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 /* XML_StopParser is present in expat 2.x */
  61 #if XML_MAJOR_VERSION > 1
  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         /*
 168          * TLS encryption (but only if it isn't already active)
 169          */
 170 #ifdef HAVE_OPENSSL
 171         if (!CC->redirect_ssl) {
 172                 cprintf("<starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'></starttls>");
 173         }
 174 #endif
 175
 176         if (!CC->logged_in) {
 177                 /* If we're not logged in yet, offer SASL as our feature set */
 178                 xmpp_output_auth_mechs();
 179
 180                 /* Also offer non-SASL authentication */
 181                 cprintf("<auth xmlns=\"http://jabber.org/features/iq-auth\"/>");
 182         }
 183
 184         /* Offer binding and sessions as part of our feature set */
 185         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\"/>");
 186         cprintf("<session xmlns=\"urn:ietf:params:xml:ns:xmpp-session\"/>");
 187
 188         cprintf("</stream:features>");
 189
 190         CC->is_async = 1;               /* XMPP sessions are inherently async-capable */
 191 }
 192
 193
 194 void xmpp_xml_start(void *data, const char *supplied_el, const char **attr) {
 195         char el[256];
 196         char *sep = NULL;
 197         int i;
 198
 199         /* Axe the namespace, we don't care about it */
 200         safestrncpy(el, supplied_el, sizeof el);
 201         while (sep = strchr(el, ':'), sep) {
 202                 strcpy(el, ++sep);
 203         }
 204
 205         /*
 206         syslog(LOG_DEBUG, "XMPP ELEMENT START: <%s>\n", el);
 207         for (i=0; attr[i] != NULL; i+=2) {
 208                 syslog(LOG_DEBUG, "                    Attribute '%s' = '%s'\n", attr[i], attr[i+1]);
 209         }
 210         uncomment for more verbosity */
 211
 212         if (!strcasecmp(el, "stream")) {
 213                 xmpp_stream_start(data, supplied_el, attr);
 214         }
 215
 216         else if (!strcasecmp(el, "query")) {
 217                 XMPP->iq_query_xmlns[0] = 0;
 218                 safestrncpy(XMPP->iq_query_xmlns, supplied_el, sizeof XMPP->iq_query_xmlns);
 219         }
 220
 221         else if (!strcasecmp(el, "bind")) {
 222                 XMPP->bind_requested = 1;
 223         }
 224
 225         else if (!strcasecmp(el, "iq")) {
 226                 for (i=0; attr[i] != NULL; i+=2) {
 227                         if (!strcasecmp(attr[i], "type")) {
 228                                 safestrncpy(XMPP->iq_type, attr[i+1], sizeof XMPP->iq_type);
 229                         }
 230                         else if (!strcasecmp(attr[i], "id")) {
 231                                 safestrncpy(XMPP->iq_id, attr[i+1], sizeof XMPP->iq_id);
 232                         }
 233                         else if (!strcasecmp(attr[i], "from")) {
 234                                 safestrncpy(XMPP->iq_from, attr[i+1], sizeof XMPP->iq_from);
 235                         }
 236                         else if (!strcasecmp(attr[i], "to")) {
 237                                 safestrncpy(XMPP->iq_to, attr[i+1], sizeof XMPP->iq_to);
 238                         }
 239                 }
 240         }
 241
 242         else if (!strcasecmp(el, "auth")) {
 243                 XMPP->sasl_auth_mech[0] = 0;
 244                 for (i=0; attr[i] != NULL; i+=2) {
 245                         if (!strcasecmp(attr[i], "mechanism")) {
 246                                 safestrncpy(XMPP->sasl_auth_mech, attr[i+1], sizeof XMPP->sasl_auth_mech);
 247                         }
 248                 }
 249         }
 250
 251         else if (!strcasecmp(el, "message")) {
 252                 for (i=0; attr[i] != NULL; i+=2) {
 253                         if (!strcasecmp(attr[i], "to")) {
 254                                 safestrncpy(XMPP->message_to, attr[i+1], sizeof XMPP->message_to);
 255                         }
 256                 }
 257         }
 258
 259         else if (!strcasecmp(el, "html")) {
 260                 ++XMPP->html_tag_level;
 261         }
 262 }
 263
 264
 265
 266 void xmpp_xml_end(void *data, const char *supplied_el) {
 267         char el[256];
 268         char *sep = NULL;
 269         char xmlbuf[256];
 270
 271         /* Axe the namespace, we don't care about it */
 272         safestrncpy(el, supplied_el, sizeof el);
 273         while (sep = strchr(el, ':'), sep) {
 274                 strcpy(el, ++sep);
 275         }
 276
 277         /*
 278         syslog(LOG_DEBUG, "XMPP ELEMENT END  : <%s>\n", el);
 279         if (XMPP->chardata_len > 0) {
 280                 syslog(LOG_DEBUG, "          chardata: %s\n", XMPP->chardata);
 281         }
 282         uncomment for more verbosity */
 283
 284         if (!strcasecmp(el, "resource")) {
 285                 if (XMPP->chardata_len > 0) {
 286                         safestrncpy(XMPP->iq_client_resource, XMPP->chardata,
 287                                 sizeof XMPP->iq_client_resource);
 288                         striplt(XMPP->iq_client_resource);
 289                 }
 290         }
 291
 292         else if (!strcasecmp(el, "username")) {         /* NON SASL ONLY */
 293                 if (XMPP->chardata_len > 0) {
 294                         safestrncpy(XMPP->iq_client_username, XMPP->chardata,
 295                                 sizeof XMPP->iq_client_username);
 296                         striplt(XMPP->iq_client_username);
 297                 }
 298         }
 299
 300         else if (!strcasecmp(el, "password")) {         /* NON SASL ONLY */
 301                 if (XMPP->chardata_len > 0) {
 302                         safestrncpy(XMPP->iq_client_password, XMPP->chardata,
 303                                 sizeof XMPP->iq_client_password);
 304                         striplt(XMPP->iq_client_password);
 305                 }
 306         }
 307
 308         else if (!strcasecmp(el, "iq")) {
 309
 310                 /*
 311                  * iq type="get" (handle queries)
 312                  */
 313                 if (!strcasecmp(XMPP->iq_type, "get")) {
 314
 315                         /*
 316                          * Query on a namespace
 317                          */
 318                         if (!IsEmptyStr(XMPP->iq_query_xmlns)) {
 319                                 xmpp_query_namespace(XMPP->iq_id, XMPP->iq_from,
 320                                                 XMPP->iq_to, XMPP->iq_query_xmlns);
 321                         }
 322
 323                         /*
 324                          * ping ( http://xmpp.org/extensions/xep-0199.html )
 325                          */
 326                         else if (XMPP->ping_requested) {
 327                                 cprintf("<iq type=\"result\" ");
 328                                 if (!IsEmptyStr(XMPP->iq_from)) {
 329                                         cprintf("to=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_from, sizeof xmlbuf));
 330                                 }
 331                                 if (!IsEmptyStr(XMPP->iq_to)) {
 332                                         cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_to, sizeof xmlbuf));
 333                                 }
 334                                 cprintf("id=\"%s\"/>", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 335                         }
 336
 337                         /*
 338                          * Unknown query ... return the XML equivalent of a blank stare
 339                          */
 340                         else {
 341                                 syslog(LOG_DEBUG,
 342                                         "Unknown query <%s> - returning <service-unavailable/>\n",
 343                                         el
 344                                 );
 345                                 cprintf("<iq type=\"error\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 346                                 cprintf("<error code=\"503\" type=\"cancel\">"
 347                                         "<service-unavailable xmlns=\"urn:ietf:params:xml:ns:xmpp-stanzas\"/>"
 348                                         "</error>"
 349                                 );
 350                                 cprintf("</iq>");
 351                         }
 352                 }
 353
 354                 /*
 355                  * Non SASL authentication
 356                  */
 357                 else if (
 358                         (!strcasecmp(XMPP->iq_type, "set"))
 359                         && (!strcasecmp(XMPP->iq_query_xmlns, "jabber:iq:auth:query"))
 360                         ) {
 361
 362                         xmpp_non_sasl_authenticate(
 363                                 XMPP->iq_id,
 364                                 XMPP->iq_client_username,
 365                                 XMPP->iq_client_password,
 366                                 XMPP->iq_client_resource
 367                         );
 368                 }
 369
 370                 /*
 371                  * If this <iq> stanza was a "bind" attempt, process it ...
 372                  */
 373                 else if (
 374                         (XMPP->bind_requested)
 375                         && (!IsEmptyStr(XMPP->iq_id))
 376                         && (!IsEmptyStr(XMPP->iq_client_resource))
 377                         && (CC->logged_in)
 378                         ) {
 379
 380                         /* Generate the "full JID" of the client resource */
 381
 382                         snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
 383                                 "%s/%s",
 384                                 CC->cs_inet_email,
 385                                 XMPP->iq_client_resource
 386                         );
 387
 388                         /* Tell the client what its JID is */
 389
 390                         cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 391                         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\">");
 392                         cprintf("<jid>%s</jid>", xmlesc(xmlbuf, XMPP->client_jid, sizeof xmlbuf));
 393                         cprintf("</bind>");
 394                         cprintf("</iq>");
 395                 }
 396
 397                 else if (XMPP->iq_session) {
 398                         cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 399                         cprintf("</iq>");
 400                 }
 401
 402                 else {
 403                         cprintf("<iq type=\"error\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 404                         cprintf("<error>Don't know howto do '%s'!</error>", xmlesc(xmlbuf, XMPP->iq_type, sizeof xmlbuf));
 405                         cprintf("</iq>");
 406                 }
 407
 408                 /* Now clear these fields out so they don't get used by a future stanza */
 409                 XMPP->iq_id[0] = 0;
 410                 XMPP->iq_from[0] = 0;
 411                 XMPP->iq_to[0] = 0;
 412                 XMPP->iq_type[0] = 0;
 413                 XMPP->iq_client_resource[0] = 0;
 414                 XMPP->iq_session = 0;
 415                 XMPP->iq_query_xmlns[0] = 0;
 416                 XMPP->bind_requested = 0;
 417                 XMPP->ping_requested = 0;
 418         }
 419
 420         else if (!strcasecmp(el, "auth")) {
 421
 422                 /* Try to authenticate (this function is responsible for the output stanza) */
 423                 xmpp_sasl_auth(XMPP->sasl_auth_mech, (XMPP->chardata != NULL ? XMPP->chardata : "") );
 424
 425                 /* Now clear these fields out so they don't get used by a future stanza */
 426                 XMPP->sasl_auth_mech[0] = 0;
 427         }
 428
 429         else if (!strcasecmp(el, "session")) {
 430                 XMPP->iq_session = 1;
 431         }
 432
 433         else if (!strcasecmp(el, "presence")) {
 434
 435                 /* Respond to a <presence> update by firing back with presence information
 436                  * on the entire wholist.  Check this assumption, it's probably wrong.
 437                  */
 438                 xmpp_wholist_presence_dump();
 439         }
 440
 441         else if ( (!strcasecmp(el, "body")) && (XMPP->html_tag_level == 0) ) {
 442                 if (XMPP->message_body != NULL) {
 443                         free(XMPP->message_body);
 444                         XMPP->message_body = NULL;
 445                 }
 446                 if (XMPP->chardata_len > 0) {
 447                         XMPP->message_body = strdup(XMPP->chardata);
 448                 }
 449         }
 450
 451         else if (!strcasecmp(el, "message")) {
 452                 xmpp_send_message(XMPP->message_to, XMPP->message_body);
 453                 XMPP->html_tag_level = 0;
 454         }
 455
 456         else if (!strcasecmp(el, "html")) {
 457                 --XMPP->html_tag_level;
 458         }
 459
 460         else if (!strcasecmp(el, "starttls")) {
 461 #ifdef HAVE_OPENSSL
 462                 cprintf("<proceed xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 463                 CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
 464                 if (!CC->redirect_ssl) CC->kill_me = KILLME_NO_CRYPTO;
 465 #else
 466                 cprintf("<failure xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 467                 CC->kill_me = KILLME_NO_CRYPTO;
 468 #endif
 469         }
 470
 471         else if (!strcasecmp(el, "ping")) {
 472                 XMPP->ping_requested = 1;
 473         }
 474
 475         else if (!strcasecmp(el, "stream")) {
 476                 syslog(LOG_DEBUG, "XMPP client shut down their stream\n");
 477                 xmpp_massacre_roster();
 478                 cprintf("</stream>\n");
 479                 CC->kill_me = KILLME_CLIENT_LOGGED_OUT;
 480         }
 481
 482         else {
 483                 syslog(LOG_DEBUG, "Ignoring unknown tag <%s>\n", el);
 484         }
 485
 486         XMPP->chardata_len = 0;
 487         if (XMPP->chardata_alloc > 0) {
 488                 XMPP->chardata[0] = 0;
 489         }
 490 }
 491
 492
 493 void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
 494 {
 495         citxmpp *X = XMPP;
 496
 497         if (X->chardata_alloc == 0) {
 498                 X->chardata_alloc = SIZ;
 499                 X->chardata = malloc(X->chardata_alloc);
 500         }
 501         if ((X->chardata_len + len + 1) > X->chardata_alloc) {
 502                 X->chardata_alloc = X->chardata_len + len + 1024;
 503                 X->chardata = realloc(X->chardata, X->chardata_alloc);
 504         }
 505         memcpy(&X->chardata[X->chardata_len], s, len);
 506         X->chardata_len += len;
 507         X->chardata[X->chardata_len] = 0;
 508 }
 509
 510
 511 /*
 512  * This cleanup function blows away the temporary memory and files used by the XMPP service.
 513  */
 514 void xmpp_cleanup_function(void) {
 515
 516         /* Don't do this stuff if this is not a XMPP session! */
 517         if (CC->h_command_function != xmpp_command_loop) return;
 518
 519         if (XMPP->chardata != NULL) {
 520                 free(XMPP->chardata);
 521                 XMPP->chardata = NULL;
 522                 XMPP->chardata_len = 0;
 523                 XMPP->chardata_alloc = 0;
 524                 if (XMPP->message_body != NULL) {
 525                         free(XMPP->message_body);
 526                 }
 527         }
 528         XML_ParserFree(XMPP->xp);
 529         free(XMPP);
 530 }
 531
 532
 533
 534 /*
 535  * Here's where our XMPP session begins its happy day.
 536  */
 537 void xmpp_greeting(void) {
 538         client_set_inbound_buf(4);
 539         strcpy(CC->cs_clientname, "XMPP session");
 540         CC->session_specific_data = malloc(sizeof(citxmpp));
 541         memset(XMPP, 0, sizeof(citxmpp));
 542         XMPP->last_event_processed = queue_event_seq;
 543
 544         /* XMPP does not use a greeting, but we still have to initialize some things. */
 545
 546         XMPP->xp = XML_ParserCreateNS("UTF-8", ':');
 547         if (XMPP->xp == NULL) {
 548                 syslog(LOG_ALERT, "Cannot create XML parser!\n");
 549                 CC->kill_me = KILLME_XML_PARSER;
 550                 return;
 551         }
 552
 553         XML_SetElementHandler(XMPP->xp, xmpp_xml_start, xmpp_xml_end);
 554         XML_SetCharacterDataHandler(XMPP->xp, xmpp_xml_chardata);
 555         // XML_SetUserData(XMPP->xp, something...);
 556
 557         /* Prevent the "billion laughs" attack against expat by disabling
 558          * internal entity expansion.  With 2.x, forcibly stop the parser
 559          * if an entity is declared - this is safer and a more obvious
 560          * failure mode.  With older versions, simply prevent expansion
 561          * of such entities. */
 562 #ifdef HAVE_XML_STOPPARSER
 563         XML_SetEntityDeclHandler(XMPP->xp, xmpp_entity_declaration);
 564 #else
 565         XML_SetDefaultHandler(XMPP->xp, NULL);
 566 #endif
 567
 568         CC->can_receive_im = 1;         /* This protocol is capable of receiving instant messages */
 569 }
 570
 571
 572 /*
 573  * Main command loop for XMPP sessions.
 574  */
 575 void xmpp_command_loop(void) {
 576         int rc;
 577         StrBuf *stream_input = NewStrBuf();
 578
 579         time(&CC->lastcmd);
 580         rc = client_read_random_blob(stream_input, 30);
 581         if (rc > 0) {
 582                 XML_Parse(XMPP->xp, ChrPtr(stream_input), rc, 0);
 583         }
 584         else {
 585                 syslog(LOG_ERR, "XMPP: client disconnected: ending session.\n");
 586                 CC->kill_me = KILLME_CLIENT_DISCONNECTED;
 587         }
 588         FreeStrBuf(&stream_input);
 589 }
 590
 591
 592 /*
 593  * Async loop for XMPP sessions (handles the transmission of unsolicited stanzas)
 594  */
 595 void xmpp_async_loop(void) {
 596         xmpp_process_events();
 597         xmpp_output_incoming_messages();
 598 }
 599
 600
 601 /*
 602  * Login hook for XMPP sessions
 603  */
 604 void xmpp_login_hook(void) {
 605         xmpp_queue_event(XMPP_EVT_LOGIN, CC->cs_inet_email);
 606 }
 607
 608
 609 /*
 610  * Logout hook for XMPP sessions
 611  */
 612 void xmpp_logout_hook(void) {
 613         xmpp_queue_event(XMPP_EVT_LOGOUT, CC->cs_inet_email);
 614 }
 615
 616
 617 const char *CitadelServiceXMPP="XMPP";
 618 extern void xmpp_cleanup_events(void);
 619 CTDL_MODULE_INIT(xmpp)
 620 {
 621         if (!threading) {
 622                 CtdlRegisterServiceHook(config.c_xmpp_c2s_port,
 623                                         NULL,
 624                                         xmpp_greeting,
 625                                         xmpp_command_loop,
 626                                         xmpp_async_loop,
 627                                         CitadelServiceXMPP
 628                 );
 629                 CtdlRegisterSessionHook(xmpp_cleanup_function, EVT_STOP);
 630                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_LOGIN);
 631                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_LOGOUT);
 632                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_UNSTEALTH);
 633                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_STEALTH);
 634                 CtdlRegisterCleanupHook(xmpp_cleanup_events);
 635
 636         }
 637
 638         /* return our module name for the log */
 639         return "xmpp";
 640 }