netbird/client/internal/wgproxy/portlookup.go

33 lines
526 B
Go

package wgproxy
import (
"fmt"
"net"
)
const (
portRangeStart = 3128
portRangeEnd = 3228
)
type portLookup struct {
}
func (pl portLookup) searchFreePort() (int, error) {
for i := portRangeStart; i <= portRangeEnd; i++ {
if pl.tryToBind(i) == nil {
return i, nil
}
}
return 0, fmt.Errorf("failed to bind free port for eBPF proxy")
}
func (pl portLookup) tryToBind(port int) error {
l, err := net.ListenPacket("udp", fmt.Sprintf(":%d", port))
if err != nil {
return err
}
_ = l.Close()
return nil
}