2 * XMPP (Jabber) service for the Citadel system
3 * Copyright (c) 2007-2015 by Art Cancro and citadel.org
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 static inline int Ctdl_GetUtf8SequenceLength(const char *CharS, const char *CharE)
94 unsigned char test = (1<<7);
96 if ((*CharS & 0xC0) != 0xC0)
100 ((test & ((unsigned char)*CharS)) != 0))
105 if ((n > 6) || ((CharE - CharS) < n))
110 char *xmlesc(char *buf, char *str, int bufsiz)
118 if (!buf) return(NULL);
127 for (ptr=str; *ptr; ptr++) {
130 strcpy(&buf[len], "<");
133 else if (ch == '>') {
134 strcpy(&buf[len], ">");
137 else if (ch == '&') {
138 strcpy(&buf[len], "&");
141 else if ((ch >= 0x20) && (ch <= 0x7F)) {
145 else if (ch < 0x20) {
146 /* we probably shouldn't be doing this */
151 IsUtf8Sequence = Ctdl_GetUtf8SequenceLength(ptr, pche);
154 while ((IsUtf8Sequence > 0) &&
165 sprintf(oct, "&#%o;", ch);
166 strcpy(&buf[len], oct);
170 if ((len + 6) > bufsiz) {
179 * We have just received a <stream> tag from the client, so send them ours
181 void xmpp_stream_start(void *data, const char *supplied_el, const char **attr)
186 if (!strcasecmp(attr[0], "to")) {
187 safestrncpy(XMPP->server_name, attr[1], sizeof XMPP->server_name);
192 cprintf("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
194 cprintf("<stream:stream ");
195 cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->server_name, sizeof xmlbuf));
196 cprintf("id=\"%08x\" ", CC->cs_pid);
197 cprintf("version=\"1.0\" ");
198 cprintf("xmlns:stream=\"http://etherx.jabber.org/streams\" ");
199 cprintf("xmlns=\"jabber:client\">");
201 /* The features of this stream are... */
202 cprintf("<stream:features>");
205 * TLS encryption (but only if it isn't already active)
208 if (!CC->redirect_ssl) {
209 cprintf("<starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'></starttls>");
213 if (!CC->logged_in) {
214 /* If we're not logged in yet, offer SASL as our feature set */
215 xmpp_output_auth_mechs();
217 /* Also offer non-SASL authentication */
218 cprintf("<auth xmlns=\"http://jabber.org/features/iq-auth\"/>");
221 /* Offer binding and sessions as part of our feature set */
222 cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\"/>");
223 cprintf("<session xmlns=\"urn:ietf:params:xml:ns:xmpp-session\"/>");
225 cprintf("</stream:features>");
227 CC->is_async = 1; /* XMPP sessions are inherently async-capable */
231 void xmpp_xml_start(void *data, const char *supplied_el, const char **attr) {
236 /* Axe the namespace, we don't care about it */
237 safestrncpy(el, supplied_el, sizeof el);
238 while (sep = strchr(el, ':'), sep) {
243 XMPP_syslog(LOG_DEBUG, "XMPP ELEMENT START: <%s>\n", el);
244 for (i=0; attr[i] != NULL; i+=2) {
245 XMPP_syslog(LOG_DEBUG, " Attribute '%s' = '%s'\n", attr[i], attr[i+1]);
247 uncomment for more verbosity */
249 if (!strcasecmp(el, "stream")) {
250 xmpp_stream_start(data, supplied_el, attr);
253 else if (!strcasecmp(el, "query")) {
254 XMPP->iq_query_xmlns[0] = 0;
255 safestrncpy(XMPP->iq_query_xmlns, supplied_el, sizeof XMPP->iq_query_xmlns);
258 else if (!strcasecmp(el, "bind")) {
259 XMPP->bind_requested = 1;
262 else if (!strcasecmp(el, "iq")) {
263 for (i=0; attr[i] != NULL; i+=2) {
264 if (!strcasecmp(attr[i], "type")) {
265 safestrncpy(XMPP->iq_type, attr[i+1], sizeof XMPP->iq_type);
267 else if (!strcasecmp(attr[i], "id")) {
268 safestrncpy(XMPP->iq_id, attr[i+1], sizeof XMPP->iq_id);
270 else if (!strcasecmp(attr[i], "from")) {
271 safestrncpy(XMPP->iq_from, attr[i+1], sizeof XMPP->iq_from);
273 else if (!strcasecmp(attr[i], "to")) {
274 safestrncpy(XMPP->iq_to, attr[i+1], sizeof XMPP->iq_to);
279 else if (!strcasecmp(el, "auth")) {
280 XMPP->sasl_auth_mech[0] = 0;
281 for (i=0; attr[i] != NULL; i+=2) {
282 if (!strcasecmp(attr[i], "mechanism")) {
283 safestrncpy(XMPP->sasl_auth_mech, attr[i+1], sizeof XMPP->sasl_auth_mech);
288 else if (!strcasecmp(el, "message")) {
289 for (i=0; attr[i] != NULL; i+=2) {
290 if (!strcasecmp(attr[i], "to")) {
291 safestrncpy(XMPP->message_to, attr[i+1], sizeof XMPP->message_to);
296 else if (!strcasecmp(el, "html")) {
297 ++XMPP->html_tag_level;
303 void xmpp_xml_end(void *data, const char *supplied_el) {
308 /* Axe the namespace, we don't care about it */
309 safestrncpy(el, supplied_el, sizeof el);
310 while (sep = strchr(el, ':'), sep) {
315 XMPP_syslog(LOG_DEBUG, "XMPP ELEMENT END : <%s>\n", el);
316 if (XMPP->chardata_len > 0) {
317 XMPP_syslog(LOG_DEBUG, " chardata: %s\n", XMPP->chardata);
319 uncomment for more verbosity */
321 if (!strcasecmp(el, "resource")) {
322 if (XMPP->chardata_len > 0) {
323 safestrncpy(XMPP->iq_client_resource, XMPP->chardata,
324 sizeof XMPP->iq_client_resource);
325 striplt(XMPP->iq_client_resource);
329 else if (!strcasecmp(el, "username")) { /* NON SASL ONLY */
330 if (XMPP->chardata_len > 0) {
331 safestrncpy(XMPP->iq_client_username, XMPP->chardata,
332 sizeof XMPP->iq_client_username);
333 striplt(XMPP->iq_client_username);
337 else if (!strcasecmp(el, "password")) { /* NON SASL ONLY */
338 if (XMPP->chardata_len > 0) {
339 safestrncpy(XMPP->iq_client_password, XMPP->chardata,
340 sizeof XMPP->iq_client_password);
341 striplt(XMPP->iq_client_password);
345 else if (!strcasecmp(el, "iq")) {
348 * iq type="get" (handle queries)
350 if (!strcasecmp(XMPP->iq_type, "get")) {
353 * Query on a namespace
355 if (!IsEmptyStr(XMPP->iq_query_xmlns)) {
356 xmpp_query_namespace(XMPP->iq_id, XMPP->iq_from,
357 XMPP->iq_to, XMPP->iq_query_xmlns);
361 * ping ( http://xmpp.org/extensions/xep-0199.html )
363 else if (XMPP->ping_requested) {
364 cprintf("<iq type=\"result\" ");
365 if (!IsEmptyStr(XMPP->iq_from)) {
366 cprintf("to=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_from, sizeof xmlbuf));
368 if (!IsEmptyStr(XMPP->iq_to)) {
369 cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_to, sizeof xmlbuf));
371 cprintf("id=\"%s\"/>", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
375 * Unknown query ... return the XML equivalent of a blank stare
378 XMPP_syslog(LOG_DEBUG,
379 "Unknown query <%s> - returning <service-unavailable/>\n",
382 cprintf("<iq type=\"error\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
383 cprintf("<error code=\"503\" type=\"cancel\">"
384 "<service-unavailable xmlns=\"urn:ietf:params:xml:ns:xmpp-stanzas\"/>"
392 * Non SASL authentication
395 (!strcasecmp(XMPP->iq_type, "set"))
396 && (!strcasecmp(XMPP->iq_query_xmlns, "jabber:iq:auth:query"))
399 xmpp_non_sasl_authenticate(
401 XMPP->iq_client_username,
402 XMPP->iq_client_password,
403 XMPP->iq_client_resource
408 * If this <iq> stanza was a "bind" attempt, process it ...
411 (XMPP->bind_requested)
412 && (!IsEmptyStr(XMPP->iq_id))
413 && (!IsEmptyStr(XMPP->iq_client_resource))
417 /* Generate the "full JID" of the client resource */
419 snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
422 XMPP->iq_client_resource
425 /* Tell the client what its JID is */
427 cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
428 cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\">");
429 cprintf("<jid>%s</jid>", xmlesc(xmlbuf, XMPP->client_jid, sizeof xmlbuf));
434 else if (XMPP->iq_session) {
435 cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
440 cprintf("<iq type=\"error\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
441 cprintf("<error>Don't know howto do '%s'!</error>", xmlesc(xmlbuf, XMPP->iq_type, sizeof xmlbuf));
445 /* Now clear these fields out so they don't get used by a future stanza */
447 XMPP->iq_from[0] = 0;
449 XMPP->iq_type[0] = 0;
450 XMPP->iq_client_resource[0] = 0;
451 XMPP->iq_session = 0;
452 XMPP->iq_query_xmlns[0] = 0;
453 XMPP->bind_requested = 0;
454 XMPP->ping_requested = 0;
457 else if (!strcasecmp(el, "auth")) {
459 /* Try to authenticate (this function is responsible for the output stanza) */
460 xmpp_sasl_auth(XMPP->sasl_auth_mech, (XMPP->chardata != NULL ? XMPP->chardata : "") );
462 /* Now clear these fields out so they don't get used by a future stanza */
463 XMPP->sasl_auth_mech[0] = 0;
466 else if (!strcasecmp(el, "session")) {
467 XMPP->iq_session = 1;
470 else if (!strcasecmp(el, "presence")) {
472 /* Respond to a <presence> update by firing back with presence information
473 * on the entire wholist. Check this assumption, it's probably wrong.
475 xmpp_wholist_presence_dump();
478 else if ( (!strcasecmp(el, "body")) && (XMPP->html_tag_level == 0) ) {
479 if (XMPP->message_body != NULL) {
480 free(XMPP->message_body);
481 XMPP->message_body = NULL;
483 if (XMPP->chardata_len > 0) {
484 XMPP->message_body = strdup(XMPP->chardata);
488 else if (!strcasecmp(el, "message")) {
489 xmpp_send_message(XMPP->message_to, XMPP->message_body);
490 XMPP->html_tag_level = 0;
493 else if (!strcasecmp(el, "html")) {
494 --XMPP->html_tag_level;
497 else if (!strcasecmp(el, "starttls")) {
499 cprintf("<proceed xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
500 CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
501 if (!CC->redirect_ssl) CC->kill_me = KILLME_NO_CRYPTO;
503 cprintf("<failure xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
504 CC->kill_me = KILLME_NO_CRYPTO;
508 else if (!strcasecmp(el, "ping")) {
509 XMPP->ping_requested = 1;
512 else if (!strcasecmp(el, "stream")) {
513 XMPPM_syslog(LOG_DEBUG, "XMPP client shut down their stream\n");
514 xmpp_massacre_roster();
515 cprintf("</stream>\n");
516 CC->kill_me = KILLME_CLIENT_LOGGED_OUT;
519 else if (!strcasecmp(el, "query")) {
520 /* already processed , no further action needed here */
523 else if (!strcasecmp(el, "bind")) {
524 /* already processed , no further action needed here */
528 XMPP_syslog(LOG_DEBUG, "Ignoring unknown tag <%s>\n", el);
531 XMPP->chardata_len = 0;
532 if (XMPP->chardata_alloc > 0) {
533 XMPP->chardata[0] = 0;
538 void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
542 if (X->chardata_alloc == 0) {
543 X->chardata_alloc = SIZ;
544 X->chardata = malloc(X->chardata_alloc);
546 if ((X->chardata_len + len + 1) > X->chardata_alloc) {
547 X->chardata_alloc = X->chardata_len + len + 1024;
548 X->chardata = realloc(X->chardata, X->chardata_alloc);
550 memcpy(&X->chardata[X->chardata_len], s, len);
551 X->chardata_len += len;
552 X->chardata[X->chardata_len] = 0;
557 * This cleanup function blows away the temporary memory and files used by the XMPP service.
559 void xmpp_cleanup_function(void) {
561 /* Don't do this stuff if this is not a XMPP session! */
562 if (CC->h_command_function != xmpp_command_loop) return;
564 if (XMPP->chardata != NULL) {
565 free(XMPP->chardata);
566 XMPP->chardata = NULL;
567 XMPP->chardata_len = 0;
568 XMPP->chardata_alloc = 0;
569 if (XMPP->message_body != NULL) {
570 free(XMPP->message_body);
573 XML_ParserFree(XMPP->xp);
580 * Here's where our XMPP session begins its happy day.
582 void xmpp_greeting(void) {
583 client_set_inbound_buf(4);
584 strcpy(CC->cs_clientname, "XMPP session");
585 CC->session_specific_data = malloc(sizeof(citxmpp));
586 memset(XMPP, 0, sizeof(citxmpp));
587 XMPP->last_event_processed = queue_event_seq;
589 /* XMPP does not use a greeting, but we still have to initialize some things. */
591 XMPP->xp = XML_ParserCreateNS("UTF-8", ':');
592 if (XMPP->xp == NULL) {
593 XMPPM_syslog(LOG_ALERT, "Cannot create XML parser!\n");
594 CC->kill_me = KILLME_XML_PARSER;
598 XML_SetElementHandler(XMPP->xp, xmpp_xml_start, xmpp_xml_end);
599 XML_SetCharacterDataHandler(XMPP->xp, xmpp_xml_chardata);
600 // XML_SetUserData(XMPP->xp, something...);
602 /* Prevent the "billion laughs" attack against expat by disabling
603 * internal entity expansion. With 2.x, forcibly stop the parser
604 * if an entity is declared - this is safer and a more obvious
605 * failure mode. With older versions, simply prevent expansion
606 * of such entities. */
607 #ifdef HAVE_XML_STOPPARSER
608 XML_SetEntityDeclHandler(XMPP->xp, xmpp_entity_declaration);
610 XML_SetDefaultHandler(XMPP->xp, NULL);
613 CC->can_receive_im = 1; /* This protocol is capable of receiving instant messages */
618 * Main command loop for XMPP sessions.
620 void xmpp_command_loop(void) {
622 StrBuf *stream_input = NewStrBuf();
625 rc = client_read_random_blob(stream_input, 30);
627 XML_Parse(XMPP->xp, ChrPtr(stream_input), rc, 0);
630 XMPPM_syslog(LOG_ERR, "client disconnected: ending session.\n");
631 CC->kill_me = KILLME_CLIENT_DISCONNECTED;
633 FreeStrBuf(&stream_input);
638 * Async loop for XMPP sessions (handles the transmission of unsolicited stanzas)
640 void xmpp_async_loop(void) {
641 xmpp_process_events();
642 xmpp_output_incoming_messages();
647 * Login hook for XMPP sessions
649 void xmpp_login_hook(void) {
650 xmpp_queue_event(XMPP_EVT_LOGIN, CC->cs_inet_email);
655 * Logout hook for XMPP sessions
657 void xmpp_logout_hook(void) {
658 xmpp_queue_event(XMPP_EVT_LOGOUT, CC->cs_inet_email);
662 void LogXMPPSrvDebugEnable(const int n)
664 XMPPSrvDebugEnable = n;
666 const char *CitadelServiceXMPP="XMPP";
667 extern void xmpp_cleanup_events(void);
668 CTDL_MODULE_INIT(xmpp)
671 CtdlRegisterServiceHook(config.c_xmpp_c2s_port,
678 CtdlRegisterDebugFlagHook(HKEY("serv_xmpp"), LogXMPPSrvDebugEnable, &XMPPSrvDebugEnable);
679 CtdlRegisterSessionHook(xmpp_cleanup_function, EVT_STOP, PRIO_STOP + 70);
680 CtdlRegisterSessionHook(xmpp_login_hook, EVT_LOGIN, PRIO_LOGIN + 90);
681 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_LOGOUT, PRIO_LOGOUT + 90);
682 CtdlRegisterSessionHook(xmpp_login_hook, EVT_UNSTEALTH, PRIO_UNSTEALTH + 1);
683 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_STEALTH, PRIO_STEALTH + 1);
684 CtdlRegisterCleanupHook(xmpp_cleanup_events);
688 /* return our module name for the log */