+++ /dev/null
-/*
- * XMPP (Jabber) service for the Citadel system
- * Copyright (c) 2007-2021 by Art Cancro and citadel.org
- *
- * This program is open source software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-
-#include "sysdep.h"
-#include <stdlib.h>
-#include <unistd.h>
-#include <stdio.h>
-#include <fcntl.h>
-#include <signal.h>
-#include <pwd.h>
-#include <errno.h>
-#include <sys/types.h>
-#include <time.h>
-#include <sys/wait.h>
-#include <string.h>
-#include <limits.h>
-#include <ctype.h>
-#include <libcitadel.h>
-#include <expat.h>
-#include "citadel.h"
-#include "server.h"
-#include "citserver.h"
-#include "support.h"
-#include "config.h"
-#include "user_ops.h"
-#include "database.h"
-#include "msgbase.h"
-#include "internet_addressing.h"
-#include "ctdl_module.h"
-#include "serv_xmpp.h"
-
-/* uncomment for more verbosity - it will log all received XML tags */
-// #define XMPP_XML_DEBUG
-
-/* XML_StopParser is present in expat 2.x */
-#if XML_MAJOR_VERSION > 1
-#define HAVE_XML_STOPPARSER
-#endif
-
-struct xmpp_event *xmpp_queue = NULL;
-
-#ifdef HAVE_XML_STOPPARSER
-/* Stop the parser if an entity declaration is hit. */
-static void xmpp_entity_declaration(void *userData, const XML_Char *entityName,
- int is_parameter_entity, const XML_Char *value,
- int value_length, const XML_Char *base,
- const XML_Char *systemId, const XML_Char *publicId,
- const XML_Char *notationName
-) {
- syslog(LOG_WARNING, "xmpp: illegal entity declaration encountered; stopping parser.");
- XML_StopParser(XMPP->xp, XML_FALSE);
-}
-#endif
-
-
-/*
- * support function for xmlesc() which helps with UTF-8 strings
- */
-static inline int Ctdl_GetUtf8SequenceLength(const char *CharS, const char *CharE)
-{
- int n = 0;
- unsigned char test = (1<<7);
-
- if ((*CharS & 0xC0) != 0xC0) {
- return 1;
- }
-
- while ((n < 8) && ((test & ((unsigned char)*CharS)) != 0)) {
- test = test >> 1;
- n ++;
- }
- if ((n > 6) || ((CharE - CharS) < n)) {
- n = 0;
- }
- return n;
-}
-
-
-/*
- * Given a source string and a target buffer, returns the string
- * properly escaped for insertion into an XML stream. Returns a
- * pointer to the target buffer for convenience.
- */
-char *xmlesc(char *buf, char *str, int bufsiz)
-{
- int IsUtf8Sequence;
- char *ptr, *pche;
- unsigned char ch;
- int inlen;
- int len = 0;
-
- if (!buf) return(NULL);
- buf[0] = 0;
- len = 0;
- if (!str) {
- return(buf);
- }
- inlen = strlen(str);
- pche = str + inlen;
-
- for (ptr=str; *ptr; ptr++) {
- ch = *ptr;
- if (ch == '<') {
- strcpy(&buf[len], "<");
- len += 4;
- }
- else if (ch == '>') {
- strcpy(&buf[len], ">");
- len += 4;
- }
- else if (ch == '&') {
- strcpy(&buf[len], "&");
- len += 5;
- }
- else if ((ch >= 0x20) && (ch <= 0x7F)) {
- buf[len++] = ch;
- buf[len] = 0;
- }
- else if (ch < 0x20) {
- buf[len++] = '_'; // we probably shouldn't be doing this
- buf[len] = 0;
- }
- else {
- IsUtf8Sequence = Ctdl_GetUtf8SequenceLength(ptr, pche);
- if (IsUtf8Sequence)
- {
- while ((IsUtf8Sequence > 0) &&
- (ptr < pche))
- {
- buf[len] = *ptr;
- ptr ++;
- --IsUtf8Sequence;
- }
- }
- else
- {
- char oct[10];
- sprintf(oct, "&#%o;", ch);
- strcpy(&buf[len], oct);
- len += strlen(oct);
- }
- }
- if ((len + 6) > bufsiz) {
- return(buf);
- }
- }
- return(buf);
-}
-
-
-/*
- * We have just received a <stream> tag from the client, so send them ours
- */
-void xmpp_stream_start(void *data, const char *supplied_el, const char **attr)
-{
- char xmlbuf[256];
-
- while (*attr) {
- if (!strcasecmp(attr[0], "to")) {
- safestrncpy(XMPP->server_name, attr[1], sizeof XMPP->server_name);
- }
- attr += 2;
- }
-
- cprintf("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
- cprintf("<stream:stream ");
- cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->server_name, sizeof xmlbuf));
- cprintf("id=\"%08x\" ", CC->cs_pid);
- cprintf("version=\"1.0\" ");
- cprintf("xmlns:stream=\"http://etherx.jabber.org/streams\" ");
- cprintf("xmlns=\"jabber:client\">");
-
- /* The features of this stream are... */
- cprintf("<stream:features>");
-
- /*
- * TLS encryption (but only if it isn't already active)
- */
-#ifdef HAVE_OPENSSL
- if (!CC->redirect_ssl) {
- cprintf("<starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'></starttls>");
- }
-#endif
-
- if (!CC->logged_in) {
- /* If we're not logged in yet, offer SASL as our feature set */
- xmpp_output_auth_mechs();
-
- /* Also offer non-SASL authentication */
- cprintf("<auth xmlns=\"http://jabber.org/features/iq-auth\"/>");
- }
-
- /* Offer binding and sessions as part of our feature set */
- cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\"/>");
- cprintf("<session xmlns=\"urn:ietf:params:xml:ns:xmpp-session\"/>");
- cprintf("</stream:features>");
-
- CC->is_async = 1; /* XMPP sessions are inherently async-capable */
-}
-
-
-void xmpp_xml_start(void *data, const char *supplied_el, const char **attr) {
- char el[256];
- char *sep = NULL;
- int i;
-
- /* Create a version of the element with the namespace removed.
- * Now we can access "el" or "supplied_el" depending on whether we want to see the whole namespace.
- */
- safestrncpy(el, supplied_el, sizeof el);
- while (sep = strchr(el, ':'), sep) {
- strcpy(el, ++sep);
- }
-
-#ifdef XMPP_XML_DEBUG
- syslog(LOG_DEBUG, "xmpp: ELEMENT START: <%s>", el);
- for (i=0; attr[i] != NULL; i+=2) {
- syslog(LOG_DEBUG, "xmpp: Attribute '%s' = '%s'", attr[i], attr[i+1]);
- }
-#endif
-
- if (!strcasecmp(el, "stream")) {
- xmpp_stream_start(data, supplied_el, attr);
- }
-
- else if (!strcasecmp(el, "query")) {
- XMPP->iq_query_xmlns[0] = 0;
- safestrncpy(XMPP->iq_query_xmlns, supplied_el, sizeof XMPP->iq_query_xmlns);
- }
-
- else if (!strcasecmp(el, "bind")) {
- XMPP->bind_requested = 1;
- }
-
- else if (!strcasecmp(el, "iq")) {
- for (i=0; attr[i] != NULL; i+=2) {
- if (!strcasecmp(attr[i], "type")) {
- safestrncpy(XMPP->iq_type, attr[i+1], sizeof XMPP->iq_type);
- }
- else if (!strcasecmp(attr[i], "id")) {
- safestrncpy(XMPP->iq_id, attr[i+1], sizeof XMPP->iq_id);
- }
- else if (!strcasecmp(attr[i], "from")) {
- safestrncpy(XMPP->iq_from, attr[i+1], sizeof XMPP->iq_from);
- }
- else if (!strcasecmp(attr[i], "to")) {
- safestrncpy(XMPP->iq_to, attr[i+1], sizeof XMPP->iq_to);
- }
- }
- }
-
- else if (!strcasecmp(el, "auth")) {
- XMPP->sasl_auth_mech[0] = 0;
- for (i=0; attr[i] != NULL; i+=2) {
- if (!strcasecmp(attr[i], "mechanism")) {
- safestrncpy(XMPP->sasl_auth_mech, attr[i+1], sizeof XMPP->sasl_auth_mech);
- }
- }
- }
-
- else if (!strcasecmp(el, "message")) {
- for (i=0; attr[i] != NULL; i+=2) {
- if (!strcasecmp(attr[i], "to")) {
- safestrncpy(XMPP->message_to, attr[i+1], sizeof XMPP->message_to);
- }
- }
- }
-
- else if (!strcasecmp(el, "html")) {
- ++XMPP->html_tag_level;
- }
-}
-
-
-void xmpp_xml_end(void *data, const char *supplied_el) {
- char el[256];
- char *sep = NULL;
- char xmlbuf[256];
-
- /* Create a version of the element with the namespace removed.
- * Now we can access "el" or "supplied_el" depending on whether we want to see the whole namespace.
- */
- safestrncpy(el, supplied_el, sizeof el);
- while (sep = strchr(el, ':'), sep) {
- strcpy(el, ++sep);
- }
-
-#ifdef XMPP_XML_DEBUG
- syslog(LOG_DEBUG, "xmpp: ELEMENT END : <%s>", el);
- if (XMPP->chardata_len > 0) {
- syslog(LOG_DEBUG, "xmpp: chardata: %s", XMPP->chardata);
- }
-#endif
-
- if (!strcasecmp(el, "resource")) {
- if (XMPP->chardata_len > 0) {
- safestrncpy(XMPP->iq_client_resource, XMPP->chardata, sizeof XMPP->iq_client_resource);
- striplt(XMPP->iq_client_resource);
- }
- }
-
- else if (!strcasecmp(el, "username")) { /* NON SASL ONLY */
- if (XMPP->chardata_len > 0) {
- safestrncpy(XMPP->iq_client_username, XMPP->chardata, sizeof XMPP->iq_client_username);
- striplt(XMPP->iq_client_username);
- }
- }
-
- else if (!strcasecmp(el, "password")) { /* NON SASL ONLY */
- if (XMPP->chardata_len > 0) {
- safestrncpy(XMPP->iq_client_password, XMPP->chardata, sizeof XMPP->iq_client_password);
- striplt(XMPP->iq_client_password);
- }
- }
-
- else if (!strcasecmp(el, "iq")) {
-
- /*
- * iq type="get" (handle queries)
- */
- if (!strcasecmp(XMPP->iq_type, "get")) {
-
- /*
- * Query on a namespace
- */
- if (!IsEmptyStr(XMPP->iq_query_xmlns)) {
- xmpp_query_namespace(XMPP->iq_id, XMPP->iq_from, XMPP->iq_to, XMPP->iq_query_xmlns);
- }
-
- /*
- * ping ( http://xmpp.org/extensions/xep-0199.html )
- */
- else if (XMPP->ping_requested) {
- cprintf("<iq type=\"result\" ");
- if (!IsEmptyStr(XMPP->iq_from)) {
- cprintf("to=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_from, sizeof xmlbuf));
- }
- if (!IsEmptyStr(XMPP->iq_to)) {
- cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_to, sizeof xmlbuf));
- }
- cprintf("id=\"%s\"/>", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
- }
-
- /*
- * Client is requesting its own vCard
- * (If we make this more elaborate, move it to a separate function)
- */
- else if (XMPP->iq_vcard) {
- cprintf("<iq type=\"result\" id=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
- cprintf("to=\"%s\">", xmlesc(xmlbuf, XMPP->iq_from, sizeof xmlbuf));
- cprintf("<vCard xmlns=\"vcard-temp\">");
- cprintf("<fn>%s</fn>", xmlesc(xmlbuf, CC->user.fullname, sizeof xmlbuf));
- cprintf("<nickname>%s</nickname>", xmlesc(xmlbuf, CC->user.fullname, sizeof xmlbuf));
- cprintf("</vCard>");
- cprintf("</iq>");
- }
-
- /*
- * Unknown query ... return the XML equivalent of a blank stare
- */
- else {
- syslog(LOG_DEBUG, "xmpp: Unknown query <%s> - returning <service-unavailable/>", el);
- cprintf("<iq type=\"error\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
- cprintf("<error code=\"503\" type=\"cancel\">"
- "<service-unavailable xmlns=\"urn:ietf:params:xml:ns:xmpp-stanzas\"/>"
- "</error>"
- );
- cprintf("</iq>");
- }
- }
-
- /*
- * Non SASL authentication
- */
- else if (
- (!strcasecmp(XMPP->iq_type, "set"))
- && (!strcasecmp(XMPP->iq_query_xmlns, "jabber:iq:auth:query"))
- ) {
- xmpp_non_sasl_authenticate(XMPP->iq_id, XMPP->iq_client_username, XMPP->iq_client_password);
- }
-
- /*
- * If this <iq> stanza was a "bind" attempt, process it ...
- */
- else if (
- (XMPP->bind_requested)
- && (!IsEmptyStr(XMPP->iq_id))
- && (CC->logged_in)
- ) {
- /* If the client has not specified a client resource, generate one */
- if (IsEmptyStr(XMPP->iq_client_resource)) {
- snprintf(XMPP->iq_client_resource, sizeof XMPP->iq_client_resource, "%d", CC->cs_pid);
- }
-
- /* Generate the "full JID" of the client (user@host/resource) */
- snprintf(XMPP->client_jid, sizeof XMPP->client_jid, "%s/%s", CC->cs_principal_id, XMPP->iq_client_resource);
-
- /* Tell the client what its JID is */
- cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
- cprintf("<bind xmlns=\"urn:ietf:params:xml:ns:xmpp-bind\">");
- cprintf("<jid>%s</jid>", xmlesc(xmlbuf, XMPP->client_jid, sizeof xmlbuf));
- cprintf("</bind>");
- cprintf("</iq>");
- }
-
- else if (XMPP->iq_session) {
- cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
- cprintf("</iq>");
- }
-
- else {
- cprintf("<iq type=\"error\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
- cprintf("<error>Don't know how to do '%s'!</error>", xmlesc(xmlbuf, XMPP->iq_type, sizeof xmlbuf));
- cprintf("</iq>");
- syslog(LOG_DEBUG, "XMPP: don't know how to do iq_type='%s' with iq_query_xmlns='%s'", XMPP->iq_type, XMPP->iq_query_xmlns);
- }
-
- /* Now clear these fields out so they don't get used by a future stanza */
- XMPP->iq_id[0] = 0;
- XMPP->iq_from[0] = 0;
- XMPP->iq_to[0] = 0;
- XMPP->iq_type[0] = 0;
- XMPP->iq_client_resource[0] = 0;
- XMPP->iq_session = 0;
- XMPP->iq_vcard = 0;
- XMPP->iq_query_xmlns[0] = 0;
- XMPP->bind_requested = 0;
- XMPP->ping_requested = 0;
- }
-
- else if (!strcasecmp(el, "auth")) {
- /* Try to authenticate (this function is responsible for the output stanza) */
- xmpp_sasl_auth(XMPP->sasl_auth_mech, (XMPP->chardata != NULL ? XMPP->chardata : "") );
-
- /* Now clear these fields out so they don't get used by a future stanza */
- XMPP->sasl_auth_mech[0] = 0;
- }
-
- else if (!strcasecmp(el, "session")) {
- XMPP->iq_session = 1;
- }
-
- else if (!strcasecmp(supplied_el, "vcard-temp:vCard")) {
- XMPP->iq_vcard = 1;
- }
-
- else if (!strcasecmp(el, "presence")) {
- /* Respond to a <presence> update by firing back with presence information
- * on the entire wholist. Check this assumption, it's probably wrong.
- */
- xmpp_wholist_presence_dump();
- }
-
- else if ( (!strcasecmp(el, "body")) && (XMPP->html_tag_level == 0) ) {
- if (XMPP->message_body != NULL) {
- free(XMPP->message_body);
- XMPP->message_body = NULL;
- }
- if (XMPP->chardata_len > 0) {
- XMPP->message_body = strdup(XMPP->chardata);
- }
- }
-
- else if (!strcasecmp(el, "message")) {
- xmpp_send_message(XMPP->message_to, XMPP->message_body);
- XMPP->html_tag_level = 0;
- }
-
- else if (!strcasecmp(el, "html")) {
- --XMPP->html_tag_level;
- }
-
- else if (!strcasecmp(el, "starttls")) {
-#ifdef HAVE_OPENSSL
- cprintf("<proceed xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
- CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
- if (!CC->redirect_ssl) CC->kill_me = KILLME_NO_CRYPTO;
-#else
- cprintf("<failure xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
- CC->kill_me = KILLME_NO_CRYPTO;
-#endif
- }
-
- else if (!strcasecmp(el, "ping")) {
- XMPP->ping_requested = 1;
- }
-
- else if (!strcasecmp(el, "stream")) {
- syslog(LOG_DEBUG, "xmpp: client shut down their stream");
- xmpp_massacre_roster();
- cprintf("</stream>\n");
- CC->kill_me = KILLME_CLIENT_LOGGED_OUT;
- }
-
- else if (!strcasecmp(el, "query")) {
- /* already processed , no further action needed here */
- }
-
- else if (!strcasecmp(el, "bind")) {
- /* already processed , no further action needed here */
- }
-
- else {
- syslog(LOG_DEBUG, "xmpp: ignoring unknown tag <%s>", el);
- }
-
- XMPP->chardata_len = 0;
- if (XMPP->chardata_alloc > 0) {
- XMPP->chardata[0] = 0;
- }
-}
-
-
-void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
-{
- citxmpp *X = XMPP;
-
- if (X->chardata_alloc == 0) {
- X->chardata_alloc = SIZ;
- X->chardata = malloc(X->chardata_alloc);
- }
- if ((X->chardata_len + len + 1) > X->chardata_alloc) {
- X->chardata_alloc = X->chardata_len + len + 1024;
- X->chardata = realloc(X->chardata, X->chardata_alloc);
- }
- memcpy(&X->chardata[X->chardata_len], s, len);
- X->chardata_len += len;
- X->chardata[X->chardata_len] = 0;
-}
-
-
-/*
- * This cleanup function blows away the temporary memory and files used by the XMPP service.
- */
-void xmpp_cleanup_function(void) {
-
- /* Don't do this stuff if this is not a XMPP session! */
- if (CC->h_command_function != xmpp_command_loop) return;
-
- if (XMPP->chardata != NULL) {
- free(XMPP->chardata);
- XMPP->chardata = NULL;
- XMPP->chardata_len = 0;
- XMPP->chardata_alloc = 0;
- if (XMPP->message_body != NULL) {
- free(XMPP->message_body);
- }
- }
- XML_ParserFree(XMPP->xp);
- free(XMPP);
-}
-
-
-/*
- * Here's where our XMPP session begins its happy day.
- */
-void xmpp_greeting(void) {
- client_set_inbound_buf(4);
- strcpy(CC->cs_clientname, "XMPP session");
- CC->session_specific_data = malloc(sizeof(citxmpp));
- memset(XMPP, 0, sizeof(citxmpp));
- XMPP->last_event_processed = queue_event_seq;
-
- /* XMPP does not use a greeting, but we still have to initialize some things. */
-
- XMPP->xp = XML_ParserCreateNS("UTF-8", ':');
- if (XMPP->xp == NULL) {
- syslog(LOG_ERR, "xmpp: cannot create XML parser");
- CC->kill_me = KILLME_XML_PARSER;
- return;
- }
-
- XML_SetElementHandler(XMPP->xp, xmpp_xml_start, xmpp_xml_end);
- XML_SetCharacterDataHandler(XMPP->xp, xmpp_xml_chardata);
- // XML_SetUserData(XMPP->xp, something...);
-
- /* Prevent the "billion laughs" attack against expat by disabling
- * internal entity expansion. With 2.x, forcibly stop the parser
- * if an entity is declared - this is safer and a more obvious
- * failure mode. With older versions, simply prevent expansion
- * of such entities. */
-#ifdef HAVE_XML_STOPPARSER
- XML_SetEntityDeclHandler(XMPP->xp, xmpp_entity_declaration);
-#else
- XML_SetDefaultHandler(XMPP->xp, NULL);
-#endif
-
- CC->can_receive_im = 1; /* This protocol is capable of receiving instant messages */
-}
-
-
-/*
- * Main command loop for XMPP sessions.
- */
-void xmpp_command_loop(void) {
- int rc;
- StrBuf *stream_input = NewStrBuf();
-
- time(&CC->lastcmd);
- rc = client_read_random_blob(stream_input, 30);
- if (rc > 0) {
- XML_Parse(XMPP->xp, ChrPtr(stream_input), rc, 0);
- }
- else {
- syslog(LOG_ERR, "xmpp: client disconnected: ending session.");
- CC->kill_me = KILLME_CLIENT_DISCONNECTED;
- }
- FreeStrBuf(&stream_input);
-}
-
-
-/*
- * Async loop for XMPP sessions (handles the transmission of unsolicited stanzas)
- */
-void xmpp_async_loop(void) {
- xmpp_process_events();
- xmpp_output_incoming_messages();
-}
-
-
-/*
- * Login hook for XMPP sessions
- */
-void xmpp_login_hook(void) {
- xmpp_queue_event(XMPP_EVT_LOGIN, CC->cs_principal_id);
-}
-
-
-/*
- * Logout hook for XMPP sessions
- */
-void xmpp_logout_hook(void) {
- xmpp_queue_event(XMPP_EVT_LOGOUT, CC->cs_principal_id);
-}
-
-
-const char *CitadelServiceXMPP="XMPP";
-CTDL_MODULE_INIT(xmpp)
-{
- if (!threading) {
- CtdlRegisterServiceHook(CtdlGetConfigInt("c_xmpp_c2s_port"),
- NULL,
- xmpp_greeting,
- xmpp_command_loop,
- xmpp_async_loop,
- CitadelServiceXMPP
- );
- CtdlRegisterSessionHook(xmpp_cleanup_function, EVT_STOP, PRIO_STOP + 70);
- CtdlRegisterSessionHook(xmpp_login_hook, EVT_LOGIN, PRIO_LOGIN + 90);
- CtdlRegisterSessionHook(xmpp_logout_hook, EVT_LOGOUT, PRIO_LOGOUT + 90);
- CtdlRegisterSessionHook(xmpp_login_hook, EVT_UNSTEALTH, PRIO_UNSTEALTH + 1);
- CtdlRegisterSessionHook(xmpp_logout_hook, EVT_STEALTH, PRIO_STEALTH + 1);
-
- }
-
- /* return our module name for the log */
- return "xmpp";
-}
projects / citadel.git / blobdiff