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#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <malloc.h>
#include <byteswap.h>
#include <gpxe/in.h>
#include <gpxe/ip.h>
#include <gpxe/ip6.h>
#include <gpxe/pkbuff.h>
#include <gpxe/tables.h>
#include <gpxe/netdevice.h>
#include <gpxe/tcpip.h>
/** @file
*
* Transport-network layer interface
*
* This file contains functions and utilities for the transport-network layer interface
*/
/** Registered network-layer protocols that support TCPIP */
static struct tcpip_net_protocol tcpip_net_protocols[0] __table_start ( tcpip_net_protocols );
static struct tcpip_net_protocol tcpip_net_protocols_end[0] __table_end ( tcpip_net_protocols );
/** Registered transport-layer protocols that support TCPIP */
static struct tcpip_protocol tcpip_protocols[0] __table_start ( tcpip_protocols );
static struct tcpip_protocol tcpip_protocols_end[0] __table_end ( tcpip_protocols );
/** Process a received packet
*
* @v pkb Packet buffer
* @v trans_proto Transport-layer protocol number
* @v src Source network-layer address
* @v dest Destination network-layer address
*
* This function expects a transport-layer segment from the network-layer
*/
void tcpip_rx ( struct pk_buff *pkb, uint8_t trans_proto, struct in_addr *src,
struct in_addr *dest ) {
struct tcpip_protocol *tcpip;
/* Identify the transport layer protocol */
for ( tcpip = tcpip_protocols; tcpip <= tcpip_protocols_end; ++tcpip ) {
if ( tcpip->trans_proto == trans_proto ) {
tcpip->rx ( pkb, src, dest );
}
}
}
/** Transmit a transport-layer segment
*
* @v pkb Packet buffer
* @v trans_proto Transport-layer protocol
* @v sock Destination socket address
* @ret Status
*/
int tcpip_tx ( struct pk_buff *pkb, struct tcpip_protocol *tcpip,
struct sockaddr *sock ) {
#if 0 /* This is the right thing to do */
struct tcpip_net_protocol *tcpip_net;
/* Identify the network layer protocol */
for ( tcpip_net = tcpip_net_protocols;
tcpip_net <= tcpip_net_protocols_end; ++tcpip_net ) {
if ( tcpip_net->sa_family == sock->sa_family ) {
DBG ( "Packet sent to %s module\n", tcpip_net->net_protocol->name );
return tcpip_net->tx ( pkb, tcpip, sock );
}
}
DBG ( "No suitable network layer protocol found for sa_family %s\n",
( sock->sa_family );
return -EAFNOSUPPORT;
}
#else
/* Identify the network layer protocol and send it using xxx_tx() */
switch ( sock->sa_family ) {
case AF_INET: /* IPv4 network family */
return ipv4_tx ( pkb, tcpip, sock );
case AF_INET6: /* IPv6 network family */
return ipv6_tx ( pkb, tcpip, sock );
}
DBG ( "Network family %d not supported", sock->sa_family );
return -EAFNOSUPPORT;
}
#endif
/**
* Calculate continued TCP/IP checkum
*
* @v partial Checksum of already-summed data, in network byte order
* @v data Data buffer
* @v len Length of data buffer
* @ret 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.
*/
unsigned int tcpip_continue_chksum ( unsigned int partial, const void *data,
size_t len ) {
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 ) & 0xffff );
}
/**
* Calculate TCP/IP checkum
*
* @v data Data buffer
* @v len Length of data buffer
* @ret 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.
*/
unsigned int tcpip_chksum ( const void *data, size_t len ) {
return tcpip_continue_chksum ( 0xffff, data, len );
}
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