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
  18 #include <stdio.h>                              // Needed for fopen() etc.
  19 #include <unistd.h>                             // Needed for close()
  20 #include <string.h>                             // Needed for strlen() etc.
  21 #include <errno.h>                              // Needed for errno etc.
  22 #include <sys/socket.h>                 // Needed for socket() etc.
  23 #include <netinet/in.h>                 // Needed for sockaddr_in
  24 #include <syslog.h>
  25
  26 #include "mDNSEmbeddedAPI.h"    // Defines the interface provided to the client layer above
  27 #include "DNSCommon.h"
  28 #include "PlatformCommon.h"
  29
  30 #ifdef NOT_HAVE_SOCKLEN_T
  31     typedef unsigned int socklen_t;
  32 #endif
  33
  34 // Bind a UDP socket to find the source address to a destination
  35 mDNSexport void mDNSPlatformSourceAddrForDest(mDNSAddr *const src, const mDNSAddr *const dst)
  36         {
  37         union { struct sockaddr s; struct sockaddr_in a4; struct sockaddr_in6 a6; } addr;
  38         socklen_t len = sizeof(addr);
  39         socklen_t inner_len = 0;
  40         int sock = socket(AF_INET, SOCK_DGRAM, 0);
  41         src->type = mDNSAddrType_None;
  42         if (sock == -1) return;
  43         if (dst->type == mDNSAddrType_IPv4)
  44                 {
  45                 inner_len = sizeof(addr.a4);
  46                 #ifndef NOT_HAVE_SA_LEN
  47                 addr.a4.sin_len         = inner_len;
  48                 #endif
  49                 addr.a4.sin_family      = AF_INET;
  50                 addr.a4.sin_port        = 1;    // Not important, any port will do
  51                 addr.a4.sin_addr.s_addr = dst->ip.v4.NotAnInteger;
  52                 }
  53         else if (dst->type == mDNSAddrType_IPv6)
  54                 {
  55                 inner_len = sizeof(addr.a6);
  56                 #ifndef NOT_HAVE_SA_LEN
  57                 addr.a6.sin6_len      = inner_len;
  58                 #endif
  59                 addr.a6.sin6_family   = AF_INET6;
  60                 addr.a6.sin6_flowinfo = 0;
  61                 addr.a6.sin6_port     = 1;      // Not important, any port will do
  62                 addr.a6.sin6_addr     = *(struct in6_addr*)&dst->ip.v6;
  63                 addr.a6.sin6_scope_id = 0;
  64                 }
  65         else return;
  66
  67         if ((connect(sock, &addr.s, inner_len)) < 0)
  68                 { LogMsg("mDNSPlatformSourceAddrForDest: connect %#a failed errno %d (%s)", dst, errno, strerror(errno)); goto exit; }
  69
  70         if ((getsockname(sock, &addr.s, &len)) < 0)
  71                 { LogMsg("mDNSPlatformSourceAddrForDest: getsockname failed errno %d (%s)", errno, strerror(errno)); goto exit; }
  72
  73         src->type = dst->type;
  74         if (dst->type == mDNSAddrType_IPv4) src->ip.v4.NotAnInteger = addr.a4.sin_addr.s_addr;
  75         else                                src->ip.v6 = *(mDNSv6Addr*)&addr.a6.sin6_addr;
  76 exit:
  77         close(sock);
  78         }
  79
  80 // dst must be at least MAX_ESCAPED_DOMAIN_NAME bytes, and option must be less than 32 bytes in length
  81 mDNSlocal mDNSBool GetConfigOption(char *dst, const char *option, FILE *f)
  82         {
  83         char buf[32+1+MAX_ESCAPED_DOMAIN_NAME]; // Option name, one space, option value
  84         unsigned int len = strlen(option);
  85         if (len + 1 + MAX_ESCAPED_DOMAIN_NAME > sizeof(buf)-1) { LogMsg("GetConfigOption: option %s too long", option); return mDNSfalse; }
  86         fseek(f, 0, SEEK_SET);  // set position to beginning of stream
  87         while (fgets(buf, sizeof(buf), f))              // Read at most sizeof(buf)-1 bytes from file, and append '\0' C-string terminator
  88                 {
  89                 if (!strncmp(buf, option, len))
  90                         {
  91                         strncpy(dst, buf + len + 1, MAX_ESCAPED_DOMAIN_NAME-1);
  92                         if (dst[MAX_ESCAPED_DOMAIN_NAME-1]) dst[MAX_ESCAPED_DOMAIN_NAME-1] = '\0';
  93                         len = strlen(dst);
  94                         if (len && dst[len-1] == '\n') dst[len-1] = '\0';  // chop newline
  95                         return mDNStrue;
  96                         }
  97                 }
  98         debugf("Option %s not set", option);
  99         return mDNSfalse;
 100         }
 101
 102 mDNSexport void ReadDDNSSettingsFromConfFile(mDNS *const m, const char *const filename, domainname *const hostname, domainname *const domain, mDNSBool *DomainDiscoveryDisabled)
 103         {
 104         char buf[MAX_ESCAPED_DOMAIN_NAME] = "";
 105         mStatus err;
 106         FILE *f = fopen(filename, "r");
 107
 108     if (hostname)                 hostname->c[0] = 0;
 109     if (domain)                   domain->c[0] = 0;
 110         if (DomainDiscoveryDisabled) *DomainDiscoveryDisabled = mDNSfalse;
 111
 112         if (f)
 113                 {
 114                 if (DomainDiscoveryDisabled && GetConfigOption(buf, "DomainDiscoveryDisabled", f) && !strcasecmp(buf, "true")) *DomainDiscoveryDisabled = mDNStrue;
 115                 if (hostname && GetConfigOption(buf, "hostname", f) && !MakeDomainNameFromDNSNameString(hostname, buf)) goto badf;
 116                 if (domain && GetConfigOption(buf, "zone", f) && !MakeDomainNameFromDNSNameString(domain, buf)) goto badf;
 117                 buf[0] = 0;
 118                 GetConfigOption(buf, "secret-64", f);  // failure means no authentication
 119                 fclose(f);
 120                 f = NULL;
 121                 }
 122         else
 123                 {
 124                 if (errno != ENOENT) LogMsg("ERROR: Config file exists, but cannot be opened.");
 125                 return;
 126                 }
 127
 128         if (domain && domain->c[0] && buf[0])
 129                 {
 130                 DomainAuthInfo *info = (DomainAuthInfo*)mDNSPlatformMemAllocate(sizeof(*info));
 131                 // for now we assume keyname = service reg domain and we use same key for service and hostname registration
 132                 err = mDNS_SetSecretForDomain(m, info, domain, domain, buf, NULL, 0, NULL);
 133                 if (err) LogMsg("ERROR: mDNS_SetSecretForDomain returned %d for domain %##s", err, domain->c);
 134                 }
 135
 136         return;
 137
 138         badf:
 139         LogMsg("ERROR: malformatted config file");
 140         if (f) fclose(f);
 141         }
 142
 143 #if MDNS_DEBUGMSGS
 144 mDNSexport void mDNSPlatformWriteDebugMsg(const char *msg)
 145         {
 146         fprintf(stderr,"%s\n", msg);
 147         fflush(stderr);
 148         }
 149 #endif
 150
 151 mDNSexport void mDNSPlatformWriteLogMsg(const char *ident, const char *buffer, mDNSLogLevel_t loglevel)
 152         {
 153 #if APPLE_OSX_mDNSResponder && LogTimeStamps
 154         extern mDNS mDNSStorage;
 155         extern mDNSu32 mDNSPlatformClockDivisor;
 156         mDNSs32 t = mDNSStorage.timenow ? mDNSStorage.timenow : mDNSPlatformClockDivisor ? mDNS_TimeNow_NoLock(&mDNSStorage) : 0;
 157         int ms = ((t < 0) ? -t : t) % 1000;
 158 #endif
 159
 160         if (mDNS_DebugMode)     // In debug mode we write to stderr
 161                 {
 162 #if APPLE_OSX_mDNSResponder && LogTimeStamps
 163                 if (ident && ident[0] && mDNSPlatformClockDivisor)
 164                         fprintf(stderr,"%8d.%03d: %s\n", (int)(t/1000), ms, buffer);
 165                 else
 166 #endif
 167                         fprintf(stderr,"%s\n", buffer);
 168                 fflush(stderr);
 169                 }
 170         else                            // else, in production mode, we write to syslog
 171                 {
 172                 static int log_inited = 0;
 173
 174                 int syslog_level = LOG_ERR;
 175                 switch (loglevel)
 176                         {
 177                         case MDNS_LOG_MSG:       syslog_level = LOG_ERR;     break;
 178                         case MDNS_LOG_OPERATION: syslog_level = LOG_WARNING; break;
 179                         case MDNS_LOG_SPS:       syslog_level = LOG_NOTICE;  break;
 180                         case MDNS_LOG_INFO:      syslog_level = LOG_INFO;    break;
 181                         case MDNS_LOG_DEBUG:     syslog_level = LOG_DEBUG;   break;
 182                         default:
 183                         fprintf(stderr, "Unknown loglevel %d, assuming LOG_ERR\n", loglevel);
 184                         fflush(stderr);
 185                         }
 186
 187                 if (!log_inited) { openlog(ident, LOG_CONS, LOG_DAEMON); log_inited++; }
 188
 189 #if APPLE_OSX_mDNSResponder && LogTimeStamps
 190                 if (ident && ident[0] && mDNSPlatformClockDivisor)
 191                         syslog(syslog_level, "%8d.%03d: %s", (int)(t/1000), ms, buffer);
 192                 else
 193 #endif
 194                         syslog(syslog_level, "%s", buffer);
 195                 }
 196         }