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>
This commit is contained in:
Arad, Ronen
2015-10-19 09:23:28 -07:00
committed by David S. Miller
parent 6ac311ae8b
commit b1974ed05e
5 changed files with 11 additions and 28 deletions

View File

@@ -124,7 +124,8 @@ struct rtnl_af_ops {
int (*fill_link_af)(struct sk_buff *skb,
const struct net_device *dev,
u32 ext_filter_mask);
size_t (*get_link_af_size)(const struct net_device *dev);
size_t (*get_link_af_size)(const struct net_device *dev,
u32 ext_filter_mask);
int (*validate_link_af)(const struct net_device *dev,
const struct nlattr *attr);