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 #if XML_MAJOR_VERSION > 0
61 /* XML_StopParser is present in expat 2.x */
62 #define HAVE_XML_STOPPARSER
65 struct xmpp_event *xmpp_queue = NULL;
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
77 syslog(LOG_WARNING, "Illegal entity declaration encountered; stopping parser.");
78 XML_StopParser(XMPP->xp, XML_FALSE);
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.
89 * BUG: this does not properly handle UTF-8
91 char *xmlesc(char *buf, char *str, int bufsiz)
97 if (!buf) return(NULL);
104 for (ptr=str; *ptr; ptr++) {
107 strcpy(&buf[len], "<");
110 else if (ch == '>') {
111 strcpy(&buf[len], ">");
114 else if (ch == '&') {
115 strcpy(&buf[len], "&");
118 else if ((ch >= 0x20) && (ch <= 0x7F)) {
122 else if (ch < 0x20) {
123 /* we probably shouldn't be doing this */
129 sprintf(oct, "&#%o;", ch);
130 strcpy(&buf[len], oct);
133 if ((len + 6) > bufsiz) {
142 * We have just received a <stream> tag from the client, so send them ours
144 void xmpp_stream_start(void *data, const char *supplied_el, const char **attr)
149 if (!strcasecmp(attr[0], "to")) {
150 safestrncpy(XMPP->server_name, attr[1], sizeof XMPP->server_name);
155 cprintf("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
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\">");
164 /* The features of this stream are... */
165 cprintf("<stream:features>");
168 * TLS encryption (but only if it isn't already active)
171 if (!CC->redirect_ssl) {
172 cprintf("<starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'></starttls>");
176 if (!CC->logged_in) {
177 /* If we're not logged in yet, offer SASL as our feature set */
178 xmpp_output_auth_mechs();
180 /* Also offer non-SASL authentication */
181 cprintf("<auth xmlns=\"http://jabber.org/features/iq-auth\"/>");
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\"/>");
188 cprintf("</stream:features>");
190 CC->is_async = 1; /* XMPP sessions are inherently async-capable */
194 void xmpp_xml_start(void *data, const char *supplied_el, const char **attr) {
199 /* Axe the namespace, we don't care about it */
200 safestrncpy(el, supplied_el, sizeof el);
201 while (sep = strchr(el, ':'), sep) {
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]);
210 uncomment for more verbosity */
212 if (!strcasecmp(el, "stream")) {
213 xmpp_stream_start(data, supplied_el, attr);
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);
221 else if (!strcasecmp(el, "bind")) {
222 XMPP->bind_requested = 1;
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);
230 else if (!strcasecmp(attr[i], "id")) {
231 safestrncpy(XMPP->iq_id, attr[i+1], sizeof XMPP->iq_id);
233 else if (!strcasecmp(attr[i], "from")) {
234 safestrncpy(XMPP->iq_from, attr[i+1], sizeof XMPP->iq_from);
236 else if (!strcasecmp(attr[i], "to")) {
237 safestrncpy(XMPP->iq_to, attr[i+1], sizeof XMPP->iq_to);
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);
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);
259 else if (!strcasecmp(el, "html")) {
260 ++XMPP->html_tag_level;
266 void xmpp_xml_end(void *data, const char *supplied_el) {
271 /* Axe the namespace, we don't care about it */
272 safestrncpy(el, supplied_el, sizeof el);
273 while (sep = strchr(el, ':'), sep) {
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);
282 uncomment for more verbosity */
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);
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);
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);
308 else if (!strcasecmp(el, "iq")) {
311 * iq type="get" (handle queries)
313 if (!strcasecmp(XMPP->iq_type, "get")) {
316 * Query on a namespace
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);
324 * ping ( http://xmpp.org/extensions/xep-0199.html )
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));
331 if (!IsEmptyStr(XMPP->iq_to)) {
332 cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_to, sizeof xmlbuf));
334 cprintf("id=\"%s\"/>", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
338 * Unknown query ... return the XML equivalent of a blank stare
342 "Unknown query <%s> - returning <service-unavailable/>\n",
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\"/>"
355 * Non SASL authentication
358 (!strcasecmp(XMPP->iq_type, "set"))
359 && (!strcasecmp(XMPP->iq_query_xmlns, "jabber:iq:auth:query"))
362 xmpp_non_sasl_authenticate(
364 XMPP->iq_client_username,
365 XMPP->iq_client_password,
366 XMPP->iq_client_resource
371 * If this <iq> stanza was a "bind" attempt, process it ...
374 (XMPP->bind_requested)
375 && (!IsEmptyStr(XMPP->iq_id))
376 && (!IsEmptyStr(XMPP->iq_client_resource))
380 /* Generate the "full JID" of the client resource */
382 snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
385 XMPP->iq_client_resource
388 /* Tell the client what its JID is */
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));
397 else if (XMPP->iq_session) {
398 cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
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));
408 /* Now clear these fields out so they don't get used by a future stanza */
410 XMPP->iq_from[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;
420 else if (!strcasecmp(el, "auth")) {
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 : "") );
425 /* Now clear these fields out so they don't get used by a future stanza */
426 XMPP->sasl_auth_mech[0] = 0;
429 else if (!strcasecmp(el, "session")) {
430 XMPP->iq_session = 1;
433 else if (!strcasecmp(el, "presence")) {
435 /* Respond to a <presence> update by firing back with presence information
436 * on the entire wholist. Check this assumption, it's probably wrong.
438 xmpp_wholist_presence_dump();
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;
446 if (XMPP->chardata_len > 0) {
447 XMPP->message_body = strdup(XMPP->chardata);
451 else if (!strcasecmp(el, "message")) {
452 xmpp_send_message(XMPP->message_to, XMPP->message_body);
453 XMPP->html_tag_level = 0;
456 else if (!strcasecmp(el, "html")) {
457 --XMPP->html_tag_level;
460 else if (!strcasecmp(el, "starttls")) {
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;
466 cprintf("<failure xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
467 CC->kill_me = KILLME_NO_CRYPTO;
471 else if (!strcasecmp(el, "ping")) {
472 XMPP->ping_requested = 1;
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;
483 syslog(LOG_DEBUG, "Ignoring unknown tag <%s>\n", el);
486 XMPP->chardata_len = 0;
487 if (XMPP->chardata_alloc > 0) {
488 XMPP->chardata[0] = 0;
493 void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
497 if (X->chardata_alloc == 0) {
498 X->chardata_alloc = SIZ;
499 X->chardata = malloc(X->chardata_alloc);
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);
505 memcpy(&X->chardata[X->chardata_len], s, len);
506 X->chardata_len += len;
507 X->chardata[X->chardata_len] = 0;
512 * This cleanup function blows away the temporary memory and files used by the XMPP service.
514 void xmpp_cleanup_function(void) {
516 /* Don't do this stuff if this is not a XMPP session! */
517 if (CC->h_command_function != xmpp_command_loop) return;
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);
528 XML_ParserFree(XMPP->xp);
535 * Here's where our XMPP session begins its happy day.
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;
544 /* XMPP does not use a greeting, but we still have to initialize some things. */
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;
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...);
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);
565 XML_SetDefaultHandler(XMPP->xp, NULL);
568 CC->can_receive_im = 1; /* This protocol is capable of receiving instant messages */
573 * Main command loop for XMPP sessions.
575 void xmpp_command_loop(void) {
577 StrBuf *stream_input = NewStrBuf();
580 rc = client_read_random_blob(stream_input, 30);
582 XML_Parse(XMPP->xp, ChrPtr(stream_input), rc, 0);
585 syslog(LOG_ERR, "XMPP: client disconnected: ending session.\n");
586 CC->kill_me = KILLME_CLIENT_DISCONNECTED;
588 FreeStrBuf(&stream_input);
593 * Async loop for XMPP sessions (handles the transmission of unsolicited stanzas)
595 void xmpp_async_loop(void) {
596 xmpp_process_events();
597 xmpp_output_incoming_messages();
602 * Login hook for XMPP sessions
604 void xmpp_login_hook(void) {
605 xmpp_queue_event(XMPP_EVT_LOGIN, CC->cs_inet_email);
610 * Logout hook for XMPP sessions
612 void xmpp_logout_hook(void) {
613 xmpp_queue_event(XMPP_EVT_LOGOUT, CC->cs_inet_email);
617 const char *CitadelServiceXMPP="XMPP";
618 extern void xmpp_cleanup_events(void);
619 CTDL_MODULE_INIT(xmpp)
622 CtdlRegisterServiceHook(config.c_xmpp_c2s_port,
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);
638 /* return our module name for the log */