Merge tag 'mfd-for-linus-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/lee...

[firefly-linux-kernel-4.4.55.git] / net / ipv4 / ip_output.c

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 1cbeba5edff90fa1ac891d4dd23cfb65464878a4..a52f50187b5495a1157c2ef8e0785da730414022 100644 (file)
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -211,6 +211,48 @@ static inline int ip_finish_output2(struct sk_buff *skb)
        return -EINVAL;
 }
 
+static int ip_finish_output_gso(struct sk_buff *skb)
+{
+       netdev_features_t features;
+       struct sk_buff *segs;
+       int ret = 0;
+
+       /* common case: locally created skb or seglen is <= mtu */
+       if (((IPCB(skb)->flags & IPSKB_FORWARDED) == 0) ||
+             skb_gso_network_seglen(skb) <= ip_skb_dst_mtu(skb))
+               return ip_finish_output2(skb);
+
+       /* Slowpath -  GSO segment length is exceeding the dst MTU.
+        *
+        * This can happen in two cases:
+        * 1) TCP GRO packet, DF bit not set
+        * 2) skb arrived via virtio-net, we thus get TSO/GSO skbs directly
+        * from host network stack.
+        */
+       features = netif_skb_features(skb);
+       segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
+       if (IS_ERR(segs)) {
+               kfree_skb(skb);
+               return -ENOMEM;
+       }
+
+       consume_skb(skb);
+
+       do {
+               struct sk_buff *nskb = segs->next;
+               int err;
+
+               segs->next = NULL;
+               err = ip_fragment(segs, ip_finish_output2);
+
+               if (err && ret == 0)
+                       ret = err;
+               segs = nskb;
+       } while (segs);
+
+       return ret;
+}
+
 static int ip_finish_output(struct sk_buff *skb)
 {
 #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM)
@@ -220,10 +262,13 @@ static int ip_finish_output(struct sk_buff *skb)
                return dst_output(skb);
        }
 #endif
-       if (skb->len > ip_skb_dst_mtu(skb) && !skb_is_gso(skb))
+       if (skb_is_gso(skb))
+               return ip_finish_output_gso(skb);
+
+       if (skb->len > ip_skb_dst_mtu(skb))
                return ip_fragment(skb, ip_finish_output2);
-       else
-               return ip_finish_output2(skb);
+
+       return ip_finish_output2(skb);
 }
 
 int ip_mc_output(struct sock *sk, struct sk_buff *skb)