/* 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-renewal-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 renewal 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 DetectDHCPRenewalTimeMatch(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_renewal_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 DetectDHCPRenewalTimeFree(DetectEngineCtx *de_ctx, void *ptr)

{

    rs_detect_u64_free(ptr);

}

/**

 * \brief Function to add the parsed dhcp renewal 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 DetectDHCPRenewalTimeSetup(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_RENEWAL_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_RENEWAL_TIME;

    sm->ctx = (void *)dd;

    SigMatchAppendSMToList(s, sm, g_buffer_id);

    return 0;

error:

    DetectDHCPRenewalTimeFree(de_ctx, dd);

    return -1;

}

/**

 * \brief Registration function for dhcp.procedure keyword.

 */

void DetectDHCPRenewalTimeRegister(void)

{

    sigmatch_table[DETECT_AL_DHCP_RENEWAL_TIME].name = "dhcp.renewal_time";

    sigmatch_table[DETECT_AL_DHCP_RENEWAL_TIME].desc = "match DHCP renewal time";

    sigmatch_table[DETECT_AL_DHCP_RENEWAL_TIME].url = "/rules/dhcp-keywords.html#dhcp-renewal-time";

    sigmatch_table[DETECT_AL_DHCP_RENEWAL_TIME].AppLayerTxMatch = DetectDHCPRenewalTimeMatch;

    sigmatch_table[DETECT_AL_DHCP_RENEWAL_TIME].Setup = DetectDHCPRenewalTimeSetup;

    sigmatch_table[DETECT_AL_DHCP_RENEWAL_TIME].Free = DetectDHCPRenewalTimeFree;

    DetectAppLayerInspectEngineRegister2("dhcp.renewal-time", ALPROTO_DHCP, SIG_FLAG_TOSERVER, 0,

            DetectEngineInspectGenericList, NULL);

    DetectAppLayerInspectEngineRegister2("dhcp.renewal-time", ALPROTO_DHCP, SIG_FLAG_TOCLIENT, 0,

            DetectEngineInspectGenericList, NULL);

    g_buffer_id = DetectBufferTypeGetByName("dhcp.renewal-time");

}