2 * XMPP (Jabber) service for the Citadel system
3 * Copyright (c) 2007-2011 by Art Cancro
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.
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.
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
28 #include <sys/types.h>
30 #if TIME_WITH_SYS_TIME
31 # include <sys/time.h>
35 # include <sys/time.h>
45 #include <libcitadel.h>
49 #include "citserver.h"
55 #include "internet_addressing.h"
57 #include "ctdl_module.h"
58 #include "serv_xmpp.h"
60 /* XML_StopParser is present in expat 2.x */
61 #if XML_MAJOR_VERSION > 1
62 #define HAVE_XML_STOPPARSER
65 struct xmpp_event *xmpp_queue = NULL;
67 int XMPPSrvDebugEnable = 0;
71 #ifdef HAVE_XML_STOPPARSER
72 /* Stop the parser if an entity declaration is hit. */
73 static void xmpp_entity_declaration(void *userData, const XML_Char *entityName,
74 int is_parameter_entity, const XML_Char *value,
75 int value_length, const XML_Char *base,
76 const XML_Char *systemId, const XML_Char *publicId,
77 const XML_Char *notationName
79 XMPPM_syslog(LOG_WARNING, "Illegal entity declaration encountered; stopping parser.");
80 XML_StopParser(XMPP->xp, XML_FALSE);
84 static inline int XMPP_GetUtf8SequenceLength(const char *CharS, const char *CharE)
86 /* if this is is migrated to strbuf, remove this copy. */
88 unsigned char test = (1<<7);
90 if ((*CharS & 0xC0) != 0xC0)
94 ((test & ((unsigned char)*CharS)) != 0))
99 if ((n > 6) || ((CharE - CharS) < n))
106 * Given a source string and a target buffer, returns the string
107 * properly escaped for insertion into an XML stream. Returns a
108 * pointer to the target buffer for convenience.
110 * BUG: this does not properly handle UTF-8
112 char *xmlesc(char *buf, char *str, int bufsiz)
121 if (!buf) return(NULL);
131 for (ptr=str; *ptr; ptr++) {
134 strcpy(&buf[len], "<");
137 else if (ch == '>') {
138 strcpy(&buf[len], ">");
141 else if (ch == '&') {
142 strcpy(&buf[len], "&");
145 else if ((ch >= 0x20) && (ch <= 0x7F)) {
149 else if (ch < 0x20) {
150 /* we probably shouldn't be doing this */
157 IsUtf8Sequence = XMPP_GetUtf8SequenceLength(&buf[len], eiptr);
160 while (IsUtf8Sequence > 0){
163 if (--IsUtf8Sequence)
170 sprintf(oct, "&#%o;", ch);
171 strcpy(&buf[len], oct);
175 if ((len + 6) > bufsiz) {
184 * We have just received a <stream> tag from the client, so send them ours
186 void xmpp_stream_start(void *data, const char *supplied_el, const char **attr)
191 if (!strcasecmp(attr[0], "to")) {
192 safestrncpy(XMPP->server_name, attr[1], sizeof XMPP->server_name);
197 cprintf("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
199 cprintf("<stream:stream ");
200 cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->server_name, sizeof xmlbuf));
201 cprintf("id=\"%08x\" ", CC->cs_pid);
202 cprintf("version=\"1.0\" ");
203 cprintf("xmlns:stream=\"http://etherx.jabber.org/streams\" ");
204 cprintf("xmlns=\"jabber:client\">");
206 /* The features of this stream are... */
207 cprintf("<stream:features>");
210 * TLS encryption (but only if it isn't already active)
213 if (!CC->redirect_ssl) {
214 cprintf("<starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'></starttls>");
218 if (!CC->logged_in) {
219 /* If we're not logged in yet, offer SASL as our feature set */
220 xmpp_output_auth_mechs();
222 /* Also offer non-SASL authentication */
223 cprintf("<auth xmlns=\"http://jabber.org/features/iq-auth\"/>");
226 /* Offer binding and sessions as part of our feature set */
227 cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\"/>");
228 cprintf("<session xmlns=\"urn:ietf:params:xml:ns:xmpp-session\"/>");
230 cprintf("</stream:features>");
232 CC->is_async = 1; /* XMPP sessions are inherently async-capable */
236 void xmpp_xml_start(void *data, const char *supplied_el, const char **attr) {
241 /* Axe the namespace, we don't care about it */
242 safestrncpy(el, supplied_el, sizeof el);
243 while (sep = strchr(el, ':'), sep) {
248 XMPP_syslog(LOG_DEBUG, "XMPP ELEMENT START: <%s>\n", el);
249 for (i=0; attr[i] != NULL; i+=2) {
250 XMPP_syslog(LOG_DEBUG, " Attribute '%s' = '%s'\n", attr[i], attr[i+1]);
252 uncomment for more verbosity */
254 if (!strcasecmp(el, "stream")) {
255 xmpp_stream_start(data, supplied_el, attr);
258 else if (!strcasecmp(el, "query")) {
259 XMPP->iq_query_xmlns[0] = 0;
260 safestrncpy(XMPP->iq_query_xmlns, supplied_el, sizeof XMPP->iq_query_xmlns);
263 else if (!strcasecmp(el, "bind")) {
264 XMPP->bind_requested = 1;
267 else if (!strcasecmp(el, "iq")) {
268 for (i=0; attr[i] != NULL; i+=2) {
269 if (!strcasecmp(attr[i], "type")) {
270 safestrncpy(XMPP->iq_type, attr[i+1], sizeof XMPP->iq_type);
272 else if (!strcasecmp(attr[i], "id")) {
273 safestrncpy(XMPP->iq_id, attr[i+1], sizeof XMPP->iq_id);
275 else if (!strcasecmp(attr[i], "from")) {
276 safestrncpy(XMPP->iq_from, attr[i+1], sizeof XMPP->iq_from);
278 else if (!strcasecmp(attr[i], "to")) {
279 safestrncpy(XMPP->iq_to, attr[i+1], sizeof XMPP->iq_to);
284 else if (!strcasecmp(el, "auth")) {
285 XMPP->sasl_auth_mech[0] = 0;
286 for (i=0; attr[i] != NULL; i+=2) {
287 if (!strcasecmp(attr[i], "mechanism")) {
288 safestrncpy(XMPP->sasl_auth_mech, attr[i+1], sizeof XMPP->sasl_auth_mech);
293 else if (!strcasecmp(el, "message")) {
294 for (i=0; attr[i] != NULL; i+=2) {
295 if (!strcasecmp(attr[i], "to")) {
296 safestrncpy(XMPP->message_to, attr[i+1], sizeof XMPP->message_to);
301 else if (!strcasecmp(el, "html")) {
302 ++XMPP->html_tag_level;
308 void xmpp_xml_end(void *data, const char *supplied_el) {
313 /* Axe the namespace, we don't care about it */
314 safestrncpy(el, supplied_el, sizeof el);
315 while (sep = strchr(el, ':'), sep) {
320 XMPP_syslog(LOG_DEBUG, "XMPP ELEMENT END : <%s>\n", el);
321 if (XMPP->chardata_len > 0) {
322 XMPP_syslog(LOG_DEBUG, " chardata: %s\n", XMPP->chardata);
324 uncomment for more verbosity */
326 if (!strcasecmp(el, "resource")) {
327 if (XMPP->chardata_len > 0) {
328 safestrncpy(XMPP->iq_client_resource, XMPP->chardata,
329 sizeof XMPP->iq_client_resource);
330 striplt(XMPP->iq_client_resource);
334 else if (!strcasecmp(el, "username")) { /* NON SASL ONLY */
335 if (XMPP->chardata_len > 0) {
336 safestrncpy(XMPP->iq_client_username, XMPP->chardata,
337 sizeof XMPP->iq_client_username);
338 striplt(XMPP->iq_client_username);
342 else if (!strcasecmp(el, "password")) { /* NON SASL ONLY */
343 if (XMPP->chardata_len > 0) {
344 safestrncpy(XMPP->iq_client_password, XMPP->chardata,
345 sizeof XMPP->iq_client_password);
346 striplt(XMPP->iq_client_password);
350 else if (!strcasecmp(el, "iq")) {
353 * iq type="get" (handle queries)
355 if (!strcasecmp(XMPP->iq_type, "get")) {
358 * Query on a namespace
360 if (!IsEmptyStr(XMPP->iq_query_xmlns)) {
361 xmpp_query_namespace(XMPP->iq_id, XMPP->iq_from,
362 XMPP->iq_to, XMPP->iq_query_xmlns);
366 * ping ( http://xmpp.org/extensions/xep-0199.html )
368 else if (XMPP->ping_requested) {
369 cprintf("<iq type=\"result\" ");
370 if (!IsEmptyStr(XMPP->iq_from)) {
371 cprintf("to=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_from, sizeof xmlbuf));
373 if (!IsEmptyStr(XMPP->iq_to)) {
374 cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_to, sizeof xmlbuf));
376 cprintf("id=\"%s\"/>", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
380 * Unknown query ... return the XML equivalent of a blank stare
383 XMPP_syslog(LOG_DEBUG,
384 "Unknown query <%s> - returning <service-unavailable/>\n",
387 cprintf("<iq type=\"error\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
388 cprintf("<error code=\"503\" type=\"cancel\">"
389 "<service-unavailable xmlns=\"urn:ietf:params:xml:ns:xmpp-stanzas\"/>"
397 * Non SASL authentication
400 (!strcasecmp(XMPP->iq_type, "set"))
401 && (!strcasecmp(XMPP->iq_query_xmlns, "jabber:iq:auth:query"))
404 xmpp_non_sasl_authenticate(
406 XMPP->iq_client_username,
407 XMPP->iq_client_password,
408 XMPP->iq_client_resource
413 * If this <iq> stanza was a "bind" attempt, process it ...
416 (XMPP->bind_requested)
417 && (!IsEmptyStr(XMPP->iq_id))
418 && (!IsEmptyStr(XMPP->iq_client_resource))
422 /* Generate the "full JID" of the client resource */
424 snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
427 XMPP->iq_client_resource
430 /* Tell the client what its JID is */
432 cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
433 cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\">");
434 cprintf("<jid>%s</jid>", xmlesc(xmlbuf, XMPP->client_jid, sizeof xmlbuf));
439 else if (XMPP->iq_session) {
440 cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
445 cprintf("<iq type=\"error\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
446 cprintf("<error>Don't know howto do '%s'!</error>", xmlesc(xmlbuf, XMPP->iq_type, sizeof xmlbuf));
450 /* Now clear these fields out so they don't get used by a future stanza */
452 XMPP->iq_from[0] = 0;
454 XMPP->iq_type[0] = 0;
455 XMPP->iq_client_resource[0] = 0;
456 XMPP->iq_session = 0;
457 XMPP->iq_query_xmlns[0] = 0;
458 XMPP->bind_requested = 0;
459 XMPP->ping_requested = 0;
462 else if (!strcasecmp(el, "auth")) {
464 /* Try to authenticate (this function is responsible for the output stanza) */
465 xmpp_sasl_auth(XMPP->sasl_auth_mech, (XMPP->chardata != NULL ? XMPP->chardata : "") );
467 /* Now clear these fields out so they don't get used by a future stanza */
468 XMPP->sasl_auth_mech[0] = 0;
471 else if (!strcasecmp(el, "session")) {
472 XMPP->iq_session = 1;
475 else if (!strcasecmp(el, "presence")) {
477 /* Respond to a <presence> update by firing back with presence information
478 * on the entire wholist. Check this assumption, it's probably wrong.
480 xmpp_wholist_presence_dump();
483 else if ( (!strcasecmp(el, "body")) && (XMPP->html_tag_level == 0) ) {
484 if (XMPP->message_body != NULL) {
485 free(XMPP->message_body);
486 XMPP->message_body = NULL;
488 if (XMPP->chardata_len > 0) {
489 XMPP->message_body = strdup(XMPP->chardata);
493 else if (!strcasecmp(el, "message")) {
494 xmpp_send_message(XMPP->message_to, XMPP->message_body);
495 XMPP->html_tag_level = 0;
498 else if (!strcasecmp(el, "html")) {
499 --XMPP->html_tag_level;
502 else if (!strcasecmp(el, "starttls")) {
504 cprintf("<proceed xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
505 CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
506 if (!CC->redirect_ssl) CC->kill_me = KILLME_NO_CRYPTO;
508 cprintf("<failure xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
509 CC->kill_me = KILLME_NO_CRYPTO;
513 else if (!strcasecmp(el, "ping")) {
514 XMPP->ping_requested = 1;
517 else if (!strcasecmp(el, "stream")) {
518 XMPPM_syslog(LOG_DEBUG, "XMPP client shut down their stream\n");
519 xmpp_massacre_roster();
520 cprintf("</stream>\n");
521 CC->kill_me = KILLME_CLIENT_LOGGED_OUT;
525 XMPP_syslog(LOG_DEBUG, "Ignoring unknown tag <%s>\n", el);
528 XMPP->chardata_len = 0;
529 if (XMPP->chardata_alloc > 0) {
530 XMPP->chardata[0] = 0;
535 void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
539 if (X->chardata_alloc == 0) {
540 X->chardata_alloc = SIZ;
541 X->chardata = malloc(X->chardata_alloc);
543 if ((X->chardata_len + len + 1) > X->chardata_alloc) {
544 X->chardata_alloc = X->chardata_len + len + 1024;
545 X->chardata = realloc(X->chardata, X->chardata_alloc);
547 memcpy(&X->chardata[X->chardata_len], s, len);
548 X->chardata_len += len;
549 X->chardata[X->chardata_len] = 0;
554 * This cleanup function blows away the temporary memory and files used by the XMPP service.
556 void xmpp_cleanup_function(void) {
558 /* Don't do this stuff if this is not a XMPP session! */
559 if (CC->h_command_function != xmpp_command_loop) return;
561 if (XMPP->chardata != NULL) {
562 free(XMPP->chardata);
563 XMPP->chardata = NULL;
564 XMPP->chardata_len = 0;
565 XMPP->chardata_alloc = 0;
566 if (XMPP->message_body != NULL) {
567 free(XMPP->message_body);
570 XML_ParserFree(XMPP->xp);
577 * Here's where our XMPP session begins its happy day.
579 void xmpp_greeting(void) {
580 client_set_inbound_buf(4);
581 strcpy(CC->cs_clientname, "XMPP session");
582 CC->session_specific_data = malloc(sizeof(citxmpp));
583 memset(XMPP, 0, sizeof(citxmpp));
584 XMPP->last_event_processed = queue_event_seq;
586 /* XMPP does not use a greeting, but we still have to initialize some things. */
588 XMPP->xp = XML_ParserCreateNS("UTF-8", ':');
589 if (XMPP->xp == NULL) {
590 XMPPM_syslog(LOG_ALERT, "Cannot create XML parser!\n");
591 CC->kill_me = KILLME_XML_PARSER;
595 XML_SetElementHandler(XMPP->xp, xmpp_xml_start, xmpp_xml_end);
596 XML_SetCharacterDataHandler(XMPP->xp, xmpp_xml_chardata);
597 // XML_SetUserData(XMPP->xp, something...);
599 /* Prevent the "billion laughs" attack against expat by disabling
600 * internal entity expansion. With 2.x, forcibly stop the parser
601 * if an entity is declared - this is safer and a more obvious
602 * failure mode. With older versions, simply prevent expansion
603 * of such entities. */
604 #ifdef HAVE_XML_STOPPARSER
605 XML_SetEntityDeclHandler(XMPP->xp, xmpp_entity_declaration);
607 XML_SetDefaultHandler(XMPP->xp, NULL);
610 CC->can_receive_im = 1; /* This protocol is capable of receiving instant messages */
615 * Main command loop for XMPP sessions.
617 void xmpp_command_loop(void) {
619 StrBuf *stream_input = NewStrBuf();
622 rc = client_read_random_blob(stream_input, 30);
624 XML_Parse(XMPP->xp, ChrPtr(stream_input), rc, 0);
627 XMPPM_syslog(LOG_ERR, "client disconnected: ending session.\n");
628 CC->kill_me = KILLME_CLIENT_DISCONNECTED;
630 FreeStrBuf(&stream_input);
635 * Async loop for XMPP sessions (handles the transmission of unsolicited stanzas)
637 void xmpp_async_loop(void) {
638 xmpp_process_events();
639 xmpp_output_incoming_messages();
644 * Login hook for XMPP sessions
646 void xmpp_login_hook(void) {
647 xmpp_queue_event(XMPP_EVT_LOGIN, CC->cs_inet_email);
652 * Logout hook for XMPP sessions
654 void xmpp_logout_hook(void) {
655 xmpp_queue_event(XMPP_EVT_LOGOUT, CC->cs_inet_email);
659 void LogXMPPSrvDebugEnable(const int n)
661 XMPPSrvDebugEnable = n;
663 const char *CitadelServiceXMPP="XMPP";
664 extern void xmpp_cleanup_events(void);
665 CTDL_MODULE_INIT(xmpp)
668 CtdlRegisterServiceHook(config.c_xmpp_c2s_port,
675 CtdlRegisterDebugFlagHook(HKEY("serv_xmpp"), LogXMPPSrvDebugEnable, &XMPPSrvDebugEnable);
676 CtdlRegisterSessionHook(xmpp_cleanup_function, EVT_STOP, PRIO_STOP + 70);
677 CtdlRegisterSessionHook(xmpp_login_hook, EVT_LOGIN, PRIO_LOGIN + 90);
678 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_LOGOUT, PRIO_LOGOUT + 90);
679 CtdlRegisterSessionHook(xmpp_login_hook, EVT_UNSTEALTH, PRIO_UNSTEALTH + 1);
680 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_STEALTH, PRIO_STEALTH + 1);
681 CtdlRegisterCleanupHook(xmpp_cleanup_events);
685 /* return our module name for the log */