From 775a321120f09420ef37ba9455371f193380a695 Mon Sep 17 00:00:00 2001
From: Jamie Liu <jamieliu@google.com>
Date: Fri, 3 Sep 2021 19:07:12 -0700
Subject: Add //pkg/sentry/seccheck.

This defines common infrastructure for dynamically-configured security checks,
including an example usage in the clone(2) path.

PiperOrigin-RevId: 394797270
---
 pkg/sentry/seccheck/seccheck_test.go | 157 +++++++++++++++++++++++++++++++++++
 1 file changed, 157 insertions(+)
 create mode 100644 pkg/sentry/seccheck/seccheck_test.go

(limited to 'pkg/sentry/seccheck/seccheck_test.go')

diff --git a/pkg/sentry/seccheck/seccheck_test.go b/pkg/sentry/seccheck/seccheck_test.go
new file mode 100644
index 000000000..687810d18
--- /dev/null
+++ b/pkg/sentry/seccheck/seccheck_test.go
@@ -0,0 +1,157 @@
+// 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 seccheck
+
+import (
+	"errors"
+	"testing"
+
+	"gvisor.dev/gvisor/pkg/context"
+)
+
+type testChecker struct {
+	CheckerDefaults
+
+	onClone func(ctx context.Context, mask CloneFieldSet, info CloneInfo) error
+}
+
+// Clone implements Checker.Clone.
+func (c *testChecker) Clone(ctx context.Context, mask CloneFieldSet, info CloneInfo) error {
+	if c.onClone == nil {
+		return nil
+	}
+	return c.onClone(ctx, mask, info)
+}
+
+func TestNoChecker(t *testing.T) {
+	var s state
+	if s.Enabled(PointClone) {
+		t.Errorf("Enabled(PointClone): got true, wanted false")
+	}
+}
+
+func TestCheckerNotRegisteredForPoint(t *testing.T) {
+	var s state
+	s.AppendChecker(&testChecker{}, &CheckerReq{})
+	if s.Enabled(PointClone) {
+		t.Errorf("Enabled(PointClone): got true, wanted false")
+	}
+}
+
+func TestCheckerRegistered(t *testing.T) {
+	var s state
+	checkerCalled := false
+	s.AppendChecker(&testChecker{onClone: func(ctx context.Context, mask CloneFieldSet, info CloneInfo) error {
+		checkerCalled = true
+		return nil
+	}}, &CheckerReq{
+		Points: []Point{PointClone},
+		Clone: CloneFields{
+			Credentials: true,
+		},
+	})
+
+	if !s.Enabled(PointClone) {
+		t.Errorf("Enabled(PointClone): got false, wanted true")
+	}
+	if !s.CloneReq().Contains(CloneFieldCredentials) {
+		t.Errorf("CloneReq().Contains(CloneFieldCredentials): got false, wanted true")
+	}
+	if err := s.Clone(context.Background(), CloneFieldSet{}, &CloneInfo{}); err != nil {
+		t.Errorf("Clone(): got %v, wanted nil", err)
+	}
+	if !checkerCalled {
+		t.Errorf("Clone() did not call Checker.Clone()")
+	}
+}
+
+func TestMultipleCheckersRegistered(t *testing.T) {
+	var s state
+	checkersCalled := [2]bool{}
+	s.AppendChecker(&testChecker{onClone: func(ctx context.Context, mask CloneFieldSet, info CloneInfo) error {
+		checkersCalled[0] = true
+		return nil
+	}}, &CheckerReq{
+		Points: []Point{PointClone},
+		Clone: CloneFields{
+			Args: true,
+		},
+	})
+	s.AppendChecker(&testChecker{onClone: func(ctx context.Context, mask CloneFieldSet, info CloneInfo) error {
+		checkersCalled[1] = true
+		return nil
+	}}, &CheckerReq{
+		Points: []Point{PointClone},
+		Clone: CloneFields{
+			Created: TaskFields{
+				ThreadID: true,
+			},
+		},
+	})
+
+	if !s.Enabled(PointClone) {
+		t.Errorf("Enabled(PointClone): got false, wanted true")
+	}
+	// CloneReq() should return the union of requested fields from all calls to
+	// AppendChecker.
+	req := s.CloneReq()
+	if !req.Contains(CloneFieldArgs) {
+		t.Errorf("req.Contains(CloneFieldArgs): got false, wanted true")
+	}
+	if !req.Created.Contains(TaskFieldThreadID) {
+		t.Errorf("req.Created.Contains(TaskFieldThreadID): got false, wanted true")
+	}
+	if err := s.Clone(context.Background(), CloneFieldSet{}, &CloneInfo{}); err != nil {
+		t.Errorf("Clone(): got %v, wanted nil", err)
+	}
+	for i := range checkersCalled {
+		if !checkersCalled[i] {
+			t.Errorf("Clone() did not call Checker.Clone() index %d", i)
+		}
+	}
+}
+
+func TestCheckpointReturnsFirstCheckerError(t *testing.T) {
+	errFirstChecker := errors.New("first Checker error")
+	errSecondChecker := errors.New("second Checker error")
+
+	var s state
+	checkersCalled := [2]bool{}
+	s.AppendChecker(&testChecker{onClone: func(ctx context.Context, mask CloneFieldSet, info CloneInfo) error {
+		checkersCalled[0] = true
+		return errFirstChecker
+	}}, &CheckerReq{
+		Points: []Point{PointClone},
+	})
+	s.AppendChecker(&testChecker{onClone: func(ctx context.Context, mask CloneFieldSet, info CloneInfo) error {
+		checkersCalled[1] = true
+		return errSecondChecker
+	}}, &CheckerReq{
+		Points: []Point{PointClone},
+	})
+
+	if !s.Enabled(PointClone) {
+		t.Errorf("Enabled(PointClone): got false, wanted true")
+	}
+	if err := s.Clone(context.Background(), CloneFieldSet{}, &CloneInfo{}); err != errFirstChecker {
+		t.Errorf("Clone(): got %v, wanted %v", err, errFirstChecker)
+	}
+	if !checkersCalled[0] {
+		t.Errorf("Clone() did not call first Checker")
+	}
+	if checkersCalled[1] {
+		t.Errorf("Clone() called second Checker")
+	}
+}
-- 
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