On Sat, Nov 09, 2019 at 03:50:17PM +0800, Li RongQing wrote:
> csum_tcpudp_magic should not be called to compute checksum
> for non-TCP/UDP packets, like ICMP with wrong checksum
This is fixing 5d1549847c76b1ffcf8e388ef4d0f229bdd1d7e8.
> Signed-off-by: Li RongQing <lirongqing@xxxxxxxxx>
> ---
> net/netfilter/utils.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/net/netfilter/utils.c b/net/netfilter/utils.c
> index 51b454d8fa9c..72eace52874e 100644
> --- a/net/netfilter/utils.c
> +++ b/net/netfilter/utils.c
> @@ -17,9 +17,12 @@ __sum16 nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
> case CHECKSUM_COMPLETE:
> if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN)
> break;
> - if ((protocol != IPPROTO_TCP && protocol != IPPROTO_UDP &&
> - !csum_fold(skb->csum)) ||
> - !csum_tcpudp_magic(iph->saddr, iph->daddr,
> + if (protocol != IPPROTO_TCP && protocol != IPPROTO_UDP) {
> + if (!csum_fold(skb->csum)) {
> + skb->ip_summed = CHECKSUM_UNNECESSARY;
> + break;
> + }
> + } else if (!csum_tcpudp_magic(iph->saddr, iph->daddr,
> skb->len - dataoff, protocol,
> skb->csum)) {
Probably disentangle this code with the following snippet?
switch (protocol) {
case IPPROTO_TCP:
case IPPROTO_UDP:
if (!csum_tcpudp_magic(iph->saddr, iph->daddr,
skb->len - dataoff, protocol,
skb->csum))
skb->ip_summed = CHECKSUM_UNNECESSARY;
break;
default:
if (!csum_fold(skb->csum))
skb->ip_summed = CHECKSUM_UNNECESSARY;
break;
}
> + if (!csum_fold(skb->csum)) {
> + skb->ip_summed = CHECKSUM_UNNECESSARY;
> + break;
> + }
> + } else if (!csum_tcpudp_magic(iph->saddr, iph->daddr,
> skb->len - dataoff, protocol,
> skb->csum)) {
> skb->ip_summed = CHECKSUM_UNNECESSARY;
> --
> 2.16.2
>
