ipv6: datagram: Refactor dst lookup and update codes to a new function

This patch moves the route lookup and update codes for connected
datagram sk to a newly created function ip6_datagram_dst_update()

It will be reused during the pmtu update in the later patch.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
index f07c1ddb5cac87a653e64fb3f75f23aaf5a5d5dc..669585e112943810dfa9416eb04325066f1bdbb6 100644 (file)
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -64,16 +64,65 @@ static void ip6_datagram_flow_key_init(struct flowi6 *fl6, struct sock *sk)
        security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
 }
 
+static int ip6_datagram_dst_update(struct sock *sk)
+{
+       struct ip6_flowlabel *flowlabel = NULL;
+       struct in6_addr *final_p, final;
+       struct ipv6_txoptions *opt;
+       struct dst_entry *dst;
+       struct inet_sock *inet = inet_sk(sk);
+       struct ipv6_pinfo *np = inet6_sk(sk);
+       struct flowi6 fl6;
+       int err = 0;
+
+       if (np->sndflow && (np->flow_label & IPV6_FLOWLABEL_MASK)) {
+               flowlabel = fl6_sock_lookup(sk, np->flow_label);
+               if (!flowlabel)
+                       return -EINVAL;
+       }
+       ip6_datagram_flow_key_init(&fl6, sk);
+
+       rcu_read_lock();
+       opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
+       final_p = fl6_update_dst(&fl6, opt, &final);
+       rcu_read_unlock();
+
+       dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
+       if (IS_ERR(dst)) {
+               err = PTR_ERR(dst);
+               goto out;
+       }
+
+       if (ipv6_addr_any(&np->saddr))
+               np->saddr = fl6.saddr;
+
+       if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
+               sk->sk_v6_rcv_saddr = fl6.saddr;
+               inet->inet_rcv_saddr = LOOPBACK4_IPV6;
+               if (sk->sk_prot->rehash)
+                       sk->sk_prot->rehash(sk);
+       }
+
+       ip6_dst_store(sk, dst,
+                     ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
+                     &sk->sk_v6_daddr : NULL,
+#ifdef CONFIG_IPV6_SUBTREES
+                     ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
+                     &np->saddr :
+#endif
+                     NULL);
+
+out:
+       fl6_sock_release(flowlabel);
+       return err;
+}
+
 static int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 {
        struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
        struct inet_sock        *inet = inet_sk(sk);
        struct ipv6_pinfo       *np = inet6_sk(sk);
-       struct in6_addr *daddr, *final_p, final;
-       struct dst_entry        *dst;
-       struct flowi6           fl6;
-       struct ip6_flowlabel    *flowlabel = NULL;
-       struct ipv6_txoptions   *opt;
+       struct in6_addr         *daddr;
        int                     addr_type;
        int                     err;
        __be32                  fl6_flowlabel = 0;
@@ -91,14 +140,8 @@ static int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int a
        if (usin->sin6_family != AF_INET6)
                return -EAFNOSUPPORT;
 
-       if (np->sndflow) {
+       if (np->sndflow)
                fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
-               if (fl6_flowlabel & IPV6_FLOWLABEL_MASK) {
-                       flowlabel = fl6_sock_lookup(sk, fl6_flowlabel);
-                       if (!flowlabel)
-                               return -EINVAL;
-               }
-       }
 
        addr_type = ipv6_addr_type(&usin->sin6_addr);
 
@@ -178,45 +221,13 @@ ipv4_connected:
         *      destination cache for it.
         */
 
-       ip6_datagram_flow_key_init(&fl6, sk);
-
-       rcu_read_lock();
-       opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
-       final_p = fl6_update_dst(&fl6, opt, &final);
-       rcu_read_unlock();
-
-       dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
-       err = 0;
-       if (IS_ERR(dst)) {
-               err = PTR_ERR(dst);
+       err = ip6_datagram_dst_update(sk);
+       if (err)
                goto out;
-       }
-
-       /* source address lookup done in ip6_dst_lookup */
-
-       if (ipv6_addr_any(&np->saddr))
-               np->saddr = fl6.saddr;
-
-       if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
-               sk->sk_v6_rcv_saddr = fl6.saddr;
-               inet->inet_rcv_saddr = LOOPBACK4_IPV6;
-               if (sk->sk_prot->rehash)
-                       sk->sk_prot->rehash(sk);
-       }
-
-       ip6_dst_store(sk, dst,
-                     ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
-                     &sk->sk_v6_daddr : NULL,
-#ifdef CONFIG_IPV6_SUBTREES
-                     ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
-                     &np->saddr :
-#endif
-                     NULL);
 
        sk->sk_state = TCP_ESTABLISHED;
        sk_set_txhash(sk);
 out:
-       fl6_sock_release(flowlabel);
        return err;
 }