fixes memory leak in func_audiohookinherit.c
[asterisk/asterisk.git] / funcs / func_audiohookinherit.c
1 /*
2  * Asterisk -- An open source telephony toolkit.
3  *
4  * Copyright (C) 2008, Digium, Inc.
5  *
6  * Mark Michelson <mmichelson@digium.com>
7  *
8  * See http://www.asterisk.org for more information about
9  * the Asterisk project. Please do not directly contact
10  * any of the maintainers of this project for assistance;
11  * the project provides a web site, mailing lists and IRC
12  * channels for your use.
13  *
14  * This program is free software, distributed under the terms of
15  * the GNU General Public License Version 2. See the LICENSE file
16  * at the top of the source tree.
17  *
18  * Please follow coding guidelines
19  * http://svn.digium.com/view/asterisk/trunk/doc/CODING-GUIDELINES
20  */
21
22 /*! \file
23  *
24  * \brief Audiohook inheritance function
25  *
26  * \author Mark Michelson <mmichelson@digium.com>
27  *
28  * \ingroup functions
29  */
30
31 #include "asterisk.h"
32 #include "asterisk/datastore.h"
33 #include "asterisk/channel.h"
34 #include "asterisk/logger.h"
35 #include "asterisk/audiohook.h"
36 #include "asterisk/pbx.h"
37 #include "asterisk/module.h"
38
39 /*** DOCUMENTATION
40         <function name = "AUDIOHOOK_INHERIT" language="en_US">
41                 <synopsis>
42                         Set whether an audiohook may be inherited to another channel
43                 </synopsis>
44                 <syntax>
45                         <parameter name="source" required="true">
46                                 <para>The built-in sources in Asterisk are</para>
47                                 <enumlist>
48                                         <enum name="MixMonitor" />
49                                         <enum name="Chanspy" />
50                                         <enum name="Volume" />
51                                         <enum name="Speex" />
52                                         <enum name="JACK_HOOK" />
53                                 </enumlist>
54                                 <para>Note that the names are not case-sensitive</para>
55                         </parameter>
56                 </syntax>
57                 <description>
58                         <para>By enabling audiohook inheritance on the channel, you are giving
59                         permission for an audiohook to be inherited by a descendent channel.
60                         Inheritance may be be disabled at any point as well.</para>
61
62                         <para>Example scenario:</para>
63                         <para>exten => 2000,1,MixMonitor(blah.wav)</para>
64                         <para>exten => 2000,n,Set(AUDIOHOOK_INHERIT(MixMonitor)=yes)</para>
65                         <para>exten => 2000,n,Dial(SIP/2000)</para>
66                         <para>
67                         </para>
68                         <para>exten => 4000,1,Dial(SIP/4000)</para>
69                         <para>
70                         </para>
71                         <para>exten => 5000,1,MixMonitor(blah2.wav)</para>
72                         <para>exten => 5000,n,Dial(SIP/5000)</para>
73                         <para>
74                         </para>
75                         <para>In this basic dialplan scenario, let's consider the following sample calls</para>
76                         <para>Call 1: Caller dials 2000. The person who answers then executes an attended</para>
77                         <para>        transfer to 4000.</para>
78                         <para>Result: Since extension 2000 set MixMonitor to be inheritable, after the</para>
79                         <para>        transfer to 4000 has completed, the call will continue to be recorded
80                         to blah.wav</para>
81                         <para>
82                         </para>
83                         <para>Call 2: Caller dials 5000. The person who answers then executes an attended</para>
84                         <para>        transfer to 4000.</para>
85                         <para>Result: Since extension 5000 did not set MixMonitor to be inheritable, the</para>
86                         <para>        recording will stop once the call has been transferred to 4000.</para>
87                 </description>
88         </function>
89  ***/
90
91 struct inheritable_audiohook {
92         AST_LIST_ENTRY(inheritable_audiohook) list;
93         char source[1];
94 };
95
96 struct audiohook_inheritance_datastore {
97         AST_LIST_HEAD (, inheritable_audiohook) allowed_list;
98 };
99
100 static void audiohook_inheritance_fixup(void *data, struct ast_channel *old_chan, struct ast_channel *new_chan);
101 static void audiohook_inheritance_destroy (void *data);
102 static const struct ast_datastore_info audiohook_inheritance_info = {
103         .type = "audiohook inheritance",
104         .destroy = audiohook_inheritance_destroy,
105         .chan_fixup = audiohook_inheritance_fixup,
106 };
107
108 /*! \brief Move audiohooks as defined by previous calls to the AUDIOHOOK_INHERIT function
109  *
110  * Move allowed audiohooks from the old channel to the new channel.
111  *
112  * \param data The ast_datastore containing audiohook inheritance information that will be moved
113  * \param old_chan The "clone" channel from a masquerade. We are moving the audiohook in question off of this channel
114  * \param new_chan The "original" channel from a masquerade. We are moving the audiohook in question to this channel
115  * \return Void
116  */
117 static void audiohook_inheritance_fixup(void *data, struct ast_channel *old_chan, struct ast_channel *new_chan)
118 {
119         struct inheritable_audiohook *audiohook = NULL;
120         struct audiohook_inheritance_datastore *datastore = data;
121
122         ast_debug(2, "inheritance fixup occurring for channels %s(%p) and %s(%p)", old_chan->name, old_chan, new_chan->name, new_chan);
123
124         AST_LIST_TRAVERSE(&datastore->allowed_list, audiohook, list) {
125                 ast_audiohook_move_by_source(old_chan, new_chan, audiohook->source);
126                 ast_debug(3, "Moved audiohook %s from %s(%p) to %s(%p)\n",
127                         audiohook->source, old_chan->name, old_chan, new_chan->name, new_chan);
128         }
129         ast_free(datastore);
130         return;
131 }
132
133 /*! \brief Destroy dynamically allocated data on an audiohook_inheritance_datastore
134  *
135  * \param data Pointer to the audiohook_inheritance_datastore in question.
136  * \return Void
137  */
138 static void audiohook_inheritance_destroy(void *data)
139 {
140         struct audiohook_inheritance_datastore *audiohook_inheritance_datastore = data;
141         struct inheritable_audiohook *inheritable_audiohook = NULL;
142
143         while ((inheritable_audiohook = AST_LIST_REMOVE_HEAD(&audiohook_inheritance_datastore->allowed_list, list))) {
144                 ast_free(inheritable_audiohook);
145         }
146 }
147
148 /*! \brief create an audiohook_inheritance_datastore and attach it to a channel
149  *
150  * \param chan The channel to which we wish to attach the new datastore
151  * \return Returns the newly created audiohook_inheritance_datastore or NULL on error
152  */
153 static struct audiohook_inheritance_datastore *setup_inheritance_datastore(struct ast_channel *chan)
154 {
155         struct ast_datastore *datastore = NULL;
156         struct audiohook_inheritance_datastore *audiohook_inheritance_datastore = NULL;
157
158         if (!(datastore = ast_datastore_alloc(&audiohook_inheritance_info, NULL))) {
159                 return NULL;
160         }
161
162         if (!(audiohook_inheritance_datastore = ast_calloc(1, sizeof(*audiohook_inheritance_datastore)))) {
163                 ast_datastore_free(datastore);
164                 return NULL;
165         }
166
167         datastore->data = audiohook_inheritance_datastore;
168         ast_channel_lock(chan);
169         ast_channel_datastore_add(chan, datastore);
170         ast_channel_unlock(chan);
171         return audiohook_inheritance_datastore;
172 }
173
174 /*! \brief Create a new inheritable_audiohook structure and add it to an audiohook_inheritance_datastore
175  *
176  * \param audiohook_inheritance_datastore The audiohook_inheritance_datastore we want to add the new inheritable_audiohook to
177  * \param source The audiohook source for the newly created inheritable_audiohook
178  * \retval 0 Success
179  * \retval non-zero Failure
180  */
181 static int setup_inheritable_audiohook(struct audiohook_inheritance_datastore *audiohook_inheritance_datastore, const char *source)
182 {
183         struct inheritable_audiohook *inheritable_audiohook = NULL;
184
185         inheritable_audiohook = ast_calloc(1, sizeof(*inheritable_audiohook) + strlen(source));
186
187         if (!inheritable_audiohook) {
188                 return -1;
189         }
190
191         strcpy(inheritable_audiohook->source, source);
192         AST_LIST_INSERT_TAIL(&audiohook_inheritance_datastore->allowed_list, inheritable_audiohook, list);
193         ast_debug(3, "Set audiohook %s to be inheritable\n", source);
194         return 0;
195 }
196
197 /*! \brief Set the permissibility of inheritance for a particular audiohook source on a channel
198  *
199  * For details regarding what happens in the function, see the inline comments
200  *
201  * \param chan The channel we are operating on
202  * \param function The name of the dialplan function (AUDIOHOOK_INHERIT)
203  * \param data The audiohook source for which we are setting inheritance permissions
204  * \param value The value indicating the permission for audiohook inheritance
205  */
206 static int func_inheritance_write(struct ast_channel *chan, const char *function, char *data, const char *value)
207 {
208         int allow;
209         struct ast_datastore *datastore = NULL;
210         struct audiohook_inheritance_datastore *inheritance_datastore = NULL;
211         struct inheritable_audiohook *inheritable_audiohook;
212
213         /* Step 1: Get data from function call */
214         if (ast_strlen_zero(data)) {
215                 ast_log(LOG_WARNING, "No argument provided to INHERITANCE function.\n");
216                 return -1;
217         }
218
219         if (ast_strlen_zero(value)) {
220                 ast_log(LOG_WARNING, "No value provided to INHERITANCE function.\n");
221                 return -1;
222         }
223
224         allow = ast_true(value);
225
226         /* Step 2: retrieve or set up datastore */
227         ast_channel_lock(chan);
228         if (!(datastore = ast_channel_datastore_find(chan, &audiohook_inheritance_info, NULL))) {
229                 ast_channel_unlock(chan);
230                 /* In the case where we cannot find the datastore, we can take a few shortcuts */
231                 if (!allow) {
232                         ast_debug(1, "Audiohook %s is already set to not be inheritable on channel %s\n", data, chan->name);
233                         return 0;
234                 } else if (!(inheritance_datastore = setup_inheritance_datastore(chan))) {
235                         ast_log(LOG_WARNING, "Unable to set up audiohook inheritance datastore on channel %s\n", chan->name);
236                         return -1;
237                 } else {
238                         return setup_inheritable_audiohook(inheritance_datastore, data);
239                 }
240         } else {
241                 inheritance_datastore = datastore->data;
242         }
243         ast_channel_unlock(chan);
244
245         /* Step 3: Traverse the list to see if we're trying something redundant */
246
247         AST_LIST_TRAVERSE_SAFE_BEGIN(&inheritance_datastore->allowed_list, inheritable_audiohook, list) {
248                 if (!strcasecmp(inheritable_audiohook->source, data)) {
249                         if (allow) {
250                                 ast_debug(2, "Audiohook source %s is already set up to be inherited from channel %s\n", data, chan->name);
251                                 return 0;
252                         } else {
253                                 ast_debug(2, "Removing inheritability of audiohook %s from channel %s\n", data, chan->name);
254                                 AST_LIST_REMOVE_CURRENT(list);
255                                 ast_free(inheritable_audiohook);
256                                 return 0;
257                         }
258                 }
259         }
260         AST_LIST_TRAVERSE_SAFE_END;
261
262         /* Step 4: There is no step 4 */
263
264         /* Step 5: This means we are addressing an audiohook source which we have not encountered yet for the channel. Create a new inheritable
265          * audiohook structure if we're allowing inheritance, or just return if not
266          */
267
268         if (allow) {
269                 return setup_inheritable_audiohook(inheritance_datastore, data);
270         } else {
271                 ast_debug(1, "Audiohook %s is already set to not be inheritable on channel %s\n", data, chan->name);
272                 return 0;
273         }
274 }
275
276 static struct ast_custom_function inheritance_function = {
277         .name = "AUDIOHOOK_INHERIT",
278         .write = func_inheritance_write,
279 };
280
281 static int unload_module(void)
282 {
283         return ast_custom_function_unregister(&inheritance_function);
284 }
285
286 static int load_module(void)
287 {
288         if (ast_custom_function_register(&inheritance_function)) {
289                 return AST_MODULE_LOAD_DECLINE;
290         } else {
291                 return AST_MODULE_LOAD_SUCCESS;
292         }
293 }
294 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Audiohook inheritance function");