nebula/udp_generic.go

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2019-11-19 18:00:20 +01:00
// +build !linux
// udp_generic implements the nebula UDP interface in pure Go stdlib. This
// means it can be used on platforms like Darwin and Windows.
package nebula
import (
"context"
"encoding/binary"
"fmt"
"net"
"strconv"
"strings"
)
type udpAddr struct {
net.UDPAddr
}
type udpConn struct {
*net.UDPConn
}
func NewUDPAddr(ip uint32, port uint16) *udpAddr {
return &udpAddr{
UDPAddr: net.UDPAddr{
IP: int2ip(ip),
Port: int(port),
},
}
}
func NewUDPAddrFromString(s string) *udpAddr {
p := strings.Split(s, ":")
if len(p) < 2 {
return nil
}
port, _ := strconv.Atoi(p[1])
return &udpAddr{
UDPAddr: net.UDPAddr{
IP: net.ParseIP(p[0]),
Port: port,
},
}
}
func NewListener(ip string, port int, multi bool) (*udpConn, error) {
lc := NewListenConfig(multi)
pc, err := lc.ListenPacket(context.TODO(), "udp4", fmt.Sprintf("%s:%d", ip, port))
if err != nil {
return nil, err
}
if uc, ok := pc.(*net.UDPConn); ok {
return &udpConn{UDPConn: uc}, nil
}
return nil, fmt.Errorf("Unexpected PacketConn: %T %#v", pc, pc)
}
func (ua *udpAddr) Equals(t *udpAddr) bool {
if t == nil || ua == nil {
return t == nil && ua == nil
}
return ua.IP.Equal(t.IP) && ua.Port == t.Port
}
func (uc *udpConn) WriteTo(b []byte, addr *udpAddr) error {
_, err := uc.UDPConn.WriteToUDP(b, &addr.UDPAddr)
return err
}
func (uc *udpConn) LocalAddr() (*udpAddr, error) {
a := uc.UDPConn.LocalAddr()
switch v := a.(type) {
case *net.UDPAddr:
return &udpAddr{UDPAddr: *v}, nil
default:
return nil, fmt.Errorf("LocalAddr returned: %#v", a)
}
}
func (u *udpConn) reloadConfig(c *Config) {
// TODO
}
type rawMessage struct {
Len uint32
}
func (u *udpConn) ListenOut(f *Interface) {
plaintext := make([]byte, mtu)
buffer := make([]byte, mtu)
header := &Header{}
fwPacket := &FirewallPacket{}
udpAddr := &udpAddr{}
nb := make([]byte, 12, 12)
for {
// Just read one packet at a time
n, rua, err := u.ReadFromUDP(buffer)
if err != nil {
l.WithError(err).Error("Failed to read packets")
continue
}
udpAddr.UDPAddr = *rua
f.readOutsidePackets(udpAddr, plaintext[:0], buffer[:n], header, fwPacket, nb)
}
}
func udp2ip(addr *udpAddr) net.IP {
return addr.IP
}
func udp2ipInt(addr *udpAddr) uint32 {
return binary.BigEndian.Uint32(addr.IP.To4())
}
func hostDidRoam(addr *udpAddr, newaddr *udpAddr) bool {
return !addr.Equals(newaddr)
}