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 "citadel.h"
  37 #include "server.h"
  38 #include "citserver.h"
  39 #include "support.h"
  40 #include "config.h"
  41 #include "room_ops.h"
  42 #include "user_ops.h"
  43 #include "policy.h"
  44 #include "database.h"
  45 #include "msgbase.h"
  46 #include "internet_addressing.h"
  47 #include "md5.h"
  48 #include "ctdl_module.h"
  49
  50 #ifdef HAVE_EXPAT
  51 #include <expat.h>
  52 #include "serv_xmpp.h"
  53
  54 struct xmpp_event *xmpp_queue = NULL;
  55
  56 /* We have just received a <stream> tag from the client, so send them ours */
  57
  58 void xmpp_stream_start(void *data, const char *supplied_el, const char **attr)
  59 {
  60         lprintf(CTDL_DEBUG, "New XMPP stream.\n");
  61
  62         while (*attr) {
  63                 if (!strcasecmp(attr[0], "to")) {
  64                         safestrncpy(XMPP->server_name, attr[1], sizeof XMPP->server_name);
  65                 }
  66                 attr += 2;
  67         }
  68
  69         cprintf("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
  70
  71         cprintf("<stream:stream ");
  72         cprintf("from=\"%s\" ", XMPP->server_name);
  73         cprintf("id=\"%08x\" ", CC->cs_pid);
  74         cprintf("version=\"1.0\" ");
  75         cprintf("xmlns:stream=\"http://etherx.jabber.org/streams\" ");
  76         cprintf("xmlns=\"jabber:client\">");
  77
  78         /* The features of this stream are... */
  79         cprintf("<stream:features>");
  80
  81 #ifdef HAVE_OPENSSL_XXXX_COMMENTED_OUT
  82         /* TLS encryption (but only if it isn't already active) */
  83         if (!CC->redirect_ssl) {
  84                 cprintf("<starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'></starttls>");
  85         }
  86 #endif
  87
  88         if (!CC->logged_in) {
  89                 /* If we're not logged in yet, offer SASL as our feature set */
  90                 xmpp_output_auth_mechs();
  91
  92                 /* Also offer non-SASL authentication */
  93                 cprintf("<auth xmlns=\"http://jabber.org/features/iq-auth\"/>");
  94         }
  95
  96         /* Offer binding and sessions as part of our feature set */
  97         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\"/>");
  98         cprintf("<session xmlns=\"urn:ietf:params:xml:ns:xmpp-session\"/>");
  99
 100         cprintf("</stream:features>");
 101
 102         CC->is_async = 1;               /* XMPP sessions are inherently async-capable */
 103 }
 104
 105
 106 void xmpp_xml_start(void *data, const char *supplied_el, const char **attr) {
 107         char el[256];
 108         char *sep = NULL;
 109         int i;
 110
 111         /* Axe the namespace, we don't care about it */
 112         safestrncpy(el, supplied_el, sizeof el);
 113         while (sep = strchr(el, ':'), sep) {
 114                 strcpy(el, ++sep);
 115         }
 116
 117         lprintf(CTDL_DEBUG, "XMPP ELEMENT START: <%s>\n", el);
 118
 119         for (i=0; attr[i] != NULL; i+=2) {
 120                 lprintf(CTDL_DEBUG, "                    Attribute '%s' = '%s'\n", attr[i], attr[i+1]);
 121         }
 122
 123         if (!strcasecmp(el, "stream")) {
 124                 xmpp_stream_start(data, supplied_el, attr);
 125         }
 126
 127         else if (!strcasecmp(el, "query")) {
 128                 XMPP->iq_query_xmlns[0] = 0;
 129                 safestrncpy(XMPP->iq_query_xmlns, supplied_el, sizeof XMPP->iq_query_xmlns);
 130         }
 131
 132         else if (!strcasecmp(el, "bind")) {
 133                 XMPP->bind_requested = 1;
 134         }
 135
 136         else if (!strcasecmp(el, "iq")) {
 137                 for (i=0; attr[i] != NULL; i+=2) {
 138                         if (!strcasecmp(attr[i], "type")) {
 139                                 safestrncpy(XMPP->iq_type, attr[i+1], sizeof XMPP->iq_type);
 140                         }
 141                         else if (!strcasecmp(attr[i], "id")) {
 142                                 safestrncpy(XMPP->iq_id, attr[i+1], sizeof XMPP->iq_id);
 143                         }
 144                         else if (!strcasecmp(attr[i], "from")) {
 145                                 safestrncpy(XMPP->iq_from, attr[i+1], sizeof XMPP->iq_from);
 146                         }
 147                         else if (!strcasecmp(attr[i], "to")) {
 148                                 safestrncpy(XMPP->iq_to, attr[i+1], sizeof XMPP->iq_to);
 149                         }
 150                 }
 151         }
 152
 153         else if (!strcasecmp(el, "auth")) {
 154                 XMPP->sasl_auth_mech[0] = 0;
 155                 for (i=0; attr[i] != NULL; i+=2) {
 156                         if (!strcasecmp(attr[i], "mechanism")) {
 157                                 safestrncpy(XMPP->sasl_auth_mech, attr[i+1], sizeof XMPP->sasl_auth_mech);
 158                         }
 159                 }
 160         }
 161
 162         else if (!strcasecmp(el, "message")) {
 163                 for (i=0; attr[i] != NULL; i+=2) {
 164                         if (!strcasecmp(attr[i], "to")) {
 165                                 safestrncpy(XMPP->message_to, attr[i+1], sizeof XMPP->message_to);
 166                         }
 167                 }
 168         }
 169
 170         else if (!strcasecmp(el, "html")) {
 171                 ++XMPP->html_tag_level;
 172         }
 173 }
 174
 175
 176
 177 void xmpp_xml_end(void *data, const char *supplied_el) {
 178         char el[256];
 179         char *sep = NULL;
 180
 181         /* Axe the namespace, we don't care about it */
 182         safestrncpy(el, supplied_el, sizeof el);
 183         while (sep = strchr(el, ':'), sep) {
 184                 strcpy(el, ++sep);
 185         }
 186
 187         lprintf(CTDL_DEBUG, "XMPP ELEMENT END  : <%s>\n", el);
 188         if (XMPP->chardata_len > 0) {
 189                 lprintf(CTDL_DEBUG, "          chardata: %s\n", XMPP->chardata);
 190         }
 191
 192         if (!strcasecmp(el, "resource")) {
 193                 if (XMPP->chardata_len > 0) {
 194                         safestrncpy(XMPP->iq_client_resource, XMPP->chardata,
 195                                 sizeof XMPP->iq_client_resource);
 196                         striplt(XMPP->iq_client_resource);
 197                 }
 198         }
 199
 200         if (!strcasecmp(el, "username")) {              /* NON SASL ONLY */
 201                 if (XMPP->chardata_len > 0) {
 202                         safestrncpy(XMPP->iq_client_username, XMPP->chardata,
 203                                 sizeof XMPP->iq_client_username);
 204                         striplt(XMPP->iq_client_username);
 205                 }
 206         }
 207
 208         if (!strcasecmp(el, "password")) {              /* NON SASL ONLY */
 209                 if (XMPP->chardata_len > 0) {
 210                         safestrncpy(XMPP->iq_client_password, XMPP->chardata,
 211                                 sizeof XMPP->iq_client_password);
 212                         striplt(XMPP->iq_client_password);
 213                 }
 214         }
 215
 216         else if (!strcasecmp(el, "iq")) {
 217
 218                 /*
 219                  * iq type="get" (handle queries)
 220                  */
 221                 if (!strcasecmp(XMPP->iq_type, "get")) {
 222
 223                         /*
 224                          * Query on a namespace
 225                          */
 226                         if (!IsEmptyStr(XMPP->iq_query_xmlns)) {
 227                                 xmpp_query_namespace(XMPP->iq_id, XMPP->iq_from,
 228                                                 XMPP->iq_to, XMPP->iq_query_xmlns);
 229                         }
 230
 231                         /*
 232                          * Unknown queries ... return the XML equivalent of a blank stare
 233                          */
 234                         else {
 235                                 cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 236                                 cprintf("</iq>");
 237                         }
 238                 }
 239
 240                 /*
 241                  * Non SASL authentication
 242                  */
 243                 else if (
 244                         (!strcasecmp(XMPP->iq_type, "set"))
 245                         && (!strcasecmp(XMPP->iq_query_xmlns, "jabber:iq:auth:query"))
 246                         ) {
 247
 248                         jabber_non_sasl_authenticate(
 249                                 XMPP->iq_id,
 250                                 XMPP->iq_client_username,
 251                                 XMPP->iq_client_password,
 252                                 XMPP->iq_client_resource
 253                         );
 254                 }
 255
 256                 /*
 257                  * If this <iq> stanza was a "bind" attempt, process it ...
 258                  */
 259                 else if (
 260                         (XMPP->bind_requested)
 261                         && (!IsEmptyStr(XMPP->iq_id))
 262                         && (!IsEmptyStr(XMPP->iq_client_resource))
 263                         && (CC->logged_in)
 264                         ) {
 265
 266                         /* Generate the "full JID" of the client resource */
 267
 268                         snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
 269                                 "%s/%s",
 270                                 CC->cs_inet_email,
 271                                 XMPP->iq_client_resource
 272                         );
 273
 274                         /* Tell the client what its JID is */
 275
 276                         cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 277                         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\">");
 278                         cprintf("<jid>%s</jid>", XMPP->client_jid);
 279                         cprintf("</bind>");
 280                         cprintf("</iq>");
 281                 }
 282
 283                 else if (XMPP->iq_session) {
 284                         cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 285                         cprintf("</iq>");
 286                 }
 287
 288                 else {
 289                         cprintf("<iq type=\"error\" id=\"%s\">", XMPP->iq_id);
 290                         cprintf("<error></error>");
 291                         cprintf("</iq>");
 292                 }
 293
 294                 /* Now clear these fields out so they don't get used by a future stanza */
 295                 XMPP->iq_id[0] = 0;
 296                 XMPP->iq_from[0] = 0;
 297                 XMPP->iq_to[0] = 0;
 298                 XMPP->iq_type[0] = 0;
 299                 XMPP->iq_client_resource[0] = 0;
 300                 XMPP->iq_session = 0;
 301                 XMPP->iq_query_xmlns[0] = 0;
 302                 XMPP->bind_requested = 0;
 303         }
 304
 305         else if (!strcasecmp(el, "auth")) {
 306
 307                 /* Try to authenticate (this function is responsible for the output stanza) */
 308                 xmpp_sasl_auth(XMPP->sasl_auth_mech, (XMPP->chardata != NULL ? XMPP->chardata : "") );
 309
 310                 /* Now clear these fields out so they don't get used by a future stanza */
 311                 XMPP->sasl_auth_mech[0] = 0;
 312         }
 313
 314         else if (!strcasecmp(el, "session")) {
 315                 XMPP->iq_session = 1;
 316         }
 317
 318         else if (!strcasecmp(el, "presence")) {
 319
 320                 /* Respond to a <presence> update by firing back with presence information
 321                  * on the entire wholist.  Check this assumption, it's probably wrong.
 322                  */
 323                 jabber_wholist_presence_dump();
 324         }
 325
 326         else if ( (!strcasecmp(el, "body")) && (XMPP->html_tag_level == 0) ) {
 327                 if (XMPP->message_body != NULL) {
 328                         free(XMPP->message_body);
 329                         XMPP->message_body = NULL;
 330                 }
 331                 if (XMPP->chardata_len > 0) {
 332                         XMPP->message_body = strdup(XMPP->chardata);
 333                 }
 334         }
 335
 336         else if (!strcasecmp(el, "message")) {
 337                 jabber_send_message(XMPP->message_to, XMPP->message_body);
 338                 XMPP->html_tag_level = 0;
 339         }
 340
 341         else if (!strcasecmp(el, "html")) {
 342                 --XMPP->html_tag_level;
 343         }
 344
 345         else if (!strcasecmp(el, "starttls")) {
 346 #ifdef HAVE_OPENSSL
 347         cprintf("<proceed xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 348         CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
 349         if (!CC->redirect_ssl) CC->kill_me = 1;
 350 #else
 351         cprintf("<failure xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 352         CC->kill_me = 1;
 353 #endif
 354         }
 355
 356         XMPP->chardata_len = 0;
 357         if (XMPP->chardata_alloc > 0) {
 358                 XMPP->chardata[0] = 0;
 359         }
 360 }
 361
 362
 363 void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
 364 {
 365         struct citxmpp *X = XMPP;
 366
 367         if (X->chardata_alloc == 0) {
 368                 X->chardata_alloc = SIZ;
 369                 X->chardata = malloc(X->chardata_alloc);
 370         }
 371         if ((X->chardata_len + len + 1) > X->chardata_alloc) {
 372                 X->chardata_alloc = X->chardata_len + len + 1024;
 373                 X->chardata = realloc(X->chardata, X->chardata_alloc);
 374         }
 375         memcpy(&X->chardata[X->chardata_len], s, len);
 376         X->chardata_len += len;
 377         X->chardata[X->chardata_len] = 0;
 378 }
 379
 380
 381 /*
 382  * This cleanup function blows away the temporary memory and files used by the XMPP service.
 383  */
 384 void xmpp_cleanup_function(void) {
 385
 386         /* Don't do this stuff if this is not a XMPP session! */
 387         if (CC->h_command_function != xmpp_command_loop) return;
 388
 389         lprintf(CTDL_DEBUG, "Performing XMPP cleanup hook\n");
 390         if (XMPP->chardata != NULL) {
 391                 free(XMPP->chardata);
 392                 XMPP->chardata = NULL;
 393                 XMPP->chardata_len = 0;
 394                 XMPP->chardata_alloc = 0;
 395                 if (XMPP->message_body != NULL) {
 396                         free(XMPP->message_body);
 397                 }
 398         }
 399         XML_ParserFree(XMPP->xp);
 400         free(XMPP);
 401 }
 402
 403
 404
 405 /*
 406  * Here's where our XMPP session begins its happy day.
 407  */
 408 void xmpp_greeting(void) {
 409         strcpy(CC->cs_clientname, "Jabber session");
 410         CC->session_specific_data = malloc(sizeof(struct citxmpp));
 411         memset(XMPP, 0, sizeof(struct citxmpp));
 412         XMPP->last_event_processed = queue_event_seq;
 413
 414         /* XMPP does not use a greeting, but we still have to initialize some things. */
 415
 416         XMPP->xp = XML_ParserCreateNS("UTF-8", ':');
 417         if (XMPP->xp == NULL) {
 418                 lprintf(CTDL_ALERT, "Cannot create XML parser!\n");
 419                 CC->kill_me = 1;
 420                 return;
 421         }
 422
 423         XML_SetElementHandler(XMPP->xp, xmpp_xml_start, xmpp_xml_end);
 424         XML_SetCharacterDataHandler(XMPP->xp, xmpp_xml_chardata);
 425         // XML_SetUserData(XMPP->xp, something...);
 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                 lprintf(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 #endif  /* HAVE_EXPAT */
 479
 480 CTDL_MODULE_INIT(jabber)
 481 {
 482         if (!threading) {
 483 #ifdef TECH_PREVIEW
 484 #ifdef HAVE_EXPAT
 485                 CtdlRegisterServiceHook(config.c_xmpp_c2s_port,
 486                                         NULL,
 487                                         xmpp_greeting,
 488                                         xmpp_command_loop,
 489                                         xmpp_async_loop,
 490                                         CitadelServiceXMPP);
 491                 CtdlRegisterSessionHook(xmpp_cleanup_function, EVT_STOP);
 492                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_LOGIN);
 493                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_LOGOUT);
 494                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_UNSTEALTH);
 495                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_STEALTH);
 496         #else
 497                 lprintf(CTDL_INFO, "This server is missing the Expat XML parser.  Jabber service will be disabled.\n");
 498 #endif
 499 #endif  /* TECH_PREVIEW */
 500         }
 501
 502         /* return our Subversion id for the Log */
 503         return "$Id$";
 504 }