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 goto fail;
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 fail:
218 wpabuf_free(msg);
219 return NULL;
220 }
221
222
223 static void advertisement_state_machine_handler(void *eloop_data,
224 void *user_ctx);
225
226
227 /**
228 * advertisement_state_machine_stop - Stop SSDP advertisements
229 * @sm: WPS UPnP state machine from upnp_wps_device_init()
230 * @send_byebye: Send byebye advertisement messages immediately
231 */
advertisement_state_machine_stop(struct upnp_wps_device_sm * sm,int send_byebye)232 void advertisement_state_machine_stop(struct upnp_wps_device_sm *sm,
233 int send_byebye)
234 {
235 struct advertisement_state_machine *a = &sm->advertisement;
236 int islast = 0;
237 struct wpabuf *msg;
238 struct sockaddr_in dest;
239
240 eloop_cancel_timeout(advertisement_state_machine_handler, NULL, sm);
241 if (!send_byebye || sm->multicast_sd < 0)
242 return;
243
244 a->type = ADVERTISE_DOWN;
245 a->state = 0;
246
247 os_memset(&dest, 0, sizeof(dest));
248 dest.sin_family = AF_INET;
249 dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
250 dest.sin_port = htons(UPNP_MULTICAST_PORT);
251
252 while (!islast) {
253 msg = next_advertisement(sm, a, &islast);
254 if (msg == NULL)
255 break;
256 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg),
257 0, (struct sockaddr *) &dest, sizeof(dest)) < 0) {
258 wpa_printf(MSG_INFO, "WPS UPnP: Advertisement sendto "
259 "failed: %d (%s)", errno, strerror(errno));
260 }
261 wpabuf_free(msg);
262 a->state++;
263 }
264 }
265
266
advertisement_state_machine_handler(void * eloop_data,void * user_ctx)267 static void advertisement_state_machine_handler(void *eloop_data,
268 void *user_ctx)
269 {
270 struct upnp_wps_device_sm *sm = user_ctx;
271 struct advertisement_state_machine *a = &sm->advertisement;
272 struct wpabuf *msg;
273 int next_timeout_msec = 100;
274 int next_timeout_sec = 0;
275 struct sockaddr_in dest;
276 int islast = 0;
277
278 /*
279 * Each is sent twice (in case lost) w/ 100 msec delay between;
280 * spec says no more than 3 times.
281 * One pair for rootdevice, one pair for uuid, and a pair each for
282 * each of the two urns.
283 * The entire sequence must be repeated before cache control timeout
284 * (which is min 1800 seconds),
285 * recommend random portion of half of the advertised cache control age
286 * to ensure against loss... perhaps 1800/4 + rand*1800/4 ?
287 * Delay random interval < 100 msec prior to initial sending.
288 * TTL of 4
289 */
290
291 wpa_printf(MSG_MSGDUMP, "WPS UPnP: Advertisement state=%d", a->state);
292 msg = next_advertisement(sm, a, &islast);
293 if (msg == NULL)
294 return;
295
296 os_memset(&dest, 0, sizeof(dest));
297 dest.sin_family = AF_INET;
298 dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
299 dest.sin_port = htons(UPNP_MULTICAST_PORT);
300
301 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0,
302 (struct sockaddr *) &dest, sizeof(dest)) == -1) {
303 wpa_printf(MSG_ERROR, "WPS UPnP: Advertisement sendto failed:"
304 "%d (%s)", errno, strerror(errno));
305 next_timeout_msec = 0;
306 next_timeout_sec = 10; /* ... later */
307 } else if (islast) {
308 a->state = 0; /* wrap around */
309 if (a->type == ADVERTISE_DOWN) {
310 wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_DOWN->UP");
311 a->type = ADVERTISE_UP;
312 /* do it all over again right away */
313 } else {
314 u16 r;
315 /*
316 * Start over again after a long timeout
317 * (see notes above)
318 */
319 next_timeout_msec = 0;
320 os_get_random((void *) &r, sizeof(r));
321 next_timeout_sec = UPNP_CACHE_SEC / 4 +
322 (((UPNP_CACHE_SEC / 4) * r) >> 16);
323 sm->advertise_count++;
324 wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_UP (#%u); "
325 "next in %d sec",
326 sm->advertise_count, next_timeout_sec);
327 }
328 } else {
329 a->state++;
330 }
331
332 wpabuf_free(msg);
333
334 eloop_register_timeout(next_timeout_sec, next_timeout_msec,
335 advertisement_state_machine_handler, NULL, sm);
336 }
337
338
339 /**
340 * advertisement_state_machine_start - Start SSDP advertisements
341 * @sm: WPS UPnP state machine from upnp_wps_device_init()
342 * Returns: 0 on success, -1 on failure
343 */
advertisement_state_machine_start(struct upnp_wps_device_sm * sm)344 int advertisement_state_machine_start(struct upnp_wps_device_sm *sm)
345 {
346 struct advertisement_state_machine *a = &sm->advertisement;
347 int next_timeout_msec;
348
349 advertisement_state_machine_stop(sm, 0);
350
351 /*
352 * Start out advertising down, this automatically switches
353 * to advertising up which signals our restart.
354 */
355 a->type = ADVERTISE_DOWN;
356 a->state = 0;
357 /* (other fields not used here) */
358
359 /* First timeout should be random interval < 100 msec */
360 next_timeout_msec = (100 * (os_random() & 0xFF)) >> 8;
361 return eloop_register_timeout(0, next_timeout_msec,
362 advertisement_state_machine_handler,
363 NULL, sm);
364 }
365
366
367 /***************************************************************************
368 * M-SEARCH replies
369 * These are very similar to the multicast advertisements, with some
370 * small changes in data content; and they are sent (UDP) to a specific
371 * unicast address instead of multicast.
372 * They are sent in response to a UDP M-SEARCH packet.
373 **************************************************************************/
374
375 /**
376 * msearchreply_state_machine_stop - Stop M-SEARCH reply state machine
377 * @a: Selected advertisement/reply state
378 */
msearchreply_state_machine_stop(struct advertisement_state_machine * a)379 void msearchreply_state_machine_stop(struct advertisement_state_machine *a)
380 {
381 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH stop");
382 dl_list_del(&a->list);
383 os_free(a);
384 }
385
386
msearchreply_state_machine_handler(void * eloop_data,void * user_ctx)387 static void msearchreply_state_machine_handler(void *eloop_data,
388 void *user_ctx)
389 {
390 struct advertisement_state_machine *a = user_ctx;
391 struct upnp_wps_device_sm *sm = eloop_data;
392 struct wpabuf *msg;
393 int next_timeout_msec = 100;
394 int next_timeout_sec = 0;
395 int islast = 0;
396
397 /*
398 * Each response is sent twice (in case lost) w/ 100 msec delay
399 * between; spec says no more than 3 times.
400 * One pair for rootdevice, one pair for uuid, and a pair each for
401 * each of the two urns.
402 */
403
404 /* TODO: should only send the requested response types */
405
406 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply state=%d (%s:%d)",
407 a->state, inet_ntoa(a->client.sin_addr),
408 ntohs(a->client.sin_port));
409 msg = next_advertisement(sm, a, &islast);
410 if (msg == NULL)
411 return;
412
413 /*
414 * Send it on the multicast socket to avoid having to set up another
415 * socket.
416 */
417 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0,
418 (struct sockaddr *) &a->client, sizeof(a->client)) < 0) {
419 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply sendto "
420 "errno %d (%s) for %s:%d",
421 errno, strerror(errno),
422 inet_ntoa(a->client.sin_addr),
423 ntohs(a->client.sin_port));
424 /* Ignore error and hope for the best */
425 }
426 wpabuf_free(msg);
427 if (islast) {
428 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply done");
429 msearchreply_state_machine_stop(a);
430 return;
431 }
432 a->state++;
433
434 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply in %d.%03d sec",
435 next_timeout_sec, next_timeout_msec);
436 eloop_register_timeout(next_timeout_sec, next_timeout_msec,
437 msearchreply_state_machine_handler, sm, a);
438 }
439
440
441 /**
442 * msearchreply_state_machine_start - Reply to M-SEARCH discovery request
443 * @sm: WPS UPnP state machine from upnp_wps_device_init()
444 * @client: Client address
445 * @mx: Maximum delay in seconds
446 *
447 * Use TTL of 4 (this was done when socket set up).
448 * A response should be given in randomized portion of min(MX,120) seconds
449 *
450 * UPnP-arch-DeviceArchitecture, 1.2.3:
451 * To be found, a device must send a UDP response to the source IP address and
452 * port that sent the request to the multicast channel. Devices respond if the
453 * ST header of the M-SEARCH request is "ssdp:all", "upnp:rootdevice", "uuid:"
454 * followed by a UUID that exactly matches one advertised by the device.
455 */
msearchreply_state_machine_start(struct upnp_wps_device_sm * sm,struct sockaddr_in * client,int mx)456 static void msearchreply_state_machine_start(struct upnp_wps_device_sm *sm,
457 struct sockaddr_in *client,
458 int mx)
459 {
460 struct advertisement_state_machine *a;
461 int next_timeout_sec;
462 int next_timeout_msec;
463 int replies;
464
465 replies = dl_list_len(&sm->msearch_replies);
466 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply start (%d "
467 "outstanding)", replies);
468 if (replies >= MAX_MSEARCH) {
469 wpa_printf(MSG_INFO, "WPS UPnP: Too many outstanding "
470 "M-SEARCH replies");
471 return;
472 }
473
474 a = os_zalloc(sizeof(*a));
475 if (a == NULL)
476 return;
477 a->type = MSEARCH_REPLY;
478 a->state = 0;
479 os_memcpy(&a->client, client, sizeof(*client));
480 /* Wait time depending on MX value */
481 next_timeout_msec = (1000 * mx * (os_random() & 0xFF)) >> 8;
482 next_timeout_sec = next_timeout_msec / 1000;
483 next_timeout_msec = next_timeout_msec % 1000;
484 if (eloop_register_timeout(next_timeout_sec, next_timeout_msec,
485 msearchreply_state_machine_handler, sm,
486 a)) {
487 /* No way to recover (from malloc failure) */
488 goto fail;
489 }
490 /* Remember for future cleanup */
491 dl_list_add(&sm->msearch_replies, &a->list);
492 return;
493
494 fail:
495 wpa_printf(MSG_INFO, "WPS UPnP: M-SEARCH reply failure!");
496 eloop_cancel_timeout(msearchreply_state_machine_handler, sm, a);
497 os_free(a);
498 }
499
500
501 /**
502 * ssdp_parse_msearch - Process a received M-SEARCH
503 * @sm: WPS UPnP state machine from upnp_wps_device_init()
504 * @client: Client address
505 * @data: NULL terminated M-SEARCH message
506 *
507 * Given that we have received a header w/ M-SEARCH, act upon it
508 *
509 * Format of M-SEARCH (case insensitive!):
510 *
511 * First line must be:
512 * M-SEARCH * HTTP/1.1
513 * Other lines in arbitrary order:
514 * HOST:239.255.255.250:1900
515 * ST:<varies -- must match>
516 * MAN:"ssdp:discover"
517 * MX:<varies>
518 *
519 * It should be noted that when Microsoft Vista is still learning its IP
520 * address, it sends out host lines like: HOST:[FF02::C]:1900
521 */
ssdp_parse_msearch(struct upnp_wps_device_sm * sm,struct sockaddr_in * client,const char * data)522 static void ssdp_parse_msearch(struct upnp_wps_device_sm *sm,
523 struct sockaddr_in *client, const char *data)
524 {
525 #ifndef CONFIG_NO_STDOUT_DEBUG
526 const char *start = data;
527 #endif /* CONFIG_NO_STDOUT_DEBUG */
528 int got_host = 0;
529 int got_st = 0, st_match = 0;
530 int got_man = 0;
531 int got_mx = 0;
532 int mx = 0;
533
534 /*
535 * Skip first line M-SEARCH * HTTP/1.1
536 * (perhaps we should check remainder of the line for syntax)
537 */
538 data += line_length(data);
539
540 /* Parse remaining lines */
541 for (; *data != '\0'; data += line_length(data)) {
542 if (token_eq(data, "host")) {
543 /* The host line indicates who the packet
544 * is addressed to... but do we really care?
545 * Note that Microsoft sometimes does funny
546 * stuff with the HOST: line.
547 */
548 #if 0 /* could be */
549 data += token_length(data);
550 data += word_separation_length(data);
551 if (*data != ':')
552 goto bad;
553 data++;
554 data += word_separation_length(data);
555 /* UPNP_MULTICAST_ADDRESS */
556 if (!str_starts(data, "239.255.255.250"))
557 goto bad;
558 data += os_strlen("239.255.255.250");
559 if (*data == ':') {
560 if (!str_starts(data, ":1900"))
561 goto bad;
562 }
563 #endif /* could be */
564 got_host = 1;
565 continue;
566 } else if (token_eq(data, "st")) {
567 /* There are a number of forms; we look
568 * for one that matches our case.
569 */
570 got_st = 1;
571 data += token_length(data);
572 data += word_separation_length(data);
573 if (*data != ':')
574 continue;
575 data++;
576 data += word_separation_length(data);
577 if (str_starts(data, "ssdp:all")) {
578 st_match = 1;
579 continue;
580 }
581 if (str_starts(data, "upnp:rootdevice")) {
582 st_match = 1;
583 continue;
584 }
585 if (str_starts(data, "uuid:")) {
586 char uuid_string[80];
587 struct upnp_wps_device_interface *iface;
588 iface = dl_list_first(
589 &sm->interfaces,
590 struct upnp_wps_device_interface,
591 list);
592 if (!iface)
593 continue;
594 data += os_strlen("uuid:");
595 uuid_bin2str(iface->wps->uuid, uuid_string,
596 sizeof(uuid_string));
597 if (str_starts(data, uuid_string))
598 st_match = 1;
599 continue;
600 }
601 #if 0
602 /* FIX: should we really reply to IGD string? */
603 if (str_starts(data, "urn:schemas-upnp-org:device:"
604 "InternetGatewayDevice:1")) {
605 st_match = 1;
606 continue;
607 }
608 #endif
609 if (str_starts(data, "urn:schemas-wifialliance-org:"
610 "service:WFAWLANConfig:1")) {
611 st_match = 1;
612 continue;
613 }
614 if (str_starts(data, "urn:schemas-wifialliance-org:"
615 "device:WFADevice:1")) {
616 st_match = 1;
617 continue;
618 }
619 continue;
620 } else if (token_eq(data, "man")) {
621 data += token_length(data);
622 data += word_separation_length(data);
623 if (*data != ':')
624 continue;
625 data++;
626 data += word_separation_length(data);
627 if (!str_starts(data, "\"ssdp:discover\"")) {
628 wpa_printf(MSG_DEBUG, "WPS UPnP: Unexpected "
629 "M-SEARCH man-field");
630 goto bad;
631 }
632 got_man = 1;
633 continue;
634 } else if (token_eq(data, "mx")) {
635 data += token_length(data);
636 data += word_separation_length(data);
637 if (*data != ':')
638 continue;
639 data++;
640 data += word_separation_length(data);
641 mx = atol(data);
642 got_mx = 1;
643 continue;
644 }
645 /* ignore anything else */
646 }
647 if (!got_host || !got_st || !got_man || !got_mx || mx < 0) {
648 wpa_printf(MSG_DEBUG, "WPS UPnP: Invalid M-SEARCH: %d %d %d "
649 "%d mx=%d", got_host, got_st, got_man, got_mx, mx);
650 goto bad;
651 }
652 if (!st_match) {
653 wpa_printf(MSG_DEBUG, "WPS UPnP: Ignored M-SEARCH (no ST "
654 "match)");
655 return;
656 }
657 if (mx > 120)
658 mx = 120; /* UPnP-arch-DeviceArchitecture, 1.2.3 */
659 msearchreply_state_machine_start(sm, client, mx);
660 return;
661
662 bad:
663 wpa_printf(MSG_INFO, "WPS UPnP: Failed to parse M-SEARCH");
664 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH data:\n%s", start);
665 }
666
667
668 /* Listening for (UDP) discovery (M-SEARCH) packets */
669
670 /**
671 * ssdp_listener_stop - Stop SSDP listered
672 * @sm: WPS UPnP state machine from upnp_wps_device_init()
673 *
674 * This function stops the SSDP listener that was started by calling
675 * ssdp_listener_start().
676 */
ssdp_listener_stop(struct upnp_wps_device_sm * sm)677 void ssdp_listener_stop(struct upnp_wps_device_sm *sm)
678 {
679 if (sm->ssdp_sd_registered) {
680 eloop_unregister_sock(sm->ssdp_sd, EVENT_TYPE_READ);
681 sm->ssdp_sd_registered = 0;
682 }
683
684 if (sm->ssdp_sd != -1) {
685 close(sm->ssdp_sd);
686 sm->ssdp_sd = -1;
687 }
688
689 eloop_cancel_timeout(msearchreply_state_machine_handler, sm,
690 ELOOP_ALL_CTX);
691 }
692
693
ssdp_listener_handler(int sd,void * eloop_ctx,void * sock_ctx)694 static void ssdp_listener_handler(int sd, void *eloop_ctx, void *sock_ctx)
695 {
696 struct upnp_wps_device_sm *sm = sock_ctx;
697 struct sockaddr_in addr; /* client address */
698 socklen_t addr_len;
699 int nread;
700 char buf[MULTICAST_MAX_READ], *pos;
701
702 addr_len = sizeof(addr);
703 nread = recvfrom(sm->ssdp_sd, buf, sizeof(buf) - 1, 0,
704 (struct sockaddr *) &addr, &addr_len);
705 if (nread <= 0)
706 return;
707 buf[nread] = '\0'; /* need null termination for algorithm */
708
709 if (str_starts(buf, "NOTIFY ")) {
710 /*
711 * Silently ignore NOTIFYs to avoid filling debug log with
712 * unwanted messages.
713 */
714 return;
715 }
716
717 pos = os_strchr(buf, '\n');
718 if (pos)
719 *pos = '\0';
720 wpa_printf(MSG_MSGDUMP, "WPS UPnP: Received SSDP packet from %s:%d: "
721 "%s", inet_ntoa(addr.sin_addr), ntohs(addr.sin_port), buf);
722 if (pos)
723 *pos = '\n';
724
725 /* Parse first line */
726 if (os_strncasecmp(buf, "M-SEARCH", os_strlen("M-SEARCH")) == 0 &&
727 !isgraph(buf[strlen("M-SEARCH")])) {
728 ssdp_parse_msearch(sm, &addr, buf);
729 return;
730 }
731
732 /* Ignore anything else */
733 }
734
735
ssdp_listener_open(void)736 int ssdp_listener_open(void)
737 {
738 struct sockaddr_in addr;
739 struct ip_mreq mcast_addr;
740 int on = 1;
741 /* per UPnP spec, keep IP packet time to live (TTL) small */
742 unsigned char ttl = 4;
743 int sd;
744
745 sd = socket(AF_INET, SOCK_DGRAM, 0);
746 if (sd < 0)
747 goto fail;
748 if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0)
749 goto fail;
750 if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)))
751 goto fail;
752 os_memset(&addr, 0, sizeof(addr));
753 addr.sin_family = AF_INET;
754 addr.sin_addr.s_addr = htonl(INADDR_ANY);
755 addr.sin_port = htons(UPNP_MULTICAST_PORT);
756 if (bind(sd, (struct sockaddr *) &addr, sizeof(addr)))
757 goto fail;
758 os_memset(&mcast_addr, 0, sizeof(mcast_addr));
759 mcast_addr.imr_interface.s_addr = htonl(INADDR_ANY);
760 mcast_addr.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
761 if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
762 (char *) &mcast_addr, sizeof(mcast_addr)))
763 goto fail;
764 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL,
765 &ttl, sizeof(ttl)))
766 goto fail;
767
768 return sd;
769
770 fail:
771 if (sd >= 0)
772 close(sd);
773 return -1;
774 }
775
776
777 /**
778 * ssdp_listener_start - Set up for receiving discovery (UDP) packets
779 * @sm: WPS UPnP state machine from upnp_wps_device_init()
780 * Returns: 0 on success, -1 on failure
781 *
782 * The SSDP listener is stopped by calling ssdp_listener_stop().
783 */
ssdp_listener_start(struct upnp_wps_device_sm * sm)784 int ssdp_listener_start(struct upnp_wps_device_sm *sm)
785 {
786 sm->ssdp_sd = ssdp_listener_open();
787
788 if (eloop_register_sock(sm->ssdp_sd, EVENT_TYPE_READ,
789 ssdp_listener_handler, NULL, sm))
790 goto fail;
791 sm->ssdp_sd_registered = 1;
792 return 0;
793
794 fail:
795 /* Error */
796 wpa_printf(MSG_ERROR, "WPS UPnP: ssdp_listener_start failed");
797 ssdp_listener_stop(sm);
798 return -1;
799 }
800
801
802 /**
803 * add_ssdp_network - Add routing entry for SSDP
804 * @net_if: Selected network interface name
805 * Returns: 0 on success, -1 on failure
806 *
807 * This function assures that the multicast address will be properly
808 * handled by Linux networking code (by a modification to routing tables).
809 * This must be done per network interface. It really only needs to be done
810 * once after booting up, but it does not hurt to call this more frequently
811 * "to be safe".
812 */
add_ssdp_network(const char * net_if)813 int add_ssdp_network(const char *net_if)
814 {
815 #ifdef __linux__
816 int ret = -1;
817 int sock = -1;
818 struct rtentry rt;
819 struct sockaddr_in *sin;
820
821 if (!net_if)
822 goto fail;
823
824 os_memset(&rt, 0, sizeof(rt));
825 sock = socket(AF_INET, SOCK_DGRAM, 0);
826 if (sock < 0)
827 goto fail;
828
829 rt.rt_dev = (char *) net_if;
830 sin = aliasing_hide_typecast(&rt.rt_dst, struct sockaddr_in);
831 sin->sin_family = AF_INET;
832 sin->sin_port = 0;
833 sin->sin_addr.s_addr = inet_addr(SSDP_TARGET);
834 sin = aliasing_hide_typecast(&rt.rt_genmask, struct sockaddr_in);
835 sin->sin_family = AF_INET;
836 sin->sin_port = 0;
837 sin->sin_addr.s_addr = inet_addr(SSDP_NETMASK);
838 rt.rt_flags = RTF_UP;
839 if (ioctl(sock, SIOCADDRT, &rt) < 0) {
840 if (errno == EPERM) {
841 wpa_printf(MSG_DEBUG, "add_ssdp_network: No "
842 "permissions to add routing table entry");
843 /* Continue to allow testing as non-root */
844 } else if (errno != EEXIST) {
845 wpa_printf(MSG_INFO, "add_ssdp_network() ioctl errno "
846 "%d (%s)", errno, strerror(errno));
847 goto fail;
848 }
849 }
850
851 ret = 0;
852
853 fail:
854 if (sock >= 0)
855 close(sock);
856
857 return ret;
858 #else /* __linux__ */
859 return 0;
860 #endif /* __linux__ */
861 }
862
863
ssdp_open_multicast_sock(u32 ip_addr,const char * forced_ifname)864 int ssdp_open_multicast_sock(u32 ip_addr, const char *forced_ifname)
865 {
866 int sd;
867 /* per UPnP-arch-DeviceArchitecture, 1. Discovery, keep IP packet
868 * time to live (TTL) small */
869 unsigned char ttl = 4;
870
871 sd = socket(AF_INET, SOCK_DGRAM, 0);
872 if (sd < 0)
873 return -1;
874
875 if (forced_ifname) {
876 #ifdef __linux__
877 struct ifreq req;
878 os_memset(&req, 0, sizeof(req));
879 os_strlcpy(req.ifr_name, forced_ifname, sizeof(req.ifr_name));
880 if (setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, &req,
881 sizeof(req)) < 0) {
882 wpa_printf(MSG_INFO, "WPS UPnP: Failed to bind "
883 "multicast socket to ifname %s: %s",
884 forced_ifname, strerror(errno));
885 close(sd);
886 return -1;
887 }
888 #endif /* __linux__ */
889 }
890
891 #if 0 /* maybe ok if we sometimes block on writes */
892 if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0) {
893 close(sd);
894 return -1;
895 }
896 #endif
897
898 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_IF,
899 &ip_addr, sizeof(ip_addr))) {
900 wpa_printf(MSG_DEBUG, "WPS: setsockopt(IP_MULTICAST_IF) %x: "
901 "%d (%s)", ip_addr, errno, strerror(errno));
902 close(sd);
903 return -1;
904 }
905 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL,
906 &ttl, sizeof(ttl))) {
907 wpa_printf(MSG_DEBUG, "WPS: setsockopt(IP_MULTICAST_TTL): "
908 "%d (%s)", errno, strerror(errno));
909 close(sd);
910 return -1;
911 }
912
913 #if 0 /* not needed, because we don't receive using multicast_sd */
914 {
915 struct ip_mreq mreq;
916 mreq.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
917 mreq.imr_interface.s_addr = ip_addr;
918 wpa_printf(MSG_DEBUG, "WPS UPnP: Multicast addr 0x%x if addr "
919 "0x%x",
920 mreq.imr_multiaddr.s_addr,
921 mreq.imr_interface.s_addr);
922 if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq,
923 sizeof(mreq))) {
924 wpa_printf(MSG_ERROR,
925 "WPS UPnP: setsockopt "
926 "IP_ADD_MEMBERSHIP errno %d (%s)",
927 errno, strerror(errno));
928 close(sd);
929 return -1;
930 }
931 }
932 #endif /* not needed */
933
934 /*
935 * TODO: What about IP_MULTICAST_LOOP? It seems to be on by default?
936 * which aids debugging I suppose but isn't really necessary?
937 */
938
939 return sd;
940 }
941
942
943 /**
944 * ssdp_open_multicast - Open socket for sending multicast SSDP messages
945 * @sm: WPS UPnP state machine from upnp_wps_device_init()
946 * Returns: 0 on success, -1 on failure
947 */
ssdp_open_multicast(struct upnp_wps_device_sm * sm)948 int ssdp_open_multicast(struct upnp_wps_device_sm *sm)
949 {
950 sm->multicast_sd = ssdp_open_multicast_sock(sm->ip_addr, NULL);
951 if (sm->multicast_sd < 0)
952 return -1;
953 return 0;
954 }
955