net: Walk fragments in __skb_splice_bits

Add walking of fragments in __skb_splice_bits.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 9d7be61..51d768e 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1918,6 +1918,7 @@ static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe,
                              struct splice_pipe_desc *spd, struct sock *sk)
 {
        int seg;
+       struct sk_buff *iter;
 
        /* map the linear part :
         * If skb->head_frag is set, this 'linear' part is backed by a
@@ -1944,6 +1945,19 @@ static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe,
                        return true;
        }
 
+       skb_walk_frags(skb, iter) {
+               if (*offset >= iter->len) {
+                       *offset -= iter->len;
+                       continue;
+               }
+               /* __skb_splice_bits() only fails if the output has no room
+                * left, so no point in going over the frag_list for the error
+                * case.
+                */
+               if (__skb_splice_bits(iter, pipe, offset, len, spd, sk))
+                       return true;
+       }
+
        return false;
 }
 
@@ -1970,9 +1984,7 @@ ssize_t skb_socket_splice(struct sock *sk,
 
 /*
  * Map data from the skb to a pipe. Should handle both the linear part,
- * the fragments, and the frag list. It does NOT handle frag lists within
- * the frag list, if such a thing exists. We'd probably need to recurse to
- * handle that cleanly.
+ * the fragments, and the frag list.
  */
 int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset,
                    struct pipe_inode_info *pipe, unsigned int tlen,
@@ -1991,29 +2003,10 @@ int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset,
                .ops = &nosteal_pipe_buf_ops,
                .spd_release = sock_spd_release,
        };
-       struct sk_buff *frag_iter;
        int ret = 0;
 
-       /*
-        * __skb_splice_bits() only fails if the output has no room left,
-        * so no point in going over the frag_list for the error case.
-        */
-       if (__skb_splice_bits(skb, pipe, &offset, &tlen, &spd, sk))
-               goto done;
-       else if (!tlen)
-               goto done;
+       __skb_splice_bits(skb, pipe, &offset, &tlen, &spd, sk);
 
-       /*
-        * now see if we have a frag_list to map
-        */
-       skb_walk_frags(skb, frag_iter) {
-               if (!tlen)
-                       break;
-               if (__skb_splice_bits(frag_iter, pipe, &offset, &tlen, &spd, sk))
-                       break;
-       }
-
-done:
        if (spd.nr_pages)
                ret = splice_cb(sk, pipe, &spd);