|
|
|
/* 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 Victor Julien <victor@inliniac.net>
|
|
|
|
*
|
|
|
|
* Implements the depth keyword
|
|
|
|
*/
|
|
|
|
|
|
|
|
#include "suricata-common.h"
|
|
|
|
|
|
|
|
#include "decode.h"
|
|
|
|
|
|
|
|
#include "detect.h"
|
|
|
|
#include "detect-parse.h"
|
|
|
|
#include "detect-content.h"
|
|
|
|
#include "detect-uricontent.h"
|
|
|
|
|
|
|
|
#include "flow-var.h"
|
|
|
|
|
|
|
|
#include "util-debug.h"
|
|
|
|
|
|
|
|
static int DetectDepthSetup (DetectEngineCtx *, Signature *, char *);
|
|
|
|
|
|
|
|
void DetectDepthRegister (void) {
|
|
|
|
sigmatch_table[DETECT_DEPTH].name = "depth";
|
|
|
|
sigmatch_table[DETECT_DEPTH].Match = NULL;
|
|
|
|
sigmatch_table[DETECT_DEPTH].Setup = DetectDepthSetup;
|
|
|
|
sigmatch_table[DETECT_DEPTH].Free = NULL;
|
|
|
|
sigmatch_table[DETECT_DEPTH].RegisterTests = NULL;
|
|
|
|
|
|
|
|
sigmatch_table[DETECT_DEPTH].flags |= SIGMATCH_PAYLOAD;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int DetectDepthSetup (DetectEngineCtx *de_ctx, Signature *s, char *depthstr)
|
|
|
|
{
|
|
|
|
char *str = depthstr;
|
|
|
|
char dubbed = 0;
|
|
|
|
|
|
|
|
/* strip "'s */
|
|
|
|
if (depthstr[0] == '\"' && depthstr[strlen(depthstr)-1] == '\"') {
|
|
|
|
str = SCStrdup(depthstr+1);
|
|
|
|
str[strlen(depthstr)-2] = '\0';
|
|
|
|
dubbed = 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
/** Search for the first previous DetectContent or uricontent
|
|
|
|
* SigMatch (it can be the same as this one) */
|
|
|
|
SigMatch *pm = SigMatchGetLastPattern(s);
|
|
|
|
if (pm == NULL) {
|
|
|
|
SCLogError(SC_ERR_DEPTH_MISSING_CONTENT, "depth needs a preceeding "
|
|
|
|
"content or uricontent option");
|
|
|
|
if (dubbed) SCFree(str);
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
|
|
|
|
switch (pm->type) {
|
|
|
|
case DETECT_URICONTENT:
|
|
|
|
{
|
|
|
|
DetectUricontentData *ud = (DetectUricontentData *)pm->ctx;
|
|
|
|
if (ud == NULL) {
|
|
|
|
SCLogError(SC_ERR_INVALID_ARGUMENT, "invalid argument");
|
|
|
|
if (dubbed) SCFree(str);
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
ud->depth = (uint32_t)atoi(str);
|
|
|
|
if (ud->uricontent_len + ud->offset > ud->depth) {
|
|
|
|
uint32_t depth = (ud->depth > ud->uricontent_len) ?
|
|
|
|
ud->depth : ud->uricontent_len;
|
|
|
|
ud->depth = ud->offset + depth;
|
|
|
|
|
|
|
|
SCLogDebug("depth increased to %"PRIu32" to match pattern len "
|
|
|
|
"and offset", ud->depth);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
case DETECT_CONTENT:
|
|
|
|
{
|
|
|
|
DetectContentData *cd = (DetectContentData *)pm->ctx;
|
|
|
|
if (cd == NULL) {
|
|
|
|
SCLogError(SC_ERR_INVALID_ARGUMENT, "invalid argument");
|
|
|
|
if (dubbed) SCFree(str);
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
cd->depth = (uint32_t)atoi(str);
|
|
|
|
if (cd->content_len + cd->offset > cd->depth) {
|
|
|
|
uint32_t depth = (cd->depth > cd->content_len) ?
|
|
|
|
cd->depth : cd->content_len;
|
|
|
|
cd->depth = cd->offset + depth;
|
|
|
|
|
|
|
|
SCLogDebug("depth increased to %"PRIu32" to match pattern len "
|
|
|
|
"and offset", cd->depth);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
default:
|
|
|
|
SCLogError(SC_ERR_DEPTH_MISSING_CONTENT, "depth needs a preceeding "
|
|
|
|
"content (or uricontent) option");
|
|
|
|
if (dubbed) SCFree(str);
|
|
|
|
return -1;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (dubbed) SCFree(str);
|
|
|
|
return 0;
|
|
|
|
}
|