diff options
Diffstat (limited to 'net/core/datagram.c')
-rw-r--r-- | net/core/datagram.c | 54 |
1 files changed, 37 insertions, 17 deletions
diff --git a/net/core/datagram.c b/net/core/datagram.c index 029b93e..8a28fc9 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -115,10 +115,10 @@ out_noerr: } /** - * skb_recv_datagram - Receive a datagram skbuff + * __skb_recv_datagram - Receive a datagram skbuff * @sk: socket * @flags: MSG_ flags - * @noblock: blocking operation? + * @peeked: returns non-zero if this packet has been seen before * @err: error code returned * * Get a datagram skbuff, understands the peeking, nonblocking wakeups @@ -143,8 +143,8 @@ out_noerr: * quite explicitly by POSIX 1003.1g, don't change them without having * the standard around please. */ -struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, - int noblock, int *err) +struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags, + int *peeked, int *err) { struct sk_buff *skb; long timeo; @@ -156,7 +156,7 @@ struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, if (error) goto no_packet; - timeo = sock_rcvtimeo(sk, noblock); + timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); do { /* Again only user level code calls this function, so nothing @@ -165,18 +165,19 @@ struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, * Look at current nfs client by the way... * However, this function was corrent in any case. 8) */ - if (flags & MSG_PEEK) { - unsigned long cpu_flags; - - spin_lock_irqsave(&sk->sk_receive_queue.lock, - cpu_flags); - skb = skb_peek(&sk->sk_receive_queue); - if (skb) + unsigned long cpu_flags; + + spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags); + skb = skb_peek(&sk->sk_receive_queue); + if (skb) { + *peeked = skb->peeked; + if (flags & MSG_PEEK) { + skb->peeked = 1; atomic_inc(&skb->users); - spin_unlock_irqrestore(&sk->sk_receive_queue.lock, - cpu_flags); - } else - skb = skb_dequeue(&sk->sk_receive_queue); + } else + __skb_unlink(skb, &sk->sk_receive_queue); + } + spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags); if (skb) return skb; @@ -194,10 +195,21 @@ no_packet: *err = error; return NULL; } +EXPORT_SYMBOL(__skb_recv_datagram); + +struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, + int noblock, int *err) +{ + int peeked; + + return __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), + &peeked, err); +} void skb_free_datagram(struct sock *sk, struct sk_buff *skb) { kfree_skb(skb); + sk_mem_reclaim(sk); } /** @@ -217,20 +229,28 @@ void skb_free_datagram(struct sock *sk, struct sk_buff *skb) * This function currently only disables BH when acquiring the * sk_receive_queue lock. Therefore it must not be used in a * context where that lock is acquired in an IRQ context. + * + * It returns 0 if the packet was removed by us. */ -void skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags) +int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags) { + int err = 0; + 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); atomic_dec(&skb->users); + err = 0; } spin_unlock_bh(&sk->sk_receive_queue.lock); } kfree_skb(skb); + sk_mem_reclaim(sk); + return err; } EXPORT_SYMBOL(skb_kill_datagram); |