diff options
| -rw-r--r-- | pkg/tcpip/stack/nic.go | 18 | ||||
| -rw-r--r-- | pkg/tcpip/stack/stack_test.go | 112 |
2 files changed, 87 insertions, 43 deletions
diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go index 3cd5fec71..230ee0697 100644 --- a/pkg/tcpip/stack/nic.go +++ b/pkg/tcpip/stack/nic.go @@ -15,6 +15,7 @@ package stack import ( + "fmt" "log" "reflect" "sort" @@ -1259,9 +1260,24 @@ func (n *NIC) DeliverNetworkPacket(linkEP LinkEndpoint, remote, local tcpip.Link func (n *NIC) forwardPacket(r *Route, protocol tcpip.NetworkProtocolNumber, pkt tcpip.PacketBuffer) { // TODO(b/143425874) Decrease the TTL field in forwarded packets. - pkt.Header = buffer.NewPrependableFromView(pkt.Data.First()) + + firstData := pkt.Data.First() pkt.Data.RemoveFirst() + if linkHeaderLen := int(n.linkEP.MaxHeaderLength()); linkHeaderLen == 0 { + pkt.Header = buffer.NewPrependableFromView(firstData) + } else { + firstDataLen := len(firstData) + + // pkt.Header should have enough capacity to hold n.linkEP's headers. + pkt.Header = buffer.NewPrependable(firstDataLen + linkHeaderLen) + + // TODO(b/151227689): avoid copying the packet when forwarding + if n := copy(pkt.Header.Prepend(firstDataLen), firstData); n != firstDataLen { + panic(fmt.Sprintf("copied %d bytes, expected %d", n, firstDataLen)) + } + } + if err := n.linkEP.WritePacket(r, nil /* gso */, protocol, pkt); err != nil { r.Stats().IP.OutgoingPacketErrors.Increment() return diff --git a/pkg/tcpip/stack/stack_test.go b/pkg/tcpip/stack/stack_test.go index e15db40fb..9515426d6 100644 --- a/pkg/tcpip/stack/stack_test.go +++ b/pkg/tcpip/stack/stack_test.go @@ -2240,56 +2240,84 @@ func TestNICStats(t *testing.T) { } func TestNICForwarding(t *testing.T) { - // Create a stack with the fake network protocol, two NICs, each with - // an address. - s := stack.New(stack.Options{ - NetworkProtocols: []stack.NetworkProtocol{fakeNetFactory()}, - }) - s.SetForwarding(true) + const nicID1 = 1 + const nicID2 = 2 + const dstAddr = tcpip.Address("\x03") - ep1 := channel.New(10, defaultMTU, "") - if err := s.CreateNIC(1, ep1); err != nil { - t.Fatal("CreateNIC #1 failed:", err) - } - if err := s.AddAddress(1, fakeNetNumber, "\x01"); err != nil { - t.Fatal("AddAddress #1 failed:", err) + tests := []struct { + name string + headerLen uint16 + }{ + { + name: "Zero header length", + }, + { + name: "Non-zero header length", + headerLen: 16, + }, } - ep2 := channel.New(10, defaultMTU, "") - if err := s.CreateNIC(2, ep2); err != nil { - t.Fatal("CreateNIC #2 failed:", err) - } - if err := s.AddAddress(2, fakeNetNumber, "\x02"); err != nil { - t.Fatal("AddAddress #2 failed:", err) - } + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + s := stack.New(stack.Options{ + NetworkProtocols: []stack.NetworkProtocol{fakeNetFactory()}, + }) + s.SetForwarding(true) - // Route all packets to address 3 to NIC 2. - { - subnet, err := tcpip.NewSubnet("\x03", "\xff") - if err != nil { - t.Fatal(err) - } - s.SetRouteTable([]tcpip.Route{{Destination: subnet, Gateway: "\x00", NIC: 2}}) - } + ep1 := channel.New(10, defaultMTU, "") + if err := s.CreateNIC(nicID1, ep1); err != nil { + t.Fatalf("CreateNIC(%d, _): %s", nicID1, err) + } + if err := s.AddAddress(nicID1, fakeNetNumber, "\x01"); err != nil { + t.Fatalf("AddAddress(%d, %d, 0x01): %s", nicID1, fakeNetNumber, err) + } - // Send a packet to address 3. - buf := buffer.NewView(30) - buf[0] = 3 - ep1.InjectInbound(fakeNetNumber, tcpip.PacketBuffer{ - Data: buf.ToVectorisedView(), - }) + ep2 := channelLinkWithHeaderLength{ + Endpoint: channel.New(10, defaultMTU, ""), + headerLength: test.headerLen, + } + if err := s.CreateNIC(nicID2, &ep2); err != nil { + t.Fatalf("CreateNIC(%d, _): %s", nicID2, err) + } + if err := s.AddAddress(nicID2, fakeNetNumber, "\x02"); err != nil { + t.Fatalf("AddAddress(%d, %d, 0x02): %s", nicID2, fakeNetNumber, err) + } - if _, ok := ep2.Read(); !ok { - t.Fatal("Packet not forwarded") - } + // Route all packets to dstAddr to NIC 2. + { + subnet, err := tcpip.NewSubnet(dstAddr, "\xff") + if err != nil { + t.Fatal(err) + } + s.SetRouteTable([]tcpip.Route{{Destination: subnet, Gateway: "\x00", NIC: nicID2}}) + } - // Test that forwarding increments Tx stats correctly. - if got, want := s.NICInfo()[2].Stats.Tx.Packets.Value(), uint64(1); got != want { - t.Errorf("got Tx.Packets.Value() = %d, want = %d", got, want) - } + // Send a packet to dstAddr. + buf := buffer.NewView(30) + buf[0] = dstAddr[0] + ep1.InjectInbound(fakeNetNumber, tcpip.PacketBuffer{ + Data: buf.ToVectorisedView(), + }) - if got, want := s.NICInfo()[2].Stats.Tx.Bytes.Value(), uint64(len(buf)); got != want { - t.Errorf("got Tx.Bytes.Value() = %d, want = %d", got, want) + pkt, ok := ep2.Read() + if !ok { + t.Fatal("packet not forwarded") + } + + // Test that the link's MaxHeaderLength is honoured. + if capacity, want := pkt.Pkt.Header.AvailableLength(), int(test.headerLen); capacity != want { + t.Errorf("got Header.AvailableLength() = %d, want = %d", capacity, want) + } + + // Test that forwarding increments Tx stats correctly. + if got, want := s.NICInfo()[nicID2].Stats.Tx.Packets.Value(), uint64(1); got != want { + t.Errorf("got Tx.Packets.Value() = %d, want = %d", got, want) + } + + if got, want := s.NICInfo()[nicID2].Stats.Tx.Bytes.Value(), uint64(len(buf)); got != want { + t.Errorf("got Tx.Bytes.Value() = %d, want = %d", got, want) + } + }) } } |