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- /*
- * Copyright (C) 2013 Michael Brown <mbrown@fensystems.co.uk>.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or any later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- * 02110-1301, USA.
- *
- * You can also choose to distribute this program under the terms of
- * the Unmodified Binary Distribution Licence (as given in the file
- * COPYING.UBDL), provided that you have satisfied its requirements.
- */
-
- FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
-
- #include <stdint.h>
- #include <stdlib.h>
- #include <ipxe/dhcppkt.h>
- #include <ipxe/init.h>
- #include <ipxe/netdevice.h>
- #include <realmode.h>
- #include <pxe_api.h>
-
- /** @file
- *
- * Cached DHCP packet
- *
- */
-
- /** Cached DHCPACK physical address
- *
- * This can be set by the prefix.
- */
- uint32_t __bss16 ( cached_dhcpack_phys );
- #define cached_dhcpack_phys __use_data16 ( cached_dhcpack_phys )
-
- /** Colour for debug messages */
- #define colour &cached_dhcpack_phys
-
- /** Cached DHCPACK */
- static struct dhcp_packet *cached_dhcpack;
-
- /**
- * Cached DHCPACK startup function
- *
- */
- static void cachedhcp_init ( void ) {
- struct dhcp_packet *dhcppkt;
- struct dhcp_packet *tmp;
- struct dhcphdr *dhcphdr;
- size_t max_len;
- size_t len;
-
- /* Do nothing if no cached DHCPACK is present */
- if ( ! cached_dhcpack_phys ) {
- DBGC ( colour, "CACHEDHCP found no cached DHCPACK\n" );
- return;
- }
-
- /* No reliable way to determine length before parsing packet;
- * start by assuming maximum length permitted by PXE.
- */
- max_len = sizeof ( BOOTPLAYER_t );
-
- /* Allocate and populate DHCP packet */
- dhcppkt = zalloc ( sizeof ( *dhcppkt ) + max_len );
- if ( ! dhcppkt ) {
- DBGC ( colour, "CACHEDHCP could not allocate copy\n" );
- return;
- }
- dhcphdr = ( ( ( void * ) dhcppkt ) + sizeof ( *dhcppkt ) );
- copy_from_user ( dhcphdr, phys_to_user ( cached_dhcpack_phys ), 0,
- max_len );
- dhcppkt_init ( dhcppkt, dhcphdr, max_len );
-
- /* Shrink packet to required length. If reallocation fails,
- * just continue to use the original packet and waste the
- * unused space.
- */
- len = dhcppkt_len ( dhcppkt );
- assert ( len <= max_len );
- tmp = realloc ( dhcppkt, ( sizeof ( *dhcppkt ) + len ) );
- if ( tmp )
- dhcppkt = tmp;
-
- /* Reinitialise packet at new address */
- dhcphdr = ( ( ( void * ) dhcppkt ) + sizeof ( *dhcppkt ) );
- dhcppkt_init ( dhcppkt, dhcphdr, len );
-
- /* Store as cached DHCPACK, and mark original copy as consumed */
- DBGC ( colour, "CACHEDHCP found cached DHCPACK at %08x+%zx\n",
- cached_dhcpack_phys, len );
- cached_dhcpack = dhcppkt;
- cached_dhcpack_phys = 0;
- }
-
- /**
- * Cached DHCPACK startup function
- *
- */
- static void cachedhcp_startup ( void ) {
-
- /* If cached DHCP packet was not claimed by any network device
- * during startup, then free it.
- */
- if ( cached_dhcpack ) {
- DBGC ( colour, "CACHEDHCP freeing unclaimed cached DHCPACK\n" );
- dhcppkt_put ( cached_dhcpack );
- cached_dhcpack = NULL;
- }
- }
-
- /** Cached DHCPACK initialisation function */
- struct init_fn cachedhcp_init_fn __init_fn ( INIT_NORMAL ) = {
- .initialise = cachedhcp_init,
- };
-
- /** Cached DHCPACK startup function */
- struct startup_fn cachedhcp_startup_fn __startup_fn ( STARTUP_LATE ) = {
- .name = "cachedhcp",
- .startup = cachedhcp_startup,
- };
-
- /**
- * Apply cached DHCPACK to network device, if applicable
- *
- * @v netdev Network device
- * @ret rc Return status code
- */
- static int cachedhcp_probe ( struct net_device *netdev ) {
- struct ll_protocol *ll_protocol = netdev->ll_protocol;
- int rc;
-
- /* Do nothing unless we have a cached DHCPACK */
- if ( ! cached_dhcpack )
- return 0;
-
- /* Do nothing unless cached DHCPACK's MAC address matches this
- * network device.
- */
- if ( memcmp ( netdev->ll_addr, cached_dhcpack->dhcphdr->chaddr,
- ll_protocol->ll_addr_len ) != 0 ) {
- DBGC ( colour, "CACHEDHCP cached DHCPACK does not match %s\n",
- netdev->name );
- return 0;
- }
- DBGC ( colour, "CACHEDHCP cached DHCPACK is for %s\n", netdev->name );
-
- /* Register as DHCP settings for this network device */
- if ( ( rc = register_settings ( &cached_dhcpack->settings,
- netdev_settings ( netdev ),
- DHCP_SETTINGS_NAME ) ) != 0 ) {
- DBGC ( colour, "CACHEDHCP could not register settings: %s\n",
- strerror ( rc ) );
- return rc;
- }
-
- /* Claim cached DHCPACK */
- dhcppkt_put ( cached_dhcpack );
- cached_dhcpack = NULL;
-
- return 0;
- }
-
- /** Cached DHCP packet network device driver */
- struct net_driver cachedhcp_driver __net_driver = {
- .name = "cachedhcp",
- .probe = cachedhcp_probe,
- };
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