libclamav/matcher-ac.c
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 /*
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  *  Copyright (C) 2002 - 2007 Tomasz Kojm <tkojm@clamav.net>
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  *
  *  This program is free software; you can redistribute it and/or modify
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  *  it under the terms of the GNU General Public License version 2 as
  *  published by the Free Software Foundation.
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  *
  *  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
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  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  *  MA 02110-1301, USA.
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  */
 
 #if HAVE_CONFIG_H
 #include "clamav-config.h"
 #endif
 
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
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 #ifdef	HAVE_UNISTD_H
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 #include <unistd.h>
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 #endif
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 #include "clamav.h"
 #include "others.h"
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 #include "matcher.h"
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 #include "matcher-ac.h"
 #include "filetypes.h"
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 #include "cltypes.h"
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 #include "str.h"
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 int cli_ac_addpatt(struct cli_matcher *root, struct cli_ac_patt *pattern)
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 {
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 	struct cli_ac_node *pt, *next, **newtable;
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 	uint8_t i;
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 	uint16_t len = MIN(root->ac_maxdepth, pattern->length);
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     for(i = 0; i < len; i++) {
 	if(pattern->pattern[i] & CLI_MATCH_WILDCARD) {
 	    len = i;
 	    break;
 	}
     }
 
     if(len < root->ac_mindepth)
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 	return CL_EPATSHORT;
 
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     pt = root->ac_root;
 
     for(i = 0; i < len; i++) {
 	if(!pt->trans) {
 	    pt->trans = (struct cli_ac_node **) cli_calloc(256, sizeof(struct cli_ac_node *));
 	    if(!pt->trans) {
 		cli_errmsg("cli_ac_addpatt: Can't allocate memory for pt->trans\n");
 		return CL_EMEM;
 	    }
 	}
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 	next = pt->trans[(unsigned char) (pattern->pattern[i] & 0xff)]; 
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 	if(!next) {
 	    next = (struct cli_ac_node *) cli_calloc(1, sizeof(struct cli_ac_node));
 	    if(!next) {
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 		cli_errmsg("cli_ac_addpatt: Can't allocate memory for AC node\n");
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 		return CL_EMEM;
 	    }
 
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 	    if(i != len - 1) {
 		next->trans = (struct cli_ac_node **) cli_calloc(256, sizeof(struct cli_ac_node *));
 		if(!next->trans) {
 		    cli_errmsg("cli_ac_addpatt: Can't allocate memory for next->trans\n");
 		    free(next);
 		    return CL_EMEM;
 		}
 	    } else {
 		next->leaf = 1;
 	    }
 
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 	    root->ac_nodes++;
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 	    newtable = (struct cli_ac_node **) cli_realloc(root->ac_nodetable, root->ac_nodes * sizeof(struct cli_ac_node *));
 	    if(!newtable) {
 		root->ac_nodes--;
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 		cli_errmsg("cli_ac_addpatt: Can't realloc ac_nodetable\n");
 		if(next->trans)
 		    free(next->trans);
 		free(next);
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 		return CL_EMEM;
 	    }
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 	    newtable[root->ac_nodes - 1] = next;
 	    root->ac_nodetable = newtable;
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 	    pt->trans[(unsigned char) (pattern->pattern[i] & 0xff)] = next;
 	    pt->leaf = 0;
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 	}
 
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 	pt = next;
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     }
 
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     root->ac_patterns++;
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     root->ac_pattable = (struct cli_ac_patt **) cli_realloc2(root->ac_pattable, root->ac_patterns * sizeof(struct cli_ac_patt *));
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     if(!root->ac_pattable) {
 	cli_errmsg("cli_ac_addpatt: Can't realloc ac_pattable\n");
 	return CL_EMEM;
     }
     root->ac_pattable[root->ac_patterns - 1] = pattern;
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     pt->final = 1;
     pattern->depth = i;
     pattern->next = pt->list;
     pt->list = pattern;
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     return CL_SUCCESS;
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 }
 
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 struct bfs_list {
     struct cli_ac_node *node;
     struct bfs_list *next;
 };
 
 static int bfs_enqueue(struct bfs_list **bfs, struct cli_ac_node *n)
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 {
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 	struct bfs_list *new;
 
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     new = (struct bfs_list *) cli_malloc(sizeof(struct bfs_list));
     if(!new) {
 	cli_errmsg("bfs_enqueue: Can't allocate memory for bfs_list\n");
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 	return CL_EMEM;
     }
     new->next = *bfs;
     new->node = n;
     *bfs = new;
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     return CL_SUCCESS;
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 }
 
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 static struct cli_ac_node *bfs_dequeue(struct bfs_list **bfs)
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 {
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 	struct bfs_list *lpt, *prev = NULL;
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 	struct cli_ac_node *pt;
 
 
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     lpt = *bfs;
     while(lpt && lpt->next) {
 	prev = lpt;
 	lpt = lpt->next;
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     }
 
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     if(!lpt) {
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 	return NULL;
     } else {
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 	pt = lpt->node;
 	free(lpt);
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 	if(prev)
 	    prev->next = NULL;
 	else
 	    *bfs = NULL;
 
 	return pt;
     }
 }
 
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 static int ac_maketrans(struct cli_matcher *root)
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 {
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 	struct bfs_list *bfs = NULL;
 	struct cli_ac_node *ac_root = root->ac_root, *child, *node, *fail;
 	struct cli_ac_patt *patt;
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 	int i, ret;
 
 
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     for(i = 0; i < 256; i++) {
 	node = ac_root->trans[i];
 	if(!node) {
 	    ac_root->trans[i] = ac_root;
 	} else {
 	    node->fail = ac_root;
 	    if((ret = bfs_enqueue(&bfs, node)))
 		return ret;
 	}
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     }
 
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     while((node = bfs_dequeue(&bfs))) {
 	if(node->leaf)
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 	    continue;
 
 	for(i = 0; i < 256; i++) {
 	    child = node->trans[i];
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 	    if(child) {
 		fail = node->fail;
 		while(fail->leaf || !fail->trans[i])
 		    fail = fail->fail;
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 		child->fail = fail->trans[i];
 
 		if(child->list) {
 		    patt = child->list;
 		    while(patt->next)
 			patt = patt->next;
 
 		    patt->next = child->fail->list;
 		} else {
 		    child->list = child->fail->list;
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 		}
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 		if(child->list)
 		    child->final = 1;
 
 		if((ret = bfs_enqueue(&bfs, child)) != 0)
 		    return ret;
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 	    }
 	}
     }
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     return CL_SUCCESS;
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 }
 
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 int cli_ac_buildtrie(struct cli_matcher *root)
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 {
     if(!root)
 	return CL_EMALFDB;
 
     if(!root->ac_root) {
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 	cli_dbgmsg("cli_ac_buildtrie: AC pattern matcher is not initialised\n");
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 	return CL_SUCCESS;
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     }
 
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     return ac_maketrans(root);
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 }
 
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 int cli_ac_init(struct cli_matcher *root, uint8_t mindepth, uint8_t maxdepth)
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 {
 
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     root->ac_root = (struct cli_ac_node *) cli_calloc(1, sizeof(struct cli_ac_node));
     if(!root->ac_root) {
 	cli_errmsg("cli_ac_init: Can't allocate memory for ac_root\n");
 	return CL_EMEM;
     }
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     root->ac_root->trans = (struct cli_ac_node **) cli_calloc(256, sizeof(struct cli_ac_node *));
     if(!root->ac_root->trans) {
 	cli_errmsg("cli_ac_init: Can't allocate memory for ac_root->trans\n");
 	free(root->ac_root);
 	return CL_EMEM;
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     }
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     root->ac_mindepth = mindepth;
     root->ac_maxdepth = maxdepth;
 
     return CL_SUCCESS;
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 }
 
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 void cli_ac_free(struct cli_matcher *root)
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 {
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 	uint32_t i, j;
 	struct cli_ac_patt *patt;
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     for(i = 0; i < root->ac_patterns; i++) {
 	patt = root->ac_pattable[i];
 
 	if(patt->prefix)
 	    free(patt->prefix);
 	else
 	    free(patt->pattern);
 	free(patt->virname);
 	if(patt->offset)
 	    free(patt->offset);
 	if(patt->alt) {
 	    free(patt->altn);
 	    for(j = 0; j < patt->alt; j++)
 		free(patt->altc[j]);
 	    free(patt->altc);
 	}
 	free(patt);
     }
     if(root->ac_pattable)
 	free(root->ac_pattable);
 
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     for(i = 0; i < root->ac_nodes; i++) {
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 	if(!root->ac_nodetable[i]->leaf)
 	    free(root->ac_nodetable[i]->trans);
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 	free(root->ac_nodetable[i]);
     }
 
     if(root->ac_nodetable)
 	free(root->ac_nodetable);
 
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     if(root->ac_root) {
 	free(root->ac_root->trans);
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 	free(root->ac_root);
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     }
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 }
 
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 #define AC_MATCH_CHAR(p,b)						\
     switch(wc = p & CLI_MATCH_WILDCARD) {				\
 	case CLI_MATCH_ALTERNATIVE:					\
 	    found = 0;							\
 	    for(j = 0; j < pattern->altn[alt]; j++) {			\
 		if(pattern->altc[alt][j] == b) {			\
 		    found = 1;						\
 		    break;						\
 		}							\
 	    }								\
 	    if(!found)							\
 		return 0;						\
 	    alt++;							\
 	    break;							\
 									\
 	case CLI_MATCH_NIBBLE_HIGH:					\
 	    if((unsigned char) (p & 0x00f0) != (b & 0xf0))		\
 		return 0;						\
 	    break;							\
 									\
 	case CLI_MATCH_NIBBLE_LOW:					\
 	    if((unsigned char) (p & 0x000f) != (b & 0x0f))		\
 		return 0;						\
 	    break;							\
 									\
 	default:							\
 	    if(wc != CLI_MATCH_IGNORE && (unsigned char) p != b)	\
 		return 0;						\
     }
 
 inline static int ac_findmatch(const unsigned char *buffer, uint32_t offset, uint32_t length, const struct cli_ac_patt *pattern)
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 {
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 	uint32_t bp;
 	uint16_t wc, i, j, alt = pattern->alt_pattern;
 	uint8_t found;
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     if(offset + pattern->length > length)
 	return 0;
 
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     if(pattern->prefix)
 	if(pattern->prefix_length > offset)
 	    return 0;
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     bp = offset + pattern->depth;
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     for(i = pattern->depth; i < pattern->length; i++) {
 	AC_MATCH_CHAR(pattern->pattern[i],buffer[bp]);
 	bp++;
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     }
 
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     if(pattern->prefix) {
 	alt = 0;
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 	bp = offset - pattern->prefix_length;
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 	for(i = 0; i < pattern->prefix_length; i++) {
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 	    AC_MATCH_CHAR(pattern->prefix[i],buffer[bp]);
 	    bp++;
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 	}
     }
 
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     return 1;
 }
 
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 int cli_ac_initdata(struct cli_ac_data *data, uint32_t partsigs, uint8_t tracklen)
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 {
 
     if(!data) {
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 	cli_errmsg("cli_ac_init: data == NULL\n");
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 	return CL_ENULLARG;
     }
 
     data->partsigs = partsigs;
 
     if(!partsigs)
 	return CL_SUCCESS;
 
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     data->offmatrix = (int32_t ***) cli_calloc(partsigs, sizeof(int32_t **));
     if(!data->offmatrix) {
 	cli_errmsg("cli_ac_init: Can't allocate memory for data->offmatrix\n");
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 	return CL_EMEM;
     }
 
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     return CL_SUCCESS;
 }
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 void cli_ac_freedata(struct cli_ac_data *data)
 {
 	uint32_t i;
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fbcef1b0
     if(data && data->partsigs) {
 	for(i = 0; i < data->partsigs; i++) {
 	    if(data->offmatrix[i]) {
 		free(data->offmatrix[i][0]);
 		free(data->offmatrix[i]);
 	    }
 	}
 	free(data->offmatrix);
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     }
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 }
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 inline static int ac_addtype(struct cli_matched_type **list, cli_file_t type, off_t offset)
 {
 	struct cli_matched_type *tnode, *tnode_last;
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     if(*list && (*list)->cnt >= MAX_EMBEDDED_OBJ)
 	return CL_SUCCESS;
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     if(!(tnode = cli_calloc(1, sizeof(struct cli_matched_type)))) {
 	cli_errmsg("cli_ac_addtype: Can't allocate memory for new type node\n");
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 	return CL_EMEM;
     }
 
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     tnode->type = type;
     tnode->offset = offset;
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     tnode_last = *list;
     while(tnode_last && tnode_last->next)
 	tnode_last = tnode_last->next;
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     if(tnode_last)
 	tnode_last->next = tnode;
     else
 	*list = tnode;
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     (*list)->cnt++;
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     return CL_SUCCESS;
 }
 
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 int cli_ac_scanbuff(const unsigned char *buffer, uint32_t length, const char **virname, const struct cli_matcher *root, struct cli_ac_data *mdata, uint8_t otfrec, uint32_t offset, cli_file_t ftype, int fd, struct cli_matched_type **ftoffset)
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 {
 	struct cli_ac_node *current;
 	struct cli_ac_patt *pt;
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         uint32_t i, bp, realoff;
 	uint16_t j;
 	int32_t **offmatrix;
 	uint8_t found;
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 	struct cli_target_info info;
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 	int type = CL_CLEAN;
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     if(!root->ac_root)
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 	return CL_CLEAN;
 
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     if(!mdata) {
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 	cli_errmsg("cli_ac_scanbuff: mdata == NULL\n");
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 	return CL_ENULLARG;
     }
 
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     memset(&info, 0, sizeof(info));
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     current = root->ac_root;
 
     for(i = 0; i < length; i++)  {
 
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 	while(current->leaf || !current->trans[buffer[i]])
 	    current = current->fail;
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 	current = current->trans[buffer[i]];
 
 	if(current->final) {
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 	    pt = current->list;
 	    while(pt) {
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 		bp = i + 1 - pt->depth;
 		if(ac_findmatch(buffer, bp, length, pt)) {
 		    realoff = offset + bp - pt->prefix_length;
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 		    if((pt->offset || pt->target) && (!pt->sigid || pt->partno == 1)) {
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 			if((fd == -1 && !ftype) || !cli_validatesig(ftype, pt->offset, realoff, &info, fd, pt->virname)) {
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 			    pt = pt->next;
 			    continue;
 			}
 		    }
 
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 		    if(pt->sigid) { /* it's a partial signature */
 
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 			if(!mdata->offmatrix[pt->sigid - 1]) {
 			    mdata->offmatrix[pt->sigid - 1] = cli_malloc(pt->parts * sizeof(int32_t *));
 			    if(!mdata->offmatrix[pt->sigid - 1]) {
 				cli_errmsg("cli_ac_scanbuff: Can't allocate memory for mdata->offmatrix[%u]\n", pt->sigid - 1);
 				return CL_EMEM;
 			    }
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 			    mdata->offmatrix[pt->sigid - 1][0] = cli_malloc(pt->parts * (AC_DEFAULT_TRACKLEN + 1) * sizeof(int32_t));
 			    if(!mdata->offmatrix[pt->sigid - 1][0]) {
 				cli_errmsg("cli_ac_scanbuff: Can't allocate memory for mdata->offmatrix[%u][0]\n", pt->sigid - 1);
 				free(mdata->offmatrix[pt->sigid - 1]);
 				mdata->offmatrix[pt->sigid - 1] = NULL;
 				return CL_EMEM;
 			    }
 			    memset(mdata->offmatrix[pt->sigid - 1][0], -1, pt->parts * (AC_DEFAULT_TRACKLEN + 1) * sizeof(int32_t));
 			    mdata->offmatrix[pt->sigid - 1][0][0] = 0;
 			    for(j = 1; j < pt->parts; j++) {
 				mdata->offmatrix[pt->sigid - 1][j] = mdata->offmatrix[pt->sigid - 1][0] + j * (AC_DEFAULT_TRACKLEN + 1);
 				 mdata->offmatrix[pt->sigid - 1][j][0] = 0;
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 			    }
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 			}
 			offmatrix = mdata->offmatrix[pt->sigid - 1];
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 			if(pt->partno != 1) {
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 			    found = 0;
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 			    for(j = 1; j <= AC_DEFAULT_TRACKLEN && offmatrix[pt->partno - 2][j] != -1; j++) {
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 				found = 1;
 				if(pt->maxdist)
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 				    if(realoff - offmatrix[pt->partno - 2][j] > pt->maxdist)
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 					found = 0;
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4e9ab8ed
 				if(found && pt->mindist)
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 				    if(realoff - offmatrix[pt->partno - 2][j] < pt->mindist)
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 					found = 0;
 
 				if(found)
 				    break;
 			    }
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 			}
4e9ab8ed
 
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 			if(pt->partno == 1 || (found && (pt->partno != pt->parts))) {
 			    offmatrix[pt->partno - 1][0] %= (AC_DEFAULT_TRACKLEN + 1);
 			    if(!offmatrix[pt->partno - 1][0])
 				offmatrix[pt->partno - 1][0]++;
 
 			    offmatrix[pt->partno - 1][offmatrix[pt->partno - 1][0]] = realoff + pt->length;
 			    if(pt->partno) /* save realoff for the first part */
 				offmatrix[pt->parts - 1][offmatrix[pt->partno - 1][0]] = realoff;
 			} else if(found && pt->partno == pt->parts) {
 			    if(pt->type) {
 				if(otfrec) {
 				    if(pt->type > type || pt->type >= CL_TYPE_SFX || pt->type == CL_TYPE_MSEXE) {
 					cli_dbgmsg("Matched signature for file type %s\n", pt->virname);
 					type = pt->type;
 					if(ftoffset && (!*ftoffset || (*ftoffset)->cnt < MAX_EMBEDDED_OBJ) && ((ftype == CL_TYPE_MSEXE && type >= CL_TYPE_SFX) || ((ftype == CL_TYPE_MSEXE || ftype == CL_TYPE_ZIP) && type == CL_TYPE_MSEXE)))  {
 					    /* FIXME: we don't know which offset of the first part is the correct one */
 					    for(j = 1; j <= AC_DEFAULT_TRACKLEN && offmatrix[0][j] != -1; j++) {
 						if(ac_addtype(ftoffset, type, offmatrix[pt->parts - 1][j])) {
 						    if(info.exeinfo.section)
 							free(info.exeinfo.section);
 						    return CL_EMEM;
a85bd2ac
 						}
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 					    }
 					}
 
fbcef1b0
 					memset(offmatrix[0], -1, pt->parts * (AC_DEFAULT_TRACKLEN + 1) * sizeof(int32_t));
 					for(j = 0; j < pt->parts; j++)
 					    offmatrix[j][0] = 0;
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 				    }
 				}
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 			    } else { /* !pt->type */
 				if(virname)
 				    *virname = pt->virname;
 
 				if(info.exeinfo.section)
 				    free(info.exeinfo.section);
 
 				return CL_VIRUS;
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 			    }
 			}
 
 		    } else { /* old type signature */
 			if(pt->type) {
b68d11d2
 			    if(otfrec) {
ee99255a
 				if(pt->type > type || pt->type >= CL_TYPE_SFX || pt->type == CL_TYPE_MSEXE) {
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 				    cli_dbgmsg("Matched signature for file type %s at %u\n", pt->virname, realoff);
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 				    type = pt->type;
ee99255a
 				    if(ftoffset && (!*ftoffset || (*ftoffset)->cnt < MAX_EMBEDDED_OBJ) && ((ftype == CL_TYPE_MSEXE && type >= CL_TYPE_SFX) || ((ftype == CL_TYPE_MSEXE || ftype == CL_TYPE_ZIP) && type == CL_TYPE_MSEXE)))  {
fbcef1b0
 
 					if(ac_addtype(ftoffset, type, realoff)) {
841161e0
 					    if(info.exeinfo.section)
 						free(info.exeinfo.section);
a85bd2ac
 					    return CL_EMEM;
 					}
 				    }
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 				}
 			    }
 			} else {
 			    if(virname)
 				*virname = pt->virname;
 
841161e0
 			    if(info.exeinfo.section)
 				free(info.exeinfo.section);
8000d078
 			    return CL_VIRUS;
 			}
 		    }
 		}
 
 		pt = pt->next;
 	    }
 	}
     }
 
841161e0
     if(info.exeinfo.section)
 	free(info.exeinfo.section);
 
b68d11d2
     return otfrec ? type : CL_CLEAN;
8000d078
 }
fbcef1b0
 
 /* FIXME: clean up the code */
 int cli_ac_addsig(struct cli_matcher *root, const char *virname, const char *hexsig, uint32_t sigid, uint16_t parts, uint16_t partno, uint16_t type, uint32_t mindist, uint32_t maxdist, const char *offset, uint8_t target)
 {
 	struct cli_ac_patt *new;
 	char *pt, *hex = NULL;
 	uint16_t i, j, ppos = 0, pend;
 	uint8_t wprefix = 0, error = 0, namelen, plen = 0;
 	int ret;
 
 #define FREE_ALT			\
     if(new->alt) {			\
 	free(new->altn);		\
 	for(i = 0; i < new->alt; i++)	\
 	    free(new->altc[i]);		\
 	free(new->altc);		\
 	free(hex);			\
     }
 
     if(strlen(hexsig) / 2 < root->ac_mindepth)
 	return CL_EPATSHORT;
 
     if((new = (struct cli_ac_patt *) cli_calloc(1, sizeof(struct cli_ac_patt))) == NULL)
 	return CL_EMEM;
 
     new->type = type;
     new->sigid = sigid;
     new->parts = parts;
     new->partno = partno;
     new->mindist = mindist;
     new->maxdist = maxdist;
     new->target = target;
     if(offset) {
 	new->offset = cli_strdup(offset);
 	if(!new->offset) {
 	    free(new);
 	    return CL_EMEM;
 	}
     }
 
     if(strchr(hexsig, '(')) {
 	    char *hexcpy, *hexnew, *start, *h, *c;
 
 	if(!(hexcpy = cli_strdup(hexsig))) {
 	    if(new->offset)
 		free(new->offset);
 	    free(new);
 	    return CL_EMEM;
 	}
 
 	if(!(hexnew = (char *) cli_calloc(strlen(hexsig) + 1, 1))) {
 	    free(hexcpy);
 	    if(new->offset)
 		free(new->offset);
 	    free(new);
 	    return CL_EMEM;
 	}
 
 	start = pt = hexcpy;
 	while((pt = strchr(start, '('))) {
 	    *pt++ = 0;
 
 	    if(!start) {
 		error = 1;
 		break;
 	    }
 
 	    strcat(hexnew, start);
 	    strcat(hexnew, "()");
 
 	    if(!(start = strchr(pt, ')'))) {
 		error = 1;
 		break;
 	    }
 	    *start++ = 0;
 
 	    new->alt++;
84fd5a61
 	    new->altn = (uint16_t *) cli_realloc2(new->altn, new->alt * sizeof(uint16_t));
fbcef1b0
 	    new->altn[new->alt - 1] = 0;
84fd5a61
 	    new->altc = (unsigned char **) cli_realloc2(new->altc, new->alt * sizeof(char *));
fbcef1b0
 	    new->altc[new->alt - 1] = NULL;
 
 	    for(i = 0; i < strlen(pt); i++)
 		if(pt[i] == '|')
 		    new->altn[new->alt - 1]++;
 
 	    if(!new->altn[new->alt - 1]) {
 		error = 1;
 		break;
 	    } else
 		new->altn[new->alt - 1]++;
 
 	    if(!(new->altc[new->alt - 1] = (unsigned char *) cli_calloc(new->altn[new->alt - 1], 1))) {
 		error = 1;
 		break;
 	    }
 
 	    for(i = 0; i < new->altn[new->alt - 1]; i++) {
 		if((h = cli_strtok(pt, i, "|")) == NULL) {
 		    error = 1;
 		    break;
 		}
 
 		if((c = cli_hex2str(h)) == NULL) {
 		    free(h);
 		    error = 1;
 		    break;
 		}
 
 		new->altc[new->alt - 1][i] = *c;
 		free(c);
 		free(h);
 	    }
 
 	    if(error)
 		break;
 	}
 
 	if(start)
 	    strcat(hexnew, start);
 
 	hex = hexnew;
 	free(hexcpy);
 
 	if(error) {
 	    FREE_ALT;
 	    if(new->offset)
 		free(new->offset);
 	    free(new);
 	    return CL_EMALFDB;
 	}
     }
 
     if((new->pattern = cli_hex2ui(new->alt ? hex : hexsig)) == NULL) {
 	FREE_ALT;
 	if(new->offset)
 	    free(new->offset);
 	free(new);
 	return CL_EMALFDB;
     }
 
     new->length = strlen(new->alt ? hex : hexsig) / 2;
 
     for(i = 0; i < root->ac_maxdepth && i < new->length; i++) {
 	if(new->pattern[i] & CLI_MATCH_WILDCARD) {
 	    wprefix = 1;
 	    break;
 	}
     }
 
     if(wprefix) {
 	pend = new->length - root->ac_mindepth + 1;
 	for(i = 0; i < pend; i++) {
 	    for(j = i; j < i + root->ac_maxdepth && j < new->length; j++) {
 		if(new->pattern[j] & CLI_MATCH_WILDCARD) {
 		    break;
 		} else {
 		    if(j - i + 1 > plen) {
 			plen = j - i + 1;
 			ppos = i;
 		    }
 		}
 		if(plen >= root->ac_maxdepth)
 		    break;
 	    }
 	    if(plen >= root->ac_maxdepth)
 		break;
 	}
 
 	if(plen < root->ac_mindepth) {
 	    cli_errmsg("cli_ac_addsig: Can't find a static subpattern of length %u\n", root->ac_mindepth);
 	    FREE_ALT;
 	    if(new->offset)
 		free(new->offset);
 	    free(new->pattern);
 	    free(new);
 	    return CL_EMALFDB;
 	}
 
 	new->prefix = new->pattern;
 	new->prefix_length = ppos;
 	new->pattern = &new->prefix[ppos];
 	new->length -= ppos;
 
 	for(i = 0; i < new->prefix_length; i++)
 	    if((new->prefix[i] & CLI_MATCH_WILDCARD) == CLI_MATCH_ALTERNATIVE)
 		new->alt_pattern++;
     }
 
     if(new->length > root->maxpatlen)
 	root->maxpatlen = new->length;
 
     if((pt = strstr(virname, " (Clam)")))
 	namelen = strlen(virname) - strlen(pt);
     else
 	namelen = strlen(virname);
 
     if(!namelen) {
 	cli_errmsg("cli_ac_addsig: No virus name\n");
 	if(new->prefix)
 	    free(new->prefix);
 	else
 	    free(new->pattern);
 	FREE_ALT;
 	if(new->offset)
 	    free(new->offset);
 	free(new);
 	return CL_EMALFDB;
     }
 
     if((new->virname = cli_calloc(namelen + 1, sizeof(char))) == NULL) {
 	if(new->prefix)
 	    free(new->prefix);
 	else
 	    free(new->pattern);
 	FREE_ALT;
 	if(new->offset)
 	    free(new->offset);
 	free(new);
 	return CL_EMEM;
     }
     strncpy(new->virname, virname, namelen);
 
     if((ret = cli_ac_addpatt(root, new))) {
 	if(new->prefix)
 	    free(new->prefix);
 	else
 	    free(new->pattern);
 	free(new->virname);
 	FREE_ALT;
 	if(new->offset)
 	    free(new->offset);
 	free(new);
 	return ret;
     }
 
     if(new->alt)
 	free(hex);
 
     return CL_SUCCESS;
 }