ho: Make sure the timer is always stopped
In case of a ho_chan_activ_nack (sent due another bug inside
both sysmobts and openbsc) the code would not stop the timer
but free the datastructure. This can lead to a clear segfault
when the timer has expired. Create a "free" function which is
responsible to detach the handover structure, stop the timer
(which is idempotent) and free the structure.
diff --git a/openbsc/src/libbsc/handover_logic.c b/openbsc/src/libbsc/handover_logic.c
index 22f9883..9284f7e 100644
--- a/openbsc/src/libbsc/handover_logic.c
+++ b/openbsc/src/libbsc/handover_logic.c
@@ -54,6 +54,13 @@
static LLIST_HEAD(bsc_handovers);
+static void handover_free(struct bsc_handover *ho)
+{
+ osmo_timer_del(&ho->T3103);
+ llist_del(&ho->list);
+ talloc_free(ho);
+}
+
static struct bsc_handover *bsc_ho_by_new_lchan(struct gsm_lchan *new_lchan)
{
struct bsc_handover *ho;
@@ -169,9 +176,7 @@
if (free_lchan)
lchan_release(ho->new_lchan, 0, RSL_REL_LOCAL_END);
- osmo_timer_del(&ho->T3103);
- llist_del(&ho->list);
- talloc_free(ho);
+ handover_free(ho);
}
/* T3103 expired: Handover has failed without HO COMPLETE or HO FAIL */
@@ -186,8 +191,7 @@
ho->new_lchan->conn->ho_lchan = NULL;
ho->new_lchan->conn = NULL;
lchan_release(ho->new_lchan, 0, RSL_REL_LOCAL_END);
- llist_del(&ho->list);
- talloc_free(ho);
+ handover_free(ho);
}
/* RSL has acknowledged activation of the new lchan */
@@ -234,8 +238,7 @@
new_lchan->conn->ho_lchan = NULL;
new_lchan->conn = NULL;
- llist_del(&ho->list);
- talloc_free(ho);
+ handover_free(ho);
/* FIXME: maybe we should try to allocate a new LCHAN here? */
@@ -282,9 +285,7 @@
rsl_lchan_set_state(ho->old_lchan, LCHAN_S_INACTIVE);
lchan_release(ho->old_lchan, 0, RSL_REL_LOCAL_END);
- llist_del(&ho->list);
- talloc_free(ho);
-
+ handover_free(ho);
return 0;
}
@@ -293,6 +294,7 @@
{
struct gsm_network *net = old_lchan->ts->trx->bts->network;
struct bsc_handover *ho;
+ struct gsm_lchan *new_lchan;
ho = bsc_ho_by_old_lchan(old_lchan);
if (!ho) {
@@ -302,15 +304,15 @@
osmo_counter_inc(net->stats.handover.failed);
- osmo_timer_del(&ho->T3103);
- llist_del(&ho->list);
+ new_lchan = ho->new_lchan;
/* release the channel and forget about it */
ho->new_lchan->conn->ho_lchan = NULL;
ho->new_lchan->conn = NULL;
- lchan_release(ho->new_lchan, 0, RSL_REL_LOCAL_END);
+ handover_free(ho);
- talloc_free(ho);
+ lchan_release(new_lchan, 0, RSL_REL_LOCAL_END);
+
return 0;
}