• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1Conditional Statements
2======================
3
4boolean
5-------
6
7Declares a run time boolean as true or false in the current namespace. The [`booleanif`](cil_conditional_statements.md#booleanif) statement contains the CIL code that will be in the binary policy file.
8
9[`boolean`](cil_conditional_statements.md#boolean) are not allowed in [`booleanif`](cil_conditional_statements.md#booleanif) blocks.
10
11**Statement definition:**
12
13```secil
14    (boolean boolean_id true|false)
15```
16
17**Where:**
18
19<table>
20<colgroup>
21<col width="25%" />
22<col width="75%" />
23</colgroup>
24<tbody>
25<tr class="odd">
26<td align="left"><p><code>boolean</code></p></td>
27<td align="left"><p>The <code>boolean</code> keyword.</p></td>
28</tr>
29<tr class="even">
30<td align="left"><p><code>boolean_id</code></p></td>
31<td align="left"><p>The <code>boolean</code> identifier.</p></td>
32</tr>
33<tr class="odd">
34<td align="left"><p><code>true | false</code></p></td>
35<td align="left"><p>The initial state of the boolean. This can be changed at run time using <strong><code>setsebool</code></strong><code>(8)</code> and its status queried using <strong><code>getsebool</code></strong><code>(8)</code>.</p></td>
36</tr>
37</tbody>
38</table>
39
40**Example:**
41
42See the [`booleanif`](cil_conditional_statements.md#booleanif) statement for an example.
43
44booleanif
45---------
46
47Contains the run time conditional statements that are instantiated in the binary policy according to the computed boolean identifier(s) state.
48
49[`call`](cil_call_macro_statements.md#call) statements are allowed within a [`booleanif`](cil_conditional_statements.md#booleanif), however the contents of the resulting macro must be limited to those of the [`booleanif`](cil_conditional_statements.md#booleanif) statement (i.e. [`allow`](cil_access_vector_rules.md#allow), [`auditallow`](cil_access_vector_rules.md#auditallow), [`dontaudit`](cil_access_vector_rules.md#dontaudit), [`typemember`](cil_type_statements.md#typemember), [`typetransition`](cil_type_statements.md#typetransition), [`typechange`](cil_type_statements.md#typechange) and the compile time [`tunableif`](cil_conditional_statements.md#tunableif) statement)).
50
51**Statement definition:**
52
53```secil
54    (booleanif boolean_id | expr ...
55        (true
56            cil_statements
57            ...)
58        (false
59            cil_statements
60            ...)
61    )
62```
63
64**Where:**
65
66<table>
67<colgroup>
68<col width="25%" />
69<col width="75%" />
70</colgroup>
71<tbody>
72<tr class="odd">
73<td align="left"><p><code>booleanif</code></p></td>
74<td align="left"><p>The <code>booleanif</code> keyword.</p></td>
75</tr>
76<tr class="even">
77<td align="left"><p><code>boolean_id</code></p></td>
78<td align="left"><p>Either a single <code>boolean</code> identifier or one or more <code>expr</code>'s.</p></td>
79</tr>
80<tr class="odd">
81<td align="left"><p><code>expr</code></p></td>
82<td align="left"><p>Zero or more <code>expr</code>'s, the valid operators and syntax are:</p>
83<p><code>    (and boolean_id boolean_id)</code></p>
84<p><code>    (or  boolean_id boolean_id)</code></p>
85<p><code>    (xor boolean_id boolean_id)</code></p>
86<p><code>    (eq  boolean_id boolean_id)</code></p>
87<p><code>    (neq boolean_id boolean_id)</code></p>
88<p><code>    (not boolean_id)</code></p></td>
89</tr>
90<tr class="even">
91<td align="left"><p><code>true</code></p></td>
92<td align="left"><p>An optional set of CIL statements that will be instantiated when the <code>boolean</code> is evaluated as <code>true</code>.</p></td>
93</tr>
94<tr class="odd">
95<td align="left"><p><code>false</code></p></td>
96<td align="left"><p>An optional set of CIL statements that will be instantiated when the <code>boolean</code> is evaluated as <code>false</code>.</p></td>
97</tr>
98</tbody>
99</table>
100
101**Examples:**
102
103The second example also shows the kernel policy language equivalent:
104
105```secil
106    (boolean disableAudio false)
107
108    (booleanif disableAudio
109        (false
110            (allow process mediaserver.audio_device (chr_file_set (rw_file_perms)))
111        )
112    )
113
114    (boolean disableAudioCapture false)
115
116    ;;; if(!disableAudio && !disableAudioCapture) {
117    (booleanif (and (not disableAudio) (not disableAudioCapture))
118        (true
119            (allow process mediaserver.audio_capture_device (chr_file_set (rw_file_perms)))
120        )
121    )
122```
123
124tunable
125-------
126
127Tunables are similar to booleans, however they are used to manage areas of CIL statements that may or may not be in the final CIL policy that will be compiled (whereas booleans are embedded in the binary policy and can be enabled or disabled during run-time).
128
129Note that tunables can be treated as booleans by the CIL compiler command line parameter `-P` or `--preserve-tunables` flags.
130
131Since [`tunableif`](cil_conditional_statements.md#tunableif) statements are resolved first, [`tunable`](cil_conditional_statements.md#tunable) statements are not allowed in [`in`](cil_container_statements.md#in), [`macro`](cil_call_macro_statements.md#macro), [`optional`](cil_container_statements.md#optional), and [`booleanif`](cil_conditional_statements.md#booleanif) blocks. To simplify processing, they are also not allowed in [`tunableif`](cil_conditional_statements.md#tunableif) blocks.
132
133**Statement definition:**
134
135```secil
136    (tunable tunable_id true|false)
137```
138
139**Where:**
140
141<table>
142<colgroup>
143<col width="25%" />
144<col width="75%" />
145</colgroup>
146<tbody>
147<tr class="odd">
148<td align="left"><p><code>tunable</code></p></td>
149<td align="left"><p>The <code>tunable</code> keyword.</p></td>
150</tr>
151<tr class="even">
152<td align="left"><p><code>tunable_id</code></p></td>
153<td align="left"><p>The <code>tunable</code> identifier.</p></td>
154</tr>
155<tr class="odd">
156<td align="left"><p><code>true | false</code></p></td>
157<td align="left"><p>The initial state of the <code>tunable</code>.</p></td>
158</tr>
159</tbody>
160</table>
161
162**Example:**
163
164See the [`tunableif`](cil_conditional_statements.md#tunableif) statement for an example.
165
166tunableif
167---------
168
169Compile time conditional statement that may or may not add CIL statements to be compiled.
170
171If tunables are being treated as booleans (by using the CIL compiler command line parameter `-P` or `--preserve-tunables` flag), then only the statements allowed in a [`booleanif`](cil_conditional_statements.md#booleanif) block are allowed in a [`tunableif`](cil_conditional_statements.md#tunableif) block. Otherwise, [`tunable`](cil_conditional_statements.md#tunable) statements are not allowed in a [`tunableif`](cil_conditional_statements.md#tunableif) block.
172
173**Statement definition:**
174
175```secil
176    (tunableif tunable_id | expr ...
177        (true
178            cil_statements
179            ...)
180        (false
181            cil_statements
182            ...)
183    )
184```
185
186**Where:**
187
188<table>
189<colgroup>
190<col width="25%" />
191<col width="75%" />
192</colgroup>
193<tbody>
194<tr class="odd">
195<td align="left"><p><code>tunableif</code></p></td>
196<td align="left"><p>The <code>tunableif</code> keyword.</p></td>
197</tr>
198<tr class="even">
199<td align="left"><p><code>tunable_id</code></p></td>
200<td align="left"><p>Either a single <code>tunable</code> identifier or one or more <code>expr</code>'s.</p></td>
201</tr>
202<tr class="odd">
203<td align="left"><p><code>expr</code></p></td>
204<td align="left"><p>Zero or more <code>expr</code>'s, the valid operators and syntax are:</p>
205<p><code>    (and tunable_id tunable_id)</code></p>
206<p><code>    (or  tunable_id tunable_id)</code></p>
207<p><code>    (xor tunable_id tunable_id)</code></p>
208<p><code>    (eq  tunable_id tunable_id)</code></p>
209<p><code>    (neq tunable_id tunable_id)</code></p>
210<p><code>    (not tunable_id)</code></p></td>
211</tr>
212<tr class="even">
213<td align="left"><p><code>true</code></p></td>
214<td align="left"><p>An optional set of CIL statements that will be instantiated when the <code>tunable</code> is evaluated as <code>true</code>.</p></td>
215</tr>
216<tr class="odd">
217<td align="left"><p><code>false</code></p></td>
218<td align="left"><p>An optional set of CIL statements that will be instantiated when the <code>tunable</code> is evaluated as <code>false</code>.</p></td>
219</tr>
220</tbody>
221</table>
222
223**Example:**
224
225This example will not add the range transition rule to the binary policy:
226
227```secil
228    (tunable range_trans_rule false)
229
230    (block init
231        (class process (process))
232        (type process)
233
234        (tunableif range_trans_rule
235            (true
236                (rangetransition process sshd.exec process low_high)
237            )
238        ) ; End tunableif
239    ) ; End block
240```
241