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| author |   Liping Zhang <liping.zhang@spreadtrum.com> | 2016-07-30 19:44:12 +0800 |
|---|---|---|
| committer |   Pablo Neira Ayuso <pablo@netfilter.org> | 2016-08-12 00:42:47 +0200 |
| commit | 9f7c824a44c9f03a5ee9b6291b0685cbdb89ae58 (patch) | |
| tree | 65e18b82c059c3be10dc0dc0732f280fc5268451 | |
| parent | netfilter: physdev: add missed blank (diff) | |
| download | linux-dev-9f7c824a44c9f03a5ee9b6291b0685cbdb89ae58.tar.xz linux-dev-9f7c824a44c9f03a5ee9b6291b0685cbdb89ae58.zip | |
netfilter: nf_dup4: remove redundant checksum recalculation
IP header checksum will be recalculated at ip_local_out, so
there's no need to calculated it here, remove it. Also update
code comments to illustrate it, and delete the misleading
comments about checksum recalculation.
Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| -rw-r--r-- | net/ipv4/netfilter/nf_dup_ipv4.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/net/ipv4/netfilter/nf_dup_ipv4.c b/net/ipv4/netfilter/nf_dup_ipv4.c index ceb187308120..cf986e1c7bbd 100644 --- a/net/ipv4/netfilter/nf_dup_ipv4.c +++ b/net/ipv4/netfilter/nf_dup_ipv4.c @@ -74,21 +74,19 @@ void nf_dup_ipv4(struct net *net, struct sk_buff *skb, unsigned int hooknum, nf_conntrack_get(skb->nfct); #endif /* - * If we are in PREROUTING/INPUT, the checksum must be recalculated - * since the length could have changed as a result of defragmentation. - * - * We also decrease the TTL to mitigate potential loops between two - * hosts. + * If we are in PREROUTING/INPUT, decrease the TTL to mitigate potential + * loops between two hosts. * * Set %IP_DF so that the original source is notified of a potentially * decreased MTU on the clone route. IPv6 does this too. + * + * IP header checksum will be recalculated at ip_local_out. */ iph = ip_hdr(skb); iph->frag_off |= htons(IP_DF); if (hooknum == NF_INET_PRE_ROUTING || hooknum == NF_INET_LOCAL_IN) --iph->ttl; - ip_send_check(iph); if (nf_dup_ipv4_route(net, skb, gw, oif)) { __this_cpu_write(nf_skb_duplicated, true); |