409 lines
11 KiB
Go
409 lines
11 KiB
Go
// OpsX VPN WireGuard probe and application proxy. The upstream Go userspace
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// engine uses an in-process network stack and does not alter OS routes.
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// The private key stays in the local 0600 device record and is never printed.
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package main
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import (
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"context"
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"encoding/base64"
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"encoding/hex"
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"encoding/json"
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"errors"
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"fmt"
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"io"
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"net"
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"net/netip"
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"os"
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"os/signal"
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"strconv"
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"strings"
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"syscall"
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"time"
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"golang.zx2c4.com/wireguard/conn"
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"golang.zx2c4.com/wireguard/device"
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"golang.zx2c4.com/wireguard/tun/netstack"
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)
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const version = "0.1.0"
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type record struct {
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PrivateKey string `json:"private_key"`
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Config struct {
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ClientAddress string `json:"client_address"`
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ServerPublicKey string `json:"server_public_key"`
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PresharedKey string `json:"preshared_key"`
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Endpoint string `json:"endpoint"`
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AllowedIPs string `json:"allowed_ips"`
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DNS string `json:"dns"`
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MTU uint32 `json:"mtu"`
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Keepalive uint32 `json:"keepalive"`
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} `json:"config"`
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}
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type result struct {
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Connected bool `json:"connected"`
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Detail string `json:"detail"`
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Target string `json:"target,omitempty"`
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}
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func readRecord(path string) (*record, error) {
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info, err := os.Lstat(path)
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if err != nil {
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return nil, fmt.Errorf("无法读取本机设备配置: %w", err)
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}
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if !info.Mode().IsRegular() || info.Mode().Perm()&0077 != 0 {
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return nil, errors.New("本机设备配置权限必须为 0600")
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}
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data, err := os.ReadFile(path)
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if err != nil {
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return nil, fmt.Errorf("无法读取本机设备配置: %w", err)
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}
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var r record
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if err := json.Unmarshal(data, &r); err != nil {
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return nil, errors.New("本机设备配置格式无效")
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}
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return &r, nil
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}
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func key(value string) (string, error) {
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b, err := base64.StdEncoding.DecodeString(value)
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if err != nil || len(b) != 32 {
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return "", errors.New("WireGuard 密钥格式无效")
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}
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return hex.EncodeToString(b), nil
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}
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func permittedRoute(value string, target netip.Addr) (bool, error) {
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for _, raw := range strings.Split(value, ",") {
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prefix, err := netip.ParsePrefix(strings.TrimSpace(raw))
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if err != nil {
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return false, errors.New("WireGuard 路由无效")
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}
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if prefix.Contains(target) {
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return true, nil
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}
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}
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return false, nil
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}
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func uapi(r *record, target netip.Addr) (string, []netip.Addr, error) {
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priv, err := key(r.PrivateKey)
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if err != nil {
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return "", nil, err
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}
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pub, err := key(r.Config.ServerPublicKey)
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if err != nil {
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return "", nil, err
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}
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psk, err := key(r.Config.PresharedKey)
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if err != nil {
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return "", nil, err
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}
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addr, err := netip.ParsePrefix(r.Config.ClientAddress)
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if err != nil {
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return "", nil, errors.New("客户端地址无效")
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}
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host, port, err := net.SplitHostPort(r.Config.Endpoint)
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if err != nil || host == "" || port == "" {
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return "", nil, errors.New("网关端点无效")
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}
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portNum, err := strconv.Atoi(port)
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if err != nil || portNum < 1 || portNum > 65535 {
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return "", nil, errors.New("网关端口无效")
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}
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if strings.ContainsAny(host, "\n\r= ") {
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return "", nil, errors.New("网关地址无效")
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}
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var allowed []string
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var permitted bool
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for _, raw := range strings.Split(r.Config.AllowedIPs, ",") {
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prefix, err := netip.ParsePrefix(strings.TrimSpace(raw))
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if err != nil {
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return "", nil, errors.New("WireGuard 路由无效")
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}
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allowed = append(allowed, "allowed_ip="+prefix.String())
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permitted = permitted || !target.IsValid() || prefix.Contains(target)
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}
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if !permitted {
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return "", nil, errors.New("探测目标不在授权路由内")
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}
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if r.Config.Keepalive > 65535 {
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return "", nil, errors.New("保活参数无效")
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}
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lines := []string{
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"private_key=" + priv, "replace_peers=true", "public_key=" + pub,
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"preshared_key=" + psk, "endpoint=" + r.Config.Endpoint,
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"persistent_keepalive_interval=" + strconv.FormatUint(uint64(r.Config.Keepalive), 10),
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}
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lines = append(lines, allowed...)
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return strings.Join(lines, "\n") + "\n", []netip.Addr{addr.Addr()}, nil
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}
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func startDevice(r *record, target netip.Addr) (*device.Device, *netstack.Net, error) {
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settings, ips, err := uapi(r, target)
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if err != nil {
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return nil, nil, err
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}
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mtu := int(r.Config.MTU)
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if mtu == 0 {
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mtu = 1420
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}
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if mtu < 576 || mtu > 9000 {
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return nil, nil, errors.New("MTU 无效")
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}
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var dns []netip.Addr
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for _, raw := range strings.Split(r.Config.DNS, ",") {
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if strings.TrimSpace(raw) == "" {
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continue
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}
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ip, err := netip.ParseAddr(strings.TrimSpace(raw))
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if err != nil {
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return nil, nil, errors.New("DNS 地址无效")
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}
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dns = append(dns, ip)
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}
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tun, stack, err := netstack.CreateNetTUN(ips, dns, mtu)
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if err != nil {
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return nil, nil, fmt.Errorf("创建 Go 网络栈失败: %w", err)
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}
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dev := device.NewDevice(tun, conn.NewDefaultBind(), device.NewLogger(device.LogLevelSilent, ""))
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if err := dev.IpcSet(settings); err != nil {
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dev.Close()
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return nil, nil, errors.New("WireGuard 连接参数无效")
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}
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if err := dev.Up(); err != nil {
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dev.Close()
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return nil, nil, fmt.Errorf("启动 Go 隧道失败: %w", err)
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}
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return dev, stack, nil
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}
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func probe(ctx context.Context, r *record, target string) error {
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addr, err := netip.ParseAddrPort(target)
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if err != nil {
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return errors.New("探测地址必须为 IP:端口")
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}
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dev, stack, err := startDevice(r, addr.Addr())
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if err != nil {
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return err
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}
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defer dev.Close()
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channel := make(chan error, 1)
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go func() {
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c, err := stack.DialContext(ctx, "tcp", target)
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if err == nil {
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_ = c.Close()
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}
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channel <- err
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}()
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select {
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case err := <-channel:
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if err != nil {
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return fmt.Errorf("VPN 出口 TCP 连接失败: %w", err)
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}
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return nil
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case <-ctx.Done():
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return errors.New("VPN 出口连接超时，请检查握手、网关 NAT 和防火墙")
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}
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}
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// A loopback-only SOCKS5 listener provides real, user-space TCP access without
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// claiming to alter the operating system's routing table. DNS is resolved in
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// the VPN netstack, and every destination is checked against AllowedIPs.
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func serveSOCKS(r *record, address string) error {
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listenAddr, err := netip.ParseAddrPort(address)
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if err != nil || !listenAddr.Addr().IsLoopback() || listenAddr.Port() == 0 {
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return errors.New("代理只允许监听明确指定的本机回环端口")
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}
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dev, stack, err := startDevice(r, netip.Addr{})
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if err != nil {
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return err
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}
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defer dev.Close()
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listener, err := net.Listen("tcp", address)
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if err != nil {
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return fmt.Errorf("本机代理监听失败: %w", err)
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}
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defer listener.Close()
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parentPID := os.Getppid()
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go func() {
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ticker := time.NewTicker(2 * time.Second)
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defer ticker.Stop()
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for range ticker.C {
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if os.Getppid() != parentPID {
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_ = listener.Close()
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return
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}
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}
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}()
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// The launcher waits for this line before reporting the proxy ready.
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_ = json.NewEncoder(os.Stdout).Encode(map[string]string{"status": "ready", "listen": address})
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stop := make(chan os.Signal, 1)
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signal.Notify(stop, os.Interrupt, syscall.SIGTERM)
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defer signal.Stop(stop)
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go func() { <-stop; _ = listener.Close() }()
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clients := make(chan struct{}, 128)
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for {
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client, err := listener.Accept()
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if err != nil {
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return nil
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}
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select {
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case clients <- struct{}{}:
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go func() {
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defer func() { <-clients }()
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handleSOCKS(client, r, stack)
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}()
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default:
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_ = client.Close()
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}
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}
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}
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func handleSOCKS(client net.Conn, r *record, stack *netstack.Net) {
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defer client.Close()
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_ = client.SetDeadline(time.Now().Add(15 * time.Second))
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var greeting [2]byte
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if _, err := io.ReadFull(client, greeting[:]); err != nil || greeting[0] != 5 {
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return
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}
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methods := make([]byte, int(greeting[1]))
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if _, err := io.ReadFull(client, methods); err != nil {
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return
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}
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noAuth := false
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for _, method := range methods {
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if method == 0 {
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noAuth = true
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}
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}
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if !noAuth {
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_, _ = client.Write([]byte{5, 255})
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return
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}
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if _, err := client.Write([]byte{5, 0}); err != nil {
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return
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}
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var header [4]byte
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if _, err := io.ReadFull(client, header[:]); err != nil || header[0] != 5 {
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return
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}
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if header[1] != 1 || header[2] != 0 {
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socksReply(client, 7)
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return
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}
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var host string
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switch header[3] {
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case 1:
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var ip [4]byte
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if _, err := io.ReadFull(client, ip[:]); err != nil {
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return
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}
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host = netip.AddrFrom4(ip).String()
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case 4:
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var ip [16]byte
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if _, err := io.ReadFull(client, ip[:]); err != nil {
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return
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}
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host = netip.AddrFrom16(ip).String()
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case 3:
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var size [1]byte
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if _, err := io.ReadFull(client, size[:]); err != nil || size[0] == 0 {
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return
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}
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name := make([]byte, size[0])
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if _, err := io.ReadFull(client, name); err != nil {
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return
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}
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host = string(name)
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default:
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socksReply(client, 8)
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return
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}
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var port [2]byte
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if _, err := io.ReadFull(client, port[:]); err != nil {
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return
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}
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portNum := int(port[0])<<8 | int(port[1])
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if portNum == 0 {
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socksReply(client, 1)
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return
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}
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addresses := []string{host}
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if _, err := netip.ParseAddr(host); err != nil {
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addresses, err = stack.LookupHost(host)
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if err != nil {
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socksReply(client, 4)
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return
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}
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}
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for _, address := range addresses {
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ip, err := netip.ParseAddr(address)
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if err != nil {
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continue
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}
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allowed, err := permittedRoute(r.Config.AllowedIPs, ip)
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if err != nil || !allowed {
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continue
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}
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ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
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upstream, err := stack.DialContext(ctx, "tcp", net.JoinHostPort(address, strconv.Itoa(portNum)))
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cancel()
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if err != nil {
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continue
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}
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defer upstream.Close()
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if err := socksReply(client, 0); err != nil {
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return
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}
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_ = client.SetDeadline(time.Time{})
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go func() { _, _ = io.Copy(upstream, client); _ = upstream.Close() }()
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_, _ = io.Copy(client, upstream)
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return
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}
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socksReply(client, 4)
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}
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func socksReply(conn net.Conn, code byte) error {
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_, err := conn.Write([]byte{5, code, 0, 1, 127, 0, 0, 1, 0, 0})
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return err
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}
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func main() {
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if len(os.Args) == 2 && os.Args[1] == "--version" {
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fmt.Println("opsx-tunnel-go " + version)
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return
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}
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if len(os.Args) != 4 || (os.Args[1] != "probe" && os.Args[1] != "proxy") {
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fmt.Fprintln(os.Stderr, "usage: opsx-tunnel-go <probe|proxy> <local-record> <IP:port|loopback:port>")
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os.Exit(2)
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}
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// stdout only contains a non-secret, machine-readable result. Never echo the
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// configuration, keys, token, or arbitrary upstream error strings.
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r, err := readRecord(os.Args[2])
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if err == nil && os.Args[1] == "proxy" {
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err = serveSOCKS(r, os.Args[3])
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if err != nil {
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fmt.Fprintln(os.Stderr, err)
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os.Exit(1)
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}
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return
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}
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if err == nil {
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ctx, cancel := context.WithTimeout(context.Background(), 12*time.Second)
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defer cancel()
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err = probe(ctx, r, os.Args[3])
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}
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res := result{Connected: err == nil, Target: os.Args[3]}
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if err == nil {
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res.Detail = "WireGuard 出口 TCP 已连通"
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} else {
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res.Detail = err.Error()
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}
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_ = json.NewEncoder(os.Stdout).Encode(res)
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if err != nil {
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os.Exit(1)
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}
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}
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