1 files changed, 30 insertions, 0 deletions
diff --git a/common/list.c b/common/list.c
index a887bcdd..579d9574 100644
--- a/common/list.c
+++ b/common/list.c
@@ -70,6 +70,36 @@ struct slist *slist_prepend(struct slist *list, void *data)
 	return entry;
 }
 
+struct slist *slist_insert_before(struct slist *list, struct slist *sibling, void *data)
+{
+	struct slist *entry, *prev, *cur;
+
+	entry = malloc(sizeof(struct slist));
+	if (!entry)
+		return list;
+
+	entry->data = data;
+	entry->next = NULL;
+
+	if (!list)
+		return entry;
+
+	for (cur = list, prev = NULL; cur != NULL; prev = cur, cur = prev->next) {
+		if (cur == sibling)
+			break;
+	}
+
+	if (!prev) {
+		entry->next = list;
+		return entry;
+	}
+
+	entry->next = prev->next;
+	prev->next = entry;
+
+	return list;
+}
+
 struct slist *slist_remove(struct slist *list, void *data)
 {
 	struct slist *l, *next, *prev = NULL, *match = NULL;