mDNSShared/PlatformCommon.c

   1 /* -*- Mode: C; tab-width: 4 -*-
   2  *
   3  * Copyright (c) 2004 Apple Computer, Inc. All rights reserved.
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16
  17     Change History (most recent first):
  18
  19 $Log: PlatformCommon.c,v $
  20 Revision 1.17  2008/03/05 00:19:09  cheshire
  21 Conditionalize LogTimeStamps so it's specific to APPLE_OSX, for now
  22
  23 Revision 1.16  2008/02/26 21:47:45  cheshire
  24 Added cast to avoid compiler warning
  25
  26 Revision 1.15  2008/02/26 21:42:26  cheshire
  27 Added 'LogTimeStamps' option, to show ms-granularity timestamps on every log message
  28
  29 Revision 1.14  2007/12/03 18:37:26  cheshire
  30 Moved mDNSPlatformWriteLogMsg & mDNSPlatformWriteDebugMsg
  31 from mDNSMacOSX.c to PlatformCommon.c, so that Posix build can use them
  32
  33 Revision 1.13  2007/10/22 20:07:07  cheshire
  34 Moved mDNSPlatformSourceAddrForDest from mDNSMacOSX.c to PlatformCommon.c so
  35 Posix build can share the code (better than just pasting it into mDNSPosix.c)
  36
  37 Revision 1.12  2007/10/16 17:19:53  cheshire
  38 <rdar://problem/3557903> Performance: Core code will not work on platforms with small stacks
  39 Cut ReadDDNSSettingsFromConfFile stack from 2112 to 1104 bytes
  40
  41 Revision 1.11  2007/07/31 23:08:34  mcguire
  42 <rdar://problem/5329542> BTMM: Make AutoTunnel mode work with multihoming
  43
  44 Revision 1.10  2007/07/11 02:59:58  cheshire
  45 <rdar://problem/5303807> Register IPv6-only hostname and don't create port mappings for AutoTunnel services
  46 Add AutoTunnel parameter to mDNS_SetSecretForDomain
  47
  48 Revision 1.9  2007/01/09 22:37:44  cheshire
  49 Remove unused ClearDomainSecrets() function
  50
  51 Revision 1.8  2006/12/22 20:59:51  cheshire
  52 <rdar://problem/4742742> Read *all* DNS keys from keychain,
  53  not just key for the system-wide default registration domain
  54
  55 Revision 1.7  2006/08/14 23:24:56  cheshire
  56 Re-licensed mDNSResponder daemon source code under Apache License, Version 2.0
  57
  58 Revision 1.6  2005/04/08 21:30:16  ksekar
  59 <rdar://problem/4007457> Compiling problems with mDNSResponder-98 on Solaris/Sparc v9
  60 Patch submitted by Bernd Kuhls
  61
  62 Revision 1.5  2005/02/01 19:33:30  ksekar
  63 <rdar://problem/3985239> Keychain format too restrictive
  64
  65 Revision 1.4  2005/01/19 19:19:21  ksekar
  66 <rdar://problem/3960191> Need a way to turn off domain discovery
  67
  68 Revision 1.3  2004/12/13 17:46:52  cheshire
  69 Use sizeof(buf) instead of fixed constant 1024
  70
  71 Revision 1.2  2004/12/01 03:30:29  cheshire
  72 <rdar://problem/3889346> Add Unicast DNS support to mDNSPosix
  73
  74 Revision 1.1  2004/12/01 01:51:35  cheshire
  75 Move ReadDDNSSettingsFromConfFile() from mDNSMacOSX.c to PlatformCommon.c
  76
  77  */
  78
  79 #include <stdio.h>                              // Needed for fopen() etc.
  80 #include <unistd.h>                             // Needed for close()
  81 #include <string.h>                             // Needed for strlen() etc.
  82 #include <errno.h>                              // Needed for errno etc.
  83 #include <sys/socket.h>                 // Needed for socket() etc.
  84 #include <netinet/in.h>                 // Needed for sockaddr_in
  85 #include <syslog.h>
  86
  87 #include "mDNSEmbeddedAPI.h"    // Defines the interface provided to the client layer above
  88 #include "DNSCommon.h"
  89 #include "PlatformCommon.h"
  90
  91 #ifdef NOT_HAVE_SOCKLEN_T
  92     typedef unsigned int socklen_t;
  93 #endif
  94
  95 // Bind a UDP socket to find the source address to a destination
  96 mDNSexport void mDNSPlatformSourceAddrForDest(mDNSAddr *const src, const mDNSAddr *const dst)
  97         {
  98         union { struct sockaddr s; struct sockaddr_in a4; struct sockaddr_in6 a6; } addr;
  99         socklen_t len = sizeof(addr);
 100         int sock = socket(AF_INET, SOCK_DGRAM, 0);
 101         src->type = mDNSAddrType_None;
 102         if (sock == -1) return;
 103         if (dst->type == mDNSAddrType_IPv4)
 104                 {
 105                 addr.a4.sin_len         = sizeof(addr.a4);
 106                 addr.a4.sin_family      = AF_INET;
 107                 addr.a4.sin_port        = 1;    // Not important, any port will do
 108                 addr.a4.sin_addr.s_addr = dst->ip.v4.NotAnInteger;
 109                 }
 110         else if (dst->type == mDNSAddrType_IPv6)
 111                 {
 112                 addr.a6.sin6_len      = sizeof(addr.a6);
 113                 addr.a6.sin6_family   = AF_INET6;
 114                 addr.a6.sin6_flowinfo = 0;
 115                 addr.a6.sin6_port     = 1;      // Not important, any port will do
 116                 addr.a6.sin6_addr     = *(struct in6_addr*)&dst->ip.v6;
 117                 addr.a6.sin6_scope_id = 0;
 118                 }
 119         else return;
 120
 121         if ((connect(sock, &addr.s, addr.s.sa_len)) < 0)
 122                 { LogMsg("mDNSPlatformSourceAddrForDest: connect %#a failed errno %d (%s)", dst, errno, strerror(errno)); goto exit; }
 123
 124         if ((getsockname(sock, &addr.s, &len)) < 0)
 125                 { LogMsg("mDNSPlatformSourceAddrForDest: getsockname failed errno %d (%s)", errno, strerror(errno)); goto exit; }
 126
 127         src->type = dst->type;
 128         if (dst->type == mDNSAddrType_IPv4) src->ip.v4.NotAnInteger = addr.a4.sin_addr.s_addr;
 129         else                                src->ip.v6 = *(mDNSv6Addr*)&addr.a6.sin6_addr;
 130 exit:
 131         close(sock);
 132         }
 133
 134 // dst must be at least MAX_ESCAPED_DOMAIN_NAME bytes, and option must be less than 32 bytes in length
 135 mDNSlocal mDNSBool GetConfigOption(char *dst, const char *option, FILE *f)
 136         {
 137         char buf[32+1+MAX_ESCAPED_DOMAIN_NAME]; // Option name, one space, option value
 138         unsigned int len = strlen(option);
 139         if (len + 1 + MAX_ESCAPED_DOMAIN_NAME > sizeof(buf)-1) { LogMsg("GetConfigOption: option %s too long", option); return mDNSfalse; }
 140         fseek(f, 0, SEEK_SET);  // set position to beginning of stream
 141         while (fgets(buf, sizeof(buf), f))              // Read at most sizeof(buf)-1 bytes from file, and append '\0' C-string terminator
 142                 {
 143                 if (!strncmp(buf, option, len))
 144                         {
 145                         strncpy(dst, buf + len + 1, MAX_ESCAPED_DOMAIN_NAME-1);
 146                         if (dst[MAX_ESCAPED_DOMAIN_NAME-1]) dst[MAX_ESCAPED_DOMAIN_NAME-1] = '\0';
 147                         len = strlen(dst);
 148                         if (len && dst[len-1] == '\n') dst[len-1] = '\0';  // chop newline
 149                         return mDNStrue;
 150                         }
 151                 }
 152         debugf("Option %s not set", option);
 153         return mDNSfalse;
 154         }
 155
 156 mDNSexport void ReadDDNSSettingsFromConfFile(mDNS *const m, const char *const filename, domainname *const hostname, domainname *const domain, mDNSBool *DomainDiscoveryDisabled)
 157         {
 158         char buf[MAX_ESCAPED_DOMAIN_NAME] = "";
 159         mStatus err;
 160         FILE *f = fopen(filename, "r");
 161
 162     if (hostname)                 hostname->c[0] = 0;
 163     if (domain)                   domain->c[0] = 0;
 164         if (DomainDiscoveryDisabled) *DomainDiscoveryDisabled = mDNSfalse;
 165
 166         if (f)
 167                 {
 168                 if (DomainDiscoveryDisabled && GetConfigOption(buf, "DomainDiscoveryDisabled", f) && !strcasecmp(buf, "true")) *DomainDiscoveryDisabled = mDNStrue;
 169                 if (hostname && GetConfigOption(buf, "hostname", f) && !MakeDomainNameFromDNSNameString(hostname, buf)) goto badf;
 170                 if (domain && GetConfigOption(buf, "zone", f) && !MakeDomainNameFromDNSNameString(domain, buf)) goto badf;
 171                 buf[0] = 0;
 172                 GetConfigOption(buf, "secret-64", f);  // failure means no authentication
 173                 fclose(f);
 174                 f = NULL;
 175                 }
 176         else
 177                 {
 178                 if (errno != ENOENT) LogMsg("ERROR: Config file exists, but cannot be opened.");
 179                 return;
 180                 }
 181
 182         if (domain && domain->c[0] && buf[0])
 183                 {
 184                 DomainAuthInfo *info = (DomainAuthInfo*)mDNSPlatformMemAllocate(sizeof(*info));
 185                 // for now we assume keyname = service reg domain and we use same key for service and hostname registration
 186                 err = mDNS_SetSecretForDomain(m, info, domain, domain, buf, mDNSfalse);
 187                 if (err) LogMsg("ERROR: mDNS_SetSecretForDomain returned %d for domain %##s", err, domain->c);
 188                 }
 189
 190         return;
 191
 192         badf:
 193         LogMsg("ERROR: malformatted config file");
 194         if (f) fclose(f);
 195         }
 196
 197 #if MDNS_DEBUGMSGS
 198 mDNSexport void mDNSPlatformWriteDebugMsg(const char *msg)
 199         {
 200         fprintf(stderr,"%s\n", msg);
 201         fflush(stderr);
 202         }
 203 #endif
 204
 205 mDNSexport void mDNSPlatformWriteLogMsg(const char *ident, const char *buffer, int logoptflags)
 206         {
 207 #if APPLE_OSX_mDNSResponder && LogTimeStamps
 208         extern mDNS mDNSStorage;
 209         extern mDNSu32 mDNSPlatformClockDivisor;
 210         mDNSs32 t = mDNSStorage.timenow ? mDNSStorage.timenow : mDNSPlatformClockDivisor ? mDNS_TimeNow_NoLock(&mDNSStorage) : 0;
 211         int ms = ((t < 0) ? -t : t) % 1000;
 212 #endif
 213
 214         if (mDNS_DebugMode)     // In debug mode we write to stderr
 215                 {
 216 #if APPLE_OSX_mDNSResponder && LogTimeStamps
 217                 if (mDNSPlatformClockDivisor)
 218                         fprintf(stderr,"%8d.%03d: %s\n", (int)(t/1000), ms, buffer);
 219                 else
 220 #endif
 221                         fprintf(stderr,"%s\n", buffer);
 222                 fflush(stderr);
 223                 }
 224         else                            // else, in production mode, we write to syslog
 225                 {
 226                 openlog(ident, LOG_CONS | logoptflags, LOG_DAEMON);
 227 #if APPLE_OSX_mDNSResponder && LogTimeStamps
 228                 if (mDNSPlatformClockDivisor)
 229                         syslog(LOG_ERR, "%8d.%03d: %s", (int)(t/1000), ms, buffer);
 230                 else
 231 #endif
 232                         syslog(LOG_ERR, "%s", buffer);
 233                 closelog();
 234                 }
 235         }