citadel/modules/xmpp/serv_xmpp.c

   1 /*
   2  * XMPP (Jabber) service for the Citadel system
   3  * Copyright (c) 2007-2011 by Art Cancro
   4  *
   5  * This program is open source software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 3 of the License, or
   8  * (at your option) any later version.
   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  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 #include "sysdep.h"
  21 #include <stdlib.h>
  22 #include <unistd.h>
  23 #include <stdio.h>
  24 #include <fcntl.h>
  25 #include <signal.h>
  26 #include <pwd.h>
  27 #include <errno.h>
  28 #include <sys/types.h>
  29
  30 #if TIME_WITH_SYS_TIME
  31 # include <sys/time.h>
  32 # include <time.h>
  33 #else
  34 # if HAVE_SYS_TIME_H
  35 #  include <sys/time.h>
  36 # else
  37 #  include <time.h>
  38 # endif
  39 #endif
  40
  41 #include <sys/wait.h>
  42 #include <string.h>
  43 #include <limits.h>
  44 #include <ctype.h>
  45 #include <libcitadel.h>
  46 #include <expat.h>
  47 #include "citadel.h"
  48 #include "server.h"
  49 #include "citserver.h"
  50 #include "support.h"
  51 #include "config.h"
  52 #include "user_ops.h"
  53 #include "database.h"
  54 #include "msgbase.h"
  55 #include "internet_addressing.h"
  56 #include "md5.h"
  57 #include "ctdl_module.h"
  58 #include "serv_xmpp.h"
  59
  60 #if XML_MAJOR_VERSION > 0
  61 /* XML_StopParser is present in expat 2.x */
  62 #define HAVE_XML_STOPPARSER
  63 #endif
  64
  65 struct xmpp_event *xmpp_queue = NULL;
  66
  67
  68
  69 #ifdef HAVE_XML_STOPPARSER
  70 /* Stop the parser if an entity declaration is hit. */
  71 static void xmpp_entity_declaration(void *userData, const XML_Char *entityName,
  72                                 int is_parameter_entity, const XML_Char *value,
  73                                 int value_length, const XML_Char *base,
  74                                 const XML_Char *systemId, const XML_Char *publicId,
  75                                 const XML_Char *notationName
  76 ) {
  77         syslog(LOG_WARNING, "Illegal entity declaration encountered; stopping parser.");
  78         XML_StopParser(XMPP->xp, XML_FALSE);
  79 }
  80 #endif
  81
  82
  83
  84 /*
  85  * Given a source string and a target buffer, returns the string
  86  * properly escaped for insertion into an XML stream.  Returns a
  87  * pointer to the target buffer for convenience.
  88  *
  89  * BUG: this does not properly handle UTF-8
  90  */
  91 char *xmlesc(char *buf, char *str, int bufsiz)
  92 {
  93         char *ptr;
  94         unsigned char ch;
  95         int len = 0;
  96
  97         if (!buf) return(NULL);
  98         buf[0] = 0;
  99         len = 0;
 100         if (!str) {
 101                 return(buf);
 102         }
 103
 104         for (ptr=str; *ptr; ptr++) {
 105                 ch = *ptr;
 106                 if (ch == '<') {
 107                         strcpy(&buf[len], "&lt;");
 108                         len += 4;
 109                 }
 110                 else if (ch == '>') {
 111                         strcpy(&buf[len], "&gt;");
 112                         len += 4;
 113                 }
 114                 else if (ch == '&') {
 115                         strcpy(&buf[len], "&amp;");
 116                         len += 5;
 117                 }
 118                 else if ((ch >= 0x20) && (ch <= 0x7F)) {
 119                         buf[len++] = ch;
 120                         buf[len] = 0;
 121                 }
 122                 else if (ch < 0x20) {
 123                         /* we probably shouldn't be doing this */
 124                         buf[len++] = '_';
 125                         buf[len] = 0;
 126                 }
 127                 else {
 128                         char oct[10];
 129                         sprintf(oct, "&#%o;", ch);
 130                         strcpy(&buf[len], oct);
 131                         len += strlen(oct);
 132                 }
 133                 if ((len + 6) > bufsiz) {
 134                         return(buf);
 135                 }
 136         }
 137         return(buf);
 138 }
 139
 140
 141 /*
 142  * We have just received a <stream> tag from the client, so send them ours
 143  */
 144 void xmpp_stream_start(void *data, const char *supplied_el, const char **attr)
 145 {
 146         char xmlbuf[256];
 147
 148         while (*attr) {
 149                 if (!strcasecmp(attr[0], "to")) {
 150                         safestrncpy(XMPP->server_name, attr[1], sizeof XMPP->server_name);
 151                 }
 152                 attr += 2;
 153         }
 154
 155         cprintf("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
 156
 157         cprintf("<stream:stream ");
 158         cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->server_name, sizeof xmlbuf));
 159         cprintf("id=\"%08x\" ", CC->cs_pid);
 160         cprintf("version=\"1.0\" ");
 161         cprintf("xmlns:stream=\"http://etherx.jabber.org/streams\" ");
 162         cprintf("xmlns=\"jabber:client\">");
 163
 164         /* The features of this stream are... */
 165         cprintf("<stream:features>");
 166
 167 #ifdef HAVE_OPENSSL
 168         /* TLS encryption (but only if it isn't already active) */
 169         if (!CC->redirect_ssl) {
 170                 cprintf("<starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'></starttls>");
 171         }
 172 #endif
 173
 174         if (!CC->logged_in) {
 175                 /* If we're not logged in yet, offer SASL as our feature set */
 176                 xmpp_output_auth_mechs();
 177
 178                 /* Also offer non-SASL authentication */
 179                 cprintf("<auth xmlns=\"http://jabber.org/features/iq-auth\"/>");
 180         }
 181
 182         /* Offer binding and sessions as part of our feature set */
 183         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\"/>");
 184         cprintf("<session xmlns=\"urn:ietf:params:xml:ns:xmpp-session\"/>");
 185
 186         cprintf("</stream:features>");
 187
 188         CC->is_async = 1;               /* XMPP sessions are inherently async-capable */
 189 }
 190
 191
 192 void xmpp_xml_start(void *data, const char *supplied_el, const char **attr) {
 193         char el[256];
 194         char *sep = NULL;
 195         int i;
 196
 197         /* Axe the namespace, we don't care about it */
 198         safestrncpy(el, supplied_el, sizeof el);
 199         while (sep = strchr(el, ':'), sep) {
 200                 strcpy(el, ++sep);
 201         }
 202
 203         /*
 204         CtdlLogPrintf(CTDL_DEBUG, "XMPP ELEMENT START: <%s>\n", el);
 205         for (i=0; attr[i] != NULL; i+=2) {
 206                 CtdlLogPrintf(CTDL_DEBUG, "                    Attribute '%s' = '%s'\n", attr[i], attr[i+1]);
 207         }
 208         uncomment for more verbosity */
 209
 210         if (!strcasecmp(el, "stream")) {
 211                 xmpp_stream_start(data, supplied_el, attr);
 212         }
 213
 214         else if (!strcasecmp(el, "query")) {
 215                 XMPP->iq_query_xmlns[0] = 0;
 216                 safestrncpy(XMPP->iq_query_xmlns, supplied_el, sizeof XMPP->iq_query_xmlns);
 217         }
 218
 219         else if (!strcasecmp(el, "bind")) {
 220                 XMPP->bind_requested = 1;
 221         }
 222
 223         else if (!strcasecmp(el, "iq")) {
 224                 for (i=0; attr[i] != NULL; i+=2) {
 225                         if (!strcasecmp(attr[i], "type")) {
 226                                 safestrncpy(XMPP->iq_type, attr[i+1], sizeof XMPP->iq_type);
 227                         }
 228                         else if (!strcasecmp(attr[i], "id")) {
 229                                 safestrncpy(XMPP->iq_id, attr[i+1], sizeof XMPP->iq_id);
 230                         }
 231                         else if (!strcasecmp(attr[i], "from")) {
 232                                 safestrncpy(XMPP->iq_from, attr[i+1], sizeof XMPP->iq_from);
 233                         }
 234                         else if (!strcasecmp(attr[i], "to")) {
 235                                 safestrncpy(XMPP->iq_to, attr[i+1], sizeof XMPP->iq_to);
 236                         }
 237                 }
 238         }
 239
 240         else if (!strcasecmp(el, "auth")) {
 241                 XMPP->sasl_auth_mech[0] = 0;
 242                 for (i=0; attr[i] != NULL; i+=2) {
 243                         if (!strcasecmp(attr[i], "mechanism")) {
 244                                 safestrncpy(XMPP->sasl_auth_mech, attr[i+1], sizeof XMPP->sasl_auth_mech);
 245                         }
 246                 }
 247         }
 248
 249         else if (!strcasecmp(el, "message")) {
 250                 for (i=0; attr[i] != NULL; i+=2) {
 251                         if (!strcasecmp(attr[i], "to")) {
 252                                 safestrncpy(XMPP->message_to, attr[i+1], sizeof XMPP->message_to);
 253                         }
 254                 }
 255         }
 256
 257         else if (!strcasecmp(el, "html")) {
 258                 ++XMPP->html_tag_level;
 259         }
 260 }
 261
 262
 263
 264 void xmpp_xml_end(void *data, const char *supplied_el) {
 265         char el[256];
 266         char *sep = NULL;
 267         char xmlbuf[256];
 268
 269         /* Axe the namespace, we don't care about it */
 270         safestrncpy(el, supplied_el, sizeof el);
 271         while (sep = strchr(el, ':'), sep) {
 272                 strcpy(el, ++sep);
 273         }
 274
 275         /*
 276         CtdlLogPrintf(CTDL_DEBUG, "XMPP ELEMENT END  : <%s>\n", el);
 277         if (XMPP->chardata_len > 0) {
 278                 CtdlLogPrintf(CTDL_DEBUG, "          chardata: %s\n", XMPP->chardata);
 279         }
 280         uncomment for more verbosity */
 281
 282         if (!strcasecmp(el, "resource")) {
 283                 if (XMPP->chardata_len > 0) {
 284                         safestrncpy(XMPP->iq_client_resource, XMPP->chardata,
 285                                 sizeof XMPP->iq_client_resource);
 286                         striplt(XMPP->iq_client_resource);
 287                 }
 288         }
 289
 290         else if (!strcasecmp(el, "username")) {         /* NON SASL ONLY */
 291                 if (XMPP->chardata_len > 0) {
 292                         safestrncpy(XMPP->iq_client_username, XMPP->chardata,
 293                                 sizeof XMPP->iq_client_username);
 294                         striplt(XMPP->iq_client_username);
 295                 }
 296         }
 297
 298         else if (!strcasecmp(el, "password")) {         /* NON SASL ONLY */
 299                 if (XMPP->chardata_len > 0) {
 300                         safestrncpy(XMPP->iq_client_password, XMPP->chardata,
 301                                 sizeof XMPP->iq_client_password);
 302                         striplt(XMPP->iq_client_password);
 303                 }
 304         }
 305
 306         else if (!strcasecmp(el, "iq")) {
 307
 308                 /*
 309                  * iq type="get" (handle queries)
 310                  */
 311                 if (!strcasecmp(XMPP->iq_type, "get")) {
 312
 313                         /*
 314                          * Query on a namespace
 315                          */
 316                         if (!IsEmptyStr(XMPP->iq_query_xmlns)) {
 317                                 xmpp_query_namespace(XMPP->iq_id, XMPP->iq_from,
 318                                                 XMPP->iq_to, XMPP->iq_query_xmlns);
 319                         }
 320
 321                         /*
 322                          * ping ( http://xmpp.org/extensions/xep-0199.html )
 323                          */
 324                         else if (XMPP->ping_requested) {
 325                                 cprintf("<iq type=\"result\" ");
 326                                 if (!IsEmptyStr(XMPP->iq_from)) {
 327                                         cprintf("to=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_from, sizeof xmlbuf));
 328                                 }
 329                                 if (!IsEmptyStr(XMPP->iq_to)) {
 330                                         cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_to, sizeof xmlbuf));
 331                                 }
 332                                 cprintf("id=\"%s\"/>", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 333                         }
 334
 335                         /*
 336                          * Unknown query ... return the XML equivalent of a blank stare
 337                          */
 338                         else {
 339                                 CtdlLogPrintf(CTDL_DEBUG,
 340                                         "Unknown query <%s> - returning <service-unavailable/>\n",
 341                                         el
 342                                 );
 343                                 cprintf("<iq type=\"error\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 344                                 cprintf("<error code=\"503\" type=\"cancel\">"
 345                                         "<service-unavailable xmlns=\"urn:ietf:params:xml:ns:xmpp-stanzas\"/>"
 346                                         "</error>"
 347                                 );
 348                                 cprintf("</iq>");
 349                         }
 350                 }
 351
 352                 /*
 353                  * Non SASL authentication
 354                  */
 355                 else if (
 356                         (!strcasecmp(XMPP->iq_type, "set"))
 357                         && (!strcasecmp(XMPP->iq_query_xmlns, "jabber:iq:auth:query"))
 358                         ) {
 359
 360                         xmpp_non_sasl_authenticate(
 361                                 XMPP->iq_id,
 362                                 XMPP->iq_client_username,
 363                                 XMPP->iq_client_password,
 364                                 XMPP->iq_client_resource
 365                         );
 366                 }
 367
 368                 /*
 369                  * If this <iq> stanza was a "bind" attempt, process it ...
 370                  */
 371                 else if (
 372                         (XMPP->bind_requested)
 373                         && (!IsEmptyStr(XMPP->iq_id))
 374                         && (!IsEmptyStr(XMPP->iq_client_resource))
 375                         && (CC->logged_in)
 376                         ) {
 377
 378                         /* Generate the "full JID" of the client resource */
 379
 380                         snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
 381                                 "%s/%s",
 382                                 CC->cs_inet_email,
 383                                 XMPP->iq_client_resource
 384                         );
 385
 386                         /* Tell the client what its JID is */
 387
 388                         cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 389                         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\">");
 390                         cprintf("<jid>%s</jid>", xmlesc(xmlbuf, XMPP->client_jid, sizeof xmlbuf));
 391                         cprintf("</bind>");
 392                         cprintf("</iq>");
 393                 }
 394
 395                 else if (XMPP->iq_session) {
 396                         cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 397                         cprintf("</iq>");
 398                 }
 399
 400                 else {
 401                         cprintf("<iq type=\"error\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 402                         cprintf("<error>Don't know howto do '%s'!</error>", xmlesc(xmlbuf, XMPP->iq_type, sizeof xmlbuf));
 403                         cprintf("</iq>");
 404                 }
 405
 406                 /* Now clear these fields out so they don't get used by a future stanza */
 407                 XMPP->iq_id[0] = 0;
 408                 XMPP->iq_from[0] = 0;
 409                 XMPP->iq_to[0] = 0;
 410                 XMPP->iq_type[0] = 0;
 411                 XMPP->iq_client_resource[0] = 0;
 412                 XMPP->iq_session = 0;
 413                 XMPP->iq_query_xmlns[0] = 0;
 414                 XMPP->bind_requested = 0;
 415                 XMPP->ping_requested = 0;
 416         }
 417
 418         else if (!strcasecmp(el, "auth")) {
 419
 420                 /* Try to authenticate (this function is responsible for the output stanza) */
 421                 xmpp_sasl_auth(XMPP->sasl_auth_mech, (XMPP->chardata != NULL ? XMPP->chardata : "") );
 422
 423                 /* Now clear these fields out so they don't get used by a future stanza */
 424                 XMPP->sasl_auth_mech[0] = 0;
 425         }
 426
 427         else if (!strcasecmp(el, "session")) {
 428                 XMPP->iq_session = 1;
 429         }
 430
 431         else if (!strcasecmp(el, "presence")) {
 432
 433                 /* Respond to a <presence> update by firing back with presence information
 434                  * on the entire wholist.  Check this assumption, it's probably wrong.
 435                  */
 436                 xmpp_wholist_presence_dump();
 437         }
 438
 439         else if ( (!strcasecmp(el, "body")) && (XMPP->html_tag_level == 0) ) {
 440                 if (XMPP->message_body != NULL) {
 441                         free(XMPP->message_body);
 442                         XMPP->message_body = NULL;
 443                 }
 444                 if (XMPP->chardata_len > 0) {
 445                         XMPP->message_body = strdup(XMPP->chardata);
 446                 }
 447         }
 448
 449         else if (!strcasecmp(el, "message")) {
 450                 xmpp_send_message(XMPP->message_to, XMPP->message_body);
 451                 XMPP->html_tag_level = 0;
 452         }
 453
 454         else if (!strcasecmp(el, "html")) {
 455                 --XMPP->html_tag_level;
 456         }
 457
 458         else if (!strcasecmp(el, "starttls")) {
 459 #ifdef HAVE_OPENSSL
 460                 cprintf("<proceed xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 461                 CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
 462                 if (!CC->redirect_ssl) CC->kill_me = 1;
 463 #else
 464                 cprintf("<failure xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 465                 CC->kill_me = 1;
 466 #endif
 467         }
 468
 469         else if (!strcasecmp(el, "ping")) {
 470                 XMPP->ping_requested = 1;
 471         }
 472
 473         else if (!strcasecmp(el, "stream")) {
 474                 CtdlLogPrintf(CTDL_DEBUG, "XMPP client shut down their stream\n");
 475                 xmpp_massacre_roster();
 476                 cprintf("</stream>\n");
 477                 CC->kill_me = 1;
 478         }
 479
 480         else {
 481                 CtdlLogPrintf(CTDL_DEBUG, "Ignoring unknown tag <%s>\n", el);
 482         }
 483
 484         XMPP->chardata_len = 0;
 485         if (XMPP->chardata_alloc > 0) {
 486                 XMPP->chardata[0] = 0;
 487         }
 488 }
 489
 490
 491 void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
 492 {
 493         citxmpp *X = XMPP;
 494
 495         if (X->chardata_alloc == 0) {
 496                 X->chardata_alloc = SIZ;
 497                 X->chardata = malloc(X->chardata_alloc);
 498         }
 499         if ((X->chardata_len + len + 1) > X->chardata_alloc) {
 500                 X->chardata_alloc = X->chardata_len + len + 1024;
 501                 X->chardata = realloc(X->chardata, X->chardata_alloc);
 502         }
 503         memcpy(&X->chardata[X->chardata_len], s, len);
 504         X->chardata_len += len;
 505         X->chardata[X->chardata_len] = 0;
 506 }
 507
 508
 509 /*
 510  * This cleanup function blows away the temporary memory and files used by the XMPP service.
 511  */
 512 void xmpp_cleanup_function(void) {
 513
 514         /* Don't do this stuff if this is not a XMPP session! */
 515         if (CC->h_command_function != xmpp_command_loop) return;
 516
 517         if (XMPP->chardata != NULL) {
 518                 free(XMPP->chardata);
 519                 XMPP->chardata = NULL;
 520                 XMPP->chardata_len = 0;
 521                 XMPP->chardata_alloc = 0;
 522                 if (XMPP->message_body != NULL) {
 523                         free(XMPP->message_body);
 524                 }
 525         }
 526         XML_ParserFree(XMPP->xp);
 527         free(XMPP);
 528 }
 529
 530
 531
 532 /*
 533  * Here's where our XMPP session begins its happy day.
 534  */
 535 void xmpp_greeting(void) {
 536         client_set_inbound_buf(4);
 537         strcpy(CC->cs_clientname, "XMPP session");
 538         CC->session_specific_data = malloc(sizeof(citxmpp));
 539         memset(XMPP, 0, sizeof(citxmpp));
 540         XMPP->last_event_processed = queue_event_seq;
 541
 542         /* XMPP does not use a greeting, but we still have to initialize some things. */
 543
 544         XMPP->xp = XML_ParserCreateNS("UTF-8", ':');
 545         if (XMPP->xp == NULL) {
 546                 CtdlLogPrintf(CTDL_ALERT, "Cannot create XML parser!\n");
 547                 CC->kill_me = 1;
 548                 return;
 549         }
 550
 551         XML_SetElementHandler(XMPP->xp, xmpp_xml_start, xmpp_xml_end);
 552         XML_SetCharacterDataHandler(XMPP->xp, xmpp_xml_chardata);
 553         // XML_SetUserData(XMPP->xp, something...);
 554
 555         /* Prevent the "billion laughs" attack against expat by disabling
 556          * internal entity expansion.  With 2.x, forcibly stop the parser
 557          * if an entity is declared - this is safer and a more obvious
 558          * failure mode.  With older versions, simply prevent expansion
 559          * of such entities. */
 560 #ifdef HAVE_XML_STOPPARSER
 561         XML_SetEntityDeclHandler(XMPP->xp, xmpp_entity_declaration);
 562 #else
 563         XML_SetDefaultHandler(XMPP->xp, NULL);
 564 #endif
 565
 566         CC->can_receive_im = 1;         /* This protocol is capable of receiving instant messages */
 567 }
 568
 569
 570 /*
 571  * Main command loop for XMPP sessions.
 572  */
 573 void xmpp_command_loop(void) {
 574         int rc;
 575         StrBuf *stream_input = NewStrBuf();
 576
 577         time(&CC->lastcmd);
 578         rc = client_read_random_blob(stream_input, 30);
 579         if (rc > 0) {
 580                 XML_Parse(XMPP->xp, ChrPtr(stream_input), rc, 0);
 581         }
 582         else {
 583                 CtdlLogPrintf(CTDL_ERR, "Client disconnected: ending session.\n");
 584                 CC->kill_me = 1;
 585         }
 586         FreeStrBuf(&stream_input);
 587 }
 588
 589
 590 /*
 591  * Async loop for XMPP sessions (handles the transmission of unsolicited stanzas)
 592  */
 593 void xmpp_async_loop(void) {
 594         xmpp_process_events();
 595         xmpp_output_incoming_messages();
 596 }
 597
 598
 599 /*
 600  * Login hook for XMPP sessions
 601  */
 602 void xmpp_login_hook(void) {
 603         xmpp_queue_event(XMPP_EVT_LOGIN, CC->cs_inet_email);
 604 }
 605
 606
 607 /*
 608  * Logout hook for XMPP sessions
 609  */
 610 void xmpp_logout_hook(void) {
 611         xmpp_queue_event(XMPP_EVT_LOGOUT, CC->cs_inet_email);
 612 }
 613
 614
 615 const char *CitadelServiceXMPP="XMPP";
 616
 617 CTDL_MODULE_INIT(xmpp)
 618 {
 619         if (!threading) {
 620                 CtdlRegisterServiceHook(config.c_xmpp_c2s_port,
 621                                         NULL,
 622                                         xmpp_greeting,
 623                                         xmpp_command_loop,
 624                                         xmpp_async_loop,
 625                                         CitadelServiceXMPP
 626                 );
 627                 CtdlRegisterSessionHook(xmpp_cleanup_function, EVT_STOP);
 628                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_LOGIN);
 629                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_LOGOUT);
 630                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_UNSTEALTH);
 631                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_STEALTH);
 632         }
 633
 634         /* return our Subversion id for the Log */
 635         return "$Id$";
 636 }