Make generate_exchange_uuid() always return the passed ast_str pointer.
[asterisk/asterisk.git] / res / res_calendar_exchange.c
1 /*
2  * Asterisk -- An open source telephony toolkit.
3  *
4  * Copyright (C) 2008 - 2009, Digium, Inc.
5  *
6  * Terry Wilson <twilson@digium.com>
7  *
8  * See http://www.asterisk.org for more information about
9  * the Asterisk project. Please do not directly contact
10  * any of the maintainers of this project for assistance;
11  * the project provides a web site, mailing lists and IRC
12  * channels for your use.
13  *
14  * This program is free software, distributed under the terms of
15  * the GNU General Public License Version 2. See the LICENSE file
16  * at the top of the source tree.
17  */
18
19 /*! \file
20  * \brief Resource for handling MS Exchange calendars
21  */
22
23 /*** MODULEINFO
24         <depend>neon</depend>
25         <depend>ical</depend>
26         <depend>iksemel</depend>
27         <support_level>core</support_level>
28 ***/
29
30 #include "asterisk.h"
31
32 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
33
34 #include <libical/ical.h>
35 #include <ne_session.h>
36 #include <ne_uri.h>
37 #include <ne_request.h>
38 #include <ne_auth.h>
39 #include <ne_redirect.h>
40 #include <iksemel.h>
41
42 #include "asterisk/module.h"
43 #include "asterisk/calendar.h"
44 #include "asterisk/lock.h"
45 #include "asterisk/config.h"
46 #include "asterisk/astobj2.h"
47 #include "asterisk/uuid.h"
48
49 static void *exchangecal_load_calendar(void *data);
50 static void *unref_exchangecal(void *obj);
51 static int exchangecal_write_event(struct ast_calendar_event *event);
52
53 static struct ast_calendar_tech exchangecal_tech = {
54         .type = "exchange",
55         .description = "MS Exchange calendars",
56         .module = AST_MODULE,
57         .load_calendar = exchangecal_load_calendar,
58         .unref_calendar = unref_exchangecal,
59         .write_event = exchangecal_write_event,
60 };
61
62 struct exchangecal_pvt {
63         AST_DECLARE_STRING_FIELDS(
64                 AST_STRING_FIELD(url);
65                 AST_STRING_FIELD(user);
66                 AST_STRING_FIELD(secret);
67         );
68         struct ast_calendar *owner;
69         ne_uri uri;
70         ne_session *session;
71         struct ao2_container *events;
72 };
73
74 struct xmlstate {
75         char tag[80];
76         int in_response;
77         int in_propstat;
78         int in_prop;
79         void *ptr;
80         struct exchangecal_pvt *pvt;
81 };
82
83 static int parse_tag(void *data, char *name, char **atts, int type)
84 {
85         struct xmlstate *state = data;
86         char *tmp;
87
88         if ((tmp = strchr(name, ':'))) {
89                 tmp++;
90         } else {
91                 return IKS_HOOK;
92         }
93
94         ast_copy_string(state->tag, tmp, sizeof(state->tag));
95
96         switch (type) {
97         case IKS_OPEN:
98                 if (!strcasecmp(state->tag, "response")) {
99                         struct ast_calendar_event *event;
100
101                         state->in_response = 1;
102                         if (!(event = ast_calendar_event_alloc(state->pvt->owner))) {
103                                 return IKS_NOMEM;
104                         }
105                         state->ptr = event;
106                 } else if (!strcasecmp(state->tag, "propstat")) {
107                         state->in_propstat = 1;
108                 } else if (!strcasecmp(state->tag, "prop")) {
109                         state->in_prop = 1;
110                 }
111                 break;
112
113         case IKS_CLOSE:
114                 if (!strcasecmp(state->tag, "response")) {
115                         struct ao2_container *events = state->pvt->events;
116                         struct ast_calendar_event *event = state->ptr;
117
118                         state->in_response = 0;
119                         if (ast_strlen_zero(event->uid)) {
120                                 ast_log(LOG_ERROR, "This event has no UID, something has gone wrong\n");
121                                 event = ast_calendar_unref_event(event);
122                                 return IKS_HOOK;
123                         }
124                         ao2_link(events, event);
125                         event = ast_calendar_unref_event(event);
126                 } else if (!strcasecmp(state->tag, "propstat")) {
127                         state->in_propstat = 0;
128                 } else if (!strcasecmp(state->tag, "prop")) {
129                         state->in_prop = 0;
130                 }
131                 break;
132
133         default:
134                 return IKS_OK;
135         }
136
137         return IKS_OK;
138 }
139
140 static time_t mstime_to_time_t(char *mstime)
141 {
142         char *read, *write;
143         icaltimetype tt;
144         for (read = write = mstime; *read; read++) {
145                 if (*read == '.') {
146                         *write++ = 'Z';
147                         *write = '\0';
148                         break;
149                 }
150                 if (*read == '-' || *read == ':')
151                         continue;
152                 *write = *read;
153                 write++;
154         }
155
156         tt = icaltime_from_string(mstime);
157         return icaltime_as_timet(tt);
158 }
159
160 static enum ast_calendar_busy_state msbusy_to_bs(const char *msbusy)
161 {
162         if (!strcasecmp(msbusy, "FREE")) {
163                 return AST_CALENDAR_BS_FREE;
164         } else if (!strcasecmp(msbusy, "TENTATIVE")) {
165                 return AST_CALENDAR_BS_BUSY_TENTATIVE;
166         } else {
167                 return AST_CALENDAR_BS_BUSY;
168         }
169 }
170
171 static int parse_cdata(void *data, char *value, size_t len)
172 {
173         char *str;
174         struct xmlstate *state = data;
175         struct ast_calendar_event *event = state->ptr;
176
177
178         str = ast_skip_blanks(value);
179
180         if (str == value + len)
181                 return IKS_OK;
182
183         if (!(str = ast_calloc(1, len + 1))) {
184                 return IKS_NOMEM;
185         }
186         memcpy(str, value, len);
187         if (!(state->in_response && state->in_propstat && state->in_prop)) {
188                 ast_free(str);
189                 return IKS_OK;
190         }
191         /* We use ast_string_field_build here because libiksemel is parsing CDATA with &lt; as
192          * new elements which is a bit odd and shouldn't happen */
193         if (!strcasecmp(state->tag, "subject")) {
194                 ast_string_field_build(event, summary, "%s%s", event->summary, str);
195         } else if (!strcasecmp(state->tag, "location")) {
196                 ast_string_field_build(event, location, "%s%s", event->location, str);
197         } else if (!strcasecmp(state->tag, "uid")) {
198                 ast_string_field_build(event, uid, "%s%s", event->location, str);
199         } else if (!strcasecmp(state->tag, "organizer")) {
200                 ast_string_field_build(event, organizer, "%s%s", event->organizer, str);
201         } else if (!strcasecmp(state->tag, "textdescription")) {
202                 ast_string_field_build(event, description, "%s%s", event->description, str);
203         } else if (!strcasecmp(state->tag, "dtstart")) {
204                 event->start = mstime_to_time_t(str);
205         } else if (!strcasecmp(state->tag, "dtend")) {
206                 event->end = mstime_to_time_t(str);
207         } else if (!strcasecmp(state->tag, "busystatus")) {
208                 event->busy_state = msbusy_to_bs(str);
209         } else if (!strcasecmp(state->tag, "reminderoffset")) {
210                 /*XXX Currently we rely on event->start being set first which means we rely on the response order
211                  * which technically should be fine since the query returns in the order we ask for, but ... */
212                 event->alarm = event->start - atoi(str);
213         }
214
215         ast_free(str);
216         return IKS_OK;
217 }
218
219 static void exchangecal_destructor(void *obj)
220 {
221         struct exchangecal_pvt *pvt = obj;
222
223         ast_debug(1, "Destroying pvt for Exchange calendar %s\n", pvt->owner->name);
224         if (pvt->session) {
225                 ne_session_destroy(pvt->session);
226         }
227         ast_string_field_free_memory(pvt);
228
229         ao2_callback(pvt->events, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, NULL, NULL);
230
231         ao2_ref(pvt->events, -1);
232 }
233
234 static void *unref_exchangecal(void *obj)
235 {
236         struct exchangecal_pvt *pvt = obj;
237
238         ao2_ref(pvt, -1);
239         return NULL;
240 }
241
242 /* It is very important to use the return value of this function as a realloc could occur */
243 static struct ast_str *generate_exchange_uuid(struct ast_str *uid)
244 {
245         char buffer[AST_UUID_STR_LEN];
246         struct ast_uuid *uuid = ast_uuid_generate();
247
248         if (!uuid) {
249                 ast_str_set(&uid, 0, "%s", "");
250                 return uid;
251         }
252
253         ast_str_set(&uid, 0, "%s", ast_uuid_to_str(uuid, buffer, AST_UUID_STR_LEN));
254
255         ast_free(uuid);
256
257         return uid;
258 }
259
260 static int is_valid_uuid(struct ast_str *uid)
261 {
262         struct ast_uuid *uuid = ast_str_to_uuid(ast_str_buffer(uid));
263
264         if (uuid) {
265                 ast_free(uuid);
266                 return 1;
267         }
268
269         return 0;
270 }
271
272 static struct ast_str *xml_encode_str(struct ast_str *dst, const char *src)
273 {
274         const char *tmp;
275         char buf[7];
276
277         for (tmp = src; *tmp; tmp++) {
278                 switch (*tmp) {
279                 case '\"':
280                         strcpy(buf, "&quot;");
281                         break;
282
283                 case '\'':
284                         strcpy(buf, "&apos;");
285                         break;
286
287                 case '&':
288                         strcpy(buf, "&amp;");
289                         break;
290
291                 case '<':
292                         strcpy(buf, "&lt;");
293                         break;
294
295                 case '>':
296                         strcpy(buf, "&gt;");
297                         break;
298
299                 default:
300                         sprintf(buf, "%c", *tmp);
301                 }
302
303                 ast_str_append(&dst, 0, "%s", buf);
304         }
305
306         return dst;
307 }
308
309 static struct ast_str *epoch_to_exchange_time(struct ast_str *dst, time_t epoch)
310 {
311         icaltimezone *utc = icaltimezone_get_utc_timezone();
312         icaltimetype tt = icaltime_from_timet_with_zone(epoch, 0, utc);
313         char tmp[30];
314         int i;
315
316         ast_copy_string(tmp, icaltime_as_ical_string(tt), sizeof(tmp));
317         for (i = 0; tmp[i]; i++) {
318                 ast_str_append(&dst, 0, "%c", tmp[i]);
319                 if (i == 3 || i == 5)
320                         ast_str_append(&dst, 0, "%c", '-');
321                 if (i == 10 || i == 12)
322                         ast_str_append(&dst, 0, "%c", ':');
323                 if (i == 14)
324                         ast_str_append(&dst, 0, "%s", ".000");
325         }
326
327         return dst;
328 }
329
330 static struct ast_str *bs_to_exchange_bs(struct ast_str *dst, enum ast_calendar_busy_state bs)
331 {
332         switch (bs) {
333         case AST_CALENDAR_BS_BUSY:
334                 ast_str_set(&dst, 0, "%s", "BUSY");
335                 break;
336
337         case AST_CALENDAR_BS_BUSY_TENTATIVE:
338                 ast_str_set(&dst, 0, "%s", "TENTATIVE");
339                 break;
340
341         default:
342                 ast_str_set(&dst, 0, "%s", "FREE");
343         }
344
345         return dst;
346 }
347
348 static int fetch_response_reader(void *data, const char *block, size_t len)
349 {
350         struct ast_str **response = data;
351         unsigned char *tmp;
352
353         if (!(tmp = ast_malloc(len + 1))) {
354                 return -1;
355         }
356         memcpy(tmp, block, len);
357         tmp[len] = '\0';
358         ast_str_append(response, 0, "%s", tmp);
359         ast_free(tmp);
360
361         return 0;
362 }
363
364 static int auth_credentials(void *userdata, const char *realm, int attempts, char *username, char *secret)
365 {
366         struct exchangecal_pvt *pvt = userdata;
367
368         if (attempts > 1) {
369                 ast_log(LOG_WARNING, "Invalid username or password for Exchange calendar '%s'\n", pvt->owner->name);
370                 return -1;
371         }
372
373         ne_strnzcpy(username, pvt->user, NE_ABUFSIZ);
374         ne_strnzcpy(secret, pvt->secret, NE_ABUFSIZ);
375
376         return 0;
377 }
378
379 static struct ast_str *exchangecal_request(struct exchangecal_pvt *pvt, const char *method, struct ast_str *req_body, struct ast_str *subdir)
380 {
381         struct ast_str *response;
382         ne_request *req;
383         int ret;
384         char buf[1000];
385
386         if (!pvt) {
387                 ast_log(LOG_ERROR, "There is no private!\n");
388                 return NULL;
389         }
390
391         if (!(response = ast_str_create(512))) {
392                 ast_log(LOG_ERROR, "Could not allocate memory for response.\n");
393                 return NULL;
394         }
395
396         snprintf(buf, sizeof(buf), "%s%s", pvt->uri.path, subdir ? ast_str_buffer(subdir) : "");
397
398         req = ne_request_create(pvt->session, method, buf);
399         ne_add_response_body_reader(req, ne_accept_2xx, fetch_response_reader, &response);
400         ne_set_request_body_buffer(req, ast_str_buffer(req_body), ast_str_strlen(req_body));
401         ne_add_request_header(req, "Content-type", "text/xml");
402
403         ret = ne_request_dispatch(req);
404         ne_request_destroy(req);
405
406         if (ret != NE_OK || !ast_str_strlen(response)) {
407                 ast_log(LOG_WARNING, "Unknown response to CalDAV calendar %s, request %s to %s: %s\n", pvt->owner->name, method, pvt->url, ne_get_error(pvt->session));
408                 ast_free(response);
409                 return NULL;
410         }
411
412         return response;
413 }
414
415 static int exchangecal_write_event(struct ast_calendar_event *event)
416 {
417         struct ast_str *body = NULL, *response = NULL, *subdir = NULL;
418         struct ast_str *uid = NULL, *summary = NULL, *description = NULL, *organizer = NULL,
419                        *location = NULL, *start = NULL, *end = NULL, *busystate = NULL;
420         int ret = -1;
421
422         if (!event) {
423                 ast_log(LOG_WARNING, "No event passed!\n");
424                 return -1;
425         }
426
427         if (!(event->start && event->end)) {
428                 ast_log(LOG_WARNING, "The event must contain a start and an end\n");
429                 return -1;
430         }
431         if (!(body = ast_str_create(512)) ||
432                 !(subdir = ast_str_create(32))) {
433                 ast_log(LOG_ERROR, "Could not allocate memory for request!\n");
434                 goto write_cleanup;
435         }
436
437         if (!(uid = ast_str_create(32)) ||
438                 !(summary = ast_str_create(32)) ||
439                 !(description = ast_str_create(32)) ||
440                 !(organizer = ast_str_create(32)) ||
441                 !(location = ast_str_create(32)) ||
442                 !(start = ast_str_create(32)) ||
443                 !(end = ast_str_create(32)) ||
444                 !(busystate = ast_str_create(32))) {
445                 ast_log(LOG_ERROR, "Unable to allocate memory for request values\n");
446                 goto write_cleanup;
447         }
448
449         if (ast_strlen_zero(event->uid)) {
450                 uid = generate_exchange_uuid(uid);
451         } else {
452                 ast_str_set(&uid, 36, "%s", event->uid);
453         }
454
455         if (!is_valid_uuid(uid)) {
456                 ast_log(LOG_WARNING, "An invalid uid was provided, you may leave this field blank to have one generated for you\n");
457                 goto write_cleanup;
458         }
459
460         summary = xml_encode_str(summary, event->summary);
461         description = xml_encode_str(description, event->description);
462         organizer = xml_encode_str(organizer, event->organizer);
463         location = xml_encode_str(location, event->location);
464         start = epoch_to_exchange_time(start, event->start);
465         end = epoch_to_exchange_time(end, event->end);
466         busystate = bs_to_exchange_bs(busystate, event->busy_state);
467
468         ast_str_append(&body, 0,
469                 "<?xml version=\"1.0\"?>\n"
470                 "<a:propertyupdate\n"
471                 "  xmlns:a=\"DAV:\"\n"
472                 "  xmlns:e=\"http://schemas.microsoft.com/exchange/\"\n"
473                 "  xmlns:mapi=\"http://schemas.microsoft.com/mapi/\"\n"
474                 "  xmlns:mapit=\"http://schemas.microsoft.com/mapi/proptag/\"\n"
475                 "  xmlns:x=\"xml:\" xmlns:cal=\"urn:schemas:calendar:\"\n"
476                 "  xmlns:dt=\"uuid:%s/\"\n" /* uid */
477                 "  xmlns:header=\"urn:schemas:mailheader:\"\n"
478                 "  xmlns:mail=\"urn:schemas:httpmail:\"\n"
479                 ">\n"
480                 "    <a:set>\n"
481                 "      <a:prop>\n"
482                 "        <a:contentclass>urn:content-classes:appointment</a:contentclass>\n"
483                 "        <e:outlookmessageclass>IPM.Appointment</e:outlookmessageclass>\n"
484                 "        <mail:subject>%s</mail:subject>\n" /* summary */
485                 "        <mail:description>%s</mail:description>\n" /* description */
486                 "        <header:to>%s</header:to>\n" /* organizer */
487                 "        <cal:location>%s</cal:location>\n" /* location */
488                 "        <cal:dtstart dt:dt=\"dateTime.tz\">%s</cal:dtstart>\n" /* start */
489                 "        <cal:dtend dt:dt=\"dateTime.tz\">%s</cal:dtend>\n" /* end */
490                 "        <cal:instancetype dt:dt=\"int\">0</cal:instancetype>\n"
491                 "        <cal:busystatus>%s</cal:busystatus>\n" /* busy_state (BUSY, FREE, BUSY_TENTATIVE) */
492                 "        <cal:meetingstatus>CONFIRMED</cal:meetingstatus>\n"
493                 "        <cal:alldayevent dt:dt=\"boolean\">0</cal:alldayevent>\n" /* XXX need to add event support for all day events */
494                 "        <cal:responserequested dt:dt=\"boolean\">0</cal:responserequested>\n"
495                 "        <mapi:finvited dt:dt=\"boolean\">1</mapi:finvited>\n"
496                 "      </a:prop>\n"
497                 "    </a:set>\n"
498                 "</a:propertyupdate>\n",
499                 ast_str_buffer(uid), ast_str_buffer(summary), ast_str_buffer(description), ast_str_buffer(organizer), ast_str_buffer(location), ast_str_buffer(start), ast_str_buffer(end), ast_str_buffer(busystate));
500         ast_verb(0, "\n\n%s\n\n", ast_str_buffer(body));
501         ast_str_set(&subdir, 0, "/Calendar/%s.eml", ast_str_buffer(uid));
502
503         if ((response = exchangecal_request(event->owner->tech_pvt, "PROPPATCH", body, subdir))) {
504                 ret = 0;
505         }
506
507 write_cleanup:
508         if (uid) {
509                 ast_free(uid);
510         }
511         if (summary) {
512                 ast_free(summary);
513         }
514         if (description) {
515                 ast_free(description);
516         }
517         if (organizer) {
518                 ast_free(organizer);
519         }
520         if (location) {
521                 ast_free(location);
522         }
523         if (start) {
524                 ast_free(start);
525         }
526         if (end) {
527                 ast_free(end);
528         }
529         if (busystate) {
530                 ast_free(busystate);
531         }
532         if (body) {
533                 ast_free(body);
534         }
535         if (response) {
536                 ast_free(response);
537         }
538         if (subdir) {
539                 ast_free(subdir);
540         }
541
542         return ret;
543 }
544
545
546 static struct ast_str *exchangecal_get_events_between(struct exchangecal_pvt *pvt, time_t start_time, time_t end_time)
547 {
548         struct ast_str *body, *response;
549         char start[80], end[80];
550         struct timeval tv = {0,};
551         struct ast_tm tm;
552
553         tv.tv_sec = start_time;
554         ast_localtime(&tv, &tm, "UTC");
555         ast_strftime(start, sizeof(start), "%Y/%m/%d %T", &tm);
556
557         tv.tv_sec = end_time;
558         ast_localtime(&tv, &tm, "UTC");
559         ast_strftime(end, sizeof(end), "%Y/%m/%d %T", &tm);
560
561         if (!(body = ast_str_create(512))) {
562                 ast_log(LOG_ERROR, "Could not allocate memory for body of request!\n");
563                 return NULL;
564         }
565
566         ast_str_append(&body, 0,
567                 "<?xml version=\"1.0\"?>\n"
568                 "<g:searchrequest xmlns:g=\"DAV:\">\n"
569                 "        <g:sql> SELECT \"urn:schemas:calendar:location\", \"urn:schemas:httpmail:subject\",\n"
570                 "                \"urn:schemas:calendar:dtstart\", \"urn:schemas:calendar:dtend\",\n"
571                 "                \"urn:schemas:calendar:busystatus\", \"urn:schemas:calendar:instancetype\",\n"
572                 "                \"urn:schemas:calendar:uid\", \"urn:schemas:httpmail:textdescription\",\n"
573                 "                \"urn:schemas:calendar:organizer\", \"urn:schemas:calendar:reminderoffset\"\n"
574                 "                FROM Scope('SHALLOW TRAVERSAL OF \"%s/Calendar\"')\n"
575                 "                WHERE NOT \"urn:schemas:calendar:instancetype\" = 1\n"
576                 "                AND \"DAV:contentclass\" = 'urn:content-classes:appointment'\n"
577                 "                AND NOT (\"urn:schemas:calendar:dtend\" &lt; '%s'\n"
578                 "                OR \"urn:schemas:calendar:dtstart\" &gt; '%s')\n"
579                 "                ORDER BY \"urn:schemas:calendar:dtstart\" ASC\n"
580                 "         </g:sql>\n"
581                 "</g:searchrequest>\n", pvt->url, start, end);
582
583         ast_debug(5, "Request:\n%s\n", ast_str_buffer(body));
584         response = exchangecal_request(pvt, "SEARCH", body, NULL);
585         ast_debug(5, "Response:\n%s\n", ast_str_buffer(response));
586         ast_free(body);
587
588         return response;
589 }
590
591 static int update_exchangecal(struct exchangecal_pvt *pvt)
592 {
593         struct xmlstate state;
594         struct timeval now = ast_tvnow();
595         time_t start, end;
596         struct ast_str *response;
597         iksparser *p;
598
599         state.pvt = pvt;
600         start = now.tv_sec;
601         end = now.tv_sec + 60 * pvt->owner->timeframe;
602         if (!(response = exchangecal_get_events_between(pvt, start, end))) {
603                 return -1;
604         }
605
606         p = iks_sax_new(&state, parse_tag, parse_cdata);
607         iks_parse(p, ast_str_buffer(response), ast_str_strlen(response), 1);
608         ast_calendar_merge_events(pvt->owner, pvt->events);
609         ast_free(response);
610
611         return 0;
612 }
613
614 static void *exchangecal_load_calendar(void *void_data)
615 {
616         struct exchangecal_pvt *pvt;
617         const struct ast_config *cfg;
618         struct ast_variable *v;
619         struct ast_calendar *cal = void_data;
620         ast_mutex_t refreshlock;
621
622         if (!(cal && (cfg = ast_calendar_config_acquire()))) {
623                 ast_log(LOG_ERROR, "You must enable calendar support for res_exchangecal to load\n");
624                 return NULL;
625         }
626
627         if (ao2_trylock(cal)) {
628                 if (cal->unloading) {
629                         ast_log(LOG_WARNING, "Unloading module, load_calendar cancelled.\n");
630                 } else {
631                         ast_log(LOG_WARNING, "Could not lock calendar, aborting!\n");
632                 }
633                 ast_calendar_config_release();
634                 return NULL;
635         }
636
637         if (!(pvt = ao2_alloc(sizeof(*pvt), exchangecal_destructor))) {
638                 ast_log(LOG_ERROR, "Could not allocate exchangecal_pvt structure for calendar: %s\n", cal->name);
639                 ast_calendar_config_release();
640                 return NULL;
641         }
642
643         pvt->owner = cal;
644
645         if (!(pvt->events = ast_calendar_event_container_alloc())) {
646                 ast_log(LOG_ERROR, "Could not allocate space for fetching events for calendar: %s\n", cal->name);
647                 pvt = unref_exchangecal(pvt);
648                 ao2_unlock(cal);
649                 ast_calendar_config_release();
650                 return NULL;
651         }
652
653         if (ast_string_field_init(pvt, 32)) {
654                 ast_log(LOG_ERROR, "Couldn't allocate string field space for calendar: %s\n", cal->name);
655                 pvt = unref_exchangecal(pvt);
656                 ao2_unlock(cal);
657                 ast_calendar_config_release();
658                 return NULL;
659         }
660
661         for (v = ast_variable_browse(cfg, cal->name); v; v = v->next) {
662                 if (!strcasecmp(v->name, "url")) {
663                         ast_string_field_set(pvt, url, v->value);
664                 } else if (!strcasecmp(v->name, "user")) {
665                         ast_string_field_set(pvt, user, v->value);
666                 } else if (!strcasecmp(v->name, "secret")) {
667                         ast_string_field_set(pvt, secret, v->value);
668                 }
669         }
670
671         ast_calendar_config_release();
672
673         if (ast_strlen_zero(pvt->url)) {
674                 ast_log(LOG_WARNING, "No URL was specified for Exchange calendar '%s' - skipping.\n", cal->name);
675                 pvt = unref_exchangecal(pvt);
676                 ao2_unlock(cal);
677                 return NULL;
678         }
679
680         if (ne_uri_parse(pvt->url, &pvt->uri) || pvt->uri.host == NULL || pvt->uri.path == NULL) {
681                 ast_log(LOG_WARNING, "Could not parse url '%s' for Exchange calendar '%s' - skipping.\n", pvt->url, cal->name);
682                 pvt = unref_exchangecal(pvt);
683                 ao2_unlock(cal);
684                 return NULL;
685         }
686
687         if (pvt->uri.scheme == NULL) {
688                 pvt->uri.scheme = "http";
689         }
690
691         if (pvt->uri.port == 0) {
692                 pvt->uri.port = ne_uri_defaultport(pvt->uri.scheme);
693         }
694
695         pvt->session = ne_session_create(pvt->uri.scheme, pvt->uri.host, pvt->uri.port);
696         ne_redirect_register(pvt->session);
697         ne_set_server_auth(pvt->session, auth_credentials, pvt);
698         if (!strcasecmp(pvt->uri.scheme, "https")) {
699                 ne_ssl_trust_default_ca(pvt->session);
700         }
701
702         cal->tech_pvt = pvt;
703
704         ast_mutex_init(&refreshlock);
705
706         /* Load it the first time */
707         update_exchangecal(pvt);
708
709         ao2_unlock(cal);
710
711         /* The only writing from another thread will be if unload is true */
712         for (;;) {
713                 struct timeval tv = ast_tvnow();
714                 struct timespec ts = {0,};
715
716                 ts.tv_sec = tv.tv_sec + (60 * pvt->owner->refresh);
717
718                 ast_mutex_lock(&refreshlock);
719                 while (!pvt->owner->unloading) {
720                         if (ast_cond_timedwait(&pvt->owner->unload, &refreshlock, &ts) == ETIMEDOUT) {
721                                 break;
722                         }
723                 }
724                 ast_mutex_unlock(&refreshlock);
725
726                 if (pvt->owner->unloading) {
727                         ast_debug(10, "Skipping refresh since we got a shutdown signal\n");
728                         return NULL;
729                 }
730
731                 ast_debug(10, "Refreshing after %d minute timeout\n", pvt->owner->refresh);
732
733                 update_exchangecal(pvt);
734         }
735
736         return NULL;
737 }
738
739 static int load_module(void)
740 {
741         ne_sock_init();
742         if (ast_calendar_register(&exchangecal_tech)) {
743                 ne_sock_exit();
744                 return AST_MODULE_LOAD_DECLINE;
745         }
746
747         return AST_MODULE_LOAD_SUCCESS;
748 }
749
750 static int unload_module(void)
751 {
752         ast_calendar_unregister(&exchangecal_tech);
753         ne_sock_exit();
754         return 0;
755 }
756
757 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "Asterisk MS Exchange Calendar Integration",
758                 .load = load_module,
759                 .unload = unload_module,
760                 .load_pri = AST_MODPRI_DEVSTATE_PLUGIN,
761         );