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**Statement definition:**
10
11    (boolean boolean_id true|false)
12
13**Where:**
14
15<table>
16<colgroup>
17<col width="25%" />
18<col width="75%" />
19</colgroup>
20<tbody>
21<tr class="odd">
22<td align="left"><p><code>boolean</code></p></td>
23<td align="left"><p>The <code>boolean</code> keyword.</p></td>
24</tr>
25<tr class="even">
26<td align="left"><p><code>boolean_id</code></p></td>
27<td align="left"><p>The <code>boolean</code> identifier.</p></td>
28</tr>
29<tr class="odd">
30<td align="left"><p><code>true | false</code></p></td>
31<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>
32</tr>
33</tbody>
34</table>
35
36**Example:**
37
38See the [`booleanif`](cil_conditional_statements.md#booleanif) statement for an example.
39
40booleanif
41---------
42
43Contains the run time conditional statements that are instantiated in the binary policy according to the computed boolean identifier(s) state.
44
45[`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)).
46
47**Statement definition:**
48
49    (booleanif boolean_id | expr ...)
50        (true
51            cil_statements
52            ...)
53        (false
54            cil_statements
55            ...)
56    )
57
58**Where:**
59
60<table>
61<colgroup>
62<col width="25%" />
63<col width="75%" />
64</colgroup>
65<tbody>
66<tr class="odd">
67<td align="left"><p><code>booleanif</code></p></td>
68<td align="left"><p>The <code>booleanif</code> keyword.</p></td>
69</tr>
70<tr class="even">
71<td align="left"><p><code>boolean_id</code></p></td>
72<td align="left"><p>Either a single <code>boolean</code> identifier or one or more <code>expr</code>'s.</p></td>
73</tr>
74<tr class="odd">
75<td align="left"><p><code>expr</code></p></td>
76<td align="left"><p>Zero or more <code>expr</code>'s, the valid operators and syntax are:</p>
77<p><code>    (and (boolean_id boolean_id))</code></p>
78<p><code>    (or  (boolean_id boolean_id))</code></p>
79<p><code>    (xor (boolean_id boolean_id))</code></p>
80<p><code>    (eq  (boolean_id boolean_id))</code></p>
81<p><code>    (neq (boolean_id boolean_id))</code></p>
82<p><code>    (not (boolean_id))</code></p></td>
83</tr>
84<tr class="even">
85<td align="left"><p><code>true</code></p></td>
86<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>
87</tr>
88<tr class="odd">
89<td align="left"><p><code>false</code></p></td>
90<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>
91</tr>
92</tbody>
93</table>
94
95**Examples:**
96
97The second example also shows the kernel policy language equivalent:
98
99    (boolean disableAudio false)
100
101    (booleanif disableAudio
102        (false
103            (allow process mediaserver.audio_device (chr_file_set (rw_file_perms)))
104        )
105    )
106
107    (boolean disableAudioCapture false)
108
109    ;;; if(!disableAudio && !disableAudioCapture) {
110    (booleanif (and (not disableAudio) (not disableAudioCapture))
111        (true
112            (allow process mediaserver.audio_capture_device (chr_file_set (rw_file_perms)))
113        )
114    )
115
116tunable
117-------
118
119Tunables 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).
120
121Note that tunables can be treated as booleans by the CIL compiler command line parameter `-P` or `--preserve-tunables` flags.
122
123**Statement definition:**
124
125    (tunable tunable_id true|false)
126
127**Where:**
128
129<table>
130<colgroup>
131<col width="25%" />
132<col width="75%" />
133</colgroup>
134<tbody>
135<tr class="odd">
136<td align="left"><p><code>tunable</code></p></td>
137<td align="left"><p>The <code>tunable</code> keyword.</p></td>
138</tr>
139<tr class="even">
140<td align="left"><p><code>tunable_id</code></p></td>
141<td align="left"><p>The <code>tunable</code> identifier.</p></td>
142</tr>
143<tr class="odd">
144<td align="left"><p><code>true | false</code></p></td>
145<td align="left"><p>The initial state of the <code>tunable</code>.</p></td>
146</tr>
147</tbody>
148</table>
149
150**Example:**
151
152See the [`tunableif`](cil_conditional_statements.md#tunableif) statement for an example.
153
154tunableif
155---------
156
157Compile time conditional statement that may or may not add CIL statements to be compiled.
158
159**Statement definition:**
160
161    (tunableif tunable_id | expr ...)
162        (true
163            cil_statements
164            ...)
165        (false
166            cil_statements
167            ...)
168    )
169
170**Where:**
171
172<table>
173<colgroup>
174<col width="25%" />
175<col width="75%" />
176</colgroup>
177<tbody>
178<tr class="odd">
179<td align="left"><p><code>tunableif</code></p></td>
180<td align="left"><p>The <code>tunableif</code> keyword.</p></td>
181</tr>
182<tr class="even">
183<td align="left"><p><code>tunable_id</code></p></td>
184<td align="left"><p>Either a single <code>tunable</code> identifier or one or more <code>expr</code>'s.</p></td>
185</tr>
186<tr class="odd">
187<td align="left"><p><code>expr</code></p></td>
188<td align="left"><p>Zero or more <code>expr</code>'s, the valid operators and syntax are:</p>
189<p><code>    (and (tunable_id tunable_id))</code></p>
190<p><code>    (or  (tunable_id tunable_id))</code></p>
191<p><code>    (xor (tunable_id tunable_id))</code></p>
192<p><code>    (eq  (tunable_id tunable_id))</code></p>
193<p><code>    (neq (tunable_id tunable_id))</code></p>
194<p><code>    (not (tunable_id))</code></p></td>
195</tr>
196<tr class="even">
197<td align="left"><p><code>true</code></p></td>
198<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>
199</tr>
200<tr class="odd">
201<td align="left"><p><code>false</code></p></td>
202<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>
203</tr>
204</tbody>
205</table>
206
207**Example:**
208
209This example will not add the range transition rule to the binary policy:
210
211    (tunable range_trans_rule false)
212
213    (block init
214        (class process (process))
215        (type process)
216
217        (tunableif range_trans_rule
218            (true
219                (rangetransition process sshd.exec process low_high)
220            )
221        ) ; End tunableif
222    ) ; End block
223