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 1.14  2007/12/03 18:37:26  cheshire
  21 Moved mDNSPlatformWriteLogMsg & mDNSPlatformWriteDebugMsg
  22 from mDNSMacOSX.c to PlatformCommon.c, so that Posix build can use them
  23
  24 Revision 1.13  2007/10/22 20:07:07  cheshire
  25 Moved mDNSPlatformSourceAddrForDest from mDNSMacOSX.c to PlatformCommon.c so
  26 Posix build can share the code (better than just pasting it into mDNSPosix.c)
  27
  28 Revision 1.12  2007/10/16 17:19:53  cheshire
  29 <rdar://problem/3557903> Performance: Core code will not work on platforms with small stacks
  30 Cut ReadDDNSSettingsFromConfFile stack from 2112 to 1104 bytes
  31
  32 Revision 1.11  2007/07/31 23:08:34  mcguire
  33 <rdar://problem/5329542> BTMM: Make AutoTunnel mode work with multihoming
  34
  35 Revision 1.10  2007/07/11 02:59:58  cheshire
  36 <rdar://problem/5303807> Register IPv6-only hostname and don't create port mappings for AutoTunnel services
  37 Add AutoTunnel parameter to mDNS_SetSecretForDomain
  38
  39 Revision 1.9  2007/01/09 22:37:44  cheshire
  40 Remove unused ClearDomainSecrets() function
  41
  42 Revision 1.8  2006/12/22 20:59:51  cheshire
  43 <rdar://problem/4742742> Read *all* DNS keys from keychain,
  44  not just key for the system-wide default registration domain
  45
  46 Revision 1.7  2006/08/14 23:24:56  cheshire
  47 Re-licensed mDNSResponder daemon source code under Apache License, Version 2.0
  48
  49 Revision 1.6  2005/04/08 21:30:16  ksekar
  50 <rdar://problem/4007457> Compiling problems with mDNSResponder-98 on Solaris/Sparc v9
  51 Patch submitted by Bernd Kuhls
  52
  53 Revision 1.5  2005/02/01 19:33:30  ksekar
  54 <rdar://problem/3985239> Keychain format too restrictive
  55
  56 Revision 1.4  2005/01/19 19:19:21  ksekar
  57 <rdar://problem/3960191> Need a way to turn off domain discovery
  58
  59 Revision 1.3  2004/12/13 17:46:52  cheshire
  60 Use sizeof(buf) instead of fixed constant 1024
  61
  62 Revision 1.2  2004/12/01 03:30:29  cheshire
  63 <rdar://problem/3889346> Add Unicast DNS support to mDNSPosix
  64
  65 Revision 1.1  2004/12/01 01:51:35  cheshire
  66 Move ReadDDNSSettingsFromConfFile() from mDNSMacOSX.c to PlatformCommon.c
  67
  68  */
  69
  70 #include <stdio.h>                              // Needed for fopen() etc.
  71 #include <unistd.h>                             // Needed for close()
  72 #include <string.h>                             // Needed for strlen() etc.
  73 #include <errno.h>                              // Needed for errno etc.
  74 #include <sys/socket.h>                 // Needed for socket() etc.
  75 #include <netinet/in.h>                 // Needed for sockaddr_in
  76 #include <syslog.h>
  77
  78 #include "mDNSEmbeddedAPI.h"    // Defines the interface provided to the client layer above
  79 #include "DNSCommon.h"
  80 #include "PlatformCommon.h"
  81
  82 #ifdef NOT_HAVE_SOCKLEN_T
  83     typedef unsigned int socklen_t;
  84 #endif
  85
  86 // Bind a UDP socket to find the source address to a destination
  87 mDNSexport void mDNSPlatformSourceAddrForDest(mDNSAddr *const src, const mDNSAddr *const dst)
  88         {
  89         union { struct sockaddr s; struct sockaddr_in a4; struct sockaddr_in6 a6; } addr;
  90         socklen_t len = sizeof(addr);
  91         int sock = socket(AF_INET, SOCK_DGRAM, 0);
  92         src->type = mDNSAddrType_None;
  93         if (sock == -1) return;
  94         if (dst->type == mDNSAddrType_IPv4)
  95                 {
  96                 addr.a4.sin_len         = sizeof(addr.a4);
  97                 addr.a4.sin_family      = AF_INET;
  98                 addr.a4.sin_port        = 1;    // Not important, any port will do
  99                 addr.a4.sin_addr.s_addr = dst->ip.v4.NotAnInteger;
 100                 }
 101         else if (dst->type == mDNSAddrType_IPv6)
 102                 {
 103                 addr.a6.sin6_len      = sizeof(addr.a6);
 104                 addr.a6.sin6_family   = AF_INET6;
 105                 addr.a6.sin6_flowinfo = 0;
 106                 addr.a6.sin6_port     = 1;      // Not important, any port will do
 107                 addr.a6.sin6_addr     = *(struct in6_addr*)&dst->ip.v6;
 108                 addr.a6.sin6_scope_id = 0;
 109                 }
 110         else return;
 111
 112         if ((connect(sock, &addr.s, addr.s.sa_len)) < 0)
 113                 { LogMsg("mDNSPlatformSourceAddrForDest: connect %#a failed errno %d (%s)", dst, errno, strerror(errno)); goto exit; }
 114
 115         if ((getsockname(sock, &addr.s, &len)) < 0)
 116                 { LogMsg("mDNSPlatformSourceAddrForDest: getsockname failed errno %d (%s)", errno, strerror(errno)); goto exit; }
 117
 118         src->type = dst->type;
 119         if (dst->type == mDNSAddrType_IPv4) src->ip.v4.NotAnInteger = addr.a4.sin_addr.s_addr;
 120         else                                src->ip.v6 = *(mDNSv6Addr*)&addr.a6.sin6_addr;
 121 exit:
 122         close(sock);
 123         }
 124
 125 // dst must be at least MAX_ESCAPED_DOMAIN_NAME bytes, and option must be less than 32 bytes in length
 126 mDNSlocal mDNSBool GetConfigOption(char *dst, const char *option, FILE *f)
 127         {
 128         char buf[32+1+MAX_ESCAPED_DOMAIN_NAME]; // Option name, one space, option value
 129         unsigned int len = strlen(option);
 130         if (len + 1 + MAX_ESCAPED_DOMAIN_NAME > sizeof(buf)-1) { LogMsg("GetConfigOption: option %s too long", option); return mDNSfalse; }
 131         fseek(f, 0, SEEK_SET);  // set position to beginning of stream
 132         while (fgets(buf, sizeof(buf), f))              // Read at most sizeof(buf)-1 bytes from file, and append '\0' C-string terminator
 133                 {
 134                 if (!strncmp(buf, option, len))
 135                         {
 136                         strncpy(dst, buf + len + 1, MAX_ESCAPED_DOMAIN_NAME-1);
 137                         if (dst[MAX_ESCAPED_DOMAIN_NAME-1]) dst[MAX_ESCAPED_DOMAIN_NAME-1] = '\0';
 138                         len = strlen(dst);
 139                         if (len && dst[len-1] == '\n') dst[len-1] = '\0';  // chop newline
 140                         return mDNStrue;
 141                         }
 142                 }
 143         debugf("Option %s not set", option);
 144         return mDNSfalse;
 145         }
 146
 147 mDNSexport void ReadDDNSSettingsFromConfFile(mDNS *const m, const char *const filename, domainname *const hostname, domainname *const domain, mDNSBool *DomainDiscoveryDisabled)
 148         {
 149         char buf[MAX_ESCAPED_DOMAIN_NAME] = "";
 150         mStatus err;
 151         FILE *f = fopen(filename, "r");
 152
 153     if (hostname)                 hostname->c[0] = 0;
 154     if (domain)                   domain->c[0] = 0;
 155         if (DomainDiscoveryDisabled) *DomainDiscoveryDisabled = mDNSfalse;
 156
 157         if (f)
 158                 {
 159                 if (DomainDiscoveryDisabled && GetConfigOption(buf, "DomainDiscoveryDisabled", f) && !strcasecmp(buf, "true")) *DomainDiscoveryDisabled = mDNStrue;
 160                 if (hostname && GetConfigOption(buf, "hostname", f) && !MakeDomainNameFromDNSNameString(hostname, buf)) goto badf;
 161                 if (domain && GetConfigOption(buf, "zone", f) && !MakeDomainNameFromDNSNameString(domain, buf)) goto badf;
 162                 buf[0] = 0;
 163                 GetConfigOption(buf, "secret-64", f);  // failure means no authentication
 164                 fclose(f);
 165                 f = NULL;
 166                 }
 167         else
 168                 {
 169                 if (errno != ENOENT) LogMsg("ERROR: Config file exists, but cannot be opened.");
 170                 return;
 171                 }
 172
 173         if (domain && domain->c[0] && buf[0])
 174                 {
 175                 DomainAuthInfo *info = (DomainAuthInfo*)mDNSPlatformMemAllocate(sizeof(*info));
 176                 // for now we assume keyname = service reg domain and we use same key for service and hostname registration
 177                 err = mDNS_SetSecretForDomain(m, info, domain, domain, buf, mDNSfalse);
 178                 if (err) LogMsg("ERROR: mDNS_SetSecretForDomain returned %d for domain %##s", err, domain->c);
 179                 }
 180
 181         return;
 182
 183         badf:
 184         LogMsg("ERROR: malformatted config file");
 185         if (f) fclose(f);
 186         }
 187
 188 #if MDNS_DEBUGMSGS
 189 mDNSexport void mDNSPlatformWriteDebugMsg(const char *msg)
 190         {
 191         fprintf(stderr,"%s\n", msg);
 192         fflush(stderr);
 193         }
 194 #endif
 195
 196 mDNSexport void mDNSPlatformWriteLogMsg(const char *ident, const char *buffer, int logoptflags)
 197         {
 198         if (mDNS_DebugMode)     // In debug mode we write to stderr
 199                 {
 200                 fprintf(stderr,"%s\n", buffer);
 201                 fflush(stderr);
 202                 }
 203         else                            // else, in production mode, we write to syslog
 204                 {
 205                 openlog(ident, LOG_CONS | logoptflags, LOG_DAEMON);
 206                 syslog(LOG_ERR, "%s", buffer);
 207                 closelog();
 208                 }
 209         }