switch to v5 (#890)

* switch from v4 to v5

* remove deprecated entities

* remove "2" suffix from entities

* rename TransportProtocol into Protocol

pkg/multicast/multicast.go

@@ -2,7 +2,6 @@
 package multicast
 
 import (
-	"fmt"
 	"net"
 	"syscall"
 )
@@ -13,37 +12,3 @@ type Conn interface {
 	SetReadBuffer(int) error
 	SyscallConn() (syscall.RawConn, error)
 }
-
-// InterfaceForSource returns a multicast-capable interface that can communicate with given IP.
-//
-// Deprecated: not used anymore.
-func InterfaceForSource(ip net.IP) (*net.Interface, error) {
-	if ip.Equal(net.ParseIP("127.0.0.1")) {
-		return nil, fmt.Errorf("IP 127.0.0.1 can't be used as source of a multicast stream. Use the LAN IP of your PC")
-	}
-
-	intfs, err := net.Interfaces()
-	if err != nil {
-		return nil, err
-	}
-
-	for _, intf := range intfs {
-		if (intf.Flags & net.FlagMulticast) == 0 {
-			continue
-		}
-
-		var addrs []net.Addr
-		addrs, err = intf.Addrs()
-		if err == nil {
-			for _, addr := range addrs {
-				var ipnet *net.IPNet
-				_, ipnet, err = net.ParseCIDR(addr.String())
-				if err == nil && ipnet.Contains(ip) {
-					return &intf, nil
-				}
-			}
-		}
-	}
-
-	return nil, fmt.Errorf("found no interface that is multicast-capable and can communicate with IP %v", ip)
-}