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/* Copyright (C) 2022 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 Eric Leblond <el@stamus-networks.com>
*
* Offer source or destination IP as a sticky buffer.
*/
#include "suricata-common.h"
#include "decode.h"
#include "conf.h"
#include "detect.h"
#include "detect-parse.h"
#include "detect-engine.h"
#include "detect-engine-mpm.h"
#include "detect-engine-prefilter.h"
#include "detect-ipaddr.h"
#define KEYWORD_NAME_SRC "ip.src"
#define KEYWORD_NAME_DST "ip.dst"
static int DetectSrcIPAddrBufferSetup(DetectEngineCtx *, Signature *, const char *);
static int DetectDestIPAddrBufferSetup(DetectEngineCtx *, Signature *, const char *);
static InspectionBuffer *GetDataSrc(DetectEngineThreadCtx *det_ctx,
const DetectEngineTransforms *transforms, Packet *p, const int list_id);
static InspectionBuffer *GetDataDst(DetectEngineThreadCtx *det_ctx,
const DetectEngineTransforms *transforms, Packet *p, const int list_id);
#ifdef UNITTESTS
static void DetectIPAddrRegisterTests(void);
#endif
static int g_src_ipaddr_buffer_id = 0;
static int g_dest_ipaddr_buffer_id = 0;
void DetectIPAddrBufferRegister(void)
{
sigmatch_table[DETECT_IPADDR_SRC].name = KEYWORD_NAME_SRC;
sigmatch_table[DETECT_IPADDR_SRC].desc = "Sticky buffer for src_ip";
sigmatch_table[DETECT_IPADDR_SRC].url = "/rules/ipaddr.html#ip-src";
sigmatch_table[DETECT_IPADDR_SRC].Setup = DetectSrcIPAddrBufferSetup;
#ifdef UNITTESTS
sigmatch_table[DETECT_IPADDR_SRC].RegisterTests = DetectIPAddrRegisterTests;
#endif
sigmatch_table[DETECT_IPADDR_SRC].flags |= SIGMATCH_NOOPT | SIGMATCH_INFO_STICKY_BUFFER;
g_src_ipaddr_buffer_id = DetectBufferTypeRegister(KEYWORD_NAME_SRC);
BUG_ON(g_src_ipaddr_buffer_id < 0);
DetectBufferTypeSupportsPacket(KEYWORD_NAME_SRC);
DetectPktMpmRegister(KEYWORD_NAME_SRC, 2, PrefilterGenericMpmPktRegister, GetDataSrc);
DetectPktInspectEngineRegister(
KEYWORD_NAME_SRC, GetDataSrc, DetectEngineInspectPktBufferGeneric);
sigmatch_table[DETECT_IPADDR_DST].name = KEYWORD_NAME_DST;
sigmatch_table[DETECT_IPADDR_DST].desc = "Sticky buffer for dest_ip";
sigmatch_table[DETECT_IPADDR_DST].url = "/rules/ipaddr.html#ip-dst";
sigmatch_table[DETECT_IPADDR_DST].Setup = DetectDestIPAddrBufferSetup;
sigmatch_table[DETECT_IPADDR_DST].flags |= SIGMATCH_NOOPT | SIGMATCH_INFO_STICKY_BUFFER;
g_dest_ipaddr_buffer_id = DetectBufferTypeRegister(KEYWORD_NAME_DST);
BUG_ON(g_dest_ipaddr_buffer_id < 0);
DetectBufferTypeSupportsPacket(KEYWORD_NAME_DST);
DetectPktMpmRegister(KEYWORD_NAME_DST, 2, PrefilterGenericMpmPktRegister, GetDataDst);
DetectPktInspectEngineRegister(
KEYWORD_NAME_DST, GetDataDst, DetectEngineInspectPktBufferGeneric);
SCLogDebug("IPAddr detect registered.");
}
static int DetectSrcIPAddrBufferSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
{
/* store list id. Content, pcre, etc will be added to the list at this
* id. */
s->init_data->list = g_src_ipaddr_buffer_id;
return 0;
}
static int DetectDestIPAddrBufferSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
{
/* store list id. Content, pcre, etc will be added to the list at this
* id. */
s->init_data->list = g_dest_ipaddr_buffer_id;
return 0;
}
/** \internal
* \brief get the data to inspect from the buffer
*
* \retval buffer or NULL in case of error
*/
static InspectionBuffer *GetDataSrc(DetectEngineThreadCtx *det_ctx,
const DetectEngineTransforms *transforms, Packet *p, const int list_id)
{
InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
if (buffer->inspect == NULL) {
if (PKT_IS_IPV4(p)) {
/* Suricata stores the IPv4 at the beginning of the field */
InspectionBufferSetup(det_ctx, list_id, buffer, p->src.address.address_un_data8, 4);
} else if (PKT_IS_IPV6(p)) {
InspectionBufferSetup(det_ctx, list_id, buffer, p->src.address.address_un_data8, 16);
} else {
return NULL;
}
InspectionBufferApplyTransforms(buffer, transforms);
}
return buffer;
}
/** \internal
* \brief get the data to inspect from the buffer
*
* \retval buffer or NULL in case of error
*/
static InspectionBuffer *GetDataDst(DetectEngineThreadCtx *det_ctx,
const DetectEngineTransforms *transforms, Packet *p, const int list_id)
{
InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
if (buffer->inspect == NULL) {
if (PKT_IS_IPV4(p)) {
/* Suricata stores the IPv4 at the beginning of the field */
InspectionBufferSetup(det_ctx, list_id, buffer, p->dst.address.address_un_data8, 4);
} else if (PKT_IS_IPV6(p)) {
InspectionBufferSetup(det_ctx, list_id, buffer, p->dst.address.address_un_data8, 16);
} else {
return NULL;
}
InspectionBufferApplyTransforms(buffer, transforms);
}
return buffer;
}
#ifdef UNITTESTS
#include "tests/detect-ipaddr.c"
#endif
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