Changed how Message-ID RFC2822 field is generated
[citadel.git] / citadel / modules / xmpp / serv_xmpp.c
1 /*
2  * XMPP (Jabber) service for the Citadel system
3  * Copyright (c) 2007-2017 by Art Cancro and citadel.org
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
70 #ifdef HAVE_XML_STOPPARSER
71 /* Stop the parser if an entity declaration is hit. */
72 static void xmpp_entity_declaration(void *userData, const XML_Char *entityName,
73                                 int is_parameter_entity, const XML_Char *value,
74                                 int value_length, const XML_Char *base,
75                                 const XML_Char *systemId, const XML_Char *publicId,
76                                 const XML_Char *notationName
77 ) {
78         syslog(LOG_WARNING, "xmpp: illegal entity declaration encountered; stopping parser.");
79         XML_StopParser(XMPP->xp, XML_FALSE);
80 }
81 #endif
82
83
84
85 /*
86  * Given a source string and a target buffer, returns the string
87  * properly escaped for insertion into an XML stream.  Returns a
88  * pointer to the target buffer for convenience.
89  */
90 static inline int Ctdl_GetUtf8SequenceLength(const char *CharS, const char *CharE)
91 {
92         int n = 0;
93         unsigned char test = (1<<7);
94
95         if ((*CharS & 0xC0) != 0xC0) 
96                 return 1;
97
98         while ((n < 8) && 
99                ((test & ((unsigned char)*CharS)) != 0)) 
100         {
101                 test = test >> 1;
102                 n ++;
103         }
104         if ((n > 6) || ((CharE - CharS) < n))
105                 n = 0;
106         return n;
107 }
108
109 char *xmlesc(char *buf, char *str, int bufsiz)
110 {
111         int IsUtf8Sequence;
112         char *ptr, *pche;
113         unsigned char ch;
114         int inlen;
115         int len = 0;
116
117         if (!buf) return(NULL);
118         buf[0] = 0;
119         len = 0;
120         if (!str) {
121                 return(buf);
122         }
123         inlen = strlen(str);
124         pche = str + inlen;
125
126         for (ptr=str; *ptr; ptr++) {
127                 ch = *ptr;
128                 if (ch == '<') {
129                         strcpy(&buf[len], "&lt;");
130                         len += 4;
131                 }
132                 else if (ch == '>') {
133                         strcpy(&buf[len], "&gt;");
134                         len += 4;
135                 }
136                 else if (ch == '&') {
137                         strcpy(&buf[len], "&amp;");
138                         len += 5;
139                 }
140                 else if ((ch >= 0x20) && (ch <= 0x7F)) {
141                         buf[len++] = ch;
142                         buf[len] = 0;
143                 }
144                 else if (ch < 0x20) {
145                         /* we probably shouldn't be doing this */
146                         buf[len++] = '_';
147                         buf[len] = 0;
148                 }
149                 else {
150                         IsUtf8Sequence =  Ctdl_GetUtf8SequenceLength(ptr, pche);
151                         if (IsUtf8Sequence)
152                         {
153                                 while ((IsUtf8Sequence > 0) && 
154                                        (ptr < pche))
155                                 {
156                                         buf[len] = *ptr;
157                                         ptr ++;
158                                         --IsUtf8Sequence;
159                                 }
160                         }
161                         else
162                         {
163                                 char oct[10];
164                                 sprintf(oct, "&#%o;", ch);
165                                 strcpy(&buf[len], oct);
166                                 len += strlen(oct);
167                         }
168                 }
169                 if ((len + 6) > bufsiz) {
170                         return(buf);
171                 }
172         }
173         return(buf);
174 }
175
176
177 /*
178  * We have just received a <stream> tag from the client, so send them ours
179  */
180 void xmpp_stream_start(void *data, const char *supplied_el, const char **attr)
181 {
182         char xmlbuf[256];
183
184         while (*attr) {
185                 if (!strcasecmp(attr[0], "to")) {
186                         safestrncpy(XMPP->server_name, attr[1], sizeof XMPP->server_name);
187                 }
188                 attr += 2;
189         }
190
191         cprintf("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
192
193         cprintf("<stream:stream ");
194         cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->server_name, sizeof xmlbuf));
195         cprintf("id=\"%08x\" ", CC->cs_pid);
196         cprintf("version=\"1.0\" ");
197         cprintf("xmlns:stream=\"http://etherx.jabber.org/streams\" ");
198         cprintf("xmlns=\"jabber:client\">");
199
200         /* The features of this stream are... */
201         cprintf("<stream:features>");
202
203         /*
204          * TLS encryption (but only if it isn't already active)
205          */ 
206 #ifdef HAVE_OPENSSL
207         if (!CC->redirect_ssl) {
208                 cprintf("<starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'></starttls>");
209         }
210 #endif
211
212         if (!CC->logged_in) {
213                 /* If we're not logged in yet, offer SASL as our feature set */
214                 xmpp_output_auth_mechs();
215
216                 /* Also offer non-SASL authentication */
217                 cprintf("<auth xmlns=\"http://jabber.org/features/iq-auth\"/>");
218         }
219
220         /* Offer binding and sessions as part of our feature set */
221         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\"/>");
222         cprintf("<session xmlns=\"urn:ietf:params:xml:ns:xmpp-session\"/>");
223
224         cprintf("</stream:features>");
225
226         CC->is_async = 1;               /* XMPP sessions are inherently async-capable */
227 }
228
229
230 void xmpp_xml_start(void *data, const char *supplied_el, const char **attr) {
231         char el[256];
232         char *sep = NULL;
233         int i;
234
235         /* Axe the namespace, we don't care about it */
236         safestrncpy(el, supplied_el, sizeof el);
237         while (sep = strchr(el, ':'), sep) {
238                 strcpy(el, ++sep);
239         }
240
241         /*
242         syslog(LOG_DEBUG, "xmpp: ELEMENT START: <%s>", el);
243         for (i=0; attr[i] != NULL; i+=2) {
244                 syslog(LOG_DEBUG, "xmpp: Attribute '%s' = '%s'", attr[i], attr[i+1]);
245         }
246         uncomment for more verbosity */
247
248         if (!strcasecmp(el, "stream")) {
249                 xmpp_stream_start(data, supplied_el, attr);
250         }
251
252         else if (!strcasecmp(el, "query")) {
253                 XMPP->iq_query_xmlns[0] = 0;
254                 safestrncpy(XMPP->iq_query_xmlns, supplied_el, sizeof XMPP->iq_query_xmlns);
255         }
256
257         else if (!strcasecmp(el, "bind")) {
258                 XMPP->bind_requested = 1;
259         }
260
261         else if (!strcasecmp(el, "iq")) {
262                 for (i=0; attr[i] != NULL; i+=2) {
263                         if (!strcasecmp(attr[i], "type")) {
264                                 safestrncpy(XMPP->iq_type, attr[i+1], sizeof XMPP->iq_type);
265                         }
266                         else if (!strcasecmp(attr[i], "id")) {
267                                 safestrncpy(XMPP->iq_id, attr[i+1], sizeof XMPP->iq_id);
268                         }
269                         else if (!strcasecmp(attr[i], "from")) {
270                                 safestrncpy(XMPP->iq_from, attr[i+1], sizeof XMPP->iq_from);
271                         }
272                         else if (!strcasecmp(attr[i], "to")) {
273                                 safestrncpy(XMPP->iq_to, attr[i+1], sizeof XMPP->iq_to);
274                         }
275                 }
276         }
277
278         else if (!strcasecmp(el, "auth")) {
279                 XMPP->sasl_auth_mech[0] = 0;
280                 for (i=0; attr[i] != NULL; i+=2) {
281                         if (!strcasecmp(attr[i], "mechanism")) {
282                                 safestrncpy(XMPP->sasl_auth_mech, attr[i+1], sizeof XMPP->sasl_auth_mech);
283                         }
284                 }
285         }
286
287         else if (!strcasecmp(el, "message")) {
288                 for (i=0; attr[i] != NULL; i+=2) {
289                         if (!strcasecmp(attr[i], "to")) {
290                                 safestrncpy(XMPP->message_to, attr[i+1], sizeof XMPP->message_to);
291                         }
292                 }
293         }
294
295         else if (!strcasecmp(el, "html")) {
296                 ++XMPP->html_tag_level;
297         }
298 }
299
300
301
302 void xmpp_xml_end(void *data, const char *supplied_el) {
303         char el[256];
304         char *sep = NULL;
305         char xmlbuf[256];
306
307         /* Axe the namespace, we don't care about it */
308         safestrncpy(el, supplied_el, sizeof el);
309         while (sep = strchr(el, ':'), sep) {
310                 strcpy(el, ++sep);
311         }
312
313         /*
314         syslog(LOG_DEBUG, "xmpp: ELEMENT END  : <%s>", el);
315         if (XMPP->chardata_len > 0) {
316                 syslog(LOG_DEBUG, "xmpp: chardata: %s", XMPP->chardata);
317         }
318         uncomment for more verbosity */
319
320         if (!strcasecmp(el, "resource")) {
321                 if (XMPP->chardata_len > 0) {
322                         safestrncpy(XMPP->iq_client_resource, XMPP->chardata,
323                                 sizeof XMPP->iq_client_resource);
324                         striplt(XMPP->iq_client_resource);
325                 }
326         }
327
328         else if (!strcasecmp(el, "username")) {         /* NON SASL ONLY */
329                 if (XMPP->chardata_len > 0) {
330                         safestrncpy(XMPP->iq_client_username, XMPP->chardata,
331                                 sizeof XMPP->iq_client_username);
332                         striplt(XMPP->iq_client_username);
333                 }
334         }
335
336         else if (!strcasecmp(el, "password")) {         /* NON SASL ONLY */
337                 if (XMPP->chardata_len > 0) {
338                         safestrncpy(XMPP->iq_client_password, XMPP->chardata,
339                                 sizeof XMPP->iq_client_password);
340                         striplt(XMPP->iq_client_password);
341                 }
342         }
343
344         else if (!strcasecmp(el, "iq")) {
345
346                 /*
347                  * iq type="get" (handle queries)
348                  */
349                 if (!strcasecmp(XMPP->iq_type, "get")) {
350
351                         /*
352                          * Query on a namespace
353                          */
354                         if (!IsEmptyStr(XMPP->iq_query_xmlns)) {
355                                 xmpp_query_namespace(XMPP->iq_id, XMPP->iq_from,
356                                                 XMPP->iq_to, XMPP->iq_query_xmlns);
357                         }
358
359                         /*
360                          * ping ( http://xmpp.org/extensions/xep-0199.html )
361                          */
362                         else if (XMPP->ping_requested) {
363                                 cprintf("<iq type=\"result\" ");
364                                 if (!IsEmptyStr(XMPP->iq_from)) {
365                                         cprintf("to=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_from, sizeof xmlbuf));
366                                 }
367                                 if (!IsEmptyStr(XMPP->iq_to)) {
368                                         cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_to, sizeof xmlbuf));
369                                 }
370                                 cprintf("id=\"%s\"/>", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
371                         }
372
373                         /*
374                          * Unknown query ... return the XML equivalent of a blank stare
375                          */
376                         else {
377                                 syslog(LOG_DEBUG, "xmpp: Unknown query <%s> - returning <service-unavailable/>", el);
378                                 cprintf("<iq type=\"error\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
379                                 cprintf("<error code=\"503\" type=\"cancel\">"
380                                         "<service-unavailable xmlns=\"urn:ietf:params:xml:ns:xmpp-stanzas\"/>"
381                                         "</error>"
382                                 );
383                                 cprintf("</iq>");
384                         }
385                 }
386
387                 /*
388                  * Non SASL authentication
389                  */
390                 else if (
391                         (!strcasecmp(XMPP->iq_type, "set"))
392                         && (!strcasecmp(XMPP->iq_query_xmlns, "jabber:iq:auth:query"))
393                         ) {
394
395                         xmpp_non_sasl_authenticate(
396                                 XMPP->iq_id,
397                                 XMPP->iq_client_username,
398                                 XMPP->iq_client_password,
399                                 XMPP->iq_client_resource
400                         );
401                 }       
402
403                 /*
404                  * If this <iq> stanza was a "bind" attempt, process it ...
405                  */
406                 else if (
407                         (XMPP->bind_requested)
408                         && (!IsEmptyStr(XMPP->iq_id))
409                         && (!IsEmptyStr(XMPP->iq_client_resource))
410                         && (CC->logged_in)
411                         ) {
412
413                         /* Generate the "full JID" of the client resource */
414
415                         snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
416                                 "%s/%s",
417                                 CC->cs_inet_email,
418                                 XMPP->iq_client_resource
419                         );
420
421                         /* Tell the client what its JID is */
422
423                         cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
424                         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\">");
425                         cprintf("<jid>%s</jid>", xmlesc(xmlbuf, XMPP->client_jid, sizeof xmlbuf));
426                         cprintf("</bind>");
427                         cprintf("</iq>");
428                 }
429
430                 else if (XMPP->iq_session) {
431                         cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
432                         cprintf("</iq>");
433                 }
434
435                 else {
436                         cprintf("<iq type=\"error\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
437                         cprintf("<error>Don't know howto do '%s'!</error>", xmlesc(xmlbuf, XMPP->iq_type, sizeof xmlbuf));
438                         cprintf("</iq>");
439                 }
440
441                 /* Now clear these fields out so they don't get used by a future stanza */
442                 XMPP->iq_id[0] = 0;
443                 XMPP->iq_from[0] = 0;
444                 XMPP->iq_to[0] = 0;
445                 XMPP->iq_type[0] = 0;
446                 XMPP->iq_client_resource[0] = 0;
447                 XMPP->iq_session = 0;
448                 XMPP->iq_query_xmlns[0] = 0;
449                 XMPP->bind_requested = 0;
450                 XMPP->ping_requested = 0;
451         }
452
453         else if (!strcasecmp(el, "auth")) {
454
455                 /* Try to authenticate (this function is responsible for the output stanza) */
456                 xmpp_sasl_auth(XMPP->sasl_auth_mech, (XMPP->chardata != NULL ? XMPP->chardata : "") );
457
458                 /* Now clear these fields out so they don't get used by a future stanza */
459                 XMPP->sasl_auth_mech[0] = 0;
460         }
461
462         else if (!strcasecmp(el, "session")) {
463                 XMPP->iq_session = 1;
464         }
465
466         else if (!strcasecmp(el, "presence")) {
467
468                 /* Respond to a <presence> update by firing back with presence information
469                  * on the entire wholist.  Check this assumption, it's probably wrong.
470                  */
471                 xmpp_wholist_presence_dump();
472         }
473
474         else if ( (!strcasecmp(el, "body")) && (XMPP->html_tag_level == 0) ) {
475                 if (XMPP->message_body != NULL) {
476                         free(XMPP->message_body);
477                         XMPP->message_body = NULL;
478                 }
479                 if (XMPP->chardata_len > 0) {
480                         XMPP->message_body = strdup(XMPP->chardata);
481                 }
482         }
483
484         else if (!strcasecmp(el, "message")) {
485                 xmpp_send_message(XMPP->message_to, XMPP->message_body);
486                 XMPP->html_tag_level = 0;
487         }
488
489         else if (!strcasecmp(el, "html")) {
490                 --XMPP->html_tag_level;
491         }
492
493         else if (!strcasecmp(el, "starttls")) {
494 #ifdef HAVE_OPENSSL
495                 cprintf("<proceed xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
496                 CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
497                 if (!CC->redirect_ssl) CC->kill_me = KILLME_NO_CRYPTO;
498 #else
499                 cprintf("<failure xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
500                 CC->kill_me = KILLME_NO_CRYPTO;
501 #endif
502         }
503
504         else if (!strcasecmp(el, "ping")) {
505                 XMPP->ping_requested = 1;
506         }
507
508         else if (!strcasecmp(el, "stream")) {
509                 syslog(LOG_DEBUG, "xmpp: client shut down their stream");
510                 xmpp_massacre_roster();
511                 cprintf("</stream>\n");
512                 CC->kill_me = KILLME_CLIENT_LOGGED_OUT;
513         }
514
515         else if (!strcasecmp(el, "query")) {
516                 /* already processed , no further action needed here */
517         }
518
519         else if (!strcasecmp(el, "bind")) {
520                 /* already processed , no further action needed here */
521         }
522
523         else {
524                 syslog(LOG_DEBUG, "xmpp: ignoring unknown tag <%s>", el);
525         }
526
527         XMPP->chardata_len = 0;
528         if (XMPP->chardata_alloc > 0) {
529                 XMPP->chardata[0] = 0;
530         }
531 }
532
533
534 void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
535 {
536         citxmpp *X = XMPP;
537
538         if (X->chardata_alloc == 0) {
539                 X->chardata_alloc = SIZ;
540                 X->chardata = malloc(X->chardata_alloc);
541         }
542         if ((X->chardata_len + len + 1) > X->chardata_alloc) {
543                 X->chardata_alloc = X->chardata_len + len + 1024;
544                 X->chardata = realloc(X->chardata, X->chardata_alloc);
545         }
546         memcpy(&X->chardata[X->chardata_len], s, len);
547         X->chardata_len += len;
548         X->chardata[X->chardata_len] = 0;
549 }
550
551
552 /*
553  * This cleanup function blows away the temporary memory and files used by the XMPP service.
554  */
555 void xmpp_cleanup_function(void) {
556
557         /* Don't do this stuff if this is not a XMPP session! */
558         if (CC->h_command_function != xmpp_command_loop) return;
559
560         if (XMPP->chardata != NULL) {
561                 free(XMPP->chardata);
562                 XMPP->chardata = NULL;
563                 XMPP->chardata_len = 0;
564                 XMPP->chardata_alloc = 0;
565                 if (XMPP->message_body != NULL) {
566                         free(XMPP->message_body);
567                 }
568         }
569         XML_ParserFree(XMPP->xp);
570         free(XMPP);
571 }
572
573
574
575 /*
576  * Here's where our XMPP session begins its happy day.
577  */
578 void xmpp_greeting(void) {
579         client_set_inbound_buf(4);
580         strcpy(CC->cs_clientname, "XMPP session");
581         CC->session_specific_data = malloc(sizeof(citxmpp));
582         memset(XMPP, 0, sizeof(citxmpp));
583         XMPP->last_event_processed = queue_event_seq;
584
585         /* XMPP does not use a greeting, but we still have to initialize some things. */
586
587         XMPP->xp = XML_ParserCreateNS("UTF-8", ':');
588         if (XMPP->xp == NULL) {
589                 syslog(LOG_ERR, "xmpp: cannot create XML parser");
590                 CC->kill_me = KILLME_XML_PARSER;
591                 return;
592         }
593
594         XML_SetElementHandler(XMPP->xp, xmpp_xml_start, xmpp_xml_end);
595         XML_SetCharacterDataHandler(XMPP->xp, xmpp_xml_chardata);
596         // XML_SetUserData(XMPP->xp, something...);
597
598         /* Prevent the "billion laughs" attack against expat by disabling
599          * internal entity expansion.  With 2.x, forcibly stop the parser
600          * if an entity is declared - this is safer and a more obvious
601          * failure mode.  With older versions, simply prevent expansion
602          * of such entities. */
603 #ifdef HAVE_XML_STOPPARSER
604         XML_SetEntityDeclHandler(XMPP->xp, xmpp_entity_declaration);
605 #else
606         XML_SetDefaultHandler(XMPP->xp, NULL);
607 #endif
608
609         CC->can_receive_im = 1;         /* This protocol is capable of receiving instant messages */
610 }
611
612
613 /* 
614  * Main command loop for XMPP sessions.
615  */
616 void xmpp_command_loop(void) {
617         int rc;
618         StrBuf *stream_input = NewStrBuf();
619
620         time(&CC->lastcmd);
621         rc = client_read_random_blob(stream_input, 30);
622         if (rc > 0) {
623                 XML_Parse(XMPP->xp, ChrPtr(stream_input), rc, 0);
624         }
625         else {
626                 syslog(LOG_ERR, "xmpp: client disconnected: ending session.");
627                 CC->kill_me = KILLME_CLIENT_DISCONNECTED;
628         }
629         FreeStrBuf(&stream_input);
630 }
631
632
633 /*
634  * Async loop for XMPP sessions (handles the transmission of unsolicited stanzas)
635  */
636 void xmpp_async_loop(void) {
637         xmpp_process_events();
638         xmpp_output_incoming_messages();
639 }
640
641
642 /*
643  * Login hook for XMPP sessions
644  */
645 void xmpp_login_hook(void) {
646         xmpp_queue_event(XMPP_EVT_LOGIN, CC->cs_inet_email);
647 }
648
649
650 /*
651  * Logout hook for XMPP sessions
652  */
653 void xmpp_logout_hook(void) {
654         xmpp_queue_event(XMPP_EVT_LOGOUT, CC->cs_inet_email);
655 }
656
657
658 const char *CitadelServiceXMPP="XMPP";
659 extern void xmpp_cleanup_events(void);
660 CTDL_MODULE_INIT(xmpp)
661 {
662         if (!threading) {
663                 CtdlRegisterServiceHook(CtdlGetConfigInt("c_xmpp_c2s_port"),
664                                         NULL,
665                                         xmpp_greeting,
666                                         xmpp_command_loop,
667                                         xmpp_async_loop,
668                                         CitadelServiceXMPP
669                 );
670                 CtdlRegisterSessionHook(xmpp_cleanup_function, EVT_STOP, PRIO_STOP + 70);
671                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_LOGIN, PRIO_LOGIN + 90);
672                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_LOGOUT, PRIO_LOGOUT + 90);
673                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_UNSTEALTH, PRIO_UNSTEALTH + 1);
674                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_STEALTH, PRIO_STEALTH + 1);
675                 CtdlRegisterCleanupHook(xmpp_cleanup_events);
676
677         }
678
679         /* return our module name for the log */
680         return "xmpp";
681 }