Merge branch 'net-l3mdev-Support-for-sockets-bound-to-enslaved-device'

David Ahern says:

====================
net: l3mdev: Support for sockets bound to enslaved device

A missing piece to the VRF puzzle is the ability to bind sockets to
devices enslaved to a VRF. This patch set adds the enslaved device
index, sdif, to IPv4 and IPv6 socket lookups. The end result for users
is the following scope options for services:

1. "global" services - sockets not bound to any device

   Allows 1 service to work across all network interfaces with
   connected sockets bound to the VRF the connection originates
   (Requires net.ipv4.tcp_l3mdev_accept=1 for TCP and
    net.ipv4.udp_l3mdev_accept=1 for UDP)

2. "VRF" local services - sockets bound to a VRF

   Sockets work across all network interfaces enslaved to a VRF but
   are limited to just the one VRF.

3. "device" services - sockets bound to a specific network interface

   Service works only through the one specific interface.

v3
- convert __inet_lookup_established in dccp_v4_err; missed in v2

v2
- remove sk_lookup struct and add sdif as an argument to existing
  functions

Changes since RFC:
- no significant logic changes; mainly whitespace cleanups
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 474d6bbc158c..ac2da4e11d5e 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -159,6 +159,16 @@ static inline bool inet6_is_jumbogram(const struct sk_buff *skb)
 }
 
 /* can not be used in TCP layer after tcp_v6_fill_cb */
+static inline int inet6_sdif(const struct sk_buff *skb)
+{
+#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
+	if (skb && ipv6_l3mdev_skb(IP6CB(skb)->flags))
+		return IP6CB(skb)->iif;
+#endif
+	return 0;
+}
+
+/* can not be used in TCP layer after tcp_v6_fill_cb */
 static inline bool inet6_exact_dif_match(struct net *net, struct sk_buff *skb)
 {
 #if defined(CONFIG_NET_L3_MASTER_DEV)