tcpip.h File Reference

Transport-network layer interface. More...

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

Go to the source code of this file.

Data Structures
struct	sockaddr_tcpip
	TCP/IP socket address. More...
struct	tcpip_protocol
	A transport-layer protocol of the TCP/IP stack (eg. More...
struct	tcpip_net_protocol
	A network-layer protocol of the TCP/IP stack (eg. More...
Defines
#define	TCPIP_EMPTY_CSUM   0xffff
	Empty checksum value.
#define	TCPIP_PROTOCOLS   __table ( struct tcpip_protocol, "tcpip_protocols" )
	TCP/IP transport-layer protocol table.
#define	__tcpip_protocol   __table_entry ( TCPIP_PROTOCOLS, 01 )
	Declare a TCP/IP transport-layer protocol.
#define	TCPIP_NET_PROTOCOLS   __table ( struct tcpip_net_protocol, "tcpip_net_protocols" )
	TCP/IP network-layer protocol table.
#define	__tcpip_net_protocol   __table_entry ( TCPIP_NET_PROTOCOLS, 01 )
	Declare a TCP/IP network-layer protocol.
Functions
	FILE_LICENCE (GPL2_OR_LATER)
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)
	Process a received TCP/IP packet.
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)
	Transmit a TCP/IP packet.
uint16_t	tcpip_continue_chksum (uint16_t partial, const void *data, size_t len)
	Calculate continued TCP/IP checkum.
uint16_t	tcpip_chksum (const void *data, size_t len)
	Calculate TCP/IP checkum.

---

Detailed Description

Transport-network layer interface.

Definition in file tcpip.h.

---

Define Documentation

#define TCPIP_EMPTY_CSUM   0xffff

Empty checksum value.

This is the TCP/IP checksum over a zero-length block of data.

Definition at line 24 of file tcpip.h.

Referenced by ipv4_rx(), and tcpip_chksum().

#define TCPIP_PROTOCOLS   __table ( struct tcpip_protocol, "tcpip_protocols" )

TCP/IP transport-layer protocol table.

Definition at line 104 of file tcpip.h.

Referenced by tcpip_rx().

struct tcpip_protocol icmp_protocol __tcpip_protocol   __table_entry ( TCPIP_PROTOCOLS, 01 ) [read]

Declare a TCP/IP transport-layer protocol.

ICMP TCP/IP protocol.

Definition at line 107 of file tcpip.h.

#define TCPIP_NET_PROTOCOLS   __table ( struct tcpip_net_protocol, "tcpip_net_protocols" )

TCP/IP network-layer protocol table.

Definition at line 110 of file tcpip.h.

Referenced by tcpip_tx().

#define __tcpip_net_protocol   __table_entry ( TCPIP_NET_PROTOCOLS, 01 )

Declare a TCP/IP network-layer protocol.

Definition at line 114 of file tcpip.h.

---

Function Documentation

FILE_LICENCE

(

GPL2_OR_LATER

)

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
	)

Process a received TCP/IP packet.

Parameters:

	iobuf	I/O buffer
	tcpip_proto	Transport-layer protocol number
	st_src	Partially-filled source address
	st_dest	Partially-filled destination address
	pshdr_csum	Pseudo-header checksum

Return values:

rc

Return status code

This function expects a transport-layer segment from the network layer. The network layer should fill in as much as it can of the source and destination addresses (i.e. it should fill in the address family and the network-layer addresses, but leave the ports and the rest of the structures as zero).

Definition at line 34 of file tcpip.c.

References DBG, EPROTONOSUPPORT, for_each_table_entry, free_iob(), tcpip_protocol::name, tcpip_protocol::rx, tcpip_protocol::tcpip_proto, and TCPIP_PROTOCOLS.

Referenced by ipv4_rx(), and ipv6_process_nxt_hdr().

                                     {
        struct tcpip_protocol *tcpip;

        /* Hand off packet to the appropriate transport-layer protocol */
        for_each_table_entry ( tcpip, TCPIP_PROTOCOLS ) {
                if ( tcpip->tcpip_proto == tcpip_proto ) {
                        DBG ( "TCP/IP received %s packet\n", tcpip->name );
                        return tcpip->rx ( iobuf, st_src, st_dest, pshdr_csum );
                }
        }

        DBG ( "Unrecognised TCP/IP protocol %d\n", tcpip_proto );
        free_iob ( iobuf );
        return -EPROTONOSUPPORT;
}

int tcpip_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
	)

Transmit a TCP/IP packet.

Parameters:

	iobuf	I/O buffer
	tcpip_protocol	Transport-layer protocol
	st_src	Source address, or NULL to use route default
	st_dest	Destination address
	netdev	Network device to use if no route found, or NULL
	trans_csum	Transport-layer checksum to complete, or NULL

Return values:

rc

Return status code

Definition at line 63 of file tcpip.c.

References DBG, EAFNOSUPPORT, for_each_table_entry, free_iob(), tcpip_net_protocol::name, tcpip_net_protocol::sa_family, sockaddr_tcpip::st_family, TCPIP_NET_PROTOCOLS, and tcpip_net_protocol::tx.

Referenced by icmp6_send_solicit(), icmp_rx(), tcp_xmit(), tcp_xmit_reset(), and udp_tx().

                                                                 {
        struct tcpip_net_protocol *tcpip_net;

        /* Hand off packet to the appropriate network-layer protocol */
        for_each_table_entry ( tcpip_net, TCPIP_NET_PROTOCOLS ) {
                if ( tcpip_net->sa_family == st_dest->st_family ) {
                        DBG ( "TCP/IP sending %s packet\n", tcpip_net->name );
                        return tcpip_net->tx ( iobuf, tcpip_protocol, st_src,
                                               st_dest, netdev, trans_csum );
                }
        }
        
        DBG ( "Unrecognised TCP/IP address family %d\n", st_dest->st_family );
        free_iob ( iobuf );
        return -EAFNOSUPPORT;
}

uint16_t tcpip_continue_chksum	(	uint16_t	partial,
		const void *	data,
		size_t	len
	)

Calculate continued TCP/IP checkum.

Parameters:

	partial	Checksum of already-summed data, in network byte order
	data	Data buffer
	len	Length of data buffer

Return values:

cksum

Updated checksum, in network byte order

Calculates a TCP/IP-style 16-bit checksum over the data block. The checksum is returned in network byte order.

This function may be used to add new data to an existing checksum. The function assumes that both the old data and the new data start on even byte offsets; if this is not the case then you will need to byte-swap either the input partial checksum, the output checksum, or both. Deciding which to swap is left as an exercise for the interested reader.

Definition at line 100 of file tcpip.c.

References be16_to_cpu, and le16_to_cpu.

Referenced by ipv4_pshdr_chksum(), ipv6_tx_csum(), tcp_rx(), tcpip_chksum(), and udp_rx().

                                              {
        unsigned int cksum = ( ( ~partial ) & 0xffff );
        unsigned int value;
        unsigned int i;
        
        for ( i = 0 ; i < len ; i++ ) {
                value = * ( ( uint8_t * ) data + i );
                if ( i & 1 ) {
                        /* Odd bytes: swap on little-endian systems */
                        value = be16_to_cpu ( value );
                } else {
                        /* Even bytes: swap on big-endian systems */
                        value = le16_to_cpu ( value );
                }
                cksum += value;
                if ( cksum > 0xffff )
                        cksum -= 0xffff;
        }
        
        return ( ~cksum );
}

uint16_t tcpip_chksum	(	const void *	data,
		size_t	len
	)

Calculate TCP/IP checkum.

Parameters:

	data	Data buffer
	len	Length of data buffer

Return values:

cksum

Checksum, in network byte order

Calculates a TCP/IP-style 16-bit checksum over the data block. The checksum is returned in network byte order.

Definition at line 133 of file tcpip.c.

References tcpip_continue_chksum(), and TCPIP_EMPTY_CSUM.

Referenced by gdbudp_send(), icmp6_send_solicit(), icmp_rx(), ipv4_rx(), ipv4_tx(), tcp_xmit(), tcp_xmit_reset(), and udp_tx().

                                                       {
        return tcpip_continue_chksum ( TCPIP_EMPTY_CSUM, data, len );
}