diff options
author | Ghanan Gowripalan <ghanan@google.com> | 2020-10-16 13:51:55 -0700 |
---|---|---|
committer | gVisor bot <gvisor-bot@google.com> | 2020-10-16 13:54:00 -0700 |
commit | dffa4c66909f034429e933f204cd49655c3e224f (patch) | |
tree | 87c78e09910fa8ec330b144ca92b6b93e06fba8e /pkg/tcpip/link/pipe | |
parent | 4d27f33b09932a7f6cc5ccb03ad6f7462d497afb (diff) |
Don't include link header when forwarding packets
Before this change, if a link header was included in an incoming packet
that is forwarded, the packet that gets sent out will take the original
packet and add a link header to it while keeping the old link header.
This would make the sent packet look like:
OUTGOING LINK HDR | INCOMING LINK HDR | NETWORK HDR | ...
Obviously this is incorrect as we should drop the incoming link header
and only include the outgoing link header. This change fixes this bug.
Test: integration_test.TestForwarding
PiperOrigin-RevId: 337571447
Diffstat (limited to 'pkg/tcpip/link/pipe')
-rw-r--r-- | pkg/tcpip/link/pipe/pipe.go | 39 |
1 files changed, 15 insertions, 24 deletions
diff --git a/pkg/tcpip/link/pipe/pipe.go b/pkg/tcpip/link/pipe/pipe.go index 76f563811..523b0d24b 100644 --- a/pkg/tcpip/link/pipe/pipe.go +++ b/pkg/tcpip/link/pipe/pipe.go @@ -26,27 +26,23 @@ import ( var _ stack.LinkEndpoint = (*Endpoint)(nil) // New returns both ends of a new pipe. -func New(linkAddr1, linkAddr2 tcpip.LinkAddress, capabilities stack.LinkEndpointCapabilities) (*Endpoint, *Endpoint) { +func New(linkAddr1, linkAddr2 tcpip.LinkAddress) (*Endpoint, *Endpoint) { ep1 := &Endpoint{ - linkAddr: linkAddr1, - capabilities: capabilities, + linkAddr: linkAddr1, } ep2 := &Endpoint{ - linkAddr: linkAddr2, - linked: ep1, - capabilities: capabilities, + linkAddr: linkAddr2, } ep1.linked = ep2 + ep2.linked = ep1 return ep1, ep2 } // Endpoint is one end of a pipe. type Endpoint struct { - capabilities stack.LinkEndpointCapabilities - linkAddr tcpip.LinkAddress - dispatcher stack.NetworkDispatcher - linked *Endpoint - onWritePacket func(*stack.PacketBuffer) + dispatcher stack.NetworkDispatcher + linked *Endpoint + linkAddr tcpip.LinkAddress } // WritePacket implements stack.LinkEndpoint. @@ -55,16 +51,11 @@ func (e *Endpoint) WritePacket(r *stack.Route, _ *stack.GSO, proto tcpip.Network return nil } - // The pipe endpoint will accept all multicast/broadcast link traffic and only - // unicast traffic destined to itself. - if len(e.linked.linkAddr) != 0 && - r.RemoteLinkAddress != e.linked.linkAddr && - r.RemoteLinkAddress != header.EthernetBroadcastAddress && - !header.IsMulticastEthernetAddress(r.RemoteLinkAddress) { - return nil - } - - e.linked.dispatcher.DeliverNetworkPacket(e.linkAddr, r.RemoteLinkAddress, proto, stack.NewPacketBuffer(stack.PacketBufferOptions{ + // Note that the local address from the perspective of this endpoint is the + // remote address from the perspective of the other end of the pipe + // (e.linked). Similarly, the remote address from the perspective of this + // endpoint is the local address on the other end. + e.linked.dispatcher.DeliverNetworkPacket(r.LocalLinkAddress /* remote */, r.RemoteLinkAddress /* local */, proto, stack.NewPacketBuffer(stack.PacketBufferOptions{ Data: buffer.NewVectorisedView(pkt.Size(), pkt.Views()), })) @@ -100,8 +91,8 @@ func (*Endpoint) MTU() uint32 { } // Capabilities implements stack.LinkEndpoint. -func (e *Endpoint) Capabilities() stack.LinkEndpointCapabilities { - return e.capabilities +func (*Endpoint) Capabilities() stack.LinkEndpointCapabilities { + return 0 } // MaxHeaderLength implements stack.LinkEndpoint. @@ -116,7 +107,7 @@ func (e *Endpoint) LinkAddress() tcpip.LinkAddress { // ARPHardwareType implements stack.LinkEndpoint. func (*Endpoint) ARPHardwareType() header.ARPHardwareType { - return header.ARPHardwareEther + return header.ARPHardwareNone } // AddHeader implements stack.LinkEndpoint. |