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
  48 static void *exchangecal_load_calendar(void *data);
  49 static void *unref_exchangecal(void *obj);
  50 static int exchangecal_write_event(struct ast_calendar_event *event);
  51
  52 static struct ast_calendar_tech exchangecal_tech = {
  53         .type = "exchange",
  54         .description = "MS Exchange calendars",
  55         .module = AST_MODULE,
  56         .load_calendar = exchangecal_load_calendar,
  57         .unref_calendar = unref_exchangecal,
  58         .write_event = exchangecal_write_event,
  59 };
  60
  61 struct exchangecal_pvt {
  62         AST_DECLARE_STRING_FIELDS(
  63                 AST_STRING_FIELD(url);
  64                 AST_STRING_FIELD(user);
  65                 AST_STRING_FIELD(secret);
  66         );
  67         struct ast_calendar *owner;
  68         ne_uri uri;
  69         ne_session *session;
  70         struct ao2_container *events;
  71 };
  72
  73 struct xmlstate {
  74         char tag[80];
  75         int in_response;
  76         int in_propstat;
  77         int in_prop;
  78         void *ptr;
  79         struct exchangecal_pvt *pvt;
  80 };
  81
  82 static int parse_tag(void *data, char *name, char **atts, int type)
  83 {
  84         struct xmlstate *state = data;
  85         char *tmp;
  86
  87         if ((tmp = strchr(name, ':'))) {
  88                 tmp++;
  89         } else {
  90                 return IKS_HOOK;
  91         }
  92
  93         ast_copy_string(state->tag, tmp, sizeof(state->tag));
  94
  95         switch (type) {
  96         case IKS_OPEN:
  97                 if (!strcasecmp(state->tag, "response")) {
  98                         struct ast_calendar_event *event;
  99
 100                         state->in_response = 1;
 101                         if (!(event = ast_calendar_event_alloc(state->pvt->owner))) {
 102                                 return IKS_NOMEM;
 103                         }
 104                         state->ptr = event;
 105                 } else if (!strcasecmp(state->tag, "propstat")) {
 106                         state->in_propstat = 1;
 107                 } else if (!strcasecmp(state->tag, "prop")) {
 108                         state->in_prop = 1;
 109                 }
 110                 break;
 111
 112         case IKS_CLOSE:
 113                 if (!strcasecmp(state->tag, "response")) {
 114                         struct ao2_container *events = state->pvt->events;
 115                         struct ast_calendar_event *event = state->ptr;
 116
 117                         state->in_response = 0;
 118                         if (ast_strlen_zero(event->uid)) {
 119                                 ast_log(LOG_ERROR, "This event has no UID, something has gone wrong\n");
 120                                 event = ast_calendar_unref_event(event);
 121                                 return IKS_HOOK;
 122                         }
 123                         ao2_link(events, event);
 124                         event = ast_calendar_unref_event(event);
 125                 } else if (!strcasecmp(state->tag, "propstat")) {
 126                         state->in_propstat = 0;
 127                 } else if (!strcasecmp(state->tag, "prop")) {
 128                         state->in_prop = 0;
 129                 }
 130                 break;
 131
 132         default:
 133                 return IKS_OK;
 134         }
 135
 136         return IKS_OK;
 137 }
 138
 139 static time_t mstime_to_time_t(char *mstime)
 140 {
 141         char *read, *write;
 142         icaltimetype tt;
 143         for (read = write = mstime; *read; read++) {
 144                 if (*read == '.') {
 145                         *write++ = 'Z';
 146                         *write = '\0';
 147                         break;
 148                 }
 149                 if (*read == '-' || *read == ':')
 150                         continue;
 151                 *write = *read;
 152                 write++;
 153         }
 154
 155         tt = icaltime_from_string(mstime);
 156         return icaltime_as_timet(tt);
 157 }
 158
 159 static enum ast_calendar_busy_state msbusy_to_bs(const char *msbusy)
 160 {
 161         if (!strcasecmp(msbusy, "FREE")) {
 162                 return AST_CALENDAR_BS_FREE;
 163         } else if (!strcasecmp(msbusy, "TENTATIVE")) {
 164                 return AST_CALENDAR_BS_BUSY_TENTATIVE;
 165         } else {
 166                 return AST_CALENDAR_BS_BUSY;
 167         }
 168 }
 169
 170 static int parse_cdata(void *data, char *value, size_t len)
 171 {
 172         char *str;
 173         struct xmlstate *state = data;
 174         struct ast_calendar_event *event = state->ptr;
 175
 176
 177         str = ast_skip_blanks(value);
 178
 179         if (str == value + len)
 180                 return IKS_OK;
 181
 182         if (!(str = ast_calloc(1, len + 1))) {
 183                 return IKS_NOMEM;
 184         }
 185         memcpy(str, value, len);
 186         if (!(state->in_response && state->in_propstat && state->in_prop)) {
 187                 ast_free(str);
 188                 return IKS_OK;
 189         }
 190         /* We use ast_string_field_build here because libiksemel is parsing CDATA with &lt; as
 191          * new elements which is a bit odd and shouldn't happen */
 192         if (!strcasecmp(state->tag, "subject")) {
 193                 ast_string_field_build(event, summary, "%s%s", event->summary, str);
 194         } else if (!strcasecmp(state->tag, "location")) {
 195                 ast_string_field_build(event, location, "%s%s", event->location, str);
 196         } else if (!strcasecmp(state->tag, "uid")) {
 197                 ast_string_field_build(event, uid, "%s%s", event->location, str);
 198         } else if (!strcasecmp(state->tag, "organizer")) {
 199                 ast_string_field_build(event, organizer, "%s%s", event->organizer, str);
 200         } else if (!strcasecmp(state->tag, "textdescription")) {
 201                 ast_string_field_build(event, description, "%s%s", event->description, str);
 202         } else if (!strcasecmp(state->tag, "dtstart")) {
 203                 event->start = mstime_to_time_t(str);
 204         } else if (!strcasecmp(state->tag, "dtend")) {
 205                 event->end = mstime_to_time_t(str);
 206         } else if (!strcasecmp(state->tag, "busystatus")) {
 207                 event->busy_state = msbusy_to_bs(str);
 208         } else if (!strcasecmp(state->tag, "reminderoffset")) {
 209                 /*XXX Currently we rely on event->start being set first which means we rely on the response order
 210                  * which technically should be fine since the query returns in the order we ask for, but ... */
 211                 event->alarm = event->start - atoi(str);
 212         }
 213
 214         ast_free(str);
 215         return IKS_OK;
 216 }
 217
 218 static void exchangecal_destructor(void *obj)
 219 {
 220         struct exchangecal_pvt *pvt = obj;
 221
 222         ast_debug(1, "Destroying pvt for Exchange calendar %s\n", pvt->owner->name);
 223         if (pvt->session) {
 224                 ne_session_destroy(pvt->session);
 225         }
 226         ast_string_field_free_memory(pvt);
 227
 228         ao2_callback(pvt->events, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, NULL, NULL);
 229
 230         ao2_ref(pvt->events, -1);
 231 }
 232
 233 static void *unref_exchangecal(void *obj)
 234 {
 235         struct exchangecal_pvt *pvt = obj;
 236
 237         ao2_ref(pvt, -1);
 238         return NULL;
 239 }
 240
 241 /* It is very important to use the return value of this function as a realloc could occur */
 242 static struct ast_str *generate_exchange_uuid(struct ast_str *uid)
 243 {
 244         unsigned short val[8];
 245         int x;
 246
 247         for (x = 0; x < 8; x++) {
 248                 val[x] = ast_random();
 249         }
 250         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]);
 251
 252         return uid;
 253 }
 254
 255 static int is_valid_uuid(struct ast_str *uid)
 256 {
 257         int i;
 258
 259         if (ast_str_strlen(uid) != 36) {
 260                 return 0;
 261         }
 262
 263         for (i = 0; i < ast_str_strlen(uid); i++) {
 264                 if (i == 8 || i == 13 || i == 18 || i == 23) {
 265                         if (ast_str_buffer(uid)[i] != '-') {
 266                                 return 0;
 267                         }
 268                 } 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))) {
 269                         return 0;
 270                 }
 271         }
 272
 273         return 1;
 274 }
 275
 276 static struct ast_str *xml_encode_str(struct ast_str *dst, const char *src)
 277 {
 278         const char *tmp;
 279         char buf[7];
 280
 281         for (tmp = src; *tmp; tmp++) {
 282                 switch (*tmp) {
 283                 case '\"':
 284                         strcpy(buf, "&quot;");
 285                         break;
 286
 287                 case '\'':
 288                         strcpy(buf, "&apos;");
 289                         break;
 290
 291                 case '&':
 292                         strcpy(buf, "&amp;");
 293                         break;
 294
 295                 case '<':
 296                         strcpy(buf, "&lt;");
 297                         break;
 298
 299                 case '>':
 300                         strcpy(buf, "&gt;");
 301                         break;
 302
 303                 default:
 304                         sprintf(buf, "%c", *tmp);
 305                 }
 306
 307                 ast_str_append(&dst, 0, "%s", buf);
 308         }
 309
 310         return dst;
 311 }
 312
 313 static struct ast_str *epoch_to_exchange_time(struct ast_str *dst, time_t epoch)
 314 {
 315         icaltimezone *utc = icaltimezone_get_utc_timezone();
 316         icaltimetype tt = icaltime_from_timet_with_zone(epoch, 0, utc);
 317         char tmp[30];
 318         int i;
 319
 320         ast_copy_string(tmp, icaltime_as_ical_string(tt), sizeof(tmp));
 321         for (i = 0; tmp[i]; i++) {
 322                 ast_str_append(&dst, 0, "%c", tmp[i]);
 323                 if (i == 3 || i == 5)
 324                         ast_str_append(&dst, 0, "%c", '-');
 325                 if (i == 10 || i == 12)
 326                         ast_str_append(&dst, 0, "%c", ':');
 327                 if (i == 14)
 328                         ast_str_append(&dst, 0, "%s", ".000");
 329         }
 330
 331         return dst;
 332 }
 333
 334 static struct ast_str *bs_to_exchange_bs(struct ast_str *dst, enum ast_calendar_busy_state bs)
 335 {
 336         switch (bs) {
 337         case AST_CALENDAR_BS_BUSY:
 338                 ast_str_set(&dst, 0, "%s", "BUSY");
 339                 break;
 340
 341         case AST_CALENDAR_BS_BUSY_TENTATIVE:
 342                 ast_str_set(&dst, 0, "%s", "TENTATIVE");
 343                 break;
 344
 345         default:
 346                 ast_str_set(&dst, 0, "%s", "FREE");
 347         }
 348
 349         return dst;
 350 }
 351
 352 static int fetch_response_reader(void *data, const char *block, size_t len)
 353 {
 354         struct ast_str **response = data;
 355         unsigned char *tmp;
 356
 357         if (!(tmp = ast_malloc(len + 1))) {
 358                 return -1;
 359         }
 360         memcpy(tmp, block, len);
 361         tmp[len] = '\0';
 362         ast_str_append(response, 0, "%s", tmp);
 363         ast_free(tmp);
 364
 365         return 0;
 366 }
 367
 368 static int auth_credentials(void *userdata, const char *realm, int attempts, char *username, char *secret)
 369 {
 370         struct exchangecal_pvt *pvt = userdata;
 371
 372         if (attempts > 1) {
 373                 ast_log(LOG_WARNING, "Invalid username or password for Exchange calendar '%s'\n", pvt->owner->name);
 374                 return -1;
 375         }
 376
 377         ne_strnzcpy(username, pvt->user, NE_ABUFSIZ);
 378         ne_strnzcpy(secret, pvt->secret, NE_ABUFSIZ);
 379
 380         return 0;
 381 }
 382
 383 static struct ast_str *exchangecal_request(struct exchangecal_pvt *pvt, const char *method, struct ast_str *req_body, struct ast_str *subdir)
 384 {
 385         struct ast_str *response;
 386         ne_request *req;
 387         int ret;
 388         char buf[1000];
 389
 390         if (!pvt) {
 391                 ast_log(LOG_ERROR, "There is no private!\n");
 392                 return NULL;
 393         }
 394
 395         if (!(response = ast_str_create(512))) {
 396                 ast_log(LOG_ERROR, "Could not allocate memory for response.\n");
 397                 return NULL;
 398         }
 399
 400         snprintf(buf, sizeof(buf), "%s%s", pvt->uri.path, subdir ? ast_str_buffer(subdir) : "");
 401
 402         req = ne_request_create(pvt->session, method, buf);
 403         ne_add_response_body_reader(req, ne_accept_2xx, fetch_response_reader, &response);
 404         ne_set_request_body_buffer(req, ast_str_buffer(req_body), ast_str_strlen(req_body));
 405         ne_add_request_header(req, "Content-type", "text/xml");
 406
 407         ret = ne_request_dispatch(req);
 408         ne_request_destroy(req);
 409
 410         if (ret != NE_OK || !ast_str_strlen(response)) {
 411                 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));
 412                 ast_free(response);
 413                 return NULL;
 414         }
 415
 416         return response;
 417 }
 418
 419 static int exchangecal_write_event(struct ast_calendar_event *event)
 420 {
 421         struct ast_str *body = NULL, *response = NULL, *subdir = NULL;
 422         struct ast_str *uid = NULL, *summary = NULL, *description = NULL, *organizer = NULL,
 423                        *location = NULL, *start = NULL, *end = NULL, *busystate = NULL;
 424         int ret = -1;
 425
 426         if (!event) {
 427                 ast_log(LOG_WARNING, "No event passed!\n");
 428                 return -1;
 429         }
 430
 431         if (!(event->start && event->end)) {
 432                 ast_log(LOG_WARNING, "The event must contain a start and an end\n");
 433                 return -1;
 434         }
 435         if (!(body = ast_str_create(512)) ||
 436                 !(subdir = ast_str_create(32))) {
 437                 ast_log(LOG_ERROR, "Could not allocate memory for request!\n");
 438                 goto write_cleanup;
 439         }
 440
 441         if (!(uid = ast_str_create(32)) ||
 442                 !(summary = ast_str_create(32)) ||
 443                 !(description = ast_str_create(32)) ||
 444                 !(organizer = ast_str_create(32)) ||
 445                 !(location = ast_str_create(32)) ||
 446                 !(start = ast_str_create(32)) ||
 447                 !(end = ast_str_create(32)) ||
 448                 !(busystate = ast_str_create(32))) {
 449                 ast_log(LOG_ERROR, "Unable to allocate memory for request values\n");
 450                 goto write_cleanup;
 451         }
 452
 453         if (ast_strlen_zero(event->uid)) {
 454                 uid = generate_exchange_uuid(uid);
 455         } else {
 456                 ast_str_set(&uid, 36, "%s", event->uid);
 457         }
 458
 459         if (!is_valid_uuid(uid)) {
 460                 ast_log(LOG_WARNING, "An invalid uid was provided, you may leave this field blank to have one generated for you\n");
 461                 goto write_cleanup;
 462         }
 463
 464         summary = xml_encode_str(summary, event->summary);
 465         description = xml_encode_str(description, event->description);
 466         organizer = xml_encode_str(organizer, event->organizer);
 467         location = xml_encode_str(location, event->location);
 468         start = epoch_to_exchange_time(start, event->start);
 469         end = epoch_to_exchange_time(end, event->end);
 470         busystate = bs_to_exchange_bs(busystate, event->busy_state);
 471
 472         ast_str_append(&body, 0,
 473                 "<?xml version=\"1.0\"?>\n"
 474                 "<a:propertyupdate\n"
 475                 "  xmlns:a=\"DAV:\"\n"
 476                 "  xmlns:e=\"http://schemas.microsoft.com/exchange/\"\n"
 477                 "  xmlns:mapi=\"http://schemas.microsoft.com/mapi/\"\n"
 478                 "  xmlns:mapit=\"http://schemas.microsoft.com/mapi/proptag/\"\n"
 479                 "  xmlns:x=\"xml:\" xmlns:cal=\"urn:schemas:calendar:\"\n"
 480                 "  xmlns:dt=\"uuid:%s/\"\n" /* uid */
 481                 "  xmlns:header=\"urn:schemas:mailheader:\"\n"
 482                 "  xmlns:mail=\"urn:schemas:httpmail:\"\n"
 483                 ">\n"
 484                 "    <a:set>\n"
 485                 "      <a:prop>\n"
 486                 "        <a:contentclass>urn:content-classes:appointment</a:contentclass>\n"
 487                 "        <e:outlookmessageclass>IPM.Appointment</e:outlookmessageclass>\n"
 488                 "        <mail:subject>%s</mail:subject>\n" /* summary */
 489                 "        <mail:description>%s</mail:description>\n" /* description */
 490                 "        <header:to>%s</header:to>\n" /* organizer */
 491                 "        <cal:location>%s</cal:location>\n" /* location */
 492                 "        <cal:dtstart dt:dt=\"dateTime.tz\">%s</cal:dtstart>\n" /* start */
 493                 "        <cal:dtend dt:dt=\"dateTime.tz\">%s</cal:dtend>\n" /* end */
 494                 "        <cal:instancetype dt:dt=\"int\">0</cal:instancetype>\n"
 495                 "        <cal:busystatus>%s</cal:busystatus>\n" /* busy_state (BUSY, FREE, BUSY_TENTATIVE) */
 496                 "        <cal:meetingstatus>CONFIRMED</cal:meetingstatus>\n"
 497                 "        <cal:alldayevent dt:dt=\"boolean\">0</cal:alldayevent>\n" /* XXX need to add event support for all day events */
 498                 "        <cal:responserequested dt:dt=\"boolean\">0</cal:responserequested>\n"
 499                 "        <mapi:finvited dt:dt=\"boolean\">1</mapi:finvited>\n"
 500                 "      </a:prop>\n"
 501                 "    </a:set>\n"
 502                 "</a:propertyupdate>\n",
 503                 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));
 504         ast_verb(0, "\n\n%s\n\n", ast_str_buffer(body));
 505         ast_str_set(&subdir, 0, "/Calendar/%s.eml", ast_str_buffer(uid));
 506
 507         if ((response = exchangecal_request(event->owner->tech_pvt, "PROPPATCH", body, subdir))) {
 508                 ret = 0;
 509         }
 510
 511 write_cleanup:
 512         if (uid) {
 513                 ast_free(uid);
 514         }
 515         if (summary) {
 516                 ast_free(summary);
 517         }
 518         if (description) {
 519                 ast_free(description);
 520         }
 521         if (organizer) {
 522                 ast_free(organizer);
 523         }
 524         if (location) {
 525                 ast_free(location);
 526         }
 527         if (start) {
 528                 ast_free(start);
 529         }
 530         if (end) {
 531                 ast_free(end);
 532         }
 533         if (busystate) {
 534                 ast_free(busystate);
 535         }
 536         if (body) {
 537                 ast_free(body);
 538         }
 539         if (response) {
 540                 ast_free(response);
 541         }
 542         if (subdir) {
 543                 ast_free(subdir);
 544         }
 545
 546         return ret;
 547 }
 548
 549
 550 static struct ast_str *exchangecal_get_events_between(struct exchangecal_pvt *pvt, time_t start_time, time_t end_time)
 551 {
 552         struct ast_str *body, *response;
 553         char start[80], end[80];
 554         struct timeval tv = {0,};
 555         struct ast_tm tm;
 556
 557         tv.tv_sec = start_time;
 558         ast_localtime(&tv, &tm, "UTC");
 559         ast_strftime(start, sizeof(start), "%Y/%m/%d %T", &tm);
 560
 561         tv.tv_sec = end_time;
 562         ast_localtime(&tv, &tm, "UTC");
 563         ast_strftime(end, sizeof(end), "%Y/%m/%d %T", &tm);
 564
 565         if (!(body = ast_str_create(512))) {
 566                 ast_log(LOG_ERROR, "Could not allocate memory for body of request!\n");
 567                 return NULL;
 568         }
 569
 570         ast_str_append(&body, 0,
 571                 "<?xml version=\"1.0\"?>\n"
 572                 "<g:searchrequest xmlns:g=\"DAV:\">\n"
 573                 "        <g:sql> SELECT \"urn:schemas:calendar:location\", \"urn:schemas:httpmail:subject\",\n"
 574                 "                \"urn:schemas:calendar:dtstart\", \"urn:schemas:calendar:dtend\",\n"
 575                 "                \"urn:schemas:calendar:busystatus\", \"urn:schemas:calendar:instancetype\",\n"
 576                 "                \"urn:schemas:calendar:uid\", \"urn:schemas:httpmail:textdescription\",\n"
 577                 "                \"urn:schemas:calendar:organizer\", \"urn:schemas:calendar:reminderoffset\"\n"
 578                 "                FROM Scope('SHALLOW TRAVERSAL OF \"%s/Calendar\"')\n"
 579                 "                WHERE NOT \"urn:schemas:calendar:instancetype\" = 1\n"
 580                 "                AND \"DAV:contentclass\" = 'urn:content-classes:appointment'\n"
 581                 "                AND NOT (\"urn:schemas:calendar:dtend\" &lt; '%s'\n"
 582                 "                OR \"urn:schemas:calendar:dtstart\" &gt; '%s')\n"
 583                 "                ORDER BY \"urn:schemas:calendar:dtstart\" ASC\n"
 584                 "         </g:sql>\n"
 585                 "</g:searchrequest>\n", pvt->url, start, end);
 586
 587         ast_debug(5, "Request:\n%s\n", ast_str_buffer(body));
 588         response = exchangecal_request(pvt, "SEARCH", body, NULL);
 589         ast_debug(5, "Response:\n%s\n", ast_str_buffer(response));
 590         ast_free(body);
 591
 592         return response;
 593 }
 594
 595 static int update_exchangecal(struct exchangecal_pvt *pvt)
 596 {
 597         struct xmlstate state;
 598         struct timeval now = ast_tvnow();
 599         time_t start, end;
 600         struct ast_str *response;
 601         iksparser *p;
 602
 603         state.pvt = pvt;
 604         start = now.tv_sec;
 605         end = now.tv_sec + 60 * pvt->owner->timeframe;
 606         if (!(response = exchangecal_get_events_between(pvt, start, end))) {
 607                 return -1;
 608         }
 609
 610         p = iks_sax_new(&state, parse_tag, parse_cdata);
 611         iks_parse(p, ast_str_buffer(response), ast_str_strlen(response), 1);
 612         ast_calendar_merge_events(pvt->owner, pvt->events);
 613         ast_free(response);
 614
 615         return 0;
 616 }
 617
 618 static void *exchangecal_load_calendar(void *void_data)
 619 {
 620         struct exchangecal_pvt *pvt;
 621         const struct ast_config *cfg;
 622         struct ast_variable *v;
 623         struct ast_calendar *cal = void_data;
 624         ast_mutex_t refreshlock;
 625
 626         if (!(cal && (cfg = ast_calendar_config_acquire()))) {
 627                 ast_log(LOG_ERROR, "You must enable calendar support for res_exchangecal to load\n");
 628                 return NULL;
 629         }
 630
 631         if (ao2_trylock(cal)) {
 632                 if (cal->unloading) {
 633                         ast_log(LOG_WARNING, "Unloading module, load_calendar cancelled.\n");
 634                 } else {
 635                         ast_log(LOG_WARNING, "Could not lock calendar, aborting!\n");
 636                 }
 637                 ast_calendar_config_release();
 638                 return NULL;
 639         }
 640
 641         if (!(pvt = ao2_alloc(sizeof(*pvt), exchangecal_destructor))) {
 642                 ast_log(LOG_ERROR, "Could not allocate exchangecal_pvt structure for calendar: %s\n", cal->name);
 643                 ast_calendar_config_release();
 644                 return NULL;
 645         }
 646
 647         pvt->owner = cal;
 648
 649         if (!(pvt->events = ast_calendar_event_container_alloc())) {
 650                 ast_log(LOG_ERROR, "Could not allocate space for fetching events for calendar: %s\n", cal->name);
 651                 pvt = unref_exchangecal(pvt);
 652                 ao2_unlock(cal);
 653                 ast_calendar_config_release();
 654                 return NULL;
 655         }
 656
 657         if (ast_string_field_init(pvt, 32)) {
 658                 ast_log(LOG_ERROR, "Couldn't allocate string field space for calendar: %s\n", cal->name);
 659                 pvt = unref_exchangecal(pvt);
 660                 ao2_unlock(cal);
 661                 ast_calendar_config_release();
 662                 return NULL;
 663         }
 664
 665         for (v = ast_variable_browse(cfg, cal->name); v; v = v->next) {
 666                 if (!strcasecmp(v->name, "url")) {
 667                         ast_string_field_set(pvt, url, v->value);
 668                 } else if (!strcasecmp(v->name, "user")) {
 669                         ast_string_field_set(pvt, user, v->value);
 670                 } else if (!strcasecmp(v->name, "secret")) {
 671                         ast_string_field_set(pvt, secret, v->value);
 672                 }
 673         }
 674
 675         ast_calendar_config_release();
 676
 677         if (ast_strlen_zero(pvt->url)) {
 678                 ast_log(LOG_WARNING, "No URL was specified for Exchange calendar '%s' - skipping.\n", cal->name);
 679                 pvt = unref_exchangecal(pvt);
 680                 ao2_unlock(cal);
 681                 return NULL;
 682         }
 683
 684         if (ne_uri_parse(pvt->url, &pvt->uri) || pvt->uri.host == NULL || pvt->uri.path == NULL) {
 685                 ast_log(LOG_WARNING, "Could not parse url '%s' for Exchange calendar '%s' - skipping.\n", pvt->url, cal->name);
 686                 pvt = unref_exchangecal(pvt);
 687                 ao2_unlock(cal);
 688                 return NULL;
 689         }
 690
 691         if (pvt->uri.scheme == NULL) {
 692                 pvt->uri.scheme = "http";
 693         }
 694
 695         if (pvt->uri.port == 0) {
 696                 pvt->uri.port = ne_uri_defaultport(pvt->uri.scheme);
 697         }
 698
 699         pvt->session = ne_session_create(pvt->uri.scheme, pvt->uri.host, pvt->uri.port);
 700         ne_redirect_register(pvt->session);
 701         ne_set_server_auth(pvt->session, auth_credentials, pvt);
 702         if (!strcasecmp(pvt->uri.scheme, "https")) {
 703                 ne_ssl_trust_default_ca(pvt->session);
 704         }
 705
 706         cal->tech_pvt = pvt;
 707
 708         ast_mutex_init(&refreshlock);
 709
 710         /* Load it the first time */
 711         update_exchangecal(pvt);
 712
 713         ao2_unlock(cal);
 714
 715         /* The only writing from another thread will be if unload is true */
 716         for (;;) {
 717                 struct timeval tv = ast_tvnow();
 718                 struct timespec ts = {0,};
 719
 720                 ts.tv_sec = tv.tv_sec + (60 * pvt->owner->refresh);
 721
 722                 ast_mutex_lock(&refreshlock);
 723                 while (!pvt->owner->unloading) {
 724                         if (ast_cond_timedwait(&pvt->owner->unload, &refreshlock, &ts) == ETIMEDOUT) {
 725                                 break;
 726                         }
 727                 }
 728                 ast_mutex_unlock(&refreshlock);
 729
 730                 if (pvt->owner->unloading) {
 731                         ast_debug(10, "Skipping refresh since we got a shutdown signal\n");
 732                         return NULL;
 733                 }
 734
 735                 ast_debug(10, "Refreshing after %d minute timeout\n", pvt->owner->refresh);
 736
 737                 update_exchangecal(pvt);
 738         }
 739
 740         return NULL;
 741 }
 742
 743 static int load_module(void)
 744 {
 745         ne_sock_init();
 746         if (ast_calendar_register(&exchangecal_tech)) {
 747                 ne_sock_exit();
 748                 return AST_MODULE_LOAD_DECLINE;
 749         }
 750
 751         return AST_MODULE_LOAD_SUCCESS;
 752 }
 753
 754 static int unload_module(void)
 755 {
 756         ast_calendar_unregister(&exchangecal_tech);
 757         ne_sock_exit();
 758         return 0;
 759 }
 760
 761 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "Asterisk MS Exchange Calendar Integration",
 762                 .load = load_module,
 763                 .unload = unload_module,
 764                 .load_pri = AST_MODPRI_DEVSTATE_PLUGIN,
 765         );