1 files changed, 134 insertions, 0 deletions
diff --git a/pkg/sentry/kernel/fd_map_test.go b/pkg/sentry/kernel/fd_map_test.go
new file mode 100644
index 000000000..e1ac900e8
--- /dev/null
+++ b/pkg/sentry/kernel/fd_map_test.go
@@ -0,0 +1,134 @@
+// Copyright 2018 Google Inc.
+//
+// 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 kernel
+
+import (
+	"testing"
+
+	"gvisor.googlesource.com/gvisor/pkg/sentry/fs/filetest"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/kernel/kdefs"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/limits"
+)
+
+const (
+	// maxFD is the maximum FD to try to create in the map.
+	// This number of open files has been seen in the wild.
+	maxFD = 2 * 1024
+)
+
+func newTestFDMap() *FDMap {
+	return &FDMap{
+		files: make(map[kdefs.FD]descriptor),
+	}
+}
+
+// TestFDMapMany allocates maxFD FDs, i.e. maxes out the FDMap,
+// until there is no room, then makes sure that NewFDAt works
+// and also that if we remove one and add one that works too.
+func TestFDMapMany(t *testing.T) {
+	file := filetest.NewTestFile(t)
+	limitSet := limits.NewLimitSet()
+	limitSet.Set(limits.NumberOfFiles, limits.Limit{maxFD, maxFD})
+
+	f := newTestFDMap()
+	for i := 0; i < maxFD; i++ {
+		if _, err := f.NewFDFrom(0, file, FDFlags{}, limitSet); err != nil {
+			t.Fatalf("Allocated %v FDs but wanted to allocate %v", i, maxFD)
+		}
+	}
+
+	if _, err := f.NewFDFrom(0, file, FDFlags{}, limitSet); err == nil {
+		t.Fatalf("f.NewFDFrom(0, r) in full map: got nil, wanted error")
+	}
+
+	if err := f.NewFDAt(1, file, FDFlags{}, limitSet); err != nil {
+		t.Fatalf("f.NewFDAt(1, r, FDFlags{}): got %v, wanted nil", err)
+	}
+}
+
+// TestFDMap does a set of simple tests to make sure simple adds,
+// removes, GetRefs, and DecRefs work. The ordering is just weird
+// enough that a table-driven approach seemed clumsy.
+func TestFDMap(t *testing.T) {
+	file := filetest.NewTestFile(t)
+	limitSet := limits.NewLimitSet()
+	limitSet.Set(limits.NumberOfFiles, limits.Limit{1, maxFD})
+
+	f := newTestFDMap()
+	if _, err := f.NewFDFrom(0, file, FDFlags{}, limitSet); err != nil {
+		t.Fatalf("Adding an FD to an empty 1-size map: got %v, want nil", err)
+	}
+
+	if _, err := f.NewFDFrom(0, file, FDFlags{}, limitSet); err == nil {
+		t.Fatalf("Adding an FD to a filled 1-size map: got nil, wanted an error")
+	}
+
+	largeLimit := limits.Limit{maxFD, maxFD}
+	limitSet.Set(limits.NumberOfFiles, largeLimit)
+
+	if fd, err := f.NewFDFrom(0, file, FDFlags{}, limitSet); err != nil {
+		t.Fatalf("Adding an FD to a resized map: got %v, want nil", err)
+	} else if fd != kdefs.FD(1) {
+		t.Fatalf("Added an FD to a resized map: got %v, want 1", fd)
+	}
+
+	if err := f.NewFDAt(1, file, FDFlags{}, limitSet); err != nil {
+		t.Fatalf("Replacing FD 1 via f.NewFDAt(1, r, FDFlags{}): got %v, wanted nil", err)
+	}
+
+	if err := f.NewFDAt(maxFD+1, file, FDFlags{}, limitSet); err == nil {
+		t.Fatalf("Using an FD that was too large via f.NewFDAt(%v, r, FDFlags{}): got nil, wanted an error", maxFD+1)
+	}
+
+	if ref := f.GetFile(1); ref == nil {
+		t.Fatalf("f.GetFile(1): got nil, wanted %v", file)
+	}
+
+	if ref := f.GetFile(2); ref != nil {
+		t.Fatalf("f.GetFile(2): got a %v, wanted nil", ref)
+	}
+
+	ref, ok := f.Remove(1)
+	if !ok {
+		t.Fatalf("f.Remove(1) for an existing FD: failed, want success")
+	}
+	ref.DecRef()
+
+	if ref, ok := f.Remove(1); ok {
+		ref.DecRef()
+		t.Fatalf("r.Remove(1) for a removed FD: got success, want failure")
+	}
+
+}
+
+func TestDescriptorFlags(t *testing.T) {
+	file := filetest.NewTestFile(t)
+	f := newTestFDMap()
+	limitSet := limits.NewLimitSet()
+	limitSet.Set(limits.NumberOfFiles, limits.Limit{maxFD, maxFD})
+
+	if err := f.NewFDAt(2, file, FDFlags{CloseOnExec: true}, limitSet); err != nil {
+		t.Fatalf("f.NewFDAt(2, r, FDFlags{}): got %v, wanted nil", err)
+	}
+
+	newFile, flags := f.GetDescriptor(2)
+	if newFile == nil {
+		t.Fatalf("f.GetFile(2): got a %v, wanted nil", newFile)
+	}
+
+	if !flags.CloseOnExec {
+		t.Fatalf("new File flags %d don't match original %d\n", flags, 0)
+	}
+}