[PATCH 5/6] Add hash support to neigh cache

[roopa at cumulusnetworks.com]

From: roopa <roopa at cumulusnetworks.com>

This patch adds keygen function to the neigh object

Signed-off-by: Shrijeet Mukherjee <shm at cumulusnetworks.com>
Signed-off-by: Nolan Leake <nolan at cumulusnetworks.com>
Signed-off-by: Roopa Prabhu <roopa at cumulusnetworks.com>
Reviewed-by: Wilson Kok <wkok at cumulusnetworks.com>
---
 lib/route/neigh.c |   50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 50 insertions(+), 0 deletions(-)

diff --git a/lib/route/neigh.c b/lib/route/neigh.c
index bb61571..a9ab736 100644
--- a/lib/route/neigh.c
+++ b/lib/route/neigh.c
@@ -151,6 +151,7 @@
 #include <netlink-local.h>
 #include <netlink/netlink.h>
 #include <netlink/utils.h>
+#include <netlink/hashtable.h>
 #include <netlink/route/rtnl.h>
 #include <netlink/route/neighbour.h>
 #include <netlink/route/link.h>
@@ -197,6 +198,54 @@ static int neigh_clone(struct nl_object *_dst, struct nl_object *_src)
 	return 0;
 }
 
+static void neigh_keygen(struct nl_object *obj, uint32_t *hashkey,
+			 uint32_t table_sz)
+{
+	struct rtnl_neigh *neigh = (struct rtnl_neigh *) obj;
+	struct neigh_hash_key *_key;
+	char *_key_b;
+	unsigned int _key_sz;
+	unsigned int sz_dst = 0;
+	void *dst = NULL;
+	struct neigh_hash_key {
+		uint32_t	n_family;
+		uint32_t	n_ifindex;
+		void 		*n_addr;
+	};
+
+	if (neigh->n_dst) {
+	    sz_dst = nl_addr_get_len(neigh->n_dst);
+	    dst = nl_addr_get_binary_addr(neigh->n_dst);
+	}
+
+	_key_sz = sizeof(struct neigh_hash_key) -
+			sizeof(void *) + sz_dst;
+
+	_key = calloc(1 , _key_sz);
+	if (!_key) {
+	    NL_DBG(2, "Warning: calloc failed for %d bytes...\n", _key_sz);
+	    *hashkey = 0;
+	}
+
+	_key_b = (char *) &(_key->n_addr);
+	_key->n_family = neigh->n_family;
+	_key->n_ifindex = neigh->n_ifindex;
+
+	NL_DBG(5, "neigh %p dst_a %p, size %d\n",
+	       neigh,
+	       &(_key->n_addr),
+	       _key_sz);
+
+	if (sz_dst)
+	    memcpy((void *)_key_b, dst, sz_dst);
+
+	*hashkey = nl_hash(_key, _key_sz, 0) % table_sz;
+
+	free(_key);
+
+	return;
+}
+
 static int neigh_compare(struct nl_object *_a, struct nl_object *_b,
 			uint32_t attrs, int flags)
 {
@@ -825,6 +874,7 @@ static struct nl_object_ops neigh_obj_ops = {
 	    [NL_DUMP_STATS]	= neigh_dump_stats,
 	},
 	.oo_compare		= neigh_compare,
+	.oo_keygen		= neigh_keygen,
 	.oo_attrs2str		= neigh_attrs2str,
 	.oo_id_attrs		= (NEIGH_ATTR_IFINDEX | NEIGH_ATTR_DST | NEIGH_ATTR_FAMILY),
 };
-- 
1.7.2.5