From 62bccb8cdb69051b95a55ab0c489e3cab261c8ef Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Thu, 4 Sep 2014 13:31:35 -0400 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- drivers/net/phy/dp83640.c | 6 +++--- include/linux/skbuff.h | 2 ++ include/net/sock.h | 1 + net/core/skbuff.c | 32 +++++++++++++++++++++++++------- net/core/sock.c | 6 ++++++ net/core/timestamping.c | 14 +++----------- 6 files changed, 40 insertions(+), 21 deletions(-) diff --git a/drivers/net/phy/dp83640.c b/drivers/net/phy/dp83640.c index d5991ac46ab0..87648b306551 100644 --- a/drivers/net/phy/dp83640.c +++ b/drivers/net/phy/dp83640.c @@ -1148,7 +1148,7 @@ static void dp83640_remove(struct phy_device *phydev) kfree_skb(skb); while ((skb = skb_dequeue(&dp83640->tx_queue)) != NULL) - skb_complete_tx_timestamp(skb, NULL); + kfree_skb(skb); clock = dp83640_clock_get(dp83640->clock); @@ -1405,7 +1405,7 @@ static void dp83640_txtstamp(struct phy_device *phydev, case HWTSTAMP_TX_ONESTEP_SYNC: if (is_sync(skb, type)) { - skb_complete_tx_timestamp(skb, NULL); + kfree_skb(skb); return; } /* fall through */ @@ -1416,7 +1416,7 @@ static void dp83640_txtstamp(struct phy_device *phydev, case HWTSTAMP_TX_OFF: default: - skb_complete_tx_timestamp(skb, NULL); + kfree_skb(skb); break; } } diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 02529fcad1ac..1cf0cfaef10a 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2690,6 +2690,8 @@ static inline ktime_t net_invalid_timestamp(void) return ktime_set(0, 0); } +struct sk_buff *skb_clone_sk(struct sk_buff *skb); + #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING void skb_clone_tx_timestamp(struct sk_buff *skb); diff --git a/include/net/sock.h b/include/net/sock.h index 3fde6130789d..e02be37a3d91 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1574,6 +1574,7 @@ struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force, void sock_wfree(struct sk_buff *skb); void skb_orphan_partial(struct sk_buff *skb); void sock_rfree(struct sk_buff *skb); +void sock_efree(struct sk_buff *skb); void sock_edemux(struct sk_buff *skb); int sock_setsockopt(struct socket *sock, int level, int op, diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 697e696c914b..a936a401564e 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3511,6 +3511,27 @@ struct sk_buff *sock_dequeue_err_skb(struct sock *sk) } 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 @@ void skb_complete_tx_timestamp(struct sk_buff *skb, { 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 f1a638ee93d9..d04005c51724 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1637,6 +1637,12 @@ 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); + 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 f48a59fd8f39..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); @@ -48,16 +47,9 @@ 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); } } -- 2.30.2