From: Gao Feng <f...@ikuai8.com>
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 <f...@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pa...@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
