nebula/tun_ios.go

118 lines
2.2 KiB
Go

// +build ios
package nebula
import (
"errors"
"fmt"
"io"
"net"
"os"
"sync"
"syscall"
)
type Tun struct {
io.ReadWriteCloser
Device string
Cidr *net.IPNet
}
func newTun(deviceName string, cidr *net.IPNet, defaultMTU int, routes []route, unsafeRoutes []route, txQueueLen int, multiqueue bool) (ifce *Tun, err error) {
return nil, fmt.Errorf("newTun not supported in iOS")
}
func newTunFromFd(deviceFd int, cidr *net.IPNet, defaultMTU int, routes []route, unsafeRoutes []route, txQueueLen int) (ifce *Tun, err error) {
if len(routes) > 0 {
return nil, fmt.Errorf("route MTU not supported in Darwin")
}
file := os.NewFile(uintptr(deviceFd), "/dev/tun")
ifce = &Tun{
Cidr: cidr,
Device: "iOS",
ReadWriteCloser: &tunReadCloser{f: file},
}
return
}
func (c *Tun) Activate() error {
return nil
}
func (c *Tun) WriteRaw(b []byte) error {
_, err := c.Write(b)
return err
}
// The following is hoisted up from water, we do this so we can inject our own fd on iOS
type tunReadCloser struct {
f io.ReadWriteCloser
rMu sync.Mutex
rBuf []byte
wMu sync.Mutex
wBuf []byte
}
func (t *tunReadCloser) Read(to []byte) (int, error) {
t.rMu.Lock()
defer t.rMu.Unlock()
if cap(t.rBuf) < len(to)+4 {
t.rBuf = make([]byte, len(to)+4)
}
t.rBuf = t.rBuf[:len(to)+4]
n, err := t.f.Read(t.rBuf)
copy(to, t.rBuf[4:])
return n - 4, err
}
func (t *tunReadCloser) Write(from []byte) (int, error) {
if len(from) == 0 {
return 0, syscall.EIO
}
t.wMu.Lock()
defer t.wMu.Unlock()
if cap(t.wBuf) < len(from)+4 {
t.wBuf = make([]byte, len(from)+4)
}
t.wBuf = t.wBuf[:len(from)+4]
// Determine the IP Family for the NULL L2 Header
ipVer := from[0] >> 4
if ipVer == 4 {
t.wBuf[3] = syscall.AF_INET
} else if ipVer == 6 {
t.wBuf[3] = syscall.AF_INET6
} else {
return 0, errors.New("unable to determine IP version from packet")
}
copy(t.wBuf[4:], from)
n, err := t.f.Write(t.wBuf)
return n - 4, err
}
func (t *tunReadCloser) Close() error {
return t.f.Close()
}
func (c *Tun) CidrNet() *net.IPNet {
return c.Cidr
}
func (c *Tun) DeviceName() string {
return c.Device
}
func (t *Tun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
return nil, fmt.Errorf("TODO: multiqueue not implemented for ios")
}