citadel/modules/xmpp/serv_xmpp.c

   1 /*
   2  * XMPP (Jabber) service for the Citadel system
   3  * Copyright (c) 2007-2011 by Art Cancro
   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 HashList *XMPP_StartHandlers = NULL;
  67 HashList *XMPP_EndHandlers = NULL;
  68
  69 int XMPPSrvDebugEnable = 0;
  70
  71
  72
  73 #ifdef HAVE_XML_STOPPARSER
  74 /* Stop the parser if an entity declaration is hit. */
  75 static void xmpp_entity_declaration(void *userData, const XML_Char *entityName,
  76                                 int is_parameter_entity, const XML_Char *value,
  77                                 int value_length, const XML_Char *base,
  78                                 const XML_Char *systemId, const XML_Char *publicId,
  79                                 const XML_Char *notationName
  80 ) {
  81         XMPPM_syslog(LOG_WARNING, "Illegal entity declaration encountered; stopping parser.");
  82         XML_StopParser(XMPP->xp, XML_FALSE);
  83 }
  84 #endif
  85
  86 static inline int XMPP_GetUtf8SequenceLength(const char *CharS, const char *CharE)
  87 {
  88         /* if this is is migrated to strbuf, remove this copy. */
  89         int n = 0;
  90         unsigned char test = (1<<7);
  91
  92         if ((*CharS & 0xC0) != 0xC0)
  93                 return 1;
  94
  95         while ((n < 8) &&
  96                ((test & ((unsigned char)*CharS)) != 0))
  97         {
  98                 test = test >> 1;
  99                 n ++;
 100         }
 101         if ((n > 6) || ((CharE - CharS) < n))
 102                 n = 0;
 103         return n;
 104 }
 105
 106
 107 /*
 108  * Given a source string and a target buffer, returns the string
 109  * properly escaped for insertion into an XML stream.  Returns a
 110  * pointer to the target buffer for convenience.
 111  *
 112  * BUG: this does not properly handle UTF-8
 113  */
 114 char *xmlesc(char *buf, char *str, int bufsiz)
 115 {
 116         char *ptr;
 117         char *eiptr;
 118         unsigned char ch;
 119         int inlen;
 120         int len = 0;
 121         int IsUtf8Sequence;
 122
 123         if (!buf) return(NULL);
 124         buf[0] = 0;
 125         len = 0;
 126         if (!str) {
 127                 return(buf);
 128         }
 129
 130         inlen = strlen(str);
 131         eiptr = str + inlen;
 132
 133         for (ptr=str; *ptr; ptr++) {
 134                 ch = *ptr;
 135                 if (ch == '<') {
 136                         strcpy(&buf[len], "&lt;");
 137                         len += 4;
 138                 }
 139                 else if (ch == '>') {
 140                         strcpy(&buf[len], "&gt;");
 141                         len += 4;
 142                 }
 143                 else if (ch == '&') {
 144                         strcpy(&buf[len], "&amp;");
 145                         len += 5;
 146                 }
 147                 else if ((ch >= 0x20) && (ch <= 0x7F)) {
 148                         buf[len++] = ch;
 149                         buf[len] = 0;
 150                 }
 151                 else if (ch < 0x20) {
 152                         /* we probably shouldn't be doing this */
 153                         buf[len++] = '_';
 154                         buf[len] = 0;
 155                 }
 156                 else {
 157                         char oct[32];
 158
 159                         IsUtf8Sequence =  XMPP_GetUtf8SequenceLength(&buf[len], eiptr);
 160                         if (IsUtf8Sequence)
 161                         {
 162                                 while (IsUtf8Sequence > 0){
 163                                         buf[len] = *ptr;
 164                                         len ++;
 165                                         if (--IsUtf8Sequence)
 166                                                 ptr++;
 167                                 }
 168                                 buf[len] = '\0';
 169                         }
 170                         else
 171                         {
 172                                 sprintf(oct, "&#%o;", ch);
 173                                 strcpy(&buf[len], oct);
 174                                 len += strlen(oct);
 175                         }
 176                 }
 177                 if ((len + 6) > bufsiz) {
 178                         return(buf);
 179                 }
 180         }
 181         return(buf);
 182 }
 183
 184
 185 /*
 186  * We have just received a <stream> tag from the client, so send them ours
 187  */
 188 void xmpp_stream_start(void *data, const char *supplied_el, const char **attr)
 189 {
 190         char xmlbuf[256];
 191
 192         while (*attr) {
 193                 if (!strcasecmp(attr[0], "to")) {
 194                         safestrncpy(XMPP->server_name, attr[1], sizeof XMPP->server_name);
 195                 }
 196                 attr += 2;
 197         }
 198
 199         cprintf("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
 200
 201         cprintf("<stream:stream ");
 202         cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->server_name, sizeof xmlbuf));
 203         cprintf("id=\"%08x\" ", CC->cs_pid);
 204         cprintf("version=\"1.0\" ");
 205         cprintf("xmlns:stream=\"http://etherx.jabber.org/streams\" ");
 206         cprintf("xmlns=\"jabber:client\">");
 207
 208         /* The features of this stream are... */
 209         cprintf("<stream:features>");
 210
 211         /*
 212          * TLS encryption (but only if it isn't already active)
 213          */
 214 #ifdef HAVE_OPENSSL
 215         if (!CC->redirect_ssl) {
 216                 cprintf("<starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'></starttls>");
 217         }
 218 #endif
 219
 220         if (!CC->logged_in) {
 221                 /* If we're not logged in yet, offer SASL as our feature set */
 222                 xmpp_output_auth_mechs();
 223
 224                 /* Also offer non-SASL authentication */
 225                 cprintf("<auth xmlns=\"http://jabber.org/features/iq-auth\"/>");
 226         }
 227
 228         /* Offer binding and sessions as part of our feature set */
 229         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\"/>");
 230         cprintf("<session xmlns=\"urn:ietf:params:xml:ns:xmpp-session\"/>");
 231
 232         cprintf("</stream:features>");
 233
 234         CC->is_async = 1;               /* XMPP sessions are inherently async-capable */
 235 }
 236
 237 void xmpp_start_query(void *data, const char *supplied_el, const char **attr)
 238 {
 239         XMPP->iq_query_xmlns[0] = 0;
 240         safestrncpy(XMPP->iq_query_xmlns, supplied_el, sizeof XMPP->iq_query_xmlns);
 241 }
 242
 243 void xmpp_start_bind(void *data, const char *supplied_el, const char **attr)
 244 {
 245         XMPP->bind_requested = 1;
 246 }
 247
 248 void xmpp_start_iq(void *data, const char *supplied_el, const char **attr)
 249 {
 250         int i;
 251         for (i=0; attr[i] != NULL; i+=2) {
 252                 if (!strcasecmp(attr[i], "type")) {
 253                         safestrncpy(XMPP->iq_type, attr[i+1], sizeof XMPP->iq_type);
 254                 }
 255                 else if (!strcasecmp(attr[i], "id")) {
 256                         safestrncpy(XMPP->iq_id, attr[i+1], sizeof XMPP->iq_id);
 257                 }
 258                 else if (!strcasecmp(attr[i], "from")) {
 259                         safestrncpy(XMPP->iq_from, attr[i+1], sizeof XMPP->iq_from);
 260                 }
 261                 else if (!strcasecmp(attr[i], "to")) {
 262                         safestrncpy(XMPP->iq_to, attr[i+1], sizeof XMPP->iq_to);
 263                 }
 264         }
 265 }
 266
 267 void xmpp_start_auth(void *data, const char *supplied_el, const char **attr)
 268 {
 269         int i;
 270
 271         XMPP->sasl_auth_mech[0] = 0;
 272         for (i=0; attr[i] != NULL; i+=2) {
 273                 if (!strcasecmp(attr[i], "mechanism")) {
 274                         safestrncpy(XMPP->sasl_auth_mech, attr[i+1], sizeof XMPP->sasl_auth_mech);
 275                 }
 276         }
 277 }
 278
 279 void xmpp_start_message(void *data, const char *supplied_el, const char **attr)
 280 {
 281         int i;
 282
 283         for (i=0; attr[i] != NULL; i+=2) {
 284                 if (!strcasecmp(attr[i], "to")) {
 285                         safestrncpy(XMPP->message_to, attr[i+1], sizeof XMPP->message_to);
 286                 }
 287         }
 288 }
 289
 290 void xmpp_start_html(void *data, const char *supplied_el, const char **attr)
 291 {
 292         ++XMPP->html_tag_level;
 293 }
 294
 295 void xmpp_xml_start(void *data, const char *supplied_el, const char **attr)
 296 {
 297         char el[256];
 298         long newlen;
 299         long len;
 300         char *sep = NULL;
 301         void *pv;
 302
 303         /* Axe the namespace, we don't care about it */
 304         newlen = len = safestrncpy(el, supplied_el, sizeof el);
 305         while (sep = strchr(el, ':'), sep)
 306         {
 307                 newlen -= ++sep - el;
 308                 memmove(el, sep, newlen + 1);
 309                 len = newlen;
 310         }
 311
 312         /*
 313         XMPP_syslog(LOG_DEBUG, "XMPP ELEMENT START: <%s>\n", el);
 314         for (i=0; attr[i] != NULL; i+=2) {
 315                 XMPP_syslog(LOG_DEBUG, "                    Attribute '%s' = '%s'\n", attr[i], attr[i+1]);
 316         }
 317         uncomment for more verbosity */
 318
 319         if (GetHash(XMPP_StartHandlers, el, len, &pv))
 320         {
 321                 xmpp_handler *h;
 322                 h = (xmpp_handler*) pv;
 323                 h->Handler(data, supplied_el, attr);
 324         }
 325
 326 }
 327
 328 void xmpp_end_resource(void *data, const char *supplied_el, const char **attr)
 329 {
 330         if (XMPP->chardata_len > 0) {
 331                 safestrncpy(XMPP->iq_client_resource, XMPP->chardata,
 332                             sizeof XMPP->iq_client_resource);
 333                 striplt(XMPP->iq_client_resource);
 334         }
 335 }
 336
 337 void xmpp_end_username(void *data, const char *supplied_el, const char **attr)
 338 {
 339         /* NON SASL ONLY */
 340         if (XMPP->chardata_len > 0) {
 341                 safestrncpy(XMPP->iq_client_username, XMPP->chardata,
 342                             sizeof XMPP->iq_client_username);
 343                 striplt(XMPP->iq_client_username);
 344         }
 345 }
 346
 347 void xmpp_end_password(void *data, const char *supplied_el, const char **attr)
 348 {               /* NON SASL ONLY */
 349         if (XMPP->chardata_len > 0) {
 350                 safestrncpy(XMPP->iq_client_password, XMPP->chardata,
 351                             sizeof XMPP->iq_client_password);
 352                 striplt(XMPP->iq_client_password);
 353         }
 354 }
 355
 356 void xmpp_end_iq(void *data, const char *supplied_el, const char **attr)
 357 {
 358         char xmlbuf[256];
 359         /*
 360          * iq type="get" (handle queries)
 361          */
 362         if (!strcasecmp(XMPP->iq_type, "get"))
 363         {
 364                 /*
 365                  * Query on a namespace
 366                  */
 367                 if (!IsEmptyStr(XMPP->iq_query_xmlns)) {
 368                         xmpp_query_namespace(XMPP->iq_id, XMPP->iq_from,
 369                                              XMPP->iq_to, XMPP->iq_query_xmlns);
 370                 }
 371
 372                 /*
 373                  * ping ( http://xmpp.org/extensions/xep-0199.html )
 374                  */
 375                 else if (XMPP->ping_requested) {
 376                         cprintf("<iq type=\"result\" ");
 377                         if (!IsEmptyStr(XMPP->iq_from)) {
 378                                 cprintf("to=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_from, sizeof xmlbuf));
 379                         }
 380                         if (!IsEmptyStr(XMPP->iq_to)) {
 381                                 cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_to, sizeof xmlbuf));
 382                         }
 383                         cprintf("id=\"%s\"/>", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 384                 }
 385
 386                 /*
 387                  * Unknown query ... return the XML equivalent of a blank stare
 388                  */
 389                 else {
 390 /*
 391                         XMPP_syslog(LOG_DEBUG,
 392                                     "Unknown query <%s> - returning <service-unavailable/>\n",
 393                                     el
 394                                 );
 395 */
 396                         cprintf("<iq type=\"error\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 397                         cprintf("<error code=\"503\" type=\"cancel\">"
 398                                 "<service-unavailable xmlns=\"urn:ietf:params:xml:ns:xmpp-stanzas\"/>"
 399                                 "</error>"
 400                                 );
 401                         cprintf("</iq>");
 402                 }
 403         }
 404
 405         /*
 406          * Non SASL authentication
 407          */
 408         else if (
 409                 (!strcasecmp(XMPP->iq_type, "set"))
 410                 && (!strcasecmp(XMPP->iq_query_xmlns, "jabber:iq:auth:query"))
 411                 ) {
 412
 413                 xmpp_non_sasl_authenticate(
 414                         XMPP->iq_id,
 415                         XMPP->iq_client_username,
 416                         XMPP->iq_client_password,
 417                         XMPP->iq_client_resource
 418                         );
 419         }
 420
 421         /*
 422          * If this <iq> stanza was a "bind" attempt, process it ...
 423          */
 424         else if (
 425                 (XMPP->bind_requested)
 426                 && (!IsEmptyStr(XMPP->iq_id))
 427                 && (!IsEmptyStr(XMPP->iq_client_resource))
 428                 && (CC->logged_in)
 429                 ) {
 430
 431                 /* Generate the "full JID" of the client resource */
 432
 433                 snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
 434                          "%s/%s",
 435                          CC->cs_inet_email,
 436                          XMPP->iq_client_resource
 437                         );
 438
 439                 /* Tell the client what its JID is */
 440
 441                 cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 442                 cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\">");
 443                 cprintf("<jid>%s</jid>", xmlesc(xmlbuf, XMPP->client_jid, sizeof xmlbuf));
 444                 cprintf("</bind>");
 445                 cprintf("</iq>");
 446         }
 447
 448         else if (XMPP->iq_session) {
 449                 cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 450                 cprintf("</iq>");
 451         }
 452
 453         else {
 454                 cprintf("<iq type=\"error\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 455                 cprintf("<error>Don't know howto do '%s'!</error>", xmlesc(xmlbuf, XMPP->iq_type, sizeof xmlbuf));
 456                 cprintf("</iq>");
 457         }
 458
 459         /* Now clear these fields out so they don't get used by a future stanza */
 460         XMPP->iq_id[0] = 0;
 461         XMPP->iq_from[0] = 0;
 462         XMPP->iq_to[0] = 0;
 463         XMPP->iq_type[0] = 0;
 464         XMPP->iq_client_resource[0] = 0;
 465         XMPP->iq_session = 0;
 466         XMPP->iq_query_xmlns[0] = 0;
 467         XMPP->bind_requested = 0;
 468         XMPP->ping_requested = 0;
 469 }
 470
 471
 472 void xmpp_end_auth(void *data, const char *supplied_el, const char **attr)
 473 {
 474         /* Try to authenticate (this function is responsible for the output stanza) */
 475         xmpp_sasl_auth(XMPP->sasl_auth_mech, (XMPP->chardata != NULL ? XMPP->chardata : "") );
 476
 477         /* Now clear these fields out so they don't get used by a future stanza */
 478         XMPP->sasl_auth_mech[0] = 0;
 479 }
 480
 481 void xmpp_end_session(void *data, const char *supplied_el, const char **attr)
 482 {
 483         XMPP->iq_session = 1;
 484 }
 485
 486 void xmpp_end_presence(void *data, const char *supplied_el, const char **attr)
 487 {
 488         /* Respond to a <presence> update by firing back with presence information
 489          * on the entire wholist.  Check this assumption, it's probably wrong.
 490          */
 491         xmpp_wholist_presence_dump();
 492 }
 493
 494 void xmpp_end_body(void *data, const char *supplied_el, const char **attr)
 495 {
 496         if (XMPP->html_tag_level == 0)
 497         {
 498                 if (XMPP->message_body != NULL)
 499                 {
 500                         free(XMPP->message_body);
 501                         XMPP->message_body = NULL;
 502                 }
 503                 if (XMPP->chardata_len > 0) {
 504                         XMPP->message_body = strdup(XMPP->chardata);
 505                 }
 506         }
 507 }
 508
 509 void xmpp_end_message(void *data, const char *supplied_el, const char **attr)
 510 {
 511         xmpp_send_message(XMPP->message_to, XMPP->message_body);
 512         XMPP->html_tag_level = 0;
 513 }
 514
 515 void xmpp_end_html(void *data, const char *supplied_el, const char **attr)
 516 {
 517         --XMPP->html_tag_level;
 518 }
 519
 520 void xmpp_end_starttls(void *data, const char *supplied_el, const char **attr)
 521 {
 522 #ifdef HAVE_OPENSSL
 523         cprintf("<proceed xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 524         CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
 525         if (!CC->redirect_ssl) CC->kill_me = KILLME_NO_CRYPTO;
 526 #else
 527         cprintf("<failure xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 528         CC->kill_me = KILLME_NO_CRYPTO;
 529 #endif
 530 }
 531
 532 void xmpp_end_ping(void *data, const char *supplied_el, const char **attr)
 533 {
 534         XMPP->ping_requested = 1;
 535 }
 536
 537 void xmpp_end_stream(void *data, const char *supplied_el, const char **attr)
 538 {
 539         XMPPM_syslog(LOG_DEBUG, "XMPP client shut down their stream\n");
 540         xmpp_massacre_roster();
 541         cprintf("</stream>\n");
 542         CC->kill_me = KILLME_CLIENT_LOGGED_OUT;
 543 }
 544
 545 void xmpp_xml_end(void *data, const char *supplied_el)
 546 {
 547         char el[256];
 548         long len;
 549         long newlen;
 550         char *sep = NULL;
 551         void *pv;
 552
 553         /* Axe the namespace, we don't care about it */
 554         newlen = len = safestrncpy(el, supplied_el, sizeof el);
 555         while (sep = strchr(el, ':'), sep) {
 556
 557                 newlen -= ++sep - el;
 558                 memmove(el, sep, newlen + 1);
 559                 len = newlen;
 560         }
 561
 562         /*
 563         XMPP_syslog(LOG_DEBUG, "XMPP ELEMENT END  : <%s>\n", el);
 564         if (XMPP->chardata_len > 0) {
 565                 XMPP_syslog(LOG_DEBUG, "          chardata: %s\n", XMPP->chardata);
 566         }
 567         uncomment for more verbosity */
 568
 569         if (GetHash(XMPP_EndHandlers, el, len, &pv))
 570         {
 571                 xmpp_handler *h;
 572                 h = (xmpp_handler*) pv;
 573                 h->Handler(data, supplied_el, NULL);
 574         }
 575         else
 576         {
 577                 XMPP_syslog(LOG_DEBUG, "Ignoring unknown tag <%s>\n", el);
 578         }
 579
 580         XMPP->chardata_len = 0;
 581         if (XMPP->chardata_alloc > 0) {
 582                 XMPP->chardata[0] = 0;
 583         }
 584 }
 585
 586
 587 void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
 588 {
 589         citxmpp *X = XMPP;
 590
 591         if (X->chardata_alloc == 0) {
 592                 X->chardata_alloc = SIZ;
 593                 X->chardata = malloc(X->chardata_alloc);
 594         }
 595         if ((X->chardata_len + len + 1) > X->chardata_alloc) {
 596                 X->chardata_alloc = X->chardata_len + len + 1024;
 597                 X->chardata = realloc(X->chardata, X->chardata_alloc);
 598         }
 599         memcpy(&X->chardata[X->chardata_len], s, len);
 600         X->chardata_len += len;
 601         X->chardata[X->chardata_len] = 0;
 602 }
 603
 604
 605 /*
 606  * This cleanup function blows away the temporary memory and files used by the XMPP service.
 607  */
 608 void xmpp_cleanup_function(void) {
 609
 610         /* Don't do this stuff if this is not a XMPP session! */
 611         if (CC->h_command_function != xmpp_command_loop) return;
 612
 613         if (XMPP->chardata != NULL) {
 614                 free(XMPP->chardata);
 615                 XMPP->chardata = NULL;
 616                 XMPP->chardata_len = 0;
 617                 XMPP->chardata_alloc = 0;
 618                 if (XMPP->message_body != NULL) {
 619                         free(XMPP->message_body);
 620                 }
 621         }
 622         XML_ParserFree(XMPP->xp);
 623         free(XMPP);
 624 }
 625
 626
 627
 628 /*
 629  * Here's where our XMPP session begins its happy day.
 630  */
 631 void xmpp_greeting(void) {
 632         client_set_inbound_buf(4);
 633         strcpy(CC->cs_clientname, "XMPP session");
 634         CC->session_specific_data = malloc(sizeof(citxmpp));
 635         memset(XMPP, 0, sizeof(citxmpp));
 636         XMPP->last_event_processed = queue_event_seq;
 637
 638         /* XMPP does not use a greeting, but we still have to initialize some things. */
 639
 640         XMPP->xp = XML_ParserCreateNS("UTF-8", ':');
 641         if (XMPP->xp == NULL) {
 642                 XMPPM_syslog(LOG_ALERT, "Cannot create XML parser!\n");
 643                 CC->kill_me = KILLME_XML_PARSER;
 644                 return;
 645         }
 646
 647         XML_SetElementHandler(XMPP->xp, xmpp_xml_start, xmpp_xml_end);
 648         XML_SetCharacterDataHandler(XMPP->xp, xmpp_xml_chardata);
 649         // XML_SetUserData(XMPP->xp, something...);
 650
 651         /* Prevent the "billion laughs" attack against expat by disabling
 652          * internal entity expansion.  With 2.x, forcibly stop the parser
 653          * if an entity is declared - this is safer and a more obvious
 654          * failure mode.  With older versions, simply prevent expansion
 655          * of such entities. */
 656 #ifdef HAVE_XML_STOPPARSER
 657         XML_SetEntityDeclHandler(XMPP->xp, xmpp_entity_declaration);
 658 #else
 659         XML_SetDefaultHandler(XMPP->xp, NULL);
 660 #endif
 661
 662         CC->can_receive_im = 1;         /* This protocol is capable of receiving instant messages */
 663 }
 664
 665
 666 /*
 667  * Main command loop for XMPP sessions.
 668  */
 669 void xmpp_command_loop(void) {
 670         int rc;
 671         StrBuf *stream_input = NewStrBuf();
 672
 673         time(&CC->lastcmd);
 674         rc = client_read_random_blob(stream_input, 30);
 675         if (rc > 0) {
 676                 XML_Parse(XMPP->xp, ChrPtr(stream_input), rc, 0);
 677         }
 678         else {
 679                 XMPPM_syslog(LOG_ERR, "client disconnected: ending session.\n");
 680                 CC->kill_me = KILLME_CLIENT_DISCONNECTED;
 681         }
 682         FreeStrBuf(&stream_input);
 683 }
 684
 685
 686 /*
 687  * Async loop for XMPP sessions (handles the transmission of unsolicited stanzas)
 688  */
 689 void xmpp_async_loop(void) {
 690         xmpp_process_events();
 691         xmpp_output_incoming_messages();
 692 }
 693
 694
 695 /*
 696  * Login hook for XMPP sessions
 697  */
 698 void xmpp_login_hook(void) {
 699         xmpp_queue_event(XMPP_EVT_LOGIN, CC->cs_inet_email);
 700 }
 701
 702
 703 /*
 704  * Logout hook for XMPP sessions
 705  */
 706 void xmpp_logout_hook(void) {
 707         xmpp_queue_event(XMPP_EVT_LOGOUT, CC->cs_inet_email);
 708 }
 709
 710
 711 void LogXMPPSrvDebugEnable(const int n)
 712 {
 713         XMPPSrvDebugEnable = n;
 714 }
 715 const char *CitadelServiceXMPP="XMPP";
 716 extern void xmpp_cleanup_events(void);
 717
 718
 719
 720 /******************************************************************************
 721  *                    XMPP handler registering logic                           *
 722  ******************************************************************************/
 723
 724 void AddXMPPStartHandler(const char *key,
 725                          long len,
 726                          xmpp_handler_func Handler,
 727                          int Flags)
 728 {
 729         xmpp_handler *h;
 730         h = (xmpp_handler*) malloc(sizeof (xmpp_handler));
 731         h->Flags = Flags;
 732         h->Handler = Handler;
 733         Put(XMPP_StartHandlers, key, len, h, NULL);
 734 }
 735
 736 void AddXMPPEndHandler(const char *key,
 737                        long len,
 738                        xmpp_handler_func Handler,
 739                        int Flags)
 740 {
 741         xmpp_handler *h;
 742         h = (xmpp_handler*) malloc(sizeof (xmpp_handler));
 743         h->Flags = Flags;
 744         h->Handler = Handler;
 745         Put(XMPP_EndHandlers, key, len, h, NULL);
 746 }
 747
 748 CTDL_MODULE_INIT(xmpp)
 749 {
 750         if (!threading) {
 751                 CtdlRegisterServiceHook(config.c_xmpp_c2s_port,
 752                                         NULL,
 753                                         xmpp_greeting,
 754                                         xmpp_command_loop,
 755                                         xmpp_async_loop,
 756                                         CitadelServiceXMPP);
 757
 758
 759                 XMPP_StartHandlers = NewHash(1, NULL);
 760                 XMPP_EndHandlers = NewHash(1, NULL);
 761
 762                 AddXMPPEndHandler(HKEY("resource"),      xmpp_end_resource, 0);
 763                 AddXMPPEndHandler(HKEY("username"),      xmpp_end_username, 0);
 764                 AddXMPPEndHandler(HKEY("password"),      xmpp_end_password, 0);
 765                 AddXMPPEndHandler(HKEY("iq"),            xmpp_end_iq, 0);
 766                 AddXMPPEndHandler(HKEY("auth"),          xmpp_end_auth, 0);
 767                 AddXMPPEndHandler(HKEY("session"),       xmpp_end_session, 0);
 768                 AddXMPPEndHandler(HKEY("presence"),      xmpp_end_presence, 0);
 769                 AddXMPPEndHandler(HKEY("body"),          xmpp_end_body, 0);
 770                 AddXMPPEndHandler(HKEY("message"),       xmpp_end_message, 0);
 771                 AddXMPPEndHandler(HKEY("html"),          xmpp_end_html, 0);
 772                 AddXMPPEndHandler(HKEY("starttls"),      xmpp_end_starttls, 0);
 773                 AddXMPPEndHandler(HKEY("ping"),          xmpp_end_ping, 0);
 774                 AddXMPPEndHandler(HKEY("stream"),        xmpp_end_stream, 0);
 775
 776
 777                 AddXMPPStartHandler(HKEY("stream"),     xmpp_stream_start, 0);
 778                 AddXMPPStartHandler(HKEY("query"),      xmpp_start_query, 0);
 779                 AddXMPPStartHandler(HKEY("bind"),       xmpp_start_bind, 0);
 780                 AddXMPPStartHandler(HKEY("iq"),         xmpp_start_iq, 0);
 781                 AddXMPPStartHandler(HKEY("auth"),       xmpp_start_auth, 0);
 782                 AddXMPPStartHandler(HKEY("message"),    xmpp_start_message, 0);
 783                 AddXMPPStartHandler(HKEY("html"),       xmpp_start_html, 0);
 784
 785
 786                 CtdlRegisterDebugFlagHook(HKEY("serv_xmpp"), LogXMPPSrvDebugEnable, &XMPPSrvDebugEnable);
 787                 CtdlRegisterSessionHook(xmpp_cleanup_function, EVT_STOP, PRIO_STOP + 70);
 788                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_LOGIN, PRIO_LOGIN + 90);
 789                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_LOGOUT, PRIO_LOGOUT + 90);
 790                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_UNSTEALTH, PRIO_UNSTEALTH + 1);
 791                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_STEALTH, PRIO_STEALTH + 1);
 792                 CtdlRegisterCleanupHook(xmpp_cleanup_events);
 793
 794         }
 795
 796         /* return our module name for the log */
 797         return "xmpp";
 798 }