Re: [Patch] MdeModulePkg: Support classless IP for DHCPv4 TransmitReceive()

["Fu, Siyuan" <siyuan.fu@intel.com>]

Reviewed-by: Fu Siyuan <siyuan.fu@intel.com>

> -----Original Message-----
> From: Wu, Jiaxin
> Sent: Thursday, August 18, 2016 1:39 PM
> To: edk2-devel@lists.01.org
> Cc: Santhapur Naveen <naveens@amiindia.co.in>; Ye, Ting
> <ting.ye@intel.com>; Fu, Siyuan <siyuan.fu@intel.com>
> Subject: [Patch] MdeModulePkg: Support classless IP for DHCPv4
> TransmitReceive()
> 
> The IP address should not be treated as classful one if DHCP options
> contain a classless IP with its true subnet mask. Otherwise, DHCPv4
> TransmitReceive() will failed. This real subnet mask will be parsed
> and recorded in DhcpSb->Netmask. So, we need check it before get the
> IP's corresponding subnet mask.
> 
> Cc: Santhapur Naveen <naveens@amiindia.co.in>
> Cc: Ye Ting <ting.ye@intel.com>
> Cc: Fu Siyuan <siyuan.fu@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
> ---
>  .../Universal/Network/Dhcp4Dxe/Dhcp4Impl.c         | 28 +++++++++++++++--
> -----
>  1 file changed, 20 insertions(+), 8 deletions(-)
> 
> diff --git a/MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Impl.c
> b/MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Impl.c
> index 4f491b4..79f7cde 100644
> --- a/MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Impl.c
> +++ b/MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Impl.c
> @@ -1,9 +1,9 @@
>  /** @file
>    This file implement the EFI_DHCP4_PROTOCOL interface.
> 
> -Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
> +Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
>  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
> 
> @@ -1186,18 +1186,20 @@ Dhcp4InstanceConfigUdpIo (
>    IN UDP_IO       *UdpIo,
>    IN VOID         *Context
>    )
>  {
>    DHCP_PROTOCOL                     *Instance;
> +  DHCP_SERVICE                      *DhcpSb;
>    EFI_DHCP4_TRANSMIT_RECEIVE_TOKEN  *Token;
>    EFI_UDP4_CONFIG_DATA              UdpConfigData;
>    IP4_ADDR                          ClientAddr;
>    IP4_ADDR                          Ip;
>    INTN                              Class;
>    IP4_ADDR                          SubnetMask;
> 
>    Instance = (DHCP_PROTOCOL *) Context;
> +  DhcpSb   = Instance->Service;
>    Token    = Instance->Token;
> 
>    ZeroMem (&UdpConfigData, sizeof (EFI_UDP4_CONFIG_DATA));
> 
>    UdpConfigData.AcceptBroadcast    = TRUE;
> @@ -1206,14 +1208,19 @@ Dhcp4InstanceConfigUdpIo (
>    UdpConfigData.DoNotFragment      = TRUE;
> 
>    ClientAddr = EFI_NTOHL (Token->Packet->Dhcp4.Header.ClientAddr);
>    Ip = HTONL (ClientAddr);
>    CopyMem (&UdpConfigData.StationAddress, &Ip, sizeof (EFI_IPv4_ADDRESS));
> -
> -  Class = NetGetIpClass (ClientAddr);
> -  ASSERT (Class < IP4_ADDR_CLASSE);
> -  SubnetMask = gIp4AllMasks[Class << 3];
> +
> +  if (DhcpSb->Netmask == 0) {
> +    Class = NetGetIpClass (ClientAddr);
> +    ASSERT (Class < IP4_ADDR_CLASSE);
> +    SubnetMask = gIp4AllMasks[Class << 3];
> +  } else {
> +    SubnetMask = DhcpSb->Netmask;
> +  }
> +
>    Ip = HTONL (SubnetMask);
>    CopyMem (&UdpConfigData.SubnetMask, &Ip, sizeof (EFI_IPv4_ADDRESS));
> 
>    if ((Token->ListenPointCount == 0) || (Token-
> >ListenPoints[0].ListenPort == 0)) {
>      UdpConfigData.StationPort = DHCP_CLIENT_PORT;
> @@ -1574,16 +1581,21 @@ EfiDhcp4TransmitReceive (
>      EndPoint.RemotePort = DHCP_SERVER_PORT;
>    } else {
>      EndPoint.RemotePort = Token->RemotePort;
>    }
> 
> +  if (DhcpSb->Netmask == 0) {
> +    Class = NetGetIpClass (ClientAddr);
> +    ASSERT (Class < IP4_ADDR_CLASSE);
> +    SubnetMask = gIp4AllMasks[Class << 3];
> +  } else {
> +    SubnetMask = DhcpSb->Netmask;
> +  }
> +
>    //
>    // Get the gateway.
>    //
> -  Class = NetGetIpClass (ClientAddr);
> -  ASSERT (Class < IP4_ADDR_CLASSE);
> -  SubnetMask = gIp4AllMasks[Class << 3];
>    ZeroMem (&Gateway, sizeof (Gateway));
>    if (!IP4_NET_EQUAL (ClientAddr, EndPoint.RemoteAddr.Addr[0],
> SubnetMask)) {
>      CopyMem (&Gateway.v4, &Token->GatewayAddress, sizeof
> (EFI_IPv4_ADDRESS));
>      Gateway.Addr[0] = NTOHL (Gateway.Addr[0]);
>    }
> --
> 1.9.5.msysgit.1