containerd/archive/tar_unix.go
Derek McGowan e20b371807
Remove umask, replace with explicit chmod after create
Call chmod on all open files and created directories to
ensure permission is set as expected without changing umask.

Fixes #1608

Signed-off-by: Derek McGowan <derek@mcgstyle.net>
2017-10-11 15:13:18 -07:00

131 lines
2.9 KiB
Go

// +build !windows
package archive
import (
"os"
"sync"
"syscall"
"github.com/containerd/continuity/sysx"
"github.com/dmcgowan/go-tar"
"github.com/opencontainers/runc/libcontainer/system"
"github.com/pkg/errors"
"golang.org/x/sys/unix"
)
func tarName(p string) (string, error) {
return p, nil
}
func chmodTarEntry(perm os.FileMode) os.FileMode {
return perm
}
func setHeaderForSpecialDevice(hdr *tar.Header, name string, fi os.FileInfo) error {
s, ok := fi.Sys().(*syscall.Stat_t)
if !ok {
return errors.New("unsupported stat type")
}
// Currently go does not fill in the major/minors
if s.Mode&syscall.S_IFBLK != 0 ||
s.Mode&syscall.S_IFCHR != 0 {
hdr.Devmajor = int64(unix.Major(uint64(s.Rdev)))
hdr.Devminor = int64(unix.Minor(uint64(s.Rdev)))
}
return nil
}
func open(p string) (*os.File, error) {
return os.Open(p)
}
func openFile(name string, flag int, perm os.FileMode) (*os.File, error) {
f, err := os.OpenFile(name, flag, perm)
if err != nil {
return nil, err
}
// Call chmod to avoid permission mask
if err := os.Chmod(name, perm); err != nil {
return nil, err
}
return f, err
}
func mkdirAll(path string, perm os.FileMode) error {
return os.MkdirAll(path, perm)
}
func mkdir(path string, perm os.FileMode) error {
if err := os.Mkdir(path, perm); err != nil {
return err
}
// Only final created directory gets explicit permission
// call to avoid permission mask
return os.Chmod(path, perm)
}
func skipFile(*tar.Header) bool {
return false
}
var (
inUserNS bool
nsOnce sync.Once
)
func setInUserNS() {
inUserNS = system.RunningInUserNS()
}
// handleTarTypeBlockCharFifo is an OS-specific helper function used by
// createTarFile to handle the following types of header: Block; Char; Fifo
func handleTarTypeBlockCharFifo(hdr *tar.Header, path string) error {
nsOnce.Do(setInUserNS)
if inUserNS {
// cannot create a device if running in user namespace
return nil
}
mode := uint32(hdr.Mode & 07777)
switch hdr.Typeflag {
case tar.TypeBlock:
mode |= unix.S_IFBLK
case tar.TypeChar:
mode |= unix.S_IFCHR
case tar.TypeFifo:
mode |= unix.S_IFIFO
}
return unix.Mknod(path, mode, int(unix.Mkdev(uint32(hdr.Devmajor), uint32(hdr.Devminor))))
}
func handleLChmod(hdr *tar.Header, path string, hdrInfo os.FileInfo) error {
if hdr.Typeflag == tar.TypeLink {
if fi, err := os.Lstat(hdr.Linkname); err == nil && (fi.Mode()&os.ModeSymlink == 0) {
if err := os.Chmod(path, hdrInfo.Mode()); err != nil {
return err
}
}
} else if hdr.Typeflag != tar.TypeSymlink {
if err := os.Chmod(path, hdrInfo.Mode()); err != nil {
return err
}
}
return nil
}
func getxattr(path, attr string) ([]byte, error) {
b, err := sysx.LGetxattr(path, attr)
if err == unix.ENOTSUP || err == sysx.ENODATA {
return nil, nil
}
return b, err
}
func setxattr(path, key, value string) error {
return sysx.LSetxattr(path, key, []byte(value), 0)
}