skb_copy_datagram_iovec() can die
[cascardo/linux.git] / net / core / datagram.c
index b6e303b..df493d6 100644 (file)
@@ -309,90 +309,6 @@ int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags)
 }
 EXPORT_SYMBOL(skb_kill_datagram);
 
-/**
- *     skb_copy_datagram_iovec - Copy a datagram to an iovec.
- *     @skb: buffer to copy
- *     @offset: offset in the buffer to start copying from
- *     @to: io vector to copy to
- *     @len: amount of data to copy from buffer to iovec
- *
- *     Note: the iovec is modified during the copy.
- */
-int skb_copy_datagram_iovec(const struct sk_buff *skb, int offset,
-                           struct iovec *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_toiovec(to, skb->data + offset, copy))
-                       goto fault;
-               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) {
-                       int err;
-                       u8  *vaddr;
-                       struct page *page = skb_frag_page(frag);
-
-                       if (copy > len)
-                               copy = len;
-                       vaddr = kmap(page);
-                       err = memcpy_toiovec(to, vaddr + frag->page_offset +
-                                            offset - start, copy);
-                       kunmap(page);
-                       if (err)
-                               goto fault;
-                       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_iovec(frag_iter,
-                                                   offset - start,
-                                                   to, copy))
-                               goto fault;
-                       if ((len -= copy) == 0)
-                               return 0;
-                       offset += copy;
-               }
-               start = end;
-       }
-       if (!len)
-               return 0;
-
-fault:
-       return -EFAULT;
-}
-EXPORT_SYMBOL(skb_copy_datagram_iovec);
-
 /**
  *     skb_copy_datagram_iter - Copy a datagram to an iovec iterator.
  *     @skb: buffer to copy
@@ -615,27 +531,25 @@ int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *from)
 EXPORT_SYMBOL(zerocopy_sg_from_iter);
 
 static int skb_copy_and_csum_datagram(const struct sk_buff *skb, int offset,
-                                     u8 __user *to, int len,
+                                     struct iov_iter *to, int len,
                                      __wsum *csump)
 {
        int start = skb_headlen(skb);
        int i, copy = start - offset;
        struct sk_buff *frag_iter;
        int pos = 0;
+       int n;
 
        /* Copy header. */
        if (copy > 0) {
-               int err = 0;
                if (copy > len)
                        copy = len;
-               *csump = csum_and_copy_to_user(skb->data + offset, to, copy,
-                                              *csump, &err);
-               if (err)
+               n = csum_and_copy_to_iter(skb->data + offset, copy, csump, to);
+               if (n != copy)
                        goto fault;
                if ((len -= copy) == 0)
                        return 0;
                offset += copy;
-               to += copy;
                pos = copy;
        }
 
@@ -647,26 +561,22 @@ static int skb_copy_and_csum_datagram(const struct sk_buff *skb, int offset,
 
                end = start + skb_frag_size(frag);
                if ((copy = end - offset) > 0) {
-                       __wsum csum2;
-                       int err = 0;
-                       u8  *vaddr;
+                       __wsum csum2 = 0;
                        struct page *page = skb_frag_page(frag);
+                       u8  *vaddr = kmap(page);
 
                        if (copy > len)
                                copy = len;
-                       vaddr = kmap(page);
-                       csum2 = csum_and_copy_to_user(vaddr +
-                                                       frag->page_offset +
-                                                       offset - start,
-                                                     to, copy, 0, &err);
+                       n = csum_and_copy_to_iter(vaddr + frag->page_offset +
+                                                 offset - start, copy,
+                                                 &csum2, to);
                        kunmap(page);
-                       if (err)
+                       if (n != copy)
                                goto fault;
                        *csump = csum_block_add(*csump, csum2, pos);
                        if (!(len -= copy))
                                return 0;
                        offset += copy;
-                       to += copy;
                        pos += copy;
                }
                start = end;
@@ -691,7 +601,6 @@ static int skb_copy_and_csum_datagram(const struct sk_buff *skb, int offset,
                        if ((len -= copy) == 0)
                                return 0;
                        offset += copy;
-                       to += copy;
                        pos += copy;
                }
                start = end;
@@ -744,20 +653,19 @@ __sum16 __skb_checksum_complete(struct sk_buff *skb)
 EXPORT_SYMBOL(__skb_checksum_complete);
 
 /**
- *     skb_copy_and_csum_datagram_iovec - Copy and checksum skb to user iovec.
+ *     skb_copy_and_csum_datagram_msg - Copy and checksum skb to user iovec.
  *     @skb: skbuff
  *     @hlen: hardware length
- *     @iov: io vector
+ *     @msg: destination
  *
  *     Caller _must_ check that skb will fit to this iovec.
  *
  *     Returns: 0       - success.
  *              -EINVAL - checksum failure.
- *              -EFAULT - fault during copy. Beware, in this case iovec
- *                        can be modified!
+ *              -EFAULT - fault during copy.
  */
-int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
-                                    int hlen, struct iovec *iov)
+int skb_copy_and_csum_datagram_msg(struct sk_buff *skb,
+                                  int hlen, struct msghdr *msg)
 {
        __wsum csum;
        int chunk = skb->len - hlen;
@@ -765,28 +673,20 @@ int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
        if (!chunk)
                return 0;
 
-       /* Skip filled elements.
-        * Pretty silly, look at memcpy_toiovec, though 8)
-        */
-       while (!iov->iov_len)
-               iov++;
-
-       if (iov->iov_len < chunk) {
+       if (iov_iter_count(&msg->msg_iter) < chunk) {
                if (__skb_checksum_complete(skb))
                        goto csum_error;
-               if (skb_copy_datagram_iovec(skb, hlen, iov, chunk))
+               if (skb_copy_datagram_msg(skb, hlen, msg, chunk))
                        goto fault;
        } else {
                csum = csum_partial(skb->data, hlen, skb->csum);
-               if (skb_copy_and_csum_datagram(skb, hlen, iov->iov_base,
+               if (skb_copy_and_csum_datagram(skb, hlen, &msg->msg_iter,
                                               chunk, &csum))
                        goto fault;
                if (csum_fold(csum))
                        goto csum_error;
                if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE))
                        netdev_rx_csum_fault(skb->dev);
-               iov->iov_len -= chunk;
-               iov->iov_base += chunk;
        }
        return 0;
 csum_error:
@@ -794,7 +694,7 @@ csum_error:
 fault:
        return -EFAULT;
 }
-EXPORT_SYMBOL(skb_copy_and_csum_datagram_iovec);
+EXPORT_SYMBOL(skb_copy_and_csum_datagram_msg);
 
 /**
  *     datagram_poll - generic datagram poll