1 files changed, 316 insertions, 0 deletions
diff --git a/pkg/tcpip/stack/nic_test.go b/pkg/tcpip/stack/nic_test.go
new file mode 100644
index 000000000..d312a79eb
--- /dev/null
+++ b/pkg/tcpip/stack/nic_test.go
@@ -0,0 +1,316 @@
+// 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 stack
+
+import (
+	"math"
+	"testing"
+	"time"
+
+	"gvisor.dev/gvisor/pkg/tcpip"
+	"gvisor.dev/gvisor/pkg/tcpip/buffer"
+	"gvisor.dev/gvisor/pkg/tcpip/header"
+)
+
+var _ LinkEndpoint = (*testLinkEndpoint)(nil)
+
+// A LinkEndpoint that throws away outgoing packets.
+//
+// We use this instead of the channel endpoint as the channel package depends on
+// the stack package which this test lives in, causing a cyclic dependency.
+type testLinkEndpoint struct {
+	dispatcher NetworkDispatcher
+}
+
+// Attach implements LinkEndpoint.Attach.
+func (e *testLinkEndpoint) Attach(dispatcher NetworkDispatcher) {
+	e.dispatcher = dispatcher
+}
+
+// IsAttached implements LinkEndpoint.IsAttached.
+func (e *testLinkEndpoint) IsAttached() bool {
+	return e.dispatcher != nil
+}
+
+// MTU implements LinkEndpoint.MTU.
+func (*testLinkEndpoint) MTU() uint32 {
+	return math.MaxUint16
+}
+
+// Capabilities implements LinkEndpoint.Capabilities.
+func (*testLinkEndpoint) Capabilities() LinkEndpointCapabilities {
+	return CapabilityResolutionRequired
+}
+
+// MaxHeaderLength implements LinkEndpoint.MaxHeaderLength.
+func (*testLinkEndpoint) MaxHeaderLength() uint16 {
+	return 0
+}
+
+// LinkAddress returns the link address of this endpoint.
+func (*testLinkEndpoint) LinkAddress() tcpip.LinkAddress {
+	return ""
+}
+
+// Wait implements LinkEndpoint.Wait.
+func (*testLinkEndpoint) Wait() {}
+
+// WritePacket implements LinkEndpoint.WritePacket.
+func (e *testLinkEndpoint) WritePacket(*Route, *GSO, tcpip.NetworkProtocolNumber, *PacketBuffer) *tcpip.Error {
+	return nil
+}
+
+// WritePackets implements LinkEndpoint.WritePackets.
+func (e *testLinkEndpoint) WritePackets(*Route, *GSO, PacketBufferList, tcpip.NetworkProtocolNumber) (int, *tcpip.Error) {
+	// Our tests don't use this so we don't support it.
+	return 0, tcpip.ErrNotSupported
+}
+
+// WriteRawPacket implements LinkEndpoint.WriteRawPacket.
+func (e *testLinkEndpoint) WriteRawPacket(buffer.VectorisedView) *tcpip.Error {
+	// Our tests don't use this so we don't support it.
+	return tcpip.ErrNotSupported
+}
+
+// ARPHardwareType implements stack.LinkEndpoint.ARPHardwareType.
+func (*testLinkEndpoint) ARPHardwareType() header.ARPHardwareType {
+	panic("not implemented")
+}
+
+// AddHeader implements stack.LinkEndpoint.AddHeader.
+func (e *testLinkEndpoint) AddHeader(local, remote tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) {
+	panic("not implemented")
+}
+
+var _ NetworkEndpoint = (*testIPv6Endpoint)(nil)
+
+// An IPv6 NetworkEndpoint that throws away outgoing packets.
+//
+// We use this instead of ipv6.endpoint because the ipv6 package depends on
+// the stack package which this test lives in, causing a cyclic dependency.
+type testIPv6Endpoint struct {
+	nicID    tcpip.NICID
+	linkEP   LinkEndpoint
+	protocol *testIPv6Protocol
+}
+
+// DefaultTTL implements NetworkEndpoint.DefaultTTL.
+func (*testIPv6Endpoint) DefaultTTL() uint8 {
+	return 0
+}
+
+// MTU implements NetworkEndpoint.MTU.
+func (e *testIPv6Endpoint) MTU() uint32 {
+	return e.linkEP.MTU() - header.IPv6MinimumSize
+}
+
+// Capabilities implements NetworkEndpoint.Capabilities.
+func (e *testIPv6Endpoint) Capabilities() LinkEndpointCapabilities {
+	return e.linkEP.Capabilities()
+}
+
+// MaxHeaderLength implements NetworkEndpoint.MaxHeaderLength.
+func (e *testIPv6Endpoint) MaxHeaderLength() uint16 {
+	return e.linkEP.MaxHeaderLength() + header.IPv6MinimumSize
+}
+
+// WritePacket implements NetworkEndpoint.WritePacket.
+func (*testIPv6Endpoint) WritePacket(*Route, *GSO, NetworkHeaderParams, *PacketBuffer) *tcpip.Error {
+	return nil
+}
+
+// WritePackets implements NetworkEndpoint.WritePackets.
+func (*testIPv6Endpoint) WritePackets(*Route, *GSO, PacketBufferList, NetworkHeaderParams) (int, *tcpip.Error) {
+	// Our tests don't use this so we don't support it.
+	return 0, tcpip.ErrNotSupported
+}
+
+// WriteHeaderIncludedPacket implements
+// NetworkEndpoint.WriteHeaderIncludedPacket.
+func (*testIPv6Endpoint) WriteHeaderIncludedPacket(*Route, *PacketBuffer) *tcpip.Error {
+	// Our tests don't use this so we don't support it.
+	return tcpip.ErrNotSupported
+}
+
+// NICID implements NetworkEndpoint.NICID.
+func (e *testIPv6Endpoint) NICID() tcpip.NICID {
+	return e.nicID
+}
+
+// HandlePacket implements NetworkEndpoint.HandlePacket.
+func (*testIPv6Endpoint) HandlePacket(*Route, *PacketBuffer) {
+}
+
+// Close implements NetworkEndpoint.Close.
+func (*testIPv6Endpoint) Close() {}
+
+// NetworkProtocolNumber implements NetworkEndpoint.NetworkProtocolNumber.
+func (*testIPv6Endpoint) NetworkProtocolNumber() tcpip.NetworkProtocolNumber {
+	return header.IPv6ProtocolNumber
+}
+
+var _ NetworkProtocol = (*testIPv6Protocol)(nil)
+
+// An IPv6 NetworkProtocol that supports the bare minimum to make a stack
+// believe it supports IPv6.
+//
+// We use this instead of ipv6.protocol because the ipv6 package depends on
+// the stack package which this test lives in, causing a cyclic dependency.
+type testIPv6Protocol struct{}
+
+// Number implements NetworkProtocol.Number.
+func (*testIPv6Protocol) Number() tcpip.NetworkProtocolNumber {
+	return header.IPv6ProtocolNumber
+}
+
+// MinimumPacketSize implements NetworkProtocol.MinimumPacketSize.
+func (*testIPv6Protocol) MinimumPacketSize() int {
+	return header.IPv6MinimumSize
+}
+
+// DefaultPrefixLen implements NetworkProtocol.DefaultPrefixLen.
+func (*testIPv6Protocol) DefaultPrefixLen() int {
+	return header.IPv6AddressSize * 8
+}
+
+// ParseAddresses implements NetworkProtocol.ParseAddresses.
+func (*testIPv6Protocol) ParseAddresses(v buffer.View) (src, dst tcpip.Address) {
+	h := header.IPv6(v)
+	return h.SourceAddress(), h.DestinationAddress()
+}
+
+// NewEndpoint implements NetworkProtocol.NewEndpoint.
+func (p *testIPv6Protocol) NewEndpoint(nicID tcpip.NICID, _ LinkAddressCache, _ TransportDispatcher, linkEP LinkEndpoint, _ *Stack) NetworkEndpoint {
+	return &testIPv6Endpoint{
+		nicID:    nicID,
+		linkEP:   linkEP,
+		protocol: p,
+	}
+}
+
+// SetOption implements NetworkProtocol.SetOption.
+func (*testIPv6Protocol) SetOption(interface{}) *tcpip.Error {
+	return nil
+}
+
+// Option implements NetworkProtocol.Option.
+func (*testIPv6Protocol) Option(interface{}) *tcpip.Error {
+	return nil
+}
+
+// Close implements NetworkProtocol.Close.
+func (*testIPv6Protocol) Close() {}
+
+// Wait implements NetworkProtocol.Wait.
+func (*testIPv6Protocol) Wait() {}
+
+// Parse implements NetworkProtocol.Parse.
+func (*testIPv6Protocol) Parse(*PacketBuffer) (tcpip.TransportProtocolNumber, bool, bool) {
+	return 0, false, false
+}
+
+var _ LinkAddressResolver = (*testIPv6Protocol)(nil)
+
+// LinkAddressProtocol implements LinkAddressResolver.
+func (*testIPv6Protocol) LinkAddressProtocol() tcpip.NetworkProtocolNumber {
+	return header.IPv6ProtocolNumber
+}
+
+// LinkAddressRequest implements LinkAddressResolver.
+func (*testIPv6Protocol) LinkAddressRequest(_, _ tcpip.Address, _ tcpip.LinkAddress, _ LinkEndpoint) *tcpip.Error {
+	return nil
+}
+
+// ResolveStaticAddress implements LinkAddressResolver.
+func (*testIPv6Protocol) ResolveStaticAddress(addr tcpip.Address) (tcpip.LinkAddress, bool) {
+	if header.IsV6MulticastAddress(addr) {
+		return header.EthernetAddressFromMulticastIPv6Address(addr), true
+	}
+	return "", false
+}
+
+// Test the race condition where a NIC is removed and an RS timer fires at the
+// same time.
+func TestRemoveNICWhileHandlingRSTimer(t *testing.T) {
+	const (
+		nicID = 1
+
+		maxRtrSolicitations = 5
+	)
+
+	e := testLinkEndpoint{}
+	s := New(Options{
+		NetworkProtocols: []NetworkProtocol{&testIPv6Protocol{}},
+		NDPConfigs: NDPConfigurations{
+			MaxRtrSolicitations:     maxRtrSolicitations,
+			RtrSolicitationInterval: minimumRtrSolicitationInterval,
+		},
+	})
+
+	if err := s.CreateNIC(nicID, &e); err != nil {
+		t.Fatalf("s.CreateNIC(%d, _) = %s", nicID, err)
+	}
+
+	s.mu.Lock()
+	// Wait for the router solicitation timer to fire and block trying to obtain
+	// the stack lock when doing link address resolution.
+	time.Sleep(minimumRtrSolicitationInterval * 2)
+	if err := s.removeNICLocked(nicID); err != nil {
+		t.Fatalf("s.removeNICLocked(%d) = %s", nicID, err)
+	}
+	s.mu.Unlock()
+}
+
+func TestDisabledRxStatsWhenNICDisabled(t *testing.T) {
+	// When the NIC is disabled, the only field that matters is the stats field.
+	// This test is limited to stats counter checks.
+	nic := NIC{
+		stats: makeNICStats(),
+	}
+
+	if got := nic.stats.DisabledRx.Packets.Value(); got != 0 {
+		t.Errorf("got DisabledRx.Packets = %d, want = 0", got)
+	}
+	if got := nic.stats.DisabledRx.Bytes.Value(); got != 0 {
+		t.Errorf("got DisabledRx.Bytes = %d, want = 0", got)
+	}
+	if got := nic.stats.Rx.Packets.Value(); got != 0 {
+		t.Errorf("got Rx.Packets = %d, want = 0", got)
+	}
+	if got := nic.stats.Rx.Bytes.Value(); got != 0 {
+		t.Errorf("got Rx.Bytes = %d, want = 0", got)
+	}
+
+	if t.Failed() {
+		t.FailNow()
+	}
+
+	nic.DeliverNetworkPacket("", "", 0, NewPacketBuffer(PacketBufferOptions{
+		Data: buffer.View([]byte{1, 2, 3, 4}).ToVectorisedView(),
+	}))
+
+	if got := nic.stats.DisabledRx.Packets.Value(); got != 1 {
+		t.Errorf("got DisabledRx.Packets = %d, want = 1", got)
+	}
+	if got := nic.stats.DisabledRx.Bytes.Value(); got != 4 {
+		t.Errorf("got DisabledRx.Bytes = %d, want = 4", got)
+	}
+	if got := nic.stats.Rx.Packets.Value(); got != 0 {
+		t.Errorf("got Rx.Packets = %d, want = 0", got)
+	}
+	if got := nic.stats.Rx.Bytes.Value(); got != 0 {
+		t.Errorf("got Rx.Bytes = %d, want = 0", got)
+	}
+}