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