diff options
Diffstat (limited to 'pkg/tcpip/stack/stack_test.go')
| -rw-r--r-- | pkg/tcpip/stack/stack_test.go | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/pkg/tcpip/stack/stack_test.go b/pkg/tcpip/stack/stack_test.go index 101ca2206..f22062889 100644 --- a/pkg/tcpip/stack/stack_test.go +++ b/pkg/tcpip/stack/stack_test.go @@ -27,6 +27,7 @@ import ( "time" "github.com/google/go-cmp/cmp" + "github.com/google/go-cmp/cmp/cmpopts" "gvisor.dev/gvisor/pkg/rand" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/buffer" @@ -3418,3 +3419,225 @@ func TestStackSendBufferSizeOption(t *testing.T) { }) } } + +func TestOutgoingSubnetBroadcast(t *testing.T) { + const ( + unspecifiedNICID = 0 + nicID1 = 1 + ) + + defaultAddr := tcpip.AddressWithPrefix{ + Address: header.IPv4Any, + PrefixLen: 0, + } + defaultSubnet := defaultAddr.Subnet() + ipv4Addr := tcpip.AddressWithPrefix{ + Address: "\xc0\xa8\x01\x3a", + PrefixLen: 24, + } + ipv4Subnet := ipv4Addr.Subnet() + ipv4SubnetBcast := ipv4Subnet.Broadcast() + ipv4Gateway := tcpip.Address("\xc0\xa8\x01\x01") + ipv4AddrPrefix31 := tcpip.AddressWithPrefix{ + Address: "\xc0\xa8\x01\x3a", + PrefixLen: 31, + } + ipv4Subnet31 := ipv4AddrPrefix31.Subnet() + ipv4Subnet31Bcast := ipv4Subnet31.Broadcast() + ipv4AddrPrefix32 := tcpip.AddressWithPrefix{ + Address: "\xc0\xa8\x01\x3a", + PrefixLen: 32, + } + ipv4Subnet32 := ipv4AddrPrefix32.Subnet() + ipv4Subnet32Bcast := ipv4Subnet32.Broadcast() + ipv6Addr := tcpip.AddressWithPrefix{ + Address: "\x20\x0a\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01", + PrefixLen: 64, + } + ipv6Subnet := ipv6Addr.Subnet() + ipv6SubnetBcast := ipv6Subnet.Broadcast() + remNetAddr := tcpip.AddressWithPrefix{ + Address: "\x64\x0a\x7b\x18", + PrefixLen: 24, + } + remNetSubnet := remNetAddr.Subnet() + remNetSubnetBcast := remNetSubnet.Broadcast() + + tests := []struct { + name string + nicAddr tcpip.ProtocolAddress + routes []tcpip.Route + remoteAddr tcpip.Address + expectedRoute stack.Route + }{ + // Broadcast to a locally attached subnet populates the broadcast MAC. + { + name: "IPv4 Broadcast to local subnet", + nicAddr: tcpip.ProtocolAddress{ + Protocol: header.IPv4ProtocolNumber, + AddressWithPrefix: ipv4Addr, + }, + routes: []tcpip.Route{ + { + Destination: ipv4Subnet, + NIC: nicID1, + }, + }, + remoteAddr: ipv4SubnetBcast, + expectedRoute: stack.Route{ + LocalAddress: ipv4Addr.Address, + RemoteAddress: ipv4SubnetBcast, + RemoteLinkAddress: header.EthernetBroadcastAddress, + NetProto: header.IPv4ProtocolNumber, + Loop: stack.PacketOut, + }, + }, + // Broadcast to a locally attached /31 subnet does not populate the + // broadcast MAC. + { + name: "IPv4 Broadcast to local /31 subnet", + nicAddr: tcpip.ProtocolAddress{ + Protocol: header.IPv4ProtocolNumber, + AddressWithPrefix: ipv4AddrPrefix31, + }, + routes: []tcpip.Route{ + { + Destination: ipv4Subnet31, + NIC: nicID1, + }, + }, + remoteAddr: ipv4Subnet31Bcast, + expectedRoute: stack.Route{ + LocalAddress: ipv4AddrPrefix31.Address, + RemoteAddress: ipv4Subnet31Bcast, + NetProto: header.IPv4ProtocolNumber, + Loop: stack.PacketOut, + }, + }, + // Broadcast to a locally attached /32 subnet does not populate the + // broadcast MAC. + { + name: "IPv4 Broadcast to local /32 subnet", + nicAddr: tcpip.ProtocolAddress{ + Protocol: header.IPv4ProtocolNumber, + AddressWithPrefix: ipv4AddrPrefix32, + }, + routes: []tcpip.Route{ + { + Destination: ipv4Subnet32, + NIC: nicID1, + }, + }, + remoteAddr: ipv4Subnet32Bcast, + expectedRoute: stack.Route{ + LocalAddress: ipv4AddrPrefix32.Address, + RemoteAddress: ipv4Subnet32Bcast, + NetProto: header.IPv4ProtocolNumber, + Loop: stack.PacketOut, + }, + }, + // IPv6 has no notion of a broadcast. + { + name: "IPv6 'Broadcast' to local subnet", + nicAddr: tcpip.ProtocolAddress{ + Protocol: header.IPv6ProtocolNumber, + AddressWithPrefix: ipv6Addr, + }, + routes: []tcpip.Route{ + { + Destination: ipv6Subnet, + NIC: nicID1, + }, + }, + remoteAddr: ipv6SubnetBcast, + expectedRoute: stack.Route{ + LocalAddress: ipv6Addr.Address, + RemoteAddress: ipv6SubnetBcast, + NetProto: header.IPv6ProtocolNumber, + Loop: stack.PacketOut, + }, + }, + // Broadcast to a remote subnet in the route table is send to the next-hop + // gateway. + { + name: "IPv4 Broadcast to remote subnet", + nicAddr: tcpip.ProtocolAddress{ + Protocol: header.IPv4ProtocolNumber, + AddressWithPrefix: ipv4Addr, + }, + routes: []tcpip.Route{ + { + Destination: remNetSubnet, + Gateway: ipv4Gateway, + NIC: nicID1, + }, + }, + remoteAddr: remNetSubnetBcast, + expectedRoute: stack.Route{ + LocalAddress: ipv4Addr.Address, + RemoteAddress: remNetSubnetBcast, + NextHop: ipv4Gateway, + NetProto: header.IPv4ProtocolNumber, + Loop: stack.PacketOut, + }, + }, + // Broadcast to an unknown subnet follows the default route. Note that this + // is essentially just routing an unknown destination IP, because w/o any + // subnet prefix information a subnet broadcast address is just a normal IP. + { + name: "IPv4 Broadcast to unknown subnet", + nicAddr: tcpip.ProtocolAddress{ + Protocol: header.IPv4ProtocolNumber, + AddressWithPrefix: ipv4Addr, + }, + routes: []tcpip.Route{ + { + Destination: defaultSubnet, + Gateway: ipv4Gateway, + NIC: nicID1, + }, + }, + remoteAddr: remNetSubnetBcast, + expectedRoute: stack.Route{ + LocalAddress: ipv4Addr.Address, + RemoteAddress: remNetSubnetBcast, + NextHop: ipv4Gateway, + NetProto: header.IPv4ProtocolNumber, + Loop: stack.PacketOut, + }, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + s := stack.New(stack.Options{ + NetworkProtocols: []stack.NetworkProtocol{ipv4.NewProtocol(), ipv6.NewProtocol()}, + }) + ep := channel.New(0, defaultMTU, "") + if err := s.CreateNIC(nicID1, ep); err != nil { + t.Fatalf("CreateNIC(%d, _): %s", nicID1, err) + } + if err := s.AddProtocolAddress(nicID1, test.nicAddr); err != nil { + t.Fatalf("AddProtocolAddress(%d, %+v): %s", nicID1, test.nicAddr, err) + } + + s.SetRouteTable(test.routes) + + var netProto tcpip.NetworkProtocolNumber + switch l := len(test.remoteAddr); l { + case header.IPv4AddressSize: + netProto = header.IPv4ProtocolNumber + case header.IPv6AddressSize: + netProto = header.IPv6ProtocolNumber + default: + t.Fatalf("got unexpected address length = %d bytes", l) + } + + if r, err := s.FindRoute(unspecifiedNICID, "" /* localAddr */, test.remoteAddr, netProto, false /* multicastLoop */); err != nil { + t.Fatalf("FindRoute(%d, '', %s, %d): %s", unspecifiedNICID, test.remoteAddr, netProto, err) + } else if diff := cmp.Diff(r, test.expectedRoute, cmpopts.IgnoreUnexported(r)); diff != "" { + t.Errorf("route mismatch (-want +got):\n%s", diff) + } + }) + } +} |