Merge branch 'timestamping'

Alexander Duyck says:

====================
This change makes it so that the core path for the phy timestamping logic
is shared between skb_tx_tstamp and skb_complete_tx_timestamp.  In addition
it provides a means of using the same skb clone type path in non phy
timestamping drivers.

The main motivation for this is to enable non-phy drivers to be able to
manipulate tx timestamp skbs for such things as putting them in lists or
setting aside buffer in the context block.

v2: Incorporated suggested changes from Willem de Bruijn and Eric Dumazet
     dropped uneeded comment
     restored order of hwtstamp vs swtstamp
     added destructor for skb
    Dropped usage of skb_complete_tx_timestamp as a kfree_skb w/ destructor

v3: Updated destructor handling and dealt with socket reference counting issues

v4: Split out combining destructors into a separate patch
====================

3 files changed, 69 insertions, 63 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 53ce536e3d6e..a936a401564e 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3511,32 +3511,33 @@ struct sk_buff *sock_dequeue_err_skb(struct sock *sk)
 }
 EXPORT_SYMBOL(sock_dequeue_err_skb);
 
-void __skb_tstamp_tx(struct sk_buff *orig_skb,
-		     struct skb_shared_hwtstamps *hwtstamps,
-		     struct sock *sk, int tstype)
+struct sk_buff *skb_clone_sk(struct sk_buff *skb)
 {
-	struct sock_exterr_skb *serr;
-	struct sk_buff *skb;
-	int err;
+	struct sock *sk = skb->sk;
+	struct sk_buff *clone;
 
-	if (!sk)
-		return;
+	if (!sk || !atomic_inc_not_zero(&sk->sk_refcnt))
+		return NULL;
 
-	if (hwtstamps) {
-		*skb_hwtstamps(orig_skb) =
-			*hwtstamps;
-	} else {
-		/*
-		 * no hardware time stamps available,
-		 * so keep the shared tx_flags and only
-		 * store software time stamp
-		 */
-		orig_skb->tstamp = ktime_get_real();
+	clone = skb_clone(skb, GFP_ATOMIC);
+	if (!clone) {
+		sock_put(sk);
+		return NULL;
 	}
 
-	skb = skb_clone(orig_skb, GFP_ATOMIC);
-	if (!skb)
-		return;
+	clone->sk = sk;
+	clone->destructor = sock_efree;
+
+	return clone;
+}
+EXPORT_SYMBOL(skb_clone_sk);
+
+static void __skb_complete_tx_timestamp(struct sk_buff *skb,
+					struct sock *sk,
+					int tstype)
+{
+	struct sock_exterr_skb *serr;
+	int err;
 
 	serr = SKB_EXT_ERR(skb);
 	memset(serr, 0, sizeof(*serr));
@@ -3554,6 +3555,42 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb,
 	if (err)
 		kfree_skb(skb);
 }
+
+void skb_complete_tx_timestamp(struct sk_buff *skb,
+			       struct skb_shared_hwtstamps *hwtstamps)
+{
+	struct sock *sk = skb->sk;
+
+	/* take a reference to prevent skb_orphan() from freeing the socket */
+	sock_hold(sk);
+
+	*skb_hwtstamps(skb) = *hwtstamps;
+	__skb_complete_tx_timestamp(skb, sk, SCM_TSTAMP_SND);
+
+	sock_put(sk);
+}
+EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp);
+
+void __skb_tstamp_tx(struct sk_buff *orig_skb,
+		     struct skb_shared_hwtstamps *hwtstamps,
+		     struct sock *sk, int tstype)
+{
+	struct sk_buff *skb;
+
+	if (!sk)
+		return;
+
+	if (hwtstamps)
+		*skb_hwtstamps(orig_skb) = *hwtstamps;
+	else
+		orig_skb->tstamp = ktime_get_real();
+
+	skb = skb_clone(orig_skb, GFP_ATOMIC);
+	if (!skb)
+		return;
+
+	__skb_complete_tx_timestamp(skb, sk, tstype);
+}
 EXPORT_SYMBOL_GPL(__skb_tstamp_tx);
 
 void skb_tstamp_tx(struct sk_buff *orig_skb,
diff --git a/net/core/sock.c b/net/core/sock.c
index f1a638ee93d9..69592cb66e3b 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1637,18 +1637,24 @@ void sock_rfree(struct sk_buff *skb)
 }
 EXPORT_SYMBOL(sock_rfree);
 
+void sock_efree(struct sk_buff *skb)
+{
+	sock_put(skb->sk);
+}
+EXPORT_SYMBOL(sock_efree);
+
+#ifdef CONFIG_INET
 void sock_edemux(struct sk_buff *skb)
 {
 	struct sock *sk = skb->sk;
 
-#ifdef CONFIG_INET
 	if (sk->sk_state == TCP_TIME_WAIT)
 		inet_twsk_put(inet_twsk(sk));
 	else
-#endif
 		sock_put(sk);
 }
 EXPORT_SYMBOL(sock_edemux);
+#endif
 
 kuid_t sock_i_uid(struct sock *sk)
 {
diff --git a/net/core/timestamping.c b/net/core/timestamping.c
index a8770391ea5b..43d3dd62fcc8 100644
--- a/net/core/timestamping.c
+++ b/net/core/timestamping.c
@@ -36,10 +36,9 @@ void skb_clone_tx_timestamp(struct sk_buff *skb)
 {
 	struct phy_device *phydev;
 	struct sk_buff *clone;
-	struct sock *sk = skb->sk;
 	unsigned int type;
 
-	if (!sk)
+	if (!skb->sk)
 		return;
 
 	type = classify(skb);
@@ -48,50 +47,14 @@ void skb_clone_tx_timestamp(struct sk_buff *skb)
 
 	phydev = skb->dev->phydev;
 	if (likely(phydev->drv->txtstamp)) {
-		if (!atomic_inc_not_zero(&sk->sk_refcnt))
+		clone = skb_clone_sk(skb);
+		if (!clone)
 			return;
-
-		clone = skb_clone(skb, GFP_ATOMIC);
-		if (!clone) {
-			sock_put(sk);
-			return;
-		}
-
-		clone->sk = sk;
 		phydev->drv->txtstamp(phydev, clone, type);
 	}
 }
 EXPORT_SYMBOL_GPL(skb_clone_tx_timestamp);
 
-void skb_complete_tx_timestamp(struct sk_buff *skb,
-			       struct skb_shared_hwtstamps *hwtstamps)
-{
-	struct sock *sk = skb->sk;
-	struct sock_exterr_skb *serr;
-	int err;
-
-	if (!hwtstamps) {
-		sock_put(sk);
-		kfree_skb(skb);
-		return;
-	}
-
-	*skb_hwtstamps(skb) = *hwtstamps;
-
-	serr = SKB_EXT_ERR(skb);
-	memset(serr, 0, sizeof(*serr));
-	serr->ee.ee_errno = ENOMSG;
-	serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
-	skb->sk = NULL;
-
-	err = sock_queue_err_skb(sk, skb);
-
-	sock_put(sk);
-	if (err)
-		kfree_skb(skb);
-}
-EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp);
-
 bool skb_defer_rx_timestamp(struct sk_buff *skb)
 {
 	struct phy_device *phydev;