diff options
Diffstat (limited to 'pkg/tcpip/stack')
| -rw-r--r-- | pkg/tcpip/stack/nic.go | 54 | ||||
| -rw-r--r-- | pkg/tcpip/stack/stack.go | 66 |
2 files changed, 93 insertions, 27 deletions
diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go index b854d868c..ddc1ddab6 100644 --- a/pkg/tcpip/stack/nic.go +++ b/pkg/tcpip/stack/nic.go @@ -734,10 +734,29 @@ func (n *nic) DeliverNetworkPacket(remote, local tcpip.LinkAddress, protocol tcp n.mu.RUnlock() // Deliver to interested packet endpoints without holding NIC lock. + var packetEPPkt *PacketBuffer deliverPacketEPs := func(ep PacketEndpoint) { - p := pkt.Clone() - p.PktType = tcpip.PacketHost - ep.HandlePacket(n.id, local, protocol, p) + if packetEPPkt == nil { + // Packet endpoints hold the full packet. + // + // We perform a deep copy because higher-level endpoints may point to + // the middle of a view that is held by a packet endpoint. Save/Restore + // does not support overlapping slices and will panic in this case. + // + // TODO(https://gvisor.dev/issue/6517): Avoid this copy once S/R supports + // overlapping slices (e.g. by passing a shallow copy of pkt to the packet + // endpoint). + packetEPPkt = NewPacketBuffer(PacketBufferOptions{ + Data: PayloadSince(pkt.LinkHeader()).ToVectorisedView(), + }) + // If a link header was populated in the original packet buffer, then + // populate it in the packet buffer we provide to packet endpoints as + // packet endpoints inspect link headers. + packetEPPkt.LinkHeader().Consume(pkt.LinkHeader().View().Size()) + packetEPPkt.PktType = tcpip.PacketHost + } + + ep.HandlePacket(n.id, local, protocol, packetEPPkt.Clone()) } if protoEPs != nil { protoEPs.forEach(deliverPacketEPs) @@ -758,13 +777,30 @@ func (n *nic) DeliverOutboundPacket(remote, local tcpip.LinkAddress, protocol tc eps := n.mu.packetEPs[header.EthernetProtocolAll] n.mu.RUnlock() + var packetEPPkt *PacketBuffer 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) + if packetEPPkt == nil { + // Packet endpoints hold the full packet. + // + // We perform a deep copy because higher-level endpoints may point to + // the middle of a view that is held by a packet endpoint. Save/Restore + // does not support overlapping slices and will panic in this case. + // + // TODO(https://gvisor.dev/issue/6517): Avoid this copy once S/R supports + // overlapping slices (e.g. by passing a shallow copy of pkt to the packet + // endpoint). + packetEPPkt = NewPacketBuffer(PacketBufferOptions{ + ReserveHeaderBytes: pkt.AvailableHeaderBytes(), + Data: PayloadSince(pkt.NetworkHeader()).ToVectorisedView(), + }) + // Add the link layer header as outgoing packets are intercepted before + // the link layer header is created and packet endpoints are interested + // in the link header. + n.LinkEndpoint.AddHeader(local, remote, protocol, packetEPPkt) + packetEPPkt.PktType = tcpip.PacketOutgoing + } + + ep.HandlePacket(n.id, local, protocol, packetEPPkt.Clone()) }) } diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go index cfa8a2e8f..cb741e540 100644 --- a/pkg/tcpip/stack/stack.go +++ b/pkg/tcpip/stack/stack.go @@ -72,7 +72,8 @@ type Stack struct { // rawFactory creates raw endpoints. If nil, raw endpoints are // disabled. It is set during Stack creation and is immutable. - rawFactory RawFactory + rawFactory RawFactory + packetEndpointWriteSupported bool demux *transportDemuxer @@ -218,6 +219,10 @@ type Options struct { // this is non-nil. RawFactory RawFactory + // AllowPacketEndpointWrite determines if packet endpoints support write + // operations. + AllowPacketEndpointWrite bool + // RandSource is an optional source to use to generate random // numbers. If omitted it defaults to a Source seeded by the data // returned by the stack secure RNG. @@ -359,23 +364,24 @@ func New(opts Options) *Stack { opts.NUDConfigs.resetInvalidFields() s := &Stack{ - transportProtocols: make(map[tcpip.TransportProtocolNumber]*transportProtocolState), - networkProtocols: make(map[tcpip.NetworkProtocolNumber]NetworkProtocol), - nics: make(map[tcpip.NICID]*nic), - defaultForwardingEnabled: make(map[tcpip.NetworkProtocolNumber]struct{}), - cleanupEndpoints: make(map[TransportEndpoint]struct{}), - PortManager: ports.NewPortManager(), - clock: clock, - stats: opts.Stats.FillIn(), - handleLocal: opts.HandleLocal, - tables: opts.IPTables, - icmpRateLimiter: NewICMPRateLimiter(), - seed: seed, - nudConfigs: opts.NUDConfigs, - uniqueIDGenerator: opts.UniqueID, - nudDisp: opts.NUDDisp, - randomGenerator: randomGenerator, - secureRNG: opts.SecureRNG, + transportProtocols: make(map[tcpip.TransportProtocolNumber]*transportProtocolState), + networkProtocols: make(map[tcpip.NetworkProtocolNumber]NetworkProtocol), + nics: make(map[tcpip.NICID]*nic), + packetEndpointWriteSupported: opts.AllowPacketEndpointWrite, + defaultForwardingEnabled: make(map[tcpip.NetworkProtocolNumber]struct{}), + cleanupEndpoints: make(map[TransportEndpoint]struct{}), + PortManager: ports.NewPortManager(), + clock: clock, + stats: opts.Stats.FillIn(), + handleLocal: opts.HandleLocal, + tables: opts.IPTables, + icmpRateLimiter: NewICMPRateLimiter(), + seed: seed, + nudConfigs: opts.NUDConfigs, + uniqueIDGenerator: opts.UniqueID, + nudDisp: opts.NUDDisp, + randomGenerator: randomGenerator, + secureRNG: opts.SecureRNG, sendBufferSize: tcpip.SendBufferSizeOption{ Min: MinBufferSize, Default: DefaultBufferSize, @@ -1653,9 +1659,27 @@ func (s *Stack) WritePacketToRemote(nicID tcpip.NICID, remote tcpip.LinkAddress, ReserveHeaderBytes: int(nic.MaxHeaderLength()), Data: payload, }) + pkt.NetworkProtocolNumber = netProto return nic.WritePacketToRemote(remote, netProto, pkt) } +// WriteRawPacket writes data directly to the specified NIC without adding any +// headers. +func (s *Stack) WriteRawPacket(nicID tcpip.NICID, proto tcpip.NetworkProtocolNumber, payload buffer.VectorisedView) tcpip.Error { + s.mu.RLock() + nic, ok := s.nics[nicID] + s.mu.RUnlock() + if !ok { + return &tcpip.ErrUnknownNICID{} + } + + pkt := NewPacketBuffer(PacketBufferOptions{ + Data: payload, + }) + pkt.NetworkProtocolNumber = proto + return nic.WriteRawPacket(pkt) +} + // NetworkProtocolInstance returns the protocol instance in the stack for the // specified network protocol. This method is public for protocol implementers // and tests to use. @@ -1947,3 +1971,9 @@ func (s *Stack) IsSubnetBroadcast(nicID tcpip.NICID, protocol tcpip.NetworkProto return false } + +// PacketEndpointWriteSupported returns true iff packet endpoints support write +// operations. +func (s *Stack) PacketEndpointWriteSupported() bool { + return s.packetEndpointWriteSupported +} |