summaryrefslogtreecommitdiff
path: root/net
diff options
context:
space:
mode:
authorHerbert Xu <herbert@gondor.apana.org.au>2014-11-07 21:22:22 +0800
committerDavid S. Miller <davem@davemloft.net>2014-11-07 12:13:34 -0500
commita8f820aa4066d2c97e75ecd1bbca8a7920b66f2c (patch)
tree69854ea942633a137e153ddd360aaa39aa2bdae6 /net
parent4e84b496fd2a226883920e0e0de4ed3f94898adf (diff)
downloadlinux-sh-a8f820aa4066d2c97e75ecd1bbca8a7920b66f2c.tar.gz
inet: Add skb_copy_datagram_iter
This patch adds skb_copy_datagram_iter, which is identical to skb_copy_datagram_iovec except that it operates on iov_iter instead of iovec. Eventually all users of skb_copy_datagram_iovec should switch over to iov_iter and then we can remove skb_copy_datagram_iovec. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/datagram.c87
1 files changed, 87 insertions, 0 deletions
diff --git a/net/core/datagram.c b/net/core/datagram.c
index fdbc9a81d4c2..84d90d087a30 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -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>
@@ -482,6 +483,92 @@ fault:
EXPORT_SYMBOL(skb_copy_datagram_const_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: iovec iterator to copy to
+ * @len: amount of data to copy from buffer to iovec
+ */
+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 (copy_to_iter(skb->data + offset, copy, to) != copy)
+ goto short_copy;
+ if ((len -= copy) == 0)
+ return 0;
+ 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) {
+ if (copy > len)
+ copy = len;
+ 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;
+ }
+ 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_iter(frag_iter, offset - start,
+ to, copy))
+ goto fault;
+ if ((len -= copy) == 0)
+ return 0;
+ 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_iter);
+
+/**
* skb_copy_datagram_from_iovec - Copy a datagram from an iovec.
* @skb: buffer to copy
* @offset: offset in the buffer to start copying to