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/*
* netsniff-ng - the packet sniffing beast
* Copyright 2012 Markus Amend <markus@netsniff-ng.org>, Deutsche Flugsicherung GmbH
* Subject to the GPL, version 2.
*
* IPv6 Hop-By-Hop Header described in RFC2460
*/
#include <stdio.h>
#include <stdint.h>
#include <netinet/in.h> /* for ntohs() */
#include "proto.h"
#include "protos.h"
#include "dissector_eth.h"
#include "built_in.h"
#include "pkt_buff.h"
struct hop_by_hophdr {
uint8_t h_next_header;
uint8_t hdr_len;
} __packed;
static void dissect_opt_hop(struct pkt_buff *pkt __maybe_unused,
ssize_t *opt_len)
{
/* Have to been upgraded.
* http://tools.ietf.org/html/rfc2460#section-4.2
* Look also for proto_ipv6_dest_opts.h, it needs
* dissect_opt(), too.
*/
if (*opt_len)
tprintf(", Option(s) recognized ");
/* If adding dissector reduce opt_len for each using of pkt_pull
* to the same size.
*/
}
static void hop_by_hop(struct pkt_buff *pkt)
{
uint16_t hdr_ext_len;
ssize_t opt_len;
struct hop_by_hophdr *hop_ops;
hop_ops = (struct hop_by_hophdr *) pkt_pull(pkt, sizeof(*hop_ops));
if (hop_ops == NULL)
return;
/* Total Header Length in Bytes */
hdr_ext_len = (hop_ops->hdr_len + 1) * 8;
/* Options length in Bytes */
opt_len = hdr_ext_len - sizeof(*hop_ops);
tprintf("\t [ Hop-by-Hop Options ");
tprintf("NextHdr (%u), ", hop_ops->h_next_header);
if (opt_len > pkt_len(pkt) || opt_len < 0){
tprintf("HdrExtLen (%u, %u Bytes, %s)", hop_ops->hdr_len,
hdr_ext_len, colorize_start_full(black, red)
"invalid" colorize_end());
return;
}
tprintf("HdrExtLen (%u, %u Bytes)", hop_ops->hdr_len,
hdr_ext_len);
dissect_opt_hop(pkt, &opt_len);
tprintf(" ]\n");
pkt_pull(pkt, opt_len);
pkt_set_proto(pkt, ð_lay3, hop_ops->h_next_header);
}
static void hop_by_hop_less(struct pkt_buff *pkt)
{
uint16_t hdr_ext_len;
ssize_t opt_len;
struct hop_by_hophdr *hop_ops;
hop_ops = (struct hop_by_hophdr *) pkt_pull(pkt, sizeof(*hop_ops));
if (hop_ops == NULL)
return;
/* Total Header Length in Bytes */
hdr_ext_len = (hop_ops->hdr_len + 1) * 8;
/* Options length in Bytes */
opt_len = hdr_ext_len - sizeof(*hop_ops);
if (opt_len > pkt_len(pkt) || opt_len < 0)
return;
tprintf(" Hop Ops");
pkt_pull(pkt, opt_len);
pkt_set_proto(pkt, ð_lay3, hop_ops->h_next_header);
}
struct protocol ipv6_hop_by_hop_ops = {
.key = 0x0,
.print_full = hop_by_hop,
.print_less = hop_by_hop_less,
};
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