Files
gluetun/internal/tun/check.go
Quentin McGaw (desktop) 6a545aa088 Maint: tun package to handle tun device operations
- Moved from openvpn package to tun package
- TUN check verifies Rdev value
- TUN create
- Inject as interface to main function
- Add integration test
- Clearer log message for end users if tun device does not exist
- Remove unix package (unneeded for tests)
- Remove tun file opening at the end of tun file creation
- Do not mock unix.Mkdev (no OS operation)
- Remove Tun operations from OpenVPN configurator
2021-08-18 15:31:08 +00:00

52 lines
1.1 KiB
Go

package tun
import (
"errors"
"fmt"
"os"
"syscall"
)
type Checker interface {
Check(path string) error
}
var (
ErrTUNNotAvailable = errors.New("TUN device is not available")
ErrTUNStat = errors.New("cannot stat TUN file")
ErrTUNInfo = errors.New("cannot get syscall stat info of TUN file")
ErrTUNBadRdev = errors.New("TUN file has an unexpected rdev")
ErrTUNClose = errors.New("cannot close TUN device")
)
// Check checks the tunnel device specified by path is present and accessible.
func (t *Tun) Check(path string) error {
f, err := os.OpenFile(path, os.O_RDWR, 0)
if err != nil {
return fmt.Errorf("%w: %s", ErrTUNNotAvailable, err)
}
defer f.Close()
info, err := f.Stat()
if err != nil {
return fmt.Errorf("%w: %s", ErrTUNStat, err)
}
sys, ok := info.Sys().(*syscall.Stat_t)
if !ok {
return ErrTUNInfo
}
const expectedRdev = 2760 // corresponds to major 10 and minor 200
if sys.Rdev != expectedRdev {
return fmt.Errorf("%w: %d instead of expected %d",
ErrTUNBadRdev, sys.Rdev, expectedRdev)
}
if err := f.Close(); err != nil {
return fmt.Errorf("%w: %s", ErrTUNClose, err)
}
return nil
}