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