pxeparent_dhcp.c

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/*
 * Copyright (C) 2009 Joshua Oreman <oremanj@rwcr.net>.
 *
 * 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 <string.h>
#include <gpxe/dhcp.h>
#include <gpxe/netdevice.h>
#include <undipreload.h>
#include <pxeparent.h>
#include <realmode.h>
#include <pxe_api.h>

/**
 * Present cached DHCP packet if it exists
 */
void __weak_impl ( get_cached_dhcpack ) ( void ) {
        struct undi_device *undi;
        struct s_PXENV_GET_CACHED_INFO get_cached_info;
        int rc;

        /* Use preloaded UNDI device to get at PXE entry point */
        undi = &preloaded_undi;
        if ( ! undi->entry.segment ) {
                DBG ( "PXEDHCP no preloaded UNDI device found\n" );
                return;
        }

        /* Check that stack is available to get cached info */
        if ( ! ( undi->flags & UNDI_FL_KEEP_ALL ) ) {
                DBG ( "PXEDHCP stack was unloaded, no cache available\n" );
                return;
        }

        /* Obtain cached DHCP packet */
        memset ( &get_cached_info, 0, sizeof ( get_cached_info ) );
        get_cached_info.PacketType = PXENV_PACKET_TYPE_DHCP_ACK;

        if ( ( rc = pxeparent_call ( undi->entry, PXENV_GET_CACHED_INFO,
                                     &get_cached_info,
                                     sizeof ( get_cached_info ) ) ) != 0 ) {
                DBG ( "PXEDHCP GET_CACHED_INFO failed: %s\n", strerror ( rc ) );
                return;
        }

        DBG ( "PXEDHCP got cached info at %04x:%04x length %d\n",
              get_cached_info.Buffer.segment, get_cached_info.Buffer.offset,
              get_cached_info.BufferSize );

        /* Present cached DHCP packet */
        store_cached_dhcpack ( real_to_user ( get_cached_info.Buffer.segment,
                                              get_cached_info.Buffer.offset ),
                               get_cached_info.BufferSize );
}