Merge release-20201130.0-46-gdf2dbe3e3 (automated)

3 files changed, 51 insertions, 80 deletions

diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go
index 4b34d0bfb..3076185cd 100644
--- a/pkg/tcpip/network/ipv4/ipv4.go
+++ b/pkg/tcpip/network/ipv4/ipv4.go
@@ -799,28 +799,12 @@ func (e *endpoint) AcquireAssignedAddress(localAddr tcpip.Address, allowTemp boo
 	defer e.mu.Unlock()
 
 	loopback := e.nic.IsLoopback()
-	addressEndpoint := e.mu.addressableEndpointState.ReadOnly().AddrOrMatching(localAddr, allowTemp, func(addressEndpoint stack.AddressEndpoint) bool {
+	return e.mu.addressableEndpointState.AcquireAssignedAddressOrMatching(localAddr, func(addressEndpoint stack.AddressEndpoint) bool {
 		subnet := addressEndpoint.Subnet()
 		// IPv4 has a notion of a subnet broadcast address and considers the
 		// loopback interface bound to an address's whole subnet (on linux).
 		return subnet.IsBroadcast(localAddr) || (loopback && subnet.Contains(localAddr))
-	})
-	if addressEndpoint != nil {
-		return addressEndpoint
-	}
-
-	if !allowTemp {
-		return nil
-	}
-
-	addr := localAddr.WithPrefix()
-	addressEndpoint, err := e.mu.addressableEndpointState.AddAndAcquireTemporaryAddress(addr, tempPEB)
-	if err != nil {
-		// AddAddress only returns an error if the address is already assigned,
-		// but we just checked above if the address exists so we expect no error.
-		panic(fmt.Sprintf("e.mu.addressableEndpointState.AddAndAcquireTemporaryAddress(%s, %d): %s", addr, tempPEB, err))
-	}
-	return addressEndpoint
+	}, allowTemp, tempPEB)
 }
 
 // AcquireOutgoingPrimaryAddress implements stack.AddressableEndpoint.
diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go
index 084c38455..8bf84601f 100644
--- a/pkg/tcpip/network/ipv6/ipv6.go
+++ b/pkg/tcpip/network/ipv6/ipv6.go
@@ -263,7 +263,7 @@ func (e *endpoint) Enable() *tcpip.Error {
 	// Addresses may have aleady completed DAD but in the time since the endpoint
 	// was last enabled, other devices may have acquired the same addresses.
 	var err *tcpip.Error
-	e.mu.addressableEndpointState.ReadOnly().ForEach(func(addressEndpoint stack.AddressEndpoint) bool {
+	e.mu.addressableEndpointState.ForEachEndpoint(func(addressEndpoint stack.AddressEndpoint) bool {
 		addr := addressEndpoint.AddressWithPrefix().Address
 		if !header.IsV6UnicastAddress(addr) {
 			return true
@@ -357,7 +357,7 @@ func (e *endpoint) disableLocked() {
 // Precondition: e.mu must be write locked.
 func (e *endpoint) stopDADForPermanentAddressesLocked() {
 	// Stop DAD for all the tentative unicast addresses.
-	e.mu.addressableEndpointState.ReadOnly().ForEach(func(addressEndpoint stack.AddressEndpoint) bool {
+	e.mu.addressableEndpointState.ForEachEndpoint(func(addressEndpoint stack.AddressEndpoint) bool {
 		if addressEndpoint.GetKind() != stack.PermanentTentative {
 			return true
 		}
@@ -1261,7 +1261,7 @@ func (e *endpoint) hasPermanentAddressRLocked(addr tcpip.Address) bool {
 //
 // Precondition: e.mu must be read or write locked.
 func (e *endpoint) getAddressRLocked(localAddr tcpip.Address) stack.AddressEndpoint {
-	return e.mu.addressableEndpointState.ReadOnly().Lookup(localAddr)
+	return e.mu.addressableEndpointState.GetAddress(localAddr)
 }
 
 // MainAddress implements stack.AddressableEndpoint.
@@ -1312,7 +1312,7 @@ func (e *endpoint) acquireOutgoingPrimaryAddressRLocked(remoteAddr tcpip.Address
 	// Create a candidate set of available addresses we can potentially use as a
 	// source address.
 	var cs []addrCandidate
-	e.mu.addressableEndpointState.ReadOnly().ForEachPrimaryEndpoint(func(addressEndpoint stack.AddressEndpoint) {
+	e.mu.addressableEndpointState.ForEachPrimaryEndpoint(func(addressEndpoint stack.AddressEndpoint) {
 		// If r is not valid for outgoing connections, it is not a valid endpoint.
 		if !addressEndpoint.IsAssigned(allowExpired) {
 			return
diff --git a/pkg/tcpip/stack/addressable_endpoint_state.go b/pkg/tcpip/stack/addressable_endpoint_state.go
index b438e3acc..6e4f5fa46 100644
--- a/pkg/tcpip/stack/addressable_endpoint_state.go
+++ b/pkg/tcpip/stack/addressable_endpoint_state.go
@@ -50,62 +50,31 @@ func (a *AddressableEndpointState) Init(networkEndpoint NetworkEndpoint) {
 	a.mu.endpoints = make(map[tcpip.Address]*addressState)
 }
 
-// ReadOnlyAddressableEndpointState provides read-only access to an
-// AddressableEndpointState.
-type ReadOnlyAddressableEndpointState struct {
-	inner *AddressableEndpointState
-}
-
-// AddrOrMatching returns an endpoint for the passed address that is consisdered
-// bound to the wrapped AddressableEndpointState.
+// GetAddress returns the AddressEndpoint for the passed address.
 //
-// If addr is an exact match with an existing address, that address is returned.
-// Otherwise, f is called with each address and the address that f returns true
-// for is returned.
+// GetAddress does not increment the address's reference count or check if the
+// address is considered bound to the endpoint.
 //
-// Returns nil of no address matches.
-func (m ReadOnlyAddressableEndpointState) AddrOrMatching(addr tcpip.Address, spoofingOrPrimiscuous bool, f func(AddressEndpoint) bool) AddressEndpoint {
-	m.inner.mu.RLock()
-	defer m.inner.mu.RUnlock()
-
-	if ep, ok := m.inner.mu.endpoints[addr]; ok {
-		if ep.IsAssigned(spoofingOrPrimiscuous) && ep.IncRef() {
-			return ep
-		}
-	}
-
-	for _, ep := range m.inner.mu.endpoints {
-		if ep.IsAssigned(spoofingOrPrimiscuous) && f(ep) && ep.IncRef() {
-			return ep
-		}
-	}
-
-	return nil
-}
-
-// Lookup returns the AddressEndpoint for the passed address.
-//
-// Returns nil if the passed address is not associated with the
-// AddressableEndpointState.
-func (m ReadOnlyAddressableEndpointState) Lookup(addr tcpip.Address) AddressEndpoint {
-	m.inner.mu.RLock()
-	defer m.inner.mu.RUnlock()
+// Returns nil if the passed address is not associated with the endpoint.
+func (a *AddressableEndpointState) GetAddress(addr tcpip.Address) AddressEndpoint {
+	a.mu.RLock()
+	defer a.mu.RUnlock()
 
-	ep, ok := m.inner.mu.endpoints[addr]
+	ep, ok := a.mu.endpoints[addr]
 	if !ok {
 		return nil
 	}
 	return ep
 }
 
-// ForEach calls f for each address pair.
+// ForEachEndpoint calls f for each address.
 //
-// If f returns false, f is no longer be called.
-func (m ReadOnlyAddressableEndpointState) ForEach(f func(AddressEndpoint) bool) {
-	m.inner.mu.RLock()
-	defer m.inner.mu.RUnlock()
+// Once f returns false, f will no longer be called.
+func (a *AddressableEndpointState) ForEachEndpoint(f func(AddressEndpoint) bool) {
+	a.mu.RLock()
+	defer a.mu.RUnlock()
 
-	for _, ep := range m.inner.mu.endpoints {
+	for _, ep := range a.mu.endpoints {
 		if !f(ep) {
 			return
 		}
@@ -113,21 +82,15 @@ func (m ReadOnlyAddressableEndpointState) ForEach(f func(AddressEndpoint) bool)
 }
 
 // ForEachPrimaryEndpoint calls f for each primary address.
-//
-// If f returns false, f is no longer be called.
-func (m ReadOnlyAddressableEndpointState) ForEachPrimaryEndpoint(f func(AddressEndpoint)) {
-	m.inner.mu.RLock()
-	defer m.inner.mu.RUnlock()
-	for _, ep := range m.inner.mu.primary {
+func (a *AddressableEndpointState) ForEachPrimaryEndpoint(f func(AddressEndpoint)) {
+	a.mu.RLock()
+	defer a.mu.RUnlock()
+
+	for _, ep := range a.mu.primary {
 		f(ep)
 	}
 }
 
-// ReadOnly returns a readonly reference to a.
-func (a *AddressableEndpointState) ReadOnly() ReadOnlyAddressableEndpointState {
-	return ReadOnlyAddressableEndpointState{inner: a}
-}
-
 func (a *AddressableEndpointState) releaseAddressState(addrState *addressState) {
 	a.mu.Lock()
 	defer a.mu.Unlock()
@@ -460,8 +423,19 @@ func (a *AddressableEndpointState) acquirePrimaryAddressRLocked(isValid func(*ad
 	return deprecatedEndpoint
 }
 
-// AcquireAssignedAddress implements AddressableEndpoint.
-func (a *AddressableEndpointState) AcquireAssignedAddress(localAddr tcpip.Address, allowTemp bool, tempPEB PrimaryEndpointBehavior) AddressEndpoint {
+// AcquireAssignedAddressOrMatching returns an address endpoint that is
+// considered assigned to the addressable endpoint.
+//
+// If the address is an exact match with an existing address, that address is
+// returned. Otherwise, if f is provided, f is called with each address and
+// the address that f returns true for is returned.
+//
+// If there is no matching address, a temporary address will be returned if
+// allowTemp is true.
+//
+// Regardless how the address was obtained, it will be acquired before it is
+// returned.
+func (a *AddressableEndpointState) AcquireAssignedAddressOrMatching(localAddr tcpip.Address, f func(AddressEndpoint) bool, allowTemp bool, tempPEB PrimaryEndpointBehavior) AddressEndpoint {
 	a.mu.Lock()
 	defer a.mu.Unlock()
 
@@ -477,6 +451,14 @@ func (a *AddressableEndpointState) AcquireAssignedAddress(localAddr tcpip.Addres
 		return addrState
 	}
 
+	if f != nil {
+		for _, addrState := range a.mu.endpoints {
+			if addrState.IsAssigned(allowTemp) && f(addrState) && addrState.IncRef() {
+				return addrState
+			}
+		}
+	}
+
 	if !allowTemp {
 		return nil
 	}
@@ -509,6 +491,11 @@ func (a *AddressableEndpointState) AcquireAssignedAddress(localAddr tcpip.Addres
 	return ep
 }
 
+// AcquireAssignedAddress implements AddressableEndpoint.
+func (a *AddressableEndpointState) AcquireAssignedAddress(localAddr tcpip.Address, allowTemp bool, tempPEB PrimaryEndpointBehavior) AddressEndpoint {
+	return a.AcquireAssignedAddressOrMatching(localAddr, nil, allowTemp, tempPEB)
+}
+
 // AcquireOutgoingPrimaryAddress implements AddressableEndpoint.
 func (a *AddressableEndpointState) AcquireOutgoingPrimaryAddress(remoteAddr tcpip.Address, allowExpired bool) AddressEndpoint {
 	a.mu.RLock()