citadel/modules/xmpp/serv_xmpp.c

   1 /*
   2  * $Id$
   3  *
   4  * XMPP (Jabber) service for the Citadel system
   5  * Copyright (c) 2007-2010 by Art Cancro
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include "sysdep.h"
  23 #include <stdlib.h>
  24 #include <unistd.h>
  25 #include <stdio.h>
  26 #include <fcntl.h>
  27 #include <signal.h>
  28 #include <pwd.h>
  29 #include <errno.h>
  30 #include <sys/types.h>
  31
  32 #if TIME_WITH_SYS_TIME
  33 # include <sys/time.h>
  34 # include <time.h>
  35 #else
  36 # if HAVE_SYS_TIME_H
  37 #  include <sys/time.h>
  38 # else
  39 #  include <time.h>
  40 # endif
  41 #endif
  42
  43 #include <sys/wait.h>
  44 #include <string.h>
  45 #include <limits.h>
  46 #include <ctype.h>
  47 #include <libcitadel.h>
  48 #include <expat.h>
  49 #include "citadel.h"
  50 #include "server.h"
  51 #include "citserver.h"
  52 #include "support.h"
  53 #include "config.h"
  54 #include "user_ops.h"
  55 #include "database.h"
  56 #include "msgbase.h"
  57 #include "internet_addressing.h"
  58 #include "md5.h"
  59 #include "ctdl_module.h"
  60 #include "serv_xmpp.h"
  61
  62 struct xmpp_event *xmpp_queue = NULL;
  63
  64 /*
  65  * Given a source string and a target buffer, returns the string
  66  * properly escaped for insertion into an XML stream.  Returns a
  67  * pointer to the target buffer for convenience.
  68  *
  69  * BUG: this does not properly handle UTF-8
  70  */
  71 char *xmlesc(char *buf, char *str, int bufsiz)
  72 {
  73         char *ptr;
  74         unsigned char ch;
  75         int len = 0;
  76
  77         if (!buf) return(NULL);
  78         buf[0] = 0;
  79         len = 0;
  80         if (!str) {
  81                 return(buf);
  82         }
  83
  84         for (ptr=str; *ptr; ptr++) {
  85                 ch = *ptr;
  86                 if (ch == '<') {
  87                         strcpy(&buf[len], "&lt;");
  88                         len += 4;
  89                 }
  90                 else if (ch == '>') {
  91                         strcpy(&buf[len], "&gt;");
  92                         len += 4;
  93                 }
  94                 else if (ch == '&') {
  95                         strcpy(&buf[len], "&amp;");
  96                         len += 5;
  97                 }
  98                 else if (ch <= 0x7F) {
  99                         buf[len++] = ch;
 100                         buf[len] = 0;
 101                 }
 102                 else if (ch > 0x7F) {
 103                         char oct[10];
 104                         sprintf(oct, "&#%o;", ch);
 105                         strcpy(&buf[len], oct);
 106                         len += strlen(oct);
 107                 }
 108                 if ((len + 6) > bufsiz) {
 109                         return(buf);
 110                 }
 111         }
 112         return(buf);
 113 }
 114
 115
 116 /*
 117  * We have just received a <stream> tag from the client, so send them ours
 118  */
 119 void xmpp_stream_start(void *data, const char *supplied_el, const char **attr)
 120 {
 121         char xmlbuf[256];
 122
 123         while (*attr) {
 124                 if (!strcasecmp(attr[0], "to")) {
 125                         safestrncpy(XMPP->server_name, attr[1], sizeof XMPP->server_name);
 126                 }
 127                 attr += 2;
 128         }
 129
 130         cprintf("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
 131
 132         cprintf("<stream:stream ");
 133         cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->server_name, sizeof xmlbuf));
 134         cprintf("id=\"%08x\" ", CC->cs_pid);
 135         cprintf("version=\"1.0\" ");
 136         cprintf("xmlns:stream=\"http://etherx.jabber.org/streams\" ");
 137         cprintf("xmlns=\"jabber:client\">");
 138
 139         /* The features of this stream are... */
 140         cprintf("<stream:features>");
 141
 142 #ifdef HAVE_OPENSSL_XXXX_COMMENTED_OUT
 143         /* TLS encryption (but only if it isn't already active) */
 144         if (!CC->redirect_ssl) {
 145                 cprintf("<starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'></starttls>");
 146         }
 147 #endif
 148
 149         if (!CC->logged_in) {
 150                 /* If we're not logged in yet, offer SASL as our feature set */
 151                 xmpp_output_auth_mechs();
 152
 153                 /* Also offer non-SASL authentication */
 154                 cprintf("<auth xmlns=\"http://jabber.org/features/iq-auth\"/>");
 155         }
 156
 157         /* Offer binding and sessions as part of our feature set */
 158         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\"/>");
 159         cprintf("<session xmlns=\"urn:ietf:params:xml:ns:xmpp-session\"/>");
 160
 161         cprintf("</stream:features>");
 162
 163         CC->is_async = 1;               /* XMPP sessions are inherently async-capable */
 164 }
 165
 166
 167 void xmpp_xml_start(void *data, const char *supplied_el, const char **attr) {
 168         char el[256];
 169         char *sep = NULL;
 170         int i;
 171
 172         /* Axe the namespace, we don't care about it */
 173         safestrncpy(el, supplied_el, sizeof el);
 174         while (sep = strchr(el, ':'), sep) {
 175                 strcpy(el, ++sep);
 176         }
 177
 178         /*
 179         CtdlLogPrintf(CTDL_DEBUG, "XMPP ELEMENT START: <%s>\n", el);
 180         for (i=0; attr[i] != NULL; i+=2) {
 181                 CtdlLogPrintf(CTDL_DEBUG, "                    Attribute '%s' = '%s'\n", attr[i], attr[i+1]);
 182         }
 183         uncomment for more verbosity */
 184
 185         if (!strcasecmp(el, "stream")) {
 186                 xmpp_stream_start(data, supplied_el, attr);
 187         }
 188
 189         else if (!strcasecmp(el, "query")) {
 190                 XMPP->iq_query_xmlns[0] = 0;
 191                 safestrncpy(XMPP->iq_query_xmlns, supplied_el, sizeof XMPP->iq_query_xmlns);
 192         }
 193
 194         else if (!strcasecmp(el, "bind")) {
 195                 XMPP->bind_requested = 1;
 196         }
 197
 198         else if (!strcasecmp(el, "iq")) {
 199                 for (i=0; attr[i] != NULL; i+=2) {
 200                         if (!strcasecmp(attr[i], "type")) {
 201                                 safestrncpy(XMPP->iq_type, attr[i+1], sizeof XMPP->iq_type);
 202                         }
 203                         else if (!strcasecmp(attr[i], "id")) {
 204                                 safestrncpy(XMPP->iq_id, attr[i+1], sizeof XMPP->iq_id);
 205                         }
 206                         else if (!strcasecmp(attr[i], "from")) {
 207                                 safestrncpy(XMPP->iq_from, attr[i+1], sizeof XMPP->iq_from);
 208                         }
 209                         else if (!strcasecmp(attr[i], "to")) {
 210                                 safestrncpy(XMPP->iq_to, attr[i+1], sizeof XMPP->iq_to);
 211                         }
 212                 }
 213         }
 214
 215         else if (!strcasecmp(el, "auth")) {
 216                 XMPP->sasl_auth_mech[0] = 0;
 217                 for (i=0; attr[i] != NULL; i+=2) {
 218                         if (!strcasecmp(attr[i], "mechanism")) {
 219                                 safestrncpy(XMPP->sasl_auth_mech, attr[i+1], sizeof XMPP->sasl_auth_mech);
 220                         }
 221                 }
 222         }
 223
 224         else if (!strcasecmp(el, "message")) {
 225                 for (i=0; attr[i] != NULL; i+=2) {
 226                         if (!strcasecmp(attr[i], "to")) {
 227                                 safestrncpy(XMPP->message_to, attr[i+1], sizeof XMPP->message_to);
 228                         }
 229                 }
 230         }
 231
 232         else if (!strcasecmp(el, "html")) {
 233                 ++XMPP->html_tag_level;
 234         }
 235 }
 236
 237
 238
 239 void xmpp_xml_end(void *data, const char *supplied_el) {
 240         char el[256];
 241         char *sep = NULL;
 242         char xmlbuf[256];
 243
 244         /* Axe the namespace, we don't care about it */
 245         safestrncpy(el, supplied_el, sizeof el);
 246         while (sep = strchr(el, ':'), sep) {
 247                 strcpy(el, ++sep);
 248         }
 249
 250         /*
 251         CtdlLogPrintf(CTDL_DEBUG, "XMPP ELEMENT END  : <%s>\n", el);
 252         if (XMPP->chardata_len > 0) {
 253                 CtdlLogPrintf(CTDL_DEBUG, "          chardata: %s\n", XMPP->chardata);
 254         }
 255         uncomment for more verbosity */
 256
 257         if (!strcasecmp(el, "resource")) {
 258                 if (XMPP->chardata_len > 0) {
 259                         safestrncpy(XMPP->iq_client_resource, XMPP->chardata,
 260                                 sizeof XMPP->iq_client_resource);
 261                         striplt(XMPP->iq_client_resource);
 262                 }
 263         }
 264
 265         else if (!strcasecmp(el, "username")) {         /* NON SASL ONLY */
 266                 if (XMPP->chardata_len > 0) {
 267                         safestrncpy(XMPP->iq_client_username, XMPP->chardata,
 268                                 sizeof XMPP->iq_client_username);
 269                         striplt(XMPP->iq_client_username);
 270                 }
 271         }
 272
 273         else if (!strcasecmp(el, "password")) {         /* NON SASL ONLY */
 274                 if (XMPP->chardata_len > 0) {
 275                         safestrncpy(XMPP->iq_client_password, XMPP->chardata,
 276                                 sizeof XMPP->iq_client_password);
 277                         striplt(XMPP->iq_client_password);
 278                 }
 279         }
 280
 281         else if (!strcasecmp(el, "iq")) {
 282
 283                 /*
 284                  * iq type="get" (handle queries)
 285                  */
 286                 if (!strcasecmp(XMPP->iq_type, "get")) {
 287
 288                         /*
 289                          * Query on a namespace
 290                          */
 291                         if (!IsEmptyStr(XMPP->iq_query_xmlns)) {
 292                                 xmpp_query_namespace(XMPP->iq_id, XMPP->iq_from,
 293                                                 XMPP->iq_to, XMPP->iq_query_xmlns);
 294                         }
 295
 296                         /*
 297                          * ping ( http://xmpp.org/extensions/xep-0199.html )
 298                          */
 299                         else if (XMPP->ping_requested) {
 300                                 cprintf("<iq type=\"result\" ");
 301                                 if (!IsEmptyStr(XMPP->iq_from)) {
 302                                         cprintf("to=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_from, sizeof xmlbuf));
 303                                 }
 304                                 if (!IsEmptyStr(XMPP->iq_to)) {
 305                                         cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_to, sizeof xmlbuf));
 306                                 }
 307                                 cprintf("id=\"%s\"/>", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 308                         }
 309
 310                         /*
 311                          * Unknown query ... return the XML equivalent of a blank stare
 312                          */
 313                         else {
 314                                 CtdlLogPrintf(CTDL_DEBUG,
 315                                         "Unknown query <%s> - returning <service-unavailable/>\n",
 316                                         el
 317                                 );
 318                                 cprintf("<iq type=\"error\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 319                                 cprintf("<error code=\"503\" type=\"cancel\">"
 320                                         "<service-unavailable xmlns=\"urn:ietf:params:xml:ns:xmpp-stanzas\"/>"
 321                                         "</error>"
 322                                 );
 323                                 cprintf("</iq>");
 324                         }
 325                 }
 326
 327                 /*
 328                  * Non SASL authentication
 329                  */
 330                 else if (
 331                         (!strcasecmp(XMPP->iq_type, "set"))
 332                         && (!strcasecmp(XMPP->iq_query_xmlns, "jabber:iq:auth:query"))
 333                         ) {
 334
 335                         xmpp_non_sasl_authenticate(
 336                                 XMPP->iq_id,
 337                                 XMPP->iq_client_username,
 338                                 XMPP->iq_client_password,
 339                                 XMPP->iq_client_resource
 340                         );
 341                 }
 342
 343                 /*
 344                  * If this <iq> stanza was a "bind" attempt, process it ...
 345                  */
 346                 else if (
 347                         (XMPP->bind_requested)
 348                         && (!IsEmptyStr(XMPP->iq_id))
 349                         && (!IsEmptyStr(XMPP->iq_client_resource))
 350                         && (CC->logged_in)
 351                         ) {
 352
 353                         /* Generate the "full JID" of the client resource */
 354
 355                         snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
 356                                 "%s/%s",
 357                                 CC->cs_inet_email,
 358                                 XMPP->iq_client_resource
 359                         );
 360
 361                         /* Tell the client what its JID is */
 362
 363                         cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 364                         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\">");
 365                         cprintf("<jid>%s</jid>", xmlesc(xmlbuf, XMPP->client_jid, sizeof xmlbuf));
 366                         cprintf("</bind>");
 367                         cprintf("</iq>");
 368                 }
 369
 370                 else if (XMPP->iq_session) {
 371                         cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 372                         cprintf("</iq>");
 373                 }
 374
 375                 else {
 376                         cprintf("<iq type=\"error\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
 377                         cprintf("<error>Don't know howto do '%s'!</error>", xmlesc(xmlbuf, XMPP->iq_type, sizeof xmlbuf));
 378                         cprintf("</iq>");
 379                 }
 380
 381                 /* Now clear these fields out so they don't get used by a future stanza */
 382                 XMPP->iq_id[0] = 0;
 383                 XMPP->iq_from[0] = 0;
 384                 XMPP->iq_to[0] = 0;
 385                 XMPP->iq_type[0] = 0;
 386                 XMPP->iq_client_resource[0] = 0;
 387                 XMPP->iq_session = 0;
 388                 XMPP->iq_query_xmlns[0] = 0;
 389                 XMPP->bind_requested = 0;
 390                 XMPP->ping_requested = 0;
 391         }
 392
 393         else if (!strcasecmp(el, "auth")) {
 394
 395                 /* Try to authenticate (this function is responsible for the output stanza) */
 396                 xmpp_sasl_auth(XMPP->sasl_auth_mech, (XMPP->chardata != NULL ? XMPP->chardata : "") );
 397
 398                 /* Now clear these fields out so they don't get used by a future stanza */
 399                 XMPP->sasl_auth_mech[0] = 0;
 400         }
 401
 402         else if (!strcasecmp(el, "session")) {
 403                 XMPP->iq_session = 1;
 404         }
 405
 406         else if (!strcasecmp(el, "presence")) {
 407
 408                 /* Respond to a <presence> update by firing back with presence information
 409                  * on the entire wholist.  Check this assumption, it's probably wrong.
 410                  */
 411                 xmpp_wholist_presence_dump();
 412         }
 413
 414         else if ( (!strcasecmp(el, "body")) && (XMPP->html_tag_level == 0) ) {
 415                 if (XMPP->message_body != NULL) {
 416                         free(XMPP->message_body);
 417                         XMPP->message_body = NULL;
 418                 }
 419                 if (XMPP->chardata_len > 0) {
 420                         XMPP->message_body = strdup(XMPP->chardata);
 421                 }
 422         }
 423
 424         else if (!strcasecmp(el, "message")) {
 425                 xmpp_send_message(XMPP->message_to, XMPP->message_body);
 426                 XMPP->html_tag_level = 0;
 427         }
 428
 429         else if (!strcasecmp(el, "html")) {
 430                 --XMPP->html_tag_level;
 431         }
 432
 433         else if (!strcasecmp(el, "starttls")) {
 434 #ifdef HAVE_OPENSSL
 435                 cprintf("<proceed xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 436                 CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
 437                 if (!CC->redirect_ssl) CC->kill_me = 1;
 438 #else
 439                 cprintf("<failure xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
 440                 CC->kill_me = 1;
 441 #endif
 442         }
 443
 444         else if (!strcasecmp(el, "ping")) {
 445                 XMPP->ping_requested = 1;
 446         }
 447
 448         else if (!strcasecmp(el, "stream")) {
 449                 CtdlLogPrintf(CTDL_DEBUG, "XMPP client shut down their stream\n");
 450                 xmpp_massacre_roster();
 451                 cprintf("</stream>\n");
 452                 CC->kill_me = 1;
 453         }
 454
 455         else {
 456                 CtdlLogPrintf(CTDL_DEBUG, "Ignoring unknown tag <%s>\n", el);
 457         }
 458
 459         XMPP->chardata_len = 0;
 460         if (XMPP->chardata_alloc > 0) {
 461                 XMPP->chardata[0] = 0;
 462         }
 463 }
 464
 465
 466 void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
 467 {
 468         citxmpp *X = XMPP;
 469
 470         if (X->chardata_alloc == 0) {
 471                 X->chardata_alloc = SIZ;
 472                 X->chardata = malloc(X->chardata_alloc);
 473         }
 474         if ((X->chardata_len + len + 1) > X->chardata_alloc) {
 475                 X->chardata_alloc = X->chardata_len + len + 1024;
 476                 X->chardata = realloc(X->chardata, X->chardata_alloc);
 477         }
 478         memcpy(&X->chardata[X->chardata_len], s, len);
 479         X->chardata_len += len;
 480         X->chardata[X->chardata_len] = 0;
 481 }
 482
 483
 484 /*
 485  * This cleanup function blows away the temporary memory and files used by the XMPP service.
 486  */
 487 void xmpp_cleanup_function(void) {
 488
 489         /* Don't do this stuff if this is not a XMPP session! */
 490         if (CC->h_command_function != xmpp_command_loop) return;
 491
 492         if (XMPP->chardata != NULL) {
 493                 free(XMPP->chardata);
 494                 XMPP->chardata = NULL;
 495                 XMPP->chardata_len = 0;
 496                 XMPP->chardata_alloc = 0;
 497                 if (XMPP->message_body != NULL) {
 498                         free(XMPP->message_body);
 499                 }
 500         }
 501         XML_ParserFree(XMPP->xp);
 502         free(XMPP);
 503 }
 504
 505
 506
 507 /*
 508  * Here's where our XMPP session begins its happy day.
 509  */
 510 void xmpp_greeting(void) {
 511         strcpy(CC->cs_clientname, "XMPP session");
 512         CC->session_specific_data = malloc(sizeof(citxmpp));
 513         memset(XMPP, 0, sizeof(citxmpp));
 514         XMPP->last_event_processed = queue_event_seq;
 515
 516         /* XMPP does not use a greeting, but we still have to initialize some things. */
 517
 518         XMPP->xp = XML_ParserCreateNS("UTF-8", ':');
 519         if (XMPP->xp == NULL) {
 520                 CtdlLogPrintf(CTDL_ALERT, "Cannot create XML parser!\n");
 521                 CC->kill_me = 1;
 522                 return;
 523         }
 524
 525         XML_SetElementHandler(XMPP->xp, xmpp_xml_start, xmpp_xml_end);
 526         XML_SetCharacterDataHandler(XMPP->xp, xmpp_xml_chardata);
 527         // XML_SetUserData(XMPP->xp, something...);
 528
 529         CC->can_receive_im = 1;         /* This protocol is capable of receiving instant messages */
 530 }
 531
 532
 533 /*
 534  * Main command loop for XMPP sessions.
 535  */
 536 void xmpp_command_loop(void) {
 537         int rc;
 538         StrBuf *stream_input = NewStrBuf();
 539
 540         time(&CC->lastcmd);
 541         rc = client_read_random_blob(stream_input, 30);
 542         if (rc > 0) {
 543                 XML_Parse(XMPP->xp, ChrPtr(stream_input), rc, 0);
 544         }
 545         else {
 546                 CtdlLogPrintf(CTDL_ERR, "Client disconnected: ending session.\n");
 547                 CC->kill_me = 1;
 548         }
 549         FreeStrBuf(&stream_input);
 550 }
 551
 552
 553 /*
 554  * Async loop for XMPP sessions (handles the transmission of unsolicited stanzas)
 555  */
 556 void xmpp_async_loop(void) {
 557         xmpp_process_events();
 558         xmpp_output_incoming_messages();
 559 }
 560
 561
 562 /*
 563  * Login hook for XMPP sessions
 564  */
 565 void xmpp_login_hook(void) {
 566         xmpp_queue_event(XMPP_EVT_LOGIN, CC->cs_inet_email);
 567 }
 568
 569
 570 /*
 571  * Logout hook for XMPP sessions
 572  */
 573 void xmpp_logout_hook(void) {
 574         xmpp_queue_event(XMPP_EVT_LOGOUT, CC->cs_inet_email);
 575 }
 576
 577
 578 const char *CitadelServiceXMPP="XMPP";
 579
 580 CTDL_MODULE_INIT(xmpp)
 581 {
 582         if (!threading) {
 583                 CtdlRegisterServiceHook(config.c_xmpp_c2s_port,
 584                                         NULL,
 585                                         xmpp_greeting,
 586                                         xmpp_command_loop,
 587                                         xmpp_async_loop,
 588                                         CitadelServiceXMPP
 589                 );
 590                 CtdlRegisterSessionHook(xmpp_cleanup_function, EVT_STOP);
 591                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_LOGIN);
 592                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_LOGOUT);
 593                 CtdlRegisterSessionHook(xmpp_login_hook, EVT_UNSTEALTH);
 594                 CtdlRegisterSessionHook(xmpp_logout_hook, EVT_STEALTH);
 595         }
 596
 597         /* return our Subversion id for the Log */
 598         return "$Id$";
 599 }