[IPV6]: Check connect(2) status for IPv6 UDP socket (Re: xfrm_lookup)

I think we should cache the per-socket route(dst_entry) only when the
IPv6 UDP socket is connect(2)'ed.
(which is same as IPv4 UDP send behavior)

Signed-off-by: Mitsuru KANDA <mk@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 2 deletions

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 2b9bf9bd177f..6001948600f3 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -639,6 +639,7 @@ static int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk,
         int tclass = -1;
         int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
         int err;
+        int connected = 0;
 
         /* destination address check */
         if (sin6) {
@@ -748,6 +749,7 @@ do_udp_sendmsg:
                 fl->fl_ip_dport = inet->dport;
                 daddr = &np->daddr;
                 fl->fl6_flowlabel = np->flow_label;
+                connected = 1;
         }
 
         if (!fl->oif)
@@ -770,6 +772,7 @@ do_udp_sendmsg:
                 }
                 if (!(opt->opt_nflen|opt->opt_flen))
                         opt = NULL;
+                connected = 0;
         }
         if (opt == NULL)
                 opt = np->opt;
@@ -787,10 +790,13 @@ do_udp_sendmsg:
                 ipv6_addr_copy(&final, &fl->fl6_dst);
                 ipv6_addr_copy(&fl->fl6_dst, rt0->addr);
                 final_p = &final;
+                connected = 0;
         }
 
-        if (!fl->oif && ipv6_addr_is_multicast(&fl->fl6_dst))
+        if (!fl->oif && ipv6_addr_is_multicast(&fl->fl6_dst)) {
                 fl->oif = np->mcast_oif;
+                connected = 0;
+        }
 
         err = ip6_dst_lookup(sk, &dst, fl);
         if (err)
@@ -846,7 +852,7 @@ do_append_data:
         else if (!corkreq)
                 err = udp_v6_push_pending_frames(sk, up);
 
-        if (dst)
+        if (dst && connected)
                 ip6_dst_store(sk, dst,
                               ipv6_addr_equal(&fl->fl6_dst, &np->daddr) ?
                               &np->daddr : NULL);