1 /*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <arpa/inet.h>
18 #include <dirent.h>
19 #include <errno.h>
20 #include <linux/if.h>
21 #include <netdb.h>
22 #include <netinet/in.h>
23 #include <stdlib.h>
24 #include <sys/socket.h>
25 #include <sys/types.h>
26 #include <string.h>
27
28 #define LOG_TAG "DnsProxyListener"
29 #define DBG 0
30
31 #include <cutils/log.h>
32 #include <sysutils/SocketClient.h>
33
34 #include "DnsProxyListener.h"
35 #include "ResponseCode.h"
36
DnsProxyListener()37 DnsProxyListener::DnsProxyListener() :
38 FrameworkListener("dnsproxyd") {
39 registerCmd(new GetAddrInfoCmd());
40 registerCmd(new GetHostByAddrCmd());
41 }
42
~GetAddrInfoHandler()43 DnsProxyListener::GetAddrInfoHandler::~GetAddrInfoHandler() {
44 free(mHost);
45 free(mService);
46 free(mHints);
47 }
48
start()49 void DnsProxyListener::GetAddrInfoHandler::start() {
50 pthread_create(&mThread, NULL,
51 DnsProxyListener::GetAddrInfoHandler::threadStart, this);
52 }
53
threadStart(void * obj)54 void* DnsProxyListener::GetAddrInfoHandler::threadStart(void* obj) {
55 GetAddrInfoHandler* handler = reinterpret_cast<GetAddrInfoHandler*>(obj);
56 handler->run();
57 delete handler;
58 pthread_exit(NULL);
59 return NULL;
60 }
61
62 // Sends 4 bytes of big-endian length, followed by the data.
63 // Returns true on success.
sendLenAndData(SocketClient * c,const int len,const void * data)64 static bool sendLenAndData(SocketClient *c, const int len, const void* data) {
65 uint32_t len_be = htonl(len);
66 return c->sendData(&len_be, 4) == 0 &&
67 (len == 0 || c->sendData(data, len) == 0);
68 }
69
run()70 void DnsProxyListener::GetAddrInfoHandler::run() {
71 if (DBG) {
72 ALOGD("GetAddrInfoHandler, now for %s / %s", mHost, mService);
73 }
74
75 struct addrinfo* result = NULL;
76 uint32_t rv = getaddrinfo(mHost, mService, mHints, &result);
77 if (rv) {
78 // getaddrinfo failed
79 mClient->sendBinaryMsg(ResponseCode::DnsProxyOperationFailed, &rv, sizeof(rv));
80 } else {
81 bool success = !mClient->sendCode(ResponseCode::DnsProxyQueryResult);
82 struct addrinfo* ai = result;
83 while (ai && success) {
84 success = sendLenAndData(mClient, sizeof(struct addrinfo), ai)
85 && sendLenAndData(mClient, ai->ai_addrlen, ai->ai_addr)
86 && sendLenAndData(mClient,
87 ai->ai_canonname ? strlen(ai->ai_canonname) + 1 : 0,
88 ai->ai_canonname);
89 ai = ai->ai_next;
90 }
91 success = success && sendLenAndData(mClient, 0, "");
92 if (!success) {
93 ALOGW("Error writing DNS result to client");
94 }
95 }
96 if (result) {
97 freeaddrinfo(result);
98 }
99 mClient->decRef();
100 }
101
GetAddrInfoCmd()102 DnsProxyListener::GetAddrInfoCmd::GetAddrInfoCmd() :
103 NetdCommand("getaddrinfo") {
104 }
105
runCommand(SocketClient * cli,int argc,char ** argv)106 int DnsProxyListener::GetAddrInfoCmd::runCommand(SocketClient *cli,
107 int argc, char **argv) {
108 if (DBG) {
109 for (int i = 0; i < argc; i++) {
110 ALOGD("argv[%i]=%s", i, argv[i]);
111 }
112 }
113 if (argc != 7) {
114 char* msg = NULL;
115 asprintf( &msg, "Invalid number of arguments to getaddrinfo: %i", argc);
116 ALOGW("%s", msg);
117 cli->sendMsg(ResponseCode::CommandParameterError, msg, false);
118 free(msg);
119 return -1;
120 }
121
122 char* name = argv[1];
123 if (strcmp("^", name) == 0) {
124 name = NULL;
125 } else {
126 name = strdup(name);
127 }
128
129 char* service = argv[2];
130 if (strcmp("^", service) == 0) {
131 service = NULL;
132 } else {
133 service = strdup(service);
134 }
135
136 struct addrinfo* hints = NULL;
137 int ai_flags = atoi(argv[3]);
138 int ai_family = atoi(argv[4]);
139 int ai_socktype = atoi(argv[5]);
140 int ai_protocol = atoi(argv[6]);
141 if (ai_flags != -1 || ai_family != -1 ||
142 ai_socktype != -1 || ai_protocol != -1) {
143 hints = (struct addrinfo*) calloc(1, sizeof(struct addrinfo));
144 hints->ai_flags = ai_flags;
145 hints->ai_family = ai_family;
146 hints->ai_socktype = ai_socktype;
147 hints->ai_protocol = ai_protocol;
148 }
149
150 if (DBG) {
151 ALOGD("GetAddrInfoHandler for %s / %s",
152 name ? name : "[nullhost]",
153 service ? service : "[nullservice]");
154 }
155
156 cli->incRef();
157 DnsProxyListener::GetAddrInfoHandler* handler =
158 new DnsProxyListener::GetAddrInfoHandler(cli, name, service, hints);
159 handler->start();
160
161 return 0;
162 }
163
164 /*******************************************************
165 * GetHostByAddr *
166 *******************************************************/
GetHostByAddrCmd()167 DnsProxyListener::GetHostByAddrCmd::GetHostByAddrCmd() :
168 NetdCommand("gethostbyaddr") {
169 }
170
runCommand(SocketClient * cli,int argc,char ** argv)171 int DnsProxyListener::GetHostByAddrCmd::runCommand(SocketClient *cli,
172 int argc, char **argv) {
173 if (DBG) {
174 for (int i = 0; i < argc; i++) {
175 ALOGD("argv[%i]=%s", i, argv[i]);
176 }
177 }
178
179 if (argc != 4) {
180 char* msg = NULL;
181 asprintf(&msg, "Invalid number of arguments to gethostbyaddr: %i", argc);
182 ALOGW("%s", msg);
183 cli->sendMsg(ResponseCode::CommandParameterError, msg, false);
184 free(msg);
185 return -1;
186 }
187
188 char* addrStr = argv[1];
189 int addrLen = atoi(argv[2]);
190 int addrFamily = atoi(argv[3]);
191
192 void* addr = malloc(sizeof(struct in6_addr));
193 errno = 0;
194 int result = inet_pton(addrFamily, addrStr, addr);
195 if (result <= 0) {
196 char* msg = NULL;
197 asprintf(&msg, "inet_pton(\"%s\") failed %s", addrStr, strerror(errno));
198 ALOGW("%s", msg);
199 cli->sendMsg(ResponseCode::OperationFailed, msg, false);
200 free(addr);
201 free(msg);
202 return -1;
203 }
204
205 cli->incRef();
206 DnsProxyListener::GetHostByAddrHandler* handler =
207 new DnsProxyListener::GetHostByAddrHandler(cli, addr, addrLen, addrFamily);
208 handler->start();
209
210 return 0;
211 }
212
~GetHostByAddrHandler()213 DnsProxyListener::GetHostByAddrHandler::~GetHostByAddrHandler() {
214 free(mAddress);
215 }
216
start()217 void DnsProxyListener::GetHostByAddrHandler::start() {
218 pthread_create(&mThread, NULL,
219 DnsProxyListener::GetHostByAddrHandler::threadStart, this);
220 }
221
threadStart(void * obj)222 void* DnsProxyListener::GetHostByAddrHandler::threadStart(void* obj) {
223 GetHostByAddrHandler* handler = reinterpret_cast<GetHostByAddrHandler*>(obj);
224 handler->run();
225 delete handler;
226 pthread_exit(NULL);
227 return NULL;
228 }
229
run()230 void DnsProxyListener::GetHostByAddrHandler::run() {
231 if (DBG) {
232 ALOGD("DnsProxyListener::GetHostByAddrHandler::run\n");
233 }
234
235 struct hostent* hp;
236
237 // NOTE gethostbyaddr should take a void* but bionic thinks it should be char*
238 hp = gethostbyaddr((char*)mAddress, mAddressLen, mAddressFamily);
239
240 if (DBG) {
241 ALOGD("GetHostByAddrHandler::run gethostbyaddr errno: %s hp->h_name = %s, name_len = %d\n",
242 hp ? "success" : strerror(errno),
243 (hp && hp->h_name) ? hp->h_name: "null",
244 (hp && hp->h_name) ? strlen(hp->h_name)+ 1 : 0);
245 }
246
247 bool failed = true;
248 if (hp) {
249 failed = mClient->sendBinaryMsg(ResponseCode::DnsProxyQueryResult,
250 hp->h_name ? hp->h_name : "",
251 hp->h_name ? strlen(hp->h_name)+ 1 : 0);
252 } else {
253 uint32_t error = h_errno;
254 failed = mClient->sendBinaryMsg(ResponseCode::DnsProxyOperationFailed,
255 &error, sizeof(error));
256 }
257
258 if (failed) {
259 ALOGW("GetHostByAddrHandler: Error writing DNS result to client\n");
260 }
261 mClient->decRef();
262 }
263