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                 </snopsis>
  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         return;
 130 }
 131
 132 /*! \brief Destroy dynamically allocated data on an audiohook_inheritance_datastore
 133  *
 134  * \param data Pointer to the audiohook_inheritance_datastore in question.
 135  * \return Void
 136  */
 137 static void audiohook_inheritance_destroy(void *data)
 138 {
 139         struct audiohook_inheritance_datastore *audiohook_inheritance_datastore = data;
 140         struct inheritable_audiohook *inheritable_audiohook = NULL;
 141
 142         while ((inheritable_audiohook = AST_LIST_REMOVE_HEAD(&audiohook_inheritance_datastore->allowed_list, list))) {
 143                 ast_free(inheritable_audiohook);
 144         }
 145 }
 146
 147 /*! \brief create an audiohook_inheritance_datastore and attach it to a channel
 148  *
 149  * \param chan The channel to which we wish to attach the new datastore
 150  * \return Returns the newly created audiohook_inheritance_datastore or NULL on error
 151  */
 152 static struct audiohook_inheritance_datastore *setup_inheritance_datastore(struct ast_channel *chan)
 153 {
 154         struct ast_datastore *datastore = NULL;
 155         struct audiohook_inheritance_datastore *audiohook_inheritance_datastore = NULL;
 156
 157         if (!(datastore = ast_datastore_alloc(&audiohook_inheritance_info, NULL))) {
 158                 return NULL;
 159         }
 160
 161         if (!(audiohook_inheritance_datastore = ast_calloc(1, sizeof(*audiohook_inheritance_datastore)))) {
 162                 ast_datastore_free(datastore);
 163                 return NULL;
 164         }
 165
 166         datastore->data = audiohook_inheritance_datastore;
 167         ast_channel_lock(chan);
 168         ast_channel_datastore_add(chan, datastore);
 169         ast_channel_unlock(chan);
 170         return audiohook_inheritance_datastore;
 171 }
 172
 173 /*! \brief Create a new inheritable_audiohook structure and add it to an audiohook_inheritance_datastore
 174  *
 175  * \param audiohook_inheritance_datastore The audiohook_inheritance_datastore we want to add the new inheritable_audiohook to
 176  * \param source The audiohook source for the newly created inheritable_audiohook
 177  * \retval 0 Success
 178  * \retval non-zero Failure
 179  */
 180 static int setup_inheritable_audiohook(struct audiohook_inheritance_datastore *audiohook_inheritance_datastore, const char *source)
 181 {
 182         struct inheritable_audiohook *inheritable_audiohook = NULL;
 183
 184         inheritable_audiohook = ast_calloc(1, sizeof(*inheritable_audiohook) + strlen(source));
 185
 186         if (!inheritable_audiohook) {
 187                 return -1;
 188         }
 189
 190         strcpy(inheritable_audiohook->source, source);
 191         AST_LIST_INSERT_TAIL(&audiohook_inheritance_datastore->allowed_list, inheritable_audiohook, list);
 192         ast_debug(3, "Set audiohook %s to be inheritable\n", source);
 193         return 0;
 194 }
 195
 196 /*! \brief Set the permissibility of inheritance for a particular audiohook source on a channel
 197  *
 198  * For details regarding what happens in the function, see the inline comments
 199  *
 200  * \param chan The channel we are operating on
 201  * \param function The name of the dialplan function (AUDIOHOOK_INHERIT)
 202  * \param data The audiohook source for which we are setting inheritance permissions
 203  * \param value The value indicating the permission for audiohook inheritance
 204  */
 205 static int func_inheritance_write(struct ast_channel *chan, const char *function, char *data, const char *value)
 206 {
 207         int allow;
 208         struct ast_datastore *datastore = NULL;
 209         struct audiohook_inheritance_datastore *inheritance_datastore = NULL;
 210         struct inheritable_audiohook *inheritable_audiohook;
 211
 212         /* Step 1: Get data from function call */
 213         if (ast_strlen_zero(data)) {
 214                 ast_log(LOG_WARNING, "No argument provided to INHERITANCE function.\n");
 215                 return -1;
 216         }
 217
 218         if (ast_strlen_zero(value)) {
 219                 ast_log(LOG_WARNING, "No value provided to INHERITANCE function.\n");
 220                 return -1;
 221         }
 222
 223         allow = ast_true(value);
 224
 225         /* Step 2: retrieve or set up datastore */
 226         ast_channel_lock(chan);
 227         if (!(datastore = ast_channel_datastore_find(chan, &audiohook_inheritance_info, NULL))) {
 228                 ast_channel_unlock(chan);
 229                 /* In the case where we cannot find the datastore, we can take a few shortcuts */
 230                 if (!allow) {
 231                         ast_debug(1, "Audiohook %s is already set to not be inheritable on channel %s\n", data, chan->name);
 232                         return 0;
 233                 } else if (!(inheritance_datastore = setup_inheritance_datastore(chan))) {
 234                         ast_log(LOG_WARNING, "Unable to set up audiohook inheritance datastore on channel %s\n", chan->name);
 235                         return -1;
 236                 } else {
 237                         return setup_inheritable_audiohook(inheritance_datastore, data);
 238                 }
 239         } else {
 240                 inheritance_datastore = datastore->data;
 241         }
 242         ast_channel_unlock(chan);
 243
 244         /* Step 3: Traverse the list to see if we're trying something redundant */
 245
 246         AST_LIST_TRAVERSE_SAFE_BEGIN(&inheritance_datastore->allowed_list, inheritable_audiohook, list) {
 247                 if (!strcasecmp(inheritable_audiohook->source, data)) {
 248                         if (allow) {
 249                                 ast_debug(2, "Audiohook source %s is already set up to be inherited from channel %s\n", data, chan->name);
 250                                 return 0;
 251                         } else {
 252                                 ast_debug(2, "Removing inheritability of audiohook %s from channel %s\n", data, chan->name);
 253                                 AST_LIST_REMOVE_CURRENT(list);
 254                                 ast_free(inheritable_audiohook);
 255                                 return 0;
 256                         }
 257                 }
 258         }
 259         AST_LIST_TRAVERSE_SAFE_END;
 260
 261         /* Step 4: There is no step 4 */
 262
 263         /* Step 5: This means we are addressing an audiohook source which we have not encountered yet for the channel. Create a new inheritable
 264          * audiohook structure if we're allowing inheritance, or just return if not
 265          */
 266
 267         if (allow) {
 268                 return setup_inheritable_audiohook(inheritance_datastore, data);
 269         } else {
 270                 ast_debug(1, "Audiohook %s is already set to not be inheritable on channel %s\n", data, chan->name);
 271                 return 0;
 272         }
 273 }
 274
 275 static struct ast_custom_function inheritance_function = {
 276         .name = "AUDIOHOOK_INHERIT",
 277         .write = func_inheritance_write,
 278 };
 279
 280 static int unload_module(void)
 281 {
 282         return ast_custom_function_unregister(&inheritance_function);
 283 }
 284
 285 static int load_module(void)
 286 {
 287         if (ast_custom_function_register(&inheritance_function)) {
 288                 return AST_MODULE_LOAD_DECLINE;
 289         } else {
 290                 return AST_MODULE_LOAD_SUCCESS;
 291         }
 292 }
 293 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Audiohook inheritance function");