Commit b26bbdae authored by Paolo Abeni's avatar Paolo Abeni Committed by David S. Miller
Browse files

udp: move scratch area helpers into the include file 



So that they can be later used by the IPv6 code, too.
Also lift the comments a bit.

Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d97af30f

include/net/udp.h

+61 −0
Original line number Diff line number Diff line
@@ -302,6 +302,67 @@ struct sock *__udp6_lib_lookup(struct net *net, 
struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,

				 __be16 sport, __be16 dport);



/* UDP uses skb->dev_scratch to cache as much information as possible and avoid

 * possibly multiple cache miss on dequeue()

 */

#if BITS_PER_LONG == 64



/* truesize, len and the bit needed to compute skb_csum_unnecessary will be on

 * cold cache lines at recvmsg time.

 * skb->len can be stored on 16 bits since the udp header has been already

 * validated and pulled.

 */

struct udp_dev_scratch {

	u32 truesize;

	u16 len;

	bool is_linear;

	bool csum_unnecessary;

};



static inline unsigned int udp_skb_len(struct sk_buff *skb)

{

	return ((struct udp_dev_scratch *)&skb->dev_scratch)->len;

}



static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb)

{

	return ((struct udp_dev_scratch *)&skb->dev_scratch)->csum_unnecessary;

}



static inline bool udp_skb_is_linear(struct sk_buff *skb)

{

	return ((struct udp_dev_scratch *)&skb->dev_scratch)->is_linear;

}



#else

static inline unsigned int udp_skb_len(struct sk_buff *skb)

{

	return skb->len;

}



static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb)

{

	return skb_csum_unnecessary(skb);

}



static inline bool udp_skb_is_linear(struct sk_buff *skb)

{

	return !skb_is_nonlinear(skb);

}

#endif



static inline int copy_linear_skb(struct sk_buff *skb, int len, int off,

				  struct iov_iter *to)

{

	int n, copy = len - off;



	n = copy_to_iter(skb->data + off, copy, to);

	if (n == copy)

		return 0;



	return -EFAULT;

}



/*

 * 	SNMP statistics for UDP and UDP-Lite

 */

net/ipv4/udp.c

+0 −60
Original line number Diff line number Diff line
@@ -1163,24 +1163,7 @@ int udp_sendpage(struct sock *sk, struct page *page, int offset, 
	return ret;

}



/* Copy as much information as possible into skb->dev_scratch to avoid

 * possibly multiple cache miss on dequeue();

 */

#if BITS_PER_LONG == 64



/* we can store multiple info here: truesize, len and the bit needed to

 * compute skb_csum_unnecessary will be on cold cache lines at recvmsg

 * time.

 * skb->len can be stored on 16 bits since the udp header has been already

 * validated and pulled.

 */

struct udp_dev_scratch {

	u32 truesize;

	u16 len;

	bool is_linear;

	bool csum_unnecessary;

};



static void udp_set_dev_scratch(struct sk_buff *skb)

{

	struct udp_dev_scratch *scratch;
@@ -1197,22 +1180,6 @@ static int udp_skb_truesize(struct sk_buff *skb) 
{

	return ((struct udp_dev_scratch *)&skb->dev_scratch)->truesize;

}



static unsigned int udp_skb_len(struct sk_buff *skb)

{

	return ((struct udp_dev_scratch *)&skb->dev_scratch)->len;

}



static bool udp_skb_csum_unnecessary(struct sk_buff *skb)

{

	return ((struct udp_dev_scratch *)&skb->dev_scratch)->csum_unnecessary;

}



static bool udp_skb_is_linear(struct sk_buff *skb)

{

	return ((struct udp_dev_scratch *)&skb->dev_scratch)->is_linear;

}



#else

static void udp_set_dev_scratch(struct sk_buff *skb)

{
@@ -1223,21 +1190,6 @@ static int udp_skb_truesize(struct sk_buff *skb) 
{

	return skb->dev_scratch;

}



static unsigned int udp_skb_len(struct sk_buff *skb)

{

	return skb->len;

}



static bool udp_skb_csum_unnecessary(struct sk_buff *skb)

{

	return skb_csum_unnecessary(skb);

}



static bool udp_skb_is_linear(struct sk_buff *skb)

{

	return !skb_is_nonlinear(skb);

}

#endif



/* fully reclaim rmem/fwd memory allocated for skb */
@@ -1598,18 +1550,6 @@ struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags, 
}

EXPORT_SYMBOL_GPL(__skb_recv_udp);



static int copy_linear_skb(struct sk_buff *skb, int len, int off,

			   struct iov_iter *to)

{

	int n, copy = len - off;



	n = copy_to_iter(skb->data + off, copy, to);

	if (n == copy)

		return 0;



	return -EFAULT;

}



/*

 * 	This should be easy, if there is something there we

 * 	return it, otherwise we block.