Provided by: libselinux1-dev_3.5-2ubuntu5_amd64 bug

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);

       int selinux_restorecon_parallel(const char *pathname,
                                       unsigned int restorecon_flags,
                                       size_t nthreads);

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_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.

RETURN VALUE

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

NOTES

       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.

SEE ALSO

       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)