webcit-ng/room_functions.c

   1 // Room functions
   2 //
   3 // Copyright (c) 1996-2022 by the citadel.org team
   4 //
   5 // This program is open source software.  It runs great on the
   6 // Linux operating system (and probably elsewhere).  You can use,
   7 // copy, and run it under the terms of the GNU General Public
   8 // License version 3.
   9 //
  10 // This program is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14
  15 #include "webcit.h"
  16
  17
  18 // Return a "zero-terminated" array of message numbers in the current room.
  19 // Caller owns the memory and must free it.  Returns NULL if any problems.
  20 long *get_msglist(struct ctdlsession *c, char *which_msgs) {
  21         char buf[1024];
  22         long *msglist = NULL;
  23         int num_msgs = 0;
  24         int num_alloc = 0;
  25
  26         ctdl_printf(c, "MSGS %s", which_msgs);
  27         ctdl_readline(c, buf, sizeof(buf));
  28         if (buf[0] == '1') {
  29                 do {
  30                         if (num_msgs >= num_alloc) {
  31                                 if (num_alloc == 0) {
  32                                         num_alloc = 1024;
  33                                         msglist = malloc(num_alloc * sizeof(long));
  34                                 }
  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 is requesting the room info banner
 109 void read_room_info_banner(struct http_transaction *h, struct ctdlsession *c) {
 110         char buf[1024];
 111
 112         ctdl_printf(c, "RINF");
 113         ctdl_readline(c, buf, sizeof(buf));
 114         if (buf[0] == '1') {
 115                 StrBuf *info = NewStrBuf();
 116                 while (ctdl_readline(c, buf, sizeof(buf)), (strcmp(buf, "000"))){
 117                         StrBufAppendPrintf(info, "%s\n", buf);
 118                 }
 119                 add_response_header(h, strdup("Content-type"), strdup("text/plain"));
 120                 h->response_code = 200;
 121                 h->response_string = strdup("OK");
 122                 h->response_body_length = StrLength(info);
 123                 h->response_body = SmashStrBuf(&info);
 124                 return;
 125         }
 126         else {
 127                 do_404(h);
 128         }
 129 }
 130
 131
 132 // Client is setting the "Last Read Pointer" (marking all messages as "seen" up to this message)
 133 void set_last_read_pointer(struct http_transaction *h, struct ctdlsession *c) {
 134         char cbuf[1024];
 135         ctdl_printf(c, "SLRP %d", atoi(get_url_param(h, "last")));
 136         ctdl_readline(c, cbuf, sizeof(cbuf));
 137         if (cbuf[0] == '2') {
 138                 do_204(h);
 139         }
 140         else {
 141                 do_404(h);
 142         }
 143 }
 144
 145
 146 // Client requested an object in a room.
 147 void object_in_room(struct http_transaction *h, struct ctdlsession *c) {
 148         char buf[1024];
 149         long msgnum = (-1);
 150         char unescaped_euid[1024];
 151
 152         extract_token(buf, h->url, 4, '/', sizeof buf);
 153
 154         if (!strncasecmp(buf, "msgs.", 5)) {            // Client is requesting a list of message numbers
 155                 unescape_input(&buf[5]);
 156                 json_msglist(h, c, &buf[5]);
 157                 return;
 158         }
 159
 160         if (!strcasecmp(buf, "info.txt")) {             // Client is requesting the room info banner
 161                 read_room_info_banner(h, c);
 162                 return;
 163         }
 164
 165         if (!strcasecmp(buf, "slrp")) {                 // Set the Last Read Pointer
 166                 set_last_read_pointer(h, c);
 167                 return;
 168         }
 169
 170         // If we get to this point, the client is requesting a specific object *in* the room.
 171
 172         if ((c->room_default_view == VIEW_CALENDAR)     // room types where objects are referenced by EUID
 173            || (c->room_default_view == VIEW_TASKS)
 174            || (c->room_default_view == VIEW_ADDRESSBOOK)
 175            ) {
 176                 safestrncpy(unescaped_euid, buf, sizeof unescaped_euid);
 177                 unescape_input(unescaped_euid);
 178                 msgnum = locate_message_by_uid(c, unescaped_euid);
 179         }
 180         else {                                          // otherwise the object is being referenced by message number
 181                 msgnum = atol(buf);
 182         }
 183
 184         // All methods except PUT require the message to already exist
 185         if ((msgnum <= 0) && (strcasecmp(h->method, "PUT"))) {
 186                 do_404(h);
 187         }
 188
 189         // If we get to this point we have a valid message number in an accessible room.
 190         syslog(LOG_DEBUG, "msgnum is %ld, method is %s", msgnum, h->method);
 191
 192         // A sixth component in the URL can be one of two things:
 193         // (1) a MIME part specifier, in which case the client wants to download that component within the message
 194         // (2) a content-type, in which ase the client wants us to try to render it a certain way
 195         if (num_tokens(h->url, '/') == 6) {
 196                 extract_token(buf, h->url, 5, '/', sizeof buf);
 197                 if (!IsEmptyStr(buf)) {
 198                         if (!strcasecmp(buf, "json")) {
 199                                 json_render_one_message(h, c, msgnum);
 200                         }
 201                         else {
 202                                 download_mime_component(h, c, msgnum, buf);
 203                         }
 204                         return;
 205                 }
 206         }
 207
 208         // Ok, we want a full message, but first let's check for the if[-none]-match headers.
 209         char *if_match = header_val(h, "If-Match");
 210         if ((if_match != NULL) && (!match_etags(if_match, msgnum))) {
 211                 do_412(h);
 212                 return;
 213         }
 214
 215         char *if_none_match = header_val(h, "If-None-Match");
 216         if ((if_none_match != NULL) && (match_etags(if_none_match, msgnum))) {
 217                 do_412(h);
 218                 return;
 219         }
 220
 221         // DOOOOOO ITTTTT!!!
 222
 223         if (!strcasecmp(h->method, "DELETE")) {
 224                 dav_delete_message(h, c, msgnum);
 225         }
 226         else if (!strcasecmp(h->method, "GET")) {
 227                 dav_get_message(h, c, msgnum);
 228         }
 229         else if (!strcasecmp(h->method, "PUT")) {
 230                 dav_put_message(h, c, unescaped_euid, msgnum);
 231         }
 232         else {
 233                 do_404(h);      // Got this far but the method made no sense?  Bummer.
 234         }
 235
 236 }
 237
 238
 239 // Called by the_room_itself() when the HTTP method is REPORT
 240 void report_the_room_itself(struct http_transaction *h, struct ctdlsession *c) {
 241         if (c->room_default_view == VIEW_CALENDAR) {
 242                 caldav_report(h, c);    // CalDAV REPORTs ... fmgwac
 243                 return;
 244         }
 245
 246         do_404(h);              // future implementations like CardDAV will require code paths here
 247 }
 248
 249
 250 // Called by the_room_itself() when the HTTP method is OPTIONS
 251 void options_the_room_itself(struct http_transaction *h, struct ctdlsession *c) {
 252         h->response_code = 200;
 253         h->response_string = strdup("OK");
 254         if (c->room_default_view == VIEW_CALENDAR) {
 255                 add_response_header(h, strdup("DAV"), strdup("1, calendar-access"));    // offer CalDAV
 256         }
 257         else if (c->room_default_view == VIEW_ADDRESSBOOK) {
 258                 add_response_header(h, strdup("DAV"), strdup("1, addressbook"));        // offer CardDAV
 259         }
 260         else {
 261                 add_response_header(h, strdup("DAV"), strdup("1"));     // ordinary WebDAV for all other room types
 262         }
 263         add_response_header(h, strdup("Allow"), strdup("OPTIONS, PROPFIND, GET, PUT, REPORT, DELETE"));
 264 }
 265
 266
 267 // Called by the_room_itself() when the HTTP method is PROPFIND
 268 void propfind_the_room_itself(struct http_transaction *h, struct ctdlsession *c) {
 269         char *e;
 270         long timestamp;
 271         int dav_depth = (header_val(h, "Depth") ? atoi(header_val(h, "Depth")) : INT_MAX);
 272         syslog(LOG_DEBUG, "Client PROPFIND requested depth: %d", dav_depth);
 273         StrBuf *Buf = NewStrBuf();
 274
 275         StrBufAppendPrintf(Buf, "<?xml version=\"1.0\" encoding=\"utf-8\"?>"
 276                            "<D:multistatus " "xmlns:D=\"DAV:\" " "xmlns:C=\"urn:ietf:params:xml:ns:caldav\"" ">");
 277
 278         // Transmit the collection resource
 279         StrBufAppendPrintf(Buf, "<D:response>");
 280         StrBufAppendPrintf(Buf, "<D:href>");
 281         StrBufXMLEscAppend(Buf, NULL, h->site_prefix, strlen(h->site_prefix), 0);
 282         StrBufAppendPrintf(Buf, "/ctdl/r/");
 283         StrBufXMLEscAppend(Buf, NULL, c->room, strlen(c->room), 0);
 284         StrBufAppendPrintf(Buf, "</D:href>");
 285
 286         StrBufAppendPrintf(Buf, "<D:propstat>");
 287         StrBufAppendPrintf(Buf, "<D:status>HTTP/1.1 200 OK</D:status>");
 288         StrBufAppendPrintf(Buf, "<D:prop>");
 289         StrBufAppendPrintf(Buf, "<D:displayname>");
 290         StrBufXMLEscAppend(Buf, NULL, c->room, strlen(c->room), 0);
 291         StrBufAppendPrintf(Buf, "</D:displayname>");
 292
 293         StrBufAppendPrintf(Buf, "<D:owner />"); // empty owner ought to be legal; see rfc3744 section 5.1
 294
 295         StrBufAppendPrintf(Buf, "<D:resourcetype><D:collection />");
 296         switch (c->room_default_view) {
 297         case VIEW_CALENDAR:
 298                 StrBufAppendPrintf(Buf, "<C:calendar />");      // RFC4791 section 4.2
 299                 break;
 300         }
 301         StrBufAppendPrintf(Buf, "</D:resourcetype>");
 302
 303         int enumerate_by_euid = 0;      // nonzero if messages will be retrieved by euid instead of msgnum
 304         switch (c->room_default_view) {
 305         case VIEW_CALENDAR:             // RFC4791 section 5.2
 306                 StrBufAppendPrintf(Buf, "<C:supported-calendar-component-set><C:comp name=\"VEVENT\"/></C:supported-calendar-component-set>");
 307                 StrBufAppendPrintf(Buf, "<C:supported-calendar-data>");
 308                 StrBufAppendPrintf(Buf, "<C:calendar-data content-type=\"text/calendar\" version=\"2.0\"/>");
 309                 StrBufAppendPrintf(Buf, "</C:supported-calendar-data>");
 310                 enumerate_by_euid = 1;
 311                 break;
 312         case VIEW_TASKS:                // RFC4791 section 5.2
 313                 StrBufAppendPrintf(Buf, "<C:supported-calendar-component-set><C:comp name=\"VTODO\"/></C:supported-calendar-component-set>");
 314                 StrBufAppendPrintf(Buf, "<C:supported-calendar-data>");
 315                 StrBufAppendPrintf(Buf, "<C:calendar-data content-type=\"text/calendar\" version=\"2.0\"/>");
 316                 StrBufAppendPrintf(Buf, "</C:supported-calendar-data>");
 317                 enumerate_by_euid = 1;
 318                 break;
 319         case VIEW_ADDRESSBOOK:          // FIXME put some sort of CardDAV crapola here when we implement it
 320                 enumerate_by_euid = 1;
 321                 break;
 322         case VIEW_WIKI:                 // FIXME invent "WikiDAV" ?
 323                 enumerate_by_euid = 1;
 324                 break;
 325         }
 326
 327         // FIXME get the mtime
 328         // StrBufAppendPrintf(Buf, "<D:getlastmodified>");
 329         // escputs(datestring);
 330         // StrBufAppendPrintf(Buf, "</D:getlastmodified>");
 331
 332         StrBufAppendPrintf(Buf, "</D:prop>");
 333         StrBufAppendPrintf(Buf, "</D:propstat>");
 334         StrBufAppendPrintf(Buf, "</D:response>\n");
 335
 336         // If a depth greater than zero was specified, transmit the collection listing
 337         // BEGIN COLLECTION
 338         if (dav_depth > 0) {
 339                 long *msglist = get_msglist(c, "ALL");
 340                 if (msglist) {
 341                         int i;
 342                         for (i = 0; (msglist[i] > 0); ++i) {
 343                                 if ((i % 10) == 0)
 344                                         syslog(LOG_DEBUG, "PROPFIND enumerated %d messages", i);
 345                                 e = NULL;       // EUID gets stored here
 346                                 timestamp = 0;
 347
 348                                 char cbuf[1024];
 349                                 ctdl_printf(c, "MSG0 %ld|3", msglist[i]);
 350                                 ctdl_readline(c, cbuf, sizeof(cbuf));
 351                                 if (cbuf[0] == '1')
 352                                         while (ctdl_readline(c, cbuf, sizeof(cbuf)), strcmp(cbuf, "000")) {
 353                                                 if ((enumerate_by_euid) && (!strncasecmp(cbuf, "exti=", 5))) {
 354                                                         // e = strdup(&cbuf[5]);
 355                                                         int elen = (2 * strlen(&cbuf[5]));
 356                                                         e = malloc(elen);
 357                                                         urlesc(e, elen, &cbuf[5]);
 358                                                 }
 359                                                 if (!strncasecmp(cbuf, "time=", 5)) {
 360                                                         timestamp = atol(&cbuf[5]);
 361                                                 }
 362                                         }
 363                                 if (e == NULL) {
 364                                         e = malloc(20);
 365                                         sprintf(e, "%ld", msglist[i]);
 366                                 }
 367                                 StrBufAppendPrintf(Buf, "<D:response>");
 368
 369                                 // Generate the 'href' tag for this message
 370                                 StrBufAppendPrintf(Buf, "<D:href>");
 371                                 StrBufXMLEscAppend(Buf, NULL, h->site_prefix, strlen(h->site_prefix), 0);
 372                                 StrBufAppendPrintf(Buf, "/ctdl/r/");
 373                                 StrBufXMLEscAppend(Buf, NULL, c->room, strlen(c->room), 0);
 374                                 StrBufAppendPrintf(Buf, "/");
 375                                 StrBufXMLEscAppend(Buf, NULL, e, strlen(e), 0);
 376                                 StrBufAppendPrintf(Buf, "</D:href>");
 377                                 StrBufAppendPrintf(Buf, "<D:propstat>");
 378                                 StrBufAppendPrintf(Buf, "<D:status>HTTP/1.1 200 OK</D:status>");
 379                                 StrBufAppendPrintf(Buf, "<D:prop>");
 380
 381                                 switch (c->room_default_view) {
 382                                 case VIEW_CALENDAR:
 383                                         StrBufAppendPrintf(Buf,
 384                                                            "<D:getcontenttype>text/calendar; component=vevent</D:getcontenttype>");
 385                                         break;
 386                                 case VIEW_TASKS:
 387                                         StrBufAppendPrintf(Buf,
 388                                                            "<D:getcontenttype>text/calendar; component=vtodo</D:getcontenttype>");
 389                                         break;
 390                                 case VIEW_ADDRESSBOOK:
 391                                         StrBufAppendPrintf(Buf, "<D:getcontenttype>text/x-vcard</D:getcontenttype>");
 392                                         break;
 393                                 }
 394
 395                                 if (timestamp > 0) {
 396                                         char *datestring = http_datestring(timestamp);
 397                                         if (datestring) {
 398                                                 StrBufAppendPrintf(Buf, "<D:getlastmodified>");
 399                                                 StrBufXMLEscAppend(Buf, NULL, datestring, strlen(datestring), 0);
 400                                                 StrBufAppendPrintf(Buf, "</D:getlastmodified>");
 401                                                 free(datestring);
 402                                         }
 403                                         if (enumerate_by_euid) {        // FIXME ajc 2017oct30 should this be inside the timestamp conditional?
 404                                                 StrBufAppendPrintf(Buf, "<D:getetag>\"%ld\"</D:getetag>", msglist[i]);
 405                                         }
 406                                 }
 407                                 StrBufAppendPrintf(Buf, "</D:prop></D:propstat></D:response>\n");
 408                                 free(e);
 409                         }
 410                         free(msglist);
 411                 };
 412         }
 413         // END COLLECTION
 414
 415         StrBufAppendPrintf(Buf, "</D:multistatus>\n");
 416
 417         add_response_header(h, strdup("Content-type"), strdup("text/xml"));
 418         h->response_code = 207;
 419         h->response_string = strdup("Multi-Status");
 420         h->response_body_length = StrLength(Buf);
 421         h->response_body = SmashStrBuf(&Buf);
 422 }
 423
 424 // some good examples here
 425 // http://blogs.nologin.es/rickyepoderi/index.php?/archives/14-Introducing-CalDAV-Part-I.html
 426
 427
 428 // Called by the_room_itself() when the HTTP method is PROPFIND
 429 void get_the_room_itself(struct http_transaction *h, struct ctdlsession *c) {
 430         JsonValue *j = NewJsonObject(HKEY("gotoroom"));
 431
 432         JsonObjectAppend(j, NewJsonPlainString(HKEY("name"), c->room, -1));
 433         JsonObjectAppend(j, NewJsonNumber(HKEY("current_view"), c->room_current_view));
 434         JsonObjectAppend(j, NewJsonNumber(HKEY("default_view"), c->room_default_view));
 435         JsonObjectAppend(j, NewJsonNumber(HKEY("new_messages"), c->new_messages));
 436         JsonObjectAppend(j, NewJsonNumber(HKEY("total_messages"), c->total_messages));
 437         JsonObjectAppend(j, NewJsonNumber(HKEY("last_seen"), c->last_seen));
 438
 439         StrBuf *sj = NewStrBuf();
 440         SerializeJson(sj, j, 1);        // '1' == free the source array
 441
 442         add_response_header(h, strdup("Content-type"), strdup("application/json"));
 443         h->response_code = 200;
 444         h->response_string = strdup("OK");
 445         h->response_body_length = StrLength(sj);
 446         h->response_body = SmashStrBuf(&sj);
 447         return;
 448 }
 449
 450
 451 // Handle REST/DAV requests for the room itself (such as /ctdl/r/roomname
 452 // or /ctdl/r/roomname/ but *not* specific objects within the room)
 453 void the_room_itself(struct http_transaction *h, struct ctdlsession *c) {
 454
 455         // OPTIONS method on the room itself usually is a DAV client assessing what's here.
 456         if (!strcasecmp(h->method, "OPTIONS")) {
 457                 options_the_room_itself(h, c);
 458                 return;
 459         }
 460
 461         // PROPFIND method on the room itself could be looking for a directory
 462         if (!strcasecmp(h->method, "PROPFIND")) {
 463                 propfind_the_room_itself(h, c);
 464                 return;
 465         }
 466
 467         // REPORT method on the room itself is probably the dreaded CalDAV tower-of-crapola
 468         if (!strcasecmp(h->method, "REPORT")) {
 469                 report_the_room_itself(h, c);
 470                 return;
 471         }
 472
 473         // GET method on the room itself is an API call, possibly from our JavaScript front end
 474         if (!strcasecmp(h->method, "get")) {
 475                 get_the_room_itself(h, c);
 476                 return;
 477         }
 478
 479         // we probably want a "go to this room" for interactive access
 480         do_404(h);
 481 }
 482
 483
 484 // Dispatcher for "/ctdl/r" and "/ctdl/r/" for the room list
 485 void room_list(struct http_transaction *h, struct ctdlsession *c) {
 486         char buf[1024];
 487         char roomname[1024];
 488
 489         ctdl_printf(c, "LKRA");
 490         ctdl_readline(c, buf, sizeof(buf));
 491         if (buf[0] != '1') {
 492                 do_502(h);
 493                 return;
 494         }
 495
 496         JsonValue *j = NewJsonArray(HKEY("lkra"));
 497         while (ctdl_readline(c, buf, sizeof(buf)), strcmp(buf, "000")) {
 498
 499                 // 0   |1      |2      |3      |4       |5 |6           |7           |8
 500                 // name|QRflags|QRfloor|QRorder|QRflags2|ra|current_view|default_view|mtime
 501                 JsonValue *jr = NewJsonObject(HKEY("room"));
 502
 503                 extract_token(roomname, buf, 0, '|', sizeof roomname);
 504                 JsonObjectAppend(jr, NewJsonPlainString(HKEY("name"), roomname, -1));
 505
 506                 JsonObjectAppend(jr, NewJsonNumber(HKEY("floor"), extract_int(buf, 2)));
 507                 JsonObjectAppend(jr, NewJsonNumber(HKEY("rorder"), extract_int(buf, 3)));
 508
 509                 int ra = extract_int(buf, 5);
 510                 JsonObjectAppend(jr, NewJsonBool(HKEY("known"), (ra & UA_KNOWN)));
 511                 JsonObjectAppend(jr, NewJsonBool(HKEY("hasnewmsgs"), (ra & UA_HASNEWMSGS)));
 512
 513                 JsonObjectAppend(jr, NewJsonNumber(HKEY("current_view"), extract_int(buf, 6)));
 514                 JsonObjectAppend(jr, NewJsonNumber(HKEY("default_view"), extract_int(buf, 7)));
 515                 JsonObjectAppend(jr, NewJsonNumber(HKEY("mtime"), extract_int(buf, 8)));
 516
 517                 JsonArrayAppend(j, jr); // add the room to the array
 518         }
 519
 520         StrBuf *sj = NewStrBuf();
 521         SerializeJson(sj, j, 1);        // '1' == free the source array
 522
 523         add_response_header(h, strdup("Content-type"), strdup("application/json"));
 524         h->response_code = 200;
 525         h->response_string = strdup("OK");
 526         h->response_body_length = StrLength(sj);
 527         h->response_body = SmashStrBuf(&sj);
 528 }
 529
 530
 531 // Dispatcher for paths starting with /ctdl/r/
 532 void ctdl_r(struct http_transaction *h, struct ctdlsession *c) {
 533         char requested_roomname[128];
 534         char buf[1024];
 535
 536         // All room-related functions require being "in" the room specified.  Are we in that room already?
 537         extract_token(requested_roomname, h->url, 3, '/', sizeof requested_roomname);
 538         unescape_input(requested_roomname);
 539
 540         if (IsEmptyStr(requested_roomname)) {   //      /ctdl/r/
 541                 room_list(h, c);
 542                 return;
 543         }
 544         // If not, try to go there.
 545         if (strcasecmp(requested_roomname, c->room)) {
 546                 ctdl_printf(c, "GOTO %s", requested_roomname);
 547                 ctdl_readline(c, buf, sizeof(buf));
 548                 if (buf[0] == '2') {
 549                         // buf[3] will indicate whether any instant messages are waiting
 550                         extract_token(c->room, &buf[4], 0, '|', sizeof c->room);
 551                         c->new_messages = extract_int(&buf[4], 1);
 552                         c->total_messages = extract_int(&buf[4], 2);
 553                         //      3       (int)info                       Info flag: set to nonzero if the user needs to read this room's info file
 554                         //      4       (int)CC->room.QRflags           Various flags associated with this room.
 555                         //      5       (long)CC->room.QRhighest        The highest message number present in this room
 556                         c->last_seen = extract_long(&buf[4], 6);        // The highest message number the user has read in this room
 557                         //      7       (int)rmailflag                  Boolean flag: 1 if this is a Mail> room, 0 otherwise.
 558                         //      8       (int)raideflag                  Nonzero if user is either Aide or a Room Aide in this room
 559                         //      9       (int)newmailcount               The number of new Mail messages the user has
 560                         //      10      (int)CC->room.QRfloor           The floor number this room resides on
 561                         c->room_current_view = extract_int(&buf[4], 11);
 562                         c->room_default_view = extract_int(&buf[4], 12);
 563                         //      13      (int)is_trash                   Boolean flag: 1 if this is the user's Trash folder, 0 otherwise.
 564                         //      14      (int)CC->room.QRflags2          More flags associated with this room
 565                         //      15      (long)CC->room.QRmtime          Timestamp of the last write activity in this room
 566                 }
 567                 else {
 568                         do_404(h);
 569                         return;
 570                 }
 571         }
 572         // At this point our Citadel client session is "in" the specified room.
 573
 574         if (num_tokens(h->url, '/') == 4) {     //      /ctdl/r/roomname
 575                 the_room_itself(h, c);
 576                 return;
 577         }
 578
 579         extract_token(buf, h->url, 4, '/', sizeof buf);
 580         if (num_tokens(h->url, '/') == 5) {
 581                 if (IsEmptyStr(buf)) {
 582                         the_room_itself(h, c);  //      /ctdl/r/roomname/       ( same as /ctdl/r/roomname )
 583                 }
 584                 else {
 585                         object_in_room(h, c);   //      /ctdl/r/roomname/object
 586                 }
 587                 return;
 588         }
 589         if (num_tokens(h->url, '/') == 6) {
 590                 object_in_room(h, c);   //      /ctdl/r/roomname/object/ or possibly /ctdl/r/roomname/object/component
 591                 return;
 592         }
 593         // If we get to this point, the client specified a valid room but requested an action we don't know how to perform.
 594         do_404(h);
 595 }