From 339d266be4b2043b01ab0db43cafc36785e9978b Mon Sep 17 00:00:00 2001 From: Ghanan Gowripalan Date: Mon, 24 Aug 2020 12:27:01 -0700 Subject: Consider loopback bound to all addresses in subnet When a loopback interface is configurd with an address and associated subnet, the loopback should treat all addresses in that subnet as an address it owns. This is mimicking linux behaviour as seen below: ``` $ ip addr show dev lo 1: lo: mtu 65536 qdisc noqueue state UNKNOWN group ... link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever $ ping 192.0.2.1 PING 192.0.2.1 (192.0.2.1) 56(84) bytes of data. ^C --- 192.0.2.1 ping statistics --- 2 packets transmitted, 0 received, 100% packet loss, time 1018ms $ ping 192.0.2.2 PING 192.0.2.2 (192.0.2.2) 56(84) bytes of data. ^C --- 192.0.2.2 ping statistics --- 3 packets transmitted, 0 received, 100% packet loss, time 2039ms $ sudo ip addr add 192.0.2.1/24 dev lo $ ip addr show dev lo 1: lo: mtu 65536 qdisc noqueue state UNKNOWN group ... link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet 192.0.2.1/24 scope global lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever $ ping 192.0.2.1 PING 192.0.2.1 (192.0.2.1) 56(84) bytes of data. 64 bytes from 192.0.2.1: icmp_seq=1 ttl=64 time=0.131 ms 64 bytes from 192.0.2.1: icmp_seq=2 ttl=64 time=0.046 ms 64 bytes from 192.0.2.1: icmp_seq=3 ttl=64 time=0.048 ms ^C --- 192.0.2.1 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2042ms rtt min/avg/max/mdev = 0.046/0.075/0.131/0.039 ms $ ping 192.0.2.2 PING 192.0.2.2 (192.0.2.2) 56(84) bytes of data. 64 bytes from 192.0.2.2: icmp_seq=1 ttl=64 time=0.131 ms 64 bytes from 192.0.2.2: icmp_seq=2 ttl=64 time=0.069 ms 64 bytes from 192.0.2.2: icmp_seq=3 ttl=64 time=0.049 ms 64 bytes from 192.0.2.2: icmp_seq=4 ttl=64 time=0.035 ms ^C --- 192.0.2.2 ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 3049ms rtt min/avg/max/mdev = 0.035/0.071/0.131/0.036 ms ``` Test: integration_test.TestLoopbackAcceptAllInSubnet PiperOrigin-RevId: 328188546 --- pkg/tcpip/tests/integration/BUILD | 6 +- pkg/tcpip/tests/integration/loopback_test.go | 229 +++++++++++++++++++++ .../tests/integration/multicast_broadcast_test.go | 2 +- 3 files changed, 235 insertions(+), 2 deletions(-) create mode 100644 pkg/tcpip/tests/integration/loopback_test.go (limited to 'pkg/tcpip/tests/integration') diff --git a/pkg/tcpip/tests/integration/BUILD b/pkg/tcpip/tests/integration/BUILD index 6d52af98a..06c7a3cd3 100644 --- a/pkg/tcpip/tests/integration/BUILD +++ b/pkg/tcpip/tests/integration/BUILD @@ -5,12 +5,16 @@ package(licenses = ["notice"]) go_test( name = "integration_test", size = "small", - srcs = ["multicast_broadcast_test.go"], + srcs = [ + "loopback_test.go", + "multicast_broadcast_test.go", + ], deps = [ "//pkg/tcpip", "//pkg/tcpip/buffer", "//pkg/tcpip/header", "//pkg/tcpip/link/channel", + "//pkg/tcpip/link/loopback", "//pkg/tcpip/network/ipv4", "//pkg/tcpip/network/ipv6", "//pkg/tcpip/stack", diff --git a/pkg/tcpip/tests/integration/loopback_test.go b/pkg/tcpip/tests/integration/loopback_test.go new file mode 100644 index 000000000..3a2f75837 --- /dev/null +++ b/pkg/tcpip/tests/integration/loopback_test.go @@ -0,0 +1,229 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package integration_test + +import ( + "testing" + + "github.com/google/go-cmp/cmp" + "gvisor.dev/gvisor/pkg/tcpip" + "gvisor.dev/gvisor/pkg/tcpip/buffer" + "gvisor.dev/gvisor/pkg/tcpip/header" + "gvisor.dev/gvisor/pkg/tcpip/link/loopback" + "gvisor.dev/gvisor/pkg/tcpip/network/ipv4" + "gvisor.dev/gvisor/pkg/tcpip/network/ipv6" + "gvisor.dev/gvisor/pkg/tcpip/stack" + "gvisor.dev/gvisor/pkg/tcpip/transport/udp" + "gvisor.dev/gvisor/pkg/waiter" +) + +// TestLoopbackAcceptAllInSubnet tests that a loopback interface considers +// itself bound to all addresses in the subnet of an assigned address. +func TestLoopbackAcceptAllInSubnet(t *testing.T) { + const ( + nicID = 1 + localPort = 80 + ) + + data := []byte{1, 2, 3, 4} + + ipv4ProtocolAddress := tcpip.ProtocolAddress{ + Protocol: header.IPv4ProtocolNumber, + AddressWithPrefix: ipv4Addr, + } + ipv4Bytes := []byte(ipv4Addr.Address) + ipv4Bytes[len(ipv4Bytes)-1]++ + otherIPv4Address := tcpip.Address(ipv4Bytes) + + ipv6ProtocolAddress := tcpip.ProtocolAddress{ + Protocol: header.IPv6ProtocolNumber, + AddressWithPrefix: ipv6Addr, + } + ipv6Bytes := []byte(ipv6Addr.Address) + ipv6Bytes[len(ipv6Bytes)-1]++ + otherIPv6Address := tcpip.Address(ipv6Bytes) + + tests := []struct { + name string + addAddress tcpip.ProtocolAddress + bindAddr tcpip.Address + dstAddr tcpip.Address + expectRx bool + }{ + { + name: "IPv4 bind to wildcard and send to assigned address", + addAddress: ipv4ProtocolAddress, + dstAddr: ipv4Addr.Address, + expectRx: true, + }, + { + name: "IPv4 bind to wildcard and send to other subnet-local address", + addAddress: ipv4ProtocolAddress, + dstAddr: otherIPv4Address, + expectRx: true, + }, + { + name: "IPv4 bind to wildcard send to other address", + addAddress: ipv4ProtocolAddress, + dstAddr: remoteIPv4Addr, + expectRx: false, + }, + { + name: "IPv4 bind to other subnet-local address and send to assigned address", + addAddress: ipv4ProtocolAddress, + bindAddr: otherIPv4Address, + dstAddr: ipv4Addr.Address, + expectRx: false, + }, + { + name: "IPv4 bind and send to other subnet-local address", + addAddress: ipv4ProtocolAddress, + bindAddr: otherIPv4Address, + dstAddr: otherIPv4Address, + expectRx: true, + }, + { + name: "IPv4 bind to assigned address and send to other subnet-local address", + addAddress: ipv4ProtocolAddress, + bindAddr: ipv4Addr.Address, + dstAddr: otherIPv4Address, + expectRx: false, + }, + + { + name: "IPv6 bind and send to assigned address", + addAddress: ipv6ProtocolAddress, + bindAddr: ipv6Addr.Address, + dstAddr: ipv6Addr.Address, + expectRx: true, + }, + { + name: "IPv6 bind to wildcard and send to assigned address", + addAddress: ipv6ProtocolAddress, + dstAddr: ipv6Addr.Address, + expectRx: true, + }, + { + name: "IPv6 bind to wildcard and send to other subnet-local address", + addAddress: ipv6ProtocolAddress, + dstAddr: otherIPv6Address, + expectRx: true, + }, + { + name: "IPv6 bind to wildcard send to other address", + addAddress: ipv6ProtocolAddress, + dstAddr: remoteIPv6Addr, + expectRx: false, + }, + { + name: "IPv6 bind to other subnet-local address and send to assigned address", + addAddress: ipv6ProtocolAddress, + bindAddr: otherIPv6Address, + dstAddr: ipv6Addr.Address, + expectRx: false, + }, + { + name: "IPv6 bind and send to other subnet-local address", + addAddress: ipv6ProtocolAddress, + bindAddr: otherIPv6Address, + dstAddr: otherIPv6Address, + expectRx: true, + }, + { + name: "IPv6 bind to assigned address and send to other subnet-local address", + addAddress: ipv6ProtocolAddress, + bindAddr: ipv6Addr.Address, + dstAddr: otherIPv6Address, + expectRx: false, + }, + { + name: "IPv6 bind and send to assigned address", + addAddress: ipv6ProtocolAddress, + bindAddr: ipv6Addr.Address, + dstAddr: ipv6Addr.Address, + expectRx: true, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + s := stack.New(stack.Options{ + NetworkProtocols: []stack.NetworkProtocol{ipv4.NewProtocol(), ipv6.NewProtocol()}, + TransportProtocols: []stack.TransportProtocol{udp.NewProtocol()}, + }) + if err := s.CreateNIC(nicID, loopback.New()); err != nil { + t.Fatalf("CreateNIC(%d, _): %s", nicID, err) + } + if err := s.AddProtocolAddress(nicID, test.addAddress); err != nil { + t.Fatalf("AddProtocolAddress(%d, %+v): %s", nicID, test.addAddress, err) + } + s.SetRouteTable([]tcpip.Route{ + tcpip.Route{ + Destination: header.IPv4EmptySubnet, + NIC: nicID, + }, + tcpip.Route{ + Destination: header.IPv6EmptySubnet, + NIC: nicID, + }, + }) + + wq := waiter.Queue{} + rep, err := s.NewEndpoint(udp.ProtocolNumber, test.addAddress.Protocol, &wq) + if err != nil { + t.Fatalf("NewEndpoint(%d, %d, _): %s", udp.ProtocolNumber, test.addAddress.Protocol, err) + } + defer rep.Close() + + bindAddr := tcpip.FullAddress{Addr: test.bindAddr, Port: localPort} + if err := rep.Bind(bindAddr); err != nil { + t.Fatalf("rep.Bind(%+v): %s", bindAddr, err) + } + + sep, err := s.NewEndpoint(udp.ProtocolNumber, test.addAddress.Protocol, &wq) + if err != nil { + t.Fatalf("NewEndpoint(%d, %d, _): %s", udp.ProtocolNumber, test.addAddress.Protocol, err) + } + defer sep.Close() + + wopts := tcpip.WriteOptions{ + To: &tcpip.FullAddress{ + Addr: test.dstAddr, + Port: localPort, + }, + } + n, _, err := sep.Write(tcpip.SlicePayload(data), wopts) + if err != nil { + t.Fatalf("sep.Write(_, _): %s", err) + } + if want := int64(len(data)); n != want { + t.Fatalf("got sep.Write(_, _) = (%d, _, nil), want = (%d, _, nil)", n, want) + } + + if gotPayload, _, err := rep.Read(nil); test.expectRx { + if err != nil { + t.Fatalf("reep.Read(nil): %s", err) + } + if diff := cmp.Diff(buffer.View(data), gotPayload); diff != "" { + t.Errorf("got UDP payload mismatch (-want +got):\n%s", diff) + } + } else { + if err != tcpip.ErrWouldBlock { + t.Fatalf("got rep.Read(nil) = (%x, _, %s), want = (_, _, %s)", gotPayload, err, tcpip.ErrWouldBlock) + } + } + }) + } +} diff --git a/pkg/tcpip/tests/integration/multicast_broadcast_test.go b/pkg/tcpip/tests/integration/multicast_broadcast_test.go index 9f0dd4d6d..52c27e045 100644 --- a/pkg/tcpip/tests/integration/multicast_broadcast_test.go +++ b/pkg/tcpip/tests/integration/multicast_broadcast_test.go @@ -430,7 +430,7 @@ func TestIncomingMulticastAndBroadcast(t *testing.T) { } } else { if err != tcpip.ErrWouldBlock { - t.Fatalf("got Read(nil) = (%x, _, %v), want = (_, _, %s)", gotPayload, err, tcpip.ErrWouldBlock) + t.Fatalf("got Read(nil) = (%x, _, %s), want = (_, _, %s)", gotPayload, err, tcpip.ErrWouldBlock) } } }) -- cgit v1.2.3