diff options
Diffstat (limited to 'net/core/datagram.c')
-rw-r--r-- | net/core/datagram.c | 45 |
1 files changed, 41 insertions, 4 deletions
diff --git a/net/core/datagram.c b/net/core/datagram.c index b71423db7785..052b71c5b1b4 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -128,6 +128,35 @@ out_noerr: goto out; } +static struct sk_buff *skb_set_peeked(struct sk_buff *skb) +{ + struct sk_buff *nskb; + + if (skb->peeked) + return skb; + + /* We have to unshare an skb before modifying it. */ + if (!skb_shared(skb)) + goto done; + + nskb = skb_clone(skb, GFP_ATOMIC); + if (!nskb) + return ERR_PTR(-ENOMEM); + + skb->prev->next = nskb; + skb->next->prev = nskb; + nskb->prev = skb->prev; + nskb->next = skb->next; + + consume_skb(skb); + skb = nskb; + +done: + skb->peeked = 1; + + return skb; +} + /** * __skb_recv_datagram - Receive a datagram skbuff * @sk: socket @@ -162,7 +191,9 @@ out_noerr: struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned int flags, int *peeked, int *off, int *err) { + struct sk_buff_head *queue = &sk->sk_receive_queue; struct sk_buff *skb, *last; + unsigned long cpu_flags; long timeo; /* * Caller is allowed not to check sk->sk_err before skb_recv_datagram() @@ -181,8 +212,6 @@ struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned int flags, * Look at current nfs client by the way... * However, this function was correct in any case. 8) */ - unsigned long cpu_flags; - struct sk_buff_head *queue = &sk->sk_receive_queue; int _off = *off; last = (struct sk_buff *)queue; @@ -196,7 +225,12 @@ struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned int flags, _off -= skb->len; continue; } - skb->peeked = 1; + + skb = skb_set_peeked(skb); + error = PTR_ERR(skb); + if (IS_ERR(skb)) + goto unlock_err; + atomic_inc(&skb->users); } else __skb_unlink(skb, queue); @@ -216,6 +250,8 @@ struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned int flags, return NULL; +unlock_err: + spin_unlock_irqrestore(&queue->lock, cpu_flags); no_packet: *err = error; return NULL; @@ -665,7 +701,8 @@ __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len) if (likely(!sum)) { if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE)) netdev_rx_csum_fault(skb->dev); - skb->ip_summed = CHECKSUM_UNNECESSARY; + if (!skb_shared(skb)) + skb->ip_summed = CHECKSUM_UNNECESSARY; } return sum; } |