nfp: flower: set ip tunnel ttl from encap action

The TTL for encapsulating headers in IPv4 UDP tunnels is taken from a
route lookup. Modify this to first check if a user has specified a TTL to
be used in the TC action.
Signed-off-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/nfp/flower/action.c

@@ -238,18 +238,12 @@ nfp_fl_set_ipv4_udp_tun(struct nfp_fl_set_ipv4_udp_tun *set_tun,
 	size_t act_size = sizeof(struct nfp_fl_set_ipv4_udp_tun);
 	struct ip_tunnel_info *ip_tun = tcf_tunnel_info(action);
 	u32 tmp_set_ip_tun_type_index = 0;
-	struct flowi4 flow = {};
 	/* Currently support one pre-tunnel so index is always 0. */
 	int pretun_idx = 0;
-	struct rtable *rt;
-	struct net *net;
-	int err;
 
 	if (ip_tun->options_len)
 		return -EOPNOTSUPP;
 
-	net = dev_net(netdev);
-
 	set_tun->head.jump_id = NFP_FL_ACTION_OPCODE_SET_IPV4_TUNNEL;
 	set_tun->head.len_lw = act_size >> NFP_FL_LW_SIZ;
 
@@ -261,19 +255,28 @@ nfp_fl_set_ipv4_udp_tun(struct nfp_fl_set_ipv4_udp_tun *set_tun,
 	set_tun->tun_type_index = cpu_to_be32(tmp_set_ip_tun_type_index);
 	set_tun->tun_id = ip_tun->key.tun_id;
 
-	/* Do a route lookup to determine ttl - if fails then use default.
-	 * Note that CONFIG_INET is a requirement of CONFIG_NET_SWITCHDEV so
-	 * must be defined here.
-	 */
-	flow.daddr = ip_tun->key.u.ipv4.dst;
-	flow.flowi4_proto = IPPROTO_UDP;
-	rt = ip_route_output_key(net, &flow);
-	err = PTR_ERR_OR_ZERO(rt);
-	if (!err) {
-		set_tun->ttl = ip4_dst_hoplimit(&rt->dst);
-		ip_rt_put(rt);
+	if (ip_tun->key.ttl) {
+		set_tun->ttl = ip_tun->key.ttl;
 	} else {
-		set_tun->ttl = net->ipv4.sysctl_ip_default_ttl;
+		struct net *net = dev_net(netdev);
+		struct flowi4 flow = {};
+		struct rtable *rt;
+		int err;
+
+		/* Do a route lookup to determine ttl - if fails then use
+		 * default. Note that CONFIG_INET is a requirement of
+		 * CONFIG_NET_SWITCHDEV so must be defined here.
+		 */
+		flow.daddr = ip_tun->key.u.ipv4.dst;
+		flow.flowi4_proto = IPPROTO_UDP;
+		rt = ip_route_output_key(net, &flow);
+		err = PTR_ERR_OR_ZERO(rt);
+		if (!err) {
+			set_tun->ttl = ip4_dst_hoplimit(&rt->dst);
+			ip_rt_put(rt);
+		} else {
+			set_tun->ttl = net->ipv4.sysctl_ip_default_ttl;
+		}
 	}
 
 	set_tun->tos = ip_tun->key.tos;