Commit b1974ed0 authored by Arad, Ronen's avatar Arad, Ronen Committed by David S. Miller
Browse files

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: default avatarRonen Arad <ronen.arad@intel.com>
Acked-by: default avatarSridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6ac311ae
......@@ -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);
......
......@@ -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 = {
......
......@@ -497,7 +497,8 @@ void rtnl_af_unregister(struct rtnl_af_ops *ops)
}
EXPORT_SYMBOL_GPL(rtnl_af_unregister);
static size_t rtnl_link_get_af_size(const struct net_device *dev)
static size_t rtnl_link_get_af_size(const struct net_device *dev,
u32 ext_filter_mask)
{
struct rtnl_af_ops *af_ops;
size_t size;
......@@ -509,7 +510,7 @@ static size_t rtnl_link_get_af_size(const struct net_device *dev)
if (af_ops->get_link_af_size) {
/* AF_* + nested data */
size += nla_total_size(sizeof(struct nlattr)) +
af_ops->get_link_af_size(dev);
af_ops->get_link_af_size(dev, ext_filter_mask);
}
}
......@@ -900,7 +901,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
+ rtnl_vfinfo_size(dev, ext_filter_mask) /* IFLA_VFINFO_LIST */
+ rtnl_port_size(dev, ext_filter_mask) /* IFLA_VF_PORTS + IFLA_PORT_SELF */
+ rtnl_link_get_size(dev) /* IFLA_LINKINFO */
+ rtnl_link_get_af_size(dev) /* IFLA_AF_SPEC */
+ rtnl_link_get_af_size(dev, ext_filter_mask) /* IFLA_AF_SPEC */
+ nla_total_size(MAX_PHYS_ITEM_ID_LEN) /* IFLA_PHYS_PORT_ID */
+ nla_total_size(MAX_PHYS_ITEM_ID_LEN) /* IFLA_PHYS_SWITCH_ID */
+ nla_total_size(1); /* IFLA_PROTO_DOWN */
......@@ -3443,4 +3444,3 @@ void __init rtnetlink_init(void)
rtnl_register(PF_BRIDGE, RTM_DELLINK, rtnl_bridge_dellink, NULL, NULL);
rtnl_register(PF_BRIDGE, RTM_SETLINK, rtnl_bridge_setlink, NULL, NULL);
}
......@@ -1644,7 +1644,8 @@ static void rtmsg_ifa(int event, struct in_ifaddr *ifa, struct nlmsghdr *nlh,
rtnl_set_sk_err(net, RTNLGRP_IPV4_IFADDR, err);
}
static size_t inet_get_link_af_size(const struct net_device *dev)
static size_t inet_get_link_af_size(const struct net_device *dev,
u32 ext_filter_mask)
{
struct in_device *in_dev = rcu_dereference_rtnl(dev->ip_ptr);
......@@ -2398,4 +2399,3 @@ void __init devinet_init(void)
rtnl_register(PF_INET, RTM_GETNETCONF, inet_netconf_get_devconf,
inet_netconf_dump_devconf, NULL);
}
......@@ -4788,7 +4788,8 @@ static int inet6_fill_ifla6_attrs(struct sk_buff *skb, struct inet6_dev *idev,
return -EMSGSIZE;
}
static size_t inet6_get_link_af_size(const struct net_device *dev)
static size_t inet6_get_link_af_size(const struct net_device *dev,
u32 ext_filter_mask)
{
if (!__in6_dev_get(dev))
return 0;
......
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