Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6

[linux-2.6-omap-h63xx.git] / net / core / datagram.c

diff --git a/net/core/datagram.c b/net/core/datagram.c
index 1bcfef51ac581562988c54fe9cee885572f819d6..f8d322e1ea9276c3f581fbda2393c829b6fd17f0 100644 (file)
--- 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>
@@ -199,6 +200,41 @@ void skb_free_datagram(struct sock *sk, struct sk_buff *skb)
        kfree_skb(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