/* * Asterisk -- An open source telephony toolkit. * * Copyright (C) 2009, Digium, Inc. * * Joshua Colp * * See http://www.asterisk.org for more information about * the Asterisk project. Please do not directly contact * any of the maintainers of this project for assistance; * the project provides a web site, mailing lists and IRC * channels for your use. * * This program is free software, distributed under the terms of * the GNU General Public License Version 2. See the LICENSE file * at the top of the source tree. */ /*! \file * * \brief Built in bridging features * * \author Joshua Colp * * \ingroup bridges */ #include "asterisk.h" ASTERISK_FILE_VERSION(__FILE__, "$Revision$") #include #include #include #include #include #include "asterisk/module.h" #include "asterisk/channel.h" #include "asterisk/bridging.h" #include "asterisk/bridging_technology.h" #include "asterisk/frame.h" #include "asterisk/file.h" #include "asterisk/app.h" #include "asterisk/astobj2.h" /*! \brief Helper function that presents dialtone and grabs extension */ static int grab_transfer(struct ast_channel *chan, char *exten, size_t exten_len, const char *context) { int res; /* Play the simple "transfer" prompt out and wait */ res = ast_stream_and_wait(chan, "pbx-transfer", AST_DIGIT_ANY); ast_stopstream(chan); /* If the person hit a DTMF digit while the above played back stick it into the buffer */ if (res) { exten[0] = (char)res; } /* Drop to dialtone so they can enter the extension they want to transfer to */ res = ast_app_dtget(chan, context, exten, exten_len, 100, 1000); return res; } /*! \brief Helper function that creates an outgoing channel and returns it immediately */ static struct ast_channel *dial_transfer(const struct ast_channel *caller, const char *exten, const char *context) { char destination[AST_MAX_EXTENSION+AST_MAX_CONTEXT+1] = ""; struct ast_channel *chan = NULL; int cause; /* Fill the variable with the extension and context we want to call */ snprintf(destination, sizeof(destination), "%s@%s", exten, context); /* Now we request that chan_local prepare to call the destination */ if (!(chan = ast_request("Local", caller->nativeformats, caller, destination, &cause))) { return NULL; } /* Before we actually dial out let's inherit the appropriate dialplan variables */ ast_channel_inherit_variables(caller, chan); /* Since the above worked fine now we actually call it and return the channel */ if (ast_call(chan, destination, 0)) { ast_hangup(chan); return NULL; } return chan; } /*! \brief Internal built in feature for blind transfers */ static int feature_blind_transfer(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, void *hook_pvt) { char exten[AST_MAX_EXTENSION] = ""; struct ast_channel *chan = NULL; struct ast_bridge_features_blind_transfer *blind_transfer = hook_pvt; const char *context = (blind_transfer && !ast_strlen_zero(blind_transfer->context) ? blind_transfer->context : bridge_channel->chan->context); /* Grab the extension to transfer to */ if (!grab_transfer(bridge_channel->chan, exten, sizeof(exten), context)) { ast_stream_and_wait(bridge_channel->chan, "pbx-invalid", AST_DIGIT_ANY); ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_WAIT); return 0; } /* Get a channel that is the destination we wish to call */ if (!(chan = dial_transfer(bridge_channel->chan, exten, context))) { ast_stream_and_wait(bridge_channel->chan, "beeperr", AST_DIGIT_ANY); ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_WAIT); return 0; } /* This is sort of the fun part. We impart the above channel onto the bridge, and have it take our place. */ ast_bridge_impart(bridge, chan, bridge_channel->chan, NULL); return 0; } /*! \brief Attended transfer feature to turn it into a threeway call */ static int attended_threeway_transfer(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, void *hook_pvt) { /* This is sort of abusing the depart state but in this instance it is only going to be handled in the below function so it is okay */ ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_DEPART); return 0; } /*! \brief Attended transfer abort feature */ static int attended_abort_transfer(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, void *hook_pvt) { struct ast_bridge_channel *called_bridge_channel = NULL; /* It is possible (albeit unlikely) that the bridge channels list may change, so we have to ensure we do all of our magic while locked */ ao2_lock(bridge); if (AST_LIST_FIRST(&bridge->channels) != bridge_channel) { called_bridge_channel = AST_LIST_FIRST(&bridge->channels); } else { called_bridge_channel = AST_LIST_LAST(&bridge->channels); } /* Now we basically eject the other channel from the bridge. This will cause their thread to hang them up, and our own code to consider the transfer failed. */ if (called_bridge_channel) { ast_bridge_change_state(called_bridge_channel, AST_BRIDGE_CHANNEL_STATE_HANGUP); } ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_END); ao2_unlock(bridge); return 0; } /*! \brief Internal built in feature for attended transfers */ static int feature_attended_transfer(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, void *hook_pvt) { char exten[AST_MAX_EXTENSION] = ""; struct ast_channel *chan = NULL; struct ast_bridge *attended_bridge = NULL; struct ast_bridge_features caller_features, called_features; enum ast_bridge_channel_state attended_bridge_result; struct ast_bridge_features_attended_transfer *attended_transfer = hook_pvt; const char *context = (attended_transfer && !ast_strlen_zero(attended_transfer->context) ? attended_transfer->context : bridge_channel->chan->context); /* Grab the extension to transfer to */ if (!grab_transfer(bridge_channel->chan, exten, sizeof(exten), context)) { ast_stream_and_wait(bridge_channel->chan, "pbx-invalid", AST_DIGIT_ANY); ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_WAIT); return 0; } /* Get a channel that is the destination we wish to call */ if (!(chan = dial_transfer(bridge_channel->chan, exten, context))) { ast_stream_and_wait(bridge_channel->chan, "beeperr", AST_DIGIT_ANY); ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_WAIT); return 0; } /* Create a bridge to use to talk to the person we are calling */ if (!(attended_bridge = ast_bridge_new(AST_BRIDGE_CAPABILITY_1TO1MIX, 0))) { ast_hangup(chan); ast_stream_and_wait(bridge_channel->chan, "beeperr", AST_DIGIT_ANY); ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_WAIT); return 0; } /* Setup our called features structure so that if they hang up we immediately get thrown out of the bridge */ ast_bridge_features_init(&called_features); ast_bridge_features_set_flag(&called_features, AST_BRIDGE_FLAG_DISSOLVE); /* This is how this is going down, we are imparting the channel we called above into this bridge first */ ast_bridge_impart(attended_bridge, chan, NULL, &called_features); /* Before we join setup a features structure with the hangup option, just in case they want to use DTMF */ ast_bridge_features_init(&caller_features); ast_bridge_features_enable(&caller_features, AST_BRIDGE_BUILTIN_HANGUP, (attended_transfer && !ast_strlen_zero(attended_transfer->complete) ? attended_transfer->complete : "*1"), NULL); ast_bridge_features_hook(&caller_features, (attended_transfer && !ast_strlen_zero(attended_transfer->threeway) ? attended_transfer->threeway : "*2"), attended_threeway_transfer, NULL, NULL); ast_bridge_features_hook(&caller_features, (attended_transfer && !ast_strlen_zero(attended_transfer->abort) ? attended_transfer->abort : "*3"), attended_abort_transfer, NULL, NULL); /* But for the caller we want to join the bridge in a blocking fashion so we don't spin around in this function doing nothing while waiting */ attended_bridge_result = ast_bridge_join(attended_bridge, bridge_channel->chan, NULL, &caller_features, NULL); /* Since the above returned the caller features structure is of no more use */ ast_bridge_features_cleanup(&caller_features); /* Drop the channel we are transferring to out of the above bridge since it has ended */ if ((attended_bridge_result != AST_BRIDGE_CHANNEL_STATE_HANGUP) && !ast_bridge_depart(attended_bridge, chan)) { /* If the user wants to turn this into a threeway transfer then do so, otherwise they take our place */ if (attended_bridge_result == AST_BRIDGE_CHANNEL_STATE_DEPART) { /* We want to impart them upon the bridge and just have us return to it as normal */ ast_bridge_impart(bridge, chan, NULL, NULL); } else { ast_bridge_impart(bridge, chan, bridge_channel->chan, NULL); } } else { ast_stream_and_wait(bridge_channel->chan, "beeperr", AST_DIGIT_ANY); ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_WAIT); } /* Now that all channels are out of it we can destroy the bridge and the called features structure */ ast_bridge_features_cleanup(&called_features); ast_bridge_destroy(attended_bridge); return 0; } /*! \brief Internal built in feature for hangup */ static int feature_hangup(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, void *hook_pvt) { /* This is very simple, we basically change the state on the bridge channel to end and the core takes care of the rest */ ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_END); return 0; } static int unload_module(void) { return 0; } static int load_module(void) { ast_bridge_features_register(AST_BRIDGE_BUILTIN_BLINDTRANSFER, feature_blind_transfer, NULL); ast_bridge_features_register(AST_BRIDGE_BUILTIN_ATTENDEDTRANSFER, feature_attended_transfer, NULL); ast_bridge_features_register(AST_BRIDGE_BUILTIN_HANGUP, feature_hangup, NULL); /* Bump up our reference count so we can't be unloaded */ ast_module_ref(ast_module_info->self); return AST_MODULE_LOAD_SUCCESS; } AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Built in bridging features");