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/*
* util/fptr_wlist.h - function pointer whitelists.
*
* Copyright (c) 2007, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
*
* This file contains functions that check function pointers.
* The functions contain a whitelist of known good callback values.
* Any other values lead to an error.
*
* This prevent heap overflow based exploits, where the callback pointer
* is overwritten by a buffer overflow (apart from this defense, buffer
* overflows should be fixed of course).
*
* Function pointers are used in
* o network code callbacks.
* o rbtree, the assertions are before the critical regions.
* in other places, assertions are before the callback.
*/
#ifndef UTIL_FPTR_WLIST_H
#define UTIL_FPTR_WLIST_H
#include "netevent.h"
/**
* Macro to perform an assertion check for fptr wlist checks.
* Does not get disabled in optimize mode. Check adds security by layers.
*/
#define fptr_ok(x) \
do { if(!(x)) \
fatal_exit("%s:%d: %s: pointer whitelist %s failed", \
__FILE__, __LINE__, __func__, #x); \
} while(0);
/**
* Check function pointer whitelist for comm_point callback values.
*
* @param fptr: function pointer to check.
* @return false if not in whitelist.
*/
int fptr_whitelist_comm_point(comm_point_callback_t *fptr);
/**
* Check function pointer whitelist for raw comm_point callback values.
*
* @param fptr: function pointer to check.
* @return false if not in whitelist.
*/
int fptr_whitelist_comm_point_raw(comm_point_callback_t *fptr);
/**
* Check function pointer whitelist for comm_timer callback values.
*
* @param fptr: function pointer to check.
* @return false if not in whitelist.
*/
int fptr_whitelist_comm_timer(void (*fptr)(void*));
/**
* Check function pointer whitelist for comm_signal callback values.
*
* @param fptr: function pointer to check.
* @return false if not in whitelist.
*/
int fptr_whitelist_comm_signal(void (*fptr)(int, void*));
/**
* Check function pointer whitelist for event structure callback values.
* This is not called by libevent itself, but checked by netevent.
*
* @param fptr: function pointer to check.
* @return false if not in whitelist.
*/
int fptr_whitelist_event(void (*fptr)(int, short, void *));
/**
* Check function pointer whitelist for rbtree cmp callback values.
*
* @param fptr: function pointer to check.
* @return false if not in whitelist.
*/
int fptr_whitelist_rbtree_cmp(int (*fptr) (const void *, const void *));
#ifdef USE_WINSOCK
/** whitelist for registry enumeration function */
int fptr_whitelist_enum_reg(void (*fptr) (HKEY, void *));
#endif /* USE_WINSOCK */
#endif /* UTIL_FPTR_WLIST_H */
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