/*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that: (1) source code
* distributions retain the above copyright notice and this paragraph
* in its entirety, and (2) distributions including binary code include
* the above copyright notice and this paragraph in its entirety in
* the documentation or other materials provided with the distribution.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND
* WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
* LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE.
*
* Original code by Francesco Fondelli (francesco dot fondelli, gmail dot com)
*/

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: print-vxlan.c,v 1.5 2024/09/02 16:15:33 christos Exp $");
#endif

/* \summary: Virtual eXtensible Local Area Network (VXLAN) printer */

/* specification: RFC 7348 */

#include <config.h>

#include "netdissect-stdinc.h"

#define ND_LONGJMP_FROM_TCHECK
#include "netdissect.h"
#include "extract.h"

static const struct tok vxlan_flags [] = {
   { 0x08, "I" },
   { 0, NULL }
};
#define VXLAN_HDR_LEN 8

/*
* VXLAN header, RFC7348
*               Virtual eXtensible Local Area Network (VXLAN): A Framework
*               for Overlaying Virtualized Layer 2 Networks over Layer 3 Networks
*
*     0                   1                   2                   3
*     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
*    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*    |R|R|R|R|I|R|R|R|            Reserved                           |
*    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*    |                VXLAN Network Identifier (VNI) |   Reserved    |
*    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/

void
vxlan_print(netdissect_options *ndo, const u_char *bp, u_int len)
{
   uint8_t flags;
   uint32_t vni;

   ndo->ndo_protocol = "vxlan";
   nd_print_protocol_caps(ndo);
   if (len < VXLAN_HDR_LEN)
       goto invalid;

   flags = GET_U_1(bp);
   bp += 1;
   ND_PRINT(", flags [%s] (0x%02x), ",
            bittok2str_nosep(vxlan_flags, "invalid", flags), flags);

   /* 1st Reserved */
   bp += 3;

   vni = GET_BE_U_3(bp);
   bp += 3;
   ND_PRINT("vni %u\n", vni);

   /* 2nd Reserved */
   ND_TCHECK_1(bp);
   bp += 1;

   ether_print(ndo, bp, len - VXLAN_HDR_LEN, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);

   return;

invalid:
   nd_print_invalid(ndo);
}