citadel/modules/jabber/serv_xmpp.c

   1 /*
   2  * $Id$
   3  *
   4  * XMPP (Jabber) service for the Citadel system
   5  * Copyright (c) 2007-2009 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 "room_ops.h"
  55 #include "user_ops.h"
  56 #include "policy.h"
  57 #include "database.h"
  58 #include "msgbase.h"
  59 #include "internet_addressing.h"
  60 #include "md5.h"
  61 #include "ctdl_module.h"
  62 #include "serv_xmpp.h"
  63
  64 struct xmpp_event *xmpp_queue = NULL;
  65
  66 /* We have just received a <stream> tag from the client, so send them ours */
  67
  68 void xmpp_stream_start(void *data, const char *supplied_el, const char **attr)
  69 {
  70         while (*attr) {
  71                 if (!strcasecmp(attr[0], "to")) {
  72                         safestrncpy(XMPP->server_name, attr[1], sizeof XMPP->server_name);
  73                 }
  74                 attr += 2;
  75         }
  76
  77         cprintf("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
  78
  79         cprintf("<stream:stream ");
  80         cprintf("from=\"%s\" ", XMPP->server_name);
  81         cprintf("id=\"%08x\" ", CC->cs_pid);
  82         cprintf("version=\"1.0\" ");
  83         cprintf("xmlns:stream=\"http://etherx.jabber.org/streams\" ");
  84         cprintf("xmlns=\"jabber:client\">");
  85
  86         /* The features of this stream are... */
  87         cprintf("<stream:features>");
  88
  89 #ifdef HAVE_OPENSSL_XXXX_COMMENTED_OUT
  90         /* TLS encryption (but only if it isn't already active) */
  91         if (!CC->redirect_ssl) {
  92                 cprintf("<starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'></starttls>");
  93         }
  94 #endif
  95
  96         if (!CC->logged_in) {
  97                 /* If we're not logged in yet, offer SASL as our feature set */
  98                 xmpp_output_auth_mechs();
  99
 100                 /* Also offer non-SASL authentication */
 101                 cprintf("<auth xmlns=\"http://jabber.org/features/iq-auth\"/>");
 102         }
 103
 104         /* Offer binding and sessions as part of our feature set */
 105         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\"/>");
 106         cprintf("<session xmlns=\"urn:ietf:params:xml:ns:xmpp-session\"/>");
 107
 108         cprintf("</stream:features>");
 109
 110         CC->is_async = 1;               /* XMPP sessions are inherently async-capable */
 111 }
 112
 113
 114 void xmpp_xml_start(void *data, const char *supplied_el, const char **attr) {
 115         char el[256];
 116         char *sep = NULL;
 117         int i;
 118
 119         /* Axe the namespace, we don't care about it */
 120         safestrncpy(el, supplied_el, sizeof el);
 121         while (sep = strchr(el, ':'), sep) {
 122                 strcpy(el, ++sep);
 123         }
 124
 125         /*
 126         CtdlLogPrintf(CTDL_DEBUG, "XMPP ELEMENT START: <%s>\n", el);
 127         for (i=0; attr[i] != NULL; i+=2) {
 128                 CtdlLogPrintf(CTDL_DEBUG, "                    Attribute '%s' = '%s'\n", attr[i], attr[i+1]);
 129         }
 130         uncomment for more verbosity */
 131
 132         if (!strcasecmp(el, "stream")) {
 133                 xmpp_stream_start(data, supplied_el, attr);
 134         }
 135
 136         else if (!strcasecmp(el, "query")) {
 137                 XMPP->iq_query_xmlns[0] = 0;
 138                 safestrncpy(XMPP->iq_query_xmlns, supplied_el, sizeof XMPP->iq_query_xmlns);
 139         }
 140
 141         else if (!strcasecmp(el, "bind")) {
 142                 XMPP->bind_requested = 1;
 143         }
 144
 145         else if (!strcasecmp(el, "iq")) {
 146                 for (i=0; attr[i] != NULL; i+=2) {
 147                         if (!strcasecmp(attr[i], "type")) {
 148                                 safestrncpy(XMPP->iq_type, attr[i+1], sizeof XMPP->iq_type);
 149                         }
 150                         else if (!strcasecmp(attr[i], "id")) {
 151                                 safestrncpy(XMPP->iq_id, attr[i+1], sizeof XMPP->iq_id);
 152                         }
 153                         else if (!strcasecmp(attr[i], "from")) {
 154                                 safestrncpy(XMPP->iq_from, attr[i+1], sizeof XMPP->iq_from);
 155                         }
 156                         else if (!strcasecmp(attr[i], "to")) {
 157                                 safestrncpy(XMPP->iq_to, attr[i+1], sizeof XMPP->iq_to);
 158                         }
 159                 }
 160         }
 161
 162         else if (!strcasecmp(el, "auth")) {
 163                 XMPP->sasl_auth_mech[0] = 0;
 164                 for (i=0; attr[i] != NULL; i+=2) {
 165                         if (!strcasecmp(attr[i], "mechanism")) {
 166                                 safestrncpy(XMPP->sasl_auth_mech, attr[i+1], sizeof XMPP->sasl_auth_mech);
 167                         }
 168                 }
 169         }
 170
 171         else if (!strcasecmp(el, "message")) {
 172                 for (i=0; attr[i] != NULL; i+=2) {
 173                         if (!strcasecmp(attr[i], "to")) {
 174                                 safestrncpy(XMPP->message_to, attr[i+1], sizeof XMPP->message_to);
 175                         }
 176                 }
 177         }
 178
 179         else if (!strcasecmp(el, "html")) {
 180                 ++XMPP->html_tag_level;
 181         }
 182 }
 183
 184
 185
 186 void xmpp_xml_end(void *data, const char *supplied_el) {
 187         char el[256];
 188         char *sep = NULL;
 189
 190         /* Axe the namespace, we don't care about it */
 191         safestrncpy(el, supplied_el, sizeof el);
 192         while (sep = strchr(el, ':'), sep) {
 193                 strcpy(el, ++sep);
 194         }
 195
 196         /*
 197         CtdlLogPrintf(CTDL_DEBUG, "XMPP ELEMENT END  : <%s>\n", el);
 198         if (XMPP->chardata_len > 0) {
 199                 CtdlLogPrintf(CTDL_DEBUG, "          chardata: %s\n", XMPP->chardata);
 200         }
 201         uncomment for more verbosity */
 202
 203         if (!strcasecmp(el, "resource")) {
 204                 if (XMPP->chardata_len > 0) {
 205                         safestrncpy(XMPP->iq_client_resource, XMPP->chardata,
 206                                 sizeof XMPP->iq_client_resource);
 207                         striplt(XMPP->iq_client_resource);
 208                 }
 209         }
 210
 211         if (!strcasecmp(el, "username")) {              /* NON SASL ONLY */
 212                 if (XMPP->chardata_len > 0) {
 213                         safestrncpy(XMPP->iq_client_username, XMPP->chardata,
 214                                 sizeof XMPP->iq_client_username);
 215                         striplt(XMPP->iq_client_username);
 216                 }
 217         }
 218
 219         if (!strcasecmp(el, "password")) {              /* NON SASL ONLY */
 220                 if (XMPP->chardata_len > 0) {
 221                         safestrncpy(XMPP->iq_client_password, XMPP->chardata,
 222                                 sizeof XMPP->iq_client_password);
 223                         striplt(XMPP->iq_client_password);
 224                 }
 225         }
 226
 227         else if (!strcasecmp(el, "iq")) {
 228
 229                 /*
 230                  * iq type="get" (handle queries)
 231                  */
 232                 if (!strcasecmp(XMPP->iq_type, "get")) {
 233
 234                         /*
 235                          * Query on a namespace
 236                          */
 237                         if (!IsEmptyStr(XMPP->iq_query_xmlns)) {
 238                                 xmpp_query_namespace(XMPP->iq_id, XMPP->iq_from,
 239                                                 XMPP->iq_to, XMPP->iq_query_xmlns);
 240                         }
 241
 242                         /*
 243                          * Unknown queries ... return the XML equivalent of a blank stare
 244                          */
 245                         else {
 246                                 cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 247                                 cprintf("</iq>");
 248                         }
 249                 }
 250
 251                 /*
 252                  * Non SASL authentication
 253                  */
 254                 else if (
 255                         (!strcasecmp(XMPP->iq_type, "set"))
 256                         && (!strcasecmp(XMPP->iq_query_xmlns, "jabber:iq:auth:query"))
 257                         ) {
 258
 259                         jabber_non_sasl_authenticate(
 260                                 XMPP->iq_id,
 261                                 XMPP->iq_client_username,
 262                                 XMPP->iq_client_password,
 263                                 XMPP->iq_client_resource
 264                         );
 265                 }
 266
 267                 /*
 268                  * If this <iq> stanza was a "bind" attempt, process it ...
 269                  */
 270                 else if (
 271                         (XMPP->bind_requested)
 272                         && (!IsEmptyStr(XMPP->iq_id))
 273                         && (!IsEmptyStr(XMPP->iq_client_resource))
 274                         && (CC->logged_in)
 275                         ) {
 276
 277                         /* Generate the "full JID" of the client resource */
 278
 279                         snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
 280                                 "%s/%s",
 281                                 CC->cs_inet_email,
 282                                 XMPP->iq_client_resource
 283                         );
 284
 285                         /* Tell the client what its JID is */
 286
 287                         cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 288                         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\">");
 289                         cprintf("<jid>%s</jid>", XMPP->client_jid);
 290                         cprintf("</bind>");
 291                         cprintf("</iq>");
 292                 }
 293
 294                 else if (XMPP->iq_session) {
 295                         cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 296                         cprintf("</iq>");
 297                 }
 298
 299                 else {
 300                         cprintf("<iq type=\"error\" id=\"%s\">", XMPP->iq_id);
 301                         cprintf("<error></error>");
 302                         cprintf("</iq>");
 303                 }
 304
 305                 /* Now clear these fields out so they don't get used by a future stanza */
 306                 XMPP->iq_id[0] = 0;
 307                 XMPP->iq_from[0] = 0;
 308                 XMPP->iq_to[0] = 0;
 309                 XMPP->iq_type[0] = 0;
 310                 XMPP->iq_client_resource[0] = 0;
 311                 XMPP->iq_session = 0;
 312                 XMPP->iq_query_xmlns[0] = 0;
 313                 XMPP->bind_requested = 0;
 314         }
 315
 316         else if (!strcasecmp(el, "auth")) {
 317
 318                 /* Try to authenticate (this function is responsible for the output stanza) */
 319                 xmpp_sasl_auth(XMPP->sasl_auth_mech, (XMPP->chardata != NULL ? XMPP->chardata : "") );
 320
 321                 /* Now clear these fields out so they don't get used by a future stanza */
 322                 XMPP->sasl_auth_mech[0] = 0;
 323         }
 324
 325         else if (!strcasecmp(el, "session")) {
 326                 XMPP->iq_session = 1;
 327         }
 328
 329         else if (!strcasecmp(el, "presence")) {
 330
 331                 /* Respond to a <presence> update by firing back with presence information
 332                  * on the entire wholist.  Check this assumption, it's probably wrong.
 333                  */
 334                 jabber_wholist_presence_dump();
 335         }
 336
 337         else if ( (!strcasecmp(el, "body")) && (XMPP->html_tag_level == 0) ) {
 338                 if (XMPP->message_body != NULL) {
 339                         free(XMPP->message_body);
 340                         XMPP->message_body = NULL;
 341                 }
 342                 if (XMPP->chardata_len > 0) {
 343                         XMPP->message_body = strdup(XMPP->chardata);
 344                 }
 345         }
 346
 347         else if (!strcasecmp(el, "message")) {
 348                 jabber_send_message(XMPP->message_to, XMPP->message_body);
 349                 XMPP->html_tag_level = 0;
 350         }
 351
 352         else if (!strcasecmp(el, "html")) {
 353                 --XMPP->html_tag_level;
 354         }
 355
 356         else if (!strcasecmp(el, "starttls")) {
 357 #ifdef HAVE_OPENSSL
 358         cprintf("<proceed xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 359         CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
 360         if (!CC->redirect_ssl) CC->kill_me = 1;
 361 #else
 362         cprintf("<failure xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 363         CC->kill_me = 1;
 364 #endif
 365         }
 366
 367         XMPP->chardata_len = 0;
 368         if (XMPP->chardata_alloc > 0) {
 369                 XMPP->chardata[0] = 0;
 370         }
 371 }
 372
 373
 374 void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
 375 {
 376         struct citxmpp *X = XMPP;
 377
 378         if (X->chardata_alloc == 0) {
 379                 X->chardata_alloc = SIZ;
 380                 X->chardata = malloc(X->chardata_alloc);
 381         }
 382         if ((X->chardata_len + len + 1) > X->chardata_alloc) {
 383                 X->chardata_alloc = X->chardata_len + len + 1024;
 384                 X->chardata = realloc(X->chardata, X->chardata_alloc);
 385         }
 386         memcpy(&X->chardata[X->chardata_len], s, len);
 387         X->chardata_len += len;
 388         X->chardata[X->chardata_len] = 0;
 389 }
 390
 391
 392 /*
 393  * This cleanup function blows away the temporary memory and files used by the XMPP service.
 394  */
 395 void xmpp_cleanup_function(void) {
 396
 397         /* Don't do this stuff if this is not a XMPP session! */
 398         if (CC->h_command_function != xmpp_command_loop) return;
 399
 400         if (XMPP->chardata != NULL) {
 401                 free(XMPP->chardata);
 402                 XMPP->chardata = NULL;
 403                 XMPP->chardata_len = 0;
 404                 XMPP->chardata_alloc = 0;
 405                 if (XMPP->message_body != NULL) {
 406                         free(XMPP->message_body);
 407                 }
 408         }
 409         XML_ParserFree(XMPP->xp);
 410         free(XMPP);
 411 }
 412
 413
 414
 415 /*
 416  * Here's where our XMPP session begins its happy day.
 417  */
 418 void xmpp_greeting(void) {
 419         strcpy(CC->cs_clientname, "Jabber session");
 420         CC->session_specific_data = malloc(sizeof(struct citxmpp));
 421         memset(XMPP, 0, sizeof(struct citxmpp));
 422         XMPP->last_event_processed = queue_event_seq;
 423
 424         /* XMPP does not use a greeting, but we still have to initialize some things. */
 425
 426         XMPP->xp = XML_ParserCreateNS("UTF-8", ':');
 427         if (XMPP->xp == NULL) {
 428                 CtdlLogPrintf(CTDL_ALERT, "Cannot create XML parser!\n");
 429                 CC->kill_me = 1;
 430                 return;
 431         }
 432
 433         XML_SetElementHandler(XMPP->xp, xmpp_xml_start, xmpp_xml_end);
 434         XML_SetCharacterDataHandler(XMPP->xp, xmpp_xml_chardata);
 435         // XML_SetUserData(XMPP->xp, something...);
 436
 437         CC->can_receive_im = 1;         /* This protocol is capable of receiving instant messages */
 438 }
 439
 440
 441 /*
 442  * Main command loop for XMPP sessions.
 443  */
 444 void xmpp_command_loop(void) {
 445         char cmdbuf[16];
 446         int retval;
 447
 448         time(&CC->lastcmd);
 449         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
 450         retval = client_read(cmdbuf, 1);
 451         if (retval != 1) {
 452                 CtdlLogPrintf(CTDL_ERR, "Client disconnected: ending session.\r\n");
 453                 CC->kill_me = 1;
 454                 return;
 455         }
 456
 457         /* FIXME ... this is woefully inefficient. */
 458
 459         XML_Parse(XMPP->xp, cmdbuf, 1, 0);
 460 }
 461
 462
 463 /*
 464  * Async loop for XMPP sessions (handles the transmission of unsolicited stanzas)
 465  */
 466 void xmpp_async_loop(void) {
 467         xmpp_process_events();
 468         jabber_output_incoming_messages();
 469 }
 470
 471
 472 /*
 473  * Login hook for XMPP sessions
 474  */
 475 void xmpp_login_hook(void) {
 476         xmpp_queue_event(XMPP_EVT_LOGIN, CC->cs_inet_email);
 477 }
 478
 479
 480 /*
 481  * Logout hook for XMPP sessions
 482  */
 483 void xmpp_logout_hook(void) {
 484         xmpp_queue_event(XMPP_EVT_LOGOUT, CC->cs_inet_email);
 485 }
 486
 487
 488 const char *CitadelServiceXMPP="XMPP";
 489
 490 CTDL_MODULE_INIT(jabber)
 491 {
 492         if (!threading) {
 493                 CtdlRegisterServiceHook(config.c_xmpp_c2s_port,
 494                                         NULL,
 495                                         xmpp_greeting,
 496                                         xmpp_command_loop,
 497                                         xmpp_async_loop,
 498                                         CitadelServiceXMPP);
 499                 CtdlRegisterSessionHook(xmpp_cleanup_function, EVT_STOP);
 500                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_LOGIN);
 501                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_LOGOUT);
 502                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_UNSTEALTH);
 503                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_STEALTH);
 504         }
 505
 506         /* return our Subversion id for the Log */
 507         return "$Id$";
 508 }