Merge branch 'master' into ip-forwarding

- Merges aleksej-paschenko's with HEAD
- Adds vfs2 support for ip_forward

1 files changed, 282 insertions, 0 deletions

diff --git a/test/iptables/iptables_util.go b/test/iptables/iptables_util.go
new file mode 100644
index 000000000..a6ec5cca3
--- /dev/null
+++ b/test/iptables/iptables_util.go
@@ -0,0 +1,282 @@
+// Copyright 2019 The gVisor Authors.
+//
+// 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.
+
+package iptables
+
+import (
+	"context"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"net"
+	"os/exec"
+	"strings"
+	"time"
+
+	"gvisor.dev/gvisor/pkg/test/testutil"
+)
+
+// filterTable calls `ip{6}tables -t filter` with the given args.
+func filterTable(ipv6 bool, args ...string) error {
+	return tableCmd(ipv6, "filter", args)
+}
+
+// natTable calls `ip{6}tables -t nat` with the given args.
+func natTable(ipv6 bool, args ...string) error {
+	return tableCmd(ipv6, "nat", args)
+}
+
+func tableCmd(ipv6 bool, table string, args []string) error {
+	args = append([]string{"-t", table}, args...)
+	binary := "iptables"
+	if ipv6 {
+		binary = "ip6tables"
+	}
+	cmd := exec.Command(binary, args...)
+	if out, err := cmd.CombinedOutput(); err != nil {
+		return fmt.Errorf("error running iptables with args %v\nerror: %v\noutput: %s", args, err, string(out))
+	}
+	return nil
+}
+
+// filterTableRules is like filterTable, but runs multiple iptables commands.
+func filterTableRules(ipv6 bool, argsList [][]string) error {
+	return tableRules(ipv6, "filter", argsList)
+}
+
+// natTableRules is like natTable, but runs multiple iptables commands.
+func natTableRules(ipv6 bool, argsList [][]string) error {
+	return tableRules(ipv6, "nat", argsList)
+}
+
+func tableRules(ipv6 bool, table string, argsList [][]string) error {
+	for _, args := range argsList {
+		if err := tableCmd(ipv6, table, args); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// listenUDP listens on a UDP port and returns the value of net.Conn.Read() for
+// the first read on that port.
+func listenUDP(ctx context.Context, port int) error {
+	localAddr := net.UDPAddr{
+		Port: port,
+	}
+	conn, err := net.ListenUDP("udp", &localAddr)
+	if err != nil {
+		return err
+	}
+	defer conn.Close()
+
+	ch := make(chan error)
+	go func() {
+		_, err = conn.Read([]byte{0})
+		ch <- err
+	}()
+
+	select {
+	case err := <-ch:
+		return err
+	case <-ctx.Done():
+		return ctx.Err()
+	}
+}
+
+// sendUDPLoop sends 1 byte UDP packets repeatedly to the IP and port specified
+// over a duration.
+func sendUDPLoop(ctx context.Context, ip net.IP, port int) error {
+	remote := net.UDPAddr{
+		IP:   ip,
+		Port: port,
+	}
+	conn, err := net.DialUDP("udp", nil, &remote)
+	if err != nil {
+		return err
+	}
+	defer conn.Close()
+
+	for {
+		// This may return an error (connection refused) if the remote
+		// hasn't started listening yet or they're dropping our
+		// packets. So we ignore Write errors and depend on the remote
+		// to report a failure if it doesn't get a packet it needs.
+		conn.Write([]byte{0})
+		select {
+		case <-ctx.Done():
+			// Being cancelled or timing out isn't an error, as we
+			// cannot tell with UDP whether we succeeded.
+			return nil
+		// Continue looping.
+		case <-time.After(200 * time.Millisecond):
+		}
+	}
+}
+
+// listenTCP listens for connections on a TCP port.
+func listenTCP(ctx context.Context, port int) error {
+	localAddr := net.TCPAddr{
+		Port: port,
+	}
+
+	// Starts listening on port.
+	lConn, err := net.ListenTCP("tcp", &localAddr)
+	if err != nil {
+		return err
+	}
+	defer lConn.Close()
+
+	// Accept connections on port.
+	ch := make(chan error)
+	go func() {
+		conn, err := lConn.AcceptTCP()
+		ch <- err
+		conn.Close()
+	}()
+
+	select {
+	case err := <-ch:
+		return err
+	case <-ctx.Done():
+		return fmt.Errorf("timed out waiting for a connection at %#v: %w", localAddr, ctx.Err())
+	}
+}
+
+// connectTCP connects to the given IP and port from an ephemeral local address.
+func connectTCP(ctx context.Context, ip net.IP, port int) error {
+	contAddr := net.TCPAddr{
+		IP:   ip,
+		Port: port,
+	}
+	// The container may not be listening when we first connect, so retry
+	// upon error.
+	callback := func() error {
+		var d net.Dialer
+		conn, err := d.DialContext(ctx, "tcp", contAddr.String())
+		if conn != nil {
+			conn.Close()
+		}
+		return err
+	}
+	if err := testutil.PollContext(ctx, callback); err != nil {
+		return fmt.Errorf("timed out waiting to connect IP on port %v, most recent error: %v", port, err)
+	}
+
+	return nil
+}
+
+// localAddrs returns a list of local network interface addresses. When ipv6 is
+// true, only IPv6 addresses are returned. Otherwise only IPv4 addresses are
+// returned.
+func localAddrs(ipv6 bool) ([]string, error) {
+	addrs, err := net.InterfaceAddrs()
+	if err != nil {
+		return nil, err
+	}
+	addrStrs := make([]string, 0, len(addrs))
+	for _, addr := range addrs {
+		// Add only IPv4 or only IPv6 addresses.
+		parts := strings.Split(addr.String(), "/")
+		if len(parts) != 2 {
+			return nil, fmt.Errorf("bad interface address: %q", addr.String())
+		}
+		if isIPv6 := net.ParseIP(parts[0]).To4() == nil; isIPv6 == ipv6 {
+			addrStrs = append(addrStrs, addr.String())
+		}
+	}
+	return filterAddrs(addrStrs, ipv6), nil
+}
+
+func filterAddrs(addrs []string, ipv6 bool) []string {
+	addrStrs := make([]string, 0, len(addrs))
+	for _, addr := range addrs {
+		// Add only IPv4 or only IPv6 addresses.
+		parts := strings.Split(addr, "/")
+		if isIPv6 := net.ParseIP(parts[0]).To4() == nil; isIPv6 == ipv6 {
+			addrStrs = append(addrStrs, parts[0])
+		}
+	}
+	return addrStrs
+}
+
+// getInterfaceName returns the name of the interface other than loopback.
+func getInterfaceName() (string, bool) {
+	iface, ok := getNonLoopbackInterface()
+	if !ok {
+		return "", false
+	}
+	return iface.Name, true
+}
+
+func getInterfaceAddrs(ipv6 bool) ([]net.IP, error) {
+	iface, ok := getNonLoopbackInterface()
+	if !ok {
+		return nil, errors.New("no non-loopback interface found")
+	}
+	addrs, err := iface.Addrs()
+	if err != nil {
+		return nil, err
+	}
+
+	// Get only IPv4 or IPv6 addresses.
+	ips := make([]net.IP, 0, len(addrs))
+	for _, addr := range addrs {
+		parts := strings.Split(addr.String(), "/")
+		var ip net.IP
+		// To16() returns IPv4 addresses as IPv4-mapped IPv6 addresses.
+		// So we check whether To4() returns nil to test whether the
+		// address is v4 or v6.
+		if v4 := net.ParseIP(parts[0]).To4(); ipv6 && v4 == nil {
+			ip = net.ParseIP(parts[0]).To16()
+		} else {
+			ip = v4
+		}
+		if ip != nil {
+			ips = append(ips, ip)
+		}
+	}
+	return ips, nil
+}
+
+func getNonLoopbackInterface() (net.Interface, bool) {
+	if interfaces, err := net.Interfaces(); err == nil {
+		for _, intf := range interfaces {
+			if intf.Name != "lo" {
+				return intf, true
+			}
+		}
+	}
+	return net.Interface{}, false
+}
+
+func htons(x uint16) uint16 {
+	buf := make([]byte, 2)
+	binary.BigEndian.PutUint16(buf, x)
+	return binary.LittleEndian.Uint16(buf)
+}
+
+func localIP(ipv6 bool) string {
+	if ipv6 {
+		return "::1"
+	}
+	return "127.0.0.1"
+}
+
+func nowhereIP(ipv6 bool) string {
+	if ipv6 {
+		return "2001:db8::1"
+	}
+	return "192.0.2.1"
+}