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         else {
  94                 /* If we've logged in, now offer binding and sessions as 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
  99         cprintf("</stream:features>");
 100
 101         CC->is_async = 1;               /* XMPP sessions are inherently async-capable */
 102 }
 103
 104
 105 void xmpp_xml_start(void *data, const char *supplied_el, const char **attr) {
 106         char el[256];
 107         char *sep = NULL;
 108         int i;
 109
 110         /* Axe the namespace, we don't care about it */
 111         safestrncpy(el, supplied_el, sizeof el);
 112         while (sep = strchr(el, ':'), sep) {
 113                 strcpy(el, ++sep);
 114         }
 115
 116         lprintf(CTDL_DEBUG, "XMPP ELEMENT START: <%s>\n", el);
 117
 118         for (i=0; attr[i] != NULL; i+=2) {
 119                 lprintf(CTDL_DEBUG, "                    Attribute '%s' = '%s'\n", attr[i], attr[i+1]);
 120         }
 121
 122         if (!strcasecmp(el, "stream")) {
 123                 xmpp_stream_start(data, supplied_el, attr);
 124         }
 125
 126         else if (!strcasecmp(el, "query")) {
 127                 XMPP->iq_query_xmlns[0] = 0;
 128                 safestrncpy(XMPP->iq_query_xmlns, supplied_el, sizeof XMPP->iq_query_xmlns);
 129         }
 130
 131         else if (!strcasecmp(el, "iq")) {
 132                 for (i=0; attr[i] != NULL; i+=2) {
 133                         if (!strcasecmp(attr[i], "type")) {
 134                                 safestrncpy(XMPP->iq_type, attr[i+1], sizeof XMPP->iq_type);
 135                         }
 136                         else if (!strcasecmp(attr[i], "id")) {
 137                                 safestrncpy(XMPP->iq_id, attr[i+1], sizeof XMPP->iq_id);
 138                         }
 139                         else if (!strcasecmp(attr[i], "from")) {
 140                                 safestrncpy(XMPP->iq_from, attr[i+1], sizeof XMPP->iq_from);
 141                         }
 142                         else if (!strcasecmp(attr[i], "to")) {
 143                                 safestrncpy(XMPP->iq_to, attr[i+1], sizeof XMPP->iq_to);
 144                         }
 145                 }
 146         }
 147
 148         else if (!strcasecmp(el, "auth")) {
 149                 XMPP->sasl_auth_mech[0] = 0;
 150                 for (i=0; attr[i] != NULL; i+=2) {
 151                         if (!strcasecmp(attr[i], "mechanism")) {
 152                                 safestrncpy(XMPP->sasl_auth_mech, attr[i+1], sizeof XMPP->sasl_auth_mech);
 153                         }
 154                 }
 155         }
 156
 157         else if (!strcasecmp(el, "message")) {
 158                 for (i=0; attr[i] != NULL; i+=2) {
 159                         if (!strcasecmp(attr[i], "to")) {
 160                                 safestrncpy(XMPP->message_to, attr[i+1], sizeof XMPP->message_to);
 161                         }
 162                 }
 163         }
 164
 165         else if (!strcasecmp(el, "html")) {
 166                 ++XMPP->html_tag_level;
 167         }
 168 }
 169
 170
 171
 172 void xmpp_xml_end(void *data, const char *supplied_el) {
 173         char el[256];
 174         char *sep = NULL;
 175
 176         /* Axe the namespace, we don't care about it */
 177         safestrncpy(el, supplied_el, sizeof el);
 178         while (sep = strchr(el, ':'), sep) {
 179                 strcpy(el, ++sep);
 180         }
 181
 182         lprintf(CTDL_DEBUG, "XMPP ELEMENT END  : <%s>\n", el);
 183         if (XMPP->chardata_len > 0) {
 184                 lprintf(CTDL_DEBUG, "          chardata: %s\n", XMPP->chardata);
 185         }
 186
 187         if (!strcasecmp(el, "resource")) {
 188                 if (XMPP->chardata_len > 0) {
 189                         safestrncpy(XMPP->iq_client_resource, XMPP->chardata,
 190                                 sizeof XMPP->iq_client_resource);
 191                 }
 192         }
 193
 194         else if (!strcasecmp(el, "iq")) {
 195
 196                 /*
 197                  * iq type="get" (handle queries)
 198                  */
 199                 if (!strcasecmp(XMPP->iq_type, "get")) {
 200
 201                         /*
 202                          * Query on a namespace
 203                          */
 204                         if (!IsEmptyStr(XMPP->iq_query_xmlns)) {
 205                                 xmpp_query_namespace(XMPP->iq_id, XMPP->iq_from,
 206                                                 XMPP->iq_to, XMPP->iq_query_xmlns);
 207                         }
 208
 209                         /*
 210                          * Unknown queries ... return the XML equivalent of a blank stare
 211                          */
 212                         else {
 213                                 cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 214                                 cprintf("</iq>");
 215                         }
 216                 }
 217
 218                 /*
 219                  * If this <iq> stanza was a "bind" attempt, process it ...
 220                  */
 221                 else if ( (!IsEmptyStr(XMPP->iq_id)) && (!IsEmptyStr(XMPP->iq_client_resource)) ) {
 222
 223                         /* Generate the "full JID" of the client resource */
 224
 225                         snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
 226                                 "%s/%s",
 227                                 CC->cs_inet_email,
 228                                 XMPP->iq_client_resource
 229                         );
 230
 231                         /* Tell the client what its JID is */
 232
 233                         cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 234                         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\">");
 235                         cprintf("<jid>%s</jid>", XMPP->client_jid);
 236                         cprintf("</bind>");
 237                         cprintf("</iq>");
 238                 }
 239
 240                 else if (XMPP->iq_session) {
 241                         cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 242                         cprintf("</iq>");
 243                 }
 244
 245                 else {
 246                         cprintf("<iq type=\"error\" id=\"%s\">", XMPP->iq_id);
 247                         cprintf("<error></error>");
 248                         cprintf("</iq>");
 249                 }
 250
 251                 /* Now clear these fields out so they don't get used by a future stanza */
 252                 XMPP->iq_id[0] = 0;
 253                 XMPP->iq_from[0] = 0;
 254                 XMPP->iq_to[0] = 0;
 255                 XMPP->iq_type[0] = 0;
 256                 XMPP->iq_client_resource[0] = 0;
 257                 XMPP->iq_session = 0;
 258                 XMPP->iq_query_xmlns[0] = 0;
 259         }
 260
 261         else if (!strcasecmp(el, "auth")) {
 262
 263                 /* Try to authenticate (this function is responsible for the output stanza) */
 264                 xmpp_sasl_auth(XMPP->sasl_auth_mech, (XMPP->chardata != NULL ? XMPP->chardata : "") );
 265
 266                 /* Now clear these fields out so they don't get used by a future stanza */
 267                 XMPP->sasl_auth_mech[0] = 0;
 268         }
 269
 270         else if (!strcasecmp(el, "session")) {
 271                 XMPP->iq_session = 1;
 272         }
 273
 274         else if (!strcasecmp(el, "presence")) {
 275
 276                 /* Respond to a <presence> update by firing back with presence information
 277                  * on the entire wholist.  Check this assumption, it's probably wrong.
 278                  */
 279                 jabber_wholist_presence_dump();
 280         }
 281
 282         else if ( (!strcasecmp(el, "body")) && (XMPP->html_tag_level == 0) ) {
 283                 if (XMPP->message_body != NULL) {
 284                         free(XMPP->message_body);
 285                         XMPP->message_body = NULL;
 286                 }
 287                 if (XMPP->chardata_len > 0) {
 288                         XMPP->message_body = strdup(XMPP->chardata);
 289                 }
 290         }
 291
 292         else if (!strcasecmp(el, "message")) {
 293                 jabber_send_message(XMPP->message_to, XMPP->message_body);
 294                 XMPP->html_tag_level = 0;
 295         }
 296
 297         else if (!strcasecmp(el, "html")) {
 298                 --XMPP->html_tag_level;
 299         }
 300
 301         else if (!strcasecmp(el, "starttls")) {
 302 #ifdef HAVE_OPENSSL
 303         cprintf("<proceed xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 304         CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
 305         if (!CC->redirect_ssl) CC->kill_me = 1;
 306 #else
 307         cprintf("<failure xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 308         CC->kill_me = 1;
 309 #endif
 310         }
 311
 312         XMPP->chardata_len = 0;
 313         if (XMPP->chardata_alloc > 0) {
 314                 XMPP->chardata[0] = 0;
 315         }
 316 }
 317
 318
 319 void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
 320 {
 321         struct citxmpp *X = XMPP;
 322
 323         if (X->chardata_alloc == 0) {
 324                 X->chardata_alloc = SIZ;
 325                 X->chardata = malloc(X->chardata_alloc);
 326         }
 327         if ((X->chardata_len + len + 1) > X->chardata_alloc) {
 328                 X->chardata_alloc = X->chardata_len + len + 1024;
 329                 X->chardata = realloc(X->chardata, X->chardata_alloc);
 330         }
 331         memcpy(&X->chardata[X->chardata_len], s, len);
 332         X->chardata_len += len;
 333         X->chardata[X->chardata_len] = 0;
 334 }
 335
 336
 337 /*
 338  * This cleanup function blows away the temporary memory and files used by the XMPP service.
 339  */
 340 void xmpp_cleanup_function(void) {
 341
 342         /* Don't do this stuff if this is not a XMPP session! */
 343         if (CC->h_command_function != xmpp_command_loop) return;
 344
 345         lprintf(CTDL_DEBUG, "Performing XMPP cleanup hook\n");
 346         if (XMPP->chardata != NULL) {
 347                 free(XMPP->chardata);
 348                 XMPP->chardata = NULL;
 349                 XMPP->chardata_len = 0;
 350                 XMPP->chardata_alloc = 0;
 351                 if (XMPP->message_body != NULL) {
 352                         free(XMPP->message_body);
 353                 }
 354         }
 355         XML_ParserFree(XMPP->xp);
 356         free(XMPP);
 357 }
 358
 359
 360
 361 /*
 362  * Here's where our XMPP session begins its happy day.
 363  */
 364 void xmpp_greeting(void) {
 365         strcpy(CC->cs_clientname, "Jabber session");
 366         CC->session_specific_data = malloc(sizeof(struct citxmpp));
 367         memset(XMPP, 0, sizeof(struct citxmpp));
 368         XMPP->last_event_processed = queue_event_seq;
 369
 370         /* XMPP does not use a greeting, but we still have to initialize some things. */
 371
 372         XMPP->xp = XML_ParserCreateNS("UTF-8", ':');
 373         if (XMPP->xp == NULL) {
 374                 lprintf(CTDL_ALERT, "Cannot create XML parser!\n");
 375                 CC->kill_me = 1;
 376                 return;
 377         }
 378
 379         XML_SetElementHandler(XMPP->xp, xmpp_xml_start, xmpp_xml_end);
 380         XML_SetCharacterDataHandler(XMPP->xp, xmpp_xml_chardata);
 381         // XML_SetUserData(XMPP->xp, something...);
 382 }
 383
 384
 385 /*
 386  * Main command loop for XMPP sessions.
 387  */
 388 void xmpp_command_loop(void) {
 389         char cmdbuf[16];
 390         int retval;
 391
 392         time(&CC->lastcmd);
 393         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
 394         retval = client_read(cmdbuf, 1);
 395         if (retval != 1) {
 396                 lprintf(CTDL_ERR, "Client disconnected: ending session.\r\n");
 397                 CC->kill_me = 1;
 398                 return;
 399         }
 400
 401         /* FIXME ... this is woefully inefficient. */
 402
 403         XML_Parse(XMPP->xp, cmdbuf, 1, 0);
 404 }
 405
 406
 407 /*
 408  * Async loop for XMPP sessions (handles the transmission of unsolicited stanzas)
 409  */
 410 void xmpp_async_loop(void) {
 411         xmpp_process_events();
 412         jabber_output_incoming_messages();
 413 }
 414
 415
 416 /*
 417  * Login hook for XMPP sessions
 418  */
 419 void xmpp_login_hook(void) {
 420         xmpp_queue_event(XMPP_EVT_LOGIN, CC->cs_inet_email);
 421 }
 422
 423
 424 /*
 425  * Logout hook for XMPP sessions
 426  */
 427 void xmpp_logout_hook(void) {
 428         xmpp_queue_event(XMPP_EVT_LOGOUT, CC->cs_inet_email);
 429 }
 430
 431
 432 const char *CitadelServiceXMPP="XMPP";
 433
 434 #endif  /* HAVE_EXPAT */
 435
 436 CTDL_MODULE_INIT(jabber)
 437 {
 438 #ifdef HAVE_EXPAT
 439         if (!threading) {
 440                 CtdlRegisterServiceHook(5222,                   /* FIXME change to config.c_xmpp_port */
 441                                         NULL,
 442                                         xmpp_greeting,
 443                                         xmpp_command_loop,
 444                                         xmpp_async_loop,
 445                                         CitadelServiceXMPP);
 446                 CtdlRegisterSessionHook(xmpp_cleanup_function, EVT_STOP);
 447                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_LOGIN);
 448                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_LOGOUT);
 449                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_UNSTEALTH);
 450                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_STEALTH);
 451         #else
 452                 lprintf(CTDL_INFO, "This server is missing the Expat XML parser.  Jabber service will be disabled.\n");
 453 #endif
 454         }
 455
 456         /* return our Subversion id for the Log */
 457         return "$Id$";
 458 }