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         if (!CC->logged_in) {
  83                 /* If we're not logged in yet, offer SASL as our feature set */
  84                 xmpp_output_auth_mechs();
  85         }
  86         else {
  87                 /* If we've logged in, now offer binding and sessions as our feature set */
  88                 cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\"/>");
  89                 cprintf("<session xmlns=\"urn:ietf:params:xml:ns:xmpp-session\"/>");
  90         }
  91
  92         cprintf("</stream:features>");
  93
  94         CC->is_async = 1;               /* XMPP sessions are inherently async-capable */
  95 }
  96
  97
  98 void xmpp_xml_start(void *data, const char *supplied_el, const char **attr) {
  99         char el[256];
 100         char *sep = NULL;
 101         int i;
 102
 103         /* Axe the namespace, we don't care about it */
 104         safestrncpy(el, supplied_el, sizeof el);
 105         while (sep = strchr(el, ':'), sep) {
 106                 strcpy(el, ++sep);
 107         }
 108
 109         lprintf(CTDL_DEBUG, "XMPP ELEMENT START: <%s>\n", el);
 110
 111         for (i=0; attr[i] != NULL; i+=2) {
 112                 lprintf(CTDL_DEBUG, "                    Attribute '%s' = '%s'\n", attr[i], attr[i+1]);
 113         }
 114
 115         if (!strcasecmp(el, "stream")) {
 116                 xmpp_stream_start(data, supplied_el, attr);
 117         }
 118
 119         else if (!strcasecmp(el, "query")) {
 120                 XMPP->iq_query_xmlns[0] = 0;
 121                 safestrncpy(XMPP->iq_query_xmlns, supplied_el, sizeof XMPP->iq_query_xmlns);
 122         }
 123
 124         else if (!strcasecmp(el, "iq")) {
 125                 for (i=0; attr[i] != NULL; i+=2) {
 126                         if (!strcasecmp(attr[i], "type")) {
 127                                 safestrncpy(XMPP->iq_type, attr[i+1], sizeof XMPP->iq_type);
 128                         }
 129                         else if (!strcasecmp(attr[i], "id")) {
 130                                 safestrncpy(XMPP->iq_id, attr[i+1], sizeof XMPP->iq_id);
 131                         }
 132                         else if (!strcasecmp(attr[i], "from")) {
 133                                 safestrncpy(XMPP->iq_from, attr[i+1], sizeof XMPP->iq_from);
 134                         }
 135                         else if (!strcasecmp(attr[i], "to")) {
 136                                 safestrncpy(XMPP->iq_to, attr[i+1], sizeof XMPP->iq_to);
 137                         }
 138                 }
 139         }
 140
 141         else if (!strcasecmp(el, "auth")) {
 142                 XMPP->sasl_auth_mech[0] = 0;
 143                 for (i=0; attr[i] != NULL; i+=2) {
 144                         if (!strcasecmp(attr[i], "mechanism")) {
 145                                 safestrncpy(XMPP->sasl_auth_mech, attr[i+1], sizeof XMPP->sasl_auth_mech);
 146                         }
 147                 }
 148         }
 149 }
 150
 151
 152
 153 void xmpp_xml_end(void *data, const char *supplied_el) {
 154         char el[256];
 155         char *sep = NULL;
 156
 157         /* Axe the namespace, we don't care about it */
 158         safestrncpy(el, supplied_el, sizeof el);
 159         while (sep = strchr(el, ':'), sep) {
 160                 strcpy(el, ++sep);
 161         }
 162
 163         lprintf(CTDL_DEBUG, "XMPP ELEMENT END  : <%s>\n", el);
 164         if (XMPP->chardata_len > 0) {
 165                 lprintf(CTDL_DEBUG, "          chardata: %s\n", XMPP->chardata);
 166         }
 167
 168         if (!strcasecmp(el, "resource")) {
 169                 if (XMPP->chardata_len > 0) {
 170                         safestrncpy(XMPP->iq_client_resource, XMPP->chardata,
 171                                 sizeof XMPP->iq_client_resource);
 172                 }
 173         }
 174
 175         else if (!strcasecmp(el, "iq")) {
 176
 177                 /*
 178                  * iq type="get" (handle queries)
 179                  */
 180                 if (!strcasecmp(XMPP->iq_type, "get")) {
 181
 182                         /*
 183                          * Query on a namespace
 184                          */
 185                         if (!IsEmptyStr(XMPP->iq_query_xmlns)) {
 186                                 xmpp_query_namespace(XMPP->iq_id, XMPP->iq_from,
 187                                                 XMPP->iq_to, XMPP->iq_query_xmlns);
 188                         }
 189
 190                         /*
 191                          * Unknown queries ... return the XML equivalent of a blank stare
 192                          */
 193                         else {
 194                                 cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 195                                 cprintf("</iq>");
 196                         }
 197                 }
 198
 199                 /*
 200                  * If this <iq> stanza was a "bind" attempt, process it ...
 201                  */
 202                 else if ( (!IsEmptyStr(XMPP->iq_id)) && (!IsEmptyStr(XMPP->iq_client_resource)) ) {
 203
 204                         /* Generate the "full JID" of the client resource */
 205
 206                         // snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
 207                         //      "%d@%s/%s",
 208                         //      CC->cs_pid,
 209                         //      config.c_fqdn,
 210                         //      XMPP->iq_client_resource
 211                         //);
 212
 213                         snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
 214                                 "%s/%s",
 215                                 CC->cs_inet_email,
 216                                 XMPP->iq_client_resource
 217                         );
 218
 219                         /* Tell the client what its JID is */
 220
 221                         cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 222                         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\">");
 223                         cprintf("<jid>%s</jid>", XMPP->client_jid);
 224                         cprintf("</bind>");
 225                         cprintf("</iq>");
 226                 }
 227
 228                 else if (XMPP->iq_session) {
 229                         cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 230                         cprintf("</iq>");
 231                 }
 232
 233                 else {
 234                         cprintf("<iq type=\"error\" id=\"%s\">", XMPP->iq_id);
 235                         cprintf("<error></error>");
 236                         cprintf("</iq>");
 237                 }
 238
 239                 /* Now clear these fields out so they don't get used by a future stanza */
 240                 XMPP->iq_id[0] = 0;
 241                 XMPP->iq_from[0] = 0;
 242                 XMPP->iq_to[0] = 0;
 243                 XMPP->iq_type[0] = 0;
 244                 XMPP->iq_client_resource[0] = 0;
 245                 XMPP->iq_session = 0;
 246                 XMPP->iq_query_xmlns[0] = 0;
 247         }
 248
 249         else if (!strcasecmp(el, "auth")) {
 250
 251                 /* Try to authenticate (this function is responsible for the output stanza) */
 252                 xmpp_sasl_auth(XMPP->sasl_auth_mech, (XMPP->chardata != NULL ? XMPP->chardata : "") );
 253
 254                 /* Now clear these fields out so they don't get used by a future stanza */
 255                 XMPP->sasl_auth_mech[0] = 0;
 256         }
 257
 258         else if (!strcasecmp(el, "session")) {
 259                 XMPP->iq_session = 1;
 260         }
 261
 262         else if (!strcasecmp(el, "presence")) {
 263
 264                 /* Respond to a <presence> update by firing back with presence information
 265                  * on the entire wholist.  Check this assumption, it's probably wrong.
 266                  */
 267                 jabber_wholist_presence_dump();
 268         }
 269
 270         XMPP->chardata_len = 0;
 271         if (XMPP->chardata_alloc > 0) {
 272                 XMPP->chardata[0] = 0;
 273         }
 274 }
 275
 276
 277 void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
 278 {
 279         struct citxmpp *X = XMPP;
 280
 281         if (X->chardata_alloc == 0) {
 282                 X->chardata_alloc = SIZ;
 283                 X->chardata = malloc(X->chardata_alloc);
 284         }
 285         if ((X->chardata_len + len + 1) > X->chardata_alloc) {
 286                 X->chardata_alloc = X->chardata_len + len + 1024;
 287                 X->chardata = realloc(X->chardata, X->chardata_alloc);
 288         }
 289         memcpy(&X->chardata[X->chardata_len], s, len);
 290         X->chardata_len += len;
 291         X->chardata[X->chardata_len] = 0;
 292 }
 293
 294
 295 /*
 296  * This cleanup function blows away the temporary memory and files used by the XMPP service.
 297  */
 298 void xmpp_cleanup_function(void) {
 299
 300         /* Don't do this stuff if this is not a XMPP session! */
 301         if (CC->h_command_function != xmpp_command_loop) return;
 302
 303         lprintf(CTDL_DEBUG, "Performing XMPP cleanup hook\n");
 304         if (XMPP->chardata != NULL) {
 305                 free(XMPP->chardata);
 306                 XMPP->chardata = NULL;
 307                 XMPP->chardata_len = 0;
 308                 XMPP->chardata_alloc = 0;
 309         }
 310         XML_ParserFree(XMPP->xp);
 311         free(XMPP);
 312 }
 313
 314
 315
 316 /*
 317  * Here's where our XMPP session begins its happy day.
 318  */
 319 void xmpp_greeting(void) {
 320         strcpy(CC->cs_clientname, "Jabber session");
 321         CC->session_specific_data = malloc(sizeof(struct citxmpp));
 322         memset(XMPP, 0, sizeof(struct citxmpp));
 323
 324         /* XMPP does not use a greeting, but we still have to initialize some things. */
 325
 326         XMPP->xp = XML_ParserCreateNS("UTF-8", ':');
 327         if (XMPP->xp == NULL) {
 328                 lprintf(CTDL_ALERT, "Cannot create XML parser!\n");
 329                 CC->kill_me = 1;
 330                 return;
 331         }
 332
 333         XML_SetElementHandler(XMPP->xp, xmpp_xml_start, xmpp_xml_end);
 334         XML_SetCharacterDataHandler(XMPP->xp, xmpp_xml_chardata);
 335         // XML_SetUserData(XMPP->xp, something...);
 336 }
 337
 338
 339 /*
 340  * Main command loop for XMPP sessions.
 341  */
 342 void xmpp_command_loop(void) {
 343         char cmdbuf[16];
 344         int retval;
 345
 346         time(&CC->lastcmd);
 347         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
 348         retval = client_read(cmdbuf, 1);
 349         if (retval != 1) {
 350                 lprintf(CTDL_ERR, "Client disconnected: ending session.\r\n");
 351                 CC->kill_me = 1;
 352                 return;
 353         }
 354
 355         /* FIXME ... this is woefully inefficient. */
 356
 357         XML_Parse(XMPP->xp, cmdbuf, 1, 0);
 358 }
 359
 360
 361 /*
 362  * Async loop for XMPP sessions (handles the transmission of unsolicited stanzas)
 363  */
 364 void xmpp_async_loop(void) {
 365         xmpp_process_events();
 366         jabber_output_incoming_messages();
 367 }
 368
 369
 370 /*
 371  * Login hook for XMPP sessions
 372  */
 373 void xmpp_login_hook(void) {
 374         xmpp_queue_event(XMPP_EVT_LOGIN, CC->cs_inet_email);
 375 }
 376
 377
 378 /*
 379  * Logout hook for XMPP sessions
 380  */
 381 void xmpp_logout_hook(void) {
 382         xmpp_queue_event(XMPP_EVT_LOGOUT, CC->cs_inet_email);
 383 }
 384
 385
 386 const char *CitadelServiceXMPP="XMPP";
 387
 388 #endif  /* HAVE_EXPAT */
 389
 390 CTDL_MODULE_INIT(jabber)
 391 {
 392 #ifdef HAVE_EXPAT
 393         if (!threading) {
 394                 CtdlRegisterServiceHook(5222,                   /* FIXME change to config.c_xmpp_port */
 395                                         NULL,
 396                                         xmpp_greeting,
 397                                         xmpp_command_loop,
 398                                         xmpp_async_loop,
 399                                         CitadelServiceXMPP);
 400                 CtdlRegisterSessionHook(xmpp_cleanup_function, EVT_STOP);
 401                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_LOGIN);
 402                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_LOGOUT);
 403
 404         #else
 405                 lprintf(CTDL_INFO, "This server is missing the Expat XML parser.  Jabber service will be disabled.\n");
 406 #endif
 407         }
 408
 409         /* return our Subversion id for the Log */
 410         return "$Id$";
 411 }