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 1.11  2007/07/31 23:08:34  mcguire
  21 <rdar://problem/5329542> BTMM: Make AutoTunnel mode work with multihoming
  22
  23 Revision 1.10  2007/07/11 02:59:58  cheshire
  24 <rdar://problem/5303807> Register IPv6-only hostname and don't create port mappings for AutoTunnel services
  25 Add AutoTunnel parameter to mDNS_SetSecretForDomain
  26
  27 Revision 1.9  2007/01/09 22:37:44  cheshire
  28 Remove unused ClearDomainSecrets() function
  29
  30 Revision 1.8  2006/12/22 20:59:51  cheshire
  31 <rdar://problem/4742742> Read *all* DNS keys from keychain,
  32  not just key for the system-wide default registration domain
  33
  34 Revision 1.7  2006/08/14 23:24:56  cheshire
  35 Re-licensed mDNSResponder daemon source code under Apache License, Version 2.0
  36
  37 Revision 1.6  2005/04/08 21:30:16  ksekar
  38 <rdar://problem/4007457> Compiling problems with mDNSResponder-98 on Solaris/Sparc v9
  39 Patch submitted by Bernd Kuhls
  40
  41 Revision 1.5  2005/02/01 19:33:30  ksekar
  42 <rdar://problem/3985239> Keychain format too restrictive
  43
  44 Revision 1.4  2005/01/19 19:19:21  ksekar
  45 <rdar://problem/3960191> Need a way to turn off domain discovery
  46
  47 Revision 1.3  2004/12/13 17:46:52  cheshire
  48 Use sizeof(buf) instead of fixed constant 1024
  49
  50 Revision 1.2  2004/12/01 03:30:29  cheshire
  51 <rdar://problem/3889346> Add Unicast DNS support to mDNSPosix
  52
  53 Revision 1.1  2004/12/01 01:51:35  cheshire
  54 Move ReadDDNSSettingsFromConfFile() from mDNSMacOSX.c to PlatformCommon.c
  55
  56  */
  57
  58 #include <stdio.h>                              // Needed for fopen() etc.
  59 #include <unistd.h>                             // Needed for close()
  60 #include <string.h>                             // Needed for strlen() etc.
  61 #include <errno.h>                      // Needed for errno etc.
  62 #include <sys/socket.h>                 // Needed for socket() etc.
  63 #include <netinet/in.h>                 // Needed for sockaddr_in
  64
  65 #include "mDNSEmbeddedAPI.h"    // Defines the interface provided to the client layer above
  66 #include "DNSCommon.h"
  67 #include "PlatformCommon.h"
  68
  69 #ifdef NOT_HAVE_SOCKLEN_T
  70     typedef unsigned int socklen_t;
  71 #endif
  72
  73 // Bind a UDP socket to find the source address to a destination
  74 mDNSexport void FindSourceAddrForIP(mDNSAddr *const dst, mDNSAddr *src)
  75         {
  76         struct sockaddr_in addr;
  77         socklen_t len = sizeof(addr);
  78         int sock = socket(AF_INET,SOCK_DGRAM,0);
  79         src->type = mDNSAddrType_None;
  80         if (sock == -1) return;
  81         if (dst->type != mDNSAddrType_IPv4) return; // Only support v4 for now
  82         addr.sin_family = AF_INET;
  83         addr.sin_port = 1;      // Not important, any port will do
  84         if (dst == NULL) addr.sin_addr.s_addr = 0x11111111;
  85         else addr.sin_addr.s_addr = dst->ip.v4.NotAnInteger;
  86         if ((connect(sock,(const struct sockaddr*)&addr,sizeof(addr))) == -1) { close(sock); return; }
  87         if ((getsockname(sock,(struct sockaddr*)&addr, &len)) == -1) { close(sock); return; }
  88         close(sock);
  89         src->type = mDNSAddrType_IPv4;
  90         src->ip.v4.NotAnInteger = addr.sin_addr.s_addr;
  91         }
  92
  93 // dst must be at least MAX_ESCAPED_DOMAIN_NAME bytes, and option must be less than 32 bytes in length
  94 mDNSlocal mDNSBool GetConfigOption(char *dst, const char *option, FILE *f)
  95         {
  96         char buf[32+1+MAX_ESCAPED_DOMAIN_NAME]; // Option name, one space, option value
  97         unsigned int len = strlen(option);
  98         if (len + 1 + MAX_ESCAPED_DOMAIN_NAME > sizeof(buf)-1) { LogMsg("GetConfigOption: option %s too long", option); return mDNSfalse; }
  99         fseek(f, 0, SEEK_SET);  // set position to beginning of stream
 100         while (fgets(buf, sizeof(buf), f))              // Read at most sizeof(buf)-1 bytes from file, and append '\0' C-string terminator
 101                 {
 102                 if (!strncmp(buf, option, len))
 103                         {
 104                         strncpy(dst, buf + len + 1, MAX_ESCAPED_DOMAIN_NAME-1);
 105                         if (dst[MAX_ESCAPED_DOMAIN_NAME-1]) dst[MAX_ESCAPED_DOMAIN_NAME-1] = '\0';
 106                         len = strlen(dst);
 107                         if (len && dst[len-1] == '\n') dst[len-1] = '\0';  // chop newline
 108                         return mDNStrue;
 109                         }
 110                 }
 111         debugf("Option %s not set", option);
 112         return mDNSfalse;
 113         }
 114
 115 mDNSexport void ReadDDNSSettingsFromConfFile(mDNS *const m, const char *const filename, domainname *const hostname, domainname *const domain, mDNSBool *DomainDiscoveryDisabled)
 116         {
 117         char buf   [MAX_ESCAPED_DOMAIN_NAME];
 118         char secret[MAX_ESCAPED_DOMAIN_NAME] = "";
 119         mStatus err;
 120         FILE *f = fopen(filename, "r");
 121
 122     if (hostname)                 hostname->c[0] = 0;
 123     if (domain)                   domain->c[0] = 0;
 124         if (DomainDiscoveryDisabled) *DomainDiscoveryDisabled = mDNSfalse;
 125
 126         if (f)
 127                 {
 128                 if (DomainDiscoveryDisabled && GetConfigOption(buf, "DomainDiscoveryDisabled", f) && !strcasecmp(buf, "true")) *DomainDiscoveryDisabled = mDNStrue;
 129                 if (hostname && GetConfigOption(buf, "hostname", f) && !MakeDomainNameFromDNSNameString(hostname, buf)) goto badf;
 130                 if (domain && GetConfigOption(buf, "zone", f) && !MakeDomainNameFromDNSNameString(domain, buf)) goto badf;
 131                 GetConfigOption(secret, "secret-64", f);  // failure means no authentication
 132                 fclose(f);
 133                 f = NULL;
 134                 }
 135         else
 136                 {
 137                 if (errno != ENOENT) LogMsg("ERROR: Config file exists, but cannot be opened.");
 138                 return;
 139                 }
 140
 141         if (domain && domain->c[0] && secret[0])
 142                 {
 143                 DomainAuthInfo *info = (DomainAuthInfo*)mDNSPlatformMemAllocate(sizeof(*info));
 144                 // for now we assume keyname = service reg domain and we use same key for service and hostname registration
 145                 err = mDNS_SetSecretForDomain(m, info, domain, domain, secret, mDNSfalse);
 146                 if (err) LogMsg("ERROR: mDNS_SetSecretForDomain returned %d for domain %##s", err, domain->c);
 147                 }
 148
 149         return;
 150
 151         badf:
 152         LogMsg("ERROR: malformatted config file");
 153         if (f) fclose(f);
 154         }