MegaBites-AI/Windows-powershell

1// Copyright (c) Microsoft Corporation.2// Licensed under the MIT License.3 4#nullable enable5 6using System;7using System.Buffers;8using System.Runtime.InteropServices;9using System.Management.Automation.Internal;10 11internal static partial class Interop12{13    internal static unsafe partial class Windows14    {15        private static bool s_WNetApiNotAvailable;16 17        [LibraryImport("mpr.dll", EntryPoint = "WNetGetConnectionW", StringMarshalling = StringMarshalling.Utf16)]18        internal static partial int WNetGetConnection(ReadOnlySpan<char> localName, Span<char> remoteName, ref int remoteNameLength);19 20        internal static int GetUNCForNetworkDrive(char drive, out string? uncPath)21        {22            uncPath = null;23            if (s_WNetApiNotAvailable)24            {25                return ERROR_NOT_SUPPORTED;26            }27 28            ReadOnlySpan<char> driveName = [drive, ':', '\0'];29            int bufferSize = MAX_PATH;30            Span<char> uncBuffer = stackalloc char[MAX_PATH];31            if (InternalTestHooks.WNetGetConnectionBufferSize > 0 && InternalTestHooks.WNetGetConnectionBufferSize <= MAX_PATH)32            {33                bufferSize = InternalTestHooks.WNetGetConnectionBufferSize;34                uncBuffer = uncBuffer.Slice(0, bufferSize);35            }36 37            char[]? rentedArray = null;38            while (true)39            {40                int errorCode;41                try42                {43                    try44                    {45                        errorCode = WNetGetConnection(driveName, uncBuffer, ref bufferSize);46                    }47                    catch (DllNotFoundException)48                    {49                        s_WNetApiNotAvailable = true;50                        return ERROR_NOT_SUPPORTED;51                    }52 53                    if (errorCode == ERROR_SUCCESS)54                    {55                        // Cannot rely on bufferSize as it's only set if56                        // the first call ended with ERROR_MORE_DATA,57                        // instead slice at the null terminator.58                        unsafe59                        {60                            fixed (char* uncBufferPtr = uncBuffer)61                            {62                                uncPath = new string(uncBufferPtr);63                            }64                        }65                    }66                }67                finally68                {69                    if (rentedArray is not null)70                    {71                        ArrayPool<char>.Shared.Return(rentedArray);72                    }73                }74 75                if (errorCode == ERROR_MORE_DATA)76                {77                    uncBuffer = rentedArray = ArrayPool<char>.Shared.Rent(bufferSize);78                }79                else80                {81                    return errorCode;82                }83            }84        }85    }86}87