package selinux
import (
"golang.org/x/sys/unix"
)
// lgetxattr returns a []byte slice containing the value of
// an extended attribute attr set for path.
func lgetxattr(path, attr string) ([]byte, error) {
// Start with a 128 length byte array
dest := make([]byte, 128)
sz, errno := doLgetxattr(path, attr, dest)
for errno == unix.ERANGE { //nolint:errorlint // unix errors are bare
// Buffer too small, use zero-sized buffer to get the actual size
sz, errno = doLgetxattr(path, attr, []byte{})
if errno != nil {
return nil, errno
}
dest = make([]byte, sz)
sz, errno = doLgetxattr(path, attr, dest)
}
if errno != nil {
return nil, errno
}
return dest[:sz], nil
}
// doLgetxattr is a wrapper that retries on EINTR
func doLgetxattr(path, attr string, dest []byte) (int, error) {
for {
sz, err := unix.Lgetxattr(path, attr, dest)
if err != unix.EINTR { //nolint:errorlint // unix errors are bare
return sz, err
}
}
}
// getxattr returns a []byte slice containing the value of
// an extended attribute attr set for path.
func getxattr(path, attr string) ([]byte, error) {
// Start with a 128 length byte array
dest := make([]byte, 128)
sz, errno := dogetxattr(path, attr, dest)
for errno == unix.ERANGE { //nolint:errorlint // unix errors are bare
// Buffer too small, use zero-sized buffer to get the actual size
sz, errno = dogetxattr(path, attr, []byte{})
if errno != nil {
return nil, errno
}
dest = make([]byte, sz)
sz, errno = dogetxattr(path, attr, dest)
}
if errno != nil {
return nil, errno
}
return dest[:sz], nil
}
// dogetxattr is a wrapper that retries on EINTR
func dogetxattr(path, attr string, dest []byte) (int, error) {
for {
sz, err := unix.Getxattr(path, attr, dest)
if err != unix.EINTR { //nolint:errorlint // unix errors are bare
return sz, err
}
}
}