citadel/modules/xmpp/serv_xmpp.c

   1 /*
   2  * $Id$
   3  *
   4  * XMPP (Jabber) service for the Citadel system
   5  * Copyright (c) 2007-2010 by Art Cancro
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include "sysdep.h"
  23 #include <stdlib.h>
  24 #include <unistd.h>
  25 #include <stdio.h>
  26 #include <fcntl.h>
  27 #include <signal.h>
  28 #include <pwd.h>
  29 #include <errno.h>
  30 #include <sys/types.h>
  31
  32 #if TIME_WITH_SYS_TIME
  33 # include <sys/time.h>
  34 # include <time.h>
  35 #else
  36 # if HAVE_SYS_TIME_H
  37 #  include <sys/time.h>
  38 # else
  39 #  include <time.h>
  40 # endif
  41 #endif
  42
  43 #include <sys/wait.h>
  44 #include <string.h>
  45 #include <limits.h>
  46 #include <ctype.h>
  47 #include <libcitadel.h>
  48 #include <expat.h>
  49 #include "citadel.h"
  50 #include "server.h"
  51 #include "citserver.h"
  52 #include "support.h"
  53 #include "config.h"
  54 #include "user_ops.h"
  55 #include "database.h"
  56 #include "msgbase.h"
  57 #include "internet_addressing.h"
  58 #include "md5.h"
  59 #include "ctdl_module.h"
  60 #include "serv_xmpp.h"
  61
  62 struct xmpp_event *xmpp_queue = NULL;
  63
  64 /* We have just received a <stream> tag from the client, so send them ours */
  65
  66 void xmpp_stream_start(void *data, const char *supplied_el, const char **attr)
  67 {
  68         while (*attr) {
  69                 if (!strcasecmp(attr[0], "to")) {
  70                         safestrncpy(XMPP->server_name, attr[1], sizeof XMPP->server_name);
  71                 }
  72                 attr += 2;
  73         }
  74
  75         cprintf("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
  76
  77         cprintf("<stream:stream ");
  78         cprintf("from=\"%s\" ", XMPP->server_name);
  79         cprintf("id=\"%08x\" ", CC->cs_pid);
  80         cprintf("version=\"1.0\" ");
  81         cprintf("xmlns:stream=\"http://etherx.jabber.org/streams\" ");
  82         cprintf("xmlns=\"jabber:client\">");
  83
  84         /* The features of this stream are... */
  85         cprintf("<stream:features>");
  86
  87 #ifdef HAVE_OPENSSL_XXXX_COMMENTED_OUT
  88         /* TLS encryption (but only if it isn't already active) */
  89         if (!CC->redirect_ssl) {
  90                 cprintf("<starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'></starttls>");
  91         }
  92 #endif
  93
  94         if (!CC->logged_in) {
  95                 /* If we're not logged in yet, offer SASL as our feature set */
  96                 xmpp_output_auth_mechs();
  97
  98                 /* Also offer non-SASL authentication */
  99                 cprintf("<auth xmlns=\"http://jabber.org/features/iq-auth\"/>");
 100         }
 101
 102         /* Offer binding and sessions as part of our feature set */
 103         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\"/>");
 104         cprintf("<session xmlns=\"urn:ietf:params:xml:ns:xmpp-session\"/>");
 105
 106         cprintf("</stream:features>");
 107
 108         CC->is_async = 1;               /* XMPP sessions are inherently async-capable */
 109 }
 110
 111
 112 void xmpp_xml_start(void *data, const char *supplied_el, const char **attr) {
 113         char el[256];
 114         char *sep = NULL;
 115         int i;
 116
 117         /* Axe the namespace, we don't care about it */
 118         safestrncpy(el, supplied_el, sizeof el);
 119         while (sep = strchr(el, ':'), sep) {
 120                 strcpy(el, ++sep);
 121         }
 122
 123         /*
 124         CtdlLogPrintf(CTDL_DEBUG, "XMPP ELEMENT START: <%s>\n", el);
 125         for (i=0; attr[i] != NULL; i+=2) {
 126                 CtdlLogPrintf(CTDL_DEBUG, "                    Attribute '%s' = '%s'\n", attr[i], attr[i+1]);
 127         }
 128         uncomment for more verbosity */
 129
 130         if (!strcasecmp(el, "stream")) {
 131                 xmpp_stream_start(data, supplied_el, attr);
 132         }
 133
 134         else if (!strcasecmp(el, "query")) {
 135                 XMPP->iq_query_xmlns[0] = 0;
 136                 safestrncpy(XMPP->iq_query_xmlns, supplied_el, sizeof XMPP->iq_query_xmlns);
 137         }
 138
 139         else if (!strcasecmp(el, "bind")) {
 140                 XMPP->bind_requested = 1;
 141         }
 142
 143         else if (!strcasecmp(el, "iq")) {
 144                 for (i=0; attr[i] != NULL; i+=2) {
 145                         if (!strcasecmp(attr[i], "type")) {
 146                                 safestrncpy(XMPP->iq_type, attr[i+1], sizeof XMPP->iq_type);
 147                         }
 148                         else if (!strcasecmp(attr[i], "id")) {
 149                                 safestrncpy(XMPP->iq_id, attr[i+1], sizeof XMPP->iq_id);
 150                         }
 151                         else if (!strcasecmp(attr[i], "from")) {
 152                                 safestrncpy(XMPP->iq_from, attr[i+1], sizeof XMPP->iq_from);
 153                         }
 154                         else if (!strcasecmp(attr[i], "to")) {
 155                                 safestrncpy(XMPP->iq_to, attr[i+1], sizeof XMPP->iq_to);
 156                         }
 157                 }
 158         }
 159
 160         else if (!strcasecmp(el, "auth")) {
 161                 XMPP->sasl_auth_mech[0] = 0;
 162                 for (i=0; attr[i] != NULL; i+=2) {
 163                         if (!strcasecmp(attr[i], "mechanism")) {
 164                                 safestrncpy(XMPP->sasl_auth_mech, attr[i+1], sizeof XMPP->sasl_auth_mech);
 165                         }
 166                 }
 167         }
 168
 169         else if (!strcasecmp(el, "message")) {
 170                 for (i=0; attr[i] != NULL; i+=2) {
 171                         if (!strcasecmp(attr[i], "to")) {
 172                                 safestrncpy(XMPP->message_to, attr[i+1], sizeof XMPP->message_to);
 173                         }
 174                 }
 175         }
 176
 177         else if (!strcasecmp(el, "html")) {
 178                 ++XMPP->html_tag_level;
 179         }
 180 }
 181
 182
 183
 184 void xmpp_xml_end(void *data, const char *supplied_el) {
 185         char el[256];
 186         char *sep = NULL;
 187
 188         /* Axe the namespace, we don't care about it */
 189         safestrncpy(el, supplied_el, sizeof el);
 190         while (sep = strchr(el, ':'), sep) {
 191                 strcpy(el, ++sep);
 192         }
 193
 194         /*
 195         CtdlLogPrintf(CTDL_DEBUG, "XMPP ELEMENT END  : <%s>\n", el);
 196         if (XMPP->chardata_len > 0) {
 197                 CtdlLogPrintf(CTDL_DEBUG, "          chardata: %s\n", XMPP->chardata);
 198         }
 199         uncomment for more verbosity */
 200
 201         if (!strcasecmp(el, "resource")) {
 202                 if (XMPP->chardata_len > 0) {
 203                         safestrncpy(XMPP->iq_client_resource, XMPP->chardata,
 204                                 sizeof XMPP->iq_client_resource);
 205                         striplt(XMPP->iq_client_resource);
 206                 }
 207         }
 208
 209         else if (!strcasecmp(el, "username")) {         /* NON SASL ONLY */
 210                 if (XMPP->chardata_len > 0) {
 211                         safestrncpy(XMPP->iq_client_username, XMPP->chardata,
 212                                 sizeof XMPP->iq_client_username);
 213                         striplt(XMPP->iq_client_username);
 214                 }
 215         }
 216
 217         else if (!strcasecmp(el, "password")) {         /* NON SASL ONLY */
 218                 if (XMPP->chardata_len > 0) {
 219                         safestrncpy(XMPP->iq_client_password, XMPP->chardata,
 220                                 sizeof XMPP->iq_client_password);
 221                         striplt(XMPP->iq_client_password);
 222                 }
 223         }
 224
 225         else if (!strcasecmp(el, "iq")) {
 226
 227                 /*
 228                  * iq type="get" (handle queries)
 229                  */
 230                 if (!strcasecmp(XMPP->iq_type, "get")) {
 231
 232                         /*
 233                          * Query on a namespace
 234                          */
 235                         if (!IsEmptyStr(XMPP->iq_query_xmlns)) {
 236                                 xmpp_query_namespace(XMPP->iq_id, XMPP->iq_from,
 237                                                 XMPP->iq_to, XMPP->iq_query_xmlns);
 238                         }
 239
 240                         /*
 241                          * ping ( http://xmpp.org/extensions/xep-0199.html )
 242                          */
 243                         else if (XMPP->ping_requested) {
 244                                 cprintf("<iq type=\"result\" ");
 245                                 if (!IsEmptyStr(XMPP->iq_from)) {
 246                                         cprintf("to=\"%s\" ", XMPP->iq_from);
 247                                 }
 248                                 if (!IsEmptyStr(XMPP->iq_to)) {
 249                                         cprintf("from=\"%s\" ", XMPP->iq_to);
 250                                 }
 251                                 cprintf("id=\"%s\"/>", XMPP->iq_id);
 252                         }
 253
 254                         /*
 255                          * Unknown query ... return the XML equivalent of a blank stare
 256                          */
 257                         else {
 258                                 CtdlLogPrintf(CTDL_DEBUG,
 259                                         "Unknown query <%s> - returning <service-unavailable/>\n",
 260                                         el
 261                                 );
 262                                 cprintf("<iq type=\"error\" id=\"%s\">", XMPP->iq_id);
 263                                 cprintf("<error code=\"503\" type=\"cancel\">"
 264                                         "<service-unavailable xmlns=\"urn:ietf:params:xml:ns:xmpp-stanzas\"/>"
 265                                         "</error>"
 266                                 );
 267                                 cprintf("</iq>");
 268                         }
 269                 }
 270
 271                 /*
 272                  * Non SASL authentication
 273                  */
 274                 else if (
 275                         (!strcasecmp(XMPP->iq_type, "set"))
 276                         && (!strcasecmp(XMPP->iq_query_xmlns, "jabber:iq:auth:query"))
 277                         ) {
 278
 279                         xmpp_non_sasl_authenticate(
 280                                 XMPP->iq_id,
 281                                 XMPP->iq_client_username,
 282                                 XMPP->iq_client_password,
 283                                 XMPP->iq_client_resource
 284                         );
 285                 }
 286
 287                 /*
 288                  * If this <iq> stanza was a "bind" attempt, process it ...
 289                  */
 290                 else if (
 291                         (XMPP->bind_requested)
 292                         && (!IsEmptyStr(XMPP->iq_id))
 293                         && (!IsEmptyStr(XMPP->iq_client_resource))
 294                         && (CC->logged_in)
 295                         ) {
 296
 297                         /* Generate the "full JID" of the client resource */
 298
 299                         snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
 300                                 "%s/%s",
 301                                 CC->cs_inet_email,
 302                                 XMPP->iq_client_resource
 303                         );
 304
 305                         /* Tell the client what its JID is */
 306
 307                         cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 308                         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\">");
 309                         cprintf("<jid>%s</jid>", XMPP->client_jid);
 310                         cprintf("</bind>");
 311                         cprintf("</iq>");
 312                 }
 313
 314                 else if (XMPP->iq_session) {
 315                         cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 316                         cprintf("</iq>");
 317                 }
 318
 319                 else {
 320                         cprintf("<iq type=\"error\" id=\"%s\">", XMPP->iq_id);
 321                         cprintf("<error></error>");
 322                         cprintf("</iq>");
 323                 }
 324
 325                 /* Now clear these fields out so they don't get used by a future stanza */
 326                 XMPP->iq_id[0] = 0;
 327                 XMPP->iq_from[0] = 0;
 328                 XMPP->iq_to[0] = 0;
 329                 XMPP->iq_type[0] = 0;
 330                 XMPP->iq_client_resource[0] = 0;
 331                 XMPP->iq_session = 0;
 332                 XMPP->iq_query_xmlns[0] = 0;
 333                 XMPP->bind_requested = 0;
 334                 XMPP->ping_requested = 0;
 335         }
 336
 337         else if (!strcasecmp(el, "auth")) {
 338
 339                 /* Try to authenticate (this function is responsible for the output stanza) */
 340                 xmpp_sasl_auth(XMPP->sasl_auth_mech, (XMPP->chardata != NULL ? XMPP->chardata : "") );
 341
 342                 /* Now clear these fields out so they don't get used by a future stanza */
 343                 XMPP->sasl_auth_mech[0] = 0;
 344         }
 345
 346         else if (!strcasecmp(el, "session")) {
 347                 XMPP->iq_session = 1;
 348         }
 349
 350         else if (!strcasecmp(el, "presence")) {
 351
 352                 /* Respond to a <presence> update by firing back with presence information
 353                  * on the entire wholist.  Check this assumption, it's probably wrong.
 354                  */
 355                 xmpp_wholist_presence_dump();
 356         }
 357
 358         else if ( (!strcasecmp(el, "body")) && (XMPP->html_tag_level == 0) ) {
 359                 if (XMPP->message_body != NULL) {
 360                         free(XMPP->message_body);
 361                         XMPP->message_body = NULL;
 362                 }
 363                 if (XMPP->chardata_len > 0) {
 364                         XMPP->message_body = strdup(XMPP->chardata);
 365                 }
 366         }
 367
 368         else if (!strcasecmp(el, "message")) {
 369                 xmpp_send_message(XMPP->message_to, XMPP->message_body);
 370                 XMPP->html_tag_level = 0;
 371         }
 372
 373         else if (!strcasecmp(el, "html")) {
 374                 --XMPP->html_tag_level;
 375         }
 376
 377         else if (!strcasecmp(el, "starttls")) {
 378 #ifdef HAVE_OPENSSL
 379                 cprintf("<proceed xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 380                 CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
 381                 if (!CC->redirect_ssl) CC->kill_me = 1;
 382 #else
 383                 cprintf("<failure xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 384                 CC->kill_me = 1;
 385 #endif
 386         }
 387
 388         else if (!strcasecmp(el, "ping")) {
 389                 XMPP->ping_requested = 1;
 390         }
 391
 392         else if (!strcasecmp(el, "stream")) {
 393                 CtdlLogPrintf(CTDL_DEBUG, "XMPP client shut down their stream\n");
 394                 /* xmpp_massacre_roster(); FIXME put this back in when it's finished */
 395                 cprintf("</stream>\n");
 396                 CC->kill_me = 1;
 397         }
 398
 399         else {
 400                 CtdlLogPrintf(CTDL_DEBUG, "Ignoring unknown tag <%s>\n", el);
 401         }
 402
 403         XMPP->chardata_len = 0;
 404         if (XMPP->chardata_alloc > 0) {
 405                 XMPP->chardata[0] = 0;
 406         }
 407 }
 408
 409
 410 void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
 411 {
 412         struct citxmpp *X = XMPP;
 413
 414         if (X->chardata_alloc == 0) {
 415                 X->chardata_alloc = SIZ;
 416                 X->chardata = malloc(X->chardata_alloc);
 417         }
 418         if ((X->chardata_len + len + 1) > X->chardata_alloc) {
 419                 X->chardata_alloc = X->chardata_len + len + 1024;
 420                 X->chardata = realloc(X->chardata, X->chardata_alloc);
 421         }
 422         memcpy(&X->chardata[X->chardata_len], s, len);
 423         X->chardata_len += len;
 424         X->chardata[X->chardata_len] = 0;
 425 }
 426
 427
 428 /*
 429  * This cleanup function blows away the temporary memory and files used by the XMPP service.
 430  */
 431 void xmpp_cleanup_function(void) {
 432
 433         /* Don't do this stuff if this is not a XMPP session! */
 434         if (CC->h_command_function != xmpp_command_loop) return;
 435
 436         if (XMPP->chardata != NULL) {
 437                 free(XMPP->chardata);
 438                 XMPP->chardata = NULL;
 439                 XMPP->chardata_len = 0;
 440                 XMPP->chardata_alloc = 0;
 441                 if (XMPP->message_body != NULL) {
 442                         free(XMPP->message_body);
 443                 }
 444         }
 445         XML_ParserFree(XMPP->xp);
 446         free(XMPP);
 447 }
 448
 449
 450
 451 /*
 452  * Here's where our XMPP session begins its happy day.
 453  */
 454 void xmpp_greeting(void) {
 455         strcpy(CC->cs_clientname, "XMPP session");
 456         CC->session_specific_data = malloc(sizeof(struct citxmpp));
 457         memset(XMPP, 0, sizeof(struct citxmpp));
 458         XMPP->last_event_processed = queue_event_seq;
 459
 460         /* XMPP does not use a greeting, but we still have to initialize some things. */
 461
 462         XMPP->xp = XML_ParserCreateNS("UTF-8", ':');
 463         if (XMPP->xp == NULL) {
 464                 CtdlLogPrintf(CTDL_ALERT, "Cannot create XML parser!\n");
 465                 CC->kill_me = 1;
 466                 return;
 467         }
 468
 469         XML_SetElementHandler(XMPP->xp, xmpp_xml_start, xmpp_xml_end);
 470         XML_SetCharacterDataHandler(XMPP->xp, xmpp_xml_chardata);
 471         // XML_SetUserData(XMPP->xp, something...);
 472
 473         CC->can_receive_im = 1;         /* This protocol is capable of receiving instant messages */
 474 }
 475
 476
 477 /*
 478  * Main command loop for XMPP sessions.
 479  */
 480 void xmpp_command_loop(void) {
 481         char cmdbuf[16];
 482         int retval;
 483
 484         time(&CC->lastcmd);
 485         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
 486         retval = client_read(cmdbuf, 1);
 487         if (retval != 1) {
 488                 CtdlLogPrintf(CTDL_ERR, "Client disconnected: ending session.\r\n");
 489                 CC->kill_me = 1;
 490                 return;
 491         }
 492
 493         /* FIXME ... this is woefully inefficient. */
 494
 495         XML_Parse(XMPP->xp, cmdbuf, 1, 0);
 496 }
 497
 498
 499 /*
 500  * Async loop for XMPP sessions (handles the transmission of unsolicited stanzas)
 501  */
 502 void xmpp_async_loop(void) {
 503         xmpp_process_events();
 504         xmpp_output_incoming_messages();
 505 }
 506
 507
 508 /*
 509  * Login hook for XMPP sessions
 510  */
 511 void xmpp_login_hook(void) {
 512         xmpp_queue_event(XMPP_EVT_LOGIN, CC->cs_inet_email);
 513 }
 514
 515
 516 /*
 517  * Logout hook for XMPP sessions
 518  */
 519 void xmpp_logout_hook(void) {
 520         xmpp_queue_event(XMPP_EVT_LOGOUT, CC->cs_inet_email);
 521 }
 522
 523
 524 const char *CitadelServiceXMPP="XMPP";
 525
 526 CTDL_MODULE_INIT(xmpp)
 527 {
 528         if (!threading) {
 529                 CtdlRegisterServiceHook(config.c_xmpp_c2s_port,
 530                                         NULL,
 531                                         xmpp_greeting,
 532                                         xmpp_command_loop,
 533                                         xmpp_async_loop,
 534                                         CitadelServiceXMPP);
 535                 CtdlRegisterSessionHook(xmpp_cleanup_function, EVT_STOP);
 536                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_LOGIN);
 537                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_LOGOUT);
 538                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_UNSTEALTH);
 539                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_STEALTH);
 540         }
 541
 542         /* return our Subversion id for the Log */
 543         return "$Id$";
 544 }