From 4ffa9c20327b9471c3eeb142347f679b69f84648 Mon Sep 17 00:00:00 2001 From: Jordan Whited Date: Mon, 20 Nov 2023 16:49:06 -0800 Subject: device: change Peer.endpoint locking to reduce contention Access to Peer.endpoint was previously synchronized by Peer.RWMutex. This has now moved to Peer.endpoint.Mutex. Peer.SendBuffers() is now the sole caller of Endpoint.ClearSrc(), which is signaled via a new bool, Peer.endpoint.clearSrcOnTx. Previous Callers of Endpoint.ClearSrc() now set this bool, primarily via peer.markEndpointSrcForClearing(). Peer.SetEndpointFromPacket() clears Peer.endpoint.clearSrcOnTx when an updated conn.Endpoint is stored. This maintains the same event order as before, i.e. a conn.Endpoint received after peer.endpoint.clearSrcOnTx is set, but before the next Peer.SendBuffers() call results in the latest conn.Endpoint source being used for the next packet transmission. These changes result in throughput improvements for single flow, parallel (-P n) flow, and bidirectional (--bidir) flow iperf3 TCP/UDP tests as measured on both Linux and Windows. Latency under load improves especially for high throughput Linux scenarios. These improvements are likely realized on all platforms to some degree, as the changes are not platform-specific. Co-authored-by: James Tucker Signed-off-by: James Tucker Signed-off-by: Jordan Whited Signed-off-by: Jason A. Donenfeld --- device/device.go | 12 ++-------- device/mobilequirks.go | 6 ++--- device/peer.go | 50 ++++++++++++++++++++++++++++------------- device/sticky_linux.go | 30 ++++++++++++------------- device/timers.go | 12 ++-------- device/uapi.go | 60 ++++++++++++++++++++++++-------------------------- 6 files changed, 86 insertions(+), 84 deletions(-) diff --git a/device/device.go b/device/device.go index f9557a0..ca26d00 100644 --- a/device/device.go +++ b/device/device.go @@ -461,11 +461,7 @@ func (device *Device) BindSetMark(mark uint32) error { // clear cached source addresses device.peers.RLock() for _, peer := range device.peers.keyMap { - peer.Lock() - defer peer.Unlock() - if peer.endpoint != nil { - peer.endpoint.ClearSrc() - } + peer.markEndpointSrcForClearing() } device.peers.RUnlock() @@ -515,11 +511,7 @@ func (device *Device) BindUpdate() error { // clear cached source addresses device.peers.RLock() for _, peer := range device.peers.keyMap { - peer.Lock() - defer peer.Unlock() - if peer.endpoint != nil { - peer.endpoint.ClearSrc() - } + peer.markEndpointSrcForClearing() } device.peers.RUnlock() diff --git a/device/mobilequirks.go b/device/mobilequirks.go index 4e5051d..0a0080e 100644 --- a/device/mobilequirks.go +++ b/device/mobilequirks.go @@ -11,9 +11,9 @@ func (device *Device) DisableSomeRoamingForBrokenMobileSemantics() { device.net.brokenRoaming = true device.peers.RLock() for _, peer := range device.peers.keyMap { - peer.Lock() - peer.disableRoaming = peer.endpoint != nil - peer.Unlock() + peer.endpoint.Lock() + peer.endpoint.disableRoaming = peer.endpoint.val != nil + peer.endpoint.Unlock() } device.peers.RUnlock() } diff --git a/device/peer.go b/device/peer.go index 2fb5da6..47a2f14 100644 --- a/device/peer.go +++ b/device/peer.go @@ -17,17 +17,20 @@ import ( type Peer struct { isRunning atomic.Bool - sync.RWMutex // Mostly protects endpoint, but is generally taken whenever we modify peer keypairs Keypairs handshake Handshake device *Device - endpoint conn.Endpoint stopping sync.WaitGroup // routines pending stop txBytes atomic.Uint64 // bytes send to peer (endpoint) rxBytes atomic.Uint64 // bytes received from peer lastHandshakeNano atomic.Int64 // nano seconds since epoch - disableRoaming bool + endpoint struct { + sync.Mutex + val conn.Endpoint + clearSrcOnTx bool // signal to val.ClearSrc() prior to next packet transmission + disableRoaming bool + } timers struct { retransmitHandshake *Timer @@ -74,8 +77,6 @@ func (device *Device) NewPeer(pk NoisePublicKey) (*Peer, error) { // create peer peer := new(Peer) - peer.Lock() - defer peer.Unlock() peer.cookieGenerator.Init(pk) peer.device = device @@ -97,7 +98,11 @@ func (device *Device) NewPeer(pk NoisePublicKey) (*Peer, error) { handshake.mutex.Unlock() // reset endpoint - peer.endpoint = nil + peer.endpoint.Lock() + peer.endpoint.val = nil + peer.endpoint.disableRoaming = false + peer.endpoint.clearSrcOnTx = false + peer.endpoint.Unlock() // init timers peer.timersInit() @@ -116,14 +121,19 @@ func (peer *Peer) SendBuffers(buffers [][]byte) error { return nil } - peer.RLock() - defer peer.RUnlock() - - if peer.endpoint == nil { + peer.endpoint.Lock() + endpoint := peer.endpoint.val + if endpoint == nil { + peer.endpoint.Unlock() return errors.New("no known endpoint for peer") } + if peer.endpoint.clearSrcOnTx { + endpoint.ClearSrc() + peer.endpoint.clearSrcOnTx = false + } + peer.endpoint.Unlock() - err := peer.device.net.bind.Send(buffers, peer.endpoint) + err := peer.device.net.bind.Send(buffers, endpoint) if err == nil { var totalLen uint64 for _, b := range buffers { @@ -267,10 +277,20 @@ func (peer *Peer) Stop() { } func (peer *Peer) SetEndpointFromPacket(endpoint conn.Endpoint) { - if peer.disableRoaming { + peer.endpoint.Lock() + defer peer.endpoint.Unlock() + if peer.endpoint.disableRoaming { + return + } + peer.endpoint.clearSrcOnTx = false + peer.endpoint.val = endpoint +} + +func (peer *Peer) markEndpointSrcForClearing() { + peer.endpoint.Lock() + defer peer.endpoint.Unlock() + if peer.endpoint.val == nil { return } - peer.Lock() - peer.endpoint = endpoint - peer.Unlock() + peer.endpoint.clearSrcOnTx = true } diff --git a/device/sticky_linux.go b/device/sticky_linux.go index f9230f8..6057ff1 100644 --- a/device/sticky_linux.go +++ b/device/sticky_linux.go @@ -110,17 +110,17 @@ func (device *Device) routineRouteListener(bind conn.Bind, netlinkSock int, netl if !ok { break } - pePtr.peer.Lock() - if &pePtr.peer.endpoint != pePtr.endpoint { - pePtr.peer.Unlock() + pePtr.peer.endpoint.Lock() + if &pePtr.peer.endpoint.val != pePtr.endpoint { + pePtr.peer.endpoint.Unlock() break } - if uint32(pePtr.peer.endpoint.(*conn.StdNetEndpoint).SrcIfidx()) == ifidx { - pePtr.peer.Unlock() + if uint32(pePtr.peer.endpoint.val.(*conn.StdNetEndpoint).SrcIfidx()) == ifidx { + pePtr.peer.endpoint.Unlock() break } - pePtr.peer.endpoint.(*conn.StdNetEndpoint).ClearSrc() - pePtr.peer.Unlock() + pePtr.peer.endpoint.clearSrcOnTx = true + pePtr.peer.endpoint.Unlock() } attr = attr[attrhdr.Len:] } @@ -134,18 +134,18 @@ func (device *Device) routineRouteListener(bind conn.Bind, netlinkSock int, netl device.peers.RLock() i := uint32(1) for _, peer := range device.peers.keyMap { - peer.RLock() - if peer.endpoint == nil { - peer.RUnlock() + peer.endpoint.Lock() + if peer.endpoint.val == nil { + peer.endpoint.Unlock() continue } - nativeEP, _ := peer.endpoint.(*conn.StdNetEndpoint) + nativeEP, _ := peer.endpoint.val.(*conn.StdNetEndpoint) if nativeEP == nil { - peer.RUnlock() + peer.endpoint.Unlock() continue } if nativeEP.DstIP().Is6() || nativeEP.SrcIfidx() == 0 { - peer.RUnlock() + peer.endpoint.Unlock() break } nlmsg := struct { @@ -188,10 +188,10 @@ func (device *Device) routineRouteListener(bind conn.Bind, netlinkSock int, netl reqPeerLock.Lock() reqPeer[i] = peerEndpointPtr{ peer: peer, - endpoint: &peer.endpoint, + endpoint: &peer.endpoint.val, } reqPeerLock.Unlock() - peer.RUnlock() + peer.endpoint.Unlock() i++ _, err := netlinkCancel.Write((*[unsafe.Sizeof(nlmsg)]byte)(unsafe.Pointer(&nlmsg))[:]) if err != nil { diff --git a/device/timers.go b/device/timers.go index e28732c..d4a4ed4 100644 --- a/device/timers.go +++ b/device/timers.go @@ -100,11 +100,7 @@ func expiredRetransmitHandshake(peer *Peer) { peer.device.log.Verbosef("%s - Handshake did not complete after %d seconds, retrying (try %d)", peer, int(RekeyTimeout.Seconds()), peer.timers.handshakeAttempts.Load()+1) /* We clear the endpoint address src address, in case this is the cause of trouble. */ - peer.Lock() - if peer.endpoint != nil { - peer.endpoint.ClearSrc() - } - peer.Unlock() + peer.markEndpointSrcForClearing() peer.SendHandshakeInitiation(true) } @@ -123,11 +119,7 @@ func expiredSendKeepalive(peer *Peer) { func expiredNewHandshake(peer *Peer) { peer.device.log.Verbosef("%s - Retrying handshake because we stopped hearing back after %d seconds", peer, int((KeepaliveTimeout + RekeyTimeout).Seconds())) /* We clear the endpoint address src address, in case this is the cause of trouble. */ - peer.Lock() - if peer.endpoint != nil { - peer.endpoint.ClearSrc() - } - peer.Unlock() + peer.markEndpointSrcForClearing() peer.SendHandshakeInitiation(false) } diff --git a/device/uapi.go b/device/uapi.go index 617dcd3..d81dae3 100644 --- a/device/uapi.go +++ b/device/uapi.go @@ -99,33 +99,31 @@ func (device *Device) IpcGetOperation(w io.Writer) error { for _, peer := range device.peers.keyMap { // Serialize peer state. - // Do the work in an anonymous function so that we can use defer. - func() { - peer.RLock() - defer peer.RUnlock() - - keyf("public_key", (*[32]byte)(&peer.handshake.remoteStatic)) - keyf("preshared_key", (*[32]byte)(&peer.handshake.presharedKey)) - sendf("protocol_version=1") - if peer.endpoint != nil { - sendf("endpoint=%s", peer.endpoint.DstToString()) - } - - nano := peer.lastHandshakeNano.Load() - secs := nano / time.Second.Nanoseconds() - nano %= time.Second.Nanoseconds() - - sendf("last_handshake_time_sec=%d", secs) - sendf("last_handshake_time_nsec=%d", nano) - sendf("tx_bytes=%d", peer.txBytes.Load()) - sendf("rx_bytes=%d", peer.rxBytes.Load()) - sendf("persistent_keepalive_interval=%d", peer.persistentKeepaliveInterval.Load()) - - device.allowedips.EntriesForPeer(peer, func(prefix netip.Prefix) bool { - sendf("allowed_ip=%s", prefix.String()) - return true - }) - }() + peer.handshake.mutex.RLock() + keyf("public_key", (*[32]byte)(&peer.handshake.remoteStatic)) + keyf("preshared_key", (*[32]byte)(&peer.handshake.presharedKey)) + peer.handshake.mutex.RUnlock() + sendf("protocol_version=1") + peer.endpoint.Lock() + if peer.endpoint.val != nil { + sendf("endpoint=%s", peer.endpoint.val.DstToString()) + } + peer.endpoint.Unlock() + + nano := peer.lastHandshakeNano.Load() + secs := nano / time.Second.Nanoseconds() + nano %= time.Second.Nanoseconds() + + sendf("last_handshake_time_sec=%d", secs) + sendf("last_handshake_time_nsec=%d", nano) + sendf("tx_bytes=%d", peer.txBytes.Load()) + sendf("rx_bytes=%d", peer.rxBytes.Load()) + sendf("persistent_keepalive_interval=%d", peer.persistentKeepaliveInterval.Load()) + + device.allowedips.EntriesForPeer(peer, func(prefix netip.Prefix) bool { + sendf("allowed_ip=%s", prefix.String()) + return true + }) } }() @@ -262,7 +260,7 @@ func (peer *ipcSetPeer) handlePostConfig() { return } if peer.created { - peer.disableRoaming = peer.device.net.brokenRoaming && peer.endpoint != nil + peer.endpoint.disableRoaming = peer.device.net.brokenRoaming && peer.endpoint.val != nil } if peer.device.isUp() { peer.Start() @@ -345,9 +343,9 @@ func (device *Device) handlePeerLine(peer *ipcSetPeer, key, value string) error if err != nil { return ipcErrorf(ipc.IpcErrorInvalid, "failed to set endpoint %v: %w", value, err) } - peer.Lock() - defer peer.Unlock() - peer.endpoint = endpoint + peer.endpoint.Lock() + defer peer.endpoint.Unlock() + peer.endpoint.val = endpoint case "persistent_keepalive_interval": device.log.Verbosef("%v - UAPI: Updating persistent keepalive interval", peer.Peer) -- cgit v1.2.3