citadel/modules/jabber/serv_xmpp.c

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