Re: [PATCH] inet: ping: Fix icmp out counting

[Ido Schimmel <idosch@idosch.org>]

Next time, please tag the patch as [PATCH net]. See:

https://docs.kernel.org/process/maintainer-netdev.html

On Wed, Dec 24, 2025 at 02:31:45PM +0800, yuan.gao@ucloud.cn wrote:
> From: "yuan.gao" <yuan.gao@ucloud.cn>
> 
> When the ping program uses an IPPROTO_ICMP socket to send ICMP_ECHO
> messages, ICMP_MIB_OUTMSGS is counted twice.
> 
>     ping_v4_sendmsg
>       ping_v4_push_pending_frames
>         ip_push_pending_frames
>           ip_finish_skb
>             __ip_make_skb
>               icmp_out_count(net, icmp_type); // first count
>       icmp_out_count(sock_net(sk), user_icmph.type); // second count
> 
> However, when the ping program uses an IPPROTO_RAW socket,
> ICMP_MIB_OUTMSGS is counted correctly only once.
> 
> Therefore, the first count should be removed.

Looks correct.

Before:

# sysctl -wq net.ipv4.ping_group_range="0 4294967294"
# nstat -z -j | jq '.[]["IcmpOutEchos"]'
0
# ping -c1 127.0.0.1 &> /dev/null
# nstat -z -j | jq '.[]["IcmpOutEchos"]'
2

After:

# sysctl -wq net.ipv4.ping_group_range="0 4294967294"
# nstat -z -j | jq '.[]["IcmpOutEchos"]'
0
# ping -c1 127.0.0.1 &> /dev/null
# nstat -z -j | jq '.[]["IcmpOutEchos"]'
1

And it's consistent with IPv6:

# sysctl -wq net.ipv4.ping_group_range="0 4294967294"
# nstat -z -j | jq '.[]["Icmp6OutEchos"]'
0
# ping -c1 ::1 &> /dev/null
# nstat -z -j | jq '.[]["Icmp6OutEchos"]'
1

> 
> Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind")
> Signed-off-by: yuan.gao <yuan.gao@ucloud.cn>

Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>