pxedhcp4initselect.c

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/*++

Copyright (c) 2004, Intel Corporation                                                         
All rights reserved. This program and the accompanying materials                          
are licensed and made available under the terms and conditions of the BSD License         
which accompanies this distribution.  The full text of the license may be found at        
http://opensource.org/licenses/bsd-license.php                                            
                                                                                          
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             

Module Name:
  PxeDhcp4InitSelect.c
  
Abstract:

--*/

#include "PxeDhcp4.h"

#define DebugPrint(x)
//
// #define DebugPrint(x) Aprint x
//

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
STATIC
INTN
offer_verify (
  IN PXE_DHCP4_PRIVATE_DATA *Private,
  IN DHCP4_PACKET           *tx_pkt,
  IN DHCP4_PACKET           *rx_pkt,
  IN UINTN                  rx_pkt_size
  )
/*++
  -2 = ignore, stop waiting
  -1 = ignore, keep waiting
  0 = accept, keep waiting
  1 = accept, stop waiting
--*/
{
  EFI_STATUS    EfiStatus;
  DHCP4_PACKET  *tmp;
  DHCP4_OP      *msg_type_op;
  DHCP4_OP      *srvid_op;
  UINT32        magik;

  //
  // Verify parameters.  Touch unused parameters to keep
  // compiler happy.
  //
  ASSERT (Private);
  ASSERT (rx_pkt);

  if (Private == NULL || rx_pkt == NULL) {
    return -2;
  }

  tx_pkt      = tx_pkt;
  rx_pkt_size = rx_pkt_size;

  //
  // This may be a BOOTP Reply or DHCP Offer packet.
  // If there is no DHCP magik number, assume that
  // this is a BOOTP Reply packet.
  //
  magik = htonl (DHCP4_MAGIK_NUMBER);

  while (!EfiCompareMem (&rx_pkt->dhcp4.magik, &magik, 4)) {
    //
    // If there is no DHCP message type option, assume
    // this is a BOOTP reply packet and cache it.
    //
    EfiStatus = find_opt (rx_pkt, DHCP4_MESSAGE_TYPE, 0, &msg_type_op);

    if (EFI_ERROR (EfiStatus)) {
      break;
    }
    //
    // If there is a DHCP message type option, it must be a
    // DHCP offer packet
    //
    if (msg_type_op->len != 1) {
      return -1;
    }

    if (msg_type_op->data[0] != DHCP4_MESSAGE_TYPE_OFFER) {
      return -1;
    }
    //
    // There must be a server identifier option.
    //
    EfiStatus = find_opt (
                  rx_pkt,
                  DHCP4_SERVER_IDENTIFIER,
                  0,
                  &srvid_op
                  );

    if (EFI_ERROR (EfiStatus)) {
      return -1;
    }

    if (srvid_op->len != 4) {
      return -1;
    }
    //
    // Good DHCP offer packet.
    //
    break;
  }
  //
  // Good DHCP (or BOOTP) packet.  Cache it!
  //
  EfiStatus = gBS->AllocatePool (
                    EfiBootServicesData,
                    (Private->offers + 1) * sizeof (DHCP4_PACKET),
                    (VOID **) &tmp
                    );

  if (EFI_ERROR (EfiStatus)) {
    return -2;
  }

  ASSERT (tmp);

  if (Private->offers != 0) {
    EfiCopyMem (
      tmp,
      Private->offer_list,
      Private->offers * sizeof (DHCP4_PACKET)
      );

    gBS->FreePool (Private->offer_list);
  }

  EfiCopyMem (&tmp[Private->offers++], rx_pkt, sizeof (DHCP4_PACKET));

  Private->offer_list = tmp;

  return 0;
}

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
STATIC
INTN
acknak_verify (
  IN PXE_DHCP4_PRIVATE_DATA *Private,
  IN DHCP4_PACKET           *tx_pkt,
  IN DHCP4_PACKET           *rx_pkt,
  IN UINTN                  rx_pkt_size
  )
/*++
  -2 = ignore, stop waiting
  -1 = ignore, keep waiting
  0 = accept, keep waiting
  1 = accept, stop waiting
--*/
{
  EFI_STATUS  EfiStatus;
  DHCP4_OP    *msg_type_op;
  DHCP4_OP    *srvid_op;
  DHCP4_OP    *renew_op;
  DHCP4_OP    *rebind_op;
  DHCP4_OP    *lease_time_op;
  UINT32      magik;

  //
  // Verify parameters.  Touch unused parameters to
  // keep compiler happy.
  //
  ASSERT (Private);
  ASSERT (rx_pkt);

  if (Private == NULL || rx_pkt == NULL) {
    return -2;
  }

  tx_pkt      = tx_pkt;
  rx_pkt_size = rx_pkt_size;

  //
  // This must be a DHCP Ack message.
  //
  magik = htonl (DHCP4_MAGIK_NUMBER);

  if (EfiCompareMem (&rx_pkt->dhcp4.magik, &magik, 4)) {
    return -1;
  }

  EfiStatus = find_opt (rx_pkt, DHCP4_MESSAGE_TYPE, 0, &msg_type_op);

  if (EFI_ERROR (EfiStatus)) {
    return -1;
  }

  if (msg_type_op->len != 1) {
    return -1;
  }

  if (msg_type_op->data[0] != DHCP4_MESSAGE_TYPE_ACK) {
    return -1;
  }
  //
  // There must be a server identifier.
  //
  EfiStatus = find_opt (rx_pkt, DHCP4_SERVER_IDENTIFIER, 0, &srvid_op);

  if (EFI_ERROR (EfiStatus)) {
    return -1;
  }

  if (srvid_op->len != 4) {
    return -1;
  }
  //
  // There should be a renewal time.
  // If there is not, we will default to the 7/8 of the rebinding time.
  //
  EfiStatus = find_opt (rx_pkt, DHCP4_RENEWAL_TIME, 0, &renew_op);

  if (EFI_ERROR (EfiStatus)) {
    renew_op = NULL;
  } else if (renew_op->len != 4) {
    renew_op = NULL;
  }
  //
  // There should be a rebinding time.
  // If there is not, we will default to 7/8 of the lease time.
  //
  EfiStatus = find_opt (rx_pkt, DHCP4_REBINDING_TIME, 0, &rebind_op);

  if (EFI_ERROR (EfiStatus)) {
    rebind_op = NULL;
  } else if (rebind_op->len != 4) {
    rebind_op = NULL;
  }
  //
  // There should be a lease time.
  // If there is not, we will default to one week.
  //
  EfiStatus = find_opt (rx_pkt, DHCP4_LEASE_TIME, 0, &lease_time_op);

  if (EFI_ERROR (EfiStatus)) {
    lease_time_op = NULL;
  } else if (lease_time_op->len != 4) {
    lease_time_op = NULL;
  }
  //
  // Packet looks good.  Double check the renew, rebind and lease times.
  //
  EfiCopyMem (&Private->ServerIp, srvid_op->data, 4);

  if (renew_op != NULL) {
    EfiCopyMem (&Private->RenewTime, renew_op->data, 4);
    Private->RenewTime = htonl (Private->RenewTime);
  } else {
    Private->RenewTime = 0;
  }

  if (rebind_op != NULL) {
    EfiCopyMem (&Private->RebindTime, rebind_op->data, 4);
    Private->RebindTime = htonl (Private->RebindTime);
  } else {
    Private->RebindTime = 0;
  }

  if (lease_time_op != NULL) {
    EfiCopyMem (&Private->LeaseTime, lease_time_op->data, 4);
    Private->LeaseTime = htonl (Private->LeaseTime);
  } else {
    Private->LeaseTime = 0;
  }

  if (Private->LeaseTime < 60) {
    Private->LeaseTime = 7 * 86400;
  }

  if (Private->RebindTime < 52 || Private->RebindTime >= Private->LeaseTime) {
    Private->RebindTime = Private->LeaseTime / 2 + Private->LeaseTime / 4 + Private->LeaseTime / 8;
  }

  if (Private->RenewTime < 45 || Private->RenewTime >= Private->RebindTime) {
    Private->RenewTime = Private->RebindTime / 2 + Private->RebindTime / 4 + Private->RebindTime / 8;
  }

  return 1;
}

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
EFI_STATUS
EFIAPI
PxeDhcp4Init (
  IN EFI_PXE_DHCP4_PROTOCOL *This,
  IN UINTN                  seconds_timeout,
  OUT UINTN                 *Offers,
  OUT DHCP4_PACKET          **OfferList
  )
{
  PXE_DHCP4_PRIVATE_DATA  *Private;
  DHCP4_PACKET            offer;
  EFI_IP_ADDRESS          bcast_ip;
  EFI_STATUS              EfiStatus;

  //
  // Verify parameters and protocol state.
  //
  if (This == NULL ||
      seconds_timeout < DHCP4_MIN_SECONDS ||
      seconds_timeout > DHCP4_MAX_SECONDS ||
      Offers == NULL ||
      OfferList == NULL
      ) {
    //
    // Return parameters are not initialized when
    // parameters are invalid!
    //
    return EFI_INVALID_PARAMETER;
  }

  *Offers     = 0;
  *OfferList  = NULL;

  //
  // Check protocol state.
  //
  if (This->Data == NULL) {
    return EFI_NOT_STARTED;
  }

  if (!This->Data->SetupCompleted) {
    return EFI_NOT_READY;
  }

#if 0
  if (!is_good_discover (&This->Data->Discover)) {
    //
    // %%TBD - check discover packet fields
    //
  }
#endif
  //
  // Get pointer to our instance data.
  //
  Private = PXE_DHCP4_PRIVATE_DATA_FROM_THIS (This);

  if (Private == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  if (Private->PxeBc == NULL) {
    return EFI_DEVICE_ERROR;
  }
  //
  // Setup variables...
  //
  Private->offers     = 0;
  Private->offer_list = NULL;

  EfiStatus = gBS->HandleProtocol (
                    Private->Handle,
                    &gEfiPxeDhcp4CallbackProtocolGuid,
                    (VOID *) &Private->callback
                    );

  if (EFI_ERROR (EfiStatus)) {
    Private->callback = NULL;
  }

  Private->function = EFI_PXE_DHCP4_FUNCTION_INIT;

  //
  // Increment the transaction ID.
  //
  {
    UINT32  xid;

    EfiCopyMem (&xid, &This->Data->Discover.dhcp4.xid, sizeof (UINT32));

    xid = htonl (htonl (xid) + 1);

    EfiCopyMem (&This->Data->Discover.dhcp4.xid, &xid, sizeof (UINT32));
  }
  //
  // Transmit discover and wait for offers...
  //
  EfiSetMem (&bcast_ip, sizeof (EFI_IP_ADDRESS), 0xFF);

  EfiStatus = tx_rx_udp (
                Private,
                &bcast_ip,
                NULL,
                NULL,
                NULL,