StdLib/BsdSocketLib/read.c

   1 /** @file
   2   Implement the read API.
   3
   4   Copyright (c) 2011, Intel Corporation
   5   All rights reserved. This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #include <SocketInternals.h>
  16
  17
  18 /**
  19   Read support routine for sockets
  20
  21   The BslSocketRead routine is called indirectly by the read file
  22   system routine.  This routine is typically used for SOCK_STREAM
  23   because it waits for receive data from the target system specified
  24   in the ::connect call.
  25
  26   @param [in] pDescriptor   Descriptor address for the file
  27   @param [in] pOffset       File offset
  28   @param [in] LengthInBytes Number of bytes to read
  29   @param [in] pBuffer       Address of the buffer to receive the data
  30
  31   @return   The number of bytes read or -1 if an error occurs.
  32             In the case of an error, ::errno contains more details.
  33
  34 **/
  35 ssize_t
  36 EFIAPI
  37 BslSocketRead (
  38   struct __filedes *pDescriptor,
  39   off_t * pOffset,
  40   size_t LengthInBytes,
  41   void * pBuffer
  42   )
  43 {
  44   ssize_t BytesRead;
  45
  46   //
  47   //  Receive the data from the remote system
  48   //
  49   BytesRead = recvfrom ( pDescriptor->MyFD,
  50                          pBuffer,
  51                          LengthInBytes,
  52                          0,
  53                          NULL,
  54                          NULL );
  55
  56   //
  57   //  Return the number of bytes read
  58   //
  59   return BytesRead;
  60 }