@@ -960,6 +960,7 @@ int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *addr,
int addr_len);
int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr);
+void ip6_datagram_release_cb(struct sock *sk);
int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
int *addr_len);
@@ -119,6 +119,26 @@ out:
return err;
}
+void ip6_datagram_release_cb(struct sock *sk)
+{
+ struct dst_entry *dst;
+
+ if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
+ return;
+
+ rcu_read_lock();
+ dst = __sk_dst_get(sk);
+ if (!dst || !dst->obsolete ||
+ dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
+ rcu_read_unlock();
+ return;
+ }
+ rcu_read_unlock();
+
+ ip6_datagram_dst_update(sk, false);
+}
+EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
+
static int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
@@ -1539,6 +1539,7 @@ struct proto udpv6_prot = {
.sendmsg = udpv6_sendmsg,
.recvmsg = udpv6_recvmsg,
.backlog_rcv = __udpv6_queue_rcv_skb,
+ .release_cb = ip6_datagram_release_cb,
.hash = udp_lib_hash,
.unhash = udp_lib_unhash,
.rehash = udp_v6_rehash,
This patch adds a release_cb for UDPv6. It does a route lookup and updates sk->sk_dst_cache if it is needed. It picks up the left-over job from ip6_sk_update_pmtu() if the sk was owned by user during the pmtu update. It takes a rcu_read_lock to protect the __sk_dst_get() operations because another thread may do ip6_dst_store() without taking the sk lock (e.g. sendmsg). Fixes: 45e4fd26683c ("ipv6: Only create RTF_CACHE routes after encountering pmtu exception") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Reported-by: Wei Wang <weiwan@google.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Wei Wang <weiwan@google.com> --- include/net/ipv6.h | 1 + net/ipv6/datagram.c | 20 ++++++++++++++++++++ net/ipv6/udp.c | 1 + 3 files changed, 22 insertions(+)