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
mDNSPlatformSourceAddrForDest(mDNSAddr * const src,const mDNSAddr * const dst)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 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;
93 exit:
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
GetConfigOption(char * dst,const char * option,FILE * f)98 mDNSlocal 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
ReadDDNSSettingsFromConfFile(mDNS * const m,const char * const filename,domainname * const hostname,domainname * const domain,mDNSBool * DomainDiscoveryDisabled)119 mDNSexport 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
155 badf:
156 LogMsg("ERROR: malformatted config file");
157 if (f) fclose(f);
158 }
159
160 #if MDNS_DEBUGMSGS
mDNSPlatformWriteDebugMsg(const char * msg)161 mDNSexport void mDNSPlatformWriteDebugMsg(const char *msg)
162 {
163 fprintf(stderr,"%s\n", msg);
164 fflush(stderr);
165 }
166 #endif
167
mDNSPlatformWriteLogMsg(const char * ident,const char * buffer,mDNSLogLevel_t loglevel)168 mDNSexport 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