4 files changed, 42 insertions, 41 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
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 2422a5f7195d..012c4621e40a 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -846,20 +846,7 @@ out:
 csum_copy_err:
 	UDP_INC_STATS_BH(UDP_MIB_INERRORS);
 
-	/* Clear queue. */
-	if (flags&MSG_PEEK) {
-		int clear = 0;
-		spin_lock_bh(&sk->sk_receive_queue.lock);
-		if (skb == skb_peek(&sk->sk_receive_queue)) {
-			__skb_unlink(skb, &sk->sk_receive_queue);
-			clear = 1;
-		}
-		spin_unlock_bh(&sk->sk_receive_queue.lock);
-		if (clear)
-			kfree_skb(skb);
-	}
-
-	skb_free_datagram(sk, skb);
+	skb_kill_datagram(sk, skb, flags);
 
 	if (noblock)
 		return -EAGAIN;	
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index a66900cda2af..66f1d12ea578 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -32,6 +32,7 @@
 #include <linux/icmpv6.h>
 #include <linux/netfilter.h>
 #include <linux/netfilter_ipv6.h>
+#include <linux/skbuff.h>
 #include <asm/uaccess.h>
 #include <asm/ioctls.h>
 #include <asm/bug.h>
@@ -433,25 +434,14 @@ out:
 	return err;
 
 csum_copy_err:
-	/* Clear queue. */
-	if (flags&MSG_PEEK) {
-		int clear = 0;
-		spin_lock_bh(&sk->sk_receive_queue.lock);
-		if (skb == skb_peek(&sk->sk_receive_queue)) {
-			__skb_unlink(skb, &sk->sk_receive_queue);
-			clear = 1;
-		}
-		spin_unlock_bh(&sk->sk_receive_queue.lock);
-		if (clear)
-			kfree_skb(skb);
-	}
+	skb_kill_datagram(sk, skb, flags);
 
 	/* Error for blocking case is chosen to masquerade
 	   as some normal condition.
 	 */
 	err = (flags&MSG_DONTWAIT) ? -EAGAIN : -EHOSTUNREACH;
 	/* FIXME: increment a raw6 drops counter here */
-	goto out_free;
+	goto out;
 }
 
 static int rawv6_push_pending_frames(struct sock *sk, struct flowi *fl,
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 5cc8731eb55b..d8538dcea813 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -36,6 +36,7 @@
 #include <linux/ipv6.h>
 #include <linux/icmpv6.h>
 #include <linux/init.h>
+#include <linux/skbuff.h>
 #include <asm/uaccess.h>
 
 #include <net/sock.h>
@@ -300,20 +301,7 @@ out:
 	return err;
 
 csum_copy_err:
-	/* Clear queue. */
-	if (flags&MSG_PEEK) {
-		int clear = 0;
-		spin_lock_bh(&sk->sk_receive_queue.lock);
-		if (skb == skb_peek(&sk->sk_receive_queue)) {
-			__skb_unlink(skb, &sk->sk_receive_queue);
-			clear = 1;
-		}
-		spin_unlock_bh(&sk->sk_receive_queue.lock);
-		if (clear)
-			kfree_skb(skb);
-	}
-
-	skb_free_datagram(sk, skb);
+	skb_kill_datagram(sk, skb, flags);
 
 	if (flags & MSG_DONTWAIT) {
 		UDP6_INC_STATS_USER(UDP_MIB_INERRORS);