/
client.go
433 lines (352 loc) · 9.23 KB
/
client.go
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package gtun
import (
"bufio"
"encoding/json"
"fmt"
"net"
"net/http"
"os/exec"
"runtime"
"strings"
"sync"
"time"
"github.com/ICKelin/gtun/common"
"github.com/ICKelin/gtun/logs"
"github.com/songgao/water"
)
var (
defaultServer = "127.0.0.1:9091"
defaultClientAuthKey = "gtun-cs-token"
defaultLayer2 = false
defaultClientConfig = &ClientConfig{
ServerAddr: defaultServer,
AuthKey: defaultClientAuthKey,
}
)
type ClientConfig struct {
ServerAddr string `toml:"server"`
AuthKey string `toml:"auth"`
layer2 bool `toml:"layer2"`
}
type Client struct {
serverAddr string
authKey string
myip string
gw string
layer2 bool
registry *Registry
}
func NewClient(cfg *ClientConfig, registry *Registry) *Client {
if cfg == nil {
cfg = defaultClientConfig
}
addr := cfg.ServerAddr
if addr == "" {
addr = defaultServer
}
authkey := cfg.AuthKey
if authkey == "" {
authkey = defaultClientAuthKey
}
return &Client{
serverAddr: addr,
authKey: authkey,
layer2: cfg.layer2,
registry: registry,
}
}
func (client *Client) Run() {
for {
server, err := client.registry.Access()
if err != nil {
logs.Error("get server address fail: %v", err)
if client.registry.must {
time.Sleep(time.Second * 3)
continue
}
}
if server == "" {
server = client.serverAddr
}
if server == "" {
logs.Error("empty server")
time.Sleep(time.Second * 3)
continue
}
conn, err := conServer(server)
if err != nil {
logs.Error("connect to server fail: %v", err)
time.Sleep(time.Second * 3)
continue
}
s2c, err := authorize(conn, client.authKey)
if err != nil {
logs.Error("auth fail: %v", err)
time.Sleep(time.Second * 3)
continue
}
logs.Info("connect to %s success, assign ip %s", server, s2c.AccessIP)
ifce, err := NewIfce(client.layer2)
if err != nil {
logs.Error("new interface fail: %v", err)
return
}
client.myip = s2c.AccessIP
client.gw = s2c.Gateway
sndqueue := make(chan []byte)
go ifaceRead(ifce, sndqueue)
err = setupIface(ifce, s2c.AccessIP, s2c.Gateway)
if err != nil {
logs.Error("setup iface fail: %v", err)
time.Sleep(time.Second * 3)
continue
}
go func() {
routes, err := downloadRoutes(s2c.RouteScriptUrl)
if err != nil {
logs.Warn("download route from %s fail: %v", s2c.RouteScriptUrl, err)
}
insertRoute(routes, s2c.AccessIP, s2c.Gateway, ifce.Name())
}()
done := make(chan struct{})
wg := &sync.WaitGroup{}
wg.Add(3)
go heartbeat(sndqueue, done, wg)
go snd(conn, sndqueue, done, wg)
go rcv(conn, ifce, wg)
wg.Wait()
ifce.Close()
logs.Info("reconnecting")
}
}
func conServer(srv string) (conn net.Conn, err error) {
tcp, err := net.DialTimeout("tcp", srv, time.Second*10)
if err != nil {
return nil, err
}
return tcp, nil
}
func authorize(conn net.Conn, key string) (s2cauthorize *common.S2CAuthorize, err error) {
c2sauthorize := &common.C2SAuthorize{
OS: common.OSID(runtime.GOOS),
Version: common.Version(),
Key: key,
}
payload, err := json.Marshal(c2sauthorize)
if err != nil {
return nil, err
}
buff, _ := common.Encode(common.C2S_AUTHORIZE, payload)
_, err = conn.Write(buff)
if err != nil {
return nil, err
}
cmd, resp, err := common.Decode(conn)
if err != nil {
return nil, err
}
if cmd != common.S2C_AUTHORIZE {
err = fmt.Errorf("invalid authorize cmd %d", cmd)
return nil, err
}
s2cauthorize = &common.S2CAuthorize{}
err = json.Unmarshal(resp, s2cauthorize)
if err != nil {
return nil, err
}
return s2cauthorize, nil
}
func rcv(conn net.Conn, ifce *water.Interface, wg *sync.WaitGroup) {
defer wg.Done()
defer conn.Close()
for {
cmd, pkt, err := common.Decode(conn)
if err != nil {
logs.Info("decode fail: %v", err)
break
}
switch cmd {
case common.S2C_HEARTBEAT:
logs.Debug("heartbeat from srv")
case common.C2C_DATA:
_, err := ifce.Write(pkt)
if err != nil {
logs.Error("read from iface fail: %v", err)
}
default:
logs.Info("unimplement cmd %d %v", int(cmd), pkt)
}
}
}
func snd(conn net.Conn, sndqueue chan []byte, done chan struct{}, wg *sync.WaitGroup) {
defer wg.Done()
defer conn.Close()
defer close(done)
for {
pkt := <-sndqueue
conn.SetWriteDeadline(time.Now().Add(time.Second * 10))
_, err := conn.Write(pkt)
conn.SetWriteDeadline(time.Time{})
if err != nil {
logs.Error("send packet fail: %v", err)
break
}
}
}
func heartbeat(sndqueue chan []byte, done chan struct{}, wg *sync.WaitGroup) {
defer wg.Done()
for {
select {
case <-done:
return
case <-time.After(time.Second * 3):
bytes, _ := common.Encode(common.C2S_HEARTBEAT, nil)
sndqueue <- bytes
}
}
}
func ifaceRead(ifce *water.Interface, sndqueue chan []byte) {
packet := make([]byte, 65536)
for {
n, err := ifce.Read(packet)
if err != nil {
logs.Error("read from iface fail: %v", err)
break
}
bytes, _ := common.Encode(common.C2C_DATA, packet[:n])
sndqueue <- bytes
}
}
func clearIfConfig(ifce *water.Interface, ip string, gw string) {
switch runtime.GOOS {
case "linux":
args := strings.Split(fmt.Sprintf("addr del %s/24 dev %s", ip, ifce.Name()), " ")
exec.Command("ip", args...).CombinedOutput()
case "darwin":
case "windows":
}
}
func setupIface(ifce *water.Interface, ip string, gw string) (err error) {
type CMD struct {
cmd string
args []string
}
cmdlist := make([]*CMD, 0)
switch runtime.GOOS {
case "linux":
cmdlist = append(cmdlist, &CMD{cmd: "ifconfig", args: []string{ifce.Name(), "up"}})
args := strings.Split(fmt.Sprintf("addr add %s/24 dev %s", ip, ifce.Name()), " ")
cmdlist = append(cmdlist, &CMD{cmd: "ip", args: args})
case "darwin":
cmdlist = append(cmdlist, &CMD{cmd: "ifconfig", args: []string{ifce.Name(), "up"}})
args := strings.Split(fmt.Sprintf("%s %s %s", ifce.Name(), ip, ip), " ")
cmdlist = append(cmdlist, &CMD{cmd: "ifconfig", args: args})
args = strings.Split(fmt.Sprintf("add -net %s/24 %s", gw, ip), " ")
cmdlist = append(cmdlist, &CMD{cmd: "route", args: args})
case "windows":
args := strings.Split(fmt.Sprintf("interface ip set address name=\"%s\" addr=%s source=static mask=255.255.255.0 gateway=%s", ifce.Name(), ip, gw), " ")
cmdlist = append(cmdlist, &CMD{cmd: "netsh", args: args})
args = strings.Split(fmt.Sprintf("delete 0.0.0.0 %s", gw), " ")
cmdlist = append(cmdlist, &CMD{cmd: "route", args: args})
}
for _, c := range cmdlist {
output, err := exec.Command(c.cmd, c.args...).CombinedOutput()
if err != nil {
return fmt.Errorf("run %s error %s", c, string(output))
}
}
return nil
}
func releaseDevice(device, ip, gateway string) (err error) {
type CMD struct {
cmd string
args []string
}
cmdlist := make([]*CMD, 0)
switch runtime.GOOS {
case "linux":
args := strings.Split(fmt.Sprintf("%s down", device), " ")
cmdlist = append(cmdlist, &CMD{cmd: "ifconfig", args: args})
case "darwin":
gw := strings.Split(gateway, ".")
if len(gw) != 4 {
break
}
s := strings.Join(gw[:3], ".")
args := strings.Split(fmt.Sprintf("delete -net %s/24 %s", s, ip), " ")
cmdlist = append(cmdlist, &CMD{cmd: "route", args: args})
args = strings.Split(fmt.Sprintf("%s delete %s", device, ip), " ")
cmdlist = append(cmdlist, &CMD{cmd: "ifconfig", args: args})
args = strings.Split(fmt.Sprintf("%s down", device), " ")
cmdlist = append(cmdlist, &CMD{cmd: "ifconfig", args: args})
}
for _, c := range cmdlist {
output, _ := exec.Command(c.cmd, c.args...).CombinedOutput()
if err != nil {
fmt.Printf("run %s error %s\n", c, string(output))
}
}
return nil
}
func downloadRoutes(url string) ([]string, error) {
routes := make([]string, 0)
logs.Info("downloading route file from: %s", url)
resp, err := http.Get(url)
if err != nil {
return nil, err
}
defer resp.Body.Close()
reader := bufio.NewReader(resp.Body)
for {
line, _, err := reader.ReadLine()
if err != nil {
break
}
// may need to validate ip/cidr format
routes = append(routes, string(line))
}
logs.Info("downloaded route file from: %s", url)
return routes, nil
}
func insertRoute(routedIPS []string, devIP, gw string, devName string) {
// Windows platform route add need iface index args.
ifceIndex := -1
ifce, err := net.InterfaceByName(devName)
if err != nil {
if runtime.GOOS == "windows" {
return
}
} else {
ifceIndex = ifce.Index
}
logs.Info("inserting routes")
for _, address := range routedIPS {
execRoute(address, devName, devIP, gw, ifceIndex)
}
logs.Info("inserted routes, routes count: %d", len(routedIPS))
}
type CMD struct {
cmd string
args []string
}
func execRoute(address, device, tunip, gateway string, ifceIndex int) {
cmd := &CMD{}
switch runtime.GOOS {
case "linux":
args := strings.Split(fmt.Sprintf("ro add %s dev %s", address, device), " ")
cmd = &CMD{cmd: "ip", args: args}
case "darwin":
args := strings.Split(fmt.Sprintf("add -net %s %s", address, tunip), " ")
cmd = &CMD{cmd: "route", args: args}
case "windows":
args := strings.Split(fmt.Sprintf("add %s %s if %d", address, gateway, ifceIndex), " ")
cmd = &CMD{cmd: "route", args: args}
default:
return
}
output, err := exec.Command(cmd.cmd, cmd.args...).CombinedOutput()
if err != nil {
logs.Debug("add %s fail %s", address, string(output))
}
logs.Debug(string(output))
}