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");