[PATCH 36/53] netfilter: xt_TCPMSS: Refactor the codes to decrease one condition check and more readable
flat view
STALE3680d
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: 2016-09-25 23:07:57
Also in:
netfilter-devel
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Gao Feng <redacted> 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 <redacted> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- 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;
--
2.1.4