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 35typedef unsigned int socklen_t; 36#endif 37 38// Bind a UDP socket to find the source address to a destination 39mDNSexport 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 memset(&addr, 0, sizeof(addr)); 48 if (dst->type == mDNSAddrType_IPv4) 49 { 50 inner_len = sizeof(addr.a4); 51 #ifndef NOT_HAVE_SA_LEN 52 addr.a4.sin_len = inner_len; 53 #endif 54 addr.a4.sin_family = AF_INET; 55 addr.a4.sin_port = 7; // Not important, any port will do 56 addr.a4.sin_addr.s_addr = dst->ip.v4.NotAnInteger; 57 } 58 else if (dst->type == mDNSAddrType_IPv6) 59 { 60 inner_len = sizeof(addr.a6); 61 #ifndef NOT_HAVE_SA_LEN 62 addr.a6.sin6_len = inner_len; 63 #endif 64 addr.a6.sin6_family = AF_INET6; 65 addr.a6.sin6_flowinfo = 0; 66 addr.a6.sin6_port = 7; // Not important, any port will do 67 addr.a6.sin6_addr = *(struct in6_addr*)&dst->ip.v6; 68 addr.a6.sin6_scope_id = 0; 69 } 70 else return; 71 72 if ((connect(sock, &addr.s, inner_len)) < 0) 73 { 74 static mDNSv4Addr dummy = { 198, 51, 100, 42 }; 75 76 // Don't spam if we can't connect to 198.51.100.42 to the console. 77 // That is our test address to out which interfaces/address should be primary and is also 78 // configured in mDNSPosix/PosixDaemon.c:Reconfigure() 79 // Failing to connect to it with EADDRNOTAVAIL is a common situation, especially on boot up. 80 if (dst->type == mDNSAddrType_IPv4 && dst->ip.v4.NotAnInteger == dummy.NotAnInteger && errno == EADDRNOTAVAIL) 81 LogInfo("mDNSPlatformSourceAddrForDest: connect %#a failed errno %d (%s)", dst, errno, strerror(errno)); 82 else 83 LogMsg("mDNSPlatformSourceAddrForDest: connect %#a failed errno %d (%s)", dst, errno, strerror(errno)); 84 goto exit; 85 } 86 87 if ((getsockname(sock, &addr.s, &len)) < 0) 88 { LogMsg("mDNSPlatformSourceAddrForDest: getsockname failed errno %d (%s)", errno, strerror(errno)); goto exit; } 89 90 src->type = dst->type; 91 if (dst->type == mDNSAddrType_IPv4) src->ip.v4.NotAnInteger = addr.a4.sin_addr.s_addr; 92 else src->ip.v6 = *(mDNSv6Addr*)&addr.a6.sin6_addr; 93exit: 94 close(sock); 95} 96 97// dst must be at least MAX_ESCAPED_DOMAIN_NAME bytes, and option must be less than 32 bytes in length 98mDNSlocal mDNSBool GetConfigOption(char *dst, const char *option, FILE *f) 99{ 100 char buf[32+1+MAX_ESCAPED_DOMAIN_NAME]; // Option name, one space, option value 101 unsigned int len = strlen(option); 102 if (len + 1 + MAX_ESCAPED_DOMAIN_NAME > sizeof(buf)-1) { LogMsg("GetConfigOption: option %s too long", option); return mDNSfalse; } 103 fseek(f, 0, SEEK_SET); // set position to beginning of stream 104 while (fgets(buf, sizeof(buf), f)) // Read at most sizeof(buf)-1 bytes from file, and append '\0' C-string terminator 105 { 106 if (!strncmp(buf, option, len)) 107 { 108 strncpy(dst, buf + len + 1, MAX_ESCAPED_DOMAIN_NAME-1); 109 if (dst[MAX_ESCAPED_DOMAIN_NAME-1]) dst[MAX_ESCAPED_DOMAIN_NAME-1] = '\0'; 110 len = strlen(dst); 111 if (len && dst[len-1] == '\n') dst[len-1] = '\0'; // chop newline 112 return mDNStrue; 113 } 114 } 115 debugf("Option %s not set", option); 116 return mDNSfalse; 117} 118 119mDNSexport void ReadDDNSSettingsFromConfFile(mDNS *const m, const char *const filename, domainname *const hostname, domainname *const domain, mDNSBool *DomainDiscoveryDisabled) 120{ 121 char buf[MAX_ESCAPED_DOMAIN_NAME] = ""; 122 mStatus err; 123 FILE *f = fopen(filename, "r"); 124 125 if (hostname) hostname->c[0] = 0; 126 if (domain) domain->c[0] = 0; 127 if (DomainDiscoveryDisabled) *DomainDiscoveryDisabled = mDNSfalse; 128 129 if (f) 130 { 131 if (DomainDiscoveryDisabled && GetConfigOption(buf, "DomainDiscoveryDisabled", f) && !strcasecmp(buf, "true")) *DomainDiscoveryDisabled = mDNStrue; 132 if (hostname && GetConfigOption(buf, "hostname", f) && !MakeDomainNameFromDNSNameString(hostname, buf)) goto badf; 133 if (domain && GetConfigOption(buf, "zone", f) && !MakeDomainNameFromDNSNameString(domain, buf)) goto badf; 134 buf[0] = 0; 135 GetConfigOption(buf, "secret-64", f); // failure means no authentication 136 fclose(f); 137 f = NULL; 138 } 139 else 140 { 141 if (errno != ENOENT) LogMsg("ERROR: Config file exists, but cannot be opened."); 142 return; 143 } 144 145 if (domain && domain->c[0] && buf[0]) 146 { 147 DomainAuthInfo *info = (DomainAuthInfo*)mDNSPlatformMemAllocate(sizeof(*info)); 148 // for now we assume keyname = service reg domain and we use same key for service and hostname registration 149 err = mDNS_SetSecretForDomain(m, info, domain, domain, buf, NULL, 0, mDNSfalse); 150 if (err) LogMsg("ERROR: mDNS_SetSecretForDomain returned %d for domain %##s", err, domain->c); 151 } 152 153 return; 154 155badf: 156 LogMsg("ERROR: malformatted config file"); 157 if (f) fclose(f); 158} 159 160#if MDNS_DEBUGMSGS 161mDNSexport void mDNSPlatformWriteDebugMsg(const char *msg) 162{ 163 fprintf(stderr,"%s\n", msg); 164 fflush(stderr); 165} 166#endif 167 168mDNSexport void mDNSPlatformWriteLogMsg(const char *ident, const char *buffer, mDNSLogLevel_t loglevel) 169{ 170#if APPLE_OSX_mDNSResponder && LogTimeStamps 171 extern mDNS mDNSStorage; 172 extern mDNSu32 mDNSPlatformClockDivisor; 173 mDNSs32 t = mDNSStorage.timenow ? mDNSStorage.timenow : mDNSPlatformClockDivisor ? mDNS_TimeNow_NoLock(&mDNSStorage) : 0; 174 int ms = ((t < 0) ? -t : t) % 1000; 175#endif 176 177 if (mDNS_DebugMode) // In debug mode we write to stderr 178 { 179#if APPLE_OSX_mDNSResponder && LogTimeStamps 180 if (ident && ident[0] && mDNSPlatformClockDivisor) 181 fprintf(stderr,"%8d.%03d: %s\n", (int)(t/1000), ms, buffer); 182 else 183#endif 184 fprintf(stderr,"%s\n", buffer); 185 fflush(stderr); 186 } 187 else // else, in production mode, we write to syslog 188 { 189 static int log_inited = 0; 190 191 int syslog_level = LOG_ERR; 192 switch (loglevel) 193 { 194#if APPLE_OSX_mDNSResponder 195 case MDNS_LOG_MSG: syslog_level = OS_LOG_TYPE_DEFAULT; break; 196 case MDNS_LOG_OPERATION: syslog_level = OS_LOG_TYPE_INFO; break; 197 case MDNS_LOG_SPS: syslog_level = OS_LOG_TYPE_INFO; break; 198 case MDNS_LOG_INFO: syslog_level = OS_LOG_TYPE_INFO; break; 199 case MDNS_LOG_DEBUG: syslog_level = OS_LOG_TYPE_DEBUG; break; 200 default: syslog_level = OS_LOG_TYPE_DEFAULT; break; 201#else 202 case MDNS_LOG_MSG: syslog_level = LOG_ERR; break; 203 case MDNS_LOG_OPERATION: syslog_level = LOG_WARNING; break; 204 case MDNS_LOG_SPS: syslog_level = LOG_NOTICE; break; 205 case MDNS_LOG_INFO: syslog_level = LOG_INFO; break; 206 case MDNS_LOG_DEBUG: syslog_level = LOG_DEBUG; break; 207 default: 208 fprintf(stderr, "Unknown loglevel %d, assuming LOG_ERR\n", loglevel); 209 fflush(stderr); 210#endif 211 } 212 213 if (!log_inited) { openlog(ident, LOG_CONS, LOG_DAEMON); log_inited++; } 214 215#if APPLE_OSX_mDNSResponder && LogTimeStamps 216 if (ident && ident[0] && mDNSPlatformClockDivisor) 217 syslog(syslog_level, "%8d.%03d: %s", (int)(t/1000), ms, buffer); 218 else 219#endif 220 { 221#if APPLE_OSX_mDNSResponder 222 mDNSPlatformLogToFile(syslog_level, buffer); 223#else 224 syslog(syslog_level, "%s", buffer); 225#endif 226 } 227 } 228} 229