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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | SEE ALSO | COLOPHON |
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selinux_restorecon(3) SELinux API documentation selinux_restorecon(3)
selinux_restorecon - restore file(s) default SELinux security
contexts
#include <selinux/restorecon.h>
int selinux_restorecon(const char *pathname,
unsigned int restorecon_flags);
int selinux_restorecon_parallel(const char *pathname,
unsigned int restorecon_flags,
size_t nthreads);
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_RESTORECON_RECURSE has been set (for descending
through directories), then selinux_restorecon() will write
an SHA1 digest of specfile entries calculated by
selabel_get_digests_all_partial_matches(3) to an extended
attribute of security.sehash once the relabeling has been
completed successfully (see the NOTES section for
details).
These digests will be checked should selinux_restorecon()
be rerun with the restorecon_flags
SELINUX_RESTORECON_RECURSE flag set. If any of the
specfile entries had been updated, the digest will also be
updated. However if the digest is the same, no relabeling
checks will take place.
The restorecon_flags that can be used to manage the usage
of the SHA1 digest are:
SELINUX_RESTORECON_SKIP_DIGEST
SELINUX_RESTORECON_IGNORE_DIGEST
restorecon_flags contains the labeling option/rules as
follows:
SELINUX_RESTORECON_SKIP_DIGEST Do not check or
update any extended attribute security.sehash
entries.
SELINUX_RESTORECON_IGNORE_DIGEST force the checking
of labels even if the stored SHA1 digest matches
the specfile entries SHA1 digest. The specfile
entries digest will be written to the
security.sehash extended attribute once relabeling
has been completed successfully provided the
SELINUX_RESTORECON_NOCHANGE flag has not been set,
and no errors have been skipped during the file
tree walk due to the
SELINUX_RESTORECON_COUNT_ERRORS flag.
SELINUX_RESTORECON_NOCHANGE don't change any file
labels (passive check) or update the digest in the
security.sehash 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 context to match the default
specfile context.
SELINUX_RESTORECON_RECURSE change file and
directory labels recursively (descend directories)
and if successful write an SHA1 digest of the
specfile entries 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 flags are set,
then SELINUX_RESTORECON_PROGRESS will take
precedence.
SELINUX_RESTORECON_PROGRESS show progress by
outputting the number of files in 1k blocks
processed to stdout. If the
SELINUX_RESTORECON_MASS_RELABEL flag is also set
then the approximate percentage complete will be
shown.
SELINUX_RESTORECON_MASS_RELABEL generally set when
relabeling the entire OS, that will then show the
approximate percentage complete. The
SELINUX_RESTORECON_PROGRESS flag must also be set.
SELINUX_RESTORECON_REALPATH convert passed-in
pathname to the canonical pathname using
realpath(3).
SELINUX_RESTORECON_XDEV prevent descending into
directories that have a different device number
than the pathname entry from which the descent
began.
SELINUX_RESTORECON_ADD_ASSOC attempt to add an
association between an inode and a specification.
If there is already an association for the inode
and it conflicts with the specification, then use
the last matching specification.
SELINUX_RESTORECON_ABORT_ON_ERROR abort on errors
during the file tree walk.
SELINUX_RESTORECON_SYSLOG_CHANGES log any label
changes to syslog(3).
SELINUX_RESTORECON_LOG_MATCHES log what specfile
context matched each file.
SELINUX_RESTORECON_IGNORE_NOENTRY ignore files that
do not exist.
SELINUX_RESTORECON_IGNORE_MOUNTS do not read
/proc/mounts to obtain a list of non-seclabel
mounts to be excluded from relabeling checks.
Setting SELINUX_RESTORECON_IGNORE_MOUNTS is useful
where there is a non-seclabel fs mounted with a
seclabel fs mounted on a directory below this.
SELINUX_RESTORECON_CONFLICT_ERROR to treat
conflicting specifications, such as where two
hardlinks for the same inode have different
contexts, as errors.
SELINUX_RESTORECON_COUNT_ERRORS Count, but
otherwise ignore, errors during the file tree walk.
Only makes a difference if the
SELINUX_RESTORECON_ABORT_ON_ERROR flag is clear.
Call selinux_restorecon_get_skipped_errors(3) for
fetching the ignored (skipped) error count after
selinux_restorecon(3) or
selinux_restorecon_parallel(3) completes with
success. In case any errors were skipped during the
file tree walk, the specfile entries SHA1 digest
will not have been written to the security.sehash
extended attribute.
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_restorecon_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 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).
By default selinux_restorecon(3) reads /proc/mounts to
obtain a list of non-seclabel mounts to be excluded from
relabeling checks unless the
SELINUX_RESTORECON_IGNORE_MOUNTS flag has been set.
selinux_restorecon_parallel() is similar to
selinux_restorecon(3), but accepts another parameter that allows
to run relabeling over multiple threads:
nthreads specifies the number of threads to use during
relabeling. When set to 1, the behavior is the same as
calling selinux_restorecon(3). When set to 0, the
function will try to use as many threads as there are
online CPU cores. When set to any other number, the
function will try to use the given number of threads.
Note that to use the parallel relabeling capability, the
calling process must be linked with the libpthread library
(either at compile time or dynamically at run time).
Otherwise the function will print a warning and fall back
to the single threaded mode.
On success, zero is returned. On error, -1 is returned and errno
is set appropriately.
1. To improve performance when relabeling file systems
recursively (e.g. the restorecon_flags
SELINUX_RESTORECON_RECURSE flag is set) selinux_restorecon()
will write a calculated SHA1 digest of the specfile entries
returned by selabel_get_digests_all_partial_matches(3) to an
extended attribute named security.sehash for each directory
in the pathname path.
2. To check the extended attribute entry use getfattr(1), for
example:
getfattr -e hex -n security.sehash /
3. Should any of the specfile entries have changed, then when
selinux_restorecon() is run again with the
SELINUX_RESTORECON_RECURSE flag set, new SHA1 digests will be
calculated and all files automatically relabeled depending on
the settings of the SELINUX_RESTORECON_SET_SPECFILE_CTX flag
(provided SELINUX_RESTORECON_NOCHANGE is not set).
4. /sys and in-memory filesystems do not support the
security.sehash extended attribute and are automatically
excluded from any relabeling checks.
5. By default stderr is used to log output messages and errors.
This may be changed by calling selinux_set_callback(3) with
the SELINUX_CB_LOG type option.
selabel_get_digests_all_partial_matches(3),
selinux_restorecon_set_sehandle(3),
selinux_restorecon_default_handle(3),
selinux_restorecon_get_skipped_errors(3),
selinux_restorecon_set_exclude_list(3),
selinux_restorecon_set_alt_rootpath(3),
selinux_restorecon_xattr(3),
selinux_set_callback(3)
This page is part of the selinux (Security-Enhanced Linux user-
space libraries and tools) project. Information about the
project can be found at
⟨https://github.com/SELinuxProject/selinux/wiki⟩. If you have a
bug report for this manual page, see
⟨https://github.com/SELinuxProject/selinux/wiki/Contributing⟩.
This page was obtained from the project's upstream Git repository
⟨https://github.com/SELinuxProject/selinux⟩ on 2024-06-14. (At
that time, the date of the most recent commit that was found in
the repository was 2023-05-11.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
Security Enhanced Linux 20 Oct 2015 selinux_restorecon(3)
Pages that refer to this page: selabel_get_digests_all_partial_matches(3), selinux_restorecon(3), selinux_restorecon_default_handle(3), selinux_restorecon_get_skipped_errors(3), selinux_restorecon_set_alt_rootpath(3), selinux_restorecon_set_exclude_list(3), selinux_restorecon_set_sehandle(3), selinux_restorecon_xattr(3), restorecon(8), setfiles(8)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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