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