Added a function to the controller to checkpoint a container.

Functionality for checkpoint is not complete, more to come.

PiperOrigin-RevId: 199500803
Change-Id: Iafb0fcde68c584270000fea898e6657a592466f7

2 files changed, 77 insertions, 0 deletions

diff --git a/pkg/sentry/control/BUILD b/pkg/sentry/control/BUILD
index 4d1d0d019..6169891f7 100644
--- a/pkg/sentry/control/BUILD
+++ b/pkg/sentry/control/BUILD
@@ -7,6 +7,7 @@ go_library(
     srcs = [
         "control.go",
         "proc.go",
+        "state.go",
     ],
     importpath = "gvisor.googlesource.com/gvisor/pkg/sentry/control",
     visibility = [
@@ -14,6 +15,7 @@ go_library(
     ],
     deps = [
         "//pkg/abi/linux",
+        "//pkg/log",
         "//pkg/sentry/fs",
         "//pkg/sentry/fs/host",
         "//pkg/sentry/kernel",
@@ -21,7 +23,9 @@ go_library(
         "//pkg/sentry/kernel/kdefs",
         "//pkg/sentry/kernel/time",
         "//pkg/sentry/limits",
+        "//pkg/sentry/state",
         "//pkg/sentry/usage",
+        "//pkg/sentry/watchdog",
         "//pkg/urpc",
     ],
 )
diff --git a/pkg/sentry/control/state.go b/pkg/sentry/control/state.go
new file mode 100644
index 000000000..cee4db636
--- /dev/null
+++ b/pkg/sentry/control/state.go
@@ -0,0 +1,73 @@
+// 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 control
+
+import (
+	"errors"
+
+	"gvisor.googlesource.com/gvisor/pkg/log"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/kernel"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/state"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/watchdog"
+	"gvisor.googlesource.com/gvisor/pkg/urpc"
+)
+
+// ErrInvalidFiles is returned when the urpc call to Save does not include an
+// appropriate file payload (e.g. there is no output file!).
+var ErrInvalidFiles = errors.New("exactly one file must be provided")
+
+// State includes state-related functions.
+type State struct {
+	Kernel   *kernel.Kernel
+	Watchdog *watchdog.Watchdog
+}
+
+// SaveOpts contains options for the Save RPC call.
+type SaveOpts struct {
+	// Key is used for state integrity check.
+	Key []byte `json:"key"`
+
+	// Metadata is the set of metadata to prepend to the state file.
+	Metadata map[string]string `json:"metadata"`
+
+	// FilePayload contains the destination for the state.
+	urpc.FilePayload
+}
+
+// Save saves the running system.
+func (s *State) Save(o *SaveOpts, _ *struct{}) error {
+	// Create an output stream.
+	if len(o.FilePayload.Files) != 1 {
+		return ErrInvalidFiles
+	}
+	defer o.FilePayload.Files[0].Close()
+
+	// Save to the first provided stream.
+	saveOpts := state.SaveOpts{
+		Destination: o.FilePayload.Files[0],
+		Key:         o.Key,
+		Metadata:    o.Metadata,
+		Callback: func(err error) {
+			if err == nil {
+				log.Infof("Save succeeded: exiting...")
+			} else {
+				log.Warningf("Save failed: exiting...")
+				s.Kernel.SetExitError(err)
+			}
+			s.Kernel.Kill(kernel.ExitStatus{})
+		},
+	}
+	return saveOpts.Save(s.Kernel, s.Watchdog)
+}