NAME

       selabel_lookup_best_match  - obtain a best match SELinux security context - Only supported
       on file backend.

SYNOPSIS

       #include <selinux/selinux.h>
       #include <selinux/label.h>

       int selabel_lookup_best_match(struct selabel_handle *hnd,
                                     char **context,
                                     const char *key,
                                     const char **links,
                                     int type);

       int selabel_lookup_best_match_raw(struct selabel_handle *hnd,
                                         char **context,
                                         const char *key,
                                         const char **links,
                                         int type);

DESCRIPTION

       selabel_lookup_best_match() performs a best match lookup  operation  on  the  handle  hnd,
       returning  the  result  in  the  memory  pointed to by context, which must be freed by the
       caller using freecon(3).  The key parameter is a file path to check for best  match  using
       zero or more link (aliases) parameters. The order of precedence for best match is:

              1.  An exact match for the real path (key) or

              2.  An exact match for any of the links (aliases), or

              3.  The longest fixed prefix match.

       The  type  parameter is an optional file mode argument that should be set to the mode bits
       of the file, as determined by lstat(2).  mode may be zero, however full matching  may  not
       occur.

       selabel_lookup_best_match_raw()  behaves  identically  to  selabel_lookup_best_match() but
       does not perform context translation.

RETURN VALUE

       On success, zero is returned.  On error, -1 is returned and errno is set appropriately.

ERRORS

       ENOENT No context corresponding to the input key and type was found.

       EINVAL The key and/or type inputs are  invalid,  or  the  context  being  returned  failed
              validation.

       ENOMEM An attempt to allocate memory failed.

NOTES

       Example  usage  -  When  a  service  creates a device node, it may also create one or more
       symlinks to the device node.  These symlinks may be the only stable name for  the  device,
       e.g.  if  the  partition is dynamically assigned.  The file label backend supports this by
       looking up the "best match" for a device node based on its real path (key) and  any  links
       to it (aliases). The order of precedence for best match is described above.

SEE ALSO

       selabel_open(3),    selabel_stats(3),   selinux_set_callback(3),   selinux(8),   lstat(2),
       selabel_file(5)