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, "iq")) {
 133                 for (i=0; attr[i] != NULL; i+=2) {
 134                         if (!strcasecmp(attr[i], "type")) {
 135                                 safestrncpy(XMPP->iq_type, attr[i+1], sizeof XMPP->iq_type);
 136                         }
 137                         else if (!strcasecmp(attr[i], "id")) {
 138                                 safestrncpy(XMPP->iq_id, attr[i+1], sizeof XMPP->iq_id);
 139                         }
 140                         else if (!strcasecmp(attr[i], "from")) {
 141                                 safestrncpy(XMPP->iq_from, attr[i+1], sizeof XMPP->iq_from);
 142                         }
 143                         else if (!strcasecmp(attr[i], "to")) {
 144                                 safestrncpy(XMPP->iq_to, attr[i+1], sizeof XMPP->iq_to);
 145                         }
 146                 }
 147         }
 148
 149         else if (!strcasecmp(el, "auth")) {
 150                 XMPP->sasl_auth_mech[0] = 0;
 151                 for (i=0; attr[i] != NULL; i+=2) {
 152                         if (!strcasecmp(attr[i], "mechanism")) {
 153                                 safestrncpy(XMPP->sasl_auth_mech, attr[i+1], sizeof XMPP->sasl_auth_mech);
 154                         }
 155                 }
 156         }
 157
 158         else if (!strcasecmp(el, "message")) {
 159                 for (i=0; attr[i] != NULL; i+=2) {
 160                         if (!strcasecmp(attr[i], "to")) {
 161                                 safestrncpy(XMPP->message_to, attr[i+1], sizeof XMPP->message_to);
 162                         }
 163                 }
 164         }
 165
 166         else if (!strcasecmp(el, "html")) {
 167                 ++XMPP->html_tag_level;
 168         }
 169 }
 170
 171
 172
 173 void xmpp_xml_end(void *data, const char *supplied_el) {
 174         char el[256];
 175         char *sep = NULL;
 176
 177         /* Axe the namespace, we don't care about it */
 178         safestrncpy(el, supplied_el, sizeof el);
 179         while (sep = strchr(el, ':'), sep) {
 180                 strcpy(el, ++sep);
 181         }
 182
 183         lprintf(CTDL_DEBUG, "XMPP ELEMENT END  : <%s>\n", el);
 184         if (XMPP->chardata_len > 0) {
 185                 lprintf(CTDL_DEBUG, "          chardata: %s\n", XMPP->chardata);
 186         }
 187
 188         if (!strcasecmp(el, "resource")) {
 189                 if (XMPP->chardata_len > 0) {
 190                         safestrncpy(XMPP->iq_client_resource, XMPP->chardata,
 191                                 sizeof XMPP->iq_client_resource);
 192                 }
 193         }
 194
 195         else if (!strcasecmp(el, "iq")) {
 196
 197                 /*
 198                  * iq type="get" (handle queries)
 199                  */
 200                 if (!strcasecmp(XMPP->iq_type, "get")) {
 201
 202                         /*
 203                          * Query on a namespace
 204                          */
 205                         if (!IsEmptyStr(XMPP->iq_query_xmlns)) {
 206                                 xmpp_query_namespace(XMPP->iq_id, XMPP->iq_from,
 207                                                 XMPP->iq_to, XMPP->iq_query_xmlns);
 208                         }
 209
 210                         /*
 211                          * Unknown queries ... return the XML equivalent of a blank stare
 212                          */
 213                         else {
 214                                 cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 215                                 cprintf("</iq>");
 216                         }
 217                 }
 218
 219                 /*
 220                  * If this <iq> stanza was a "bind" attempt, process it ...
 221                  */
 222                 else if ( (!IsEmptyStr(XMPP->iq_id)) && (!IsEmptyStr(XMPP->iq_client_resource)) ) {
 223
 224                         /* Generate the "full JID" of the client resource */
 225
 226                         snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
 227                                 "%s/%s",
 228                                 CC->cs_inet_email,
 229                                 XMPP->iq_client_resource
 230                         );
 231
 232                         /* Tell the client what its JID is */
 233
 234                         cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 235                         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\">");
 236                         cprintf("<jid>%s</jid>", XMPP->client_jid);
 237                         cprintf("</bind>");
 238                         cprintf("</iq>");
 239                 }
 240
 241                 else if (XMPP->iq_session) {
 242                         cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 243                         cprintf("</iq>");
 244                 }
 245
 246                 else {
 247                         cprintf("<iq type=\"error\" id=\"%s\">", XMPP->iq_id);
 248                         cprintf("<error></error>");
 249                         cprintf("</iq>");
 250                 }
 251
 252                 /* Now clear these fields out so they don't get used by a future stanza */
 253                 XMPP->iq_id[0] = 0;
 254                 XMPP->iq_from[0] = 0;
 255                 XMPP->iq_to[0] = 0;
 256                 XMPP->iq_type[0] = 0;
 257                 XMPP->iq_client_resource[0] = 0;
 258                 XMPP->iq_session = 0;
 259                 XMPP->iq_query_xmlns[0] = 0;
 260         }
 261
 262         else if (!strcasecmp(el, "auth")) {
 263
 264                 /* Try to authenticate (this function is responsible for the output stanza) */
 265                 xmpp_sasl_auth(XMPP->sasl_auth_mech, (XMPP->chardata != NULL ? XMPP->chardata : "") );
 266
 267                 /* Now clear these fields out so they don't get used by a future stanza */
 268                 XMPP->sasl_auth_mech[0] = 0;
 269         }
 270
 271         else if (!strcasecmp(el, "session")) {
 272                 XMPP->iq_session = 1;
 273         }
 274
 275         else if (!strcasecmp(el, "presence")) {
 276
 277                 /* Respond to a <presence> update by firing back with presence information
 278                  * on the entire wholist.  Check this assumption, it's probably wrong.
 279                  */
 280                 jabber_wholist_presence_dump();
 281         }
 282
 283         else if ( (!strcasecmp(el, "body")) && (XMPP->html_tag_level == 0) ) {
 284                 if (XMPP->message_body != NULL) {
 285                         free(XMPP->message_body);
 286                         XMPP->message_body = NULL;
 287                 }
 288                 if (XMPP->chardata_len > 0) {
 289                         XMPP->message_body = strdup(XMPP->chardata);
 290                 }
 291         }
 292
 293         else if (!strcasecmp(el, "message")) {
 294                 jabber_send_message(XMPP->message_to, XMPP->message_body);
 295                 XMPP->html_tag_level = 0;
 296         }
 297
 298         else if (!strcasecmp(el, "html")) {
 299                 --XMPP->html_tag_level;
 300         }
 301
 302         else if (!strcasecmp(el, "starttls")) {
 303 #ifdef HAVE_OPENSSL
 304         cprintf("<proceed xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 305         CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
 306         if (!CC->redirect_ssl) CC->kill_me = 1;
 307 #else
 308         cprintf("<failure xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 309         CC->kill_me = 1;
 310 #endif
 311         }
 312
 313         XMPP->chardata_len = 0;
 314         if (XMPP->chardata_alloc > 0) {
 315                 XMPP->chardata[0] = 0;
 316         }
 317 }
 318
 319
 320 void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
 321 {
 322         struct citxmpp *X = XMPP;
 323
 324         if (X->chardata_alloc == 0) {
 325                 X->chardata_alloc = SIZ;
 326                 X->chardata = malloc(X->chardata_alloc);
 327         }
 328         if ((X->chardata_len + len + 1) > X->chardata_alloc) {
 329                 X->chardata_alloc = X->chardata_len + len + 1024;
 330                 X->chardata = realloc(X->chardata, X->chardata_alloc);
 331         }
 332         memcpy(&X->chardata[X->chardata_len], s, len);
 333         X->chardata_len += len;
 334         X->chardata[X->chardata_len] = 0;
 335 }
 336
 337
 338 /*
 339  * This cleanup function blows away the temporary memory and files used by the XMPP service.
 340  */
 341 void xmpp_cleanup_function(void) {
 342
 343         /* Don't do this stuff if this is not a XMPP session! */
 344         if (CC->h_command_function != xmpp_command_loop) return;
 345
 346         lprintf(CTDL_DEBUG, "Performing XMPP cleanup hook\n");
 347         if (XMPP->chardata != NULL) {
 348                 free(XMPP->chardata);
 349                 XMPP->chardata = NULL;
 350                 XMPP->chardata_len = 0;
 351                 XMPP->chardata_alloc = 0;
 352                 if (XMPP->message_body != NULL) {
 353                         free(XMPP->message_body);
 354                 }
 355         }
 356         XML_ParserFree(XMPP->xp);
 357         free(XMPP);
 358 }
 359
 360
 361
 362 /*
 363  * Here's where our XMPP session begins its happy day.
 364  */
 365 void xmpp_greeting(void) {
 366         strcpy(CC->cs_clientname, "Jabber session");
 367         CC->session_specific_data = malloc(sizeof(struct citxmpp));
 368         memset(XMPP, 0, sizeof(struct citxmpp));
 369         XMPP->last_event_processed = queue_event_seq;
 370
 371         /* XMPP does not use a greeting, but we still have to initialize some things. */
 372
 373         XMPP->xp = XML_ParserCreateNS("UTF-8", ':');
 374         if (XMPP->xp == NULL) {
 375                 lprintf(CTDL_ALERT, "Cannot create XML parser!\n");
 376                 CC->kill_me = 1;
 377                 return;
 378         }
 379
 380         XML_SetElementHandler(XMPP->xp, xmpp_xml_start, xmpp_xml_end);
 381         XML_SetCharacterDataHandler(XMPP->xp, xmpp_xml_chardata);
 382         // XML_SetUserData(XMPP->xp, something...);
 383 }
 384
 385
 386 /*
 387  * Main command loop for XMPP sessions.
 388  */
 389 void xmpp_command_loop(void) {
 390         char cmdbuf[16];
 391         int retval;
 392
 393         time(&CC->lastcmd);
 394         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
 395         retval = client_read(cmdbuf, 1);
 396         if (retval != 1) {
 397                 lprintf(CTDL_ERR, "Client disconnected: ending session.\r\n");
 398                 CC->kill_me = 1;
 399                 return;
 400         }
 401
 402         /* FIXME ... this is woefully inefficient. */
 403
 404         XML_Parse(XMPP->xp, cmdbuf, 1, 0);
 405 }
 406
 407
 408 /*
 409  * Async loop for XMPP sessions (handles the transmission of unsolicited stanzas)
 410  */
 411 void xmpp_async_loop(void) {
 412         xmpp_process_events();
 413         jabber_output_incoming_messages();
 414 }
 415
 416
 417 /*
 418  * Login hook for XMPP sessions
 419  */
 420 void xmpp_login_hook(void) {
 421         xmpp_queue_event(XMPP_EVT_LOGIN, CC->cs_inet_email);
 422 }
 423
 424
 425 /*
 426  * Logout hook for XMPP sessions
 427  */
 428 void xmpp_logout_hook(void) {
 429         xmpp_queue_event(XMPP_EVT_LOGOUT, CC->cs_inet_email);
 430 }
 431
 432
 433 const char *CitadelServiceXMPP="XMPP";
 434
 435 #endif  /* HAVE_EXPAT */
 436
 437 CTDL_MODULE_INIT(jabber)
 438 {
 439 #ifdef HAVE_EXPAT
 440         if (!threading) {
 441                 CtdlRegisterServiceHook(config.c_xmpp_c2s_port,
 442                                         NULL,
 443                                         xmpp_greeting,
 444                                         xmpp_command_loop,
 445                                         xmpp_async_loop,
 446                                         CitadelServiceXMPP);
 447                 CtdlRegisterSessionHook(xmpp_cleanup_function, EVT_STOP);
 448                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_LOGIN);
 449                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_LOGOUT);
 450                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_UNSTEALTH);
 451                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_STEALTH);
 452         #else
 453                 lprintf(CTDL_INFO, "This server is missing the Expat XML parser.  Jabber service will be disabled.\n");
 454 #endif
 455         }
 456
 457         /* return our Subversion id for the Log */
 458         return "$Id$";
 459 }