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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.
*/
#include "suricata-common.h"
#include "rust.h"
#include "detect-dhcp-rebinding-time.h"
#include "detect-engine.h"
#include "detect-engine-mpm.h"
#include "detect-engine-prefilter.h"
#include "detect-engine-uint.h"
#include "detect-parse.h"
static int g_buffer_id = 0;
/**
* \internal
* \brief Function to match rebinding time of a TX
*
* \param t Pointer to thread vars.
* \param det_ctx Pointer to the pattern matcher thread.
* \param f Pointer to the current flow.
* \param flags Flags.
* \param state App layer state.
* \param s Pointer to the Signature.
* \param m Pointer to the sigmatch that we will cast into
* DetectU64Data.
*
* \retval 0 no match.
* \retval 1 match.
*/
static int DetectDHCPRebindingTimeMatch(DetectEngineThreadCtx *det_ctx, Flow *f, uint8_t flags,
void *state, void *txv, const Signature *s, const SigMatchCtx *ctx)
{
SCEnter();
uint64_t res;
if (rs_dhcp_tx_get_rebinding_time(txv, &res)) {
const DetectU64Data *dd = (const DetectU64Data *)ctx;
if (DetectU64Match(res, dd)) {
SCReturnInt(1);
}
}
SCReturnInt(0);
}
/**
* \internal
* \brief Function to free memory associated with DetectU64Data.
*
* \param de_ptr Pointer to DetectU64Data.
*/
static void DetectDHCPRebindingTimeFree(DetectEngineCtx *de_ctx, void *ptr)
{
rs_detect_u64_free(ptr);
}
/**
* \brief Function to add the parsed dhcp rebinding time field into the current signature.
*
* \param de_ctx Pointer to the Detection Engine Context.
* \param s Pointer to the Current Signature.
* \param rawstr Pointer to the user provided flags options.
* \param type Defines if this is notBefore or notAfter.
*
* \retval 0 on Success.
* \retval -1 on Failure.
*/
static int DetectDHCPRebindingTimeSetup(DetectEngineCtx *de_ctx, Signature *s, const char *rawstr)
{
if (DetectSignatureSetAppProto(s, ALPROTO_DHCP) != 0)
return -1;
DetectU64Data *dd = DetectU64Parse(rawstr);
if (dd == NULL) {
SCLogError("Parsing \'%s\' failed for %s", rawstr,
sigmatch_table[DETECT_AL_DHCP_REBINDING_TIME].name);
return -1;
}
/* okay so far so good, lets get this into a SigMatch
* and put it in the Signature. */
SigMatch *sm = SigMatchAlloc();
if (sm == NULL)
goto error;
sm->type = DETECT_AL_DHCP_REBINDING_TIME;
sm->ctx = (void *)dd;
SigMatchAppendSMToList(s, sm, g_buffer_id);
return 0;
error:
DetectDHCPRebindingTimeFree(de_ctx, dd);
return -1;
}
/**
* \brief Registration function for dhcp.procedure keyword.
*/
void DetectDHCPRebindingTimeRegister(void)
{
sigmatch_table[DETECT_AL_DHCP_REBINDING_TIME].name = "dhcp.rebinding_time";
sigmatch_table[DETECT_AL_DHCP_REBINDING_TIME].desc = "match DHCP rebinding time";
sigmatch_table[DETECT_AL_DHCP_REBINDING_TIME].url =
"/rules/dhcp-keywords.html#dhcp-rebinding-time";
sigmatch_table[DETECT_AL_DHCP_REBINDING_TIME].AppLayerTxMatch = DetectDHCPRebindingTimeMatch;
sigmatch_table[DETECT_AL_DHCP_REBINDING_TIME].Setup = DetectDHCPRebindingTimeSetup;
sigmatch_table[DETECT_AL_DHCP_REBINDING_TIME].Free = DetectDHCPRebindingTimeFree;
DetectAppLayerInspectEngineRegister2("dhcp.rebinding-time", ALPROTO_DHCP, SIG_FLAG_TOSERVER, 0,
DetectEngineInspectGenericList, NULL);
DetectAppLayerInspectEngineRegister2("dhcp.rebinding-time", ALPROTO_DHCP, SIG_FLAG_TOCLIENT, 0,
DetectEngineInspectGenericList, NULL);
g_buffer_id = DetectBufferTypeGetByName("dhcp.rebinding-time");
}
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