--- /dev/null
+/*
+ * Function to go through an ical component set and convert all non-UTC
+ * date/time properties to UTC. It also strips out any VTIMEZONE
+ * subcomponents afterwards, because they're irrelevant.
+ *
+ * Everything here will work on both a fully encapsulated VCALENDAR component
+ * or any type of subcomponent.
+ */
+
+#include "webcit.h"
+#include "webserver.h"
+
+/*
+ * Figure out which time zone needs to be used for timestamps that are
+ * not UTC and do not have a time zone specified.
+ *
+ */
+icaltimezone *get_default_icaltimezone(void) {
+
+ icaltimezone *zone = NULL;
+ const char *default_zone_name = ChrPtr(WC->serv_info->serv_default_cal_zone);
+
+ if (!zone) {
+ zone = icaltimezone_get_builtin_timezone(default_zone_name);
+ }
+ if (!zone) {
+ syslog(LOG_WARNING, "Unable to load '%s' time zone. Defaulting to UTC.\n", default_zone_name);
+ zone = icaltimezone_get_utc_timezone();
+ }
+ if (!zone) {
+ syslog(LOG_ERR, "Unable to load UTC time zone!\n");
+ }
+ return zone;
+}
+
+
+/*
+ * Back end function for ical_dezonify()
+ *
+ * We supply this with the master component, the relevant component,
+ * and the property (which will be a DTSTART, DTEND, etc.)
+ * which we want to convert to UTC.
+ */
+void ical_dezonify_backend(icalcomponent *cal,
+ icalcomponent *rcal,
+ icalproperty *prop) {
+
+ icaltimezone *t = NULL;
+ icalparameter *param;
+ const char *tzid = NULL;
+ struct icaltimetype TheTime;
+ int utc_declared_as_tzid = 0; /* Component declared 'TZID=GMT' instead of using Z syntax */
+
+ /* Give me nothing and I will give you nothing in return. */
+ if (cal == NULL) return;
+
+ /* Hunt for a TZID parameter in this property. */
+ param = icalproperty_get_first_parameter(prop, ICAL_TZID_PARAMETER);
+
+ /* Get the stringish name of this TZID. */
+ if (param != NULL) {
+ tzid = icalparameter_get_tzid(param);
+
+ /* Convert it to an icaltimezone type. */
+ if (tzid != NULL) {
+#ifdef DBG_ICAL
+ syslog(LOG_DEBUG, " * Stringy supplied timezone is: '%s'\n", tzid);
+#endif
+ if ( (!strcasecmp(tzid, "UTC")) || (!strcasecmp(tzid, "GMT")) ) {
+ utc_declared_as_tzid = 1;
+#ifdef DBG_ICAL
+ syslog(LOG_DEBUG, " * ...and we handle that internally.\n");
+#endif
+ }
+ else {
+ /* try attached first */
+ t = icalcomponent_get_timezone(cal, tzid);
+#ifdef DBG_ICAL
+ syslog(LOG_DEBUG, " * ...and I %s have tzdata for that zone.\n",
+ (t ? "DO" : "DO NOT")
+ );
+#endif
+ /* then try built-in timezones */
+ if (!t) {
+ t = icaltimezone_get_builtin_timezone(tzid);
+#ifdef DBG_ICAL
+ if (t) {
+ syslog(LOG_DEBUG, " * Using system tzdata!\n");
+ }
+#endif
+ }
+ }
+ }
+
+ }
+
+ /* Now we know the timezone. Convert to UTC. */
+
+ if (icalproperty_isa(prop) == ICAL_DTSTART_PROPERTY) {
+ TheTime = icalproperty_get_dtstart(prop);
+ }
+ else if (icalproperty_isa(prop) == ICAL_DTEND_PROPERTY) {
+ TheTime = icalproperty_get_dtend(prop);
+ }
+ else if (icalproperty_isa(prop) == ICAL_DUE_PROPERTY) {
+ TheTime = icalproperty_get_due(prop);
+ }
+ else if (icalproperty_isa(prop) == ICAL_EXDATE_PROPERTY) {
+ TheTime = icalproperty_get_exdate(prop);
+ }
+ else {
+ return;
+ }
+
+#ifdef DBG_ICAL
+ syslog(LOG_DEBUG, " * Was: %s\n", icaltime_as_ical_string(TheTime));
+#endif
+
+ if (icaltime_is_utc(TheTime)) {
+#ifdef DBG_ICAL
+ syslog(LOG_DEBUG, " * This property is ALREADY UTC.\n");
+#endif
+ }
+
+ else if (utc_declared_as_tzid) {
+#ifdef DBG_ICAL
+ syslog(LOG_DEBUG, " * Replacing '%s' TZID with 'Z' suffix.\n", tzid);
+#endif
+ TheTime.zone = icaltimezone_get_utc_timezone();
+ }
+
+ else {
+ /* Do the conversion. */
+ if (t != NULL) {
+#ifdef DBG_ICAL
+ syslog(LOG_DEBUG, " * Timezone prop found. Converting to UTC.\n");
+#endif
+ }
+ else {
+#ifdef DBG_ICAL
+ syslog(LOG_DEBUG, " * Converting default timezone to UTC.\n");
+#endif
+ }
+
+ if (t == NULL) {
+ t = get_default_icaltimezone();
+ }
+ icaltimezone_convert_time(&TheTime, t, icaltimezone_get_utc_timezone());
+ TheTime.zone = icaltimezone_get_utc_timezone();
+ }
+
+ icalproperty_remove_parameter_by_kind(prop, ICAL_TZID_PARAMETER);
+#ifdef DBG_ICAL
+ syslog(LOG_DEBUG, " * Now: %s\n", icaltime_as_ical_string(TheTime));
+#endif
+
+ /* Now add the converted property back in. */
+ if (icalproperty_isa(prop) == ICAL_DTSTART_PROPERTY) {
+ icalproperty_set_dtstart(prop, TheTime);
+ }
+ else if (icalproperty_isa(prop) == ICAL_DTEND_PROPERTY) {
+ icalproperty_set_dtend(prop, TheTime);
+ }
+ else if (icalproperty_isa(prop) == ICAL_DUE_PROPERTY) {
+ icalproperty_set_due(prop, TheTime);
+ }
+ else if (icalproperty_isa(prop) == ICAL_EXDATE_PROPERTY) {
+ icalproperty_set_exdate(prop, TheTime);
+ }
+}
+
+
+/*
+ * Recursive portion of ical_dezonify()
+ */
+void ical_dezonify_recurse(icalcomponent *cal, icalcomponent *rcal) {
+ icalcomponent *c;
+ icalproperty *p;
+
+ /*
+ * Recurse through all subcomponents *except* VTIMEZONE ones.
+ */
+ for (c=icalcomponent_get_first_component(
+ rcal, ICAL_ANY_COMPONENT);
+ c != NULL;
+ c = icalcomponent_get_next_component(
+ rcal, ICAL_ANY_COMPONENT)
+ ) {
+ if (icalcomponent_isa(c) != ICAL_VTIMEZONE_COMPONENT) {
+ ical_dezonify_recurse(cal, c);
+ }
+ }
+
+ /*
+ * Now look for DTSTART and DTEND properties
+ */
+ for (p=icalcomponent_get_first_property(rcal, ICAL_ANY_PROPERTY);
+ p != NULL;
+ p = icalcomponent_get_next_property(rcal, ICAL_ANY_PROPERTY)
+ ) {
+ if (
+ (icalproperty_isa(p) == ICAL_DTSTART_PROPERTY)
+ || (icalproperty_isa(p) == ICAL_DTEND_PROPERTY)
+ || (icalproperty_isa(p) == ICAL_DUE_PROPERTY)
+ || (icalproperty_isa(p) == ICAL_EXDATE_PROPERTY)
+ ) {
+ ical_dezonify_backend(cal, rcal, p);
+ }
+ }
+}
+
+
+/*
+ * Convert all DTSTART and DTEND properties in all subcomponents to UTC.
+ * This function will search any VTIMEZONE subcomponents to learn the
+ * relevant timezone information.
+ */
+void ical_dezonify(icalcomponent *cal) {
+ icalcomponent *vt = NULL;
+
+#ifdef DBG_ICAL
+ syslog(LOG_DEBUG, "ical_dezonify() started\n");
+#endif
+
+ /* Convert all times to UTC */
+ ical_dezonify_recurse(cal, cal);
+
+ /* Strip out VTIMEZONE subcomponents -- we don't need them anymore */
+ while (vt = icalcomponent_get_first_component(
+ cal, ICAL_VTIMEZONE_COMPONENT), vt != NULL) {
+ icalcomponent_remove_component(cal, vt);
+ icalcomponent_free(vt);
+ }
+
+#ifdef DBG_ICAL
+ syslog(LOG_DEBUG, "ical_dezonify() completed\n");
+#endif
+}
+
projects / citadel.git / blobdiff