Remove dead code from features.c; refactor pickup code into pickup.c

This patch does the following:
 * It moves the pickup code out of features.c and into pickup.c
 * It removes the vast majority of dead code out of features.c. In particular,
   this includes the parking code.

(issue ASTERISK-22134)



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@396060 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 423 insertions, 0 deletions

diff --git a/main/pickup.c b/main/pickup.c
new file mode 100644
index 000000000..611126af1
--- /dev/null
+++ b/main/pickup.c
@@ -0,0 +1,423 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 1999 - 2013, Digium, Inc.
+ * Copyright (C) 2012, Russell Bryant
+ *
+ * Matt Jordan <mjordan@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 Routines implementing call pickup
+ *
+ * \author Matt Jordan <mjordan@digium.com>
+ */
+
+/*!
+ * \li Call pickup uses the configuration file \ref features.conf
+ * \addtogroup configuration_file Configuration Files
+ */
+
+/*** MODULEINFO
+	<support_level>core</support_level>
+ ***/
+
+/*** DOCUMENTATION
+	<managerEvent language="en_US" name="Pickup">
+		<managerEventInstance class="EVENT_FLAG_CALL">
+			<synopsis>Raised when a call pickup occurs.</synopsis>
+			<syntax>
+				<xi:include xpointer="xpointer(/docs/managerEvent[@name='Newchannel']/managerEventInstance/syntax/parameter)" />
+				<parameter name="TargetChannel"/>
+				<parameter name="TargetChannelState"><para>A numeric code for the channel's current state, related to TargetChannelStateDesc</para></parameter>
+				<parameter name="TargetChannelStateDesc">
+					<enumlist>
+						<enum name="Down"/>
+						<enum name="Rsrvd"/>
+						<enum name="OffHook"/>
+						<enum name="Dialing"/>
+						<enum name="Ring"/>
+						<enum name="Ringing"/>
+						<enum name="Up"/>
+						<enum name="Busy"/>
+						<enum name="Dialing Offhook"/>
+						<enum name="Pre-ring"/>
+						<enum name="Unknown"/>
+					</enumlist>
+				</parameter>
+				<parameter name="TargetCallerIDNum"/>
+				<parameter name="TargetCallerIDName"/>
+				<parameter name="TargetConnectedLineNum"/>
+				<parameter name="TargetConnectedLineName"/>
+				<parameter name="TargetAccountCode"/>
+				<parameter name="TargetContext"/>
+				<parameter name="TargetExten"/>
+				<parameter name="TargetPriority"/>
+				<parameter name="TargetUniqueid"/>
+			</syntax>
+		</managerEventInstance>
+	</managerEvent>
+ ***/
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#include "asterisk/pickup.h"
+#include "asterisk/channel.h"
+#include "asterisk/pbx.h"
+#include "asterisk/app.h"
+#include "asterisk/callerid.h"
+#include "asterisk/causes.h"
+#include "asterisk/stasis.h"
+#include "asterisk/stasis_channels.h"
+#include "asterisk/features_config.h"
+
+static struct ast_manager_event_blob *call_pickup_to_ami(struct stasis_message *message);
+
+STASIS_MESSAGE_TYPE_DEFN(
+	ast_call_pickup_type,
+	.to_ami = call_pickup_to_ami);
+
+
+/*!
+ * The presence of this datastore on the channel indicates that
+ * someone is attemting to pickup or has picked up the channel.
+ * The purpose is to prevent a race between two channels
+ * attempting to pickup the same channel.
+ */
+static const struct ast_datastore_info pickup_active = {
+	.type = "pickup-active",
+};
+
+int ast_can_pickup(struct ast_channel *chan)
+{
+	if (!ast_channel_pbx(chan) && !ast_channel_masq(chan) && !ast_test_flag(ast_channel_flags(chan), AST_FLAG_ZOMBIE)
+		&& (ast_channel_state(chan) == AST_STATE_RINGING
+			|| ast_channel_state(chan) == AST_STATE_RING
+			/*
+			 * Check the down state as well because some SIP devices do not
+			 * give 180 ringing when they can just give 183 session progress
+			 * instead.  Issue 14005.  (Some ISDN switches as well for that
+			 * matter.)
+			 */
+			|| ast_channel_state(chan) == AST_STATE_DOWN)
+		&& !ast_channel_datastore_find(chan, &pickup_active, NULL)) {
+		return 1;
+	}
+	return 0;
+}
+
+static int find_channel_by_group(void *obj, void *arg, void *data, int flags)
+{
+	struct ast_channel *target = obj; /*!< Potential pickup target */
+	struct ast_channel *chan = arg;   /*!< Channel wanting to pickup call */
+
+	if (chan == target) {
+		return 0;
+	}
+
+	ast_channel_lock(target);
+	if (ast_can_pickup(target)) {
+		/* Lock both channels. */
+		while (ast_channel_trylock(chan)) {
+			ast_channel_unlock(target);
+			sched_yield();
+			ast_channel_lock(target);
+		}
+
+		/*
+		 * Both callgroup and namedcallgroup pickup variants are
+		 * matched independently.  Checking for named group match is
+		 * done last since it's a more expensive operation.
+		 */
+		if ((ast_channel_pickupgroup(chan) & ast_channel_callgroup(target))
+			|| (ast_namedgroups_intersect(ast_channel_named_pickupgroups(chan),
+				ast_channel_named_callgroups(target)))) {
+			struct ao2_container *candidates = data;/*!< Candidate channels found. */
+
+			/* This is a candidate to pickup */
+			ao2_link(candidates, target);
+		}
+		ast_channel_unlock(chan);
+	}
+	ast_channel_unlock(target);
+
+	return 0;
+}
+
+struct ast_channel *ast_pickup_find_by_group(struct ast_channel *chan)
+{
+	struct ao2_container *candidates;/*!< Candidate channels found to pickup. */
+	struct ast_channel *target;/*!< Potential pickup target */
+
+	candidates = ao2_container_alloc_options(AO2_ALLOC_OPT_LOCK_NOLOCK, 1, NULL, NULL);
+	if (!candidates) {
+		return NULL;
+	}
+
+	/* Find all candidate targets by group. */
+	ast_channel_callback(find_channel_by_group, chan, candidates, 0);
+
+	/* Find the oldest pickup target candidate */
+	target = NULL;
+	for (;;) {
+		struct ast_channel *candidate;/*!< Potential new older target */
+		struct ao2_iterator iter;
+
+		iter = ao2_iterator_init(candidates, 0);
+		while ((candidate = ao2_iterator_next(&iter))) {
+			if (!target) {
+				/* First target. */
+				target = candidate;
+				continue;
+			}
+			if (ast_tvcmp(ast_channel_creationtime(candidate), ast_channel_creationtime(target)) < 0) {
+				/* We have a new target. */
+				ast_channel_unref(target);
+				target = candidate;
+				continue;
+			}
+			ast_channel_unref(candidate);
+		}
+		ao2_iterator_destroy(&iter);
+		if (!target) {
+			/* No candidates found. */
+			break;
+		}
+
+		/* The found channel must be locked and ref'd. */
+		ast_channel_lock(target);
+
+		/* Recheck pickup ability */
+		if (ast_can_pickup(target)) {
+			/* This is the channel to pickup. */
+			break;
+		}
+
+		/* Someone else picked it up or the call went away. */
+		ast_channel_unlock(target);
+		ao2_unlink(candidates, target);
+		target = ast_channel_unref(target);
+	}
+	ao2_ref(candidates, -1);
+
+	return target;
+}
+
+/*!
+ * \brief Pickup a call
+ * \param chan channel that initiated pickup.
+ *
+ * Walk list of channels, checking it is not itself, channel is pbx one,
+ * check that the callgroup for both channels are the same and the channel is ringing.
+ * Answer calling channel, flag channel as answered on queue, masq channels together.
+ */
+int ast_pickup_call(struct ast_channel *chan)
+{
+	struct ast_channel *target;/*!< Potential pickup target */
+	int res = -1;
+	RAII_VAR(struct ast_features_pickup_config *, pickup_cfg, NULL, ao2_cleanup);
+	const char *pickup_sound;
+	const char *fail_sound;
+
+	ast_debug(1, "Pickup attempt by %s\n", ast_channel_name(chan));
+	ast_channel_lock(chan);
+	pickup_cfg = ast_get_chan_features_pickup_config(chan);
+	if (!pickup_cfg) {
+		ast_log(LOG_ERROR, "Unable to retrieve pickup configuration. Unable to play pickup sounds\n");
+	}
+	pickup_sound = ast_strdupa(pickup_cfg ? pickup_cfg->pickupsound : "");
+	fail_sound = ast_strdupa(pickup_cfg ? pickup_cfg->pickupfailsound : "");
+	ast_channel_unlock(chan);
+
+	/* The found channel is already locked. */
+	target = ast_pickup_find_by_group(chan);
+	if (target) {
+		ast_log(LOG_NOTICE, "Pickup %s attempt by %s\n", ast_channel_name(target), ast_channel_name(chan));
+
+		res = ast_do_pickup(chan, target);
+		ast_channel_unlock(target);
+		if (!res) {
+			if (!ast_strlen_zero(pickup_sound)) {
+				pbx_builtin_setvar_helper(target, "BRIDGE_PLAY_SOUND", pickup_sound);
+			}
+		} else {
+			ast_log(LOG_WARNING, "Pickup %s failed by %s\n", ast_channel_name(target), ast_channel_name(chan));
+		}
+		target = ast_channel_unref(target);
+	}
+
+	if (res < 0) {
+		ast_debug(1, "No call pickup possible... for %s\n", ast_channel_name(chan));
+		if (!ast_strlen_zero(fail_sound)) {
+			ast_answer(chan);
+			ast_stream_and_wait(chan, fail_sound, "");
+		}
+	}
+
+	return res;
+}
+
+static struct ast_manager_event_blob *call_pickup_to_ami(struct stasis_message *message)
+{
+	struct ast_multi_channel_blob *contents = stasis_message_data(message);
+	struct ast_channel_snapshot *chan;
+	struct ast_channel_snapshot *target;
+	struct ast_manager_event_blob *res;
+
+	RAII_VAR(struct ast_str *, channel_str, NULL, ast_free);
+	RAII_VAR(struct ast_str *, target_str, NULL, ast_free);
+
+	chan = ast_multi_channel_blob_get_channel(contents, "channel");
+	target = ast_multi_channel_blob_get_channel(contents, "target");
+
+	ast_assert(chan != NULL && target != NULL);
+
+	if (!(channel_str = ast_manager_build_channel_state_string(chan))) {
+		return NULL;
+	}
+
+	if (!(target_str = ast_manager_build_channel_state_string_prefix(target, "Target"))) {
+		return NULL;
+	}
+
+	res = ast_manager_event_blob_create(EVENT_FLAG_CALL, "Pickup",
+		"%s"
+		"%s",
+		ast_str_buffer(channel_str),
+		ast_str_buffer(target_str));
+
+	return res;
+}
+
+static int send_call_pickup_stasis_message(struct ast_channel *picking_up, struct ast_channel_snapshot *chan, struct ast_channel_snapshot *target)
+{
+	RAII_VAR(struct ast_multi_channel_blob *, pickup_payload, NULL, ao2_cleanup);
+	RAII_VAR(struct stasis_message *, msg, NULL, ao2_cleanup);
+
+	if (!(pickup_payload = ast_multi_channel_blob_create(ast_json_null()))) {
+		return -1;
+	}
+
+	ast_multi_channel_blob_add_channel(pickup_payload, "channel", chan);
+	ast_multi_channel_blob_add_channel(pickup_payload, "target", target);
+
+	if (!(msg = stasis_message_create(ast_call_pickup_type(), pickup_payload))) {
+		return -1;
+	}
+
+	stasis_publish(ast_channel_topic(picking_up), msg);
+	return 0;
+}
+
+int ast_do_pickup(struct ast_channel *chan, struct ast_channel *target)
+{
+	struct ast_party_connected_line connected_caller;
+	struct ast_datastore *ds_pickup;
+	const char *chan_name;/*!< A masquerade changes channel names. */
+	const char *target_name;/*!< A masquerade changes channel names. */
+	int res = -1;
+
+	RAII_VAR(struct ast_channel_snapshot *, chan_snapshot, NULL, ao2_cleanup);
+	RAII_VAR(struct ast_channel_snapshot *, target_snapshot, NULL, ao2_cleanup);
+
+	target_name = ast_strdupa(ast_channel_name(target));
+	ast_debug(1, "Call pickup on '%s' by '%s'\n", target_name, ast_channel_name(chan));
+
+	/* Mark the target to block any call pickup race. */
+	ds_pickup = ast_datastore_alloc(&pickup_active, NULL);
+	if (!ds_pickup) {
+		ast_log(LOG_WARNING,
+			"Unable to create channel datastore on '%s' for call pickup\n", target_name);
+		return -1;
+	}
+	ast_channel_datastore_add(target, ds_pickup);
+
+	ast_party_connected_line_init(&connected_caller);
+	ast_party_connected_line_copy(&connected_caller, ast_channel_connected(target));
+	ast_channel_unlock(target);/* The pickup race is avoided so we do not need the lock anymore. */
+	/* Reset any earlier private connected id representation */
+	ast_party_id_reset(&connected_caller.priv);
+
+	connected_caller.source = AST_CONNECTED_LINE_UPDATE_SOURCE_ANSWER;
+	if (ast_channel_connected_line_sub(NULL, chan, &connected_caller, 0) &&
+		ast_channel_connected_line_macro(NULL, chan, &connected_caller, 0, 0)) {
+		ast_channel_update_connected_line(chan, &connected_caller, NULL);
+	}
+	ast_party_connected_line_free(&connected_caller);
+
+	ast_channel_lock(chan);
+	chan_name = ast_strdupa(ast_channel_name(chan));
+	ast_connected_line_copy_from_caller(&connected_caller, ast_channel_caller(chan));
+	ast_channel_unlock(chan);
+	connected_caller.source = AST_CONNECTED_LINE_UPDATE_SOURCE_ANSWER;
+
+	if (ast_answer(chan)) {
+		ast_log(LOG_WARNING, "Unable to answer '%s'\n", chan_name);
+		goto pickup_failed;
+	}
+
+	if (ast_queue_control(chan, AST_CONTROL_ANSWER)) {
+		ast_log(LOG_WARNING, "Unable to queue answer on '%s'\n", chan_name);
+		goto pickup_failed;
+	}
+
+	ast_channel_queue_connected_line_update(chan, &connected_caller, NULL);
+
+	/* setting the HANGUPCAUSE so the ringing channel knows this call was not a missed call */
+	ast_channel_hangupcause_set(chan, AST_CAUSE_ANSWERED_ELSEWHERE);
+
+	if (!(chan_snapshot = ast_channel_snapshot_create(chan))) {
+		goto pickup_failed;
+	}
+
+	if (!(target_snapshot = ast_channel_snapshot_create(target))) {
+		goto pickup_failed;
+	}
+
+	if (ast_channel_move(target, chan)) {
+		ast_log(LOG_WARNING, "Unable to complete call pickup of '%s' with '%s'\n",
+			chan_name, target_name);
+		goto pickup_failed;
+	}
+
+	/* target points to the channel that did the pickup at this point, so use that channel's topic instead of chan */
+	send_call_pickup_stasis_message(target, chan_snapshot, target_snapshot);
+
+	res = 0;
+
+pickup_failed:
+	ast_channel_lock(target);
+	if (!ast_channel_datastore_remove(target, ds_pickup)) {
+		ast_datastore_free(ds_pickup);
+	}
+	ast_party_connected_line_free(&connected_caller);
+
+	return res;
+}
+
+/*! \internal \brief Clean up resources on Asterisk shutdown */
+static void pickup_shutdown(void)
+{
+	STASIS_MESSAGE_TYPE_CLEANUP(ast_call_pickup_type);
+}
+
+int ast_pickup_init(void)
+{
+	STASIS_MESSAGE_TYPE_INIT(ast_call_pickup_type);
+	ast_register_atexit(pickup_shutdown);
+
+	return 0;
+}