DnsProxyListener.cpp revision d2617936acc15567fc5111bbdb4dde20845c3cba 
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_iface.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 "NetdConstants.h"
39#include "DnsProxyListener.h"
40#include "ResponseCode.h"
41
42DnsProxyListener::DnsProxyListener(UidMarkMap *map) :
43                 FrameworkListener("dnsproxyd") {
44    registerCmd(new GetAddrInfoCmd(map));
45    registerCmd(new GetHostByAddrCmd(map));
46    registerCmd(new GetHostByNameCmd(map));
47    mUidMarkMap = map;
48}
49
50DnsProxyListener::GetAddrInfoHandler::GetAddrInfoHandler(SocketClient *c,
51                                                         char* host,
52                                                         char* service,
53                                                         struct addrinfo* hints,
54                                                         char* iface,
55                                                         pid_t pid,
56                                                         uid_t uid,
57                                                         int mark)
58        : mClient(c),
59          mHost(host),
60          mService(service),
61          mHints(hints),
62          mIface(iface),
63          mPid(pid),
64          mUid(uid),
65          mMark(mark) {
66}
67
68DnsProxyListener::GetAddrInfoHandler::~GetAddrInfoHandler() {
69    free(mHost);
70    free(mService);
71    free(mHints);
72    free(mIface);
73}
74
75void DnsProxyListener::GetAddrInfoHandler::start() {
76    pthread_t thread;
77    pthread_create(&thread, NULL,
78                   DnsProxyListener::GetAddrInfoHandler::threadStart, this);
79    pthread_detach(thread);
80}
81
82void* DnsProxyListener::GetAddrInfoHandler::threadStart(void* obj) {
83    GetAddrInfoHandler* handler = reinterpret_cast<GetAddrInfoHandler*>(obj);
84    handler->run();
85    delete handler;
86    pthread_exit(NULL);
87    return NULL;
88}
89
90// Sends 4 bytes of big-endian length, followed by the data.
91// Returns true on success.
92static bool sendLenAndData(SocketClient *c, const int len, const void* data) {
93    uint32_t len_be = htonl(len);
94    return c->sendData(&len_be, 4) == 0 &&
95        (len == 0 || c->sendData(data, len) == 0);
96}
97
98// Returns true on success
99static bool sendhostent(SocketClient *c, struct hostent *hp) {
100    bool success = true;
101    int i;
102    if (hp->h_name != NULL) {
103        success &= sendLenAndData(c, strlen(hp->h_name)+1, hp->h_name);
104    } else {
105        success &= sendLenAndData(c, 0, "") == 0;
106    }
107
108    for (i=0; hp->h_aliases[i] != NULL; i++) {
109        success &= sendLenAndData(c, strlen(hp->h_aliases[i])+1, hp->h_aliases[i]);
110    }
111    success &= sendLenAndData(c, 0, ""); // null to indicate we're done
112
113    uint32_t buf = htonl(hp->h_addrtype);
114    success &= c->sendData(&buf, sizeof(buf)) == 0;
115
116    buf = htonl(hp->h_length);
117    success &= c->sendData(&buf, sizeof(buf)) == 0;
118
119    for (i=0; hp->h_addr_list[i] != NULL; i++) {
120        success &= sendLenAndData(c, 16, hp->h_addr_list[i]);
121    }
122    success &= sendLenAndData(c, 0, ""); // null to indicate we're done
123    return success;
124}
125
126void DnsProxyListener::GetAddrInfoHandler::run() {
127    if (DBG) {
128        ALOGD("GetAddrInfoHandler, now for %s / %s / %s", mHost, mService, mIface);
129    }
130
131    char tmp[IF_NAMESIZE + 1];
132    if (mIface == NULL) {
133        //fall back to the per uid interface if no per pid interface exists
134        if(!_resolv_get_pids_associated_interface(mPid, tmp, sizeof(tmp)))
135            _resolv_get_uids_associated_interface(mUid, tmp, sizeof(tmp));
136    }
137
138    struct addrinfo* result = NULL;
139    uint32_t rv = android_getaddrinfoforiface(mHost, mService, mHints, mIface ? mIface : tmp,
140            mMark, &result);
141    if (rv) {
142        // getaddrinfo failed
143        mClient->sendBinaryMsg(ResponseCode::DnsProxyOperationFailed, &rv, sizeof(rv));
144    } else {
145        bool success = !mClient->sendCode(ResponseCode::DnsProxyQueryResult);
146        struct addrinfo* ai = result;
147        while (ai && success) {
148            success = sendLenAndData(mClient, sizeof(struct addrinfo), ai)
149                && sendLenAndData(mClient, ai->ai_addrlen, ai->ai_addr)
150                && sendLenAndData(mClient,
151                                  ai->ai_canonname ? strlen(ai->ai_canonname) + 1 : 0,
152                                  ai->ai_canonname);
153            ai = ai->ai_next;
154        }
155        success = success && sendLenAndData(mClient, 0, "");
156        if (!success) {
157            ALOGW("Error writing DNS result to client");
158        }
159    }
160    if (result) {
161        freeaddrinfo(result);
162    }
163    mClient->decRef();
164}
165
166DnsProxyListener::GetAddrInfoCmd::GetAddrInfoCmd(UidMarkMap *uidMarkMap) :
167    NetdCommand("getaddrinfo") {
168        mUidMarkMap = uidMarkMap;
169}
170
171int DnsProxyListener::GetAddrInfoCmd::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    if (argc != 8) {
179        char* msg = NULL;
180        asprintf( &msg, "Invalid number of arguments to getaddrinfo: %i", argc);
181        ALOGW("%s", msg);
182        cli->sendMsg(ResponseCode::CommandParameterError, msg, false);
183        free(msg);
184        return -1;
185    }
186
187    char* name = argv[1];
188    if (strcmp("^", name) == 0) {
189        name = NULL;
190    } else {
191        name = strdup(name);
192    }
193
194    char* service = argv[2];
195    if (strcmp("^", service) == 0) {
196        service = NULL;
197    } else {
198        service = strdup(service);
199    }
200
201    char* iface = argv[7];
202    if (strcmp(iface, "^") == 0) {
203        iface = NULL;
204    } else {
205        iface = strdup(iface);
206    }
207
208    struct addrinfo* hints = NULL;
209    int ai_flags = atoi(argv[3]);
210    int ai_family = atoi(argv[4]);
211    int ai_socktype = atoi(argv[5]);
212    int ai_protocol = atoi(argv[6]);
213    pid_t pid = cli->getPid();
214    uid_t uid = cli->getUid();
215
216    if (ai_flags != -1 || ai_family != -1 ||
217        ai_socktype != -1 || ai_protocol != -1) {
218        hints = (struct addrinfo*) calloc(1, sizeof(struct addrinfo));
219        hints->ai_flags = ai_flags;
220        hints->ai_family = ai_family;
221        hints->ai_socktype = ai_socktype;
222        hints->ai_protocol = ai_protocol;
223    }
224
225    if (DBG) {
226        ALOGD("GetAddrInfoHandler for %s / %s / %s / %d / %d",
227             name ? name : "[nullhost]",
228             service ? service : "[nullservice]",
229             iface ? iface : "[nulliface]",
230             pid, uid);
231    }
232
233    cli->incRef();
234    DnsProxyListener::GetAddrInfoHandler* handler =
235        new DnsProxyListener::GetAddrInfoHandler(cli, name, service, hints, iface, pid, uid,
236                                    mUidMarkMap->getMark(uid));
237    handler->start();
238
239    return 0;
240}
241
242/*******************************************************
243 *                  GetHostByName                      *
244 *******************************************************/
245DnsProxyListener::GetHostByNameCmd::GetHostByNameCmd(UidMarkMap *uidMarkMap) :
246        NetdCommand("gethostbyname") {
247            mUidMarkMap = uidMarkMap;
248}
249
250int DnsProxyListener::GetHostByNameCmd::runCommand(SocketClient *cli,
251                                            int argc, char **argv) {
252    if (DBG) {
253        for (int i = 0; i < argc; i++) {
254            ALOGD("argv[%i]=%s", i, argv[i]);
255        }
256    }
257    if (argc != 4) {
258        char* msg = NULL;
259        asprintf(&msg, "Invalid number of arguments to gethostbyname: %i", argc);
260        ALOGW("%s", msg);
261        cli->sendMsg(ResponseCode::CommandParameterError, msg, false);
262        free(msg);
263        return -1;
264    }
265
266    pid_t pid = cli->getPid();
267    uid_t uid = cli->getUid();
268    char* iface = argv[1];
269    char* name = argv[2];
270    int af = atoi(argv[3]);
271
272    if (strcmp(iface, "^") == 0) {
273        iface = NULL;
274    } else {
275        iface = strdup(iface);
276    }
277
278    if (strcmp(name, "^") == 0) {
279        name = NULL;
280    } else {
281        name = strdup(name);
282    }
283
284    cli->incRef();
285    DnsProxyListener::GetHostByNameHandler* handler =
286            new DnsProxyListener::GetHostByNameHandler(cli, pid, uid, iface, name, af,
287                    mUidMarkMap->getMark(uid));
288    handler->start();
289
290    return 0;
291}
292
293DnsProxyListener::GetHostByNameHandler::GetHostByNameHandler(SocketClient* c,
294                                                             pid_t pid,
295                                                             uid_t uid,
296                                                             char* iface,
297                                                             char* name,
298                                                             int af,
299                                                             int mark)
300        : mClient(c),
301          mPid(pid),
302          mUid(uid),
303          mIface(iface),
304          mName(name),
305          mAf(af),
306          mMark(mark) {
307}
308
309DnsProxyListener::GetHostByNameHandler::~GetHostByNameHandler() {
310    free(mIface);
311    free(mName);
312}
313
314void DnsProxyListener::GetHostByNameHandler::start() {
315    pthread_t thread;
316    pthread_create(&thread, NULL,
317            DnsProxyListener::GetHostByNameHandler::threadStart, this);
318    pthread_detach(thread);
319}
320
321void* DnsProxyListener::GetHostByNameHandler::threadStart(void* obj) {
322    GetHostByNameHandler* handler = reinterpret_cast<GetHostByNameHandler*>(obj);
323    handler->run();
324    delete handler;
325    pthread_exit(NULL);
326    return NULL;
327}
328
329void DnsProxyListener::GetHostByNameHandler::run() {
330    if (DBG) {
331        ALOGD("DnsProxyListener::GetHostByNameHandler::run\n");
332    }
333
334    char iface[IF_NAMESIZE + 1];
335    if (mIface == NULL) {
336        //fall back to the per uid interface if no per pid interface exists
337        if(!_resolv_get_pids_associated_interface(mPid, iface, sizeof(iface)))
338            _resolv_get_uids_associated_interface(mUid, iface, sizeof(iface));
339    }
340
341    struct hostent* hp;
342
343    hp = android_gethostbynameforiface(mName, mAf, mIface ? mIface : iface, mMark);
344
345    if (DBG) {
346        ALOGD("GetHostByNameHandler::run gethostbyname errno: %s hp->h_name = %s, name_len = %d\n",
347                hp ? "success" : strerror(errno),
348                (hp && hp->h_name) ? hp->h_name: "null",
349                (hp && hp->h_name) ? strlen(hp->h_name)+ 1 : 0);
350    }
351
352    bool success = true;
353    if (hp) {
354        success = mClient->sendCode(ResponseCode::DnsProxyQueryResult) == 0;
355        success &= sendhostent(mClient, hp);
356    } else {
357        success = mClient->sendBinaryMsg(ResponseCode::DnsProxyOperationFailed, NULL, 0) == 0;
358    }
359
360    if (!success) {
361        ALOGW("GetHostByNameHandler: Error writing DNS result to client\n");
362    }
363    mClient->decRef();
364}
365
366
367/*******************************************************
368 *                  GetHostByAddr                      *
369 *******************************************************/
370DnsProxyListener::GetHostByAddrCmd::GetHostByAddrCmd(UidMarkMap *uidMarkMap) :
371        NetdCommand("gethostbyaddr") {
372        mUidMarkMap = uidMarkMap;
373}
374
375int DnsProxyListener::GetHostByAddrCmd::runCommand(SocketClient *cli,
376                                            int argc, char **argv) {
377    if (DBG) {
378        for (int i = 0; i < argc; i++) {
379            ALOGD("argv[%i]=%s", i, argv[i]);
380        }
381    }
382    if (argc != 5) {
383        char* msg = NULL;
384        asprintf(&msg, "Invalid number of arguments to gethostbyaddr: %i", argc);
385        ALOGW("%s", msg);
386        cli->sendMsg(ResponseCode::CommandParameterError, msg, false);
387        free(msg);
388        return -1;
389    }
390
391    char* addrStr = argv[1];
392    int addrLen = atoi(argv[2]);
393    int addrFamily = atoi(argv[3]);
394    pid_t pid = cli->getPid();
395    uid_t uid = cli->getUid();
396    char* iface = argv[4];
397
398    if (strcmp(iface, "^") == 0) {
399        iface = NULL;
400    } else {
401        iface = strdup(iface);
402    }
403
404    void* addr = malloc(sizeof(struct in6_addr));
405    errno = 0;
406    int result = inet_pton(addrFamily, addrStr, addr);
407    if (result <= 0) {
408        char* msg = NULL;
409        asprintf(&msg, "inet_pton(\"%s\") failed %s", addrStr, strerror(errno));
410        ALOGW("%s", msg);
411        cli->sendMsg(ResponseCode::OperationFailed, msg, false);
412        free(addr);
413        free(msg);
414        return -1;
415    }
416
417    cli->incRef();
418    DnsProxyListener::GetHostByAddrHandler* handler =
419            new DnsProxyListener::GetHostByAddrHandler(cli, addr, addrLen, addrFamily, iface, pid,
420                    uid, mUidMarkMap->getMark(uid));
421    handler->start();
422
423    return 0;
424}
425
426DnsProxyListener::GetHostByAddrHandler::GetHostByAddrHandler(SocketClient* c,
427                                                             void* address,
428                                                             int   addressLen,
429                                                             int   addressFamily,
430                                                             char* iface,
431                                                             pid_t pid,
432                                                             uid_t uid,
433                                                             int mark)
434        : mClient(c),
435          mAddress(address),
436          mAddressLen(addressLen),
437          mAddressFamily(addressFamily),
438          mIface(iface),
439          mPid(pid),
440          mUid(uid),
441          mMark(mark) {
442}
443
444DnsProxyListener::GetHostByAddrHandler::~GetHostByAddrHandler() {
445    free(mAddress);
446    free(mIface);
447}
448
449void DnsProxyListener::GetHostByAddrHandler::start() {
450    pthread_t thread;
451    pthread_create(&thread, NULL,
452                   DnsProxyListener::GetHostByAddrHandler::threadStart, this);
453    pthread_detach(thread);
454}
455
456void* DnsProxyListener::GetHostByAddrHandler::threadStart(void* obj) {
457    GetHostByAddrHandler* handler = reinterpret_cast<GetHostByAddrHandler*>(obj);
458    handler->run();
459    delete handler;
460    pthread_exit(NULL);
461    return NULL;
462}
463
464void DnsProxyListener::GetHostByAddrHandler::run() {
465    if (DBG) {
466        ALOGD("DnsProxyListener::GetHostByAddrHandler::run\n");
467    }
468
469    char tmp[IF_NAMESIZE + 1];
470    if (mIface == NULL) {
471        //fall back to the per uid interface if no per pid interface exists
472        if(!_resolv_get_pids_associated_interface(mPid, tmp, sizeof(tmp)))
473            _resolv_get_uids_associated_interface(mUid, tmp, sizeof(tmp));
474    }
475    struct hostent* hp;
476
477    // NOTE gethostbyaddr should take a void* but bionic thinks it should be char*
478    hp = android_gethostbyaddrforiface((char*)mAddress, mAddressLen, mAddressFamily,
479            mIface ? mIface : tmp, mMark);
480
481    if (DBG) {
482        ALOGD("GetHostByAddrHandler::run gethostbyaddr errno: %s hp->h_name = %s, name_len = %d\n",
483                hp ? "success" : strerror(errno),
484                (hp && hp->h_name) ? hp->h_name: "null",
485                (hp && hp->h_name) ? strlen(hp->h_name)+ 1 : 0);
486    }
487
488    bool success = true;
489    if (hp) {
490        success = mClient->sendCode(ResponseCode::DnsProxyQueryResult) == 0;
491        success &= sendhostent(mClient, hp);
492    } else {
493        success = mClient->sendBinaryMsg(ResponseCode::DnsProxyOperationFailed, NULL, 0) == 0;
494    }
495
496    if (!success) {
497        ALOGW("GetHostByAddrHandler: Error writing DNS result to client\n");
498    }
499    mClient->decRef();
500}
501