Provide silent variation of nl_cache_require()

Use in addr and tc layer to avoid warnings being printed if no
cache is available.

4 files changed, 17 insertions, 9 deletions

diff --git a/include/netlink/cache.h b/include/netlink/cache.h
index e17b015..f8073f0 100644
--- a/include/netlink/cache.h
+++ b/include/netlink/cache.h
@@ -107,6 +107,7 @@ extern int			nl_cache_mngt_unregister(struct nl_cache_ops *);
 extern void			nl_cache_mngt_provide(struct nl_cache *);
 extern void			nl_cache_mngt_unprovide(struct nl_cache *);
 extern struct nl_cache *	nl_cache_mngt_require(const char *);
+extern struct nl_cache *	__nl_cache_mngt_require(const char *);
 
 struct nl_cache_mngr;
 
diff --git a/lib/cache_mngt.c b/lib/cache_mngt.c
index d57d836..a9ecf27 100644
--- a/lib/cache_mngt.c
+++ b/lib/cache_mngt.c
@@ -217,6 +217,17 @@ void nl_cache_mngt_unprovide(struct nl_cache *cache)
 		ops->co_major_cache = NULL;
 }
 
+struct nl_cache *__nl_cache_mngt_require(const char *name)
+{
+	struct nl_cache_ops *ops;
+
+	ops = nl_cache_ops_lookup(name);
+	if (ops)
+		return ops->co_major_cache;
+	
+	return NULL;
+}
+
 /**
  * Demand the use of a global cache
  * @arg name		name of the required object type
@@ -229,19 +240,15 @@ void nl_cache_mngt_unprovide(struct nl_cache *cache)
  */
 struct nl_cache *nl_cache_mngt_require(const char *name)
 {
-	struct nl_cache_ops *ops;
+	struct nl_cache *cache;
 
-	ops = nl_cache_ops_lookup(name);
-	if (!ops || !ops->co_major_cache) {
+	if (!(cache = __nl_cache_mngt_require(name)))
 		fprintf(stderr, "Application BUG: Your application must "
 			"call nl_cache_mngt_provide() and\nprovide a valid "
 			"%s cache to be used for internal lookups.\nSee the "
 			" API documentation for more details.\n", name);
-
-		return NULL;
-	}
 	
-	return ops->co_major_cache;
+	return cache;
 }
 
 /** @} */
diff --git a/lib/route/addr.c b/lib/route/addr.c
index fa6d76d..4ca6335 100644
--- a/lib/route/addr.c
+++ b/lib/route/addr.c
@@ -294,7 +294,7 @@ static int addr_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
 		addr->ce_mask |= ADDR_ATTR_ANYCAST;
 	}
 
-	if ((link_cache = nl_cache_mngt_require("route/link"))) {
+	if ((link_cache = __nl_cache_mngt_require("route/link"))) {
 		struct rtnl_link *link;
 
 		if ((link = rtnl_link_get(link_cache, addr->a_ifindex))) {
diff --git a/lib/route/tc.c b/lib/route/tc.c
index 03920aa..da8c75f 100644
--- a/lib/route/tc.c
+++ b/lib/route/tc.c
@@ -176,7 +176,7 @@ compat_xstats:
 			return err;
 	}
 
-	if ((link_cache = nl_cache_mngt_require("route/link"))) {
+	if ((link_cache = __nl_cache_mngt_require("route/link"))) {
 		struct rtnl_link *link;
 
 		if ((link = rtnl_link_get(link_cache, tc->tc_ifindex))) {