diff options
| -rw-r--r-- | include/linux/skbuff.h | 3 | ||||
| -rw-r--r-- | net/core/datagram.c | 116 |
2 files changed, 119 insertions, 0 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index d048347a010a..a01cd9ad0b51 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2659,10 +2659,13 @@ static inline int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen, 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 zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *frm, int offset, size_t count); int skb_copy_datagram_iter(const struct sk_buff *from, int offset, struct iov_iter *to, int size); +int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm); 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); diff --git a/net/core/datagram.c b/net/core/datagram.c index 26391a3fe3e5..3ea038431ceb 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -572,6 +572,78 @@ fault: } 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) +{ + 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 (copy_from_iter(skb->data + offset, copy, from) != 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) { + size_t copied; + + if (copy > len) + copy = len; + copied = copy_page_from_iter(skb_frag_page(frag), + frag->page_offset + offset - start, + copy, from); + if (copied != copy) + 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_from_iter(frag_iter, + offset - start, + from, 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_from_iter); + /** * zerocopy_sg_from_iovec - Build a zerocopy datagram from an iovec * @skb: buffer to copy @@ -643,6 +715,50 @@ int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from, } EXPORT_SYMBOL(zerocopy_sg_from_iovec); +int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *from) +{ + int len = iov_iter_count(from); + int copy = min_t(int, skb_headlen(skb), len); + int frag = 0; + + /* copy up to skb headlen */ + if (skb_copy_datagram_from_iter(skb, 0, from, copy)) + return -EFAULT; + + while (iov_iter_count(from)) { + struct page *pages[MAX_SKB_FRAGS]; + size_t start; + ssize_t copied; + unsigned long truesize; + int n = 0; + + if (frag == MAX_SKB_FRAGS) + return -EMSGSIZE; + + copied = iov_iter_get_pages(from, pages, ~0U, + MAX_SKB_FRAGS - frag, &start); + if (copied < 0) + return -EFAULT; + + iov_iter_advance(from, copied); + + truesize = PAGE_ALIGN(copied + start); + skb->data_len += copied; + skb->len += copied; + skb->truesize += truesize; + atomic_add(truesize, &skb->sk->sk_wmem_alloc); + while (copied) { + int size = min_t(int, copied, PAGE_SIZE - start); + skb_fill_page_desc(skb, frag++, pages[n], start, size); + start = 0; + copied -= size; + n++; + } + } + return 0; +} +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, __wsum *csump) |