/*
- * $Id$
- *
* XMPP (Jabber) service for the Citadel system
- * Copyright (c) 2007-2010 by Art Cancro
+ * Copyright (c) 2007-2018 by Art Cancro and citadel.org
*
- * This program is free software; you can redistribute it and/or modify
+ * 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.
#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;
-/* We have just received a <stream> tag from the client, so send them ours */
+#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
+
+
+/*
+ * 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.
+ */
+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;
+}
+
+
+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) {
+ /* we probably shouldn't be doing this */
+ buf[len++] = '_';
+ 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);
cprintf("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
cprintf("<stream:stream ");
- cprintf("from=\"%s\" ", XMPP->server_name);
+ 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\" ");
/* The features of this stream are... */
cprintf("<stream:features>");
-#ifdef HAVE_OPENSSL_XXXX_COMMENTED_OUT
- /* TLS encryption (but only if it isn't already active) */
+ /*
+ * 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>");
}
strcpy(el, ++sep);
}
- /*
- CtdlLogPrintf(CTDL_DEBUG, "XMPP ELEMENT START: <%s>\n", el);
+#ifdef XMPP_XML_DEBUG
+ syslog(LOG_DEBUG, "xmpp: ELEMENT START: <%s>", el);
for (i=0; attr[i] != NULL; i+=2) {
- CtdlLogPrintf(CTDL_DEBUG, " Attribute '%s' = '%s'\n", attr[i], attr[i+1]);
+ syslog(LOG_DEBUG, "xmpp: Attribute '%s' = '%s'", attr[i], attr[i+1]);
}
- uncomment for more verbosity */
+#endif
if (!strcasecmp(el, "stream")) {
xmpp_stream_start(data, supplied_el, attr);
void xmpp_xml_end(void *data, const char *supplied_el) {
char el[256];
char *sep = NULL;
+ char xmlbuf[256];
/* Axe the namespace, we don't care about it */
safestrncpy(el, supplied_el, sizeof el);
strcpy(el, ++sep);
}
- /*
- CtdlLogPrintf(CTDL_DEBUG, "XMPP ELEMENT END : <%s>\n", el);
+#ifdef XMPP_XML_DEBUG
+ syslog(LOG_DEBUG, "xmpp: ELEMENT END : <%s>", el);
if (XMPP->chardata_len > 0) {
- CtdlLogPrintf(CTDL_DEBUG, " chardata: %s\n", XMPP->chardata);
+ syslog(LOG_DEBUG, "xmpp: chardata: %s", XMPP->chardata);
}
- uncomment for more verbosity */
+#endif
if (!strcasecmp(el, "resource")) {
if (XMPP->chardata_len > 0) {
- safestrncpy(XMPP->iq_client_resource, XMPP->chardata,
- sizeof XMPP->iq_client_resource);
+ 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);
+ 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);
+ safestrncpy(XMPP->iq_client_password, XMPP->chardata, sizeof XMPP->iq_client_password);
striplt(XMPP->iq_client_password);
}
}
* 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);
+ xmpp_query_namespace(XMPP->iq_id, XMPP->iq_from, XMPP->iq_to, XMPP->iq_query_xmlns);
}
/*
else if (XMPP->ping_requested) {
cprintf("<iq type=\"result\" ");
if (!IsEmptyStr(XMPP->iq_from)) {
- cprintf("to=\"%s\" ", XMPP->iq_from);
+ cprintf("to=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_from, sizeof xmlbuf));
}
if (!IsEmptyStr(XMPP->iq_to)) {
- cprintf("from=\"%s\" ", XMPP->iq_to);
+ cprintf("from=\"%s\" ", xmlesc(xmlbuf, XMPP->iq_to, sizeof xmlbuf));
}
- cprintf("id=\"%s\"/>", XMPP->iq_id);
+ cprintf("id=\"%s\"/>", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
}
/*
* Unknown query ... return the XML equivalent of a blank stare
*/
else {
- CtdlLogPrintf(CTDL_DEBUG,
- "Unknown query <%s> - returning <service-unavailable/>\n",
- el
- );
- cprintf("<iq type=\"error\" id=\"%s\">", XMPP->iq_id);
+ 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>"
xmpp_non_sasl_authenticate(
XMPP->iq_id,
XMPP->iq_client_username,
- XMPP->iq_client_password,
- XMPP->iq_client_resource
+ XMPP->iq_client_password
);
}
else if (
(XMPP->bind_requested)
&& (!IsEmptyStr(XMPP->iq_id))
- && (!IsEmptyStr(XMPP->iq_client_resource))
&& (CC->logged_in)
- ) {
+ ) {
- /* Generate the "full JID" of the client resource */
+ /* If the client has not specified a client resource, generate one */
- snprintf(XMPP->client_jid, sizeof XMPP->client_jid,
- "%s/%s",
- CC->cs_inet_email,
- XMPP->iq_client_resource
- );
+ 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 resource */
+ snprintf(XMPP->client_jid, sizeof XMPP->client_jid, "%s/%s", CC->cs_inet_email, XMPP->iq_client_resource);
/* Tell the client what its JID is */
- cprintf("<iq type=\"result\" id=\"%s\">", XMPP->iq_id);
+ 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>", XMPP->client_jid);
+ 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\">", XMPP->iq_id);
+ cprintf("<iq type=\"result\" id=\"%s\">", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf));
cprintf("</iq>");
}
else {
- cprintf("<iq type=\"error\" id=\"%s\">", XMPP->iq_id);
- cprintf("<error></error>");
+ 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 */
#ifdef HAVE_OPENSSL
cprintf("<proceed xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
- if (!CC->redirect_ssl) CC->kill_me = 1;
+ if (!CC->redirect_ssl) CC->kill_me = KILLME_NO_CRYPTO;
#else
cprintf("<failure xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>");
- CC->kill_me = 1;
+ CC->kill_me = KILLME_NO_CRYPTO;
#endif
}
}
else if (!strcasecmp(el, "stream")) {
- CtdlLogPrintf(CTDL_DEBUG, "XMPP client shut down their stream\n");
- /* xmpp_massacre_roster(); FIXME put this back in when it's finished */
+ syslog(LOG_DEBUG, "xmpp: client shut down their stream");
+ xmpp_massacre_roster();
cprintf("</stream>\n");
- CC->kill_me = 1;
+ 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 {
- CtdlLogPrintf(CTDL_DEBUG, "Ignoring unknown tag <%s>\n", el);
+ syslog(LOG_DEBUG, "xmpp: ignoring unknown tag <%s>", el);
}
XMPP->chardata_len = 0;
void xmpp_xml_chardata(void *data, const XML_Char *s, int len)
{
- struct citxmpp *X = XMPP;
+ citxmpp *X = XMPP;
if (X->chardata_alloc == 0) {
X->chardata_alloc = SIZ;
}
-
/*
* 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(struct citxmpp));
- memset(XMPP, 0, sizeof(struct citxmpp));
+ 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) {
- CtdlLogPrintf(CTDL_ALERT, "Cannot create XML parser!\n");
- CC->kill_me = 1;
+ syslog(LOG_ERR, "xmpp: cannot create XML parser");
+ CC->kill_me = KILLME_XML_PARSER;
return;
}
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) {
- char cmdbuf[16];
- int retval;
+ int rc;
+ StrBuf *stream_input = NewStrBuf();
time(&CC->lastcmd);
- memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
- retval = client_read(cmdbuf, 1);
- if (retval != 1) {
- CtdlLogPrintf(CTDL_ERR, "Client disconnected: ending session.\r\n");
- CC->kill_me = 1;
- return;
+ rc = client_read_random_blob(stream_input, 30);
+ if (rc > 0) {
+ XML_Parse(XMPP->xp, ChrPtr(stream_input), rc, 0);
}
-
- /* FIXME ... this is woefully inefficient. */
-
- XML_Parse(XMPP->xp, cmdbuf, 1, 0);
+ else {
+ syslog(LOG_ERR, "xmpp: client disconnected: ending session.");
+ CC->kill_me = KILLME_CLIENT_DISCONNECTED;
+ }
+ FreeStrBuf(&stream_input);
}
const char *CitadelServiceXMPP="XMPP";
-
+extern void xmpp_cleanup_events(void);
CTDL_MODULE_INIT(xmpp)
{
if (!threading) {
- CtdlRegisterServiceHook(config.c_xmpp_c2s_port,
+ CtdlRegisterServiceHook(CtdlGetConfigInt("c_xmpp_c2s_port"),
NULL,
xmpp_greeting,
xmpp_command_loop,
xmpp_async_loop,
- CitadelServiceXMPP);
- CtdlRegisterSessionHook(xmpp_cleanup_function, EVT_STOP);
- CtdlRegisterSessionHook(xmpp_login_hook, EVT_LOGIN);
- CtdlRegisterSessionHook(xmpp_logout_hook, EVT_LOGOUT);
- CtdlRegisterSessionHook(xmpp_login_hook, EVT_UNSTEALTH);
- CtdlRegisterSessionHook(xmpp_logout_hook, EVT_STEALTH);
+ 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);
+ CtdlRegisterCleanupHook(xmpp_cleanup_events);
+
}
- /* return our Subversion id for the Log */
- return "$Id$";
+ /* return our module name for the log */
+ return "xmpp";
}
projects / citadel.git / blobdiff