From e646b657f6983017783914a951039e323120dc55 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Mon, 11 Apr 2016 15:29:37 -0700 Subject: [PATCH] ipv6: udp: Do a route lookup and update during release_cb 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 Reported-by: Wei Wang Cc: Cong Wang Cc: Eric Dumazet Cc: Wei Wang Signed-off-by: David S. Miller --- include/net/ipv6.h | 1 + net/ipv6/datagram.c | 20 ++++++++++++++++++++ net/ipv6/udp.c | 1 + 3 files changed, 22 insertions(+) diff --git a/include/net/ipv6.h b/include/net/ipv6.h index fd02e90b1289..1be050ada8c5 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -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); diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c index 59e01f27db9f..9dd3882fe6bf 100644 --- a/net/ipv6/datagram.c +++ b/net/ipv6/datagram.c @@ -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; diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 8125931106be..6bc5c664fa46 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -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,