建立 Windows 到 WSL 的端口轉發

Set-WSLPortForward.ps1

<#
.SYNOPSIS
    建立 Windows 到 WSL 的端口轉發

.DESCRIPTION
    此函數會建立從 Windows IP 到 WSL IP 的端口轉發規則，
    允許外部連線透過 Windows 主機連接到 WSL 內的服務。

.PARAMETER ListenPort
    Windows 端監聽的端口號

.PARAMETER ConnectPort
    WSL 端連接的端口號

.PARAMETER Force
    跳過確認提示，直接執行

.EXAMPLE
    Set-WSLPortForward -ListenPort 22 -ConnectPort 22
    建立 SSH 轉發 (22 → 22)

.EXAMPLE
    Set-WSLPortForward -ListenPort 8080 -ConnectPort 80 -Force
    建立 HTTP 轉發 (8080 → 80) 並跳過確認提示

.NOTES
    需要以管理員權限執行
#>
function Set-WSLPortForward {
    [CmdletBinding()]
    param(
        [Parameter(
            Position = 0,
            HelpMessage = "Port number for Windows to listen on"
        )] [ValidateRange(1, 65535)] [Alias("LP", "Listen")]
        [int]$ListenPort,

        [Parameter(
            Position = 1,
            HelpMessage = "Port number to connect to in WSL"
        )] [ValidateRange(1, 65535)] [Alias("CP", "Connect")]
        [int]$ConnectPort = 22,

        [Parameter(
            HelpMessage = "Skip confirmation prompt"
        )] [Alias("F")]
        [switch]$Force
    )
    # 取得 WSL 主機名稱和 IP 地址
    $w = (wsl hostname -I).Split()[0]
    $e = (Get-NetIPConfiguration | Where-Object { $_.IPv4DefaultGateway -and $_.NetAdapter.Status -eq "Up" }).IPv4Address.IPAddress | Select-Object -First 1
    # 如果 WSL 和 Windows 使用相同的 IP 地址，則不需要轉發
    if (!$e -or $w -eq $e) { Write-Host "WSL and Windows share the same IP, no port forwarding needed" -ForegroundColor Yellow; return }
    # 顯示轉發規則
    Write-Host "`nSetting up port forwarding:" -ForegroundColor Yellow
    Write-Host "  External connection ${e}:${ListenPort} → Forward to WSL ${w}:${ConnectPort}"
    # 等待確認執行 (除非使用 -Force 參數)
    if ($Force -or (Read-Host "`nConfirm execution? (Y/N)") -eq 'Y') {
        # netsh 透明代理函數
        function Invoke-Netsh {
            param(
                [Parameter(ValueFromRemainingArguments)]
                [string[]]$Arguments
            )
            # 保存原始編碼
            $originalEncoding = $global:OutputEncoding
            $originalInputEncoding = [console]::InputEncoding
            $originalOutputEncoding = [console]::OutputEncoding
            # 切換為原始編碼
            $global:OutputEncoding=[console]::InputEncoding=[console]::OutputEncoding = [Text.Encoding]::UTF8
            # 執行 netsh 命令
            try {
                $result = & netsh @Arguments 2>&1
                if ($LASTEXITCODE -ne 0) {
                    Write-Error ($result -join "`n"); return
                } else { Write-Output $result }
            }
            # 恢復原始編碼
            finally {
                $global:OutputEncoding = $originalEncoding
                [console]::InputEncoding = $originalInputEncoding
                [console]::OutputEncoding = $originalOutputEncoding
            }
        }

        try {
            # 刪除現有規則
            Invoke-Netsh interface portproxy delete v4tov4 "listenaddress=$e" "listenport=$ListenPort" -ErrorAction Stop
            # 建立新的轉發規則
            Invoke-Netsh interface portproxy add v4tov4 "listenaddress=$e" "listenport=$ListenPort" "connectaddress=$w" "connectport=$ConnectPort" -ErrorAction Stop
            # 顯示轉發規則
            Invoke-Netsh interface portproxy show v4tov4
        } catch { Write-Error $_ }
    } else {
        Write-Host "`nOperation cancelled" -ForegroundColor Yellow
    }
} # Set-WSLPortForward -ListenPort 22 -ConnectPort 22 -Force