net: accept UFO datagrams from tuntap and packet

[uclinux-h8/linux.git] / net / ipv4 / udp_offload.c

diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index e360d55..01801b7 100644 (file)
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -187,16 +187,57 @@ out_unlock:
 }
 EXPORT_SYMBOL(skb_udp_tunnel_segment);
 
-static struct sk_buff *udp4_tunnel_segment(struct sk_buff *skb,
-                                          netdev_features_t features)
+static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
+                                        netdev_features_t features)
 {
        struct sk_buff *segs = ERR_PTR(-EINVAL);
+       unsigned int mss;
+       __wsum csum;
+       struct udphdr *uh;
+       struct iphdr *iph;
 
        if (skb->encapsulation &&
            (skb_shinfo(skb)->gso_type &
-            (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM)))
+            (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) {
                segs = skb_udp_tunnel_segment(skb, features, false);
+               goto out;
+       }
+
+       if (!pskb_may_pull(skb, sizeof(struct udphdr)))
+               goto out;
+
+       mss = skb_shinfo(skb)->gso_size;
+       if (unlikely(skb->len <= mss))
+               goto out;
+
+       /* Do software UFO. Complete and fill in the UDP checksum as
+        * HW cannot do checksum of UDP packets sent as multiple
+        * IP fragments.
+        */
 
+       uh = udp_hdr(skb);
+       iph = ip_hdr(skb);
+
+       uh->check = 0;
+       csum = skb_checksum(skb, 0, skb->len, 0);
+       uh->check = udp_v4_check(skb->len, iph->saddr, iph->daddr, csum);
+       if (uh->check == 0)
+               uh->check = CSUM_MANGLED_0;
+
+       skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+       /* If there is no outer header we can fake a checksum offload
+        * due to the fact that we have already done the checksum in
+        * software prior to segmenting the frame.
+        */
+       if (!skb->encap_hdr_csum)
+               features |= NETIF_F_HW_CSUM;
+
+       /* Fragment the skb. IP headers of the fragments are updated in
+        * inet_gso_segment()
+        */
+       segs = skb_segment(skb, features);
+out:
        return segs;
 }
 
@@ -330,7 +371,7 @@ static int udp4_gro_complete(struct sk_buff *skb, int nhoff)
 
 static const struct net_offload udpv4_offload = {
        .callbacks = {
-               .gso_segment = udp4_tunnel_segment,
+               .gso_segment = udp4_ufo_fragment,
                .gro_receive  = udp4_gro_receive,
                .gro_complete = udp4_gro_complete,
        },