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Commit 7f6d4670 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'iov_iter' 



Herbert Xu says:

====================
Replace skb_copy_datagram_const_iovec with iterator version

This patch series adds the helper skb_copy_datagram_iter, which
is meant to replace both skb_copy_datagram_iovec and its evil
twin skb_copy_datagram_const_iovec.

It then converts tun and macvtap over to the new helper and finally
removes skb_copy_datagram_const_iovec which is only used by tun
and macvtap.

The copy_to_iter return value issue pointed out by Al has now been
fixed.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 4e84b496 bfe1be38

drivers/net/macvtap.c

+21 −25
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/cdev.h>

#include <linux/idr.h>

#include <linux/fs.h>

#include <linux/uio.h>



#include <net/ipv6.h>

#include <net/net_namespace.h>
@@ -778,31 +779,29 @@ static ssize_t macvtap_aio_write(struct kiocb *iocb, const struct iovec *iv, 
/* Put packet to the user space buffer */

static ssize_t macvtap_put_user(struct macvtap_queue *q,

				const struct sk_buff *skb,

				const struct iovec *iv, int len)

				struct iov_iter *iter)

{

	int ret;

	int vnet_hdr_len = 0;

	int vlan_offset = 0;

	int copied, total;

	int total;



	if (q->flags & IFF_VNET_HDR) {

		struct virtio_net_hdr vnet_hdr;

		vnet_hdr_len = q->vnet_hdr_sz;

		if ((len -= vnet_hdr_len) < 0)

		if (iov_iter_count(iter) < vnet_hdr_len)

			return -EINVAL;



		macvtap_skb_to_vnet_hdr(skb, &vnet_hdr);



		if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, sizeof(vnet_hdr)))

		if (copy_to_iter(&vnet_hdr, sizeof(vnet_hdr), iter) !=

		    sizeof(vnet_hdr))

			return -EFAULT;

	}

	total = copied = vnet_hdr_len;

	total = vnet_hdr_len;

	total += skb->len;



	if (!vlan_tx_tag_present(skb))

		len = min_t(int, skb->len, len);

	else {

		int copy;

	if (vlan_tx_tag_present(skb)) {

		struct {

			__be16 h_vlan_proto;

			__be16 h_vlan_TCI;
@@ -811,37 +810,33 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q, 
		veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));



		vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);

		len = min_t(int, skb->len + VLAN_HLEN, len);

		total += VLAN_HLEN;



		copy = min_t(int, vlan_offset, len);

		ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy);

		len -= copy;

		copied += copy;

		if (ret || !len)

		ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);

		if (ret || !iov_iter_count(iter))

			goto done;



		copy = min_t(int, sizeof(veth), len);

		ret = memcpy_toiovecend(iv, (void *)&veth, copied, copy);

		len -= copy;

		copied += copy;

		if (ret || !len)

		ret = copy_to_iter(&veth, sizeof(veth), iter);

		if (ret != sizeof(veth) || !iov_iter_count(iter))

			goto done;

	}



	ret = skb_copy_datagram_const_iovec(skb, vlan_offset, iv, copied, len);

	ret = skb_copy_datagram_iter(skb, vlan_offset, iter,

				     skb->len - vlan_offset);



done:

	return ret ? ret : total;

}



static ssize_t macvtap_do_read(struct macvtap_queue *q,

			       const struct iovec *iv, unsigned long len,

			       const struct iovec *iv, unsigned long segs,

			       unsigned long len,

			       int noblock)

{

	DEFINE_WAIT(wait);

	struct sk_buff *skb;

	ssize_t ret = 0;

	struct iov_iter iter;



	while (len) {

		if (!noblock)
@@ -863,7 +858,8 @@ static ssize_t macvtap_do_read(struct macvtap_queue *q, 
			schedule();

			continue;

		}

		ret = macvtap_put_user(q, skb, iv, len);

		iov_iter_init(&iter, READ, iv, segs, len);

		ret = macvtap_put_user(q, skb, &iter);

		kfree_skb(skb);

		break;

	}
@@ -886,7 +882,7 @@ static ssize_t macvtap_aio_read(struct kiocb *iocb, const struct iovec *iv, 
		goto out;

	}



	ret = macvtap_do_read(q, iv, len, file->f_flags & O_NONBLOCK);

	ret = macvtap_do_read(q, iv, count, len, file->f_flags & O_NONBLOCK);

	ret = min_t(ssize_t, ret, len);

	if (ret > 0)

		iocb->ki_pos = ret;
@@ -1117,7 +1113,7 @@ static int macvtap_recvmsg(struct kiocb *iocb, struct socket *sock, 
	int ret;

	if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))

		return -EINVAL;

	ret = macvtap_do_read(q, m->msg_iov, total_len,

	ret = macvtap_do_read(q, m->msg_iov, m->msg_iovlen, total_len,

			  flags & MSG_DONTWAIT);

	if (ret > total_len) {

		m->msg_flags |= MSG_TRUNC;

drivers/net/tun.c

+30 −35
Original line number Diff line number Diff line
@@ -71,6 +71,7 @@ 
#include <net/rtnetlink.h>

#include <net/sock.h>

#include <linux/seq_file.h>

#include <linux/uio.h>



#include <asm/uaccess.h>
@@ -1230,11 +1231,11 @@ static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv, 
static ssize_t tun_put_user(struct tun_struct *tun,

			    struct tun_file *tfile,

			    struct sk_buff *skb,

			    const struct iovec *iv, int len)

			    struct iov_iter *iter)

{

	struct tun_pi pi = { 0, skb->protocol };

	ssize_t total = 0;

	int vlan_offset = 0, copied;

	ssize_t total;

	int vlan_offset;

	int vlan_hlen = 0;

	int vnet_hdr_sz = 0;
@@ -1244,23 +1245,25 @@ static ssize_t tun_put_user(struct tun_struct *tun, 
	if (tun->flags & TUN_VNET_HDR)

		vnet_hdr_sz = tun->vnet_hdr_sz;



	total = skb->len + vlan_hlen + vnet_hdr_sz;



	if (!(tun->flags & TUN_NO_PI)) {

		if ((len -= sizeof(pi)) < 0)

		if (iov_iter_count(iter) < sizeof(pi))

			return -EINVAL;



		if (len < skb->len + vlan_hlen + vnet_hdr_sz) {

		total += sizeof(pi);

		if (iov_iter_count(iter) < total) {

			/* Packet will be striped */

			pi.flags |= TUN_PKT_STRIP;

		}



		if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))

		if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))

			return -EFAULT;

		total += sizeof(pi);

	}



	if (vnet_hdr_sz) {

		struct virtio_net_hdr gso = { 0 }; /* no info leak */

		if ((len -= vnet_hdr_sz) < 0)

		if (iov_iter_count(iter) < vnet_hdr_sz)

			return -EINVAL;



		if (skb_is_gso(skb)) {
@@ -1299,17 +1302,12 @@ static ssize_t tun_put_user(struct tun_struct *tun, 
			gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;

		} /* else everything is zero */



		if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,

					       sizeof(gso))))

		if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso))

			return -EFAULT;

		total += vnet_hdr_sz;

	}



	copied = total;

	len = min_t(int, skb->len + vlan_hlen, len);

	total += skb->len + vlan_hlen;

	if (vlan_hlen) {

		int copy, ret;

		int ret;

		struct {

			__be16 h_vlan_proto;

			__be16 h_vlan_TCI;
@@ -1320,36 +1318,32 @@ static ssize_t tun_put_user(struct tun_struct *tun, 


		vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);



		copy = min_t(int, vlan_offset, len);

		ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy);

		len -= copy;

		copied += copy;

		if (ret || !len)

		ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);

		if (ret || !iov_iter_count(iter))

			goto done;



		copy = min_t(int, sizeof(veth), len);

		ret = memcpy_toiovecend(iv, (void *)&veth, copied, copy);

		len -= copy;

		copied += copy;

		if (ret || !len)

		ret = copy_to_iter(&veth, sizeof(veth), iter);

		if (ret != sizeof(veth) || !iov_iter_count(iter))

			goto done;

	}



	skb_copy_datagram_const_iovec(skb, vlan_offset, iv, copied, len);

	skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);



done:

	tun->dev->stats.tx_packets++;

	tun->dev->stats.tx_bytes += len;

	tun->dev->stats.tx_bytes += skb->len + vlan_hlen;



	return total;

}



static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,

			   const struct iovec *iv, ssize_t len, int noblock)

			   const struct iovec *iv, unsigned long segs,

			   ssize_t len, int noblock)

{

	struct sk_buff *skb;

	ssize_t ret = 0;

	int peeked, err, off = 0;

	struct iov_iter iter;



	tun_debug(KERN_INFO, tun, "tun_do_read\n");
@@ -1362,11 +1356,12 @@ static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile, 
	/* Read frames from queue */

	skb = __skb_recv_datagram(tfile->socket.sk, noblock ? MSG_DONTWAIT : 0,

				  &peeked, &off, &err);

	if (skb) {

		ret = tun_put_user(tun, tfile, skb, iv, len);

	if (!skb)

		return ret;



	iov_iter_init(&iter, READ, iv, segs, len);

	ret = tun_put_user(tun, tfile, skb, &iter);

	kfree_skb(skb);

	} else

		ret = err;



	return ret;

}
@@ -1387,7 +1382,7 @@ static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, 
		goto out;

	}



	ret = tun_do_read(tun, tfile, iv, len,

	ret = tun_do_read(tun, tfile, iv, count, len,

			  file->f_flags & O_NONBLOCK);

	ret = min_t(ssize_t, ret, len);

	if (ret > 0)
@@ -1488,7 +1483,7 @@ static int tun_recvmsg(struct kiocb *iocb, struct socket *sock, 
					 SOL_PACKET, TUN_TX_TIMESTAMP);

		goto out;

	}

	ret = tun_do_read(tun, tfile, m->msg_iov, total_len,

	ret = tun_do_read(tun, tfile, m->msg_iov, m->msg_iovlen, total_len,

			  flags & MSG_DONTWAIT);

	if (ret > total_len) {

		m->msg_flags |= MSG_TRUNC;

include/linux/skbuff.h

+3 −3
Original line number Diff line number Diff line
@@ -150,6 +150,7 @@ 
struct net_device;

struct scatterlist;

struct pipe_inode_info;

struct iov_iter;



#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)

struct nf_conntrack {
@@ -2650,9 +2651,8 @@ int skb_copy_datagram_from_iovec(struct sk_buff *skb, int offset, 
				 int len);

int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *frm,

			   int offset, size_t count);

int skb_copy_datagram_const_iovec(const struct sk_buff *from, int offset,

				  const struct iovec *to, int to_offset,

				  int size);

int skb_copy_datagram_iter(const struct sk_buff *from, int offset,

			   struct iov_iter *to, int size);

void skb_free_datagram(struct sock *sk, struct sk_buff *skb);

void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb);

int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags);

net/core/datagram.c

+27 −29
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ 
#include <linux/spinlock.h>

#include <linux/slab.h>

#include <linux/pagemap.h>

#include <linux/uio.h>



#include <net/protocol.h>

#include <linux/skbuff.h>
@@ -393,34 +394,30 @@ int skb_copy_datagram_iovec(const struct sk_buff *skb, int offset, 
EXPORT_SYMBOL(skb_copy_datagram_iovec);



/**

 *	skb_copy_datagram_const_iovec - Copy a datagram to an iovec.

 *	skb_copy_datagram_iter - Copy a datagram to an iovec iterator.

 *	@skb: buffer to copy

 *	@offset: offset in the buffer to start copying from

 *	@to: io vector to copy to

 *	@to_offset: offset in the io vector to start copying to

 *	@to: iovec iterator to copy to

 *	@len: amount of data to copy from buffer to iovec

 *

 *	Returns 0 or -EFAULT.

 *	Note: the iovec is not modified during the copy.

 */

int skb_copy_datagram_const_iovec(const struct sk_buff *skb, int offset,

				  const struct iovec *to, int to_offset,

				  int len)

int skb_copy_datagram_iter(const struct sk_buff *skb, int offset,

			   struct iov_iter *to, int len)

{

	int start = skb_headlen(skb);

	int i, copy = start - offset;

	struct sk_buff *frag_iter;



	trace_skb_copy_datagram_iovec(skb, len);



	/* Copy header. */

	if (copy > 0) {

		if (copy > len)

			copy = len;

		if (memcpy_toiovecend(to, skb->data + offset, to_offset, copy))

			goto fault;

		if (copy_to_iter(skb->data + offset, copy, to) != copy)

			goto short_copy;

		if ((len -= copy) == 0)

			return 0;

		offset += copy;

		to_offset += copy;

	}



	/* Copy paged appendix. Hmm... why does this look so complicated? */
@@ -432,22 +429,15 @@ int skb_copy_datagram_const_iovec(const struct sk_buff *skb, int offset, 


		end = start + skb_frag_size(frag);

		if ((copy = end - offset) > 0) {

			int err;

			u8  *vaddr;

			struct page *page = skb_frag_page(frag);



			if (copy > len)

				copy = len;

			vaddr = kmap(page);

			err = memcpy_toiovecend(to, vaddr + frag->page_offset +

						offset - start, to_offset, copy);

			kunmap(page);

			if (err)

				goto fault;

			if (copy_page_to_iter(skb_frag_page(frag),

					      frag->page_offset + offset -

					      start, copy, to) != copy)

				goto short_copy;

			if (!(len -= copy))

				return 0;

			offset += copy;

			to_offset += copy;

		}

		start = end;

	}
@@ -461,25 +451,33 @@ int skb_copy_datagram_const_iovec(const struct sk_buff *skb, int offset, 
		if ((copy = end - offset) > 0) {

			if (copy > len)

				copy = len;

			if (skb_copy_datagram_const_iovec(frag_iter,

							  offset - start,

							  to, to_offset,

							  copy))

			if (skb_copy_datagram_iter(frag_iter, offset - start,

						   to, copy))

				goto fault;

			if ((len -= copy) == 0)

				return 0;

			offset += copy;

			to_offset += copy;

		}

		start = end;

	}

	if (!len)

		return 0;



	/* This is not really a user copy fault, but rather someone

	 * gave us a bogus length on the skb.  We should probably

	 * print a warning here as it may indicate a kernel bug.

	 */



fault:

	return -EFAULT;



short_copy:

	if (iov_iter_count(to))

		goto fault;



	return 0;

}

EXPORT_SYMBOL(skb_copy_datagram_const_iovec);

EXPORT_SYMBOL(skb_copy_datagram_iter);



/**

 *	skb_copy_datagram_from_iovec - Copy a datagram from an iovec.