ipv6: Add generic UDP Tunnel segmentation

Similar to commit 731362674580cb0c696cd1b1a03d8461a10cf90a
(tunneling: Add generic Tunnel segmentation)

This patch adds generic tunneling offloading support for
IPv6-UDP based tunnels.

This can be used by tunneling protocols like VXLAN.

Cc: Jesse Gross <jesse@nicira.com>
Cc: Pravin B Shelar <pshelar@nicira.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index a263b990ee11d7bf504512c4c722e927d1e8ed66..d82de72281009c1b93d1cbde1bac91c023ecd930 100644 (file)
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -91,6 +91,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
        unsigned int unfrag_ip6hlen;
        u8 *prevhdr;
        int offset = 0;
+       bool tunnel;
 
        if (unlikely(skb_shinfo(skb)->gso_type &
                     ~(SKB_GSO_UDP |
@@ -106,6 +107,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
        if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
                goto out;
 
+       tunnel = skb->encapsulation;
        ipv6h = ipv6_hdr(skb);
        __skb_pull(skb, sizeof(*ipv6h));
        segs = ERR_PTR(-EPROTONOSUPPORT);
@@ -126,7 +128,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
                ipv6h = ipv6_hdr(skb);
                ipv6h->payload_len = htons(skb->len - skb->mac_len -
                                           sizeof(*ipv6h));
-               if (proto == IPPROTO_UDP) {
+               if (!tunnel && proto == IPPROTO_UDP) {
                        unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
                        fptr = (struct frag_hdr *)(skb_network_header(skb) +
                                unfrag_ip6hlen);

diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c
index 5d1b8d7ac9931c7d0cbe35c06318d08659a5af7b..7e5e5acc96197c0012a5be89272d14d2bef08c57 100644 (file)
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -21,26 +21,79 @@ static int udp6_ufo_send_check(struct sk_buff *skb)
        const struct ipv6hdr *ipv6h;
        struct udphdr *uh;
 
-       /* UDP Tunnel offload on ipv6 is not yet supported. */
-       if (skb->encapsulation)
-               return -EINVAL;
-
        if (!pskb_may_pull(skb, sizeof(*uh)))
                return -EINVAL;
 
-       ipv6h = ipv6_hdr(skb);
-       uh = udp_hdr(skb);
+       if (likely(!skb->encapsulation)) {
+               ipv6h = ipv6_hdr(skb);
+               uh = udp_hdr(skb);
+
+               uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len,
+                                            IPPROTO_UDP, 0);
+               skb->csum_start = skb_transport_header(skb) - skb->head;
+               skb->csum_offset = offsetof(struct udphdr, check);
+               skb->ip_summed = CHECKSUM_PARTIAL;
+       }
 
-       uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len,
-                                    IPPROTO_UDP, 0);
-       skb->csum_start = skb_transport_header(skb) - skb->head;
-       skb->csum_offset = offsetof(struct udphdr, check);
-       skb->ip_summed = CHECKSUM_PARTIAL;
        return 0;
 }
 
+static struct sk_buff *skb_udp6_tunnel_segment(struct sk_buff *skb,
+                                              netdev_features_t features)
+{
+       struct sk_buff *segs = ERR_PTR(-EINVAL);
+       int mac_len = skb->mac_len;
+       int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
+       int outer_hlen;
+       netdev_features_t enc_features;
+
+       if (unlikely(!pskb_may_pull(skb, tnl_hlen)))
+               goto out;
+
+       skb->encapsulation = 0;
+       __skb_pull(skb, tnl_hlen);
+       skb_reset_mac_header(skb);
+       skb_set_network_header(skb, skb_inner_network_offset(skb));
+       skb->mac_len = skb_inner_network_offset(skb);
+
+       /* segment inner packet. */
+       enc_features = skb->dev->hw_enc_features & netif_skb_features(skb);
+       segs = skb_mac_gso_segment(skb, enc_features);
+       if (!segs || IS_ERR(segs))
+               goto out;
+
+       outer_hlen = skb_tnl_header_len(skb);
+       skb = segs;
+       do {
+               struct udphdr *uh;
+               struct ipv6hdr *ipv6h;
+               int udp_offset = outer_hlen - tnl_hlen;
+               u32 len;
+
+               skb->mac_len = mac_len;
+
+               skb_push(skb, outer_hlen);
+               skb_reset_mac_header(skb);
+               skb_set_network_header(skb, mac_len);
+               skb_set_transport_header(skb, udp_offset);
+               uh = udp_hdr(skb);
+               uh->len = htons(skb->len - udp_offset);
+               ipv6h = ipv6_hdr(skb);
+               len = skb->len - udp_offset;
+
+               uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
+                                            len, IPPROTO_UDP, 0);
+               uh->check = csum_fold(skb_checksum(skb, udp_offset, len, 0));
+               if (uh->check == 0)
+                       uh->check = CSUM_MANGLED_0;
+               skb->ip_summed = CHECKSUM_NONE;
+       } while ((skb = skb->next));
+out:
+       return segs;
+}
+
 static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
-       netdev_features_t features)
+                                        netdev_features_t features)
 {
        struct sk_buff *segs = ERR_PTR(-EINVAL);
        unsigned int mss;
@@ -75,47 +128,51 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
                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.
-        */
-       offset = skb_checksum_start_offset(skb);
-       csum = skb_checksum(skb, offset, skb->len - offset, 0);
-       offset += skb->csum_offset;
-       *(__sum16 *)(skb->data + offset) = csum_fold(csum);
-       skb->ip_summed = CHECKSUM_NONE;
-
-       /* Check if there is enough headroom to insert fragment header. */
-       tnl_hlen = skb_tnl_header_len(skb);
-       if (skb_headroom(skb) < (tnl_hlen + frag_hdr_sz)) {
-               if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz))
-                       goto out;
+       if (skb->encapsulation && skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL)
+               segs = skb_udp6_tunnel_segment(skb, features);
+       else {
+               /* Do software UFO. Complete and fill in the UDP checksum as HW cannot
+                * do checksum of UDP packets sent as multiple IP fragments.
+                */
+               offset = skb_checksum_start_offset(skb);
+               csum = skb_checksum(skb, offset, skb->len - offset, 0);
+               offset += skb->csum_offset;
+               *(__sum16 *)(skb->data + offset) = csum_fold(csum);
+               skb->ip_summed = CHECKSUM_NONE;
+
+               /* Check if there is enough headroom to insert fragment header. */
+               tnl_hlen = skb_tnl_header_len(skb);
+               if (skb_headroom(skb) < (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.
+                */
+               unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
+               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;
+               ipv6_select_ident(fptr, (struct rt6_info *)skb_dst(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);
        }
 
-       /* Find the unfragmentable header and shift it left by frag_hdr_sz
-        * bytes to insert fragment header.
-        */
-       unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
-       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;
-       ipv6_select_ident(fptr, (struct rt6_info *)skb_dst(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;
 }