/*

OLSR MDNS plugin.

Written by Saverio Proto <zioproto@gmail.com> and Claudio Pisa <clauz@ninux.org>.

    This file is part of OLSR MDNS PLUGIN.

    The OLSR MDNS PLUGIN is free software: you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by

    the Free Software Foundation, either version 3 of the License, or

    (at your option) any later version.

    The OLSR MDNS PLUGIN is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License

    along with Foobar.  If not, see <http://www.gnu.org/licenses/>.

 */

#ifndef _MDNS_PACKET_H

#define _MDNS_PACKET_H

/* System includes */

#include <net/if.h> /* IFNAMSIZ, IFHWADDRLEN */

#include <sys/types.h> /* u_int8_t, u_int16_t */

/* BMF-encapsulated packets are Ethernet-IP-UDP packets, which start

 * with a 8-bytes BMF header (struct TEncapHeader), followed by the

 * encapsulated Ethernet-IP packet itself */

struct TEncapHeader

{

  /* Use a standard Type-Length-Value (TLV) element */

  u_int8_t type;

  u_int8_t len;

  u_int16_t reserved; /* Always 0 */

  u_int32_t crc32;

} __attribute__((__packed__));

#define ENCAP_HDR_LEN ((int)sizeof(struct TEncapHeader))

#define BMF_ENCAP_TYPE 1

#define BMF_ENCAP_LEN 6

struct TSaveTtl

{

  u_int8_t ttl;

  u_int16_t check;

} __attribute__((__packed__));

int IsIpFragment(unsigned char* ipPacket);

u_int16_t GetIpTotalLength(unsigned char* ipPacket);

unsigned int GetIpHeaderLength(unsigned char* ipPacket);

u_int8_t GetTtl(unsigned char* ipPacket);

void SaveTtlAndChecksum(unsigned char* ipPacket, struct TSaveTtl* sttl);

void RestoreTtlAndChecksum(unsigned char* ipPacket, struct TSaveTtl* sttl);

void DecreaseTtlAndUpdateHeaderChecksum(unsigned char* ipPacket);

struct ip* GetIpHeader(unsigned char* encapsulationUdpData);

unsigned char* GetIpPacket(unsigned char* encapsulationUdpData);

#endif /* _MDNS_PACKET_H */