lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Sat, 23 Nov 2019 15:58:18 +0100 From: Oliver Herms <oliver.peter.herms@...il.com> To: davem@...emloft.net, kuznet@....inr.ac.ru, yoshfuji@...ux-ipv6.org Cc: netdev@...r.kernel.org Subject: [PATCH] net: ip/tnl: Set iph->id only when don't fragment is not set In IPv4 the identification field ensures that fragments of different datagrams are not mixed by the receiver. Packets with Don't Fragment (DF) flag set are not to be fragmented in transit and thus don't need an identification. Calculating the identification takes significant CPU time. This patch will increase IP tunneling performance by ~10% unless DF is not set. However, DF is set by default which is best practice. Signed-off-by: Oliver Herms <oliver.peter.herms@...il.com> --- net/ipv4/ip_tunnel_core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c index 1452a97914a0..8636c1e0e7b7 100644 --- a/net/ipv4/ip_tunnel_core.c +++ b/net/ipv4/ip_tunnel_core.c @@ -73,7 +73,9 @@ void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb, iph->daddr = dst; iph->saddr = src; iph->ttl = ttl; - __ip_select_ident(net, iph, skb_shinfo(skb)->gso_segs ?: 1); + + if (unlikely((iph->frag_off & htons(IP_DF)) == false)) + __ip_select_ident(net, iph, skb_shinfo(skb)->gso_segs ?: 1); err = ip_local_out(net, sk, skb); -- 2.19.1
Powered by blists - more mailing lists