update EncReader and EncWriter interface function args to have concrete types (#844)

* Update LightHouseHandlerFunc to remove EncWriter param.
* Move EncWriter to interface
* EncReader, too

udp/conn.go

@@ -9,7 +9,6 @@ const MTU = 9001
 
 type EncReader func(
 	addr *Addr,
-	via interface{},
 	out []byte,
 	packet []byte,
 	header *header.H,

udp/temp.go

@@ -1,22 +1,9 @@
 package udp
 
 import (
-	"github.com/slackhq/nebula/header"
 	"github.com/slackhq/nebula/iputil"
 )
 
-type EncWriter interface {
-	SendVia(via interface{},
-		relay interface{},
-		ad,
-		nb,
-		out []byte,
-		nocopy bool,
-	)
-	SendMessageToVpnIp(t header.MessageType, st header.MessageSubType, vpnIp iputil.VpnIp, p, nb, out []byte)
-	Handshake(vpnIp iputil.VpnIp)
-}
-
 //TODO: The items in this file belong in their own packages but doing that in a single PR is a nightmare
 
-type LightHouseHandlerFunc func(rAddr *Addr, vpnIp iputil.VpnIp, p []byte, w EncWriter)
+type LightHouseHandlerFunc func(rAddr *Addr, vpnIp iputil.VpnIp, p []byte)

udp/udp_generic.go

@@ -86,6 +86,6 @@ func (u *Conn) ListenOut(r EncReader, lhf LightHouseHandlerFunc, cache *firewall
 
 		udpAddr.IP = rua.IP
 		udpAddr.Port = uint16(rua.Port)
-		r(udpAddr, nil, plaintext[:0], buffer[:n], h, fwPacket, lhf, nb, q, cache.Get(u.l))
+		r(udpAddr, plaintext[:0], buffer[:n], h, fwPacket, lhf, nb, q, cache.Get(u.l))
 	}
 }

udp/udp_linux.go

@@ -145,7 +145,7 @@ func (u *Conn) ListenOut(r EncReader, lhf LightHouseHandlerFunc, cache *firewall
 		for i := 0; i < n; i++ {
 			udpAddr.IP = names[i][8:24]
 			udpAddr.Port = binary.BigEndian.Uint16(names[i][2:4])
-			r(udpAddr, nil, plaintext[:0], buffers[i][:msgs[i].Len], h, fwPacket, lhf, nb, q, cache.Get(u.l))
+			r(udpAddr, plaintext[:0], buffers[i][:msgs[i].Len], h, fwPacket, lhf, nb, q, cache.Get(u.l))
 		}
 	}
 }

udp/udp_tester.go

@@ -122,7 +122,7 @@ func (u *Conn) ListenOut(r EncReader, lhf LightHouseHandlerFunc, cache *firewall
 		}
 		ua.Port = p.FromPort
 		copy(ua.IP, p.FromIp.To16())
-		r(ua, nil, plaintext[:0], p.Data, h, fwPacket, lhf, nb, q, cache.Get(u.l))
+		r(ua, plaintext[:0], p.Data, h, fwPacket, lhf, nb, q, cache.Get(u.l))
 	}
 }