diff options
Diffstat (limited to 'src/arch/i386/interface/pxe/pxe_preboot.c')
| -rw-r--r-- | src/arch/i386/interface/pxe/pxe_preboot.c | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/src/arch/i386/interface/pxe/pxe_preboot.c b/src/arch/i386/interface/pxe/pxe_preboot.c new file mode 100644 index 00000000..8220d1f2 --- /dev/null +++ b/src/arch/i386/interface/pxe/pxe_preboot.c @@ -0,0 +1,352 @@ +/** @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. + */ + +#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 "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_fakeproxydhcpack }, +}; + +/* 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 ); + + /* Save as PXE net device */ + pxe_set_netdev ( netdev ); + + /* Hook INT 1A */ + pxe_hook_int1a(); + + 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" ); + + /* Unhook INT 1A */ + pxe_unhook_int1a(); + + /* Clear PXE net device */ + pxe_set_netdev ( NULL ); + + /* Prepare for unload */ + shutdown ( SHUTDOWN_BOOT ); + + 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; +} |