91 lines
1.7 KiB
Go
91 lines
1.7 KiB
Go
package connection
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import (
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"fmt"
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"net"
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"sync"
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"github.com/google/uuid"
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)
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// TODO: TUN-5422 Unregister session
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const (
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sessionIDLen = len(uuid.UUID{})
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)
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type udpSessions struct {
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lock sync.RWMutex
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sessions map[uuid.UUID]*net.UDPConn
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localIP net.IP
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}
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func newUDPSessions(localIP net.IP) *udpSessions {
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return &udpSessions{
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sessions: make(map[uuid.UUID]*net.UDPConn),
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localIP: localIP,
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}
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}
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func (us *udpSessions) register(id uuid.UUID, dstIP net.IP, dstPort uint16) (*net.UDPConn, error) {
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us.lock.Lock()
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defer us.lock.Unlock()
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dstAddr := &net.UDPAddr{
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IP: dstIP,
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Port: int(dstPort),
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}
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conn, err := net.DialUDP("udp", us.localAddr(), dstAddr)
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if err != nil {
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return nil, err
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}
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us.sessions[id] = conn
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return conn, nil
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}
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func (us *udpSessions) unregister(id uuid.UUID) {
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us.lock.Lock()
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defer us.lock.Unlock()
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delete(us.sessions, id)
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}
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func (us *udpSessions) send(id uuid.UUID, payload []byte) error {
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us.lock.RLock()
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defer us.lock.RUnlock()
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conn, ok := us.sessions[id]
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if !ok {
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return fmt.Errorf("session %s not found", id)
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}
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_, err := conn.Write(payload)
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return err
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}
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func (ud *udpSessions) localAddr() *net.UDPAddr {
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// TODO: Determine the IP to bind to
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return &net.UDPAddr{
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IP: ud.localIP,
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Port: 0,
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}
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}
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// TODO: TUN-5421 allow user to specify which IP to bind to
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func GetLocalIP() (net.IP, error) {
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addrs, err := net.InterfaceAddrs()
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if err != nil {
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return nil, err
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}
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for _, addr := range addrs {
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// Find the IP that is not loop back
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var ip net.IP
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switch v := addr.(type) {
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case *net.IPNet:
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ip = v.IP
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case *net.IPAddr:
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ip = v.IP
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}
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if !ip.IsLoopback() {
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return ip, nil
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}
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}
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return nil, fmt.Errorf("cannot determine IP to bind to")
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}
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