geneve: use generic function for tunnel IPv4 route lookup

The route lookup can be done now via generic function
udp_tunnel_dst_lookup() to replace the custom implementation in
geneve_get_v4_rt().

Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 572c3e3..23041ee 100644 (file)
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -800,58 +800,6 @@ static u8 geneve_get_dsfield(struct sk_buff *skb, struct net_device *dev,
        return dsfield;
 }
 
-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,
-                                      __be16 dport, __be16 sport,
-                                      __u8 *full_tos)
-{
-       bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
-       struct geneve_dev *geneve = netdev_priv(dev);
-       struct dst_cache *dst_cache;
-       struct rtable *rt = NULL;
-       __u8 tos;
-
-       if (!gs4)
-               return ERR_PTR(-EIO);
-
-       memset(fl4, 0, sizeof(*fl4));
-       fl4->flowi4_mark = skb->mark;
-       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;
-       fl4->flowi4_flags = info->key.flow_flags;
-
-       tos = geneve_get_dsfield(skb, dev, info, &use_cache);
-       fl4->flowi4_tos = RT_TOS(tos);
-       if (full_tos)
-               *full_tos = tos;
-
-       dst_cache = (struct dst_cache *)&info->dst_cache;
-       if (use_cache) {
-               rt = dst_cache_get_ip4(dst_cache, &fl4->saddr);
-               if (rt)
-                       return rt;
-       }
-       rt = ip_route_output_key(geneve->net, fl4);
-       if (IS_ERR(rt)) {
-               netdev_dbg(dev, "no route to %pI4\n", &fl4->daddr);
-               return ERR_PTR(-ENETUNREACH);
-       }
-       if (rt->dst.dev == dev) { /* is this necessary? */
-               netdev_dbg(dev, "circular route to %pI4\n", &fl4->daddr);
-               ip_rt_put(rt);
-               return ERR_PTR(-ELOOP);
-       }
-       if (use_cache)
-               dst_cache_set_ip4(dst_cache, &rt->dst, fl4->saddr);
-       return rt;
-}
-
 #if IS_ENABLED(CONFIG_IPV6)
 static struct dst_entry *geneve_get_v6_dst(struct sk_buff *skb,
                                           struct net_device *dev,
@@ -911,19 +859,28 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
        struct geneve_sock *gs4 = rcu_dereference(geneve->sock4);
        const struct ip_tunnel_key *key = &info->key;
        struct rtable *rt;
-       struct flowi4 fl4;
-       __u8 full_tos;
+       bool use_cache;
        __u8 tos, ttl;
        __be16 df = 0;
+       __be32 saddr;
        __be16 sport;
        int err;
 
        if (!pskb_inet_may_pull(skb))
                return -EINVAL;
 
+       if (!gs4)
+               return -EIO;
+
+       use_cache = ip_tunnel_dst_cache_usable(skb, info);
+       tos = geneve_get_dsfield(skb, dev, info, &use_cache);
        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, &full_tos);
+
+       rt = udp_tunnel_dst_lookup(skb, dev, geneve->net, 0, &saddr,
+                                  &info->key,
+                                  sport, geneve->cfg.info.key.tp_dst, tos,
+                                  use_cache ?
+                                  (struct dst_cache *)&info->dst_cache : NULL);
        if (IS_ERR(rt))
                return PTR_ERR(rt);
 
@@ -946,8 +903,8 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
                                return -ENOMEM;
                        }
 
-                       unclone->key.u.ipv4.dst = fl4.saddr;
-                       unclone->key.u.ipv4.src = fl4.daddr;
+                       unclone->key.u.ipv4.dst = saddr;
+                       unclone->key.u.ipv4.src = info->key.u.ipv4.dst;
                }
 
                if (!pskb_may_pull(skb, ETH_HLEN)) {
@@ -961,13 +918,12 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
                return -EMSGSIZE;
        }
 
+       tos = ip_tunnel_ecn_encap(tos, ip_hdr(skb), skb);
        if (geneve->cfg.collect_md) {
-               tos = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
                ttl = key->ttl;
 
                df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
        } else {
-               tos = ip_tunnel_ecn_encap(full_tos, ip_hdr(skb), skb);
                if (geneve->cfg.ttl_inherit)
                        ttl = ip_tunnel_get_ttl(ip_hdr(skb), skb);
                else
@@ -995,7 +951,7 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
        if (unlikely(err))
                return err;
 
-       udp_tunnel_xmit_skb(rt, gs4->sock->sk, skb, fl4.saddr, fl4.daddr,
+       udp_tunnel_xmit_skb(rt, gs4->sock->sk, skb, saddr, info->key.u.ipv4.dst,
                            tos, ttl, df, sport, geneve->cfg.info.key.tp_dst,
                            !net_eq(geneve->net, dev_net(geneve->dev)),
                            !(info->key.tun_flags & TUNNEL_CSUM));
@@ -1144,19 +1100,29 @@ static int geneve_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
 
        if (ip_tunnel_info_af(info) == AF_INET) {
                struct rtable *rt;
-               struct flowi4 fl4;
-
                struct geneve_sock *gs4 = rcu_dereference(geneve->sock4);
+               bool use_cache;
+               __be32 saddr;
+               u8 tos;
+
+               if (!gs4)
+                       return -EIO;
+
+               use_cache = ip_tunnel_dst_cache_usable(skb, info);
+               tos = geneve_get_dsfield(skb, dev, info, &use_cache);
                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, NULL);
+               rt = udp_tunnel_dst_lookup(skb, dev, geneve->net, 0, &saddr,
+                                          &info->key,
+                                          sport, geneve->cfg.info.key.tp_dst,
+                                          tos,
+                                          use_cache ? &info->dst_cache : NULL);
                if (IS_ERR(rt))
                        return PTR_ERR(rt);
 
                ip_rt_put(rt);
-               info->key.u.ipv4.src = fl4.saddr;
+               info->key.u.ipv4.src = saddr;
 #if IS_ENABLED(CONFIG_IPV6)
        } else if (ip_tunnel_info_af(info) == AF_INET6) {
                struct dst_entry *dst;