From 65101aeca52241a05e66f23c96eb896c9412718d Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Tue, 16 May 2017 11:20:13 +0200 Subject: [PATCH] net/sock: factor out dequeue/peek with offset code And update __sk_queue_drop_skb() to work on the specified queue. This will help the udp protocol to use an additional private rx queue in a later patch. Signed-off-by: Paolo Abeni Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- include/linux/skbuff.h | 7 ++++ include/net/sock.h | 4 +-- net/core/datagram.c | 90 ++++++++++++++++++++++++++++---------------------- 3 files changed, 60 insertions(+), 41 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index a098d95..bfc7892 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -3056,6 +3056,13 @@ static inline void skb_frag_list_init(struct sk_buff *skb) int __skb_wait_for_more_packets(struct sock *sk, int *err, long *timeo_p, const struct sk_buff *skb); +struct sk_buff *__skb_try_recv_from_queue(struct sock *sk, + struct sk_buff_head *queue, + unsigned int flags, + void (*destructor)(struct sock *sk, + struct sk_buff *skb), + int *peeked, int *off, int *err, + struct sk_buff **last); struct sk_buff *__skb_try_recv_datagram(struct sock *sk, unsigned flags, void (*destructor)(struct sock *sk, struct sk_buff *skb), diff --git a/include/net/sock.h b/include/net/sock.h index f33e3d1..42264035 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2035,8 +2035,8 @@ void sk_reset_timer(struct sock *sk, struct timer_list *timer, void sk_stop_timer(struct sock *sk, struct timer_list *timer); -int __sk_queue_drop_skb(struct sock *sk, struct sk_buff *skb, - unsigned int flags, +int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue, + struct sk_buff *skb, unsigned int flags, void (*destructor)(struct sock *sk, struct sk_buff *skb)); int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); diff --git a/net/core/datagram.c b/net/core/datagram.c index db1866f2..a4592b4 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -161,6 +161,43 @@ done: return skb; } +struct sk_buff *__skb_try_recv_from_queue(struct sock *sk, + struct sk_buff_head *queue, + unsigned int flags, + void (*destructor)(struct sock *sk, + struct sk_buff *skb), + int *peeked, int *off, int *err, + struct sk_buff **last) +{ + struct sk_buff *skb; + + *last = queue->prev; + skb_queue_walk(queue, skb) { + if (flags & MSG_PEEK) { + if (*off >= skb->len && (skb->len || *off || + skb->peeked)) { + *off -= skb->len; + continue; + } + if (!skb->len) { + skb = skb_set_peeked(skb); + if (unlikely(IS_ERR(skb))) { + *err = PTR_ERR(skb); + return skb; + } + } + *peeked = 1; + atomic_inc(&skb->users); + } else { + __skb_unlink(skb, queue); + if (destructor) + destructor(sk, skb); + } + return skb; + } + return NULL; +} + /** * __skb_try_recv_datagram - Receive a datagram skbuff * @sk: socket @@ -216,46 +253,20 @@ struct sk_buff *__skb_try_recv_datagram(struct sock *sk, unsigned int flags, *peeked = 0; do { + int _off = *off; + /* Again only user level code calls this function, so nothing * interrupt level will suddenly eat the receive_queue. * * Look at current nfs client by the way... * However, this function was correct in any case. 8) */ - int _off = *off; - - *last = (struct sk_buff *)queue; spin_lock_irqsave(&queue->lock, cpu_flags); - skb_queue_walk(queue, skb) { - *last = skb; - if (flags & MSG_PEEK) { - if (_off >= skb->len && (skb->len || _off || - skb->peeked)) { - _off -= skb->len; - continue; - } - if (!skb->len) { - skb = skb_set_peeked(skb); - if (IS_ERR(skb)) { - error = PTR_ERR(skb); - spin_unlock_irqrestore(&queue->lock, - cpu_flags); - goto no_packet; - } - } - *peeked = 1; - atomic_inc(&skb->users); - } else { - __skb_unlink(skb, queue); - if (destructor) - destructor(sk, skb); - } - spin_unlock_irqrestore(&queue->lock, cpu_flags); - *off = _off; - return skb; - } - + skb = __skb_try_recv_from_queue(sk, queue, flags, destructor, + peeked, &_off, err, last); spin_unlock_irqrestore(&queue->lock, cpu_flags); + if (skb) + return skb; if (!sk_can_busy_loop(sk)) break; @@ -335,8 +346,8 @@ void __skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb, int len) } EXPORT_SYMBOL(__skb_free_datagram_locked); -int __sk_queue_drop_skb(struct sock *sk, struct sk_buff *skb, - unsigned int flags, +int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue, + struct sk_buff *skb, unsigned int flags, void (*destructor)(struct sock *sk, struct sk_buff *skb)) { @@ -344,15 +355,15 @@ int __sk_queue_drop_skb(struct sock *sk, struct sk_buff *skb, if (flags & MSG_PEEK) { err = -ENOENT; - spin_lock_bh(&sk->sk_receive_queue.lock); - if (skb == skb_peek(&sk->sk_receive_queue)) { - __skb_unlink(skb, &sk->sk_receive_queue); + spin_lock_bh(&sk_queue->lock); + if (skb == skb_peek(sk_queue)) { + __skb_unlink(skb, sk_queue); atomic_dec(&skb->users); if (destructor) destructor(sk, skb); err = 0; } - spin_unlock_bh(&sk->sk_receive_queue.lock); + spin_unlock_bh(&sk_queue->lock); } atomic_inc(&sk->sk_drops); @@ -383,7 +394,8 @@ EXPORT_SYMBOL(__sk_queue_drop_skb); int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags) { - int err = __sk_queue_drop_skb(sk, skb, flags, NULL); + int err = __sk_queue_drop_skb(sk, &sk->sk_receive_queue, skb, flags, + NULL); kfree_skb(skb); sk_mem_reclaim_partial(sk); -- 2.7.4