[PATCH v2 10/17] switch AF_PACKET and AF_UNIX to skb_copy_datagram_from_iter()

From: Al Viro
Date: Tue Nov 25 2014 - 09:04:46 EST


From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

... and kill skb_copy_datagram_iovec()

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
include/linux/skbuff.h | 3 --
net/core/datagram.c | 88 ++----------------------------------------------
net/packet/af_packet.c | 11 ++++--
net/unix/af_unix.c | 11 ++++--
4 files changed, 18 insertions(+), 95 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 178cdbd..7691ad5 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2656,9 +2656,6 @@ static inline int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen,
{
return skb_copy_and_csum_datagram_iovec(skb, hlen, msg->msg_iov);
}
-int skb_copy_datagram_from_iovec(struct sk_buff *skb, int offset,
- const struct iovec *from, int from_offset,
- int len);
int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
struct iov_iter *from, int len);
int skb_copy_datagram_iter(const struct sk_buff *from, int offset,
diff --git a/net/core/datagram.c b/net/core/datagram.c
index c4d832e..b6e303b 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -480,98 +480,14 @@ short_copy:
EXPORT_SYMBOL(skb_copy_datagram_iter);

/**
- * skb_copy_datagram_from_iovec - Copy a datagram from an iovec.
+ * skb_copy_datagram_from_iter - Copy a datagram from an iov_iter.
* @skb: buffer to copy
* @offset: offset in the buffer to start copying to
- * @from: io vector to copy to
- * @from_offset: offset in the io vector to start copying from
+ * @from: the copy source
* @len: amount of data to copy to buffer from iovec
*
* Returns 0 or -EFAULT.
- * Note: the iovec is not modified during the copy.
*/
-int skb_copy_datagram_from_iovec(struct sk_buff *skb, int offset,
- const struct iovec *from, int from_offset,
- int len)
-{
- int start = skb_headlen(skb);
- int i, copy = start - offset;
- struct sk_buff *frag_iter;
-
- /* Copy header. */
- if (copy > 0) {
- if (copy > len)
- copy = len;
- if (memcpy_fromiovecend(skb->data + offset, from, from_offset,
- copy))
- goto fault;
- if ((len -= copy) == 0)
- return 0;
- offset += copy;
- from_offset += copy;
- }
-
- /* Copy paged appendix. Hmm... why does this look so complicated? */
- for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
- int end;
- const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
-
- WARN_ON(start > offset + len);
-
- 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_fromiovecend(vaddr + frag->page_offset +
- offset - start,
- from, from_offset, copy);
- kunmap(page);
- if (err)
- goto fault;
-
- if (!(len -= copy))
- return 0;
- offset += copy;
- from_offset += copy;
- }
- start = end;
- }
-
- skb_walk_frags(skb, frag_iter) {
- int end;
-
- WARN_ON(start > offset + len);
-
- end = start + frag_iter->len;
- if ((copy = end - offset) > 0) {
- if (copy > len)
- copy = len;
- if (skb_copy_datagram_from_iovec(frag_iter,
- offset - start,
- from,
- from_offset,
- copy))
- goto fault;
- if ((len -= copy) == 0)
- return 0;
- offset += copy;
- from_offset += copy;
- }
- start = end;
- }
- if (!len)
- return 0;
-
-fault:
- return -EFAULT;
-}
-EXPORT_SYMBOL(skb_copy_datagram_from_iovec);
-
int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
struct iov_iter *from,
int len)
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 108d7f3..dfb148e 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2408,6 +2408,10 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
unsigned short gso_type = 0;
int hlen, tlen;
int extra_len = 0;
+ struct iov_iter from;
+ ssize_t n;
+
+ iov_iter_init(&from, WRITE, msg->msg_iov, msg->msg_iovlen, len);

/*
* Get and verify the address.
@@ -2446,8 +2450,9 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)

len -= vnet_hdr_len;

- err = memcpy_from_msg((void *)&vnet_hdr, msg, vnet_hdr_len);
- if (err < 0)
+ err = -EFAULT;
+ n = copy_from_iter(&vnet_hdr, vnet_hdr_len, &from);
+ if (n != vnet_hdr_len)
goto out_unlock;

if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
@@ -2517,7 +2522,7 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
}

/* Returns -EFAULT on error */
- err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len);
+ err = skb_copy_datagram_from_iter(skb, offset, &from, len);
if (err)
goto out_free;

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 5eee625..4450d62 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1459,6 +1459,9 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
struct scm_cookie tmp_scm;
int max_level;
int data_len = 0;
+ struct iov_iter from;
+
+ iov_iter_init(&from, WRITE, msg->msg_iov, msg->msg_iovlen, len);

if (NULL == siocb->scm)
siocb->scm = &tmp_scm;
@@ -1516,7 +1519,7 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
skb_put(skb, len - data_len);
skb->data_len = data_len;
skb->len = len;
- err = skb_copy_datagram_from_iovec(skb, 0, msg->msg_iov, 0, len);
+ err = skb_copy_datagram_from_iter(skb, 0, &from, len);
if (err)
goto out_free;

@@ -1638,6 +1641,9 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
bool fds_sent = false;
int max_level;
int data_len;
+ struct iov_iter from;
+
+ iov_iter_init(&from, WRITE, msg->msg_iov, msg->msg_iovlen, len);

if (NULL == siocb->scm)
siocb->scm = &tmp_scm;
@@ -1694,8 +1700,7 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
skb_put(skb, size - data_len);
skb->data_len = data_len;
skb->len = size;
- err = skb_copy_datagram_from_iovec(skb, 0, msg->msg_iov,
- sent, size);
+ err = skb_copy_datagram_from_iter(skb, 0, &from, size);
if (err) {
kfree_skb(skb);
goto out_err;
--
1.7.10.4

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