Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.ServiceModel/System/ServiceModel/Activation/SharedMemory.cs

@@ -0,0 +1,166 @@
+//----------------------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//----------------------------------------------------------------------------
+
+namespace System.ServiceModel.Activation
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Runtime;
+    using System.Runtime.InteropServices;
+    using System.Runtime.Versioning;
+    using System.Security;
+    using System.Security.Principal;
+    using System.Security.Permissions;
+    using System.ServiceModel.Channels;
+    using System.Threading;
+    using System.ServiceModel;
+    using System.ComponentModel;
+
+    unsafe class SharedMemory : IDisposable
+    {
+        SafeFileMappingHandle fileMapping;
+
+        SharedMemory(SafeFileMappingHandle fileMapping)
+        {
+            this.fileMapping = fileMapping;
+        }
+
+        [PermissionSet(SecurityAction.Demand, Unrestricted = true), SecuritySafeCritical]
+        public static unsafe SharedMemory Create(string name, Guid content, List<SecurityIdentifier> allowedSids)
+        {
+            int errorCode = UnsafeNativeMethods.ERROR_SUCCESS;
+            byte[] binarySecurityDescriptor = SecurityDescriptorHelper.FromSecurityIdentifiers(allowedSids, UnsafeNativeMethods.GENERIC_READ);
+            SafeFileMappingHandle fileMapping;
+            UnsafeNativeMethods.SECURITY_ATTRIBUTES securityAttributes = new UnsafeNativeMethods.SECURITY_ATTRIBUTES();
+            fixed (byte* pinnedSecurityDescriptor = binarySecurityDescriptor)
+            {
+                securityAttributes.lpSecurityDescriptor = (IntPtr)pinnedSecurityDescriptor;
+                fileMapping = UnsafeNativeMethods.CreateFileMapping((IntPtr)(-1), securityAttributes, UnsafeNativeMethods.PAGE_READWRITE, 0, sizeof(SharedMemoryContents), name);
+                errorCode = Marshal.GetLastWin32Error();
+            }
+
+            if (fileMapping.IsInvalid)
+            {
+                fileMapping.SetHandleAsInvalid();
+                fileMapping.Close();
+                throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new Win32Exception(errorCode));
+            }
+
+            SharedMemory sharedMemory = new SharedMemory(fileMapping);
+            SafeViewOfFileHandle view;
+
+            // Ignore return value.
+            GetView(fileMapping, true, out view);
+
+            try
+            {
+                SharedMemoryContents* contents = (SharedMemoryContents*)view.DangerousGetHandle();
+                contents->pipeGuid = content;
+                Thread.MemoryBarrier();
+                contents->isInitialized = true;
+                return sharedMemory;
+            }
+            finally
+            {
+                view.Close();
+            }
+        }
+
+        public void Dispose()
+        {
+            if (fileMapping != null)
+            {
+                fileMapping.Close();
+                fileMapping = null;
+            }
+        }
+
+        static bool GetView(SafeFileMappingHandle fileMapping, bool writable, out SafeViewOfFileHandle handle)
+        {
+            handle = UnsafeNativeMethods.MapViewOfFile(fileMapping, writable ? UnsafeNativeMethods.FILE_MAP_WRITE : UnsafeNativeMethods.FILE_MAP_READ, 0, 0, (IntPtr)sizeof(SharedMemoryContents));
+            int errorCode = Marshal.GetLastWin32Error();
+            if (!handle.IsInvalid)
+            {
+                return true;
+            }
+            else
+            {
+                handle.SetHandleAsInvalid();
+                fileMapping.Close();
+
+                // Only return false when it's reading time.
+                if (!writable && errorCode == UnsafeNativeMethods.ERROR_FILE_NOT_FOUND)
+                {
+                    return false;
+                }
+
+                throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new Win32Exception(errorCode));
+            }
+        }
+
+        [PermissionSet(SecurityAction.Demand, Unrestricted = true), SecuritySafeCritical]
+        public static string Read(string name)
+        {
+            string content;
+            if (Read(name, out content))
+            {
+                return content;
+            }
+
+            throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new Win32Exception(UnsafeNativeMethods.ERROR_FILE_NOT_FOUND));
+        }
+
+        [PermissionSet(SecurityAction.Demand, Unrestricted = true), SecuritySafeCritical]
+        [ResourceConsumption(ResourceScope.Machine)]
+        public static bool Read(string name, out string content)
+        {
+            content = null;
+
+            SafeFileMappingHandle fileMapping = UnsafeNativeMethods.OpenFileMapping(UnsafeNativeMethods.FILE_MAP_READ, false, ListenerConstants.GlobalPrefix + name);
+            int errorCode = Marshal.GetLastWin32Error();
+            if (fileMapping.IsInvalid)
+            {
+                fileMapping.SetHandleAsInvalid();
+                fileMapping.Close();
+                if (errorCode == UnsafeNativeMethods.ERROR_FILE_NOT_FOUND)
+                {
+                    return false;
+                }
+
+                throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new Win32Exception(errorCode));
+            }
+
+            try
+            {
+                SafeViewOfFileHandle view;
+                if (!GetView(fileMapping, false, out view))
+                {
+                    return false;
+                }
+
+                try
+                {
+                    SharedMemoryContents* contents = (SharedMemoryContents*)view.DangerousGetHandle();
+                    content = contents->isInitialized ? contents->pipeGuid.ToString() : null;
+                    return true;
+                }
+                finally
+                {
+                    view.Close();
+                }
+            }
+            finally
+            {
+                fileMapping.Close();
+            }
+        }
+
+        [StructLayout(LayoutKind.Sequential)]
+        struct SharedMemoryContents
+        {
+            public bool isInitialized;
+            public Guid pipeGuid;
+        }
+    }
+}