net-timestamp: Make the clone operation stand-alone from phy timestamping
The phy timestamping takes a different path than the regular timestamping
does in that it will create a clone first so that the packets needing to be
timestamped can be placed in a queue, or the context block could be used.
In order to support these use cases I am pulling the core of the code out
so it can be used in other drivers beyond just phy devices.
In addition I have added a destructor named sock_efree which is meant to
provide a simple way for dropping the reference to skb exceptions that
aren't part of either the receive or send windows for the socket, and I
have removed some duplication in spots where this destructor could be used
in place of sock_edemux.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 697e696..a936a40 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3511,6 +3511,27 @@
}
EXPORT_SYMBOL(sock_dequeue_err_skb);
+struct sk_buff *skb_clone_sk(struct sk_buff *skb)
+{
+ struct sock *sk = skb->sk;
+ struct sk_buff *clone;
+
+ if (!sk || !atomic_inc_not_zero(&sk->sk_refcnt))
+ return NULL;
+
+ clone = skb_clone(skb, GFP_ATOMIC);
+ if (!clone) {
+ sock_put(sk);
+ return NULL;
+ }
+
+ 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)
@@ -3540,14 +3561,11 @@
{
struct sock *sk = skb->sk;
- skb->sk = NULL;
+ /* take a reference to prevent skb_orphan() from freeing the socket */
+ sock_hold(sk);
- if (hwtstamps) {
- *skb_hwtstamps(skb) = *hwtstamps;
- __skb_complete_tx_timestamp(skb, sk, SCM_TSTAMP_SND);
- } else {
- kfree_skb(skb);
- }
+ *skb_hwtstamps(skb) = *hwtstamps;
+ __skb_complete_tx_timestamp(skb, sk, SCM_TSTAMP_SND);
sock_put(sk);
}
diff --git a/net/core/sock.c b/net/core/sock.c
index f1a638e..d04005c 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1637,6 +1637,12 @@
}
EXPORT_SYMBOL(sock_rfree);
+void sock_efree(struct sk_buff *skb)
+{
+ sock_put(skb->sk);
+}
+EXPORT_SYMBOL(sock_efree);
+
void sock_edemux(struct sk_buff *skb)
{
struct sock *sk = skb->sk;
diff --git a/net/core/timestamping.c b/net/core/timestamping.c
index f48a59f..43d3dd6 100644
--- a/net/core/timestamping.c
+++ b/net/core/timestamping.c
@@ -36,10 +36,9 @@
{
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);
@@ -48,16 +47,9 @@
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);
}
}