From: Pablo Neira Ayuso <pablo@netfilter.org>
To: Phil Sutter <phil@nwl.cc>
Cc: netfilter-devel@vger.kernel.org, netdev@vger.kernel.org,
Eric Garver <eric@garver.life>
Subject: Re: [nf-next PATCH] net: netfilter: Support iif matches in POSTROUTING
Date: Thu, 14 Nov 2019 00:08:42 +0100 [thread overview]
Message-ID: <20191113230842.blotm5i3ftz24rml@salvia> (raw)
In-Reply-To: <20191112161437.19511-1-phil@nwl.cc>
On Tue, Nov 12, 2019 at 05:14:37PM +0100, Phil Sutter wrote:
> Instead of generally passing NULL to NF_HOOK_COND() for input device,
> pass skb->dev which contains input device for routed skbs.
>
> Note that iptables (both legacy and nft) reject rules with input
> interface match from being added to POSTROUTING chains, but nftables
> allows this.
Yes, it allows this but it will not ever match, right? So even if the
rule is loaded, it will be useless.
Do you have a usecase in mind that would benefit from this specifically?
> Cc: Eric Garver <eric@garver.life>
> Signed-off-by: Phil Sutter <phil@nwl.cc>
> ---
> net/ipv4/ip_output.c | 4 ++--
> net/ipv4/xfrm4_output.c | 2 +-
> net/ipv6/ip6_output.c | 4 ++--
> net/ipv6/xfrm6_output.c | 2 +-
> 4 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
> index 3d8baaaf7086d..9d83cb320dcb7 100644
> --- a/net/ipv4/ip_output.c
> +++ b/net/ipv4/ip_output.c
> @@ -422,7 +422,7 @@ int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb)
>
> int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb)
> {
> - struct net_device *dev = skb_dst(skb)->dev;
> + struct net_device *dev = skb_dst(skb)->dev, *indev = skb->dev;
>
> IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
>
> @@ -430,7 +430,7 @@ int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb)
> skb->protocol = htons(ETH_P_IP);
>
> return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
> - net, sk, skb, NULL, dev,
> + net, sk, skb, indev, dev,
> ip_finish_output,
> !(IPCB(skb)->flags & IPSKB_REROUTED));
> }
> diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c
> index ecff3fce98073..89ba7c87de5df 100644
> --- a/net/ipv4/xfrm4_output.c
> +++ b/net/ipv4/xfrm4_output.c
> @@ -92,7 +92,7 @@ static int __xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb)
> int xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb)
> {
> return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
> - net, sk, skb, NULL, skb_dst(skb)->dev,
> + net, sk, skb, skb->dev, skb_dst(skb)->dev,
> __xfrm4_output,
> !(IPCB(skb)->flags & IPSKB_REROUTED));
> }
> diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
> index 71827b56c0063..945508a7cb0f1 100644
> --- a/net/ipv6/ip6_output.c
> +++ b/net/ipv6/ip6_output.c
> @@ -160,7 +160,7 @@ static int ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *s
>
> int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
> {
> - struct net_device *dev = skb_dst(skb)->dev;
> + struct net_device *dev = skb_dst(skb)->dev, *indev = skb->dev;
> struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
>
> skb->protocol = htons(ETH_P_IPV6);
> @@ -173,7 +173,7 @@ int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
> }
>
> return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
> - net, sk, skb, NULL, dev,
> + net, sk, skb, indev, dev,
> ip6_finish_output,
> !(IP6CB(skb)->flags & IP6SKB_REROUTED));
> }
> diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
> index eecac1b7148e5..fbe51d40bd7e9 100644
> --- a/net/ipv6/xfrm6_output.c
> +++ b/net/ipv6/xfrm6_output.c
> @@ -187,7 +187,7 @@ static int __xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
> int xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
> {
> return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
> - net, sk, skb, NULL, skb_dst(skb)->dev,
> + net, sk, skb, skb->dev, skb_dst(skb)->dev,
> __xfrm6_output,
> !(IP6CB(skb)->flags & IP6SKB_REROUTED));
> }
> --
> 2.24.0
>
next prev parent reply other threads:[~2019-11-13 23:08 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-12 16:14 [nf-next PATCH] net: netfilter: Support iif matches in POSTROUTING Phil Sutter
2019-11-13 23:08 ` Pablo Neira Ayuso [this message]
2019-11-14 10:47 ` Phil Sutter
2019-11-15 22:36 ` Pablo Neira Ayuso
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191113230842.blotm5i3ftz24rml@salvia \
--to=pablo@netfilter.org \
--cc=eric@garver.life \
--cc=netdev@vger.kernel.org \
--cc=netfilter-devel@vger.kernel.org \
--cc=phil@nwl.cc \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox