/*

    mtr  --  a network diagnostic tool

    Copyright (C) 2016  Matt Kimball

    This program is free software; you can redistribute it and/or modify

    it under the terms of the GNU General Public License version 2 as

    published by the Free Software Foundation.

    This program 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 this program; if not, write to the Free Software

    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#ifndef PROTOCOLS_H

#define PROTOCOLS_H

/*  ICMPv4 type codes  */

#define ICMP_ECHOREPLY 0

#define ICMP_DEST_UNREACH 3

#define ICMP_ECHO 8

#define ICMP_TIME_EXCEEDED 11

/*  ICMP_DEST_UNREACH codes */

#define ICMP_PORT_UNREACH 3

/*  ICMPv6 type codes  */

#define ICMP6_DEST_UNREACH 1

#define ICMP6_TIME_EXCEEDED 3

#define ICMP6_ECHO 128

#define ICMP6_ECHOREPLY 129

/*  ICMP6_DEST_UNREACH codes */

#define ICMP6_PORT_UNREACH 4

/*

    The minimum size of the ICMP "original datagram" when

    using ICMP extensions

*/

#define ICMP_ORIGINAL_DATAGRAM_MIN_SIZE 128

/*  The classnum and type of MPLS labels in an ICMP extension object  */

#define ICMP_EXT_MPLS_CLASSNUM 1

#define ICMP_EXT_MPLS_CTYPE 1

#define HTTP_PORT 80

/*  We can't rely on header files to provide this information, because

    the fields have different names between, for instance, Linux and 

    Solaris  */

struct ICMPHeader {

    uint8_t type;

    uint8_t code;

    uint16_t checksum;

    uint16_t id;

    uint16_t sequence;

};

/*  ICMP extension header, which might contain MPLS labels  */

/*  See RFC 4884  */

struct ICMPExtensionHeader {

    uint8_t version;

    uint8_t reserved;

    uint16_t checksum;

};

/*  An object in an extended ICMP object  */

struct ICMPExtensionObject {

    uint16_t len;

    uint8_t classnum;

    uint8_t ctype;

};

/*  An MPLS label included in an ICMP extension  */

/*  See RFC 4950  */

struct ICMPExtMPLSLabel {

    uint8_t label[3];           // Low 4 bits are Experimental Use, Stack

    uint8_t ttl;

};

/* Structure of an UDP header.  */

struct UDPHeader {

    uint16_t srcport;

    uint16_t dstport;

    uint16_t length;

    uint16_t checksum;

};

/* Structure of an TCP header, as far as we need it.  */

struct TCPHeader {

    uint16_t srcport;

    uint16_t dstport;

    uint32_t seq;

};

/* Structure of an SCTP header */

struct SCTPHeader {

    uint16_t srcport;

    uint16_t dstport;

    uint32_t veri_tag;

};

/* Structure of an IPv4 UDP pseudoheader.  */

struct UDPPseudoHeader {

    uint32_t saddr;

    uint32_t daddr;

    uint8_t zero;

    uint8_t protocol;

    uint16_t len;

};

/*  Structure of an IP header.  */

struct IPHeader {

    uint8_t version;

    uint8_t tos;

    uint16_t len;

    uint16_t id;

    uint16_t frag;

    uint8_t ttl;

    uint8_t protocol;

    uint16_t check;

    uint32_t saddr;

    uint32_t daddr;

};

/*  IP version 6 header  */

struct IP6Header {

    uint8_t version;

    uint8_t flow[3];

    uint16_t len;

    uint8_t protocol;

    uint8_t ttl;

    uint8_t saddr[16];

    uint8_t daddr[16];

};

/*  The pseudo-header used for checksum computation for ICMPv6 and UDPv6  */

struct IP6PseudoHeader {

    uint8_t saddr[16];

    uint8_t daddr[16];

    uint32_t len;

    uint8_t zero[3];

    uint8_t protocol;

};

#endif