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
  55 /* We have just received a <stream> tag from the client, so send them ours */
  56
  57 void xmpp_stream_start(void *data, const char *supplied_el, const char **attr)
  58 {
  59
  60         lprintf(CTDL_DEBUG, "New stream detected.\n");
  61
  62         while (*attr) {
  63                 if (!strcasecmp(attr[0], "to")) {
  64                         safestrncpy(XMPP->server_name, attr[1], sizeof XMPP->server_name);
  65                 }
  66                 attr += 2;
  67         }
  68
  69         cprintf("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
  70
  71         cprintf("<stream:stream ");
  72         cprintf("from=\"%s\" ", XMPP->server_name);
  73         cprintf("id=\"%08x\" ", CC->cs_pid);
  74         cprintf("version=\"1.0\" ");
  75         cprintf("xmlns:stream=\"http://etherx.jabber.org/streams\" ");
  76         cprintf("xmlns=\"jabber:client\">");
  77
  78         /* The features of this stream are... */
  79         cprintf("<stream:features>");
  80
  81         if (!CC->logged_in) {
  82                 /* If we're not logged in yet, offer SASL as our feature set */
  83                 xmpp_output_auth_mechs();
  84         }
  85         else {
  86                 /* If we've logged in, now offer binding and sessions as our feature set */
  87                 cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\"/>");
  88                 cprintf("<session xmlns=\"urn:ietf:params:xml:ns:xmpp-session\"/>");
  89         }
  90
  91         cprintf("</stream:features>");
  92
  93         CC->is_async = 1;               /* XMPP sessions are inherently async-capable */
  94 }
  95
  96
  97 void xmpp_xml_start(void *data, const char *supplied_el, const char **attr) {
  98         char el[256];
  99         char *sep = NULL;
 100         int i;
 101
 102         /* Axe the namespace, we don't care about it */
 103         safestrncpy(el, supplied_el, sizeof el);
 104         while (sep = strchr(el, ':'), sep) {
 105                 strcpy(el, ++sep);
 106         }
 107
 108         lprintf(CTDL_DEBUG, "XMPP ELEMENT START: <%s>\n", el);
 109
 110         for (i=0; attr[i] != NULL; i+=2) {
 111                 lprintf(CTDL_DEBUG, "                    Attribute '%s' = '%s'\n", attr[i], attr[i+1]);
 112         }
 113
 114         if (!strcasecmp(el, "stream")) {
 115                 xmpp_stream_start(data, supplied_el, attr);
 116         }
 117
 118         else if (!strcasecmp(el, "query")) {
 119                 XMPP->iq_query_xmlns[0] = 0;
 120                 safestrncpy(XMPP->iq_query_xmlns, supplied_el, sizeof XMPP->iq_query_xmlns);
 121         }
 122
 123         else if (!strcasecmp(el, "iq")) {
 124                 for (i=0; attr[i] != NULL; i+=2) {
 125                         if (!strcasecmp(attr[i], "type")) {
 126                                 safestrncpy(XMPP->iq_type, attr[i+1], sizeof XMPP->iq_type);
 127                         }
 128                         else if (!strcasecmp(attr[i], "id")) {
 129                                 safestrncpy(XMPP->iq_id, attr[i+1], sizeof XMPP->iq_id);
 130                         }
 131                         else if (!strcasecmp(attr[i], "from")) {
 132                                 safestrncpy(XMPP->iq_from, attr[i+1], sizeof XMPP->iq_from);
 133                         }
 134                         else if (!strcasecmp(attr[i], "to")) {
 135                                 safestrncpy(XMPP->iq_to, attr[i+1], sizeof XMPP->iq_to);
 136                         }
 137                 }
 138         }
 139
 140         else if (!strcasecmp(el, "auth")) {
 141                 XMPP->sasl_auth_mech[0] = 0;
 142                 for (i=0; attr[i] != NULL; i+=2) {
 143                         if (!strcasecmp(attr[i], "mechanism")) {
 144                                 safestrncpy(XMPP->sasl_auth_mech, attr[i+1], sizeof XMPP->sasl_auth_mech);
 145                         }
 146                 }
 147         }
 148 }
 149
 150
 151
 152 void xmpp_xml_end(void *data, const char *supplied_el) {
 153         char el[256];
 154         char *sep = NULL;
 155
 156         /* Axe the namespace, we don't care about it */
 157         safestrncpy(el, supplied_el, sizeof el);
 158         while (sep = strchr(el, ':'), sep) {
 159                 strcpy(el, ++sep);
 160         }
 161
 162         lprintf(CTDL_DEBUG, "XMPP ELEMENT END  : <%s>\n", el);
 163         if (XMPP->chardata_len > 0) {
 164                 lprintf(CTDL_DEBUG, "          chardata: %s\n", XMPP->chardata);
 165         }
 166
 167         if (!strcasecmp(el, "resource")) {
 168                 if (XMPP->chardata_len > 0) {
 169                         safestrncpy(XMPP->iq_client_resource, XMPP->chardata,
 170                                 sizeof XMPP->iq_client_resource);
 171                 }
 172         }
 173
 174         else if (!strcasecmp(el, "iq")) {
 175
 176                 /*
 177                  * iq type="get" (handle queries)
 178                  */
 179                 if (!strcasecmp(XMPP->iq_type, "get")) {
 180
 181                         /*
 182                          * Query on a namespace
 183                          */
 184                         if (!IsEmptyStr(XMPP->iq_query_xmlns)) {
 185                                 xmpp_query_namespace(XMPP->iq_id, XMPP->iq_from,
 186                                                 XMPP->iq_to, XMPP->iq_query_xmlns);
 187                         }
 188
 189                         /*
 190                          * Unknown queries ... return the XML equivalent of a blank stare
 191                          */
 192                         else {
 193                                 cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 194                                 cprintf("</iq>");
 195                         }
 196                 }
 197
 198                 /*
 199                  * If this <iq> stanza was a "bind" attempt, process it ...
 200                  */
 201                 else if ( (!IsEmptyStr(XMPP->iq_id)) && (!IsEmptyStr(XMPP->iq_client_resource)) ) {
 202
 203                         /* Generate the "full JID" of the client resource */
 204
 205                         // snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
 206                         //      "%d@%s/%s",
 207                         //      CC->cs_pid,
 208                         //      config.c_fqdn,
 209                         //      XMPP->iq_client_resource
 210                         //);
 211
 212                         snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
 213                                 "%s/%s",
 214                                 CC->cs_inet_email,
 215                                 XMPP->iq_client_resource
 216                         );
 217
 218                         /* Tell the client what its JID is */
 219
 220                         cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 221                         cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\">");
 222                         cprintf("<jid>%s</jid>", XMPP->client_jid);
 223                         cprintf("</bind>");
 224                         cprintf("</iq>");
 225                 }
 226
 227                 else if (XMPP->iq_session) {
 228                         cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
 229                         cprintf("</iq>");
 230                 }
 231
 232                 else {
 233                         cprintf("<iq type=\"error\" id=\"%s\">", XMPP->iq_id);
 234                         cprintf("<error></error>");
 235                         cprintf("</iq>");
 236                 }
 237
 238                 /* Now clear these fields out so they don't get used by a future stanza */
 239                 XMPP->iq_id[0] = 0;
 240                 XMPP->iq_from[0] = 0;
 241                 XMPP->iq_to[0] = 0;
 242                 XMPP->iq_type[0] = 0;
 243                 XMPP->iq_client_resource[0] = 0;
 244                 XMPP->iq_session = 0;
 245                 XMPP->iq_query_xmlns[0] = 0;
 246         }
 247
 248         else if (!strcasecmp(el, "auth")) {
 249
 250                 /* Try to authenticate (this function is responsible for the output stanza) */
 251                 xmpp_sasl_auth(XMPP->sasl_auth_mech, (XMPP->chardata != NULL ? XMPP->chardata : "") );
 252
 253                 /* Now clear these fields out so they don't get used by a future stanza */
 254                 XMPP->sasl_auth_mech[0] = 0;
 255         }
 256
 257         else if (!strcasecmp(el, "session")) {
 258                 XMPP->iq_session = 1;
 259         }
 260
 261         else if (!strcasecmp(el, "presence")) {
 262
 263                 /* Respond to a <presence> update by firing back with presence information
 264                  * on the entire wholist.  Check this assumption, it's probably wrong.
 265                  */
 266                 jabber_wholist_presence_dump();
 267         }
 268
 269         XMPP->chardata_len = 0;
 270         if (XMPP->chardata_alloc > 0) {
 271                 XMPP->chardata[0] = 0;
 272         }
 273 }
 274
 275
 276 void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
 277 {
 278         struct citxmpp *X = XMPP;
 279
 280         if (X->chardata_alloc == 0) {
 281                 X->chardata_alloc = SIZ;
 282                 X->chardata = malloc(X->chardata_alloc);
 283         }
 284         if ((X->chardata_len + len + 1) > X->chardata_alloc) {
 285                 X->chardata_alloc = X->chardata_len + len + 1024;
 286                 X->chardata = realloc(X->chardata, X->chardata_alloc);
 287         }
 288         memcpy(&X->chardata[X->chardata_len], s, len);
 289         X->chardata_len += len;
 290         X->chardata[X->chardata_len] = 0;
 291 }
 292
 293
 294 /*
 295  * This cleanup function blows away the temporary memory and files used by the XMPP service.
 296  */
 297 void xmpp_cleanup_function(void) {
 298
 299         /* Don't do this stuff if this is not a XMPP session! */
 300         if (CC->h_command_function != xmpp_command_loop) return;
 301
 302         lprintf(CTDL_DEBUG, "Performing XMPP cleanup hook\n");
 303         if (XMPP->chardata != NULL) {
 304                 free(XMPP->chardata);
 305                 XMPP->chardata = NULL;
 306                 XMPP->chardata_len = 0;
 307                 XMPP->chardata_alloc = 0;
 308         }
 309         XML_ParserFree(XMPP->xp);
 310         free(XMPP);
 311 }
 312
 313
 314
 315 /*
 316  * Here's where our XMPP session begins its happy day.
 317  */
 318 void xmpp_greeting(void) {
 319         strcpy(CC->cs_clientname, "Jabber session");
 320         CC->session_specific_data = malloc(sizeof(struct citxmpp));
 321         memset(XMPP, 0, sizeof(struct citxmpp));
 322
 323         /* XMPP does not use a greeting, but we still have to initialize some things. */
 324
 325         XMPP->xp = XML_ParserCreateNS("UTF-8", ':');
 326         if (XMPP->xp == NULL) {
 327                 lprintf(CTDL_ALERT, "Cannot create XML parser!\n");
 328                 CC->kill_me = 1;
 329                 return;
 330         }
 331
 332         XML_SetElementHandler(XMPP->xp, xmpp_xml_start, xmpp_xml_end);
 333         XML_SetCharacterDataHandler(XMPP->xp, xmpp_xml_chardata);
 334         // XML_SetUserData(XMPP->xp, something...);
 335 }
 336
 337
 338 /*
 339  * Main command loop for XMPP sessions.
 340  */
 341 void xmpp_command_loop(void) {
 342         char cmdbuf[16];
 343         int retval;
 344
 345         time(&CC->lastcmd);
 346         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
 347         retval = client_read(cmdbuf, 1);
 348         if (retval != 1) {
 349                 lprintf(CTDL_ERR, "Client disconnected: ending session.\r\n");
 350                 CC->kill_me = 1;
 351                 return;
 352         }
 353
 354         /* FIXME ... this is woefully inefficient. */
 355
 356         XML_Parse(XMPP->xp, cmdbuf, 1, 0);
 357 }
 358
 359
 360 /*
 361  * Async loop for XMPP sessions (handles the transmission of unsolicited stanzas)
 362  */
 363 void xmpp_async_loop(void) {
 364         jabber_output_incoming_messages();
 365 }
 366
 367
 368 const char *CitadelServiceXMPP="XMPP";
 369
 370 #endif  /* HAVE_EXPAT */
 371
 372 CTDL_MODULE_INIT(jabber)
 373 {
 374 #ifdef HAVE_EXPAT
 375         if (!threading) {
 376                 CtdlRegisterServiceHook(5222,                   /* FIXME change to config.c_xmpp_port */
 377                                         NULL,
 378                                         xmpp_greeting,
 379                                         xmpp_command_loop,
 380                                         xmpp_async_loop,
 381                                         CitadelServiceXMPP);
 382                 CtdlRegisterSessionHook(xmpp_cleanup_function, EVT_STOP);
 383         #else
 384                 lprintf(CTDL_INFO, "This server is missing the Expat XML parser.  Jabber service will be disabled.\n");
 385 #endif
 386         }
 387
 388         /* return our Subversion id for the Log */
 389         return "$Id$";
 390 }