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/* Copyright (C) 2007-2010 Open Information Security Foundation
*
* You can copy, redistribute or modify this Program under the terms of
* the GNU General Public License version 2 as published by the Free
* Software Foundation.
*
* 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
* version 2 along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
/**
* \file
*
* \author Brian Rectanus <brectanu@gmail.com>
*/
#ifndef __DETECT_BYTEJUMP_H__
#define __DETECT_BYTEJUMP_H__
/** Bytejump Base */
#define DETECT_BYTEJUMP_BASE_UNSET 0 /**< Unset type value string (automatic)*/
#define DETECT_BYTEJUMP_BASE_OCT 8 /**< "oct" type value string */
#define DETECT_BYTEJUMP_BASE_DEC 10 /**< "dec" type value string */
#define DETECT_BYTEJUMP_BASE_HEX 16 /**< "hex" type value string */
/** Bytejump Flags */
#define DETECT_BYTEJUMP_BEGIN 0x01 /**< "from_beginning" jump */
#define DETECT_BYTEJUMP_LITTLE 0x02 /**< "little" endian value */
#define DETECT_BYTEJUMP_BIG 0x04 /**< "big" endian value */
#define DETECT_BYTEJUMP_STRING 0x08 /**< "string" value */
#define DETECT_BYTEJUMP_RELATIVE 0x10 /**< "relative" offset */
#define DETECT_BYTEJUMP_ALIGN 0x20 /**< "align" offset */
#define DETECT_BYTEJUMP_DCE 0x40 /**< "dce" enabled */
#define DETECT_BYTEJUMP_OFFSET_BE 0x80 /**< "byte extract" enabled */
typedef struct DetectBytejumpData_ {
uint8_t nbytes; /**< Number of bytes to compare */
uint8_t base; /**< String value base (oct|dec|hex) */
uint8_t flags; /**< Flags (big|little|relative|string) */
uint32_t multiplier; /**< Multiplier for nbytes (multiplier n)*/
int32_t offset; /**< Offset in payload to extract value */
int32_t post_offset; /**< Offset to adjust post-jump */
} DetectBytejumpData;
/* prototypes */
/**
* Registration function for byte_jump.
*
* \todo add support for no_stream and stream_only
*/
void DetectBytejumpRegister (void);
/**
* This function is used to add the parsed byte_jump data
* into the current signature.
*
* \param de_ctx pointer to the Detection Engine Context
* \param s pointer to the Current Signature
* \param optstr pointer to the user provided options
*
* \retval 0 on Success
* \retval -1 on Failure
*/
int DetectBytejumpSetup(DetectEngineCtx *, Signature *, char *);
/**
* \brief this function will free memory associated with DetectBytejumpData
*
* \param data pointer to DetectBytejumpData
*/
void DetectBytejumpFree(void *ptr);
/**
* This function is used to parse byte_jump options passed via
*
* byte_jump: bytes, offset [,flags [, ...]]
*
* flags: "big", "little", "relative", "string", "oct", "dec", "hex"
* "align", "from beginning", "multiplier N", "post_offset N"
*
* \param optstr Pointer to the user provided byte_jump options
* \param offset Used to pass the offset back, if byte_jump uses a byte_extract
* var.
*
* \retval data pointer to DetectBytejumpData on success
* \retval NULL on failure
*/
DetectBytejumpData *DetectBytejumpParse(char *optstr, char **offset);
/**
* This function is used to match byte_jump
*
* \param t pointer to thread vars
* \param det_ctx pointer to the pattern matcher thread
* \param p pointer to the current packet
* \param m pointer to the sigmatch that we will cast into DetectBytejumpData
*
* \retval -1 error
* \retval 0 no match
* \retval 1 match
*
* \todo The return seems backwards. We should return a non-zero error code.
* One of the error codes is "no match". As-is if someone accidentally
* does: if (DetectBytejumpMatch(...)) { match }, then they catch an
* error as a match.
*/
int DetectBytejumpMatch(ThreadVars *t, DetectEngineThreadCtx *det_ctx,
Packet *p, Signature *s, const SigMatchCtx *ctx);
int DetectBytejumpDoMatch(DetectEngineThreadCtx *, Signature *, const SigMatchCtx *,
uint8_t *, uint32_t, uint8_t, int32_t);
#endif /* __DETECT_BYTEJUMP_H__ */
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