Add pickup by channel

(Closes issue #11161)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@94773 65c4cc65-6c06-0410-ace0-fbb531ad65f3

apps/app_pickupchan.c

+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Gary Cook
+ *
+ * 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 Pickup a ringing channel
+ *
+ * \author Gary Cook
+ *
+ * \ingroup applications
+ */
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "asterisk/file.h"
+#include "asterisk/logger.h"
+#include "asterisk/channel.h"
+#include "asterisk/pbx.h"
+#include "asterisk/module.h"
+#include "asterisk/lock.h"
+#include "asterisk/app.h"
+#include "asterisk/options.h"
+
+static const char *app = "PickupChan";
+static const char *synopsis = "Pickup a ringing channel";
+static const char *descrip =
+"  PickupChan(channel[&channel...]): This application can pickup any ringing channel\n";
+
+/* Helper function that determines whether a channel is capable of being picked up */
+static int can_pickup(struct ast_channel *chan)
+{
+	ast_debug(3, "Checking Pickup '%s' state '%s ( %d )'\n", chan->name, ast_state2str(chan->_state), chan->_state);
+
+	if (!chan->pbx && (chan->_state == AST_STATE_RINGING || chan->_state == AST_STATE_RING)) {
+		return 1;
+	} else {
+		return 0;
+	}
+}
+
+/* Helper Function to walk through ALL channels checking NAME and STATE */
+static struct ast_channel *my_ast_get_channel_by_name_locked(char *channame)
+{
+	struct ast_channel *chan;
+	char *chkchan = alloca(strlen(channame) + 2);
+
+	/* need to append a '-' for the comparison so we check full channel name,
+	 * i.e SIP/hgc- , use a temporary variable so original stays the same for
+	 * debugging.
+	 */
+	strcpy(chkchan, channame);
+	strcat(chkchan, "-");
+
+	for (chan = ast_walk_channel_by_name_prefix_locked(NULL, channame, strlen(channame));
+		 chan;
+		 chan = ast_walk_channel_by_name_prefix_locked(chan, channame, strlen(channame))) {
+		if (!strncasecmp(chan->name, chkchan, strlen(chkchan)) && can_pickup(chan))
+			return chan;
+		ast_channel_unlock(chan);
+	}
+	return NULL;
+}
+
+/* Perform actual pickup between two channels */
+static int pickup_do(struct ast_channel *chan, struct ast_channel *target)
+{
+	int res = 0;
+
+	ast_debug(3, "Call pickup on '%s' by '%s'\n", target->name, chan->name);
+
+	if ((res = ast_answer(chan))) {
+		ast_log(LOG_WARNING, "Unable to answer '%s'\n", chan->name);
+		return -1;
+	}
+
+	if ((res = ast_queue_control(chan, AST_CONTROL_ANSWER))) {
+		ast_log(LOG_WARNING, "Unable to queue answer on '%s'\n", chan->name);
+		return -1;
+	}
+
+	if ((res = ast_channel_masquerade(target, chan))) {
+		ast_log(LOG_WARNING, "Unable to masquerade '%s' into '%s'\n", chan->name, target->name);
+		return -1;
+	}
+
+	return res;
+}
+
+/* Attempt to pick up specified channel named , does not use context */
+static int pickup_by_channel(struct ast_channel *chan, char *pickup)
+{
+	int res = 0;
+	struct ast_channel *target;
+
+	if (!(target = my_ast_get_channel_by_name_locked(pickup)))
+		return -1;
+
+	/* Just check that we are not picking up the SAME as target */
+	if (chan->name != target->name && chan != target) {
+		res = pickup_do(chan, target);
+		ast_channel_unlock(target);
+	}
+
+	return res;
+}
+
+/* Main application entry point */
+static int pickupchan_exec(struct ast_channel *chan, void *data)
+{
+	int res = 0;
+	struct ast_module_user *u = NULL;
+	char *tmp = ast_strdupa(data);
+	char *pickup = NULL, *context = NULL;
+
+	if (ast_strlen_zero(data)) {
+		ast_log(LOG_WARNING, "Pickup requires an argument (channel)!\n");
+		return -1;	
+	}
+
+	u = ast_module_user_add(chan);
+
+	/* Parse channel (and ignore context if there) */
+	while (!ast_strlen_zero(tmp) && (pickup = strsep(&tmp, "&"))) {
+		if ((context = strchr(pickup , '@'))) {
+			*context++ = '\0';
+		}
+		if (!strncasecmp(chan->name, pickup , strlen(pickup))) {
+			ast_log(LOG_NOTICE, "Cannot pickup your own channel %s.\n", pickup);
+		} else {
+			if (!pickup_by_channel(chan, pickup)) {
+				break;
+			}
+			ast_log(LOG_NOTICE, "No target channel found for %s.\n", pickup);
+		}
+	}
+
+	ast_module_user_remove(u);
+
+	return res;
+}
+
+static int unload_module(void)
+{
+	return ast_unregister_application(app);
+}
+
+static int load_module(void)
+{
+	return ast_register_application(app, pickupchan_exec, synopsis, descrip);
+}
+
+AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Channel Pickup Application");