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routine.go
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routine.go
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package wireproxy
import (
"bytes"
"context"
srand "crypto/rand"
"crypto/subtle"
"encoding/binary"
"encoding/json"
"errors"
"golang.org/x/net/icmp"
"golang.org/x/net/ipv4"
"golang.org/x/net/ipv6"
"golang.zx2c4.com/wireguard/device"
"io"
"log"
"math/rand"
"net"
"net/http"
"os"
"path"
"strconv"
"strings"
"time"
"github.com/sourcegraph/conc"
"github.com/things-go/go-socks5"
"github.com/things-go/go-socks5/bufferpool"
"net/netip"
"golang.zx2c4.com/wireguard/tun/netstack"
)
// errorLogger is the logger to print error message
var errorLogger = log.New(os.Stderr, "ERROR: ", log.LstdFlags)
// CredentialValidator stores the authentication data of a socks5 proxy
type CredentialValidator struct {
username string
password string
}
// VirtualTun stores a reference to netstack network and DNS configuration
type VirtualTun struct {
Tnet *netstack.Net
Dev *device.Device
SystemDNS bool
Conf *DeviceConfig
// PingRecord stores the last time an IP was pinged
PingRecord map[string]uint64
}
// RoutineSpawner spawns a routine (e.g. socks5, tcp static routes) after the configuration is parsed
type RoutineSpawner interface {
SpawnRoutine(vt *VirtualTun)
}
type addressPort struct {
address string
port uint16
}
// LookupAddr lookups a hostname.
// DNS traffic may or may not be routed depending on VirtualTun's setting
func (d VirtualTun) LookupAddr(ctx context.Context, name string) ([]string, error) {
if d.SystemDNS {
return net.DefaultResolver.LookupHost(ctx, name)
}
return d.Tnet.LookupContextHost(ctx, name)
}
// ResolveAddrWithContext resolves a hostname and returns an AddrPort.
// DNS traffic may or may not be routed depending on VirtualTun's setting
func (d VirtualTun) ResolveAddrWithContext(ctx context.Context, name string) (*netip.Addr, error) {
addrs, err := d.LookupAddr(ctx, name)
if err != nil {
return nil, err
}
size := len(addrs)
if size == 0 {
return nil, errors.New("no address found for: " + name)
}
rand.Shuffle(size, func(i, j int) {
addrs[i], addrs[j] = addrs[j], addrs[i]
})
var addr netip.Addr
for _, saddr := range addrs {
addr, err = netip.ParseAddr(saddr)
if err == nil {
break
}
}
if err != nil {
return nil, err
}
return &addr, nil
}
// Resolve resolves a hostname and returns an IP.
// DNS traffic may or may not be routed depending on VirtualTun's setting
func (d VirtualTun) Resolve(ctx context.Context, name string) (context.Context, net.IP, error) {
addr, err := d.ResolveAddrWithContext(ctx, name)
if err != nil {
return nil, nil, err
}
return ctx, addr.AsSlice(), nil
}
func parseAddressPort(endpoint string) (*addressPort, error) {
name, sport, err := net.SplitHostPort(endpoint)
if err != nil {
return nil, err
}
port, err := strconv.Atoi(sport)
if err != nil || port < 0 || port > 65535 {
return nil, &net.OpError{Op: "dial", Err: errors.New("port must be numeric")}
}
return &addressPort{address: name, port: uint16(port)}, nil
}
func (d VirtualTun) resolveToAddrPort(endpoint *addressPort) (*netip.AddrPort, error) {
addr, err := d.ResolveAddrWithContext(context.Background(), endpoint.address)
if err != nil {
return nil, err
}
addrPort := netip.AddrPortFrom(*addr, endpoint.port)
return &addrPort, nil
}
// SpawnRoutine spawns a socks5 server.
func (config *Socks5Config) SpawnRoutine(vt *VirtualTun) {
var authMethods []socks5.Authenticator
if username := config.Username; username != "" {
authMethods = append(authMethods, socks5.UserPassAuthenticator{
Credentials: socks5.StaticCredentials{username: config.Password},
})
} else {
authMethods = append(authMethods, socks5.NoAuthAuthenticator{})
}
options := []socks5.Option{
socks5.WithDial(vt.Tnet.DialContext),
socks5.WithResolver(vt),
socks5.WithAuthMethods(authMethods),
socks5.WithBufferPool(bufferpool.NewPool(256 * 1024)),
}
server := socks5.NewServer(options...)
if err := server.ListenAndServe("tcp", config.BindAddress); err != nil {
log.Fatal(err)
}
}
// SpawnRoutine spawns a http server.
func (config *HTTPConfig) SpawnRoutine(vt *VirtualTun) {
server := &HTTPServer{
config: config,
dial: vt.Tnet.Dial,
auth: CredentialValidator{config.Username, config.Password},
}
if config.Username != "" || config.Password != "" {
server.authRequired = true
}
if err := server.ListenAndServe("tcp", config.BindAddress); err != nil {
log.Fatal(err)
}
}
// Valid checks the authentication data in CredentialValidator and compare them
// to username and password in constant time.
func (c CredentialValidator) Valid(username, password string) bool {
u := subtle.ConstantTimeCompare([]byte(c.username), []byte(username))
p := subtle.ConstantTimeCompare([]byte(c.password), []byte(password))
return u&p == 1
}
// connForward copy data from `from` to `to`
func connForward(from io.ReadWriteCloser, to io.ReadWriteCloser) {
_, err := io.Copy(to, from)
if err != nil {
errorLogger.Printf("Cannot forward traffic: %s\n", err.Error())
}
}
// tcpClientForward starts a new connection via wireguard and forward traffic from `conn`
func tcpClientForward(vt *VirtualTun, raddr *addressPort, conn net.Conn) {
target, err := vt.resolveToAddrPort(raddr)
if err != nil {
errorLogger.Printf("TCP Server Tunnel to %s: %s\n", target, err.Error())
return
}
tcpAddr := TCPAddrFromAddrPort(*target)
sconn, err := vt.Tnet.DialTCP(tcpAddr)
if err != nil {
errorLogger.Printf("TCP Client Tunnel to %s: %s\n", target, err.Error())
return
}
go func() {
wg := conc.NewWaitGroup()
wg.Go(func() {
connForward(sconn, conn)
})
wg.Go(func() {
connForward(conn, sconn)
})
wg.Wait()
_ = sconn.Close()
_ = conn.Close()
sconn = nil
conn = nil
}()
}
// STDIOTcpForward starts a new connection via wireguard and forward traffic from `conn`
func STDIOTcpForward(vt *VirtualTun, raddr *addressPort) {
target, err := vt.resolveToAddrPort(raddr)
if err != nil {
errorLogger.Printf("Name resolution error for %s: %s\n", raddr.address, err.Error())
return
}
// os.Stdout has previously been remapped to stderr, se we can't use it
stdout, err := os.OpenFile("/dev/stdout", os.O_WRONLY, 0)
if err != nil {
errorLogger.Printf("Failed to open /dev/stdout: %s\n", err.Error())
return
}
tcpAddr := TCPAddrFromAddrPort(*target)
sconn, err := vt.Tnet.DialTCP(tcpAddr)
if err != nil {
errorLogger.Printf("TCP Client Tunnel to %s (%s): %s\n", target, tcpAddr, err.Error())
return
}
go func() {
wg := conc.NewWaitGroup()
wg.Go(func() {
connForward(os.Stdin, sconn)
})
wg.Go(func() {
connForward(sconn, stdout)
})
wg.Wait()
_ = sconn.Close()
sconn = nil
}()
}
// SpawnRoutine spawns a local TCP server which acts as a proxy to the specified target
func (conf *TCPClientTunnelConfig) SpawnRoutine(vt *VirtualTun) {
raddr, err := parseAddressPort(conf.Target)
if err != nil {
log.Fatal(err)
}
server, err := net.ListenTCP("tcp", conf.BindAddress)
if err != nil {
log.Fatal(err)
}
for {
conn, err := server.Accept()
if err != nil {
log.Fatal(err)
}
go tcpClientForward(vt, raddr, conn)
}
}
// SpawnRoutine connects to the specified target and plumbs it to STDIN / STDOUT
func (conf *STDIOTunnelConfig) SpawnRoutine(vt *VirtualTun) {
raddr, err := parseAddressPort(conf.Target)
if err != nil {
log.Fatal(err)
}
go STDIOTcpForward(vt, raddr)
}
// tcpServerForward starts a new connection locally and forward traffic from `conn`
func tcpServerForward(vt *VirtualTun, raddr *addressPort, conn net.Conn) {
target, err := vt.resolveToAddrPort(raddr)
if err != nil {
errorLogger.Printf("TCP Server Tunnel to %s: %s\n", target, err.Error())
return
}
tcpAddr := TCPAddrFromAddrPort(*target)
sconn, err := net.DialTCP("tcp", nil, tcpAddr)
if err != nil {
errorLogger.Printf("TCP Server Tunnel to %s: %s\n", target, err.Error())
return
}
go func() {
gr := conc.NewWaitGroup()
gr.Go(func() {
connForward(sconn, conn)
})
gr.Go(func() {
connForward(conn, sconn)
})
gr.Wait()
_ = sconn.Close()
_ = conn.Close()
sconn = nil
conn = nil
}()
}
// SpawnRoutine spawns a TCP server on wireguard which acts as a proxy to the specified target
func (conf *TCPServerTunnelConfig) SpawnRoutine(vt *VirtualTun) {
raddr, err := parseAddressPort(conf.Target)
if err != nil {
log.Fatal(err)
}
addr := &net.TCPAddr{Port: conf.ListenPort}
server, err := vt.Tnet.ListenTCP(addr)
if err != nil {
log.Fatal(err)
}
for {
conn, err := server.Accept()
if err != nil {
log.Fatal(err)
}
go tcpServerForward(vt, raddr, conn)
}
}
func (d VirtualTun) ServeHTTP(w http.ResponseWriter, r *http.Request) {
log.Printf("Health metric request: %s\n", r.URL.Path)
switch path.Clean(r.URL.Path) {
case "/readyz":
body, err := json.Marshal(d.PingRecord)
if err != nil {
errorLogger.Printf("Failed to get device metrics: %s\n", err.Error())
w.WriteHeader(http.StatusInternalServerError)
return
}
status := http.StatusOK
for _, record := range d.PingRecord {
lastPong := time.Unix(int64(record), 0)
// +2 seconds to account for the time it takes to ping the IP
if time.Since(lastPong) > time.Duration(d.Conf.CheckAliveInterval+2)*time.Second {
status = http.StatusServiceUnavailable
break
}
}
w.WriteHeader(status)
_, _ = w.Write(body)
_, _ = w.Write([]byte("\n"))
case "/metrics":
get, err := d.Dev.IpcGet()
if err != nil {
errorLogger.Printf("Failed to get device metrics: %s\n", err.Error())
w.WriteHeader(http.StatusInternalServerError)
return
}
var buf bytes.Buffer
for _, peer := range strings.Split(get, "\n") {
pair := strings.SplitN(peer, "=", 2)
if len(pair) != 2 {
buf.WriteString(peer)
continue
}
if pair[0] == "private_key" || pair[0] == "preshared_key" {
pair[1] = "REDACTED"
}
buf.WriteString(pair[0])
buf.WriteString("=")
buf.WriteString(pair[1])
buf.WriteString("\n")
}
w.WriteHeader(http.StatusOK)
_, _ = w.Write(buf.Bytes())
default:
w.WriteHeader(http.StatusNotFound)
}
}
func (d VirtualTun) pingIPs() {
for _, addr := range d.Conf.CheckAlive {
socket, err := d.Tnet.Dial("ping", addr.String())
if err != nil {
errorLogger.Printf("Failed to ping %s: %s\n", addr, err.Error())
continue
}
data := make([]byte, 16)
_, _ = srand.Read(data)
requestPing := icmp.Echo{
Seq: rand.Intn(1 << 16),
Data: data,
}
var icmpBytes []byte
if addr.Is4() {
icmpBytes, _ = (&icmp.Message{Type: ipv4.ICMPTypeEcho, Code: 0, Body: &requestPing}).Marshal(nil)
} else if addr.Is6() {
icmpBytes, _ = (&icmp.Message{Type: ipv6.ICMPTypeEchoRequest, Code: 0, Body: &requestPing}).Marshal(nil)
} else {
errorLogger.Printf("Failed to ping %s: invalid address: %s\n", addr, addr.String())
continue
}
_ = socket.SetReadDeadline(time.Now().Add(time.Duration(d.Conf.CheckAliveInterval) * time.Second))
_, err = socket.Write(icmpBytes)
if err != nil {
errorLogger.Printf("Failed to ping %s: %s\n", addr, err.Error())
continue
}
addr := addr
go func() {
n, err := socket.Read(icmpBytes[:])
if err != nil {
errorLogger.Printf("Failed to read ping response from %s: %s\n", addr, err.Error())
return
}
replyPacket, err := icmp.ParseMessage(1, icmpBytes[:n])
if err != nil {
errorLogger.Printf("Failed to parse ping response from %s: %s\n", addr, err.Error())
return
}
if addr.Is4() {
replyPing, ok := replyPacket.Body.(*icmp.Echo)
if !ok {
errorLogger.Printf("Failed to parse ping response from %s: invalid reply type: %s\n", addr, replyPacket.Type)
return
}
if !bytes.Equal(replyPing.Data, requestPing.Data) || replyPing.Seq != requestPing.Seq {
errorLogger.Printf("Failed to parse ping response from %s: invalid ping reply: %v\n", addr, replyPing)
return
}
}
if addr.Is6() {
replyPing, ok := replyPacket.Body.(*icmp.RawBody)
if !ok {
errorLogger.Printf("Failed to parse ping response from %s: invalid reply type: %s\n", addr, replyPacket.Type)
return
}
seq := binary.BigEndian.Uint16(replyPing.Data[2:4])
pongBody := replyPing.Data[4:]
if !bytes.Equal(pongBody, requestPing.Data) || int(seq) != requestPing.Seq {
errorLogger.Printf("Failed to parse ping response from %s: invalid ping reply: %v\n", addr, replyPing)
return
}
}
d.PingRecord[addr.String()] = uint64(time.Now().Unix())
defer socket.Close()
}()
}
}
func (d VirtualTun) StartPingIPs() {
for _, addr := range d.Conf.CheckAlive {
d.PingRecord[addr.String()] = 0
}
go func() {
for {
d.pingIPs()
time.Sleep(time.Duration(d.Conf.CheckAliveInterval) * time.Second)
}
}()
}