From: Florian Westphal <fw@strlen.de>
To: Praveen Chaudhary <praveen5582@gmail.com>
Cc: davem@davemloft.net, fw@strlen.de, kadlec@netfilter.org,
pablo@netfilter.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, Zhenggen Xu <zxu@linkedin.com>,
Andy Stracner <astracner@linkedin.com>
Subject: Re: [PATCH] [netfilter]: Fix skb->csum calculation when netfilter manipulation for NF_NAT_MANIP_SRC\DST is done on IPV6 packet.
Date: Wed, 23 Oct 2019 21:33:37 +0200 [thread overview]
Message-ID: <20191023193337.GP25052@breakpoint.cc> (raw)
In-Reply-To: <1571857342-8407-2-git-send-email-pchaudhary@linkedin.com>
Praveen Chaudhary <praveen5582@gmail.com> wrote:
> Update skb->csum, when netfilter code updates IPV6 SRC\DST address in IPV6 HEADER due to iptable rule.
>
> Signed-off-by: Praveen Chaudhary <pchaudhary@linkedin.com>
> Signed-off-by: Zhenggen Xu <zxu@linkedin.com>
> Signed-off-by: Andy Stracner <astracner@linkedin.com>
> ---
> include/net/checksum.h | 2 ++
> net/core/utils.c | 13 +++++++++++++
> net/netfilter/nf_nat_proto.c | 2 ++
> 3 files changed, 17 insertions(+)
>
> diff --git a/include/net/checksum.h b/include/net/checksum.h
> index 97bf488..d7d28b7 100644
> --- a/include/net/checksum.h
> +++ b/include/net/checksum.h
> @@ -145,6 +145,8 @@ void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
> void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb,
> const __be32 *from, const __be32 *to,
> bool pseudohdr);
> +void inet_proto_skb_csum_replace16(struct sk_buff *skb,
> + const __be32 *from, const __be32 *to);
> void inet_proto_csum_replace_by_diff(__sum16 *sum, struct sk_buff *skb,
> __wsum diff, bool pseudohdr);
>
> diff --git a/net/core/utils.c b/net/core/utils.c
> index 6b6e51d..ab3284b 100644
> --- a/net/core/utils.c
> +++ b/net/core/utils.c
> @@ -458,6 +458,19 @@ void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb,
> }
> EXPORT_SYMBOL(inet_proto_csum_replace16);
>
> +void inet_proto_skb_csum_replace16(struct sk_buff *skb,
> + const __be32 *from, const __be32 *to)
> +{
> + __be32 diff[] = {
> + ~from[0], ~from[1], ~from[2], ~from[3],
> + to[0], to[1], to[2], to[3],
> + };
> + if (skb->ip_summed == CHECKSUM_COMPLETE)
> + skb->csum = csum_partial(diff, sizeof(diff),
> + skb->csum);
> +}
> +EXPORT_SYMBOL(inet_proto_skb_csum_replace16);
> +
> void inet_proto_csum_replace_by_diff(__sum16 *sum, struct sk_buff *skb,
> __wsum diff, bool pseudohdr)
> {
> diff --git a/net/netfilter/nf_nat_proto.c b/net/netfilter/nf_nat_proto.c
> index 0a59c14..de94590 100644
> --- a/net/netfilter/nf_nat_proto.c
> +++ b/net/netfilter/nf_nat_proto.c
> @@ -467,6 +467,8 @@ static void nf_nat_ipv6_csum_update(struct sk_buff *skb,
> }
> inet_proto_csum_replace16(check, skb, oldip->s6_addr32,
> newip->s6_addr32, true);
> + inet_proto_skb_csum_replace16(skb, oldip->s6_addr32,
> + newip->s6_addr32);
This is confusing.
You're saying that inet_proto_csum_replace16() is producing a wrong
skb->csum. So why are you adding a new function to do the
csum calculation instead of fixing inet_proto_csum_replace16() to do
the right thing?
next prev parent reply other threads:[~2019-10-23 19:33 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-23 19:02 [PATCH] Fix skb->csum calculation when netfilter manipulation for NF_NAT_MANIP_SRC\DST is done on IPV6 packet Praveen Chaudhary
2019-10-23 19:02 ` [PATCH] [netfilter]: " Praveen Chaudhary
2019-10-23 19:33 ` Florian Westphal [this message]
2019-10-23 20:56 ` [PATCH] [netfilter]: Fix skb->csum calculation when netfilter Praveen Chaudhary
[not found] ` <CAJ_cd4qHM3kqz24Uywpyyz0mPz7axiNZk0Q385ROd4O8XZ11fA@mail.gmail.com>
2019-10-24 1:12 ` [PATCH] [netfilter]: Fix skb->csum calculation when netfilter manipulation for NF_NAT_MANIP_SRC\DST is done on IPV6 packet Florian Westphal
2019-10-24 5:19 ` [netfilter]: Fix skb->csum calculation when netfilter Praveen Chaudhary
2019-10-28 22:27 [PATCH] [netfilter]: Fix skb->csum calculation when netfilter manipulation for NF_NAT_MANIP_SRC\DST is done on IPV6 packet Praveen Chaudhary
2019-10-28 22:27 ` Praveen Chaudhary
2019-10-29 16:09 ` Florian Westphal
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