[RFC PATCH 5/5] Make cache manager event handling continue looking if a cache returned NL_SKIP

[roopa at cumulusnetworks.com]

From: roopa <roopa at cumulusnetworks.com>

Today libnl event_input only looks through the first cache that supports
the input msgtype.

This patch makes cache manager continue looking through caches if a particular
cache returned NL_SKIP. Also changes include_cb to return NL_SKIP if the
cache event_filter returns anything other than NL_OK (This is required to
support the above)

This change is required to support more than one cache handing the
same msg type. In the current context it is bridge_link and link caches.
link and bridge link cache handle the same msg types but with different
families. The link cache cache_include returns NL_SKIP if it receives
a msg of family AF_BRIDGE. With this patch cache manager will continue
to look through more caches that support the msgtype.

Signed-off-by: Roopa Prabhu <roopa at cumulusnetworks.com>
Reviewed-by: Wilson Kok <wkok at cumulusnetworks.com>
Reviewed-by: Nolan Leake <nolan at cumulusnetworks.com>
Reviewed-by: Shrijeet Mukherjee <shm at cumulusnetworks.com>
---
 lib/cache_mngr.c |   36 +++++++++++++++++++++++++-----------
 1 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/lib/cache_mngr.c b/lib/cache_mngr.c
index cdf2b7b..856c6e8 100644
--- a/lib/cache_mngr.c
+++ b/lib/cache_mngr.c
@@ -46,6 +46,7 @@ static int include_cb(struct nl_object *obj, struct nl_parser_param *p)
 {
 	struct nl_cache_assoc *ca = p->pp_arg;
 	struct nl_cache_ops *ops = ca->ca_cache->c_ops;
+	int err;
 
 	NL_DBG(2, "Including object %p into cache %p\n", obj, ca->ca_cache);
 #ifdef NL_DEBUG
@@ -54,8 +55,8 @@ static int include_cb(struct nl_object *obj, struct nl_parser_param *p)
 #endif
 
 	if (ops->co_event_filter)
-		if (ops->co_event_filter(ca->ca_cache, obj) != NL_OK)
-			return 0;
+		if ((err = ops->co_event_filter(ca->ca_cache, obj)) != NL_OK)
+			return err;
 
 	if (ops->co_include_event)
 		return ops->co_include_event(ca->ca_cache, obj, ca->ca_change,
@@ -71,6 +72,7 @@ static int event_input(struct nl_msg *msg, void *arg)
 	int type = nlmsg_hdr(msg)->nlmsg_type;
 	struct nl_cache_ops *ops;
 	int i, n;
+	int err;
 	struct nl_parser_param p = {
 		.pp_cb = include_cb,
 	};
@@ -89,19 +91,31 @@ static int event_input(struct nl_msg *msg, void *arg)
 		if (mngr->cm_assocs[i].ca_cache) {
 			ops = mngr->cm_assocs[i].ca_cache->c_ops;
 			for (n = 0; ops->co_msgtypes[n].mt_id >= 0; n++)
-				if (ops->co_msgtypes[n].mt_id == type)
-					goto found;
+				if (ops->co_msgtypes[n].mt_id == type) {
+					NL_DBG(2, "Associated message %p to cache %p\n",
+					       msg, mngr->cm_assocs[i].ca_cache);
+
+					p.pp_arg = &mngr->cm_assocs[i];
+
+					err = nl_cache_parse(ops, NULL,
+							     nlmsg_hdr(msg), &p);
+					if (err == NL_SKIP) {
+					    /*
+					     * If this cache skipped the msg, Look for
+					     * the msg type in other caches
+					     */
+					    NL_DBG(2, "Skip associating message %p to "
+						   "cache %p\n", msg,
+						   mngr->cm_assocs[i].ca_cache);
+					    continue;
+					}
+					else
+					    return err;
+				}
 		}
 	}
 
 	return NL_SKIP;
-
-found:
-	NL_DBG(2, "Associated message %p to cache %p\n",
-	       msg, mngr->cm_assocs[i].ca_cache);
-	p.pp_arg = &mngr->cm_assocs[i];
-
-	return nl_cache_parse(ops, NULL, nlmsg_hdr(msg), &p);
 }
 
 /**
-- 
1.7.2.5