diff options
Diffstat (limited to 'pkg/tcpip/stack/nic.go')
| -rw-r--r-- | pkg/tcpip/stack/nic.go | 78 |
1 files changed, 57 insertions, 21 deletions
diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go index a6237dd5f..5d037a27e 100644 --- a/pkg/tcpip/stack/nic.go +++ b/pkg/tcpip/stack/nic.go @@ -54,9 +54,9 @@ type NIC struct { sync.RWMutex spoofing bool promiscuous bool - // packetEPs is protected by mu, but the contained PacketEndpoint - // values are not. - packetEPs map[tcpip.NetworkProtocolNumber][]PacketEndpoint + // packetEPs is protected by mu, but the contained packetEndpointList are + // not. + packetEPs map[tcpip.NetworkProtocolNumber]*packetEndpointList } } @@ -82,6 +82,39 @@ type DirectionStats struct { Bytes *tcpip.StatCounter } +type packetEndpointList struct { + mu sync.RWMutex + + // eps is protected by mu, but the contained PacketEndpoint values are not. + eps []PacketEndpoint +} + +func (p *packetEndpointList) add(ep PacketEndpoint) { + p.mu.Lock() + defer p.mu.Unlock() + p.eps = append(p.eps, ep) +} + +func (p *packetEndpointList) remove(ep PacketEndpoint) { + p.mu.Lock() + defer p.mu.Unlock() + for i, epOther := range p.eps { + if epOther == ep { + p.eps = append(p.eps[:i], p.eps[i+1:]...) + break + } + } +} + +// forEach calls fn with each endpoints in p while holding the read lock on p. +func (p *packetEndpointList) forEach(fn func(PacketEndpoint)) { + p.mu.RLock() + defer p.mu.RUnlock() + for _, ep := range p.eps { + fn(ep) + } +} + // newNIC returns a new NIC using the default NDP configurations from stack. func newNIC(stack *Stack, id tcpip.NICID, name string, ep LinkEndpoint, ctx NICContext) *NIC { // TODO(b/141011931): Validate a LinkEndpoint (ep) is valid. For @@ -102,7 +135,7 @@ func newNIC(stack *Stack, id tcpip.NICID, name string, ep LinkEndpoint, ctx NICC stats: makeNICStats(), networkEndpoints: make(map[tcpip.NetworkProtocolNumber]NetworkEndpoint), } - nic.mu.packetEPs = make(map[tcpip.NetworkProtocolNumber][]PacketEndpoint) + nic.mu.packetEPs = make(map[tcpip.NetworkProtocolNumber]*packetEndpointList) // Check for Neighbor Unreachability Detection support. var nud NUDHandler @@ -125,11 +158,11 @@ func newNIC(stack *Stack, id tcpip.NICID, name string, ep LinkEndpoint, ctx NICC // Register supported packet and network endpoint protocols. for _, netProto := range header.Ethertypes { - nic.mu.packetEPs[netProto] = []PacketEndpoint{} + nic.mu.packetEPs[netProto] = new(packetEndpointList) } for _, netProto := range stack.networkProtocols { netNum := netProto.Number() - nic.mu.packetEPs[netNum] = nil + nic.mu.packetEPs[netNum] = new(packetEndpointList) nic.networkEndpoints[netNum] = netProto.NewEndpoint(nic, stack, nud, nic) } @@ -638,15 +671,23 @@ func (n *NIC) DeliverNetworkPacket(remote, local tcpip.LinkAddress, protocol tcp pkt.RXTransportChecksumValidated = n.LinkEndpoint.Capabilities()&CapabilityRXChecksumOffload != 0 // Are any packet type sockets listening for this network protocol? - packetEPs := n.mu.packetEPs[protocol] - // Add any other packet type sockets that may be listening for all protocols. - packetEPs = append(packetEPs, n.mu.packetEPs[header.EthernetProtocolAll]...) + protoEPs := n.mu.packetEPs[protocol] + // Other packet type sockets that are listening for all protocols. + anyEPs := n.mu.packetEPs[header.EthernetProtocolAll] n.mu.RUnlock() - for _, ep := range packetEPs { + + // Deliver to interested packet endpoints without holding NIC lock. + deliverPacketEPs := func(ep PacketEndpoint) { p := pkt.Clone() p.PktType = tcpip.PacketHost ep.HandlePacket(n.id, local, protocol, p) } + if protoEPs != nil { + protoEPs.forEach(deliverPacketEPs) + } + if anyEPs != nil { + anyEPs.forEach(deliverPacketEPs) + } // Parse headers. netProto := n.stack.NetworkProtocolInstance(protocol) @@ -687,16 +728,17 @@ func (n *NIC) DeliverOutboundPacket(remote, local tcpip.LinkAddress, protocol tc // We do not deliver to protocol specific packet endpoints as on Linux // only ETH_P_ALL endpoints get outbound packets. // Add any other packet sockets that maybe listening for all protocols. - packetEPs := n.mu.packetEPs[header.EthernetProtocolAll] + eps := n.mu.packetEPs[header.EthernetProtocolAll] n.mu.RUnlock() - for _, ep := range packetEPs { + + eps.forEach(func(ep PacketEndpoint) { p := pkt.Clone() p.PktType = tcpip.PacketOutgoing // Add the link layer header as outgoing packets are intercepted // before the link layer header is created. n.LinkEndpoint.AddHeader(local, remote, protocol, p) ep.HandlePacket(n.id, local, protocol, p) - } + }) } // DeliverTransportPacket delivers the packets to the appropriate transport @@ -849,7 +891,7 @@ func (n *NIC) registerPacketEndpoint(netProto tcpip.NetworkProtocolNumber, ep Pa if !ok { return tcpip.ErrNotSupported } - n.mu.packetEPs[netProto] = append(eps, ep) + eps.add(ep) return nil } @@ -862,13 +904,7 @@ func (n *NIC) unregisterPacketEndpoint(netProto tcpip.NetworkProtocolNumber, ep if !ok { return } - - for i, epOther := range eps { - if epOther == ep { - n.mu.packetEPs[netProto] = append(eps[:i], eps[i+1:]...) - return - } - } + eps.remove(ep) } // isValidForOutgoing returns true if the endpoint can be used to send out a |