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