[NETFILTER]: Fix fragmentation issues with bridge netfilter

The conntrack code doesn't do re-fragmentation of defragmented packets
anymore but relies on fragmentation in the IP layer. Purely bridged
packets don't pass through the IP layer, so the bridge netfilter code
needs to take care of fragmentation itself.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index f29450b..3da9264 100644
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -765,6 +765,15 @@
 	return NF_STOLEN;
 }
 
+static int br_nf_dev_queue_xmit(struct sk_buff *skb)
+{
+	if (skb->protocol == htons(ETH_P_IP) &&
+	    skb->len > skb->dev->mtu &&
+	    !(skb_shinfo(skb)->ufo_size || skb_shinfo(skb)->tso_size))
+		return ip_fragment(skb, br_dev_queue_push_xmit);
+	else
+		return br_dev_queue_push_xmit(skb);
+}
 
 /* PF_BRIDGE/POST_ROUTING ********************************************/
 static unsigned int br_nf_post_routing(unsigned int hook, struct sk_buff **pskb,
@@ -824,7 +833,7 @@
 		realoutdev = nf_bridge->netoutdev;
 #endif
 	NF_HOOK(pf, NF_IP_POST_ROUTING, skb, NULL, realoutdev,
-		br_dev_queue_push_xmit);
+		br_nf_dev_queue_xmit);
 
 	return NF_STOLEN;
 
@@ -869,7 +878,7 @@
 
 	if ((out->hard_start_xmit == br_dev_xmit &&
 	     okfn != br_nf_forward_finish &&
-	     okfn != br_nf_local_out_finish && okfn != br_dev_queue_push_xmit)
+	     okfn != br_nf_local_out_finish && okfn != br_nf_dev_queue_xmit)
 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
 	    || ((out->priv_flags & IFF_802_1Q_VLAN) &&
 		VLAN_DEV_INFO(out)->real_dev->hard_start_xmit == br_dev_xmit)