/* Copyright (C) 2007-2022 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.

 */

/**

 * \ingroup decode

 *

 * @{

 */

/**

 * \file

 *

 * \author Breno Silva <breno.silva@gmail.com>

 *

 * Decode 802.1q

 */

#include "suricata-common.h"

#include "decode.h"

#include "decode-vlan.h"

#include "decode-events.h"

#include "util-validate.h"

#include "util-unittest.h"

#include "util-debug.h"

/**

 * \internal

 * \brief this function is used to decode IEEE802.1q packets

 *

 * \param tv pointer to the thread vars

 * \param dtv pointer code thread vars

 * \param p pointer to the packet struct

 * \param pkt pointer to the raw packet

 * \param len packet len

 * \param pq pointer to the packet queue

 *

 */

int DecodeVLAN(ThreadVars *tv, DecodeThreadVars *dtv, Packet *p,

        const uint8_t *pkt, uint32_t len)

{

    DEBUG_VALIDATE_BUG_ON(pkt == NULL);

    uint16_t proto;

    if (p->vlan_idx == 0)

        StatsIncr(tv, dtv->counter_vlan);

    else if (p->vlan_idx == 1)

        StatsIncr(tv, dtv->counter_vlan_qinq);

    else if (p->vlan_idx == 2)

        StatsIncr(tv, dtv->counter_vlan_qinqinq);

    if(len < VLAN_HEADER_LEN)    {

        ENGINE_SET_INVALID_EVENT(p, VLAN_HEADER_TOO_SMALL);

        return TM_ECODE_FAILED;

    }

    if (!PacketIncreaseCheckLayers(p)) {

        return TM_ECODE_FAILED;

    }

    if (p->vlan_idx > VLAN_MAX_LAYER_IDX) {

        ENGINE_SET_EVENT(p,VLAN_HEADER_TOO_MANY_LAYERS);

        return TM_ECODE_FAILED;

    }

    VLANHdr *vlan_hdr = (VLANHdr *)pkt;

    proto = GET_VLAN_PROTO(vlan_hdr);

    SCLogDebug("p %p pkt %p VLAN protocol %04x VLAN PRI %d VLAN CFI %d VLAN ID %d Len: %" PRIu32 "",

            p, pkt, proto, GET_VLAN_PRIORITY(vlan_hdr), GET_VLAN_CFI(vlan_hdr),

            GET_VLAN_ID(vlan_hdr), len);

    p->vlan_id[p->vlan_idx++] = (uint16_t)GET_VLAN_ID(vlan_hdr);

    if (DecodeNetworkLayer(tv, dtv, proto, p,

                pkt + VLAN_HEADER_LEN, len - VLAN_HEADER_LEN) == false) {

        ENGINE_SET_INVALID_EVENT(p, VLAN_UNKNOWN_TYPE);

        return TM_ECODE_FAILED;

    }

    return TM_ECODE_OK;

}

typedef struct IEEE8021ahHdr_ {

    uint32_t flags;

    uint8_t c_destination[6];

    uint8_t c_source[6];

    uint16_t type;              /**< next protocol */

}  __attribute__((__packed__)) IEEE8021ahHdr;

#define IEEE8021AH_HEADER_LEN sizeof(IEEE8021ahHdr)

int DecodeIEEE8021ah(ThreadVars *tv, DecodeThreadVars *dtv, Packet *p,

        const uint8_t *pkt, uint32_t len)

{

    DEBUG_VALIDATE_BUG_ON(pkt == NULL);

    StatsIncr(tv, dtv->counter_ieee8021ah);

    if (len < IEEE8021AH_HEADER_LEN) {

        ENGINE_SET_INVALID_EVENT(p, IEEE8021AH_HEADER_TOO_SMALL);

        return TM_ECODE_FAILED;

    }

    IEEE8021ahHdr *hdr = (IEEE8021ahHdr *)pkt;

    const uint16_t next_proto = SCNtohs(hdr->type);

    DecodeNetworkLayer(tv, dtv, next_proto, p,

            pkt + IEEE8021AH_HEADER_LEN, len - IEEE8021AH_HEADER_LEN);

    return TM_ECODE_OK;

}

#ifdef UNITTESTS

#include "util-unittest-helper.h"

#include "packet.h"

/** \todo Must GRE+VLAN and Multi-Vlan packets to

 * create more tests

 */

/**

 * \test DecodeVLANTest01 test if vlan header is too small.

 *

 *  \retval 1 on success

 *  \retval 0 on failure

 */

static int DecodeVLANtest01 (void)

{

    uint8_t raw_vlan[] = { 0x00, 0x20, 0x08 };

    Packet *p = PacketGetFromAlloc();

    if (unlikely(p == NULL))

        return 0;

    ThreadVars tv;

    DecodeThreadVars dtv;

    memset(&tv, 0, sizeof(ThreadVars));

    memset(&dtv, 0, sizeof(DecodeThreadVars));

    DecodeVLAN(&tv, &dtv, p, raw_vlan, sizeof(raw_vlan));

    if(ENGINE_ISSET_EVENT(p,VLAN_HEADER_TOO_SMALL))  {

        SCFree(p);

        return 1;

    }

    SCFree(p);

    return 0;

}

/**

 * \test DecodeVLANTest02 test if vlan header has unknown type.

 *

 *  \retval 1 on success

 *  \retval 0 on failure

 */

static int DecodeVLANtest02 (void)

{

    uint8_t raw_vlan[] = {

        0x00, 0x20, 0x01, 0x00, 0x45, 0x00, 0x00, 0x34,

        0x3b, 0x36, 0x40, 0x00, 0x40, 0x06, 0xb7, 0xc9,

        0x83, 0x97, 0x20, 0x81, 0x83, 0x97, 0x20, 0x15,

        0x04, 0x8a, 0x17, 0x70, 0x4e, 0x14, 0xdf, 0x55,

        0x4d, 0x3d, 0x5a, 0x61, 0x80, 0x10, 0x6b, 0x50,

        0x3c, 0x4c, 0x00, 0x00, 0x01, 0x01, 0x08, 0x0a,

        0x00, 0x04, 0xf0, 0xc8, 0x01, 0x99, 0xa3, 0xf3};

    Packet *p = PacketGetFromAlloc();

    if (unlikely(p == NULL))

        return 0;

    ThreadVars tv;

    DecodeThreadVars dtv;

    memset(&tv, 0, sizeof(ThreadVars));

    memset(&dtv, 0, sizeof(DecodeThreadVars));

    DecodeVLAN(&tv, &dtv, p, raw_vlan, sizeof(raw_vlan));

    if(ENGINE_ISSET_EVENT(p,VLAN_UNKNOWN_TYPE))  {

        SCFree(p);

        return 1;

    }

    SCFree(p);

    return 0;

}

/**

 * \test DecodeVLANTest02 test a good vlan header.

 *

 *  \retval 1 on success

 *  \retval 0 on failure

 */

static int DecodeVLANtest03 (void)

{

    uint8_t raw_vlan[] = {

        0x00, 0x20, 0x08, 0x00, 0x45, 0x00, 0x00, 0x34,

        0x3b, 0x36, 0x40, 0x00, 0x40, 0x06, 0xb7, 0xc9,

        0x83, 0x97, 0x20, 0x81, 0x83, 0x97, 0x20, 0x15,

        0x04, 0x8a, 0x17, 0x70, 0x4e, 0x14, 0xdf, 0x55,

        0x4d, 0x3d, 0x5a, 0x61, 0x80, 0x10, 0x6b, 0x50,

        0x3c, 0x4c, 0x00, 0x00, 0x01, 0x01, 0x08, 0x0a,

        0x00, 0x04, 0xf0, 0xc8, 0x01, 0x99, 0xa3, 0xf3};

    Packet *p = PacketGetFromAlloc();

    if (unlikely(p == NULL))

        return 0;

    ThreadVars tv;

    DecodeThreadVars dtv;

    memset(&tv, 0, sizeof(ThreadVars));

    memset(&dtv, 0, sizeof(DecodeThreadVars));

    FlowInitConfig(FLOW_QUIET);

    DecodeVLAN(&tv, &dtv, p, raw_vlan, sizeof(raw_vlan));

    if(p->vlan_id[0] == 0) {

        goto error;

    }

    if(ENGINE_ISSET_EVENT(p,VLAN_HEADER_TOO_SMALL))  {

        goto error;

    }

    if(ENGINE_ISSET_EVENT(p,VLAN_UNKNOWN_TYPE))  {

        goto error;

    }

    PacketRecycle(p);

    FlowShutdown();

    SCFree(p);

    return 1;

error:

    PacketRecycle(p);

    FlowShutdown();

    SCFree(p);

    return 0;

}

#endif /* UNITTESTS */

void DecodeVLANRegisterTests(void)

{

#ifdef UNITTESTS

    UtRegisterTest("DecodeVLANtest01", DecodeVLANtest01);

    UtRegisterTest("DecodeVLANtest02", DecodeVLANtest02);

    UtRegisterTest("DecodeVLANtest03", DecodeVLANtest03);

#endif /* UNITTESTS */

}

/**

 * @}

 */