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Commit a60e3cc7 authored by Hannes Frederic Sowa's avatar Hannes Frederic Sowa Committed by David S. Miller
Browse files

net: make skb_splice_bits more configureable 



Prepare skb_splice_bits to be able to deal with AF_UNIX sockets.

AF_UNIX sockets don't use lock_sock/release_sock and thus we have to
use a callback to make the locking and unlocking configureable.

Signed-off-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 869e7c62

include/linux/skbuff.h

+9 −2
Original line number Original line Diff line number Diff line
@@ -35,6 +35,7 @@ 
#include <linux/netdev_features.h>

#include <linux/netdev_features.h>

#include <linux/sched.h>

#include <linux/sched.h>

#include <net/flow_dissector.h>

#include <net/flow_dissector.h>

#include <linux/splice.h>





/* A. Checksumming of received packets by device.

/* A. Checksumming of received packets by device.

 *

 *
@@ -2699,9 +2700,15 @@ int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len); 
int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);

int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);

__wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,

__wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,

			      int len, __wsum csum);

			      int len, __wsum csum);

int skb_splice_bits(struct sk_buff *skb, unsigned int offset,

ssize_t skb_socket_splice(struct sock *sk,

			  struct pipe_inode_info *pipe,

			  struct splice_pipe_desc *spd);

int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset,

		    struct pipe_inode_info *pipe, unsigned int len,

		    struct pipe_inode_info *pipe, unsigned int len,

		    unsigned int flags);

		    unsigned int flags,

		    ssize_t (*splice_cb)(struct sock *,

					 struct pipe_inode_info *,

					 struct splice_pipe_desc *));

void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);

void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);

unsigned int skb_zerocopy_headlen(const struct sk_buff *from);

unsigned int skb_zerocopy_headlen(const struct sk_buff *from);

int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,

int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,

net/core/skbuff.c

+28 −17
Original line number Original line Diff line number Diff line
@@ -1870,15 +1870,39 @@ static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe, 
	return false;

	return false;

}

}





ssize_t skb_socket_splice(struct sock *sk,

			  struct pipe_inode_info *pipe,

			  struct splice_pipe_desc *spd)

{

	int ret;



	/* Drop the socket lock, otherwise we have reverse

	 * locking dependencies between sk_lock and i_mutex

	 * here as compared to sendfile(). We enter here

	 * with the socket lock held, and splice_to_pipe() will

	 * grab the pipe inode lock. For sendfile() emulation,

	 * we call into ->sendpage() with the i_mutex lock held

	 * and networking will grab the socket lock.

	 */

	release_sock(sk);

	ret = splice_to_pipe(pipe, spd);

	lock_sock(sk);



	return ret;

}



/*

/*

 * Map data from the skb to a pipe. Should handle both the linear part,

 * Map data from the skb to a pipe. Should handle both the linear part,

 * the fragments, and the frag list. It does NOT handle frag lists within

 * the fragments, and the frag list. It does NOT handle frag lists within

 * the frag list, if such a thing exists. We'd probably need to recurse to

 * the frag list, if such a thing exists. We'd probably need to recurse to

 * handle that cleanly.

 * handle that cleanly.

 */

 */

int skb_splice_bits(struct sk_buff *skb, unsigned int offset,

int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset,

		    struct pipe_inode_info *pipe, unsigned int tlen,

		    struct pipe_inode_info *pipe, unsigned int tlen,

		    unsigned int flags)

		    unsigned int flags,

		    ssize_t (*splice_cb)(struct sock *,

					 struct pipe_inode_info *,

					 struct splice_pipe_desc *))

{

{

	struct partial_page partial[MAX_SKB_FRAGS];

	struct partial_page partial[MAX_SKB_FRAGS];

	struct page *pages[MAX_SKB_FRAGS];

	struct page *pages[MAX_SKB_FRAGS];
@@ -1891,7 +1915,6 @@ int skb_splice_bits(struct sk_buff *skb, unsigned int offset, 
		.spd_release = sock_spd_release,

		.spd_release = sock_spd_release,

	};

	};

	struct sk_buff *frag_iter;

	struct sk_buff *frag_iter;

	struct sock *sk = skb->sk;

	int ret = 0;

	int ret = 0;





	/*

	/*
@@ -1914,20 +1937,8 @@ int skb_splice_bits(struct sk_buff *skb, unsigned int offset, 
	}

	}





done:

done:

	if (spd.nr_pages) {

	if (spd.nr_pages)

		/*

		ret = splice_cb(sk, pipe, &spd);

		 * Drop the socket lock, otherwise we have reverse

		 * locking dependencies between sk_lock and i_mutex

		 * here as compared to sendfile(). We enter here

		 * with the socket lock held, and splice_to_pipe() will

		 * grab the pipe inode lock. For sendfile() emulation,

		 * we call into ->sendpage() with the i_mutex lock held

		 * and networking will grab the socket lock.

		 */

		release_sock(sk);

		ret = splice_to_pipe(pipe, &spd);

		lock_sock(sk);

	}





	return ret;

	return ret;

}

}

net/ipv4/tcp.c

+3 −2
Original line number Original line Diff line number Diff line
@@ -695,8 +695,9 @@ static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, 
	struct tcp_splice_state *tss = rd_desc->arg.data;

	struct tcp_splice_state *tss = rd_desc->arg.data;

	int ret;

	int ret;





	ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len),

	ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe,

			      tss->flags);

			      min(rd_desc->count, len), tss->flags,

			      skb_socket_splice);

	if (ret > 0)

	if (ret > 0)

		rd_desc->count -= ret;

		rd_desc->count -= ret;

	return ret;

	return ret;