channeldb: remove address resolution from channeldb

channeldb/addr.go

@@ -0,0 +1,103 @@
+package channeldb
+
+import (
+	"io"
+	"net"
+)
+
+// addressType specifies the network protocol and version that should be used
+// when connecting to a node at a particular address.
+type addressType uint8
+
+const (
+	// tcp4Addr denotes an IPv4 TCP address.
+	tcp4Addr addressType = 0
+
+	// tcp6Addr denotes an IPv6 TCP address.
+	tcp6Addr addressType = 1
+
+	// v2OnionAddr denotes a version 2 Tor onion service address.
+	v2OnionAddr addressType = 2
+
+	// v3OnionAddr denotes a version 3 Tor (prop224) onion service addresses.
+	v3OnionAddr addressType = 3
+)
+
+// deserializeAddr reads the serialized raw representation of an address and
+// deserializes it into the actual address, to avoid performing address
+// resolution in the database module
+func deserializeAddr(r io.Reader) (net.Addr, error) {
+	var scratch [8]byte
+	var address net.Addr
+
+	if _, err := r.Read(scratch[:1]); err != nil {
+		return nil, err
+	}
+
+	// TODO(roasbeef): also add onion addrs
+	switch addressType(scratch[0]) {
+	case tcp4Addr:
+		addr := &net.TCPAddr{}
+		var ip [4]byte
+		if _, err := r.Read(ip[:]); err != nil {
+			return nil, err
+		}
+		addr.IP = (net.IP)(ip[:])
+		if _, err := r.Read(scratch[:2]); err != nil {
+			return nil, err
+		}
+		addr.Port = int(byteOrder.Uint16(scratch[:2]))
+		address = addr
+	case tcp6Addr:
+		addr := &net.TCPAddr{}
+		var ip [16]byte
+		if _, err := r.Read(ip[:]); err != nil {
+			return nil, err
+		}
+		addr.IP = (net.IP)(ip[:])
+		if _, err := r.Read(scratch[:2]); err != nil {
+			return nil, err
+		}
+		addr.Port = int(byteOrder.Uint16(scratch[:2]))
+		address = addr
+	default:
+		return nil, ErrUnknownAddressType
+	}
+
+	return address, nil
+}
+
+// serializeAddr serializes an address into a raw byte representation so it
+// can be deserialized without requiring address resolution
+func serializeAddr(w io.Writer, address net.Addr) error {
+	var scratch [16]byte
+
+	if address.Network() == "tcp" {
+		if address.(*net.TCPAddr).IP.To4() != nil {
+			scratch[0] = uint8(tcp4Addr)
+			if _, err := w.Write(scratch[:1]); err != nil {
+				return err
+			}
+			copy(scratch[:4], address.(*net.TCPAddr).IP.To4())
+			if _, err := w.Write(scratch[:4]); err != nil {
+				return err
+			}
+		} else {
+			scratch[0] = uint8(tcp6Addr)
+			if _, err := w.Write(scratch[:1]); err != nil {
+				return err
+			}
+			copy(scratch[:], address.(*net.TCPAddr).IP.To16())
+			if _, err := w.Write(scratch[:]); err != nil {
+				return err
+			}
+		}
+		byteOrder.PutUint16(scratch[:2],
+			uint16(address.(*net.TCPAddr).Port))
+		if _, err := w.Write(scratch[:2]); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}