1selinux_restorecon(3) SELinux API documentation selinux_restorecon(3)
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6 selinux_restorecon - restore file(s) default SELinux security contexts
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9 #include <selinux/restorecon.h>
10 int selinux_restorecon(const char *pathname,
12 unsigned int restorecon_flags);
13 int selinux_restorecon_parallel(const char *pathname,
15 unsigned int restorecon_flags,
16 size_t nthreads);
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19 selinux_restorecon() restores file default security contexts on
20 filesystems that support extended attributes (see xattr(7)), based on:
21 pathname containing a directory or file to be relabeled.
23 If this is a directory and the restorecon_flags SELINUX_RESTORE‐
24 CON_RECURSE has been set (for descending through directories),
25 then selinux_restorecon() will write an SHA256 digest of spec‐
26 file entries calculated by selabel_get_digests_all_par‐
27 tial_matches(3) to an extended attribute of security.sehash once
28 the relabeling has been completed successfully (see the NOTES
29 section for details).
30 These digests will be checked should selinux_restorecon() be re‐
31 run with the restorecon_flags SELINUX_RESTORECON_RECURSE flag
32 set. If any of the specfile entries had been updated, the digest
33 will also be updated. However if the digest is the same, no re‐
34 labeling checks will take place.
35 The restorecon_flags that can be used to manage the usage of the
36 SHA256 digest are:
37 SELINUX_RESTORECON_SKIP_DIGEST
38 SELINUX_RESTORECON_IGNORE_DIGEST
39 restorecon_flags contains the labeling option/rules as follows:
41 SELINUX_RESTORECON_SKIP_DIGEST Do not check or update any
44 extended attribute security.sehash entries.
45 SELINUX_RESTORECON_IGNORE_DIGEST force the checking of
47 labels even if the stored SHA256 digest matches the spec‐
48 file entries SHA256 digest. The specfile entries digest
49 will be written to the security.sehash extended attribute
50 once relabeling has been completed successfully provided
51 the SELINUX_RESTORECON_NOCHANGE flag has not been set,
52 and no errors have been skipped during the file tree walk
53 due to the SELINUX_RESTORECON_COUNT_ERRORS flag.
54 SELINUX_RESTORECON_NOCHANGE don't change any file labels
56 (passive check) or update the digest in the security.se‐
57 hash extended attribute.
58 SELINUX_RESTORECON_SET_SPECFILE_CTX If set, reset the
60 files label to match the default specfile context. If
61 not set only reset the files "type" component of the con‐
62 text to match the default specfile context.
63 SELINUX_RESTORECON_RECURSE change file and directory la‐
65 bels recursively (descend directories) and if successful
66 write an SHA256 digest of the specfile entries to an ex‐
67 tended attribute as described in the NOTES section.
68 SELINUX_RESTORECON_VERBOSE log file label changes.
70 Note that if SELINUX_RESTORECON_VERBOSE and
71 SELINUX_RESTORECON_PROGRESS flags are set, then
72 SELINUX_RESTORECON_PROGRESS will take precedence.
73 SELINUX_RESTORECON_PROGRESS show progress by outputting
75 the number of files in 1k blocks processed to stdout. If
76 the SELINUX_RESTORECON_MASS_RELABEL flag is also set then
77 the approximate percentage complete will be shown.
78 SELINUX_RESTORECON_MASS_RELABEL generally set when rela‐
80 beling the entire OS, that will then show the approximate
81 percentage complete. The SELINUX_RESTORECON_PROGRESS flag
82 must also be set.
83 SELINUX_RESTORECON_REALPATH convert passed-in pathname to
85 the canonical pathname using realpath(3).
86 SELINUX_RESTORECON_XDEV prevent descending into directo‐
88 ries that have a different device number than the path‐
89 name entry from which the descent began.
90 SELINUX_RESTORECON_ADD_ASSOC attempt to add an associa‐
92 tion between an inode and a specification. If there is
93 already an association for the inode and it conflicts
94 with the specification, then use the last matching speci‐
95 fication.
96 SELINUX_RESTORECON_ABORT_ON_ERROR abort on errors during
98 the file tree walk.
99 SELINUX_RESTORECON_SYSLOG_CHANGES log any label changes
101 to syslog(3).
102 SELINUX_RESTORECON_LOG_MATCHES log what specfile context
104 matched each file.
105 SELINUX_RESTORECON_IGNORE_NOENTRY ignore files that do
107 not exist.
108 SELINUX_RESTORECON_IGNORE_MOUNTS do not read /proc/mounts
110 to obtain a list of non-seclabel mounts to be excluded
111 from relabeling checks.
112 Setting SELINUX_RESTORECON_IGNORE_MOUNTS is useful where
113 there is a non-seclabel fs mounted with a seclabel fs
114 mounted on a directory below this.
115 SELINUX_RESTORECON_CONFLICT_ERROR to treat conflicting
117 specifications, such as where two hardlinks for the same
118 inode have different contexts, as errors.
119 SELINUX_RESTORECON_COUNT_ERRORS Count, but otherwise ig‐
121 nore, errors during the file tree walk. Only makes a dif‐
122 ference if the SELINUX_RESTORECON_ABORT_ON_ERROR flag is
123 clear. Call selinux_restorecon_get_skipped_errors(3) for
124 fetching the ignored (skipped) error count after
125 selinux_restorecon(3) or selinux_restorecon_parallel(3)
126 completes with success. In case any errors were skipped
127 during the file tree walk, the specfile entries SHA1 di‐
128 gest will not have been written to the security.sehash
129 extended attribute.
130 The behavior regarding the checking and updating of the SHA256
132 digest described above is the default behavior. It is possible
133 to change this by first calling selabel_open(3) and not enabling
134 the SELABEL_OPT_DIGEST option, then calling selinux_restore‐
135 con_set_sehandle(3) to set the handle to be used by selinux_re‐
136 storecon(3).
137 If the pathname is a directory path, then it is possible to set
139 directories to be excluded from the path by calling selinux_re‐
140 storecon_set_exclude_list(3) with a NULL terminated list before
141 calling selinux_restorecon(3).
142 By default selinux_restorecon(3) reads /proc/mounts to obtain a
144 list of non-seclabel mounts to be excluded from relabeling
145 checks unless the SELINUX_RESTORECON_IGNORE_MOUNTS flag has been
146 set.
147 selinux_restorecon_parallel() is similar to selinux_restorecon(3), but
149 accepts another parameter that allows to run relabeling over multiple
150 threads:
151 nthreads specifies the number of threads to use during relabel‐
153 ing. When set to 1, the behavior is the same as calling
154 selinux_restorecon(3). When set to 0, the function will try to
155 use as many threads as there are online CPU cores. When set to
156 any other number, the function will try to use the given number
157 of threads.
158 Note that to use the parallel relabeling capability, the calling
160 process must be linked with the libpthread library (either at
161 compile time or dynamically at run time). Otherwise the function
162 will print a warning and fall back to the single threaded mode.
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165 On success, zero is returned. On error, -1 is returned and errno is
166 set appropriately.
167
169 1. To improve performance when relabeling file systems recursively
170 (e.g. the restorecon_flags SELINUX_RESTORECON_RECURSE flag is set)
171 selinux_restorecon() will write a calculated SHA256 digest of the
172 specfile entries returned by selabel_get_digests_all_par‐
173 tial_matches(3) to an extended attribute named security.sehash for
174 each directory in the pathname path.
175 2. To check the extended attribute entry use getfattr(1), for example:
177 getfattr -e hex -n security.sehash /
179 3. Should any of the specfile entries have changed, then when
181 selinux_restorecon() is run again with the SELINUX_RESTORECON_RE‐
182 CURSE flag set, new SHA256 digests will be calculated and all files
183 automatically relabeled depending on the settings of the
184 SELINUX_RESTORECON_SET_SPECFILE_CTX flag (provided SELINUX_RESTORE‐
185 CON_NOCHANGE is not set).
186 4. /sys and in-memory filesystems do not support the security.sehash
188 extended attribute and are automatically excluded from any relabel‐
189 ing checks.
190 5. By default stderr is used to log output messages and errors. This
192 may be changed by calling selinux_set_callback(3) with the
193 SELINUX_CB_LOG type option.
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196 selabel_get_digests_all_partial_matches(3),
197 selinux_restorecon_set_sehandle(3),
198 selinux_restorecon_default_handle(3),
199 selinux_restorecon_get_skipped_errors(3),
200 selinux_restorecon_set_exclude_list(3),
201 selinux_restorecon_set_alt_rootpath(3),
202 selinux_restorecon_xattr(3),
203 selinux_set_callback(3)
204Security Enhanced Linux 20 Oct 2015 selinux_restorecon(3)