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 CAL "urn:ietf:params:xml:ns:caldav:" // Shorthand for the XML namespace of CalDAV
8 #define CALLEN sizeof(CAL)-1 // And the length of that string
10 // A CalDAV REPORT can only be one type. This is stored in the report_type member.
18 // Data type for CalDAV Report Parameters.
19 // As we slog our way through the XML we learn what the client is asking for
20 // and build up the contents of this data type.
22 int tag_nesting_level; // not needed, just kept for pretty-printing
23 enum cr_type report_type; // which RFC4791 section 7 REPORT are we generating
24 StrBuf *Chardata; // XML chardata in between tags is built up here
25 StrBuf *Hrefs; // list of items requested by a `calendar-multiget` REPORT
26 Array *filters; // If the query contains a FILTER stanza, the filter criteria are populated here
27 int filter_nest; // tag nesting level where a FILTER stanza begins
31 // XML parser callback
32 void caldav_xml_start(void *data, const char *el, const char **attr) {
33 struct cr_params *crp = (struct cr_params *) data;
35 #ifdef DEBUG_XML_PARSE
40 for (i=0; i<crp->tag_nesting_level; ++i) {
43 syslog(LOG_DEBUG, "%s<%s>", indent, el);
45 ++crp->tag_nesting_level;
46 #ifdef DEBUG_XML_PARSE
48 for (i=0; i<crp->tag_nesting_level; ++i) {
51 for (i = 0; attr[i] != NULL; i += 2) {
52 syslog(LOG_DEBUG, "%sAttribute '%s' = '%s'", indent, attr[i], attr[i + 1]);
57 // RFC4791 7.8 "calendar-query" REPORT - Client will send a lot of search criteria.
58 if (!strcasecmp(el, CAL"calendar-query")) {
59 crp->report_type = cr_calendar_query;
62 // RFC4791 7.9 "calendar-multiget" REPORT - Client will supply a list of specific hrefs.
63 else if (!strcasecmp(el, CAL"calendar-multiget")) {
64 crp->report_type = cr_calendar_multiget;
67 // RFC4791 7.10 "free-busy-query" REPORT
68 else if (!strcasecmp(el, CAL"free-busy-query")) {
69 crp->report_type = cr_freebusy_query;
72 // RFC4791 9.7 create a filter array if this query contains a "filter" stanza
73 else if (!strcasecmp(el, CAL"filter")) {
74 crp->filters = array_new(SIZ);
75 crp->filter_nest = crp->tag_nesting_level;
78 // Handle the filters defined in RFC4791 9.7.1 through 9.7.5
79 else if ( ( (!strcasecmp(el, CAL"comp-filter"))
80 || (!strcasecmp(el, CAL"prop-filter"))
81 || (!strcasecmp(el, CAL"param-filter"))
82 || (!strcasecmp(el, CAL"is-not-defined"))
83 || (!strcasecmp(el, CAL"text-match"))
85 && (crp->filters) // Make sure we actually allocated an array
90 int len = snprintf(newfilter, SIZ, "%d|", crp->tag_nesting_level - crp->filter_nest - 1);
91 len += snprintf(&newfilter[len], SIZ-len, "%s", &el[CALLEN]); // filter name without the namespace
93 len += snprintf(&newfilter[len], SIZ-len, "|%s", attr[a++]); // now save the attributes
95 array_append(crp->filters, newfilter);
101 // XML parser callback
102 void caldav_xml_end(void *data, const char *el) {
103 struct cr_params *crp = (struct cr_params *) data;
105 --crp->tag_nesting_level;
107 #ifdef DEBUG_XML_PARSE
112 for (i=0; i<crp->tag_nesting_level; ++i) {
115 syslog(LOG_DEBUG, "%s</%s>", indent, el);
119 if ((!strcasecmp(el, "DAV::href")) || (!strcasecmp(el, "DAV:href"))) {
120 if (crp->Hrefs == NULL) { // append crp->Chardata to crp->Hrefs
121 crp->Hrefs = NewStrBuf();
124 StrBufAppendBufPlain(crp->Hrefs, HKEY("|"), 0);
126 StrBufAppendBuf(crp->Hrefs, crp->Chardata, 0);
129 if (crp->Chardata != NULL) { // Tag is closed; chardata is now out of scope.
130 FreeStrBuf(&crp->Chardata); // Free the buffer.
131 crp->Chardata = NULL;
136 // XML parser callback
137 void caldav_xml_chardata(void *data, const XML_Char *s, int len) {
138 struct cr_params *crp = (struct cr_params *) data;
140 char *app = malloc(len+1);
147 if (crp->Chardata == NULL) {
148 crp->Chardata = NewStrBuf();
151 StrBufAppendBufPlain(crp->Chardata, app, len, 0);
153 #ifdef DEBUG_XML_PARSE
155 string_trim(app); // remove leading/trailing whitespace. ok to mangle it because we've already appended.
156 if (!IsEmptyStr(app)) {
160 for (i=0; i<crp->tag_nesting_level; ++i) {
163 syslog(LOG_DEBUG, "%s%s", indent, app, len);
173 // Called by caldav_report_one_item() to fetch a message (by number) in the current room,
174 // and return only the icalendar data as a StrBuf. Returns NULL if not found.
176 // NOTE: this function expects that "MSGP text/calendar" was issued at the beginning
177 // of a REPORT operation to set our preferred MIME type to calendar data.
178 StrBuf *fetch_ical(struct ctdlsession *c, long msgnum) {
182 ctdl_printf(c, "MSG4 %ld", msgnum);
183 ctdl_readline(c, buf, sizeof(buf));
188 while (ctdl_readline(c, buf, sizeof(buf)), strcmp(buf, "000")) {
189 if (Buf != NULL) { // already in body
190 StrBufAppendPrintf(Buf, "%s\n", buf);
192 else if (IsEmptyStr(buf)) { // beginning of body
201 // Called by multiple REPORT types to actually perform the output in "multiget" format.
202 // We need to already know the source message number and the href, but also already have the output data.
203 void cal_multiget_out(long msgnum, StrBuf *ThisHref, StrBuf *Caldata, StrBuf *ReportOut) {
205 StrBufAppendPrintf(ReportOut, "<D:response>");
206 StrBufAppendPrintf(ReportOut, "<D:href>");
207 StrBufXMLEscAppend(ReportOut, ThisHref, NULL, 0, 0);
208 StrBufAppendPrintf(ReportOut, "</D:href>");
209 StrBufAppendPrintf(ReportOut, "<D:propstat>");
211 if (Caldata != NULL) {
212 // syslog(LOG_DEBUG, "caldav_report_one_item(%s) 200 OK", ChrPtr(ThisHref));
213 StrBufAppendPrintf(ReportOut, "<D:status>");
214 StrBufAppendPrintf(ReportOut, "HTTP/1.1 200 OK");
215 StrBufAppendPrintf(ReportOut, "</D:status>");
216 StrBufAppendPrintf(ReportOut, "<D:prop>");
217 StrBufAppendPrintf(ReportOut, "<D:getetag>");
218 StrBufAppendPrintf(ReportOut, "%ld", msgnum);
219 StrBufAppendPrintf(ReportOut, "</D:getetag>");
220 StrBufAppendPrintf(ReportOut, "<C:calendar-data>");
221 StrBufXMLEscAppend(ReportOut, Caldata, NULL, 0, 0);
222 StrBufAppendPrintf(ReportOut, "</C:calendar-data>");
223 StrBufAppendPrintf(ReportOut, "</D:prop>");
226 // syslog(LOG_DEBUG, "caldav_report_one_item(%s) 404 not found", ChrPtr(ThisHref));
227 StrBufAppendPrintf(ReportOut, "<D:status>");
228 StrBufAppendPrintf(ReportOut, "HTTP/1.1 404 not found");
229 StrBufAppendPrintf(ReportOut, "</D:status>");
232 StrBufAppendPrintf(ReportOut, "</D:propstat>");
233 StrBufAppendPrintf(ReportOut, "</D:response>");
237 // Called by caldav_report() to output a single item.
238 // Our policy is to throw away the list of properties the client asked for, and just send everything.
239 void caldav_report_one_item(struct http_transaction *h, struct ctdlsession *c, StrBuf *ReportOut, StrBuf *ThisHref) {
241 StrBuf *Caldata = NULL;
244 euid = strrchr(ChrPtr(ThisHref), '/');
249 euid = (char *) ChrPtr(ThisHref);
252 char *unescaped_euid = strdup(euid);
253 if (!unescaped_euid) {
256 unescape_input(unescaped_euid);
258 msgnum = locate_message_by_uid(c, unescaped_euid);
259 free(unescaped_euid);
261 Caldata = fetch_ical(c, msgnum);
267 cal_multiget_out(msgnum, ThisHref, Caldata, ReportOut);
269 if (Caldata != NULL) {
270 FreeStrBuf(&Caldata);
275 // Recursive function to apply CalDAV FILTERS to a calendar item.
276 // Returns zero if the calendar item was disqualified by a filter, nonzero if the calendar item still qualifies.
277 int caldav_apply_filters(void *cal, Array *filters, int start_at_level) {
279 int f = 0; // filter number iterator
280 int qual = 1; // 0 for disqualify, 1 for qualify
281 int previous_level = -1;
283 while ( (f<array_len(filters)) && (qual) ) {
285 // Tokenize the filter (a future performance hack would be to pre-tokenize instead of storing delimited strings)
286 char this_filter[SIZ];
287 safestrncpy(this_filter, array_get_element_at(filters, f), sizeof(this_filter));
288 char *t[10] = { NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL } ;
289 char *ft = this_filter;
291 while ( (t[num_tokens]=strtok_r(ft, "|", &ft)) && (num_tokens<10) ) {
294 int level = atoi(t[0]);
295 syslog(LOG_DEBUG, "caldav_apply_filters() filter=%d, level=%d, <%s>", f, level, array_get_element_at(filters, f) );
297 // Handle the individual filters defined in RFC4791 9.7.1 through 9.7.5
299 if (level < previous_level) {
300 syslog(LOG_DEBUG, "caldav: walking back down");
304 else if (level < start_at_level) {
305 syslog(LOG_DEBUG, "caldav: start_at_level=%d, level=%d, skipping this rule", start_at_level, level);
308 else if (!strcasecmp(t[1], "comp-filter")) { // RFC4791 9.7.1 - filter by component
309 syslog(LOG_DEBUG, "component filter at level %d", level);
311 // Root element is NOT a component, but the root filter is "comp-filter" -- reject!
312 if ( (!icalcomponent_isa_component(cal)) && (level == 0) ) {
313 syslog(LOG_DEBUG, "caldav: root element is not a component, rejecting");
317 // Current element is a component and the filter is "comp-filter" -- see if it matches the requested type
318 if ( (icalcomponent_isa_component(cal))
320 && (!strcasecmp(t[2], "name"))
322 if (icalcomponent_isa(cal) == icalcomponent_string_to_kind(t[3]) ) {
323 syslog(LOG_DEBUG, "caldav: component at level %d is <%s>, looking for <%s>, recursing...",
325 icalcomponent_kind_to_string(icalcomponent_isa(cal)), t[3]
328 // We have a match. Drill down into the subcomponents.
330 icalcomponent *c = NULL;
331 int number_of_subcomponents = 0;
332 int number_of_matches = 0;
333 for ( c = icalcomponent_get_first_component(cal, ICAL_ANY_COMPONENT);
335 c = icalcomponent_get_next_component(cal, ICAL_ANY_COMPONENT)
337 ++number_of_subcomponents;
338 if (caldav_apply_filters(c, filters, level+1)) {
339 syslog(LOG_DEBUG, "Subcomponent %d might match", number_of_subcomponents);
343 if (number_of_matches > 0) { // something matched
346 else if (number_of_subcomponents > 0) { // nothing matched
347 return(0); // but only fail if there *were* subcomponents.
352 syslog(LOG_DEBUG, "caldav: component at level %d is <%s>, looking for <%s>, rejecting",
354 icalcomponent_kind_to_string(icalcomponent_isa(cal)),
363 else if (!strcasecmp(t[1], "prop-filter")) { // RFC4791 9.7.2 - filter by property
364 syslog(LOG_DEBUG, "property filter FIXME not implemented yet");
367 else if (!strcasecmp(t[1], "param-filter")) { // RFC4791 9.7.3 - filter by parameter
368 syslog(LOG_DEBUG, "parameter filter FIXME not implemented yet");
371 else if (!strcasecmp(t[1], "is-not-defined")) { // RFC4791 9.7.4
372 syslog(LOG_DEBUG, "is-not-defined filter FIXME not implemented yet");
375 else if (!strcasecmp(t[1], "text-match")) { // RFC4791 9.7.5
376 syslog(LOG_DEBUG, "text match filter FIXME not implemented yet");
382 syslog(LOG_DEBUG, "caldav: we reached the end of level %d , returning %d", start_at_level, qual);
387 // Called by report_the_room_itself() in room_functions.c when a CalDAV REPORT method
388 // is requested on a calendar room. We fire up an XML Parser to decode the request and
389 // hopefully produce the correct output.
390 void caldav_report(struct http_transaction *h, struct ctdlsession *c) {
391 struct cr_params crp;
394 memset(&crp, 0, sizeof(struct cr_params));
396 XML_Parser xp = XML_ParserCreateNS("UTF-8", ':');
398 syslog(LOG_INFO, "Cannot create XML parser!");
403 XML_SetElementHandler(xp, caldav_xml_start, caldav_xml_end);
404 XML_SetCharacterDataHandler(xp, caldav_xml_chardata);
405 XML_SetUserData(xp, &crp);
406 XML_SetDefaultHandler(xp, NULL); // Disable internal entity expansion to prevent "billion laughs attack"
407 XML_Parse(xp, h->request_body, h->request_body_length, 1);
410 if (crp.Chardata != NULL) { // Discard any trailing chardata ... normally nothing here
411 FreeStrBuf(&crp.Chardata);
415 // We're going to make a lot of MSG4 calls, and the preferred MIME type we want is "text/calendar".
416 // The iCalendar standard is mature now, and we are no longer interested in text/x-vcal or application/ics.
417 ctdl_printf(c, "MSGP text/calendar");
418 ctdl_readline(c, buf, sizeof buf);
420 // Now begin the REPORT.
421 syslog(LOG_DEBUG, "CalDAV REPORT type is: %d", crp.report_type);
422 StrBuf *ReportOut = NewStrBuf();
423 StrBufAppendPrintf(ReportOut,
424 "<?xml version=\"1.0\" encoding=\"utf-8\"?>"
427 "xmlns:C=\"urn:ietf:params:xml:ns:caldav\""
431 // RFC4791 7.8 "calendar-query" REPORT - Client will send a lot of search criteria.
432 if (crp.report_type == cr_calendar_query) {
434 Array *msglist = get_msglist(c, "ALL");
435 if (msglist != NULL) {
436 for (i = 0; i < array_len(msglist); ++i) {
438 memcpy(&m, array_get_element_at(msglist, i), sizeof(long));
440 // load and parse one calendar item
441 StrBuf *one_item = fetch_ical(c, m);
442 icalcomponent *cal = icalcomponent_new_from_string(ChrPtr(one_item));
444 // Does this calendar item qualify for output?
447 // If there was a filter stanza, run this calendar item through the filters.
448 syslog(LOG_DEBUG, "Evaluating message \033[33m%ld\033[0m...", m);
449 qualify = caldav_apply_filters(cal, crp.filters, 0);
450 syslog(LOG_DEBUG, "Message %ld %s\033[0m qualify", m, (qualify ? "\033[32mDOES" : "\033[31mDOES NOT"));
451 syslog(LOG_DEBUG, "");
453 // Did this calendar item match the query? If so, output it.
455 // FIXME need to populate the Href instead of NULL
456 cal_multiget_out(m, NULL, one_item, ReportOut);
459 icalcomponent_free(cal);
460 FreeStrBuf(&one_item);
467 // RFC4791 7.9 "calendar-multiget" REPORT - go get the specific Hrefs the client asked for.
468 // Can we move this back into citserver too?
469 else if ( (crp.report_type == cr_calendar_multiget) && (crp.Hrefs != NULL) ) {
471 StrBuf *ThisHref = NewStrBuf();
472 const char *pvset = NULL;
473 while (StrBufExtract_NextToken(ThisHref, crp.Hrefs, &pvset, '|') >= 0) {
474 StrBufTrim(ThisHref); // remove leading/trailing whitespace from the href
475 caldav_report_one_item(h, c, ReportOut, ThisHref);
477 FreeStrBuf(&ThisHref);
480 // RFC4791 7.10 "free-busy-query" REPORT
481 else if (crp.report_type == cr_freebusy_query) {
482 // FIXME build this REPORT. At the moment we send an empty multistatus.
485 // Free any query parameters that might have been allocated during the xml parse
486 if (crp.Hrefs != NULL) {
487 FreeStrBuf(&crp.Hrefs);
491 array_free(crp.filters);
495 StrBufAppendPrintf(ReportOut, "</D:multistatus>\n"); // End the REPORT.
497 add_response_header(h, strdup("Content-type"), strdup("text/xml"));
498 h->response_code = 207;
499 h->response_string = strdup("Multi-Status");
500 h->response_body_length = StrLength(ReportOut);
501 h->response_body = SmashStrBuf(&ReportOut);