reinvent connection_for_subscr() and move to libmsc

Implement connection_for_subscr() from a completely different angle: instead of
looking up lchans in bts structs, look up the subscriber in the global list of
gsm_subscriber_connection. static lchan_find() is thus obsoleted.

All callers of connection_for_subscr() live in libmsc, so move to libmsc.

The move and edit are done in a single commit since the old and new
implementation have nothing in common.

Future: osmo-cscn will use this, without bts being present.

Remove implementation of connection_for_subscr() from channel_test.c -- it is
possible that the abort() in there was intended for a regression test, but
actually it seems the implementation was merely added for linking reasons, and
the abort() added to guard against the NULL return value: no comment nor the
commit log indicate that the abort() is test critical; the addition was the
only change in channel_test.c for that commit; at the same time a
connection_for_subscr() call was added in libmsc.

Change-Id: I5e0ba0ecf1726ebd540800f4e98fdfc937c904ff

1 files changed, 14 insertions, 0 deletions

diff --git a/openbsc/src/libmsc/gsm_subscriber.c b/openbsc/src/libmsc/gsm_subscriber.c
index 08198c765..4ec0eadf9 100644
--- a/openbsc/src/libmsc/gsm_subscriber.c
+++ b/openbsc/src/libmsc/gsm_subscriber.c
@@ -374,3 +374,17 @@ void subscr_expire(struct gsm_subscriber_group *sgrp)
 {
 	db_subscriber_expire(sgrp->net, subscr_expire_callback);
 }
+
+struct gsm_subscriber_connection *connection_for_subscr(struct gsm_subscriber *subscr)
+{
+	/* FIXME: replace this with a backpointer in gsm_subscriber? */
+	struct gsm_network *net = subscr->group->net;
+	struct gsm_subscriber_connection *conn;
+
+	llist_for_each_entry(conn, &net->subscr_conns, entry) {
+		if (conn->subscr == subscr)
+			return conn;
+	}
+
+	return NULL;
+}