src/stun.c

branch
cpw.khc.msnp14
changeset 20472
6a6d2ef151e6
parent 13912
463b4fa9f067
parent 20469
b2836a24d81e
child 20473
91e1b3a49d10
equal deleted inserted replaced
13912:463b4fa9f067 20472:6a6d2ef151e6
1 /**
2 * @file stun.c STUN (RFC3489) Implementation
3 * @ingroup core
4 *
5 * gaim
6 *
7 * STUN implementation inspired by jstun [http://jstun.javawi.de/]
8 *
9 * Gaim is the legal property of its developers, whose names are too numerous
10 * to list here. Please refer to the COPYRIGHT file distributed with this
11 * source distribution.
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
26 *
27 */
28
29 #include "internal.h"
30
31 #ifndef _WIN32
32 #include <net/if.h>
33 #include <sys/ioctl.h>
34 #endif
35
36 /* Solaris */
37 #if defined (__SVR4) && defined (__sun)
38 #include <sys/sockio.h>
39 #endif
40
41 #include "debug.h"
42 #include "account.h"
43 #include "dnssrv.h"
44 #include "network.h"
45 #include "proxy.h"
46 #include "stun.h"
47 #include "prefs.h"
48
49 #define MSGTYPE_BINDINGREQUEST 0x0001
50 #define MSGTYPE_BINDINGRESPONSE 0x0101
51
52 #define ATTRIB_MAPPEDADDRESS 0x0001
53
54 struct stun_header {
55 guint16 type;
56 guint16 len;
57 guint32 transid[4];
58 };
59
60 struct stun_attrib {
61 guint16 type;
62 guint16 len;
63 };
64
65 #ifdef NOTYET
66 struct stun_change {
67 struct stun_header hdr;
68 struct stun_attrib attrib;
69 char value[4];
70 };
71 #endif
72
73 struct stun_conn {
74 int fd;
75 struct sockaddr_in addr;
76 int test;
77 int retry;
78 guint incb;
79 guint timeout;
80 struct stun_header *packet;
81 size_t packetsize;
82 };
83
84 static GaimStunNatDiscovery nattype = {
85 GAIM_STUN_STATUS_UNDISCOVERED,
86 GAIM_STUN_NAT_TYPE_PUBLIC_IP,
87 "\0", NULL, 0};
88
89 static GSList *callbacks = NULL;
90
91 static void close_stun_conn(struct stun_conn *sc) {
92
93 if (sc->incb)
94 gaim_input_remove(sc->incb);
95
96 if (sc->timeout)
97 gaim_timeout_remove(sc->timeout);
98
99 if (sc->fd)
100 close(sc->fd);
101
102 g_free(sc);
103 }
104
105 static void do_callbacks() {
106 while(callbacks) {
107 StunCallback cb = callbacks->data;
108 if(cb)
109 cb(&nattype);
110 callbacks = g_slist_remove(callbacks, cb);
111 }
112 }
113
114 static gboolean timeoutfunc(gpointer data) {
115 struct stun_conn *sc = data;
116 if(sc->retry >= 2) {
117 gaim_debug_info("stun", "request timed out, giving up.\n");
118 if(sc->test == 2)
119 nattype.type = GAIM_STUN_NAT_TYPE_SYMMETRIC;
120
121 /* set unknown */
122 nattype.status = GAIM_STUN_STATUS_UNKNOWN;
123
124 nattype.lookup_time = time(NULL);
125
126 /* callbacks */
127 do_callbacks();
128
129 /* we don't need to remove the timeout (returning FALSE) */
130 sc->timeout = 0;
131 close_stun_conn(sc);
132
133 return FALSE;
134 }
135 gaim_debug_info("stun", "request timed out, retrying.\n");
136 sc->retry++;
137 sendto(sc->fd, sc->packet, sc->packetsize, 0,
138 (struct sockaddr *)&(sc->addr), sizeof(struct sockaddr_in));
139 return TRUE;
140 }
141
142 #ifdef NOTYET
143 static void do_test2(struct stun_conn *sc) {
144 struct stun_change data;
145 data.hdr.type = htons(0x0001);
146 data.hdr.len = 0;
147 data.hdr.transid[0] = rand();
148 data.hdr.transid[1] = ntohl(((int)'g' << 24) + ((int)'a' << 16) + ((int)'i' << 8) + (int)'m');
149 data.hdr.transid[2] = rand();
150 data.hdr.transid[3] = rand();
151 data.attrib.type = htons(0x003);
152 data.attrib.len = htons(4);
153 data.value[3] = 6;
154 sc->packet = (struct stun_header*)&data;
155 sc->packetsize = sizeof(struct stun_change);
156 sc->retry = 0;
157 sc->test = 2;
158 sendto(sc->fd, sc->packet, sc->packetsize, 0, (struct sockaddr *)&(sc->addr), sizeof(struct sockaddr_in));
159 sc->timeout = gaim_timeout_add(500, (GSourceFunc) timeoutfunc, sc);
160 }
161 #endif
162
163 static void reply_cb(gpointer data, gint source, GaimInputCondition cond) {
164 struct stun_conn *sc = data;
165 char buffer[65536];
166 char *tmp;
167 int len;
168 struct in_addr in;
169 struct stun_attrib *attrib;
170 struct stun_header *hdr;
171 struct ifconf ifc;
172 struct ifreq *ifr;
173 struct sockaddr_in *sinptr;
174
175 len = recv(source, buffer, sizeof(buffer) - 1, 0);
176 if (!len) {
177 gaim_debug_info("stun", "unable to read stun response\n");
178 return;
179 }
180 buffer[len] = '\0';
181
182 if (len < sizeof(struct stun_header)) {
183 gaim_debug_info("stun", "got invalid response\n");
184 return;
185 }
186
187 hdr = (struct stun_header*) buffer;
188 if (len != (ntohs(hdr->len) + sizeof(struct stun_header))) {
189 gaim_debug_info("stun", "got incomplete response\n");
190 return;
191 }
192
193 /* wrong transaction */
194 if(hdr->transid[0] != sc->packet->transid[0]
195 || hdr->transid[1] != sc->packet->transid[1]
196 || hdr->transid[2] != sc->packet->transid[2]
197 || hdr->transid[3] != sc->packet->transid[3]) {
198 gaim_debug_info("stun", "got wrong transid\n");
199 return;
200 }
201
202 if(sc->test==1) {
203 if (hdr->type != MSGTYPE_BINDINGRESPONSE) {
204 gaim_debug_info("stun",
205 "Expected Binding Response, got %d\n",
206 hdr->type);
207 return;
208 }
209
210 tmp = buffer + sizeof(struct stun_header);
211 while((buffer + len) > (tmp + sizeof(struct stun_attrib))) {
212 attrib = (struct stun_attrib*) tmp;
213 tmp += sizeof(struct stun_attrib);
214
215 if (!((buffer + len) > (tmp + ntohs(attrib->len))))
216 break;
217
218 if(attrib->type == htons(ATTRIB_MAPPEDADDRESS)
219 && ntohs(attrib->len) == 8) {
220 char *ip;
221 /* Skip the first unused byte,
222 * the family(1 byte), and the port(2 bytes);
223 * then read the 4 byte IPv4 address */
224 memcpy(&in.s_addr, tmp + 4, 4);
225 ip = inet_ntoa(in);
226 if(ip)
227 strcpy(nattype.publicip, ip);
228 }
229
230 tmp += ntohs(attrib->len);
231 }
232 gaim_debug_info("stun", "got public ip %s\n", nattype.publicip);
233 nattype.status = GAIM_STUN_STATUS_DISCOVERED;
234 nattype.type = GAIM_STUN_NAT_TYPE_UNKNOWN_NAT;
235 nattype.lookup_time = time(NULL);
236
237 /* is it a NAT? */
238
239 ifc.ifc_len = sizeof(buffer);
240 ifc.ifc_req = (struct ifreq *) buffer;
241 ioctl(source, SIOCGIFCONF, &ifc);
242
243 tmp = buffer;
244 while(tmp < buffer + ifc.ifc_len) {
245 ifr = (struct ifreq *) tmp;
246
247 tmp += sizeof(struct ifreq);
248
249 if(ifr->ifr_addr.sa_family == AF_INET) {
250 /* we only care about ipv4 interfaces */
251 sinptr = (struct sockaddr_in *) &ifr->ifr_addr;
252 if(sinptr->sin_addr.s_addr == in.s_addr) {
253 /* no NAT */
254 gaim_debug_info("stun", "no nat");
255 nattype.type = GAIM_STUN_NAT_TYPE_PUBLIC_IP;
256 }
257 }
258 }
259
260 #ifndef NOTYET
261 close_stun_conn(sc);
262 do_callbacks();
263 #else
264 gaim_timeout_remove(sc->timeout);
265 sc->timeout = 0;
266
267 do_test2(sc);
268 } else if(sc->test == 2) {
269 close_stun_conn(sc);
270 nattype.type = GAIM_STUN_NAT_TYPE_FULL_CONE;
271 do_callbacks();
272 #endif
273 }
274 }
275
276
277 static void hbn_listen_cb(int fd, gpointer data) {
278 GSList *hosts = data;
279 struct stun_conn *sc;
280 static struct stun_header hdr_data;
281 int ret;
282
283 if(fd < 0) {
284 nattype.status = GAIM_STUN_STATUS_UNKNOWN;
285 nattype.lookup_time = time(NULL);
286 do_callbacks();
287 return;
288 }
289
290 sc = g_new0(struct stun_conn, 1);
291 sc->fd = fd;
292
293 sc->addr.sin_family = AF_INET;
294 sc->addr.sin_port = htons(gaim_network_get_port_from_fd(fd));
295 sc->addr.sin_addr.s_addr = INADDR_ANY;
296
297 sc->incb = gaim_input_add(fd, GAIM_INPUT_READ, reply_cb, sc);
298
299 ret = GPOINTER_TO_INT(hosts->data);
300 hosts = g_slist_remove(hosts, hosts->data);
301 memcpy(&(sc->addr), hosts->data, sizeof(struct sockaddr_in));
302 g_free(hosts->data);
303 hosts = g_slist_remove(hosts, hosts->data);
304 while(hosts) {
305 hosts = g_slist_remove(hosts, hosts->data);
306 g_free(hosts->data);
307 hosts = g_slist_remove(hosts, hosts->data);
308 }
309
310 hdr_data.type = htons(MSGTYPE_BINDINGREQUEST);
311 hdr_data.len = 0;
312 hdr_data.transid[0] = rand();
313 hdr_data.transid[1] = ntohl(((int)'g' << 24) + ((int)'a' << 16) + ((int)'i' << 8) + (int)'m');
314 hdr_data.transid[2] = rand();
315 hdr_data.transid[3] = rand();
316
317 if(sendto(sc->fd, &hdr_data, sizeof(struct stun_header), 0,
318 (struct sockaddr *)&(sc->addr),
319 sizeof(struct sockaddr_in)) < sizeof(struct stun_header)) {
320 nattype.status = GAIM_STUN_STATUS_UNKNOWN;
321 nattype.lookup_time = time(NULL);
322 do_callbacks();
323 close_stun_conn(sc);
324 return;
325 }
326 sc->test = 1;
327 sc->packet = &hdr_data;
328 sc->packetsize = sizeof(struct stun_header);
329 sc->timeout = gaim_timeout_add(500, (GSourceFunc) timeoutfunc, sc);
330 }
331
332 static void hbn_cb(GSList *hosts, gpointer data, const char *error_message) {
333
334 if(!hosts || !hosts->data) {
335 nattype.status = GAIM_STUN_STATUS_UNDISCOVERED;
336 nattype.lookup_time = time(NULL);
337 do_callbacks();
338 return;
339 }
340
341 if (!gaim_network_listen_range(12108, 12208, SOCK_DGRAM, hbn_listen_cb, hosts)) {
342 nattype.status = GAIM_STUN_STATUS_UNKNOWN;
343 nattype.lookup_time = time(NULL);
344 do_callbacks();
345 return;
346 }
347
348
349 }
350
351 static void do_test1(GaimSrvResponse *resp, int results, gpointer sdata) {
352 const char *servername = sdata;
353 int port = 3478;
354
355 if(results) {
356 servername = resp[0].hostname;
357 port = resp[0].port;
358 }
359 gaim_debug_info("stun", "got %d SRV responses, server: %s, port: %d\n",
360 results, servername, port);
361
362 gaim_gethostbyname_async(servername, port, hbn_cb, NULL);
363 g_free(resp);
364 }
365
366 static gboolean call_callback(gpointer data) {
367 StunCallback cb = data;
368 cb(&nattype);
369 return FALSE;
370 }
371
372 GaimStunNatDiscovery *gaim_stun_discover(StunCallback cb) {
373 const char *servername = gaim_prefs_get_string("/core/network/stun_server");
374
375 gaim_debug_info("stun", "using server %s\n", servername);
376
377 if(nattype.status == GAIM_STUN_STATUS_DISCOVERING) {
378 if(cb)
379 callbacks = g_slist_append(callbacks, cb);
380 return &nattype;
381 }
382
383 if(nattype.status != GAIM_STUN_STATUS_UNDISCOVERED) {
384 gboolean use_cached_result = TRUE;
385
386 /** Deal with the server name having changed since we did the
387 lookup */
388 if (servername && strlen(servername) > 1
389 && ((nattype.servername
390 && strcmp(servername, nattype.servername))
391 || !nattype.servername)) {
392 use_cached_result = FALSE;
393 }
394
395 /* If we don't have a successful status and it has been 5
396 minutes since we last did a lookup, redo the lookup */
397 if (nattype.status != GAIM_STUN_STATUS_DISCOVERED
398 && (time(NULL) - nattype.lookup_time) > 300) {
399 use_cached_result = FALSE;
400 }
401
402 if (use_cached_result) {
403 if(cb)
404 gaim_timeout_add(10, call_callback, cb);
405 return &nattype;
406 }
407 }
408
409 if(!servername || (strlen(servername) < 2)) {
410 nattype.status = GAIM_STUN_STATUS_UNKNOWN;
411 nattype.lookup_time = time(NULL);
412 if(cb)
413 gaim_timeout_add(10, call_callback, cb);
414 return &nattype;
415 }
416
417 nattype.status = GAIM_STUN_STATUS_DISCOVERING;
418 nattype.publicip[0] = '\0';
419 g_free(nattype.servername);
420 nattype.servername = g_strdup(servername);
421
422 callbacks = g_slist_append(callbacks, cb);
423 gaim_srv_resolve("stun", "udp", servername, do_test1,
424 (gpointer) servername);
425
426 return &nattype;
427 }
428
429 void gaim_stun_init() {
430 gaim_prefs_add_string("/core/network/stun_server", "");
431 gaim_stun_discover(NULL);
432 }

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