MdeModulePkg/Universal/Network/PxeDhcp4Dxe/PxeDhcp4Release.c

   1 /** @file
   2
   3 Copyright (c) 2004, 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
  22 #include "PxeDhcp4.h"
  23
  24 /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
  25 EFI_STATUS
  26 EFIAPI
  27 PxeDhcp4Release (
  28   IN EFI_PXE_DHCP4_PROTOCOL *This
  29   )
  30 {
  31   PXE_DHCP4_PRIVATE_DATA  *Private;
  32   EFI_IP_ADDRESS          ServerIp;
  33   EFI_IP_ADDRESS          client_ip;
  34   EFI_IP_ADDRESS          gateway_ip;
  35   EFI_IP_ADDRESS          subnet_mask;
  36   EFI_STATUS              efi_status;
  37   DHCP4_OP                *op;
  38   UINT8                   op_list[20];
  39
  40   //
  41   // Check for invalid parameters.
  42   //
  43   if (This == NULL) {
  44     return EFI_INVALID_PARAMETER;
  45   }
  46   //
  47   // Release does nothing if the protocol has never been setup.
  48   //
  49   if (This->Data == NULL) {
  50     return EFI_NOT_STARTED;
  51   }
  52   //
  53   // Fail if we do not have valid instance data.
  54   //
  55   Private = PXE_DHCP4_PRIVATE_DATA_FROM_THIS (This);
  56
  57   if (Private == NULL) {
  58     return EFI_INVALID_PARAMETER;
  59   }
  60
  61   if (Private->PxeBc == NULL) {
  62     return EFI_DEVICE_ERROR;
  63   }
  64   //
  65   // If this is a BOOTP session and there is not a DHCP Ack
  66   // packet, just release storage and return.
  67   //
  68   if (This->Data->IsBootp || !This->Data->IsAck) {
  69     gBS->FreePool (This->Data);
  70     This->Data = NULL;
  71
  72     if (Private->StopPxeBc) {
  73       Private->PxeBc->Stop (Private->PxeBc);
  74     }
  75
  76     return EFI_SUCCESS;
  77   }
  78   //
  79   // Build option list for DHCP Release packet.
  80   // If any errors occur, just release storage and return.
  81   //
  82   //
  83   // Message type is first.
  84   //
  85   op_list[0]  = DHCP4_MESSAGE_TYPE;
  86   op_list[1]  = 1;
  87   op_list[2]  = DHCP4_MESSAGE_TYPE_RELEASE;
  88
  89   //
  90   // Followed by server identifier.
  91   //
  92   efi_status = find_opt (
  93                 &This->Data->Request,
  94                 DHCP4_SERVER_IDENTIFIER,
  95                 0,
  96                 &op
  97                 );
  98
  99   if (EFI_ERROR (efi_status)) {
 100     gBS->FreePool (This->Data);
 101     This->Data = NULL;
 102
 103     if (Private->StopPxeBc) {
 104       Private->PxeBc->Stop (Private->PxeBc);
 105     }
 106
 107     return EFI_SUCCESS;
 108   }
 109
 110   if (op->len != 4) {
 111     gBS->FreePool (This->Data);
 112     This->Data = NULL;
 113
 114     if (Private->StopPxeBc) {
 115       Private->PxeBc->Stop (Private->PxeBc);
 116     }
 117
 118     return EFI_SUCCESS;
 119   }
 120
 121   CopyMem (&ServerIp, op->data, 4);
 122
 123   op_list[3]  = DHCP4_SERVER_IDENTIFIER;
 124   op_list[4]  = 4;
 125   CopyMem (&op_list[5], &ServerIp, 4);
 126
 127   //
 128   // Followed by end.
 129   //
 130   op_list[9] = DHCP4_END;
 131
 132   //
 133   // We need a subnet mask for IP stack operation.
 134   //
 135   efi_status = find_opt (
 136                 &This->Data->AckNak,
 137                 DHCP4_SUBNET_MASK,
 138                 0,
 139                 &op
 140                 );
 141
 142   if (EFI_ERROR (efi_status)) {
 143     gBS->FreePool (This->Data);
 144     This->Data = NULL;
 145
 146     if (Private->StopPxeBc) {
 147       Private->PxeBc->Stop (Private->PxeBc);
 148     }
 149
 150     return EFI_SUCCESS;
 151   }
 152
 153   if (op->len != 4) {
 154     gBS->FreePool (This->Data);
 155     This->Data = NULL;
 156
 157     if (Private->StopPxeBc) {
 158       Private->PxeBc->Stop (Private->PxeBc);
 159     }
 160
 161     return EFI_SUCCESS;
 162   }
 163
 164   ZeroMem (&subnet_mask, sizeof (EFI_IP_ADDRESS));
 165   CopyMem (&subnet_mask, op->data, 4);
 166
 167   //
 168   // Gateway IP address may be needed.
 169   //
 170   ZeroMem (&gateway_ip, sizeof (EFI_IP_ADDRESS));
 171   CopyMem (&gateway_ip, &This->Data->AckNak.dhcp4.giaddr, 4);
 172
 173   //
 174   // Client IP address needed for IP stack operation.
 175   //
 176   ZeroMem (&client_ip, sizeof (EFI_IP_ADDRESS));
 177   CopyMem (&client_ip, &This->Data->AckNak.dhcp4.yiaddr, 4);
 178
 179   //
 180   // Enable UDP...
 181   //
 182   efi_status = start_udp (Private, &client_ip, &subnet_mask);
 183
 184   if (EFI_ERROR (efi_status)) {
 185     gBS->FreePool (This->Data);
 186     This->Data = NULL;
 187
 188     if (Private->StopPxeBc) {
 189       Private->PxeBc->Stop (Private->PxeBc);
 190     }
 191
 192     return efi_status;
 193   }
 194   //
 195   // Gather information out of DHCP request packet needed for
 196   // DHCP release packet.
 197   //
 198   //
 199   // Setup DHCP Release packet.
 200   //
 201   CopyMem (&This->Data->Request.dhcp4.ciaddr, &client_ip, 4);
 202
 203   ZeroMem (&This->Data->Request.dhcp4.yiaddr, 12);
 204
 205   ZeroMem (&This->Data->Request.dhcp4.sname, 64 + 128);
 206
 207   This->Data->Request.dhcp4.hops  = 0;
 208   This->Data->Request.dhcp4.secs  = 0;
 209   This->Data->Request.dhcp4.flags = 0;
 210
 211   ZeroMem (
 212     &This->Data->Request.dhcp4.options,
 213     sizeof This->Data->Request.dhcp4.options
 214     );
 215
 216   CopyMem (&This->Data->Request.dhcp4.options, op_list, 10);
 217
 218   //
 219   // Transmit DHCP Release packet.
 220   //
 221   tx_udp (
 222     Private,
 223     &ServerIp,
 224     &gateway_ip,
 225     &client_ip,
 226     &This->Data->Request,
 227     DHCP4_MAX_PACKET_SIZE - (DHCP4_UDP_HEADER_SIZE + DHCP4_IP_HEADER_SIZE)
 228     );
 229
 230   gBS->Stall (1000000); /* 1/10th second */
 231
 232   //
 233   // Shutdown PXE BaseCode and release local storage.
 234   //
 235   stop_udp (Private);
 236
 237   gBS->FreePool (This->Data);
 238   This->Data = NULL;
 239
 240   if (Private->StopPxeBc) {
 241     Private->PxeBc->Stop (Private->PxeBc);
 242   }
 243
 244   return EFI_SUCCESS;
 245 }
 246
 247 /* eof - PxeDhcp4Release.c */