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;
18 zone = icaltimezone_get_builtin_timezone(default_zone_name);
21 syslog(LOG_WARNING, "ical_dezonify: unable to load '%s' time zone, defaulting to UTC", default_zone_name);
22 zone = icaltimezone_get_utc_timezone();
25 syslog(LOG_ERR, "ical_dezonify: unable to load UTC time zone!");
31 // Back end function for ical_dezonify()
33 // We supply this with the master component, the relevant component, and the property
34 // (which will be a DTSTART, DTEND, etc.) which we want to convert to UTC.
35 void ical_dezonify_backend(icalcomponent *cal, icalcomponent *rcal, icalproperty *prop) {
37 icaltimezone *t = NULL;
39 const char *tzid = NULL;
40 struct icaltimetype TheTime;
41 int utc_declared_as_tzid = 0; // Component declared 'TZID=GMT' instead of using Z syntax
43 // Give me nothing and I will give you nothing in return.
44 if (cal == NULL) return;
46 // Hunt for a TZID parameter in this property.
47 param = icalproperty_get_first_parameter(prop, ICAL_TZID_PARAMETER);
49 // Get the stringish name of this TZID.
51 tzid = icalparameter_get_tzid(param);
53 // Convert it to an icaltimezone type.
56 syslog(LOG_DEBUG, "ical_dezonify: Stringy supplied timezone is: '%s'\n", tzid);
58 if ( (!strcasecmp(tzid, "UTC")) || (!strcasecmp(tzid, "GMT")) ) {
59 utc_declared_as_tzid = 1;
61 syslog(LOG_DEBUG, "ical_dezonify: ...and we handle that internally.\n");
66 t = icalcomponent_get_timezone(cal, tzid);
68 syslog(LOG_DEBUG, "ical_dezonify: ...and I %s have tzdata for that zone.\n",
72 // then try built-in timezones
74 t = icaltimezone_get_builtin_timezone(tzid);
77 syslog(LOG_DEBUG, "ical_dezonify: Using system tzdata!\n");
86 // Now we know the timezone. Convert to UTC.
88 if (icalproperty_isa(prop) == ICAL_DTSTART_PROPERTY) {
89 TheTime = icalproperty_get_dtstart(prop);
91 else if (icalproperty_isa(prop) == ICAL_DTEND_PROPERTY) {
92 TheTime = icalproperty_get_dtend(prop);
94 else if (icalproperty_isa(prop) == ICAL_DUE_PROPERTY) {
95 TheTime = icalproperty_get_due(prop);
97 else if (icalproperty_isa(prop) == ICAL_EXDATE_PROPERTY) {
98 TheTime = icalproperty_get_exdate(prop);
105 syslog(LOG_DEBUG, "ical_dezonify: was: %s\n", icaltime_as_ical_string(TheTime));
108 if (icaltime_is_utc(TheTime)) {
110 syslog(LOG_DEBUG, "ical_dezonify: this property is ALREADY UTC");
114 else if (utc_declared_as_tzid) {
116 syslog(LOG_DEBUG, "ical_dezonify: replacing '%s' TZID with 'Z' suffix", tzid);
118 TheTime.zone = icaltimezone_get_utc_timezone();
122 // Do the conversion.
125 syslog(LOG_DEBUG, "ical_dezonify: timezone prop found, converting to UTC");
130 syslog(LOG_DEBUG, "ical_dezonify: converting default timezone to UTC");
135 t = get_default_icaltimezone();
137 icaltimezone_convert_time(&TheTime, t, icaltimezone_get_utc_timezone());
138 TheTime.zone = icaltimezone_get_utc_timezone();
141 icalproperty_remove_parameter_by_kind(prop, ICAL_TZID_PARAMETER);
143 syslog(LOG_DEBUG, "ical_dezonify: now: %s", icaltime_as_ical_string(TheTime));
146 // Now add the converted property back in.
147 if (icalproperty_isa(prop) == ICAL_DTSTART_PROPERTY) {
148 icalproperty_set_dtstart(prop, TheTime);
150 else if (icalproperty_isa(prop) == ICAL_DTEND_PROPERTY) {
151 icalproperty_set_dtend(prop, TheTime);
153 else if (icalproperty_isa(prop) == ICAL_DUE_PROPERTY) {
154 icalproperty_set_due(prop, TheTime);
156 else if (icalproperty_isa(prop) == ICAL_EXDATE_PROPERTY) {
157 icalproperty_set_exdate(prop, TheTime);
162 // Recursive portion of ical_dezonify()
163 void ical_dezonify_recurse(icalcomponent *cal, icalcomponent *rcal) {
167 // Recurse through all subcomponents *except* VTIMEZONE ones.
168 for ( c=icalcomponent_get_first_component(rcal, ICAL_ANY_COMPONENT);
170 c = icalcomponent_get_next_component(rcal, ICAL_ANY_COMPONENT)
172 if (icalcomponent_isa(c) != ICAL_VTIMEZONE_COMPONENT) {
173 ical_dezonify_recurse(cal, c);
177 // Now look for DTSTART and DTEND properties
178 for ( p=icalcomponent_get_first_property(rcal, ICAL_ANY_PROPERTY);
180 p = icalcomponent_get_next_property(rcal, ICAL_ANY_PROPERTY)
183 (icalproperty_isa(p) == ICAL_DTSTART_PROPERTY)
184 || (icalproperty_isa(p) == ICAL_DTEND_PROPERTY)
185 || (icalproperty_isa(p) == ICAL_DUE_PROPERTY)
186 || (icalproperty_isa(p) == ICAL_EXDATE_PROPERTY)
188 ical_dezonify_backend(cal, rcal, p);
194 // Convert all DTSTART and DTEND properties in all subcomponents to UTC.
195 // This function will search any VTIMEZONE subcomponents to learn the
196 // relevant timezone information.
197 void ical_dezonify(icalcomponent *cal) {
198 icalcomponent *vt = NULL;
201 syslog(LOG_DEBUG, "ical_dezonify() started");
204 // Convert all times to UTC
205 ical_dezonify_recurse(cal, cal);
207 // Strip out VTIMEZONE subcomponents -- we don't need them anymore.
208 while (vt = icalcomponent_get_first_component(cal, ICAL_VTIMEZONE_COMPONENT), vt != NULL) {
209 icalcomponent_remove_component(cal, vt);
210 icalcomponent_free(vt);
214 syslog(LOG_DEBUG, "ical_dezonify() completed");