diff --git a/tsnet/packet_filter_test.go b/tsnet/packet_filter_test.go new file mode 100644 index 000000000..462234222 --- /dev/null +++ b/tsnet/packet_filter_test.go @@ -0,0 +1,248 @@ +// Copyright (c) Tailscale Inc & AUTHORS +// SPDX-License-Identifier: BSD-3-Clause + +package tsnet + +import ( + "context" + "fmt" + "net/netip" + "testing" + "time" + + "tailscale.com/ipn" + "tailscale.com/tailcfg" + "tailscale.com/types/ipproto" + "tailscale.com/types/key" + "tailscale.com/types/netmap" + "tailscale.com/util/must" + "tailscale.com/wgengine/filter" +) + +// waitFor blocks until a NetMap is seen on the IPN bus that satisfies the given +// function f. Note: has no timeout, should be called with a ctx that has an +// appropriate timeout set. +func waitFor(t testing.TB, ctx context.Context, s *Server, f func(*netmap.NetworkMap) bool) error { + t.Helper() + watcher, err := s.localClient.WatchIPNBus(ctx, ipn.NotifyInitialNetMap) + if err != nil { + t.Fatalf("error watching IPN bus: %s", err) + } + defer watcher.Close() + + for { + n, err := watcher.Next() + if err != nil { + return fmt.Errorf("getting next ipn.Notify from IPN bus: %w", err) + } + if n.NetMap != nil { + if f(n.NetMap) { + return nil + } + } + } +} + +// TestPacketFilterFromNetmap tests all of the client code for processing +// netmaps and turning them into packet filters together. Only the control-plane +// side is mocked out. +func TestPacketFilterFromNetmap(t *testing.T) { + t.Parallel() + + var key key.NodePublic + must.Do(key.UnmarshalText([]byte("nodekey:5c8f86d5fc70d924e55f02446165a5dae8f822994ad26bcf4b08fd841f9bf261"))) + + type check struct { + src string + dst string + port uint16 + want filter.Response + } + + tests := []struct { + name string + mapResponse *tailcfg.MapResponse + waitTest func(*netmap.NetworkMap) bool + + incrementalMapResponse *tailcfg.MapResponse // optional + incrementalWaitTest func(*netmap.NetworkMap) bool // optional + + checks []check + }{ + { + name: "IP_based_peers", + mapResponse: &tailcfg.MapResponse{ + Node: &tailcfg.Node{ + Addresses: []netip.Prefix{netip.MustParsePrefix("1.1.1.1/32")}, + }, + Peers: []*tailcfg.Node{{ + ID: 2, + Name: "foo", + Key: key, + Addresses: []netip.Prefix{netip.MustParsePrefix("2.2.2.2/32")}, + CapMap: nil, + }}, + PacketFilter: []tailcfg.FilterRule{{ + SrcIPs: []string{"2.2.2.2/32"}, + DstPorts: []tailcfg.NetPortRange{{ + IP: "1.1.1.1/32", + Ports: tailcfg.PortRange{ + First: 22, + Last: 22, + }, + }}, + IPProto: []int{int(ipproto.TCP)}, + }}, + }, + waitTest: func(nm *netmap.NetworkMap) bool { + return len(nm.Peers) > 0 + }, + checks: []check{ + {src: "2.2.2.2", dst: "1.1.1.1", port: 22, want: filter.Accept}, + {src: "2.2.2.2", dst: "1.1.1.1", port: 23, want: filter.Drop}, // different port + {src: "3.3.3.3", dst: "1.1.1.1", port: 22, want: filter.Drop}, // different src + {src: "2.2.2.2", dst: "1.1.1.2", port: 22, want: filter.Drop}, // different dst + }, + }, + { + name: "capmap_based_peers", + mapResponse: &tailcfg.MapResponse{ + Node: &tailcfg.Node{ + Addresses: []netip.Prefix{netip.MustParsePrefix("1.1.1.1/32")}, + }, + Peers: []*tailcfg.Node{{ + ID: 2, + Name: "foo", + Key: key, + Addresses: []netip.Prefix{netip.MustParsePrefix("2.2.2.2/32")}, + CapMap: tailcfg.NodeCapMap{"X": nil}, + }}, + PacketFilter: []tailcfg.FilterRule{{ + SrcIPs: []string{"cap:X"}, + DstPorts: []tailcfg.NetPortRange{{ + IP: "1.1.1.1/32", + Ports: tailcfg.PortRange{ + First: 22, + Last: 22, + }, + }}, + IPProto: []int{int(ipproto.TCP)}, + }}, + }, + waitTest: func(nm *netmap.NetworkMap) bool { + return len(nm.Peers) > 0 + }, + checks: []check{ + {src: "2.2.2.2", dst: "1.1.1.1", port: 22, want: filter.Accept}, + {src: "2.2.2.2", dst: "1.1.1.1", port: 23, want: filter.Drop}, // different port + {src: "3.3.3.3", dst: "1.1.1.1", port: 22, want: filter.Drop}, // different src + {src: "2.2.2.2", dst: "1.1.1.2", port: 22, want: filter.Drop}, // different dst + }, + }, + { + name: "capmap_based_peers_changed", + mapResponse: &tailcfg.MapResponse{ + Node: &tailcfg.Node{ + Addresses: []netip.Prefix{netip.MustParsePrefix("1.1.1.1/32")}, + CapMap: tailcfg.NodeCapMap{"X-sigil": nil}, + }, + PacketFilter: []tailcfg.FilterRule{{ + SrcIPs: []string{"cap:label-1"}, + DstPorts: []tailcfg.NetPortRange{{ + IP: "1.1.1.1/32", + Ports: tailcfg.PortRange{ + First: 22, + Last: 22, + }, + }}, + IPProto: []int{int(ipproto.TCP)}, + }}, + }, + waitTest: func(nm *netmap.NetworkMap) bool { + return nm.SelfNode.HasCap("X-sigil") + }, + incrementalMapResponse: &tailcfg.MapResponse{ + PeersChanged: []*tailcfg.Node{{ + ID: 2, + Name: "foo", + Key: key, + Addresses: []netip.Prefix{netip.MustParsePrefix("2.2.2.2/32")}, + CapMap: tailcfg.NodeCapMap{"label-1": nil}, + }}, + }, + incrementalWaitTest: func(nm *netmap.NetworkMap) bool { + return len(nm.Peers) > 0 + }, + checks: []check{ + {src: "2.2.2.2", dst: "1.1.1.1", port: 22, want: filter.Accept}, + {src: "2.2.2.2", dst: "1.1.1.1", port: 23, want: filter.Drop}, // different port + {src: "3.3.3.3", dst: "1.1.1.1", port: 22, want: filter.Drop}, // different src + {src: "2.2.2.2", dst: "1.1.1.2", port: 22, want: filter.Drop}, // different dst + }, + }, + } + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + t.Parallel() + ctx, cancel := context.WithTimeout(t.Context(), 30*time.Second) + defer cancel() + + controlURL, c := startControl(t) + s, _, pubKey := startServer(t, ctx, controlURL, "node") + + if test.waitTest(s.lb.NetMap()) { + t.Fatal("waitTest already passes before sending initial netmap: this will be flaky") + } + + if !c.AddRawMapResponse(pubKey, test.mapResponse) { + t.Fatalf("could not send map response to %s", pubKey) + } + + if err := waitFor(t, ctx, s, test.waitTest); err != nil { + t.Fatalf("waitFor: %s", err) + } + + pf := s.lb.GetFilterForTest() + + for _, check := range test.checks { + got := pf.Check(netip.MustParseAddr(check.src), netip.MustParseAddr(check.dst), check.port, ipproto.TCP) + + want := check.want + if test.incrementalMapResponse != nil { + want = filter.Drop + } + if got != want { + t.Errorf("check %s -> %s:%d, got: %s, want: %s", check.src, check.dst, check.port, got, want) + } + } + + if test.incrementalMapResponse != nil { + if test.incrementalWaitTest == nil { + t.Fatal("incrementalWaitTest must be set if incrementalMapResponse is set") + } + + if test.incrementalWaitTest(s.lb.NetMap()) { + t.Fatal("incrementalWaitTest already passes before sending incremental netmap: this will be flaky") + } + + if !c.AddRawMapResponse(pubKey, test.incrementalMapResponse) { + t.Fatalf("could not send map response to %s", pubKey) + } + + if err := waitFor(t, ctx, s, test.incrementalWaitTest); err != nil { + t.Fatalf("waitFor: %s", err) + } + + pf := s.lb.GetFilterForTest() + + for _, check := range test.checks { + got := pf.Check(netip.MustParseAddr(check.src), netip.MustParseAddr(check.dst), check.port, ipproto.TCP) + if got != check.want { + t.Errorf("check %s -> %s:%d, got: %s, want: %s", check.src, check.dst, check.port, got, check.want) + } + } + } + + }) + } +}