNS_ReceivePCPPacket: Epoch invalid, %#a likely rebooted, waiting %u ticks", &m->Router, waitTicks); + RecreateNATMappings(m, waitTicks); + // we can ignore the rest of this packet, as new requests are about to go out + return; + } + + if (strippedOpCode == PCPOp_Announce) + return; + + // We globally keep track of the most recent error code for mappings. + // This seems bad to do with PCP, but best not change it now. + m->LastNATMapResultCode = reply->result; + + if (!reply->result) + { + if (len < sizeof(PCPMapReply)) + { + LogMsg("uDNS_ReceivePCPPacket: mapping response too short (%d bytes)", len); + return; + } + + // Check the nonce + if (reply->nonce[0] != m->PCPNonce[0] || reply->nonce[1] != m->PCPNonce[1] || reply->nonce[2] != m->PCPNonce[2]) + { + LogMsg("uDNS_ReceivePCPPacket: invalid nonce, ignoring. received { %x %x %x } expected { %x %x %x }", + reply->nonce[0], reply->nonce[1], reply->nonce[2], + m->PCPNonce[0], m->PCPNonce[1], m->PCPNonce[2]); + return; + } + + // Get the values + protocol = reply->protocol; + intport = reply->intPort; + extport = reply->extPort; + + // Get the external address, which should be mapped, since we only support IPv4 + if (!mDNSAddrIPv4FromMappedIPv6(&reply->extAddress, &mappedAddress)) + { + LogMsg("uDNS_ReceivePCPPacket: unexpected external address: %.16a", &reply->extAddress); + reply->result = NATErr_NetFail; + // fall through to report the error + } + else if (mDNSIPv4AddressIsZero(mappedAddress)) + { + // If this is the deletion case, we will have sent the zero IPv4-mapped address + // in our request, and the server should reflect it in the response, so we + // should not log about receiving a zero address. And in this case, we no + // longer have a NATTraversal to report errors back to, so it's ok to set the + // result here. + // In other cases, a zero address is an error, and we will have a NATTraversal + // to report back to, so set an error and fall through to report it. + // CheckNATMappings will log the error. + reply->result = NATErr_NetFail; + } + } + else + { + LogInfo("uDNS_ReceivePCPPacket: error received from server. opcode %X result %X lifetime %X epoch %X", + reply->opCode, reply->result, reply->lifetime, reply->epoch); + + // If the packet is long enough, get the protocol & intport for matching to report + // the error + if (len >= sizeof(PCPMapReply)) + { + protocol = reply->protocol; + intport = reply->intPort; + } + } + + for (ptr = m->NATTraversals; ptr; ptr=ptr->next) + { + mDNSu8 ptrProtocol = ((ptr->Protocol & NATOp_MapTCP) == NATOp_MapTCP ? PCPProto_TCP : PCPProto_UDP); + if ((protocol == ptrProtocol && mDNSSameIPPort(ptr->IntPort, intport)) || + (!ptr->Protocol && protocol == PCPProto_TCP && mDNSSameIPPort(DiscardPort, intport))) + { + natTraversalHandlePortMapReplyWithAddress(m, ptr, InterfaceID, reply->result ? NATErr_NetFail : NATErr_None, mappedAddress, extport, reply->lifetime, NATTProtocolPCP); + } + } +} + +mDNSexport void uDNS_ReceiveNATPacket(mDNS *m, const mDNSInterfaceID InterfaceID, mDNSu8 *pkt, mDNSu16 len) +{ + if (len == 0) + LogMsg("uDNS_ReceiveNATPacket: zero length packet"); + else if (pkt[0] == PCP_VERS) + uDNS_ReceivePCPPacket(m, InterfaceID, pkt, len); + else if (pkt[0] == NATMAP_VERS) + uDNS_ReceiveNATPMPPacket(m, InterfaceID, pkt, len); + else + LogMsg("uDNS_ReceiveNATPacket: packet with version %u (expected %u or %u)", pkt[0], PCP_VERS, NATMAP_VERS); +} + +// <rdar://problem/3925163> Shorten DNS-SD queries to avoid NAT bugs +// <rdar://problem/4288449> Add check to avoid crashing NAT gateways that have buggy DNS relay code +// +// We know of bugs in home NAT gateways that cause them to crash if they receive certain DNS queries. +// The DNS queries that make them crash are perfectly legal DNS queries, but even if they weren't, +// the gateway shouldn't crash -- in today's world of viruses and network attacks, software has to +// be written assuming that a malicious attacker could send them any packet, properly-formed or not. +// Still, we don't want to be crashing people's home gateways, so we go out of our way to avoid +// the queries that crash them. +// +// Some examples: +// +// 1. Any query where the name ends in ".in-addr.arpa." and the text before this is 32 or more bytes. +// The query type does not need to be PTR -- the gateway will crash for any query type. +// e.g. "ping long-name-crashes-the-buggy-router.in-addr.arpa" will crash one of these. +// +// 2. Any query that results in a large response with the TC bit set. +// +// 3. Any PTR query that doesn't begin with four decimal numbers. +// These gateways appear to assume that the only possible PTR query is a reverse-mapping query +// (e.g. "1.0.168.192.in-addr.arpa") and if they ever get a PTR query where the first four +// labels are not all decimal numbers in the range 0-255, they handle that by crashing. +// These gateways also ignore the remainder of the name following the four decimal numbers +// -- whether or not it actually says in-addr.arpa, they just make up an answer anyway. +// +// The challenge therefore is to craft a query that will discern whether the DNS server +// is one of these buggy ones, without crashing it. Furthermore we don't want our test +// queries making it all the way to the root name servers, putting extra load on those +// name servers and giving Apple a bad reputation. To this end we send this query: +// dig -t ptr 1.0.0.127.dnsbugtest.1.0.0.127.in-addr.arpa. +// +// The text preceding the ".in-addr.arpa." is under 32 bytes, so it won't cause crash (1). +// It will not yield a large response with the TC bit set, so it won't cause crash (2). +// It starts with four decimal numbers, so it won't cause crash (3). +// The name falls within the "1.0.0.127.in-addr.arpa." domain, the reverse-mapping name for the local +// loopback address, and therefore the query will black-hole at the first properly-configured DNS server +// it reaches, making it highly unlikely that this query will make it all the way to the root. +// +// Finally, the correct response to this query is NXDOMAIN or a similar error, but the +// gateways that ignore the remainder of the name following the four decimal numbers +// give themselves away by actually returning a result for this nonsense query. + +mDNSlocal const domainname *DNSRelayTestQuestion = (const domainname*) + "\x1" "1" "\x1" "0" "\x1" "0" "\x3" "127" "\xa" "dnsbugtest" + "\x1" "1" "\x1" "0" "\x1" "0" "\x3" "127" "\x7" "in-addr" "\x4" "arpa"; + +// See comments above for DNSRelayTestQuestion +// If this is the kind of query that has the risk of crashing buggy DNS servers, we do a test question first +mDNSlocal mDNSBool NoTestQuery(DNSQuestion *q) +{ + int i; + mDNSu8 *p = q->qname.c; + if (q->AuthInfo) return(mDNStrue); // Don't need a test query for private queries sent directly to authoritative server over TLS/TCP + if (q->qtype != kDNSType_PTR) return(mDNStrue); // Don't need a test query for any non-PTR queries + for (i=0; i<4; i++) // If qname does not begin with num.num.num.num, can't skip the test query + { + if (p[0] < 1 || p[0] > 3) return(mDNSfalse); + if ( p[1] < '0' || p[1] > '9' ) return(mDNSfalse); + if (p[0] >= 2 && (p[2] < '0' || p[2] > '9')) return(mDNSfalse); + if (p[0] >= 3 && (p[3] < '0' || p[3] > '9')) return(mDNSfalse); + p += 1 + p[0]; + } + // If remainder of qname is ".in-addr.arpa.", this is a vanilla reverse-mapping query and + // we can safely do it without needing a test query first, otherwise we need the test query. + return(SameDomainName((domainname*)p, (const domainname*)"\x7" "in-addr" "\x4" "arpa")); +} + +// Returns mDNStrue if response was handled +mDNSlocal mDNSBool uDNS_ReceiveTestQuestionResponse(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end, + const mDNSAddr *const srcaddr, const mDNSIPPort srcport) +{ + const mDNSu8 *ptr = msg->data; + DNSQuestion pktq; + DNSServer *s; + mDNSu32 result = 0; + + // 1. Find out if this is an answer to one of our test questions + if (msg->h.numQuestions != 1) return(mDNSfalse); + ptr = getQuestion(msg, ptr, end, mDNSInterface_Any, &pktq); + if (!ptr) return(mDNSfalse); + if (pktq.qtype != kDNSType_PTR || pktq.qclass != kDNSClass_IN) return(mDNSfalse); + if (!SameDomainName(&pktq.qname, DNSRelayTestQuestion)) return(mDNSfalse); + + // 2. If the DNS relay gave us a positive response, then it's got buggy firmware + // else, if the DNS relay gave us an error or no-answer response, it passed our test + if ((msg->h.flags.b[1] & kDNSFlag1_RC_Mask) == kDNSFlag1_RC_NoErr && msg->h.numAnswers > 0) + result = DNSServer_Failed; + else + result = DNSServer_Passed; + + // 3. Find occurrences of this server in our list, and mark them appropriately + for (s = m->DNSServers; s; s = s->next) + { + mDNSBool matchaddr = (s->teststate != result && mDNSSameAddress(srcaddr, &s->addr) && mDNSSameIPPort(srcport, s->port)); + mDNSBool matchid = (s->teststate == DNSServer_Untested && mDNSSameOpaque16(msg->h.id, s->testid)); + if (matchaddr || matchid) + { + DNSQuestion *q; + s->teststate = result; + if (result == DNSServer_Passed) + { + LogInfo("DNS Server %#a:%d (%#a:%d) %d passed%s", + &s->addr, mDNSVal16(s->port), srcaddr, mDNSVal16(srcport), mDNSVal16(s->testid), + matchaddr ? "" : " NOTE: Reply did not come from address to which query was sent"); + } + else + { + LogMsg("NOTE: Wide-Area Service Discovery disabled to avoid crashing defective DNS relay %#a:%d (%#a:%d) %d%s", + &s->addr, mDNSVal16(s->port), srcaddr, mDNSVal16(srcport), mDNSVal16(s->testid), + matchaddr ? "" : " NOTE: Reply did not come from address to which query was sent"); + } + + // If this server has just changed state from DNSServer_Untested to DNSServer_Passed, then retrigger any waiting questions. + // We use the NoTestQuery() test so that we only retrigger questions that were actually blocked waiting for this test to complete. + if (result == DNSServer_Passed) // Unblock any questions that were waiting for this result + for (q = m->Questions; q; q=q->next) + if (q->qDNSServer == s && !NoTestQuery(q)) + { + q->ThisQInterval = INIT_UCAST_POLL_INTERVAL / QuestionIntervalStep; + q->unansweredQueries = 0; + q->LastQTime = m->timenow - q->ThisQInterval; + m->NextScheduledQuery = m->timenow; + } + } + } + + return(mDNStrue); // Return mDNStrue to tell uDNS_ReceiveMsg it doesn't need to process this packet further +} + +// Called from mDNSCoreReceive with the lock held +mDNSexport void uDNS_ReceiveMsg(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *const srcaddr, const mDNSIPPort srcport) +{ + DNSQuestion *qptr; + mStatus err = mStatus_NoError; + + mDNSu8 StdR = kDNSFlag0_QR_Response | kDNSFlag0_OP_StdQuery; + mDNSu8 UpdateR = kDNSFlag0_QR_Response | kDNSFlag0_OP_Update; + mDNSu8 QR_OP = (mDNSu8)(msg->h.flags.b[0] & kDNSFlag0_QROP_Mask); + mDNSu8 rcode = (mDNSu8)(msg->h.flags.b[1] & kDNSFlag1_RC_Mask); + + (void)srcport; // Unused + + debugf("uDNS_ReceiveMsg from %#-15a with " + "%2d Question%s %2d Answer%s %2d Authorit%s %2d Additional%s %d bytes", + srcaddr, + msg->h.numQuestions, msg->h.numQuestions == 1 ? ", " : "s,", + msg->h.numAnswers, msg->h.numAnswers == 1 ? ", " : "s,", + msg->h.numAuthorities, msg->h.numAuthorities == 1 ? "y, " : "ies,", + msg->h.numAdditionals, msg->h.numAdditionals == 1 ? "" : "s", end - msg->data); + + if (QR_OP == StdR) + { + //if (srcaddr && recvLLQResponse(m, msg, end, srcaddr, srcport)) return; + if (uDNS_ReceiveTestQuestionResponse(m, msg, end, srcaddr, srcport)) return; + for (qptr = m->Questions; qptr; qptr = qptr->next) + if (msg->h.flags.b[0] & kDNSFlag0_TC && mDNSSameOpaque16(qptr->TargetQID, msg->h.id) && m->timenow - qptr->LastQTime < RESPONSE_WINDOW) + { + if (!srcaddr) LogMsg("uDNS_ReceiveMsg: TCP DNS response had TC bit set: ignoring"); + else + { + // Don't reuse TCP connections. We might have failed over to a different DNS server + // while the first TCP connection is in progress. We need a new TCP connection to the + // new DNS server. So, always try to establish a new connection. + if (qptr->tcp) { DisposeTCPConn(qptr->tcp); qptr->tcp = mDNSNULL; } + qptr->tcp = MakeTCPConn(m, mDNSNULL, mDNSNULL, kTCPSocketFlags_Zero, srcaddr, srcport, mDNSNULL, qptr, mDNSNULL); + } + } + } + + if (QR_OP == UpdateR) + { + mDNSu32 lease = GetPktLease(m, msg, end); + mDNSs32 expire = m->timenow + (mDNSs32)lease * mDNSPlatformOneSecond; + mDNSu32 random = mDNSRandom((mDNSs32)lease * mDNSPlatformOneSecond/10); + + //rcode = kDNSFlag1_RC_ServFail; // Simulate server failure (rcode 2) + + // Walk through all the records that matches the messageID. There could be multiple + // records if we had sent them in a group + if (m->CurrentRecord) + LogMsg("uDNS_ReceiveMsg ERROR m->CurrentRecord already set %s", ARDisplayString(m, m->CurrentRecord)); + m->CurrentRecord = m->ResourceRecords; + while (m->CurrentRecord) + { + AuthRecord *rptr = m->CurrentRecord; + m->CurrentRecord = m->CurrentRecord->next; + if (AuthRecord_uDNS(rptr) && mDNSSameOpaque16(rptr->updateid, msg->h.id)) + { + err = checkUpdateResult(m, rptr->resrec.name, rcode, msg, end); + if (!err && rptr->uselease && lease) + if (rptr->expire - expire >= 0 || rptr->state != regState_UpdatePending) + { + rptr->expire = expire; + rptr->refreshCount = 0; + } + // We pass the random value to make sure that if we update multiple + // records, they all get the same random value + hndlRecordUpdateReply(m, rptr, err, random); + } + } + } + debugf("Received unexpected response: ID %d matches no active records", mDNSVal16(msg->h.id)); +} + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - Query Routines +#endif + +mDNSexport void sendLLQRefresh(mDNS *m, DNSQuestion *q) +{ + mDNSu8 *end; + LLQOptData llq; + mDNSu8 *limit = m->omsg.data + AbsoluteMaxDNSMessageData; + + if (q->ReqLease) + if ((q->state == LLQ_Established && q->ntries >= kLLQ_MAX_TRIES) || q->expire - m->timenow < 0) + { + LogMsg("Unable to refresh LLQ %##s (%s) - will retry in %d seconds", q->qname.c, DNSTypeName(q->qtype), LLQ_POLL_INTERVAL / mDNSPlatformOneSecond); + StartLLQPolling(m,q); + return; + } + + llq.vers = kLLQ_Vers; + llq.llqOp = kLLQOp_Refresh; + llq.err = q->tcp ? GetLLQEventPort(m, &q->servAddr) : LLQErr_NoError; // If using TCP tell server what UDP port to send notifications to + llq.id = q->id; + llq.llqlease = q->ReqLease; + + InitializeDNSMessage(&m->omsg.h, q->TargetQID, uQueryFlags); + end = putLLQ(&m->omsg, m->omsg.data, q, &llq); + if (!end) { LogMsg("sendLLQRefresh: putLLQ failed %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); return; } + + // Note that we (conditionally) add HINFO and TSIG here, since the question might be going away, + // so we may not be able to reference it (most importantly it's AuthInfo) when we actually send the message + end = putHINFO(m, &m->omsg, end, q->AuthInfo, limit); + if (!end) { LogMsg("sendLLQRefresh: putHINFO failed %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); return; } + + if (PrivateQuery(q)) + { + DNSDigest_SignMessageHostByteOrder(&m->omsg, &end, q->AuthInfo); + if (!end) { LogMsg("sendLLQRefresh: DNSDigest_SignMessage failed %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); return; } + } + + if (PrivateQuery(q) && !q->tcp) + { + LogInfo("sendLLQRefresh setting up new TLS session %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); + if (!q->nta) + { + // Note: If a question is in LLQ_Established state, we never free the zone data for the + // question (PrivateQuery). If we free, we reset the state to something other than LLQ_Established. + // This function is called only if the query is in LLQ_Established state and hence nta should + // never be NULL. In spite of that, we have seen q->nta being NULL in the field. Just refetch the + // zone data in that case. + q->nta = StartGetZoneData(m, &q->qname, ZoneServiceLLQ, LLQGotZoneData, q); + return; + // ThisQInterval is not adjusted when we return from here which means that we will get called back + // again immediately. As q->servAddr and q->servPort are still valid and the nta->Host is initialized + // without any additional discovery for PrivateQuery, things work. + } + q->tcp = MakeTCPConn(m, &m->omsg, end, kTCPSocketFlags_UseTLS, &q->servAddr, q->servPort, &q->nta->Host, q, mDNSNULL); + } + else + { + mStatus err; + + // if AuthInfo and AuthInfo->AutoTunnel is set, we use the TCP socket but don't need to pass the AuthInfo as + // we already protected the message above. + LogInfo("sendLLQRefresh: using existing %s session %##s (%s)", PrivateQuery(q) ? "TLS" : "UDP", + q->qname.c, DNSTypeName(q->qtype)); + + err = mDNSSendDNSMessage(m, &m->omsg, end, mDNSInterface_Any, q->LocalSocket, &q->servAddr, q->servPort, q->tcp ? q->tcp->sock : mDNSNULL, mDNSNULL, mDNSfalse); + if (err) + { + LogMsg("sendLLQRefresh: mDNSSendDNSMessage%s failed: %d", q->tcp ? " (TCP)" : "", err); + if (q->tcp) { DisposeTCPConn(q->tcp); q->tcp = mDNSNULL; } + } + } + + q->ntries++; + + debugf("sendLLQRefresh ntries %d %##s (%s)", q->ntries, q->qname.c, DNSTypeName(q->qtype)); + + q->LastQTime = m->timenow; + SetNextQueryTime(m, q); +} + +mDNSexport void LLQGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneInfo) +{ + DNSQuestion *q = (DNSQuestion *)zoneInfo->ZoneDataContext; + + mDNS_Lock(m); + + // If we get here it means that the GetZoneData operation has completed. + // We hold on to the zone data if it is AutoTunnel as we use the hostname + // in zoneInfo during the TLS connection setup. + q->servAddr = zeroAddr; + q->servPort = zeroIPPort; + + if (!err && zoneInfo && !mDNSIPPortIsZero(zoneInfo->Port) && !mDNSAddressIsZero(&zoneInfo->Addr) && zoneInfo->Host.c[0]) + { + q->servAddr = zoneInfo->Addr; + q->servPort = zoneInfo->Port; + if (!PrivateQuery(q)) + { + // We don't need the zone data as we use it only for the Host information which we + // don't need if we are not going to use TLS connections. + if (q->nta) + { + if (q->nta != zoneInfo) LogMsg("LLQGotZoneData: nta (%p) != zoneInfo (%p) %##s (%s)", q->nta, zoneInfo, q->qname.c, DNSTypeName(q->qtype)); + CancelGetZoneData(m, q->nta); + q->nta = mDNSNULL; + } + } + q->ntries = 0; + debugf("LLQGotZoneData %#a:%d", &q->servAddr, mDNSVal16(q->servPort)); + startLLQHandshake(m, q); + } + else + { + if (q->nta) + { + if (q->nta != zoneInfo) LogMsg("LLQGotZoneData: nta (%p) != zoneInfo (%p) %##s (%s)", q->nta, zoneInfo, q->qname.c, DNSTypeName(q->qtype)); + CancelGetZoneData(m, q->nta); + q->nta = mDNSNULL; + } + StartLLQPolling(m,q); + if (err == mStatus_NoSuchNameErr) + { + // this actually failed, so mark it by setting address to all ones + q->servAddr.type = mDNSAddrType_IPv4; + q->servAddr.ip.v4 = onesIPv4Addr; + } + } + + mDNS_Unlock(m); +} + +// Called in normal callback context (i.e. mDNS_busy and mDNS_reentrancy are both 1) +mDNSlocal void PrivateQueryGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneInfo) +{ + DNSQuestion *q = (DNSQuestion *) zoneInfo->ZoneDataContext; + + LogInfo("PrivateQueryGotZoneData %##s (%s) err %d Zone %##s Private %d", q->qname.c, DNSTypeName(q->qtype), err, zoneInfo->ZoneName.c, zoneInfo->ZonePrivate); + + if (q->nta != zoneInfo) LogMsg("PrivateQueryGotZoneData:ERROR!!: nta (%p) != zoneInfo (%p) %##s (%s)", q->nta, zoneInfo, q->qname.c, DNSTypeName(q->qtype)); + + if (err || !zoneInfo || mDNSAddressIsZero(&zoneInfo->Addr) || mDNSIPPortIsZero(zoneInfo->Port) || !zoneInfo->Host.c[0]) + { + LogInfo("PrivateQueryGotZoneData: ERROR!! %##s (%s) invoked with error code %d %p %#a:%d", + q->qname.c, DNSTypeName(q->qtype), err, zoneInfo, + zoneInfo ? &zoneInfo->Addr : mDNSNULL, + zoneInfo ? mDNSVal16(zoneInfo->Port) : 0); + CancelGetZoneData(m, q->nta); + q->nta = mDNSNULL; + return; + } + + if (!zoneInfo->ZonePrivate) + { + debugf("Private port lookup failed -- retrying without TLS -- %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); + q->AuthInfo = mDNSNULL; // Clear AuthInfo so we try again non-private + q->ThisQInterval = InitialQuestionInterval; + q->LastQTime = m->timenow - q->ThisQInterval; + CancelGetZoneData(m, q->nta); + q->nta = mDNSNULL; + mDNS_Lock(m); + SetNextQueryTime(m, q); + mDNS_Unlock(m); + return; + // Next call to uDNS_CheckCurrentQuestion() will do this as a non-private query + } + + if (!PrivateQuery(q)) + { + LogMsg("PrivateQueryGotZoneData: ERROR!! Not a private query %##s (%s) AuthInfo %p", q->qname.c, DNSTypeName(q->qtype), q->AuthInfo); + CancelGetZoneData(m, q->nta); + q->nta = mDNSNULL; + return; + } + + q->TargetQID = mDNS_NewMessageID(m); + if (q->tcp) { DisposeTCPConn(q->tcp); q->tcp = mDNSNULL; } + if (!q->nta) { LogMsg("PrivateQueryGotZoneData:ERROR!! nta is NULL for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); return; } + q->tcp = MakeTCPConn(m, mDNSNULL, mDNSNULL, kTCPSocketFlags_UseTLS, &zoneInfo->Addr, zoneInfo->Port, &q->nta->Host, q, mDNSNULL); + if (q->nta) { CancelGetZoneData(m, q->nta); q->nta = mDNSNULL; } +} + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - Dynamic Updates +#endif + +// Called in normal callback context (i.e. mDNS_busy and mDNS_reentrancy are both 1) +mDNSexport void RecordRegistrationGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneData) +{ + AuthRecord *newRR = (AuthRecord*)zoneData->ZoneDataContext; + AuthRecord *ptr; + int c1, c2; + + if (newRR->nta != zoneData) + LogMsg("RecordRegistrationGotZoneData: nta (%p) != zoneData (%p) %##s (%s)", newRR->nta, zoneData, newRR->resrec.name->c, DNSTypeName(newRR->resrec.rrtype)); + + if (m->mDNS_busy != m->mDNS_reentrancy) + LogMsg("RecordRegistrationGotZoneData: mDNS_busy (%ld) != mDNS_reentrancy (%ld)", m->mDNS_busy, m->mDNS_reentrancy); + + // make sure record is still in list (!!!) + for (ptr = m->ResourceRecords; ptr; ptr = ptr->next) if (ptr == newRR) break; + if (!ptr) + { + LogMsg("RecordRegistrationGotZoneData - RR no longer in list. Discarding."); + CancelGetZoneData(m, newRR->nta); + newRR->nta = mDNSNULL; + return; + } + + // check error/result + if (err) + { + if (err != mStatus_NoSuchNameErr) LogMsg("RecordRegistrationGotZoneData: error %d", err); + CancelGetZoneData(m, newRR->nta); + newRR->nta = mDNSNULL; + return; + } + + if (!zoneData) { LogMsg("ERROR: RecordRegistrationGotZoneData invoked with NULL result and no error"); return; } + + if (newRR->resrec.rrclass != zoneData->ZoneClass) + { + LogMsg("ERROR: New resource record's class (%d) does not match zone class (%d)", newRR->resrec.rrclass, zoneData->ZoneClass); + CancelGetZoneData(m, newRR->nta); + newRR->nta = mDNSNULL; + return; + } + + // Don't try to do updates to the root name server. + // We might be tempted also to block updates to any single-label name server (e.g. com, edu, net, etc.) but some + // organizations use their own private pseudo-TLD, like ".home", etc, and we don't want to block that. + if (zoneData->ZoneName.c[0] == 0) + { + LogInfo("RecordRegistrationGotZoneData: No name server found claiming responsibility for \"%##s\"!", newRR->resrec.name->c); + CancelGetZoneData(m, newRR->nta); + newRR->nta = mDNSNULL; + return; + } + + // Store discovered zone data + c1 = CountLabels(newRR->resrec.name); + c2 = CountLabels(&zoneData->ZoneName); + if (c2 > c1) + { + LogMsg("RecordRegistrationGotZoneData: Zone \"%##s\" is longer than \"%##s\"", zoneData->ZoneName.c, newRR->resrec.name->c); + CancelGetZoneData(m, newRR->nta); + newRR->nta = mDNSNULL; + return; + } + newRR->zone = SkipLeadingLabels(newRR->resrec.name, c1-c2); + if (!SameDomainName(newRR->zone, &zoneData->ZoneName)) + { + LogMsg("RecordRegistrationGotZoneData: Zone \"%##s\" does not match \"%##s\" for \"%##s\"", newRR->zone->c, zoneData->ZoneName.c, newRR->resrec.name->c); + CancelGetZoneData(m, newRR->nta); + newRR->nta = mDNSNULL; + return; + } + + if (mDNSIPPortIsZero(zoneData->Port) || mDNSAddressIsZero(&zoneData->Addr) || !zoneData->Host.c[0]) + { + LogInfo("RecordRegistrationGotZoneData: No _dns-update._udp service found for \"%##s\"!", newRR->resrec.name->c); + CancelGetZoneData(m, newRR->nta); + newRR->nta = mDNSNULL; + return; + } + + newRR->Private = zoneData->ZonePrivate; + debugf("RecordRegistrationGotZoneData: Set zone information for %##s %##s to %#a:%d", + newRR->resrec.name->c, zoneData->ZoneName.c, &zoneData->Addr, mDNSVal16(zoneData->Port)); + + // If we are deregistering, uDNS_DeregisterRecord will do that as it has the zone data now. + if (newRR->state == regState_DeregPending) + { + mDNS_Lock(m); + uDNS_DeregisterRecord(m, newRR); + mDNS_Unlock(m); + return; + } + + if (newRR->resrec.rrtype == kDNSType_SRV) + { + const domainname *target; + // Reevaluate the target always as NAT/Target could have changed while + // we were fetching zone data. + mDNS_Lock(m); + target = GetServiceTarget(m, newRR); + mDNS_Unlock(m); + if (!target || target->c[0] == 0) + { + domainname *t = GetRRDomainNameTarget(&newRR->resrec); + LogInfo("RecordRegistrationGotZoneData - no target for %##s", newRR->resrec.name->c); + if (t) t->c[0] = 0; + newRR->resrec.rdlength = newRR->resrec.rdestimate = 0; + newRR->state = regState_NoTarget; + CancelGetZoneData(m, newRR->nta); + newRR->nta = mDNSNULL; + return; + } + } + // If we have non-zero service port (always?) + // and a private address, and update server is non-private + // and this service is AutoTarget + // then initiate a NAT mapping request. On completion it will do SendRecordRegistration() for us + if (newRR->resrec.rrtype == kDNSType_SRV && !mDNSIPPortIsZero(newRR->resrec.rdata->u.srv.port) && + mDNSv4AddrIsRFC1918(&m->AdvertisedV4.ip.v4) && newRR->nta && !mDNSAddrIsRFC1918(&newRR->nta->Addr) && + newRR->AutoTarget == Target_AutoHostAndNATMAP) + { + DomainAuthInfo *AuthInfo; + AuthInfo = GetAuthInfoForName(m, newRR->resrec.name); + if (AuthInfo && AuthInfo->AutoTunnel) + { + domainname *t = GetRRDomainNameTarget(&newRR->resrec); + LogMsg("RecordRegistrationGotZoneData: ERROR!! AutoTunnel has Target_AutoHostAndNATMAP for %s", ARDisplayString(m, newRR)); + if (t) t->c[0] = 0; + newRR->resrec.rdlength = newRR->resrec.rdestimate = 0; + newRR->state = regState_NoTarget; + CancelGetZoneData(m, newRR->nta); + newRR->nta = mDNSNULL; + return; + } + // During network transitions, we are called multiple times in different states. Setup NAT + // state just once for this record. + if (!newRR->NATinfo.clientContext) + { + LogInfo("RecordRegistrationGotZoneData StartRecordNatMap %s", ARDisplayString(m, newRR)); + newRR->state = regState_NATMap; + StartRecordNatMap(m, newRR); + return; + } + else LogInfo("RecordRegistrationGotZoneData: StartRecordNatMap for %s, state %d, context %p", ARDisplayString(m, newRR), newRR->state, newRR->NATinfo.clientContext); + } + mDNS_Lock(m); + // We want IsRecordMergeable to check whether it is a record whose update can be + // sent with others. We set the time before we call IsRecordMergeable, so that + // it does not fail this record based on time. We are interested in other checks + // at this time. If a previous update resulted in error, then don't reset the + // interval. Preserve the back-off so that we don't keep retrying aggressively. + if (newRR->updateError == mStatus_NoError) + { + newRR->ThisAPInterval = INIT_RECORD_REG_INTERVAL; + newRR->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; + } + if (IsRecordMergeable(m, newRR, m->timenow + MERGE_DELAY_TIME)) + { + // Delay the record registration by MERGE_DELAY_TIME so that we can merge them + // into one update + LogInfo("RecordRegistrationGotZoneData: Delayed registration for %s", ARDisplayString(m, newRR)); + newRR->LastAPTime += MERGE_DELAY_TIME; + } + mDNS_Unlock(m); +} + +mDNSlocal void SendRecordDeregistration(mDNS *m, AuthRecord *rr) +{ + mDNSu8 *ptr = m->omsg.data; + mDNSu8 *limit; + DomainAuthInfo *AuthInfo; + + mDNS_CheckLock(m); + + if (!rr->nta || mDNSIPv4AddressIsZero(rr->nta->Addr.ip.v4)) + { + LogMsg("SendRecordDeRegistration: No zone info for Resource record %s RecordType %d", ARDisplayString(m, rr), rr->resrec.RecordType); + return; + } + + limit = ptr + AbsoluteMaxDNSMessageData; + AuthInfo = GetAuthInfoForName_internal(m, rr->resrec.name); + limit -= RRAdditionalSize(m, AuthInfo); + + rr->updateid = mDNS_NewMessageID(m); + InitializeDNSMessage(&m->omsg.h, rr->updateid, UpdateReqFlags); + + // set zone + ptr = putZone(&m->omsg, ptr, limit, rr->zone, mDNSOpaque16fromIntVal(rr->resrec.rrclass)); + if (!ptr) goto exit; + + ptr = BuildUpdateMessage(m, ptr, rr, limit); + + if (!ptr) goto exit; + + if (rr->Private) + { + LogInfo("SendRecordDeregistration TCP %p %s", rr->tcp, ARDisplayString(m, rr)); + if (rr->tcp) LogInfo("SendRecordDeregistration: Disposing existing TCP connection for %s", ARDisplayString(m, rr)); + if (rr->tcp) { DisposeTCPConn(rr->tcp); rr->tcp = mDNSNULL; } + if (!rr->nta) { LogMsg("SendRecordDeregistration:Private:ERROR!! nta is NULL for %s", ARDisplayString(m, rr)); return; } + rr->tcp = MakeTCPConn(m, &m->omsg, ptr, kTCPSocketFlags_UseTLS, &rr->nta->Addr, rr->nta->Port, &rr->nta->Host, mDNSNULL, rr); + } + else + { + mStatus err; + LogInfo("SendRecordDeregistration UDP %s", ARDisplayString(m, rr)); + if (!rr->nta) { LogMsg("SendRecordDeregistration:ERROR!! nta is NULL for %s", ARDisplayString(m, rr)); return; } + err = mDNSSendDNSMessage(m, &m->omsg, ptr, mDNSInterface_Any, mDNSNULL, &rr->nta->Addr, rr->nta->Port, mDNSNULL, GetAuthInfoForName_internal(m, rr->resrec.name), mDNSfalse); + if (err) debugf("ERROR: SendRecordDeregistration - mDNSSendDNSMessage - %d", err); + //if (rr->state == regState_DeregPending) CompleteDeregistration(m, rr); // Don't touch rr after this + } + SetRecordRetry(m, rr, 0); + return; +exit: + LogMsg("SendRecordDeregistration: Error formatting message for %s", ARDisplayString(m, rr)); +} + +mDNSexport mStatus uDNS_DeregisterRecord(mDNS *const m, AuthRecord *const rr) +{ + DomainAuthInfo *info; + + LogInfo("uDNS_DeregisterRecord: Resource Record %s, state %d", ARDisplayString(m, rr), rr->state); + + switch (rr->state) + { + case regState_Refresh: + case regState_Pending: + case regState_UpdatePending: + case regState_Registered: break; + case regState_DeregPending: break; + + case regState_NATError: + case regState_NATMap: + // A record could be in NoTarget to start with if the corresponding SRV record could not find a target. + // It is also possible to reenter the NoTarget state when we move to a network with a NAT that has + // no {PCP, NAT-PMP, UPnP/IGD} support. In that case before we entered NoTarget, we already deregistered with + // the server. + case regState_NoTarget: + case regState_Unregistered: + case regState_Zero: + default: + LogInfo("uDNS_DeregisterRecord: State %d for %##s type %s", rr->state, rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype)); + // This function may be called during sleep when there are no sleep proxy servers + if (rr->resrec.RecordType == kDNSRecordTypeDeregistering) CompleteDeregistration(m, rr); + return mStatus_NoError; + } + + // if unsent rdata is queued, free it. + // + // The data may be queued in QueuedRData or InFlightRData. + // + // 1) If the record is in Registered state, we store it in InFlightRData and copy the same in "rdata" + // *just* before sending the update to the server. Till we get the response, InFlightRData and "rdata" + // in the resource record are same. We don't want to free in that case. It will be freed when "rdata" + // is freed. If they are not same, the update has not been sent and we should free it here. + // + // 2) If the record is in UpdatePending state, we queue the update in QueuedRData. When the previous update + // comes back from the server, we copy it from QueuedRData to InFlightRData and repeat (1). This implies + // that QueuedRData can never be same as "rdata" in the resource record. As long as we have something + // left in QueuedRData, we should free it here. + + if (rr->InFlightRData && rr->UpdateCallback) + { + if (rr->InFlightRData != rr->resrec.rdata) + { + LogInfo("uDNS_DeregisterRecord: Freeing InFlightRData for %s", ARDisplayString(m, rr)); + rr->UpdateCallback(m, rr, rr->InFlightRData, rr->InFlightRDLen); + rr->InFlightRData = mDNSNULL; + } + else + LogInfo("uDNS_DeregisterRecord: InFlightRData same as rdata for %s", ARDisplayString(m, rr)); + } + + if (rr->QueuedRData && rr->UpdateCallback) + { + if (rr->QueuedRData == rr->resrec.rdata) + LogMsg("uDNS_DeregisterRecord: ERROR!! QueuedRData same as rdata for %s", ARDisplayString(m, rr)); + else + { + LogInfo("uDNS_DeregisterRecord: Freeing QueuedRData for %s", ARDisplayString(m, rr)); + rr->UpdateCallback(m, rr, rr->QueuedRData, rr->QueuedRDLen); + rr->QueuedRData = mDNSNULL; + } + } + + // If a current group registration is pending, we can't send this deregisration till that registration + // has reached the server i.e., the ordering is important. Previously, if we did not send this + // registration in a group, then the previous connection will be torn down as part of sending the + // deregistration. If we send this in a group, we need to locate the resource record that was used + // to send this registration and terminate that connection. This means all the updates on that might + // be lost (assuming the response is not waiting for us at the socket) and the retry will send the + // update again sometime in the near future. + // + // NOTE: SSL handshake failures normally free the TCP connection immediately. Hence, you may not + // find the TCP below there. This case can happen only when tcp is trying to actively retransmit + // the request or SSL negotiation taking time i.e resource record is actively trying to get the + // message to the server. During that time a deregister has to happen. + + if (!mDNSOpaque16IsZero(rr->updateid)) + { + AuthRecord *anchorRR; + mDNSBool found = mDNSfalse; + for (anchorRR = m->ResourceRecords; anchorRR; anchorRR = anchorRR->next) + { + if (AuthRecord_uDNS(rr) && mDNSSameOpaque16(anchorRR->updateid, rr->updateid) && anchorRR->tcp) + { + LogInfo("uDNS_DeregisterRecord: Found Anchor RR %s terminated", ARDisplayString(m, anchorRR)); + if (found) + LogMsg("uDNS_DeregisterRecord: ERROR: Another anchorRR %s found", ARDisplayString(m, anchorRR)); + DisposeTCPConn(anchorRR->tcp); + anchorRR->tcp = mDNSNULL; + found = mDNStrue; + } + } + if (!found) LogInfo("uDNSDeregisterRecord: Cannot find the anchor Resource Record for %s, not an error", ARDisplayString(m, rr)); + } + + // Retry logic for deregistration should be no different from sending registration the first time. + // Currently ThisAPInterval most likely is set to the refresh interval + rr->state = regState_DeregPending; + rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; + rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; + info = GetAuthInfoForName_internal(m, rr->resrec.name); + if (IsRecordMergeable(m, rr, m->timenow + MERGE_DELAY_TIME)) + { + // Delay the record deregistration by MERGE_DELAY_TIME so that we can merge them + // into one update. If the domain is being deleted, delay by 2 * MERGE_DELAY_TIME + // so that we can merge all the AutoTunnel records and the service records in + // one update (they get deregistered a little apart) + if (info && info->deltime) rr->LastAPTime += (2 * MERGE_DELAY_TIME); + else rr->LastAPTime += MERGE_DELAY_TIME; + } + // IsRecordMergeable could have returned false for several reasons e.g., DontMerge is set or + // no zone information. Most likely it is the latter, CheckRecordUpdates will fetch the zone + // data when it encounters this record. + + if (m->NextuDNSEvent - (rr->LastAPTime + rr->ThisAPInterval) >= 0) + m->NextuDNSEvent = (rr->LastAPTime + rr->ThisAPInterval); + + return mStatus_NoError; +} + +mDNSexport mStatus uDNS_UpdateRecord(mDNS *m, AuthRecord *rr) +{ + LogInfo("uDNS_UpdateRecord: Resource Record %##s, state %d", rr->resrec.name->c, rr->state); + switch(rr->state) + { + case regState_DeregPending: + case regState_Unregistered: + // not actively registered + goto unreg_error; + + case regState_NATMap: + case regState_NoTarget: + // change rdata directly since it hasn't been sent yet + if (rr->UpdateCallback) rr->UpdateCallback(m, rr, rr->resrec.rdata, rr->resrec.rdlength); + SetNewRData(&rr->resrec, rr->NewRData, rr->newrdlength); + rr->NewRData = mDNSNULL; + return mStatus_NoError; + + case regState_Pending: + case regState_Refresh: + case regState_UpdatePending: + // registration in-flight. queue rdata and return + if (rr->QueuedRData && rr->UpdateCallback) + // if unsent rdata is already queued, free it before we replace it + rr->UpdateCallback(m, rr, rr->QueuedRData, rr->QueuedRDLen); + rr->QueuedRData = rr->NewRData; + rr->QueuedRDLen = rr->newrdlength; + rr->NewRData = mDNSNULL; + return mStatus_NoError; + + case regState_Registered: + rr->OrigRData = rr->resrec.rdata; + rr->OrigRDLen = rr->resrec.rdlength; + rr->InFlightRData = rr->NewRData; + rr->InFlightRDLen = rr->newrdlength; + rr->NewRData = mDNSNULL; + rr->state = regState_UpdatePending; + rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; + rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; + SetNextuDNSEvent(m, rr); + return mStatus_NoError; + + case regState_NATError: + LogMsg("ERROR: uDNS_UpdateRecord called for record %##s with bad state regState_NATError", rr->resrec.name->c); + return mStatus_UnknownErr; // states for service records only + + default: LogMsg("uDNS_UpdateRecord: Unknown state %d for %##s", rr->state, rr->resrec.name->c); + } + +unreg_error: + LogMsg("uDNS_UpdateRecord: Requested update of record %##s type %d, in erroneous state %d", + rr->resrec.name->c, rr->resrec.rrtype, rr->state); + return mStatus_Invalid; +} + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - Periodic Execution Routines +#endif + +mDNSlocal void handle_unanswered_query(mDNS *const m) +{ + DNSQuestion *q = m->CurrentQuestion; + + if (q->unansweredQueries >= MAX_DNSSEC_UNANSWERED_QUERIES && DNSSECOptionalQuestion(q)) + { + // If we are not receiving any responses for DNSSEC question, it could be due to + // a broken middlebox or a DNS server that does not understand the EDNS0/DOK option that + // silently drops the packets. Also as per RFC 5625 there are certain buggy DNS Proxies + // that are known to drop these pkts. To handle this, we turn off sending the EDNS0/DOK + // option if we have not received any responses indicating that the server or + // the middlebox is DNSSEC aware. If we receive at least one response to a DNSSEC + // question, we don't turn off validation. Also, we wait for MAX_DNSSEC_RETRANSMISSIONS + // before turning off validation to accomodate packet loss. + // + // Note: req_DO affects only DNSSEC_VALIDATION_SECURE_OPTIONAL questions; + // DNSSEC_VALIDATION_SECURE questions ignores req_DO. + + if (q->qDNSServer && !q->qDNSServer->DNSSECAware && q->qDNSServer->req_DO) + { + q->qDNSServer->retransDO++; + if (q->qDNSServer->retransDO == MAX_DNSSEC_RETRANSMISSIONS) + { + LogInfo("handle_unanswered_query: setting req_DO false for %#a", &q->qDNSServer->addr); + q->qDNSServer->req_DO = mDNSfalse; + } + } + + if (!q->qDNSServer->req_DO) + { + q->ValidationState = DNSSECValNotRequired; + q->ValidationRequired = DNSSEC_VALIDATION_NONE; + + if (q->ProxyQuestion) + q->ProxyDNSSECOK = mDNSfalse; + LogInfo("handle_unanswered_query: unanswered query for %##s (%s), so turned off validation for %#a", + q->qname.c, DNSTypeName(q->qtype), &q->qDNSServer->addr); + } + } +} + +// The question to be checked is not passed in as an explicit parameter; +// instead it is implicit that the question to be checked is m->CurrentQuestion. +mDNSexport void uDNS_CheckCurrentQuestion(mDNS *const m) +{ + DNSQuestion *q = m->CurrentQuestion; + if (m->timenow - NextQSendTime(q) < 0) return; + + if (q->LongLived) + { + switch (q->state) + { + case LLQ_InitialRequest: startLLQHandshake(m, q); break; + case LLQ_SecondaryRequest: + // For PrivateQueries, we need to start the handshake again as we don't do the Challenge/Response step + if (PrivateQuery(q)) + startLLQHandshake(m, q); + else + sendChallengeResponse(m, q, mDNSNULL); + break; + case LLQ_Established: sendLLQRefresh(m, q); break; + case LLQ_Poll: break; // Do nothing (handled below) + } + } + + handle_unanswered_query(m); + // We repeat the check above (rather than just making this the "else" case) because startLLQHandshake can change q->state to LLQ_Poll + if (!(q->LongLived && q->state != LLQ_Poll)) + { + if (q->unansweredQueries >= MAX_UCAST_UNANSWERED_QUERIES) + { + DNSServer *orig = q->qDNSServer; + if (orig) + LogInfo("uDNS_CheckCurrentQuestion: Sent %d unanswered queries for %##s (%s) to %#a:%d (%##s)", + q->unansweredQueries, q->qname.c, DNSTypeName(q->qtype), &orig->addr, mDNSVal16(orig->port), orig->domain.c); + + PenalizeDNSServer(m, q, zeroID); + q->noServerResponse = 1; + } + // There are two cases here. + // + // 1. We have only one DNS server for this question. It is not responding even after we sent MAX_UCAST_UNANSWERED_QUERIES. + // In that case, we need to keep retrying till we get a response. But we need to backoff as we retry. We set + // noServerResponse in the block above and below we do not touch the question interval. When we come here, we + // already waited for the response. We need to send another query right at this moment. We do that below by + // reinitializing dns servers and reissuing the query. + // + // 2. We have more than one DNS server. If at least one server did not respond, we would have set noServerResponse + // either now (the last server in the list) or before (non-last server in the list). In either case, if we have + // reached the end of DNS server list, we need to try again from the beginning. Ideally we should try just the + // servers that did not respond, but for simplicity we try all the servers. Once we reached the end of list, we + // set triedAllServersOnce so that we don't try all the servers aggressively. See PenalizeDNSServer. + if (!q->qDNSServer && q->noServerResponse) + { + DNSServer *new; + DNSQuestion *qptr; + q->triedAllServersOnce = 1; + // Re-initialize all DNS servers for this question. If we have a DNSServer, DNSServerChangeForQuestion will + // handle all the work including setting the new DNS server. + SetValidDNSServers(m, q); + new = GetServerForQuestion(m, q); + if (new) + { + LogInfo("uDNS_checkCurrentQuestion: Retrying question %p %##s (%s) DNS Server %#a:%d ThisQInterval %d", + q, q->qname.c, DNSTypeName(q->qtype), new ? &new->addr : mDNSNULL, mDNSVal16(new ? new->port : zeroIPPort), q->ThisQInterval); + DNSServerChangeForQuestion(m, q, new); + } + for (qptr = q->next ; qptr; qptr = qptr->next) + if (qptr->DuplicateOf == q) { qptr->validDNSServers = q->validDNSServers; qptr->qDNSServer = q->qDNSServer; } + } + if (q->qDNSServer && q->qDNSServer->teststate != DNSServer_Disabled) + { + mDNSu8 *end = m->omsg.data; + mStatus err = mStatus_NoError; + mDNSBool private = mDNSfalse; + + InitializeDNSMessage(&m->omsg.h, q->TargetQID, (DNSSECQuestion(q) ? DNSSecQFlags : uQueryFlags)); + + if (q->qDNSServer->teststate != DNSServer_Untested || NoTestQuery(q)) + { + end = putQuestion(&m->omsg, m->omsg.data, m->omsg.data + AbsoluteMaxDNSMessageData, &q->qname, q->qtype, q->qclass); + if (DNSSECQuestion(q) && !q->qDNSServer->cellIntf) + { + if (q->ProxyQuestion) + end = DNSProxySetAttributes(q, &m->omsg.h, &m->omsg, end, m->omsg.data + AbsoluteMaxDNSMessageData); + else + end = putDNSSECOption(&m->omsg, end, m->omsg.data + AbsoluteMaxDNSMessageData); + } + private = PrivateQuery(q); + } + else if (m->timenow - q->qDNSServer->lasttest >= INIT_UCAST_POLL_INTERVAL) // Make sure at least three seconds has elapsed since last test query + { + LogInfo("Sending DNS test query to %#a:%d", &q->qDNSServer->addr, mDNSVal16(q->qDNSServer->port)); + q->ThisQInterval = INIT_UCAST_POLL_INTERVAL / QuestionIntervalStep; + q->qDNSServer->lasttest = m->timenow; + end = putQuestion(&m->omsg, m->omsg.data, m->omsg.data + AbsoluteMaxDNSMessageData, DNSRelayTestQuestion, kDNSType_PTR, kDNSClass_IN); + q->qDNSServer->testid = m->omsg.h.id; + } + + if (end > m->omsg.data && (q->qDNSServer->teststate != DNSServer_Failed || NoTestQuery(q))) + { + //LogMsg("uDNS_CheckCurrentQuestion %p %d %p %##s (%s)", q, NextQSendTime(q) - m->timenow, private, q->qname.c, DNSTypeName(q->qtype)); + if (private) + { + if (q->nta) CancelGetZoneData(m, q->nta); + q->nta = StartGetZoneData(m, &q->qname, q->LongLived ? ZoneServiceLLQ : ZoneServiceQuery, PrivateQueryGotZoneData, q); + if (q->state == LLQ_Poll) q->ThisQInterval = (LLQ_POLL_INTERVAL + mDNSRandom(LLQ_POLL_INTERVAL/10)) / QuestionIntervalStep; + } + else + { + debugf("uDNS_CheckCurrentQuestion sending %p %##s (%s) %#a:%d UnansweredQueries %d", + q, q->qname.c, DNSTypeName(q->qtype), + q->qDNSServer ? &q->qDNSServer->addr : mDNSNULL, mDNSVal16(q->qDNSServer ? q->qDNSServer->port : zeroIPPort), q->unansweredQueries); + if (!q->LocalSocket) + { + q->LocalSocket = mDNSPlatformUDPSocket(m, zeroIPPort); + if (q->LocalSocket) + mDNSPlatformSetDelegatePID(q->LocalSocket, &q->qDNSServer->addr, q); + } + if (!q->LocalSocket) err = mStatus_NoMemoryErr; // If failed to make socket (should be very rare), we'll try again next time + else err = mDNSSendDNSMessage(m, &m->omsg, end, q->qDNSServer->interface, q->LocalSocket, &q->qDNSServer->addr, q->qDNSServer->port, mDNSNULL, mDNSNULL, q->UseBackgroundTrafficClass); + } + } + + if (err != mStatus_TransientErr) // if it is not a transient error backoff and DO NOT flood queries unnecessarily + { + q->ThisQInterval = q->ThisQInterval * QuestionIntervalStep; // Only increase interval if send succeeded + q->unansweredQueries++; + if (q->ThisQInterval > MAX_UCAST_POLL_INTERVAL) + q->ThisQInterval = MAX_UCAST_POLL_INTERVAL; + if (private && q->state != LLQ_Poll) + { + // We don't want to retransmit too soon. Hence, we always schedule our first + // retransmisson at 3 seconds rather than one second + if (q->ThisQInterval < (3 * mDNSPlatformOneSecond)) + q->ThisQInterval = q->ThisQInterval * QuestionIntervalStep; + if (q->ThisQInterval > LLQ_POLL_INTERVAL) + q->ThisQInterval = LLQ_POLL_INTERVAL; + LogInfo("uDNS_CheckCurrentQuestion: private non polling question for %##s (%s) will be retried in %d ms", q->qname.c, DNSTypeName(q->qtype), q->ThisQInterval); + } + if (q->qDNSServer->cellIntf) + { + // We don't want to retransmit too soon. Schedule our first retransmisson at + // MIN_UCAST_RETRANS_TIMEOUT seconds. + if (q->ThisQInterval < MIN_UCAST_RETRANS_TIMEOUT) + q->ThisQInterval = MIN_UCAST_RETRANS_TIMEOUT; + } + debugf("uDNS_CheckCurrentQuestion: Increased ThisQInterval to %d for %##s (%s), cell %d", q->ThisQInterval, q->qname.c, DNSTypeName(q->qtype), q->qDNSServer->cellIntf); + } + q->LastQTime = m->timenow; + SetNextQueryTime(m, q); + } + else + { + // If we have no server for this query, or the only server is a disabled one, then we deliver + // a transient failure indication to the client. This is important for things like iPhone + // where we want to return timely feedback to the user when no network is available. + // After calling MakeNegativeCacheRecord() we store the resulting record in the + // cache so that it will be visible to other clients asking the same question. + // (When we have a group of identical questions, only the active representative of the group gets + // passed to uDNS_CheckCurrentQuestion -- we only want one set of query packets hitting the wire -- + // but we want *all* of the questions to get answer callbacks.) + CacheRecord *rr; + const mDNSu32 slot = HashSlot(&q->qname); + CacheGroup *const cg = CacheGroupForName(m, slot, q->qnamehash, &q->qname); + + if (!q->qDNSServer) + { + if (!mDNSOpaque64IsZero(&q->validDNSServers)) + LogMsg("uDNS_CheckCurrentQuestion: ERROR!!: valid DNSServer bits not zero 0x%x, 0x%x for question %##s (%s)", + q->validDNSServers.l[1], q->validDNSServers.l[0], q->qname.c, DNSTypeName(q->qtype)); + // If we reached the end of list while picking DNS servers, then we don't want to deactivate the + // question. Try after 60 seconds. We find this by looking for valid DNSServers for this question, + // if we find any, then we must have tried them before we came here. This avoids maintaining + // another state variable to see if we had valid DNS servers for this question. + SetValidDNSServers(m, q); + if (mDNSOpaque64IsZero(&q->validDNSServers)) + { + LogInfo("uDNS_CheckCurrentQuestion: no DNS server for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); + q->ThisQInterval = 0; + } + else + { + DNSQuestion *qptr; + // Pretend that we sent this question. As this is an ActiveQuestion, the NextScheduledQuery should + // be set properly. Also, we need to properly backoff in cases where we don't set the question to + // MaxQuestionInterval when we answer the question e.g., LongLived, we need to keep backing off + q->ThisQInterval = q->ThisQInterval * QuestionIntervalStep; + q->LastQTime = m->timenow; + SetNextQueryTime(m, q); + // Pick a new DNS server now. Otherwise, when the cache is 80% of its expiry, we will try + // to send a query and come back to the same place here and log the above message. + q->qDNSServer = GetServerForQuestion(m, q); + for (qptr = q->next ; qptr; qptr = qptr->next) + if (qptr->DuplicateOf == q) { qptr->validDNSServers = q->validDNSServers; qptr->qDNSServer = q->qDNSServer; } + LogInfo("uDNS_checkCurrentQuestion: Tried all DNS servers, retry question %p SuppressUnusable %d %##s (%s) with DNS Server %#a:%d after 60 seconds, ThisQInterval %d", + q, q->SuppressUnusable, q->qname.c, DNSTypeName(q->qtype), + q->qDNSServer ? &q->qDNSServer->addr : mDNSNULL, mDNSVal16(q->qDNSServer ? q->qDNSServer->port : zeroIPPort), q->ThisQInterval); + } + } + else + { + q->ThisQInterval = 0; + LogMsg("uDNS_CheckCurrentQuestion DNS server %#a:%d for %##s is disabled", &q->qDNSServer->addr, mDNSVal16(q->qDNSServer->port), q->qname.c); + } + + if (cg) + { + for (rr = cg->members; rr; rr=rr->next) + { + if (SameNameRecordAnswersQuestion(&rr->resrec, q)) + { + LogInfo("uDNS_CheckCurrentQuestion: Purged resourcerecord %s", CRDisplayString(m, rr)); + mDNS_PurgeCacheResourceRecord(m, rr); + } + } + } + // For some of the WAB queries that we generate form within the mDNSResponder, most of the home routers + // don't understand and return ServFail/NXDomain. In those cases, we don't want to try too often. We try + // every fifteen minutes in that case + MakeNegativeCacheRecord(m, &m->rec.r, &q->qname, q->qnamehash, q->qtype, q->qclass, (DomainEnumQuery(&q->qname) ? 60 * 15 : 60), mDNSInterface_Any, q->qDNSServer); + q->unansweredQueries = 0; + if (!mDNSOpaque16IsZero(q->responseFlags)) + m->rec.r.responseFlags = q->responseFlags; + // We're already using the m->CurrentQuestion pointer, so CacheRecordAdd can't use it to walk the question list. + // To solve this problem we set rr->DelayDelivery to a nonzero value (which happens to be 'now') so that we + // momentarily defer generating answer callbacks until mDNS_Execute time. + CreateNewCacheEntry(m, slot, cg, NonZeroTime(m->timenow), mDNStrue, mDNSNULL); + ScheduleNextCacheCheckTime(m, slot, NonZeroTime(m->timenow)); + m->rec.r.responseFlags = zeroID; + m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it + // MUST NOT touch m->CurrentQuestion (or q) after this -- client callback could have deleted it + } + } +} + +mDNSexport void CheckNATMappings(mDNS *m) +{ + mStatus err = mStatus_NoError; + mDNSBool rfc1918 = mDNSv4AddrIsRFC1918(&m->AdvertisedV4.ip.v4); + mDNSBool HaveRoutable = !rfc1918 && !mDNSIPv4AddressIsZero(m->AdvertisedV4.ip.v4); + m->NextScheduledNATOp = m->timenow + 0x3FFFFFFF; + + if (HaveRoutable) m->ExtAddress = m->AdvertisedV4.ip.v4; + + if (m->NATTraversals && rfc1918) // Do we need to open a socket to receive multicast announcements from router? + { + if (m->NATMcastRecvskt == mDNSNULL) // If we are behind a NAT and the socket hasn't been opened yet, open it + { + // we need to log a message if we can't get our socket, but only the first time (after success) + static mDNSBool needLog = mDNStrue; + m->NATMcastRecvskt = mDNSPlatformUDPSocket(m, NATPMPAnnouncementPort); + if (!m->NATMcastRecvskt) + { + if (needLog) + { + LogMsg("CheckNATMappings: Failed to allocate port 5350 UDP multicast socket for PCP & NAT-PMP announcements"); + needLog = mDNSfalse; + } + } + else + needLog = mDNStrue; + } + } + else // else, we don't want to listen for announcements, so close them if they're open + { + if (m->NATMcastRecvskt) { mDNSPlatformUDPClose(m->NATMcastRecvskt); m->NATMcastRecvskt = mDNSNULL; } + if (m->SSDPSocket) { debugf("CheckNATMappings destroying SSDPSocket %p", &m->SSDPSocket); mDNSPlatformUDPClose(m->SSDPSocket); m->SSDPSocket = mDNSNULL; } + } + + uDNS_RequestAddress(m); + + if (m->CurrentNATTraversal) LogMsg("WARNING m->CurrentNATTraversal already in use"); + m->CurrentNATTraversal = m->NATTraversals; + + while (m->CurrentNATTraversal) + { + NATTraversalInfo *cur = m->CurrentNATTraversal; + mDNSv4Addr EffectiveAddress = HaveRoutable ? m->AdvertisedV4.ip.v4 : cur->NewAddress; + m->CurrentNATTraversal = m->CurrentNATTraversal->next; + + if (HaveRoutable) // If not RFC 1918 address, our own address and port are effectively our external address and port + { + cur->ExpiryTime = 0; + cur->NewResult = mStatus_NoError; + } + else // Check if it's time to send port mapping packet(s) + { + if (m->timenow - cur->retryPortMap >= 0) // Time to send a mapping request for this packet + { + if (cur->ExpiryTime && cur->ExpiryTime - m->timenow < 0) // Mapping has expired + { + cur->ExpiryTime = 0; + cur->retryInterval = NATMAP_INIT_RETRY; + } + + err = uDNS_SendNATMsg(m, cur, mDNStrue); // Will also do UPnP discovery for us, if necessary + + if (cur->ExpiryTime) // If have active mapping then set next renewal time halfway to expiry + NATSetNextRenewalTime(m, cur); + else // else no mapping; use exponential backoff sequence + { + if (cur->retryInterval < NATMAP_INIT_RETRY ) cur->retryInterval = NATMAP_INIT_RETRY; + else if (cur->retryInterval < NATMAP_MAX_RETRY_INTERVAL / 2) cur->retryInterval *= 2; + else cur->retryInterval = NATMAP_MAX_RETRY_INTERVAL; + cur->retryPortMap = m->timenow + cur->retryInterval; + } + } + + if (m->NextScheduledNATOp - cur->retryPortMap > 0) + { + m->NextScheduledNATOp = cur->retryPortMap; + } + } + + // Notify the client if necessary. We invoke the callback if: + // (1) We have an effective address, + // or we've tried and failed a couple of times to discover it + // AND + // (2) the client requested the address only, + // or the client won't need a mapping because we have a routable address, + // or the client has an expiry time and therefore a successful mapping, + // or we've tried and failed a couple of times (see "Time line" below) + // AND + // (3) we have new data to give the client that's changed since the last callback + // + // Time line is: Send, Wait 500ms, Send, Wait 1sec, Send, Wait 2sec, Send + // At this point we've sent three requests without an answer, we've just sent our fourth request, + // retryInterval is now 4 seconds, which is greater than NATMAP_INIT_RETRY * 8 (2 seconds), + // so we return an error result to the caller. + if (!mDNSIPv4AddressIsZero(EffectiveAddress) || cur->retryInterval > NATMAP_INIT_RETRY * 8) + { + const mStatus EffectiveResult = cur->NewResult ? cur->NewResult : mDNSv4AddrIsRFC1918(&EffectiveAddress) ? mStatus_DoubleNAT : mStatus_NoError; + const mDNSIPPort ExternalPort = HaveRoutable ? cur->IntPort : + !mDNSIPv4AddressIsZero(EffectiveAddress) && cur->ExpiryTime ? cur->RequestedPort : zeroIPPort; + + if (!cur->Protocol || HaveRoutable || cur->ExpiryTime || cur->retryInterval > NATMAP_INIT_RETRY * 8) + { + if (!mDNSSameIPv4Address(cur->ExternalAddress, EffectiveAddress) || + !mDNSSameIPPort (cur->ExternalPort, ExternalPort) || + cur->Result != EffectiveResult) + { + //LogMsg("NAT callback %d %d %d", cur->Protocol, cur->ExpiryTime, cur->retryInterval); + if (cur->Protocol && mDNSIPPortIsZero(ExternalPort) && !mDNSIPv4AddressIsZero(m->Router.ip.v4)) + { + if (!EffectiveResult) + LogInfo("CheckNATMapping: Failed to obtain NAT port mapping %p from router %#a external address %.4a internal port %5d interval %d error %d", + cur, &m->Router, &EffectiveAddress, mDNSVal16(cur->IntPort), cur->retryInterval, EffectiveResult); + else + LogMsg("CheckNATMapping: Failed to obtain NAT port mapping %p from router %#a external address %.4a internal port %5d interval %d error %d", + cur, &m->Router, &EffectiveAddress, mDNSVal16(cur->IntPort), cur->retryInterval, EffectiveResult); + } + + cur->ExternalAddress = EffectiveAddress; + cur->ExternalPort = ExternalPort; + cur->Lifetime = cur->ExpiryTime && !mDNSIPPortIsZero(ExternalPort) ? + (cur->ExpiryTime - m->timenow + mDNSPlatformOneSecond/2) / mDNSPlatformOneSecond : 0; + cur->Result = EffectiveResult; + mDNS_DropLockBeforeCallback(); // Allow client to legally make mDNS API calls from the callback + if (cur->clientCallback) + cur->clientCallback(m, cur); + mDNS_ReclaimLockAfterCallback(); // Decrement mDNS_reentrancy to block mDNS API calls again + // MUST NOT touch cur after invoking the callback + } + } + } + } +} + +mDNSlocal mDNSs32 CheckRecordUpdates(mDNS *m) +{ + AuthRecord *rr; + mDNSs32 nextevent = m->timenow + 0x3FFFFFFF; + + CheckGroupRecordUpdates(m); + + for (rr = m->ResourceRecords; rr; rr = rr->next) + { + if (!AuthRecord_uDNS(rr)) continue; + if (rr->state == regState_NoTarget) {debugf("CheckRecordUpdates: Record %##s in NoTarget", rr->resrec.name->c); continue;} + // While we are waiting for the port mapping, we have nothing to do. The port mapping callback + // will take care of this + if (rr->state == regState_NATMap) {debugf("CheckRecordUpdates: Record %##s in NATMap", rr->resrec.name->c); continue;} + if (rr->state == regState_Pending || rr->state == regState_DeregPending || rr->state == regState_UpdatePending || + rr->state == regState_Refresh || rr->state == regState_Registered) + { + if (rr->LastAPTime + rr->ThisAPInterval - m->timenow <= 0) + { + if (rr->tcp) { DisposeTCPConn(rr->tcp); rr->tcp = mDNSNULL; } + if (!rr->nta || mDNSIPv4AddressIsZero(rr->nta->Addr.ip.v4)) + { + // Zero out the updateid so that if we have a pending response from the server, it won't + // be accepted as a valid response. If we accept the response, we might free the new "nta" + if (rr->nta) { rr->updateid = zeroID; CancelGetZoneData(m, rr->nta); } + rr->nta = StartGetZoneData(m, rr->resrec.name, ZoneServiceUpdate, RecordRegistrationGotZoneData, rr); + + // We have just started the GetZoneData. We need to wait for it to finish. SetRecordRetry here + // schedules the update timer to fire in the future. + // + // There are three cases. + // + // 1) When the updates are sent the first time, the first retry is intended to be at three seconds + // in the future. But by calling SetRecordRetry here we set it to nine seconds. But it does not + // matter because when the answer comes back, RecordRegistrationGotZoneData resets the interval + // back to INIT_RECORD_REG_INTERVAL. This also gives enough time for the query. + // + // 2) In the case of update errors (updateError), this causes further backoff as + // RecordRegistrationGotZoneData does not reset the timer. This is intentional as in the case of + // errors, we don't want to update aggressively. + // + // 3) We might be refreshing the update. This is very similar to case (1). RecordRegistrationGotZoneData + // resets it back to INIT_RECORD_REG_INTERVAL. + // + SetRecordRetry(m, rr, 0); + } + else if (rr->state == regState_DeregPending) SendRecordDeregistration(m, rr); + else SendRecordRegistration(m, rr); + } + } + if (nextevent - (rr->LastAPTime + rr->ThisAPInterval) > 0) + nextevent = (rr->LastAPTime + rr->ThisAPInterval); + } + return nextevent; +} + +mDNSexport void uDNS_Tasks(mDNS *const m) +{ + mDNSs32 nexte; + DNSServer *d; + + m->NextuDNSEvent = m->timenow + 0x3FFFFFFF; + + nexte = CheckRecordUpdates(m); + if (m->NextuDNSEvent - nexte > 0) + m->NextuDNSEvent = nexte; + + for (d = m->DNSServers; d; d=d->next) + if (d->penaltyTime) + { + if (m->timenow - d->penaltyTime >= 0) + { + LogInfo("DNS server %#a:%d out of penalty box", &d->addr, mDNSVal16(d->port)); + d->penaltyTime = 0; + } + else + if (m->NextuDNSEvent - d->penaltyTime > 0) + m->NextuDNSEvent = d->penaltyTime; + } + + if (m->CurrentQuestion) + LogMsg("uDNS_Tasks ERROR m->CurrentQuestion already set: %##s (%s)", m->CurrentQuestion->qname.c, DNSTypeName(m->CurrentQuestion->qtype)); + m->CurrentQuestion = m->Questions; + while (m->CurrentQuestion && m->CurrentQuestion != m->NewQuestions) + { + DNSQuestion *const q = m->CurrentQuestion; + if (ActiveQuestion(q) && !mDNSOpaque16IsZero(q->TargetQID)) + { + uDNS_CheckCurrentQuestion(m); + if (q == m->CurrentQuestion) + if (m->NextuDNSEvent - NextQSendTime(q) > 0) + m->NextuDNSEvent = NextQSendTime(q); + } + // If m->CurrentQuestion wasn't modified out from under us, advance it now + // We can't do this at the start of the loop because uDNS_CheckCurrentQuestion() + // depends on having m->CurrentQuestion point to the right question + if (m->CurrentQuestion == q) + m->CurrentQuestion = q->next; + } + m->CurrentQuestion = mDNSNULL; +} + +// *************************************************************************** +#if COMPILER_LIKES_PRAGMA_MARK +#pragma mark - Startup, Shutdown, and Sleep +#endif + +mDNSexport void SleepRecordRegistrations(mDNS *m) +{ + AuthRecord *rr; + for (rr = m->ResourceRecords; rr; rr=rr->next) + { + if (AuthRecord_uDNS(rr)) + { + // Zero out the updateid so that if we have a pending response from the server, it won't + // be accepted as a valid response. + if (rr->nta) { rr->updateid = zeroID; CancelGetZoneData(m, rr->nta); rr->nta = mDNSNULL; } + + if (rr->NATinfo.clientContext) + { + mDNS_StopNATOperation_internal(m, &rr->NATinfo); + rr->NATinfo.clientContext = mDNSNULL; + } + // We are waiting to update the resource record. The original data of the record is + // in OrigRData and the updated value is in InFlightRData. Free the old and the new + // one will be registered when we come back. + if (rr->state == regState_UpdatePending) + { + // act as if the update succeeded, since we're about to delete the name anyway + rr->state = regState_Registered; + // deallocate old RData + if (rr->UpdateCallback) rr->UpdateCallback(m, rr, rr->OrigRData, rr->OrigRDLen); + SetNewRData(&rr->resrec, rr->InFlightRData, rr->InFlightRDLen); + rr->OrigRData = mDNSNULL; + rr->InFlightRData = mDNSNULL; + } + + // If we have not begun the registration process i.e., never sent a registration packet, + // then uDNS_DeregisterRecord will not send a deregistration + uDNS_DeregisterRecord(m, rr); + + // When we wake, we call ActivateUnicastRegistration which starts at StartGetZoneData + } + } +} + +mDNSexport void mDNS_AddSearchDomain(const domainname *const domain, mDNSInterfaceID InterfaceID) +{ + SearchListElem **p; + SearchListElem *tmp = mDNSNULL; + + // Check to see if we already have this domain in our list + for (p = &SearchList; *p; p = &(*p)->next) + if (((*p)->InterfaceID == InterfaceID) && SameDomainName(&(*p)->domain, domain)) + { + // If domain is already in list, and marked for deletion, unmark the delete + // Be careful not to touch the other flags that may be present + LogInfo("mDNS_AddSearchDomain already in list %##s", domain->c); + if ((*p)->flag & SLE_DELETE) (*p)->flag &= ~SLE_DELETE; + tmp = *p; + *p = tmp->next; + tmp->next = mDNSNULL; + break; + } + + + // move to end of list so that we maintain the same order + while (*p) p = &(*p)->next; + + if (tmp) *p = tmp; + else + { + // if domain not in list, add to list, mark as add (1) + *p = mDNSPlatformMemAllocate(sizeof(SearchListElem)); + if (!*p) { LogMsg("ERROR: mDNS_AddSearchDomain - malloc"); return; } + mDNSPlatformMemZero(*p, sizeof(SearchListElem)); + AssignDomainName(&(*p)->domain, domain); + (*p)->next = mDNSNULL; + (*p)->InterfaceID = InterfaceID; + LogInfo("mDNS_AddSearchDomain created new %##s, InterfaceID %p", domain->c, InterfaceID); + } +} + +mDNSlocal void FreeARElemCallback(mDNS *const m, AuthRecord *const rr, mStatus result) +{ + (void)m; // unused + if (result == mStatus_MemFree) mDNSPlatformMemFree(rr->RecordContext); +} + +mDNSlocal void FoundDomain(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord) +{ + SearchListElem *slElem = question->QuestionContext; + mStatus err; + const char *name; + + if (answer->rrtype != kDNSType_PTR) return; + if (answer->RecordType == kDNSRecordTypePacketNegative) return; + if (answer->InterfaceID == mDNSInterface_LocalOnly) return; + + if (question == &slElem->BrowseQ) name = mDNS_DomainTypeNames[mDNS_DomainTypeBrowse]; + else if (question == &slElem->DefBrowseQ) name = mDNS_DomainTypeNames[mDNS_DomainTypeBrowseDefault]; + else if (question == &slElem->AutomaticBrowseQ) name = mDNS_DomainTypeNames[mDNS_DomainTypeBrowseAutomatic]; + else if (question == &slElem->RegisterQ) name = mDNS_DomainTypeNames[mDNS_DomainTypeRegistration]; + else if (question == &slElem->DefRegisterQ) name = mDNS_DomainTypeNames[mDNS_DomainTypeRegistrationDefault]; + else { LogMsg("FoundDomain - unknown question"); return; } + + LogInfo("FoundDomain: %p %s %s Q %##s A %s", answer->InterfaceID, AddRecord ? "Add" : "Rmv", name, question->qname.c, RRDisplayString(m, answer)); + + if (AddRecord) + { + ARListElem *arElem = mDNSPlatformMemAllocate(sizeof(ARListElem)); + if (!arElem) { LogMsg("ERROR: FoundDomain out of memory"); return; } + mDNS_SetupResourceRecord(&arElem->ar, mDNSNULL, mDNSInterface_LocalOnly, kDNSType_PTR, 7200, kDNSRecordTypeShared, AuthRecordLocalOnly, FreeARElemCallback, arElem); + MakeDomainNameFromDNSNameString(&arElem->ar.namestorage, name); + AppendDNSNameString (&arElem->ar.namestorage, "local"); + AssignDomainName(&arElem->ar.resrec.rdata->u.name, &answer->rdata->u.name); + LogInfo("FoundDomain: Registering %s", ARDisplayString(m, &arElem->ar)); + err = mDNS_Register(m, &arElem->ar); + if (err) { LogMsg("ERROR: FoundDomain - mDNS_Register returned %d", err); mDNSPlatformMemFree(arElem); return; } + arElem->next = slElem->AuthRecs; + slElem->AuthRecs = arElem; + } + else + { + ARListElem **ptr = &slElem->AuthRecs; + while (*ptr) + { + if (SameDomainName(&(*ptr)->ar.resrec.rdata->u.name, &answer->rdata->u.name)) + { + ARListElem *dereg = *ptr; + *ptr = (*ptr)->next; + LogInfo("FoundDomain: Deregistering %s", ARDisplayString(m, &dereg->ar)); + err = mDNS_Deregister(m, &dereg->ar); + if (err) LogMsg("ERROR: FoundDomain - mDNS_Deregister returned %d", err); + // Memory will be freed in the FreeARElemCallback + } + else + ptr = &(*ptr)->next; + } + } +} + +#if APPLE_OSX_mDNSResponder && MACOSX_MDNS_MALLOC_DEBUGGING +mDNSexport void udns_validatelists(void *const v) +{ + mDNS *const m = v; + + NATTraversalInfo *n; + for (n = m->NATTraversals; n; n=n->next) + if (n->next == (NATTraversalInfo *)~0 || n->clientCallback == (NATTraversalClientCallback) ~0) + LogMemCorruption("m->NATTraversals: %p is garbage", n); + + DNSServer *d; + for (d = m->DNSServers; d; d=d->next) + if (d->next == (DNSServer *)~0 || d->teststate > DNSServer_Disabled) + LogMemCorruption("m->DNSServers: %p is garbage (%d)", d, d->teststate); + + DomainAuthInfo *info; + for (info = m->AuthInfoList; info; info = info->next) + if (info->next == (DomainAuthInfo *)~0) + LogMemCorruption("m->AuthInfoList: %p is garbage", info); + + HostnameInfo *hi; + for (hi = m->Hostnames; hi; hi = hi->next) + if (hi->next == (HostnameInfo *)~0 || hi->StatusCallback == (mDNSRecordCallback*)~0) + LogMemCorruption("m->Hostnames: %p is garbage", n); + + SearchListElem *ptr; + for (ptr = SearchList; ptr; ptr = ptr->next) + if (ptr->next == (SearchListElem *)~0 || ptr->AuthRecs == (void*)~0) + LogMemCorruption("SearchList: %p is garbage (%X)", ptr, ptr->AuthRecs); +} +#endif + +// This should probably move to the UDS daemon -- the concept of legacy clients and automatic registration / automatic browsing +// is really a UDS API issue, not something intrinsic to uDNS + +mDNSlocal void uDNS_DeleteWABQueries(mDNS *const m, SearchListElem *ptr, int delete) +{ + const char *name1 = mDNSNULL; + const char *name2 = mDNSNULL; + ARListElem **arList = &ptr->AuthRecs; + domainname namestorage1, namestorage2; + mStatus err; + + // "delete" parameter indicates the type of query. + switch (delete) + { + case UDNS_WAB_BROWSE_QUERY: + mDNS_StopGetDomains(m, &ptr->BrowseQ); + mDNS_StopGetDomains(m, &ptr->DefBrowseQ); + name1 = mDNS_DomainTypeNames[mDNS_DomainTypeBrowse]; + name2 = mDNS_DomainTypeNames[mDNS_DomainTypeBrowseDefault]; + break; + case UDNS_WAB_LBROWSE_QUERY: + mDNS_StopGetDomains(m, &ptr->AutomaticBrowseQ); + name1 = mDNS_DomainTypeNames[mDNS_DomainTypeBrowseAutomatic]; + break; + case UDNS_WAB_REG_QUERY: + mDNS_StopGetDomains(m, &ptr->RegisterQ); + mDNS_StopGetDomains(m, &ptr->DefRegisterQ); + name1 = mDNS_DomainTypeNames[mDNS_DomainTypeRegistration]; + name2 = mDNS_DomainTypeNames[mDNS_DomainTypeRegistrationDefault]; + break; + default: + LogMsg("uDNS_DeleteWABQueries: ERROR!! returning from default"); + return; + } + // When we get the results to the domain enumeration queries, we add a LocalOnly + // entry. For example, if we issue a domain enumeration query for b._dns-sd._udp.xxxx.com, + // and when we get a response, we add a LocalOnly entry b._dns-sd._udp.local whose RDATA + // points to what we got in the response. Locate the appropriate LocalOnly entries and delete + // them. + if (name1) + { + MakeDomainNameFromDNSNameString(&namestorage1, name1); + AppendDNSNameString(&namestorage1, "local"); + } + if (name2) + { + MakeDomainNameFromDNSNameString(&namestorage2, name2); + AppendDNSNameString(&namestorage2, "local"); + } + while (*arList) + { + ARListElem *dereg = *arList; + if ((name1 && SameDomainName(&dereg->ar.namestorage, &namestorage1)) || + (name2 && SameDomainName(&dereg->ar.namestorage, &namestorage2))) + { + LogInfo("uDNS_DeleteWABQueries: Deregistering PTR %##s -> %##s", dereg->ar.resrec.name->c, dereg->ar.resrec.rdata->u.name.c); + *arList = dereg->next; + err = mDNS_Deregister(m, &dereg->ar); + if (err) LogMsg("uDNS_DeleteWABQueries:: ERROR!! mDNS_Deregister returned %d", err); + // Memory will be freed in the FreeARElemCallback + } + else + { + LogInfo("uDNS_DeleteWABQueries: Skipping PTR %##s -> %##s", dereg->ar.resrec.name->c, dereg->ar.resrec.rdata->u.name.c); + arList = &(*arList)->next; + } + } +} + +mDNSexport void uDNS_SetupWABQueries(mDNS *const m) +{ + SearchListElem **p = &SearchList, *ptr; + mStatus err; + int action = 0; + + // step 1: mark each element for removal + for (ptr = SearchList; ptr; ptr = ptr->next) + ptr->flag |= SLE_DELETE; + + // Make sure we have the search domains from the platform layer so that if we start the WAB + // queries below, we have the latest information. + mDNS_Lock(m); + if (!mDNSPlatformSetDNSConfig(m, mDNSfalse, mDNStrue, mDNSNULL, mDNSNULL, mDNSNULL, mDNSfalse)) + { + // If the configuration did not change, clear the flag so that we don't free the searchlist. + // We still have to start the domain enumeration queries as we may not have started them + // before. + for (ptr = SearchList; ptr; ptr = ptr->next) + ptr->flag &= ~SLE_DELETE; + LogInfo("uDNS_SetupWABQueries: No config change"); + } + mDNS_Unlock(m); + + if (m->WABBrowseQueriesCount) + action |= UDNS_WAB_BROWSE_QUERY; + if (m->WABLBrowseQueriesCount) + action |= UDNS_WAB_LBROWSE_QUERY; + if (m->WABRegQueriesCount) + action |= UDNS_WAB_REG_QUERY; + + + // delete elems marked for removal, do queries for elems marked add + while (*p) + { + ptr = *p; + LogInfo("uDNS_SetupWABQueries:action 0x%x: Flags 0x%x, AuthRecs %p, InterfaceID %p %##s", action, ptr->flag, ptr->AuthRecs, ptr->InterfaceID, ptr->domain.c); + // If SLE_DELETE is set, stop all the queries, deregister all the records and free the memory. + // Otherwise, check to see what the "action" requires. If a particular action bit is not set and + // we have started the corresponding queries as indicated by the "flags", stop those queries and + // deregister the records corresponding to them. + if ((ptr->flag & SLE_DELETE) || + (!(action & UDNS_WAB_BROWSE_QUERY) && (ptr->flag & SLE_WAB_BROWSE_QUERY_STARTED)) || + (!(action & UDNS_WAB_LBROWSE_QUERY) && (ptr->flag & SLE_WAB_LBROWSE_QUERY_STARTED)) || + (!(action & UDNS_WAB_REG_QUERY) && (ptr->flag & SLE_WAB_REG_QUERY_STARTED))) + { + if (ptr->flag & SLE_DELETE) + { + ARListElem *arList = ptr->AuthRecs; + ptr->AuthRecs = mDNSNULL; + *p = ptr->next; + + // If the user has "local" in their DNS searchlist, we ignore that for the purposes of domain enumeration queries + // We suppressed the domain enumeration for scoped search domains below. When we enable that + // enable this. + if ((ptr->flag & SLE_WAB_BROWSE_QUERY_STARTED) && + !SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) + { + LogInfo("uDNS_SetupWABQueries: DELETE Browse for domain %##s", ptr->domain.c); + mDNS_StopGetDomains(m, &ptr->BrowseQ); + mDNS_StopGetDomains(m, &ptr->DefBrowseQ); + } + if ((ptr->flag & SLE_WAB_LBROWSE_QUERY_STARTED) && + !SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) + { + LogInfo("uDNS_SetupWABQueries: DELETE Legacy Browse for domain %##s", ptr->domain.c); + mDNS_StopGetDomains(m, &ptr->AutomaticBrowseQ); + } + if ((ptr->flag & SLE_WAB_REG_QUERY_STARTED) && + !SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) + { + LogInfo("uDNS_SetupWABQueries: DELETE Registration for domain %##s", ptr->domain.c); + mDNS_StopGetDomains(m, &ptr->RegisterQ); + mDNS_StopGetDomains(m, &ptr->DefRegisterQ); + } + + mDNSPlatformMemFree(ptr); + + // deregister records generated from answers to the query + while (arList) + { + ARListElem *dereg = arList; + arList = arList->next; + LogInfo("uDNS_SetupWABQueries: DELETE Deregistering PTR %##s -> %##s", dereg->ar.resrec.name->c, dereg->ar.resrec.rdata->u.name.c); + err = mDNS_Deregister(m, &dereg->ar); + if (err) LogMsg("uDNS_SetupWABQueries:: ERROR!! mDNS_Deregister returned %d", err); + // Memory will be freed in the FreeARElemCallback + } + continue; + } + + // If the user has "local" in their DNS searchlist, we ignore that for the purposes of domain enumeration queries + // We suppressed the domain enumeration for scoped search domains below. When we enable that + // enable this. + if (!(action & UDNS_WAB_BROWSE_QUERY) && (ptr->flag & SLE_WAB_BROWSE_QUERY_STARTED) && + !SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) + { + LogInfo("uDNS_SetupWABQueries: Deleting Browse for domain %##s", ptr->domain.c); + ptr->flag &= ~SLE_WAB_BROWSE_QUERY_STARTED; + uDNS_DeleteWABQueries(m, ptr, UDNS_WAB_BROWSE_QUERY); + } + + if (!(action & UDNS_WAB_LBROWSE_QUERY) && (ptr->flag & SLE_WAB_LBROWSE_QUERY_STARTED) && + !SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) + { + LogInfo("uDNS_SetupWABQueries: Deleting Legacy Browse for domain %##s", ptr->domain.c); + ptr->flag &= ~SLE_WAB_LBROWSE_QUERY_STARTED; + uDNS_DeleteWABQueries(m, ptr, UDNS_WAB_LBROWSE_QUERY); + } + + if (!(action & UDNS_WAB_REG_QUERY) && (ptr->flag & SLE_WAB_REG_QUERY_STARTED) && + !SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) + { + LogInfo("uDNS_SetupWABQueries: Deleting Registration for domain %##s", ptr->domain.c); + ptr->flag &= ~SLE_WAB_REG_QUERY_STARTED; + uDNS_DeleteWABQueries(m, ptr, UDNS_WAB_REG_QUERY); + } + + // Fall through to handle the ADDs + } + + if ((action & UDNS_WAB_BROWSE_QUERY) && !(ptr->flag & SLE_WAB_BROWSE_QUERY_STARTED)) + { + // If the user has "local" in their DNS searchlist, we ignore that for the purposes of domain enumeration queries. + // Also, suppress the domain enumeration for scoped search domains for now until there is a need. + if (!SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) + { + mStatus err1, err2; + err1 = mDNS_GetDomains(m, &ptr->BrowseQ, mDNS_DomainTypeBrowse, &ptr->domain, ptr->InterfaceID, FoundDomain, ptr); + if (err1) + { + LogMsg("uDNS_SetupWABQueries: GetDomains for domain %##s returned error(s):\n" + "%d (mDNS_DomainTypeBrowse)\n", ptr->domain.c, err1); + } + else + { + LogInfo("uDNS_SetupWABQueries: Starting Browse for domain %##s", ptr->domain.c); + } + err2 = mDNS_GetDomains(m, &ptr->DefBrowseQ, mDNS_DomainTypeBrowseDefault, &ptr->domain, ptr->InterfaceID, FoundDomain, ptr); + if (err2) + { + LogMsg("uDNS_SetupWABQueries: GetDomains for domain %##s returned error(s):\n" + "%d (mDNS_DomainTypeBrowseDefault)\n", ptr->domain.c, err2); + } + else + { + LogInfo("uDNS_SetupWABQueries: Starting Default Browse for domain %##s", ptr->domain.c); + } + // For simplicity, we mark a single bit for denoting that both the browse queries have started. + // It is not clear as to why one would fail to start and the other would succeed in starting up. + // If that happens, we will try to stop both the queries and one of them won't be in the list and + // it is not a hard error. + if (!err1 || !err2) + { + ptr->flag |= SLE_WAB_BROWSE_QUERY_STARTED; + } + } + } + if ((action & UDNS_WAB_LBROWSE_QUERY) && !(ptr->flag & SLE_WAB_LBROWSE_QUERY_STARTED)) + { + // If the user has "local" in their DNS searchlist, we ignore that for the purposes of domain enumeration queries. + // Also, suppress the domain enumeration for scoped search domains for now until there is a need. + if (!SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) + { + mStatus err1; + err1 = mDNS_GetDomains(m, &ptr->AutomaticBrowseQ, mDNS_DomainTypeBrowseAutomatic, &ptr->domain, ptr->InterfaceID, FoundDomain, ptr); + if (err1) + { + LogMsg("uDNS_SetupWABQueries: GetDomains for domain %##s returned error(s):\n" + "%d (mDNS_DomainTypeBrowseAutomatic)\n", + ptr->domain.c, err1); + } + else + { + ptr->flag |= SLE_WAB_LBROWSE_QUERY_STARTED; + LogInfo("uDNS_SetupWABQueries: Starting Legacy Browse for domain %##s", ptr->domain.c); + } + } + } + if ((action & UDNS_WAB_REG_QUERY) && !(ptr->flag & SLE_WAB_REG_QUERY_STARTED)) + { + // If the user has "local" in their DNS searchlist, we ignore that for the purposes of domain enumeration queries. + // Also, suppress the domain enumeration for scoped search domains for now until there is a need. + if (!SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) + { + mStatus err1, err2; + err1 = mDNS_GetDomains(m, &ptr->RegisterQ, mDNS_DomainTypeRegistration, &ptr->domain, ptr->InterfaceID, FoundDomain, ptr); + if (err1) + { + LogMsg("uDNS_SetupWABQueries: GetDomains for domain %##s returned error(s):\n" + "%d (mDNS_DomainTypeRegistration)\n", ptr->domain.c, err1); + } + else + { + LogInfo("uDNS_SetupWABQueries: Starting Registration for domain %##s", ptr->domain.c); + } + err2 = mDNS_GetDomains(m, &ptr->DefRegisterQ, mDNS_DomainTypeRegistrationDefault, &ptr->domain, ptr->InterfaceID, FoundDomain, ptr); + if (err2) + { + LogMsg("uDNS_SetupWABQueries: GetDomains for domain %##s returned error(s):\n" + "%d (mDNS_DomainTypeRegistrationDefault)", ptr->domain.c, err2); + } + else + { + LogInfo("uDNS_SetupWABQueries: Starting Default Registration for domain %##s", ptr->domain.c); + } + if (!err1 || !err2) + { + ptr->flag |= SLE_WAB_REG_QUERY_STARTED; + } + } + } + + p = &ptr->next; + } +} + +// mDNS_StartWABQueries is called once per API invocation where normally +// one of the bits is set. +mDNSexport void uDNS_StartWABQueries(mDNS *const m, int queryType) +{ + if (queryType & UDNS_WAB_BROWSE_QUERY) + { + m->WABBrowseQueriesCount++; + LogInfo("uDNS_StartWABQueries: Browse query count %d", m->WABBrowseQueriesCount); + } + if (queryType & UDNS_WAB_LBROWSE_QUERY) + { + m->WABLBrowseQueriesCount++; + LogInfo("uDNS_StartWABQueries: Legacy Browse query count %d", m->WABLBrowseQueriesCount); + } + if (queryType & UDNS_WAB_REG_QUERY) + { + m->WABRegQueriesCount++; + LogInfo("uDNS_StartWABQueries: Reg query count %d", m->WABRegQueriesCount); + } + uDNS_SetupWABQueries(m); +} + +// mDNS_StopWABQueries is called once per API invocation where normally +// one of the bits is set. +mDNSexport void uDNS_StopWABQueries(mDNS *const m, int queryType) +{ + if (queryType & UDNS_WAB_BROWSE_QUERY) + { + m->WABBrowseQueriesCount--; + LogInfo("uDNS_StopWABQueries: Browse query count %d", m->WABBrowseQueriesCount); + } + if (queryType & UDNS_WAB_LBROWSE_QUERY) + { + m->WABLBrowseQueriesCount--; + LogInfo("uDNS_StopWABQueries: Legacy Browse query count %d", m->WABLBrowseQueriesCount); + } + if (queryType & UDNS_WAB_REG_QUERY) + { + m->WABRegQueriesCount--; + LogInfo("uDNS_StopWABQueries: Reg query count %d", m->WABRegQueriesCount); + } + uDNS_SetupWABQueries(m); +} + +mDNSexport domainname *uDNS_GetNextSearchDomain(mDNS *const m, mDNSInterfaceID InterfaceID, mDNSs8 *searchIndex, mDNSBool ignoreDotLocal) +{ + SearchListElem *p = SearchList; + int count = *searchIndex; + (void) m; // unused + + if (count < 0) { LogMsg("uDNS_GetNextSearchDomain: count %d less than zero", count); return mDNSNULL; } + + // Skip the domains that we already looked at before. Guard against "p" + // being NULL. When search domains change we may not set the SearchListIndex + // of the question to zero immediately e.g., domain enumeration query calls + // uDNS_SetupWABQueries which reads in the new search domain but does not + // restart the questions immediately. Questions are restarted as part of + // network change and hence temporarily SearchListIndex may be out of range. + + for (; count && p; count--) + p = p->next; + + while (p) + { + int labels = CountLabels(&p->domain); + if (labels > 0) + { + const domainname *d = SkipLeadingLabels(&p->domain, labels - 1); + if (SameDomainLabel(d->c, (const mDNSu8 *)"\x4" "arpa")) + { + LogInfo("uDNS_GetNextSearchDomain: skipping search domain %##s, InterfaceID %p", p->domain.c, p->InterfaceID); + (*searchIndex)++; + p = p->next; + continue; + } + if (ignoreDotLocal && SameDomainLabel(d->c, (const mDNSu8 *)"\x5" "local")) + { + LogInfo("uDNS_GetNextSearchDomain: skipping local domain %##s, InterfaceID %p", p->domain.c, p->InterfaceID); + (*searchIndex)++; + p = p->next; + continue; + } + } + // Point to the next one in the list which we will look at next time. + (*searchIndex)++; + // When we are appending search domains in a ActiveDirectory domain, the question's InterfaceID + // set to mDNSInterface_Unicast. Match the unscoped entries in that case. + if (((InterfaceID == mDNSInterface_Unicast) && (p->InterfaceID == mDNSInterface_Any)) || + p->InterfaceID == InterfaceID) + { + LogInfo("uDNS_GetNextSearchDomain returning domain %##s, InterfaceID %p", p->domain.c, p->InterfaceID); + return &p->domain; + } + LogInfo("uDNS_GetNextSearchDomain skipping domain %##s, InterfaceID %p", p->domain.c, p->InterfaceID); + p = p->next; + } + return mDNSNULL; +} + +mDNSlocal void FlushAddressCacheRecords(mDNS *const m) +{ + mDNSu32 slot; + CacheGroup *cg; + CacheRecord *cr; + FORALL_CACHERECORDS(slot, cg, cr) + { + if (cr->resrec.InterfaceID) continue; + + // If a resource record can answer A or AAAA, they need to be flushed so that we will + // deliver an ADD or RMV + if (RRTypeAnswersQuestionType(&cr->resrec, kDNSType_A) || + RRTypeAnswersQuestionType(&cr->resrec, kDNSType_AAAA)) + { + LogInfo("FlushAddressCacheRecords: Purging Resourcerecord %s", CRDisplayString(m, cr)); + mDNS_PurgeCacheResourceRecord(m, cr); + } + } +} + +// Retry questions which has seach domains appended +mDNSexport void RetrySearchDomainQuestions(mDNS *const m) +{ + DNSQuestion *q; + mDNSBool found = mDNSfalse; + + // Check to see if there are any questions which needs search domains to be applied. + // If there is none, search domains can't possibly affect them. + for (q = m->Questions; q; q = q->next) + { + if (q->AppendSearchDomains) + { + found = mDNStrue; + break; + } + } + if (!found) + { + LogInfo("RetrySearchDomainQuestions: Questions with AppendSearchDomain not found"); + return; + } + LogInfo("RetrySearchDomainQuestions: Question with AppendSearchDomain found %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); + // Purge all the A/AAAA cache records and restart the queries. mDNSCoreRestartAddressQueries + // does this. When we restart the question, we first want to try the new search domains rather + // than use the entries that is already in the cache. When we appended search domains, we might + // have created cache entries which is no longer valid as there are new search domains now + mDNSCoreRestartAddressQueries(m, mDNStrue, FlushAddressCacheRecords, mDNSNULL, mDNSNULL); +} + +// Construction of Default Browse domain list (i.e. when clients pass NULL) is as follows: +// 1) query for b._dns-sd._udp.local on LocalOnly interface +// (.local manually generated via explicit callback) +// 2) for each search domain (from prefs pane), query for b._dns-sd._udp.<searchdomain>. +// 3) for each result from (2), register LocalOnly PTR record b._dns-sd._udp.local. -> <result> +// 4) result above should generate a callback from question in (1). result added to global list +// 5) global list delivered to client via GetSearchDomainList() +// 6) client calls to enumerate domains now go over LocalOnly interface +// (!!!KRS may add outgoing interface in addition) + +struct CompileTimeAssertionChecks_uDNS +{ + // Check our structures are reasonable sizes. Including overly-large buffers, or embedding + // other overly-large structures instead of having a pointer to them, can inadvertently + // cause structure sizes (and therefore memory usage) to balloon unreasonably. + char sizecheck_tcpInfo_t [(sizeof(tcpInfo_t) <= 9056) ? 1 : -1]; + char sizecheck_SearchListElem[(sizeof(SearchListElem) <= 5000) ? 1 : -1]; +}; + +#else // !UNICAST_DISABLED + +mDNSexport const domainname *GetServiceTarget(mDNS *m, AuthRecord *const rr) +{ + (void) m; + (void) rr; + + return mDNSNULL; +} + +mDNSexport DomainAuthInfo *GetAuthInfoForName_internal(mDNS *m, const domainname *const name) +{ + (void) m; + (void) name; + + return mDNSNULL; +} + +mDNSexport DomainAuthInfo *GetAuthInfoForQuestion(mDNS *m, const DNSQuestion *const q) +{ + (void) m; + (void) q; + + return mDNSNULL; +} + +mDNSexport void startLLQHandshake(mDNS *m, DNSQuestion *q) +{ + (void) m; + (void) q; +} + +mDNSexport void DisposeTCPConn(struct tcpInfo_t *tcp) +{ + (void) tcp; +} + +mDNSexport mStatus mDNS_StartNATOperation_internal(mDNS *m, NATTraversalInfo *traversal) +{ + (void) m; + (void) traversal; + + return mStatus_UnsupportedErr; +} + +mDNSexport mStatus mDNS_StopNATOperation_internal(mDNS *m, NATTraversalInfo *traversal) +{ + (void) m; + (void) traversal; + + return mStatus_UnsupportedErr; +} + +mDNSexport void sendLLQRefresh(mDNS *m, DNSQuestion *q) +{ + (void) m; + (void) q; +} + +mDNSexport ZoneData *StartGetZoneData(mDNS *const m, const domainname *const name, const ZoneService target, ZoneDataCallback callback, void *ZoneDataContext) +{ + (void) m; + (void) name; + (void) target; + (void) callback; + (void) ZoneDataContext; + + return mDNSNULL; +} + +mDNSexport void RecordRegistrationGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneData) +{ + (void) m; + (void) err; + (void) zoneData; +} + +mDNSexport uDNS_LLQType uDNS_recvLLQResponse(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, + const mDNSAddr *const srcaddr, const mDNSIPPort srcport, DNSQuestion **matchQuestion) +{ + (void) m; + (void) msg; + (void) end; + (void) srcaddr; + (void) srcport; + (void) matchQuestion; + + return uDNS_LLQ_Not; +} + +mDNSexport void PenalizeDNSServer(mDNS *const m, DNSQuestion *q, mDNSOpaque16 responseFlags) +{ + (void) m; + (void) q; + (void) responseFlags; +} + +mDNSexport void mDNS_AddSearchDomain(const domainname *const domain, mDNSInterfaceID InterfaceID) +{ + (void) domain; + (void) InterfaceID; +} + +mDNSexport void RetrySearchDomainQuestions(mDNS *const m) +{ + (void) m; +} + +mDNSexport mStatus mDNS_SetSecretForDomain(mDNS *m, DomainAuthInfo *info, const domainname *domain, const domainname *keyname, const char *b64keydata, const domainname *hostname, mDNSIPPort *port, mDNSBool autoTunnel) +{ + (void) m; + (void) info; + (void) domain; + (void) keyname; + (void) b64keydata; + (void) hostname; + (void) port; + (void) autoTunnel; + + return mStatus_UnsupportedErr; +} + +mDNSexport domainname *uDNS_GetNextSearchDomain(mDNS *const m, mDNSInterfaceID InterfaceID, mDNSs8 *searchIndex, mDNSBool ignoreDotLocal) +{ + (void) m; + (void) InterfaceID; + (void) searchIndex; + (void) ignoreDotLocal; + + return mDNSNULL; +} + +mDNSexport DomainAuthInfo *GetAuthInfoForName(mDNS *m, const domainname *const name) +{ + (void) m; + (void) name; + + return mDNSNULL; +} + +mDNSexport mStatus mDNS_StartNATOperation(mDNS *const m, NATTraversalInfo *traversal) +{ + (void) m; + (void) traversal; + + return mStatus_UnsupportedErr; +} + +mDNSexport mStatus mDNS_StopNATOperation(mDNS *const m, NATTraversalInfo *traversal) +{ + (void) m; + (void) traversal; + + return mStatus_UnsupportedErr; +} + +mDNSexport DNSServer *mDNS_AddDNSServer(mDNS *const m, const domainname *d, const mDNSInterfaceID interface, const mDNSs32 serviceID, const mDNSAddr *addr, + const mDNSIPPort port, mDNSu32 scoped, mDNSu32 timeout, mDNSBool cellIntf, mDNSu16 resGroupID, mDNSBool reqA, + mDNSBool reqAAAA, mDNSBool reqDO) +{ + (void) m; + (void) d; + (void) interface; + (void) serviceID; + (void) addr; + (void) port; + (void) scoped; + (void) timeout; + (void) cellIntf; + (void) resGroupID; + (void) reqA; + (void) reqAAAA; + (void) reqDO; + + return mDNSNULL; +} + +mDNSexport void uDNS_SetupWABQueries(mDNS *const m) +{ + (void) m; +} + +mDNSexport void uDNS_StartWABQueries(mDNS *const m, int queryType) +{ + (void) m; + (void) queryType; +} + +mDNSexport void uDNS_StopWABQueries(mDNS *const m, int queryType) +{ + (void) m; + (void) queryType; +} + +mDNSexport void mDNS_AddDynDNSHostName(mDNS *m, const domainname *fqdn, mDNSRecordCallback *StatusCallback, const void *StatusContext) +{ + (void) m; + (void) fqdn; + (void) StatusCallback; + (void) StatusContext; +} +mDNSexport void mDNS_SetPrimaryInterfaceInfo(mDNS *m, const mDNSAddr *v4addr, const mDNSAddr *v6addr, const mDNSAddr *router) +{ + (void) m; + (void) v4addr; + (void) v6addr; + (void) router; +} + +mDNSexport void mDNS_RemoveDynDNSHostName(mDNS *m, const domainname *fqdn) +{ + (void) m; + (void) fqdn; +} + +mDNSexport void RecreateNATMappings(mDNS *const m, const mDNSu32 waitTicks) +{ + (void) m; + (void) waitTicks; +} + +mDNSexport mDNSBool IsGetZoneDataQuestion(DNSQuestion *q) +{ + (void)q; + + return mDNSfalse; +} + +#endif // !UNICAST_DISABLED |