drivers/platformLChown: return early

This is purely aesthetical -- in case we can't get struct stat_t,
return early. This improves readability and decreases the indentation.

No functional change. Please review this with --ignore-space-change.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This commit is contained in:
Kir Kolyshkin 2020-03-11 08:03:43 -07:00
parent e517250392
commit 1e8bf20d6b
1 changed files with 56 additions and 55 deletions

View File

@ -12,66 +12,67 @@ import (
)
func platformLChown(path string, info os.FileInfo, toHost, toContainer *idtools.IDMappings) error {
sysinfo := info.Sys()
if st, ok := sysinfo.(*syscall.Stat_t); ok {
// Map an on-disk UID/GID pair from host to container
// using the first map, then back to the host using the
// second map. Skip that first step if they're 0, to
// compensate for cases where a parent layer should
// have had a mapped value, but didn't.
uid, gid := int(st.Uid), int(st.Gid)
if toContainer != nil {
pair := idtools.IDPair{
UID: uid,
GID: gid,
}
mappedUID, mappedGID, err := toContainer.ToContainer(pair)
if err != nil {
if (uid != 0) || (gid != 0) {
return fmt.Errorf("error mapping host ID pair %#v for %q to container: %v", pair, path, err)
}
mappedUID, mappedGID = uid, gid
}
uid, gid = mappedUID, mappedGID
st, ok := info.Sys().(*syscall.Stat_t)
if !ok {
return nil
}
// Map an on-disk UID/GID pair from host to container
// using the first map, then back to the host using the
// second map. Skip that first step if they're 0, to
// compensate for cases where a parent layer should
// have had a mapped value, but didn't.
uid, gid := int(st.Uid), int(st.Gid)
if toContainer != nil {
pair := idtools.IDPair{
UID: uid,
GID: gid,
}
if toHost != nil {
pair := idtools.IDPair{
UID: uid,
GID: gid,
mappedUID, mappedGID, err := toContainer.ToContainer(pair)
if err != nil {
if (uid != 0) || (gid != 0) {
return fmt.Errorf("error mapping host ID pair %#v for %q to container: %v", pair, path, err)
}
mappedPair, err := toHost.ToHost(pair)
if err != nil {
return fmt.Errorf("error mapping container ID pair %#v for %q to host: %v", pair, path, err)
}
uid, gid = mappedPair.UID, mappedPair.GID
mappedUID, mappedGID = uid, gid
}
uid, gid = mappedUID, mappedGID
}
if toHost != nil {
pair := idtools.IDPair{
UID: uid,
GID: gid,
}
mappedPair, err := toHost.ToHost(pair)
if err != nil {
return fmt.Errorf("error mapping container ID pair %#v for %q to host: %v", pair, path, err)
}
uid, gid = mappedPair.UID, mappedPair.GID
}
if uid != int(st.Uid) || gid != int(st.Gid) {
stat, err := os.Lstat(path)
if err != nil {
return fmt.Errorf("%s: lstat(%q): %v", os.Args[0], path, err)
}
cap, err := system.Lgetxattr(path, "security.capability")
if err != nil && err != system.ErrNotSupportedPlatform {
return fmt.Errorf("%s: Lgetxattr(%q): %v", os.Args[0], path, err)
}
if uid != int(st.Uid) || gid != int(st.Gid) {
stat, err := os.Lstat(path)
if err != nil {
return fmt.Errorf("%s: lstat(%q): %v", os.Args[0], path, err)
}
cap, err := system.Lgetxattr(path, "security.capability")
if err != nil && err != system.ErrNotSupportedPlatform {
return fmt.Errorf("%s: Lgetxattr(%q): %v", os.Args[0], path, err)
}
// Make the change.
if err := syscall.Lchown(path, uid, gid); err != nil {
return fmt.Errorf("%s: chown(%q): %v", os.Args[0], path, err)
}
// Restore the SUID and SGID bits if they were originally set.
if (stat.Mode()&os.ModeSymlink == 0) && stat.Mode()&(os.ModeSetuid|os.ModeSetgid) != 0 {
if err := os.Chmod(path, stat.Mode()); err != nil {
return fmt.Errorf("%s: chmod(%q): %v", os.Args[0], path, err)
}
}
if cap != nil {
if err := system.Lsetxattr(path, "security.capability", cap, 0); err != nil {
return fmt.Errorf("%s: Lsetxattr(%q): %v", os.Args[0], path, err)
}
}
// Make the change.
if err := syscall.Lchown(path, uid, gid); err != nil {
return fmt.Errorf("%s: chown(%q): %v", os.Args[0], path, err)
}
// Restore the SUID and SGID bits if they were originally set.
if (stat.Mode()&os.ModeSymlink == 0) && stat.Mode()&(os.ModeSetuid|os.ModeSetgid) != 0 {
if err := os.Chmod(path, stat.Mode()); err != nil {
return fmt.Errorf("%s: chmod(%q): %v", os.Args[0], path, err)
}
}
if cap != nil {
if err := system.Lsetxattr(path, "security.capability", cap, 0); err != nil {
return fmt.Errorf("%s: Lsetxattr(%q): %v", os.Args[0], path, err)
}
}
}
return nil
}