Fix sandbox and gofer capabilities

Capabilities.Set() adds capabilities,
but doesn't remove existing ones that might have been loaded. Fixed
the code and added tests.

PiperOrigin-RevId: 213726369
Change-Id: Id7fa6fce53abf26c29b13b9157bb4c6616986fba

1 files changed, 121 insertions, 0 deletions

diff --git a/runsc/cmd/capability_test.go b/runsc/cmd/capability_test.go
new file mode 100644
index 000000000..be9ef2e7b
--- /dev/null
+++ b/runsc/cmd/capability_test.go
@@ -0,0 +1,121 @@
+// 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 cmd
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/syndtr/gocapability/capability"
+	"gvisor.googlesource.com/gvisor/pkg/log"
+	"gvisor.googlesource.com/gvisor/runsc/boot"
+	"gvisor.googlesource.com/gvisor/runsc/container"
+	"gvisor.googlesource.com/gvisor/runsc/specutils"
+	"gvisor.googlesource.com/gvisor/runsc/test/testutil"
+)
+
+func init() {
+	log.SetLevel(log.Debug)
+	if err := testutil.ConfigureExePath(); err != nil {
+		panic(err.Error())
+	}
+}
+
+func checkProcessCaps(pid int, wantCaps *specs.LinuxCapabilities) error {
+	curCaps, err := capability.NewPid2(pid)
+	if err != nil {
+		return fmt.Errorf("capability.NewPid2(%d) failed: %v", pid, err)
+	}
+	if err := curCaps.Load(); err != nil {
+		return fmt.Errorf("unable to load capabilities: %v", err)
+	}
+	fmt.Printf("Capabilities (PID: %d): %v\n", pid, curCaps)
+
+	for _, c := range allCapTypes {
+		if err := checkCaps(c, curCaps, wantCaps); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func checkCaps(which capability.CapType, curCaps capability.Capabilities, wantCaps *specs.LinuxCapabilities) error {
+	wantNames := getCaps(which, wantCaps)
+	for name, c := range capFromName {
+		want := specutils.ContainsStr(wantNames, name)
+		got := curCaps.Get(which, c)
+		if want != got {
+			if want {
+				return fmt.Errorf("capability %v:%s should be set", which, name)
+			}
+			return fmt.Errorf("capability %v:%s should NOT be set", which, name)
+		}
+	}
+	return nil
+}
+
+func TestCapabilities(t *testing.T) {
+	stop := testutil.StartReaper()
+	defer stop()
+
+	spec := testutil.NewSpecWithArgs("/bin/sleep", "10000")
+	caps := []string{
+		"CAP_CHOWN",
+		"CAP_SYS_PTRACE", // ptrace is added due to the platform choice.
+	}
+	spec.Process.Capabilities = &specs.LinuxCapabilities{
+		Permitted:   caps,
+		Bounding:    caps,
+		Effective:   caps,
+		Inheritable: caps,
+	}
+
+	conf := testutil.TestConfig()
+
+	// Use --network=host to make sandbox use spec's capabilities.
+	conf.Network = boot.NetworkHost
+
+	rootDir, bundleDir, err := testutil.SetupContainer(spec, conf)
+	if err != nil {
+		t.Fatalf("error setting up container: %v", err)
+	}
+	defer os.RemoveAll(rootDir)
+	defer os.RemoveAll(bundleDir)
+
+	// Create and start the container.
+	c, err := container.Create(testutil.UniqueContainerID(), spec, conf, bundleDir, "", "")
+	if err != nil {
+		t.Fatalf("error creating container: %v", err)
+	}
+	defer c.Destroy()
+	if err := c.Start(conf); err != nil {
+		t.Fatalf("error starting container: %v", err)
+	}
+
+	// Check that sandbox and gofer have the proper capabilities.
+	if err := checkProcessCaps(c.Sandbox.Pid, spec.Process.Capabilities); err != nil {
+		t.Error(err)
+	}
+	if err := checkProcessCaps(c.GoferPid, goferCaps); err != nil {
+		t.Error(err)
+	}
+}
+
+func TestMain(m *testing.M) {
+	testutil.RunAsRoot()
+	os.Exit(m.Run())
+}