diff options
Diffstat (limited to 'net/core/datagram.c')
| -rw-r--r-- | net/core/datagram.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/net/core/datagram.c b/net/core/datagram.c index 1bcfef51ac58..f8d322e1ea92 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -47,6 +47,7 @@ #include <linux/rtnetlink.h> #include <linux/poll.h> #include <linux/highmem.h> +#include <linux/spinlock.h> #include <net/protocol.h> #include <linux/skbuff.h> @@ -200,6 +201,41 @@ void skb_free_datagram(struct sock *sk, struct sk_buff *skb) } /** + * skb_kill_datagram - Free a datagram skbuff forcibly + * @sk: socket + * @skb: datagram skbuff + * @flags: MSG_ flags + * + * This function frees a datagram skbuff that was received by + * skb_recv_datagram. The flags argument must match the one + * used for skb_recv_datagram. + * + * If the MSG_PEEK flag is set, and the packet is still on the + * receive queue of the socket, it will be taken off the queue + * before it is freed. + * + * 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. + */ + +void skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags) +{ + if (flags & MSG_PEEK) { + 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); + } + spin_unlock_bh(&sk->sk_receive_queue.lock); + } + + kfree_skb(skb); +} + +EXPORT_SYMBOL(skb_kill_datagram); + +/** * skb_copy_datagram_iovec - Copy a datagram to an iovec. * @skb: buffer to copy * @offset: offset in the buffer to start copying from |