github.com/SagerNet/gvisor@v0.0.0-20210707092255-7731c139d75c/test/iptables/filter_output.go

// Copyright 2020 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"
	"errors"
	"fmt"
	"net"
)

func init() {
	RegisterTestCase(&FilterOutputDropTCPDestPort{})
	RegisterTestCase(&FilterOutputDropTCPSrcPort{})
	RegisterTestCase(&FilterOutputDestination{})
	RegisterTestCase(&FilterOutputInvertDestination{})
	RegisterTestCase(&FilterOutputAcceptTCPOwner{})
	RegisterTestCase(&FilterOutputDropTCPOwner{})
	RegisterTestCase(&FilterOutputAcceptUDPOwner{})
	RegisterTestCase(&FilterOutputDropUDPOwner{})
	RegisterTestCase(&FilterOutputOwnerFail{})
	RegisterTestCase(&FilterOutputAcceptGIDOwner{})
	RegisterTestCase(&FilterOutputDropGIDOwner{})
	RegisterTestCase(&FilterOutputInvertGIDOwner{})
	RegisterTestCase(&FilterOutputInvertUIDOwner{})
	RegisterTestCase(&FilterOutputInvertUIDAndGIDOwner{})
	RegisterTestCase(&FilterOutputInterfaceAccept{})
	RegisterTestCase(&FilterOutputInterfaceDrop{})
	RegisterTestCase(&FilterOutputInterface{})
	RegisterTestCase(&FilterOutputInterfaceBeginsWith{})
	RegisterTestCase(&FilterOutputInterfaceInvertDrop{})
	RegisterTestCase(&FilterOutputInterfaceInvertAccept{})
}

// FilterOutputDropTCPDestPort tests that connections are not accepted on
// specified source ports.
type FilterOutputDropTCPDestPort struct{ baseCase }

var _ TestCase = (*FilterOutputDropTCPDestPort)(nil)

// Name implements TestCase.Name.
func (*FilterOutputDropTCPDestPort) Name() string {
	return "FilterOutputDropTCPDestPort"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputDropTCPDestPort) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	if err := filterTable(ipv6, "-A", "OUTPUT", "-p", "tcp", "-m", "tcp", "--dport", "1024:65535", "-j", "DROP"); err != nil {
		return err
	}

	// Listen for TCP packets on accept port.
	timedCtx, cancel := context.WithTimeout(ctx, NegativeTimeout)
	defer cancel()
	if err := listenTCP(timedCtx, acceptPort, ipv6); err == nil {
		return fmt.Errorf("connection destined to port %d should not be accepted, but got accepted", dropPort)
	} else if !errors.Is(err, context.DeadlineExceeded) {
		return fmt.Errorf("error reading: %v", err)
	}

	return nil
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputDropTCPDestPort) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	timedCtx, cancel := context.WithTimeout(ctx, NegativeTimeout)
	defer cancel()
	if err := connectTCP(timedCtx, ip, acceptPort, ipv6); err == nil {
		return fmt.Errorf("connection on port %d should not be accepted, but got accepted", dropPort)
	}

	return nil
}

// FilterOutputDropTCPSrcPort tests that connections are not accepted on
// specified source ports.
type FilterOutputDropTCPSrcPort struct{ baseCase }

var _ TestCase = (*FilterOutputDropTCPSrcPort)(nil)

// Name implements TestCase.Name.
func (*FilterOutputDropTCPSrcPort) Name() string {
	return "FilterOutputDropTCPSrcPort"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputDropTCPSrcPort) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	if err := filterTable(ipv6, "-A", "OUTPUT", "-p", "tcp", "-m", "tcp", "--sport", fmt.Sprintf("%d", dropPort), "-j", "DROP"); err != nil {
		return err
	}

	// Listen for TCP packets on drop port.
	timedCtx, cancel := context.WithTimeout(ctx, NegativeTimeout)
	defer cancel()
	if err := listenTCP(timedCtx, dropPort, ipv6); err == nil {
		return fmt.Errorf("connection on port %d should not be accepted, but got accepted", dropPort)
	} else if !errors.Is(err, context.DeadlineExceeded) {
		return fmt.Errorf("error reading: %v", err)
	}

	return nil
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputDropTCPSrcPort) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	timedCtx, cancel := context.WithTimeout(ctx, NegativeTimeout)
	defer cancel()
	if err := connectTCP(timedCtx, ip, dropPort, ipv6); err == nil {
		return fmt.Errorf("connection destined to port %d should not be accepted, but got accepted", dropPort)
	}

	return nil
}

// FilterOutputAcceptTCPOwner tests that TCP connections from uid owner are accepted.
type FilterOutputAcceptTCPOwner struct{ baseCase }

var _ TestCase = (*FilterOutputAcceptTCPOwner)(nil)

// Name implements TestCase.Name.
func (*FilterOutputAcceptTCPOwner) Name() string {
	return "FilterOutputAcceptTCPOwner"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputAcceptTCPOwner) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	if err := filterTable(ipv6, "-A", "OUTPUT", "-p", "tcp", "-m", "owner", "--uid-owner", "root", "-j", "ACCEPT"); err != nil {
		return err
	}

	// Listen for TCP packets on accept port.
	return listenTCP(ctx, acceptPort, ipv6)
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputAcceptTCPOwner) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	return connectTCP(ctx, ip, acceptPort, ipv6)
}

// FilterOutputDropTCPOwner tests that TCP connections from uid owner are dropped.
type FilterOutputDropTCPOwner struct{ baseCase }

var _ TestCase = (*FilterOutputDropTCPOwner)(nil)

// Name implements TestCase.Name.
func (*FilterOutputDropTCPOwner) Name() string {
	return "FilterOutputDropTCPOwner"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputDropTCPOwner) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	if err := filterTable(ipv6, "-A", "OUTPUT", "-p", "tcp", "-m", "owner", "--uid-owner", "root", "-j", "DROP"); err != nil {
		return err
	}

	// Listen for TCP packets on accept port.
	timedCtx, cancel := context.WithTimeout(ctx, NegativeTimeout)
	defer cancel()
	if err := listenTCP(timedCtx, acceptPort, ipv6); err == nil {
		return fmt.Errorf("connection on port %d should be dropped, but got accepted", acceptPort)
	} else if !errors.Is(err, context.DeadlineExceeded) {
		return fmt.Errorf("error reading: %v", err)
	}

	return nil
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputDropTCPOwner) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	timedCtx, cancel := context.WithTimeout(ctx, NegativeTimeout)
	defer cancel()
	if err := connectTCP(timedCtx, ip, acceptPort, ipv6); err == nil {
		return fmt.Errorf("connection destined to port %d should be dropped, but got accepted", acceptPort)
	}

	return nil
}

// FilterOutputAcceptUDPOwner tests that UDP packets from uid owner are accepted.
type FilterOutputAcceptUDPOwner struct{ localCase }

var _ TestCase = (*FilterOutputAcceptUDPOwner)(nil)

// Name implements TestCase.Name.
func (*FilterOutputAcceptUDPOwner) Name() string {
	return "FilterOutputAcceptUDPOwner"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputAcceptUDPOwner) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	if err := filterTable(ipv6, "-A", "OUTPUT", "-p", "udp", "-m", "owner", "--uid-owner", "root", "-j", "ACCEPT"); err != nil {
		return err
	}

	// Send UDP packets on acceptPort.
	return sendUDPLoop(ctx, ip, acceptPort, ipv6)
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputAcceptUDPOwner) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	// Listen for UDP packets on acceptPort.
	return listenUDP(ctx, acceptPort, ipv6)
}

// FilterOutputDropUDPOwner tests that UDP packets from uid owner are dropped.
type FilterOutputDropUDPOwner struct{ localCase }

var _ TestCase = (*FilterOutputDropUDPOwner)(nil)

// Name implements TestCase.Name.
func (*FilterOutputDropUDPOwner) Name() string {
	return "FilterOutputDropUDPOwner"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputDropUDPOwner) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	if err := filterTable(ipv6, "-A", "OUTPUT", "-p", "udp", "-m", "owner", "--uid-owner", "root", "-j", "DROP"); err != nil {
		return err
	}

	// Send UDP packets on dropPort.
	return sendUDPLoop(ctx, ip, dropPort, ipv6)
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputDropUDPOwner) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	// Listen for UDP packets on dropPort.
	timedCtx, cancel := context.WithTimeout(ctx, NegativeTimeout)
	defer cancel()
	if err := listenUDP(timedCtx, dropPort, ipv6); err == nil {
		return fmt.Errorf("packets should not be received")
	} else if !errors.Is(err, context.DeadlineExceeded) {
		return fmt.Errorf("error reading: %v", err)
	}

	return nil
}

// FilterOutputOwnerFail tests that without uid/gid option, owner rule
// will fail.
type FilterOutputOwnerFail struct{ baseCase }

var _ TestCase = (*FilterOutputOwnerFail)(nil)

// Name implements TestCase.Name.
func (*FilterOutputOwnerFail) Name() string {
	return "FilterOutputOwnerFail"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputOwnerFail) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	if err := filterTable(ipv6, "-A", "OUTPUT", "-p", "udp", "-m", "owner", "-j", "ACCEPT"); err == nil {
		return fmt.Errorf("invalid argument")
	}

	return nil
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputOwnerFail) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	// no-op.
	return nil
}

// FilterOutputAcceptGIDOwner tests that TCP connections from gid owner are accepted.
type FilterOutputAcceptGIDOwner struct{ baseCase }

var _ TestCase = (*FilterOutputAcceptGIDOwner)(nil)

// Name implements TestCase.Name.
func (*FilterOutputAcceptGIDOwner) Name() string {
	return "FilterOutputAcceptGIDOwner"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputAcceptGIDOwner) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	if err := filterTable(ipv6, "-A", "OUTPUT", "-p", "tcp", "-m", "owner", "--gid-owner", "root", "-j", "ACCEPT"); err != nil {
		return err
	}

	// Listen for TCP packets on accept port.
	return listenTCP(ctx, acceptPort, ipv6)
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputAcceptGIDOwner) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	return connectTCP(ctx, ip, acceptPort, ipv6)
}

// FilterOutputDropGIDOwner tests that TCP connections from gid owner are dropped.
type FilterOutputDropGIDOwner struct{ baseCase }

var _ TestCase = (*FilterOutputDropGIDOwner)(nil)

// Name implements TestCase.Name.
func (*FilterOutputDropGIDOwner) Name() string {
	return "FilterOutputDropGIDOwner"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputDropGIDOwner) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	if err := filterTable(ipv6, "-A", "OUTPUT", "-p", "tcp", "-m", "owner", "--gid-owner", "root", "-j", "DROP"); err != nil {
		return err
	}

	// Listen for TCP packets on accept port.
	timedCtx, cancel := context.WithTimeout(ctx, NegativeTimeout)
	defer cancel()
	if err := listenTCP(timedCtx, acceptPort, ipv6); err == nil {
		return fmt.Errorf("connection on port %d should not be accepted, but got accepted", acceptPort)
	} else if !errors.Is(err, context.DeadlineExceeded) {
		return fmt.Errorf("error reading: %v", err)
	}

	return nil
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputDropGIDOwner) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	timedCtx, cancel := context.WithTimeout(ctx, NegativeTimeout)
	defer cancel()
	if err := connectTCP(timedCtx, ip, acceptPort, ipv6); err == nil {
		return fmt.Errorf("connection destined to port %d should not be accepted, but got accepted", acceptPort)
	}

	return nil
}

// FilterOutputInvertGIDOwner tests that TCP connections from gid owner are dropped.
type FilterOutputInvertGIDOwner struct{ baseCase }

var _ TestCase = (*FilterOutputInvertGIDOwner)(nil)

// Name implements TestCase.Name.
func (*FilterOutputInvertGIDOwner) Name() string {
	return "FilterOutputInvertGIDOwner"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputInvertGIDOwner) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	rules := [][]string{
		{"-A", "OUTPUT", "-p", "tcp", "-m", "owner", "!", "--gid-owner", "root", "-j", "ACCEPT"},
		{"-A", "OUTPUT", "-p", "tcp", "-j", "DROP"},
	}
	if err := filterTableRules(ipv6, rules); err != nil {
		return err
	}

	// Listen for TCP packets on accept port.
	timedCtx, cancel := context.WithTimeout(ctx, NegativeTimeout)
	defer cancel()
	if err := listenTCP(timedCtx, acceptPort, ipv6); err == nil {
		return fmt.Errorf("connection on port %d should not be accepted, but got accepted", acceptPort)
	} else if !errors.Is(err, context.DeadlineExceeded) {
		return fmt.Errorf("error reading: %v", err)
	}

	return nil
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputInvertGIDOwner) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	timedCtx, cancel := context.WithTimeout(ctx, NegativeTimeout)
	defer cancel()
	if err := connectTCP(timedCtx, ip, acceptPort, ipv6); err == nil {
		return fmt.Errorf("connection destined to port %d should not be accepted, but got accepted", acceptPort)
	}

	return nil
}

// FilterOutputInvertUIDOwner tests that TCP connections from gid owner are dropped.
type FilterOutputInvertUIDOwner struct{ baseCase }

var _ TestCase = (*FilterOutputInvertUIDOwner)(nil)

// Name implements TestCase.Name.
func (*FilterOutputInvertUIDOwner) Name() string {
	return "FilterOutputInvertUIDOwner"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputInvertUIDOwner) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	rules := [][]string{
		{"-A", "OUTPUT", "-p", "tcp", "-m", "owner", "!", "--uid-owner", "root", "-j", "DROP"},
		{"-A", "OUTPUT", "-p", "tcp", "-j", "ACCEPT"},
	}
	if err := filterTableRules(ipv6, rules); err != nil {
		return err
	}

	// Listen for TCP packets on accept port.
	return listenTCP(ctx, acceptPort, ipv6)
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputInvertUIDOwner) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	return connectTCP(ctx, ip, acceptPort, ipv6)
}

// FilterOutputInvertUIDAndGIDOwner tests that TCP connections from uid and gid
// owner are dropped.
type FilterOutputInvertUIDAndGIDOwner struct{ baseCase }

var _ TestCase = (*FilterOutputInvertUIDAndGIDOwner)(nil)

// Name implements TestCase.Name.
func (*FilterOutputInvertUIDAndGIDOwner) Name() string {
	return "FilterOutputInvertUIDAndGIDOwner"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputInvertUIDAndGIDOwner) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	rules := [][]string{
		{"-A", "OUTPUT", "-p", "tcp", "-m", "owner", "!", "--uid-owner", "root", "!", "--gid-owner", "root", "-j", "ACCEPT"},
		{"-A", "OUTPUT", "-p", "tcp", "-j", "DROP"},
	}
	if err := filterTableRules(ipv6, rules); err != nil {
		return err
	}

	// Listen for TCP packets on accept port.
	timedCtx, cancel := context.WithTimeout(ctx, NegativeTimeout)
	defer cancel()
	if err := listenTCP(timedCtx, acceptPort, ipv6); err == nil {
		return fmt.Errorf("connection on port %d should not be accepted, but got accepted", acceptPort)
	} else if !errors.Is(err, context.DeadlineExceeded) {
		return fmt.Errorf("error reading: %v", err)
	}

	return nil
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputInvertUIDAndGIDOwner) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	timedCtx, cancel := context.WithTimeout(ctx, NegativeTimeout)
	defer cancel()
	if err := connectTCP(timedCtx, ip, acceptPort, ipv6); err == nil {
		return fmt.Errorf("connection destined to port %d should not be accepted, but got accepted", acceptPort)
	}

	return nil
}

// FilterOutputDestination tests that we can selectively allow packets to
// certain destinations.
type FilterOutputDestination struct{ localCase }

var _ TestCase = (*FilterOutputDestination)(nil)

// Name implements TestCase.Name.
func (*FilterOutputDestination) Name() string {
	return "FilterOutputDestination"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputDestination) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	var rules [][]string
	if ipv6 {
		rules = [][]string{
			{"-A", "OUTPUT", "-d", ip.String(), "-j", "ACCEPT"},
			// Allow solicited node multicast addresses so we can send neighbor
			// solicitations.
			{"-A", "OUTPUT", "-d", "ff02::1:ff00:0/104", "-j", "ACCEPT"},
			{"-P", "OUTPUT", "DROP"},
		}
	} else {
		rules = [][]string{
			{"-A", "OUTPUT", "-d", ip.String(), "-j", "ACCEPT"},
			{"-P", "OUTPUT", "DROP"},
		}
	}
	if err := filterTableRules(ipv6, rules); err != nil {
		return err
	}

	return sendUDPLoop(ctx, ip, acceptPort, ipv6)
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputDestination) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	return listenUDP(ctx, acceptPort, ipv6)
}

// FilterOutputInvertDestination tests that we can selectively allow packets
// not headed for a particular destination.
type FilterOutputInvertDestination struct{ localCase }

var _ TestCase = (*FilterOutputInvertDestination)(nil)

// Name implements TestCase.Name.
func (*FilterOutputInvertDestination) Name() string {
	return "FilterOutputInvertDestination"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputInvertDestination) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	rules := [][]string{
		{"-A", "OUTPUT", "!", "-d", localIP(ipv6), "-j", "ACCEPT"},
		{"-P", "OUTPUT", "DROP"},
	}
	if err := filterTableRules(ipv6, rules); err != nil {
		return err
	}

	return sendUDPLoop(ctx, ip, acceptPort, ipv6)
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputInvertDestination) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	return listenUDP(ctx, acceptPort, ipv6)
}

// FilterOutputInterfaceAccept tests that packets are sent via interface
// matching the iptables rule.
type FilterOutputInterfaceAccept struct{ localCase }

var _ TestCase = (*FilterOutputInterfaceAccept)(nil)

// Name implements TestCase.Name.
func (*FilterOutputInterfaceAccept) Name() string {
	return "FilterOutputInterfaceAccept"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputInterfaceAccept) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	ifname, ok := getInterfaceName()
	if !ok {
		return fmt.Errorf("no interface is present, except loopback")
	}
	if err := filterTable(ipv6, "-A", "OUTPUT", "-p", "udp", "-o", ifname, "-j", "ACCEPT"); err != nil {
		return err
	}

	return sendUDPLoop(ctx, ip, acceptPort, ipv6)
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputInterfaceAccept) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	return listenUDP(ctx, acceptPort, ipv6)
}

// FilterOutputInterfaceDrop tests that packets are not sent via interface
// matching the iptables rule.
type FilterOutputInterfaceDrop struct{ localCase }

var _ TestCase = (*FilterOutputInterfaceDrop)(nil)

// Name implements TestCase.Name.
func (*FilterOutputInterfaceDrop) Name() string {
	return "FilterOutputInterfaceDrop"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputInterfaceDrop) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	ifname, ok := getInterfaceName()
	if !ok {
		return fmt.Errorf("no interface is present, except loopback")
	}
	if err := filterTable(ipv6, "-A", "OUTPUT", "-p", "udp", "-o", ifname, "-j", "DROP"); err != nil {
		return err
	}

	return sendUDPLoop(ctx, ip, acceptPort, ipv6)
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputInterfaceDrop) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	timedCtx, cancel := context.WithTimeout(ctx, NegativeTimeout)
	defer cancel()
	if err := listenUDP(timedCtx, acceptPort, ipv6); err == nil {
		return fmt.Errorf("packets should not be received on port %v, but are received", acceptPort)
	} else if !errors.Is(err, context.DeadlineExceeded) {
		return fmt.Errorf("error reading: %v", err)
	}

	return nil
}

// FilterOutputInterface tests that packets are sent via interface which is
// not matching the interface name in the iptables rule.
type FilterOutputInterface struct{ localCase }

var _ TestCase = (*FilterOutputInterface)(nil)

// Name implements TestCase.Name.
func (*FilterOutputInterface) Name() string {
	return "FilterOutputInterface"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputInterface) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	if err := filterTable(ipv6, "-A", "OUTPUT", "-p", "udp", "-o", "lo", "-j", "DROP"); err != nil {
		return err
	}

	return sendUDPLoop(ctx, ip, acceptPort, ipv6)
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputInterface) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	return listenUDP(ctx, acceptPort, ipv6)
}

// FilterOutputInterfaceBeginsWith tests that packets are not sent via an
// interface which begins with the given interface name.
type FilterOutputInterfaceBeginsWith struct{ localCase }

var _ TestCase = (*FilterOutputInterfaceBeginsWith)(nil)

// Name implements TestCase.Name.
func (*FilterOutputInterfaceBeginsWith) Name() string {
	return "FilterOutputInterfaceBeginsWith"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputInterfaceBeginsWith) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	if err := filterTable(ipv6, "-A", "OUTPUT", "-p", "udp", "-o", "e+", "-j", "DROP"); err != nil {
		return err
	}

	return sendUDPLoop(ctx, ip, acceptPort, ipv6)
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputInterfaceBeginsWith) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	timedCtx, cancel := context.WithTimeout(ctx, NegativeTimeout)
	defer cancel()
	if err := listenUDP(timedCtx, acceptPort, ipv6); err == nil {
		return fmt.Errorf("packets should not be received on port %v, but are received", acceptPort)
	} else if !errors.Is(err, context.DeadlineExceeded) {
		return fmt.Errorf("error reading: %v", err)
	}

	return nil
}

// FilterOutputInterfaceInvertDrop tests that we selectively do not send
// packets via interface not matching the interface name.
type FilterOutputInterfaceInvertDrop struct{ baseCase }

var _ TestCase = (*FilterOutputInterfaceInvertDrop)(nil)

// Name implements TestCase.Name.
func (*FilterOutputInterfaceInvertDrop) Name() string {
	return "FilterOutputInterfaceInvertDrop"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputInterfaceInvertDrop) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	if err := filterTable(ipv6, "-A", "OUTPUT", "-p", "tcp", "!", "-o", "lo", "-j", "DROP"); err != nil {
		return err
	}

	// Listen for TCP packets on accept port.
	timedCtx, cancel := context.WithTimeout(ctx, NegativeTimeout)
	defer cancel()
	if err := listenTCP(timedCtx, acceptPort, ipv6); err == nil {
		return fmt.Errorf("connection on port %d should not be accepted, but got accepted", acceptPort)
	} else if !errors.Is(err, context.DeadlineExceeded) {
		return fmt.Errorf("error reading: %v", err)
	}

	return nil
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputInterfaceInvertDrop) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	timedCtx, cancel := context.WithTimeout(ctx, NegativeTimeout)
	defer cancel()
	if err := connectTCP(timedCtx, ip, acceptPort, ipv6); err == nil {
		return fmt.Errorf("connection destined to port %d should not be accepted, but got accepted", acceptPort)
	}

	return nil
}

// FilterOutputInterfaceInvertAccept tests that we can selectively send packets
// not matching the specific outgoing interface.
type FilterOutputInterfaceInvertAccept struct{ baseCase }

var _ TestCase = (*FilterOutputInterfaceInvertAccept)(nil)

// Name implements TestCase.Name.
func (*FilterOutputInterfaceInvertAccept) Name() string {
	return "FilterOutputInterfaceInvertAccept"
}

// ContainerAction implements TestCase.ContainerAction.
func (*FilterOutputInterfaceInvertAccept) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	if err := filterTable(ipv6, "-A", "OUTPUT", "-p", "tcp", "!", "-o", "lo", "-j", "ACCEPT"); err != nil {
		return err
	}

	// Listen for TCP packets on accept port.
	return listenTCP(ctx, acceptPort, ipv6)
}

// LocalAction implements TestCase.LocalAction.
func (*FilterOutputInterfaceInvertAccept) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
	return connectTCP(ctx, ip, acceptPort, ipv6)
}