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                 }
 197         }
 198
 199         else if (!strcasecmp(el, "iq")) {
 200
 201                 /*
 202                  * iq type="get" (handle queries)
 203                  */
 204                 if (!strcasecmp(XMPP->iq_type, "get")) {
 205
 206                         /*
 207                          * Query on a namespace
 208                          */
 209                         if (!IsEmptyStr(XMPP->iq_query_xmlns)) {
 210                                 xmpp_query_namespace(XMPP->iq_id, XMPP->iq_from,
 211                                                 XMPP->iq_to, XMPP->iq_query_xmlns);
 212                         }
 213
 214                         /*
 215                          * Unknown queries ... return the XML equivalent of a blank stare
 216                          */
 217                         else {
 218                                 cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 219                                 cprintf("</iq>");
 220                         }
 221                 }
 222
 223                 /*
 224                  * If this <iq> stanza was a "bind" attempt, process it ...
 225                  */
 226                 else if (
 227                         (XMPP->bind_requested)
 228                         && (!IsEmptyStr(XMPP->iq_id))
 229                         && (!IsEmptyStr(XMPP->iq_client_resource))
 230                         && (CC->logged_in)
 231                         ) {
 232
 233                         /* Generate the "full JID" of the client resource */
 234
 235                         snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
 236                                 "%s/%s",
 237                                 CC->cs_inet_email,
 238                                 XMPP->iq_client_resource
 239                         );
 240
 241                         /* Tell the client what its JID is */
 242
 243                         cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 244                         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\">");
 245                         cprintf("<jid>%s</jid>", XMPP->client_jid);
 246                         cprintf("</bind>");
 247                         cprintf("</iq>");
 248                 }
 249
 250                 else if (XMPP->iq_session) {
 251                         cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 252                         cprintf("</iq>");
 253                 }
 254
 255                 else {
 256                         cprintf("<iq type=\"error\" id=\"%s\">", XMPP->iq_id);
 257                         cprintf("<error></error>");
 258                         cprintf("</iq>");
 259                 }
 260
 261                 /* Now clear these fields out so they don't get used by a future stanza */
 262                 XMPP->iq_id[0] = 0;
 263                 XMPP->iq_from[0] = 0;
 264                 XMPP->iq_to[0] = 0;
 265                 XMPP->iq_type[0] = 0;
 266                 XMPP->iq_client_resource[0] = 0;
 267                 XMPP->iq_session = 0;
 268                 XMPP->iq_query_xmlns[0] = 0;
 269                 XMPP->bind_requested = 0;
 270         }
 271
 272         else if (!strcasecmp(el, "auth")) {
 273
 274                 /* Try to authenticate (this function is responsible for the output stanza) */
 275                 xmpp_sasl_auth(XMPP->sasl_auth_mech, (XMPP->chardata != NULL ? XMPP->chardata : "") );
 276
 277                 /* Now clear these fields out so they don't get used by a future stanza */
 278                 XMPP->sasl_auth_mech[0] = 0;
 279         }
 280
 281         else if (!strcasecmp(el, "session")) {
 282                 XMPP->iq_session = 1;
 283         }
 284
 285         else if (!strcasecmp(el, "presence")) {
 286
 287                 /* Respond to a <presence> update by firing back with presence information
 288                  * on the entire wholist.  Check this assumption, it's probably wrong.
 289                  */
 290                 jabber_wholist_presence_dump();
 291         }
 292
 293         else if ( (!strcasecmp(el, "body")) && (XMPP->html_tag_level == 0) ) {
 294                 if (XMPP->message_body != NULL) {
 295                         free(XMPP->message_body);
 296                         XMPP->message_body = NULL;
 297                 }
 298                 if (XMPP->chardata_len > 0) {
 299                         XMPP->message_body = strdup(XMPP->chardata);
 300                 }
 301         }
 302
 303         else if (!strcasecmp(el, "message")) {
 304                 jabber_send_message(XMPP->message_to, XMPP->message_body);
 305                 XMPP->html_tag_level = 0;
 306         }
 307
 308         else if (!strcasecmp(el, "html")) {
 309                 --XMPP->html_tag_level;
 310         }
 311
 312         else if (!strcasecmp(el, "starttls")) {
 313 #ifdef HAVE_OPENSSL
 314         cprintf("<proceed xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 315         CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
 316         if (!CC->redirect_ssl) CC->kill_me = 1;
 317 #else
 318         cprintf("<failure xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 319         CC->kill_me = 1;
 320 #endif
 321         }
 322
 323         XMPP->chardata_len = 0;
 324         if (XMPP->chardata_alloc > 0) {
 325                 XMPP->chardata[0] = 0;
 326         }
 327 }
 328
 329
 330 void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
 331 {
 332         struct citxmpp *X = XMPP;
 333
 334         if (X->chardata_alloc == 0) {
 335                 X->chardata_alloc = SIZ;
 336                 X->chardata = malloc(X->chardata_alloc);
 337         }
 338         if ((X->chardata_len + len + 1) > X->chardata_alloc) {
 339                 X->chardata_alloc = X->chardata_len + len + 1024;
 340                 X->chardata = realloc(X->chardata, X->chardata_alloc);
 341         }
 342         memcpy(&X->chardata[X->chardata_len], s, len);
 343         X->chardata_len += len;
 344         X->chardata[X->chardata_len] = 0;
 345 }
 346
 347
 348 /*
 349  * This cleanup function blows away the temporary memory and files used by the XMPP service.
 350  */
 351 void xmpp_cleanup_function(void) {
 352
 353         /* Don't do this stuff if this is not a XMPP session! */
 354         if (CC->h_command_function != xmpp_command_loop) return;
 355
 356         lprintf(CTDL_DEBUG, "Performing XMPP cleanup hook\n");
 357         if (XMPP->chardata != NULL) {
 358                 free(XMPP->chardata);
 359                 XMPP->chardata = NULL;
 360                 XMPP->chardata_len = 0;
 361                 XMPP->chardata_alloc = 0;
 362                 if (XMPP->message_body != NULL) {
 363                         free(XMPP->message_body);
 364                 }
 365         }
 366         XML_ParserFree(XMPP->xp);
 367         free(XMPP);
 368 }
 369
 370
 371
 372 /*
 373  * Here's where our XMPP session begins its happy day.
 374  */
 375 void xmpp_greeting(void) {
 376         strcpy(CC->cs_clientname, "Jabber session");
 377         CC->session_specific_data = malloc(sizeof(struct citxmpp));
 378         memset(XMPP, 0, sizeof(struct citxmpp));
 379         XMPP->last_event_processed = queue_event_seq;
 380
 381         /* XMPP does not use a greeting, but we still have to initialize some things. */
 382
 383         XMPP->xp = XML_ParserCreateNS("UTF-8", ':');
 384         if (XMPP->xp == NULL) {
 385                 lprintf(CTDL_ALERT, "Cannot create XML parser!\n");
 386                 CC->kill_me = 1;
 387                 return;
 388         }
 389
 390         XML_SetElementHandler(XMPP->xp, xmpp_xml_start, xmpp_xml_end);
 391         XML_SetCharacterDataHandler(XMPP->xp, xmpp_xml_chardata);
 392         // XML_SetUserData(XMPP->xp, something...);
 393 }
 394
 395
 396 /*
 397  * Main command loop for XMPP sessions.
 398  */
 399 void xmpp_command_loop(void) {
 400         char cmdbuf[16];
 401         int retval;
 402
 403         time(&CC->lastcmd);
 404         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
 405         retval = client_read(cmdbuf, 1);
 406         if (retval != 1) {
 407                 lprintf(CTDL_ERR, "Client disconnected: ending session.\r\n");
 408                 CC->kill_me = 1;
 409                 return;
 410         }
 411
 412         /* FIXME ... this is woefully inefficient. */
 413
 414         XML_Parse(XMPP->xp, cmdbuf, 1, 0);
 415 }
 416
 417
 418 /*
 419  * Async loop for XMPP sessions (handles the transmission of unsolicited stanzas)
 420  */
 421 void xmpp_async_loop(void) {
 422         xmpp_process_events();
 423         jabber_output_incoming_messages();
 424 }
 425
 426
 427 /*
 428  * Login hook for XMPP sessions
 429  */
 430 void xmpp_login_hook(void) {
 431         xmpp_queue_event(XMPP_EVT_LOGIN, CC->cs_inet_email);
 432 }
 433
 434
 435 /*
 436  * Logout hook for XMPP sessions
 437  */
 438 void xmpp_logout_hook(void) {
 439         xmpp_queue_event(XMPP_EVT_LOGOUT, CC->cs_inet_email);
 440 }
 441
 442
 443 const char *CitadelServiceXMPP="XMPP";
 444
 445 #endif  /* HAVE_EXPAT */
 446
 447 CTDL_MODULE_INIT(jabber)
 448 {
 449 #ifdef HAVE_EXPAT
 450         if (!threading) {
 451                 CtdlRegisterServiceHook(config.c_xmpp_c2s_port,
 452                                         NULL,
 453                                         xmpp_greeting,
 454                                         xmpp_command_loop,
 455                                         xmpp_async_loop,
 456                                         CitadelServiceXMPP);
 457                 CtdlRegisterSessionHook(xmpp_cleanup_function, EVT_STOP);
 458                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_LOGIN);
 459                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_LOGOUT);
 460                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_UNSTEALTH);
 461                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_STEALTH);
 462         #else
 463                 lprintf(CTDL_INFO, "This server is missing the Expat XML parser.  Jabber service will be disabled.\n");
 464 #endif
 465         }
 466
 467         /* return our Subversion id for the Log */
 468         return "$Id$";
 469 }