OSX/libsecurityd/lib/SharedMemoryClient.h

   1 /*
   2  * Copyright (c) 2016-2017 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #ifndef __SHAREDMEMORYCLIENT__
  25 #define __SHAREDMEMORYCLIENT__
  26
  27 #include <string>
  28 #include <stdlib.h>
  29 #include <securityd_client/SharedMemoryCommon.h>
  30 #include <security_utilities/threading.h>
  31
  32 namespace Security
  33 {
  34
  35
  36 enum UnavailableReason {kURNone, kURMessageDropped, kURMessagePending, kURNoMessage, kURBufferCorrupt};
  37
  38 class SharedMemoryClient
  39 {
  40 protected:
  41         std::string mSegmentName;
  42         size_t mSegmentSize;
  43         Mutex mMutex;
  44     uid_t mUID;
  45
  46         u_int8_t* mSegment;
  47         u_int8_t* mDataArea;
  48         u_int8_t* mDataPtr;
  49         u_int8_t* mDataMax;
  50
  51         SegmentOffsetType GetProducerCount ();
  52
  53         void ReadData (void* buffer, SegmentOffsetType bytesToRead);
  54         SegmentOffsetType ReadOffset ();
  55
  56 public:
  57         SharedMemoryClient (const char* segmentName, SegmentOffsetType segmentSize, uid_t uid = 0);
  58         virtual ~SharedMemoryClient ();
  59
  60         bool ReadMessage (void* message, SegmentOffsetType &length, UnavailableReason &ur);
  61
  62     const char* GetSegmentName() { return mSegmentName.c_str (); }
  63     size_t GetSegmentSize() { return mSegmentSize; }
  64
  65     uid_t getUID() const { return mUID; }
  66
  67     bool uninitialized() { return (mSegment == NULL || mSegment == MAP_FAILED); }
  68 };
  69
  70 };  /* namespace */
  71
  72
  73 #endif
  74