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