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