1 /*
2 * UPnP SSDP for WPS
3 * Copyright (c) 2000-2003 Intel Corporation
4 * Copyright (c) 2006-2007 Sony Corporation
5 * Copyright (c) 2008-2009 Atheros Communications
6 * Copyright (c) 2009-2013, Jouni Malinen <j@w1.fi>
7 *
8 * See wps_upnp.c for more details on licensing and code history.
9 */
10
11 #include "includes.h"
12
13 #include <fcntl.h>
14 #include <sys/ioctl.h>
15 #include <net/route.h>
16 #ifdef __linux__
17 #include <net/if.h>
18 #endif /* __linux__ */
19
20 #include "common.h"
21 #include "uuid.h"
22 #include "eloop.h"
23 #include "wps.h"
24 #include "wps_upnp.h"
25 #include "wps_upnp_i.h"
26
27 #define UPNP_CACHE_SEC (UPNP_CACHE_SEC_MIN + 1) /* cache time we use */
28 #define UPNP_CACHE_SEC_MIN 1800 /* min cachable time per UPnP standard */
29 #define UPNP_ADVERTISE_REPEAT 2 /* no more than 3 */
30 #define MAX_MSEARCH 20 /* max simultaneous M-SEARCH replies ongoing */
31 #define SSDP_TARGET "239.0.0.0"
32 #define SSDP_NETMASK "255.0.0.0"
33
34
35 /* Check tokens for equality, where tokens consist of letters, digits,
36 * underscore and hyphen, and are matched case insensitive.
37 */
token_eq(const char * s1,const char * s2)38 static int token_eq(const char *s1, const char *s2)
39 {
40 int c1;
41 int c2;
42 int end1 = 0;
43 int end2 = 0;
44 for (;;) {
45 c1 = *s1++;
46 c2 = *s2++;
47 if (isalpha(c1) && isupper(c1))
48 c1 = tolower(c1);
49 if (isalpha(c2) && isupper(c2))
50 c2 = tolower(c2);
51 end1 = !(isalnum(c1) || c1 == '_' || c1 == '-');
52 end2 = !(isalnum(c2) || c2 == '_' || c2 == '-');
53 if (end1 || end2 || c1 != c2)
54 break;
55 }
56 return end1 && end2; /* reached end of both words? */
57 }
58
59
60 /* Return length of token (see above for definition of token) */
token_length(const char * s)61 static int token_length(const char *s)
62 {
63 const char *begin = s;
64 for (;; s++) {
65 int c = *s;
66 int end = !(isalnum(c) || c == '_' || c == '-');
67 if (end)
68 break;
69 }
70 return s - begin;
71 }
72
73
74 /* return length of interword separation.
75 * This accepts only spaces/tabs and thus will not traverse a line
76 * or buffer ending.
77 */
word_separation_length(const char * s)78 static int word_separation_length(const char *s)
79 {
80 const char *begin = s;
81 for (;; s++) {
82 int c = *s;
83 if (c == ' ' || c == '\t')
84 continue;
85 break;
86 }
87 return s - begin;
88 }
89
90
91 /* No. of chars through (including) end of line */
line_length(const char * l)92 static int line_length(const char *l)
93 {
94 const char *lp = l;
95 while (*lp && *lp != '\n')
96 lp++;
97 if (*lp == '\n')
98 lp++;
99 return lp - l;
100 }
101
102
str_starts(const char * str,const char * start)103 static int str_starts(const char *str, const char *start)
104 {
105 return os_strncmp(str, start, os_strlen(start)) == 0;
106 }
107
108
109 /***************************************************************************
110 * Advertisements.
111 * These are multicast to the world to tell them we are here.
112 * The individual packets are spread out in time to limit loss,
113 * and then after a much longer period of time the whole sequence
114 * is repeated again (for NOTIFYs only).
115 **************************************************************************/
116
117 /**
118 * next_advertisement - Build next message and advance the state machine
119 * @a: Advertisement state
120 * @islast: Buffer for indicating whether this is the last message (= 1)
121 * Returns: The new message (caller is responsible for freeing this)
122 *
123 * Note: next_advertisement is shared code with msearchreply_* functions
124 */
125 static struct wpabuf *
next_advertisement(struct upnp_wps_device_sm * sm,struct advertisement_state_machine * a,int * islast)126 next_advertisement(struct upnp_wps_device_sm *sm,
127 struct advertisement_state_machine *a, int *islast)
128 {
129 struct wpabuf *msg;
130 char *NTString = "";
131 char uuid_string[80];
132 struct upnp_wps_device_interface *iface;
133
134 *islast = 0;
135 iface = dl_list_first(&sm->interfaces,
136 struct upnp_wps_device_interface, list);
137 if (!iface)
138 return NULL;
139 uuid_bin2str(iface->wps->uuid, uuid_string, sizeof(uuid_string));
140 msg = wpabuf_alloc(800); /* more than big enough */
141 if (msg == NULL)
142 return NULL;
143 switch (a->type) {
144 case ADVERTISE_UP:
145 case ADVERTISE_DOWN:
146 NTString = "NT";
147 wpabuf_put_str(msg, "NOTIFY * HTTP/1.1\r\n");
148 wpabuf_printf(msg, "HOST: %s:%d\r\n",
149 UPNP_MULTICAST_ADDRESS, UPNP_MULTICAST_PORT);
150 wpabuf_printf(msg, "CACHE-CONTROL: max-age=%d\r\n",
151 UPNP_CACHE_SEC);
152 wpabuf_printf(msg, "NTS: %s\r\n",
153 (a->type == ADVERTISE_UP ?
154 "ssdp:alive" : "ssdp:byebye"));
155 break;
156 case MSEARCH_REPLY:
157 NTString = "ST";
158 wpabuf_put_str(msg, "HTTP/1.1 200 OK\r\n");
159 wpabuf_printf(msg, "CACHE-CONTROL: max-age=%d\r\n",
160 UPNP_CACHE_SEC);
161
162 wpabuf_put_str(msg, "DATE: ");
163 format_date(msg);
164 wpabuf_put_str(msg, "\r\n");
165
166 wpabuf_put_str(msg, "EXT:\r\n");
167 break;
168 }
169
170 if (a->type != ADVERTISE_DOWN) {
171 /* Where others may get our XML files from */
172 wpabuf_printf(msg, "LOCATION: http://%s:%d/%s\r\n",
173 sm->ip_addr_text, sm->web_port,
174 UPNP_WPS_DEVICE_XML_FILE);
175 }
176
177 /* The SERVER line has three comma-separated fields:
178 * operating system / version
179 * upnp version
180 * software package / version
181 * However, only the UPnP version is really required, the
182 * others can be place holders... for security reasons
183 * it is better to NOT provide extra information.
184 */
185 wpabuf_put_str(msg, "SERVER: Unspecified, UPnP/1.0, Unspecified\r\n");
186
187 switch (a->state / UPNP_ADVERTISE_REPEAT) {
188 case 0:
189 wpabuf_printf(msg, "%s: upnp:rootdevice\r\n", NTString);
190 wpabuf_printf(msg, "USN: uuid:%s::upnp:rootdevice\r\n",
191 uuid_string);
192 break;
193 case 1:
194 wpabuf_printf(msg, "%s: uuid:%s\r\n", NTString, uuid_string);
195 wpabuf_printf(msg, "USN: uuid:%s\r\n", uuid_string);
196 break;
197 case 2:
198 wpabuf_printf(msg, "%s: urn:schemas-wifialliance-org:device:"
199 "WFADevice:1\r\n", NTString);
200 wpabuf_printf(msg, "USN: uuid:%s::urn:schemas-wifialliance-"
201 "org:device:WFADevice:1\r\n", uuid_string);
202 break;
203 case 3:
204 wpabuf_printf(msg, "%s: urn:schemas-wifialliance-org:service:"
205 "WFAWLANConfig:1\r\n", NTString);
206 wpabuf_printf(msg, "USN: uuid:%s::urn:schemas-wifialliance-"
207 "org:service:WFAWLANConfig:1\r\n", uuid_string);
208 break;
209 }
210 wpabuf_put_str(msg, "\r\n");
211
212 if (a->state + 1 >= 4 * UPNP_ADVERTISE_REPEAT)
213 *islast = 1;
214
215 return msg;
216 }
217
218
219 static void advertisement_state_machine_handler(void *eloop_data,
220 void *user_ctx);
221
222
223 /**
224 * advertisement_state_machine_stop - Stop SSDP advertisements
225 * @sm: WPS UPnP state machine from upnp_wps_device_init()
226 * @send_byebye: Send byebye advertisement messages immediately
227 */
advertisement_state_machine_stop(struct upnp_wps_device_sm * sm,int send_byebye)228 void advertisement_state_machine_stop(struct upnp_wps_device_sm *sm,
229 int send_byebye)
230 {
231 struct advertisement_state_machine *a = &sm->advertisement;
232 int islast = 0;
233 struct wpabuf *msg;
234 struct sockaddr_in dest;
235
236 eloop_cancel_timeout(advertisement_state_machine_handler, NULL, sm);
237 if (!send_byebye || sm->multicast_sd < 0)
238 return;
239
240 a->type = ADVERTISE_DOWN;
241 a->state = 0;
242
243 os_memset(&dest, 0, sizeof(dest));
244 dest.sin_family = AF_INET;
245 dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
246 dest.sin_port = htons(UPNP_MULTICAST_PORT);
247
248 while (!islast) {
249 msg = next_advertisement(sm, a, &islast);
250 if (msg == NULL)
251 break;
252 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg),
253 0, (struct sockaddr *) &dest, sizeof(dest)) < 0) {
254 wpa_printf(MSG_INFO, "WPS UPnP: Advertisement sendto "
255 "failed: %d (%s)", errno, strerror(errno));
256 }
257 wpabuf_free(msg);
258 a->state++;
259 }
260 }
261
262
advertisement_state_machine_handler(void * eloop_data,void * user_ctx)263 static void advertisement_state_machine_handler(void *eloop_data,
264 void *user_ctx)
265 {
266 struct upnp_wps_device_sm *sm = user_ctx;
267 struct advertisement_state_machine *a = &sm->advertisement;
268 struct wpabuf *msg;
269 int next_timeout_msec = 100;
270 int next_timeout_sec = 0;
271 struct sockaddr_in dest;
272 int islast = 0;
273
274 /*
275 * Each is sent twice (in case lost) w/ 100 msec delay between;
276 * spec says no more than 3 times.
277 * One pair for rootdevice, one pair for uuid, and a pair each for
278 * each of the two urns.
279 * The entire sequence must be repeated before cache control timeout
280 * (which is min 1800 seconds),
281 * recommend random portion of half of the advertised cache control age
282 * to ensure against loss... perhaps 1800/4 + rand*1800/4 ?
283 * Delay random interval < 100 msec prior to initial sending.
284 * TTL of 4
285 */
286
287 wpa_printf(MSG_MSGDUMP, "WPS UPnP: Advertisement state=%d", a->state);
288 msg = next_advertisement(sm, a, &islast);
289 if (msg == NULL)
290 return;
291
292 os_memset(&dest, 0, sizeof(dest));
293 dest.sin_family = AF_INET;
294 dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
295 dest.sin_port = htons(UPNP_MULTICAST_PORT);
296
297 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0,
298 (struct sockaddr *) &dest, sizeof(dest)) == -1) {
299 wpa_printf(MSG_ERROR, "WPS UPnP: Advertisement sendto failed:"
300 "%d (%s)", errno, strerror(errno));
301 next_timeout_msec = 0;
302 next_timeout_sec = 10; /* ... later */
303 } else if (islast) {
304 a->state = 0; /* wrap around */
305 if (a->type == ADVERTISE_DOWN) {
306 wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_DOWN->UP");
307 a->type = ADVERTISE_UP;
308 /* do it all over again right away */
309 } else {
310 u16 r;
311 /*
312 * Start over again after a long timeout
313 * (see notes above)
314 */
315 next_timeout_msec = 0;
316 if (os_get_random((void *) &r, sizeof(r)) < 0)
317 r = 32768;
318 next_timeout_sec = UPNP_CACHE_SEC / 4 +
319 (((UPNP_CACHE_SEC / 4) * r) >> 16);
320 sm->advertise_count++;
321 wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_UP (#%u); "
322 "next in %d sec",
323 sm->advertise_count, next_timeout_sec);
324 }
325 } else {
326 a->state++;
327 }
328
329 wpabuf_free(msg);
330
331 eloop_register_timeout(next_timeout_sec, next_timeout_msec,
332 advertisement_state_machine_handler, NULL, sm);
333 }
334
335
336 /**
337 * advertisement_state_machine_start - Start SSDP advertisements
338 * @sm: WPS UPnP state machine from upnp_wps_device_init()
339 * Returns: 0 on success, -1 on failure
340 */
advertisement_state_machine_start(struct upnp_wps_device_sm * sm)341 int advertisement_state_machine_start(struct upnp_wps_device_sm *sm)
342 {
343 struct advertisement_state_machine *a = &sm->advertisement;
344 int next_timeout_msec;
345
346 advertisement_state_machine_stop(sm, 0);
347
348 /*
349 * Start out advertising down, this automatically switches
350 * to advertising up which signals our restart.
351 */
352 a->type = ADVERTISE_DOWN;
353 a->state = 0;
354 /* (other fields not used here) */
355
356 /* First timeout should be random interval < 100 msec */
357 next_timeout_msec = (100 * (os_random() & 0xFF)) >> 8;
358 return eloop_register_timeout(0, next_timeout_msec,
359 advertisement_state_machine_handler,
360 NULL, sm);
361 }
362
363
364 /***************************************************************************
365 * M-SEARCH replies
366 * These are very similar to the multicast advertisements, with some
367 * small changes in data content; and they are sent (UDP) to a specific
368 * unicast address instead of multicast.
369 * They are sent in response to a UDP M-SEARCH packet.
370 **************************************************************************/
371
372 /**
373 * msearchreply_state_machine_stop - Stop M-SEARCH reply state machine
374 * @a: Selected advertisement/reply state
375 */
msearchreply_state_machine_stop(struct advertisement_state_machine * a)376 void msearchreply_state_machine_stop(struct advertisement_state_machine *a)
377 {
378 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH stop");
379 dl_list_del(&a->list);
380 os_free(a);
381 }
382
383
msearchreply_state_machine_handler(void * eloop_data,void * user_ctx)384 static void msearchreply_state_machine_handler(void *eloop_data,
385 void *user_ctx)
386 {
387 struct advertisement_state_machine *a = user_ctx;
388 struct upnp_wps_device_sm *sm = eloop_data;
389 struct wpabuf *msg;
390 int next_timeout_msec = 100;
391 int next_timeout_sec = 0;
392 int islast = 0;
393
394 /*
395 * Each response is sent twice (in case lost) w/ 100 msec delay
396 * between; spec says no more than 3 times.
397 * One pair for rootdevice, one pair for uuid, and a pair each for
398 * each of the two urns.
399 */
400
401 /* TODO: should only send the requested response types */
402
403 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply state=%d (%s:%d)",
404 a->state, inet_ntoa(a->client.sin_addr),
405 ntohs(a->client.sin_port));
406 msg = next_advertisement(sm, a, &islast);
407 if (msg == NULL)
408 return;
409
410 /*
411 * Send it on the multicast socket to avoid having to set up another
412 * socket.
413 */
414 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0,
415 (struct sockaddr *) &a->client, sizeof(a->client)) < 0) {
416 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply sendto "
417 "errno %d (%s) for %s:%d",
418 errno, strerror(errno),
419 inet_ntoa(a->client.sin_addr),
420 ntohs(a->client.sin_port));
421 /* Ignore error and hope for the best */
422 }
423 wpabuf_free(msg);
424 if (islast) {
425 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply done");
426 msearchreply_state_machine_stop(a);
427 return;
428 }
429 a->state++;
430
431 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply in %d.%03d sec",
432 next_timeout_sec, next_timeout_msec);
433 eloop_register_timeout(next_timeout_sec, next_timeout_msec,
434 msearchreply_state_machine_handler, sm, a);
435 }
436
437
438 /**
439 * msearchreply_state_machine_start - Reply to M-SEARCH discovery request
440 * @sm: WPS UPnP state machine from upnp_wps_device_init()
441 * @client: Client address
442 * @mx: Maximum delay in seconds
443 *
444 * Use TTL of 4 (this was done when socket set up).
445 * A response should be given in randomized portion of min(MX,120) seconds
446 *
447 * UPnP-arch-DeviceArchitecture, 1.2.3:
448 * To be found, a device must send a UDP response to the source IP address and
449 * port that sent the request to the multicast channel. Devices respond if the
450 * ST header of the M-SEARCH request is "ssdp:all", "upnp:rootdevice", "uuid:"
451 * followed by a UUID that exactly matches one advertised by the device.
452 */
msearchreply_state_machine_start(struct upnp_wps_device_sm * sm,struct sockaddr_in * client,int mx)453 static void msearchreply_state_machine_start(struct upnp_wps_device_sm *sm,
454 struct sockaddr_in *client,
455 int mx)
456 {
457 struct advertisement_state_machine *a;
458 int next_timeout_sec;
459 int next_timeout_msec;
460 int replies;
461
462 replies = dl_list_len(&sm->msearch_replies);
463 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply start (%d "
464 "outstanding)", replies);
465 if (replies >= MAX_MSEARCH) {
466 wpa_printf(MSG_INFO, "WPS UPnP: Too many outstanding "
467 "M-SEARCH replies");
468 return;
469 }
470
471 a = os_zalloc(sizeof(*a));
472 if (a == NULL)
473 return;
474 a->type = MSEARCH_REPLY;
475 a->state = 0;
476 os_memcpy(&a->client, client, sizeof(*client));
477 /* Wait time depending on MX value */
478 next_timeout_msec = (1000 * mx * (os_random() & 0xFF)) >> 8;
479 next_timeout_sec = next_timeout_msec / 1000;
480 next_timeout_msec = next_timeout_msec % 1000;
481 if (eloop_register_timeout(next_timeout_sec, next_timeout_msec,
482 msearchreply_state_machine_handler, sm,
483 a)) {
484 /* No way to recover (from malloc failure) */
485 goto fail;
486 }
487 /* Remember for future cleanup */
488 dl_list_add(&sm->msearch_replies, &a->list);
489 return;
490
491 fail:
492 wpa_printf(MSG_INFO, "WPS UPnP: M-SEARCH reply failure!");
493 eloop_cancel_timeout(msearchreply_state_machine_handler, sm, a);
494 os_free(a);
495 }
496
497
498 /**
499 * ssdp_parse_msearch - Process a received M-SEARCH
500 * @sm: WPS UPnP state machine from upnp_wps_device_init()
501 * @client: Client address
502 * @data: NULL terminated M-SEARCH message
503 *
504 * Given that we have received a header w/ M-SEARCH, act upon it
505 *
506 * Format of M-SEARCH (case insensitive!):
507 *
508 * First line must be:
509 * M-SEARCH * HTTP/1.1
510 * Other lines in arbitrary order:
511 * HOST:239.255.255.250:1900
512 * ST:<varies -- must match>
513 * MAN:"ssdp:discover"
514 * MX:<varies>
515 *
516 * It should be noted that when Microsoft Vista is still learning its IP
517 * address, it sends out host lines like: HOST:[FF02::C]:1900
518 */
ssdp_parse_msearch(struct upnp_wps_device_sm * sm,struct sockaddr_in * client,const char * data)519 static void ssdp_parse_msearch(struct upnp_wps_device_sm *sm,
520 struct sockaddr_in *client, const char *data)
521 {
522 #ifndef CONFIG_NO_STDOUT_DEBUG
523 const char *start = data;
524 #endif /* CONFIG_NO_STDOUT_DEBUG */
525 int got_host = 0;
526 int got_st = 0, st_match = 0;
527 int got_man = 0;
528 int got_mx = 0;
529 int mx = 0;
530
531 /*
532 * Skip first line M-SEARCH * HTTP/1.1
533 * (perhaps we should check remainder of the line for syntax)
534 */
535 data += line_length(data);
536
537 /* Parse remaining lines */
538 for (; *data != '\0'; data += line_length(data)) {
539 if (token_eq(data, "host")) {
540 /* The host line indicates who the packet
541 * is addressed to... but do we really care?
542 * Note that Microsoft sometimes does funny
543 * stuff with the HOST: line.
544 */
545 #if 0 /* could be */
546 data += token_length(data);
547 data += word_separation_length(data);
548 if (*data != ':')
549 goto bad;
550 data++;
551 data += word_separation_length(data);
552 /* UPNP_MULTICAST_ADDRESS */
553 if (!str_starts(data, "239.255.255.250"))
554 goto bad;
555 data += os_strlen("239.255.255.250");
556 if (*data == ':') {
557 if (!str_starts(data, ":1900"))
558 goto bad;
559 }
560 #endif /* could be */
561 got_host = 1;
562 continue;
563 } else if (token_eq(data, "st")) {
564 /* There are a number of forms; we look
565 * for one that matches our case.
566 */
567 got_st = 1;
568 data += token_length(data);
569 data += word_separation_length(data);
570 if (*data != ':')
571 continue;
572 data++;
573 data += word_separation_length(data);
574 if (str_starts(data, "ssdp:all")) {
575 st_match = 1;
576 continue;
577 }
578 if (str_starts(data, "upnp:rootdevice")) {
579 st_match = 1;
580 continue;
581 }
582 if (str_starts(data, "uuid:")) {
583 char uuid_string[80];
584 struct upnp_wps_device_interface *iface;
585 iface = dl_list_first(
586 &sm->interfaces,
587 struct upnp_wps_device_interface,
588 list);
589 if (!iface)
590 continue;
591 data += os_strlen("uuid:");
592 uuid_bin2str(iface->wps->uuid, uuid_string,
593 sizeof(uuid_string));
594 if (str_starts(data, uuid_string))
595 st_match = 1;
596 continue;
597 }
598 #if 0
599 /* FIX: should we really reply to IGD string? */
600 if (str_starts(data, "urn:schemas-upnp-org:device:"
601 "InternetGatewayDevice:1")) {
602 st_match = 1;
603 continue;
604 }
605 #endif
606 if (str_starts(data, "urn:schemas-wifialliance-org:"
607 "service:WFAWLANConfig:1")) {
608 st_match = 1;
609 continue;
610 }
611 if (str_starts(data, "urn:schemas-wifialliance-org:"
612 "device:WFADevice:1")) {
613 st_match = 1;
614 continue;
615 }
616 continue;
617 } else if (token_eq(data, "man")) {
618 data += token_length(data);
619 data += word_separation_length(data);
620 if (*data != ':')
621 continue;
622 data++;
623 data += word_separation_length(data);
624 if (!str_starts(data, "\"ssdp:discover\"")) {
625 wpa_printf(MSG_DEBUG, "WPS UPnP: Unexpected "
626 "M-SEARCH man-field");
627 goto bad;
628 }
629 got_man = 1;
630 continue;
631 } else if (token_eq(data, "mx")) {
632 data += token_length(data);
633 data += word_separation_length(data);
634 if (*data != ':')
635 continue;
636 data++;
637 data += word_separation_length(data);
638 mx = atol(data);
639 got_mx = 1;
640 continue;
641 }
642 /* ignore anything else */
643 }
644 if (!got_host || !got_st || !got_man || !got_mx || mx < 0) {
645 wpa_printf(MSG_DEBUG, "WPS UPnP: Invalid M-SEARCH: %d %d %d "
646 "%d mx=%d", got_host, got_st, got_man, got_mx, mx);
647 goto bad;
648 }
649 if (!st_match) {
650 wpa_printf(MSG_DEBUG, "WPS UPnP: Ignored M-SEARCH (no ST "
651 "match)");
652 return;
653 }
654 if (mx > 120)
655 mx = 120; /* UPnP-arch-DeviceArchitecture, 1.2.3 */
656 msearchreply_state_machine_start(sm, client, mx);
657 return;
658
659 bad:
660 wpa_printf(MSG_INFO, "WPS UPnP: Failed to parse M-SEARCH");
661 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH data:\n%s", start);
662 }
663
664
665 /* Listening for (UDP) discovery (M-SEARCH) packets */
666
667 /**
668 * ssdp_listener_stop - Stop SSDP listered
669 * @sm: WPS UPnP state machine from upnp_wps_device_init()
670 *
671 * This function stops the SSDP listener that was started by calling
672 * ssdp_listener_start().
673 */
ssdp_listener_stop(struct upnp_wps_device_sm * sm)674 void ssdp_listener_stop(struct upnp_wps_device_sm *sm)
675 {
676 if (sm->ssdp_sd_registered) {
677 eloop_unregister_sock(sm->ssdp_sd, EVENT_TYPE_READ);
678 sm->ssdp_sd_registered = 0;
679 }
680
681 if (sm->ssdp_sd != -1) {
682 close(sm->ssdp_sd);
683 sm->ssdp_sd = -1;
684 }
685
686 eloop_cancel_timeout(msearchreply_state_machine_handler, sm,
687 ELOOP_ALL_CTX);
688 }
689
690
ssdp_listener_handler(int sd,void * eloop_ctx,void * sock_ctx)691 static void ssdp_listener_handler(int sd, void *eloop_ctx, void *sock_ctx)
692 {
693 struct upnp_wps_device_sm *sm = sock_ctx;
694 struct sockaddr_in addr; /* client address */
695 socklen_t addr_len;
696 int nread;
697 char buf[MULTICAST_MAX_READ], *pos;
698
699 addr_len = sizeof(addr);
700 nread = recvfrom(sm->ssdp_sd, buf, sizeof(buf) - 1, 0,
701 (struct sockaddr *) &addr, &addr_len);
702 if (nread <= 0)
703 return;
704 buf[nread] = '\0'; /* need null termination for algorithm */
705
706 if (str_starts(buf, "NOTIFY ")) {
707 /*
708 * Silently ignore NOTIFYs to avoid filling debug log with
709 * unwanted messages.
710 */
711 return;
712 }
713
714 pos = os_strchr(buf, '\n');
715 if (pos)
716 *pos = '\0';
717 wpa_printf(MSG_MSGDUMP, "WPS UPnP: Received SSDP packet from %s:%d: "
718 "%s", inet_ntoa(addr.sin_addr), ntohs(addr.sin_port), buf);
719 if (pos)
720 *pos = '\n';
721
722 /* Parse first line */
723 if (os_strncasecmp(buf, "M-SEARCH", os_strlen("M-SEARCH")) == 0 &&
724 !isgraph(buf[strlen("M-SEARCH")])) {
725 ssdp_parse_msearch(sm, &addr, buf);
726 return;
727 }
728
729 /* Ignore anything else */
730 }
731
732
ssdp_listener_open(void)733 int ssdp_listener_open(void)
734 {
735 struct sockaddr_in addr;
736 struct ip_mreq mcast_addr;
737 int on = 1;
738 /* per UPnP spec, keep IP packet time to live (TTL) small */
739 unsigned char ttl = 4;
740 int sd;
741
742 sd = socket(AF_INET, SOCK_DGRAM, 0);
743 if (sd < 0 ||
744 fcntl(sd, F_SETFL, O_NONBLOCK) != 0 ||
745 setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)))
746 goto fail;
747 os_memset(&addr, 0, sizeof(addr));
748 addr.sin_family = AF_INET;
749 addr.sin_addr.s_addr = htonl(INADDR_ANY);
750 addr.sin_port = htons(UPNP_MULTICAST_PORT);
751 if (bind(sd, (struct sockaddr *) &addr, sizeof(addr)))
752 goto fail;
753 os_memset(&mcast_addr, 0, sizeof(mcast_addr));
754 mcast_addr.imr_interface.s_addr = htonl(INADDR_ANY);
755 mcast_addr.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
756 if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
757 (char *) &mcast_addr, sizeof(mcast_addr)) ||
758 setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL,
759 &ttl, sizeof(ttl)))
760 goto fail;
761
762 return sd;
763
764 fail:
765 if (sd >= 0)
766 close(sd);
767 return -1;
768 }
769
770
771 /**
772 * ssdp_listener_start - Set up for receiving discovery (UDP) packets
773 * @sm: WPS UPnP state machine from upnp_wps_device_init()
774 * Returns: 0 on success, -1 on failure
775 *
776 * The SSDP listener is stopped by calling ssdp_listener_stop().
777 */
ssdp_listener_start(struct upnp_wps_device_sm * sm)778 int ssdp_listener_start(struct upnp_wps_device_sm *sm)
779 {
780 sm->ssdp_sd = ssdp_listener_open();
781
782 if (eloop_register_sock(sm->ssdp_sd, EVENT_TYPE_READ,
783 ssdp_listener_handler, NULL, sm))
784 goto fail;
785 sm->ssdp_sd_registered = 1;
786 return 0;
787
788 fail:
789 /* Error */
790 wpa_printf(MSG_ERROR, "WPS UPnP: ssdp_listener_start failed");
791 ssdp_listener_stop(sm);
792 return -1;
793 }
794
795
796 /**
797 * add_ssdp_network - Add routing entry for SSDP
798 * @net_if: Selected network interface name
799 * Returns: 0 on success, -1 on failure
800 *
801 * This function assures that the multicast address will be properly
802 * handled by Linux networking code (by a modification to routing tables).
803 * This must be done per network interface. It really only needs to be done
804 * once after booting up, but it does not hurt to call this more frequently
805 * "to be safe".
806 */
add_ssdp_network(const char * net_if)807 int add_ssdp_network(const char *net_if)
808 {
809 #ifdef __linux__
810 int ret = -1;
811 int sock = -1;
812 struct rtentry rt;
813 struct sockaddr_in *sin;
814
815 if (!net_if)
816 goto fail;
817
818 os_memset(&rt, 0, sizeof(rt));
819 sock = socket(AF_INET, SOCK_DGRAM, 0);
820 if (sock < 0)
821 goto fail;
822
823 rt.rt_dev = (char *) net_if;
824 sin = aliasing_hide_typecast(&rt.rt_dst, struct sockaddr_in);
825 sin->sin_family = AF_INET;
826 sin->sin_port = 0;
827 sin->sin_addr.s_addr = inet_addr(SSDP_TARGET);
828 sin = aliasing_hide_typecast(&rt.rt_genmask, struct sockaddr_in);
829 sin->sin_family = AF_INET;
830 sin->sin_port = 0;
831 sin->sin_addr.s_addr = inet_addr(SSDP_NETMASK);
832 rt.rt_flags = RTF_UP;
833 if (ioctl(sock, SIOCADDRT, &rt) < 0) {
834 if (errno == EPERM) {
835 wpa_printf(MSG_DEBUG, "add_ssdp_network: No "
836 "permissions to add routing table entry");
837 /* Continue to allow testing as non-root */
838 } else if (errno != EEXIST) {
839 wpa_printf(MSG_INFO, "add_ssdp_network() ioctl errno "
840 "%d (%s)", errno, strerror(errno));
841 goto fail;
842 }
843 }
844
845 ret = 0;
846
847 fail:
848 if (sock >= 0)
849 close(sock);
850
851 return ret;
852 #else /* __linux__ */
853 return 0;
854 #endif /* __linux__ */
855 }
856
857
ssdp_open_multicast_sock(u32 ip_addr,const char * forced_ifname)858 int ssdp_open_multicast_sock(u32 ip_addr, const char *forced_ifname)
859 {
860 int sd;
861 /* per UPnP-arch-DeviceArchitecture, 1. Discovery, keep IP packet
862 * time to live (TTL) small */
863 unsigned char ttl = 4;
864
865 sd = socket(AF_INET, SOCK_DGRAM, 0);
866 if (sd < 0)
867 return -1;
868
869 if (forced_ifname) {
870 #ifdef __linux__
871 struct ifreq req;
872 os_memset(&req, 0, sizeof(req));
873 os_strlcpy(req.ifr_name, forced_ifname, sizeof(req.ifr_name));
874 if (setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, &req,
875 sizeof(req)) < 0) {
876 wpa_printf(MSG_INFO, "WPS UPnP: Failed to bind "
877 "multicast socket to ifname %s: %s",
878 forced_ifname, strerror(errno));
879 close(sd);
880 return -1;
881 }
882 #endif /* __linux__ */
883 }
884
885 #if 0 /* maybe ok if we sometimes block on writes */
886 if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0) {
887 close(sd);
888 return -1;
889 }
890 #endif
891
892 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_IF,
893 &ip_addr, sizeof(ip_addr))) {
894 wpa_printf(MSG_DEBUG, "WPS: setsockopt(IP_MULTICAST_IF) %x: "
895 "%d (%s)", ip_addr, errno, strerror(errno));
896 close(sd);
897 return -1;
898 }
899 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL,
900 &ttl, sizeof(ttl))) {
901 wpa_printf(MSG_DEBUG, "WPS: setsockopt(IP_MULTICAST_TTL): "
902 "%d (%s)", errno, strerror(errno));
903 close(sd);
904 return -1;
905 }
906
907 #if 0 /* not needed, because we don't receive using multicast_sd */
908 {
909 struct ip_mreq mreq;
910 mreq.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
911 mreq.imr_interface.s_addr = ip_addr;
912 wpa_printf(MSG_DEBUG, "WPS UPnP: Multicast addr 0x%x if addr "
913 "0x%x",
914 mreq.imr_multiaddr.s_addr,
915 mreq.imr_interface.s_addr);
916 if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq,
917 sizeof(mreq))) {
918 wpa_printf(MSG_ERROR,
919 "WPS UPnP: setsockopt "
920 "IP_ADD_MEMBERSHIP errno %d (%s)",
921 errno, strerror(errno));
922 close(sd);
923 return -1;
924 }
925 }
926 #endif /* not needed */
927
928 /*
929 * TODO: What about IP_MULTICAST_LOOP? It seems to be on by default?
930 * which aids debugging I suppose but isn't really necessary?
931 */
932
933 return sd;
934 }
935
936
937 /**
938 * ssdp_open_multicast - Open socket for sending multicast SSDP messages
939 * @sm: WPS UPnP state machine from upnp_wps_device_init()
940 * Returns: 0 on success, -1 on failure
941 */
ssdp_open_multicast(struct upnp_wps_device_sm * sm)942 int ssdp_open_multicast(struct upnp_wps_device_sm *sm)
943 {
944 sm->multicast_sd = ssdp_open_multicast_sock(sm->ip_addr, NULL);
945 if (sm->multicast_sd < 0)
946 return -1;
947 return 0;
948 }
949