Add image verifier transfer service plugin system based on a binary directory

Signed-off-by: Ethan Lowman <ethan.lowman@datadoghq.com>

pkg/imageverifier/bindir/processes_windows.go

@@ -0,0 +1,105 @@
+//go:build windows
+
+/*
+   Copyright The containerd 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 bindir
+
+import (
+	"context"
+	"fmt"
+	"os/exec"
+	"unsafe"
+
+	"github.com/containerd/containerd/log"
+	"golang.org/x/sys/windows"
+)
+
+type process struct {
+	cmd *exec.Cmd
+
+	jobHandle     *windows.Handle
+	processHandle *windows.Handle
+}
+
+// Configure the verifier command so that killing it kills all child
+// processes of the verifier process.
+//
+// Job/process management based on:
+// https://devblogs.microsoft.com/oldnewthing/20131209-00/?p=2433
+func startProcess(ctx context.Context, cmd *exec.Cmd) (*process, error) {
+	p := &process{
+		cmd: cmd,
+	}
+
+	jobHandle, err := windows.CreateJobObject(nil, nil)
+	if err != nil {
+		return nil, fmt.Errorf("creating job object: %w", err)
+	}
+	p.jobHandle = &jobHandle
+
+	info := windows.JOBOBJECT_EXTENDED_LIMIT_INFORMATION{
+		BasicLimitInformation: windows.JOBOBJECT_BASIC_LIMIT_INFORMATION{
+			LimitFlags: windows.JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE,
+		},
+	}
+	_, err = windows.SetInformationJobObject(
+		jobHandle,
+		windows.JobObjectExtendedLimitInformation,
+		uintptr(unsafe.Pointer(&info)),
+		uint32(unsafe.Sizeof(info)),
+	)
+	if err != nil {
+		p.cleanup(ctx)
+		return nil, fmt.Errorf("setting limits for job object: %w", err)
+	}
+
+	if err := cmd.Start(); err != nil {
+		p.cleanup(ctx)
+		return nil, fmt.Errorf("starting process: %w", err)
+	}
+
+	processHandle, err := windows.OpenProcess(
+		windows.PROCESS_QUERY_INFORMATION|windows.PROCESS_SET_QUOTA|windows.PROCESS_TERMINATE,
+		false,
+		uint32(cmd.Process.Pid),
+	)
+	if err != nil {
+		return nil, fmt.Errorf("getting handle for verifier process: %w", err)
+	}
+	p.processHandle = &processHandle
+
+	err = windows.AssignProcessToJobObject(jobHandle, processHandle)
+	if err != nil {
+		p.cleanup(ctx)
+		return nil, fmt.Errorf("associating new process to job object: %w", err)
+	}
+
+	return p, nil
+}
+
+func (p *process) cleanup(ctx context.Context) {
+	if p.jobHandle != nil {
+		if err := windows.CloseHandle(*p.jobHandle); err != nil {
+			log.G(ctx).WithError(err).Error("failed to close job handle")
+		}
+	}
+	if p.processHandle != nil {
+		if err := windows.CloseHandle(*p.processHandle); err != nil {
+			log.G(ctx).WithError(err).Error("failed to close process handle")
+		}
+	}
+}