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Commit 65101aec authored by Paolo Abeni's avatar Paolo Abeni Committed by David S. Miller
Browse files

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: default avatarPaolo Abeni <pabeni@redhat.com>
Acked-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9dca599b

include/linux/skbuff.h

+7 −0
Original line number Diff line number Diff line
@@ -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),

include/net/sock.h

+2 −2
Original line number Diff line number Diff line
@@ -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);

net/core/datagram.c

+51 −39
Original line number Diff line number Diff line
@@ -161,6 +161,43 @@ static struct sk_buff *skb_set_peeked(struct sk_buff *skb) 
	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);

			}

		skb = __skb_try_recv_from_queue(sk, queue, flags, destructor,

						peeked, &_off, err, last);

		spin_unlock_irqrestore(&queue->lock, cpu_flags);

			*off = _off;

		if (skb)

			return skb;

		}



		spin_unlock_irqrestore(&queue->lock, cpu_flags);



		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);