created interface for transport-network interface
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Nikhil Chandru Rao
parent
8b0cac40ca
commit
fdc05e2664
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#ifndef _GPXE_INTERFACE_H
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#define _GPXE_INTERFACE_H
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/** @file
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*
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* Transport-network layer interface
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*
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*/
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#include <stdint.h>
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#include <gpxe/in.h>
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#include <gpxe/tables.h>
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struct pk_buff;
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struct net_protocol;
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struct trans_protocol;
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struct tcpip_net_protocol;
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/**
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* A transport-layer protocol
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*/
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struct trans_protocol {
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/** Protocol name */
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const char *name;
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/**
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* Process received packet
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*
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* @v pkb Packet buffer
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* @v netdev Network device
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* @v ll_source Link-layer source address
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*
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* This method takes ownership of the packet buffer.
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*/
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void ( * rx ) ( struct pk_buff *pkb, struct in_addr *src_net_addr, struct in_addr *dest_net_addr );
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/**
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* Transport-layer protocol number
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*
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* This is a constant of the type IP_XXX
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*/
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uint8_t trans_proto;
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};
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/**
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* A TCPIP supporting protocol
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*/
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struct tcpip_net_protocol {
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/** Network protocol */
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struct net_protocol *net_protocol;
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/** Network address family */
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sa_family_t sa_family;
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/** Complete transport-layer checksum calculation
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*
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* @v pkb Packet buffer
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* @v trans_proto Transport-layer protocol number
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*
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* This function expects a network-layer datagram in its packet with the protocol field in the
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* IP header to be filled up. It constructs a psuedo-header using the information provided in
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* the IP header and computes the checksum over the pseudo-header. The checksum offset in the
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* transport layer header can be determined without the need of an offset value as
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*
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* void *csum_offset = pkb->data + NET_HLEN + csum_offset ( trans_proto );
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*
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* where,
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* csum_offset ( IP_TCP ) = 16
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* csum_offset ( IP_UDP ) = 6
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*/
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void ( * tx_csum ) ( struct pk_buff *pkb );
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};
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/**
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* Register a transport-layer protocol
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*
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* @v protocol Transport-layer protocol
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*/
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#define TRANS_PROTOCOL( protocol ) \
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struct trans_protocol protocol __table ( trans_protocols, 01 )
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#define TCPIP_NET_PROTOCOL( protocol ) \
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struct tcpip_net_protocol protocol __table ( tcpip_net_protocols, 01 )
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extern void trans_rx ( struct pk_buff *pkb, uint8_t trans_proto, struct in_addr *src, struct in_addr *dest );
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extern int trans_tx ( struct pk_buff *pkb, uint8_t trans_proto, struct sockaddr *dest );
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extern uint16_t calc_chksum ( void *data, size_t len );
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/** Do we need these functions? -Nikhil, 24-6-06 */
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extern struct trans_protocol * find_trans_protocol ( uint8_t trans_proto );
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extern struct tcpip_net_protocol * find_tcpip_net_protocol ( sa_family_t sa_family );
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#endif /* _GPXE_INTERFACE_H */
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#include <stdint.h>
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#include <string.h>
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#include <errno.h>
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#include <malloc.h>
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#include <byteswap.h>
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#include <gpxe/in.h>
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#include <gpxe/ip.h>
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#include <gpxe/pkbuff.h>
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#include <gpxe/tables.h>
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#include <gpxe/netdevice.h>
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#include <gpxe/interface.h>
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/** @file
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*
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* Transport-network layer interface
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*
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* This file contains functions and utilities for the transport-network layer interface
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*/
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/** Registered protocols that support TCPIP */
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static struct tcpip_net_protocol tcpip_net_protocols[0] __table_start ( tcpip_net_protocols );
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static struct tcpip_net_protocol tcpip_net_protocols_end[0] __table_end ( tcpip_net_protocols );
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struct trans_protocol;
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/** Registered transport-layer protocols */
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static struct trans_protocol trans_protocols[0] __table_start ( trans_protocols );
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static struct trans_protocol trans_protocols_end[0] __table_end ( trans_protocols );
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/** Identify TCPIP net protocol
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*
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* @v sa_family Network address family
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* @ret tcpip Protocol supporting TCPIP, or NULL
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*/
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static struct tcpip_net_protocol * tcpip_find_protocol ( sa_family_t sa_family ) {
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struct tcpip_net_protocol *tcpip;
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for ( tcpip = tcpip_net_protocols; tcpip < tcpip_net_protocols_end; tcpip++ ) {
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if ( tcpip->sa_family == sa_family ) {
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return tcpip;
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}
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}
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return NULL;
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}
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/** Identify transport-layer protocol
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*
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* @v trans_proto Transport-layer protocol number, IP_XXX
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* @ret trans_protocol Transport-layer protocol, or NULL
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*/
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struct trans_protocol* find_trans_protocol ( uint8_t trans_proto ) {
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struct trans_protocol *trans_protocol;
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for ( trans_protocol = trans_protocols; trans_protocol <= trans_protocols_end; ++trans_protocol ) {
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if ( trans_protocol->trans_proto == trans_proto ) {
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return trans_protocol;
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}
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}
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return NULL;
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}
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/** Process a received packet
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*
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* @v pkb Packet buffer
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* @v trans_proto Transport-layer protocol number
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* @v src Source network-layer address
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* @v dest Destination network-layer address
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*
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* This function expects a transport-layer segment from the network-layer
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*/
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void trans_rx ( struct pk_buff *pkb, uint8_t trans_proto, struct in_addr *src, struct in_addr *dest ) {
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struct trans_protocol *trans_protocol;
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/* Identify the transport layer protocol */
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for ( trans_protocol = trans_protocols; trans_protocol <= trans_protocols_end; ++trans_protocol ) {
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if ( trans_protocol->trans_proto == trans_proto ) {
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DBG ( "Packet sent to %s module", trans_protocol->name );
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trans_protocol->rx ( pkb, src, dest );
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}
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}
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}
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/** Transmit a transport-layer segment
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*
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* @v pkb Packet buffer
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* @v trans_proto Transport-layer protocol
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* @v sock Destination socket address
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* @ret Status
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*/
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int trans_tx ( struct pk_buff *pkb, uint8_t trans_proto, struct sockaddr *sock ) {
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/* Identify the network layer protocol and send it using xxx_tx() */
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switch ( sock->sa_family ) {
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case AF_INET: /* IPv4 network family */
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return ipv4_tx ( pkb, trans_proto, &sock->sin.sin_addr );
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case AF_INET6: /* IPv6 network family */
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return ipv6_tx ( pkb, trans_proto, &sock->sin6.sin6_addr );
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default:
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DBG ( "Network family %d not supported", sock->sa_family );
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}
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return -EPROTONOSUPPORT;
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}
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/**
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* Calculate internet checksum
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*
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* @v data Pointer to the data
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* @v len Length of data to be checksummed
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* @ret chksum 16 bit internet checksum
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*
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* This function calculates the internet checksum (refer RFC1071) for len bytes beginning at the location data
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*/
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uint16_t calc_chksum ( void *data, size_t len ) {
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register long sum = 0;
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uint16_t checksum;
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unsigned short *temp;
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while ( len > 1 ) {
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temp = (unsigned short*) data++;
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sum += *temp;
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len -= 2;
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}
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if ( len > 0 ) {
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sum += *(unsigned char *)data;
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}
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while ( sum >> 16 ) {
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sum = ( sum & 0xffff ) + ( sum >> 16 );
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}
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checksum = ~sum;
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return checksum;
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}
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