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/*
* decode_vrrp.c
*
* Virtual Router Redundancy Protocol.
*
* Copyright (c) 2000 Eric Jackson <ericj@monkey.org>
* Copyright (c) 2000 Dug Song <dugsong@monkey.org>
*
* $Id: decode_vrrp.c,v 1.5 2001/03/15 08:33:03 dugsong Exp $
*/
#include "config.h"
#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <arpa/inet.h>
#include "buf.h"
#include "decode.h"
struct vrrp_header {
u_char vr_vers; /* Version */
u_char vr_vrid; /* Virtual Router ID */
u_char vr_prio; /* Router Priority */
u_char vr_naddr; /* # of addresses */
u_char vr_auth; /* Type of Authentication */
u_char vr_advr; /* ADVERTISEMENT Interval */
u_short vr_cksum; /* Checksum */
/* vr_naddr * 4 # of addresses */
};
#define VRRP_AUTH_NONE 0
#define VRRP_AUTH_SIMPLE 1
#define VRRP_AUTH_AH 2
#define VRRP_AUTH_DATA_LEN 8
int
decode_vrrp(u_char *buf, int len, u_char *obuf, int olen)
{
struct buf *b, inbuf, outbuf;
struct vrrp_header *vrrp;
buf_init(&inbuf, buf, len);
buf_init(&outbuf, obuf, olen);
vrrp = (struct vrrp_header *)buf_ptr(&inbuf);
if (buf_len(&inbuf) < sizeof(*vrrp))
return (0);
/* We only care about VRRP_AUTH_SIMPLE */
if (ntohs(vrrp->vr_auth) != VRRP_AUTH_SIMPLE)
return (0);
/* XXX - probably want to verify checksum */
/* Forward to Authentication Data */
buf_skip(&inbuf, sizeof(*vrrp) + 8 + (vrrp->vr_naddr * 4));
if ((b = buf_tok(&inbuf, NULL, VRRP_AUTH_DATA_LEN)) == NULL)
return (0);
buf_put(&outbuf, buf_ptr(b), buf_len(b));
buf_put(&outbuf, "\n", 1);
buf_end(&outbuf);
return (buf_len(&outbuf));
}
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