gre: add sequence number for collect md mode.
Currently GRE sequence number can only be used in native
tunnel mode. This patch adds sequence number support for
gre collect metadata mode. RFC2890 defines GRE sequence
number to be specific to the traffic flow identified by the
key. However, this patch does not implement per-key seqno.
The sequence number is shared in the same tunnel device.
That is, different tunnel keys using the same collect_md
tunnel share single sequence number.
Signed-off-by: William Tu <u9012063@gmail.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 0fe1d69..95fd225 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -522,6 +522,7 @@ static struct rtable *prepare_fb_xmit(struct sk_buff *skb,
static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
__be16 proto)
{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
struct ip_tunnel_info *tun_info;
const struct ip_tunnel_key *key;
struct rtable *rt = NULL;
@@ -545,9 +546,11 @@ static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM)))
goto err_free_rt;
- flags = tun_info->key.tun_flags & (TUNNEL_CSUM | TUNNEL_KEY);
+ flags = tun_info->key.tun_flags &
+ (TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
gre_build_header(skb, tunnel_hlen, flags, proto,
- tunnel_id_to_key32(tun_info->key.tun_id), 0);
+ tunnel_id_to_key32(tun_info->key.tun_id),
+ (flags | TUNNEL_SEQ) ? htonl(tunnel->o_seqno++) : 0);
df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;