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