denyhosts/clamav/libclamav/matcher-ac.h

185 lines
6.2 KiB
C

/*
* Copyright (C) 2013-2022 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
* Copyright (C) 2007-2013 Sourcefire, Inc.
*
* Authors: Tomasz Kojm
*
* This program is free software; you can redistribute it and/or modify
* it 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
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
#ifndef __MATCHER_AC_H
#define __MATCHER_AC_H
#include <sys/types.h>
#include "filetypes.h"
#include "clamav-types.h"
#include "fmap.h"
#include "hashtab.h"
#define AC_CH_MAXDIST 32
#define ACPATT_ALTN_MAXNEST 15
/* AC scanning modes */
#define AC_SCAN_VIR 1
#define AC_SCAN_FT 2
/* Pattern options */
#define ACPATT_OPTION_NOOPTS 0x00
#define ACPATT_OPTION_NOCASE 0x01
#define ACPATT_OPTION_FULLWORD 0x02
#define ACPATT_OPTION_WIDE 0x04
#define ACPATT_OPTION_ASCII 0x08
#define ACPATT_OPTION_ONCE 0x80
struct cli_subsig_matches {
uint32_t last;
uint32_t next;
uint32_t offsets[16]; /* offsets[] is variable length */
};
struct cli_lsig_matches {
uint32_t subsigs;
struct cli_subsig_matches *matches[1]; /* matches[] is variable length */
};
typedef struct cli_ac_data {
uint32_t ***offmatrix;
uint32_t partsigs, lsigs, reloffsigs;
uint32_t **lsigcnt;
uint32_t **lsigsuboff_last, **lsigsuboff_first;
struct cli_lsig_matches **lsig_matches;
uint8_t *yr_matches;
uint32_t *offset;
uint32_t macro_lastmatch[32];
/** Hashset for versioninfo matching */
const struct cli_hashset *vinfo;
uint32_t min_partno;
} cli_ac_data;
struct cli_alt_node {
uint16_t *str;
uint16_t len;
uint8_t unique;
struct cli_alt_node *next;
};
struct cli_ac_special {
union {
unsigned char *byte;
unsigned char **f_str;
struct cli_alt_node *v_str;
} alt;
uint16_t len[2], num; /* 0=MIN, 1=MAX */
uint16_t type, negative;
};
struct cli_ac_patt {
uint16_t *pattern, *prefix, length[3], prefix_length[3];
uint32_t mindist, maxdist;
uint32_t sigid;
uint32_t lsigid[3];
uint16_t ch[2];
char *virname;
void *customdata;
uint16_t ch_mindist[2];
uint16_t ch_maxdist[2];
uint16_t parts, partno, special, special_pattern;
struct cli_ac_special **special_table;
uint16_t rtype, type;
uint32_t offdata[4], offset_min, offset_max;
uint32_t boundary;
uint8_t depth;
uint8_t sigopts;
};
struct cli_ac_list {
struct cli_ac_patt *me;
union {
struct cli_ac_node *node;
struct cli_ac_list *next;
};
struct cli_ac_list *next_same;
};
struct cli_ac_node {
struct cli_ac_list *list;
struct cli_ac_node **trans, *fail;
};
#define IS_LEAF(node) (!node->trans)
#define IS_FINAL(node) (!!node->list)
struct cli_ac_result {
const char *virname;
void *customdata;
off_t offset;
struct cli_ac_result *next;
};
#include "matcher.h"
/**
* @brief Add a simple sub-pattern into the AC trie.
*
* Simple sub-patterns may not include any wildcards or [a-b] anchored byte ranges.
*/
cl_error_t cli_ac_addpatt(struct cli_matcher *root, struct cli_ac_patt *pattern);
/**
* @brief Increment the count for a subsignature of a logical signature.
*
* This is and alternative to lsig_increment_subsig_match() for use in subsigs that don't have a specific offset,
* like byte-compare subsigs and fuzzy-hash subsigs.
*/
void lsig_increment_subsig_match(struct cli_ac_data *mdata, uint32_t lsig_id, uint32_t subsig_id);
cl_error_t cli_ac_initdata(struct cli_ac_data *data, uint32_t partsigs, uint32_t lsigs, uint32_t reloffsigs, uint8_t tracklen);
/**
* @brief Increment the count for a subsignature of a logical signature.
*
* Increment a logical signature subsignature match count.
*
* @param root The root storing all pattern matching data. I.e. "the database in memory."
* @param mdata Match result data
* @param lsig_id The current logical signature id
* @param subsig_id The current subsignature id
* @param realoff Offset where the match occured
* @param partial 0 if whole pattern, or >0 for a partial-patterns. That is one split with wildcards like * or {n-m}.
* @return cl_error_t
*/
cl_error_t lsig_sub_matched(const struct cli_matcher *root, struct cli_ac_data *mdata, uint32_t lsig_id, uint32_t subsig_id, uint32_t realoff, int partial);
cl_error_t cli_ac_chkmacro(struct cli_matcher *root, struct cli_ac_data *data, unsigned lsigid1);
int cli_ac_chklsig(const char *expr, const char *end, uint32_t *lsigcnt, unsigned int *cnt, uint64_t *ids, unsigned int parse_only);
void cli_ac_freedata(struct cli_ac_data *data);
cl_error_t cli_ac_scanbuff(const unsigned char *buffer, uint32_t length, const char **virname, void **customdata, struct cli_ac_result **res, const struct cli_matcher *root, struct cli_ac_data *mdata, uint32_t offset, cli_file_t ftype, struct cli_matched_type **ftoffset, unsigned int mode, cli_ctx *ctx);
cl_error_t cli_ac_buildtrie(struct cli_matcher *root);
cl_error_t cli_ac_init(struct cli_matcher *root, uint8_t mindepth, uint8_t maxdepth, uint8_t dconf_prefiltering);
cl_error_t cli_ac_caloff(const struct cli_matcher *root, struct cli_ac_data *data, const struct cli_target_info *info);
void cli_ac_free(struct cli_matcher *root);
/**
* @brief Add a complex sub-pattern into the AC trie.
*
* Complex sub-patterns are the body content between `{n-m}` and `{*}` wildcards in content match signatures.
* And `{n}` wildcards should have already been replaced with `??` characters and are included in the patterns.
*/
cl_error_t cli_ac_addsig(struct cli_matcher *root, const char *virname, const char *hexsig, uint8_t sigopts, uint32_t sigid, uint16_t parts, uint16_t partno, uint16_t rtype, uint16_t type, uint32_t mindist, uint32_t maxdist, const char *offset, const uint32_t *lsigid, unsigned int options);
#endif