[SRU,Xenial,1/7] sock: add sk_dst_pending_confirm flag

Message ID 20170908070142.4440-2-daniel.axtens@canonical.com
State New
Headers show
Series
  • Fixes for LP#1715812
Related show

Commit Message

Daniel Axtens Sept. 8, 2017, 7:01 a.m.
From: Julian Anastasov <ja@ssi.bg>

BugLink: https://bugs.launchpad.net/bugs/1715812

Add new sock flag to allow sockets to confirm neighbour.
When same struct dst_entry can be used for many different
neighbours we can not use it for pending confirmations.
As not all call paths lock the socket use full word for
the flag.

Add sk_dst_confirm as replacement for dst_confirm when
called for received packets.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(backported from commit 9b8805a325591cf5b6b9df71200de25a2bd721fd)
Signed-off-by: Daniel Axtens <daniel.axtens@canonical.com>
---
 include/net/sock.h | 11 +++++++++++
 net/core/sock.c    |  2 ++
 2 files changed, 13 insertions(+)

Patch

diff --git a/include/net/sock.h b/include/net/sock.h
index 3d5ff7436f41..08d2bb9e66ee 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -254,6 +254,7 @@  struct cg_proto;
   *	@sk_wq: sock wait queue and async head
   *	@sk_rx_dst: receive input route used by early demux
   *	@sk_dst_cache: destination cache
+  *	@sk_dst_pending_confirm: need to confirm neighbour
   *	@sk_policy: flow policy
   *	@sk_receive_queue: incoming packets
   *	@sk_wmem_alloc: transmit queue bytes committed
@@ -397,6 +398,7 @@  struct sock {
 	atomic_t		sk_omem_alloc;
 	int			sk_sndbuf;
 	struct sk_buff_head	sk_write_queue;
+	__u32			sk_dst_pending_confirm;
 	kmemcheck_bitfield_begin(flags);
 	unsigned int		sk_shutdown  : 2,
 				sk_no_check_tx : 1,
@@ -1748,6 +1750,7 @@  static inline void dst_negative_advice(struct sock *sk)
 		if (ndst != dst) {
 			rcu_assign_pointer(sk->sk_dst_cache, ndst);
 			sk_tx_queue_clear(sk);
+			sk->sk_dst_pending_confirm = 0;
 		}
 	}
 }
@@ -1758,6 +1761,7 @@  __sk_dst_set(struct sock *sk, struct dst_entry *dst)
 	struct dst_entry *old_dst;
 
 	sk_tx_queue_clear(sk);
+	sk->sk_dst_pending_confirm = 0;
 	/*
 	 * This can be called while sk is owned by the caller only,
 	 * with no state that can be checked in a rcu_dereference_check() cond
@@ -1773,6 +1777,7 @@  sk_dst_set(struct sock *sk, struct dst_entry *dst)
 	struct dst_entry *old_dst;
 
 	sk_tx_queue_clear(sk);
+	sk->sk_dst_pending_confirm = 0;
 	old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
 	dst_release(old_dst);
 }
@@ -1793,6 +1798,12 @@  struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
 
 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
 
+static inline void sk_dst_confirm(struct sock *sk)
+{
+	if (!sk->sk_dst_pending_confirm)
+		sk->sk_dst_pending_confirm = 1;
+}
+
 bool sk_mc_loop(struct sock *sk);
 
 static inline bool sk_can_gso(const struct sock *sk)
diff --git a/net/core/sock.c b/net/core/sock.c
index bd2fad27891e..6c890806868d 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -532,6 +532,7 @@  struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
 
 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
 		sk_tx_queue_clear(sk);
+		sk->sk_dst_pending_confirm = 0;
 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
 		dst_release(dst);
 		return NULL;
@@ -1540,6 +1541,7 @@  struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
 				af_family_clock_key_strings[newsk->sk_family]);
 
 		newsk->sk_dst_cache	= NULL;
+		newsk->sk_dst_pending_confirm = 0;
 		newsk->sk_wmem_queued	= 0;
 		newsk->sk_forward_alloc = 0;
 		newsk->sk_send_head	= NULL;