snet: test for Windows-specific error codes

pkg/snet/BUILD.bazel

@@ -14,6 +14,8 @@ go_library(
         "scmp.go",
         "snet.go",
         "svcaddr.go",
+        "udp_range_windows.go",
+        "udp_range.go",
         "udpaddr.go",
         "writer.go",
     ],

pkg/snet/snet.go

@@ -38,10 +38,8 @@ package snet
 
 import (
 	"context"
-	"errors"
 	"net"
 	"net/netip"
-	"syscall"
 
 	"github.com/scionproto/scion/pkg/addr"
 	"github.com/scionproto/scion/pkg/log"
@@ -178,42 +176,3 @@ func (n *SCIONNetwork) Listen(
 	log.FromCtx(ctx).Debug("UDP socket openned on", "addr", packetConn.LocalAddr())
 	return NewCookedConn(packetConn, n.Topology, WithReplyPather(n.ReplyPather))
 }
-
-func listenUDPRange(addr *net.UDPAddr, start, end uint16) (*net.UDPConn, error) {
-	// XXX(JordiSubira): For now, we iterate on the complete SCION/UDP
-	// range, in decreasing order, taking the first unused port.
-	//
-	// If the defined range, intersects with the well-known port range, i.e.,
-	// 1-1023, we just start considering from 1024 onwards.
-	// The decreasing order first try to use the higher port numbers, normally used
-	// by ephemeral connections, letting free the lower port numbers, normally used
-	// by longer-lived applications, e.g., server applications.
-	//
-	// Ideally we would only take a standard ephemeral range, e.g., 32768-65535,
-	// Unfortunately, this range was ocuppied by the old dispatcher.
-	// The default range for the dispatched ports is 31000-32767.
-	// By configuration other port ranges may be defined and restricting to the default
-	// range for applications may cause problems.
-	//
-	// TODO: Replace this implementation with pseudorandom port checking.
-	restrictedStart := start
-	if start < 1024 {
-		restrictedStart = 1024
-	}
-	for port := end; port >= restrictedStart; port-- {
-		pconn, err := net.ListenUDP(addr.Network(), &net.UDPAddr{
-			IP:   addr.IP,
-			Port: int(port),
-		})
-		if err == nil {
-			return pconn, nil
-		}
-		if errors.Is(err, syscall.EADDRINUSE) {
-			continue
-		}
-		return nil, err
-	}
-	return nil, serrors.Wrap("binding to port range", syscall.EADDRINUSE,
-		"start", restrictedStart, "end", end)
-
-}

pkg/snet/udp_range.go

@@ -0,0 +1,65 @@
+// Copyright 2017 ETH Zurich
+// Copyright 2019 ETH Zurich, Anapaya Systems
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !windows
+
+package snet
+
+import (
+	"errors"
+	"net"
+	"syscall"
+
+	"github.com/scionproto/scion/pkg/private/serrors"
+)
+
+func listenUDPRange(addr *net.UDPAddr, start, end uint16) (*net.UDPConn, error) {
+	// XXX(JordiSubira): For now, we iterate on the complete SCION/UDP
+	// range, in decreasing order, taking the first unused port.
+	//
+	// If the defined range, intersects with the well-known port range, i.e.,
+	// 1-1023, we just start considering from 1024 onwards.
+	// The decreasing order first try to use the higher port numbers, normally used
+	// by ephemeral connections, letting free the lower port numbers, normally used
+	// by longer-lived applications, e.g., server applications.
+	//
+	// Ideally we would only take a standard ephemeral range, e.g., 32768-65535,
+	// Unfortunately, this range was ocuppied by the old dispatcher.
+	// The default range for the dispatched ports is 31000-32767.
+	// By configuration other port ranges may be defined and restricting to the default
+	// range for applications may cause problems.
+	//
+	// TODO: Replace this implementation with pseudorandom port checking.
+	restrictedStart := start
+	if start < 1024 {
+		restrictedStart = 1024
+	}
+	for port := end; port >= restrictedStart; port-- {
+		pconn, err := net.ListenUDP(addr.Network(), &net.UDPAddr{
+			IP:   addr.IP,
+			Port: int(port),
+		})
+		if err == nil {
+			return pconn, nil
+		}
+		if errors.Is(err, syscall.EADDRINUSE) {
+			continue
+		}
+		return nil, err
+	}
+	return nil, serrors.Wrap("binding to port range", syscall.EADDRINUSE,
+		"start", restrictedStart, "end", end)
+
+}

pkg/snet/udp_range_windows.go

@@ -0,0 +1,50 @@
+// Copyright 2017 ETH Zurich
+// Copyright 2019 ETH Zurich, Anapaya Systems
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build windows
+
+package snet
+
+import (
+	"errors"
+	"net"
+
+	"github.com/scionproto/scion/pkg/private/serrors"
+	"golang.org/x/sys/windows"
+)
+
+func listenUDPRange(addr *net.UDPAddr, start, end uint16) (*net.UDPConn, error) {
+	// Windows sockets return different error codes
+	restrictedStart := start
+	if start < 1024 {
+		restrictedStart = 1024
+	}
+	for port := end; port >= restrictedStart; port-- {
+		pconn, err := net.ListenUDP(addr.Network(), &net.UDPAddr{
+			IP:   addr.IP,
+			Port: int(port),
+		})
+		if err == nil {
+			return pconn, nil
+		}
+		if errors.Is(err, windows.WSAEADDRINUSE) {
+			continue
+		}
+		return nil, err
+	}
+	return nil, serrors.Wrap("binding to port range", windows.WSAEADDRINUSE,
+		"start", restrictedStart, "end", end)
+
+}