selinux_restorecon(3) SELinux API documentation selinux_restorecon(3)
NAME
selinux_restorecon - restore file(s) default SELinux security contexts
SYNOPSIS
#include <selinux/restorecon.h>
int selinux_restorecon(const char *pathname,
unsigned int restorecon_flags);
DESCRIPTION
selinux_restorecon() restores file default security contexts on
filesystems that support extended attributes (see xattr(7)), based on:
pathname containing a directory or file to be relabeled.
If this is a directory and the restorecon_flags SELINUX_RESTORE-
CON_RECURSE has been set (for decending through directories),
then selinux_restorecon() will write an SHA1 digest of the com-
bined specfiles (see the NOTES section for details) to an
extended attribute of security.restorecon_last once the relabel-
ing has been completed successfully. This digest will be checked
should selinux_restorecon() be rerun with the restorecon_flags
SELINUX_RESTORECON_RECURSE flag set. If any of the specfiles had
been updated, the digest will also be updated. However if the
digest is the same, no relabeling checks will take place (unless
the SELINUX_RESTORECON_IGNORE_DIGEST flag is set).
restorecon_flags contains the labeling option/rules as follows:
SELINUX_RESTORECON_IGNORE_DIGEST force the checking of
labels even if the stored SHA1 digest matches the spec-
files SHA1 digest. The specfiles digest will be written
to the security.restorecon_last extended attribute once
relabeling has been completed successfully provided the
SELINUX_RESTORECON_NOCHANGE flag has not been set.
SELINUX_RESTORECON_NOCHANGE don't change any file labels
(passive check) or update the digest in the secu-
rity.restorecon_last extended attribute.
SELINUX_RESTORECON_SET_SPECFILE_CTX If set, reset the
files label to match the default specfile context. If
not set only reset the files "type" component of the con-
text to match the default specfile context.
SELINUX_RESTORECON_RECURSE change file and directory
labels recursively (descend directories) and if success-
ful write an SHA1 digest of the combined specfiles to an
extended attribute as described in the NOTES section.
SELINUX_RESTORECON_VERBOSE log file label changes.
Note that if SELINUX_RESTORECON_VERBOSE and
SELINUX_RESTORECON_PROGRESS are set, then
SELINUX_RESTORECON_PROGRESS will take precedence.
SELINUX_RESTORECON_PROGRESS show progress by printing *
to stdout every 1000 files.
SELINUX_RESTORECON_REALPATH convert passed-in pathname to
the canonical pathname using realpath(3).
SELINUX_RESTORECON_XDEV prevent descending into directo-
ries that have a different device number than the path-
name entry from which the descent began.
The behavior regarding the checking and updating of the SHA1
digest described above is the default behavior. It is possible
to change this by first calling selabel_open(3) and not enabling
the SELABEL_OPT_DIGEST option, then calling selinux_restore-
con_set_sehandle(3) to set the handle to be used by
selinux_restorecon(3).
If the pathname is a directory path, then it is possible to set
files/directories to be excluded from the path by calling
selinux_restorecon_set_exclude_list(3) with a NULL terminated
list before calling selinux_restorecon(3).
RETURN VALUE
On success, zero is returned. On error, -1 is returned and errno is
set appropriately.
NOTES
To improve performance when relabeling file systems recursively (e.g.
the restorecon_flags SELINUX_RESTORECON_RECURSE flag is set)
selinux_restorecon() will write an SHA1 digest of the specfiles that
are processed by selabel_open(3) to an extended attribute named secu-
rity.restorecon_last to the directory specified in the pathname.
To check the extended attribute entry use getfattr(1), for example:
getfattr -e hex -n security.restorecon_last /
The SHA1 digest is calculated by selabel_open(3) concatenating the
specfiles it reads during initialisation with the resulting digest and
list of specfiles being retrieved by selabel_digest(3).
The specfiles consist of the mandatory file_contexts file plus any
subs, subs_dist, local and homedir entries (text or binary versions) as
determined by any selabel_open(3) options e.g. SELABEL_OPT_BASEONLY.
Should any of the specfiles have changed, then when selinux_restore-
con() is run again with the SELINUX_RESTORECON_RECURSE flag set, a new
SHA1 digest will be calculated and all files will be automatically
relabeled depending on the settings of the SELINUX_RESTORECON_SET_SPEC-
FILE_CTX flag (provided SELINUX_RESTORECON_NOCHANGE is not set).
/sys and in-memory filesystems do not support the security.restore-
con_last extended attribute and are automatically excluded from any
relabeling checks.
selinux_restorecon() does not check whether mounted filesystems support
the seclabel option (i.e. support extended attributes as described in
xattr(7)). To exclude these filesystems from any relabeling checks
selinux_restorecon_set_exclude_list(3) should be called prior to
selinux_restorecon() with a NULL terminated exclude_list of these
filesystems.
SEE ALSO
selinux_restorecon_set_sehandle(3),
selinux_restorecon_default_handle(3),
selinux_restorecon_set_exclude_list(3),
Security Enhanced Linux 20 Oct 2015 selinux_restorecon(3)
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