| Message ID | 20201207130303.30774-1-phil@nwl.cc (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | xfrm: interface: Don't hide plain packets from netfilter | expand |
On Mon, Dec 07, 2020 at 02:03:03PM +0100, Phil Sutter wrote: > With an IPsec tunnel without dedicated interface, netfilter sees locally > generated packets twice as they exit the physical interface: Once as "the > inner packet" with IPsec context attached and once as the encrypted > (ESP) packet. > > With xfrm_interface, the inner packet did not traverse NF_INET_LOCAL_OUT > hook anymore, making it impossible to match on both inner header values > and associated IPsec data from that hook. > > Fix this by looping packets transmitted from xfrm_interface through > NF_INET_LOCAL_OUT before passing them on to dst_output(), which makes > behaviour consistent again from netfilter's point of view. > > Fixes: f203b76d78092 ("xfrm: Add virtual xfrm interfaces") > Signed-off-by: Phil Sutter <phil@nwl.cc> > --- > net/xfrm/xfrm_interface.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c > index aa4cdcf69d471..24af61c95b4d4 100644 > --- a/net/xfrm/xfrm_interface.c > +++ b/net/xfrm/xfrm_interface.c > @@ -317,7 +317,8 @@ xfrmi_xmit2(struct sk_buff *skb, struct net_device *dev, struct flowi *fl) > skb_dst_set(skb, dst); > skb->dev = tdev; > > - err = dst_output(xi->net, skb->sk, skb); > + err = NF_HOOK(skb_dst(skb)->ops->family, NF_INET_LOCAL_OUT, xi->net, > + skb->sk, skb, NULL, skb_dst(skb)->dev, dst_output); > if (net_xmit_eval(err) == 0) { > struct pcpu_sw_netstats *tstats = this_cpu_ptr(dev->tstats); This is networking code, so please send your patch also to the netdev list: netdev@vger.kernel.org
diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c index aa4cdcf69d471..24af61c95b4d4 100644 --- a/net/xfrm/xfrm_interface.c +++ b/net/xfrm/xfrm_interface.c @@ -317,7 +317,8 @@ xfrmi_xmit2(struct sk_buff *skb, struct net_device *dev, struct flowi *fl) skb_dst_set(skb, dst); skb->dev = tdev; - err = dst_output(xi->net, skb->sk, skb); + err = NF_HOOK(skb_dst(skb)->ops->family, NF_INET_LOCAL_OUT, xi->net, + skb->sk, skb, NULL, skb_dst(skb)->dev, dst_output); if (net_xmit_eval(err) == 0) { struct pcpu_sw_netstats *tstats = this_cpu_ptr(dev->tstats);
With an IPsec tunnel without dedicated interface, netfilter sees locally generated packets twice as they exit the physical interface: Once as "the inner packet" with IPsec context attached and once as the encrypted (ESP) packet. With xfrm_interface, the inner packet did not traverse NF_INET_LOCAL_OUT hook anymore, making it impossible to match on both inner header values and associated IPsec data from that hook. Fix this by looping packets transmitted from xfrm_interface through NF_INET_LOCAL_OUT before passing them on to dst_output(), which makes behaviour consistent again from netfilter's point of view. Fixes: f203b76d78092 ("xfrm: Add virtual xfrm interfaces") Signed-off-by: Phil Sutter <phil@nwl.cc> --- net/xfrm/xfrm_interface.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)