bridge_basic.c

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013 Digium, Inc.
 *
 * Richard Mudgett <rmudgett@digium.com>
 *
 * 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 Basic bridge class.  It is a subclass of struct ast_bridge.
 *
 * \author Richard Mudgett <rmudgett@digium.com>
 *
 * See Also:
 * \arg \ref AstCREDITS
 */


#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include "asterisk/channel.h"
#include "asterisk/utils.h"
#include "asterisk/linkedlists.h"
#include "asterisk/bridge.h"
#include "asterisk/bridge_internal.h"
#include "asterisk/bridge_basic.h"
#include "asterisk/bridge_after.h"
#include "asterisk/astobj2.h"
#include "asterisk/features_config.h"
#include "asterisk/pbx.h"
#include "asterisk/file.h"
#include "asterisk/app.h"
#include "asterisk/dial.h"
#include "asterisk/stasis_bridges.h"
#include "asterisk/stasis_channels.h"
#include "asterisk/features.h"
#include "asterisk/format_cache.h"
#include "asterisk/test.h"

#define NORMAL_FLAGS	(AST_BRIDGE_FLAG_DISSOLVE_HANGUP | AST_BRIDGE_FLAG_DISSOLVE_EMPTY \
			| AST_BRIDGE_FLAG_SMART)

#define TRANSFER_FLAGS AST_BRIDGE_FLAG_SMART

struct attended_transfer_properties;

enum bridge_basic_personality_type {
	/*! Index for "normal" basic bridge personality */
	BRIDGE_BASIC_PERSONALITY_NORMAL,
	/*! Index for attended transfer basic bridge personality */
	BRIDGE_BASIC_PERSONALITY_ATXFER,
	/*! Indicates end of enum. Must always remain the last element */
	BRIDGE_BASIC_PERSONALITY_END,
};

/*!
 * \brief Change basic bridge personality
 *
 * Changing personalities allows for the bridge to remain in use but have
 * properties such as its v_table and its flags change.
 *
 * \param bridge The bridge
 * \param type The personality to change the bridge to
 * \user_data Private data to attach to the personality.
 */
static void bridge_basic_change_personality(struct ast_bridge *bridge,
		enum bridge_basic_personality_type type, void *user_data);

/* ------------------------------------------------------------------- */

static const struct ast_datastore_info dtmf_features_info = {
	.type = "bridge-dtmf-features",
	.destroy = ast_free_ptr,
};

/*!
 * \internal
 * \since 12.0.0
 * \brief read a feature code character and set it on for the give feature_flags struct
 *
 * \param feature_flags flags being modifed
 * \param feature feature code provided - should be an uppercase letter
 *
 * \retval 0 if the feature was set successfully
 * \retval -1 failure because the requested feature code isn't handled by this function
 */
static int set_feature_flag_from_char(struct ast_flags *feature_flags, char feature)
{
	switch (feature) {
	case 'T':
		ast_set_flag(feature_flags, AST_FEATURE_REDIRECT);
		return 0;
	case 'K':
		ast_set_flag(feature_flags, AST_FEATURE_PARKCALL);
		return 0;
	case 'H':
		ast_set_flag(feature_flags, AST_FEATURE_DISCONNECT);
		return 0;
	case 'W':
		ast_set_flag(feature_flags, AST_FEATURE_AUTOMON);
		return 0;
	case 'X':
		ast_set_flag(feature_flags, AST_FEATURE_AUTOMIXMON);
		return 0;
	default:
		return -1;
	}
}

/*!
 * \internal
 * \since 12.0.0
 * \brief Write a features string to a string buffer based on the feature flags provided
 *
 * \param feature_flags pointer to the feature flags to write from.
 * \param buffer pointer to a string buffer to write the features
 * \param buffer_size size of the buffer provided (should be able to fit all feature codes)
 *
 * \retval 0 on successful write
 * \retval -1 failure due to running out of buffer space
 */
static int dtmf_features_flags_to_string(struct ast_flags *feature_flags, char *buffer, size_t buffer_size)
{
	size_t buffer_expended = 0;
	unsigned int cur_feature;
	static const struct {
		char letter;
		unsigned int flag;
	} associations[] = {
		{ 'T', AST_FEATURE_REDIRECT },
		{ 'K', AST_FEATURE_PARKCALL },
		{ 'H', AST_FEATURE_DISCONNECT },
		{ 'W', AST_FEATURE_AUTOMON },
		{ 'X', AST_FEATURE_AUTOMIXMON },
	};

	for (cur_feature = 0; cur_feature < ARRAY_LEN(associations); cur_feature++) {
		if (ast_test_flag(feature_flags, associations[cur_feature].flag)) {
			if (buffer_expended == buffer_size - 1) {
				buffer[buffer_expended] = '\0';
				return -1;
			}
			buffer[buffer_expended++] = associations[cur_feature].letter;
		}
	}

	buffer[buffer_expended] = '\0';
	return 0;
}

static int build_dtmf_features(struct ast_flags *flags, const char *features)
{
	const char *feature;

	char missing_features[strlen(features) + 1];
	size_t number_of_missing_features = 0;

	for (feature = features; *feature; feature++) {
		if (!isupper(*feature)) {
			ast_log(LOG_ERROR, "Features string '%s' rejected because it contains non-uppercase feature.\n", features);
			return -1;
		}

		if (set_feature_flag_from_char(flags, *feature)) {
			missing_features[number_of_missing_features++] = *feature;
		}
	}

	missing_features[number_of_missing_features] = '\0';

	if (number_of_missing_features) {
		ast_log(LOG_WARNING, "Features '%s' from features string '%s' can not be applied.\n", missing_features, features);
	}

	return 0;
}

int ast_bridge_features_ds_set_string(struct ast_channel *chan, const char *features)
{
	struct ast_flags flags = {0};

	if (build_dtmf_features(&flags, features)) {
		return -1;
	}

	ast_channel_lock(chan);
	if (ast_bridge_features_ds_set(chan, &flags)) {