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117 lines
2.9 KiB
C
117 lines
2.9 KiB
C
/* Copyright (C) 2020-2021 Open Information Security Foundation
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*
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* You can copy, redistribute or modify this Program under the terms of
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* the GNU General Public License version 2 as published by the Free
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* Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* version 2 along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*/
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/**
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* \ingroup decode
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*
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* @{
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*/
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/**
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* \file
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*
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* \author Victor Julien <victor@inliniac.net>
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*
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* Decodes ERSPAN Types I and II
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*/
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#include "suricata-common.h"
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#include "suricata.h"
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#include "decode.h"
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#include "decode-events.h"
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#include "decode-erspan.h"
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#include "util-validate.h"
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#include "util-unittest.h"
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#include "util-debug.h"
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#include "conf.h"
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/**
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* \brief Functions to decode ERSPAN Type I and II packets
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*/
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/*
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* \brief ERSPAN Type I was configurable in 5.0.x but is no longer configurable.
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*
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* Issue a warning if a configuration setting is found.
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*/
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void DecodeERSPANConfig(void)
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{
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int enabled = 0;
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if (ConfGetBool("decoder.erspan.typeI.enabled", &enabled) == 1) {
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SCLogWarning("ERSPAN Type I is no longer configurable and it is always"
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" enabled; ignoring configuration setting.");
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}
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}
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/**
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* \brief ERSPAN Type I
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*/
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int DecodeERSPANTypeI(ThreadVars *tv, DecodeThreadVars *dtv, Packet *p,
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const uint8_t *pkt, uint32_t len)
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{
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StatsIncr(tv, dtv->counter_erspan);
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return DecodeEthernet(tv, dtv, p, pkt, len);
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}
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/**
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* \brief ERSPAN Type II
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*/
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int DecodeERSPAN(ThreadVars *tv, DecodeThreadVars *dtv, Packet *p, const uint8_t *pkt, uint32_t len)
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{
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DEBUG_VALIDATE_BUG_ON(pkt == NULL);
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StatsIncr(tv, dtv->counter_erspan);
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if (len < sizeof(ErspanHdr)) {
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ENGINE_SET_EVENT(p,ERSPAN_HEADER_TOO_SMALL);
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return TM_ECODE_FAILED;
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}
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if (!PacketIncreaseCheckLayers(p)) {
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return TM_ECODE_FAILED;
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}
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const ErspanHdr *ehdr = (const ErspanHdr *)pkt;
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uint16_t version = SCNtohs(ehdr->ver_vlan) >> 12;
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uint16_t vlan_id = SCNtohs(ehdr->ver_vlan) & 0x0fff;
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SCLogDebug("ERSPAN: version %u vlan %u", version, vlan_id);
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/* only v1 is tested at this time */
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if (version != 1) {
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ENGINE_SET_EVENT(p,ERSPAN_UNSUPPORTED_VERSION);
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return TM_ECODE_FAILED;
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}
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if (vlan_id > 0) {
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if (p->vlan_idx > VLAN_MAX_LAYER_IDX) {
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ENGINE_SET_EVENT(p,ERSPAN_TOO_MANY_VLAN_LAYERS);
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return TM_ECODE_FAILED;
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}
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p->vlan_id[p->vlan_idx] = vlan_id;
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p->vlan_idx++;
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}
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return DecodeEthernet(tv, dtv, p, pkt + sizeof(ErspanHdr), len - sizeof(ErspanHdr));
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}
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/**
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* @}
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*/
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