net: accept UFO datagrams from tuntap and packet

[uclinux-h8/linux.git] / net / ipv6 / udp_offload.c

diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c
index 455fd4e..a0f89ad 100644 (file)
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -17,15 +17,94 @@
 #include <net/ip6_checksum.h>
 #include "ip6_offload.h"
 
-static struct sk_buff *udp6_tunnel_segment(struct sk_buff *skb,
-                                          netdev_features_t features)
+static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
+                                        netdev_features_t features)
 {
        struct sk_buff *segs = ERR_PTR(-EINVAL);
+       unsigned int mss;
+       unsigned int unfrag_ip6hlen, unfrag_len;
+       struct frag_hdr *fptr;
+       u8 *packet_start, *prevhdr;
+       u8 nexthdr;
+       u8 frag_hdr_sz = sizeof(struct frag_hdr);
+       __wsum csum;
+       int tnl_hlen;
+       int err;
+
+       mss = skb_shinfo(skb)->gso_size;
+       if (unlikely(skb->len <= mss))
+               goto out;
 
        if (skb->encapsulation && skb_shinfo(skb)->gso_type &
            (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))
                segs = skb_udp_tunnel_segment(skb, features, true);
+       else {
+               const struct ipv6hdr *ipv6h;
+               struct udphdr *uh;
+
+               if (!pskb_may_pull(skb, sizeof(struct udphdr)))
+                       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);
+               ipv6h = ipv6_hdr(skb);
+
+               uh->check = 0;
+               csum = skb_checksum(skb, 0, skb->len, 0);
+               uh->check = udp_v6_check(skb->len, &ipv6h->saddr,
+                                         &ipv6h->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;
+
+               /* Check if there is enough headroom to insert fragment header. */
+               tnl_hlen = skb_tnl_header_len(skb);
+               if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) {
+                       if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz))
+                               goto out;
+               }
+
+               /* Find the unfragmentable header and shift it left by frag_hdr_sz
+                * bytes to insert fragment header.
+                */
+               err = ip6_find_1stfragopt(skb, &prevhdr);
+               if (err < 0)
+                       return ERR_PTR(err);
+               unfrag_ip6hlen = err;
+               nexthdr = *prevhdr;
+               *prevhdr = NEXTHDR_FRAGMENT;
+               unfrag_len = (skb_network_header(skb) - skb_mac_header(skb)) +
+                            unfrag_ip6hlen + tnl_hlen;
+               packet_start = (u8 *) skb->head + SKB_GSO_CB(skb)->mac_offset;
+               memmove(packet_start-frag_hdr_sz, packet_start, unfrag_len);
+
+               SKB_GSO_CB(skb)->mac_offset -= frag_hdr_sz;
+               skb->mac_header -= frag_hdr_sz;
+               skb->network_header -= frag_hdr_sz;
+
+               fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen);
+               fptr->nexthdr = nexthdr;
+               fptr->reserved = 0;
+               fptr->identification = ipv6_proxy_select_ident(dev_net(skb->dev), skb);
+
+               /* Fragment the skb. ipv6 header and the remaining fields of the
+                * fragment header are updated in ipv6_gso_segment()
+                */
+               segs = skb_segment(skb, features);
+       }
 
+out:
        return segs;
 }
 
@@ -75,7 +154,7 @@ static int udp6_gro_complete(struct sk_buff *skb, int nhoff)
 
 static const struct net_offload udpv6_offload = {
        .callbacks = {
-               .gso_segment    =       udp6_tunnel_segment,
+               .gso_segment    =       udp6_ufo_fragment,
                .gro_receive    =       udp6_gro_receive,
                .gro_complete   =       udp6_gro_complete,
        },