1 files changed, 22 insertions, 1 deletions

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 5dbec21856f4..6f843aff628c 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -867,6 +867,7 @@ static int __ip_append_data(struct sock *sk,
                             unsigned int flags)
 {
         struct inet_sock *inet = inet_sk(sk);
+        struct ubuf_info *uarg = NULL;
         struct sk_buff *skb;
 
         struct ip_options *opt = cork->opt;
@@ -916,6 +917,19 @@ static int __ip_append_data(struct sock *sk,
             (!exthdrlen || (rt->dst.dev->features & NETIF_F_HW_ESP_TX_CSUM)))
                 csummode = CHECKSUM_PARTIAL;
 
+        if (flags & MSG_ZEROCOPY && length && sock_flag(sk, SOCK_ZEROCOPY)) {
+                uarg = sock_zerocopy_realloc(sk, length, skb_zcopy(skb));
+                if (!uarg)
+                        return -ENOBUFS;
+                if (rt->dst.dev->features & NETIF_F_SG &&
+                    csummode == CHECKSUM_PARTIAL) {
+                        paged = true;
+                } else {
+                        uarg->zerocopy = 0;
+                        skb_zcopy_set(skb, uarg);
+                }
+        }
+
         cork->length += length;
 
         /* So, what's going on in the loop below?
@@ -1006,6 +1020,7 @@ alloc_new_skb:
                         cork->tx_flags = 0;
                         skb_shinfo(skb)->tskey = tskey;
                         tskey = 0;
+                        skb_zcopy_set(skb, uarg);
 
                         /*
                          *      Find where to start putting bytes.
@@ -1068,7 +1083,7 @@ alloc_new_skb:
                                 err = -EFAULT;
                                 goto error;
                         }
-                } else {
+                } else if (!uarg || !uarg->zerocopy) {
                         int i = skb_shinfo(skb)->nr_frags;
 
                         err = -ENOMEM;
@@ -1098,6 +1113,10 @@ alloc_new_skb:
                         skb->data_len += copy;
                         skb->truesize += copy;
                         wmem_alloc_delta += copy;
+                } else {
+                        err = skb_zerocopy_iter_dgram(skb, from, copy);
+                        if (err < 0)
+                                goto error;
                 }
                 offset += copy;
                 length -= copy;
@@ -1105,11 +1124,13 @@ alloc_new_skb:
 
         if (wmem_alloc_delta)
                 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc);
+        sock_zerocopy_put(uarg);
         return 0;
 
 error_efault:
         err = -EFAULT;
 error:
+        sock_zerocopy_put_abort(uarg);
         cork->length -= length;
         IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS);
         refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc);