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1File Labeling Statements
2========================
3
4filecon
5-------
6
7Define entries for labeling files. The compiler will produce these entries in a file called **`file_contexts`**`(5)` by default in the `cwd`. The compiler option `[-f|--filecontext <filename>]` may be used to specify a different path or file name.
8
9**Statement definition:**
10
11```secil
12    (filecon "path" file_type context_id)
13```
14
15**Where:**
16
17<table>
18<colgroup>
19<col width="25%" />
20<col width="75%" />
21</colgroup>
22<tbody>
23<tr class="odd">
24<td align="left"><p><code>filecon</code></p></td>
25<td align="left"><p>The <code>filecon</code> keyword.</p></td>
26</tr>
27<tr class="even">
28<td align="left"><p><code>path</code></p></td>
29<td align="left"><p>A string representing the file path that may be in the form of a regular expression. The string must be enclosed within double quotes (e.g. <code>&quot;/this/is/a/path(/.*)?&quot;</code>)</p></td>
30</tr>
31<tr class="odd">
32<td align="left"><p><code>file_type</code></p></td>
33<td align="left"><p>A single keyword representing a file type in the <code>file_contexts</code> file as follows:</p>
34<table>
35<colgroup>
36<col width="44%" />
37<col width="55%" />
38</colgroup>
39<tbody>
40<tr class="odd">
41<td align="left"><p><strong>keyword</strong></p></td>
42<td align="left"><p><strong>file_contexts entry</strong></p></td>
43</tr>
44<tr class="even">
45<td align="left"><p><code>file</code></p></td>
46<td align="left"><p><code>--</code></p></td>
47</tr>
48<tr class="odd">
49<td align="left"><p><code>dir</code></p></td>
50<td align="left"><p><code>-d</code></p></td>
51</tr>
52<tr class="even">
53<td align="left"><p><code>char</code></p></td>
54<td align="left"><p><code>-c</code></p></td>
55</tr>
56<tr class="odd">
57<td align="left"><p><code>block</code></p></td>
58<td align="left"><p><code>-b</code></p></td>
59</tr>
60<tr class="even">
61<td align="left"><p><code>socket</code></p></td>
62<td align="left"><p><code>-s</code></p></td>
63</tr>
64<tr class="odd">
65<td align="left"><p><code>pipe</code></p></td>
66<td align="left"><p><code>-p</code></p></td>
67</tr>
68<tr class="even">
69<td align="left"><p><code>symlink</code></p></td>
70<td align="left"><p><code>-l</code></p></td>
71</tr>
72<tr class="odd">
73<td align="left"><p><code>any</code></p></td>
74<td align="left"><p>no entry</p></td>
75</tr>
76</tbody>
77</table></td>
78</tr>
79<tr class="even">
80<td align="left"><p><code>context_id</code></p></td>
81<td align="left"><p>The security context to be allocated to the file, which may be:</p>
82<ul>
83<li><p>A previously declared <code>context</code> identifier or an anonymous security context (<code>user role type levelrange</code>), the range MUST be defined whether the policy is MLS/MCS enabled or not.</p></li>
84<li><p>An empty context list represented by <code>()</code> can be used to indicate that matching files should not be re-labeled. This will be interpreted as <code>&lt;&lt;none&gt;&gt;</code> within the <strong><code>file_contexts</code></strong><code>(5)</code> file.</p></li>
85</ul></td>
86</tr>
87</tbody>
88</table>
89
90**Examples:**
91
92These examples use one named, one anonymous and one empty context definition:
93
94```secil
95    (context runas_exec_context (u object_r exec low_low))
96
97    (filecon "/system/bin/run-as" file runas_exec_context)
98    (filecon "/dev/socket/wpa_wlan[0-9]" any u:object_r:wpa.socket:s0-s0)
99    (filecon "/data/local/mine" dir ())
100```
101
102to resolve/build `file_contexts` entries of (assuming MLS enabled policy):
103
104```
105    /system/bin/run-as  -- u:object_r:runas.exec:s0
106    /dev/socket/wpa_wlan[0-9]   u:object_r:wpa.socket:s0
107    /data/local/mine -d <<none>>
108```
109
110fsuse
111-----
112
113Label filesystems that support SELinux security contexts.
114
115**Statement definition:**
116
117```secil
118    (fsuse fstype fsname context_id)
119```
120
121**Where:**
122
123<table>
124<colgroup>
125<col width="25%" />
126<col width="75%" />
127</colgroup>
128<tbody>
129<tr class="odd">
130<td align="left"><p><code>fsuse</code></p></td>
131<td align="left"><p>The <code>fsuse</code> keyword.</p></td>
132</tr>
133<tr class="even">
134<td align="left"><p><code>fstype</code></p></td>
135<td align="left"><p>A single keyword representing the type of filesystem as follows:</p>
136<ul>
137<li><p><code>task</code> - For pseudo filesystems supporting task related services such as pipes and sockets.</p></li>
138<li><p><code>trans</code> - For pseudo filesystems such as pseudo terminals and temporary objects.</p></li>
139<li><p><code>xattr</code> - Filesystems supporting the extended attribute <code>security.selinux</code>. The labeling is persistent for filesystems that support extended attributes.</p></li>
140</ul></td>
141</tr>
142<tr class="odd">
143<td align="left"><p><code>fsname</code></p></td>
144<td align="left"><p>Name of the supported filesystem (e.g. <code>ext4</code> or <code>pipefs</code>).</p></td>
145</tr>
146<tr class="even">
147<td align="left"><p><code>context_id</code></p></td>
148<td align="left"><p>The security context to be allocated to the network interface.</p>
149<p>A previously declared <code>context</code> identifier or an anonymous security context (<code>user role type levelrange</code>), the range MUST be defined whether the policy is MLS/MCS enabled or not.</p></td>
150</tr>
151</tbody>
152</table>
153
154**Examples:**
155
156The [context](#context) identifiers are declared in the `file` namespace and the [`fsuse`](cil_file_labeling_statements.md#fsuse) statements in the global namespace:
157
158```secil
159    (block file
160        (type labeledfs)
161        (roletype object_r labeledfs)
162        (context labeledfs_context (u object_r labeledfs low_low))
163
164        (type pipefs)
165        (roletype object_r pipefs)
166        (context pipefs_context (u object_r pipefs low_low))
167        ...
168    )
169
170    (fsuse xattr ex4 file.labeledfs_context)
171    (fsuse xattr btrfs file.labeledfs_context)
172
173    (fsuse task pipefs file.pipefs_context)
174    (fsuse task sockfs file.sockfs_context)
175
176    (fsuse trans devpts file.devpts_context)
177    (fsuse trans tmpfs file.tmpfs_context)
178```
179
180genfscon
181--------
182
183Used to allocate a security context to filesystems that cannot support any of the [`fsuse`](cil_file_labeling_statements.md#fsuse) file labeling options. Generally a filesystem would have a single default security context assigned by [`genfscon`](cil_file_labeling_statements.md#genfscon) from the root `(/)` that would then be inherited by all files and directories on that filesystem. The exception to this is the `/proc` filesystem, where directories can be labeled with a specific security context (as shown in the examples).
184
185**Statement definition:**
186
187```secil
188    (genfscon fsname path context_id)
189```
190
191**Where:**
192
193<table>
194<colgroup>
195<col width="25%" />
196<col width="75%" />
197</colgroup>
198<tbody>
199<tr class="odd">
200<td align="left"><p><code>genfscon</code></p></td>
201<td align="left"><p>The <code>genfscon</code> keyword.</p></td>
202</tr>
203<tr class="even">
204<td align="left"><p><code>fsname</code></p></td>
205<td align="left"><p>Name of the supported filesystem (e.g. <code>rootfs</code> or <code>proc</code>).</p></td>
206</tr>
207<tr class="odd">
208<td align="left"><p><code>path</code></p></td>
209<td align="left"><p>If <code>fsname</code> is <code>proc</code>, then the partial path (see examples). For all other types this must be ‘<code>/</code>’.</p></td>
210</tr>
211<tr class="even">
212<td align="left"><p><code>context_id</code></p></td>
213<td align="left"><p>A previously declared <code>context</code> identifier or an anonymous security context (<code>user role type levelrange</code>), the range MUST be defined whether the policy is MLS/MCS enabled or not.</p></td>
214</tr>
215</tbody>
216</table>
217
218**Examples:**
219
220The [context](#context) identifiers are declared in the `file` namespace and the [`genfscon`](cil_file_labeling_statements.md#genfscon) statements are then inserted using the [`in`](cil_container_statements.md#in) container statement:
221
222```secil
223    (file
224        (type rootfs)
225        (roletype object_r rootfs)
226        (context rootfs_context (u object_r rootfs low_low))
227
228        (type proc)
229        (roletype object_r proc)
230        (context rootfs_context (u object_r proc low_low))
231        ...
232    )
233
234    (in file
235        (genfscon rootfs / rootfs_context)
236        ; proc labeling can be further refined (longest matching prefix).
237        (genfscon proc / proc_context)
238        (genfscon proc /net/xt_qtaguid/ctrl qtaguid_proc_context)
239        (genfscon proc /sysrq-trigger sysrq_proc_context)
240        (genfscon selinuxfs / selinuxfs_context)
241    )
242```
243