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 #include <pthread.h> 28 #include <resolv_netid.h> 29 #include <net/if.h> 30 31 #define LOG_TAG "DnsProxyListener" 32 #define DBG 0 33 #define VDBG 0 34 35 #include <cutils/log.h> 36 #include <sysutils/SocketClient.h> 37 38 #include "Fwmark.h" 39 #include "DnsProxyListener.h" 40 #include "NetdConstants.h" 41 #include "NetworkController.h" 42 #include "ResponseCode.h" 43 44 DnsProxyListener::DnsProxyListener(const NetworkController* netCtrl) : 45 FrameworkListener("dnsproxyd"), mNetCtrl(netCtrl) { 46 registerCmd(new GetAddrInfoCmd(this)); 47 registerCmd(new GetHostByAddrCmd(this)); 48 registerCmd(new GetHostByNameCmd(this)); 49 } 50 51 DnsProxyListener::GetAddrInfoHandler::GetAddrInfoHandler(SocketClient *c, 52 char* host, 53 char* service, 54 struct addrinfo* hints, 55 unsigned netId, 56 uint32_t mark) 57 : mClient(c), 58 mHost(host), 59 mService(service), 60 mHints(hints), 61 mNetId(netId), 62 mMark(mark) { 63 } 64 65 DnsProxyListener::GetAddrInfoHandler::~GetAddrInfoHandler() { 66 free(mHost); 67 free(mService); 68 free(mHints); 69 } 70 71 void DnsProxyListener::GetAddrInfoHandler::start() { 72 pthread_t thread; 73 pthread_create(&thread, NULL, 74 DnsProxyListener::GetAddrInfoHandler::threadStart, this); 75 pthread_detach(thread); 76 } 77 78 void* DnsProxyListener::GetAddrInfoHandler::threadStart(void* obj) { 79 GetAddrInfoHandler* handler = reinterpret_cast<GetAddrInfoHandler*>(obj); 80 handler->run(); 81 delete handler; 82 pthread_exit(NULL); 83 return NULL; 84 } 85 86 // Sends 4 bytes of big-endian length, followed by the data. 87 // Returns true on success. 88 static bool sendLenAndData(SocketClient *c, const int len, const void* data) { 89 uint32_t len_be = htonl(len); 90 return c->sendData(&len_be, 4) == 0 && 91 (len == 0 || c->sendData(data, len) == 0); 92 } 93 94 // Returns true on success 95 static bool sendhostent(SocketClient *c, struct hostent *hp) { 96 bool success = true; 97 int i; 98 if (hp->h_name != NULL) { 99 success &= sendLenAndData(c, strlen(hp->h_name)+1, hp->h_name); 100 } else { 101 success &= sendLenAndData(c, 0, "") == 0; 102 } 103 104 for (i=0; hp->h_aliases[i] != NULL; i++) { 105 success &= sendLenAndData(c, strlen(hp->h_aliases[i])+1, hp->h_aliases[i]); 106 } 107 success &= sendLenAndData(c, 0, ""); // null to indicate we're done 108 109 uint32_t buf = htonl(hp->h_addrtype); 110 success &= c->sendData(&buf, sizeof(buf)) == 0; 111 112 buf = htonl(hp->h_length); 113 success &= c->sendData(&buf, sizeof(buf)) == 0; 114 115 for (i=0; hp->h_addr_list[i] != NULL; i++) { 116 success &= sendLenAndData(c, 16, hp->h_addr_list[i]); 117 } 118 success &= sendLenAndData(c, 0, ""); // null to indicate we're done 119 return success; 120 } 121 122 void DnsProxyListener::GetAddrInfoHandler::run() { 123 if (DBG) { 124 ALOGD("GetAddrInfoHandler, now for %s / %s / %u / %u", mHost, mService, mNetId, mMark); 125 } 126 127 struct addrinfo* result = NULL; 128 uint32_t rv = android_getaddrinfofornet(mHost, mService, mHints, mNetId, mMark, &result); 129 if (rv) { 130 // getaddrinfo failed 131 mClient->sendBinaryMsg(ResponseCode::DnsProxyOperationFailed, &rv, sizeof(rv)); 132 } else { 133 bool success = !mClient->sendCode(ResponseCode::DnsProxyQueryResult); 134 struct addrinfo* ai = result; 135 while (ai && success) { 136 success = sendLenAndData(mClient, sizeof(struct addrinfo), ai) 137 && sendLenAndData(mClient, ai->ai_addrlen, ai->ai_addr) 138 && sendLenAndData(mClient, 139 ai->ai_canonname ? strlen(ai->ai_canonname) + 1 : 0, 140 ai->ai_canonname); 141 ai = ai->ai_next; 142 } 143 success = success && sendLenAndData(mClient, 0, ""); 144 if (!success) { 145 ALOGW("Error writing DNS result to client"); 146 } 147 } 148 if (result) { 149 freeaddrinfo(result); 150 } 151 mClient->decRef(); 152 } 153 154 DnsProxyListener::GetAddrInfoCmd::GetAddrInfoCmd(const DnsProxyListener* dnsProxyListener) : 155 NetdCommand("getaddrinfo"), 156 mDnsProxyListener(dnsProxyListener) { 157 } 158 159 int DnsProxyListener::GetAddrInfoCmd::runCommand(SocketClient *cli, 160 int argc, char **argv) { 161 if (DBG) { 162 for (int i = 0; i < argc; i++) { 163 ALOGD("argv[%i]=%s", i, argv[i]); 164 } 165 } 166 if (argc != 8) { 167 char* msg = NULL; 168 asprintf( &msg, "Invalid number of arguments to getaddrinfo: %i", argc); 169 ALOGW("%s", msg); 170 cli->sendMsg(ResponseCode::CommandParameterError, msg, false); 171 free(msg); 172 return -1; 173 } 174 175 char* name = argv[1]; 176 if (strcmp("^", name) == 0) { 177 name = NULL; 178 } else { 179 name = strdup(name); 180 } 181 182 char* service = argv[2]; 183 if (strcmp("^", service) == 0) { 184 service = NULL; 185 } else { 186 service = strdup(service); 187 } 188 189 struct addrinfo* hints = NULL; 190 int ai_flags = atoi(argv[3]); 191 int ai_family = atoi(argv[4]); 192 int ai_socktype = atoi(argv[5]); 193 int ai_protocol = atoi(argv[6]); 194 unsigned netId = strtoul(argv[7], NULL, 10); 195 uid_t uid = cli->getUid(); 196 197 uint32_t mark = mDnsProxyListener->mNetCtrl->getNetworkForDns(&netId, uid); 198 199 if (ai_flags != -1 || ai_family != -1 || 200 ai_socktype != -1 || ai_protocol != -1) { 201 hints = (struct addrinfo*) calloc(1, sizeof(struct addrinfo)); 202 hints->ai_flags = ai_flags; 203 hints->ai_family = ai_family; 204 hints->ai_socktype = ai_socktype; 205 hints->ai_protocol = ai_protocol; 206 207 // Only implement AI_ADDRCONFIG if application is using default network since our 208 // implementation only works on the default network. 209 if ((hints->ai_flags & AI_ADDRCONFIG) && 210 netId != mDnsProxyListener->mNetCtrl->getDefaultNetwork()) { 211 hints->ai_flags &= ~AI_ADDRCONFIG; 212 } 213 } 214 215 if (DBG) { 216 ALOGD("GetAddrInfoHandler for %s / %s / %u / %d / %u", 217 name ? name : "[nullhost]", 218 service ? service : "[nullservice]", 219 netId, uid, mark); 220 } 221 222 cli->incRef(); 223 DnsProxyListener::GetAddrInfoHandler* handler = 224 new DnsProxyListener::GetAddrInfoHandler(cli, name, service, hints, netId, mark); 225 handler->start(); 226 227 return 0; 228 } 229 230 /******************************************************* 231 * GetHostByName * 232 *******************************************************/ 233 DnsProxyListener::GetHostByNameCmd::GetHostByNameCmd(const DnsProxyListener* dnsProxyListener) : 234 NetdCommand("gethostbyname"), 235 mDnsProxyListener(dnsProxyListener) { 236 } 237 238 int DnsProxyListener::GetHostByNameCmd::runCommand(SocketClient *cli, 239 int argc, char **argv) { 240 if (DBG) { 241 for (int i = 0; i < argc; i++) { 242 ALOGD("argv[%i]=%s", i, argv[i]); 243 } 244 } 245 if (argc != 4) { 246 char* msg = NULL; 247 asprintf(&msg, "Invalid number of arguments to gethostbyname: %i", argc); 248 ALOGW("%s", msg); 249 cli->sendMsg(ResponseCode::CommandParameterError, msg, false); 250 free(msg); 251 return -1; 252 } 253 254 uid_t uid = cli->getUid(); 255 unsigned netId = strtoul(argv[1], NULL, 10); 256 char* name = argv[2]; 257 int af = atoi(argv[3]); 258 259 if (strcmp(name, "^") == 0) { 260 name = NULL; 261 } else { 262 name = strdup(name); 263 } 264 265 uint32_t mark = mDnsProxyListener->mNetCtrl->getNetworkForDns(&netId, uid); 266 267 cli->incRef(); 268 DnsProxyListener::GetHostByNameHandler* handler = 269 new DnsProxyListener::GetHostByNameHandler(cli, name, af, netId, mark); 270 handler->start(); 271 272 return 0; 273 } 274 275 DnsProxyListener::GetHostByNameHandler::GetHostByNameHandler(SocketClient* c, 276 char* name, 277 int af, 278 unsigned netId, 279 uint32_t mark) 280 : mClient(c), 281 mName(name), 282 mAf(af), 283 mNetId(netId), 284 mMark(mark) { 285 } 286 287 DnsProxyListener::GetHostByNameHandler::~GetHostByNameHandler() { 288 free(mName); 289 } 290 291 void DnsProxyListener::GetHostByNameHandler::start() { 292 pthread_t thread; 293 pthread_create(&thread, NULL, 294 DnsProxyListener::GetHostByNameHandler::threadStart, this); 295 pthread_detach(thread); 296 } 297 298 void* DnsProxyListener::GetHostByNameHandler::threadStart(void* obj) { 299 GetHostByNameHandler* handler = reinterpret_cast<GetHostByNameHandler*>(obj); 300 handler->run(); 301 delete handler; 302 pthread_exit(NULL); 303 return NULL; 304 } 305 306 void DnsProxyListener::GetHostByNameHandler::run() { 307 if (DBG) { 308 ALOGD("DnsProxyListener::GetHostByNameHandler::run\n"); 309 } 310 311 struct hostent* hp; 312 313 hp = android_gethostbynamefornet(mName, mAf, mNetId, mMark); 314 315 if (DBG) { 316 ALOGD("GetHostByNameHandler::run gethostbyname errno: %s hp->h_name = %s, name_len = %zu\n", 317 hp ? "success" : strerror(errno), 318 (hp && hp->h_name) ? hp->h_name : "null", 319 (hp && hp->h_name) ? strlen(hp->h_name) + 1 : 0); 320 } 321 322 bool success = true; 323 if (hp) { 324 success = mClient->sendCode(ResponseCode::DnsProxyQueryResult) == 0; 325 success &= sendhostent(mClient, hp); 326 } else { 327 success = mClient->sendBinaryMsg(ResponseCode::DnsProxyOperationFailed, NULL, 0) == 0; 328 } 329 330 if (!success) { 331 ALOGW("GetHostByNameHandler: Error writing DNS result to client\n"); 332 } 333 mClient->decRef(); 334 } 335 336 337 /******************************************************* 338 * GetHostByAddr * 339 *******************************************************/ 340 DnsProxyListener::GetHostByAddrCmd::GetHostByAddrCmd(const DnsProxyListener* dnsProxyListener) : 341 NetdCommand("gethostbyaddr"), 342 mDnsProxyListener(dnsProxyListener) { 343 } 344 345 int DnsProxyListener::GetHostByAddrCmd::runCommand(SocketClient *cli, 346 int argc, char **argv) { 347 if (DBG) { 348 for (int i = 0; i < argc; i++) { 349 ALOGD("argv[%i]=%s", i, argv[i]); 350 } 351 } 352 if (argc != 5) { 353 char* msg = NULL; 354 asprintf(&msg, "Invalid number of arguments to gethostbyaddr: %i", argc); 355 ALOGW("%s", msg); 356 cli->sendMsg(ResponseCode::CommandParameterError, msg, false); 357 free(msg); 358 return -1; 359 } 360 361 char* addrStr = argv[1]; 362 int addrLen = atoi(argv[2]); 363 int addrFamily = atoi(argv[3]); 364 uid_t uid = cli->getUid(); 365 unsigned netId = strtoul(argv[4], NULL, 10); 366 367 void* addr = malloc(sizeof(struct in6_addr)); 368 errno = 0; 369 int result = inet_pton(addrFamily, addrStr, addr); 370 if (result <= 0) { 371 char* msg = NULL; 372 asprintf(&msg, "inet_pton(\"%s\") failed %s", addrStr, strerror(errno)); 373 ALOGW("%s", msg); 374 cli->sendMsg(ResponseCode::OperationFailed, msg, false); 375 free(addr); 376 free(msg); 377 return -1; 378 } 379 380 uint32_t mark = mDnsProxyListener->mNetCtrl->getNetworkForDns(&netId, uid); 381 382 cli->incRef(); 383 DnsProxyListener::GetHostByAddrHandler* handler = 384 new DnsProxyListener::GetHostByAddrHandler(cli, addr, addrLen, addrFamily, netId, mark); 385 handler->start(); 386 387 return 0; 388 } 389 390 DnsProxyListener::GetHostByAddrHandler::GetHostByAddrHandler(SocketClient* c, 391 void* address, 392 int addressLen, 393 int addressFamily, 394 unsigned netId, 395 uint32_t mark) 396 : mClient(c), 397 mAddress(address), 398 mAddressLen(addressLen), 399 mAddressFamily(addressFamily), 400 mNetId(netId), 401 mMark(mark) { 402 } 403 404 DnsProxyListener::GetHostByAddrHandler::~GetHostByAddrHandler() { 405 free(mAddress); 406 } 407 408 void DnsProxyListener::GetHostByAddrHandler::start() { 409 pthread_t thread; 410 pthread_create(&thread, NULL, 411 DnsProxyListener::GetHostByAddrHandler::threadStart, this); 412 pthread_detach(thread); 413 } 414 415 void* DnsProxyListener::GetHostByAddrHandler::threadStart(void* obj) { 416 GetHostByAddrHandler* handler = reinterpret_cast<GetHostByAddrHandler*>(obj); 417 handler->run(); 418 delete handler; 419 pthread_exit(NULL); 420 return NULL; 421 } 422 423 void DnsProxyListener::GetHostByAddrHandler::run() { 424 if (DBG) { 425 ALOGD("DnsProxyListener::GetHostByAddrHandler::run\n"); 426 } 427 struct hostent* hp; 428 429 // NOTE gethostbyaddr should take a void* but bionic thinks it should be char* 430 hp = android_gethostbyaddrfornet((char*)mAddress, mAddressLen, mAddressFamily, mNetId, mMark); 431 432 if (DBG) { 433 ALOGD("GetHostByAddrHandler::run gethostbyaddr errno: %s hp->h_name = %s, name_len = %zu\n", 434 hp ? "success" : strerror(errno), 435 (hp && hp->h_name) ? hp->h_name : "null", 436 (hp && hp->h_name) ? strlen(hp->h_name) + 1 : 0); 437 } 438 439 bool success = true; 440 if (hp) { 441 success = mClient->sendCode(ResponseCode::DnsProxyQueryResult) == 0; 442 success &= sendhostent(mClient, hp); 443 } else { 444 success = mClient->sendBinaryMsg(ResponseCode::DnsProxyOperationFailed, NULL, 0) == 0; 445 } 446 447 if (!success) { 448 ALOGW("GetHostByAddrHandler: Error writing DNS result to client\n"); 449 } 450 mClient->decRef(); 451 } 452
