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 <libical/ical.h>
  33 #include <ne_session.h>
  34 #include <ne_uri.h>
  35 #include <ne_request.h>
  36 #include <ne_auth.h>
  37 #include <ne_redirect.h>
  38 #include <iksemel.h>
  39
  40 #include "asterisk/module.h"
  41 #include "asterisk/calendar.h"
  42 #include "asterisk/lock.h"
  43 #include "asterisk/config.h"
  44 #include "asterisk/astobj2.h"
  45
  46 static void *exchangecal_load_calendar(void *data);
  47 static void *unref_exchangecal(void *obj);
  48 static int exchangecal_write_event(struct ast_calendar_event *event);
  49
  50 static struct ast_calendar_tech exchangecal_tech = {
  51         .type = "exchange",
  52         .description = "MS Exchange calendars",
  53         .module = AST_MODULE,
  54         .load_calendar = exchangecal_load_calendar,
  55         .unref_calendar = unref_exchangecal,
  56         .write_event = exchangecal_write_event,
  57 };
  58
  59 struct exchangecal_pvt {
  60         AST_DECLARE_STRING_FIELDS(
  61                 AST_STRING_FIELD(url);
  62                 AST_STRING_FIELD(user);
  63                 AST_STRING_FIELD(secret);
  64         );
  65         struct ast_calendar *owner;
  66         ne_uri uri;
  67         ne_session *session;
  68         struct ao2_container *events;
  69 };
  70
  71 struct xmlstate {
  72         char tag[80];
  73         int in_response;
  74         int in_propstat;
  75         int in_prop;
  76         void *ptr;
  77         struct exchangecal_pvt *pvt;
  78 };
  79
  80 static int parse_tag(void *data, char *name, char **atts, int type)
  81 {
  82         struct xmlstate *state = data;
  83         char *tmp;
  84
  85         if ((tmp = strchr(name, ':'))) {
  86                 tmp++;
  87         } else {
  88                 return IKS_HOOK;
  89         }
  90
  91         ast_copy_string(state->tag, tmp, sizeof(state->tag));
  92
  93         switch (type) {
  94         case IKS_OPEN:
  95                 if (!strcasecmp(state->tag, "response")) {
  96                         struct ast_calendar_event *event;
  97
  98                         state->in_response = 1;
  99                         if (!(event = ast_calendar_event_alloc(state->pvt->owner))) {
 100                                 return IKS_NOMEM;
 101                         }
 102                         state->ptr = event;
 103                 } else if (!strcasecmp(state->tag, "propstat")) {
 104                         state->in_propstat = 1;
 105                 } else if (!strcasecmp(state->tag, "prop")) {
 106                         state->in_prop = 1;
 107                 }
 108                 break;
 109
 110         case IKS_CLOSE:
 111                 if (!strcasecmp(state->tag, "response")) {
 112                         struct ao2_container *events = state->pvt->events;
 113                         struct ast_calendar_event *event = state->ptr;
 114
 115                         state->in_response = 0;
 116                         if (ast_strlen_zero(event->uid)) {
 117                                 ast_log(LOG_ERROR, "This event has no UID, something has gone wrong\n");
 118                                 event = ast_calendar_unref_event(event);
 119                                 return IKS_HOOK;
 120                         }
 121                         ao2_link(events, event);
 122                         event = ast_calendar_unref_event(event);
 123                 } else if (!strcasecmp(state->tag, "propstat")) {
 124                         state->in_propstat = 0;
 125                 } else if (!strcasecmp(state->tag, "prop")) {
 126                         state->in_prop = 0;
 127                 }
 128                 break;
 129
 130         default:
 131                 return IKS_OK;
 132         }
 133
 134         return IKS_OK;
 135 }
 136
 137 static time_t mstime_to_time_t(char *mstime)
 138 {
 139         char *read, *write;
 140         icaltimetype tt;
 141         for (read = write = mstime; *read; read++) {
 142                 if (*read == '.') {
 143                         *write++ = 'Z';
 144                         *write = '\0';
 145                         break;
 146                 }
 147                 if (*read == '-' || *read == ':')
 148                         continue;
 149                 *write = *read;
 150                 write++;
 151         }
 152
 153         tt = icaltime_from_string(mstime);
 154         return icaltime_as_timet(tt);
 155 }
 156
 157 static enum ast_calendar_busy_state msbusy_to_bs(const char *msbusy)
 158 {
 159         if (!strcasecmp(msbusy, "FREE")) {
 160                 return AST_CALENDAR_BS_FREE;
 161         } else if (!strcasecmp(msbusy, "TENTATIVE")) {
 162                 return AST_CALENDAR_BS_BUSY_TENTATIVE;
 163         } else {
 164                 return AST_CALENDAR_BS_BUSY;
 165         }
 166 }
 167
 168 static int parse_cdata(void *data, char *value, size_t len)
 169 {
 170         char *str;
 171         struct xmlstate *state = data;
 172         struct ast_calendar_event *event = state->ptr;
 173
 174
 175         str = ast_skip_blanks(value);
 176
 177         if (str == value + len)
 178                 return IKS_OK;
 179
 180         if (!(str = ast_calloc(1, len + 1))) {
 181                 return IKS_NOMEM;
 182         }
 183         memcpy(str, value, len);
 184         if (!(state->in_response && state->in_propstat && state->in_prop)) {
 185                 ast_free(str);
 186                 return IKS_OK;
 187         }
 188         /* We use ast_string_field_build here because libiksemel is parsing CDATA with &lt; as
 189          * new elements which is a bit odd and shouldn't happen */
 190         if (!strcasecmp(state->tag, "subject")) {
 191                 ast_string_field_build(event, summary, "%s%s", event->summary, str);
 192         } else if (!strcasecmp(state->tag, "location")) {
 193                 ast_string_field_build(event, location, "%s%s", event->location, str);
 194         } else if (!strcasecmp(state->tag, "uid")) {
 195                 ast_string_field_build(event, uid, "%s%s", event->location, str);
 196         } else if (!strcasecmp(state->tag, "organizer")) {
 197                 ast_string_field_build(event, organizer, "%s%s", event->organizer, str);
 198         } else if (!strcasecmp(state->tag, "textdescription")) {
 199                 ast_string_field_build(event, description, "%s%s", event->description, str);
 200         } else if (!strcasecmp(state->tag, "dtstart")) {
 201                 event->start = mstime_to_time_t(str);
 202         } else if (!strcasecmp(state->tag, "dtend")) {
 203                 event->end = mstime_to_time_t(str);
 204         } else if (!strcasecmp(state->tag, "busystatus")) {
 205                 event->busy_state = msbusy_to_bs(str);
 206         } else if (!strcasecmp(state->tag, "reminderoffset")) {
 207                 /*XXX Currently we rely on event->start being set first which means we rely on the response order
 208                  * which technically should be fine since the query returns in the order we ask for, but ... */
 209                 event->alarm = event->start - atoi(str);
 210         }
 211
 212         ast_free(str);
 213         return IKS_OK;
 214 }
 215
 216 static void exchangecal_destructor(void *obj)
 217 {
 218         struct exchangecal_pvt *pvt = obj;
 219
 220         ast_debug(1, "Destroying pvt for Exchange calendar %s\n", pvt->owner->name);
 221         if (pvt->session) {
 222                 ne_session_destroy(pvt->session);
 223         }
 224         ast_string_field_free_memory(pvt);
 225
 226         ao2_callback(pvt->events, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, NULL, NULL);
 227
 228         ao2_ref(pvt->events, -1);
 229 }
 230
 231 static void *unref_exchangecal(void *obj)
 232 {
 233         struct exchangecal_pvt *pvt = obj;
 234
 235         ao2_ref(pvt, -1);
 236         return NULL;
 237 }
 238
 239 /* It is very important to use the return value of this function as a realloc could occur */
 240 static struct ast_str *generate_exchange_uuid(struct ast_str *uid)
 241 {
 242         unsigned short val[8];
 243         int x;
 244
 245         for (x = 0; x < 8; x++) {
 246                 val[x] = ast_random();
 247         }
 248         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]);
 249
 250         return uid;
 251 }
 252
 253 static int is_valid_uuid(struct ast_str *uid)
 254 {
 255         int i;
 256
 257         if (ast_str_strlen(uid) != 36) {
 258                 return 0;
 259         }
 260
 261         for (i = 0; i < ast_str_strlen(uid); i++) {
 262                 if (i == 8 || i == 13 || i == 18 || i == 23) {
 263                         if (ast_str_buffer(uid)[i] != '-') {
 264                                 return 0;
 265                         }
 266                 } 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))) {
 267                         return 0;
 268                 }
 269         }
 270
 271         return 1;
 272 }
 273
 274 static struct ast_str *xml_encode_str(struct ast_str *dst, const char *src)
 275 {
 276         const char *tmp;
 277         char buf[7];
 278
 279         for (tmp = src; *tmp; tmp++) {
 280                 switch (*tmp) {
 281                 case '\"':
 282                         strcpy(buf, "&quot;");
 283                         break;
 284
 285                 case '\'':
 286                         strcpy(buf, "&apos;");
 287                         break;
 288
 289                 case '&':
 290                         strcpy(buf, "&amp;");
 291                         break;
 292
 293                 case '<':
 294                         strcpy(buf, "&lt;");
 295                         break;
 296
 297                 case '>':
 298                         strcpy(buf, "&gt;");
 299                         break;
 300
 301                 default:
 302                         sprintf(buf, "%c", *tmp);
 303                 }
 304
 305                 ast_str_append(&dst, 0, "%s", buf);
 306         }
 307
 308         return dst;
 309 }
 310
 311 static struct ast_str *epoch_to_exchange_time(struct ast_str *dst, time_t epoch)
 312 {
 313         icaltimezone *utc = icaltimezone_get_utc_timezone();
 314         icaltimetype tt = icaltime_from_timet_with_zone(epoch, 0, utc);
 315         char tmp[30];
 316         int i;
 317
 318         ast_copy_string(tmp, icaltime_as_ical_string(tt), sizeof(tmp));
 319         for (i = 0; tmp[i]; i++) {
 320                 ast_str_append(&dst, 0, "%c", tmp[i]);
 321                 if (i == 3 || i == 5)
 322                         ast_str_append(&dst, 0, "%c", '-');
 323                 if (i == 10 || i == 12)
 324                         ast_str_append(&dst, 0, "%c", ':');
 325                 if (i == 14)
 326                         ast_str_append(&dst, 0, "%s", ".000");
 327         }
 328
 329         return dst;
 330 }
 331
 332 static struct ast_str *bs_to_exchange_bs(struct ast_str *dst, enum ast_calendar_busy_state bs)
 333 {
 334         switch (bs) {
 335         case AST_CALENDAR_BS_BUSY:
 336                 ast_str_set(&dst, 0, "%s", "BUSY");
 337                 break;
 338
 339         case AST_CALENDAR_BS_BUSY_TENTATIVE:
 340                 ast_str_set(&dst, 0, "%s", "TENTATIVE");
 341                 break;
 342
 343         default:
 344                 ast_str_set(&dst, 0, "%s", "FREE");
 345         }
 346
 347         return dst;
 348 }
 349
 350 static int fetch_response_reader(void *data, const char *block, size_t len)
 351 {
 352         struct ast_str **response = data;
 353         unsigned char *tmp;
 354
 355         if (!(tmp = ast_malloc(len + 1))) {
 356                 return -1;
 357         }
 358         memcpy(tmp, block, len);
 359         tmp[len] = '\0';
 360         ast_str_append(response, 0, "%s", tmp);
 361         ast_free(tmp);
 362
 363         return 0;
 364 }
 365
 366 static int auth_credentials(void *userdata, const char *realm, int attempts, char *username, char *secret)
 367 {
 368         struct exchangecal_pvt *pvt = userdata;
 369
 370         if (attempts > 1) {
 371                 ast_log(LOG_WARNING, "Invalid username or password for Exchange calendar '%s'\n", pvt->owner->name);
 372                 return -1;
 373         }
 374
 375         ne_strnzcpy(username, pvt->user, NE_ABUFSIZ);
 376         ne_strnzcpy(secret, pvt->secret, NE_ABUFSIZ);
 377
 378         return 0;
 379 }
 380
 381 static struct ast_str *exchangecal_request(struct exchangecal_pvt *pvt, const char *method, struct ast_str *req_body, struct ast_str *subdir)
 382 {
 383         struct ast_str *response;
 384         ne_request *req;
 385         int ret;
 386         char buf[1000];
 387
 388         if (!pvt) {
 389                 ast_log(LOG_ERROR, "There is no private!\n");
 390                 return NULL;
 391         }
 392
 393         if (!(response = ast_str_create(512))) {
 394                 ast_log(LOG_ERROR, "Could not allocate memory for response.\n");
 395                 return NULL;
 396         }
 397
 398         snprintf(buf, sizeof(buf), "%s%s", pvt->uri.path, subdir ? ast_str_buffer(subdir) : "");
 399
 400         req = ne_request_create(pvt->session, method, buf);
 401         ne_add_response_body_reader(req, ne_accept_2xx, fetch_response_reader, &response);
 402         ne_set_request_body_buffer(req, ast_str_buffer(req_body), ast_str_strlen(req_body));
 403         ne_add_request_header(req, "Content-type", "text/xml");
 404
 405         ret = ne_request_dispatch(req);
 406
 407         if (ret != NE_OK || !ast_str_strlen(response)) {
 408                 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));
 409                 ast_free(response);
 410                 return NULL;
 411         }
 412
 413         return response;
 414 }
 415
 416 static int exchangecal_write_event(struct ast_calendar_event *event)
 417 {
 418         struct ast_str *body = NULL, *response = NULL, *subdir = NULL;
 419         struct ast_str *uid = NULL, *summary = NULL, *description = NULL, *organizer = NULL,
 420                        *location = NULL, *start = NULL, *end = NULL, *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                 !(response = ast_str_create(512))) {
 435                 ast_log(LOG_ERROR, "Could not allocate memory for request and response!\n");
 436                 goto write_cleanup;
 437         }
 438
 439         if (!(uid = ast_str_create(32)) ||
 440                 !(summary = ast_str_create(32)) ||
 441                 !(description = ast_str_create(32)) ||
 442                 !(organizer = ast_str_create(32)) ||
 443                 !(location = ast_str_create(32)) ||
 444                 !(start = ast_str_create(32)) ||
 445                 !(end = ast_str_create(32)) ||
 446                 !(busystate = ast_str_create(32))) {
 447                 ast_log(LOG_ERROR, "Unable to allocate memory for request values\n");
 448                 goto write_cleanup;
 449         }
 450
 451         if (ast_strlen_zero(event->uid)) {
 452                 uid = generate_exchange_uuid(uid);
 453         } else {
 454                 ast_str_set(&uid, 36, "%s", event->uid);
 455         }
 456
 457         if (!is_valid_uuid(uid)) {
 458                 ast_log(LOG_WARNING, "An invalid uid was provided, you may leave this field blank to have one generated for you\n");
 459                 goto write_cleanup;
 460         }
 461
 462         summary = xml_encode_str(summary, event->summary);
 463         description = xml_encode_str(description, event->description);
 464         organizer = xml_encode_str(organizer, event->organizer);
 465         location = xml_encode_str(location, event->location);
 466         start = epoch_to_exchange_time(start, event->start);
 467         end = epoch_to_exchange_time(end, event->end);
 468         busystate = bs_to_exchange_bs(busystate, event->busy_state);
 469
 470         ast_str_append(&body, 0,
 471                 "<?xml version=\"1.0\"?>\n"
 472                 "<a:propertyupdate\n"
 473                 "  xmlns:a=\"DAV:\"\n"
 474                 "  xmlns:e=\"http://schemas.microsoft.com/exchange/\"\n"
 475                 "  xmlns:mapi=\"http://schemas.microsoft.com/mapi/\"\n"
 476                 "  xmlns:mapit=\"http://schemas.microsoft.com/mapi/proptag/\"\n"
 477                 "  xmlns:x=\"xml:\" xmlns:cal=\"urn:schemas:calendar:\"\n"
 478                 "  xmlns:dt=\"uuid:%s/\"\n" /* uid */
 479                 "  xmlns:header=\"urn:schemas:mailheader:\"\n"
 480                 "  xmlns:mail=\"urn:schemas:httpmail:\"\n"
 481                 ">\n"
 482                 "    <a:set>\n"
 483                 "      <a:prop>\n"
 484                 "        <a:contentclass>urn:content-classes:appointment</a:contentclass>\n"
 485                 "        <e:outlookmessageclass>IPM.Appointment</e:outlookmessageclass>\n"
 486                 "        <mail:subject>%s</mail:subject>\n" /* summary */
 487                 "        <mail:description>%s</mail:description>\n" /* description */
 488                 "        <header:to>%s</header:to>\n" /* organizer */
 489                 "        <cal:location>%s</cal:location>\n" /* location */
 490                 "        <cal:dtstart dt:dt=\"dateTime.tz\">%s</cal:dtstart>\n" /* start */
 491                 "        <cal:dtend dt:dt=\"dateTime.tz\">%s</cal:dtend>\n" /* end */
 492                 "        <cal:instancetype dt:dt=\"int\">0</cal:instancetype>\n"
 493                 "        <cal:busystatus>%s</cal:busystatus>\n" /* busy_state (BUSY, FREE, BUSY_TENTATIVE) */
 494                 "        <cal:meetingstatus>CONFIRMED</cal:meetingstatus>\n"
 495                 "        <cal:alldayevent dt:dt=\"boolean\">0</cal:alldayevent>\n" /* XXX need to add event support for all day events */
 496                 "        <cal:responserequested dt:dt=\"boolean\">0</cal:responserequested>\n"
 497                 "        <mapi:finvited dt:dt=\"boolean\">1</mapi:finvited>\n"
 498                 "      </a:prop>\n"
 499                 "    </a:set>\n"
 500                 "</a:propertyupdate>\n",
 501                 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));
 502         ast_verb(0, "\n\n%s\n\n", ast_str_buffer(body));
 503         ast_str_set(&subdir, 0, "/Calendar/%s.eml", ast_str_buffer(uid));
 504
 505         response = exchangecal_request(event->owner->tech_pvt, "PROPPATCH", body, subdir);
 506
 507         ret = 0;
 508 write_cleanup:
 509         if (uid) {
 510                 ast_free(uid);
 511         }
 512         if (summary) {
 513                 ast_free(summary);
 514         }
 515         if (description) {
 516                 ast_free(description);
 517         }
 518         if (organizer) {
 519                 ast_free(organizer);
 520         }
 521         if (location) {
 522                 ast_free(location);
 523         }
 524         if (start) {
 525                 ast_free(start);
 526         }
 527         if (end) {
 528                 ast_free(end);
 529         }
 530         if (busystate) {
 531                 ast_free(busystate);
 532         }
 533         if (body) {
 534                 ast_free(body);
 535         }
 536         if (response) {
 537                 ast_free(response);
 538         }
 539         if (subdir) {
 540                 ast_free(subdir);
 541         }
 542
 543         return ret;
 544 }
 545
 546
 547 static struct ast_str *exchangecal_get_events_between(struct exchangecal_pvt *pvt, time_t start_time, time_t end_time)
 548 {
 549         struct ast_str *body, *response;
 550         char start[80], end[80];
 551         struct timeval tv = {0,};
 552         struct ast_tm tm;
 553
 554         tv.tv_sec = start_time;
 555         ast_localtime(&tv, &tm, "UTC");
 556         ast_strftime(start, sizeof(start), "%Y/%m/%d %T", &tm);
 557
 558         tv.tv_sec = end_time;
 559         ast_localtime(&tv, &tm, "UTC");
 560         ast_strftime(end, sizeof(end), "%Y/%m/%d %T", &tm);
 561
 562         if (!(body = ast_str_create(512))) {
 563                 ast_log(LOG_ERROR, "Could not allocate memory for body of request!\n");
 564                 return NULL;
 565         }
 566
 567         ast_str_append(&body, 0,
 568                 "<?xml version=\"1.0\"?>\n"
 569                 "<g:searchrequest xmlns:g=\"DAV:\">\n"
 570                 "        <g:sql> SELECT \"urn:schemas:calendar:location\", \"urn:schemas:httpmail:subject\",\n"
 571                 "                \"urn:schemas:calendar:dtstart\", \"urn:schemas:calendar:dtend\",\n"
 572                 "                \"urn:schemas:calendar:busystatus\", \"urn:schemas:calendar:instancetype\",\n"
 573                 "                \"urn:schemas:calendar:uid\", \"urn:schemas:httpmail:textdescription\",\n"
 574                 "                \"urn:schemas:calendar:organizer\", \"urn:schemas:calendar:reminderoffset\"\n"
 575                 "                FROM Scope('SHALLOW TRAVERSAL OF \"%s/Calendar\"')\n"
 576                 "                WHERE NOT \"urn:schemas:calendar:instancetype\" = 1\n"
 577                 "                AND \"DAV:contentclass\" = 'urn:content-classes:appointment'\n"
 578                 "                AND NOT (\"urn:schemas:calendar:dtend\" &lt; '%s'\n"
 579                 "                OR \"urn:schemas:calendar:dtstart\" &gt; '%s')\n"
 580                 "                ORDER BY \"urn:schemas:calendar:dtstart\" ASC\n"
 581                 "         </g:sql>\n"
 582                 "</g:searchrequest>\n", pvt->url, start, end);
 583
 584         ast_debug(5, "Request:\n%s\n", ast_str_buffer(body));
 585         response = exchangecal_request(pvt, "SEARCH", body, NULL);
 586         ast_debug(5, "Response:\n%s\n", ast_str_buffer(response));
 587         ast_free(body);
 588
 589         return response;
 590 }
 591
 592 static int update_exchangecal(struct exchangecal_pvt *pvt)
 593 {
 594         struct xmlstate state;
 595         struct timeval now = ast_tvnow();
 596         time_t start, end;
 597         struct ast_str *response;
 598         iksparser *p;
 599
 600         state.pvt = pvt;
 601         start = now.tv_sec;
 602         end = now.tv_sec + 60 * pvt->owner->timeframe;
 603         if (!(response = exchangecal_get_events_between(pvt, start, end))) {
 604                 return -1;
 605         }
 606
 607         p = iks_sax_new(&state, parse_tag, parse_cdata);
 608         iks_parse(p, ast_str_buffer(response), ast_str_strlen(response), 1);
 609         ast_calendar_merge_events(pvt->owner, pvt->events);
 610         ast_free(response);
 611
 612         return 0;
 613 }
 614
 615 static void *exchangecal_load_calendar(void *void_data)
 616 {
 617         struct exchangecal_pvt *pvt;
 618         const struct ast_config *cfg;
 619         struct ast_variable *v;
 620         struct ast_calendar *cal = void_data;
 621         ast_mutex_t refreshlock;
 622
 623         if (!(cal && (cfg = ast_calendar_config_acquire()))) {
 624                 ast_log(LOG_ERROR, "You must enable calendar support for res_exchangecal to load\n");
 625                 return NULL;
 626         }
 627
 628         if (ao2_trylock(cal)) {
 629                 if (cal->unloading) {
 630                         ast_log(LOG_WARNING, "Unloading module, load_calendar cancelled.\n");
 631                 } else {
 632                         ast_log(LOG_WARNING, "Could not lock calendar, aborting!\n");
 633                 }
 634                 ast_calendar_config_release();
 635                 return NULL;
 636         }
 637
 638         if (!(pvt = ao2_alloc(sizeof(*pvt), exchangecal_destructor))) {
 639                 ast_log(LOG_ERROR, "Could not allocate exchangecal_pvt structure for calendar: %s\n", cal->name);
 640                 ast_calendar_config_release();
 641                 return NULL;
 642         }
 643
 644         pvt->owner = cal;
 645
 646         if (!(pvt->events = ast_calendar_event_container_alloc())) {
 647                 ast_log(LOG_ERROR, "Could not allocate space for fetching events for calendar: %s\n", cal->name);
 648                 pvt = unref_exchangecal(pvt);
 649                 ao2_unlock(cal);
 650                 ast_calendar_config_release();
 651                 return NULL;
 652         }
 653
 654         if (ast_string_field_init(pvt, 32)) {
 655                 ast_log(LOG_ERROR, "Couldn't allocate string field space for calendar: %s\n", cal->name);
 656                 pvt = unref_exchangecal(pvt);
 657                 ao2_unlock(cal);
 658                 ast_calendar_config_release();
 659                 return NULL;
 660         }
 661
 662         for (v = ast_variable_browse(cfg, cal->name); v; v = v->next) {
 663                 if (!strcasecmp(v->name, "url")) {
 664                         ast_string_field_set(pvt, url, v->value);
 665                 } else if (!strcasecmp(v->name, "user")) {
 666                         ast_string_field_set(pvt, user, v->value);
 667                 } else if (!strcasecmp(v->name, "secret")) {
 668                         ast_string_field_set(pvt, secret, v->value);
 669                 }
 670         }
 671
 672         ast_calendar_config_release();
 673
 674         if (ast_strlen_zero(pvt->url)) {
 675                 ast_log(LOG_WARNING, "No URL was specified for Exchange calendar '%s' - skipping.\n", cal->name);
 676                 pvt = unref_exchangecal(pvt);
 677                 ao2_unlock(cal);
 678                 return NULL;
 679         }
 680
 681         if (ne_uri_parse(pvt->url, &pvt->uri) || pvt->uri.host == NULL || pvt->uri.path == NULL) {
 682                 ast_log(LOG_WARNING, "Could not parse url '%s' for Exchange calendar '%s' - skipping.\n", pvt->url, cal->name);
 683                 pvt = unref_exchangecal(pvt);
 684                 ao2_unlock(cal);
 685                 return NULL;
 686         }
 687
 688         if (pvt->uri.scheme == NULL) {
 689                 pvt->uri.scheme = "http";
 690         }
 691
 692         if (pvt->uri.port == 0) {
 693                 pvt->uri.port = ne_uri_defaultport(pvt->uri.scheme);
 694         }
 695
 696         pvt->session = ne_session_create(pvt->uri.scheme, pvt->uri.host, pvt->uri.port);
 697         ne_redirect_register(pvt->session);
 698         ne_set_server_auth(pvt->session, auth_credentials, pvt);
 699         if (!strcasecmp(pvt->uri.scheme, "https")) {
 700                 ne_ssl_trust_default_ca(pvt->session);
 701         }
 702
 703         cal->tech_pvt = pvt;
 704
 705         ast_mutex_init(&refreshlock);
 706
 707         /* Load it the first time */
 708         update_exchangecal(pvt);
 709
 710         ao2_unlock(cal);
 711
 712         /* The only writing from another thread will be if unload is true */
 713         for (;;) {
 714                 struct timeval tv = ast_tvnow();
 715                 struct timespec ts = {0,};
 716
 717                 ts.tv_sec = tv.tv_sec + (60 * pvt->owner->refresh);
 718
 719                 ast_mutex_lock(&refreshlock);
 720                 while (!pvt->owner->unloading) {
 721                         if (ast_cond_timedwait(&pvt->owner->unload, &refreshlock, &ts) == ETIMEDOUT) {
 722                                 break;
 723                         }
 724                 }
 725                 ast_mutex_unlock(&refreshlock);
 726
 727                 if (pvt->owner->unloading) {
 728                         ast_debug(10, "Skipping refresh since we got a shutdown signal\n");
 729                         return NULL;
 730                 }
 731
 732                 ast_debug(10, "Refreshing after %d minute timeout\n", pvt->owner->refresh);
 733
 734                 update_exchangecal(pvt);
 735         }
 736
 737         return NULL;
 738 }
 739
 740 static int load_module(void)
 741 {
 742         ne_sock_init();
 743         if (ast_calendar_register(&exchangecal_tech)) {
 744                 ne_sock_exit();
 745                 return AST_MODULE_LOAD_DECLINE;
 746         }
 747
 748         return AST_MODULE_LOAD_SUCCESS;
 749 }
 750
 751 static int unload_module(void)
 752 {
 753         ast_calendar_unregister(&exchangecal_tech);
 754         ne_sock_exit();
 755         return 0;
 756 }
 757
 758 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "Asterisk MS Exchange Calendar Integration",
 759                 .load = load_module,
 760                 .unload = unload_module,
 761                 .load_pri = AST_MODPRI_DEVSTATE_PLUGIN,
 762         );