Commit 0b922b7a authored by David Ahern's avatar David Ahern Committed by David S. Miller
Browse files

net: original ingress device index in PKTINFO 



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: default avatarDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 74b20582

include/net/ip.h

+1 −0
Original line number Diff line number Diff line
@@ -36,6 +36,7 @@ 
struct sock;



struct inet_skb_parm {

	int			iif;

	struct ip_options	opt;		/* Compiled IP options		*/

	unsigned char		flags;

net/ipv4/ip_input.c

+1 −0
Original line number Diff line number Diff line
@@ -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;



	/* Must drop socket now because of tproxy. */

	skb_orphan(skb);

net/ipv4/ip_sockglue.c

+6 −1
Original line number Diff line number Diff line
@@ -1193,7 +1193,12 @@ void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb) 
		       ipv6_sk_rxinfo(sk);



	if (prepare && skb_rtable(skb)) {

		pktinfo->ipi_ifindex = inet_iif(skb);

		/* skb->cb is overloaded: prior to this point it is IP{6}CB

		 * which has interface index (iif) as the first member of the

		 * underlying inet{6}_skb_parm struct. This code then overlays

		 * PKTINFO_SKB_CB and in_pktinfo also has iif as the first

		 * element so the iif is picked up from the prior IPCB

		 */

		pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb);

	} else {

		pktinfo->ipi_ifindex = 0;

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