From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julian Anastasov Subject: Re: [PATCH net-next 06/13] net: original ingress device index in PKTINFO Date: Thu, 5 May 2016 11:41:27 +0300 (EEST) Message-ID: References: <1462419210-10463-1-git-send-email-dsa@cumulusnetworks.com> <1462419210-10463-7-git-send-email-dsa@cumulusnetworks.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: netdev@vger.kernel.org To: David Ahern Return-path: Received: from ja.ssi.bg ([178.16.129.10]:52933 "EHLO ja.ssi.bg" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1756159AbcEEIlg (ORCPT ); Thu, 5 May 2016 04:41:36 -0400 In-Reply-To: <1462419210-10463-7-git-send-email-dsa@cumulusnetworks.com> Sender: netdev-owner@vger.kernel.org List-ID: Hello, On Wed, 4 May 2016, David Ahern wrote: > Applications such as OSPF and BFD need the original ingress device not > the VRF device; the latter can be derived from the former. To that end > add the skb_iif to inet_skb_parm and set it in ipv4 code after clearing > the skb control buffer similar to IPv6. From there the pktinfo can just > pull it from cb with the PKTINFO_SKB_CB cast. > > The previous patch moving the skb->dev change to L3 means nothing else > is needed for IPv6; it just works. > > Signed-off-by: David Ahern > --- > include/net/ip.h | 1 + > net/ipv4/ip_input.c | 1 + > net/ipv4/ip_sockglue.c | 9 +++++++-- > 3 files changed, 9 insertions(+), 2 deletions(-) > > diff --git a/include/net/ip.h b/include/net/ip.h > index 247ac82e9cf2..37165fba3741 100644 > --- a/include/net/ip.h > +++ b/include/net/ip.h > @@ -36,6 +36,7 @@ > struct sock; > > struct inet_skb_parm { > + int iif; > struct ip_options opt; /* Compiled IP options */ > unsigned char flags; > > diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c > index 37375eedeef9..4b351af3e67b 100644 > --- a/net/ipv4/ip_input.c > +++ b/net/ipv4/ip_input.c > @@ -478,6 +478,7 @@ int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, > > /* Remove any debris in the socket control block */ > memset(IPCB(skb), 0, sizeof(struct inet_skb_parm)); > + IPCB(skb)->iif = skb->skb_iif; For loopback traffic (including looped back multicast) this is now a zero :( Can inet_iif be moved to ip_rcv_finish instead? Still, we spend cycles in fast path in case nobody listens for such info. > /* Must drop socket now because of tproxy. */ > skb_orphan(skb); > diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c > index bdb222c0c6a2..dbcd027c38e7 100644 > --- a/net/ipv4/ip_sockglue.c > +++ b/net/ipv4/ip_sockglue.c > @@ -476,9 +476,9 @@ static bool ipv4_datagram_support_cmsg(const struct sock *sk, > (!skb->dev)) > return false; > > + /* see comment in ipv4_pktinfo_prepare about CB re-use */ > info = PKTINFO_SKB_CB(skb); > info->ipi_spec_dst.s_addr = ip_hdr(skb)->saddr; > - info->ipi_ifindex = skb->dev->ifindex; This code is only for SOF_TIMESTAMPING_OPT_CMSG. I'm not sure skb passes ip_rcv in all cases. So, we can not easily remove it. Regards