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authorArad, Ronen <ronen.arad@intel.com>2015-10-19 09:23:28 -0700
committerDavid S. Miller <davem@davemloft.net>2015-10-21 19:15:20 -0700
commitb1974ed05ea90264d534a200e8a13932ad55f8b8 (patch)
tree854bca789c6a4e38dadbb9e5373742b970830fe7 /net/bridge/br_netlink.c
parent6ac311ae8bfb47de09f349e781e26373944d2ee3 (diff)
downloadlinux-b1974ed05ea90264d534a200e8a13932ad55f8b8.tar.gz
netlink: Rightsize IFLA_AF_SPEC size calculation
if_nlmsg_size() overestimates the minimum allocation size of netlink
dump request (when called from rtnl_calcit()) or the size of the
message (when called from rtnl_getlink()). This is because
ext_filter_mask is not supported by rtnl_link_get_af_size() and
rtnl_link_get_size().

The over-estimation is significant when at least one netdev has many
VLANs configured (8 bytes for each configured VLAN).

This patch-set "rightsizes" the protocol specific attribute size
calculation by propagating ext_filter_mask to rtnl_link_get_af_size()
and adding this a argument to get_link_af_size op in rtnl_af_ops.

Bridge module already used filtering aware sizing for notifications.
br_get_link_af_size_filtered() is consistent with the modified
get_link_af_size op so it replaces br_get_link_af_size() in br_af_ops.
br_get_link_af_size() becomes unused and thus removed.

Signed-off-by: Ronen Arad <ronen.arad@intel.com>
Acked-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/bridge/br_netlink.c')
-rw-r--r--net/bridge/br_netlink.c21
1 files changed, 1 insertions, 20 deletions
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 94b4de8c4646..40197ff8918a 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1214,29 +1214,10 @@ static int br_fill_info(struct sk_buff *skb, const struct net_device *brdev)
 	return 0;
 }
 
-static size_t br_get_link_af_size(const struct net_device *dev)
-{
-	struct net_bridge_port *p;
-	struct net_bridge *br;
-	int num_vlans = 0;
-
-	if (br_port_exists(dev)) {
-		p = br_port_get_rtnl(dev);
-		num_vlans = br_get_num_vlan_infos(nbp_vlan_group(p),
-						  RTEXT_FILTER_BRVLAN);
-	} else if (dev->priv_flags & IFF_EBRIDGE) {
-		br = netdev_priv(dev);
-		num_vlans = br_get_num_vlan_infos(br_vlan_group(br),
-						  RTEXT_FILTER_BRVLAN);
-	}
-
-	/* Each VLAN is returned in bridge_vlan_info along with flags */
-	return num_vlans * nla_total_size(sizeof(struct bridge_vlan_info));
-}
 
 static struct rtnl_af_ops br_af_ops __read_mostly = {
 	.family			= AF_BRIDGE,
-	.get_link_af_size	= br_get_link_af_size,
+	.get_link_af_size	= br_get_link_af_size_filtered,
 };
 
 struct rtnl_link_ops br_link_ops __read_mostly = {