package nebula import ( "encoding/binary" "encoding/json" "fmt" "net" "strconv" "strings" "syscall" "unsafe" "golang.org/x/sys/unix" ) //TODO: make it support reload as best you can! type udpConn struct { sysFd int } type udpAddr struct { IP uint32 Port uint16 } func NewUDPAddr(ip uint32, port uint16) *udpAddr { return &udpAddr{IP: ip, Port: port} } func NewUDPAddrFromString(s string) *udpAddr { p := strings.Split(s, ":") if len(p) < 2 { return nil } port, _ := strconv.Atoi(p[1]) return &udpAddr{ IP: ip2int(net.ParseIP(p[0])), Port: uint16(port), } } type rawSockaddr struct { Family uint16 Data [14]uint8 } type rawSockaddrAny struct { Addr rawSockaddr Pad [96]int8 } var x int func NewListener(ip string, port int, multi bool) (*udpConn, error) { syscall.ForkLock.RLock() fd, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, syscall.IPPROTO_UDP) if err == nil { syscall.CloseOnExec(fd) } syscall.ForkLock.RUnlock() if err != nil { syscall.Close(fd) return nil, fmt.Errorf("unable to open socket: %s", err) } var lip [4]byte copy(lip[:], net.ParseIP(ip).To4()) if err = syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, unix.SO_REUSEPORT, 1); err != nil { return nil, fmt.Errorf("unable to set SO_REUSEPORT: %s", err) } if err = syscall.Bind(fd, &syscall.SockaddrInet4{Port: port}); err != nil { return nil, fmt.Errorf("unable to bind to socket: %s", err) } //TODO: this may be useful for forcing threads into specific cores //syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, unix.SO_INCOMING_CPU, x) //v, err := syscall.GetsockoptInt(fd, syscall.SOL_SOCKET, unix.SO_INCOMING_CPU) //l.Println(v, err) return &udpConn{sysFd: fd}, err } func (u *udpConn) SetRecvBuffer(n int) error { return syscall.SetsockoptInt(u.sysFd, syscall.SOL_SOCKET, syscall.SO_RCVBUFFORCE, n) } func (u *udpConn) SetSendBuffer(n int) error { return syscall.SetsockoptInt(u.sysFd, syscall.SOL_SOCKET, syscall.SO_SNDBUFFORCE, n) } func (u *udpConn) GetRecvBuffer() (int, error) { return syscall.GetsockoptInt(int(u.sysFd), syscall.SOL_SOCKET, syscall.SO_RCVBUF) } func (u *udpConn) GetSendBuffer() (int, error) { return syscall.GetsockoptInt(int(u.sysFd), syscall.SOL_SOCKET, syscall.SO_SNDBUF) } func (u *udpConn) LocalAddr() (*udpAddr, error) { var rsa rawSockaddrAny var rLen = syscall.SizeofSockaddrAny _, _, err := syscall.Syscall( syscall.SYS_GETSOCKNAME, uintptr(u.sysFd), uintptr(unsafe.Pointer(&rsa)), uintptr(unsafe.Pointer(&rLen)), ) if err != 0 { return nil, err } addr := &udpAddr{} if rsa.Addr.Family == syscall.AF_INET { addr.Port = uint16(rsa.Addr.Data[0])<<8 + uint16(rsa.Addr.Data[1]) addr.IP = uint32(rsa.Addr.Data[2])<<24 + uint32(rsa.Addr.Data[3])<<16 + uint32(rsa.Addr.Data[4])<<8 + uint32(rsa.Addr.Data[5]) } else { addr.Port = 0 addr.IP = 0 } return addr, nil } func (u *udpConn) ListenOut(f *Interface) { plaintext := make([]byte, mtu) header := &Header{} fwPacket := &FirewallPacket{} udpAddr := &udpAddr{} nb := make([]byte, 12, 12) //TODO: should we track this? //metric := metrics.GetOrRegisterHistogram("test.batch_read", nil, metrics.NewExpDecaySample(1028, 0.015)) msgs, buffers, names := u.PrepareRawMessages(f.udpBatchSize) for { n, err := u.ReadMulti(msgs) if err != nil { l.WithError(err).Error("Failed to read packets") continue } //metric.Update(int64(n)) for i := 0; i < n; i++ { udpAddr.IP = binary.BigEndian.Uint32(names[i][4:8]) udpAddr.Port = binary.BigEndian.Uint16(names[i][2:4]) f.readOutsidePackets(udpAddr, plaintext[:0], buffers[i][:msgs[i].Len], header, fwPacket, nb) } } } func (u *udpConn) Read(addr *udpAddr, b []byte) ([]byte, error) { var rsa rawSockaddrAny var rLen = syscall.SizeofSockaddrAny for { n, _, err := syscall.Syscall6( syscall.SYS_RECVFROM, uintptr(u.sysFd), uintptr(unsafe.Pointer(&b[0])), uintptr(len(b)), uintptr(0), uintptr(unsafe.Pointer(&rsa)), uintptr(unsafe.Pointer(&rLen)), ) if err != 0 { return nil, &net.OpError{Op: "read", Err: err} } if rsa.Addr.Family == syscall.AF_INET { addr.Port = uint16(rsa.Addr.Data[0])<<8 + uint16(rsa.Addr.Data[1]) addr.IP = uint32(rsa.Addr.Data[2])<<24 + uint32(rsa.Addr.Data[3])<<16 + uint32(rsa.Addr.Data[4])<<8 + uint32(rsa.Addr.Data[5]) } else { addr.Port = 0 addr.IP = 0 } return b[:n], nil } } func (u *udpConn) ReadMulti(msgs []rawMessage) (int, error) { for { n, _, err := syscall.Syscall6( syscall.SYS_RECVMMSG, uintptr(u.sysFd), uintptr(unsafe.Pointer(&msgs[0])), uintptr(len(msgs)), unix.MSG_WAITFORONE, 0, 0, ) if err != 0 { return 0, &net.OpError{Op: "recvmmsg", Err: err} } return int(n), nil } } func (u *udpConn) WriteTo(b []byte, addr *udpAddr) error { var rsa syscall.RawSockaddrInet4 //TODO: sometimes addr is nil! rsa.Family = syscall.AF_INET p := (*[2]byte)(unsafe.Pointer(&rsa.Port)) p[0] = byte(addr.Port >> 8) p[1] = byte(addr.Port) rsa.Addr[0] = byte(addr.IP & 0xff000000 >> 24) rsa.Addr[1] = byte(addr.IP & 0x00ff0000 >> 16) rsa.Addr[2] = byte(addr.IP & 0x0000ff00 >> 8) rsa.Addr[3] = byte(addr.IP & 0x000000ff) for { _, _, err := syscall.Syscall6( syscall.SYS_SENDTO, uintptr(u.sysFd), uintptr(unsafe.Pointer(&b[0])), uintptr(len(b)), uintptr(0), uintptr(unsafe.Pointer(&rsa)), uintptr(syscall.SizeofSockaddrInet4), ) if err != 0 { return &net.OpError{Op: "sendto", Err: err} } //TODO: handle incomplete writes return nil } } func (u *udpConn) reloadConfig(c *Config) { b := c.GetInt("listen.read_buffer", 0) if b > 0 { err := u.SetRecvBuffer(b) if err == nil { s, err := u.GetRecvBuffer() if err == nil { l.WithField("size", s).Info("listen.read_buffer was set") } else { l.WithError(err).Warn("Failed to get listen.read_buffer") } } else { l.WithError(err).Error("Failed to set listen.read_buffer") } } b = c.GetInt("listen.write_buffer", 0) if b > 0 { err := u.SetSendBuffer(b) if err == nil { s, err := u.GetSendBuffer() if err == nil { l.WithField("size", s).Info("listen.write_buffer was set") } else { l.WithError(err).Warn("Failed to get listen.write_buffer") } } else { l.WithError(err).Error("Failed to set listen.write_buffer") } } } func (ua *udpAddr) Equals(t *udpAddr) bool { if t == nil || ua == nil { return t == nil && ua == nil } return ua.IP == t.IP && ua.Port == t.Port } func (ua *udpAddr) Copy() *udpAddr { return &udpAddr{ Port: ua.Port, IP: ua.IP, } } func (ua *udpAddr) String() string { return fmt.Sprintf("%s:%v", int2ip(ua.IP), ua.Port) } func (ua *udpAddr) MarshalJSON() ([]byte, error) { return json.Marshal(m{"ip": int2ip(ua.IP), "port": ua.Port}) } func udp2ip(addr *udpAddr) net.IP { return int2ip(addr.IP) } func udp2ipInt(addr *udpAddr) uint32 { return addr.IP } func hostDidRoam(addr *udpAddr, newaddr *udpAddr) bool { return !addr.Equals(newaddr) }