citadel/ical_dezonify.c

   1 /*
   2  * $Id$
   3  *
   4  * Function to go through an ical component set and convert all non-UTC
   5  * date/time properties to UTC.  It also strips out any VTIMEZONE
   6  * subcomponents afterwards, because they're irrelevant.
   7  *
   8  */
   9
  10
  11 #include "sysdep.h"
  12 #include <stdlib.h>
  13 #include <unistd.h>
  14 #include <sys/types.h>
  15 #include <limits.h>
  16 #include <stdio.h>
  17 #include <string.h>
  18 #include <strings.h>
  19 #include <libical/ical.h>
  20 #include <libcitadel.h>
  21 #include "citadel.h"
  22 #include "server.h"
  23 #include "citserver.h"
  24 #include "sysdep_decls.h"
  25 #include "support.h"
  26 #include "config.h"
  27 #include "ical_dezonify.h"
  28
  29 #include "ctdl_module.h"
  30
  31
  32 /*
  33  * Figure out which time zone needs to be used for timestamps that are
  34  * not UTC and do not have a time zone specified.
  35  */
  36 icaltimezone *get_default_icaltimezone(void) {
  37
  38         icaltimezone *zone = NULL;
  39         char *default_zone_name = config.c_default_cal_zone;
  40         //char *default_zone_name = "America/New_York";
  41
  42         if (!zone) {
  43                 zone = icaltimezone_get_builtin_timezone(default_zone_name);
  44         }
  45         if (!zone) {
  46                 CtdlLogPrintf(CTDL_ALERT,
  47                         "Unable to load '%s' time zone.  Defaulting to UTC.\n",
  48                         default_zone_name);
  49                 zone = icaltimezone_get_utc_timezone();
  50         }
  51         if (!zone) {
  52                 CtdlLogPrintf(1, "Unable to load UTC time zone!\n");
  53         }
  54         return zone;
  55 }
  56
  57
  58 /*
  59  * Back end function for ical_dezonify()
  60  *
  61  * We supply this with the master component, the relevant component,
  62  * and the property (which will be a DTSTART, DTEND, etc.)
  63  * which we want to convert to UTC.
  64  */
  65 void ical_dezonify_backend(icalcomponent *cal,
  66                         icalcomponent *rcal,
  67                         icalproperty *prop) {
  68
  69         icaltimezone *t = NULL;
  70         icalparameter *param;
  71         const char *tzid = NULL;
  72         struct icaltimetype TheTime;
  73         int utc_declared_as_tzid = 0;   /**< Component declared 'TZID=GMT' instead of using Z syntax */
  74
  75         /* Give me nothing and I will give you nothing in return. */
  76         if (cal == NULL) return;
  77
  78         /* Hunt for a TZID parameter in this property. */
  79         param = icalproperty_get_first_parameter(prop, ICAL_TZID_PARAMETER);
  80
  81         /* Get the stringish name of this TZID. */
  82         if (param != NULL) {
  83                 tzid = icalparameter_get_tzid(param);
  84
  85                 /* Convert it to an icaltimezone type. */
  86                 if (tzid != NULL) {
  87                         /* CtdlLogPrintf(9, "                * Stringy supplied timezone is: '%s'\n", tzid); */
  88                         if ( (!strcasecmp(tzid, "UTC")) || (!strcasecmp(tzid, "GMT")) ) {
  89                                 utc_declared_as_tzid = 1;
  90                                 /* CtdlLogPrintf(9, "                * ...and we handle that internally.\n"); */
  91                         }
  92                         else {
  93                                 /* try attached first */
  94                                 t = icalcomponent_get_timezone(cal, tzid);
  95 /*
  96                                 lprintf(9, "                * ...and I %s have tzdata for that zone.\n",
  97                                         (t ? "DO" : "DO NOT")
  98                                 );
  99 */
 100                                 /* then try built-in timezones */
 101                                 if (!t) {
 102                                         t = icaltimezone_get_builtin_timezone(tzid);
 103 /*
 104                                         if (t) {
 105                                                 lprintf(9, "                * Using system tzdata!\n");
 106                                         }
 107 */
 108                                 }
 109                         }
 110                 }
 111
 112         }
 113
 114         /* Now we know the timezone.  Convert to UTC. */
 115
 116         if (icalproperty_isa(prop) == ICAL_DTSTART_PROPERTY) {
 117                 TheTime = icalproperty_get_dtstart(prop);
 118         }
 119         else if (icalproperty_isa(prop) == ICAL_DTEND_PROPERTY) {
 120                 TheTime = icalproperty_get_dtend(prop);
 121         }
 122         else if (icalproperty_isa(prop) == ICAL_DUE_PROPERTY) {
 123                 TheTime = icalproperty_get_due(prop);
 124         }
 125         else if (icalproperty_isa(prop) == ICAL_EXDATE_PROPERTY) {
 126                 TheTime = icalproperty_get_exdate(prop);
 127         }
 128         else {
 129                 return;
 130         }
 131
 132         /* CtdlLogPrintf(9, "                * Was: %s\n", icaltime_as_ical_string(TheTime)); */
 133
 134         if (TheTime.is_utc) {
 135                 /* CtdlLogPrintf(9, "                * This property is ALREADY UTC.\n"); */
 136         }
 137
 138         else if (utc_declared_as_tzid) {
 139                 /* CtdlLogPrintf(9, "                * Replacing '%s' TZID with 'Z' suffix.\n", tzid); */
 140                 TheTime.is_utc = 1;
 141         }
 142
 143         else {
 144                 /* Do the conversion. */
 145                 if (t != NULL) {
 146                         /* CtdlLogPrintf(9, "                * Timezone prop found.  Converting to UTC.\n"); */
 147                 }
 148                 else {
 149                         /* CtdlLogPrintf(9, "                * Converting default timezone to UTC.\n"); */
 150                 }
 151
 152                 if (t == NULL) {
 153                         t = get_default_icaltimezone();
 154                 }
 155
 156                 icaltimezone_convert_time(&TheTime,
 157                                         t,
 158                                         icaltimezone_get_utc_timezone()
 159                 );
 160                 TheTime.is_utc = 1;
 161         }
 162
 163         icalproperty_remove_parameter_by_kind(prop, ICAL_TZID_PARAMETER);
 164         /* CtdlLogPrintf(9, "                * Now: %s\n", icaltime_as_ical_string(TheTime)); */
 165
 166         /* Now add the converted property back in. */
 167         if (icalproperty_isa(prop) == ICAL_DTSTART_PROPERTY) {
 168                 icalproperty_set_dtstart(prop, TheTime);
 169         }
 170         else if (icalproperty_isa(prop) == ICAL_DTEND_PROPERTY) {
 171                 icalproperty_set_dtend(prop, TheTime);
 172         }
 173         else if (icalproperty_isa(prop) == ICAL_DUE_PROPERTY) {
 174                 icalproperty_set_due(prop, TheTime);
 175         }
 176         else if (icalproperty_isa(prop) == ICAL_EXDATE_PROPERTY) {
 177                 icalproperty_set_exdate(prop, TheTime);
 178         }
 179 }
 180
 181
 182 /*
 183  * Recursive portion of ical_dezonify()
 184  */
 185 void ical_dezonify_recurse(icalcomponent *cal, icalcomponent *rcal) {
 186         icalcomponent *c;
 187         icalproperty *p;
 188
 189         /*
 190          * Recurse through all subcomponents *except* VTIMEZONE ones.
 191          */
 192         for (c=icalcomponent_get_first_component(
 193                                         rcal, ICAL_ANY_COMPONENT);
 194                 c != NULL;
 195                 c = icalcomponent_get_next_component(
 196                                         rcal, ICAL_ANY_COMPONENT)
 197         ) {
 198                 if (icalcomponent_isa(c) != ICAL_VTIMEZONE_COMPONENT) {
 199                         ical_dezonify_recurse(cal, c);
 200                 }
 201         }
 202
 203         /*
 204          * Now look for DTSTART and DTEND properties
 205          */
 206         for (p=icalcomponent_get_first_property(rcal, ICAL_ANY_PROPERTY);
 207                 p != NULL;
 208                 p = icalcomponent_get_next_property(rcal, ICAL_ANY_PROPERTY)
 209         ) {
 210                 if (
 211                         (icalproperty_isa(p) == ICAL_DTSTART_PROPERTY)
 212                         || (icalproperty_isa(p) == ICAL_DTEND_PROPERTY)
 213                         || (icalproperty_isa(p) == ICAL_DUE_PROPERTY)
 214                         || (icalproperty_isa(p) == ICAL_EXDATE_PROPERTY)
 215                    ) {
 216                         ical_dezonify_backend(cal, rcal, p);
 217                 }
 218         }
 219 }
 220
 221
 222 /*
 223  * Convert all DTSTART and DTEND properties in all subcomponents to UTC.
 224  * This function will search any VTIMEZONE subcomponents to learn the
 225  * relevant timezone information.
 226  */
 227 void ical_dezonify(icalcomponent *cal) {
 228         icalcomponent *vt = NULL;
 229
 230         /* CtdlLogPrintf(9, "ical_dezonify() started\n"); */
 231
 232         /* Convert all times to UTC */
 233         ical_dezonify_recurse(cal, cal);
 234
 235         /* Strip out VTIMEZONE subcomponents -- we don't need them anymore */
 236         while (vt = icalcomponent_get_first_component(
 237                         cal, ICAL_VTIMEZONE_COMPONENT), vt != NULL) {
 238                 icalcomponent_remove_component(cal, vt);
 239                 icalcomponent_free(vt);
 240         }
 241
 242         /* CtdlLogPrintf(9, "ical_dezonify() completed\n"); */
 243 }