1 // Go through an ical component set and convert all non-UTC date/time properties to UTC.
2 // It also strips out any VTIMEZONE subcomponents afterwards, because they are now unreferenced.
4 // Everything here will work on both components and subcomponents. If subcomponents are discovered it will recurse through them.
6 // Copyright (c) 2002-2024 by the citadel.org team (Art Cancro et al)
7 // This program is open source software. Use, duplication, or disclosure is subject to the GNU General Public License v3.
10 #include "webserver.h"
12 // Figure out which time zone needs to be used for timestamps that are not UTC and do not have a time zone specified.
13 icaltimezone *get_default_icaltimezone(void) {
15 icaltimezone *zone = NULL;
16 const char *default_zone_name = ChrPtr(WC->serv_info->serv_default_cal_zone); // mmmmmm ... calzone
19 zone = icaltimezone_get_builtin_timezone(default_zone_name);
22 syslog(LOG_WARNING, "ical_dezonify: unable to load '%s' time zone, defaulting to UTC", default_zone_name);
23 zone = icaltimezone_get_utc_timezone();
26 syslog(LOG_ERR, "ical_dezonify: unable to load UTC time zone!");
32 // Back end function for ical_dezonify()
34 // We supply this with the master component, the relevant component, and the property
35 // (which will be a DTSTART, DTEND, etc.) which we want to convert to UTC.
36 void ical_dezonify_backend(icalcomponent *cal, icalcomponent *rcal, icalproperty *prop) {
38 icaltimezone *t = NULL;
40 const char *tzid = NULL;
41 struct icaltimetype TheTime;
42 int utc_declared_as_tzid = 0; // Component declared 'TZID=GMT' instead of using Z syntax
44 // Give me nothing and I will give you nothing in return.
45 if (cal == NULL) return;
47 // Hunt for a TZID parameter in this property.
48 param = icalproperty_get_first_parameter(prop, ICAL_TZID_PARAMETER);
50 // Get the stringish name of this TZID.
52 tzid = icalparameter_get_tzid(param);
54 // Convert it to an icaltimezone type.
57 syslog(LOG_DEBUG, "ical_dezonify: Stringy supplied timezone is: '%s'\n", tzid);
59 if ( (!strcasecmp(tzid, "UTC")) || (!strcasecmp(tzid, "GMT")) ) {
60 utc_declared_as_tzid = 1;
62 syslog(LOG_DEBUG, "ical_dezonify: ...and we handle that internally.\n");
67 t = icalcomponent_get_timezone(cal, tzid);
69 syslog(LOG_DEBUG, "ical_dezonify: ...and I %s have tzdata for that zone.\n",
73 // then try built-in timezones
75 t = icaltimezone_get_builtin_timezone(tzid);
78 syslog(LOG_DEBUG, "ical_dezonify: Using system tzdata!\n");
87 // Now we know the timezone. Convert to UTC.
89 if (icalproperty_isa(prop) == ICAL_DTSTART_PROPERTY) {
90 TheTime = icalproperty_get_dtstart(prop);
92 else if (icalproperty_isa(prop) == ICAL_DTEND_PROPERTY) {
93 TheTime = icalproperty_get_dtend(prop);
95 else if (icalproperty_isa(prop) == ICAL_DUE_PROPERTY) {
96 TheTime = icalproperty_get_due(prop);
98 else if (icalproperty_isa(prop) == ICAL_EXDATE_PROPERTY) {
99 TheTime = icalproperty_get_exdate(prop);
106 syslog(LOG_DEBUG, "ical_dezonify: was: %s\n", icaltime_as_ical_string(TheTime));
109 if (icaltime_is_utc(TheTime)) {
111 syslog(LOG_DEBUG, "ical_dezonify: this property is ALREADY UTC");
115 else if (utc_declared_as_tzid) {
117 syslog(LOG_DEBUG, "ical_dezonify: replacing '%s' TZID with 'Z' suffix", tzid);
119 TheTime.zone = icaltimezone_get_utc_timezone();
123 // Do the conversion.
126 syslog(LOG_DEBUG, "ical_dezonify: timezone prop found, converting to UTC");
131 syslog(LOG_DEBUG, "ical_dezonify: converting default timezone to UTC");
136 t = get_default_icaltimezone();
138 icaltimezone_convert_time(&TheTime, t, icaltimezone_get_utc_timezone());
139 TheTime.zone = icaltimezone_get_utc_timezone();
142 icalproperty_remove_parameter_by_kind(prop, ICAL_TZID_PARAMETER);
144 syslog(LOG_DEBUG, "ical_dezonify: now: %s", icaltime_as_ical_string(TheTime));
147 // Now add the converted property back in.
148 if (icalproperty_isa(prop) == ICAL_DTSTART_PROPERTY) {
149 icalproperty_set_dtstart(prop, TheTime);
151 else if (icalproperty_isa(prop) == ICAL_DTEND_PROPERTY) {
152 icalproperty_set_dtend(prop, TheTime);
154 else if (icalproperty_isa(prop) == ICAL_DUE_PROPERTY) {
155 icalproperty_set_due(prop, TheTime);
157 else if (icalproperty_isa(prop) == ICAL_EXDATE_PROPERTY) {
158 icalproperty_set_exdate(prop, TheTime);
163 // Recursive portion of ical_dezonify()
164 void ical_dezonify_recurse(icalcomponent *cal, icalcomponent *rcal) {
168 // Recurse through all subcomponents *except* VTIMEZONE ones.
169 for ( c=icalcomponent_get_first_component(rcal, ICAL_ANY_COMPONENT);
171 c = icalcomponent_get_next_component(rcal, ICAL_ANY_COMPONENT)
173 if (icalcomponent_isa(c) != ICAL_VTIMEZONE_COMPONENT) {
174 ical_dezonify_recurse(cal, c);
178 // Now look for DTSTART and DTEND properties
179 for ( p=icalcomponent_get_first_property(rcal, ICAL_ANY_PROPERTY);
181 p = icalcomponent_get_next_property(rcal, ICAL_ANY_PROPERTY)
184 (icalproperty_isa(p) == ICAL_DTSTART_PROPERTY)
185 || (icalproperty_isa(p) == ICAL_DTEND_PROPERTY)
186 || (icalproperty_isa(p) == ICAL_DUE_PROPERTY)
187 || (icalproperty_isa(p) == ICAL_EXDATE_PROPERTY)
189 ical_dezonify_backend(cal, rcal, p);
195 // Convert all DTSTART and DTEND properties in all subcomponents to UTC.
196 // This function will search any VTIMEZONE subcomponents to learn the
197 // relevant timezone information.
198 void ical_dezonify(icalcomponent *cal) {
199 icalcomponent *vt = NULL;
202 syslog(LOG_DEBUG, "ical_dezonify() started");
205 // Convert all times to UTC
206 ical_dezonify_recurse(cal, cal);
208 // Strip out VTIMEZONE subcomponents -- we don't need them anymore.
209 while (vt = icalcomponent_get_first_component(cal, ICAL_VTIMEZONE_COMPONENT), vt != NULL) {
210 icalcomponent_remove_component(cal, vt);
211 icalcomponent_free(vt);
215 syslog(LOG_DEBUG, "ical_dezonify() completed");