Improve IP/Port parsing

network/netutils/address.go

@@ -2,39 +2,45 @@ package netutils
 
 import (
 	"errors"
-	"fmt"
 	"net"
 	"strconv"
+
+	"github.com/safing/portmaster/network/packet"
 )
 
 var errInvalidIP = errors.New("invalid IP address")
 
-// IPFromAddr extracts or parses the IP address contained in the given address.
-func IPFromAddr(addr net.Addr) (net.IP, error) {
+// IPPortFromAddr extracts or parses the IP address and port contained in the given address.
+func IPPortFromAddr(addr net.Addr) (ip net.IP, port uint16, err error) {
 	// Convert addr to IP if needed.
 	switch v := addr.(type) {
 	case *net.TCPAddr:
-		return v.IP, nil
+		return v.IP, uint16(v.Port), nil
 	case *net.UDPAddr:
-		return v.IP, nil
+		return v.IP, uint16(v.Port), nil
 	case *net.IPAddr:
-		return v.IP, nil
+		return v.IP, 0, nil
+	case *net.UnixAddr:
+		return nil, 0, errors.New("unix addresses don't have IPs")
 	default:
-		// Parse via string.
-		host, _, err := net.SplitHostPort(addr.String())
-		if err != nil {
-			return nil, fmt.Errorf("failed to split host and port of %q: %w", addr, err)
-		}
-		ip := net.ParseIP(host)
-		if ip == nil {
-			return nil, fmt.Errorf("address %q does not contain a valid IP address", addr)
-		}
-		return ip, nil
+		return ParseIPPort(addr.String())
 	}
 }
 
-// ParseHostPort parses a <ip>:port formatted address.
-func ParseHostPort(address string) (net.IP, uint16, error) {
+// ProtocolFromNetwork returns the protocol from the given net, as used in the "net" golang stdlib.
+func ProtocolFromNetwork(net string) (protocol packet.IPProtocol) {
+	switch net {
+	case "tcp", "tcp4", "tcp6":
+		return packet.TCP
+	case "udp", "udp4", "udp6":
+		return packet.UDP
+	default:
+		return 0
+	}
+}
+
+// ParseIPPort parses a <ip>:port formatted address.
+func ParseIPPort(address string) (net.IP, uint16, error) {
 	ipString, portString, err := net.SplitHostPort(address)
 	if err != nil {
 		return nil, 0, err