summaryrefslogtreecommitdiffhomepage
path: root/pkg/tcpip
diff options
context:
space:
mode:
authorBhasker Hariharan <bhaskerh@google.com>2021-05-11 10:26:17 -0700
committergVisor bot <gvisor-bot@google.com>2021-05-11 10:30:33 -0700
commitebebb3059f7c5dbe42af85715f1c51c23461463b (patch)
tree184e34bc36d4e1f0341eb35460889519c44b4b94 /pkg/tcpip
parent60bdf7ed31bc32bb8413cfdb67cd906ca3d5955a (diff)
Change AcquireAssignedAddress to use RLock.
This is a hot path for all incoming packets and we don't need an exclusive lock here as we are not modifying any of the fields protected by mu here. PiperOrigin-RevId: 373181254
Diffstat (limited to 'pkg/tcpip')
-rw-r--r--pkg/tcpip/network/ipv4/ipv4.go12
-rw-r--r--pkg/tcpip/network/ipv6/ipv6.go12
-rw-r--r--pkg/tcpip/stack/addressable_endpoint_state.go52
3 files changed, 49 insertions, 27 deletions
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go
index 19657fde1..4031032d0 100644
--- a/pkg/tcpip/network/ipv4/ipv4.go
+++ b/pkg/tcpip/network/ipv4/ipv4.go
@@ -990,8 +990,8 @@ func (e *endpoint) Close() {
// AddAndAcquirePermanentAddress implements stack.AddressableEndpoint.
func (e *endpoint) AddAndAcquirePermanentAddress(addr tcpip.AddressWithPrefix, peb stack.PrimaryEndpointBehavior, configType stack.AddressConfigType, deprecated bool) (stack.AddressEndpoint, tcpip.Error) {
- e.mu.Lock()
- defer e.mu.Unlock()
+ e.mu.RLock()
+ defer e.mu.RUnlock()
ep, err := e.mu.addressableEndpointState.AddAndAcquirePermanentAddress(addr, peb, configType, deprecated)
if err == nil {
@@ -1002,8 +1002,8 @@ func (e *endpoint) AddAndAcquirePermanentAddress(addr tcpip.AddressWithPrefix, p
// RemovePermanentAddress implements stack.AddressableEndpoint.
func (e *endpoint) RemovePermanentAddress(addr tcpip.Address) tcpip.Error {
- e.mu.Lock()
- defer e.mu.Unlock()
+ e.mu.RLock()
+ defer e.mu.RUnlock()
return e.mu.addressableEndpointState.RemovePermanentAddress(addr)
}
@@ -1016,8 +1016,8 @@ func (e *endpoint) MainAddress() tcpip.AddressWithPrefix {
// AcquireAssignedAddress implements stack.AddressableEndpoint.
func (e *endpoint) AcquireAssignedAddress(localAddr tcpip.Address, allowTemp bool, tempPEB stack.PrimaryEndpointBehavior) stack.AddressEndpoint {
- e.mu.Lock()
- defer e.mu.Unlock()
+ e.mu.RLock()
+ defer e.mu.RUnlock()
loopback := e.nic.IsLoopback()
return e.mu.addressableEndpointState.AcquireAssignedAddressOrMatching(localAddr, func(addressEndpoint stack.AddressEndpoint) bool {
diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go
index 4fdb2793d..029d5f51b 100644
--- a/pkg/tcpip/network/ipv6/ipv6.go
+++ b/pkg/tcpip/network/ipv6/ipv6.go
@@ -1546,8 +1546,8 @@ func (e *endpoint) NetworkProtocolNumber() tcpip.NetworkProtocolNumber {
func (e *endpoint) AddAndAcquirePermanentAddress(addr tcpip.AddressWithPrefix, peb stack.PrimaryEndpointBehavior, configType stack.AddressConfigType, deprecated bool) (stack.AddressEndpoint, tcpip.Error) {
// TODO(b/169350103): add checks here after making sure we no longer receive
// an empty address.
- e.mu.Lock()
- defer e.mu.Unlock()
+ e.mu.RLock()
+ defer e.mu.RUnlock()
return e.addAndAcquirePermanentAddressLocked(addr, peb, configType, deprecated)
}
@@ -1588,8 +1588,8 @@ func (e *endpoint) addAndAcquirePermanentAddressLocked(addr tcpip.AddressWithPre
// RemovePermanentAddress implements stack.AddressableEndpoint.
func (e *endpoint) RemovePermanentAddress(addr tcpip.Address) tcpip.Error {
- e.mu.Lock()
- defer e.mu.Unlock()
+ e.mu.RLock()
+ defer e.mu.RUnlock()
addressEndpoint := e.getAddressRLocked(addr)
if addressEndpoint == nil || !addressEndpoint.GetKind().IsPermanent() {
@@ -1666,8 +1666,8 @@ func (e *endpoint) MainAddress() tcpip.AddressWithPrefix {
// AcquireAssignedAddress implements stack.AddressableEndpoint.
func (e *endpoint) AcquireAssignedAddress(localAddr tcpip.Address, allowTemp bool, tempPEB stack.PrimaryEndpointBehavior) stack.AddressEndpoint {
- e.mu.Lock()
- defer e.mu.Unlock()
+ e.mu.RLock()
+ defer e.mu.RUnlock()
return e.acquireAddressOrCreateTempLocked(localAddr, allowTemp, tempPEB)
}
diff --git a/pkg/tcpip/stack/addressable_endpoint_state.go b/pkg/tcpip/stack/addressable_endpoint_state.go
index e5590ecc0..ce9cebdaa 100644
--- a/pkg/tcpip/stack/addressable_endpoint_state.go
+++ b/pkg/tcpip/stack/addressable_endpoint_state.go
@@ -440,33 +440,54 @@ func (a *AddressableEndpointState) acquirePrimaryAddressRLocked(isValid func(*ad
// 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()
+ lookup := func() *addressState {
+ if addrState, ok := a.mu.endpoints[localAddr]; ok {
+ if !addrState.IsAssigned(allowTemp) {
+ return nil
+ }
- if addrState, ok := a.mu.endpoints[localAddr]; ok {
- if !addrState.IsAssigned(allowTemp) {
- return nil
- }
+ if !addrState.IncRef() {
+ panic(fmt.Sprintf("failed to increase the reference count for address = %s", addrState.addr))
+ }
- if !addrState.IncRef() {
- panic(fmt.Sprintf("failed to increase the reference count for address = %s", addrState.addr))
+ return addrState
}
- return addrState
- }
-
- if f != nil {
- for _, addrState := range a.mu.endpoints {
- if addrState.IsAssigned(allowTemp) && f(addrState) && addrState.IncRef() {
- return addrState
+ if f != nil {
+ for _, addrState := range a.mu.endpoints {
+ if addrState.IsAssigned(allowTemp) && f(addrState) && addrState.IncRef() {
+ return addrState
+ }
}
}
+ return nil
+ }
+ // Avoid exclusive lock on mu unless we need to add a new address.
+ a.mu.RLock()
+ ep := lookup()
+ a.mu.RUnlock()
+
+ if ep != nil {
+ return ep
}
if !allowTemp {
return nil
}
+ // Acquire state lock in exclusive mode as we need to add a new temporary
+ // endpoint.
+ a.mu.Lock()
+ defer a.mu.Unlock()
+
+ // Do the lookup again in case another goroutine added the address in the time
+ // we released and acquired the lock.
+ ep = lookup()
+ if ep != nil {
+ return ep
+ }
+
+ // Proceed to add a new temporary endpoint.
addr := localAddr.WithPrefix()
ep, err := a.addAndAcquireAddressLocked(addr, tempPEB, AddressConfigStatic, false /* deprecated */, false /* permanent */)
if err != nil {
@@ -475,6 +496,7 @@ func (a *AddressableEndpointState) AcquireAssignedAddressOrMatching(localAddr tc
// expect no error.
panic(fmt.Sprintf("a.addAndAcquireAddressLocked(%s, %d, %d, false, false): %s", addr, tempPEB, AddressConfigStatic, err))
}
+
// From https://golang.org/doc/faq#nil_error:
//
// Under the covers, interfaces are implemented as two elements, a type T and