/* -*- 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. */ #include // For printf() #include // For exit() etc. #include // For strlen() etc. #include // For select() #include // For SIGINT, SIGTERM #include // For errno, EINTR #include // For INADDR_NONE #include // For inet_addr() #include // For gethostbyname() #include "mDNSEmbeddedAPI.h" // Defines the interface to the client layer above #include "mDNSPosix.h" // Defines the specific types needed to run mDNS on this platform #include "ExampleClientApp.h" // Compatibility workaround: Solaris 2.5 has no INADDR_NONE #ifndef INADDR_NONE #define INADDR_NONE (mDNSu32)0xffffffff #endif //************************************************************************************************************* // Globals static mDNS mDNSStorage; // mDNS core uses this to store its globals static mDNS_PlatformSupport PlatformStorage; // Stores this platform's globals mDNSexport const char ProgramName[] = "mDNSProxyResponderPosix"; //************************************************************************************************************* // Proxy Host Registration typedef struct { mDNSv4Addr ip; domainlabel hostlabel; // Conforms to standard DNS letter-digit-hyphen host name rules AuthRecord RR_A; // 'A' (address) record for our ".local" name AuthRecord RR_PTR; // PTR (reverse lookup) record } ProxyHost; mDNSlocal void HostNameCallback(mDNS *const m, AuthRecord *const rr, mStatus result) { ProxyHost *f = (ProxyHost*)rr->RecordContext; if (result == mStatus_NoError) debugf("Host name successfully registered: %##s", rr->resrec.name->c); else { debugf("Host name conflict for %##s", rr->resrec.name->c); mDNS_Deregister(m, &f->RR_A); mDNS_Deregister(m, &f->RR_PTR); exit(-1); } } mDNSlocal mStatus mDNS_RegisterProxyHost(mDNS *m, ProxyHost *p) { char buffer[32]; mDNS_SetupResourceRecord(&p->RR_A, mDNSNULL, mDNSInterface_Any, kDNSType_A, 60, kDNSRecordTypeUnique, AuthRecordAny, HostNameCallback, p); mDNS_SetupResourceRecord(&p->RR_PTR, mDNSNULL, mDNSInterface_Any, kDNSType_PTR, 60, kDNSRecordTypeKnownUnique, AuthRecordAny, HostNameCallback, p); p->RR_A.namestorage.c[0] = 0; AppendDomainLabel(&p->RR_A.namestorage, &p->hostlabel); AppendLiteralLabelString(&p->RR_A.namestorage, "local"); // 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->ip.b[3], p->ip.b[2], p->ip.b[1], p->ip.b[0]); MakeDomainNameFromDNSNameString(&p->RR_PTR.namestorage, buffer); p->RR_PTR.ForceMCast = mDNStrue; // This PTR points to our dot-local name, so don't ever try to write it into a uDNS server p->RR_A.resrec.rdata->u.ipv4 = p->ip; AssignDomainName(&p->RR_PTR.resrec.rdata->u.name, p->RR_A.resrec.name); mDNS_Register(m, &p->RR_A); mDNS_Register(m, &p->RR_PTR); debugf("Made Proxy Host Records for %##s", p->RR_A.resrec.name->c); return(mStatus_NoError); } //************************************************************************************************************* // Service Registration // This sample ServiceCallback just calls mDNS_RenameAndReregisterService to automatically pick a new // unique name for the service. For a device such as a printer, this may be appropriate. // For a device with a user interface, and a screen, and a keyboard, the appropriate // response may be to prompt the user and ask them to choose a new name for the service. mDNSlocal void ServiceCallback(mDNS *const m, ServiceRecordSet *const sr, mStatus result) { switch (result) { case mStatus_NoError: debugf("Callback: %##s Name Registered", sr->RR_SRV.resrec.name->c); break; case mStatus_NameConflict: debugf("Callback: %##s Name Conflict", sr->RR_SRV.resrec.name->c); break; case mStatus_MemFree: debugf("Callback: %##s Memory Free", sr->RR_SRV.resrec.name->c); break; default: debugf("Callback: %##s Unknown Result %ld", sr->RR_SRV.resrec.name->c, result); break; } if (result == mStatus_NoError) { char buffer[MAX_ESCAPED_DOMAIN_NAME]; ConvertDomainNameToCString(sr->RR_SRV.resrec.name, buffer); printf("Service %s now registered and active\n", buffer); } if (result == mStatus_NameConflict) { char buffer1[MAX_ESCAPED_DOMAIN_NAME], buffer2[MAX_ESCAPED_DOMAIN_NAME]; ConvertDomainNameToCString(sr->RR_SRV.resrec.name, buffer1); mDNS_RenameAndReregisterService(m, sr, mDNSNULL); ConvertDomainNameToCString(sr->RR_SRV.resrec.name, buffer2); printf("Name Conflict! %s renamed as %s\n", buffer1, buffer2); } } // RegisterService() is a simple wrapper function which takes C string // parameters, converts them to domainname parameters, and calls mDNS_RegisterService() mDNSlocal void RegisterService(mDNS *m, ServiceRecordSet *recordset, const char name[], const char type[], const char domain[], const domainname *host, mDNSu16 PortAsNumber, int argc, char **argv) { domainlabel n; domainname t, d; unsigned char txtbuffer[1024], *bptr = txtbuffer; char buffer[MAX_ESCAPED_DOMAIN_NAME]; MakeDomainLabelFromLiteralString(&n, name); MakeDomainNameFromDNSNameString(&t, type); MakeDomainNameFromDNSNameString(&d, domain); while (argc) { int len = strlen(argv[0]); if (len > 255 || bptr + 1 + len >= txtbuffer + sizeof(txtbuffer)) break; printf("STR: %s\n", argv[0]); bptr[0] = len; strcpy((char*)(bptr+1), argv[0]); bptr += 1 + len; argc--; argv++; } mDNS_RegisterService(m, recordset, &n, &t, &d, // Name, type, domain host, mDNSOpaque16fromIntVal(PortAsNumber), txtbuffer, bptr-txtbuffer, // TXT data, length mDNSNULL, 0, // Subtypes mDNSInterface_Any, // Interface ID ServiceCallback, mDNSNULL, 0); // Callback, context, flags ConvertDomainNameToCString(recordset->RR_SRV.resrec.name, buffer); printf("Made Service Records for %s\n", buffer); } //************************************************************************************************************* // Service non-existence assertion // (claiming a service name without actually providing a service at that name, to prevent anyone else using that name) // This is useful to avoid confusion between similar services // e.g. A printer that implements IPP printing service using the name "My Printer", but doesn't implement LPR service, // should also claim the LPR service name "My Printer" to stop a different printer offering LPR service under the same name, // since it would be confusing to users to have two equivalent services with the same name. mDNSlocal void NoSuchServiceCallback(mDNS *const m, AuthRecord *const rr, mStatus result) { const domainname *proxyhostname = (const domainname *)rr->RecordContext; switch (result) { case mStatus_NoError: debugf("Callback: %##s Name Registered", rr->resrec.name->c); break; case mStatus_NameConflict: debugf("Callback: %##s Name Conflict", rr->resrec.name->c); break; case mStatus_MemFree: debugf("Callback: %##s Memory Free", rr->resrec.name->c); break; default: debugf("Callback: %##s Unknown Result %ld", rr->resrec.name->c, result); break; } if (result == mStatus_NoError) { char buffer[MAX_ESCAPED_DOMAIN_NAME]; ConvertDomainNameToCString(rr->resrec.name, buffer); printf("Non-existence assertion %s now registered and active\n", buffer); } if (result == mStatus_NameConflict) { domainlabel n; domainname t, d; char buffer1[MAX_ESCAPED_DOMAIN_NAME], buffer2[MAX_ESCAPED_DOMAIN_NAME]; ConvertDomainNameToCString(rr->resrec.name, buffer1); DeconstructServiceName(rr->resrec.name, &n, &t, &d); IncrementLabelSuffix(&n, mDNStrue); mDNS_RegisterNoSuchService(m, rr, &n, &t, &d, proxyhostname, mDNSInterface_Any, NoSuchServiceCallback, mDNSNULL, 0); ConvertDomainNameToCString(rr->resrec.name, buffer2); printf("Name Conflict! %s renamed as %s\n", buffer1, buffer2); } } mDNSlocal void RegisterNoSuchService(mDNS *m, AuthRecord *const rr, domainname *proxyhostname, const char name[], const char type[], const char domain[]) { domainlabel n; domainname t, d; char buffer[MAX_ESCAPED_DOMAIN_NAME]; MakeDomainLabelFromLiteralString(&n, name); MakeDomainNameFromDNSNameString(&t, type); MakeDomainNameFromDNSNameString(&d, domain); mDNS_RegisterNoSuchService(m, rr, &n, &t, &d, proxyhostname, mDNSInterface_Any, NoSuchServiceCallback, proxyhostname, 0); ConvertDomainNameToCString(rr->resrec.name, buffer); printf("Made Non-existence Record for %s\n", buffer); } //************************************************************************************************************* // Main mDNSexport int main(int argc, char **argv) { mStatus status; sigset_t signals; if (argc < 3) goto usage; status = mDNS_Init(&mDNSStorage, &PlatformStorage, mDNS_Init_NoCache, mDNS_Init_ZeroCacheSize, mDNS_Init_DontAdvertiseLocalAddresses, mDNS_Init_NoInitCallback, mDNS_Init_NoInitCallbackContext); if (status) { fprintf(stderr, "Daemon start: mDNS_Init failed %d\n", (int)status); return(status); } mDNSPosixListenForSignalInEventLoop(SIGINT); mDNSPosixListenForSignalInEventLoop(SIGTERM); if (!strcmp(argv[1], "-")) { domainname proxyhostname; AuthRecord proxyrecord; if (argc < 5) goto usage; proxyhostname.c[0] = 0; AppendLiteralLabelString(&proxyhostname, argv[2]); AppendLiteralLabelString(&proxyhostname, "local"); RegisterNoSuchService(&mDNSStorage, &proxyrecord, &proxyhostname, argv[3], argv[4], "local."); } else { ProxyHost proxyhost; ServiceRecordSet proxyservice; proxyhost.ip.NotAnInteger = inet_addr(argv[1]); if (proxyhost.ip.NotAnInteger == INADDR_NONE) // INADDR_NONE is 0xFFFFFFFF { struct hostent *h = gethostbyname(argv[1]); if (h) proxyhost.ip.NotAnInteger = *(long*)h->h_addr; } if (proxyhost.ip.NotAnInteger == INADDR_NONE) // INADDR_NONE is 0xFFFFFFFF { fprintf(stderr, "%s is not valid host address\n", argv[1]); return(-1); } MakeDomainLabelFromLiteralString(&proxyhost.hostlabel, argv[2]); mDNS_RegisterProxyHost(&mDNSStorage, &proxyhost); if (argc >=6) RegisterService(&mDNSStorage, &proxyservice, argv[3], argv[4], "local.", proxyhost.RR_A.resrec.name, atoi(argv[5]), argc-6, &argv[6]); } do { struct timeval timeout = { FutureTime, 0 }; // wait until SIGINT or SIGTERM mDNSBool gotSomething; mDNSPosixRunEventLoopOnce(&mDNSStorage, &timeout, &signals, &gotSomething); } while ( !( sigismember( &signals, SIGINT) || sigismember( &signals, SIGTERM))); mDNS_Close(&mDNSStorage); return(0); usage: fprintf(stderr, "%s ip hostlabel [srvname srvtype port txt [txt ...]]\n", argv[0]); fprintf(stderr, "ip Real IP address (or valid host name) of the host where the service actually resides\n"); fprintf(stderr, "hostlabel First label of the dot-local host name to create for this host, e.g. \"foo\" for \"foo.local.\"\n"); fprintf(stderr, "srvname Descriptive name of service, e.g. \"Stuart's Ink Jet Printer\"\n"); fprintf(stderr, "srvtype IANA service type, e.g. \"_ipp._tcp\" or \"_ssh._tcp\", etc.\n"); fprintf(stderr, "port Port number where the service resides (1-65535)\n"); fprintf(stderr, "txt Additional name/value pairs specified in service definition, e.g. \"pdl=application/postscript\"\n"); fprintf(stderr, "e.g. %s 169.254.12.34 thehost (just create a dot-local host name)\n", argv[0]); fprintf(stderr, "or %s 169.254.12.34 thehost \"My Printer\" _printer._tcp. 515 rp=lpt1 pdl=application/postscript\n", argv[0]); fprintf(stderr, "or %s - thehost \"My Printer\" _printer._tcp. (assertion of non-existence)\n", argv[0]); return(-1); }