Files
kubevpn/pkg/tun/tun.go
2023-02-19 12:14:47 +08:00

140 lines
3.1 KiB
Go

package tun
import (
"errors"
"net"
"os"
"time"
"github.com/containernetworking/cni/pkg/types"
log "github.com/sirupsen/logrus"
"github.com/wencaiwulue/kubevpn/pkg/core"
"golang.zx2c4.com/wireguard/device"
"golang.zx2c4.com/wireguard/tun"
"github.com/wencaiwulue/kubevpn/pkg/config"
)
// Config is the config for TUN device.
type Config struct {
Name string
Addr string
MTU int
Routes []types.Route
Gateway string
}
type tunListener struct {
addr net.Addr
conns chan net.Conn
closed chan struct{}
config Config
}
// Listener TunListener creates a listener for tun tunnel.
func Listener(config Config) (net.Listener, error) {
ln := &tunListener{
conns: make(chan net.Conn, 1),
closed: make(chan struct{}),
config: config,
}
conn, ifce, err := createTun(config)
if err != nil {
return nil, err
}
addrs, _ := ifce.Addrs()
log.Debugf("[tun] %s: name: %s, mtu: %d, addrs: %s", conn.LocalAddr(), ifce.Name, ifce.MTU, addrs)
ln.addr = conn.LocalAddr()
ln.conns <- conn
return ln, nil
}
func (l *tunListener) Accept() (net.Conn, error) {
select {
case conn := <-l.conns:
return conn, nil
case <-l.closed:
}
return nil, errors.New("accept on closed listener")
}
func (l *tunListener) Addr() net.Addr {
return l.addr
}
func (l *tunListener) Close() error {
select {
case <-l.closed:
return errors.New("listener has been closed")
default:
close(l.closed)
}
return nil
}
type tunConn struct {
ifce tun.Device
addr net.Addr
}
func (c *tunConn) Read(b []byte) (n int, err error) {
offset := device.MessageTransportHeaderSize
bytes := core.LPool.Get().([]byte)
core.LPool.Put(bytes)
size, err := c.ifce.Read(bytes[:], offset)
if size == 0 || size > device.MaxSegmentSize-device.MessageTransportHeaderSize {
return 0, nil
}
return copy(b, bytes[offset:offset+size]), nil
}
func (c *tunConn) Write(b []byte) (n int, err error) {
if len(b) < device.MessageTransportHeaderSize {
return 0, err
}
bytes := core.LPool.Get().([]byte)
defer core.LPool.Put(bytes)
copy(bytes[device.MessageTransportOffsetContent:], b)
return c.ifce.Write(bytes[:device.MessageTransportOffsetContent+len(b)], device.MessageTransportOffsetContent)
}
func (c *tunConn) Close() (err error) {
return c.ifce.Close()
}
func (c *tunConn) LocalAddr() net.Addr {
return c.addr
}
func (c *tunConn) RemoteAddr() net.Addr {
return &net.IPAddr{}
}
func (c *tunConn) SetDeadline(time.Time) error {
return &net.OpError{Op: "set", Net: "tun", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
}
func (c *tunConn) SetReadDeadline(time.Time) error {
return &net.OpError{Op: "set", Net: "tun", Source: nil, Addr: nil, Err: errors.New("read deadline not supported")}
}
func (c *tunConn) SetWriteDeadline(time.Time) error {
return &net.OpError{Op: "set", Net: "tun", Source: nil, Addr: nil, Err: errors.New("write deadline not supported")}
}
// AddRoutes for outer called
func AddRoutes(routes ...types.Route) error {
env := os.Getenv(config.EnvTunNameOrLUID)
return addTunRoutes(env, routes...)
}
func GetInterface() (*net.Interface, error) {
return getInterface()
}