1 // Function to go through an ical component set and convert all non-UTC
2 // date/time properties to UTC. It also strips out any VTIMEZONE
3 // subcomponents afterwards, because they're irrelevant.
5 // Everything here will work on both components and subcomponents. If subcomponents are discovered it will recurse through them.
7 // Copyright (c) 2002-2024 by the citadel.org team (Art Cancro et al)
8 // This program is open source software. Use, duplication, or disclosure is subject to the GNU General Public License v3.
11 #include "webserver.h"
13 // Figure out which time zone needs to be used for timestamps that are
14 // not UTC and do not have a time zone specified.
15 icaltimezone *get_default_icaltimezone(void) {
17 icaltimezone *zone = NULL;
18 const char *default_zone_name = ChrPtr(WC->serv_info->serv_default_cal_zone);
21 zone = icaltimezone_get_builtin_timezone(default_zone_name);
24 syslog(LOG_WARNING, "Unable to load '%s' time zone. Defaulting to UTC.\n", default_zone_name);
25 zone = icaltimezone_get_utc_timezone();
28 syslog(LOG_ERR, "Unable to load UTC time zone!\n");
34 // Back end function for ical_dezonify()
36 // We supply this with the master component, the relevant component,
37 // and the property (which will be a DTSTART, DTEND, etc.)
38 // which we want to convert to UTC.
39 void ical_dezonify_backend(icalcomponent *cal, icalcomponent *rcal, icalproperty *prop) {
41 icaltimezone *t = NULL;
43 const char *tzid = NULL;
44 struct icaltimetype TheTime;
45 int utc_declared_as_tzid = 0; // Component declared 'TZID=GMT' instead of using Z syntax
47 // Give me nothing and I will give you nothing in return.
48 if (cal == NULL) return;
50 // Hunt for a TZID parameter in this property.
51 param = icalproperty_get_first_parameter(prop, ICAL_TZID_PARAMETER);
53 // Get the stringish name of this TZID.
55 tzid = icalparameter_get_tzid(param);
57 // Convert it to an icaltimezone type.
60 syslog(LOG_DEBUG, " * Stringy supplied timezone is: '%s'\n", tzid);
62 if ( (!strcasecmp(tzid, "UTC")) || (!strcasecmp(tzid, "GMT")) ) {
63 utc_declared_as_tzid = 1;
65 syslog(LOG_DEBUG, " * ...and we handle that internally.\n");
70 t = icalcomponent_get_timezone(cal, tzid);
72 syslog(LOG_DEBUG, " * ...and I %s have tzdata for that zone.\n",
76 // then try built-in timezones
78 t = icaltimezone_get_builtin_timezone(tzid);
81 syslog(LOG_DEBUG, " * Using system tzdata!\n");
90 // Now we know the timezone. Convert to UTC.
92 if (icalproperty_isa(prop) == ICAL_DTSTART_PROPERTY) {
93 TheTime = icalproperty_get_dtstart(prop);
95 else if (icalproperty_isa(prop) == ICAL_DTEND_PROPERTY) {
96 TheTime = icalproperty_get_dtend(prop);
98 else if (icalproperty_isa(prop) == ICAL_DUE_PROPERTY) {
99 TheTime = icalproperty_get_due(prop);
101 else if (icalproperty_isa(prop) == ICAL_EXDATE_PROPERTY) {
102 TheTime = icalproperty_get_exdate(prop);
109 syslog(LOG_DEBUG, " * Was: %s\n", icaltime_as_ical_string(TheTime));
112 if (icaltime_is_utc(TheTime)) {
114 syslog(LOG_DEBUG, " * This property is ALREADY UTC.\n");
118 else if (utc_declared_as_tzid) {
120 syslog(LOG_DEBUG, " * Replacing '%s' TZID with 'Z' suffix.\n", tzid);
122 TheTime.zone = icaltimezone_get_utc_timezone();
126 // Do the conversion.
129 syslog(LOG_DEBUG, " * Timezone prop found. Converting to UTC.\n");
134 syslog(LOG_DEBUG, " * Converting default timezone to UTC.\n");
139 t = get_default_icaltimezone();
141 icaltimezone_convert_time(&TheTime, t, icaltimezone_get_utc_timezone());
142 TheTime.zone = icaltimezone_get_utc_timezone();
145 icalproperty_remove_parameter_by_kind(prop, ICAL_TZID_PARAMETER);
147 syslog(LOG_DEBUG, " * Now: %s\n", icaltime_as_ical_string(TheTime));
150 // Now add the converted property back in.
151 if (icalproperty_isa(prop) == ICAL_DTSTART_PROPERTY) {
152 icalproperty_set_dtstart(prop, TheTime);
154 else if (icalproperty_isa(prop) == ICAL_DTEND_PROPERTY) {
155 icalproperty_set_dtend(prop, TheTime);
157 else if (icalproperty_isa(prop) == ICAL_DUE_PROPERTY) {
158 icalproperty_set_due(prop, TheTime);
160 else if (icalproperty_isa(prop) == ICAL_EXDATE_PROPERTY) {
161 icalproperty_set_exdate(prop, TheTime);
166 // Recursive portion of ical_dezonify()
167 void ical_dezonify_recurse(icalcomponent *cal, icalcomponent *rcal) {
171 // Recurse through all subcomponents *except* VTIMEZONE ones.
172 for ( c=icalcomponent_get_first_component(rcal, ICAL_ANY_COMPONENT);
174 c = icalcomponent_get_next_component(rcal, ICAL_ANY_COMPONENT)
176 if (icalcomponent_isa(c) != ICAL_VTIMEZONE_COMPONENT) {
177 ical_dezonify_recurse(cal, c);
181 // Now look for DTSTART and DTEND properties
182 for ( p=icalcomponent_get_first_property(rcal, ICAL_ANY_PROPERTY);
184 p = icalcomponent_get_next_property(rcal, ICAL_ANY_PROPERTY)
187 (icalproperty_isa(p) == ICAL_DTSTART_PROPERTY)
188 || (icalproperty_isa(p) == ICAL_DTEND_PROPERTY)
189 || (icalproperty_isa(p) == ICAL_DUE_PROPERTY)
190 || (icalproperty_isa(p) == ICAL_EXDATE_PROPERTY)
192 ical_dezonify_backend(cal, rcal, p);
198 // Convert all DTSTART and DTEND properties in all subcomponents to UTC.
199 // This function will search any VTIMEZONE subcomponents to learn the
200 // relevant timezone information.
201 void ical_dezonify(icalcomponent *cal) {
202 icalcomponent *vt = NULL;
205 syslog(LOG_DEBUG, "ical_dezonify() started\n");
208 // Convert all times to UTC
209 ical_dezonify_recurse(cal, cal);
211 // Strip out VTIMEZONE subcomponents -- we don't need them anymore.
212 while (vt = icalcomponent_get_first_component(cal, ICAL_VTIMEZONE_COMPONENT), vt != NULL) {
213 icalcomponent_remove_component(cal, vt);
214 icalcomponent_free(vt);
218 syslog(LOG_DEBUG, "ical_dezonify() completed\n");