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 #if APPLE_OSX_mDNSResponder 27 #include <os/log.h> 28 #endif 29 30 #include "mDNSEmbeddedAPI.h" // Defines the interface provided to the client layer above 31 #include "DNSCommon.h" 32 #include "PlatformCommon.h" 33 34 #ifdef NOT_HAVE_SOCKLEN_T 35 typedef unsigned int socklen_t; 36 #endif 37 38 // Bind a UDP socket to find the source address to a destination 39 mDNSexport void mDNSPlatformSourceAddrForDest(mDNSAddr *const src, const mDNSAddr *const dst) 40 { 41 union { struct sockaddr s; struct sockaddr_in a4; struct sockaddr_in6 a6; } addr; 42 socklen_t len = sizeof(addr); 43 socklen_t inner_len = 0; 44 int sock = socket(AF_INET, SOCK_DGRAM, 0); 45 src->type = mDNSAddrType_None; 46 if (sock == -1) return; 47 if (dst->type == mDNSAddrType_IPv4) 48 { 49 inner_len = sizeof(addr.a4); 50 #ifndef NOT_HAVE_SA_LEN 51 addr.a4.sin_len = inner_len; 52 #endif 53 addr.a4.sin_family = AF_INET; 54 addr.a4.sin_port = 1; // Not important, any port will do 55 addr.a4.sin_addr.s_addr = dst->ip.v4.NotAnInteger; 56 } 57 else if (dst->type == mDNSAddrType_IPv6) 58 { 59 inner_len = sizeof(addr.a6); 60 #ifndef NOT_HAVE_SA_LEN 61 addr.a6.sin6_len = inner_len; 62 #endif 63 addr.a6.sin6_family = AF_INET6; 64 addr.a6.sin6_flowinfo = 0; 65 addr.a6.sin6_port = 1; // Not important, any port will do 66 addr.a6.sin6_addr = *(struct in6_addr*)&dst->ip.v6; 67 addr.a6.sin6_scope_id = 0; 68 } 69 else return; 70 71 if ((connect(sock, &addr.s, inner_len)) < 0) { 72 if (errno != ENETUNREACH) { 73 LogMsg("mDNSPlatformSourceAddrForDest: connect %#a failed errno %d " 74 "(%s)", dst, errno, strerror(errno)); 75 } 76 goto exit; 77 } 78 79 if ((getsockname(sock, &addr.s, &len)) < 0) 80 { LogMsg("mDNSPlatformSourceAddrForDest: getsockname failed errno %d (%s)", errno, strerror(errno)); goto exit; } 81 82 src->type = dst->type; 83 if (dst->type == mDNSAddrType_IPv4) src->ip.v4.NotAnInteger = addr.a4.sin_addr.s_addr; 84 else src->ip.v6 = *(mDNSv6Addr*)&addr.a6.sin6_addr; 85 exit: 86 close(sock); 87 } 88 89 // dst must be at least MAX_ESCAPED_DOMAIN_NAME bytes, and option must be less than 32 bytes in length 90 mDNSlocal mDNSBool GetConfigOption(char *dst, const char *option, FILE *f) 91 { 92 char buf[32+1+MAX_ESCAPED_DOMAIN_NAME]; // Option name, one space, option value 93 unsigned int len = strlen(option); 94 if (len + 1 + MAX_ESCAPED_DOMAIN_NAME > sizeof(buf)-1) { LogMsg("GetConfigOption: option %s too long", option); return mDNSfalse; } 95 fseek(f, 0, SEEK_SET); // set position to beginning of stream 96 while (fgets(buf, sizeof(buf), f)) // Read at most sizeof(buf)-1 bytes from file, and append '\0' C-string terminator 97 { 98 if (!strncmp(buf, option, len)) 99 { 100 strncpy(dst, buf + len + 1, MAX_ESCAPED_DOMAIN_NAME-1); 101 if (dst[MAX_ESCAPED_DOMAIN_NAME-1]) dst[MAX_ESCAPED_DOMAIN_NAME-1] = '\0'; 102 len = strlen(dst); 103 if (len && dst[len-1] == '\n') dst[len-1] = '\0'; // chop newline 104 return mDNStrue; 105 } 106 } 107 debugf("Option %s not set", option); 108 return mDNSfalse; 109 } 110 111 mDNSexport void ReadDDNSSettingsFromConfFile(mDNS *const m, const char *const filename, domainname *const hostname, domainname *const domain, mDNSBool *DomainDiscoveryDisabled) 112 { 113 char buf[MAX_ESCAPED_DOMAIN_NAME] = ""; 114 mStatus err; 115 FILE *f = fopen(filename, "r"); 116 117 if (hostname) hostname->c[0] = 0; 118 if (domain) domain->c[0] = 0; 119 if (DomainDiscoveryDisabled) *DomainDiscoveryDisabled = mDNSfalse; 120 121 if (f) 122 { 123 if (DomainDiscoveryDisabled && GetConfigOption(buf, "DomainDiscoveryDisabled", f) && !strcasecmp(buf, "true")) *DomainDiscoveryDisabled = mDNStrue; 124 if (hostname && GetConfigOption(buf, "hostname", f) && !MakeDomainNameFromDNSNameString(hostname, buf)) goto badf; 125 if (domain && GetConfigOption(buf, "zone", f) && !MakeDomainNameFromDNSNameString(domain, buf)) goto badf; 126 buf[0] = 0; 127 GetConfigOption(buf, "secret-64", f); // failure means no authentication 128 fclose(f); 129 f = NULL; 130 } 131 else 132 { 133 if (errno != ENOENT) LogMsg("ERROR: Config file exists, but cannot be opened."); 134 return; 135 } 136 137 if (domain && domain->c[0] && buf[0]) 138 { 139 DomainAuthInfo *info = (DomainAuthInfo*)mDNSPlatformMemAllocate(sizeof(*info)); 140 // for now we assume keyname = service reg domain and we use same key for service and hostname registration 141 err = mDNS_SetSecretForDomain(m, info, domain, domain, buf, NULL, 0, mDNSfalse); 142 if (err) LogMsg("ERROR: mDNS_SetSecretForDomain returned %d for domain %##s", err, domain->c); 143 } 144 145 return; 146 147 badf: 148 LogMsg("ERROR: malformatted config file"); 149 if (f) fclose(f); 150 } 151 152 #if MDNS_DEBUGMSGS 153 mDNSexport void mDNSPlatformWriteDebugMsg(const char *msg) 154 { 155 fprintf(stderr,"%s\n", msg); 156 fflush(stderr); 157 } 158 #endif 159 160 mDNSexport void mDNSPlatformWriteLogMsg(const char *ident, const char *buffer, mDNSLogLevel_t loglevel) 161 { 162 #if APPLE_OSX_mDNSResponder && LogTimeStamps 163 extern mDNS mDNSStorage; 164 extern mDNSu32 mDNSPlatformClockDivisor; 165 mDNSs32 t = mDNSStorage.timenow ? mDNSStorage.timenow : mDNSPlatformClockDivisor ? mDNS_TimeNow_NoLock(&mDNSStorage) : 0; 166 int ms = ((t < 0) ? -t : t) % 1000; 167 #endif 168 169 if (mDNS_DebugMode) // In debug mode we write to stderr 170 { 171 #if APPLE_OSX_mDNSResponder && LogTimeStamps 172 if (ident && ident[0] && mDNSPlatformClockDivisor) 173 fprintf(stderr,"%8d.%03d: %s\n", (int)(t/1000), ms, buffer); 174 else 175 #endif 176 fprintf(stderr,"%s\n", buffer); 177 fflush(stderr); 178 } 179 else // else, in production mode, we write to syslog 180 { 181 static int log_inited = 0; 182 183 int syslog_level = LOG_ERR; 184 switch (loglevel) 185 { 186 #if APPLE_OSX_mDNSResponder 187 case MDNS_LOG_MSG: syslog_level = OS_LOG_TYPE_DEFAULT; break; 188 case MDNS_LOG_OPERATION: syslog_level = OS_LOG_TYPE_INFO; break; 189 case MDNS_LOG_SPS: syslog_level = OS_LOG_TYPE_INFO; break; 190 case MDNS_LOG_INFO: syslog_level = OS_LOG_TYPE_INFO; break; 191 case MDNS_LOG_DEBUG: syslog_level = OS_LOG_TYPE_DEBUG; break; 192 default: syslog_level = OS_LOG_TYPE_DEFAULT; break; 193 #else 194 case MDNS_LOG_MSG: syslog_level = LOG_ERR; break; 195 case MDNS_LOG_OPERATION: syslog_level = LOG_WARNING; break; 196 case MDNS_LOG_SPS: syslog_level = LOG_NOTICE; break; 197 case MDNS_LOG_INFO: syslog_level = LOG_INFO; break; 198 case MDNS_LOG_DEBUG: syslog_level = LOG_DEBUG; break; 199 default: 200 fprintf(stderr, "Unknown loglevel %d, assuming LOG_ERR\n", loglevel); 201 fflush(stderr); 202 #endif 203 } 204 205 if (!log_inited) { openlog(ident, LOG_CONS, LOG_DAEMON); log_inited++; } 206 207 #if APPLE_OSX_mDNSResponder && LogTimeStamps 208 if (ident && ident[0] && mDNSPlatformClockDivisor) 209 syslog(syslog_level, "%8d.%03d: %s", (int)(t/1000), ms, buffer); 210 else 211 #endif 212 { 213 #if APPLE_OSX_mDNSResponder 214 mDNSPlatformLogToFile(syslog_level, buffer); 215 #else 216 syslog(syslog_level, "%s", buffer); 217 #endif 218 } 219 } 220 } 221