filter: Allocate each ctr group with a different idx

Fixes following runtime warning:
libosmocore/src/rate_ctr.c:219 counter group 'nat:filter' already exists for index 0, instead using index 1. This is a software bug that needs fixing.

Forward-port from openbsc.git c08d58802e03a45f95b8f7d28b29dc7026f664ba.

Change-Id: I7c5054c374281bb1d4bd1ecd76ddcca7a010d50a

1 files changed, 18 insertions, 2 deletions

diff --git a/src/libfilter/bsc_msg_acc.c b/src/libfilter/bsc_msg_acc.c
index f0232eed7..46077b321 100644
--- a/src/libfilter/bsc_msg_acc.c
+++ b/src/libfilter/bsc_msg_acc.c
@@ -41,6 +41,21 @@ static const struct rate_ctr_group_desc bsc_cfg_acc_list_desc = {
 	.class_id = OSMO_STATS_CLASS_GLOBAL,
 };
 
+/*! Find an unused index for this rate counter group.
+ *  \param[in] head List of allocated ctr groups of the same type
+ *  \returns the largest used index number + 1, or 0 if none exist yet. */
+static unsigned int rate_ctr_get_unused_idx(struct llist_head *head)
+{
+	unsigned int idx = 0;
+	struct bsc_msg_acc_lst *lst;
+
+	llist_for_each_entry(lst, head, list) {
+		if (idx <= lst->stats->idx)
+			idx = lst->stats->idx + 1;
+	}
+	return idx;
+}
+
 
 int bsc_msg_acc_lst_check_allow(struct bsc_msg_acc_lst *lst, const char *mi_string)
 {
@@ -73,6 +88,7 @@ struct bsc_msg_acc_lst *bsc_msg_acc_lst_find(struct llist_head *head, const char
 struct bsc_msg_acc_lst *bsc_msg_acc_lst_get(void *ctx, struct llist_head *head, const char *name)
 {
 	struct bsc_msg_acc_lst *lst;
+	unsigned int new_idx;
 
 	lst = bsc_msg_acc_lst_find(head, name);
 	if (lst)
@@ -84,8 +100,8 @@ struct bsc_msg_acc_lst *bsc_msg_acc_lst_get(void *ctx, struct llist_head *head,
 		return NULL;
 	}
 
-	/* TODO: get the index right */
-	lst->stats = rate_ctr_group_alloc(lst, &bsc_cfg_acc_list_desc, 0);
+	new_idx = rate_ctr_get_unused_idx(head);
+	lst->stats = rate_ctr_group_alloc(lst, &bsc_cfg_acc_list_desc, new_idx);
 	if (!lst->stats) {
 		talloc_free(lst);
 		return NULL;