2009-02-17 07:59:15 +01:00
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/*
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* Copyright (C) 2009 Michael Brown <mbrown@fensystems.co.uk>.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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2009-05-01 16:41:06 +02:00
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FILE_LICENCE ( GPL2_OR_LATER );
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2009-02-17 07:59:15 +01:00
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#include <string.h>
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#include <errno.h>
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2010-04-19 21:16:01 +02:00
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#include <ipxe/iobuf.h>
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#include <ipxe/in.h>
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#include <ipxe/tcpip.h>
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#include <ipxe/icmp.h>
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2009-02-17 07:59:15 +01:00
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/** @file
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*
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* ICMP protocol
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*
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*/
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struct tcpip_protocol icmp_protocol __tcpip_protocol;
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/**
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* Process a received packet
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*
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* @v iobuf I/O buffer
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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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* @v pshdr_csum Pseudo-header checksum
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* @ret rc Return status code
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*/
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static int icmp_rx ( struct io_buffer *iobuf, struct sockaddr_tcpip *st_src,
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struct sockaddr_tcpip *st_dest,
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uint16_t pshdr_csum __unused ) {
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struct icmp_header *icmp = iobuf->data;
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size_t len = iob_len ( iobuf );
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unsigned int csum;
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int rc;
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/* Sanity check */
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if ( len < sizeof ( *icmp ) ) {
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DBG ( "ICMP packet too short at %zd bytes (min %zd bytes)\n",
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len, sizeof ( *icmp ) );
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rc = -EINVAL;
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goto done;
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}
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/* Verify checksum */
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csum = tcpip_chksum ( icmp, len );
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if ( csum != 0 ) {
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DBG ( "ICMP checksum incorrect (is %04x, should be 0000)\n",
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csum );
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DBG_HD ( icmp, len );
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rc = -EINVAL;
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goto done;
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}
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/* We respond only to pings */
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if ( icmp->type != ICMP_ECHO_REQUEST ) {
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DBG ( "ICMP ignoring type %d\n", icmp->type );
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rc = 0;
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goto done;
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}
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DBG ( "ICMP responding to ping\n" );
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/* Change type to response and recalculate checksum */
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icmp->type = ICMP_ECHO_RESPONSE;
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icmp->chksum = 0;
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icmp->chksum = tcpip_chksum ( icmp, len );
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/* Transmit the response */
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if ( ( rc = tcpip_tx ( iob_disown ( iobuf ), &icmp_protocol, st_dest,
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st_src, NULL, NULL ) ) != 0 ) {
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DBG ( "ICMP could not transmit ping response: %s\n",
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strerror ( rc ) );
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goto done;
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}
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done:
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free_iob ( iobuf );
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return rc;
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}
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/** ICMP TCP/IP protocol */
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struct tcpip_protocol icmp_protocol __tcpip_protocol = {
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.name = "ICMP",
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.rx = icmp_rx,
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.tcpip_proto = IP_ICMP,
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};
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