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