Commit 105bae32 authored by Adrian Moreno's avatar Adrian Moreno Committed by Jakub Kicinski
Browse files

rtnetlink: honor RTEXT_FILTER_SKIP_STATS in IFLA_STATS 

Gathering interface statistics can be a relatively expensive operation
on certain systems as it requires iterating over all the cpus.

RTEXT_FILTER_SKIP_STATS was first introduced [1] to skip AF_INET6
statistics from interface dumps and it was then extended [2] to
also exclude IFLA_VF_INFO.

The semantics of the flag does not seem to be limited to AF_INET
or VF statistics and having a way to query the interface status
(e.g: carrier, address) without retrieving its statistics seems
reasonable. So this patch extends the use RTEXT_FILTER_SKIP_STATS
to also affect IFLA_STATS.

[1] https://lore.kernel.org/all/20150911204848.GC9687@oracle.com/
[2] https://lore.kernel.org/all/20230611105108.122586-1-gal@nvidia.com/



Signed-off-by: default avatarAdrian Moreno <amorenoz@redhat.com>
Reviewed-by: default avatarToke Høiland-Jørgensen <toke@redhat.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarNicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://patch.msgid.link/20251103154006.1189707-1-amorenoz@redhat.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 255d75ef

net/core/rtnetlink.c

+11 −4
Original line number Diff line number Diff line
@@ -1270,13 +1270,13 @@ static size_t rtnl_dpll_pin_size(const struct net_device *dev) 
static noinline size_t if_nlmsg_size(const struct net_device *dev,

				     u32 ext_filter_mask)

{

	return NLMSG_ALIGN(sizeof(struct ifinfomsg))

	size_t size;



	size = NLMSG_ALIGN(sizeof(struct ifinfomsg))

	       + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */

	       + nla_total_size(IFALIASZ) /* IFLA_IFALIAS */

	       + nla_total_size(IFNAMSIZ) /* IFLA_QDISC */

	       + nla_total_size_64bit(sizeof(struct rtnl_link_ifmap))

	       + nla_total_size(sizeof(struct rtnl_link_stats))

	       + nla_total_size_64bit(sizeof(struct rtnl_link_stats64))

	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */

	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_BROADCAST */

	       + nla_total_size(4) /* IFLA_TXQLEN */
@@ -1329,6 +1329,12 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev, 
	       + nla_total_size(2)  /* IFLA_HEADROOM */

	       + nla_total_size(2)  /* IFLA_TAILROOM */

	       + 0;



	if (!(ext_filter_mask & RTEXT_FILTER_SKIP_STATS))

		size += nla_total_size(sizeof(struct rtnl_link_stats)) +

			nla_total_size_64bit(sizeof(struct rtnl_link_stats64));



	return size;

}



static int rtnl_vf_ports_fill(struct sk_buff *skb, struct net_device *dev)
@@ -2123,7 +2129,8 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, 
	if (rtnl_phys_switch_id_fill(skb, dev))

		goto nla_put_failure;



	if (rtnl_fill_stats(skb, dev))

	if (!(ext_filter_mask & RTEXT_FILTER_SKIP_STATS) &&

	    rtnl_fill_stats(skb, dev))

		goto nla_put_failure;



	if (rtnl_fill_vf(skb, dev, ext_filter_mask))