diff options
Diffstat (limited to 'gpxe/src/net/fakedhcp.c')
| -rw-r--r-- | gpxe/src/net/fakedhcp.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/gpxe/src/net/fakedhcp.c b/gpxe/src/net/fakedhcp.c new file mode 100644 index 00000000..c3054db1 --- /dev/null +++ b/gpxe/src/net/fakedhcp.c @@ -0,0 +1,205 @@ +/* + * Copyright (C) 2008 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., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <stdint.h> +#include <stdlib.h> +#include <stdio.h> +#include <errno.h> +#include <string.h> +#include <gpxe/settings.h> +#include <gpxe/netdevice.h> +#include <gpxe/dhcppkt.h> +#include <gpxe/fakedhcp.h> + +/** @file + * + * Fake DHCP packets + * + */ + +/** + * Copy settings to DHCP packet + * + * @v dest Destination DHCP packet + * @v source Source settings block + * @v encapsulator Encapsulating setting tag number, or zero + * @ret rc Return status code + */ +static int copy_encap_settings ( struct dhcp_packet *dest, + struct settings *source, + unsigned int encapsulator ) { + struct setting setting = { .name = "" }; + unsigned int subtag; + unsigned int tag; + int len; + int check_len; + int rc; + + for ( subtag = DHCP_MIN_OPTION; subtag <= DHCP_MAX_OPTION; subtag++ ) { + tag = DHCP_ENCAP_OPT ( encapsulator, subtag ); + switch ( tag ) { + case DHCP_EB_ENCAP: + case DHCP_VENDOR_ENCAP: + /* Process encapsulated settings */ + if ( ( rc = copy_encap_settings ( dest, source, + tag ) ) != 0 ) + return rc; + break; + default: + /* Copy setting, if present */ + setting.tag = tag; + len = fetch_setting_len ( source, &setting ); + if ( len < 0 ) + break; + { + char buf[len]; + + check_len = fetch_setting ( source, &setting, + buf, sizeof (buf)); + assert ( check_len == len ); + if ( ( rc = dhcppkt_store ( dest, tag, buf, + sizeof(buf) )) !=0) + return rc; + } + break; + } + } + + return 0; +} + +/** + * Copy settings to DHCP packet + * + * @v dest Destination DHCP packet + * @v source Source settings block + * @ret rc Return status code + */ +static int copy_settings ( struct dhcp_packet *dest, + struct settings *source ) { + return copy_encap_settings ( dest, source, 0 ); +} + +/** + * Create fake DHCPDISCOVER packet + * + * @v netdev Network device + * @v data Buffer for DHCP packet + * @v max_len Size of DHCP packet buffer + * @ret rc Return status code + * + * Used by external code. + */ +int create_fakedhcpdiscover ( struct net_device *netdev, + void *data, size_t max_len ) { + struct dhcp_packet dhcppkt; + int rc; + + if ( ( rc = create_dhcp_request ( &dhcppkt, netdev, NULL, data, + max_len ) ) != 0 ) { + DBG ( "Could not create DHCPDISCOVER: %s\n", + strerror ( rc ) ); + return rc; + } + + return 0; +} + +/** + * Create fake DHCPACK packet + * + * @v netdev Network device + * @v data Buffer for DHCP packet + * @v max_len Size of DHCP packet buffer + * @ret rc Return status code + * + * Used by external code. + */ +int create_fakedhcpack ( struct net_device *netdev, + void *data, size_t max_len ) { + struct dhcp_packet dhcppkt; + int rc; + + /* Create base DHCPACK packet */ + if ( ( rc = create_dhcp_packet ( &dhcppkt, netdev, DHCPACK, NULL, + data, max_len ) ) != 0 ) { + DBG ( "Could not create DHCPACK: %s\n", strerror ( rc ) ); + return rc; + } + + /* Merge in globally-scoped settings, then netdev-specific + * settings. Do it in this order so that netdev-specific + * settings take precedence regardless of stated priorities. + */ + if ( ( rc = copy_settings ( &dhcppkt, NULL ) ) != 0 ) { + DBG ( "Could not set DHCPACK global settings: %s\n", + strerror ( rc ) ); + return rc; + } + if ( ( rc = copy_settings ( &dhcppkt, + netdev_settings ( netdev ) ) ) != 0 ) { + DBG ( "Could not set DHCPACK netdev settings: %s\n", + strerror ( rc ) ); + return rc; + } + + return 0; +} + +/** + * Create ProxyDHCPACK packet + * + * @v netdev Network device + * @v data Buffer for DHCP packet + * @v max_len Size of DHCP packet buffer + * @ret rc Return status code + * + * Used by external code. + */ +int create_fakeproxydhcpack ( struct net_device *netdev, + void *data, size_t max_len ) { + struct dhcp_packet dhcppkt; + struct settings *settings; + int rc; + + /* Identify ProxyDHCP settings */ + settings = find_settings ( PROXYDHCP_SETTINGS_NAME ); + + /* No ProxyDHCP settings => return empty block */ + if ( ! settings ) { + memset ( data, 0, max_len ); + return 0; + } + + /* Create base DHCPACK packet */ + if ( ( rc = create_dhcp_packet ( &dhcppkt, netdev, DHCPACK, NULL, + data, max_len ) ) != 0 ) { + DBG ( "Could not create ProxyDHCPACK: %s\n", + strerror ( rc ) ); + return rc; + } + + /* Merge in ProxyDHCP options */ + if ( ( rc = copy_settings ( &dhcppkt, settings ) ) != 0 ) { + DBG ( "Could not set ProxyDHCPACK settings: %s\n", + strerror ( rc ) ); + return rc; + } + + return 0; +} |