tipc: add dst_cache support for udp media

As other udp/ip tunnels do, tipc udp media should also have a
lockless dst_cache supported on its tx path.

Here we add dst_cache into udp_replicast to support dst cache
for both rmcast and rcast, and rmcast uses ub->rcast and each
rcast uses its own node in ub->rcast.list.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 47 insertions, 25 deletions

diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c
index 1405ccc9101c..b8962df07d36 100644
--- a/net/tipc/udp_media.c
+++ b/net/tipc/udp_media.c
@@ -76,6 +76,7 @@ struct udp_media_addr {
 /* struct udp_replicast - container for UDP remote addresses */
 struct udp_replicast {
         struct udp_media_addr addr;
+        struct dst_cache dst_cache;
         struct rcu_head rcu;
         struct list_head list;
 };
@@ -158,22 +159,27 @@ static int tipc_udp_addr2msg(char *msg, struct tipc_media_addr *a)
 /* tipc_send_msg - enqueue a send request */
 static int tipc_udp_xmit(struct net *net, struct sk_buff *skb,
                          struct udp_bearer *ub, struct udp_media_addr *src,
-                         struct udp_media_addr *dst)
+                         struct udp_media_addr *dst, struct dst_cache *cache)
 {
+        struct dst_entry *ndst = dst_cache_get(cache);
         int ttl, err = 0;
-        struct rtable *rt;
 
         if (dst->proto == htons(ETH_P_IP)) {
-                struct flowi4 fl = {
-                        .daddr = dst->ipv4.s_addr,
-                        .saddr = src->ipv4.s_addr,
-                        .flowi4_mark = skb->mark,
-                        .flowi4_proto = IPPROTO_UDP
-                };
-                rt = ip_route_output_key(net, &fl);
-                if (IS_ERR(rt)) {
-                        err = PTR_ERR(rt);
-                        goto tx_error;
+                struct rtable *rt = (struct rtable *)ndst;
+
+                if (!rt) {
+                        struct flowi4 fl = {
+                                .daddr = dst->ipv4.s_addr,
+                                .saddr = src->ipv4.s_addr,
+                                .flowi4_mark = skb->mark,
+                                .flowi4_proto = IPPROTO_UDP
+                        };
+                        rt = ip_route_output_key(net, &fl);
+                        if (IS_ERR(rt)) {
+                                err = PTR_ERR(rt);
+                                goto tx_error;
+                        }
+                        dst_cache_set_ip4(cache, &rt->dst, fl.saddr);
                 }
 
                 ttl = ip4_dst_hoplimit(&rt->dst);
@@ -182,17 +188,19 @@ static int tipc_udp_xmit(struct net *net, struct sk_buff *skb,
                                     dst->port, false, true);
 #if IS_ENABLED(CONFIG_IPV6)
         } else {
-                struct dst_entry *ndst;
-                struct flowi6 fl6 = {
-                        .flowi6_oif = ub->ifindex,
-                        .daddr = dst->ipv6,
-                        .saddr = src->ipv6,
-                        .flowi6_proto = IPPROTO_UDP
-                };
-                err = ipv6_stub->ipv6_dst_lookup(net, ub->ubsock->sk, &ndst,
-                                                 &fl6);
-                if (err)
-                        goto tx_error;
+                if (!ndst) {
+                        struct flowi6 fl6 = {
+                                .flowi6_oif = ub->ifindex,
+                                .daddr = dst->ipv6,
+                                .saddr = src->ipv6,
+                                .flowi6_proto = IPPROTO_UDP
+                        };
+                        err = ipv6_stub->ipv6_dst_lookup(net, ub->ubsock->sk,
+                                                         &ndst, &fl6);
+                        if (err)
+                                goto tx_error;
+                        dst_cache_set_ip6(cache, ndst, &fl6.saddr);
+                }
                 ttl = ip6_dst_hoplimit(ndst);
                 err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb, NULL,
                                            &src->ipv6, &dst->ipv6, 0, ttl, 0,
@@ -230,7 +238,8 @@ static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
         }
 
         if (addr->broadcast != TIPC_REPLICAST_SUPPORT)
-                return tipc_udp_xmit(net, skb, ub, src, dst);
+                return tipc_udp_xmit(net, skb, ub, src, dst,
+                                     &ub->rcast.dst_cache);
 
         /* Replicast, send an skb to each configured IP address */
         list_for_each_entry_rcu(rcast, &ub->rcast.list, list) {
@@ -242,7 +251,8 @@ static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
                         goto out;
                 }
 
-                err = tipc_udp_xmit(net, _skb, ub, src, &rcast->addr);
+                err = tipc_udp_xmit(net, _skb, ub, src, &rcast->addr,
+                                    &rcast->dst_cache);
                 if (err)
                         goto out;
         }
@@ -286,6 +296,11 @@ static int tipc_udp_rcast_add(struct tipc_bearer *b,
         if (!rcast)
                 return -ENOMEM;
 
+        if (dst_cache_init(&rcast->dst_cache, GFP_ATOMIC)) {
+                kfree(rcast);
+                return -ENOMEM;
+        }
+
         memcpy(&rcast->addr, addr, sizeof(struct udp_media_addr));
 
         if (ntohs(addr->proto) == ETH_P_IP)
@@ -742,6 +757,10 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
         tuncfg.encap_destroy = NULL;
         setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
 
+        err = dst_cache_init(&ub->rcast.dst_cache, GFP_ATOMIC);
+        if (err)
+                goto err;
+
         /**
          * The bcast media address port is used for all peers and the ip
          * is used if it's a multicast address.
@@ -756,6 +775,7 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
 
         return 0;
 err:
+        dst_cache_destroy(&ub->rcast.dst_cache);
         if (ub->ubsock)
                 udp_tunnel_sock_release(ub->ubsock);
         kfree(ub);
@@ -769,10 +789,12 @@ static void cleanup_bearer(struct work_struct *work)
         struct udp_replicast *rcast, *tmp;
 
         list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
+                dst_cache_destroy(&rcast->dst_cache);
                 list_del_rcu(&rcast->list);
                 kfree_rcu(rcast, rcu);
         }
 
+        dst_cache_destroy(&ub->rcast.dst_cache);
         if (ub->ubsock)
                 udp_tunnel_sock_release(ub->ubsock);
         synchronize_net();