Mon Mar 19 11:30:29 2012

Asterisk developer's documentation


res_calendar_icalendar.c

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 2008 - 2009, Digium, Inc.
00005  *
00006  * Terry Wilson <twilson@digium.com>
00007  *
00008  * See http://www.asterisk.org for more information about
00009  * the Asterisk project. Please do not directly contact
00010  * any of the maintainers of this project for assistance;
00011  * the project provides a web site, mailing lists and IRC
00012  * channels for your use.
00013  *
00014  * This program is free software, distributed under the terms of
00015  * the GNU General Public License Version 2. See the LICENSE file
00016  * at the top of the source tree.
00017  */
00018 
00019 /*! \file
00020  * \brief Resource for handling iCalendar calendars
00021  */
00022 
00023 /*** MODULEINFO
00024    <depend>neon</depend>
00025    <depend>ical</depend>
00026    <support_level>core</support_level>
00027 ***/
00028 
00029 #include "asterisk.h"
00030 
00031 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 328209 $")
00032 
00033 #include <libical/ical.h>
00034 #include <ne_session.h>
00035 #include <ne_uri.h>
00036 #include <ne_request.h>
00037 #include <ne_auth.h>
00038 #include <ne_redirect.h>
00039 
00040 #include "asterisk/module.h"
00041 #include "asterisk/calendar.h"
00042 #include "asterisk/lock.h"
00043 #include "asterisk/config.h"
00044 #include "asterisk/astobj2.h"
00045 
00046 static void *ical_load_calendar(void *data);
00047 static void *unref_icalendar(void *obj);
00048 
00049 static struct ast_calendar_tech ical_tech = {
00050    .type = "ical",
00051    .module = AST_MODULE,
00052    .description = "iCalendar .ics calendars",
00053    .load_calendar = ical_load_calendar,
00054    .unref_calendar = unref_icalendar,
00055 };
00056 
00057 struct icalendar_pvt {
00058    AST_DECLARE_STRING_FIELDS(
00059       AST_STRING_FIELD(url);
00060       AST_STRING_FIELD(user);
00061       AST_STRING_FIELD(secret);
00062    );
00063    struct ast_calendar *owner;
00064    ne_uri uri;
00065    ne_session *session;
00066    icalcomponent *data;
00067    struct ao2_container *events;
00068 };
00069 
00070 static void icalendar_destructor(void *obj)
00071 {
00072    struct icalendar_pvt *pvt = obj;
00073 
00074    ast_debug(1, "Destroying pvt for iCalendar %s\n", pvt->owner->name);
00075    if (pvt->session) {
00076       ne_session_destroy(pvt->session);
00077    }
00078    if (pvt->data) {
00079       icalcomponent_free(pvt->data);
00080    }
00081    ast_string_field_free_memory(pvt);
00082 
00083    ao2_callback(pvt->events, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, NULL, NULL);
00084 
00085    ao2_ref(pvt->events, -1);
00086 }
00087 
00088 static void *unref_icalendar(void *obj)
00089 {
00090    struct icalendar_pvt *pvt = obj;
00091 
00092    ao2_ref(pvt, -1);
00093    return NULL;
00094 }
00095 
00096 static int fetch_response_reader(void *data, const char *block, size_t len)
00097 {
00098    struct ast_str **response = data;
00099    unsigned char *tmp;
00100 
00101    if (!(tmp = ast_malloc(len + 1))) {
00102       return -1;
00103    }
00104    memcpy(tmp, block, len);
00105    tmp[len] = '\0';
00106    ast_str_append(response, 0, "%s", tmp);
00107    ast_free(tmp);
00108 
00109    return 0;
00110 }
00111 
00112 static int auth_credentials(void *userdata, const char *realm, int attempts, char *username, char *secret)
00113 {
00114    struct icalendar_pvt *pvt = userdata;
00115 
00116    if (attempts > 1) {
00117       ast_log(LOG_WARNING, "Invalid username or password for iCalendar '%s'\n", pvt->owner->name);
00118       return -1;
00119    }
00120 
00121    ne_strnzcpy(username, pvt->user, NE_ABUFSIZ);
00122    ne_strnzcpy(secret, pvt->secret, NE_ABUFSIZ);
00123 
00124    return 0;
00125 }
00126 
00127 static icalcomponent *fetch_icalendar(struct icalendar_pvt *pvt)
00128 {
00129    int ret;
00130    struct ast_str *response;
00131    ne_request *req;
00132    icalcomponent *comp = NULL;
00133 
00134    if (!pvt) {
00135       ast_log(LOG_ERROR, "There is no private!\n");
00136    }
00137 
00138    if (!(response = ast_str_create(512))) {
00139       ast_log(LOG_ERROR, "Could not allocate memory for response.\n");
00140       return NULL;
00141    }
00142 
00143    req = ne_request_create(pvt->session, "GET", pvt->uri.path);
00144    ne_add_response_body_reader(req, ne_accept_2xx, fetch_response_reader, &response);
00145 
00146    ret = ne_request_dispatch(req);
00147    ne_request_destroy(req);
00148    if (ret != NE_OK || !ast_str_strlen(response)) {
00149       ast_log(LOG_WARNING, "Unable to retrieve iCalendar '%s' from '%s': %s\n", pvt->owner->name, pvt->url, ne_get_error(pvt->session));
00150       ast_free(response);
00151       return NULL;
00152    }
00153 
00154    if (!ast_strlen_zero(ast_str_buffer(response))) {
00155       comp = icalparser_parse_string(ast_str_buffer(response));
00156    }
00157    ast_free(response);
00158 
00159    return comp;
00160 }
00161 
00162 static time_t icalfloat_to_timet(icaltimetype time) 
00163 {
00164    struct ast_tm tm = {0,};
00165    struct timeval tv;
00166 
00167    tm.tm_mday = time.day;
00168    tm.tm_mon = time.month - 1;
00169    tm.tm_year = time.year - 1900;
00170    tm.tm_hour = time.hour;
00171    tm.tm_min = time.minute;
00172    tm.tm_sec = time.second;
00173    tm.tm_isdst = -1;
00174    tv = ast_mktime(&tm, NULL);
00175 
00176    return tv.tv_sec;
00177 }
00178 
00179 /* span->start & span->end may be dates or floating times which have no timezone,
00180  * which would mean that they should apply to the local timezone for all recepients.
00181  * For example, if a meeting was set for 1PM-2PM floating time, people in different time
00182  * zones would not be scheduled at the same local times.  Dates are often treated as
00183  * floating times, so all day events will need to be converted--so we can trust the
00184  * span here, and instead will grab the start and end from the component, which will
00185  * allow us to test for floating times or dates.
00186  */
00187 
00188 static void icalendar_add_event(icalcomponent *comp, struct icaltime_span *span, void *data)
00189 {
00190    struct icalendar_pvt *pvt = data;
00191    struct ast_calendar_event *event;
00192    icaltimezone *utc = icaltimezone_get_utc_timezone();
00193    icaltimetype start, end, tmp;
00194    icalcomponent *valarm;
00195    icalproperty *prop;
00196    struct icaltriggertype trigger;
00197 
00198    if (!(pvt && pvt->owner)) {
00199       ast_log(LOG_ERROR, "Require a private structure with an ownenr\n");
00200       return;
00201    }
00202 
00203    if (!(event = ast_calendar_event_alloc(pvt->owner))) {
00204       ast_log(LOG_ERROR, "Could not allocate an event!\n");
00205       return;
00206    }
00207 
00208    start = icalcomponent_get_dtstart(comp);
00209    end = icalcomponent_get_dtend(comp);
00210 
00211    event->start = icaltime_get_tzid(start) ? span->start : icalfloat_to_timet(start);
00212    event->end = icaltime_get_tzid(end) ? span->end : icalfloat_to_timet(end);
00213    event->busy_state = span->is_busy ? AST_CALENDAR_BS_BUSY : AST_CALENDAR_BS_FREE;
00214 
00215    if ((prop = icalcomponent_get_first_property(comp, ICAL_SUMMARY_PROPERTY))) {
00216       ast_string_field_set(event, summary, icalproperty_get_value_as_string(prop));
00217    }
00218 
00219    if ((prop = icalcomponent_get_first_property(comp, ICAL_DESCRIPTION_PROPERTY))) {
00220       ast_string_field_set(event, description, icalproperty_get_value_as_string(prop));
00221    }
00222 
00223    if ((prop = icalcomponent_get_first_property(comp, ICAL_ORGANIZER_PROPERTY))) {
00224       ast_string_field_set(event, organizer, icalproperty_get_value_as_string(prop));
00225    }
00226 
00227    if ((prop = icalcomponent_get_first_property(comp, ICAL_LOCATION_PROPERTY))) {
00228       ast_string_field_set(event, location, icalproperty_get_value_as_string(prop));
00229    }
00230 
00231    if ((prop = icalcomponent_get_first_property(comp, ICAL_CATEGORIES_PROPERTY))) {
00232       ast_string_field_set(event, categories, icalproperty_get_value_as_string(prop));
00233    }
00234 
00235    if ((prop = icalcomponent_get_first_property(comp, ICAL_PRIORITY_PROPERTY))) {
00236       event->priority = icalvalue_get_integer(icalproperty_get_value(prop));
00237    }
00238 
00239    if ((prop = icalcomponent_get_first_property(comp, ICAL_UID_PROPERTY))) {
00240       ast_string_field_set(event, uid, icalproperty_get_value_as_string(prop));
00241    } else {
00242       ast_log(LOG_WARNING, "No UID found, but one is required. Generating, but updates may not be acurate\n");
00243       if (!ast_strlen_zero(event->summary)) {
00244          ast_string_field_set(event, uid, event->summary);
00245       } else {
00246          char tmp[100];
00247          snprintf(tmp, sizeof(tmp), "%lu", event->start);
00248          ast_string_field_set(event, uid, tmp);
00249       }
00250    }
00251 
00252    /* Get the attendees */
00253    for (prop = icalcomponent_get_first_property(comp, ICAL_ATTENDEE_PROPERTY);
00254          prop; prop = icalcomponent_get_next_property(comp, ICAL_ATTENDEE_PROPERTY)) {
00255       struct ast_calendar_attendee *attendee;
00256       const char *data;
00257 
00258       if (!(attendee = ast_calloc(1, sizeof(*attendee)))) {
00259          event = ast_calendar_unref_event(event);
00260          return;
00261       }
00262       data = icalproperty_get_attendee(prop);
00263       if (!ast_strlen_zero(data)) {
00264          attendee->data = ast_strdup(data);;
00265          AST_LIST_INSERT_TAIL(&event->attendees, attendee, next);
00266       }
00267    }
00268 
00269 
00270    /* Only set values for alarm based on VALARM.  Can be overriden in main/calendar.c by autoreminder
00271     * therefore, go ahead and add events even if their is no VALARM or it is malformed
00272     * Currently we are only getting the first VALARM and are handling repitition in main/calendar.c from calendar.conf */
00273    if (!(valarm = icalcomponent_get_first_component(comp, ICAL_VALARM_COMPONENT))) {
00274       ao2_link(pvt->events, event);
00275       event = ast_calendar_unref_event(event);
00276       return;
00277    }
00278 
00279    if (!(prop = icalcomponent_get_first_property(valarm, ICAL_TRIGGER_PROPERTY))) {
00280       ast_log(LOG_WARNING, "VALARM has no TRIGGER, skipping!\n");
00281       ao2_link(pvt->events, event);
00282       event = ast_calendar_unref_event(event);
00283       return;
00284    }
00285 
00286    trigger = icalproperty_get_trigger(prop);
00287 
00288    if (icaltriggertype_is_null_trigger(trigger)) {
00289       ast_log(LOG_WARNING, "Bad TRIGGER for VALARM, skipping!\n");
00290       ao2_link(pvt->events, event);
00291       event = ast_calendar_unref_event(event);
00292       return;
00293    }
00294 
00295    if (!icaltime_is_null_time(trigger.time)) { /* This is an absolute time */
00296       tmp = icaltime_convert_to_zone(trigger.time, utc);
00297       event->alarm = icaltime_as_timet_with_zone(tmp, utc);
00298    } else { /* Offset from either dtstart or dtend */
00299       /* XXX Technically you can check RELATED to see if the event fires from the END of the event
00300        * But, I'm not sure I've ever seen anyone implement it in calendaring software, so I'm ignoring for now */
00301       tmp = icaltime_add(start, trigger.duration);
00302       event->alarm = icaltime_as_timet_with_zone(tmp, utc);
00303    }
00304 
00305    ao2_link(pvt->events, event);
00306    event = ast_calendar_unref_event(event);
00307 
00308    return;
00309 }
00310 
00311  static void icalendar_update_events(struct icalendar_pvt *pvt)
00312 {
00313    struct icaltimetype start_time, end_time;
00314    icalcomponent *iter;
00315 
00316    if (!pvt) {
00317       ast_log(LOG_ERROR, "iCalendar is NULL\n");
00318       return;
00319    }
00320 
00321    if (!pvt->owner) {
00322       ast_log(LOG_ERROR, "iCalendar is an orphan!\n");
00323       return;
00324    }
00325 
00326    if (!pvt->data) {
00327       ast_log(LOG_ERROR, "The iCalendar has not been parsed!\n");
00328       return;
00329    }
00330 
00331    start_time = icaltime_current_time_with_zone(icaltimezone_get_utc_timezone());
00332    end_time = icaltime_current_time_with_zone(icaltimezone_get_utc_timezone());
00333    end_time.second += pvt->owner->timeframe * 60;
00334    icaltime_normalize(end_time);
00335 
00336    for (iter = icalcomponent_get_first_component(pvt->data, ICAL_VEVENT_COMPONENT);
00337         iter;
00338        iter = icalcomponent_get_next_component(pvt->data, ICAL_VEVENT_COMPONENT))
00339    {
00340       icalcomponent_foreach_recurrence(iter, start_time, end_time, icalendar_add_event, pvt);
00341    }
00342 
00343    ast_calendar_merge_events(pvt->owner, pvt->events);
00344 }
00345 
00346 static void *ical_load_calendar(void *void_data)
00347 {
00348    struct icalendar_pvt *pvt;
00349    const struct ast_config *cfg;
00350    struct ast_variable *v;
00351    struct ast_calendar *cal = void_data;
00352    ast_mutex_t refreshlock;
00353 
00354    if (!(cal && (cfg = ast_calendar_config_acquire()))) {
00355       ast_log(LOG_ERROR, "You must enable calendar support for res_icalendar to load\n");
00356       return NULL;
00357    }
00358    if (ao2_trylock(cal)) {
00359       if (cal->unloading) {
00360          ast_log(LOG_WARNING, "Unloading module, load_calendar cancelled.\n");
00361       } else {
00362          ast_log(LOG_WARNING, "Could not lock calendar, aborting!\n");
00363       }
00364       ast_calendar_config_release();
00365       return NULL;
00366    }
00367 
00368    if (!(pvt = ao2_alloc(sizeof(*pvt), icalendar_destructor))) {
00369       ast_log(LOG_ERROR, "Could not allocate icalendar_pvt structure for calendar: %s\n", cal->name);
00370       ast_calendar_config_release();
00371       return NULL;
00372    }
00373 
00374    pvt->owner = cal;
00375 
00376    if (!(pvt->events = ast_calendar_event_container_alloc())) {
00377       ast_log(LOG_ERROR, "Could not allocate space for fetching events for calendar: %s\n", cal->name);
00378       pvt = unref_icalendar(pvt);
00379       ao2_unlock(cal);
00380       ast_calendar_config_release();
00381       return NULL;
00382    }
00383 
00384    if (ast_string_field_init(pvt, 32)) {
00385       ast_log(LOG_ERROR, "Couldn't allocate string field space for calendar: %s\n", cal->name);
00386       pvt = unref_icalendar(pvt);
00387       ao2_unlock(cal);
00388       ast_calendar_config_release();
00389       return NULL;
00390    }
00391 
00392    for (v = ast_variable_browse(cfg, cal->name); v; v = v->next) {
00393       if (!strcasecmp(v->name, "url")) {
00394          ast_string_field_set(pvt, url, v->value);
00395       } else if (!strcasecmp(v->name, "user")) {
00396          ast_string_field_set(pvt, user, v->value);
00397       } else if (!strcasecmp(v->name, "secret")) {
00398          ast_string_field_set(pvt, secret, v->value);
00399       }
00400    }
00401 
00402    ast_calendar_config_release();
00403 
00404    if (ast_strlen_zero(pvt->url)) {
00405       ast_log(LOG_WARNING, "No URL was specified for iCalendar '%s' - skipping.\n", cal->name);
00406       pvt = unref_icalendar(pvt);
00407       ao2_unlock(cal);
00408       return NULL;
00409    }
00410 
00411    if (ne_uri_parse(pvt->url, &pvt->uri) || pvt->uri.host == NULL || pvt->uri.path == NULL) {
00412       ast_log(LOG_WARNING, "Could not parse url '%s' for iCalendar '%s' - skipping.\n", pvt->url, cal->name);
00413       pvt = unref_icalendar(pvt);
00414       ao2_unlock(cal);
00415       return NULL;
00416    }
00417 
00418    if (pvt->uri.scheme == NULL) {
00419       pvt->uri.scheme = "http";
00420    }
00421 
00422    if (pvt->uri.port == 0) {
00423       pvt->uri.port = ne_uri_defaultport(pvt->uri.scheme);
00424    }
00425 
00426    pvt->session = ne_session_create(pvt->uri.scheme, pvt->uri.host, pvt->uri.port);
00427    ne_redirect_register(pvt->session);
00428    ne_set_server_auth(pvt->session, auth_credentials, pvt);
00429    if (!strcasecmp(pvt->uri.scheme, "https")) {
00430       ne_ssl_trust_default_ca(pvt->session);
00431    }
00432 
00433    cal->tech_pvt = pvt;
00434 
00435    ast_mutex_init(&refreshlock);
00436 
00437    /* Load it the first time */
00438    if (!(pvt->data = fetch_icalendar(pvt))) {
00439       ast_log(LOG_WARNING, "Unable to parse iCalendar '%s'\n", cal->name);
00440    }
00441 
00442    icalendar_update_events(pvt);
00443 
00444    ao2_unlock(cal);
00445 
00446    /* The only writing from another thread will be if unload is true */
00447    for(;;) {
00448       struct timeval tv = ast_tvnow();
00449       struct timespec ts = {0,};
00450 
00451       ts.tv_sec = tv.tv_sec + (60 * pvt->owner->refresh);
00452 
00453       ast_mutex_lock(&refreshlock);
00454       while (!pvt->owner->unloading) {
00455          if (ast_cond_timedwait(&pvt->owner->unload, &refreshlock, &ts) == ETIMEDOUT) {
00456             break;
00457          }
00458       }
00459       ast_mutex_unlock(&refreshlock);
00460 
00461       if (pvt->owner->unloading) {
00462          ast_debug(10, "Skipping refresh since we got a shutdown signal\n");
00463          return NULL;
00464       }
00465 
00466       ast_debug(10, "Refreshing after %d minute timeout\n", pvt->owner->refresh);
00467 
00468       if (!(pvt->data = fetch_icalendar(pvt))) {
00469          ast_log(LOG_WARNING, "Unable to parse iCalendar '%s'\n", pvt->owner->name);
00470          continue;
00471       }
00472 
00473       icalendar_update_events(pvt);
00474    }
00475 
00476    return NULL;
00477 }
00478 
00479 static int load_module(void)
00480 {
00481    ne_sock_init();
00482    if (ast_calendar_register(&ical_tech)) {
00483       ne_sock_exit();
00484       return AST_MODULE_LOAD_DECLINE;
00485    }
00486 
00487    return AST_MODULE_LOAD_SUCCESS;
00488 }
00489 
00490 static int unload_module(void)
00491 {
00492    ast_calendar_unregister(&ical_tech);
00493    ne_sock_exit();
00494    return 0;
00495 }
00496 
00497 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "Asterisk iCalendar .ics file integration",
00498       .load = load_module,
00499       .unload = unload_module,
00500       .load_pri = AST_MODPRI_DEVSTATE_PLUGIN,
00501    );

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