diff options
Diffstat (limited to 'pkg/sentry/control')
| -rw-r--r-- | pkg/sentry/control/BUILD | 8 | ||||
| -rw-r--r-- | pkg/sentry/control/events.go | 65 | ||||
| -rw-r--r-- | pkg/sentry/control/fs.go | 93 | ||||
| -rw-r--r-- | pkg/sentry/control/lifecycle.go | 36 | ||||
| -rw-r--r-- | pkg/sentry/control/usage.go | 183 |
5 files changed, 385 insertions, 0 deletions
diff --git a/pkg/sentry/control/BUILD b/pkg/sentry/control/BUILD index deaf5fa23..a4934a565 100644 --- a/pkg/sentry/control/BUILD +++ b/pkg/sentry/control/BUILD @@ -6,16 +6,22 @@ go_library( name = "control", srcs = [ "control.go", + "events.go", + "fs.go", + "lifecycle.go", "logging.go", "pprof.go", "proc.go", "state.go", + "usage.go", ], visibility = [ "//:sandbox", ], deps = [ "//pkg/abi/linux", + "//pkg/context", + "//pkg/eventchannel", "//pkg/fd", "//pkg/log", "//pkg/sentry/fdimport", @@ -35,6 +41,8 @@ go_library( "//pkg/sync", "//pkg/tcpip/link/sniffer", "//pkg/urpc", + "//pkg/usermem", + "@org_golang_x_sys//unix:go_default_library", ], ) diff --git a/pkg/sentry/control/events.go b/pkg/sentry/control/events.go new file mode 100644 index 000000000..92e437ae7 --- /dev/null +++ b/pkg/sentry/control/events.go @@ -0,0 +1,65 @@ +// Copyright 2021 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 control + +import ( + "errors" + "fmt" + + "gvisor.dev/gvisor/pkg/eventchannel" + "gvisor.dev/gvisor/pkg/urpc" +) + +// EventsOpts are the arguments for eventchannel-related commands. +type EventsOpts struct { + urpc.FilePayload +} + +// Events is the control server state for eventchannel-related commands. +type Events struct { + emitter eventchannel.Emitter +} + +// AttachDebugEmitter receives a connected unix domain socket FD from the client +// and establishes it as a new emitter for the sentry eventchannel. Any existing +// emitters are replaced on a subsequent attach. +func (e *Events) AttachDebugEmitter(o *EventsOpts, _ *struct{}) error { + if len(o.FilePayload.Files) < 1 { + return errors.New("no output writer provided") + } + + sock, err := o.ReleaseFD(0) + if err != nil { + return err + } + sockFD := sock.Release() + + // SocketEmitter takes ownership of sockFD. + emitter, err := eventchannel.SocketEmitter(sockFD) + if err != nil { + return fmt.Errorf("failed to create SocketEmitter for FD %d: %v", sockFD, err) + } + + // If there is already a debug emitter, close the old one. + if e.emitter != nil { + e.emitter.Close() + } + + e.emitter = eventchannel.DebugEmitterFrom(emitter) + + // Register the new stream destination. + eventchannel.AddEmitter(e.emitter) + return nil +} diff --git a/pkg/sentry/control/fs.go b/pkg/sentry/control/fs.go new file mode 100644 index 000000000..d19b21f2d --- /dev/null +++ b/pkg/sentry/control/fs.go @@ -0,0 +1,93 @@ +// Copyright 2021 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 control + +import ( + "fmt" + "io" + "os" + + "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/sentry/fs" + "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/urpc" + "gvisor.dev/gvisor/pkg/usermem" +) + +// CatOpts contains options for the Cat RPC call. +type CatOpts struct { + // Files are the filesystem paths for the files to cat. + Files []string `json:"files"` + + // FilePayload contains the destination for output. + urpc.FilePayload +} + +// Fs includes fs-related functions. +type Fs struct { + Kernel *kernel.Kernel +} + +// Cat is a RPC stub which prints out and returns the content of the files. +func (f *Fs) Cat(o *CatOpts, _ *struct{}) error { + // Create an output stream. + if len(o.FilePayload.Files) != 1 { + return ErrInvalidFiles + } + + output := o.FilePayload.Files[0] + for _, file := range o.Files { + if err := cat(f.Kernel, file, output); err != nil { + return fmt.Errorf("cannot read from file %s: %v", file, err) + } + } + + return nil +} + +// fileReader encapsulates a fs.File and provides an io.Reader interface. +type fileReader struct { + ctx context.Context + file *fs.File +} + +// Read implements io.Reader.Read. +func (f *fileReader) Read(p []byte) (int, error) { + n, err := f.file.Readv(f.ctx, usermem.BytesIOSequence(p)) + return int(n), err +} + +func cat(k *kernel.Kernel, path string, output *os.File) error { + ctx := k.SupervisorContext() + mns := k.GlobalInit().Leader().MountNamespace() + root := mns.Root() + defer root.DecRef(ctx) + + remainingTraversals := uint(fs.DefaultTraversalLimit) + d, err := mns.FindInode(ctx, root, nil, path, &remainingTraversals) + if err != nil { + return fmt.Errorf("cannot find file %s: %v", path, err) + } + defer d.DecRef(ctx) + + file, err := d.Inode.GetFile(ctx, d, fs.FileFlags{Read: true}) + if err != nil { + return fmt.Errorf("cannot get file for path %s: %v", path, err) + } + defer file.DecRef(ctx) + + _, err = io.Copy(output, &fileReader{ctx: ctx, file: file}) + return err +} diff --git a/pkg/sentry/control/lifecycle.go b/pkg/sentry/control/lifecycle.go new file mode 100644 index 000000000..67abf497d --- /dev/null +++ b/pkg/sentry/control/lifecycle.go @@ -0,0 +1,36 @@ +// Copyright 2021 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 control + +import ( + "gvisor.dev/gvisor/pkg/sentry/kernel" +) + +// Lifecycle provides functions related to starting and stopping tasks. +type Lifecycle struct { + Kernel *kernel.Kernel +} + +// Pause pauses all tasks, blocking until they are stopped. +func (l *Lifecycle) Pause(_, _ *struct{}) error { + l.Kernel.Pause() + return nil +} + +// Resume resumes all tasks. +func (l *Lifecycle) Resume(_, _ *struct{}) error { + l.Kernel.Unpause() + return nil +} diff --git a/pkg/sentry/control/usage.go b/pkg/sentry/control/usage.go new file mode 100644 index 000000000..cc78d3f45 --- /dev/null +++ b/pkg/sentry/control/usage.go @@ -0,0 +1,183 @@ +// Copyright 2021 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 control + +import ( + "fmt" + "os" + "runtime" + + "golang.org/x/sys/unix" + "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/sentry/usage" + "gvisor.dev/gvisor/pkg/urpc" +) + +// Usage includes usage-related RPC stubs. +type Usage struct { + Kernel *kernel.Kernel +} + +// MemoryUsageOpts contains usage options. +type MemoryUsageOpts struct { + // Full indicates that a full accounting should be done. If Full is not + // specified, then a partial accounting will be done, and Unknown will + // contain a majority of memory. See Collect for more information. + Full bool `json:"Full"` +} + +// MemoryUsage is a memory usage structure. +type MemoryUsage struct { + Unknown uint64 `json:"Unknown"` + System uint64 `json:"System"` + Anonymous uint64 `json:"Anonymous"` + PageCache uint64 `json:"PageCache"` + Mapped uint64 `json:"Mapped"` + Tmpfs uint64 `json:"Tmpfs"` + Ramdiskfs uint64 `json:"Ramdiskfs"` + Total uint64 `json:"Total"` +} + +// MemoryUsageFileOpts contains usage file options. +type MemoryUsageFileOpts struct { + // Version is used to ensure both sides agree on the format of the + // shared memory buffer. + Version uint64 `json:"Version"` +} + +// MemoryUsageFile contains the file handle to the usage file. +type MemoryUsageFile struct { + urpc.FilePayload +} + +// UsageFD returns the file that tracks the memory usage of the application. +func (u *Usage) UsageFD(opts *MemoryUsageFileOpts, out *MemoryUsageFile) error { + // Only support version 1 for now. + if opts.Version != 1 { + return fmt.Errorf("unsupported version requested: %d", opts.Version) + } + + mf := u.Kernel.MemoryFile() + *out = MemoryUsageFile{ + FilePayload: urpc.FilePayload{ + Files: []*os.File{ + usage.MemoryAccounting.File, + mf.File(), + }, + }, + } + + return nil +} + +// Collect returns memory used by the sandboxed application. +func (u *Usage) Collect(opts *MemoryUsageOpts, out *MemoryUsage) error { + if opts.Full { + // Ensure everything is up to date. + if err := u.Kernel.MemoryFile().UpdateUsage(); err != nil { + return err + } + + // Copy out a snapshot. + snapshot, total := usage.MemoryAccounting.Copy() + *out = MemoryUsage{ + System: snapshot.System, + Anonymous: snapshot.Anonymous, + PageCache: snapshot.PageCache, + Mapped: snapshot.Mapped, + Tmpfs: snapshot.Tmpfs, + Ramdiskfs: snapshot.Ramdiskfs, + Total: total, + } + } else { + // Get total usage from the MemoryFile implementation. + total, err := u.Kernel.MemoryFile().TotalUsage() + if err != nil { + return err + } + + // The memory accounting is guaranteed to be accurate only when + // UpdateUsage is called. If UpdateUsage is not called, then only Mapped + // will be up-to-date. + snapshot, _ := usage.MemoryAccounting.Copy() + *out = MemoryUsage{ + Unknown: total, + Mapped: snapshot.Mapped, + Total: total + snapshot.Mapped, + } + + } + + return nil +} + +// UsageReduceOpts contains options to Usage.Reduce(). +type UsageReduceOpts struct { + // If Wait is true, Reduce blocks until all activity initiated by + // Usage.Reduce() has completed. + Wait bool `json:"wait"` +} + +// UsageReduceOutput contains output from Usage.Reduce(). +type UsageReduceOutput struct{} + +// Reduce requests that the sentry attempt to reduce its memory usage. +func (u *Usage) Reduce(opts *UsageReduceOpts, out *UsageReduceOutput) error { + mf := u.Kernel.MemoryFile() + mf.StartEvictions() + if opts.Wait { + mf.WaitForEvictions() + } + return nil +} + +// MemoryUsageRecord contains the mapping and platform memory file. +type MemoryUsageRecord struct { + mmap uintptr + stats *usage.RTMemoryStats + mf os.File +} + +// NewMemoryUsageRecord creates a new MemoryUsageRecord from usageFile and +// platformFile. +func NewMemoryUsageRecord(usageFile, platformFile os.File) (*MemoryUsageRecord, error) { + mmap, _, e := unix.RawSyscall6(unix.SYS_MMAP, 0, usage.RTMemoryStatsSize, unix.PROT_READ, unix.MAP_SHARED, usageFile.Fd(), 0) + if e != 0 { + return nil, fmt.Errorf("mmap returned %d, want 0", e) + } + + m := MemoryUsageRecord{ + mmap: mmap, + stats: usage.RTMemoryStatsPointer(mmap), + mf: platformFile, + } + + runtime.SetFinalizer(&m, finalizer) + return &m, nil +} + +func finalizer(m *MemoryUsageRecord) { + unix.RawSyscall(unix.SYS_MUNMAP, m.mmap, usage.RTMemoryStatsSize, 0) +} + +// Fetch fetches the usage info from a MemoryUsageRecord. +func (m *MemoryUsageRecord) Fetch() (mapped, unknown, total uint64, err error) { + var stat unix.Stat_t + if err := unix.Fstat(int(m.mf.Fd()), &stat); err != nil { + return 0, 0, 0, err + } + fmem := uint64(stat.Blocks) * 512 + return m.stats.RTMapped, fmem, m.stats.RTMapped + fmem, nil +} |