From 50f4c7b73f831a53fa9ddeb9bdf4cfb5b23d3aa7 Mon Sep 17 00:00:00 2001 From: Gao Feng Date: Wed, 7 Sep 2016 10:40:24 +0800 Subject: netfilter: xt_TCPMSS: Refactor the codes to decrease one condition check and more readable The origin codes perform two condition checks with dst_mtu(skb_dst(skb)) and in_mtu. And the last statement is "min(dst_mtu(skb_dst(skb)), in_mtu) - minlen". It may let reader think about how about the result. Would it be negative. Now assign the result of min(dst_mtu(skb_dst(skb)), in_mtu) to a new variable, then only perform one condition check, and it is more readable. Signed-off-by: Gao Feng Signed-off-by: Pablo Neira Ayuso --- net/netfilter/xt_TCPMSS.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/net/netfilter/xt_TCPMSS.c b/net/netfilter/xt_TCPMSS.c index e118397254af..872db2d0e2a9 100644 --- a/net/netfilter/xt_TCPMSS.c +++ b/net/netfilter/xt_TCPMSS.c @@ -110,18 +110,14 @@ tcpmss_mangle_packet(struct sk_buff *skb, if (info->mss == XT_TCPMSS_CLAMP_PMTU) { struct net *net = par->net; unsigned int in_mtu = tcpmss_reverse_mtu(net, skb, family); + unsigned int min_mtu = min(dst_mtu(skb_dst(skb)), in_mtu); - if (dst_mtu(skb_dst(skb)) <= minlen) { + if (min_mtu <= minlen) { net_err_ratelimited("unknown or invalid path-MTU (%u)\n", - dst_mtu(skb_dst(skb))); + min_mtu); return -1; } - if (in_mtu <= minlen) { - net_err_ratelimited("unknown or invalid path-MTU (%u)\n", - in_mtu); - return -1; - } - newmss = min(dst_mtu(skb_dst(skb)), in_mtu) - minlen; + newmss = min_mtu - minlen; } else newmss = info->mss; -- cgit v1.2.3