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