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