/** @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 <malloc.h>
#include <gpxe/uaccess.h>
#include <gpxe/dhcp.h>
#include "pxe.h"
#include "pxe_callbacks.h"

/**
 * UNLOAD BASE CODE STACK
 *
 * @v None				-
 * @ret ...
 *
 */
PXENV_EXIT_t pxenv_unload_stack ( struct s_PXENV_UNLOAD_STACK *unload_stack ) {
	DBG ( "PXENV_UNLOAD_STACK" );

#if 0
	/* We need to call cleanup() at some point.  The network card
	 * has already been disabled by ENSURE_CAN_UNLOAD(), but for
	 * the sake of completeness we should call the console_fini()
	 * etc. that are part of cleanup().
	 *
	 * There seems to be a lack of consensus on which is the final
	 * PXE API call to make, but it's a fairly safe bet that all
	 * the potential shutdown sequences will include a call to
	 * PXENV_UNLOAD_STACK at some point, so we may as well do it
	 * here.
	 */
	cleanup();

	if ( ! success ) {
		unload_stack->Status = PXENV_STATUS_KEEP_ALL;
		return PXENV_EXIT_FAILURE;
	}
#endif

	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 dhcp_packet dhcppkt;
	void *data = NULL;
	size_t len;
	int msgtype;
	struct dhcp_option_block *options;
	userptr_t buffer;
	int rc;

	DBG ( "PXENV_GET_CACHED_INFO %d", get_cached_info->PacketType );

	/* This is really, really awkward to support with our multiple
	 * sources of options.
	 */
	if ( get_cached_info->BufferLimit == 0 ) {
		DBG ( " without an external buffer.  Aargh." );
		goto err;
	}

	DBG ( " to %04x:%04x+%x\n", get_cached_info->Buffer.segment,
	      get_cached_info->Buffer.offset, get_cached_info->BufferLimit );

	/* Allocate space for temporary copy */
	len = get_cached_info->BufferLimit;
	data = malloc ( len );
	if ( ! data ) {
		DBG ( " out of memory" );
		goto err;
	}

	/* Construct DHCP packet */
	if ( get_cached_info->PacketType == PXENV_PACKET_TYPE_DHCP_DISCOVER ) {
		msgtype = DHCPDISCOVER;
		options = &dhcp_request_options;
	} else {
		msgtype = DHCPACK;
		options = NULL;
	}
	if ( ( rc = create_dhcp_packet ( pxe_netdev, msgtype, data, len,
					 &dhcppkt ) ) != 0 ) {
		DBG ( " failed to build packet" );
		goto err;
	}
	if ( ( rc = copy_dhcp_packet_options ( &dhcppkt, options ) ) != 0 ) {
		DBG ( " failed to copy options" );
		goto err;
	}

	/* Copy packet to client buffer */
	buffer = real_to_user ( get_cached_info->Buffer.segment,
				get_cached_info->Buffer.offset );
	copy_to_user ( buffer, 0, data, len );

	free ( data );
	get_cached_info->Status = PXENV_STATUS_SUCCESS;
	return PXENV_EXIT_SUCCESS;

 err:
	if ( data )
		free ( data );
	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 ) {
	DBG ( "PXENV_RESTART_TFTP" );

#if 0
	/* Words cannot describe the complete mismatch between the PXE
	 * specification and any possible version of reality...
	 */
	restart_tftp->Buffer = PXE_LOAD_ADDRESS; /* Fixed by spec, apparently */
	restart_tftp->BufferSize = get_free_base_memory() - PXE_LOAD_ADDRESS; /* Near enough */
	DBG ( "(" );
	tftp_exit = pxe_api_call ( PXENV_TFTP_READ_FILE, (union u_PXENV_ANY*)restart_tftp );
	DBG ( ")" );
	if ( tftp_exit != PXENV_EXIT_SUCCESS ) return tftp_exit;

	/* Fire up the new NBP */
	restart_tftp->Status = xstartpxe();
#endif

	/* 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 ) {

	DBG ( "PXENV_START_UNDI" );

#if 0
	/* Record PCI bus & devfn passed by caller, so we know which
	 * NIC they want to use.
	 *
	 * If they don't match our already-existing NIC structure, set
	 * values to ensure that the specified NIC is used at the next
	 * call to pxe_intialise_nic().
	 */
	bus = ( start_undi->AX >> 8 ) & 0xff;
	devfn = start_undi->AX & 0xff;

#warning "device probing mechanism has completely changed"
#if 0
	if ( ( pci->dev.driver == NULL ) ||
	     ( pci->dev.bus != bus ) || ( pci->dev.devfn != devfn ) ) {
		/* This is quite a bit of a hack and relies on
		 * knowledge of the internal operation of Etherboot's
		 * probe mechanism.
		 */
		DBG ( " set PCI %hhx:%hhx.%hhx",
		      bus, PCI_SLOT(devfn), PCI_FUNC(devfn) );
		dev->type = BOOT_NIC;
		dev->to_probe = PROBE_PCI;
		memset ( &dev->state, 0, sizeof(dev->state) );
		pci->advance = 1;
		pci->dev.use_specified = 1;
		pci->dev.bus = bus;
		pci->dev.devfn = devfn;
	}
#endif

#endif

	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" );

#if 0
	if ( ! ensure_pxe_state(CAN_UNLOAD) ) {
		stop_undi->Status = PXENV_STATUS_KEEP_UNDI;
		return PXENV_EXIT_FAILURE;
	}
#endif

	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;
}