/** @file
 Perform DNS resolution based on UEFI DNS protocols.

Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include "IScsiImpl.h"

/**
  Notify the callback function when an event is triggered.

  @param[in]  Event           The triggered event.
  @param[in]  Context         The opaque parameter to the function.

**/
VOID
EFIAPI
IScsiCommonNotify (
  IN EFI_EVENT           Event,
  IN VOID                *Context
  )
{
  *((BOOLEAN *) Context) = TRUE;
}

/**
  Retrieve the host address using the EFI_DNS4_PROTOCOL.

  @param[in]  Image               The handle of the driver image.
  @param[in]  Controller          The handle of the controller.
  @param[in, out]  NvData         The Session config data structure.

  @retval EFI_SUCCESS             Operation succeeded.
  @retval EFI_OUT_OF_RESOURCES    Failed to allocate needed resources.
  @retval EFI_DEVICE_ERROR        An unexpected network error occurred.
  @retval Others                  Other errors as indicated.

**/
EFI_STATUS
IScsiDns4 (
  IN     EFI_HANDLE                      Image,
  IN     EFI_HANDLE                      Controller,
  IN OUT ISCSI_SESSION_CONFIG_NVDATA     *NvData
  )
{
  EFI_STATUS                      Status;
  EFI_DNS4_PROTOCOL               *Dns4;
  EFI_DNS4_CONFIG_DATA            Dns4CfgData;
  EFI_DNS4_COMPLETION_TOKEN       Token;
  BOOLEAN                         IsDone;
  EFI_HANDLE                      Dns4Handle;
  EFI_IP4_CONFIG2_PROTOCOL        *Ip4Config2;
  EFI_IPv4_ADDRESS                *DnsServerList;
  UINTN                           DnsServerListCount;
  UINTN                           DataSize;
  CHAR16                          *HostName;

  DnsServerList      = NULL;
  DnsServerListCount = 0;
  Dns4Handle         = NULL;
  Dns4               = NULL;
  ZeroMem (&Token, sizeof (EFI_DNS4_COMPLETION_TOKEN));

  //
  // Get DNS server list from EFI IPv4 Configuration II protocol.
  //
  Status = gBS->HandleProtocol (Controller, &gEfiIp4Config2ProtocolGuid, (VOID **) &Ip4Config2);
  if (!EFI_ERROR (Status)) {
    //
    // Get the required size.
    //
    DataSize = 0;
    Status   = Ip4Config2->GetData (Ip4Config2, Ip4Config2DataTypeDnsServer, &DataSize, NULL);
    if (Status == EFI_BUFFER_TOO_SMALL) {
      DnsServerList = AllocatePool (DataSize);
      if (DnsServerList == NULL) {
        return EFI_OUT_OF_RESOURCES;
      }

      Status   = Ip4Config2->GetData (Ip4Config2, Ip4Config2DataTypeDnsServer, &DataSize, DnsServerList);
      if (EFI_ERROR (Status)) {
        FreePool (DnsServerList);
        DnsServerList = NULL;
      } else {
        DnsServerListCount = DataSize / sizeof (EFI_IPv4_ADDRESS);
      }
    }
  }


  //
  // Create a DNS child instance and get the protocol.
  //
  Status = NetLibCreateServiceChild (
             Controller,
             Image,
             &gEfiDns4ServiceBindingProtocolGuid,
             &Dns4Handle
             );
  if (EFI_ERROR (Status)) {
    goto Exit;
  }

  Status = gBS->OpenProtocol (
                  Dns4Handle,
                  &gEfiDns4ProtocolGuid,
                  (VOID **) &Dns4,
                  Image,
                  Controller,
                  EFI_OPEN_PROTOCOL_BY_DRIVER
                  );
  if (EFI_ERROR (Status)) {
    goto Exit;
  }

  //
  // Configure DNS4 instance for the DNS server address and protocol.
  //
  ZeroMem (&Dns4CfgData, sizeof (Dns4CfgData));
  Dns4CfgData.DnsServerListCount = DnsServerListCount;
  Dns4CfgData.DnsServerList      = DnsServerList;
  Dns4CfgData.EnableDnsCache     = TRUE;
  IP4_COPY_ADDRESS (&Dns4CfgData.StationIp, &NvData->LocalIp);
  IP4_COPY_ADDRESS (&Dns4CfgData.SubnetMask, &NvData->SubnetMask);
  Dns4CfgData.Protocol           = EFI_IP_PROTO_UDP;
  Status = Dns4->Configure (
                   Dns4,
                   &Dns4CfgData
                   );
  if (EFI_ERROR (Status)) {
    goto Exit;
  }

  //
  // Create event to set the is done flag when name resolution is finished.
  //
  ZeroMem (&Token, sizeof (Token));
  Status = gBS->CreateEvent (
                  EVT_NOTIFY_SIGNAL,
                  TPL_NOTIFY,
                  IScsiCommonNotify,
                  &IsDone,
                  &Token.Event
                  );
  if (EFI_ERROR (Status)) {
    goto Exit;
  }

  //
  // Start asynchronous name resolution.
  //
  Token.Status = EFI_NOT_READY;
  IsDone       = FALSE;

  HostName = (CHAR16 *) AllocateZeroPool (ISCSI_NAME_MAX_SIZE);
  if (HostName == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  AsciiStrToUnicodeStrS (
    NvData->TargetUrl,
    HostName,
    ISCSI_NAME_MAX_SIZE
    );

  Status = Dns4->HostNameToIp (Dns4, HostName, &Token);
  if (EFI_ERROR (Status)) {
    goto Exit;
  }

  while (!IsDone) {
    Dns4->Poll (Dns4);
  }

  //
  // Name resolution is done, check result.
  //
  Status = Token.Status;
  if (!EFI_ERROR (Status)) {
    if (Token.RspData.H2AData == NULL) {
      Status = EFI_DEVICE_ERROR;
      goto Exit;
    }
    if (Token.RspData.H2AData->IpCount == 0 || Token.RspData.H2AData->IpList == NULL) {
      Status = EFI_DEVICE_ERROR;
      goto Exit;
    }
    //
    // We just return the first IP address from DNS protocol.
    //
    IP4_COPY_ADDRESS (&NvData->TargetIp.v4, Token.RspData.H2AData->IpList);
    Status = EFI_SUCCESS;
  }

Exit:

  if (Token.Event != NULL) {
    gBS->CloseEvent (Token.Event);
  }
  if (Token.RspData.H2AData != NULL) {
    if (Token.RspData.H2AData->IpList != NULL) {
      FreePool (Token.RspData.H2AData->IpList);
    }
    FreePool (Token.RspData.H2AData);
  }

  if (Dns4 != NULL) {
    Dns4->Configure (Dns4, NULL);

    gBS->CloseProtocol (
           Dns4Handle,
           &gEfiDns4ProtocolGuid,
           Image,
           Controller
           );
  }

  if (Dns4Handle != NULL) {
    NetLibDestroyServiceChild (
      Controller,
      Image,
      &gEfiDns4ServiceBindingProtocolGuid,
      Dns4Handle
      );
  }

  return Status;
}

/**
  Retrieve the host address using the EFI_DNS6_PROTOCOL.

  @param[in]  Image               The handle of the driver image.
  @param[in]  Controller          The handle of the controller.
  @param[in, out]  NvData         The Session config data structure.

  @retval EFI_SUCCESS             Operation succeeded.
  @retval EFI_OUT_OF_RESOURCES    Failed to allocate needed resources.
  @retval EFI_DEVICE_ERROR        An unexpected network error occurred.
  @retval Others                  Other errors as indicated.

**/
EFI_STATUS
IScsiDns6 (
  IN     EFI_HANDLE                      Image,
  IN     EFI_HANDLE                      Controller,
  IN OUT ISCSI_SESSION_CONFIG_NVDATA     *NvData
  )
{
  EFI_STATUS                      Status;
  EFI_DNS6_PROTOCOL               *Dns6;
  EFI_DNS6_CONFIG_DATA            Dns6ConfigData;
  EFI_DNS6_COMPLETION_TOKEN       Token;
  EFI_HANDLE                      Dns6Handle;
  EFI_IP6_CONFIG_PROTOCOL         *Ip6Config;
  EFI_IPv6_ADDRESS                *DnsServerList;
  UINTN                           DnsServerListCount;
  UINTN                           DataSize;
  BOOLEAN                         IsDone;
  CHAR16                          *HostName;

  DnsServerList       = NULL;
  DnsServerListCount  = 0;
  Dns6                = NULL;
  Dns6Handle          = NULL;
  ZeroMem (&Token, sizeof (EFI_DNS6_COMPLETION_TOKEN));

  //
  // Get DNS server list from EFI IPv6 Configuration protocol.
  //
  Status = gBS->HandleProtocol (Controller, &gEfiIp6ConfigProtocolGuid, (VOID **) &Ip6Config);
  if (!EFI_ERROR (Status)) {
    //
    // Get the required size.
    //
    DataSize = 0;
    Status = Ip6Config->GetData (Ip6Config, Ip6ConfigDataTypeDnsServer, &DataSize, NULL);
    if (Status == EFI_BUFFER_TOO_SMALL) {
      DnsServerList = AllocatePool (DataSize);
      if (DnsServerList == NULL) {
        return EFI_OUT_OF_RESOURCES;
      }

      Status = Ip6Config->GetData (Ip6Config, Ip6ConfigDataTypeDnsServer, &DataSize, DnsServerList);
      if (EFI_ERROR (Status)) {
        FreePool (DnsServerList);
        DnsServerList = NULL;
      } else {
        DnsServerListCount = DataSize / sizeof (EFI_IPv6_ADDRESS);
      }
    }
  }

  //
  // Create a DNSv6 child instance and get the protocol.
  //
  Status = NetLibCreateServiceChild (
             Controller,
             Image,
             &gEfiDns6ServiceBindingProtocolGuid,
             &Dns6Handle
             );
  if (EFI_ERROR (Status)) {
    goto Exit;
  }

  Status = gBS->OpenProtocol (
                  Dns6Handle,
                  &gEfiDns6ProtocolGuid,
                  (VOID **) &Dns6,
                  Image,
                  Controller,
                  EFI_OPEN_PROTOCOL_BY_DRIVER
                  );
  if (EFI_ERROR (Status)) {
    goto Exit;
  }

  //
  // Configure DNS6 instance for the DNS server address and protocol.
  //
  ZeroMem (&Dns6ConfigData, sizeof (EFI_DNS6_CONFIG_DATA));
  Dns6ConfigData.DnsServerCount = (UINT32)DnsServerListCount;
  Dns6ConfigData.DnsServerList  = DnsServerList;
  Dns6ConfigData.EnableDnsCache = TRUE;
  Dns6ConfigData.Protocol       = EFI_IP_PROTO_UDP;
  Status = Dns6->Configure (
                   Dns6,
                   &Dns6ConfigData
                   );
  if (EFI_ERROR (Status)) {
    goto Exit;
  }

  Token.Status = EFI_NOT_READY;
  IsDone       = FALSE;
  //
  // Create event to set the  IsDone flag when name resolution is finished.
  //
  Status = gBS->CreateEvent (
                  EVT_NOTIFY_SIGNAL,
                  TPL_NOTIFY,
                  IScsiCommonNotify,
                  &IsDone,
                  &Token.Event
                  );
  if (EFI_ERROR (Status)) {
    goto Exit;
  }

  //
  // Start asynchronous name resolution.
  //
  HostName = (CHAR16 *) AllocateZeroPool (ISCSI_NAME_MAX_SIZE);
  if (HostName == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  AsciiStrToUnicodeStrS (
    NvData->TargetUrl,
    HostName,
    ISCSI_NAME_MAX_SIZE
    );
  Status = Dns6->HostNameToIp (Dns6, HostName, &Token);
  if (EFI_ERROR (Status)) {
    goto Exit;
  }

  while (!IsDone) {
    Dns6->Poll (Dns6);
  }

  //
  // Name resolution is done, check result.
  //
  Status = Token.Status;
  if (!EFI_ERROR (Status)) {
    if (Token.RspData.H2AData == NULL) {
      Status = EFI_DEVICE_ERROR;
      goto Exit;
    }
    if (Token.RspData.H2AData->IpCount == 0 || Token.RspData.H2AData->IpList == NULL) {
      Status = EFI_DEVICE_ERROR;
      goto Exit;
    }
    //
    // We just return the first IPv6 address from DNS protocol.
    //
    IP6_COPY_ADDRESS (&NvData->TargetIp.v6, Token.RspData.H2AData->IpList);
    Status = EFI_SUCCESS;
  }

Exit:

  if (Token.Event != NULL) {
    gBS->CloseEvent (Token.Event);
  }
  if (Token.RspData.H2AData != NULL) {
    if (Token.RspData.H2AData->IpList != NULL) {
      FreePool (Token.RspData.H2AData->IpList);
    }
    FreePool (Token.RspData.H2AData);
  }

  if (Dns6 != NULL) {
    Dns6->Configure (Dns6, NULL);

    gBS->CloseProtocol (
           Dns6Handle,
           &gEfiDns6ProtocolGuid,
           Image,
           Controller
           );
  }

  if (Dns6Handle != NULL) {
    NetLibDestroyServiceChild (
      Controller,
      Image,
      &gEfiDns6ServiceBindingProtocolGuid,
      Dns6Handle
      );
  }

  return Status;
}