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);
87 * Given a source string and a target buffer, returns the string
88 * properly escaped for insertion into an XML stream. Returns a
89 * pointer to the target buffer for convenience.
91 * BUG: this does not properly handle UTF-8
93 char *xmlesc(char *buf, char *str, int bufsiz)
99 if (!buf) return(NULL);
106 for (ptr=str; *ptr; ptr++) {
109 strcpy(&buf[len], "<");
112 else if (ch == '>') {
113 strcpy(&buf[len], ">");
116 else if (ch == '&') {
117 strcpy(&buf[len], "&");
120 else if ((ch >= 0x20) && (ch <= 0x7F)) {
124 else if (ch < 0x20) {
125 /* we probably shouldn't be doing this */
131 sprintf(oct, "&#%o;", ch);
132 strcpy(&buf[len], oct);
135 if ((len + 6) > bufsiz) {
144 * We have just received a <stream> tag from the client, so send them ours
146 void xmpp_stream_start(void *data, const char *supplied_el, const char **attr)
151 if (!strcasecmp(attr[0], "to")) {
152 safestrncpy(XMPP->server_name, attr[1], sizeof XMPP->server_name);
157 cprintf("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
159 cprintf("<stream:stream ");
160 cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->server_name, sizeof xmlbuf));
161 cprintf("id=\"%08x\" ", CC->cs_pid);
162 cprintf("version=\"1.0\" ");
163 cprintf("xmlns:stream=\"http://etherx.jabber.org/streams\" ");
164 cprintf("xmlns=\"jabber:client\">");
166 /* The features of this stream are... */
167 cprintf("<stream:features>");
170 * TLS encryption (but only if it isn't already active)
173 if (!CC->redirect_ssl) {
174 cprintf("<starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'></starttls>");
178 if (!CC->logged_in) {
179 /* If we're not logged in yet, offer SASL as our feature set */
180 xmpp_output_auth_mechs();
182 /* Also offer non-SASL authentication */
183 cprintf("<auth xmlns=\"http://jabber.org/features/iq-auth\"/>");
186 /* Offer binding and sessions as part of our feature set */
187 cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\"/>");
188 cprintf("<session xmlns=\"urn:ietf:params:xml:ns:xmpp-session\"/>");
190 cprintf("</stream:features>");
192 CC->is_async = 1; /* XMPP sessions are inherently async-capable */
196 void xmpp_xml_start(void *data, const char *supplied_el, const char **attr) {
201 /* Axe the namespace, we don't care about it */
202 safestrncpy(el, supplied_el, sizeof el);
203 while (sep = strchr(el, ':'), sep) {
208 XMPP_syslog(LOG_DEBUG, "XMPP ELEMENT START: <%s>\n", el);
209 for (i=0; attr[i] != NULL; i+=2) {
210 XMPP_syslog(LOG_DEBUG, " Attribute '%s' = '%s'\n", attr[i], attr[i+1]);
212 uncomment for more verbosity */
214 if (!strcasecmp(el, "stream")) {
215 xmpp_stream_start(data, supplied_el, attr);
218 else if (!strcasecmp(el, "query")) {
219 XMPP->iq_query_xmlns[0] = 0;
220 safestrncpy(XMPP->iq_query_xmlns, supplied_el, sizeof XMPP->iq_query_xmlns);
223 else if (!strcasecmp(el, "bind")) {
224 XMPP->bind_requested = 1;
227 else if (!strcasecmp(el, "iq")) {
228 for (i=0; attr[i] != NULL; i+=2) {
229 if (!strcasecmp(attr[i], "type")) {
230 safestrncpy(XMPP->iq_type, attr[i+1], sizeof XMPP->iq_type);
232 else if (!strcasecmp(attr[i], "id")) {
233 safestrncpy(XMPP->iq_id, attr[i+1], sizeof XMPP->iq_id);
235 else if (!strcasecmp(attr[i], "from")) {
236 safestrncpy(XMPP->iq_from, attr[i+1], sizeof XMPP->iq_from);
238 else if (!strcasecmp(attr[i], "to")) {
239 safestrncpy(XMPP->iq_to, attr[i+1], sizeof XMPP->iq_to);
244 else if (!strcasecmp(el, "auth")) {
245 XMPP->sasl_auth_mech[0] = 0;
246 for (i=0; attr[i] != NULL; i+=2) {
247 if (!strcasecmp(attr[i], "mechanism")) {
248 safestrncpy(XMPP->sasl_auth_mech, attr[i+1], sizeof XMPP->sasl_auth_mech);
253 else if (!strcasecmp(el, "message")) {
254 for (i=0; attr[i] != NULL; i+=2) {
255 if (!strcasecmp(attr[i], "to")) {
256 safestrncpy(XMPP->message_to, attr[i+1], sizeof XMPP->message_to);
261 else if (!strcasecmp(el, "html")) {
262 ++XMPP->html_tag_level;
268 void xmpp_xml_end(void *data, const char *supplied_el) {
273 /* Axe the namespace, we don't care about it */
274 safestrncpy(el, supplied_el, sizeof el);
275 while (sep = strchr(el, ':'), sep) {
280 XMPP_syslog(LOG_DEBUG, "XMPP ELEMENT END : <%s>\n", el);
281 if (XMPP->chardata_len > 0) {
282 XMPP_syslog(LOG_DEBUG, " chardata: %s\n", XMPP->chardata);
284 uncomment for more verbosity */
286 if (!strcasecmp(el, "resource")) {
287 if (XMPP->chardata_len > 0) {
288 safestrncpy(XMPP->iq_client_resource, XMPP->chardata,
289 sizeof XMPP->iq_client_resource);
290 striplt(XMPP->iq_client_resource);
294 else if (!strcasecmp(el, "username")) { /* NON SASL ONLY */
295 if (XMPP->chardata_len > 0) {
296 safestrncpy(XMPP->iq_client_username, XMPP->chardata,
297 sizeof XMPP->iq_client_username);
298 striplt(XMPP->iq_client_username);
302 else if (!strcasecmp(el, "password")) { /* NON SASL ONLY */
303 if (XMPP->chardata_len > 0) {
304 safestrncpy(XMPP->iq_client_password, XMPP->chardata,
305 sizeof XMPP->iq_client_password);
306 striplt(XMPP->iq_client_password);
310 else if (!strcasecmp(el, "iq")) {
313 * iq type="get" (handle queries)
315 if (!strcasecmp(XMPP->iq_type, "get")) {
318 * Query on a namespace
320 if (!IsEmptyStr(XMPP->iq_query_xmlns)) {
321 xmpp_query_namespace(XMPP->iq_id, XMPP->iq_from,
322 XMPP->iq_to, XMPP->iq_query_xmlns);
326 * ping ( http://xmpp.org/extensions/xep-0199.html )
328 else if (XMPP->ping_requested) {
329 cprintf("<iq type=\"result\" ");
330 if (!IsEmptyStr(XMPP->iq_from)) {
331 cprintf("to=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_from, sizeof xmlbuf));
333 if (!IsEmptyStr(XMPP->iq_to)) {
334 cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_to, sizeof xmlbuf));
336 cprintf("id=\"%s\"/>", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
340 * Unknown query ... return the XML equivalent of a blank stare
343 XMPP_syslog(LOG_DEBUG,
344 "Unknown query <%s> - returning <service-unavailable/>\n",
347 cprintf("<iq type=\"error\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
348 cprintf("<error code=\"503\" type=\"cancel\">"
349 "<service-unavailable xmlns=\"urn:ietf:params:xml:ns:xmpp-stanzas\"/>"
357 * Non SASL authentication
360 (!strcasecmp(XMPP->iq_type, "set"))
361 && (!strcasecmp(XMPP->iq_query_xmlns, "jabber:iq:auth:query"))
364 xmpp_non_sasl_authenticate(
366 XMPP->iq_client_username,
367 XMPP->iq_client_password,
368 XMPP->iq_client_resource
373 * If this <iq> stanza was a "bind" attempt, process it ...
376 (XMPP->bind_requested)
377 && (!IsEmptyStr(XMPP->iq_id))
378 && (!IsEmptyStr(XMPP->iq_client_resource))
382 /* Generate the "full JID" of the client resource */
384 snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
387 XMPP->iq_client_resource
390 /* Tell the client what its JID is */
392 cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
393 cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\">");
394 cprintf("<jid>%s</jid>", xmlesc(xmlbuf, XMPP->client_jid, sizeof xmlbuf));
399 else if (XMPP->iq_session) {
400 cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
405 cprintf("<iq type=\"error\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
406 cprintf("<error>Don't know howto do '%s'!</error>", xmlesc(xmlbuf, XMPP->iq_type, sizeof xmlbuf));
410 /* Now clear these fields out so they don't get used by a future stanza */
412 XMPP->iq_from[0] = 0;
414 XMPP->iq_type[0] = 0;
415 XMPP->iq_client_resource[0] = 0;
416 XMPP->iq_session = 0;
417 XMPP->iq_query_xmlns[0] = 0;
418 XMPP->bind_requested = 0;
419 XMPP->ping_requested = 0;
422 else if (!strcasecmp(el, "auth")) {
424 /* Try to authenticate (this function is responsible for the output stanza) */
425 xmpp_sasl_auth(XMPP->sasl_auth_mech, (XMPP->chardata != NULL ? XMPP->chardata : "") );
427 /* Now clear these fields out so they don't get used by a future stanza */
428 XMPP->sasl_auth_mech[0] = 0;
431 else if (!strcasecmp(el, "session")) {
432 XMPP->iq_session = 1;
435 else if (!strcasecmp(el, "presence")) {
437 /* Respond to a <presence> update by firing back with presence information
438 * on the entire wholist. Check this assumption, it's probably wrong.
440 xmpp_wholist_presence_dump();
443 else if ( (!strcasecmp(el, "body")) && (XMPP->html_tag_level == 0) ) {
444 if (XMPP->message_body != NULL) {
445 free(XMPP->message_body);
446 XMPP->message_body = NULL;
448 if (XMPP->chardata_len > 0) {
449 XMPP->message_body = strdup(XMPP->chardata);
453 else if (!strcasecmp(el, "message")) {
454 xmpp_send_message(XMPP->message_to, XMPP->message_body);
455 XMPP->html_tag_level = 0;
458 else if (!strcasecmp(el, "html")) {
459 --XMPP->html_tag_level;
462 else if (!strcasecmp(el, "starttls")) {
464 cprintf("<proceed xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
465 CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
466 if (!CC->redirect_ssl) CC->kill_me = KILLME_NO_CRYPTO;
468 cprintf("<failure xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
469 CC->kill_me = KILLME_NO_CRYPTO;
473 else if (!strcasecmp(el, "ping")) {
474 XMPP->ping_requested = 1;
477 else if (!strcasecmp(el, "stream")) {
478 XMPPM_syslog(LOG_DEBUG, "XMPP client shut down their stream\n");
479 xmpp_massacre_roster();
480 cprintf("</stream>\n");
481 CC->kill_me = KILLME_CLIENT_LOGGED_OUT;
485 XMPP_syslog(LOG_DEBUG, "Ignoring unknown tag <%s>\n", el);
488 XMPP->chardata_len = 0;
489 if (XMPP->chardata_alloc > 0) {
490 XMPP->chardata[0] = 0;
495 void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
499 if (X->chardata_alloc == 0) {
500 X->chardata_alloc = SIZ;
501 X->chardata = malloc(X->chardata_alloc);
503 if ((X->chardata_len + len + 1) > X->chardata_alloc) {
504 X->chardata_alloc = X->chardata_len + len + 1024;
505 X->chardata = realloc(X->chardata, X->chardata_alloc);
507 memcpy(&X->chardata[X->chardata_len], s, len);
508 X->chardata_len += len;
509 X->chardata[X->chardata_len] = 0;
514 * This cleanup function blows away the temporary memory and files used by the XMPP service.
516 void xmpp_cleanup_function(void) {
518 /* Don't do this stuff if this is not a XMPP session! */
519 if (CC->h_command_function != xmpp_command_loop) return;
521 if (XMPP->chardata != NULL) {
522 free(XMPP->chardata);
523 XMPP->chardata = NULL;
524 XMPP->chardata_len = 0;
525 XMPP->chardata_alloc = 0;
526 if (XMPP->message_body != NULL) {
527 free(XMPP->message_body);
530 XML_ParserFree(XMPP->xp);
537 * Here's where our XMPP session begins its happy day.
539 void xmpp_greeting(void) {
540 client_set_inbound_buf(4);
541 strcpy(CC->cs_clientname, "XMPP session");
542 CC->session_specific_data = malloc(sizeof(citxmpp));
543 memset(XMPP, 0, sizeof(citxmpp));
544 XMPP->last_event_processed = queue_event_seq;
546 /* XMPP does not use a greeting, but we still have to initialize some things. */
548 XMPP->xp = XML_ParserCreateNS("UTF-8", ':');
549 if (XMPP->xp == NULL) {
550 XMPPM_syslog(LOG_ALERT, "Cannot create XML parser!\n");
551 CC->kill_me = KILLME_XML_PARSER;
555 XML_SetElementHandler(XMPP->xp, xmpp_xml_start, xmpp_xml_end);
556 XML_SetCharacterDataHandler(XMPP->xp, xmpp_xml_chardata);
557 // XML_SetUserData(XMPP->xp, something...);
559 /* Prevent the "billion laughs" attack against expat by disabling
560 * internal entity expansion. With 2.x, forcibly stop the parser
561 * if an entity is declared - this is safer and a more obvious
562 * failure mode. With older versions, simply prevent expansion
563 * of such entities. */
564 #ifdef HAVE_XML_STOPPARSER
565 XML_SetEntityDeclHandler(XMPP->xp, xmpp_entity_declaration);
567 XML_SetDefaultHandler(XMPP->xp, NULL);
570 CC->can_receive_im = 1; /* This protocol is capable of receiving instant messages */
575 * Main command loop for XMPP sessions.
577 void xmpp_command_loop(void) {
579 StrBuf *stream_input = NewStrBuf();
582 rc = client_read_random_blob(stream_input, 30);
584 XML_Parse(XMPP->xp, ChrPtr(stream_input), rc, 0);
587 XMPPM_syslog(LOG_ERR, "client disconnected: ending session.\n");
588 CC->kill_me = KILLME_CLIENT_DISCONNECTED;
590 FreeStrBuf(&stream_input);
595 * Async loop for XMPP sessions (handles the transmission of unsolicited stanzas)
597 void xmpp_async_loop(void) {
598 xmpp_process_events();
599 xmpp_output_incoming_messages();
604 * Login hook for XMPP sessions
606 void xmpp_login_hook(void) {
607 xmpp_queue_event(XMPP_EVT_LOGIN, CC->cs_inet_email);
612 * Logout hook for XMPP sessions
614 void xmpp_logout_hook(void) {
615 xmpp_queue_event(XMPP_EVT_LOGOUT, CC->cs_inet_email);
619 void LogXMPPSrvDebugEnable(const int n)
621 XMPPSrvDebugEnable = n;
623 const char *CitadelServiceXMPP="XMPP";
624 extern void xmpp_cleanup_events(void);
625 CTDL_MODULE_INIT(xmpp)
628 CtdlRegisterServiceHook(config.c_xmpp_c2s_port,
635 CtdlRegisterDebugFlagHook(HKEY("serv_xmpp"), LogXMPPSrvDebugEnable, &XMPPSrvDebugEnable);
636 CtdlRegisterSessionHook(xmpp_cleanup_function, EVT_STOP, PRIO_STOP + 70);
637 CtdlRegisterSessionHook(xmpp_login_hook, EVT_LOGIN, PRIO_LOGIN + 90);
638 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_LOGOUT, PRIO_LOGOUT + 90);
639 CtdlRegisterSessionHook(xmpp_login_hook, EVT_UNSTEALTH, PRIO_UNSTEALTH + 1);
640 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_STEALTH, PRIO_STEALTH + 1);
641 CtdlRegisterCleanupHook(xmpp_cleanup_events);
645 /* return our module name for the log */