geneve: add transport ports in route lookup for geneve

This patch adds transport ports information for route lookup so that
IPsec can select Geneve tunnel traffic to do encryption. This is
needed for OVS/OVN IPsec with encrypted Geneve tunnels.

This can be tested by configuring a host-host VPN using an IKE
daemon and specifying port numbers. For example, for an
Openswan-type configuration, the following parameters should be
configured on both hosts and IPsec set up as-per normal:

$ cat /etc/ipsec.conf

conn in
...
left=$IP1
right=$IP2
...
leftprotoport=udp/6081
rightprotoport=udp
...
conn out
...
left=$IP1
right=$IP2
...
leftprotoport=udp
rightprotoport=udp/6081
...

The tunnel can then be setup using "ip" on both hosts (but
changing the relevant IP addresses):

$ ip link add tun type geneve id 1000 remote $IP2
$ ip addr add 192.168.0.1/24 dev tun
$ ip link set tun up

This can then be tested by pinging from $IP1:

$ ping 192.168.0.2

Without this patch the traffic is unencrypted on the wire.

Fixes: 2d07dc79 ("geneve: add initial netdev driver for GENEVE tunnels")
Signed-off-by: Qiuyu Xiao <qiuyu.xiao.qyx@gmail.com>
Signed-off-by: Mark Gray <mark.d.gray@redhat.com>
Reviewed-by: Greg Rose <gvrose8192@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/geneve.c

@@ -777,7 +777,8 @@ static struct rtable *geneve_get_v4_rt(struct sk_buff *skb,
 				       struct net_device *dev,
 				       struct geneve_sock *gs4,
 				       struct flowi4 *fl4,
-				       const struct ip_tunnel_info *info)
+				       const struct ip_tunnel_info *info,
+				       __be16 dport, __be16 sport)
 {
 	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
 	struct geneve_dev *geneve = netdev_priv(dev);
@@ -793,6 +794,8 @@ static struct rtable *geneve_get_v4_rt(struct sk_buff *skb,
 	fl4->flowi4_proto = IPPROTO_UDP;
 	fl4->daddr = info->key.u.ipv4.dst;
 	fl4->saddr = info->key.u.ipv4.src;
+	fl4->fl4_dport = dport;
+	fl4->fl4_sport = sport;
 
 	tos = info->key.tos;
 	if ((tos == 1) && !geneve->cfg.collect_md) {
@@ -827,7 +830,8 @@ static struct dst_entry *geneve_get_v6_dst(struct sk_buff *skb,
 					   struct net_device *dev,
 					   struct geneve_sock *gs6,
 					   struct flowi6 *fl6,
-					   const struct ip_tunnel_info *info)
+					   const struct ip_tunnel_info *info,
+					   __be16 dport, __be16 sport)
 {
 	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
 	struct geneve_dev *geneve = netdev_priv(dev);
@@ -843,6 +847,9 @@ static struct dst_entry *geneve_get_v6_dst(struct sk_buff *skb,
 	fl6->flowi6_proto = IPPROTO_UDP;
 	fl6->daddr = info->key.u.ipv6.dst;
 	fl6->saddr = info->key.u.ipv6.src;
+	fl6->fl6_dport = dport;
+	fl6->fl6_sport = sport;
+
 	prio = info->key.tos;
 	if ((prio == 1) && !geneve->cfg.collect_md) {
 		prio = ip_tunnel_get_dsfield(ip_hdr(skb), skb);
@@ -889,7 +896,9 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
 	__be16 sport;
 	int err;
 
-	rt = geneve_get_v4_rt(skb, dev, gs4, &fl4, info);
+	sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
+	rt = geneve_get_v4_rt(skb, dev, gs4, &fl4, info,
+			      geneve->cfg.info.key.tp_dst, sport);
 	if (IS_ERR(rt))
 		return PTR_ERR(rt);
 
@@ -919,7 +928,6 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
 		return -EMSGSIZE;
 	}
 
-	sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
 	if (geneve->cfg.collect_md) {
 		tos = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
 		ttl = key->ttl;
@@ -974,7 +982,9 @@ static int geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
 	__be16 sport;
 	int err;
 
-	dst = geneve_get_v6_dst(skb, dev, gs6, &fl6, info);
+	sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
+	dst = geneve_get_v6_dst(skb, dev, gs6, &fl6, info,
+				geneve->cfg.info.key.tp_dst, sport);
 	if (IS_ERR(dst))
 		return PTR_ERR(dst);
 
@@ -1003,7 +1013,6 @@ static int geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
 		return -EMSGSIZE;
 	}
 
-	sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
 	if (geneve->cfg.collect_md) {
 		prio = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
 		ttl = key->ttl;
@@ -1085,13 +1094,18 @@ static int geneve_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
 {
 	struct ip_tunnel_info *info = skb_tunnel_info(skb);
 	struct geneve_dev *geneve = netdev_priv(dev);
+	__be16 sport;
 
 	if (ip_tunnel_info_af(info) == AF_INET) {
 		struct rtable *rt;
 		struct flowi4 fl4;
+
 		struct geneve_sock *gs4 = rcu_dereference(geneve->sock4);
+		sport = udp_flow_src_port(geneve->net, skb,
+					  1, USHRT_MAX, true);
 
-		rt = geneve_get_v4_rt(skb, dev, gs4, &fl4, info);
+		rt = geneve_get_v4_rt(skb, dev, gs4, &fl4, info,
+				      geneve->cfg.info.key.tp_dst, sport);
 		if (IS_ERR(rt))
 			return PTR_ERR(rt);
 
@@ -1101,9 +1115,13 @@ static int geneve_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
 	} else if (ip_tunnel_info_af(info) == AF_INET6) {
 		struct dst_entry *dst;
 		struct flowi6 fl6;
+
 		struct geneve_sock *gs6 = rcu_dereference(geneve->sock6);
+		sport = udp_flow_src_port(geneve->net, skb,
+					  1, USHRT_MAX, true);
 
-		dst = geneve_get_v6_dst(skb, dev, gs6, &fl6, info);
+		dst = geneve_get_v6_dst(skb, dev, gs6, &fl6, info,
+					geneve->cfg.info.key.tp_dst, sport);
 		if (IS_ERR(dst))
 			return PTR_ERR(dst);
 
@@ -1114,8 +1132,7 @@ static int geneve_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
 		return -EINVAL;
 	}
 
-	info->key.tp_src = udp_flow_src_port(geneve->net, skb,
-					     1, USHRT_MAX, true);
+	info->key.tp_src = sport;
 	info->key.tp_dst = geneve->cfg.info.key.tp_dst;
 	return 0;
 }