On Fri, Feb 14, 2020 at 11:20 PM Martin Varghese
[off-list ref] wrote:

From: Martin Varghese <redacted>

The Bareudp tunnel module provides a generic L3 encapsulation
tunnelling module for tunnelling different protocols like MPLS,
IP,NSH etc inside a UDP tunnel.

Signed-off-by: Martin Varghese <redacted>

A few small points

 net/ipv4/route.c                     |  48 +++
 net/ipv6/ip6_output.c                |  70 ++++

Both protocols have route.c and ip(6)_output.c files. For the sake of
consistency, both should ideally be in route.c. Did you choose
ip6_output.c for a reason?

There are also a couple of reverse christmas tree violations.

+struct rtable *ip_route_output_tunnel(struct sk_buff *skb,
+                                     struct net_device *dev,
+                                     struct net *net, __be32 *saddr,
+                                     const struct ip_tunnel_info *info,
+                                     u8 protocol, bool use_cache)
+{
+#ifdef CONFIG_DST_CACHE
+       struct dst_cache *dst_cache;
+#endif
+       struct rtable *rt = NULL;
+       struct flowi4 fl4;
+       __u8 tos;
+
+       memset(&fl4, 0, sizeof(fl4));
+       fl4.flowi4_mark = skb->mark;
+       fl4.flowi4_proto = protocol;
+       fl4.daddr = info->key.u.ipv4.dst;
+       fl4.saddr = info->key.u.ipv4.src;
+
+       tos = info->key.tos;
+       fl4.flowi4_tos = RT_TOS(tos);
+#ifdef CONFIG_DST_CACHE
+       dst_cache = (struct dst_cache *)&info->dst_cache;
+       if (use_cache) {
+               rt = dst_cache_get_ip4(dst_cache, saddr);
+               if (rt)
+                       return rt;
+       }
+#endif

This is the same in geneve, but no need to initialize fl4 on a cache
hit. Then can also be restructured to only have a single #ifdef block.