webcit-ng/room_functions.c

   1 //
   2 // Room functions
   3 //
   4 // Copyright (c) 1996-2021 by the citadel.org team
   5 //
   6 // This program is open source software.  It runs great on the
   7 // Linux operating system (and probably elsewhere).  You can use,
   8 // copy, and run it under the terms of the GNU General Public
   9 // License version 3.
  10 //
  11 // This program is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 #include "webcit.h"
  17
  18
  19 // Return a "zero-terminated" array of message numbers in the current room.
  20 // Caller owns the memory and must free it.  Returns NULL if any problems.
  21 long *get_msglist(struct ctdlsession *c, char *which_msgs) {
  22         char buf[1024];
  23         long *msglist = NULL;
  24         int num_msgs = 0;
  25         int num_alloc = 0;
  26
  27         ctdl_printf(c, "MSGS %s", which_msgs);
  28         ctdl_readline(c, buf, sizeof(buf));
  29         if (buf[0] == '1') {
  30                 do {
  31                         if (num_msgs >= num_alloc) {
  32                                 if (num_alloc == 0) {
  33                                         num_alloc = 1024;
  34                                         msglist = malloc(num_alloc * sizeof(long));
  35                                 } else {
  36                                         num_alloc *= 2;
  37                                         msglist = realloc(msglist, num_alloc * sizeof(long));
  38                                 }
  39                         }
  40                         ctdl_readline(c, buf, sizeof(buf));
  41                         msglist[num_msgs++] = atol(buf);
  42                 } while (strcmp(buf, "000"));   // this makes the last element a "0" terminator
  43         }
  44         return msglist;
  45 }
  46
  47
  48 // Supplied with a list of potential matches from an If-Match: or If-None-Match: header, and
  49 // a message number (which we always use as the entity tag in Citadel), return nonzero if the
  50 // message number matches any of the supplied tags in the string.
  51 int match_etags(char *taglist, long msgnum) {
  52         int num_tags = num_tokens(taglist, ',');
  53         int i = 0;
  54         char tag[1024];
  55
  56         if (msgnum <= 0) {                                      // no msgnum?  no match.
  57                 return (0);
  58         }
  59
  60         for (i = 0; i < num_tags; ++i) {
  61                 extract_token(tag, taglist, i, ',', sizeof tag);
  62                 striplt(tag);
  63                 char *lq = (strchr(tag, '"'));
  64                 char *rq = (strrchr(tag, '"'));
  65                 if (lq < rq) {                                  // has two double quotes
  66                         strcpy(rq, "");
  67                         strcpy(tag, ++lq);
  68                 }
  69                 striplt(tag);
  70                 if (!strcmp(tag, "*")) {                        // wildcard match
  71                         return (1);
  72                 }
  73                 long tagmsgnum = atol(tag);
  74                 if ((tagmsgnum > 0) && (tagmsgnum == msgnum)) { // match
  75                         return (1);
  76                 }
  77         }
  78
  79         return (0);                                             // no match
  80 }
  81
  82
  83 // Client is requesting a message list
  84 void json_msglist(struct http_transaction *h, struct ctdlsession *c, char *which) {
  85         int i = 0;
  86         long *msglist = get_msglist(c, which);
  87         JsonValue *j = NewJsonArray(HKEY("msgs"));
  88
  89         if (msglist != NULL) {
  90                 for (i = 0; msglist[i] > 0; ++i) {
  91                         JsonArrayAppend(j, NewJsonNumber(HKEY("m"), msglist[i]));
  92                 }
  93                 free(msglist);
  94         }
  95
  96         StrBuf *sj = NewStrBuf();
  97         SerializeJson(sj, j, 1);        // '1' == free the source array
  98
  99         add_response_header(h, strdup("Content-type"), strdup("application/json"));
 100         h->response_code = 200;
 101         h->response_string = strdup("OK");
 102         h->response_body_length = StrLength(sj);
 103         h->response_body = SmashStrBuf(&sj);
 104         return;
 105 }
 106
 107
 108 // Client requested an object in a room.
 109 void object_in_room(struct http_transaction *h, struct ctdlsession *c) {
 110         char buf[1024];
 111         long msgnum = (-1);
 112         char unescaped_euid[1024];
 113
 114         extract_token(buf, h->uri, 4, '/', sizeof buf);
 115
 116         if (!strncasecmp(buf, "msgs.", 5)) {    // Client is requesting a list of message numbers
 117                 unescape_input(&buf[5]);
 118                 json_msglist(h, c, &buf[5]);
 119                 return;
 120         }
 121 #if 0
 122         if (!strncasecmp(buf, "threads", 5)) {  // Client is requesting a threaded view (still kind of fuzzy here)
 123                 threaded_view(h, c, &buf[5]);
 124                 return;
 125         }
 126
 127         if (!strncasecmp(buf, "flat", 5)) {     // Client is requesting a flat view (still kind of fuzzy here)
 128                 flat_view(h, c, &buf[5]);
 129                 return;
 130         }
 131 #endif
 132
 133         if ((c->room_default_view == VIEW_CALENDAR)     // room types where objects are referenced by EUID
 134             || (c->room_default_view == VIEW_TASKS)
 135             || (c->room_default_view == VIEW_ADDRESSBOOK)
 136             ) {
 137                 safestrncpy(unescaped_euid, buf, sizeof unescaped_euid);
 138                 unescape_input(unescaped_euid);
 139                 msgnum = locate_message_by_uid(c, unescaped_euid);
 140         }
 141         else {
 142                 msgnum = atol(buf);
 143         }
 144
 145         // All methods except PUT require the message to already exist
 146         if ((msgnum <= 0) && (strcasecmp(h->method, "PUT"))) {
 147                 do_404(h);
 148         }
 149
 150         // If we get to this point we have a valid message number in an accessible room.
 151         syslog(LOG_DEBUG, "msgnum is %ld, method is %s", msgnum, h->method);
 152
 153         // A sixth component in the URL can be one of two things:
 154         // (1) a MIME part specifier, in which case the client wants to download that component within the message
 155         // (2) a content-type, in which ase the client wants us to try to render it a certain way
 156         if (num_tokens(h->uri, '/') == 6) {
 157                 extract_token(buf, h->uri, 5, '/', sizeof buf);
 158                 if (!IsEmptyStr(buf)) {
 159                         if (!strcasecmp(buf, "json")) {
 160                                 json_render_one_message(h, c, msgnum);
 161                         } else {
 162                                 download_mime_component(h, c, msgnum, buf);
 163                         }
 164                         return;
 165                 }
 166         }
 167
 168         // Ok, we want a full message, but first let's check for the if[-none]-match headers.
 169         char *if_match = header_val(h, "If-Match");
 170         if ((if_match != NULL) && (!match_etags(if_match, msgnum))) {
 171                 do_412(h);
 172                 return;
 173         }
 174
 175         char *if_none_match = header_val(h, "If-None-Match");
 176         if ((if_none_match != NULL) && (match_etags(if_none_match, msgnum))) {
 177                 do_412(h);
 178                 return;
 179         }
 180
 181         // DOOOOOO ITTTTT!!!
 182
 183         if (!strcasecmp(h->method, "DELETE")) {
 184                 dav_delete_message(h, c, msgnum);
 185         }
 186         else if (!strcasecmp(h->method, "GET")) {
 187                 dav_get_message(h, c, msgnum);
 188         }
 189         else if (!strcasecmp(h->method, "PUT")) {
 190                 dav_put_message(h, c, unescaped_euid, msgnum);
 191         }
 192         else {
 193                 do_404(h);      // Got this far but the method made no sense?  Bummer.
 194         }
 195
 196 }
 197
 198
 199 // Called by the_room_itself() when the HTTP method is REPORT
 200 void report_the_room_itself(struct http_transaction *h, struct ctdlsession *c) {
 201         if (c->room_default_view == VIEW_CALENDAR) {
 202                 caldav_report(h, c);    // CalDAV REPORTs ... fmgwac
 203                 return;
 204         }
 205
 206         do_404(h);              // future implementations like CardDAV will require code paths here
 207 }
 208
 209
 210 // Called by the_room_itself() when the HTTP method is OPTIONS
 211 void options_the_room_itself(struct http_transaction *h, struct ctdlsession *c) {
 212         h->response_code = 200;
 213         h->response_string = strdup("OK");
 214         if (c->room_default_view == VIEW_CALENDAR) {
 215                 add_response_header(h, strdup("DAV"), strdup("1, calendar-access"));    // offer CalDAV
 216         }
 217         else if (c->room_default_view == VIEW_ADDRESSBOOK) {
 218                 add_response_header(h, strdup("DAV"), strdup("1, addressbook"));        // offer CardDAV
 219         }
 220         else {
 221                 add_response_header(h, strdup("DAV"), strdup("1"));     // ordinary WebDAV for all other room types
 222         }
 223         add_response_header(h, strdup("Allow"), strdup("OPTIONS, PROPFIND, GET, PUT, REPORT, DELETE"));
 224 }
 225
 226
 227 // Called by the_room_itself() when the HTTP method is PROPFIND
 228 void propfind_the_room_itself(struct http_transaction *h, struct ctdlsession *c) {
 229         char *e;
 230         long timestamp;
 231         int dav_depth = (header_val(h, "Depth") ? atoi(header_val(h, "Depth")) : INT_MAX);
 232         syslog(LOG_DEBUG, "Client PROPFIND requested depth: %d", dav_depth);
 233         StrBuf *Buf = NewStrBuf();
 234
 235         StrBufAppendPrintf(Buf, "<?xml version=\"1.0\" encoding=\"utf-8\"?>"
 236                            "<D:multistatus " "xmlns:D=\"DAV:\" " "xmlns:C=\"urn:ietf:params:xml:ns:caldav\"" ">");
 237
 238         // Transmit the collection resource
 239         StrBufAppendPrintf(Buf, "<D:response>");
 240         StrBufAppendPrintf(Buf, "<D:href>");
 241         StrBufXMLEscAppend(Buf, NULL, h->site_prefix, strlen(h->site_prefix), 0);
 242         StrBufAppendPrintf(Buf, "/ctdl/r/");
 243         StrBufXMLEscAppend(Buf, NULL, c->room, strlen(c->room), 0);
 244         StrBufAppendPrintf(Buf, "</D:href>");
 245
 246         StrBufAppendPrintf(Buf, "<D:propstat>");
 247         StrBufAppendPrintf(Buf, "<D:status>HTTP/1.1 200 OK</D:status>");
 248         StrBufAppendPrintf(Buf, "<D:prop>");
 249         StrBufAppendPrintf(Buf, "<D:displayname>");
 250         StrBufXMLEscAppend(Buf, NULL, c->room, strlen(c->room), 0);
 251         StrBufAppendPrintf(Buf, "</D:displayname>");
 252
 253         StrBufAppendPrintf(Buf, "<D:owner />"); // empty owner ought to be legal; see rfc3744 section 5.1
 254
 255         StrBufAppendPrintf(Buf, "<D:resourcetype><D:collection />");
 256         switch (c->room_default_view) {
 257         case VIEW_CALENDAR:
 258                 StrBufAppendPrintf(Buf, "<C:calendar />");      // RFC4791 section 4.2
 259                 break;
 260         }
 261         StrBufAppendPrintf(Buf, "</D:resourcetype>");
 262
 263         int enumerate_by_euid = 0;      // nonzero if messages will be retrieved by euid instead of msgnum
 264         switch (c->room_default_view) {
 265         case VIEW_CALENDAR:             // RFC4791 section 5.2
 266                 StrBufAppendPrintf(Buf, "<C:supported-calendar-component-set><C:comp name=\"VEVENT\"/></C:supported-calendar-component-set>");
 267                 StrBufAppendPrintf(Buf, "<C:supported-calendar-data>");
 268                 StrBufAppendPrintf(Buf, "<C:calendar-data content-type=\"text/calendar\" version=\"2.0\"/>");
 269                 StrBufAppendPrintf(Buf, "</C:supported-calendar-data>");
 270                 enumerate_by_euid = 1;
 271                 break;
 272         case VIEW_TASKS:                // RFC4791 section 5.2
 273                 StrBufAppendPrintf(Buf, "<C:supported-calendar-component-set><C:comp name=\"VTODO\"/></C:supported-calendar-component-set>");
 274                 StrBufAppendPrintf(Buf, "<C:supported-calendar-data>");
 275                 StrBufAppendPrintf(Buf, "<C:calendar-data content-type=\"text/calendar\" version=\"2.0\"/>");
 276                 StrBufAppendPrintf(Buf, "</C:supported-calendar-data>");
 277                 enumerate_by_euid = 1;
 278                 break;
 279         case VIEW_ADDRESSBOOK:          // FIXME put some sort of CardDAV crapola here when we implement it
 280                 enumerate_by_euid = 1;
 281                 break;
 282         case VIEW_WIKI:                 // FIXME invent "WikiDAV" ?
 283                 enumerate_by_euid = 1;
 284                 break;
 285         }
 286
 287         // FIXME get the mtime
 288         // StrBufAppendPrintf(Buf, "<D:getlastmodified>");
 289         // escputs(datestring);
 290         // StrBufAppendPrintf(Buf, "</D:getlastmodified>");
 291
 292         StrBufAppendPrintf(Buf, "</D:prop>");
 293         StrBufAppendPrintf(Buf, "</D:propstat>");
 294         StrBufAppendPrintf(Buf, "</D:response>\n");
 295
 296         // If a depth greater than zero was specified, transmit the collection listing
 297         // BEGIN COLLECTION
 298         if (dav_depth > 0) {
 299                 long *msglist = get_msglist(c, "ALL");
 300                 if (msglist) {
 301                         int i;
 302                         for (i = 0; (msglist[i] > 0); ++i) {
 303                                 if ((i % 10) == 0)
 304                                         syslog(LOG_DEBUG, "PROPFIND enumerated %d messages", i);
 305                                 e = NULL;       // EUID gets stored here
 306                                 timestamp = 0;
 307
 308                                 char cbuf[1024];
 309                                 ctdl_printf(c, "MSG0 %ld|3", msglist[i]);
 310                                 ctdl_readline(c, cbuf, sizeof(cbuf));
 311                                 if (cbuf[0] == '1')
 312                                         while (ctdl_readline(c, cbuf, sizeof(cbuf)), strcmp(cbuf, "000")) {
 313                                                 if ((enumerate_by_euid) && (!strncasecmp(cbuf, "exti=", 5))) {
 314                                                         // e = strdup(&cbuf[5]);
 315                                                         int elen = (2 * strlen(&cbuf[5]));
 316                                                         e = malloc(elen);
 317                                                         urlesc(e, elen, &cbuf[5]);
 318                                                 }
 319                                                 if (!strncasecmp(cbuf, "time=", 5)) {
 320                                                         timestamp = atol(&cbuf[5]);
 321                                                 }
 322                                         }
 323                                 if (e == NULL) {
 324                                         e = malloc(20);
 325                                         sprintf(e, "%ld", msglist[i]);
 326                                 }
 327                                 StrBufAppendPrintf(Buf, "<D:response>");
 328
 329                                 // Generate the 'href' tag for this message
 330                                 StrBufAppendPrintf(Buf, "<D:href>");
 331                                 StrBufXMLEscAppend(Buf, NULL, h->site_prefix, strlen(h->site_prefix), 0);
 332                                 StrBufAppendPrintf(Buf, "/ctdl/r/");
 333                                 StrBufXMLEscAppend(Buf, NULL, c->room, strlen(c->room), 0);
 334                                 StrBufAppendPrintf(Buf, "/");
 335                                 StrBufXMLEscAppend(Buf, NULL, e, strlen(e), 0);
 336                                 StrBufAppendPrintf(Buf, "</D:href>");
 337                                 StrBufAppendPrintf(Buf, "<D:propstat>");
 338                                 StrBufAppendPrintf(Buf, "<D:status>HTTP/1.1 200 OK</D:status>");
 339                                 StrBufAppendPrintf(Buf, "<D:prop>");
 340
 341                                 switch (c->room_default_view) {
 342                                 case VIEW_CALENDAR:
 343                                         StrBufAppendPrintf(Buf,
 344                                                            "<D:getcontenttype>text/calendar; component=vevent</D:getcontenttype>");
 345                                         break;
 346                                 case VIEW_TASKS:
 347                                         StrBufAppendPrintf(Buf,
 348                                                            "<D:getcontenttype>text/calendar; component=vtodo</D:getcontenttype>");
 349                                         break;
 350                                 case VIEW_ADDRESSBOOK:
 351                                         StrBufAppendPrintf(Buf, "<D:getcontenttype>text/x-vcard</D:getcontenttype>");
 352                                         break;
 353                                 }
 354
 355                                 if (timestamp > 0) {
 356                                         char *datestring = http_datestring(timestamp);
 357                                         if (datestring) {
 358                                                 StrBufAppendPrintf(Buf, "<D:getlastmodified>");
 359                                                 StrBufXMLEscAppend(Buf, NULL, datestring, strlen(datestring), 0);
 360                                                 StrBufAppendPrintf(Buf, "</D:getlastmodified>");
 361                                                 free(datestring);
 362                                         }
 363                                         if (enumerate_by_euid)  // FIXME ajc 2017oct30 should this be inside the timestamp conditional?
 364                                         {
 365                                                 StrBufAppendPrintf(Buf, "<D:getetag>\"%ld\"</D:getetag>", msglist[i]);
 366                                         }
 367                                 }
 368                                 StrBufAppendPrintf(Buf, "</D:prop></D:propstat></D:response>\n");
 369                                 free(e);
 370                         }
 371                         free(msglist);
 372                 };
 373         }
 374         // END COLLECTION
 375
 376         StrBufAppendPrintf(Buf, "</D:multistatus>\n");
 377
 378         add_response_header(h, strdup("Content-type"), strdup("text/xml"));
 379         h->response_code = 207;
 380         h->response_string = strdup("Multi-Status");
 381         h->response_body_length = StrLength(Buf);
 382         h->response_body = SmashStrBuf(&Buf);
 383 }
 384
 385 // some good examples here
 386 // http://blogs.nologin.es/rickyepoderi/index.php?/archives/14-Introducing-CalDAV-Part-I.html
 387
 388
 389 // Called by the_room_itself() when the HTTP method is PROPFIND
 390 void get_the_room_itself(struct http_transaction *h, struct ctdlsession *c) {
 391         JsonValue *j = NewJsonObject(HKEY("gotoroom"));
 392
 393         JsonObjectAppend(j, NewJsonPlainString(HKEY("name"), c->room, -1));
 394         JsonObjectAppend(j, NewJsonNumber(HKEY("current_view"), c->room_current_view));
 395         JsonObjectAppend(j, NewJsonNumber(HKEY("default_view"), c->room_default_view));
 396         JsonObjectAppend(j, NewJsonNumber(HKEY("new_messages"), c->new_messages));
 397         JsonObjectAppend(j, NewJsonNumber(HKEY("total_messages"), c->total_messages));
 398         JsonObjectAppend(j, NewJsonNumber(HKEY("last_seen"), c->last_seen));
 399
 400         StrBuf *sj = NewStrBuf();
 401         SerializeJson(sj, j, 1);        // '1' == free the source array
 402
 403         add_response_header(h, strdup("Content-type"), strdup("application/json"));
 404         h->response_code = 200;
 405         h->response_string = strdup("OK");
 406         h->response_body_length = StrLength(sj);
 407         h->response_body = SmashStrBuf(&sj);
 408         return;
 409 }
 410
 411
 412 // Handle REST/DAV requests for the room itself (such as /ctdl/r/roomname
 413 // or /ctdl/r/roomname/ but *not* specific objects within the room)
 414 void the_room_itself(struct http_transaction *h, struct ctdlsession *c) {
 415
 416         // OPTIONS method on the room itself usually is a DAV client assessing what's here.
 417         if (!strcasecmp(h->method, "OPTIONS")) {
 418                 options_the_room_itself(h, c);
 419                 return;
 420         }
 421
 422         // PROPFIND method on the room itself could be looking for a directory
 423         if (!strcasecmp(h->method, "PROPFIND")) {
 424                 propfind_the_room_itself(h, c);
 425                 return;
 426         }
 427
 428         // REPORT method on the room itself is probably the dreaded CalDAV tower-of-crapola
 429         if (!strcasecmp(h->method, "REPORT")) {
 430                 report_the_room_itself(h, c);
 431                 return;
 432         }
 433
 434         // GET method on the room itself is an API call, possibly from our JavaScript front end
 435         if (!strcasecmp(h->method, "get")) {
 436                 get_the_room_itself(h, c);
 437                 return;
 438         }
 439
 440         // we probably want a "go to this room" for interactive access
 441         do_404(h);
 442 }
 443
 444
 445 // Dispatcher for "/ctdl/r" and "/ctdl/r/" for the room list
 446 void room_list(struct http_transaction *h, struct ctdlsession *c) {
 447         char buf[1024];
 448         char roomname[1024];
 449
 450         ctdl_printf(c, "LKRA");
 451         ctdl_readline(c, buf, sizeof(buf));
 452         if (buf[0] != '1') {
 453                 do_502(h);
 454                 return;
 455         }
 456
 457         JsonValue *j = NewJsonArray(HKEY("lkra"));
 458         while (ctdl_readline(c, buf, sizeof(buf)), strcmp(buf, "000")) {
 459
 460                 // name|QRflags|QRfloor|QRorder|QRflags2|ra|current_view|default_view|mtime
 461                 JsonValue *jr = NewJsonObject(HKEY("room"));
 462
 463                 extract_token(roomname, buf, 0, '|', sizeof roomname);
 464                 JsonObjectAppend(jr, NewJsonPlainString(HKEY("name"), roomname, -1));
 465
 466                 int ra = extract_int(buf, 5);
 467                 JsonObjectAppend(jr, NewJsonBool(HKEY("known"), (ra & UA_KNOWN)));
 468                 JsonObjectAppend(jr, NewJsonBool(HKEY("hasnewmsgs"), (ra & UA_HASNEWMSGS)));
 469
 470                 int floor = extract_int(buf, 2);
 471                 JsonObjectAppend(jr, NewJsonNumber(HKEY("floor"), floor));
 472
 473                 int rorder = extract_int(buf, 3);
 474                 JsonObjectAppend(jr, NewJsonNumber(HKEY("rorder"), rorder));
 475
 476                 JsonArrayAppend(j, jr); // add the room to the array
 477         }
 478
 479         StrBuf *sj = NewStrBuf();
 480         SerializeJson(sj, j, 1);        // '1' == free the source array
 481
 482         add_response_header(h, strdup("Content-type"), strdup("application/json"));
 483         h->response_code = 200;
 484         h->response_string = strdup("OK");
 485         h->response_body_length = StrLength(sj);
 486         h->response_body = SmashStrBuf(&sj);
 487 }
 488
 489
 490 // Dispatcher for paths starting with /ctdl/r/
 491 void ctdl_r(struct http_transaction *h, struct ctdlsession *c) {
 492         char requested_roomname[128];
 493         char buf[1024];
 494
 495         // All room-related functions require being "in" the room specified.  Are we in that room already?
 496         extract_token(requested_roomname, h->uri, 3, '/', sizeof requested_roomname);
 497         unescape_input(requested_roomname);
 498
 499         if (IsEmptyStr(requested_roomname))     //      /ctdl/r/
 500         {
 501                 room_list(h, c);
 502                 return;
 503         }
 504         // If not, try to go there.
 505         if (strcasecmp(requested_roomname, c->room)) {
 506                 ctdl_printf(c, "GOTO %s", requested_roomname);
 507                 ctdl_readline(c, buf, sizeof(buf));
 508                 if (buf[0] == '2') {
 509                         // buf[3] will indicate whether any instant messages are waiting
 510                         extract_token(c->room, &buf[4], 0, '|', sizeof c->room);
 511                         c->new_messages = extract_int(&buf[4], 1);
 512                         c->total_messages = extract_int(&buf[4], 2);
 513                         //      3       (int)info                       Info flag: set to nonzero if the user needs to read this room's info file
 514                         //      4       (int)CCC->room.QRflags          Various flags associated with this room.
 515                         //      5       (long)CCC->room.QRhighest       The highest message number present in this room
 516                         c->last_seen = extract_long(&buf[4], 6);        // The highest message number the user has read in this room
 517                         //      7       (int)rmailflag                  Boolean flag: 1 if this is a Mail> room, 0 otherwise.
 518                         //      8       (int)raideflag                  Nonzero if user is either Aide or a Room Aide in this room
 519                         //      9       (int)newmailcount               The number of new Mail messages the user has
 520                         //      10      (int)CCC->room.QRfloor          The floor number this room resides on
 521                         c->room_current_view = extract_int(&buf[4], 11);
 522                         c->room_default_view = extract_int(&buf[4], 12);
 523                         //      13      (int)is_trash                   Boolean flag: 1 if this is the user's Trash folder, 0 otherwise.
 524                         //      14      (int)CCC->room.QRflags2         More flags associated with this room
 525                         //      15      (long)CCC->room.QRmtime         Timestamp of the last write activity in this room
 526                 } else {
 527                         do_404(h);
 528                         return;
 529                 }
 530         }
 531         // At this point our Citadel client session is "in" the specified room.
 532
 533         if (num_tokens(h->uri, '/') == 4)       //      /ctdl/r/roomname
 534         {
 535                 the_room_itself(h, c);
 536                 return;
 537         }
 538
 539         extract_token(buf, h->uri, 4, '/', sizeof buf);
 540         if (num_tokens(h->uri, '/') == 5) {
 541                 if (IsEmptyStr(buf)) {
 542                         the_room_itself(h, c);  //      /ctdl/r/roomname/       ( same as /ctdl/r/roomname )
 543                 } else {
 544                         object_in_room(h, c);   //      /ctdl/r/roomname/object
 545                 }
 546                 return;
 547         }
 548         if (num_tokens(h->uri, '/') == 6) {
 549                 object_in_room(h, c);   //      /ctdl/r/roomname/object/ or possibly /ctdl/r/roomname/object/component
 550                 return;
 551         }
 552         // If we get to this point, the client specified a valid room but requested an action we don't know how to perform.
 553         do_404(h);
 554 }