Cloak/cmd/ck-client/ck-client.go
2019-09-01 20:23:45 +01:00

348 lines
8.3 KiB
Go

// +build go1.11
package main
import (
"crypto/rand"
"encoding/base64"
"encoding/binary"
"flag"
"fmt"
"io"
"net"
"os"
"sync"
"sync/atomic"
"time"
"github.com/cbeuw/Cloak/internal/client"
mux "github.com/cbeuw/Cloak/internal/multiplex"
"github.com/cbeuw/Cloak/internal/util"
log "github.com/sirupsen/logrus"
)
var version string
func makeSession(sta *client.State, isAdmin bool) *mux.Session {
log.Info("Attemtping to start a new session")
if !isAdmin {
// sessionID is usergenerated. There shouldn't be a security concern because the scope of
// sessionID is limited to its UID.
quad := make([]byte, 4)
rand.Read(quad)
atomic.StoreUint32(&sta.SessionID, binary.BigEndian.Uint32(quad))
}
d := net.Dialer{Control: protector}
connsCh := make(chan net.Conn, sta.NumConn)
var _sessionKey atomic.Value
var wg sync.WaitGroup
for i := 0; i < sta.NumConn; i++ {
wg.Add(1)
go func() {
makeconn:
connectingIP := sta.RemoteHost
if net.ParseIP(connectingIP).To4() == nil {
// IPv6 needs square brackets
connectingIP = "[" + connectingIP + "]"
}
remoteConn, err := d.Dial("tcp", connectingIP+":"+sta.RemotePort)
if err != nil {
log.Errorf("Failed to establish new connections to remote: %v", err)
// TODO increase the interval if failed multiple times
time.Sleep(time.Second * 3)
goto makeconn
}
var sk []byte
remoteConn, sk, err = sta.Transport.PrepareConnection(sta, remoteConn)
if err != nil {
remoteConn.Close()
log.Errorf("Failed to prepare connection to remote: %v", err)
time.Sleep(time.Second * 3)
goto makeconn
}
_sessionKey.Store(sk)
connsCh <- remoteConn
wg.Done()
}()
}
wg.Wait()
log.Debug("All underlying connections established")
sessionKey := _sessionKey.Load().([]byte)
obfuscator, err := mux.GenerateObfs(sta.EncryptionMethod, sessionKey, sta.Transport.HasRecordLayer())
if err != nil {
log.Fatal(err)
}
seshConfig := &mux.SessionConfig{
Obfuscator: obfuscator,
Valve: nil,
UnitRead: sta.Transport.UnitReadFunc(),
Unordered: sta.Unordered,
}
sesh := mux.MakeSession(sta.SessionID, seshConfig)
for i := 0; i < sta.NumConn; i++ {
conn := <-connsCh
sesh.AddConnection(conn)
}
log.Infof("Session %v established", sta.SessionID)
return sesh
}
func routeUDP(sta *client.State, adminUID []byte) {
var sesh *mux.Session
localUDPAddr, err := net.ResolveUDPAddr("udp", sta.LocalHost+":"+sta.LocalPort)
if err != nil {
log.Fatal(err)
}
start:
localConn, err := net.ListenUDP("udp", localUDPAddr)
if err != nil {
log.Fatal(err)
}
var otherEnd atomic.Value
data := make([]byte, 10240)
i, oe, err := localConn.ReadFromUDP(data)
if err != nil {
log.Errorf("Failed to read first packet from proxy client: %v", err)
localConn.Close()
return
}
otherEnd.Store(oe)
if sesh == nil || sesh.IsClosed() {
sesh = makeSession(sta, adminUID != nil)
}
log.Debugf("proxy local address %v", otherEnd.Load().(*net.UDPAddr).String())
stream, err := sesh.OpenStream()
if err != nil {
log.Errorf("Failed to open stream: %v", err)
localConn.Close()
//localConnWrite.Close()
return
}
_, err = stream.Write(data[:i])
if err != nil {
log.Errorf("Failed to write to stream: %v", err)
localConn.Close()
//localConnWrite.Close()
stream.Close()
return
}
// stream to proxy
go func() {
buf := make([]byte, 16380)
for {
i, err := io.ReadAtLeast(stream, buf, 1)
if err != nil {
log.Print(err)
localConn.Close()
stream.Close()
break
}
i, err = localConn.WriteToUDP(buf[:i], otherEnd.Load().(*net.UDPAddr))
if err != nil {
log.Print(err)
localConn.Close()
stream.Close()
break
}
}
}()
// proxy to stream
buf := make([]byte, 16380)
if sta.Timeout != 0 {
localConn.SetReadDeadline(time.Now().Add(sta.Timeout))
}
for {
if sta.Timeout != 0 {
localConn.SetReadDeadline(time.Now().Add(sta.Timeout))
}
i, oe, err := localConn.ReadFromUDP(buf)
if err != nil {
localConn.Close()
stream.Close()
break
}
otherEnd.Store(oe)
i, err = stream.Write(buf[:i])
if err != nil {
localConn.Close()
stream.Close()
break
}
}
goto start
}
func routeTCP(sta *client.State, adminUID []byte) {
tcpListener, err := net.Listen("tcp", sta.LocalHost+":"+sta.LocalPort)
if err != nil {
log.Fatal(err)
}
var sesh *mux.Session
for {
localConn, err := tcpListener.Accept()
if err != nil {
log.Fatal(err)
continue
}
if sesh == nil || sesh.IsClosed() {
sesh = makeSession(sta, adminUID != nil)
}
go func() {
data := make([]byte, 10240)
i, err := io.ReadAtLeast(localConn, data, 1)
if err != nil {
log.Errorf("Failed to read first packet from proxy client: %v", err)
localConn.Close()
return
}
stream, err := sesh.OpenStream()
if err != nil {
log.Errorf("Failed to open stream: %v", err)
localConn.Close()
return
}
_, err = stream.Write(data[:i])
if err != nil {
log.Errorf("Failed to write to stream: %v", err)
localConn.Close()
stream.Close()
return
}
go util.Pipe(localConn, stream, 0)
util.Pipe(stream, localConn, sta.Timeout)
}()
}
}
func main() {
// Should be 127.0.0.1 to listen to a proxy client on this machine
var localHost string
// port used by proxy clients to communicate with cloak client
var localPort string
// The ip of the proxy server
var remoteHost string
// The proxy port,should be 443
var remotePort string
var proxyMethod string
var udp bool
var config string
var b64AdminUID string
log_init()
log.SetLevel(log.DebugLevel)
if os.Getenv("SS_LOCAL_HOST") != "" {
localHost = os.Getenv("SS_LOCAL_HOST")
localPort = os.Getenv("SS_LOCAL_PORT")
remoteHost = os.Getenv("SS_REMOTE_HOST")
remotePort = os.Getenv("SS_REMOTE_PORT")
config = os.Getenv("SS_PLUGIN_OPTIONS")
} else {
flag.StringVar(&localHost, "i", "127.0.0.1", "localHost: Cloak listens to proxy clients on this ip")
flag.StringVar(&localPort, "l", "1984", "localPort: Cloak listens to proxy clients on this port")
flag.StringVar(&remoteHost, "s", "", "remoteHost: IP of your proxy server")
flag.StringVar(&remotePort, "p", "443", "remotePort: proxy port, should be 443")
flag.BoolVar(&udp, "u", false, "udp: set this flag if the underlying proxy is using UDP protocol")
flag.StringVar(&config, "c", "ckclient.json", "config: path to the configuration file or options seperated with semicolons")
flag.StringVar(&proxyMethod, "proxy", "", "proxy: the proxy method's name. It must match exactly with the corresponding entry in server's ProxyBook")
flag.StringVar(&b64AdminUID, "a", "", "adminUID: enter the adminUID to serve the admin api")
askVersion := flag.Bool("v", false, "Print the version number")
printUsage := flag.Bool("h", false, "Print this message")
verbosity := flag.String("verbosity", "info", "verbosity level")
flag.Parse()
if *askVersion {
fmt.Printf("ck-client %s", version)
return
}
if *printUsage {
flag.Usage()
return
}
lvl, err := log.ParseLevel(*verbosity)
if err != nil {
log.Fatal(err)
}
log.SetLevel(lvl)
log.Info("Starting standalone mode")
}
sta := &client.State{
LocalHost: localHost,
LocalPort: localPort,
RemoteHost: remoteHost,
RemotePort: remotePort,
Now: time.Now,
}
err := sta.ParseConfig(config)
if err != nil {
log.Fatal(err)
}
if proxyMethod != "" {
sta.ProxyMethod = proxyMethod
}
if os.Getenv("SS_LOCAL_HOST") != "" {
sta.ProxyMethod = "shadowsocks"
}
if sta.LocalPort == "" {
log.Fatal("Must specify localPort")
}
if sta.RemoteHost == "" {
log.Fatal("Must specify remoteHost")
}
listeningIP := sta.LocalHost
if net.ParseIP(listeningIP).To4() == nil {
// IPv6 needs square brackets
listeningIP = "[" + listeningIP + "]"
}
var adminUID []byte
if b64AdminUID != "" {
adminUID, err = base64.StdEncoding.DecodeString(b64AdminUID)
if err != nil {
log.Fatal(err)
}
}
if adminUID != nil {
log.Infof("API base is %v:%v", listeningIP, sta.LocalPort)
sta.SessionID = 0
sta.UID = adminUID
sta.NumConn = 1
} else {
var network string
if udp {
network = "UDP"
sta.Unordered = true
} else {
network = "TCP"
sta.Unordered = false
}
log.Infof("Listening on %v %v:%v for %v client", network, listeningIP, sta.LocalPort, sta.ProxyMethod)
}
if udp {
routeUDP(sta, adminUID)
} else {
routeTCP(sta, adminUID)
}
}