fs.CopyDir: support sockets and pipes

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

fs/copy.go

@@ -22,6 +22,8 @@ import (
 	"os"
 	"path/filepath"
 	"sync"
+
+	"github.com/sirupsen/logrus"
 )
 
 var bufferPool = &sync.Pool{
@@ -152,15 +154,15 @@ func copyDirectory(dst, src string, inodes map[uint64]string, o *copyDirOpts) er
 			if err := os.Symlink(link, target); err != nil {
 				return fmt.Errorf("failed to create symlink: %s: %w", target, err)
 			}
-		case (fi.Mode() & os.ModeDevice) == os.ModeDevice:
-			if err := copyDevice(target, fi); err != nil {
-				return fmt.Errorf("failed to create device: %w", err)
+		case (fi.Mode() & os.ModeDevice) == os.ModeDevice,
+			(fi.Mode() & os.ModeNamedPipe) == os.ModeNamedPipe,
+			(fi.Mode() & os.ModeSocket) == os.ModeSocket:
+			if err := copyIrregular(target, fi); err != nil {
+				return fmt.Errorf("failed to create irregular file: %w", err)
 			}
 		default:
-			// TODO: Support pipes and sockets
-			if err != nil {
-				return fmt.Errorf("unsupported mode %s: %w", fi.Mode(), err)
-			}
+			logrus.Warnf("unsupported mode: %s: %s", source, fi.Mode())
+			continue
 		}
 
 		if err := copyFileInfo(fi, source, target); err != nil {

fs/copy_darwin.go → fs/copy_irregular_freebsd.go

@@ -1,6 +1,3 @@
-//go:build darwin
-// +build darwin
-
 /*
    Copyright The containerd Authors.
 
@@ -20,17 +17,20 @@
 package fs
 
 import (
-	"errors"
+	"fmt"
 	"os"
 	"syscall"
-
-	"golang.org/x/sys/unix"
 )
 
-func copyDevice(dst string, fi os.FileInfo) error {
-	st, ok := fi.Sys().(*syscall.Stat_t)
+// copyIrregular covers devices, pipes, and sockets
+func copyIrregular(dst string, fi os.FileInfo) error {
+	st, ok := fi.Sys().(*syscall.Stat_t) // not *unix.Stat_t
 	if !ok {
-		return errors.New("unsupported stat type")
+		return fmt.Errorf("unsupported stat type: %s: %v", dst, fi.Mode())
+	}
+	var rDev uint64 // uint64 on FreeBSD, int on other unixen
+	if fi.Mode()&os.ModeDevice == os.ModeDevice {
+		rDev = st.Rdev
 	}
-	return unix.Mknod(dst, uint32(fi.Mode()), int(st.Rdev))
+	return syscall.Mknod(dst, uint32(st.Mode), rDev)
 }

fs/copy_device_unix.go → fs/copy_irregular_unix.go

@@ -1,5 +1,5 @@
-//go:build openbsd || solaris || netbsd
-// +build openbsd solaris netbsd
+//go:build !windows && !freebsd
+// +build !windows,!freebsd
 
 /*
    Copyright The containerd Authors.
@@ -20,17 +20,21 @@
 package fs
 
 import (
-	"errors"
+	"fmt"
 	"os"
 	"syscall"
-
-	"golang.org/x/sys/unix"
 )
 
-func copyDevice(dst string, fi os.FileInfo) error {
-	st, ok := fi.Sys().(*syscall.Stat_t)
+// copyIrregular covers devices, pipes, and sockets
+func copyIrregular(dst string, fi os.FileInfo) error {
+	st, ok := fi.Sys().(*syscall.Stat_t) // not *unix.Stat_t
 	if !ok {
-		return errors.New("unsupported stat type")
+		return fmt.Errorf("unsupported stat type: %s: %v", dst, fi.Mode())
+	}
+	var rDev int
+	if fi.Mode()&os.ModeDevice == os.ModeDevice {
+		rDev = int(st.Rdev)
 	}
-	return unix.Mknod(dst, uint32(fi.Mode()), int(st.Rdev))
+	//nolint:unconvert
+	return syscall.Mknod(dst, uint32(st.Mode), rDev)
 }

fs/copy_linux.go

@@ -17,7 +17,6 @@
 package fs
 
 import (
-	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -144,11 +143,3 @@ func copyXAttrs(dst, src string, excludes map[string]struct{}, errorHandler XAtt
 
 	return nil
 }
-
-func copyDevice(dst string, fi os.FileInfo) error {
-	st, ok := fi.Sys().(*syscall.Stat_t)
-	if !ok {
-		return errors.New("unsupported stat type")
-	}
-	return unix.Mknod(dst, uint32(fi.Mode()), int(st.Rdev))
-}

fs/copy_unix_test.go

@@ -22,10 +22,13 @@ package fs
 import (
 	"io/ioutil"
 	"os"
+	"path/filepath"
+	"syscall"
 	"testing"
 
 	"github.com/containerd/continuity/fs/fstest"
 	"github.com/containerd/continuity/sysx"
+	"golang.org/x/sys/unix"
 )
 
 func assertXAttr(t *testing.T, dir, xattr, xval string, xerr error) {
@@ -86,3 +89,88 @@ func TestCopyDirWithXAttrExcludes(t *testing.T) {
 		assertXAttr(t, dst, "user.test-x", "", sysx.ENODATA)
 	})
 }
+
+func TestCopyIrregular(t *testing.T) {
+	var prepared int
+	prepareSrc := func(src string) {
+		f0Pipe := filepath.Join(src, "f0.pipe")
+		if err := unix.Mkfifo(f0Pipe, 0600); err != nil {
+			t.Fatal(err)
+		}
+		prepared++
+		f1Normal := filepath.Join(src, "f1.normal")
+		if err := ioutil.WriteFile(f1Normal, []byte("content of f1.normal"), 0600); err != nil {
+			t.Fatal(err)
+		}
+		prepared++
+		f2Socket := filepath.Join(src, "f2.sock")
+		if err := unix.Mknod(f2Socket, 0600|unix.S_IFSOCK, 0); err != nil {
+			t.Fatal(err)
+		}
+		prepared++
+		f3Dev := filepath.Join(src, "f3.dev")
+		if err := unix.Mknod(f3Dev, 0600|unix.S_IFCHR, 42); err != nil {
+			t.Logf("skipping testing S_IFCHR: %v", err)
+		} else {
+			prepared++
+		}
+	}
+
+	verifyDst := func(dst string) {
+		entries, err := ioutil.ReadDir(dst)
+		if err != nil {
+			t.Fatal(err)
+		}
+		var verified int
+		for _, f := range entries {
+			name := f.Name()
+			full := filepath.Join(dst, name)
+			fi, err := os.Stat(full)
+			if err != nil {
+				t.Fatal(err)
+			}
+			mode := fi.Mode()
+			switch name {
+			case "f0.pipe":
+				if mode&os.ModeNamedPipe != os.ModeNamedPipe {
+					t.Fatalf("unexpected mode of %s: %v", name, mode)
+				}
+			case "f1.normal":
+				b, err := ioutil.ReadFile(full)
+				if err != nil {
+					t.Fatal(err)
+				}
+				if string(b) != "content of f1.normal" {
+					t.Fatalf("unexpected content of %s: %q", name, string(b))
+				}
+			case "f2.sock":
+				if mode&os.ModeSocket != os.ModeSocket {
+					t.Fatalf("unexpected mode of %s: %v", name, mode)
+				}
+			case "f3.dev":
+				if mode&os.ModeDevice != os.ModeDevice {
+					t.Fatalf("unexpected mode of %s: %v", name, mode)
+				}
+				sys, ok := fi.Sys().(*syscall.Stat_t)
+				if !ok {
+					t.Fatalf("unexpected type: %v", fi.Sys())
+				}
+				if sys.Rdev != 42 {
+					t.Fatalf("unexpected rdev of %s: %d", name, sys.Rdev)
+				}
+			}
+			verified++
+		}
+		if verified != prepared {
+			t.Fatalf("prepared %d files, verified %d files", prepared, verified)
+		}
+	}
+
+	src := t.TempDir()
+	dst := t.TempDir()
+	prepareSrc(src)
+	if err := CopyDir(dst, src); err != nil {
+		t.Fatal(err)
+	}
+	verifyDst(dst)
+}

fs/copy_windows.go

@@ -85,6 +85,6 @@ func copyXAttrs(dst, src string, excludes map[string]struct{}, errorHandler XAtt
 	return nil
 }
 
-func copyDevice(dst string, fi os.FileInfo) error {
-	return errors.New("device copy not supported")
+func copyIrregular(dst string, fi os.FileInfo) error {
+	return errors.New("irregular copy not supported")
 }