From ad1968ed5665c7541d6920edbd7c7492b7db3046 Mon Sep 17 00:00:00 2001 From: Rahat Mahmood Date: Tue, 21 Jan 2020 14:25:14 -0800 Subject: Implement sysfs. PiperOrigin-RevId: 290822487 --- pkg/abi/linux/file.go | 13 +++ pkg/sentry/fsimpl/kernfs/BUILD | 3 +- pkg/sentry/fsimpl/kernfs/kernfs_test.go | 175 ++++++------------------------- pkg/sentry/fsimpl/proc/BUILD | 13 +-- pkg/sentry/fsimpl/proc/boot_test.go | 149 -------------------------- pkg/sentry/fsimpl/proc/tasks_test.go | 13 +-- pkg/sentry/fsimpl/sys/BUILD | 35 +++++++ pkg/sentry/fsimpl/sys/sys.go | 124 ++++++++++++++++++++++ pkg/sentry/fsimpl/sys/sys_test.go | 90 ++++++++++++++++ pkg/sentry/fsimpl/testutil/BUILD | 36 +++++++ pkg/sentry/fsimpl/testutil/kernel.go | 149 ++++++++++++++++++++++++++ pkg/sentry/fsimpl/testutil/testutil.go | 178 ++++++++++++++++++++++++++++++++ 12 files changed, 663 insertions(+), 315 deletions(-) delete mode 100644 pkg/sentry/fsimpl/proc/boot_test.go create mode 100644 pkg/sentry/fsimpl/sys/BUILD create mode 100644 pkg/sentry/fsimpl/sys/sys.go create mode 100644 pkg/sentry/fsimpl/sys/sys_test.go create mode 100644 pkg/sentry/fsimpl/testutil/BUILD create mode 100644 pkg/sentry/fsimpl/testutil/kernel.go create mode 100644 pkg/sentry/fsimpl/testutil/testutil.go (limited to 'pkg') diff --git a/pkg/abi/linux/file.go b/pkg/abi/linux/file.go index 16791d03e..6fbdd668d 100644 --- a/pkg/abi/linux/file.go +++ b/pkg/abi/linux/file.go @@ -180,6 +180,19 @@ const ( DT_WHT = 14 ) +// DirentType are the friendly strings for linux_dirent64.d_type. +var DirentType = abi.ValueSet{ + DT_UNKNOWN: "DT_UNKNOWN", + DT_FIFO: "DT_FIFO", + DT_CHR: "DT_CHR", + DT_DIR: "DT_DIR", + DT_BLK: "DT_BLK", + DT_REG: "DT_REG", + DT_LNK: "DT_LNK", + DT_SOCK: "DT_SOCK", + DT_WHT: "DT_WHT", +} + // Values for preadv2/pwritev2. const ( // Note: gVisor does not implement the RWF_HIPRI feature, but the flag is diff --git a/pkg/sentry/fsimpl/kernfs/BUILD b/pkg/sentry/fsimpl/kernfs/BUILD index 809178250..66d409785 100644 --- a/pkg/sentry/fsimpl/kernfs/BUILD +++ b/pkg/sentry/fsimpl/kernfs/BUILD @@ -51,13 +51,12 @@ go_test( deps = [ ":kernfs", "//pkg/abi/linux", - "//pkg/fspath", "//pkg/sentry/context", "//pkg/sentry/context/contexttest", + "//pkg/sentry/fsimpl/testutil", "//pkg/sentry/kernel/auth", "//pkg/sentry/usermem", "//pkg/sentry/vfs", - "//pkg/sync", "//pkg/syserror", "@com_github_google_go-cmp//cmp:go_default_library", ], diff --git a/pkg/sentry/fsimpl/kernfs/kernfs_test.go b/pkg/sentry/fsimpl/kernfs/kernfs_test.go index 5c9d580e1..a5fdfbde5 100644 --- a/pkg/sentry/fsimpl/kernfs/kernfs_test.go +++ b/pkg/sentry/fsimpl/kernfs/kernfs_test.go @@ -17,20 +17,17 @@ package kernfs_test import ( "bytes" "fmt" - "io" - "runtime" "testing" "github.com/google/go-cmp/cmp" "gvisor.dev/gvisor/pkg/abi/linux" - "gvisor.dev/gvisor/pkg/fspath" "gvisor.dev/gvisor/pkg/sentry/context" "gvisor.dev/gvisor/pkg/sentry/context/contexttest" "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/testutil" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/usermem" "gvisor.dev/gvisor/pkg/sentry/vfs" - "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/syserror" ) @@ -41,21 +38,11 @@ const staticFileContent = "This is sample content for a static test file." // filesystem. See newTestSystem. type RootDentryFn func(*auth.Credentials, *filesystem) *kernfs.Dentry -// TestSystem represents the context for a single test. -type TestSystem struct { - t *testing.T - ctx context.Context - creds *auth.Credentials - vfs *vfs.VirtualFilesystem - mns *vfs.MountNamespace - root vfs.VirtualDentry -} - // newTestSystem sets up a minimal environment for running a test, including an // instance of a test filesystem. Tests can control the contents of the // filesystem by providing an appropriate rootFn, which should return a // pre-populated root dentry. -func newTestSystem(t *testing.T, rootFn RootDentryFn) *TestSystem { +func newTestSystem(t *testing.T, rootFn RootDentryFn) *testutil.System { ctx := contexttest.Context(t) creds := auth.CredentialsFromContext(ctx) v := vfs.New() @@ -66,57 +53,7 @@ func newTestSystem(t *testing.T, rootFn RootDentryFn) *TestSystem { if err != nil { t.Fatalf("Failed to create testfs root mount: %v", err) } - - s := &TestSystem{ - t: t, - ctx: ctx, - creds: creds, - vfs: v, - mns: mns, - root: mns.Root(), - } - runtime.SetFinalizer(s, func(s *TestSystem) { s.root.DecRef() }) - return s -} - -// PathOpAtRoot constructs a vfs.PathOperation for a path from the -// root of the test filesystem. -// -// Precondition: path should be relative path. -func (s *TestSystem) 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 *TestSystem) 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 -} - -func (s *TestSystem) ReadToEnd(fd *vfs.FileDescription) (string, error) { - buf := make([]byte, usermem.PageSize) - bufIOSeq := usermem.BytesIOSequence(buf) - opts := vfs.ReadOptions{} - - var content bytes.Buffer - for { - n, err := fd.Impl().Read(s.ctx, bufIOSeq, opts) - if n == 0 || err != nil { - if err == io.EOF { - err = nil - } - return content.String(), err - } - content.Write(buf[:n]) - } + return testutil.NewSystem(ctx, t, v, mns) } type fsType struct { @@ -260,6 +197,7 @@ func TestBasic(t *testing.T) { "file1": fs.newFile(creds, staticFileContent), }) }) + defer sys.Destroy() sys.GetDentryOrDie(sys.PathOpAtRoot("file1")).DecRef() } @@ -269,9 +207,10 @@ func TestMkdirGetDentry(t *testing.T) { "dir1": fs.newDir(creds, 0755, nil), }) }) + defer sys.Destroy() pop := sys.PathOpAtRoot("dir1/a new directory") - if err := sys.vfs.MkdirAt(sys.ctx, sys.creds, &pop, &vfs.MkdirOptions{Mode: 0755}); err != nil { + if err := sys.VFS.MkdirAt(sys.Ctx, sys.Creds, &pop, &vfs.MkdirOptions{Mode: 0755}); err != nil { t.Fatalf("MkdirAt for PathOperation %+v failed: %v", pop, err) } sys.GetDentryOrDie(pop).DecRef() @@ -283,20 +222,21 @@ func TestReadStaticFile(t *testing.T) { "file1": fs.newFile(creds, staticFileContent), }) }) + defer sys.Destroy() pop := sys.PathOpAtRoot("file1") - fd, err := sys.vfs.OpenAt(sys.ctx, sys.creds, &pop, &vfs.OpenOptions{}) + fd, err := sys.VFS.OpenAt(sys.Ctx, sys.Creds, &pop, &vfs.OpenOptions{}) if err != nil { - sys.t.Fatalf("OpenAt for PathOperation %+v failed: %v", pop, err) + t.Fatalf("OpenAt for PathOperation %+v failed: %v", pop, err) } defer fd.DecRef() content, err := sys.ReadToEnd(fd) if err != nil { - sys.t.Fatalf("Read failed: %v", err) + t.Fatalf("Read failed: %v", err) } if diff := cmp.Diff(staticFileContent, content); diff != "" { - sys.t.Fatalf("Read returned unexpected data:\n--- want\n+++ got\n%v", diff) + t.Fatalf("Read returned unexpected data:\n--- want\n+++ got\n%v", diff) } } @@ -306,83 +246,44 @@ func TestCreateNewFileInStaticDir(t *testing.T) { "dir1": fs.newDir(creds, 0755, nil), }) }) + defer sys.Destroy() pop := sys.PathOpAtRoot("dir1/newfile") opts := &vfs.OpenOptions{Flags: linux.O_CREAT | linux.O_EXCL, Mode: defaultMode} - fd, err := sys.vfs.OpenAt(sys.ctx, sys.creds, &pop, opts) + fd, err := sys.VFS.OpenAt(sys.Ctx, sys.Creds, &pop, opts) if err != nil { - sys.t.Fatalf("OpenAt(pop:%+v, opts:%+v) failed: %v", pop, opts, err) + t.Fatalf("OpenAt(pop:%+v, opts:%+v) failed: %v", pop, opts, err) } // Close the file. The file should persist. fd.DecRef() - fd, err = sys.vfs.OpenAt(sys.ctx, sys.creds, &pop, &vfs.OpenOptions{}) + fd, err = sys.VFS.OpenAt(sys.Ctx, sys.Creds, &pop, &vfs.OpenOptions{}) if err != nil { - sys.t.Fatalf("OpenAt(pop:%+v) = %+v failed: %v", pop, fd, err) + t.Fatalf("OpenAt(pop:%+v) = %+v failed: %v", pop, fd, err) } fd.DecRef() } -// 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 - dirents map[string]vfs.Dirent -} - -// Handle implements vfs.IterDirentsCallback.Handle. -func (d *direntCollector) Handle(dirent vfs.Dirent) bool { - d.mu.Lock() - if d.dirents == nil { - d.dirents = make(map[string]vfs.Dirent) - } - d.dirents[dirent.Name] = dirent - d.mu.Unlock() - return true -} - -// 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 %d, got: %+v", name, typ, dirent) - } - return nil -} - func TestDirFDReadWrite(t *testing.T) { sys := newTestSystem(t, func(creds *auth.Credentials, fs *filesystem) *kernfs.Dentry { return fs.newReadonlyDir(creds, 0755, nil) }) + defer sys.Destroy() pop := sys.PathOpAtRoot("/") - fd, err := sys.vfs.OpenAt(sys.ctx, sys.creds, &pop, &vfs.OpenOptions{}) + fd, err := sys.VFS.OpenAt(sys.Ctx, sys.Creds, &pop, &vfs.OpenOptions{}) if err != nil { - sys.t.Fatalf("OpenAt for PathOperation %+v failed: %v", pop, err) + t.Fatalf("OpenAt for PathOperation %+v failed: %v", pop, err) } defer fd.DecRef() // Read/Write should fail for directory FDs. - if _, err := fd.Read(sys.ctx, usermem.BytesIOSequence([]byte{}), vfs.ReadOptions{}); err != syserror.EISDIR { - sys.t.Fatalf("Read for directory FD failed with unexpected error: %v", err) + if _, err := fd.Read(sys.Ctx, usermem.BytesIOSequence([]byte{}), vfs.ReadOptions{}); err != syserror.EISDIR { + t.Fatalf("Read for directory FD failed with unexpected error: %v", err) } - if _, err := fd.Write(sys.ctx, usermem.BytesIOSequence([]byte{}), vfs.WriteOptions{}); err != syserror.EISDIR { - sys.t.Fatalf("Wrire for directory FD failed with unexpected error: %v", err) + if _, err := fd.Write(sys.Ctx, usermem.BytesIOSequence([]byte{}), vfs.WriteOptions{}); err != syserror.EISDIR { + t.Fatalf("Write for directory FD failed with unexpected error: %v", err) } } @@ -397,30 +298,12 @@ func TestDirFDIterDirents(t *testing.T) { "file1": fs.newFile(creds, staticFileContent), }) }) + defer sys.Destroy() pop := sys.PathOpAtRoot("/") - fd, err := sys.vfs.OpenAt(sys.ctx, sys.creds, &pop, &vfs.OpenOptions{}) - if err != nil { - sys.t.Fatalf("OpenAt for PathOperation %+v failed: %v", pop, err) - } - defer fd.DecRef() - - collector := &direntCollector{} - if err := fd.IterDirents(sys.ctx, collector); err != nil { - sys.t.Fatalf("IterDirent failed: %v", err) - } - - // Root directory should contain ".", ".." and 3 children: - if collector.count() != 5 { - sys.t.Fatalf("IterDirent returned too many dirents") - } - for _, dirName := range []string{".", "..", "dir1", "dir2"} { - if err := collector.contains(dirName, linux.DT_DIR); err != nil { - sys.t.Fatalf("IterDirent had unexpected results: %v", err) - } - } - if err := collector.contains("file1", linux.DT_REG); err != nil { - sys.t.Fatalf("IterDirent had unexpected results: %v", err) - } - + sys.AssertDirectoryContains(&pop, map[string]testutil.DirentType{ + "dir1": linux.DT_DIR, + "dir2": linux.DT_DIR, + "file1": linux.DT_REG, + }) } diff --git a/pkg/sentry/fsimpl/proc/BUILD b/pkg/sentry/fsimpl/proc/BUILD index f69aa19c4..c5b79fb38 100644 --- a/pkg/sentry/fsimpl/proc/BUILD +++ b/pkg/sentry/fsimpl/proc/BUILD @@ -44,30 +44,19 @@ go_test( name = "proc_test", size = "small", srcs = [ - "boot_test.go", "tasks_sys_test.go", "tasks_test.go", ], embed = [":proc"], deps = [ "//pkg/abi/linux", - "//pkg/cpuid", "//pkg/fspath", - "//pkg/memutil", "//pkg/sentry/context", "//pkg/sentry/context/contexttest", - "//pkg/sentry/fs", + "//pkg/sentry/fsimpl/testutil", "//pkg/sentry/inet", "//pkg/sentry/kernel", "//pkg/sentry/kernel/auth", - "//pkg/sentry/kernel/sched", - "//pkg/sentry/limits", - "//pkg/sentry/loader", - "//pkg/sentry/pgalloc", - "//pkg/sentry/platform", - "//pkg/sentry/platform/kvm", - "//pkg/sentry/platform/ptrace", - "//pkg/sentry/time", "//pkg/sentry/usermem", "//pkg/sentry/vfs", "//pkg/syserror", diff --git a/pkg/sentry/fsimpl/proc/boot_test.go b/pkg/sentry/fsimpl/proc/boot_test.go deleted file mode 100644 index 84a93ee56..000000000 --- a/pkg/sentry/fsimpl/proc/boot_test.go +++ /dev/null @@ -1,149 +0,0 @@ -// 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 proc - -import ( - "flag" - "fmt" - "os" - "runtime" - - "gvisor.dev/gvisor/pkg/abi/linux" - "gvisor.dev/gvisor/pkg/cpuid" - "gvisor.dev/gvisor/pkg/memutil" - "gvisor.dev/gvisor/pkg/sentry/context" - "gvisor.dev/gvisor/pkg/sentry/fs" - "gvisor.dev/gvisor/pkg/sentry/kernel" - "gvisor.dev/gvisor/pkg/sentry/kernel/auth" - "gvisor.dev/gvisor/pkg/sentry/kernel/sched" - "gvisor.dev/gvisor/pkg/sentry/limits" - "gvisor.dev/gvisor/pkg/sentry/loader" - "gvisor.dev/gvisor/pkg/sentry/pgalloc" - "gvisor.dev/gvisor/pkg/sentry/platform" - "gvisor.dev/gvisor/pkg/sentry/time" - - // Platforms are plugable. - _ "gvisor.dev/gvisor/pkg/sentry/platform/kvm" - _ "gvisor.dev/gvisor/pkg/sentry/platform/ptrace" -) - -var ( - platformFlag = flag.String("platform", "ptrace", "specify which platform to use") -) - -// boot initializes a new bare bones kernel for test. -func boot() (*kernel.Kernel, error) { - platformCtr, err := platform.Lookup(*platformFlag) - if err != nil { - return nil, fmt.Errorf("platform not found: %v", err) - } - deviceFile, err := platformCtr.OpenDevice() - if err != nil { - return nil, fmt.Errorf("creating platform: %v", err) - } - plat, err := platformCtr.New(deviceFile) - if err != nil { - return nil, fmt.Errorf("creating platform: %v", err) - } - - k := &kernel.Kernel{ - Platform: plat, - } - - mf, err := createMemoryFile() - if err != nil { - return nil, err - } - k.SetMemoryFile(mf) - - // Pass k as the platform since it is savable, unlike the actual platform. - vdso, err := loader.PrepareVDSO(nil, k) - if err != nil { - return nil, fmt.Errorf("creating vdso: %v", err) - } - - // Create timekeeper. - tk, err := kernel.NewTimekeeper(k, vdso.ParamPage.FileRange()) - if err != nil { - return nil, fmt.Errorf("creating timekeeper: %v", err) - } - tk.SetClocks(time.NewCalibratedClocks()) - - creds := auth.NewRootCredentials(auth.NewRootUserNamespace()) - - // Initiate the Kernel object, which is required by the Context passed - // to createVFS in order to mount (among other things) procfs. - if err = k.Init(kernel.InitKernelArgs{ - ApplicationCores: uint(runtime.GOMAXPROCS(-1)), - FeatureSet: cpuid.HostFeatureSet(), - Timekeeper: tk, - RootUserNamespace: creds.UserNamespace, - Vdso: vdso, - RootUTSNamespace: kernel.NewUTSNamespace("hostname", "domain", creds.UserNamespace), - RootIPCNamespace: kernel.NewIPCNamespace(creds.UserNamespace), - RootAbstractSocketNamespace: kernel.NewAbstractSocketNamespace(), - PIDNamespace: kernel.NewRootPIDNamespace(creds.UserNamespace), - }); err != nil { - return nil, fmt.Errorf("initializing kernel: %v", err) - } - - ctx := k.SupervisorContext() - - // Create mount namespace without root as it's the minimum required to create - // the global thread group. - mntns, err := fs.NewMountNamespace(ctx, nil) - if err != nil { - return nil, err - } - ls, err := limits.NewLinuxLimitSet() - if err != nil { - return nil, err - } - tg := k.NewThreadGroup(mntns, k.RootPIDNamespace(), kernel.NewSignalHandlers(), linux.SIGCHLD, ls) - k.TestOnly_SetGlobalInit(tg) - - return k, nil -} - -// createTask creates a new bare bones task for tests. -func createTask(ctx context.Context, name string, tc *kernel.ThreadGroup) (*kernel.Task, error) { - k := kernel.KernelFromContext(ctx) - config := &kernel.TaskConfig{ - Kernel: k, - ThreadGroup: tc, - TaskContext: &kernel.TaskContext{Name: name}, - Credentials: auth.CredentialsFromContext(ctx), - AllowedCPUMask: sched.NewFullCPUSet(k.ApplicationCores()), - UTSNamespace: kernel.UTSNamespaceFromContext(ctx), - IPCNamespace: kernel.IPCNamespaceFromContext(ctx), - AbstractSocketNamespace: kernel.NewAbstractSocketNamespace(), - } - return k.TaskSet().NewTask(config) -} - -func createMemoryFile() (*pgalloc.MemoryFile, error) { - const memfileName = "test-memory" - memfd, err := memutil.CreateMemFD(memfileName, 0) - if err != nil { - return nil, fmt.Errorf("error creating memfd: %v", err) - } - memfile := os.NewFile(uintptr(memfd), memfileName) - mf, err := pgalloc.NewMemoryFile(memfile, pgalloc.MemoryFileOpts{}) - if err != nil { - memfile.Close() - return nil, fmt.Errorf("error creating pgalloc.MemoryFile: %v", err) - } - return mf, nil -} diff --git a/pkg/sentry/fsimpl/proc/tasks_test.go b/pkg/sentry/fsimpl/proc/tasks_test.go index 002d2f73b..41977d816 100644 --- a/pkg/sentry/fsimpl/proc/tasks_test.go +++ b/pkg/sentry/fsimpl/proc/tasks_test.go @@ -24,6 +24,7 @@ import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/fspath" "gvisor.dev/gvisor/pkg/sentry/context" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/testutil" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/usermem" @@ -134,7 +135,7 @@ func checkFiles(gots []vfs.Dirent, wants map[string]vfs.Dirent) ([]vfs.Dirent, e } func setup() (context.Context, *vfs.VirtualFilesystem, vfs.VirtualDentry, error) { - k, err := boot() + k, err := testutil.Boot() if err != nil { return nil, nil, vfs.VirtualDentry{}, fmt.Errorf("creating kernel: %v", err) } @@ -206,7 +207,7 @@ func TestTasks(t *testing.T) { var tasks []*kernel.Task for i := 0; i < 5; i++ { tc := k.NewThreadGroup(nil, k.RootPIDNamespace(), kernel.NewSignalHandlers(), linux.SIGCHLD, k.GlobalInit().Limits()) - task, err := createTask(ctx, fmt.Sprintf("name-%d", i), tc) + task, err := testutil.CreateTask(ctx, fmt.Sprintf("name-%d", i), tc) if err != nil { t.Fatalf("CreateTask(): %v", err) } @@ -298,7 +299,7 @@ func TestTasksOffset(t *testing.T) { k := kernel.KernelFromContext(ctx) for i := 0; i < 3; i++ { tc := k.NewThreadGroup(nil, k.RootPIDNamespace(), kernel.NewSignalHandlers(), linux.SIGCHLD, k.GlobalInit().Limits()) - if _, err := createTask(ctx, fmt.Sprintf("name-%d", i), tc); err != nil { + if _, err := testutil.CreateTask(ctx, fmt.Sprintf("name-%d", i), tc); err != nil { t.Fatalf("CreateTask(): %v", err) } } @@ -417,7 +418,7 @@ func TestTask(t *testing.T) { k := kernel.KernelFromContext(ctx) tc := k.NewThreadGroup(nil, k.RootPIDNamespace(), kernel.NewSignalHandlers(), linux.SIGCHLD, k.GlobalInit().Limits()) - _, err = createTask(ctx, "name", tc) + _, err = testutil.CreateTask(ctx, "name", tc) if err != nil { t.Fatalf("CreateTask(): %v", err) } @@ -458,7 +459,7 @@ func TestProcSelf(t *testing.T) { k := kernel.KernelFromContext(ctx) tc := k.NewThreadGroup(nil, k.RootPIDNamespace(), kernel.NewSignalHandlers(), linux.SIGCHLD, k.GlobalInit().Limits()) - task, err := createTask(ctx, "name", tc) + task, err := testutil.CreateTask(ctx, "name", tc) if err != nil { t.Fatalf("CreateTask(): %v", err) } @@ -555,7 +556,7 @@ func TestTree(t *testing.T) { var tasks []*kernel.Task for i := 0; i < 5; i++ { tc := k.NewThreadGroup(nil, k.RootPIDNamespace(), kernel.NewSignalHandlers(), linux.SIGCHLD, k.GlobalInit().Limits()) - task, err := createTask(uberCtx, fmt.Sprintf("name-%d", i), tc) + task, err := testutil.CreateTask(uberCtx, fmt.Sprintf("name-%d", i), tc) if err != nil { t.Fatalf("CreateTask(): %v", err) } diff --git a/pkg/sentry/fsimpl/sys/BUILD b/pkg/sentry/fsimpl/sys/BUILD new file mode 100644 index 000000000..ee3c842bd --- /dev/null +++ b/pkg/sentry/fsimpl/sys/BUILD @@ -0,0 +1,35 @@ +load("//tools/go_stateify:defs.bzl", "go_library") +load("@io_bazel_rules_go//go:def.bzl", "go_test") + +package(licenses = ["notice"]) + +go_library( + name = "sys", + srcs = [ + "sys.go", + ], + importpath = "gvisor.dev/gvisor/pkg/sentry/fsimpl/sys", + deps = [ + "//pkg/abi/linux", + "//pkg/sentry/context", + "//pkg/sentry/fsimpl/kernfs", + "//pkg/sentry/kernel", + "//pkg/sentry/kernel/auth", + "//pkg/sentry/vfs", + "//pkg/syserror", + ], +) + +go_test( + name = "sys_test", + srcs = ["sys_test.go"], + deps = [ + ":sys", + "//pkg/abi/linux", + "//pkg/sentry/fsimpl/testutil", + "//pkg/sentry/kernel", + "//pkg/sentry/kernel/auth", + "//pkg/sentry/vfs", + "@com_github_google_go-cmp//cmp:go_default_library", + ], +) diff --git a/pkg/sentry/fsimpl/sys/sys.go b/pkg/sentry/fsimpl/sys/sys.go new file mode 100644 index 000000000..1305ad01d --- /dev/null +++ b/pkg/sentry/fsimpl/sys/sys.go @@ -0,0 +1,124 @@ +// 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 sys implements sysfs. +package sys + +import ( + "bytes" + "fmt" + + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/sentry/context" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs" + "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/syserror" +) + +// FilesystemType implements vfs.FilesystemType. +type FilesystemType struct{} + +// filesystem implements vfs.FilesystemImpl. +type filesystem struct { + kernfs.Filesystem +} + +// GetFilesystem implements vfs.FilesystemType.GetFilesystem. +func (FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.VirtualFilesystem, creds *auth.Credentials, source string, opts vfs.GetFilesystemOptions) (*vfs.Filesystem, *vfs.Dentry, error) { + fs := &filesystem{} + fs.Filesystem.Init(vfsObj) + k := kernel.KernelFromContext(ctx) + maxCPUCores := k.ApplicationCores() + defaultSysDirMode := linux.FileMode(0755) + + root := fs.newDir(creds, defaultSysDirMode, map[string]*kernfs.Dentry{ + "block": fs.newDir(creds, defaultSysDirMode, nil), + "bus": fs.newDir(creds, defaultSysDirMode, nil), + "class": fs.newDir(creds, defaultSysDirMode, map[string]*kernfs.Dentry{ + "power_supply": fs.newDir(creds, defaultSysDirMode, nil), + }), + "dev": fs.newDir(creds, defaultSysDirMode, nil), + "devices": fs.newDir(creds, defaultSysDirMode, map[string]*kernfs.Dentry{ + "system": fs.newDir(creds, defaultSysDirMode, map[string]*kernfs.Dentry{ + "cpu": fs.newDir(creds, defaultSysDirMode, map[string]*kernfs.Dentry{ + "online": fs.newCPUFile(creds, maxCPUCores, linux.FileMode(0444)), + "possible": fs.newCPUFile(creds, maxCPUCores, linux.FileMode(0444)), + "present": fs.newCPUFile(creds, maxCPUCores, linux.FileMode(0444)), + }), + }), + }), + "firmware": fs.newDir(creds, defaultSysDirMode, nil), + "fs": fs.newDir(creds, defaultSysDirMode, nil), + "kernel": fs.newDir(creds, defaultSysDirMode, nil), + "module": fs.newDir(creds, defaultSysDirMode, nil), + "power": fs.newDir(creds, defaultSysDirMode, nil), + }) + return fs.VFSFilesystem(), root.VFSDentry(), nil +} + +// dir implements kernfs.Inode. +type dir struct { + kernfs.InodeAttrs + kernfs.InodeNoDynamicLookup + kernfs.InodeNotSymlink + kernfs.InodeDirectoryNoNewChildren + + kernfs.OrderedChildren + dentry kernfs.Dentry +} + +func (fs *filesystem) newDir(creds *auth.Credentials, mode linux.FileMode, contents map[string]*kernfs.Dentry) *kernfs.Dentry { + d := &dir{} + d.InodeAttrs.Init(creds, fs.NextIno(), linux.ModeDirectory|0755) + d.OrderedChildren.Init(kernfs.OrderedChildrenOptions{}) + d.dentry.Init(d) + + d.IncLinks(d.OrderedChildren.Populate(&d.dentry, contents)) + + return &d.dentry +} + +// SetStat implements kernfs.Inode.SetStat. +func (d *dir) SetStat(fs *vfs.Filesystem, opts vfs.SetStatOptions) error { + return syserror.EPERM +} + +// Open implements kernfs.Inode.Open. +func (d *dir) Open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, flags uint32) (*vfs.FileDescription, error) { + fd := &kernfs.GenericDirectoryFD{} + fd.Init(rp.Mount(), vfsd, &d.OrderedChildren, flags) + return fd.VFSFileDescription(), nil +} + +// cpuFile implements kernfs.Inode. +type cpuFile struct { + kernfs.DynamicBytesFile + maxCores uint +} + +// Generate implements vfs.DynamicBytesSource.Generate. +func (c *cpuFile) Generate(ctx context.Context, buf *bytes.Buffer) error { + fmt.Fprintf(buf, "0-%d", c.maxCores-1) + return nil +} + +func (fs *filesystem) newCPUFile(creds *auth.Credentials, maxCores uint, mode linux.FileMode) *kernfs.Dentry { + c := &cpuFile{maxCores: maxCores} + c.DynamicBytesFile.Init(creds, fs.NextIno(), c, mode) + d := &kernfs.Dentry{} + d.Init(c) + return d +} diff --git a/pkg/sentry/fsimpl/sys/sys_test.go b/pkg/sentry/fsimpl/sys/sys_test.go new file mode 100644 index 000000000..60a1634a9 --- /dev/null +++ b/pkg/sentry/fsimpl/sys/sys_test.go @@ -0,0 +1,90 @@ +// 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 sys_test + +import ( + "fmt" + "testing" + + "github.com/google/go-cmp/cmp" + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/sys" + "gvisor.dev/gvisor/pkg/sentry/fsimpl/testutil" + "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/vfs" +) + +func newTestSystem(t *testing.T) *testutil.System { + k, err := testutil.Boot() + if err != nil { + t.Fatalf("Failed to create test kernel: %v", err) + } + ctx := k.SupervisorContext() + creds := auth.CredentialsFromContext(ctx) + v := vfs.New() + v.MustRegisterFilesystemType("sysfs", sys.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{ + AllowUserMount: true, + }) + + mns, err := v.NewMountNamespace(ctx, creds, "", "sysfs", &vfs.GetFilesystemOptions{}) + if err != nil { + t.Fatalf("Failed to create new mount namespace: %v", err) + } + return testutil.NewSystem(ctx, t, v, mns) +} + +func TestReadCPUFile(t *testing.T) { + s := newTestSystem(t) + defer s.Destroy() + k := kernel.KernelFromContext(s.Ctx) + maxCPUCores := k.ApplicationCores() + + expected := fmt.Sprintf("0-%d", maxCPUCores-1) + + for _, fname := range []string{"online", "possible", "present"} { + pop := s.PathOpAtRoot(fmt.Sprintf("devices/system/cpu/%s", fname)) + fd, err := s.VFS.OpenAt(s.Ctx, s.Creds, &pop, &vfs.OpenOptions{}) + if err != nil { + t.Fatalf("OpenAt(pop:%+v) = %+v failed: %v", pop, fd, err) + } + defer fd.DecRef() + content, err := s.ReadToEnd(fd) + if err != nil { + t.Fatalf("Read failed: %v", err) + } + if diff := cmp.Diff(expected, content); diff != "" { + t.Fatalf("Read returned unexpected data:\n--- want\n+++ got\n%v", diff) + } + } +} + +func TestSysRootContainsExpectedEntries(t *testing.T) { + s := newTestSystem(t) + defer s.Destroy() + pop := s.PathOpAtRoot("/") + s.AssertDirectoryContains(&pop, map[string]testutil.DirentType{ + "block": linux.DT_DIR, + "bus": linux.DT_DIR, + "class": linux.DT_DIR, + "dev": linux.DT_DIR, + "devices": linux.DT_DIR, + "firmware": linux.DT_DIR, + "fs": linux.DT_DIR, + "kernel": linux.DT_DIR, + "module": linux.DT_DIR, + "power": linux.DT_DIR, + }) +} diff --git a/pkg/sentry/fsimpl/testutil/BUILD b/pkg/sentry/fsimpl/testutil/BUILD new file mode 100644 index 000000000..4e70d84a7 --- /dev/null +++ b/pkg/sentry/fsimpl/testutil/BUILD @@ -0,0 +1,36 @@ +load("//tools/go_stateify:defs.bzl", "go_library") + +package(licenses = ["notice"]) + +go_library( + name = "testutil", + testonly = 1, + srcs = [ + "kernel.go", + "testutil.go", + ], + importpath = "gvisor.dev/gvisor/pkg/sentry/fsimpl/testutil", + visibility = ["//pkg/sentry:internal"], + deps = [ + "//pkg/abi/linux", + "//pkg/cpuid", + "//pkg/fspath", + "//pkg/memutil", + "//pkg/sentry/context", + "//pkg/sentry/fs", + "//pkg/sentry/kernel", + "//pkg/sentry/kernel/auth", + "//pkg/sentry/kernel/sched", + "//pkg/sentry/limits", + "//pkg/sentry/loader", + "//pkg/sentry/pgalloc", + "//pkg/sentry/platform", + "//pkg/sentry/platform/kvm", + "//pkg/sentry/platform/ptrace", + "//pkg/sentry/time", + "//pkg/sentry/usermem", + "//pkg/sentry/vfs", + "//pkg/sync", + "@com_github_google_go-cmp//cmp:go_default_library", + ], +) diff --git a/pkg/sentry/fsimpl/testutil/kernel.go b/pkg/sentry/fsimpl/testutil/kernel.go new file mode 100644 index 000000000..295da2d52 --- /dev/null +++ b/pkg/sentry/fsimpl/testutil/kernel.go @@ -0,0 +1,149 @@ +// 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 + +import ( + "flag" + "fmt" + "os" + "runtime" + + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/cpuid" + "gvisor.dev/gvisor/pkg/memutil" + "gvisor.dev/gvisor/pkg/sentry/context" + "gvisor.dev/gvisor/pkg/sentry/fs" + "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/kernel/sched" + "gvisor.dev/gvisor/pkg/sentry/limits" + "gvisor.dev/gvisor/pkg/sentry/loader" + "gvisor.dev/gvisor/pkg/sentry/pgalloc" + "gvisor.dev/gvisor/pkg/sentry/platform" + "gvisor.dev/gvisor/pkg/sentry/time" + + // Platforms are plugable. + _ "gvisor.dev/gvisor/pkg/sentry/platform/kvm" + _ "gvisor.dev/gvisor/pkg/sentry/platform/ptrace" +) + +var ( + platformFlag = flag.String("platform", "ptrace", "specify which platform to use") +) + +// Boot initializes a new bare bones kernel for test. +func Boot() (*kernel.Kernel, error) { + platformCtr, err := platform.Lookup(*platformFlag) + if err != nil { + return nil, fmt.Errorf("platform not found: %v", err) + } + deviceFile, err := platformCtr.OpenDevice() + if err != nil { + return nil, fmt.Errorf("creating platform: %v", err) + } + plat, err := platformCtr.New(deviceFile) + if err != nil { + return nil, fmt.Errorf("creating platform: %v", err) + } + + k := &kernel.Kernel{ + Platform: plat, + } + + mf, err := createMemoryFile() + if err != nil { + return nil, err + } + k.SetMemoryFile(mf) + + // Pass k as the platform since it is savable, unlike the actual platform. + vdso, err := loader.PrepareVDSO(nil, k) + if err != nil { + return nil, fmt.Errorf("creating vdso: %v", err) + } + + // Create timekeeper. + tk, err := kernel.NewTimekeeper(k, vdso.ParamPage.FileRange()) + if err != nil { + return nil, fmt.Errorf("creating timekeeper: %v", err) + } + tk.SetClocks(time.NewCalibratedClocks()) + + creds := auth.NewRootCredentials(auth.NewRootUserNamespace()) + + // Initiate the Kernel object, which is required by the Context passed + // to createVFS in order to mount (among other things) procfs. + if err = k.Init(kernel.InitKernelArgs{ + ApplicationCores: uint(runtime.GOMAXPROCS(-1)), + FeatureSet: cpuid.HostFeatureSet(), + Timekeeper: tk, + RootUserNamespace: creds.UserNamespace, + Vdso: vdso, + RootUTSNamespace: kernel.NewUTSNamespace("hostname", "domain", creds.UserNamespace), + RootIPCNamespace: kernel.NewIPCNamespace(creds.UserNamespace), + RootAbstractSocketNamespace: kernel.NewAbstractSocketNamespace(), + PIDNamespace: kernel.NewRootPIDNamespace(creds.UserNamespace), + }); err != nil { + return nil, fmt.Errorf("initializing kernel: %v", err) + } + + ctx := k.SupervisorContext() + + // Create mount namespace without root as it's the minimum required to create + // the global thread group. + mntns, err := fs.NewMountNamespace(ctx, nil) + if err != nil { + return nil, err + } + ls, err := limits.NewLinuxLimitSet() + if err != nil { + return nil, err + } + tg := k.NewThreadGroup(mntns, k.RootPIDNamespace(), kernel.NewSignalHandlers(), linux.SIGCHLD, ls) + k.TestOnly_SetGlobalInit(tg) + + return k, nil +} + +// CreateTask creates a new bare bones task for tests. +func CreateTask(ctx context.Context, name string, tc *kernel.ThreadGroup) (*kernel.Task, error) { + k := kernel.KernelFromContext(ctx) + config := &kernel.TaskConfig{ + Kernel: k, + ThreadGroup: tc, + TaskContext: &kernel.TaskContext{Name: name}, + Credentials: auth.CredentialsFromContext(ctx), + AllowedCPUMask: sched.NewFullCPUSet(k.ApplicationCores()), + UTSNamespace: kernel.UTSNamespaceFromContext(ctx), + IPCNamespace: kernel.IPCNamespaceFromContext(ctx), + AbstractSocketNamespace: kernel.NewAbstractSocketNamespace(), + } + return k.TaskSet().NewTask(config) +} + +func createMemoryFile() (*pgalloc.MemoryFile, error) { + const memfileName = "test-memory" + memfd, err := memutil.CreateMemFD(memfileName, 0) + if err != nil { + return nil, fmt.Errorf("error creating memfd: %v", err) + } + memfile := os.NewFile(uintptr(memfd), memfileName) + mf, err := pgalloc.NewMemoryFile(memfile, pgalloc.MemoryFileOpts{}) + if err != nil { + memfile.Close() + return nil, fmt.Errorf("error creating pgalloc.MemoryFile: %v", err) + } + return mf, nil +} diff --git a/pkg/sentry/fsimpl/testutil/testutil.go b/pkg/sentry/fsimpl/testutil/testutil.go new file mode 100644 index 000000000..eada31d94 --- /dev/null +++ b/pkg/sentry/fsimpl/testutil/testutil.go @@ -0,0 +1,178 @@ +// 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/fspath" + "gvisor.dev/gvisor/pkg/sentry/context" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/usermem" + "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/sync" +) + +// 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 + mns *vfs.MountNamespace + root vfs.VirtualDentry +} + +// NewSystem constructs a System. +// +// Precondition: Caller must hold a reference on mns, 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, + mns: mns, + root: mns.Root(), + } + return s +} + +// Destroy release resources associated with a test system. +func (s *System) Destroy() { + s.root.DecRef() + s.mns.DecRef(s.VFS) // Reference on mns 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 + +// AssertDirectoryContains verifies that a directory at pop contains the entries +// specified. AssertDirectoryContains implicitly checks for "." and "..", these +// need not be included in entries. +func (s *System) AssertDirectoryContains(pop *vfs.PathOperation, entries map[string]DirentType) { + // Also implicitly check for "." and "..". + entries["."] = linux.DT_DIR + entries[".."] = linux.DT_DIR + + 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) + } + + collectedEntries := make(map[string]DirentType) + for _, dirent := range collector.dirents { + collectedEntries[dirent.Name] = dirent.Type + } + if diff := cmp.Diff(entries, collectedEntries); 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 + dirents map[string]vfs.Dirent +} + +// Handle implements vfs.IterDirentsCallback.Handle. +func (d *DirentCollector) Handle(dirent vfs.Dirent) bool { + d.mu.Lock() + if d.dirents == nil { + d.dirents = make(map[string]vfs.Dirent) + } + d.dirents[dirent.Name] = dirent + d.mu.Unlock() + return true +} + +// 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 +} -- cgit v1.2.3