gvisor/pkg/sentry/kernel/fd_map_test.go

137 lines
4.1 KiB
Go

// 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})
origFlags := FDFlags{CloseOnExec: true}
if err := f.NewFDAt(2, file, origFlags, limitSet); err != nil {
t.Fatalf("f.NewFDAt(2, r, FDFlags{}): got %v, wanted nil", err)
}
newFile, newFlags := f.GetDescriptor(2)
if newFile == nil {
t.Fatalf("f.GetFile(2): got a %v, wanted nil", newFile)
}
if newFlags != origFlags {
t.Fatalf("new File flags %+v don't match original %+v", newFlags, origFlags)
}
}