c7cd5d6726
If `unix.Lgetxattr` returns an error, then `sz == -1` which will cause a
runtime panic if `errno == unix.ERANGE`.
Signed-off-by: Sascha Grunert <sgrunert@suse.com>
(cherry picked from commit 4138cd22ab)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
38 lines
1.2 KiB
Go
38 lines
1.2 KiB
Go
package system // import "github.com/docker/docker/pkg/system"
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import "golang.org/x/sys/unix"
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// Lgetxattr retrieves the value of the extended attribute identified by attr
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// and associated with the given path in the file system.
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// It will returns a nil slice and nil error if the xattr is not set.
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func Lgetxattr(path string, attr string) ([]byte, error) {
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// Start with a 128 length byte array
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dest := make([]byte, 128)
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sz, errno := unix.Lgetxattr(path, attr, dest)
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switch {
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case errno == unix.ENODATA:
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return nil, nil
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case errno == unix.ERANGE:
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// 128 byte array might just not be good enough. A dummy buffer is used
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// to get the real size of the xattrs on disk
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sz, errno = unix.Lgetxattr(path, attr, []byte{})
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if errno != nil {
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return nil, errno
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}
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dest = make([]byte, sz)
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sz, errno = unix.Lgetxattr(path, attr, dest)
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if errno != nil {
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return nil, errno
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}
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case errno != nil:
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return nil, errno
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}
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return dest[:sz], nil
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}
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// Lsetxattr sets the value of the extended attribute identified by attr
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// and associated with the given path in the file system.
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func Lsetxattr(path string, attr string, data []byte, flags int) error {
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return unix.Lsetxattr(path, attr, data, flags)
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}
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