usr/src/cmd/cmd-inet/usr.lib/mdnsd/PlatformCommon.c

   1 /* -*- Mode: C; tab-width: 4 -*-
   2  *
   3  * Copyright (c) 2004-2015 Apple 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         if (errno != ENETUNREACH)
  69                 LogMsg("mDNSPlatformSourceAddrForDest: connect %#a failed errno %d (%s)", dst, errno,
  70                     strerror(errno));
  71         goto exit;
  72     }
  73
  74     if ((getsockname(sock, &addr.s, &len)) < 0)
  75     { LogMsg("mDNSPlatformSourceAddrForDest: getsockname failed errno %d (%s)", errno, strerror(errno)); goto exit; }
  76
  77     src->type = dst->type;
  78     if (dst->type == mDNSAddrType_IPv4) src->ip.v4.NotAnInteger = addr.a4.sin_addr.s_addr;
  79     else src->ip.v6 = *(mDNSv6Addr*)&addr.a6.sin6_addr;
  80 exit:
  81     close(sock);
  82 }
  83
  84 // dst must be at least MAX_ESCAPED_DOMAIN_NAME bytes, and option must be less than 32 bytes in length
  85 mDNSlocal mDNSBool GetConfigOption(char *dst, const char *option, FILE *f)
  86 {
  87     char buf[32+1+MAX_ESCAPED_DOMAIN_NAME]; // Option name, one space, option value
  88     unsigned int len = strlen(option);
  89     if (len + 1 + MAX_ESCAPED_DOMAIN_NAME > sizeof(buf)-1) { LogMsg("GetConfigOption: option %s too long", option); return mDNSfalse; }
  90     fseek(f, 0, SEEK_SET);  // set position to beginning of stream
  91     while (fgets(buf, sizeof(buf), f))      // Read at most sizeof(buf)-1 bytes from file, and append '\0' C-string terminator
  92     {
  93         if (!strncmp(buf, option, len))
  94         {
  95             strncpy(dst, buf + len + 1, MAX_ESCAPED_DOMAIN_NAME-1);
  96             if (dst[MAX_ESCAPED_DOMAIN_NAME-1]) dst[MAX_ESCAPED_DOMAIN_NAME-1] = '\0';
  97             len = strlen(dst);
  98             if (len && dst[len-1] == '\n') dst[len-1] = '\0';  // chop newline
  99             return mDNStrue;
 100         }
 101     }
 102     debugf("Option %s not set", option);
 103     return mDNSfalse;
 104 }
 105
 106 mDNSexport void ReadDDNSSettingsFromConfFile(mDNS *const m, const char *const filename, domainname *const hostname, domainname *const domain, mDNSBool *DomainDiscoveryDisabled)
 107 {
 108     char buf[MAX_ESCAPED_DOMAIN_NAME] = "";
 109     mStatus err;
 110     FILE *f = fopen(filename, "r");
 111
 112     if (hostname) hostname->c[0] = 0;
 113     if (domain) domain->c[0] = 0;
 114     if (DomainDiscoveryDisabled) *DomainDiscoveryDisabled = mDNSfalse;
 115
 116     if (f)
 117     {
 118         if (DomainDiscoveryDisabled && GetConfigOption(buf, "DomainDiscoveryDisabled", f) && !strcasecmp(buf, "true")) *DomainDiscoveryDisabled = mDNStrue;
 119         if (hostname && GetConfigOption(buf, "hostname", f) && !MakeDomainNameFromDNSNameString(hostname, buf)) goto badf;
 120         if (domain && GetConfigOption(buf, "zone", f) && !MakeDomainNameFromDNSNameString(domain, buf)) goto badf;
 121         buf[0] = 0;
 122         GetConfigOption(buf, "secret-64", f);  // failure means no authentication
 123         fclose(f);
 124         f = NULL;
 125     }
 126     else
 127     {
 128         if (errno != ENOENT) LogMsg("ERROR: Config file exists, but cannot be opened.");
 129         return;
 130     }
 131
 132     if (domain && domain->c[0] && buf[0])
 133     {
 134         DomainAuthInfo *info = (DomainAuthInfo*)mDNSPlatformMemAllocate(sizeof(*info));
 135         // for now we assume keyname = service reg domain and we use same key for service and hostname registration
 136         err = mDNS_SetSecretForDomain(m, info, domain, domain, buf, NULL, 0, mDNSfalse);
 137         if (err) LogMsg("ERROR: mDNS_SetSecretForDomain returned %d for domain %##s", err, domain->c);
 138     }
 139
 140     return;
 141
 142 badf:
 143     LogMsg("ERROR: malformatted config file");
 144     if (f) fclose(f);
 145 }
 146
 147 #if MDNS_DEBUGMSGS
 148 mDNSexport void mDNSPlatformWriteDebugMsg(const char *msg)
 149 {
 150     fprintf(stderr,"%s\n", msg);
 151     fflush(stderr);
 152 }
 153 #endif
 154
 155 mDNSexport void mDNSPlatformWriteLogMsg(const char *ident, const char *buffer, mDNSLogLevel_t loglevel)
 156 {
 157 #if APPLE_OSX_mDNSResponder && LogTimeStamps
 158     extern mDNS mDNSStorage;
 159     extern mDNSu32 mDNSPlatformClockDivisor;
 160     mDNSs32 t = mDNSStorage.timenow ? mDNSStorage.timenow : mDNSPlatformClockDivisor ? mDNS_TimeNow_NoLock(&mDNSStorage) : 0;
 161     int ms = ((t < 0) ? -t : t) % 1000;
 162 #endif
 163
 164     if (mDNS_DebugMode) // In debug mode we write to stderr
 165     {
 166 #if APPLE_OSX_mDNSResponder && LogTimeStamps
 167         if (ident && ident[0] && mDNSPlatformClockDivisor)
 168             fprintf(stderr,"%8d.%03d: %s\n", (int)(t/1000), ms, buffer);
 169         else
 170 #endif
 171         fprintf(stderr,"%s\n", buffer);
 172         fflush(stderr);
 173     }
 174     else                // else, in production mode, we write to syslog
 175     {
 176         static int log_inited = 0;
 177
 178         int syslog_level = LOG_ERR;
 179         switch (loglevel)
 180         {
 181         case MDNS_LOG_MSG:       syslog_level = LOG_ERR;     break;
 182         case MDNS_LOG_OPERATION: syslog_level = LOG_WARNING; break;
 183         case MDNS_LOG_SPS:       syslog_level = LOG_NOTICE;  break;
 184         case MDNS_LOG_INFO:      syslog_level = LOG_INFO;    break;
 185         case MDNS_LOG_DEBUG:     syslog_level = LOG_DEBUG;   break;
 186         default:
 187             fprintf(stderr, "Unknown loglevel %d, assuming LOG_ERR\n", loglevel);
 188             fflush(stderr);
 189         }
 190
 191         if (!log_inited) { openlog(ident, LOG_CONS, LOG_DAEMON); log_inited++; }
 192
 193 #if APPLE_OSX_mDNSResponder && LogTimeStamps
 194         if (ident && ident[0] && mDNSPlatformClockDivisor)
 195             syslog(syslog_level, "%8d.%03d: %s", (int)(t/1000), ms, buffer);
 196         else
 197 #endif
 198         {
 199 #if APPLE_OSX_mDNSResponder
 200             mDNSPlatformLogToFile(syslog_level, buffer);
 201 #else
 202             syslog(syslog_level, "%s", buffer);
 203 #endif
 204         }
 205     }
 206 }