mDNSShared/PlatformCommon.c

   1 /* -*- Mode: C; tab-width: 4 -*-
   2  *
   3  * Copyright (c) 2004 Apple Computer, Inc. All rights reserved.
   4  *
   5  * @APPLE_LICENSE_HEADER_START@
   6  *
   7  * This file contains Original Code and/or Modifications of Original Code
   8  * as defined in and that are subject to the Apple Public Source License
   9  * Version 2.0 (the 'License'). You may not use this file except in
  10  * compliance with the License. Please obtain a copy of the License at
  11  * http://www.opensource.apple.com/apsl/ and read it before using this
  12  * file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  19  * Please see the License for the specific language governing rights and
  20  * limitations under the License.
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  22  * @APPLE_LICENSE_HEADER_END@
  23
  24     Change History (most recent first):
  25
  26 $Log: PlatformCommon.c,v $
  27 Revision 1.4  2005/01/19 19:19:21  ksekar
  28 <rdar://problem/3960191> Need a way to turn off domain discovery
  29
  30 Revision 1.3  2004/12/13 17:46:52  cheshire
  31 Use sizeof(buf) instead of fixed constant 1024
  32
  33 Revision 1.2  2004/12/01 03:30:29  cheshire
  34 <rdar://problem/3889346> Add Unicast DNS support to mDNSPosix
  35
  36 Revision 1.1  2004/12/01 01:51:35  cheshire
  37 Move ReadDDNSSettingsFromConfFile() from mDNSMacOSX.c to PlatformCommon.c
  38
  39  */
  40
  41 #include <stdio.h>                              // Needed for fopen() etc.
  42 #include <unistd.h>                             // Needed for close()
  43 #include <string.h>                             // Needed for strlen() etc.
  44 #include <sys/errno.h>                  // Needed for errno etc.
  45 #include <sys/socket.h>                 // Needed for socket() etc.
  46 #include <netinet/in.h>                 // Needed for sockaddr_in
  47
  48 #include "mDNSEmbeddedAPI.h"    // Defines the interface provided to the client layer above
  49 #include "PlatformCommon.h"
  50
  51 #ifdef NOT_HAVE_SOCKLEN_T
  52     typedef unsigned int socklen_t;
  53 #endif
  54
  55 // Bind a UDP socket to a global destination to find the default route's interface address
  56 mDNSexport void FindDefaultRouteIP(mDNSAddr *a)
  57         {
  58         struct sockaddr_in addr;
  59         socklen_t len = sizeof(addr);
  60         int sock = socket(AF_INET,SOCK_DGRAM,0);
  61         a->type = mDNSAddrType_None;
  62         if (sock == -1) return;
  63         addr.sin_family = AF_INET;
  64         addr.sin_port = 1;      // Not important, any port and public address will do
  65         addr.sin_addr.s_addr = 0x11111111;
  66         if ((connect(sock,(const struct sockaddr*)&addr,sizeof(addr))) == -1) { close(sock); return; }
  67         if ((getsockname(sock,(struct sockaddr*)&addr, &len)) == -1) { close(sock); return; }
  68         close(sock);
  69         a->type = mDNSAddrType_IPv4;
  70         a->ip.v4.NotAnInteger = addr.sin_addr.s_addr;
  71         }
  72
  73 // dst must be at least MAX_ESCAPED_DOMAIN_NAME bytes, and option must be less than 32 bytes in length
  74 mDNSlocal mDNSBool GetConfigOption(char *dst, const char *option, FILE *f)
  75         {
  76         char buf[32+1+MAX_ESCAPED_DOMAIN_NAME]; // Option name, one space, option value
  77         unsigned int len = strlen(option);
  78         if (len + 1 + MAX_ESCAPED_DOMAIN_NAME > sizeof(buf)-1) { LogMsg("GetConfigOption: option %s too long", option); return mDNSfalse; }
  79         fseek(f, 0, SEEK_SET);  // set position to beginning of stream
  80         while (fgets(buf, sizeof(buf), f))              // Read at most sizeof(buf)-1 bytes from file, and append '\0' C-string terminator
  81                 {
  82                 if (!strncmp(buf, option, len))
  83                         {
  84                         strncpy(dst, buf + len + 1, MAX_ESCAPED_DOMAIN_NAME-1);
  85                         if (dst[MAX_ESCAPED_DOMAIN_NAME-1]) dst[MAX_ESCAPED_DOMAIN_NAME-1] = '\0';
  86                         len = strlen(dst);
  87                         if (len && dst[len-1] == '\n') dst[len-1] = '\0';  // chop newline
  88                         return mDNStrue;
  89                         }
  90                 }
  91         debugf("Option %s not set", option);
  92         return mDNSfalse;
  93         }
  94
  95 mDNSexport void ReadDDNSSettingsFromConfFile(mDNS *const m, const char *const filename, domainname *const hostname, domainname *const domain, mDNSBool *DomainDiscoveryDisabled)
  96         {
  97         char buf   [MAX_ESCAPED_DOMAIN_NAME];
  98         char secret[MAX_ESCAPED_DOMAIN_NAME] = "";
  99         int slen;
 100         mStatus err;
 101         FILE *f = fopen(filename, "r");
 102
 103     if (hostname)                 hostname->c[0] = 0;
 104     if (domain)                   domain->c[0] = 0;
 105         if (DomainDiscoveryDisabled) *DomainDiscoveryDisabled = mDNSfalse;
 106
 107         if (f)
 108                 {
 109                 if (DomainDiscoveryDisabled && GetConfigOption(buf, "DomainDiscoveryDisabled", f) && !strcasecmp(buf, "true")) *DomainDiscoveryDisabled = mDNStrue;
 110                 if (hostname && GetConfigOption(buf, "hostname", f) && !MakeDomainNameFromDNSNameString(hostname, buf)) goto badf;
 111                 if (domain && GetConfigOption(buf, "zone", f) && !MakeDomainNameFromDNSNameString(domain, buf)) goto badf;
 112                 GetConfigOption(secret, "secret-64", f);  // failure means no authentication
 113                 fclose(f);
 114                 f = NULL;
 115                 }
 116         else
 117                 {
 118                 if (errno != ENOENT) LogMsg("ERROR: Config file exists, but cannot be opened.");
 119                 return;
 120                 }
 121
 122         if (domain && domain->c[0] && secret[0])
 123                 {
 124                 // for now we assume keyname = service reg domain and we use same key for service and hostname registration
 125                 slen = strlen(secret);
 126                 err = mDNS_SetSecretForZone(m, domain, domain, secret, slen, mDNStrue);
 127                 if (err) LogMsg("ERROR: mDNS_SetSecretForZone returned %d for domain %##s", err, domain->c);
 128                 }
 129
 130         return;
 131
 132         badf:
 133         LogMsg("ERROR: malformatted config file");
 134         if (f) fclose(f);
 135         }