tunneling: Add generic Tunnel segmentation.
Adds generic tunneling offloading support for IPv4-UDP based
tunnels.
GSO type is added to request this offload for a skb.
netdev feature NETIF_F_UDP_TUNNEL is added for hardware offloaded
udp-tunnel support. Currently no device supports this feature,
software offload is used.
This can be used by tunneling protocols like VXLAN.
CC: Jesse Gross <jesse@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 265c42c..41760e0 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2272,31 +2272,88 @@
int udp4_ufo_send_check(struct sk_buff *skb)
{
- const struct iphdr *iph;
- struct udphdr *uh;
-
- if (!pskb_may_pull(skb, sizeof(*uh)))
+ if (!pskb_may_pull(skb, sizeof(struct udphdr)))
return -EINVAL;
- iph = ip_hdr(skb);
- uh = udp_hdr(skb);
+ if (likely(!skb->encapsulation)) {
+ const struct iphdr *iph;
+ struct udphdr *uh;
- uh->check = ~csum_tcpudp_magic(iph->saddr, iph->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;
+ iph = ip_hdr(skb);
+ uh = udp_hdr(skb);
+
+ uh->check = ~csum_tcpudp_magic(iph->saddr, iph->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_udp_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;
+ int udp_offset = outer_hlen - tnl_hlen;
+
+ 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);
+
+ /* csum segment if tunnel sets skb with csum. */
+ if (unlikely(uh->check)) {
+ struct iphdr *iph = ip_hdr(skb);
+
+ uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
+ skb->len - udp_offset,
+ IPPROTO_UDP, 0);
+ uh->check = csum_fold(skb_checksum(skb, udp_offset,
+ skb->len - udp_offset, 0));
+ if (uh->check == 0)
+ uh->check = CSUM_MANGLED_0;
+
+ }
+ skb->ip_summed = CHECKSUM_NONE;
+ } while ((skb = skb->next));
+out:
+ return segs;
+}
+
struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
netdev_features_t features)
{
struct sk_buff *segs = ERR_PTR(-EINVAL);
unsigned int mss;
- int offset;
- __wsum csum;
-
mss = skb_shinfo(skb)->gso_size;
if (unlikely(skb->len <= mss))
goto out;
@@ -2306,6 +2363,7 @@
int type = skb_shinfo(skb)->gso_type;
if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY |
+ SKB_GSO_UDP_TUNNEL |
SKB_GSO_GRE) ||
!(type & (SKB_GSO_UDP))))
goto out;
@@ -2316,20 +2374,27 @@
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;
-
/* Fragment the skb. IP headers of the fragments are updated in
* inet_gso_segment()
*/
- segs = skb_segment(skb, features);
+ if (skb->encapsulation && skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL)
+ segs = skb_udp_tunnel_segment(skb, features);
+ else {
+ int offset;
+ __wsum csum;
+
+ /* 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;
+
+ segs = skb_segment(skb, features);
+ }
out:
return segs;
}
-