Automated rollback of changelist 268047073

PiperOrigin-RevId: 268757842

6 files changed, 15 insertions, 290 deletions

diff --git a/pkg/tcpip/header/ipv6.go b/pkg/tcpip/header/ipv6.go
index e606e3463..093850e25 100644
--- a/pkg/tcpip/header/ipv6.go
+++ b/pkg/tcpip/header/ipv6.go
@@ -76,13 +76,6 @@ const (
 	// IPv6Version is the version of the ipv6 protocol.
 	IPv6Version = 6
 
-	// IPv6AllNodesMulticastAddress is a link-local multicast group that
-	// all IPv6 nodes MUST join, as per RFC 4291, section 2.8. Packets
-	// destined to this address will reach all nodes on a link.
-	//
-	// The address is ff02::1.
-	IPv6AllNodesMulticastAddress tcpip.Address = "\xff\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01"
-
 	// IPv6MinimumMTU is the minimum MTU required by IPv6, per RFC 2460,
 	// section 5.
 	IPv6MinimumMTU = 1280
diff --git a/pkg/tcpip/network/ipv6/BUILD b/pkg/tcpip/network/ipv6/BUILD
index d02ca0227..c71b69123 100644
--- a/pkg/tcpip/network/ipv6/BUILD
+++ b/pkg/tcpip/network/ipv6/BUILD
@@ -25,7 +25,6 @@ go_test(
     size = "small",
     srcs = [
         "icmp_test.go",
-        "ipv6_test.go",
         "ndp_test.go",
     ],
     embed = [":ipv6"],
@@ -37,7 +36,6 @@ go_test(
         "//pkg/tcpip/link/sniffer",
         "//pkg/tcpip/stack",
         "//pkg/tcpip/transport/icmp",
-        "//pkg/tcpip/transport/udp",
         "//pkg/waiter",
     ],
 )
diff --git a/pkg/tcpip/network/ipv6/icmp_test.go b/pkg/tcpip/network/ipv6/icmp_test.go
index 653d984e9..a6a1a5232 100644
--- a/pkg/tcpip/network/ipv6/icmp_test.go
+++ b/pkg/tcpip/network/ipv6/icmp_test.go
@@ -222,6 +222,9 @@ func newTestContext(t *testing.T) *testContext {
 	if err := c.s0.AddAddress(1, ProtocolNumber, lladdr0); err != nil {
 		t.Fatalf("AddAddress lladdr0: %v", err)
 	}
+	if err := c.s0.AddAddress(1, ProtocolNumber, header.SolicitedNodeAddr(lladdr0)); err != nil {
+		t.Fatalf("AddAddress sn lladdr0: %v", err)
+	}
 
 	c.linkEP1 = channel.New(256, defaultMTU, linkAddr1)
 	wrappedEP1 := stack.LinkEndpoint(endpointWithResolutionCapability{LinkEndpoint: c.linkEP1})
@@ -231,6 +234,9 @@ func newTestContext(t *testing.T) *testContext {
 	if err := c.s1.AddAddress(1, ProtocolNumber, lladdr1); err != nil {
 		t.Fatalf("AddAddress lladdr1: %v", err)
 	}
+	if err := c.s1.AddAddress(1, ProtocolNumber, header.SolicitedNodeAddr(lladdr1)); err != nil {
+		t.Fatalf("AddAddress sn lladdr1: %v", err)
+	}
 
 	subnet0, err := tcpip.NewSubnet(lladdr1, tcpip.AddressMask(strings.Repeat("\xff", len(lladdr1))))
 	if err != nil {
diff --git a/pkg/tcpip/network/ipv6/ipv6_test.go b/pkg/tcpip/network/ipv6/ipv6_test.go
deleted file mode 100644
index b07e99dd4..000000000
--- a/pkg/tcpip/network/ipv6/ipv6_test.go
+++ /dev/null
@@ -1,215 +0,0 @@
-// 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 ipv6
-
-import (
-	"testing"
-
-	"gvisor.dev/gvisor/pkg/tcpip"
-	"gvisor.dev/gvisor/pkg/tcpip/buffer"
-	"gvisor.dev/gvisor/pkg/tcpip/header"
-	"gvisor.dev/gvisor/pkg/tcpip/link/channel"
-	"gvisor.dev/gvisor/pkg/tcpip/stack"
-	"gvisor.dev/gvisor/pkg/tcpip/transport/icmp"
-	"gvisor.dev/gvisor/pkg/tcpip/transport/udp"
-	"gvisor.dev/gvisor/pkg/waiter"
-)
-
-const (
-	addr1 = "\x0a\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01"
-	addr2 = "\x0a\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02"
-	// The least significant 3 bytes are the same as addr2 so both addr2 and
-	// addr3 will have the same solicited-node address.
-	addr3 = "\x0a\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x02"
-)
-
-// testReceiveICMP tests receiving an ICMP packet from src to dst. want is the
-// expected Neighbor Advertisement received count after receiving the packet.
-func testReceiveICMP(t *testing.T, s *stack.Stack, e *channel.Endpoint, src, dst tcpip.Address, want uint64) {
-	t.Helper()
-
-	// Receive ICMP packet.
-	hdr := buffer.NewPrependable(header.IPv6MinimumSize + header.ICMPv6NeighborAdvertSize)
-	pkt := header.ICMPv6(hdr.Prepend(header.ICMPv6NeighborAdvertSize))
-	pkt.SetType(header.ICMPv6NeighborAdvert)
-	pkt.SetChecksum(header.ICMPv6Checksum(pkt, src, dst, buffer.VectorisedView{}))
-	payloadLength := hdr.UsedLength()
-	ip := header.IPv6(hdr.Prepend(header.IPv6MinimumSize))
-	ip.Encode(&header.IPv6Fields{
-		PayloadLength: uint16(payloadLength),
-		NextHeader:    uint8(header.ICMPv6ProtocolNumber),
-		HopLimit:      255,
-		SrcAddr:       src,
-		DstAddr:       dst,
-	})
-
-	e.Inject(ProtocolNumber, hdr.View().ToVectorisedView())
-
-	stats := s.Stats().ICMP.V6PacketsReceived
-
-	if got := stats.NeighborAdvert.Value(); got != want {
-		t.Fatalf("got NeighborAdvert = %d, want = %d", got, want)
-	}
-}
-
-// testReceiveICMP tests receiving a UDP packet from src to dst. want is the
-// expected UDP received count after receiving the packet.
-func testReceiveUDP(t *testing.T, s *stack.Stack, e *channel.Endpoint, src, dst tcpip.Address, want uint64) {
-	t.Helper()
-
-	wq := waiter.Queue{}
-	we, ch := waiter.NewChannelEntry(nil)
-	wq.EventRegister(&we, waiter.EventIn)
-	defer wq.EventUnregister(&we)
-	defer close(ch)
-
-	ep, err := s.NewEndpoint(udp.ProtocolNumber, ProtocolNumber, &wq)
-	if err != nil {
-		t.Fatalf("NewEndpoint failed: %v", err)
-	}
-	defer ep.Close()
-
-	if err := ep.Bind(tcpip.FullAddress{Addr: dst, Port: 80}); err != nil {
-		t.Fatalf("ep.Bind(...) failed: %v", err)
-	}
-
-	// Receive UDP Packet.
-	hdr := buffer.NewPrependable(header.IPv6MinimumSize + header.UDPMinimumSize)
-	u := header.UDP(hdr.Prepend(header.UDPMinimumSize))
-	u.Encode(&header.UDPFields{
-		SrcPort: 5555,
-		DstPort: 80,
-		Length:  header.UDPMinimumSize,
-	})
-
-	// UDP pseudo-header checksum.
-	sum := header.PseudoHeaderChecksum(udp.ProtocolNumber, src, dst, header.UDPMinimumSize)
-
-	// UDP checksum
-	sum = header.Checksum(header.UDP([]byte{}), sum)
-	u.SetChecksum(^u.CalculateChecksum(sum))
-
-	payloadLength := hdr.UsedLength()
-	ip := header.IPv6(hdr.Prepend(header.IPv6MinimumSize))
-	ip.Encode(&header.IPv6Fields{
-		PayloadLength: uint16(payloadLength),
-		NextHeader:    uint8(udp.ProtocolNumber),
-		HopLimit:      255,
-		SrcAddr:       src,
-		DstAddr:       dst,
-	})
-
-	e.Inject(ProtocolNumber, hdr.View().ToVectorisedView())
-
-	stat := s.Stats().UDP.PacketsReceived
-
-	if got := stat.Value(); got != want {
-		t.Fatalf("got UDPPacketsReceived = %d, want = %d", got, want)
-	}
-}
-
-// TestReceiveOnAllNodesMulticastAddr tests that IPv6 endpoints receive ICMP and
-// UDP packets destined to the IPv6 link-local all-nodes multicast address.
-func TestReceiveOnAllNodesMulticastAddr(t *testing.T) {
-	tests := []struct {
-		name         string
-		protocolName string
-		rxf          func(t *testing.T, s *stack.Stack, e *channel.Endpoint, src, dst tcpip.Address, want uint64)
-	}{
-		{"ICMP", icmp.ProtocolName6, testReceiveICMP},
-		{"UDP", udp.ProtocolName, testReceiveUDP},
-	}
-
-	for _, test := range tests {
-		t.Run(test.name, func(t *testing.T) {
-			s := stack.New([]string{ProtocolName}, []string{test.protocolName}, stack.Options{})
-			e := channel.New(10, 1280, linkAddr1)
-			if err := s.CreateNIC(1, e); err != nil {
-				t.Fatalf("CreateNIC(_) = %s", err)
-			}
-
-			// Should receive a packet destined to the all-nodes
-			// multicast address.
-			test.rxf(t, s, e, addr1, header.IPv6AllNodesMulticastAddress, 1)
-		})
-	}
-}
-
-// TestReceiveOnSolicitedNodeAddr tests that IPv6 endpoints receive ICMP and UDP
-// packets destined to the IPv6 solicited-node address of an assigned IPv6
-// address.
-func TestReceiveOnSolicitedNodeAddr(t *testing.T) {
-	tests := []struct {
-		name         string
-		protocolName string
-		rxf          func(t *testing.T, s *stack.Stack, e *channel.Endpoint, src, dst tcpip.Address, want uint64)
-	}{
-		{"ICMP", icmp.ProtocolName6, testReceiveICMP},
-		{"UDP", udp.ProtocolName, testReceiveUDP},
-	}
-
-	snmc := header.SolicitedNodeAddr(addr2)
-
-	for _, test := range tests {
-		t.Run(test.name, func(t *testing.T) {
-			s := stack.New([]string{ProtocolName}, []string{test.protocolName}, stack.Options{})
-			e := channel.New(10, 1280, linkAddr1)
-			if err := s.CreateNIC(1, e); err != nil {
-				t.Fatalf("CreateNIC(_) = %s", err)
-			}
-
-			// Should not receive a packet destined to the solicited
-			// node address of addr2/addr3 yet as we haven't added
-			// those addresses.
-			test.rxf(t, s, e, addr1, snmc, 0)
-
-			if err := s.AddAddress(1, ProtocolNumber, addr2); err != nil {
-				t.Fatalf("AddAddress(_, %d, %s) = %s", ProtocolNumber, addr2, err)
-			}
-
-			// Should receive a packet destined to the solicited
-			// node address of addr2/addr3 now that we have added
-			// added addr2.
-			test.rxf(t, s, e, addr1, snmc, 1)
-
-			if err := s.AddAddress(1, ProtocolNumber, addr3); err != nil {
-				t.Fatalf("AddAddress(_, %d, %s) = %s", ProtocolNumber, addr3, err)
-			}
-
-			// Should still receive a packet destined to the
-			// solicited node address of addr2/addr3 now that we
-			// have added addr3.
-			test.rxf(t, s, e, addr1, snmc, 2)
-
-			if err := s.RemoveAddress(1, addr2); err != nil {
-				t.Fatalf("RemoveAddress(_, %s) = %s", addr2, err)
-			}
-
-			// Should still receive a packet destined to the
-			// solicited node address of addr2/addr3 now that we
-			// have removed addr2.
-			test.rxf(t, s, e, addr1, snmc, 3)
-
-			if err := s.RemoveAddress(1, addr3); err != nil {
-				t.Fatalf("RemoveAddress(_, %s) = %s", addr3, err)
-			}
-
-			// Should not receive a packet destined to the solicited
-			// node address of addr2/addr3 yet as both of them got
-			// removed.
-			test.rxf(t, s, e, addr1, snmc, 3)
-		})
-	}
-}
diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go
index 249a19946..43719085e 100644
--- a/pkg/tcpip/stack/nic.go
+++ b/pkg/tcpip/stack/nic.go
@@ -102,25 +102,6 @@ func newNIC(stack *Stack, id tcpip.NICID, name string, ep LinkEndpoint, loopback
 	}
 }
 
-// enable enables the NIC. enable will attach the link to its LinkEndpoint and
-// join the IPv6 All-Nodes Multicast address (ff02::1).
-func (n *NIC) enable() *tcpip.Error {
-	n.attachLinkEndpoint()
-
-	// Join the IPv6 All-Nodes Multicast group if the stack is configured to
-	// use IPv6. This is required to ensure that this node properly receives
-	// and responds to the various NDP messages that are destined to the
-	// all-nodes multicast address. An example is the Neighbor Advertisement
-	// when we perform Duplicate Address Detection, or Router Advertisement
-	// when we do Router Discovery. See RFC 4862, section 5.4.2 and RFC 4861
-	// section 4.2 for more information.
-	if _, ok := n.stack.networkProtocols[header.IPv6ProtocolNumber]; ok {
-		return n.joinGroup(header.IPv6ProtocolNumber, header.IPv6AllNodesMulticastAddress)
-	}
-
-	return nil
-}
-
 // attachLinkEndpoint attaches the NIC to the endpoint, which will enable it
 // to start delivering packets.
 func (n *NIC) attachLinkEndpoint() {
@@ -358,15 +339,6 @@ func (n *NIC) addAddressLocked(protocolAddress tcpip.ProtocolAddress, peb Primar
 		}
 	}
 
-	// If we are adding an IPv6 address, join the solicited-node multicast
-	// address for a unicast protocolAddress.
-	if protocolAddress.Protocol == header.IPv6ProtocolNumber && !header.IsV6MulticastAddress(protocolAddress.AddressWithPrefix.Address) {
-		snmc := header.SolicitedNodeAddr(protocolAddress.AddressWithPrefix.Address)
-		if err := n.joinGroupLocked(protocolAddress.Protocol, snmc); err != nil {
-			return nil, err
-		}
-	}
-
 	n.endpoints[id] = ref
 
 	l, ok := n.primary[protocolAddress.Protocol]
@@ -495,27 +467,13 @@ func (n *NIC) removeEndpoint(r *referencedNetworkEndpoint) {
 }
 
 func (n *NIC) removePermanentAddressLocked(addr tcpip.Address) *tcpip.Error {
-	r, ok := n.endpoints[NetworkEndpointID{addr}]
-	if !ok || r.getKind() != permanent {
+	r := n.endpoints[NetworkEndpointID{addr}]
+	if r == nil || r.getKind() != permanent {
 		return tcpip.ErrBadLocalAddress
 	}
 
 	r.setKind(permanentExpired)
-	if !r.decRefLocked() {
-		// The endpoint still has references to it.
-		return nil
-	}
-
-	// At this point the endpoint is deleted.
-
-	// If we are removing an IPv6 address, leave the solicited-node
-	// multicast address for a unicast addr.
-	if r.protocol == header.IPv6ProtocolNumber && !header.IsV6MulticastAddress(addr) {
-		snmc := header.SolicitedNodeAddr(addr)
-		if err := n.leaveGroupLocked(snmc); err != nil {
-			return err
-		}
-	}
+	r.decRefLocked()
 
 	return nil
 }
@@ -533,13 +491,6 @@ func (n *NIC) joinGroup(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address
 	n.mu.Lock()
 	defer n.mu.Unlock()
 
-	return n.joinGroupLocked(protocol, addr)
-}
-
-// joinGroupLocked adds a new endpoint for the given multicast address, if none
-// exists yet. Otherwise it just increments its count. n MUST be locked before
-// joinGroupLocked is called.
-func (n *NIC) joinGroupLocked(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address) *tcpip.Error {
 	id := NetworkEndpointID{addr}
 	joins := n.mcastJoins[id]
 	if joins == 0 {
@@ -567,13 +518,6 @@ func (n *NIC) leaveGroup(addr tcpip.Address) *tcpip.Error {
 	n.mu.Lock()
 	defer n.mu.Unlock()
 
-	return n.leaveGroupLocked(addr)
-}
-
-// leaveGroupLocked decrements the count for the given multicast address, and
-// when it reaches zero removes the endpoint for this address. n MUST be locked
-// before leaveGroupLocked is called.
-func (n *NIC) leaveGroupLocked(addr tcpip.Address) *tcpip.Error {
 	id := NetworkEndpointID{addr}
 	joins := n.mcastJoins[id]
 	switch joins {
@@ -858,14 +802,11 @@ func (r *referencedNetworkEndpoint) decRef() {
 }
 
 // decRefLocked is the same as decRef but assumes that the NIC.mu mutex is
-// locked. Returns true if the endpoint was removed.
-func (r *referencedNetworkEndpoint) decRefLocked() bool {
+// locked.
+func (r *referencedNetworkEndpoint) decRefLocked() {
 	if atomic.AddInt32(&r.refs, -1) == 0 {
 		r.nic.removeEndpointLocked(r)
-		return true
 	}
-
-	return false
 }
 
 // incRef increments the ref count. It must only be called when the caller is
diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go
index 1fe21b68e..a961e8ebe 100644
--- a/pkg/tcpip/stack/stack.go
+++ b/pkg/tcpip/stack/stack.go
@@ -633,7 +633,7 @@ func (s *Stack) createNIC(id tcpip.NICID, name string, ep LinkEndpoint, enabled,
 
 	s.nics[id] = n
 	if enabled {
-		return n.enable()
+		n.attachLinkEndpoint()
 	}
 
 	return nil
@@ -680,7 +680,9 @@ func (s *Stack) EnableNIC(id tcpip.NICID) *tcpip.Error {
 		return tcpip.ErrUnknownNICID
 	}
 
-	return nic.enable()
+	nic.attachLinkEndpoint()
+
+	return nil
 }
 
 // CheckNIC checks if a NIC is usable.