X-Git-Url: https://code.citadel.org/?a=blobdiff_plain;f=citadel%2Fmodules%2Fxmpp%2Fserv_xmpp.c;h=34c6e5d2e7c767a0c3f5cc490cd842ef13609b0b;hb=a7d7e3f128e15f282f2a96aba513823aa9603c22;hp=d9271e46469235b1fdc731e47bd6186e7f7a6d4b;hpb=6a969c7e8f80199f8b8bd5d76b40eb3f53ab3ca4;p=citadel.git diff --git a/citadel/modules/xmpp/serv_xmpp.c b/citadel/modules/xmpp/serv_xmpp.c index d9271e464..34c6e5d2e 100644 --- a/citadel/modules/xmpp/serv_xmpp.c +++ b/citadel/modules/xmpp/serv_xmpp.c @@ -1,10 +1,8 @@ /* - * $Id$ - * * XMPP (Jabber) service for the Citadel system - * Copyright (c) 2007-2010 by Art Cancro + * Copyright (c) 2007-2017 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. @@ -59,19 +57,64 @@ #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 + + + /* * 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. - * - * BUG: this does not properly handle UTF-8 */ +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) { - char *ptr; + int IsUtf8Sequence; + char *ptr, *pche; unsigned char ch; + int inlen; int len = 0; if (!buf) return(NULL); @@ -80,6 +123,8 @@ char *xmlesc(char *buf, char *str, int bufsiz) if (!str) { return(buf); } + inlen = strlen(str); + pche = str + inlen; for (ptr=str; *ptr; ptr++) { ch = *ptr; @@ -95,15 +140,34 @@ char *xmlesc(char *buf, char *str, int bufsiz) strcpy(&buf[len], "&"); len += 5; } - else if (ch <= 0x7F) { + else if ((ch >= 0x20) && (ch <= 0x7F)) { buf[len++] = ch; buf[len] = 0; } - else if (ch > 0x7F) { - char oct[10]; - sprintf(oct, "&#%o;", ch); - strcpy(&buf[len], oct); - len += strlen(oct); + 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); @@ -139,8 +203,10 @@ void xmpp_stream_start(void *data, const char *supplied_el, const char **attr) /* The features of this stream are... */ cprintf(""); -#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(""); } @@ -175,12 +241,12 @@ void xmpp_xml_start(void *data, const char *supplied_el, const char **attr) { 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); @@ -247,12 +313,12 @@ void xmpp_xml_end(void *data, const char *supplied_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) { @@ -311,10 +377,7 @@ void xmpp_xml_end(void *data, const char *supplied_el) { * Unknown query ... return the XML equivalent of a blank stare */ else { - CtdlLogPrintf(CTDL_DEBUG, - "Unknown query <%s> - returning \n", - el - ); + syslog(LOG_DEBUG, "xmpp: Unknown query <%s> - returning ", el); cprintf("", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf)); cprintf("" "" @@ -374,8 +437,9 @@ void xmpp_xml_end(void *data, const char *supplied_el) { else { cprintf("", xmlesc(xmlbuf, XMPP->iq_id, sizeof xmlbuf)); - cprintf("Don't know howto do '%s'!", xmlesc(xmlbuf, XMPP->iq_type, sizeof xmlbuf)); + cprintf("Don't know how to do '%s'!", xmlesc(xmlbuf, XMPP->iq_type, sizeof xmlbuf)); cprintf(""); + 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 */ @@ -434,10 +498,10 @@ void xmpp_xml_end(void *data, const char *supplied_el) { #ifdef HAVE_OPENSSL cprintf(""); CtdlModuleStartCryptoMsgs(NULL, NULL, NULL); - if (!CC->redirect_ssl) CC->kill_me = 1; + if (!CC->redirect_ssl) CC->kill_me = KILLME_NO_CRYPTO; #else cprintf(""); - CC->kill_me = 1; + CC->kill_me = KILLME_NO_CRYPTO; #endif } @@ -446,14 +510,22 @@ void xmpp_xml_end(void *data, const char *supplied_el) { } else if (!strcasecmp(el, "stream")) { - CtdlLogPrintf(CTDL_DEBUG, "XMPP client shut down their stream\n"); + syslog(LOG_DEBUG, "xmpp: client shut down their stream"); xmpp_massacre_roster(); cprintf("\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; @@ -508,6 +580,7 @@ void xmpp_cleanup_function(void) { * 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)); @@ -517,8 +590,8 @@ void xmpp_greeting(void) { 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; } @@ -526,6 +599,17 @@ void xmpp_greeting(void) { 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 */ } @@ -543,8 +627,8 @@ void xmpp_command_loop(void) { XML_Parse(XMPP->xp, ChrPtr(stream_input), rc, 0); } else { - CtdlLogPrintf(CTDL_ERR, "Client disconnected: ending session.\n"); - CC->kill_me = 1; + syslog(LOG_ERR, "xmpp: client disconnected: ending session."); + CC->kill_me = KILLME_CLIENT_DISCONNECTED; } FreeStrBuf(&stream_input); } @@ -576,24 +660,26 @@ void xmpp_logout_hook(void) { 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); + 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"; }