src/arch/i386/interface/pxeparent/pxeparent_dhcp.c

   1 /*
   2  * Copyright (C) 2009 Joshua Oreman <oremanj@rwcr.net>.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * License, or any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17  */
  18
  19 FILE_LICENCE ( GPL2_OR_LATER );
  20
  21 #include <string.h>
  22 #include <gpxe/dhcp.h>
  23 #include <gpxe/netdevice.h>
  24 #include <undipreload.h>
  25 #include <pxeparent.h>
  26 #include <realmode.h>
  27 #include <pxe_api.h>
  28
  29 /**
  30  * Present cached DHCP packet if it exists
  31  */
  32 void get_cached_dhcpack ( void ) {
  33         struct undi_device *undi;
  34         struct s_PXENV_GET_CACHED_INFO get_cached_info;
  35         int rc;
  36
  37         /* Use preloaded UNDI device to get at PXE entry point */
  38         undi = &preloaded_undi;
  39         if ( ! undi->entry.segment ) {
  40                 DBG ( "PXEDHCP no preloaded UNDI device found\n" );
  41                 return;
  42         }
  43
  44         /* Check that stack is available to get cached info */
  45         if ( ! ( undi->flags & UNDI_FL_KEEP_ALL ) ) {
  46                 DBG ( "PXEDHCP stack was unloaded, no cache available\n" );
  47                 return;
  48         }
  49
  50         /* Obtain cached DHCP packet */
  51         memset ( &get_cached_info, 0, sizeof ( get_cached_info ) );
  52         get_cached_info.PacketType = PXENV_PACKET_TYPE_DHCP_ACK;
  53
  54         if ( ( rc = pxeparent_call ( undi->entry, PXENV_GET_CACHED_INFO,
  55                                      &get_cached_info,
  56                                      sizeof ( get_cached_info ) ) ) != 0 ) {
  57                 DBG ( "PXEDHCP GET_CACHED_INFO failed: %s\n", strerror ( rc ) );
  58                 return;
  59         }
  60
  61         DBG ( "PXEDHCP got cached info at %04x:%04x length %d\n",
  62               get_cached_info.Buffer.segment, get_cached_info.Buffer.offset,
  63               get_cached_info.BufferSize );
  64
  65         /* Present cached DHCP packet */
  66         store_cached_dhcpack ( real_to_user ( get_cached_info.Buffer.segment,
  67                                               get_cached_info.Buffer.offset ),
  68                                get_cached_info.BufferSize );
  69 }