/* -*- Mode: C; tab-width: 4 -*- * * Copyright (c) 2003-2004 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. File: daemon.c Contains: main & associated Application layer for mDNSResponder on Linux. Change History (most recent first): $Log: PosixDaemon.c,v $ Revision 1.29.2.1 2006/08/29 06:24:34 cheshire Re-licensed mDNSResponder daemon source code under Apache License, Version 2.0 Revision 1.29 2005/08/04 03:37:45 mkrochma Temporary workaround to fix posix after mDNS_SetPrimaryInterfaceInfo changed Revision 1.28 2005/07/19 11:21:09 cheshire Unix Domain Socket leak in mdnsd Revision 1.27 2005/02/04 00:39:59 cheshire Move ParseDNSServers() from PosixDaemon.c to mDNSPosix.c so all Posix client layers can use it Revision 1.26 2005/02/02 02:21:30 cheshire Update references to "mDNSResponder" to say "mdnsd" instead Revision 1.25 2005/01/27 20:01:50 cheshire udsSupportRemoveFDFromEventLoop() needs to close the file descriptor as well Revision 1.24 2005/01/19 19:20:49 ksekar Need a way to turn off domain discovery Revision 1.23 2004/12/16 20:17:11 cheshire Cache memory management improvements Revision 1.22 2004/12/10 13:12:08 cheshire Create no-op function RecordUpdatedNiceLabel(), required by uds_daemon.c Revision 1.21 2004/12/01 20:57:20 ksekar Wide Area Service Discovery must be split-DNS aware Revision 1.20 2004/12/01 04:28:43 cheshire Darwin patches for Solaris and Suse Use version of daemon() provided in mDNSUNP.c instead of local copy Revision 1.19 2004/12/01 03:30:29 cheshire Add Unicast DNS support to mDNSPosix Revision 1.18 2004/11/30 22:45:59 cheshire Minor code tidying Revision 1.17 2004/11/30 22:18:59 cheshire Posix needs to read the list of unicast DNS servers and set server list Revision 1.16 2004/09/21 21:05:12 cheshire Move duplicate code out of mDNSMacOSX/daemon.c and mDNSPosix/PosixDaemon.c, into mDNSShared/uds_daemon.c Revision 1.15 2004/09/17 01:08:53 cheshire Renamed mDNSClientAPI.h to mDNSEmbeddedAPI.h The name "mDNSClientAPI.h" is misleading to new developers looking at this code. The interfaces declared in that file are ONLY appropriate to single-address-space embedded applications. For clients on general-purpose computers, the interfaces defined in dns_sd.h should be used. Revision 1.14 2004/09/16 00:24:49 cheshire Fix unsafe use of mDNSPlatformTimeNow() Revision 1.13 2004/08/11 01:59:41 cheshire Remove "mDNS *globalInstance" parameter from udsserver_init() Revision 1.12 2004/06/28 23:19:19 cheshire Fix "Daemon_Init declared but never defined" warning on Linux Revision 1.11 2004/06/25 00:26:27 rpantos Changes to fix the Posix build on Solaris. Revision 1.10 2004/06/08 04:59:40 cheshire Tidy up wording -- log messages are already prefixed with "mDNSResponder", so don't need to repeat it Revision 1.9 2004/05/29 00:14:20 rpantos Runtime check to disable prod mdnsd on OS X. Revision 1.8 2004/04/07 01:19:04 cheshire Hash slot value should be unsigned Revision 1.7 2004/02/14 06:34:57 cheshire Use LogMsg instead of fprintf( stderr Revision 1.6 2004/02/14 01:10:42 rpantos Allow daemon to run if 'nobody' is not defined, with a warning. (For Roku HD1000.) Revision 1.5 2004/02/05 07:45:43 cheshire Add Log header Revision 1.4 2004/01/28 21:14:23 cheshire Reconcile debug_mode and gDebugLogging into a single flag (mDNS_DebugMode) Revision 1.3 2004/01/19 19:51:46 cheshire Fix compiler error (mixed declarations and code) on some versions of Linux Revision 1.2 2003/12/11 03:03:51 rpantos Clean up mDNSPosix so that it builds on OS X again. Revision 1.1 2003/12/08 20:47:02 rpantos Add support for mDNSResponder on Linux. */ #pragma ident "%Z%%M% %I% %E% SMI" #include #include #include #include #include #include #include #include #include #include "mDNSEmbeddedAPI.h" #include "mDNSDebug.h" #include "mDNSPosix.h" #include "uds_daemon.h" #include "PlatformCommon.h" #include "mDNSUNP.h" #ifndef MDNSD_USER #define MDNSD_USER "nobody" #endif #define CONFIG_FILE "/etc/mdnsd.conf" static domainname DynDNSZone; // Default wide-area zone for service registration static domainname DynDNSHostname; #define RR_CACHE_SIZE 500 static CacheEntity gRRCache[RR_CACHE_SIZE]; extern const char mDNSResponderVersionString[]; static void Reconfigure(mDNS *m) { mDNSAddr DynDNSIP; mDNS_SetPrimaryInterfaceInfo(m, NULL, NULL, NULL); mDNS_DeleteDNSServers(m); if (ParseDNSServers(m, uDNS_SERVERS_FILE) < 0) LogMsg("Unable to parse DNS server list. Unicast DNS-SD unavailable"); ReadDDNSSettingsFromConfFile(m, CONFIG_FILE, &DynDNSHostname, &DynDNSZone, NULL); FindDefaultRouteIP(&DynDNSIP); if (DynDNSHostname.c[0]) mDNS_AddDynDNSHostName(m, &DynDNSHostname, NULL, NULL); if (DynDNSIP.type) mDNS_SetPrimaryInterfaceInfo(m, &DynDNSIP, NULL, NULL); } // Do appropriate things at startup with command line arguments. Calls exit() if unhappy. static void ParseCmdLinArgs(int argc, char **argv) { if (argc > 1) { if (0 == strcmp(argv[1], "-debug")) mDNS_DebugMode = mDNStrue; else printf("Usage: %s [-debug]\n", argv[0]); } if (!mDNS_DebugMode) { int result = daemon(0, 0); if (result != 0) { LogMsg("Could not run as daemon - exiting"); exit(result); } #if __APPLE__ LogMsg("The POSIX mdnsd should only be used on OS X for testing - exiting"); exit(-1); #endif } } static void DumpStateLog(mDNS *const m) // Dump a little log of what we've been up to. { LogMsgIdent(mDNSResponderVersionString, "---- BEGIN STATE LOG ----"); udsserver_info(m); LogMsgIdent(mDNSResponderVersionString, "---- END STATE LOG ----"); } static mStatus MainLoop(mDNS *m) // Loop until we quit. { sigset_t signals; mDNSBool gotData = mDNSfalse; mDNSPosixListenForSignalInEventLoop(SIGINT); mDNSPosixListenForSignalInEventLoop(SIGTERM); mDNSPosixListenForSignalInEventLoop(SIGUSR1); mDNSPosixListenForSignalInEventLoop(SIGPIPE); mDNSPosixListenForSignalInEventLoop(SIGHUP) ; for (; ;) { // Work out how long we expect to sleep before the next scheduled task struct timeval timeout; mDNSs32 ticks; // Only idle if we didn't find any data the last time around if (!gotData) { mDNSs32 nextTimerEvent = mDNS_Execute(m); nextTimerEvent = udsserver_idle(nextTimerEvent); ticks = nextTimerEvent - mDNS_TimeNow(m); if (ticks < 1) ticks = 1; } else // otherwise call EventLoop again with 0 timemout ticks = 0; timeout.tv_sec = ticks / mDNSPlatformOneSecond; timeout.tv_usec = (ticks % mDNSPlatformOneSecond) * 1000000 / mDNSPlatformOneSecond; (void) mDNSPosixRunEventLoopOnce(m, &timeout, &signals, &gotData); if (sigismember(&signals, SIGHUP )) Reconfigure(m); if (sigismember(&signals, SIGUSR1)) DumpStateLog(m); // SIGPIPE happens when we try to write to a dead client; death should be detected soon in request_callback() and cleaned up. if (sigismember(&signals, SIGPIPE)) LogMsg("Received SIGPIPE - ignoring"); if (sigismember(&signals, SIGINT) || sigismember(&signals, SIGTERM)) break; } return EINTR; } int main(int argc, char **argv) { #define mDNSRecord mDNSStorage mDNS_PlatformSupport platformStorage; mStatus err; bzero(&mDNSRecord, sizeof mDNSRecord); bzero(&platformStorage, sizeof platformStorage); ParseCmdLinArgs(argc, argv); LogMsgIdent(mDNSResponderVersionString, "starting"); err = mDNS_Init(&mDNSRecord, &platformStorage, gRRCache, RR_CACHE_SIZE, mDNS_Init_AdvertiseLocalAddresses, mDNS_Init_NoInitCallback, mDNS_Init_NoInitCallbackContext); if (mStatus_NoError == err) err = udsserver_init(); Reconfigure(&mDNSRecord); // Now that we're finished with anything privileged, switch over to running as "nobody" if (mStatus_NoError == err) { const struct passwd *pw = getpwnam(MDNSD_USER); if (pw != NULL) setuid(pw->pw_uid); else #ifdef MDNSD_NOROOT { LogMsg("WARNING: mdnsd exiting because user \""MDNSD_USER"\" does not exist"); err = mStatus_Invalid; } #else LogMsg("WARNING: mdnsd continuing as root because user \""MDNSD_USER"\" does not exist"); #endif } if (mStatus_NoError == err) err = MainLoop(&mDNSRecord); LogMsgIdent(mDNSResponderVersionString, "stopping"); mDNS_Close(&mDNSRecord); if (udsserver_exit() < 0) LogMsg("ExitCallback: udsserver_exit failed"); #if MDNS_DEBUGMSGS > 0 printf("mDNSResponder exiting normally with %ld\n", err); #endif return err; } // uds_daemon support //////////////////////////////////////////////////////////// #undef LogMalloc #if MDNS_MALLOC_DEBUGGING >= 2 #define LogMalloc LogMsg #else #define LogMalloc(ARGS...) ((void)0) #endif mStatus udsSupportAddFDToEventLoop(int fd, udsEventCallback callback, void *context) /* Support routine for uds_daemon.c */ { // Depends on the fact that udsEventCallback == mDNSPosixEventCallback return mDNSPosixAddFDToEventLoop(fd, callback, context); } mStatus udsSupportRemoveFDFromEventLoop(int fd) // Note: This also CLOSES the file descriptor { mStatus err = mDNSPosixRemoveFDFromEventLoop(fd); close(fd); return err; } mDNSexport void RecordUpdatedNiceLabel(mDNS *const m, mDNSs32 delay) { (void)m; (void)delay; // No-op, for now } #if MACOSX_MDNS_MALLOC_DEBUGGING >= 1 void *mallocL(char *msg, unsigned int size) { unsigned long *mem = malloc(size+8); if (!mem) { LogMsg("malloc( %s : %d ) failed", msg, size); return(NULL); } else { LogMalloc("malloc( %s : %lu ) = %p", msg, size, &mem[2]); mem[0] = 0xDEAD1234; mem[1] = size; //bzero(&mem[2], size); memset(&mem[2], 0xFF, size); // validatelists(&mDNSStorage); return(&mem[2]); } } void freeL(char *msg, void *x) { if (!x) LogMsg("free( %s @ NULL )!", msg); else { unsigned long *mem = ((unsigned long *)x) - 2; if (mem[0] != 0xDEAD1234) { LogMsg("free( %s @ %p ) !!!! NOT ALLOCATED !!!!", msg, &mem[2]); return; } if (mem[1] > 8000) { LogMsg("free( %s : %ld @ %p) too big!", msg, mem[1], &mem[2]); return; } LogMalloc("free( %s : %ld @ %p)", msg, mem[1], &mem[2]); //bzero(mem, mem[1]+8); memset(mem, 0xDD, mem[1]+8); // validatelists(&mDNSStorage); free(mem); } } #endif // MACOSX_MDNS_MALLOC_DEBUGGING >= 1 // For convenience when using the "strings" command, this is the last thing in the file #if mDNSResponderVersion > 1 mDNSexport const char mDNSResponderVersionString[] = "mDNSResponder-" STRINGIFY(mDNSResponderVersion) " (" __DATE__ " " __TIME__ ") "; #elif MDNS_VERSIONSTR_NODTS mDNSexport const char mDNSResponderVersionString[] = "mDNSResponder (Engineering Build) "; #else mDNSexport const char mDNSResponderVersionString[] = "mDNSResponder (Engineering Build) (" __DATE__ " " __TIME__ ") "; #endif