EdkModulePkg/Universal/Network/PxeDhcp4/Dxe/PxeDhcp4Release.c

   1 /*++
   2
   3 Copyright (c) 2006, Intel Corporation
   4 All rights reserved. This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 Module Name:
  13   PxeDhcp4Release.c
  14
  15 Abstract:
  16   Transmit release packet, free allocations and shutdown PxeDhcp4.
  17
  18 --*/
  19
  20
  21 #include "PxeDhcp4.h"
  22
  23 /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
  24 EFI_STATUS
  25 EFIAPI
  26 PxeDhcp4Release (
  27   IN EFI_PXE_DHCP4_PROTOCOL *This
  28   )
  29 {
  30   PXE_DHCP4_PRIVATE_DATA  *Private;
  31   EFI_IP_ADDRESS          ServerIp;
  32   EFI_IP_ADDRESS          client_ip;
  33   EFI_IP_ADDRESS          gateway_ip;
  34   EFI_IP_ADDRESS          subnet_mask;
  35   EFI_STATUS              efi_status;
  36   DHCP4_OP                *op;
  37   UINT8                   op_list[20];
  38
  39   //
  40   // Check for invalid parameters.
  41   //
  42   if (This == NULL) {
  43     return EFI_INVALID_PARAMETER;
  44   }
  45   //
  46   // Release does nothing if the protocol has never been setup.
  47   //
  48   if (This->Data == NULL) {
  49     return EFI_NOT_STARTED;
  50   }
  51   //
  52   // Fail if we do not have valid instance data.
  53   //
  54   Private = PXE_DHCP4_PRIVATE_DATA_FROM_THIS (This);
  55
  56   if (Private == NULL) {
  57     return EFI_INVALID_PARAMETER;
  58   }
  59
  60   if (Private->PxeBc == NULL) {
  61     return EFI_DEVICE_ERROR;
  62   }
  63   //
  64   // If this is a BOOTP session and there is not a DHCP Ack
  65   // packet, just release storage and return.
  66   //
  67   if (This->Data->IsBootp || !This->Data->IsAck) {
  68     gBS->FreePool (This->Data);
  69     This->Data = NULL;
  70
  71     if (Private->StopPxeBc) {
  72       Private->PxeBc->Stop (Private->PxeBc);
  73     }
  74
  75     return EFI_SUCCESS;
  76   }
  77   //
  78   // Build option list for DHCP Release packet.
  79   // If any errors occur, just release storage and return.
  80   //
  81   //
  82   // Message type is first.
  83   //
  84   op_list[0]  = DHCP4_MESSAGE_TYPE;
  85   op_list[1]  = 1;
  86   op_list[2]  = DHCP4_MESSAGE_TYPE_RELEASE;
  87
  88   //
  89   // Followed by server identifier.
  90   //
  91   efi_status = find_opt (
  92                 &This->Data->Request,
  93                 DHCP4_SERVER_IDENTIFIER,
  94                 0,
  95                 &op
  96                 );
  97
  98   if (EFI_ERROR (efi_status)) {
  99     gBS->FreePool (This->Data);
 100     This->Data = NULL;
 101
 102     if (Private->StopPxeBc) {
 103       Private->PxeBc->Stop (Private->PxeBc);
 104     }
 105
 106     return EFI_SUCCESS;
 107   }
 108
 109   if (op->len != 4) {
 110     gBS->FreePool (This->Data);
 111     This->Data = NULL;
 112
 113     if (Private->StopPxeBc) {
 114       Private->PxeBc->Stop (Private->PxeBc);
 115     }
 116
 117     return EFI_SUCCESS;
 118   }
 119
 120   CopyMem (&ServerIp, op->data, 4);
 121
 122   op_list[3]  = DHCP4_SERVER_IDENTIFIER;
 123   op_list[4]  = 4;
 124   CopyMem (&op_list[5], &ServerIp, 4);
 125
 126   //
 127   // Followed by end.
 128   //
 129   op_list[9] = DHCP4_END;
 130
 131   //
 132   // We need a subnet mask for IP stack operation.
 133   //
 134   efi_status = find_opt (
 135                 &This->Data->AckNak,
 136                 DHCP4_SUBNET_MASK,
 137                 0,
 138                 &op
 139                 );
 140
 141   if (EFI_ERROR (efi_status)) {
 142     gBS->FreePool (This->Data);
 143     This->Data = NULL;
 144
 145     if (Private->StopPxeBc) {
 146       Private->PxeBc->Stop (Private->PxeBc);
 147     }
 148
 149     return EFI_SUCCESS;
 150   }
 151
 152   if (op->len != 4) {
 153     gBS->FreePool (This->Data);
 154     This->Data = NULL;
 155
 156     if (Private->StopPxeBc) {
 157       Private->PxeBc->Stop (Private->PxeBc);
 158     }
 159
 160     return EFI_SUCCESS;
 161   }
 162
 163   ZeroMem (&subnet_mask, sizeof (EFI_IP_ADDRESS));
 164   CopyMem (&subnet_mask, op->data, 4);
 165
 166   //
 167   // Gateway IP address may be needed.
 168   //
 169   ZeroMem (&gateway_ip, sizeof (EFI_IP_ADDRESS));
 170   CopyMem (&gateway_ip, &This->Data->AckNak.dhcp4.giaddr, 4);
 171
 172   //
 173   // Client IP address needed for IP stack operation.
 174   //
 175   ZeroMem (&client_ip, sizeof (EFI_IP_ADDRESS));
 176   CopyMem (&client_ip, &This->Data->AckNak.dhcp4.yiaddr, 4);
 177
 178   //
 179   // Enable UDP...
 180   //
 181   efi_status = start_udp (Private, &client_ip, &subnet_mask);
 182
 183   if (EFI_ERROR (efi_status)) {
 184     gBS->FreePool (This->Data);
 185     This->Data = NULL;
 186
 187     if (Private->StopPxeBc) {
 188       Private->PxeBc->Stop (Private->PxeBc);
 189     }
 190
 191     return efi_status;
 192   }
 193   //
 194   // Gather information out of DHCP request packet needed for
 195   // DHCP release packet.
 196   //
 197   //
 198   // Setup DHCP Release packet.
 199   //
 200   CopyMem (&This->Data->Request.dhcp4.ciaddr, &client_ip, 4);
 201
 202   ZeroMem (&This->Data->Request.dhcp4.yiaddr, 12);
 203
 204   ZeroMem (&This->Data->Request.dhcp4.sname, 64 + 128);
 205
 206   This->Data->Request.dhcp4.hops  = 0;
 207   This->Data->Request.dhcp4.secs  = 0;
 208   This->Data->Request.dhcp4.flags = 0;
 209
 210   ZeroMem (
 211     &This->Data->Request.dhcp4.options,
 212     sizeof This->Data->Request.dhcp4.options
 213     );
 214
 215   CopyMem (&This->Data->Request.dhcp4.options, op_list, 10);
 216
 217   //
 218   // Transmit DHCP Release packet.
 219   //
 220   tx_udp (
 221     Private,
 222     &ServerIp,
 223     &gateway_ip,
 224     &client_ip,
 225     &This->Data->Request,
 226     DHCP4_MAX_PACKET_SIZE - (DHCP4_UDP_HEADER_SIZE + DHCP4_IP_HEADER_SIZE)
 227     );
 228
 229   gBS->Stall (1000000); /* 1/10th second */
 230
 231   //
 232   // Shutdown PXE BaseCode and release local storage.
 233   //
 234   stop_udp (Private);
 235
 236   gBS->FreePool (This->Data);
 237   This->Data = NULL;
 238
 239   if (Private->StopPxeBc) {
 240     Private->PxeBc->Stop (Private->PxeBc);
 241   }
 242
 243   return EFI_SUCCESS;
 244 }
 245
 246 /* eof - PxeDhcp4Release.c */