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ip.h

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/*!     \file include/net/ip.h
 *      \brief IP (Internet Protocol) layer header.
 *      \author Andrea Righi <drizzt@inwind.it>
 *      \date Last update: 2003-11-09
 *      \note Copyright (&copy;) 2003 Andrea Righi
 */

#ifndef IP_H
#define IP_H

//! IP version 4.
#define IP_V4                   4
//! IP version 6.
#define IP_V6                   6

//! Maximum IP frame length.
#define IP_FRAME_LEN            65535
//! Minimum IP header length.
#define IP_HEAD_MIN_LEN         20
//! Default TTL (Time To Live).
#define IP_DEFAULT_TTL          64

//! ICMP (Internet Control Message Protocol) packet type.
#define IPPROTO_ICMP            1
//! IGMP (Internet Group Message Protocol) packet type.
#define IPPROTO_IGMP            2
//! TCP (Transmition Control Protocol) packet type.
#define IPPROTO_TCP             6
//! UDP (User Datagram Protocol) packet type.
#define IPPROTO_UDP             17

//! Type of service :: Minimum delay.
#define IP_TOS_MIN_DELAY        0x10
//! Type of service :: Maximum throughput.
#define IP_TOS_MAX_THRU         0x08
//! Type of service :: Maximum rely.
#define IP_TOS_MAX_RELY         0x04
//! Type of service :: Minimum cost.
#define IP_TOS_MIN_COST         0x02

// Fragment flags                                                       //
//! More Fragments.
#define IP_FLAG_MF              0x2000
//! Don't Fragment.
#define IP_FLAG_DF              0x4000
//! The CE flag.
#define IP_FLAG_CE              0x8000
//! The flag mask.
#define IP_FLAG_MASK            0x1FFF

/** \ingroup Network
 *  \defgroup NetIP IP (Internet Protocol) layer
 *  The IP (Internet Protocol) layer.
 *  @{
 */

//! Create an IP address in the binary network format
//! from the notation "a.b.c.d".
#define IP_ADDRESS(a, b, c, d)  ((a) | (b) << 8 | (c) << 16 | (d) << 24)
//! Get the 1st most significant byte of a host-format IP address.
#define IP_A(ip)                ((uint8_t) ((ip) >> 24))
//! Get the 2nd most significant byte of a host-format IP address.
#define IP_B(ip)                ((uint8_t) ((ip) >> 16))
//! Get the 3rd most significant byte of a host-format IP address.
#define IP_C(ip)                ((uint8_t) ((ip) >>  8))
//! Get the less significant byte of a host-format IP address.
#define IP_D(ip)                ((uint8_t) ((ip) >>  0))

//! Loopback IP address.
#define INADDR_LOOPBACK         IP_ADDRESS(127, 0, 0, 1)
//! Null IP address.
#define INADDR_ANY              IP_ADDRESS(0, 0, 0, 0)
//! Broadcast IP address.
#define INADDR_BROADCAST        IP_ADDRESS(255, 255, 255, 255)

//! IP address type (in binary network format).
typedef uint32_t in_addr_t;

//! The IP packet structure.
typedef struct ip
{
#if __BYTE_ORDER__ == __LITTLE_ENDIAN__
        uint8_t ip_hdr_len:4;   //!< The header length.
        uint8_t ip_version:4;   //!< The IP version.
#else
        uint8_t ip_version:4;   //!< The IP version.
        uint8_t ip_hdr_len:4;   //!< The IP header length.
#endif
        //! Type of Service.
        uint8_t ip_tos;
        //! IP packet length (both data and header).
        uint16_t ip_len;

        //! Identification.
        uint16_t ip_id;
        //! Fragment offset.
        uint16_t ip_off;

        //! Time To Live.
        uint8_t ip_ttl;
        //! The type of the upper-level protocol.
        uint8_t ip_proto;
        //! IP header checksum.
        uint16_t ip_chk;

        //! IP source address (in network format).
        uint32_t ip_src;
        //! IP destination address (in network format).
        uint32_t ip_dst;
} __attribute__ ((packed)) ip_t;

// --- Prototypes ----------------------------------------------------- //

uint16_t ip_checksum(const void *buf, size_t hdr_len);
void set_host_ip_net(in_addr_t ip, in_addr_t netmask);
in_addr_t get_host_ip();
in_addr_t get_host_netmask();
in_addr_t get_host_bcast();
void to_ip_layer(ip_t *packet);
int inet_aton(const char *cp, in_addr_t *inp);
int send_ip_packet(uint32_t ip_to, const void *data, size_t len, uint8_t ttl, uint8_t proto);

/** @} */ // end of NetIP

#endif

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