Move shim package to pkg

Signed-off-by: Maksym Pavlenko <pavlenko.maksym@gmail.com>

pkg/shim/util_windows.go

@@ -0,0 +1,87 @@
+/*
+   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 shim
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"os"
+	"syscall"
+	"time"
+
+	winio "github.com/Microsoft/go-winio"
+)
+
+const shimBinaryFormat = "containerd-shim-%s-%s.exe"
+
+func getSysProcAttr() *syscall.SysProcAttr {
+	return nil
+}
+
+// AnonReconnectDialer returns a dialer for an existing npipe on containerd reconnection
+func AnonReconnectDialer(address string, timeout time.Duration) (net.Conn, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+
+	c, err := winio.DialPipeContext(ctx, address)
+	if os.IsNotExist(err) {
+		return nil, fmt.Errorf("npipe not found on reconnect: %w", os.ErrNotExist)
+	} else if err == context.DeadlineExceeded {
+		return nil, fmt.Errorf("timed out waiting for npipe %s: %w", address, err)
+	} else if err != nil {
+		return nil, err
+	}
+	return c, nil
+}
+
+// AnonDialer returns a dialer for a npipe
+func AnonDialer(address string, timeout time.Duration) (net.Conn, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+
+	// If there is nobody serving the pipe we limit the timeout for this case to
+	// 5 seconds because any shim that would serve this endpoint should serve it
+	// within 5 seconds.
+	serveTimer := time.NewTimer(5 * time.Second)
+	defer serveTimer.Stop()
+	for {
+		c, err := winio.DialPipeContext(ctx, address)
+		if err != nil {
+			if os.IsNotExist(err) {
+				select {
+				case <-serveTimer.C:
+					return nil, fmt.Errorf("pipe not found before timeout: %w", os.ErrNotExist)
+				default:
+					// Wait 10ms for the shim to serve and try again.
+					time.Sleep(10 * time.Millisecond)
+					continue
+				}
+			} else if err == context.DeadlineExceeded {
+				return nil, fmt.Errorf("timed out waiting for npipe %s: %w", address, err)
+			}
+			return nil, err
+		}
+		return c, nil
+	}
+}
+
+// RemoveSocket removes the socket at the specified address if
+// it exists on the filesystem
+func RemoveSocket(address string) error {
+	return nil
+}