vectorscan/src/nfa/callback.h
2015-10-20 09:13:35 +11:00

77 lines
3.2 KiB
C

/*
* Copyright (c) 2015, Intel Corporation
*
* 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 Intel Corporation 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 OWNER 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
* \brief NFA Callback definitions, used at runtime.
*/
#ifndef NFA_CALLBACK_H
#define NFA_CALLBACK_H
#include "ue2common.h"
/** \brief The type for an NFA callback.
*
* This is a function that takes as arguments the current offset where the
* match occurs, the id of the match and the context pointer that was passed
* into the NFA API function that executed the NFA.
*
* The offset where the match occurs will be the offset after the character
* that caused the match. Thus, if we have a buffer containing 'abc', then a
* pattern that matches an empty string will have an offset of 0, a pattern
* that matches 'a' will have an offset of 1, and a pattern that matches 'abc'
* will have an offset of 3, which will be a value that is 'beyond' the size of
* the buffer. That is, if we have n characters in the buffer, there are n+1
* different potential offsets for matches.
*
* This function should return an int - currently the possible return values
* are 0, which means 'stop running the engine' or non-zero, which means
* 'continue matching'.
*/
typedef int (*NfaCallback)(u64a offset, ReportID id, void *context);
/** \brief The type for an NFA callback which also tracks start of match.
*
* see \ref NfaCallback
*/
typedef int (*SomNfaCallback)(u64a from_offset, u64a to_offset, ReportID id,
void *context);
/**
* standard \ref NfaCallback return value indicating that engine execution
* should continue. (any non-zero value will serve this purpose)
*/
#define MO_CONTINUE_MATCHING 1
/**
* \ref NfaCallback return value indicating that engine execution should halt.
*/
#define MO_HALT_MATCHING 0
#endif // NFA_CALLBACK_H