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>
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 94b4de8..40197ff 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1214,29 +1214,10 @@
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 = {