282 lines
8.6 KiB
Go
282 lines
8.6 KiB
Go
// Copyright 2019 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 testutil provides common test utilities for kernfs-based
|
|
// filesystems.
|
|
package testutil
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
"strings"
|
|
"testing"
|
|
|
|
"github.com/google/go-cmp/cmp"
|
|
"gvisor.dev/gvisor/pkg/abi/linux"
|
|
"gvisor.dev/gvisor/pkg/context"
|
|
"gvisor.dev/gvisor/pkg/fspath"
|
|
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
|
|
"gvisor.dev/gvisor/pkg/sentry/vfs"
|
|
"gvisor.dev/gvisor/pkg/sync"
|
|
"gvisor.dev/gvisor/pkg/usermem"
|
|
)
|
|
|
|
// System represents the context for a single test.
|
|
//
|
|
// Test systems must be explicitly destroyed with System.Destroy.
|
|
type System struct {
|
|
t *testing.T
|
|
Ctx context.Context
|
|
Creds *auth.Credentials
|
|
VFS *vfs.VirtualFilesystem
|
|
Root vfs.VirtualDentry
|
|
MntNs *vfs.MountNamespace
|
|
}
|
|
|
|
// NewSystem constructs a System.
|
|
//
|
|
// Precondition: Caller must hold a reference on MntNs, whose ownership
|
|
// is transferred to the new System.
|
|
func NewSystem(ctx context.Context, t *testing.T, v *vfs.VirtualFilesystem, mns *vfs.MountNamespace) *System {
|
|
s := &System{
|
|
t: t,
|
|
Ctx: ctx,
|
|
Creds: auth.CredentialsFromContext(ctx),
|
|
VFS: v,
|
|
MntNs: mns,
|
|
Root: mns.Root(),
|
|
}
|
|
return s
|
|
}
|
|
|
|
// WithSubtest creates a temporary test system with a new test harness,
|
|
// referencing all other resources from the original system. This is useful when
|
|
// a system is reused for multiple subtests, and the T needs to change for each
|
|
// case. Note that this is safe when test cases run in parallel, as all
|
|
// resources referenced by the system are immutable, or handle interior
|
|
// mutations in a thread-safe manner.
|
|
//
|
|
// The returned system must not outlive the original and should not be destroyed
|
|
// via System.Destroy.
|
|
func (s *System) WithSubtest(t *testing.T) *System {
|
|
return &System{
|
|
t: t,
|
|
Ctx: s.Ctx,
|
|
Creds: s.Creds,
|
|
VFS: s.VFS,
|
|
MntNs: s.MntNs,
|
|
Root: s.Root,
|
|
}
|
|
}
|
|
|
|
// WithTemporaryContext constructs a temporary test system with a new context
|
|
// ctx. The temporary system borrows all resources and references from the
|
|
// original system. The returned temporary system must not outlive the original
|
|
// system, and should not be destroyed via System.Destroy.
|
|
func (s *System) WithTemporaryContext(ctx context.Context) *System {
|
|
return &System{
|
|
t: s.t,
|
|
Ctx: ctx,
|
|
Creds: s.Creds,
|
|
VFS: s.VFS,
|
|
MntNs: s.MntNs,
|
|
Root: s.Root,
|
|
}
|
|
}
|
|
|
|
// Destroy release resources associated with a test system.
|
|
func (s *System) Destroy() {
|
|
s.Root.DecRef()
|
|
s.MntNs.DecRef() // Reference on MntNs passed to NewSystem.
|
|
}
|
|
|
|
// ReadToEnd reads the contents of fd until EOF to a string.
|
|
func (s *System) ReadToEnd(fd *vfs.FileDescription) (string, error) {
|
|
buf := make([]byte, usermem.PageSize)
|
|
bufIOSeq := usermem.BytesIOSequence(buf)
|
|
opts := vfs.ReadOptions{}
|
|
|
|
var content strings.Builder
|
|
for {
|
|
n, err := fd.Read(s.Ctx, bufIOSeq, opts)
|
|
if n == 0 || err != nil {
|
|
if err == io.EOF {
|
|
err = nil
|
|
}
|
|
return content.String(), err
|
|
}
|
|
content.Write(buf[:n])
|
|
}
|
|
}
|
|
|
|
// PathOpAtRoot constructs a PathOperation with the given path from
|
|
// the root of the filesystem.
|
|
func (s *System) PathOpAtRoot(path string) *vfs.PathOperation {
|
|
return &vfs.PathOperation{
|
|
Root: s.Root,
|
|
Start: s.Root,
|
|
Path: fspath.Parse(path),
|
|
}
|
|
}
|
|
|
|
// GetDentryOrDie attempts to resolve a dentry referred to by the
|
|
// provided path operation. If unsuccessful, the test fails.
|
|
func (s *System) GetDentryOrDie(pop *vfs.PathOperation) vfs.VirtualDentry {
|
|
vd, err := s.VFS.GetDentryAt(s.Ctx, s.Creds, pop, &vfs.GetDentryOptions{})
|
|
if err != nil {
|
|
s.t.Fatalf("GetDentryAt(pop:%+v) failed: %v", pop, err)
|
|
}
|
|
return vd
|
|
}
|
|
|
|
// DirentType is an alias for values for linux_dirent64.d_type.
|
|
type DirentType = uint8
|
|
|
|
// ListDirents lists the Dirents for a directory at pop.
|
|
func (s *System) ListDirents(pop *vfs.PathOperation) *DirentCollector {
|
|
fd, err := s.VFS.OpenAt(s.Ctx, s.Creds, pop, &vfs.OpenOptions{Flags: linux.O_RDONLY})
|
|
if err != nil {
|
|
s.t.Fatalf("OpenAt for PathOperation %+v failed: %v", pop, err)
|
|
}
|
|
defer fd.DecRef()
|
|
|
|
collector := &DirentCollector{}
|
|
if err := fd.IterDirents(s.Ctx, collector); err != nil {
|
|
s.t.Fatalf("IterDirent failed: %v", err)
|
|
}
|
|
return collector
|
|
}
|
|
|
|
// AssertAllDirentTypes verifies that the set of dirents in collector contains
|
|
// exactly the specified set of expected entries. AssertAllDirentTypes respects
|
|
// collector.skipDots, and implicitly checks for "." and ".." accordingly.
|
|
func (s *System) AssertAllDirentTypes(collector *DirentCollector, expected map[string]DirentType) {
|
|
// Also implicitly check for "." and "..", if enabled.
|
|
if !collector.skipDots {
|
|
expected["."] = linux.DT_DIR
|
|
expected[".."] = linux.DT_DIR
|
|
}
|
|
|
|
dentryTypes := make(map[string]DirentType)
|
|
collector.mu.Lock()
|
|
for _, dirent := range collector.dirents {
|
|
dentryTypes[dirent.Name] = dirent.Type
|
|
}
|
|
collector.mu.Unlock()
|
|
if diff := cmp.Diff(expected, dentryTypes); diff != "" {
|
|
s.t.Fatalf("IterDirent had unexpected results:\n--- want\n+++ got\n%v", diff)
|
|
}
|
|
}
|
|
|
|
// AssertDirentOffsets verifies that collector contains at least the entries
|
|
// specified in expected, with the given NextOff field. Entries specified in
|
|
// expected but missing from collector result in failure. Extra entries in
|
|
// collector are ignored. AssertDirentOffsets respects collector.skipDots, and
|
|
// implicitly checks for "." and ".." accordingly.
|
|
func (s *System) AssertDirentOffsets(collector *DirentCollector, expected map[string]int64) {
|
|
// Also implicitly check for "." and "..", if enabled.
|
|
if !collector.skipDots {
|
|
expected["."] = 1
|
|
expected[".."] = 2
|
|
}
|
|
|
|
dentryNextOffs := make(map[string]int64)
|
|
collector.mu.Lock()
|
|
for _, dirent := range collector.dirents {
|
|
// Ignore extra entries in dentries that are not in expected.
|
|
if _, ok := expected[dirent.Name]; ok {
|
|
dentryNextOffs[dirent.Name] = dirent.NextOff
|
|
}
|
|
}
|
|
collector.mu.Unlock()
|
|
if diff := cmp.Diff(expected, dentryNextOffs); diff != "" {
|
|
s.t.Fatalf("IterDirent had unexpected results:\n--- want\n+++ got\n%v", diff)
|
|
}
|
|
}
|
|
|
|
// DirentCollector provides an implementation for vfs.IterDirentsCallback for
|
|
// testing. It simply iterates to the end of a given directory FD and collects
|
|
// all dirents emitted by the callback.
|
|
type DirentCollector struct {
|
|
mu sync.Mutex
|
|
order []*vfs.Dirent
|
|
dirents map[string]*vfs.Dirent
|
|
// When the collector is used in various Assert* functions, should "." and
|
|
// ".." be implicitly checked?
|
|
skipDots bool
|
|
}
|
|
|
|
// SkipDotsChecks enables or disables the implicit checks on "." and ".." when
|
|
// the collector is used in various Assert* functions. Note that "." and ".."
|
|
// are still collected if passed to d.Handle, so the caller should only disable
|
|
// the checks when they aren't expected.
|
|
func (d *DirentCollector) SkipDotsChecks(value bool) {
|
|
d.skipDots = value
|
|
}
|
|
|
|
// Handle implements vfs.IterDirentsCallback.Handle.
|
|
func (d *DirentCollector) Handle(dirent vfs.Dirent) error {
|
|
d.mu.Lock()
|
|
if d.dirents == nil {
|
|
d.dirents = make(map[string]*vfs.Dirent)
|
|
}
|
|
d.order = append(d.order, &dirent)
|
|
d.dirents[dirent.Name] = &dirent
|
|
d.mu.Unlock()
|
|
return nil
|
|
}
|
|
|
|
// Count returns the number of dirents currently in the collector.
|
|
func (d *DirentCollector) Count() int {
|
|
d.mu.Lock()
|
|
defer d.mu.Unlock()
|
|
return len(d.dirents)
|
|
}
|
|
|
|
// Contains checks whether the collector has a dirent with the given name and
|
|
// type.
|
|
func (d *DirentCollector) Contains(name string, typ uint8) error {
|
|
d.mu.Lock()
|
|
defer d.mu.Unlock()
|
|
dirent, ok := d.dirents[name]
|
|
if !ok {
|
|
return fmt.Errorf("No dirent named %q found", name)
|
|
}
|
|
if dirent.Type != typ {
|
|
return fmt.Errorf("Dirent named %q found, but was expecting type %s, got: %+v", name, linux.DirentType.Parse(uint64(typ)), dirent)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Dirents returns all dirents discovered by this collector.
|
|
func (d *DirentCollector) Dirents() map[string]*vfs.Dirent {
|
|
d.mu.Lock()
|
|
dirents := make(map[string]*vfs.Dirent)
|
|
for n, d := range d.dirents {
|
|
dirents[n] = d
|
|
}
|
|
d.mu.Unlock()
|
|
return dirents
|
|
}
|
|
|
|
// OrderedDirents returns an ordered list of dirents as discovered by this
|
|
// collector.
|
|
func (d *DirentCollector) OrderedDirents() []*vfs.Dirent {
|
|
d.mu.Lock()
|
|
dirents := make([]*vfs.Dirent, len(d.order))
|
|
copy(dirents, d.order)
|
|
d.mu.Unlock()
|
|
return dirents
|
|
}
|