tcpip.h

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#ifndef _GPXE_TCPIP_H
#define _GPXE_TCPIP_H

/** @file
 *
 * Transport-network layer interface
 *
 */

FILE_LICENCE ( GPL2_OR_LATER );

#include <stdint.h>
#include <gpxe/socket.h>
#include <gpxe/in.h>
#include <gpxe/tables.h>

struct io_buffer;
struct net_device;

/** Empty checksum value
 *
 * This is the TCP/IP checksum over a zero-length block of data.
 */
#define TCPIP_EMPTY_CSUM 0xffff

/**
 * TCP/IP socket address
 *
 * This contains the fields common to socket addresses for all TCP/IP
 * address families.
 */
struct sockaddr_tcpip {
        /** Socket address family (part of struct @c sockaddr) */
        sa_family_t st_family;
        /** TCP/IP port */
        uint16_t st_port;
        /** Padding
         *
         * This ensures that a struct @c sockaddr_tcpip is large
         * enough to hold a socket address for any TCP/IP address
         * family.
         */
        char pad[ sizeof ( struct sockaddr ) -
                  ( sizeof ( sa_family_t ) + sizeof ( uint16_t ) ) ];
} __attribute__ (( may_alias ));

/** 
 * A transport-layer protocol of the TCP/IP stack (eg. UDP, TCP, etc)
 */
struct tcpip_protocol {
        /** Protocol name */
        const char *name;
        /**
         * Process received packet
         *
         * @v iobuf             I/O buffer
         * @v st_src            Partially-filled source address
         * @v st_dest           Partially-filled destination address
         * @v pshdr_csum        Pseudo-header checksum
         * @ret rc              Return status code
         *
         * This method takes ownership of the I/O buffer.
         */
        int ( * rx ) ( struct io_buffer *iobuf, struct sockaddr_tcpip *st_src,
                       struct sockaddr_tcpip *st_dest, uint16_t pshdr_csum );
        /** 
         * Transport-layer protocol number
         *
         * This is a constant of the type IP_XXX
         */
        uint8_t tcpip_proto;
};

/**
 * A network-layer protocol of the TCP/IP stack (eg. IPV4, IPv6, etc)
 */
struct tcpip_net_protocol {
        /** Protocol name */
        const char *name;
        /** Network address family */
        sa_family_t sa_family;
        /**
         * Transmit packet
         *
         * @v iobuf             I/O buffer
         * @v tcpip_protocol    Transport-layer protocol
         * @v st_src            Source address, or NULL to use default
         * @v st_dest           Destination address
         * @v netdev            Network device (or NULL to route automatically)
         * @v trans_csum        Transport-layer checksum to complete, or NULL
         * @ret rc              Return status code
         *
         * This function takes ownership of the I/O buffer.
         */
        int ( * tx ) ( struct io_buffer *iobuf,
                       struct tcpip_protocol *tcpip_protocol,
                       struct sockaddr_tcpip *st_src,
                       struct sockaddr_tcpip *st_dest,
                       struct net_device *netdev,
                       uint16_t *trans_csum );
};

/** TCP/IP transport-layer protocol table */
#define TCPIP_PROTOCOLS __table ( struct tcpip_protocol, "tcpip_protocols" )

/** Declare a TCP/IP transport-layer protocol */
#define __tcpip_protocol __table_entry ( TCPIP_PROTOCOLS, 01 )

/** TCP/IP network-layer protocol table */
#define TCPIP_NET_PROTOCOLS \
        __table ( struct tcpip_net_protocol, "tcpip_net_protocols" )

/** Declare a TCP/IP network-layer protocol */
#define __tcpip_net_protocol __table_entry ( TCPIP_NET_PROTOCOLS, 01 )

extern int tcpip_rx ( struct io_buffer *iobuf, uint8_t tcpip_proto,
                      struct sockaddr_tcpip *st_src,
                      struct sockaddr_tcpip *st_dest, uint16_t pshdr_csum );
extern int tcpip_tx ( struct io_buffer *iobuf, struct tcpip_protocol *tcpip,
                      struct sockaddr_tcpip *st_src,
                      struct sockaddr_tcpip *st_dest,
                      struct net_device *netdev,
                      uint16_t *trans_csum );
extern uint16_t tcpip_continue_chksum ( uint16_t partial,
                                        const void *data, size_t len );
extern uint16_t tcpip_chksum ( const void *data, size_t len );

#endif /* _GPXE_TCPIP_H */