/** @file
*
* PXE Preboot API
*
*/
/* PXE API interface for Etherboot.
*
* Copyright (C) 2004 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.
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <gpxe/uaccess.h>
#include <gpxe/dhcp.h>
#include <gpxe/fakedhcp.h>
#include <gpxe/device.h>
#include <gpxe/netdevice.h>
#include <gpxe/isapnp.h>
#include <gpxe/init.h>
#include <gpxe/if_ether.h>
#include <basemem_packet.h>
#include <biosint.h>
#include "pxe.h"
#include "pxe_call.h"
/* Avoid dragging in isapnp.o unnecessarily */
uint16_t isapnp_read_port;
/** Zero-based versions of PXENV_GET_CACHED_INFO::PacketType */
enum pxe_cached_info_indices {
CACHED_INFO_DHCPDISCOVER = ( PXENV_PACKET_TYPE_DHCP_DISCOVER - 1 ),
CACHED_INFO_DHCPACK = ( PXENV_PACKET_TYPE_DHCP_ACK - 1 ),
CACHED_INFO_BINL = ( PXENV_PACKET_TYPE_CACHED_REPLY - 1 ),
NUM_CACHED_INFOS
};
/** A cached DHCP packet */
union pxe_cached_info {
struct dhcphdr dhcphdr;
/* This buffer must be *exactly* the size of a BOOTPLAYER_t
* structure, otherwise WinPE will die horribly. It takes the
* size of *our* buffer and feeds it in to us as the size of
* one of *its* buffers. If our buffer is larger than it
* expects, we therefore end up overwriting part of its data
* segment, since it tells us to do so. (D'oh!)
*
* Note that a BOOTPLAYER_t is not necessarily large enough to
* hold a DHCP packet; this is a flaw in the PXE spec.
*/
BOOTPLAYER_t packet;
} __attribute__ (( packed ));
/** A PXE DHCP packet creator */
struct pxe_dhcp_packet_creator {
/** Create DHCP packet
*
* @v netdev Network device
* @v data Buffer for DHCP packet
* @v max_len Size of DHCP packet buffer
* @ret rc Return status code
*/
int ( * create ) ( struct net_device *netdev, void *data,
size_t max_len );
};
/** PXE DHCP packet creators */
static struct pxe_dhcp_packet_creator pxe_dhcp_packet_creators[] = {
[CACHED_INFO_DHCPDISCOVER] = { create_fakedhcpdiscover },
[CACHED_INFO_DHCPACK] = { create_fakedhcpack },
[CACHED_INFO_BINL] = { create_fakepxebsack },
};
/* The case in which the caller doesn't supply a buffer is really
* awkward to support given that we have multiple sources of options,
* and that we don't actually store the DHCP packets. (We may not
* even have performed DHCP; we may have obtained all configuration
* from non-volatile stored options or from the command line.)
*
* Some NBPs rely on the buffers we provide being persistent, so we
* can't just use the temporary packet buffer. 4.5kB of base memory
* always wasted just because some clients are too lazy to provide
* their own buffers...
*/
static union pxe_cached_info __bss16_array ( cached_info, [NUM_CACHED_INFOS] );
#define cached_info __use_data16 ( cached_info )
/**
* Set PXE cached TFTP filename
*
* @v filename TFTP filename
*
* This is a bug-for-bug compatibility hack needed in order to work
* with Microsoft Remote Installation Services (RIS). The filename
* used in a call to PXENV_RESTART_TFTP or PXENV_TFTP_READ_FILE must
* be returned as the DHCP filename in subsequent calls to
* PXENV_GET_CACHED_INFO.
*/
void pxe_set_cached_filename ( const unsigned char *filename ) {
memcpy ( cached_info[CACHED_INFO_DHCPACK].dhcphdr.file, filename,
sizeof ( cached_info[CACHED_INFO_DHCPACK].dhcphdr.file ) );
memcpy ( cached_info[CACHED_INFO_BINL].dhcphdr.file, filename,
sizeof ( cached_info[CACHED_INFO_BINL].dhcphdr.file ) );
}
/**
* UNLOAD BASE CODE STACK
*
* @v None -
* @ret ...
*
*/
PXENV_EXIT_t pxenv_unload_stack ( struct s_PXENV_UNLOAD_STACK *unload_stack ) {
DBG ( "PXENV_UNLOAD_STACK" );
unload_stack->Status = PXENV_STATUS_SUCCESS;
return PXENV_EXIT_SUCCESS;
}
/* PXENV_GET_CACHED_INFO
*
* Status: working
*/
PXENV_EXIT_t pxenv_get_cached_info ( struct s_PXENV_GET_CACHED_INFO
*get_cached_info ) {
struct pxe_dhcp_packet_creator *creator;
union pxe_cached_info *info;
unsigned int idx;
size_t len;
userptr_t buffer;
int rc;
DBG ( "PXENV_GET_CACHED_INFO %d", get_cached_info->PacketType );
DBG ( " to %04x:%04x+%x", get_cached_info->Buffer.segment,
get_cached_info->Buffer.offset, get_cached_info->BufferSize );
/* Sanity check */
idx = ( get_cached_info->PacketType - 1 );
if ( idx >= NUM_CACHED_INFOS ) {
DBG ( " bad PacketType" );
goto err;
}
info = &cached_info[idx];
/* Construct cached version of packet, if not already constructed. */
if ( ! info->dhcphdr.op ) {
/* Construct DHCP packet */
creator = &pxe_dhcp_packet_creators[idx];
if ( ( rc = creator->create ( pxe_netdev, info,
sizeof ( *info ) ) ) != 0 ) {
DBG ( " failed to build packet" );
goto err;
}
}
len = get_cached_info->BufferSize;
if ( len == 0 ) {
/* Point client at our cached buffer.
*
* To add to the fun, Intel decided at some point in
* the evolution of the PXE specification to add the
* BufferLimit field, which we are meant to fill in
* with the length of our packet buffer, so that the
* caller can safely modify the boot server reply
* packet stored therein. However, this field was not
* present in earlier versions of the PXE spec, and
* there is at least one PXE NBP (Altiris) which
* allocates only exactly enough space for this
* earlier, shorter version of the structure. If we
* actually fill in the BufferLimit field, we
* therefore risk trashing random areas of the
* caller's memory. If we *don't* fill it in, then
* the caller is at liberty to assume that whatever
* random value happened to be in that location
* represents the length of the buffer we've just
* passed back to it.
*
* Since older PXE stacks won't fill this field in
* anyway, it's probably safe to assume that no
* callers actually rely on it, so we choose to not
* fill it in.
*/
get_cached_info->Buffer.segment = rm_ds;
get_cached_info->Buffer.offset = __from_data16 ( info );
get_cached_info->BufferSize = sizeof ( *info );
DBG ( " returning %04x:%04x+%04x['%x']",
get_cached_info->Buffer.segment,
get_cached_info->Buffer.offset,
get_cached_info->BufferSize,
get_cached_info->BufferLimit );
} else {
/* Copy packet to client buffer */
if ( len > sizeof ( *info ) )
len = sizeof ( *info );
if ( len < sizeof ( *info ) )
DBG ( " buffer may be too short" );
buffer = real_to_user ( get_cached_info->Buffer.segment,
get_cached_info->Buffer.offset );
copy_to_user ( buffer, 0, info, len );
get_cached_info->BufferSize = len;
}
get_cached_info->Status = PXENV_STATUS_SUCCESS;
return PXENV_EXIT_SUCCESS;
err:
get_cached_info->Status = PXENV_STATUS_OUT_OF_RESOURCES;
return PXENV_EXIT_FAILURE;
}
/* PXENV_RESTART_TFTP
*
* Status: working
*/
PXENV_EXIT_t pxenv_restart_tftp ( struct s_PXENV_TFTP_READ_FILE
*restart_tftp ) {
PXENV_EXIT_t tftp_exit;
DBG ( "PXENV_RESTART_TFTP " );
/* Intel bug-for-bug hack */
pxe_set_cached_filename ( restart_tftp->FileName );
/* Words cannot describe the complete mismatch between the PXE
* specification and any possible version of reality...
*/
restart_tftp->Buffer = PXE_LOAD_PHYS; /* Fixed by spec, apparently */
restart_tftp->BufferSize = ( 0xa0000 - PXE_LOAD_PHYS ); /* Near enough */
tftp_exit = pxenv_tftp_read_file ( restart_tftp );
if ( tftp_exit != PXENV_EXIT_SUCCESS )
return tftp_exit;
/* Fire up the new NBP */
restart_tftp->Status = pxe_start_nbp();
/* Not sure what "SUCCESS" actually means, since we can only
* return if the new NBP failed to boot...
*/
return PXENV_EXIT_SUCCESS;
}
/* PXENV_START_UNDI
*
* Status: working
*/
PXENV_EXIT_t pxenv_start_undi ( struct s_PXENV_START_UNDI *start_undi ) {
unsigned int bus_type;
unsigned int location;
struct net_device *netdev;
DBG ( "PXENV_START_UNDI %04x:%04x:%04x",
start_undi->AX, start_undi->BX, start_undi->DX );
/* Determine bus type and location. Use a heuristic to decide
* whether we are PCI or ISAPnP
*/
if ( ( start_undi->DX >= ISAPNP_READ_PORT_MIN ) &&
( start_undi->DX <= ISAPNP_READ_PORT_MAX ) &&
( start_undi->BX >= ISAPNP_CSN_MIN ) &&
( start_undi->BX <= ISAPNP_CSN_MAX ) ) {
bus_type = BUS_TYPE_ISAPNP;
location = start_undi->BX;
/* Record ISAPnP read port for use by isapnp.c */
isapnp_read_port = start_undi->DX;
} else {
bus_type = BUS_TYPE_PCI;
location = start_undi->AX;
}
/* Probe for devices, etc. */
startup();
/* Look for a matching net device */
netdev = find_netdev_by_location ( bus_type, location );
if ( ! netdev ) {
DBG ( " no net device found" );
start_undi->Status = PXENV_STATUS_UNDI_CANNOT_INITIALIZE_NIC;
return PXENV_EXIT_FAILURE;
}
DBG ( " using netdev %s", netdev->name );
/* Activate PXE */
pxe_activate ( netdev );
start_undi->Status = PXENV_STATUS_SUCCESS;
return PXENV_EXIT_SUCCESS;
}
/* PXENV_STOP_UNDI
*
* Status: working
*/
PXENV_EXIT_t pxenv_stop_undi ( struct s_PXENV_STOP_UNDI *stop_undi ) {
DBG ( "PXENV_STOP_UNDI" );
/* Deactivate PXE */
pxe_deactivate();
/* Prepare for unload */
shutdown ( SHUTDOWN_BOOT );
/* Check to see if we still have any hooked interrupts */
if ( hooked_bios_interrupts != 0 ) {
DBG ( "PXENV_STOP_UNDI failed: %d interrupts still hooked\n",
hooked_bios_interrupts );
stop_undi->Status = PXENV_STATUS_KEEP_UNDI;
return PXENV_EXIT_FAILURE;
}
stop_undi->Status = PXENV_STATUS_SUCCESS;
return PXENV_EXIT_SUCCESS;
}
/* PXENV_START_BASE
*
* Status: won't implement (requires major structural changes)
*/
PXENV_EXIT_t pxenv_start_base ( struct s_PXENV_START_BASE *start_base ) {
DBG ( "PXENV_START_BASE" );
start_base->Status = PXENV_STATUS_UNSUPPORTED;
return PXENV_EXIT_FAILURE;
}
/* PXENV_STOP_BASE
*
* Status: working
*/
PXENV_EXIT_t pxenv_stop_base ( struct s_PXENV_STOP_BASE *stop_base ) {
DBG ( "PXENV_STOP_BASE" );
/* The only time we will be called is when the NBP is trying
* to shut down the PXE stack. There's nothing we need to do
* in this call.
*/
stop_base->Status = PXENV_STATUS_SUCCESS;
return PXENV_EXIT_SUCCESS;
}