rtnetlink: RTEXT_FILTER_SKIP_STATS support to avoid dumping inet/inet6 stats
Many commonly used functions like getifaddrs() invoke RTM_GETLINK
to dump the interface information, and do not need the
the AF_INET6 statististics that are always returned by default
from rtnl_fill_ifinfo().
Computing the statistics can be an expensive operation that impacts
scaling, so it is desirable to avoid this if the information is
not needed.
This patch adds a the RTEXT_FILTER_SKIP_STATS extended info flag that
can be passed with netlink_request() to avoid statistics computation
for the ifinfo path.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index 18fdb98..aff6ceb 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -122,7 +122,8 @@
int family;
int (*fill_link_af)(struct sk_buff *skb,
- const struct net_device *dev);
+ const struct net_device *dev,
+ u32 ext_filter_mask);
size_t (*get_link_af_size)(const struct net_device *dev);
int (*validate_link_af)(const struct net_device *dev,
diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index 06625b4..4db0b3c 100644
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -667,6 +667,7 @@
#define RTEXT_FILTER_VF (1 << 0)
#define RTEXT_FILTER_BRVLAN (1 << 1)
#define RTEXT_FILTER_BRVLAN_COMPRESSED (1 << 2)
+#define RTEXT_FILTER_SKIP_STATS (1 << 3)
/* End of information exported to user level */
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index a466821..e545229 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1272,7 +1272,7 @@
if (!(af = nla_nest_start(skb, af_ops->family)))
goto nla_put_failure;
- err = af_ops->fill_link_af(skb, dev);
+ err = af_ops->fill_link_af(skb, dev, ext_filter_mask);
/*
* Caller may return ENODATA to indicate that there
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 2d9cb17..7350084 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1654,7 +1654,8 @@
return nla_total_size(IPV4_DEVCONF_MAX * 4); /* IFLA_INET_CONF */
}
-static int inet_fill_link_af(struct sk_buff *skb, const struct net_device *dev)
+static int inet_fill_link_af(struct sk_buff *skb, const struct net_device *dev,
+ u32 ext_filter_mask)
{
struct in_device *in_dev = rcu_dereference_rtnl(dev->ip_ptr);
struct nlattr *nla;
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 030fefd..75d3dde 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4729,7 +4729,8 @@
}
}
-static int inet6_fill_ifla6_attrs(struct sk_buff *skb, struct inet6_dev *idev)
+static int inet6_fill_ifla6_attrs(struct sk_buff *skb, struct inet6_dev *idev,
+ u32 ext_filter_mask)
{
struct nlattr *nla;
struct ifla_cacheinfo ci;
@@ -4749,6 +4750,9 @@
/* XXX - MC not implemented */
+ if (ext_filter_mask & RTEXT_FILTER_SKIP_STATS)
+ return 0;
+
nla = nla_reserve(skb, IFLA_INET6_STATS, IPSTATS_MIB_MAX * sizeof(u64));
if (!nla)
goto nla_put_failure;
@@ -4784,14 +4788,15 @@
return inet6_ifla6_size();
}
-static int inet6_fill_link_af(struct sk_buff *skb, const struct net_device *dev)
+static int inet6_fill_link_af(struct sk_buff *skb, const struct net_device *dev,
+ u32 ext_filter_mask)
{
struct inet6_dev *idev = __in6_dev_get(dev);
if (!idev)
return -ENODATA;
- if (inet6_fill_ifla6_attrs(skb, idev) < 0)
+ if (inet6_fill_ifla6_attrs(skb, idev, ext_filter_mask) < 0)
return -EMSGSIZE;
return 0;
@@ -4946,7 +4951,7 @@
if (!protoinfo)
goto nla_put_failure;
- if (inet6_fill_ifla6_attrs(skb, idev) < 0)
+ if (inet6_fill_ifla6_attrs(skb, idev, 0) < 0)
goto nla_put_failure;
nla_nest_end(skb, protoinfo);