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/* Copyright (C) 2007-2021 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>
*
* Implements the sameip keyword.
*/
#include "suricata-common.h"
#include "decode.h"
#include "detect.h"
#include "detect-parse.h"
#include "detect-engine.h"
#include "detect-engine-mpm.h"
#include "detect-engine-build.h"
#include "detect-sameip.h"
#include "util-unittest.h"
#include "util-unittest-helper.h"
static int DetectSameipMatch(DetectEngineThreadCtx *, Packet *,
const Signature *, const SigMatchCtx *);
static int DetectSameipSetup(DetectEngineCtx *, Signature *, const char *);
#ifdef UNITTESTS
static void DetectSameipRegisterTests(void);
#endif
/**
* \brief Registration function for sameip: keyword
* \todo add support for no_stream and stream_only
*/
void DetectSameipRegister(void)
{
sigmatch_table[DETECT_SAMEIP].name = "sameip";
sigmatch_table[DETECT_SAMEIP].desc = "check if the IP address of the source is the same as the IP address of the destination";
sigmatch_table[DETECT_SAMEIP].url = "/rules/header-keywords.html#sameip";
sigmatch_table[DETECT_SAMEIP].Match = DetectSameipMatch;
sigmatch_table[DETECT_SAMEIP].Setup = DetectSameipSetup;
#ifdef UNITTESTS
sigmatch_table[DETECT_SAMEIP].RegisterTests = DetectSameipRegisterTests;
#endif
sigmatch_table[DETECT_SAMEIP].flags = SIGMATCH_NOOPT;
}
/**
* \internal
* \brief This function is used to match packets with same src/dst IPs
*
* \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 DetectSameipData
*
* \retval 0 no match
* \retval 1 match
*/
static int DetectSameipMatch(DetectEngineThreadCtx *det_ctx,
Packet *p, const Signature *s, const SigMatchCtx *ctx)
{
return CMP_ADDR(&p->src, &p->dst) ? 1 : 0;
}
/**
* \internal
* \brief this function is used to add the sameip option into the 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
*/
static int DetectSameipSetup(DetectEngineCtx *de_ctx, Signature *s, const char *optstr)
{
SigMatch *sm = NULL;
/* Get this into a SigMatch and put it in the Signature. */
sm = SigMatchAlloc();
if (sm == NULL)
goto error;
sm->type = DETECT_SAMEIP;
sm->ctx = NULL;
SigMatchAppendSMToList(s, sm, DETECT_SM_LIST_MATCH);
s->flags |= SIG_FLAG_REQUIRE_PACKET;
return 0;
error:
if (sm != NULL)
SCFree(sm);
return -1;
}
#ifdef UNITTESTS
#include "detect-engine-alert.h"
/* NOTE: No parameters, so no parse tests */
/**
* \internal
* \brief This test tests sameip success and failure.
*/
static int DetectSameipSigTest01(void)
{
uint8_t *buf = (uint8_t *)
"GET / HTTP/1.0\r\n"
"\r\n";
uint16_t buflen = strlen((char *)buf);
Packet *p1 = NULL;
Packet *p2 = NULL;
ThreadVars th_v;
DetectEngineThreadCtx *det_ctx;
memset(&th_v, 0, sizeof(th_v));
/* First packet has same IPs */
p1 = UTHBuildPacketSrcDst(buf, buflen, IPPROTO_TCP, "1.2.3.4", "1.2.3.4");
/* Second packet does not have same IPs */
p2 = UTHBuildPacketSrcDst(buf, buflen, IPPROTO_TCP, "1.2.3.4", "4.3.2.1");
DetectEngineCtx *de_ctx = DetectEngineCtxInit();
FAIL_IF_NULL(de_ctx);
de_ctx->flags |= DE_QUIET;
de_ctx->sig_list = SigInit(de_ctx,
"alert tcp any any -> any any "
"(msg:\"Testing sameip\"; sameip; sid:1;)");
FAIL_IF_NULL(de_ctx->sig_list);
SigGroupBuild(de_ctx);
DetectEngineThreadCtxInit(&th_v, (void *)de_ctx, (void *)&det_ctx);
SigMatchSignatures(&th_v, de_ctx, det_ctx, p1);
FAIL_IF(PacketAlertCheck(p1, 1) == 0);
SigMatchSignatures(&th_v, de_ctx, det_ctx, p2);
FAIL_IF(PacketAlertCheck(p2, 1) != 0);
DetectEngineThreadCtxDeinit(&th_v, (void *)det_ctx);
DetectEngineCtxFree(de_ctx);
PASS;
}
/**
* \internal
* \brief This function registers unit tests for DetectSameip
*/
static void DetectSameipRegisterTests(void)
{
UtRegisterTest("DetectSameipSigTest01", DetectSameipSigTest01);
}
#endif /* UNITTESTS */
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