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 iCalnedar 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 <neon/ne_session.h>
  34 #include <neon/ne_uri.h>
  35 #include <neon/ne_request.h>
  36 #include <neon/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         );