source: bootcd/isolinux/syslinux-6.03/gpxe/src/net/cachedhcp.c

/*
 * 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <gpxe/dhcp.h>
#include <gpxe/dhcppkt.h>
#include <gpxe/netdevice.h>
#include <gpxe/iobuf.h>
#include <gpxe/uaccess.h>

/** @file
 *
 * Cached DHCP packet handling
 *
 */

/**
 * Store cached DHCPACK packet
 *
 * @v data              User pointer to cached DHCP packet data
 * @v len               Length of cached DHCP packet data
 * @ret rc              Return status code
 *
 * This function should be called by the architecture-specific
 * get_cached_dhcpack() handler.
 */
void store_cached_dhcpack ( userptr_t data, size_t len ) {
        struct dhcp_packet *dhcppkt;
        struct dhcphdr *dhcphdr;
        struct settings *parent;
        int rc;

        /* Create DHCP packet */
        dhcppkt = zalloc ( sizeof ( *dhcppkt ) + len );
        if ( ! dhcppkt )
                return;

        /* Fill in data for DHCP packet */
        dhcphdr = ( ( ( void * ) dhcppkt ) + sizeof ( * dhcppkt ) );
        copy_from_user ( dhcphdr, data, 0, len );
        dhcppkt_init ( dhcppkt, dhcphdr, len );
        DBG_HD ( dhcppkt->options.data, dhcppkt->options.len );

        /* Register settings on the last opened network device.
         * This will have the effect of registering cached settings
         * with a network device when "dhcp netX" is performed for that
         * device, which is usually what we want.
         */
        parent = netdev_settings ( last_opened_netdev() );
        if ( ( rc = register_settings ( &dhcppkt->settings, parent ) ) != 0 )
                DBG ( "DHCP could not register cached settings: %s\n",
                      strerror ( rc ) );

        dhcppkt_put ( dhcppkt );

        DBG ( "DHCP registered cached settings\n" );
}