Merge release-20200921.0-60-g48915bded (automated)

1 files changed, 64 insertions, 12 deletions

diff --git a/pkg/tcpip/network/arp/arp.go b/pkg/tcpip/network/arp/arp.go
index b025bb087..4bb7a417c 100644
--- a/pkg/tcpip/network/arp/arp.go
+++ b/pkg/tcpip/network/arp/arp.go
@@ -18,6 +18,8 @@
 package arp
 
 import (
+	"sync/atomic"
+
 	"gvisor.dev/gvisor/pkg/tcpip"
 	"gvisor.dev/gvisor/pkg/tcpip/buffer"
 	"gvisor.dev/gvisor/pkg/tcpip/header"
@@ -33,15 +35,57 @@ const (
 	ProtocolAddress = tcpip.Address("arp")
 )
 
-// endpoint implements stack.NetworkEndpoint.
+var _ stack.AddressableEndpoint = (*endpoint)(nil)
+var _ stack.NetworkEndpoint = (*endpoint)(nil)
+
 type endpoint struct {
-	protocol      *protocol
-	nicID         tcpip.NICID
+	stack.AddressableEndpointState
+
+	protocol *protocol
+
+	// enabled is set to 1 when the NIC is enabled and 0 when it is disabled.
+	//
+	// Must be accessed using atomic operations.
+	enabled uint32
+
+	nic           stack.NetworkInterface
 	linkEP        stack.LinkEndpoint
 	linkAddrCache stack.LinkAddressCache
 	nud           stack.NUDHandler
 }
 
+func (e *endpoint) Enable() *tcpip.Error {
+	if !e.nic.Enabled() {
+		return tcpip.ErrNotPermitted
+	}
+
+	e.setEnabled(true)
+	return nil
+}
+
+func (e *endpoint) Enabled() bool {
+	return e.nic.Enabled() && e.isEnabled()
+}
+
+// isEnabled returns true if the endpoint is enabled, regardless of the
+// enabled status of the NIC.
+func (e *endpoint) isEnabled() bool {
+	return atomic.LoadUint32(&e.enabled) == 1
+}
+
+// setEnabled sets the enabled status for the endpoint.
+func (e *endpoint) setEnabled(v bool) {
+	if v {
+		atomic.StoreUint32(&e.enabled, 1)
+	} else {
+		atomic.StoreUint32(&e.enabled, 0)
+	}
+}
+
+func (e *endpoint) Disable() {
+	e.setEnabled(false)
+}
+
 // DefaultTTL is unused for ARP. It implements stack.NetworkEndpoint.
 func (e *endpoint) DefaultTTL() uint8 {
 	return 0
@@ -53,7 +97,7 @@ func (e *endpoint) MTU() uint32 {
 }
 
 func (e *endpoint) NICID() tcpip.NICID {
-	return e.nicID
+	return e.nic.ID()
 }
 
 func (e *endpoint) Capabilities() stack.LinkEndpointCapabilities {
@@ -64,7 +108,9 @@ func (e *endpoint) MaxHeaderLength() uint16 {
 	return e.linkEP.MaxHeaderLength() + header.ARPSize
 }
 
-func (e *endpoint) Close() {}
+func (e *endpoint) Close() {
+	e.AddressableEndpointState.Cleanup()
+}
 
 func (e *endpoint) WritePacket(*stack.Route, *stack.GSO, stack.NetworkHeaderParams, *stack.PacketBuffer) *tcpip.Error {
 	return tcpip.ErrNotSupported
@@ -85,6 +131,10 @@ func (e *endpoint) WriteHeaderIncludedPacket(r *stack.Route, pkt *stack.PacketBu
 }
 
 func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
+	if !e.isEnabled() {
+		return
+	}
+
 	h := header.ARP(pkt.NetworkHeader().View())
 	if !h.IsValid() {
 		return
@@ -95,15 +145,15 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
 		localAddr := tcpip.Address(h.ProtocolAddressTarget())
 
 		if e.nud == nil {
-			if e.linkAddrCache.CheckLocalAddress(e.nicID, header.IPv4ProtocolNumber, localAddr) == 0 {
+			if e.linkAddrCache.CheckLocalAddress(e.NICID(), header.IPv4ProtocolNumber, localAddr) == 0 {
 				return // we have no useful answer, ignore the request
 			}
 
 			addr := tcpip.Address(h.ProtocolAddressSender())
 			linkAddr := tcpip.LinkAddress(h.HardwareAddressSender())
-			e.linkAddrCache.AddLinkAddress(e.nicID, addr, linkAddr)
+			e.linkAddrCache.AddLinkAddress(e.NICID(), addr, linkAddr)
 		} else {
-			if r.Stack().CheckLocalAddress(e.nicID, header.IPv4ProtocolNumber, localAddr) == 0 {
+			if r.Stack().CheckLocalAddress(e.NICID(), header.IPv4ProtocolNumber, localAddr) == 0 {
 				return // we have no useful answer, ignore the request
 			}
 
@@ -129,7 +179,7 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
 		linkAddr := tcpip.LinkAddress(h.HardwareAddressSender())
 
 		if e.nud == nil {
-			e.linkAddrCache.AddLinkAddress(e.nicID, addr, linkAddr)
+			e.linkAddrCache.AddLinkAddress(e.NICID(), addr, linkAddr)
 			return
 		}
 
@@ -161,14 +211,16 @@ func (*protocol) ParseAddresses(v buffer.View) (src, dst tcpip.Address) {
 	return tcpip.Address(h.ProtocolAddressSender()), ProtocolAddress
 }
 
-func (p *protocol) NewEndpoint(nicID tcpip.NICID, linkAddrCache stack.LinkAddressCache, nud stack.NUDHandler, dispatcher stack.TransportDispatcher, sender stack.LinkEndpoint, st *stack.Stack) stack.NetworkEndpoint {
-	return &endpoint{
+func (p *protocol) NewEndpoint(nic stack.NetworkInterface, linkAddrCache stack.LinkAddressCache, nud stack.NUDHandler, dispatcher stack.TransportDispatcher, sender stack.LinkEndpoint, st *stack.Stack) stack.NetworkEndpoint {
+	e := &endpoint{
 		protocol:      p,
-		nicID:         nicID,
+		nic:           nic,
 		linkEP:        sender,
 		linkAddrCache: linkAddrCache,
 		nud:           nud,
 	}
+	e.AddressableEndpointState.Init(e)
+	return e
 }
 
 // LinkAddressProtocol implements stack.LinkAddressResolver.LinkAddressProtocol.