1 // This file contains functions which handle all of the CalDAV "REPORT" queries specified in RFC4791 section 7.
2 // Copyright (c) 2023-2024 by the citadel.org team
3 // This program is open source software. Use, duplication, or disclosure is subject to the GNU General Public License v3.
7 #define CALDAV "urn:ietf:params:xml:ns:caldav:" // Shorthand for the XML namespace of CalDAV
8 #define CALDAVLEN sizeof(CALDAV)-1 // And the length of that string
10 const char *the_beginning_of_time = "19010101T010101Z";
11 const char *the_end_of_time = "99991231T235959Z";
13 // A CalDAV REPORT can only be one type. This is stored in the report_type member.
20 // Data type for CalDAV Report Parameters.
21 // As we slog our way through the XML we learn what the client is asking for
22 // and build up the contents of this data type.
24 int comp_filter_nesting_level;
25 enum cr_type report_type; // which RFC4791 section 7 REPORT are we generating
26 StrBuf *Chardata; // XML chardata in between tags is built up here
27 StrBuf *Hrefs; // list of items requested by a `calendar-multiget` REPORT
28 Array *filters; // If the query contains a FILTER stanza, the filter criteria are populated here
29 int filter_nest; // tag nesting level where a FILTER stanza begins
30 int in_prop; // nonzero if we are within the parsing a <DAV::prop> stanza?
31 int yes_getetag; // nonzero if client has requested the "getetag" property
32 int yes_calendar_data; // nonzero if client has requested the "calendar-data" property
36 // XML parser callback
37 void caldav_xml_start(void *data, const char *el, const char **attr) {
38 struct cr_params *crp = (struct cr_params *) data;
40 #ifdef DEBUG_XML_PARSE
42 syslog(LOG_DEBUG, "<%s>", el);
43 for (int i = 0; attr[i] != NULL; i += 2) {
44 syslog(LOG_DEBUG, "Attribute '%s' = '%s'", attr[i], attr[i + 1]);
49 // if we are already within a webdav prop stanza, child nodes name properties the client wants to receive.
51 syslog(LOG_DEBUG, "\033[41m\033[37m\033[1mprop:%s\033[0m", el);
53 if (!strcasecmp(el, "DAV::getetag")) {
56 else if (!strcasecmp(el, CALDAV"calendar-data")) {
57 crp->yes_calendar_data = 1;
63 // webdav prop (not caldav "prop") element
64 if (!strcasecmp(el, "DAV::prop")) {
66 syslog(LOG_DEBUG, "\033[41m\033[37m\033[1mprop:%d\033[0m", crp->in_prop);
69 // webdav allprop (not caldav "allprop") element
70 if (!strcasecmp(el, "DAV::allprop")) {
72 crp->yes_calendar_data = 1;
75 // RFC4791 7.8 "calendar-query" REPORT - Client will send a lot of search criteria.
76 if (!strcasecmp(el, CALDAV"calendar-query")) {
77 crp->report_type = cr_calendar_query;
80 // RFC4791 7.9 "calendar-multiget" REPORT - Client will supply a list of specific hrefs.
81 else if (!strcasecmp(el, CALDAV"calendar-multiget")) {
82 crp->report_type = cr_calendar_multiget;
85 // RFC4791 7.10 "free-busy-query" REPORT
86 else if (!strcasecmp(el, CALDAV"free-busy-query")) {
87 crp->report_type = cr_freebusy_query;
90 // RFC4791 9.7 create a filter array if this query contains a "filter" stanza
91 else if (!strcasecmp(el, CALDAV"filter")) {
92 crp->filters = array_new(SIZ);
93 crp->filter_nest = crp->comp_filter_nesting_level;
96 // Handle the filters defined in RFC4791 9.7.1 through 9.7.5
97 else if ( ( (!strcasecmp(el, CALDAV"comp-filter"))
98 || (!strcasecmp(el, CALDAV"prop-filter"))
99 || (!strcasecmp(el, CALDAV"param-filter"))
100 || (!strcasecmp(el, CALDAV"is-not-defined"))
101 || (!strcasecmp(el, CALDAV"text-match"))
102 || (!strcasecmp(el, CALDAV"time-range"))
104 && (crp->filters) // Make sure we actually allocated an array
107 if (!strcasecmp(el, CALDAV"comp-filter")) {
108 ++crp->comp_filter_nesting_level;
113 int len = snprintf(newfilter, SIZ, "%d|", crp->comp_filter_nesting_level - crp->filter_nest - 1);
114 len += snprintf(&newfilter[len], SIZ-len, "%s", &el[CALDAVLEN]); // filter name without the namespace
116 len += snprintf(&newfilter[len], SIZ-len, "|%s", attr[a++]); // now save the attributes
118 array_append(crp->filters, newfilter);
123 // XML parser callback
124 void caldav_xml_end(void *data, const char *el) {
125 struct cr_params *crp = (struct cr_params *) data;
127 #ifdef DEBUG_XML_PARSE
130 syslog(LOG_DEBUG, "</%s>", el);
134 // webdav prop (not caldav "prop") filter
135 if (!strcasecmp(el, "DAV::prop")) {
137 syslog(LOG_DEBUG, "\033[41m\033[37m\033[1mprop:%d\033[0m", crp->in_prop);
140 if (!strcasecmp(el, CALDAV"comp-filter")) {
141 --crp->comp_filter_nesting_level;
144 if ((!strcasecmp(el, "DAV::href")) || (!strcasecmp(el, "DAV:href"))) {
145 if (crp->Hrefs == NULL) { // append crp->Chardata to crp->Hrefs
146 crp->Hrefs = NewStrBuf();
149 StrBufAppendBufPlain(crp->Hrefs, HKEY("|"), 0);
151 StrBufAppendBuf(crp->Hrefs, crp->Chardata, 0);
154 if (crp->Chardata != NULL) { // Tag is closed; chardata is now out of scope.
155 FreeStrBuf(&crp->Chardata); // Free the buffer.
156 crp->Chardata = NULL;
161 // XML parser callback
162 void caldav_xml_chardata(void *data, const XML_Char *s, int len) {
163 struct cr_params *crp = (struct cr_params *) data;
165 char *app = malloc(len+1);
172 if (crp->Chardata == NULL) {
173 crp->Chardata = NewStrBuf();
176 StrBufAppendBufPlain(crp->Chardata, app, len, 0);
178 #ifdef DEBUG_XML_PARSE
180 string_trim(app); // remove leading/trailing whitespace. ok to mangle it because we've already appended.
181 if (!IsEmptyStr(app)) {
183 syslog(LOG_DEBUG, "%s", app, len);
193 // Called by caldav_report_one_item() to fetch a message (by number) in the current room,
194 // and return only the icalendar data as a StrBuf. Returns NULL if not found.
196 // NOTE: this function expects that "MSGP text/calendar" was issued at the beginning
197 // of a REPORT operation to set our preferred MIME type to calendar data.
198 StrBuf *fetch_ical(struct ctdlsession *c, long msgnum) {
202 ctdl_printf(c, "MSG4 %ld", msgnum);
203 ctdl_readline(c, buf, sizeof(buf));
208 while (ctdl_readline(c, buf, sizeof(buf)), strcmp(buf, "000")) {
209 if (Buf != NULL) { // already in body
210 StrBufAppendPrintf(Buf, "%s\n", buf);
212 else if (IsEmptyStr(buf)) { // beginning of body
221 // Called by multiple REPORT types to actually perform the output in "multiget" format.
222 // We need to already know the source message number and the href, but also already have the output data.
223 void cal_multiget_out(long msgnum, StrBuf *ThisHref, StrBuf *Caldata, StrBuf *ReportOut, struct cr_params *crp) {
225 StrBufAppendPrintf(ReportOut, "<D:response>");
226 StrBufAppendPrintf(ReportOut, "<D:href>");
227 StrBufXMLEscAppend(ReportOut, ThisHref, NULL, 0, 0);
228 StrBufAppendPrintf(ReportOut, "</D:href>");
229 StrBufAppendPrintf(ReportOut, "<D:propstat>");
231 if (Caldata != NULL) {
232 // syslog(LOG_DEBUG, "caldav_report_one_item(%s) 200 OK", ChrPtr(ThisHref));
233 StrBufAppendPrintf(ReportOut, "<D:status>");
234 StrBufAppendPrintf(ReportOut, "HTTP/1.1 200 OK");
235 StrBufAppendPrintf(ReportOut, "</D:status>");
236 StrBufAppendPrintf(ReportOut, "<D:prop>");
238 if (crp->yes_getetag) {
239 StrBufAppendPrintf(ReportOut, "<D:getetag>");
240 StrBufAppendPrintf(ReportOut, "%ld", msgnum);
241 StrBufAppendPrintf(ReportOut, "</D:getetag>");
244 if (crp->yes_calendar_data) {
245 StrBufAppendPrintf(ReportOut, "<C:calendar-data>");
246 StrBufXMLEscAppend(ReportOut, Caldata, NULL, 0, 0);
247 StrBufAppendPrintf(ReportOut, "</C:calendar-data>");
250 StrBufAppendPrintf(ReportOut, "</D:prop>");
253 // syslog(LOG_DEBUG, "caldav_report_one_item(%s) 404 not found", ChrPtr(ThisHref));
254 StrBufAppendPrintf(ReportOut, "<D:status>");
255 StrBufAppendPrintf(ReportOut, "HTTP/1.1 404 not found");
256 StrBufAppendPrintf(ReportOut, "</D:status>");
259 StrBufAppendPrintf(ReportOut, "</D:propstat>");
260 StrBufAppendPrintf(ReportOut, "</D:response>");
264 // Called by caldav_report() to output a single item.
265 // Our policy is to throw away the list of properties the client asked for, and just send everything.
266 void caldav_report_one_item(struct http_transaction *h, struct ctdlsession *c, StrBuf *ReportOut, StrBuf *ThisHref, struct cr_params *crp) {
268 StrBuf *Caldata = NULL;
271 euid = strrchr(ChrPtr(ThisHref), '/');
276 euid = (char *) ChrPtr(ThisHref);
279 char *unescaped_euid = strdup(euid);
280 if (!unescaped_euid) {
283 unescape_input(unescaped_euid);
285 msgnum = locate_message_by_uid(c, unescaped_euid);
286 free(unescaped_euid);
288 Caldata = fetch_ical(c, msgnum);
294 cal_multiget_out(msgnum, ThisHref, Caldata, ReportOut, crp);
296 if (Caldata != NULL) {
297 FreeStrBuf(&Caldata);
302 // Compare function for "time-range" tests (RFC4791 section 9.9)
303 // Returns nonzero if the supplied icalcomponent occurs within the specified time range
305 // IMPLEMENTATION NOTE:
306 // ical_ctdl_is_overlap() works because icaltime_compare() is really smart.
307 // It looks at the time zone of the dtstart/dtend and can apparently go back up the icalcomponent
308 // hierarchy to find its time zone data. I tested this by creating an event with a fictional
309 // time zone and it did the right thing. It even showed the fictional name to me. This saves us
310 // from having to convert everything to UTC before comparing. Nice!
312 int caldav_time_range_filter_matches(icalcomponent *cal, char *start_str, char *end_str) {
314 struct icaltimetype search_start = icaltime_from_string(start_str); // time range being searched
315 struct icaltimetype search_end = icaltime_from_string(end_str);
317 struct icaltimetype dtstart = icalcomponent_get_dtstart(cal); // time of event
318 struct icaltimetype dtend = icalcomponent_get_dtend(cal);
319 if (icaltime_is_null_time(dtend)) {
323 // If it is a recurring event, RRULE is available at this level. We can handle it here.
324 icalproperty *rrule = icalcomponent_get_first_property(cal, ICAL_RRULE_PROPERTY);
326 struct icaldurationtype dur = icaltime_subtract(dtend, dtstart); // recurrences need duration to find dtend
327 struct icalrecurrencetype recur = icalproperty_get_rrule(rrule);
328 icalrecur_iterator *ritr = icalrecur_iterator_new(recur, dtstart); // iterate through recurrences
329 while (dtstart = icalrecur_iterator_next(ritr), !icaltime_is_null_time(dtstart)) {
330 dtend = icaltime_add(dtstart, dur);
332 // Does THIS recurrence match the query? If so, free the memory we used and stop iterating.
333 if (ical_ctdl_is_overlap(dtstart, dtend, search_start, search_end)) {
334 icalrecur_iterator_free(ritr);
339 icalrecur_iterator_free(ritr);
340 return(0); // compared all recurrences, no match was found for any of them
343 // For non recurring events, do a simple time range compare.
344 return(ical_ctdl_is_overlap(dtstart, dtend, search_start, search_end)); // We have a convenience function for this.
348 // Recursive function to apply CalDAV FILTERS to a calendar item.
349 // Returns zero if the calendar item was disqualified by a filter, nonzero if the calendar item still qualifies.
350 int caldav_apply_filters(void *cal, Array *filters, int apply_at_level) {
352 int f = 0; // filter number iterator
353 int qual = 1; // 0 for disqualify, 1 for qualify
354 int previous_level = -1;
355 int disregard_further_comp_filters = 0;
357 while ( (f<array_len(filters)) && (qual) ) {
359 // Tokenize the filter (a future performance hack would be to pre-tokenize instead of storing delimited strings)
360 char this_filter[SIZ];
361 safestrncpy(this_filter, array_get_element_at(filters, f), sizeof(this_filter));
362 char *t[10] = { NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL } ;
363 char *ft = this_filter;
365 while ( (t[num_tokens]=strtok_r(ft, "|", &ft)) && (num_tokens<10) ) {
368 int this_rule_level = atoi(t[0]);
369 // syslog(LOG_DEBUG, "caldav_apply_filters() filter=%d, level=%d, <%s>", f, this_rule_level, array_get_element_at(filters, f) );
371 // Handle the individual filters defined in RFC4791 9.7.1 through 9.7.5
373 if (apply_at_level < previous_level) {
374 // syslog(LOG_DEBUG, "caldav: walking back down");
378 else if (this_rule_level != apply_at_level) {
379 // syslog(LOG_DEBUG, "caldav: apply_at_level=%d, this_rule_level=%d, skipping this rule", apply_at_level, this_rule_level);
382 else if ( (!strcasecmp(t[1], "comp-filter")) // RFC4791 9.7.1 - filter by component
383 && (!disregard_further_comp_filters) // one is enough to succeed
385 // syslog(LOG_DEBUG, "component filter at level %d", this_rule_level);
387 // comp-filter requires exactly one parameter (name="VXXXX")
388 if (num_tokens < 4) {
389 syslog(LOG_DEBUG, "caldav: comp-filter has no parameters - rejecting");
393 // Root element is NOT a component, but the root filter is "comp-filter" -- reject!
394 if ( (!icalcomponent_isa_component(cal)) && (this_rule_level == 0) ) {
395 syslog(LOG_DEBUG, "caldav: root element is not a component, rejecting");
399 // Current element is a component and the filter is "comp-filter" -- see if it matches the requested type
400 if ( (icalcomponent_isa_component(cal))
401 && (!strcasecmp(t[2], "name"))
403 if (icalcomponent_isa(cal) == icalcomponent_string_to_kind(t[3]) ) {
404 // syslog(LOG_DEBUG, "caldav: component at level %d is <%s>, looking for <%s>, recursing...",
406 //icalcomponent_kind_to_string(icalcomponent_isa(cal)), t[3]
409 // We have a match. Drill down into the subcomponents.
411 icalcomponent *c = NULL;
412 int number_of_subcomponents = 0;
413 int number_of_matches = 0;
414 for ( c = icalcomponent_get_first_component(cal, ICAL_ANY_COMPONENT);
416 c = icalcomponent_get_next_component(cal, ICAL_ANY_COMPONENT)
418 ++number_of_subcomponents;
419 if (caldav_apply_filters(c, filters, apply_at_level+1)) {
420 syslog(LOG_DEBUG, "Subcomponent %d might match", number_of_subcomponents);
424 if (number_of_matches > 0) { // something matched
426 disregard_further_comp_filters = 1;
429 else if (number_of_subcomponents > 0) { // nothing matched
430 return(0); // but only fail if there *were* subcomponents.
435 //syslog(LOG_DEBUG, "caldav: component at level %d is <%s>, looking for <%s>, rejecting",
437 //icalcomponent_kind_to_string(icalcomponent_isa(cal)),
446 else if (!strcasecmp(t[1], "prop-filter")) { // RFC4791 9.7.2 - filter by property
447 syslog(LOG_DEBUG, "property filter at level %d FIXME not implemented yet", this_rule_level);
450 else if (!strcasecmp(t[1], "param-filter")) { // RFC4791 9.7.3 - filter by parameter
451 syslog(LOG_DEBUG, "parameter filter at level %d FIXME not implemented yet", this_rule_level);
454 else if (!strcasecmp(t[1], "is-not-defined")) { // RFC4791 9.7.4
455 syslog(LOG_DEBUG, "is-not-defined filter at level %d FIXME not implemented yet", this_rule_level);
458 else if (!strcasecmp(t[1], "text-match")) { // RFC4791 9.7.5
459 syslog(LOG_DEBUG, "text match filter at level %d FIXME not implemented yet", this_rule_level);
462 else if (!strcasecmp(t[1], "time-range")) { // RFC4791 9.9
463 syslog(LOG_DEBUG, "time range filter at level %d", this_rule_level);
464 char *tr_start = (char *)the_beginning_of_time; // default if not specified
465 char *tr_end = (char *)the_end_of_time; // default if not specified
466 for (int i=2; (i+1)<num_tokens; i+=2) {
467 if (!strcasecmp(t[i], "start")) {
470 else if (!strcasecmp(t[i], "end")) {
474 if (caldav_time_range_filter_matches(cal, tr_start, tr_end)) {
475 syslog(LOG_DEBUG, "time range matches");
478 syslog(LOG_DEBUG, "time range does not match -- rejecting");
486 // syslog(LOG_DEBUG, "caldav: we reached the end of level %d , returning %d", apply_at_level, qual);
491 // Called by report_the_room_itself() in room_functions.c when a CalDAV REPORT method
492 // is requested on a calendar room. We fire up an XML Parser to decode the request and
493 // hopefully produce the correct output.
494 void caldav_report(struct http_transaction *h, struct ctdlsession *c) {
495 struct cr_params crp;
498 memset(&crp, 0, sizeof(struct cr_params));
500 XML_Parser xp = XML_ParserCreateNS("UTF-8", ':');
502 syslog(LOG_INFO, "Cannot create XML parser!");
507 XML_SetElementHandler(xp, caldav_xml_start, caldav_xml_end);
508 XML_SetCharacterDataHandler(xp, caldav_xml_chardata);
509 XML_SetUserData(xp, &crp);
510 XML_SetDefaultHandler(xp, NULL); // Disable internal entity expansion to prevent "billion laughs attack"
511 XML_Parse(xp, h->request_body, h->request_body_length, 1);
514 if (crp.Chardata != NULL) { // Discard any trailing chardata ... normally nothing here
515 FreeStrBuf(&crp.Chardata);
519 // We're going to make a lot of MSG4 calls, and the preferred MIME type we want is "text/calendar".
520 // The iCalendar standard is mature now, and we are no longer interested in text/x-vcal or application/ics.
521 ctdl_printf(c, "MSGP text/calendar");
522 ctdl_readline(c, buf, sizeof buf);
524 // Now begin the REPORT.
525 syslog(LOG_DEBUG, "CalDAV REPORT type is: %d", crp.report_type);
526 StrBuf *ReportOut = NewStrBuf();
527 StrBufAppendPrintf(ReportOut,
528 "<?xml version=\"1.0\" encoding=\"utf-8\"?>"
529 "<D:multistatus xmlns:D=\"DAV:\" xmlns:C=\"urn:ietf:params:xml:ns:caldav\">"
532 // RFC4791 7.8 "calendar-query" REPORT - Client will send a lot of search criteria.
533 if (crp.report_type == cr_calendar_query) {
535 Array *msglist = get_msglist(c, "ALL");
536 if (msglist != NULL) {
537 for (i = 0; i < array_len(msglist); ++i) {
539 memcpy(&m, array_get_element_at(msglist, i), sizeof(long));
541 // load and parse one calendar item
542 StrBuf *one_item = fetch_ical(c, m);
543 icalcomponent *cal = icalcomponent_new_from_string(ChrPtr(one_item));
545 // Does this calendar item qualify for output? Run this calendar item through the filters.
546 // syslog(LOG_DEBUG, "Evaluating message \033[33m%ld\033[0m...", m);
547 if (caldav_apply_filters(cal, crp.filters, 0)) {
548 syslog(LOG_DEBUG, "Message %ld \033[32mQUALIFIES\033[0m", m);
550 // FIXME need to populate the Href instead of NULL
551 StrBuf *FIXME = NewStrBufPlain(HKEY("https://FIX.ME.COM/WOW/EEK"));
552 cal_multiget_out(m, FIXME, one_item, ReportOut, &crp);
556 syslog(LOG_DEBUG, "Message %ld \033[31mDOES NOT QUALIFY\033[0m", m);
558 // syslog(LOG_DEBUG, "");
560 icalcomponent_free(cal);
561 FreeStrBuf(&one_item);
568 // RFC4791 7.9 "calendar-multiget" REPORT - go get the specific Hrefs the client asked for.
569 // Can we move this back into citserver too?
570 else if ( (crp.report_type == cr_calendar_multiget) && (crp.Hrefs != NULL) ) {
572 StrBuf *ThisHref = NewStrBuf();
573 const char *pvset = NULL;
574 while (StrBufExtract_NextToken(ThisHref, crp.Hrefs, &pvset, '|') >= 0) {
575 StrBufTrim(ThisHref); // remove leading/trailing whitespace from the href
576 caldav_report_one_item(h, c, ReportOut, ThisHref, &crp);
578 FreeStrBuf(&ThisHref);
581 // RFC4791 7.10 "free-busy-query" REPORT
582 else if (crp.report_type == cr_freebusy_query) {
583 // FIXME build this REPORT. At the moment we send an empty multistatus.
586 // Free any query parameters that might have been allocated during the xml parse
587 if (crp.Hrefs != NULL) {
588 FreeStrBuf(&crp.Hrefs);
592 array_free(crp.filters);
596 StrBufAppendPrintf(ReportOut, "</D:multistatus>\n"); // End the REPORT.
598 add_response_header(h, strdup("Content-type"), strdup("text/xml"));
599 h->response_code = 207;
600 h->response_string = strdup("Multi-Status");
601 h->response_body_length = StrLength(ReportOut);
602 h->response_body = SmashStrBuf(&ReportOut);