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-rw-r--r--test/iptables/nat.go917
1 files changed, 0 insertions, 917 deletions
diff --git a/test/iptables/nat.go b/test/iptables/nat.go
deleted file mode 100644
index 7ff8510a7..000000000
--- a/test/iptables/nat.go
+++ /dev/null
@@ -1,917 +0,0 @@
-// 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"
- "syscall"
-
- "gvisor.dev/gvisor/pkg/binary"
- "gvisor.dev/gvisor/pkg/usermem"
-)
-
-const redirectPort = 42
-
-func init() {
- RegisterTestCase(&NATPreRedirectUDPPort{})
- RegisterTestCase(&NATPreRedirectTCPPort{})
- RegisterTestCase(&NATPreRedirectTCPOutgoing{})
- RegisterTestCase(&NATOutRedirectTCPIncoming{})
- RegisterTestCase(&NATOutRedirectUDPPort{})
- RegisterTestCase(&NATOutRedirectTCPPort{})
- RegisterTestCase(&NATDropUDP{})
- RegisterTestCase(&NATAcceptAll{})
- RegisterTestCase(&NATPreRedirectIP{})
- RegisterTestCase(&NATPreDontRedirectIP{})
- RegisterTestCase(&NATPreRedirectInvert{})
- RegisterTestCase(&NATOutRedirectIP{})
- RegisterTestCase(&NATOutDontRedirectIP{})
- RegisterTestCase(&NATOutRedirectInvert{})
- RegisterTestCase(&NATRedirectRequiresProtocol{})
- RegisterTestCase(&NATLoopbackSkipsPrerouting{})
- RegisterTestCase(&NATPreOriginalDst{})
- RegisterTestCase(&NATOutOriginalDst{})
- RegisterTestCase(&NATPreRECVORIGDSTADDR{})
- RegisterTestCase(&NATOutRECVORIGDSTADDR{})
-}
-
-// NATPreRedirectUDPPort tests that packets are redirected to different port.
-type NATPreRedirectUDPPort struct{ containerCase }
-
-var _ TestCase = (*NATPreRedirectUDPPort)(nil)
-
-// Name implements TestCase.Name.
-func (*NATPreRedirectUDPPort) Name() string {
- return "NATPreRedirectUDPPort"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATPreRedirectUDPPort) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- if err := natTable(ipv6, "-A", "PREROUTING", "-p", "udp", "-j", "REDIRECT", "--to-ports", fmt.Sprintf("%d", redirectPort)); err != nil {
- return err
- }
-
- if err := listenUDP(ctx, redirectPort); err != nil {
- return fmt.Errorf("packets on port %d should be allowed, but encountered an error: %v", redirectPort, err)
- }
-
- return nil
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATPreRedirectUDPPort) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- return sendUDPLoop(ctx, ip, acceptPort)
-}
-
-// NATPreRedirectTCPPort tests that connections are redirected on specified ports.
-type NATPreRedirectTCPPort struct{ baseCase }
-
-var _ TestCase = (*NATPreRedirectTCPPort)(nil)
-
-// Name implements TestCase.Name.
-func (*NATPreRedirectTCPPort) Name() string {
- return "NATPreRedirectTCPPort"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATPreRedirectTCPPort) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- if err := natTable(ipv6, "-A", "PREROUTING", "-p", "tcp", "-m", "tcp", "--dport", fmt.Sprintf("%d", dropPort), "-j", "REDIRECT", "--to-ports", fmt.Sprintf("%d", acceptPort)); err != nil {
- return err
- }
-
- // Listen for TCP packets on redirect port.
- return listenTCP(ctx, acceptPort)
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATPreRedirectTCPPort) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- return connectTCP(ctx, ip, dropPort)
-}
-
-// NATPreRedirectTCPOutgoing verifies that outgoing TCP connections aren't
-// affected by PREROUTING connection tracking.
-type NATPreRedirectTCPOutgoing struct{ baseCase }
-
-var _ TestCase = (*NATPreRedirectTCPOutgoing)(nil)
-
-// Name implements TestCase.Name.
-func (*NATPreRedirectTCPOutgoing) Name() string {
- return "NATPreRedirectTCPOutgoing"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATPreRedirectTCPOutgoing) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- // Redirect all incoming TCP traffic to a closed port.
- if err := natTable(ipv6, "-A", "PREROUTING", "-p", "tcp", "-j", "REDIRECT", "--to-ports", fmt.Sprintf("%d", dropPort)); err != nil {
- return err
- }
-
- // Establish a connection to the host process.
- return connectTCP(ctx, ip, acceptPort)
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATPreRedirectTCPOutgoing) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- return listenTCP(ctx, acceptPort)
-}
-
-// NATOutRedirectTCPIncoming verifies that incoming TCP connections aren't
-// affected by OUTPUT connection tracking.
-type NATOutRedirectTCPIncoming struct{ baseCase }
-
-var _ TestCase = (*NATOutRedirectTCPIncoming)(nil)
-
-// Name implements TestCase.Name.
-func (*NATOutRedirectTCPIncoming) Name() string {
- return "NATOutRedirectTCPIncoming"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATOutRedirectTCPIncoming) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- // Redirect all outgoing TCP traffic to a closed port.
- if err := natTable(ipv6, "-A", "OUTPUT", "-p", "tcp", "-j", "REDIRECT", "--to-ports", fmt.Sprintf("%d", dropPort)); err != nil {
- return err
- }
-
- // Establish a connection to the host process.
- return listenTCP(ctx, acceptPort)
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATOutRedirectTCPIncoming) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- return connectTCP(ctx, ip, acceptPort)
-}
-
-// NATOutRedirectUDPPort tests that packets are redirected to different port.
-type NATOutRedirectUDPPort struct{ containerCase }
-
-var _ TestCase = (*NATOutRedirectUDPPort)(nil)
-
-// Name implements TestCase.Name.
-func (*NATOutRedirectUDPPort) Name() string {
- return "NATOutRedirectUDPPort"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATOutRedirectUDPPort) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- return loopbackTest(ctx, ipv6, net.ParseIP(nowhereIP(ipv6)), "-A", "OUTPUT", "-p", "udp", "-j", "REDIRECT", "--to-ports", fmt.Sprintf("%d", acceptPort))
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATOutRedirectUDPPort) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- // No-op.
- return nil
-}
-
-// NATDropUDP tests that packets are not received in ports other than redirect
-// port.
-type NATDropUDP struct{ containerCase }
-
-var _ TestCase = (*NATDropUDP)(nil)
-
-// Name implements TestCase.Name.
-func (*NATDropUDP) Name() string {
- return "NATDropUDP"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATDropUDP) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- if err := natTable(ipv6, "-A", "PREROUTING", "-p", "udp", "-j", "REDIRECT", "--to-ports", fmt.Sprintf("%d", redirectPort)); err != nil {
- return err
- }
-
- timedCtx, cancel := context.WithTimeout(ctx, NegativeTimeout)
- defer cancel()
- if err := listenUDP(timedCtx, acceptPort); err == nil {
- return fmt.Errorf("packets on port %d should have been redirected to port %d", acceptPort, redirectPort)
- } else if !errors.Is(err, context.DeadlineExceeded) {
- return fmt.Errorf("error reading: %v", err)
- }
-
- return nil
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATDropUDP) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- return sendUDPLoop(ctx, ip, acceptPort)
-}
-
-// NATAcceptAll tests that all UDP packets are accepted.
-type NATAcceptAll struct{ containerCase }
-
-var _ TestCase = (*NATAcceptAll)(nil)
-
-// Name implements TestCase.Name.
-func (*NATAcceptAll) Name() string {
- return "NATAcceptAll"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATAcceptAll) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- if err := natTable(ipv6, "-A", "PREROUTING", "-p", "udp", "-j", "ACCEPT"); err != nil {
- return err
- }
-
- if err := listenUDP(ctx, acceptPort); err != nil {
- return fmt.Errorf("packets on port %d should be allowed, but encountered an error: %v", acceptPort, err)
- }
-
- return nil
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATAcceptAll) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- return sendUDPLoop(ctx, ip, acceptPort)
-}
-
-// NATOutRedirectIP uses iptables to select packets based on destination IP and
-// redirects them.
-type NATOutRedirectIP struct{ baseCase }
-
-var _ TestCase = (*NATOutRedirectIP)(nil)
-
-// Name implements TestCase.Name.
-func (*NATOutRedirectIP) Name() string {
- return "NATOutRedirectIP"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATOutRedirectIP) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- // Redirect OUTPUT packets to a listening localhost port.
- return loopbackTest(ctx, ipv6, net.ParseIP(nowhereIP(ipv6)),
- "-A", "OUTPUT",
- "-d", nowhereIP(ipv6),
- "-p", "udp",
- "-j", "REDIRECT", "--to-port", fmt.Sprintf("%d", acceptPort))
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATOutRedirectIP) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- // No-op.
- return nil
-}
-
-// NATOutDontRedirectIP tests that iptables matching with "-d" does not match
-// packets it shouldn't.
-type NATOutDontRedirectIP struct{ localCase }
-
-var _ TestCase = (*NATOutDontRedirectIP)(nil)
-
-// Name implements TestCase.Name.
-func (*NATOutDontRedirectIP) Name() string {
- return "NATOutDontRedirectIP"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATOutDontRedirectIP) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- if err := natTable(ipv6, "-A", "OUTPUT", "-d", localIP(ipv6), "-p", "udp", "-j", "REDIRECT", "--to-port", fmt.Sprintf("%d", dropPort)); err != nil {
- return err
- }
- return sendUDPLoop(ctx, ip, acceptPort)
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATOutDontRedirectIP) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- return listenUDP(ctx, acceptPort)
-}
-
-// NATOutRedirectInvert tests that iptables can match with "! -d".
-type NATOutRedirectInvert struct{ baseCase }
-
-var _ TestCase = (*NATOutRedirectInvert)(nil)
-
-// Name implements TestCase.Name.
-func (*NATOutRedirectInvert) Name() string {
- return "NATOutRedirectInvert"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATOutRedirectInvert) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- // Redirect OUTPUT packets to a listening localhost port.
- dest := "192.0.2.2"
- if ipv6 {
- dest = "2001:db8::2"
- }
- return loopbackTest(ctx, ipv6, net.ParseIP(nowhereIP(ipv6)),
- "-A", "OUTPUT",
- "!", "-d", dest,
- "-p", "udp",
- "-j", "REDIRECT", "--to-port", fmt.Sprintf("%d", acceptPort))
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATOutRedirectInvert) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- // No-op.
- return nil
-}
-
-// NATPreRedirectIP tests that we can use iptables to select packets based on
-// destination IP and redirect them.
-type NATPreRedirectIP struct{ containerCase }
-
-var _ TestCase = (*NATPreRedirectIP)(nil)
-
-// Name implements TestCase.Name.
-func (*NATPreRedirectIP) Name() string {
- return "NATPreRedirectIP"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATPreRedirectIP) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- addrs, err := localAddrs(ipv6)
- if err != nil {
- return err
- }
-
- var rules [][]string
- for _, addr := range addrs {
- rules = append(rules, []string{"-A", "PREROUTING", "-p", "udp", "-d", addr, "-j", "REDIRECT", "--to-ports", fmt.Sprintf("%d", acceptPort)})
- }
- if err := natTableRules(ipv6, rules); err != nil {
- return err
- }
- return listenUDP(ctx, acceptPort)
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATPreRedirectIP) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- return sendUDPLoop(ctx, ip, dropPort)
-}
-
-// NATPreDontRedirectIP tests that iptables matching with "-d" does not match
-// packets it shouldn't.
-type NATPreDontRedirectIP struct{ containerCase }
-
-var _ TestCase = (*NATPreDontRedirectIP)(nil)
-
-// Name implements TestCase.Name.
-func (*NATPreDontRedirectIP) Name() string {
- return "NATPreDontRedirectIP"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATPreDontRedirectIP) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- if err := natTable(ipv6, "-A", "PREROUTING", "-p", "udp", "-d", localIP(ipv6), "-j", "REDIRECT", "--to-ports", fmt.Sprintf("%d", dropPort)); err != nil {
- return err
- }
- return listenUDP(ctx, acceptPort)
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATPreDontRedirectIP) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- return sendUDPLoop(ctx, ip, acceptPort)
-}
-
-// NATPreRedirectInvert tests that iptables can match with "! -d".
-type NATPreRedirectInvert struct{ containerCase }
-
-var _ TestCase = (*NATPreRedirectInvert)(nil)
-
-// Name implements TestCase.Name.
-func (*NATPreRedirectInvert) Name() string {
- return "NATPreRedirectInvert"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATPreRedirectInvert) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- if err := natTable(ipv6, "-A", "PREROUTING", "-p", "udp", "!", "-d", localIP(ipv6), "-j", "REDIRECT", "--to-ports", fmt.Sprintf("%d", acceptPort)); err != nil {
- return err
- }
- return listenUDP(ctx, acceptPort)
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATPreRedirectInvert) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- return sendUDPLoop(ctx, ip, dropPort)
-}
-
-// NATRedirectRequiresProtocol tests that use of the --to-ports flag requires a
-// protocol to be specified with -p.
-type NATRedirectRequiresProtocol struct{ baseCase }
-
-var _ TestCase = (*NATRedirectRequiresProtocol)(nil)
-
-// Name implements TestCase.Name.
-func (*NATRedirectRequiresProtocol) Name() string {
- return "NATRedirectRequiresProtocol"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATRedirectRequiresProtocol) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- if err := natTable(ipv6, "-A", "PREROUTING", "-d", localIP(ipv6), "-j", "REDIRECT", "--to-ports", fmt.Sprintf("%d", acceptPort)); err == nil {
- return errors.New("expected an error using REDIRECT --to-ports without a protocol")
- }
- return nil
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATRedirectRequiresProtocol) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- // No-op.
- return nil
-}
-
-// NATOutRedirectTCPPort tests that connections are redirected on specified ports.
-type NATOutRedirectTCPPort struct{ baseCase }
-
-var _ TestCase = (*NATOutRedirectTCPPort)(nil)
-
-// Name implements TestCase.Name.
-func (*NATOutRedirectTCPPort) Name() string {
- return "NATOutRedirectTCPPort"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATOutRedirectTCPPort) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- if err := natTable(ipv6, "-A", "OUTPUT", "-p", "tcp", "-m", "tcp", "--dport", fmt.Sprintf("%d", dropPort), "-j", "REDIRECT", "--to-ports", fmt.Sprintf("%d", acceptPort)); err != nil {
- return err
- }
-
- localAddr := net.TCPAddr{
- IP: net.ParseIP(localIP(ipv6)),
- Port: acceptPort,
- }
-
- // Starts listening on port.
- lConn, err := net.ListenTCP("tcp", &localAddr)
- if err != nil {
- return err
- }
- defer lConn.Close()
-
- // Accept connections on port.
- if err := connectTCP(ctx, ip, dropPort); err != nil {
- return err
- }
-
- conn, err := lConn.AcceptTCP()
- if err != nil {
- return err
- }
- conn.Close()
-
- return nil
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATOutRedirectTCPPort) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- return nil
-}
-
-// NATLoopbackSkipsPrerouting tests that packets sent via loopback aren't
-// affected by PREROUTING rules.
-type NATLoopbackSkipsPrerouting struct{ baseCase }
-
-var _ TestCase = (*NATLoopbackSkipsPrerouting)(nil)
-
-// Name implements TestCase.Name.
-func (*NATLoopbackSkipsPrerouting) Name() string {
- return "NATLoopbackSkipsPrerouting"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATLoopbackSkipsPrerouting) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- // Redirect anything sent to localhost to an unused port.
- dest := []byte{127, 0, 0, 1}
- if err := natTable(ipv6, "-A", "PREROUTING", "-p", "tcp", "-j", "REDIRECT", "--to-port", fmt.Sprintf("%d", dropPort)); err != nil {
- return err
- }
-
- // Establish a connection via localhost. If the PREROUTING rule did apply to
- // loopback traffic, the connection would fail.
- sendCh := make(chan error)
- go func() {
- sendCh <- connectTCP(ctx, dest, acceptPort)
- }()
-
- if err := listenTCP(ctx, acceptPort); err != nil {
- return err
- }
- return <-sendCh
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATLoopbackSkipsPrerouting) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- // No-op.
- return nil
-}
-
-// NATPreOriginalDst tests that SO_ORIGINAL_DST returns the pre-NAT destination
-// of PREROUTING NATted packets.
-type NATPreOriginalDst struct{ baseCase }
-
-var _ TestCase = (*NATPreOriginalDst)(nil)
-
-// Name implements TestCase.Name.
-func (*NATPreOriginalDst) Name() string {
- return "NATPreOriginalDst"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATPreOriginalDst) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- // Redirect incoming TCP connections to acceptPort.
- if err := natTable(ipv6, "-A", "PREROUTING",
- "-p", "tcp",
- "--destination-port", fmt.Sprintf("%d", dropPort),
- "-j", "REDIRECT", "--to-port", fmt.Sprintf("%d", acceptPort)); err != nil {
- return err
- }
-
- addrs, err := getInterfaceAddrs(ipv6)
- if err != nil {
- return err
- }
- return listenForRedirectedConn(ctx, ipv6, addrs)
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATPreOriginalDst) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- return connectTCP(ctx, ip, dropPort)
-}
-
-// NATOutOriginalDst tests that SO_ORIGINAL_DST returns the pre-NAT destination
-// of OUTBOUND NATted packets.
-type NATOutOriginalDst struct{ baseCase }
-
-var _ TestCase = (*NATOutOriginalDst)(nil)
-
-// Name implements TestCase.Name.
-func (*NATOutOriginalDst) Name() string {
- return "NATOutOriginalDst"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATOutOriginalDst) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- // Redirect incoming TCP connections to acceptPort.
- if err := natTable(ipv6, "-A", "OUTPUT", "-p", "tcp", "-j", "REDIRECT", "--to-port", fmt.Sprintf("%d", acceptPort)); err != nil {
- return err
- }
-
- connCh := make(chan error)
- go func() {
- connCh <- connectTCP(ctx, ip, dropPort)
- }()
-
- if err := listenForRedirectedConn(ctx, ipv6, []net.IP{ip}); err != nil {
- return err
- }
- return <-connCh
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATOutOriginalDst) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- // No-op.
- return nil
-}
-
-func listenForRedirectedConn(ctx context.Context, ipv6 bool, originalDsts []net.IP) error {
- // The net package doesn't give guaranteed access to the connection's
- // underlying FD, and thus we cannot call getsockopt. We have to use
- // traditional syscalls.
-
- // Create the listening socket, bind, listen, and accept.
- family := syscall.AF_INET
- if ipv6 {
- family = syscall.AF_INET6
- }
- sockfd, err := syscall.Socket(family, syscall.SOCK_STREAM, 0)
- if err != nil {
- return err
- }
- defer syscall.Close(sockfd)
-
- var bindAddr syscall.Sockaddr
- if ipv6 {
- bindAddr = &syscall.SockaddrInet6{
- Port: acceptPort,
- Addr: [16]byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, // in6addr_any
- }
- } else {
- bindAddr = &syscall.SockaddrInet4{
- Port: acceptPort,
- Addr: [4]byte{0, 0, 0, 0}, // INADDR_ANY
- }
- }
- if err := syscall.Bind(sockfd, bindAddr); err != nil {
- return err
- }
-
- if err := syscall.Listen(sockfd, 1); err != nil {
- return err
- }
-
- // Block on accept() in another goroutine.
- connCh := make(chan int)
- errCh := make(chan error)
- go func() {
- for {
- connFD, _, err := syscall.Accept(sockfd)
- if errors.Is(err, syscall.EINTR) {
- continue
- }
- if err != nil {
- errCh <- err
- return
- }
- connCh <- connFD
- return
- }
- }()
-
- // Wait for accept() to return or for the context to finish.
- var connFD int
- select {
- case <-ctx.Done():
- return ctx.Err()
- case err := <-errCh:
- return err
- case connFD = <-connCh:
- }
- defer syscall.Close(connFD)
-
- // Verify that, despite listening on acceptPort, SO_ORIGINAL_DST
- // indicates the packet was sent to originalDst:dropPort.
- if ipv6 {
- got, err := originalDestination6(connFD)
- if err != nil {
- return err
- }
- return addrMatches6(got, originalDsts, dropPort)
- }
-
- got, err := originalDestination4(connFD)
- if err != nil {
- return err
- }
- return addrMatches4(got, originalDsts, dropPort)
-}
-
-// loopbackTests runs an iptables rule and ensures that packets sent to
-// dest:dropPort are received by localhost:acceptPort.
-func loopbackTest(ctx context.Context, ipv6 bool, dest net.IP, args ...string) error {
- if err := natTable(ipv6, args...); err != nil {
- return err
- }
- sendCh := make(chan error, 1)
- listenCh := make(chan error, 1)
- go func() {
- sendCh <- sendUDPLoop(ctx, dest, dropPort)
- }()
- go func() {
- listenCh <- listenUDP(ctx, acceptPort)
- }()
- select {
- case err := <-listenCh:
- return err
- case err := <-sendCh:
- return err
- }
-}
-
-// NATPreRECVORIGDSTADDR tests that IP{V6}_RECVORIGDSTADDR gets the post-NAT
-// address on the PREROUTING chain.
-type NATPreRECVORIGDSTADDR struct{ containerCase }
-
-var _ TestCase = (*NATPreRECVORIGDSTADDR)(nil)
-
-// Name implements TestCase.Name.
-func (*NATPreRECVORIGDSTADDR) Name() string {
- return "NATPreRECVORIGDSTADDR"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATPreRECVORIGDSTADDR) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- if err := natTable(ipv6, "-A", "PREROUTING", "-p", "udp", "-j", "REDIRECT", "--to-ports", fmt.Sprintf("%d", redirectPort)); err != nil {
- return err
- }
-
- if err := recvWithRECVORIGDSTADDR(ctx, ipv6, nil, redirectPort); err != nil {
- return err
- }
-
- return nil
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATPreRECVORIGDSTADDR) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- return sendUDPLoop(ctx, ip, acceptPort)
-}
-
-// NATOutRECVORIGDSTADDR tests that IP{V6}_RECVORIGDSTADDR gets the post-NAT
-// address on the OUTPUT chain.
-type NATOutRECVORIGDSTADDR struct{ containerCase }
-
-var _ TestCase = (*NATOutRECVORIGDSTADDR)(nil)
-
-// Name implements TestCase.Name.
-func (*NATOutRECVORIGDSTADDR) Name() string {
- return "NATOutRECVORIGDSTADDR"
-}
-
-// ContainerAction implements TestCase.ContainerAction.
-func (*NATOutRECVORIGDSTADDR) ContainerAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- if err := natTable(ipv6, "-A", "OUTPUT", "-p", "udp", "-j", "REDIRECT", "--to-ports", fmt.Sprintf("%d", redirectPort)); err != nil {
- return err
- }
-
- sendCh := make(chan error)
- go func() {
- // Packets will be sent to a non-container IP and redirected
- // back to the container.
- sendCh <- sendUDPLoop(ctx, ip, acceptPort)
- }()
-
- expectedIP := &net.IP{127, 0, 0, 1}
- if ipv6 {
- expectedIP = &net.IP{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1}
- }
- if err := recvWithRECVORIGDSTADDR(ctx, ipv6, expectedIP, redirectPort); err != nil {
- return err
- }
-
- select {
- case err := <-sendCh:
- return err
- default:
- return nil
- }
-}
-
-// LocalAction implements TestCase.LocalAction.
-func (*NATOutRECVORIGDSTADDR) LocalAction(ctx context.Context, ip net.IP, ipv6 bool) error {
- // No-op.
- return nil
-}
-
-func recvWithRECVORIGDSTADDR(ctx context.Context, ipv6 bool, expectedDst *net.IP, port uint16) error {
- // The net package doesn't give guaranteed access to a connection's
- // underlying FD, and thus we cannot call getsockopt. We have to use
- // traditional syscalls for IP_RECVORIGDSTADDR.
-
- // Create the listening socket.
- var (
- family = syscall.AF_INET
- level = syscall.SOL_IP
- option = syscall.IP_RECVORIGDSTADDR
- bindAddr syscall.Sockaddr = &syscall.SockaddrInet4{
- Port: int(port),
- Addr: [4]byte{0, 0, 0, 0}, // INADDR_ANY
- }
- )
- if ipv6 {
- family = syscall.AF_INET6
- level = syscall.SOL_IPV6
- option = 74 // IPV6_RECVORIGDSTADDR, which is missing from the syscall package.
- bindAddr = &syscall.SockaddrInet6{
- Port: int(port),
- Addr: [16]byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, // in6addr_any
- }
- }
- sockfd, err := syscall.Socket(family, syscall.SOCK_DGRAM, 0)
- if err != nil {
- return fmt.Errorf("failed Socket(%d, %d, 0): %w", family, syscall.SOCK_DGRAM, err)
- }
- defer syscall.Close(sockfd)
-
- if err := syscall.Bind(sockfd, bindAddr); err != nil {
- return fmt.Errorf("failed Bind(%d, %+v): %v", sockfd, bindAddr, err)
- }
-
- // Enable IP_RECVORIGDSTADDR.
- if err := syscall.SetsockoptInt(sockfd, level, option, 1); err != nil {
- return fmt.Errorf("failed SetsockoptByte(%d, %d, %d, 1): %v", sockfd, level, option, err)
- }
-
- addrCh := make(chan interface{})
- errCh := make(chan error)
- go func() {
- var addr interface{}
- var err error
- if ipv6 {
- addr, err = recvOrigDstAddr6(sockfd)
- } else {
- addr, err = recvOrigDstAddr4(sockfd)
- }
- if err != nil {
- errCh <- err
- } else {
- addrCh <- addr
- }
- }()
-
- // Wait to receive a packet.
- var addr interface{}
- select {
- case <-ctx.Done():
- return ctx.Err()
- case err := <-errCh:
- return err
- case addr = <-addrCh:
- }
-
- // Get a list of local IPs to verify that the packet now appears to have
- // been sent to us.
- var localAddrs []net.IP
- if expectedDst != nil {
- localAddrs = []net.IP{*expectedDst}
- } else {
- localAddrs, err = getInterfaceAddrs(ipv6)
- if err != nil {
- return fmt.Errorf("failed to get local interfaces: %w", err)
- }
- }
-
- // Verify that the address has the post-NAT port and address.
- if ipv6 {
- return addrMatches6(addr.(syscall.RawSockaddrInet6), localAddrs, redirectPort)
- }
- return addrMatches4(addr.(syscall.RawSockaddrInet4), localAddrs, redirectPort)
-}
-
-func recvOrigDstAddr4(sockfd int) (syscall.RawSockaddrInet4, error) {
- buf, err := recvOrigDstAddr(sockfd, syscall.SOL_IP, syscall.SizeofSockaddrInet4)
- if err != nil {
- return syscall.RawSockaddrInet4{}, err
- }
- var addr syscall.RawSockaddrInet4
- binary.Unmarshal(buf, usermem.ByteOrder, &addr)
- return addr, nil
-}
-
-func recvOrigDstAddr6(sockfd int) (syscall.RawSockaddrInet6, error) {
- buf, err := recvOrigDstAddr(sockfd, syscall.SOL_IP, syscall.SizeofSockaddrInet6)
- if err != nil {
- return syscall.RawSockaddrInet6{}, err
- }
- var addr syscall.RawSockaddrInet6
- binary.Unmarshal(buf, usermem.ByteOrder, &addr)
- return addr, nil
-}
-
-func recvOrigDstAddr(sockfd int, level uintptr, addrSize int) ([]byte, error) {
- buf := make([]byte, 64)
- oob := make([]byte, syscall.CmsgSpace(addrSize))
- for {
- _, oobn, _, _, err := syscall.Recvmsg(
- sockfd,
- buf, // Message buffer.
- oob, // Out-of-band buffer.
- 0) // Flags.
- if errors.Is(err, syscall.EINTR) {
- continue
- }
- if err != nil {
- return nil, fmt.Errorf("failed when calling Recvmsg: %w", err)
- }
- oob = oob[:oobn]
-
- // Parse out the control message.
- msgs, err := syscall.ParseSocketControlMessage(oob)
- if err != nil {
- return nil, fmt.Errorf("failed to parse control message: %w", err)
- }
- return msgs[0].Data, nil
- }
-}
-
-func addrMatches4(got syscall.RawSockaddrInet4, wantAddrs []net.IP, port uint16) error {
- for _, wantAddr := range wantAddrs {
- want := syscall.RawSockaddrInet4{
- Family: syscall.AF_INET,
- Port: htons(port),
- }
- copy(want.Addr[:], wantAddr.To4())
- if got == want {
- return nil
- }
- }
- return fmt.Errorf("got %+v, but wanted one of %+v (note: port numbers are in network byte order)", got, wantAddrs)
-}
-
-func addrMatches6(got syscall.RawSockaddrInet6, wantAddrs []net.IP, port uint16) error {
- for _, wantAddr := range wantAddrs {
- want := syscall.RawSockaddrInet6{
- Family: syscall.AF_INET6,
- Port: htons(port),
- }
- copy(want.Addr[:], wantAddr.To16())
- if got == want {
- return nil
- }
- }
- return fmt.Errorf("got %+v, but wanted one of %+v (note: port numbers are in network byte order)", got, wantAddrs)
-}