Line data Source code
1 : /*
2 : * UPnP WPS Device - Event processing
3 : * Copyright (c) 2000-2003 Intel Corporation
4 : * Copyright (c) 2006-2007 Sony Corporation
5 : * Copyright (c) 2008-2009 Atheros Communications
6 : * Copyright (c) 2009-2010, 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 : #include <assert.h>
13 :
14 : #include "common.h"
15 : #include "eloop.h"
16 : #include "uuid.h"
17 : #include "http_client.h"
18 : #include "wps_defs.h"
19 : #include "wps_upnp.h"
20 : #include "wps_upnp_i.h"
21 :
22 : /*
23 : * Event message generation (to subscribers)
24 : *
25 : * We make a separate copy for each message for each subscriber. This memory
26 : * wasted could be limited (adding code complexity) by sharing copies, keeping
27 : * a usage count and freeing when zero.
28 : *
29 : * Sending a message requires using a HTTP over TCP NOTIFY
30 : * (like a PUT) which requires a number of states..
31 : */
32 :
33 : #define MAX_EVENTS_QUEUED 20 /* How far behind queued events */
34 : #define MAX_FAILURES 10 /* Drop subscription after this many failures */
35 :
36 : /* How long to wait before sending event */
37 : #define EVENT_DELAY_SECONDS 0
38 : #define EVENT_DELAY_MSEC 0
39 :
40 : /*
41 : * Event information that we send to each subscriber is remembered in this
42 : * struct. The event cannot be sent by simple UDP; it has to be sent by a HTTP
43 : * over TCP transaction which requires various states.. It may also need to be
44 : * retried at a different address (if more than one is available).
45 : *
46 : * TODO: As an optimization we could share data between subscribers.
47 : */
48 : struct wps_event_ {
49 : struct dl_list list;
50 : struct subscription *s; /* parent */
51 : unsigned subscriber_sequence; /* which event for this subscription*/
52 : unsigned int retry; /* which retry */
53 : struct subscr_addr *addr; /* address to connect to */
54 : struct wpabuf *data; /* event data to send */
55 : struct http_client *http_event;
56 : };
57 :
58 :
59 : /* event_clean -- clean sockets etc. of event
60 : * Leaves data, retry count etc. alone.
61 : */
62 67 : static void event_clean(struct wps_event_ *e)
63 : {
64 67 : if (e->s->current_event == e)
65 64 : e->s->current_event = NULL;
66 67 : http_client_free(e->http_event);
67 67 : e->http_event = NULL;
68 67 : }
69 :
70 :
71 : /* event_delete -- delete single unqueued event
72 : * (be sure to dequeue first if need be)
73 : */
74 57 : static void event_delete(struct wps_event_ *e)
75 : {
76 57 : wpa_printf(MSG_DEBUG, "WPS UPnP: Delete event %p", e);
77 57 : event_clean(e);
78 57 : wpabuf_free(e->data);
79 57 : os_free(e);
80 57 : }
81 :
82 :
83 : /* event_dequeue -- get next event from the queue
84 : * Returns NULL if empty.
85 : */
86 76 : static struct wps_event_ *event_dequeue(struct subscription *s)
87 : {
88 : struct wps_event_ *e;
89 76 : e = dl_list_first(&s->event_queue, struct wps_event_, list);
90 76 : if (e) {
91 64 : wpa_printf(MSG_DEBUG, "WPS UPnP: Dequeue event %p for "
92 : "subscription %p", e, s);
93 64 : dl_list_del(&e->list);
94 : }
95 76 : return e;
96 : }
97 :
98 :
99 : /* event_delete_all -- delete entire event queue and current event */
100 12 : void event_delete_all(struct subscription *s)
101 : {
102 : struct wps_event_ *e;
103 24 : while ((e = event_dequeue(s)) != NULL)
104 0 : event_delete(e);
105 12 : if (s->current_event) {
106 0 : event_delete(s->current_event);
107 : /* will set: s->current_event = NULL; */
108 : }
109 12 : }
110 :
111 :
112 : /**
113 : * event_retry - Called when we had a failure delivering event msg
114 : * @e: Event
115 : * @do_next_address: skip address e.g. on connect fail
116 : */
117 10 : static void event_retry(struct wps_event_ *e, int do_next_address)
118 : {
119 10 : struct subscription *s = e->s;
120 10 : struct upnp_wps_device_sm *sm = s->sm;
121 :
122 10 : wpa_printf(MSG_DEBUG, "WPS UPnP: Retry event %p for subscription %p",
123 : e, s);
124 10 : event_clean(e);
125 : /* will set: s->current_event = NULL; */
126 :
127 10 : if (do_next_address) {
128 10 : e->retry++;
129 10 : wpa_printf(MSG_DEBUG, "WPS UPnP: Try address %d", e->retry);
130 : }
131 10 : if (e->retry >= dl_list_len(&s->addr_list)) {
132 3 : wpa_printf(MSG_DEBUG, "WPS UPnP: Giving up on sending event "
133 3 : "for %s", e->addr->domain_and_port);
134 3 : event_delete(e);
135 3 : s->last_event_failed = 1;
136 3 : if (!dl_list_empty(&s->event_queue))
137 0 : event_send_all_later(s->sm);
138 13 : return;
139 : }
140 7 : dl_list_add(&s->event_queue, &e->list);
141 7 : event_send_all_later(sm);
142 : }
143 :
144 :
145 64 : static struct wpabuf * event_build_message(struct wps_event_ *e)
146 : {
147 : struct wpabuf *buf;
148 : char *b;
149 :
150 64 : buf = wpabuf_alloc(1000 + wpabuf_len(e->data));
151 64 : if (buf == NULL)
152 0 : return NULL;
153 64 : wpabuf_printf(buf, "NOTIFY %s HTTP/1.1\r\n", e->addr->path);
154 64 : wpabuf_put_str(buf, "SERVER: Unspecified, UPnP/1.0, Unspecified\r\n");
155 64 : wpabuf_printf(buf, "HOST: %s\r\n", e->addr->domain_and_port);
156 64 : wpabuf_put_str(buf, "CONTENT-TYPE: text/xml; charset=\"utf-8\"\r\n"
157 : "NT: upnp:event\r\n"
158 : "NTS: upnp:propchange\r\n");
159 64 : wpabuf_put_str(buf, "SID: uuid:");
160 64 : b = wpabuf_put(buf, 0);
161 64 : uuid_bin2str(e->s->uuid, b, 80);
162 64 : wpabuf_put(buf, os_strlen(b));
163 64 : wpabuf_put_str(buf, "\r\n");
164 64 : wpabuf_printf(buf, "SEQ: %u\r\n", e->subscriber_sequence);
165 64 : wpabuf_printf(buf, "CONTENT-LENGTH: %d\r\n",
166 64 : (int) wpabuf_len(e->data));
167 64 : wpabuf_put_str(buf, "\r\n"); /* terminating empty line */
168 64 : wpabuf_put_buf(buf, e->data);
169 64 : return buf;
170 : }
171 :
172 :
173 10 : static void event_addr_failure(struct wps_event_ *e)
174 : {
175 10 : struct subscription *s = e->s;
176 :
177 10 : e->addr->num_failures++;
178 20 : wpa_printf(MSG_DEBUG, "WPS UPnP: Failed to send event %p to %s "
179 : "(num_failures=%u)",
180 20 : e, e->addr->domain_and_port, e->addr->num_failures);
181 :
182 10 : if (e->addr->num_failures < MAX_FAILURES) {
183 : /* Try other addresses, if available */
184 10 : event_retry(e, 1);
185 10 : return;
186 : }
187 :
188 : /*
189 : * If other side doesn't like what we say, forget about them.
190 : * (There is no way to tell other side that we are dropping them...).
191 : */
192 0 : wpa_printf(MSG_DEBUG, "WPS UPnP: Deleting subscription %p "
193 0 : "address %s due to errors", s, e->addr->domain_and_port);
194 0 : dl_list_del(&e->addr->list);
195 0 : subscr_addr_delete(e->addr);
196 0 : e->addr = NULL;
197 :
198 0 : if (dl_list_empty(&s->addr_list)) {
199 : /* if we've given up on all addresses */
200 0 : wpa_printf(MSG_DEBUG, "WPS UPnP: Removing subscription %p "
201 : "with no addresses", s);
202 0 : dl_list_del(&s->list);
203 0 : subscription_destroy(s);
204 0 : return;
205 : }
206 :
207 : /* Try other addresses, if available */
208 0 : event_retry(e, 0);
209 : }
210 :
211 :
212 64 : static void event_http_cb(void *ctx, struct http_client *c,
213 : enum http_client_event event)
214 : {
215 64 : struct wps_event_ *e = ctx;
216 64 : struct subscription *s = e->s;
217 :
218 64 : wpa_printf(MSG_DEBUG, "WPS UPnP: HTTP client callback: e=%p c=%p "
219 : "event=%d", e, c, event);
220 64 : switch (event) {
221 : case HTTP_CLIENT_OK:
222 54 : wpa_printf(MSG_DEBUG,
223 : "WPS UPnP: Got event %p reply OK from %s",
224 54 : e, e->addr->domain_and_port);
225 54 : e->addr->num_failures = 0;
226 54 : s->last_event_failed = 0;
227 54 : event_delete(e);
228 :
229 : /* Schedule sending more if there is more to send */
230 54 : if (!dl_list_empty(&s->event_queue))
231 1 : event_send_all_later(s->sm);
232 54 : break;
233 : case HTTP_CLIENT_FAILED:
234 10 : wpa_printf(MSG_DEBUG, "WPS UPnP: Event send failure");
235 10 : event_addr_failure(e);
236 10 : break;
237 : case HTTP_CLIENT_INVALID_REPLY:
238 0 : wpa_printf(MSG_DEBUG, "WPS UPnP: Invalid reply");
239 0 : event_addr_failure(e);
240 0 : break;
241 : case HTTP_CLIENT_TIMEOUT:
242 0 : wpa_printf(MSG_DEBUG, "WPS UPnP: Event send timeout");
243 0 : event_addr_failure(e);
244 0 : break;
245 : }
246 64 : }
247 :
248 :
249 : /* event_send_start -- prepare to send a event message to subscriber
250 : *
251 : * This gets complicated because:
252 : * -- The message is sent via TCP and we have to keep the stream open
253 : * for 30 seconds to get a response... then close it.
254 : * -- But we might have other event happen in the meantime...
255 : * we have to queue them, if we lose them then the subscriber will
256 : * be forced to unsubscribe and subscribe again.
257 : * -- If multiple URLs are provided then we are supposed to try successive
258 : * ones after 30 second timeout.
259 : * -- The URLs might use domain names instead of dotted decimal addresses,
260 : * and resolution of those may cause unwanted sleeping.
261 : * -- Doing the initial TCP connect can take a while, so we have to come
262 : * back after connection and then send the data.
263 : *
264 : * Returns nonzero on error;
265 : *
266 : * Prerequisite: No current event send (s->current_event == NULL)
267 : * and non-empty queue.
268 : */
269 64 : static int event_send_start(struct subscription *s)
270 : {
271 : struct wps_event_ *e;
272 : unsigned int itry;
273 : struct wpabuf *buf;
274 :
275 : /*
276 : * Assume we are called ONLY with no current event and ONLY with
277 : * nonempty event queue and ONLY with at least one address to send to.
278 : */
279 64 : if (dl_list_empty(&s->addr_list))
280 0 : return -1;
281 64 : if (s->current_event)
282 0 : return -1;
283 64 : if (dl_list_empty(&s->event_queue))
284 0 : return -1;
285 :
286 64 : s->current_event = e = event_dequeue(s);
287 :
288 : /* Use address according to number of retries */
289 64 : itry = 0;
290 92 : dl_list_for_each(e->addr, &s->addr_list, struct subscr_addr, list)
291 92 : if (itry++ == e->retry)
292 64 : break;
293 64 : if (itry < e->retry)
294 0 : return -1;
295 :
296 64 : buf = event_build_message(e);
297 64 : if (buf == NULL) {
298 0 : event_retry(e, 0);
299 0 : return -1;
300 : }
301 :
302 64 : e->http_event = http_client_addr(&e->addr->saddr, buf, 0,
303 : event_http_cb, e);
304 64 : if (e->http_event == NULL) {
305 0 : wpabuf_free(buf);
306 0 : event_retry(e, 0);
307 0 : return -1;
308 : }
309 :
310 64 : return 0;
311 : }
312 :
313 :
314 : /* event_send_all_later_handler -- actually send events as needed */
315 65 : static void event_send_all_later_handler(void *eloop_data, void *user_ctx)
316 : {
317 65 : struct upnp_wps_device_sm *sm = user_ctx;
318 : struct subscription *s, *tmp;
319 65 : int nerrors = 0;
320 :
321 65 : sm->event_send_all_queued = 0;
322 130 : dl_list_for_each_safe(s, tmp, &sm->subscriptions, struct subscription,
323 : list) {
324 129 : if (s->current_event == NULL /* not busy */ &&
325 64 : !dl_list_empty(&s->event_queue) /* more to do */) {
326 64 : if (event_send_start(s))
327 0 : nerrors++;
328 : }
329 : }
330 :
331 65 : if (nerrors) {
332 : /* Try again later */
333 0 : event_send_all_later(sm);
334 : }
335 65 : }
336 :
337 :
338 : /* event_send_all_later -- schedule sending events to all subscribers
339 : * that need it.
340 : * This avoids two problems:
341 : * -- After getting a subscription, we should not send the first event
342 : * until after our reply is fully queued to be sent back,
343 : * -- Possible stack depth or infinite recursion issues.
344 : */
345 77 : void event_send_all_later(struct upnp_wps_device_sm *sm)
346 : {
347 : /*
348 : * The exact time in the future isn't too important. Waiting a bit
349 : * might let us do several together.
350 : */
351 77 : if (sm->event_send_all_queued)
352 89 : return;
353 65 : sm->event_send_all_queued = 1;
354 65 : eloop_register_timeout(EVENT_DELAY_SECONDS, EVENT_DELAY_MSEC,
355 : event_send_all_later_handler, NULL, sm);
356 : }
357 :
358 :
359 : /* event_send_stop_all -- cleanup */
360 16 : void event_send_stop_all(struct upnp_wps_device_sm *sm)
361 : {
362 16 : if (sm->event_send_all_queued)
363 0 : eloop_cancel_timeout(event_send_all_later_handler, NULL, sm);
364 16 : sm->event_send_all_queued = 0;
365 16 : }
366 :
367 :
368 : /**
369 : * event_add - Add a new event to a queue
370 : * @s: Subscription
371 : * @data: Event data (is copied; caller retains ownership)
372 : * @probereq: Whether this is a Probe Request event
373 : * Returns: 0 on success, -1 on error, 1 on max event queue limit reached
374 : */
375 57 : int event_add(struct subscription *s, const struct wpabuf *data, int probereq)
376 : {
377 : struct wps_event_ *e;
378 : unsigned int len;
379 :
380 57 : len = dl_list_len(&s->event_queue);
381 57 : if (len >= MAX_EVENTS_QUEUED) {
382 0 : wpa_printf(MSG_DEBUG, "WPS UPnP: Too many events queued for "
383 : "subscriber %p", s);
384 0 : if (probereq)
385 0 : return 1;
386 :
387 : /* Drop oldest entry to allow EAP event to be stored. */
388 0 : e = event_dequeue(s);
389 0 : if (!e)
390 0 : return 1;
391 0 : event_delete(e);
392 : }
393 :
394 57 : if (s->last_event_failed && probereq && len > 0) {
395 : /*
396 : * Avoid queuing frames for subscribers that may have left
397 : * without unsubscribing.
398 : */
399 0 : wpa_printf(MSG_DEBUG, "WPS UPnP: Do not queue more Probe "
400 : "Request frames for subscription %p since last "
401 : "delivery failed", s);
402 0 : return -1;
403 : }
404 :
405 57 : e = os_zalloc(sizeof(*e));
406 57 : if (e == NULL)
407 0 : return -1;
408 57 : dl_list_init(&e->list);
409 57 : e->s = s;
410 57 : e->data = wpabuf_dup(data);
411 57 : if (e->data == NULL) {
412 0 : os_free(e);
413 0 : return -1;
414 : }
415 57 : e->subscriber_sequence = s->next_subscriber_sequence++;
416 57 : if (s->next_subscriber_sequence == 0)
417 0 : s->next_subscriber_sequence++;
418 57 : wpa_printf(MSG_DEBUG, "WPS UPnP: Queue event %p for subscriber %p "
419 : "(queue len %u)", e, s, len + 1);
420 57 : dl_list_add_tail(&s->event_queue, &e->list);
421 57 : event_send_all_later(s->sm);
422 57 : return 0;
423 : }
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