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