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[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 /*** MODULEINFO
32         <support_level>core</support_level>
33  ***/
34
35 #include "asterisk.h"
36 #include "asterisk/datastore.h"
37 #include "asterisk/channel.h"
38 #include "asterisk/logger.h"
39 #include "asterisk/audiohook.h"
40 #include "asterisk/pbx.h"
41 #include "asterisk/module.h"
42
43 /*** DOCUMENTATION
44         <function name = "AUDIOHOOK_INHERIT" language="en_US">
45                 <synopsis>
46                         Set whether an audiohook may be inherited to another channel
47                 </synopsis>
48                 <syntax>
49                         <parameter name="source" required="true">
50                                 <para>The built-in sources in Asterisk are</para>
51                                 <enumlist>
52                                         <enum name="MixMonitor" />
53                                         <enum name="Chanspy" />
54                                         <enum name="Volume" />
55                                         <enum name="Speex" />
56                                         <enum name="pitch_shift" />
57                                         <enum name="JACK_HOOK" />
58                                         <enum name="Mute" />
59                                 </enumlist>
60                                 <para>Note that the names are not case-sensitive</para>
61                         </parameter>
62                 </syntax>
63                 <description>
64                         <para>By enabling audiohook inheritance on the channel, you are giving
65                         permission for an audiohook to be inherited by a descendent channel.
66                         Inheritance may be be disabled at any point as well.</para>
67
68                         <para>Example scenario:</para>
69                         <para>exten => 2000,1,MixMonitor(blah.wav)</para>
70                         <para>exten => 2000,n,Set(AUDIOHOOK_INHERIT(MixMonitor)=yes)</para>
71                         <para>exten => 2000,n,Dial(SIP/2000)</para>
72                         <para>
73                         </para>
74                         <para>exten => 4000,1,Dial(SIP/4000)</para>
75                         <para>
76                         </para>
77                         <para>exten => 5000,1,MixMonitor(blah2.wav)</para>
78                         <para>exten => 5000,n,Dial(SIP/5000)</para>
79                         <para>
80                         </para>
81                         <para>In this basic dialplan scenario, let's consider the following sample calls</para>
82                         <para>Call 1: Caller dials 2000. The person who answers then executes an attended</para>
83                         <para>        transfer to 4000.</para>
84                         <para>Result: Since extension 2000 set MixMonitor to be inheritable, after the</para>
85                         <para>        transfer to 4000 has completed, the call will continue to be recorded
86                         to blah.wav</para>
87                         <para>
88                         </para>
89                         <para>Call 2: Caller dials 5000. The person who answers then executes an attended</para>
90                         <para>        transfer to 4000.</para>
91                         <para>Result: Since extension 5000 did not set MixMonitor to be inheritable, the</para>
92                         <para>        recording will stop once the call has been transferred to 4000.</para>
93                 </description>
94         </function>
95  ***/
96
97 struct inheritable_audiohook {
98         AST_LIST_ENTRY(inheritable_audiohook) list;
99         char source[1];
100 };
101
102 struct audiohook_inheritance_datastore {
103         AST_LIST_HEAD (, inheritable_audiohook) allowed_list;
104 };
105
106 static void audiohook_inheritance_fixup(void *data, struct ast_channel *old_chan, struct ast_channel *new_chan);
107 static void audiohook_inheritance_destroy (void *data);
108 static const struct ast_datastore_info audiohook_inheritance_info = {
109         .type = "audiohook inheritance",
110         .destroy = audiohook_inheritance_destroy,
111         .chan_fixup = audiohook_inheritance_fixup,
112 };
113
114 /*! \brief Move audiohooks as defined by previous calls to the AUDIOHOOK_INHERIT function
115  *
116  * Move allowed audiohooks from the old channel to the new channel.
117  *
118  * \param data The ast_datastore containing audiohook inheritance information that will be moved
119  * \param old_chan The "clone" channel from a masquerade. We are moving the audiohook in question off of this channel
120  * \param new_chan The "original" channel from a masquerade. We are moving the audiohook in question to this channel
121  * \return Void
122  */
123 static void audiohook_inheritance_fixup(void *data, struct ast_channel *old_chan, struct ast_channel *new_chan)
124 {
125         struct inheritable_audiohook *audiohook = NULL;
126         struct audiohook_inheritance_datastore *datastore = data;
127
128         ast_debug(2, "inheritance fixup occurring for channels %s(%p) and %s(%p)", ast_channel_name(old_chan), old_chan, ast_channel_name(new_chan), new_chan);
129
130         AST_LIST_TRAVERSE(&datastore->allowed_list, audiohook, list) {
131                 ast_audiohook_move_by_source(old_chan, new_chan, audiohook->source);
132                 ast_debug(3, "Moved audiohook %s from %s(%p) to %s(%p)\n",
133                         audiohook->source, ast_channel_name(old_chan), old_chan, ast_channel_name(new_chan), new_chan);
134         }
135         return;
136 }
137
138 /*! \brief Destroy dynamically allocated data on an audiohook_inheritance_datastore
139  *
140  * \param data Pointer to the audiohook_inheritance_datastore in question.
141  * \return Void
142  */
143 static void audiohook_inheritance_destroy(void *data)
144 {
145         struct audiohook_inheritance_datastore *audiohook_inheritance_datastore = data;
146         struct inheritable_audiohook *inheritable_audiohook = NULL;
147
148         while ((inheritable_audiohook = AST_LIST_REMOVE_HEAD(&audiohook_inheritance_datastore->allowed_list, list))) {
149                 ast_free(inheritable_audiohook);
150         }
151
152         ast_free(audiohook_inheritance_datastore);
153 }
154
155 /*! \brief create an audiohook_inheritance_datastore and attach it to a channel
156  *
157  * \param chan The channel to which we wish to attach the new datastore
158  * \return Returns the newly created audiohook_inheritance_datastore or NULL on error
159  */
160 static struct audiohook_inheritance_datastore *setup_inheritance_datastore(struct ast_channel *chan)
161 {
162         struct ast_datastore *datastore = NULL;
163         struct audiohook_inheritance_datastore *audiohook_inheritance_datastore = NULL;
164
165         if (!(datastore = ast_datastore_alloc(&audiohook_inheritance_info, NULL))) {
166                 return NULL;
167         }
168
169         if (!(audiohook_inheritance_datastore = ast_calloc(1, sizeof(*audiohook_inheritance_datastore)))) {
170                 ast_datastore_free(datastore);
171                 return NULL;
172         }
173
174         datastore->data = audiohook_inheritance_datastore;
175         ast_channel_lock(chan);
176         ast_channel_datastore_add(chan, datastore);
177         ast_channel_unlock(chan);
178         return audiohook_inheritance_datastore;
179 }
180
181 /*! \brief Create a new inheritable_audiohook structure and add it to an audiohook_inheritance_datastore
182  *
183  * \param audiohook_inheritance_datastore The audiohook_inheritance_datastore we want to add the new inheritable_audiohook to
184  * \param source The audiohook source for the newly created inheritable_audiohook
185  * \retval 0 Success
186  * \retval non-zero Failure
187  */
188 static int setup_inheritable_audiohook(struct audiohook_inheritance_datastore *audiohook_inheritance_datastore, const char *source)
189 {
190         struct inheritable_audiohook *inheritable_audiohook = NULL;
191
192         inheritable_audiohook = ast_calloc(1, sizeof(*inheritable_audiohook) + strlen(source));
193
194         if (!inheritable_audiohook) {
195                 return -1;
196         }
197
198         strcpy(inheritable_audiohook->source, source);
199         AST_LIST_INSERT_TAIL(&audiohook_inheritance_datastore->allowed_list, inheritable_audiohook, list);
200         ast_debug(3, "Set audiohook %s to be inheritable\n", source);
201         return 0;
202 }
203
204 /*! \brief Set the permissibility of inheritance for a particular audiohook source on a channel
205  *
206  * For details regarding what happens in the function, see the inline comments
207  *
208  * \param chan The channel we are operating on
209  * \param function The name of the dialplan function (AUDIOHOOK_INHERIT)
210  * \param data The audiohook source for which we are setting inheritance permissions
211  * \param value The value indicating the permission for audiohook inheritance
212  */
213 static int func_inheritance_write(struct ast_channel *chan, const char *function, char *data, const char *value)
214 {
215         int allow;
216         struct ast_datastore *datastore = NULL;
217         struct audiohook_inheritance_datastore *inheritance_datastore = NULL;
218         struct inheritable_audiohook *inheritable_audiohook;
219
220         /* Step 1: Get data from function call */
221         if (ast_strlen_zero(data)) {
222                 ast_log(LOG_WARNING, "No argument provided to INHERITANCE function.\n");
223                 return -1;
224         }
225
226         if (ast_strlen_zero(value)) {
227                 ast_log(LOG_WARNING, "No value provided to INHERITANCE function.\n");
228                 return -1;
229         }
230
231         allow = ast_true(value);
232
233         /* Step 2: retrieve or set up datastore */
234         ast_channel_lock(chan);
235         if (!(datastore = ast_channel_datastore_find(chan, &audiohook_inheritance_info, NULL))) {
236                 ast_channel_unlock(chan);
237                 /* In the case where we cannot find the datastore, we can take a few shortcuts */
238                 if (!allow) {
239                         ast_debug(1, "Audiohook %s is already set to not be inheritable on channel %s\n", data, ast_channel_name(chan));
240                         return 0;
241                 } else if (!(inheritance_datastore = setup_inheritance_datastore(chan))) {
242                         ast_log(LOG_WARNING, "Unable to set up audiohook inheritance datastore on channel %s\n", ast_channel_name(chan));
243                         return -1;
244                 } else {
245                         return setup_inheritable_audiohook(inheritance_datastore, data);
246                 }
247         } else {
248                 inheritance_datastore = datastore->data;
249         }
250         ast_channel_unlock(chan);
251
252         /* Step 3: Traverse the list to see if we're trying something redundant */
253
254         AST_LIST_TRAVERSE_SAFE_BEGIN(&inheritance_datastore->allowed_list, inheritable_audiohook, list) {
255                 if (!strcasecmp(inheritable_audiohook->source, data)) {
256                         if (allow) {
257                                 ast_debug(2, "Audiohook source %s is already set up to be inherited from channel %s\n", data, ast_channel_name(chan));
258                                 return 0;
259                         } else {
260                                 ast_debug(2, "Removing inheritability of audiohook %s from channel %s\n", data, ast_channel_name(chan));
261                                 AST_LIST_REMOVE_CURRENT(list);
262                                 ast_free(inheritable_audiohook);
263                                 return 0;
264                         }
265                 }
266         }
267         AST_LIST_TRAVERSE_SAFE_END;
268
269         /* Step 4: There is no step 4 */
270
271         /* Step 5: This means we are addressing an audiohook source which we have not encountered yet for the channel. Create a new inheritable
272          * audiohook structure if we're allowing inheritance, or just return if not
273          */
274
275         if (allow) {
276                 return setup_inheritable_audiohook(inheritance_datastore, data);
277         } else {
278                 ast_debug(1, "Audiohook %s is already set to not be inheritable on channel %s\n", data, ast_channel_name(chan));
279                 return 0;
280         }
281 }
282
283 static struct ast_custom_function inheritance_function = {
284         .name = "AUDIOHOOK_INHERIT",
285         .write = func_inheritance_write,
286 };
287
288 static int unload_module(void)
289 {
290         return ast_custom_function_unregister(&inheritance_function);
291 }
292
293 static int load_module(void)
294 {
295         if (ast_custom_function_register(&inheritance_function)) {
296                 return AST_MODULE_LOAD_DECLINE;
297         } else {
298                 return AST_MODULE_LOAD_SUCCESS;
299         }
300 }
301 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Audiohook inheritance function");