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/* ethernet.c */
/*
* Routines for taking ethernet packets apart.
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is the MPEG TS, PS and ES tools.
*
* The Initial Developer of the Original Code is Amino Communications Ltd.
* Portions created by the Initial Developer are Copyright (C) 2008
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Richard Watts, Kynesim <rrw@kynesim.co.uk>
*
* ***** END LICENSE BLOCK *****
*/
#include "ethernet.h"
#include <string.h>
#include "misc_fns.h"
int ethernet_packet_from_pcap(pcaprec_hdr_t *hdr,
const uint8_t *data,
const uint32_t len,
ethernet_packet_t *pkt,
uint32_t *out_st,
uint32_t *out_len)
{
uint32_t eoh;
const uint8_t *p = data;
const uint8_t * const eop = data + len;
pkt->vlan_count = 0;
// 14 bytes of src,dest,type ..
if (len < 14)
{
return ETHERNET_ERR_PKT_TOO_SHORT;
}
// PCap doesn't store CRCs - it stores [dst] [src] [type]
memcpy(pkt->dst_addr, p, 6);
p += 6;
memcpy(pkt->src_addr, p, 6);
p += 6;
// Type/Length is big-endian.
pkt->typeorlen = uint_16_be(p);
p += 2;
// 0x5DC is the maximum frame length in IEEE 802.3 - anything
// above that here is a type.
//
// Length is just the data length.
if (pkt->typeorlen <= 0x5DC)
{
(*out_len) = pkt->typeorlen;
eoh = 14;
}
else
{
// Look for VLAN
while (pkt->typeorlen == 0x8100)
{
if (pkt->vlan_count >= ETHERNET_VLANS_MAX)
{
return ETHERNET_ERR_TOO_MANY_VLANS;
}
if (p + 4 > eop)
{
return ETHERNET_ERR_PKT_TOO_SHORT;
}
pkt->vlans[pkt->vlan_count].pcp = (p[0] >> 5) & 7;
pkt->vlans[pkt->vlan_count].cfi = (p[0] >> 4) & 1;
pkt->vlans[pkt->vlan_count].vid = uint_16_be(p) & 0xfff;
p += 2;
++pkt->vlan_count;
pkt->typeorlen = uint_16_be(p);
p += 2;
}
eoh = p - data;
// pcap doesn't store the checksum or pad ..
(*out_len) = len - eoh;
}
(*out_st) = eoh;
return 0;
}
/* End file */
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