Use configure to determine the prefixes and include directories properly.
[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 ***/
28 #include "asterisk.h"
29
30 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
31
32 #include <ical.h>
33 #include <ne_session.h>
34 #include <ne_uri.h>
35 #include <ne_request.h>
36 #include <ne_auth.h>
37 #include <iksemel.h>
38
39 #include "asterisk/module.h"
40 #include "asterisk/calendar.h"
41 #include "asterisk/lock.h"
42 #include "asterisk/config.h"
43 #include "asterisk/astobj2.h"
44
45 static void *exchangecal_load_calendar(void *data);
46 static void *unref_exchangecal(void *obj);
47 static int exchangecal_write_event(struct ast_calendar_event *event);
48
49 static struct ast_calendar_tech exchangecal_tech = {
50         .type = "exchange",
51         .description = "MS Exchange calendars",
52         .module = AST_MODULE,
53         .load_calendar = exchangecal_load_calendar,
54         .unref_calendar = unref_exchangecal,
55         .write_event = exchangecal_write_event,
56 };
57
58 struct exchangecal_pvt {
59         AST_DECLARE_STRING_FIELDS(
60                 AST_STRING_FIELD(url);
61                 AST_STRING_FIELD(user);
62                 AST_STRING_FIELD(secret);
63         );
64         struct ast_calendar *owner;
65         ne_uri uri;
66         ne_session *session;
67         struct ao2_container *events;
68 };
69
70 struct xmlstate {
71         char tag[80];
72         int in_response;
73         int in_propstat;
74         int in_prop;
75         void *ptr;
76         struct exchangecal_pvt *pvt;
77 };
78
79 static int parse_tag(void *data, char *name, char **atts, int type)
80 {
81         struct xmlstate *state = data;
82         char *tmp;
83
84         if ((tmp = strchr(name, ':'))) {
85                 tmp++;
86         } else {
87                 return IKS_HOOK;
88         }
89
90         ast_copy_string(state->tag, tmp, sizeof(state->tag));
91
92         switch (type) {
93         case IKS_OPEN:
94                 if (!strcasecmp(state->tag, "response")) {
95                         struct ast_calendar_event *event;
96
97                         state->in_response = 1;
98                         if (!(event = ast_calendar_event_alloc(state->pvt->owner))) {
99                                 return IKS_NOMEM;
100                         }
101                         state->ptr = event;
102                 } else if (!strcasecmp(state->tag, "propstat")) {
103                         state->in_propstat = 1;
104                 } else if (!strcasecmp(state->tag, "prop")) {
105                         state->in_prop = 1;
106                 }
107                 break;
108
109         case IKS_CLOSE:
110                 if (!strcasecmp(state->tag, "response")) {
111                         struct ao2_container *events = state->pvt->events;
112                         struct ast_calendar_event *event = state->ptr;
113
114                         state->in_response = 0;
115                         if (ast_strlen_zero(event->uid)) {
116                                 ast_log(LOG_ERROR, "This event has no UID, something has gone wrong\n");
117                                 event = ast_calendar_unref_event(event);
118                                 return IKS_HOOK;
119                         }
120                         ao2_link(events, event);
121                         event = ast_calendar_unref_event(event);
122                 } else if (!strcasecmp(state->tag, "propstat")) {
123                         state->in_propstat = 0;
124                 } else if (!strcasecmp(state->tag, "prop")) {
125                         state->in_prop = 0;
126                 }
127                 break;
128
129         default:
130                 return IKS_OK;
131         }
132
133         return IKS_OK;
134 }
135
136 static time_t mstime_to_time_t(char *mstime)
137 {
138         char *read, *write;
139         icaltimetype tt;
140         for (read = write = mstime; *read; read++) {
141                 if (*read == '.') {
142                         *write++ = 'Z';
143                         *write = '\0';
144                         break;
145                 }
146                 if (*read == '-' || *read == ':')
147                         continue;
148                 *write = *read;
149                 write++;
150         }
151
152         tt = icaltime_from_string(mstime);
153         return icaltime_as_timet(tt);
154 }
155
156 static enum ast_calendar_busy_state msbusy_to_bs(const char *msbusy)
157 {
158         if (!strcasecmp(msbusy, "FREE")) {
159                 return AST_CALENDAR_BS_FREE;
160         } else if (!strcasecmp(msbusy, "TENTATIVE")) {
161                 return AST_CALENDAR_BS_BUSY_TENTATIVE;
162         } else {
163                 return AST_CALENDAR_BS_BUSY;
164         }
165 }
166
167 static int parse_cdata(void *data, char *value, size_t len)
168 {
169         char *str;
170         struct xmlstate *state = data;
171         struct ast_calendar_event *event = state->ptr;
172
173
174         str = ast_skip_blanks(value);
175
176         if (str == value + len)
177                 return IKS_OK;
178
179         if (!(str = ast_calloc(1, len + 1))) {
180                 return IKS_NOMEM;
181         }
182         memcpy(str, value, len);
183         if (!(state->in_response && state->in_propstat && state->in_prop)) {
184                 ast_free(str);
185                 return IKS_OK;
186         }
187         /* We use ast_string_field_build here because libiksemel is parsing CDATA with &lt; as
188          * new elements which is a bit odd and shouldn't happen */
189         if (!strcasecmp(state->tag, "subject")) {
190                 ast_string_field_build(event, summary, "%s%s", event->summary, str);
191         } else if (!strcasecmp(state->tag, "location")) {
192                 ast_string_field_build(event, location, "%s%s", event->location, str);
193         } else if (!strcasecmp(state->tag, "uid")) {
194                 ast_string_field_build(event, uid, "%s%s", event->location, str);
195         } else if (!strcasecmp(state->tag, "organizer")) {
196                 ast_string_field_build(event, organizer, "%s%s", event->organizer, str);
197         } else if (!strcasecmp(state->tag, "textdescription")) {
198                 ast_string_field_build(event, description, "%s%s", event->description, str);
199         } else if (!strcasecmp(state->tag, "dtstart")) {
200                 event->start = mstime_to_time_t(str);
201         } else if (!strcasecmp(state->tag, "dtend")) {
202                 event->end = mstime_to_time_t(str);
203         } else if (!strcasecmp(state->tag, "busystatus")) {
204                 event->busy_state = msbusy_to_bs(str);
205         } else if (!strcasecmp(state->tag, "reminderoffset")) {
206                 /*XXX Currently we rely on event->start being set first which means we rely on the response order
207                  * which technically should be fine since the query returns in the order we ask for, but ... */
208                 event->alarm = event->start - atoi(str);
209         }
210
211         ast_free(str);
212         return IKS_OK;
213 }
214
215 static void exchangecal_destructor(void *obj)
216 {
217         struct exchangecal_pvt *pvt = obj;
218
219         ast_debug(1, "Destroying pvt for Exchange calendar %s\n", pvt->owner->name);
220         if (pvt->session) {
221                 ne_session_destroy(pvt->session);
222         }
223         ast_string_field_free_memory(pvt);
224
225         ao2_callback(pvt->events, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, NULL, NULL);
226
227         ao2_ref(pvt->events, -1);
228 }
229
230 static void *unref_exchangecal(void *obj)
231 {
232         struct exchangecal_pvt *pvt = obj;
233
234         ao2_ref(pvt, -1);
235         return NULL;
236 }
237
238 /* It is very important to use the return value of this function as a realloc could occur */
239 static struct ast_str *generate_exchange_uuid(struct ast_str *uid)
240 {
241         unsigned short val[8];
242         int x;
243
244         for (x = 0; x < 8; x++) {
245                 val[x] = ast_random();
246         }
247         ast_str_set(&uid, 0, "%04x%04x-%04x-%04x-%04x-%04x%04x%04x", val[0], val[1], val[2], val[3], val[4], val[5], val[6], val[7]);
248
249         return uid;
250 }
251
252 static int is_valid_uuid(struct ast_str *uid)
253 {
254         int i;
255
256         if (ast_str_strlen(uid) != 36) {
257                 return 0;
258         }
259
260         for (i = 0; i < ast_str_strlen(uid); i++) {
261                 if (i == 8 || i == 13 || i == 18 || i == 23) {
262                         if (ast_str_buffer(uid)[i] != '-') {
263                                 return 0;
264                         }
265                 } else if (!((ast_str_buffer(uid)[i] > 47 && ast_str_buffer(uid)[i] < 58) || (ast_str_buffer(uid)[i] > 96 && ast_str_buffer(uid)[i] < 103))) {
266                         return 0;
267                 }
268         }
269
270         return 1;
271 }
272
273 static struct ast_str *xml_encode_str(struct ast_str *dst, const char *src)
274 {
275         const char *tmp;
276         char buf[7];
277
278         for (tmp = src; *tmp; tmp++) {
279                 switch (*tmp) {
280                 case '\"':
281                         strcpy(buf, "&quot;");
282                         break;
283
284                 case '\'':
285                         strcpy(buf, "&apos;");
286                         break;
287
288                 case '&':
289                         strcpy(buf, "&amp;");
290                         break;
291
292                 case '<':
293                         strcpy(buf, "&lt;");
294                         break;
295
296                 case '>':
297                         strcpy(buf, "&gt;");
298                         break;
299
300                 default:
301                         sprintf(buf, "%c", *tmp);
302                 }
303
304                 ast_str_append(&dst, 0, "%s", buf);
305         }
306
307         return dst;
308 }
309
310 static struct ast_str *epoch_to_exchange_time(struct ast_str *dst, time_t epoch)
311 {
312         icaltimezone *utc = icaltimezone_get_utc_timezone();
313         icaltimetype tt = icaltime_from_timet_with_zone(epoch, 0, utc);
314         char tmp[30];
315         int i;
316
317         ast_copy_string(tmp, icaltime_as_ical_string(tt), sizeof(tmp));
318         for (i = 0; tmp[i]; i++) {
319                 ast_str_append(&dst, 0, "%c", tmp[i]);
320                 if (i == 3 || i == 5)
321                         ast_str_append(&dst, 0, "%c", '-');
322                 if (i == 10 || i == 12)
323                         ast_str_append(&dst, 0, "%c", ':');
324                 if (i == 14)
325                         ast_str_append(&dst, 0, "%s", ".000");
326         }
327
328         return dst;
329 }
330
331 static struct ast_str *bs_to_exchange_bs(struct ast_str *dst, enum ast_calendar_busy_state bs)
332 {
333         switch (bs) {
334         case AST_CALENDAR_BS_BUSY:
335                 ast_str_set(&dst, 0, "%s", "BUSY");
336                 break;
337
338         case AST_CALENDAR_BS_BUSY_TENTATIVE:
339                 ast_str_set(&dst, 0, "%s", "TENTATIVE");
340                 break;
341
342         default:
343                 ast_str_set(&dst, 0, "%s", "FREE");
344         }
345
346         return dst;
347 }
348
349 static int fetch_response_reader(void *data, const char *block, size_t len)
350 {
351         struct ast_str **response = data;
352         unsigned char *tmp;
353
354         if (!(tmp = ast_malloc(len + 1))) {
355                 return -1;
356         }
357         memcpy(tmp, block, len);
358         tmp[len] = '\0';
359         ast_str_append(response, 0, "%s", tmp);
360         ast_free(tmp);
361
362         return 0;
363 }
364
365 static int auth_credentials(void *userdata, const char *realm, int attempts, char *username, char *secret)
366 {
367         struct exchangecal_pvt *pvt = userdata;
368
369         if (attempts > 1) {
370                 ast_log(LOG_WARNING, "Invalid username or password for Exchange calendar '%s'\n", pvt->owner->name);
371                 return -1;
372         }
373
374         ne_strnzcpy(username, pvt->user, NE_ABUFSIZ);
375         ne_strnzcpy(secret, pvt->secret, NE_ABUFSIZ);
376
377         return 0;
378 }
379
380 static struct ast_str *exchangecal_request(struct exchangecal_pvt *pvt, const char *method, struct ast_str *req_body, struct ast_str *subdir)
381 {
382         struct ast_str *response;
383         ne_request *req;
384         int ret;
385         char buf[1000];
386
387         if (!pvt) {
388                 ast_log(LOG_ERROR, "There is no private!\n");
389                 return NULL;
390         }
391
392         if (!(response = ast_str_create(512))) {
393                 ast_log(LOG_ERROR, "Could not allocate memory for response.\n");
394                 return NULL;
395         }
396
397         snprintf(buf, sizeof(buf), "%s%s", pvt->uri.path, subdir ? ast_str_buffer(subdir) : "");
398
399         req = ne_request_create(pvt->session, method, buf);
400         ne_add_response_body_reader(req, ne_accept_2xx, fetch_response_reader, &response);
401         ne_set_request_body_buffer(req, ast_str_buffer(req_body), ast_str_strlen(req_body));
402         ne_add_request_header(req, "Content-type", "text/xml");
403
404         ret = ne_request_dispatch(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                 !(response = ast_str_create(512))) {
434                 ast_log(LOG_ERROR, "Could not allocate memory for request and response!\n");
435                 goto write_cleanup;
436         }
437
438         if (!(uid = ast_str_create(32)) ||
439                 !(summary = ast_str_create(32)) ||
440                 !(description = ast_str_create(32)) ||
441                 !(organizer = ast_str_create(32)) ||
442                 !(location = ast_str_create(32)) ||
443                 !(start = ast_str_create(32)) ||
444                 !(end = ast_str_create(32)) ||
445                 !(busystate = ast_str_create(32))) {
446                 ast_log(LOG_ERROR, "Unable to allocate memory for request values\n");
447                 goto write_cleanup;
448         }
449
450         if (ast_strlen_zero(event->uid)) {
451                 uid = generate_exchange_uuid(uid);
452         } else {
453                 ast_str_set(&uid, 36, "%s", event->uid);
454         }
455
456         if (!is_valid_uuid(uid)) {
457                 ast_log(LOG_WARNING, "An invalid uid was provided, you may leave this field blank to have one generated for you\n");
458                 goto write_cleanup;
459         }
460
461         summary = xml_encode_str(summary, event->summary);
462         description = xml_encode_str(description, event->description);
463         organizer = xml_encode_str(organizer, event->organizer);
464         location = xml_encode_str(location, event->location);
465         start = epoch_to_exchange_time(start, event->start);
466         end = epoch_to_exchange_time(end, event->end);
467         busystate = bs_to_exchange_bs(busystate, event->busy_state);
468
469         ast_str_append(&body, 0,
470                 "<?xml version=\"1.0\"?>\n"
471                 "<a:propertyupdate\n"
472                 "  xmlns:a=\"DAV:\"\n"
473                 "  xmlns:e=\"http://schemas.microsoft.com/exchange/\"\n"
474                 "  xmlns:mapi=\"http://schemas.microsoft.com/mapi/\"\n"
475                 "  xmlns:mapit=\"http://schemas.microsoft.com/mapi/proptag/\"\n"
476                 "  xmlns:x=\"xml:\" xmlns:cal=\"urn:schemas:calendar:\"\n"
477                 "  xmlns:dt=\"uuid:%s/\"\n" /* uid */
478                 "  xmlns:header=\"urn:schemas:mailheader:\"\n"
479                 "  xmlns:mail=\"urn:schemas:httpmail:\"\n"
480                 ">\n"
481                 "    <a:set>\n"
482                 "      <a:prop>\n"
483                 "        <a:contentclass>urn:content-classes:appointment</a:contentclass>\n"
484                 "        <e:outlookmessageclass>IPM.Appointment</e:outlookmessageclass>\n"
485                 "        <mail:subject>%s</mail:subject>\n" /* summary */
486                 "        <mail:description>%s</mail:description>\n" /* description */
487                 "        <header:to>%s</header:to>\n" /* organizer */
488                 "        <cal:location>%s</cal:location>\n" /* location */
489                 "        <cal:dtstart dt:dt=\"dateTime.tz\">%s</cal:dtstart>\n" /* start */
490                 "        <cal:dtend dt:dt=\"dateTime.tz\">%s</cal:dtend>\n" /* end */
491                 "        <cal:instancetype dt:dt=\"int\">0</cal:instancetype>\n"
492                 "        <cal:busystatus>%s</cal:busystatus>\n" /* busy_state (BUSY, FREE, BUSY_TENTATIVE) */
493                 "        <cal:meetingstatus>CONFIRMED</cal:meetingstatus>\n"
494                 "        <cal:alldayevent dt:dt=\"boolean\">0</cal:alldayevent>\n" /* XXX need to add event support for all day events */
495                 "        <cal:responserequested dt:dt=\"boolean\">0</cal:responserequested>\n"
496                 "        <mapi:finvited dt:dt=\"boolean\">1</mapi:finvited>\n"
497                 "      </a:prop>\n"
498                 "    </a:set>\n"
499                 "</a:propertyupdate>\n",
500                 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));
501         ast_verb(0, "\n\n%s\n\n", ast_str_buffer(body));
502         ast_str_set(&subdir, 0, "/Calendar/%s.eml", ast_str_buffer(uid));
503
504         response = exchangecal_request(event->owner->tech_pvt, "PROPPATCH", body, subdir);
505
506         ret = 0;
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_set_server_auth(pvt->session, auth_credentials, pvt);
697         if (!strcasecmp(pvt->uri.scheme, "https")) {
698                 ne_ssl_trust_default_ca(pvt->session);
699         }
700
701         cal->tech_pvt = pvt;
702
703         ast_mutex_init(&refreshlock);
704
705         /* Load it the first time */
706         update_exchangecal(pvt);
707
708         ao2_unlock(cal);
709
710         /* The only writing from another thread will be if unload is true */
711         for (;;) {
712                 struct timeval tv = ast_tvnow();
713                 struct timespec ts = {0,};
714
715                 ts.tv_sec = tv.tv_sec + (60 * pvt->owner->refresh);
716
717                 ast_mutex_lock(&refreshlock);
718                 while (!pvt->owner->unloading) {
719                         if (ast_cond_timedwait(&pvt->owner->unload, &refreshlock, &ts) == ETIMEDOUT) {
720                                 break;
721                         }
722                 }
723                 ast_mutex_unlock(&refreshlock);
724
725                 if (pvt->owner->unloading) {
726                         ast_debug(10, "Skipping refresh since we got a shutdown signal\n");
727                         return NULL;
728                 }
729
730                 ast_debug(10, "Refreshing after %d minute timeout\n", pvt->owner->refresh);
731
732                 update_exchangecal(pvt);
733         }
734
735         return NULL;
736 }
737
738 static int load_module(void)
739 {
740         ne_sock_init();
741         if (ast_calendar_register(&exchangecal_tech)) {
742                 ne_sock_exit();
743                 return AST_MODULE_LOAD_DECLINE;
744         }
745
746         return AST_MODULE_LOAD_SUCCESS;
747 }
748
749 static int unload_module(void)
750 {
751         ast_calendar_unregister(&exchangecal_tech);
752         ne_sock_exit();
753         return 0;
754 }
755
756 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "Asterisk MS Exchange Calendar Integration",
757                 .load = load_module,
758                 .unload = unload_module,
759         );