library

/*! \file net.h \brief Network support library. */
//*****************************************************************************
//
// File Name    : 'net.h'
// Title                : Network support library
// Author               : Pascal Stang
// Created              : 8/30/2004
// Revised              : 7/3/2005
// Version              : 0.1
// Target MCU   : Atmel AVR series
// Editor Tabs  : 4
//
///     \ingroup network
///     \defgroup net Network support library (net.c)
///     \code #include "net/net.h" \endcode
///     \par Description
///             This is a general network support library including a multitude of 
///             structure definitions for various types of network packets, functions
///             and macros for switching byte order, and an RFC-compliant function
///             for calculating checksums.
//
//      This code is distributed under the GNU Public License
//              which can be found at http://www.gnu.org/licenses/gpl.txt
//*****************************************************************************
//@{

#ifndef NET_H
#define NET_H

#include <inttypes.h>
#include "global.h"

// Representation of a 48-bit Ethernet address.
struct netEthAddr
{
        uint8_t addr[6];
} GNUC_PACKED;

// The Ethernet header
struct netEthHeader
{
        struct netEthAddr dest;
        struct netEthAddr src;
        uint16_t type;
} GNUC_PACKED;

#define ETH_HEADER_LEN  14

#define ETHTYPE_ARP 0x0806
#define ETHTYPE_IP  0x0800
#define ETHTYPE_IP6 0x86dd 

// The ARP header
struct netArpHeader
{
        uint16_t        hwtype;
        uint16_t        protocol;
        uint8_t         hwlen;
        uint8_t         protolen;
        uint16_t        opcode;
        struct          netEthAddr shwaddr;
        uint32_t        sipaddr;
        struct          netEthAddr dhwaddr;
        uint32_t        dipaddr; 
} GNUC_PACKED;

#define ARP_OPCODE_REQUEST      1
#define ARP_OPCODE_REPLY        2
#define ARP_HWTYPE_ETH          1

// The IP header
struct netIpHeader
{
        uint8_t         vhl;
        uint8_t         tos;
        uint16_t        len;
        uint16_t        ipid;
        uint16_t        ipoffset;
        uint8_t         ttl;
        uint8_t         proto;
        uint16_t        ipchksum;
        uint32_t        srcipaddr;
        uint32_t        destipaddr;
} GNUC_PACKED;
#define IP_HEADER_LEN   20

#define IP_PROTO_ICMP   1
#define IP_PROTO_TCP    6
#define IP_PROTO_UDP    17

// The ICMP header
struct netIcmpHeader
{
        uint8_t         type;
        uint8_t         icode;
        uint16_t        icmpchksum;
        uint16_t        id;
        uint16_t        seqno;
} GNUC_PACKED;
#define ICMP_HEADER_LEN 8

#define ICMP_TYPE_ECHOREPLY             0
#define ICMP_TYPE_ECHOREQUEST   8

// The UDP header
struct netUdpHeader
{
        uint16_t        srcport;
        uint16_t        destport;
        uint16_t        udplen;
        uint16_t        udpchksum;
} GNUC_PACKED;
#define UDP_HEADER_LEN  8

// The TCP header
struct netTcpHeader
{
        uint16_t        srcport;
        uint16_t        destport;
        uint32_t        seqno;
        uint32_t        ackno;
        uint8_t         tcpoffset;
        uint8_t         flags;
        uint16_t        wnd;
        uint16_t        tcpchksum;
        uint16_t        urgp;
//      uint8_t         optdata[4];
} GNUC_PACKED;
#define TCP_HEADER_LEN  20

#define TCP_FLAGS_FIN   0x01
#define TCP_FLAGS_SYN   0x02
#define TCP_FLAGS_RST   0x04
#define TCP_FLAGS_PSH   0x08
#define TCP_FLAGS_ACK   0x10
#define TCP_FLAGS_URG   0x20

// Ethernet/ARP header
struct netEthArpHeader
{
        struct netEthHeader eth;
        struct netArpHeader arp;
} GNUC_PACKED;

// Ethernet/IP header
struct netEthIpHeader
{
        struct netEthHeader eth;
        struct netIpHeader  ip;
} GNUC_PACKED;

// The IP header
typedef struct netIpHeader ip_hdr;

// The IP/TCP headers
typedef struct
{
        struct netIpHeader  ip;
        struct netTcpHeader tcp;
} tcpip_hdr;

// The IP/ICMP headers
typedef struct {
        struct netIpHeader  ip;
        struct netIcmpHeader icmp;
} icmpip_hdr;


// The UDP and IP headers
typedef struct {
        struct netIpHeader  ip;
        struct netUdpHeader udp;
} udpip_hdr;


//! Convert dot-notation IP address into 32-bit word.
/// Example: IPDOT(192l,168l,1l,1l)
#define IPDOT(a,b,c,d)  ((a<<24)|(b<<16)|(c<<8)|(d))

//! Host-to-Network SHORT (16-bit) byte-order swap (macro).
#define HTONS(s)                ((s<<8) | (s>>8))
//! Host-to-Network LONG (32-bit) byte-order swap (macro).
#define HTONL(l)                ((l<<24) | ((l&0x00FF0000l)>>8) | ((l&0x0000FF00l)<<8) | (l>>24))

//! Host-to-Network SHORT (16-bit) byte-order swap (function).
uint16_t htons(uint16_t val);
//! Host-to-Network LONG (32-bit) byte-order swap (function).
uint32_t htonl(uint32_t val);

//! Calculate IP-style checksum from data.
uint16_t netChecksum(void *data, uint16_t len);

//! Print Ethernet address in XX:XX:XX:XX:XX:XX format.
void netPrintEthAddr(struct netEthAddr* ethaddr);
//! Print IP address in dot notation.
void netPrintIPAddr(uint32_t ipaddr);
//! Print Ethernet header information.
void netPrintEthHeader(struct netEthHeader* eth_hdr);
//! Print IP header information.
void netPrintIpHeader(struct netIpHeader* ipheader);
//! Print TCP header information.
void netPrintTcpHeader(struct netTcpHeader* tcpheader);

#endif
//@}