diff options
Diffstat (limited to 'mDNSResponder/mDNSPosix/Identify.c')
| -rw-r--r-- | mDNSResponder/mDNSPosix/Identify.c | 376 |
1 files changed, 376 insertions, 0 deletions
diff --git a/mDNSResponder/mDNSPosix/Identify.c b/mDNSResponder/mDNSPosix/Identify.c new file mode 100644 index 00000000..003ac631 --- /dev/null +++ b/mDNSResponder/mDNSPosix/Identify.c @@ -0,0 +1,376 @@ +/* -*- Mode: C; tab-width: 4 -*- + * + * Copyright (c) 2002-2004 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. + * + */ + +//************************************************************************************************************* +// Incorporate mDNS.c functionality + +// We want to use the functionality provided by "mDNS.c", +// except we'll sneak a peek at the packets before forwarding them to the normal mDNSCoreReceive() routine +#define mDNSCoreReceive __MDNS__mDNSCoreReceive +#include "mDNS.c" +#undef mDNSCoreReceive + +//************************************************************************************************************* +// Headers + +#include <unistd.h> +#include <stdio.h> +#include <string.h> +#include <errno.h> +#include <sys/socket.h> +#include <netinet/in.h> +#include <netinet/in_systm.h> // For n_long, required by <netinet/ip.h> below +#include <netinet/ip.h> // For IPTOS_LOWDELAY etc. +#include <arpa/inet.h> +#include <signal.h> + +#include "mDNSEmbeddedAPI.h" // Defines the interface to the mDNS core code +#include "mDNSPosix.h" // Defines the specific types needed to run mDNS on this platform +#include "ExampleClientApp.h" + +//************************************************************************************************************* +// Globals + +static mDNS mDNSStorage; // mDNS core uses this to store its globals +static mDNS_PlatformSupport PlatformStorage; // Stores this platform's globals +#define RR_CACHE_SIZE 500 +static CacheEntity gRRCache[RR_CACHE_SIZE]; +mDNSexport const char ProgramName[] = "mDNSIdentify"; + +static volatile int StopNow; // 0 means running, 1 means stop because we got an answer, 2 means stop because of Ctrl-C +static volatile int NumAnswers, NumAddr, NumAAAA, NumHINFO; +static char hostname[MAX_ESCAPED_DOMAIN_NAME], hardware[256], software[256]; +static mDNSAddr lastsrc, hostaddr, target; +static mDNSOpaque16 lastid, id; + +//************************************************************************************************************* +// Utilities + +// Special version of printf that knows how to print IP addresses, DNS-format name strings, etc. +mDNSlocal mDNSu32 mprintf(const char *format, ...) IS_A_PRINTF_STYLE_FUNCTION(1,2); +mDNSlocal mDNSu32 mprintf(const char *format, ...) +{ + mDNSu32 length; + unsigned char buffer[512]; + va_list ptr; + va_start(ptr,format); + length = mDNS_vsnprintf((char *)buffer, sizeof(buffer), format, ptr); + va_end(ptr); + printf("%s", buffer); + return(length); +} + +//************************************************************************************************************* +// Main code + +mDNSexport void mDNSCoreReceive(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end, + const mDNSAddr *const srcaddr, const mDNSIPPort srcport, const mDNSAddr *const dstaddr, const mDNSIPPort dstport, + const mDNSInterfaceID InterfaceID) +{ + (void)dstaddr; // Unused + // Snag copy of header ID, then call through + lastid = msg->h.id; + lastsrc = *srcaddr; + + // We *want* to allow off-net unicast responses here. + // For now, the simplest way to allow that is to pretend it was received via multicast so that mDNSCore doesn't reject the packet + __MDNS__mDNSCoreReceive(m, msg, end, srcaddr, srcport, &AllDNSLinkGroup_v4, dstport, InterfaceID); +} + +mDNSlocal void NameCallback(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord) +{ + (void)m; // Unused + (void)question; // Unused + (void)AddRecord; // Unused + if (!id.NotAnInteger) id = lastid; + if (answer->rrtype == kDNSType_PTR || answer->rrtype == kDNSType_CNAME) + { + ConvertDomainNameToCString(&answer->rdata->u.name, hostname); + StopNow = 1; + mprintf("%##s %s %##s\n", answer->name->c, DNSTypeName(answer->rrtype), answer->rdata->u.name.c); + } +} + +mDNSlocal void InfoCallback(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord) +{ + (void)m; // Unused + (void)question; // Unused + (void)AddRecord; // Unused + if (answer->rrtype == kDNSType_A) + { + if (!id.NotAnInteger) id = lastid; + NumAnswers++; + NumAddr++; + mprintf("%##s %s %.4a\n", answer->name->c, DNSTypeName(answer->rrtype), &answer->rdata->u.ipv4); + hostaddr.type = mDNSAddrType_IPv4; // Prefer v4 target to v6 target, for now + hostaddr.ip.v4 = answer->rdata->u.ipv4; + } + else if (answer->rrtype == kDNSType_AAAA) + { + if (!id.NotAnInteger) id = lastid; + NumAnswers++; + NumAAAA++; + mprintf("%##s %s %.16a\n", answer->name->c, DNSTypeName(answer->rrtype), &answer->rdata->u.ipv6); + if (!hostaddr.type) // Prefer v4 target to v6 target, for now + { + hostaddr.type = mDNSAddrType_IPv6; + hostaddr.ip.v6 = answer->rdata->u.ipv6; + } + } + else if (answer->rrtype == kDNSType_HINFO) + { + mDNSu8 *p = answer->rdata->u.data; + strncpy(hardware, (char*)(p+1), p[0]); + hardware[p[0]] = 0; + p += 1 + p[0]; + strncpy(software, (char*)(p+1), p[0]); + software[p[0]] = 0; + NumAnswers++; + NumHINFO++; + } + + // If we've got everything we're looking for, don't need to wait any more + if (/*NumHINFO && */ (NumAddr || NumAAAA)) StopNow = 1; +} + +mDNSlocal void ServicesCallback(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord) +{ + (void)m; // Unused + (void)question; // Unused + (void)AddRecord; // Unused + // Right now the mDNSCore targeted-query code is incomplete -- + // it issues targeted queries, but accepts answers from anywhere + // For now, we'll just filter responses here so we don't get confused by responses from someone else + if (answer->rrtype == kDNSType_PTR && mDNSSameAddress(&lastsrc, &target)) + { + NumAnswers++; + mprintf("%##s %s %##s\n", answer->name->c, DNSTypeName(answer->rrtype), answer->rdata->u.name.c); + } +} + +mDNSlocal void WaitForAnswer(mDNS *const m, int seconds) +{ + struct timeval end; + gettimeofday(&end, NULL); + end.tv_sec += seconds; + StopNow = 0; + NumAnswers = 0; + while (!StopNow) + { + int nfds = 0; + fd_set readfds; + struct timeval now, remain = end; + int result; + + FD_ZERO(&readfds); + gettimeofday(&now, NULL); + if (remain.tv_usec < now.tv_usec) { remain.tv_usec += 1000000; remain.tv_sec--; } + if (remain.tv_sec < now.tv_sec) + { + if (!NumAnswers) printf("No response after %d seconds\n", seconds); + return; + } + remain.tv_usec -= now.tv_usec; + remain.tv_sec -= now.tv_sec; + mDNSPosixGetFDSet(m, &nfds, &readfds, &remain); + result = select(nfds, &readfds, NULL, NULL, &remain); + if (result >= 0) mDNSPosixProcessFDSet(m, &readfds); + else if (errno != EINTR) StopNow = 2; + } +} + +mDNSlocal mStatus StartQuery(DNSQuestion *q, char *qname, mDNSu16 qtype, const mDNSAddr *target, mDNSQuestionCallback callback) +{ + lastsrc = zeroAddr; + if (qname) MakeDomainNameFromDNSNameString(&q->qname, qname); + q->InterfaceID = mDNSInterface_Any; + q->flags = 0; + q->Target = target ? *target : zeroAddr; + q->TargetPort = MulticastDNSPort; + q->TargetQID = zeroID; + q->qtype = qtype; + q->qclass = kDNSClass_IN; + q->LongLived = mDNSfalse; + q->ExpectUnique = mDNSfalse; // Don't want to stop after the first response packet + q->ForceMCast = mDNStrue; // Query via multicast, even for apparently uDNS names like 1.1.1.17.in-addr.arpa. + q->ReturnIntermed = mDNStrue; + q->SuppressUnusable = mDNSfalse; + q->SearchListIndex = 0; + q->AppendSearchDomains = 0; + q->RetryWithSearchDomains = mDNSfalse; + q->TimeoutQuestion = 0; + q->ValidationRequired = 0; + q->ValidatingResponse = 0; + q->WakeOnResolve = 0; + q->UseBackgroundTrafficClass = mDNSfalse; + q->ProxyQuestion = 0; + q->qnameOrig = mDNSNULL; + q->AnonInfo = mDNSNULL; + q->pid = mDNSPlatformGetPID(); + q->QuestionCallback = callback; + q->QuestionContext = NULL; + + //mprintf("%##s %s ?\n", q->qname.c, DNSTypeName(qtype)); + return(mDNS_StartQuery(&mDNSStorage, q)); +} + +mDNSlocal void DoOneQuery(DNSQuestion *q, char *qname, mDNSu16 qtype, const mDNSAddr *target, mDNSQuestionCallback callback) +{ + mStatus status = StartQuery(q, qname, qtype, target, callback); + if (status != mStatus_NoError) + StopNow = 2; + else + { + WaitForAnswer(&mDNSStorage, 4); + mDNS_StopQuery(&mDNSStorage, q); + } +} + +mDNSlocal int DoQuery(DNSQuestion *q, char *qname, mDNSu16 qtype, const mDNSAddr *target, mDNSQuestionCallback callback) +{ + DoOneQuery(q, qname, qtype, target, callback); + if (StopNow == 0 && NumAnswers == 0 && target && target->type) + { + mprintf("%##s %s Trying multicast\n", q->qname.c, DNSTypeName(q->qtype)); + DoOneQuery(q, qname, qtype, NULL, callback); + } + if (StopNow == 0 && NumAnswers == 0) + mprintf("%##s %s *** No Answer ***\n", q->qname.c, DNSTypeName(q->qtype)); + return(StopNow); +} + +mDNSlocal void HandleSIG(int signal) +{ + (void)signal; // Unused + debugf("%s",""); + debugf("HandleSIG"); + StopNow = 2; +} + +mDNSexport int main(int argc, char **argv) +{ + const char *progname = strrchr(argv[0], '/') ? strrchr(argv[0], '/') + 1 : argv[0]; + int this_arg = 1; + mStatus status; + struct in_addr s4; +#if HAVE_IPV6 + struct in6_addr s6; +#endif + char buffer[256]; + DNSQuestion q; + + if (argc < 2) goto usage; + + // Since this is a special command-line tool, we want LogMsg() errors to go to stderr, not syslog + mDNS_DebugMode = mDNStrue; + + // Initialise the mDNS core. + status = mDNS_Init(&mDNSStorage, &PlatformStorage, + gRRCache, RR_CACHE_SIZE, + mDNS_Init_DontAdvertiseLocalAddresses, + mDNS_Init_NoInitCallback, mDNS_Init_NoInitCallbackContext); + if (status) { fprintf(stderr, "Daemon start: mDNS_Init failed %d\n", (int)status); return(status); } + + signal(SIGINT, HandleSIG); // SIGINT is what you get for a Ctrl-C + signal(SIGTERM, HandleSIG); + + while (this_arg < argc) + { + char *arg = argv[this_arg++]; + if (this_arg > 2) printf("\n"); + + lastid = id = zeroID; + hostaddr = target = zeroAddr; + hostname[0] = hardware[0] = software[0] = 0; + NumAddr = NumAAAA = NumHINFO = 0; + + if (inet_pton(AF_INET, arg, &s4) == 1) + { + mDNSu8 *p = (mDNSu8 *)&s4; + // 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(buffer, sizeof(buffer), "%d.%d.%d.%d.in-addr.arpa.", p[3], p[2], p[1], p[0]); + printf("%s\n", buffer); + target.type = mDNSAddrType_IPv4; + target.ip.v4.NotAnInteger = s4.s_addr; + DoQuery(&q, buffer, kDNSType_PTR, &target, NameCallback); + if (StopNow == 2) break; + } +#if HAVE_IPV6 + else if (inet_pton(AF_INET6, arg, &s6) == 1) + { + int i; + mDNSu8 *p = (mDNSu8 *)&s6; + for (i = 0; i < 16; i++) + { + static const char hexValues[] = "0123456789ABCDEF"; + buffer[i * 4 ] = hexValues[p[15-i] & 0x0F]; + buffer[i * 4 + 1] = '.'; + buffer[i * 4 + 2] = hexValues[p[15-i] >> 4]; + buffer[i * 4 + 3] = '.'; + } + mDNS_snprintf(&buffer[64], sizeof(buffer)-64, "ip6.arpa."); + target.type = mDNSAddrType_IPv6; + mDNSPlatformMemCopy(&target.ip.v6, &s6, sizeof(target.ip.v6)); + DoQuery(&q, buffer, kDNSType_PTR, &target, NameCallback); + if (StopNow == 2) break; + } +#endif + else { + if (strlen(arg) >= sizeof(hostname)) { + fprintf(stderr, "hostname must be < %d characters\n", (int)sizeof(hostname)); + goto usage; + } + strcpy(hostname, arg); + } + + // Now we have the host name; get its A, AAAA, and HINFO + if (hostname[0]) DoQuery(&q, hostname, kDNSQType_ANY, &target, InfoCallback); + if (StopNow == 2) break; + + if (hardware[0] || software[0]) + { + printf("HINFO Hardware: %s\n", hardware); + printf("HINFO Software: %s\n", software); + } + else if (NumAnswers) printf("%s has no HINFO record\n", hostname); + else printf("Incorrect dot-local hostname, address, or no mDNSResponder running on that machine\n"); + + if (NumAnswers) + { + // Because of the way we use lastsrc in ServicesCallback, we need to clear the cache to make sure we're getting fresh answers + mDNS *const m = &mDNSStorage; + mDNSu32 slot; + CacheGroup *cg; + CacheRecord *rr; + FORALL_CACHERECORDS(slot, cg, rr) + { + mDNS_PurgeCacheResourceRecord(m, rr); + } + if (target.type == 0) target = hostaddr; // Make sure the services query is targeted + DoQuery(&q, "_services._dns-sd._udp.local.", kDNSType_PTR, &target, ServicesCallback); + if (StopNow == 2) break; + } + } + + mDNS_Close(&mDNSStorage); + return(0); + +usage: + fprintf(stderr, "Usage: %s <dot-local hostname> or <IPv4 address> or <IPv6 address> ...\n", progname); + return(-1); +} |