linsk/nettap/nettap.go
2023-09-01 14:41:19 +01:00

43 lines
802 B
Go

package nettap
import (
"crypto/rand"
"fmt"
"net"
"github.com/pkg/errors"
)
type TapNet struct {
HostIP net.IP
GuestIP net.IP
HostCIDR string
GuestCIDR string
}
func GenerateNet() (TapNet, error) {
// This is a Linsk internal network IPv6 prefix.
hostIP := []byte(net.ParseIP("fe8f:5980:3253:7df4:0f4b:6db1::"))
_, err := rand.Read(hostIP[len(hostIP)-4:])
if err != nil {
return TapNet{}, errors.Wrap(err, "random read")
}
// Put the last bit to zero.
hostIP[len(hostIP)-1] &= 0xfe
guestIP := make([]byte, len(hostIP))
copy(guestIP, hostIP)
// Put the last bit to one.
guestIP[len(hostIP)-1] |= 0x1
return TapNet{
HostIP: hostIP,
GuestIP: guestIP,
HostCIDR: fmt.Sprintf("%v/127", net.IP(hostIP)),
GuestCIDR: fmt.Sprintf("%v/127", net.IP(guestIP)),
}, nil
}