Add named callgroups/pickupgroups

This patch adds named calledgroups/pickupgroups to Asterisk.  Named groups are
implemented in parallel to the existing numbered callgroup/pickupgroup
implementation.  However, unlike the existing implementation, which is limited
to a maximum of 64 defined groups, the number of defined groups allowed for
named callgroups/pickupgroups is effectively unlimited.

Named groups are configured with the keywords "namedcallgroup" and
"namedpickupgroup".  This corresponds to the numbered group definitions of
"callgroup" and "pickupgroup".  Note that as the implementation of named groups
coexists with the existing numbered implementation, a defined named group of
"4" does not equate to numbered group 4.

Support for the named groups has been added to the SIP, DAHDI, and mISDN channel
drivers.

Review: https://reviewboard.asterisk.org/r/2043

Uploaded by:
	Guenther Kelleter(license #6372)



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@370831 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 40 insertions, 6 deletions

diff --git a/main/features.c b/main/features.c
index 5d0f8ec5d..0794a2f94 100644
--- a/main/features.c
+++ b/main/features.c
@@ -7679,10 +7679,19 @@ static int find_channel_by_group(void *obj, void *arg, void *data, int flags)
 	struct ast_channel *chan = data;/*!< Channel wanting to pickup call */
 
 	ast_channel_lock(target);
-	if (chan != target && (ast_channel_pickupgroup(chan) & ast_channel_callgroup(target))
-		&& ast_can_pickup(target)) {
-		/* Return with the channel still locked on purpose */
-		return CMP_MATCH | CMP_STOP;
+
+	/*
+	 * Both, callgroup and namedcallgroup pickup variants are matched independently.
+	 * Checking for named group match is done last since it's a rather expensive operation.
+	 */
+	if (chan != target && ast_can_pickup(target)
+		&& ((ast_channel_pickupgroup(chan) & ast_channel_callgroup(target))
+			|| (ast_namedgroups_intersect(ast_channel_named_pickupgroups(chan), ast_channel_named_callgroups(target))))) {
+		/*
+		 * Return with the channel unlocked on purpose, else we would lock many channels with the chance for deadlock
+		 */
+		ast_channel_unlock(target);
+		return CMP_MATCH;
 	}
 	ast_channel_unlock(target);
 
@@ -7700,11 +7709,36 @@ static int find_channel_by_group(void *obj, void *arg, void *data, int flags)
 int ast_pickup_call(struct ast_channel *chan)
 {
 	struct ast_channel *target;/*!< Potential pickup target */
+	struct ao2_iterator *targets_it;/*!< Potential pickup targets, must find the oldest of them */
+	struct ast_channel *candidate;/*!< Potential new older target */
 	int res = -1;
 	ast_debug(1, "pickup attempt by %s\n", ast_channel_name(chan));
 
-	/* The found channel is already locked. */
-	target = ast_channel_callback(find_channel_by_group, NULL, chan, 0);
+	/*
+	 * Transfer all pickup-able channels to another container-iterator.
+	 * Iterate it to find the oldest channel.
+	 */
+	targets_it = (struct ao2_iterator *)ast_channel_callback(find_channel_by_group, NULL, chan, OBJ_MULTIPLE);
+
+	target = NULL;
+	while ((candidate = ao2_iterator_next(targets_it))) {
+		if (!target || ast_tvcmp(ast_channel_creationtime(candidate), ast_channel_creationtime(target)) < 0) {
+			target = candidate;
+		}
+		ast_channel_unref(candidate);
+	}
+	if (target) {
+		/* The found channel must be locked and ref'd. */
+		ast_channel_lock(ast_channel_ref(target));
+		/* Recheck pickup ability */
+		if (!ast_can_pickup(target)) {
+			ast_channel_unlock(target);
+			target = ast_channel_unref(target);/* Bad luck */
+		}
+	}
+
+	ao2_iterator_destroy(targets_it);
+
 	if (target) {
 		ast_log(LOG_NOTICE, "pickup %s attempt by %s\n", ast_channel_name(target), ast_channel_name(chan));