176 lines
4.8 KiB
C
176 lines
4.8 KiB
C
/*
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* Copyright (C) 2013 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., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*
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* You can also choose to distribute this program under the terms of
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* the Unmodified Binary Distribution Licence (as given in the file
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* COPYING.UBDL), provided that you have satisfied its requirements.
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*/
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FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
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#include <stdint.h>
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#include <stdlib.h>
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#include <ipxe/dhcppkt.h>
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#include <ipxe/init.h>
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#include <ipxe/netdevice.h>
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#include <realmode.h>
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#include <pxe_api.h>
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/** @file
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*
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* Cached DHCP packet
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*
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*/
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/** Cached DHCPACK physical address
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*
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* This can be set by the prefix.
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*/
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uint32_t __bss16 ( cached_dhcpack_phys );
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#define cached_dhcpack_phys __use_data16 ( cached_dhcpack_phys )
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/** Colour for debug messages */
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#define colour &cached_dhcpack_phys
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/** Cached DHCPACK */
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static struct dhcp_packet *cached_dhcpack;
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/**
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* Cached DHCPACK startup function
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*
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*/
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static void cachedhcp_init ( void ) {
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struct dhcp_packet *dhcppkt;
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struct dhcp_packet *tmp;
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struct dhcphdr *dhcphdr;
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size_t len;
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/* Do nothing if no cached DHCPACK is present */
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if ( ! cached_dhcpack_phys ) {
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DBGC ( colour, "CACHEDHCP found no cached DHCPACK\n" );
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return;
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}
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/* No reliable way to determine length before parsing packet;
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* start by assuming maximum length permitted by PXE.
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*/
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len = sizeof ( BOOTPLAYER_t );
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/* Allocate and populate DHCP packet */
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dhcppkt = zalloc ( sizeof ( *dhcppkt ) + len );
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if ( ! dhcppkt ) {
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DBGC ( colour, "CACHEDHCP could not allocate copy\n" );
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return;
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}
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dhcphdr = ( ( ( void * ) dhcppkt ) + sizeof ( *dhcppkt ) );
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copy_from_user ( dhcphdr, phys_to_user ( cached_dhcpack_phys ), 0,
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len );
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dhcppkt_init ( dhcppkt, dhcphdr, len );
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/* Resize packet to required length. If reallocation fails,
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* just continue to use the original packet.
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*/
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len = dhcppkt_len ( dhcppkt );
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tmp = realloc ( dhcppkt, ( sizeof ( *dhcppkt ) + len ) );
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if ( tmp )
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dhcppkt = tmp;
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/* Reinitialise packet at new address */
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dhcphdr = ( ( ( void * ) dhcppkt ) + sizeof ( *dhcppkt ) );
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dhcppkt_init ( dhcppkt, dhcphdr, len );
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/* Store as cached DHCPACK, and mark original copy as consumed */
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DBGC ( colour, "CACHEDHCP found cached DHCPACK at %08x+%zx\n",
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cached_dhcpack_phys, len );
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cached_dhcpack = dhcppkt;
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cached_dhcpack_phys = 0;
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}
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/**
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* Cached DHCPACK startup function
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*
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*/
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static void cachedhcp_startup ( void ) {
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/* If cached DHCP packet was not claimed by any network device
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* during startup, then free it.
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*/
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if ( cached_dhcpack ) {
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DBGC ( colour, "CACHEDHCP freeing unclaimed cached DHCPACK\n" );
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dhcppkt_put ( cached_dhcpack );
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cached_dhcpack = NULL;
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}
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}
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/** Cached DHCPACK initialisation function */
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struct init_fn cachedhcp_init_fn __init_fn ( INIT_NORMAL ) = {
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.initialise = cachedhcp_init,
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};
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/** Cached DHCPACK startup function */
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struct startup_fn cachedhcp_startup_fn __startup_fn ( STARTUP_LATE ) = {
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.startup = cachedhcp_startup,
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};
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/**
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* Apply cached DHCPACK to network device, if applicable
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*
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* @v netdev Network device
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* @ret rc Return status code
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*/
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static int cachedhcp_probe ( struct net_device *netdev ) {
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struct ll_protocol *ll_protocol = netdev->ll_protocol;
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int rc;
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/* Do nothing unless we have a cached DHCPACK */
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if ( ! cached_dhcpack )
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return 0;
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/* Do nothing unless cached DHCPACK's MAC address matches this
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* network device.
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*/
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if ( memcmp ( netdev->ll_addr, cached_dhcpack->dhcphdr->chaddr,
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ll_protocol->ll_addr_len ) != 0 ) {
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DBGC ( colour, "CACHEDHCP cached DHCPACK does not match %s\n",
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netdev->name );
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return 0;
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}
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DBGC ( colour, "CACHEDHCP cached DHCPACK is for %s\n", netdev->name );
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/* Register as DHCP settings for this network device */
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if ( ( rc = register_settings ( &cached_dhcpack->settings,
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netdev_settings ( netdev ),
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DHCP_SETTINGS_NAME ) ) != 0 ) {
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DBGC ( colour, "CACHEDHCP could not register settings: %s\n",
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strerror ( rc ) );
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return rc;
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}
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/* Claim cached DHCPACK */
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dhcppkt_put ( cached_dhcpack );
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cached_dhcpack = NULL;
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return 0;
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}
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/** Cached DHCP packet network device driver */
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struct net_driver cachedhcp_driver __net_driver = {
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.name = "cachedhcp",
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.probe = cachedhcp_probe,
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};
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