mirror of
https://github.com/xcat2/xNBA.git
synced 2024-12-16 16:21:32 +00:00
a3d508b648
Added a large number of missing calls to free_pkb(). In the case of UDP, no received packets were ever freed, which lead to memory exhaustion remarkably quickly once pxelinux started up. In general, any function with _rx() in its name which accepts a pk_buff *must* either call free_pkb() or pass the pkb to another _rx() function (e.g. the next layer up the stack). Since the UDP (and TCP) layers don't pass packet buffers up to the higher-layer protocols (the "applications"), they must free the packet buffer after calling the application's newdata() method.
140 lines
4.3 KiB
C
140 lines
4.3 KiB
C
#include <stdint.h>
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#include <string.h>
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#include <errno.h>
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#include <byteswap.h>
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#include <gpxe/pkbuff.h>
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#include <gpxe/tables.h>
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#include <gpxe/tcpip.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
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* TCP/IP transport-network layer interface
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*/
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/** Registered network-layer protocols that support TCP/IP */
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static struct tcpip_net_protocol
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tcpip_net_protocols[0] __table_start ( tcpip_net_protocols );
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static struct tcpip_net_protocol
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tcpip_net_protocols_end[0] __table_end ( tcpip_net_protocols );
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/** Registered transport-layer protocols that support TCP/IP */
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static struct tcpip_protocol
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tcpip_protocols[0]__table_start ( tcpip_protocols );
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static struct tcpip_protocol
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tcpip_protocols_end[0] __table_end ( tcpip_protocols );
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/** Process a received TCP/IP packet
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*
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* @v pkb Packet buffer
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* @v tcpip_proto Transport-layer protocol number
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* @v st_src Partially-filled source address
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* @v st_dest Partially-filled destination address
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* @ret rc Return status code
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*
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* This function expects a transport-layer segment from the network
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* layer. The network layer should fill in as much as it can of the
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* source and destination addresses (i.e. it should fill in the
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* address family and the network-layer addresses, but leave the ports
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* and the rest of the structures as zero).
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*/
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int tcpip_rx ( struct pk_buff *pkb, uint8_t tcpip_proto,
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struct sockaddr_tcpip *st_src,
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struct sockaddr_tcpip *st_dest ) {
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struct tcpip_protocol *tcpip;
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/* Hand off packet to the appropriate transport-layer protocol */
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for ( tcpip = tcpip_protocols; tcpip < tcpip_protocols_end; tcpip++ ) {
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if ( tcpip->tcpip_proto == tcpip_proto ) {
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DBG ( "TCP/IP received %s packet\n", tcpip->name );
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return tcpip->rx ( pkb, st_src, st_dest );
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}
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}
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DBG ( "Unrecognised TCP/IP protocol %d\n", tcpip_proto );
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free_pkb ( pkb );
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return -EPROTONOSUPPORT;
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}
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/** Transmit a TCP/IP packet
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*
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* @v pkb Packet buffer
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* @v tcpip_protocol Transport-layer protocol
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* @v st_dest Destination address
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* @ret rc Return status code
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*/
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int tcpip_tx ( struct pk_buff *pkb, struct tcpip_protocol *tcpip_protocol,
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struct sockaddr_tcpip *st_dest ) {
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struct tcpip_net_protocol *tcpip_net;
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/* Hand off packet to the appropriate network-layer protocol */
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for ( tcpip_net = tcpip_net_protocols ;
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tcpip_net < tcpip_net_protocols_end ; tcpip_net++ ) {
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if ( tcpip_net->sa_family == st_dest->st_family ) {
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DBG ( "TCP/IP sending %s packet\n", tcpip_net->name );
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return tcpip_net->tx ( pkb, tcpip_protocol, st_dest );
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}
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}
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DBG ( "Unrecognised TCP/IP address family %d\n", st_dest->st_family );
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free_pkb ( pkb );
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return -EAFNOSUPPORT;
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}
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/**
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* Calculate continued TCP/IP checkum
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*
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* @v partial Checksum of already-summed data, in network byte order
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* @v data Data buffer
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* @v len Length of data buffer
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* @ret cksum Updated checksum, in network byte order
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*
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* Calculates a TCP/IP-style 16-bit checksum over the data block. The
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* checksum is returned in network byte order.
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*
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* This function may be used to add new data to an existing checksum.
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* The function assumes that both the old data and the new data start
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* on even byte offsets; if this is not the case then you will need to
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* byte-swap either the input partial checksum, the output checksum,
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* or both. Deciding which to swap is left as an exercise for the
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* interested reader.
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*/
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unsigned int tcpip_continue_chksum ( unsigned int partial, const void *data,
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size_t len ) {
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unsigned int cksum = ( ( ~partial ) & 0xffff );
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unsigned int value;
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unsigned int i;
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for ( i = 0 ; i < len ; i++ ) {
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value = * ( ( uint8_t * ) data + i );
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if ( i & 1 ) {
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/* Odd bytes: swap on little-endian systems */
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value = be16_to_cpu ( value );
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} else {
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/* Even bytes: swap on big-endian systems */
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value = le16_to_cpu ( value );
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}
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cksum += value;
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if ( cksum > 0xffff )
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cksum -= 0xffff;
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}
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return ( ( ~cksum ) & 0xffff );
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}
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/**
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* Calculate TCP/IP checkum
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*
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* @v data Data buffer
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* @v len Length of data buffer
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* @ret cksum Checksum, in network byte order
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*
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* Calculates a TCP/IP-style 16-bit checksum over the data block. The
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* checksum is returned in network byte order.
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*/
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unsigned int tcpip_chksum ( const void *data, size_t len ) {
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return tcpip_continue_chksum ( 0xffff, data, len );
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}
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