esp6: support ipv6 nexthdrs process for beet gso segment

For beet mode, when it's ipv6 inner address with nexthdrs set,
the packet format might be:

    ----------------------------------------------------
    | outer  |     | dest |     |      |  ESP    | ESP |
    | IP6 hdr| ESP | opts.| TCP | Data | Trailer | ICV |
    ----------------------------------------------------

Before doing gso segment in xfrm6_beet_gso_segment(), it should
skip all nexthdrs and get the real transport proto, and set
transport_header properly.

This patch is to fix it by simply calling ipv6_skip_exthdr()
in xfrm6_beet_gso_segment().

v1->v2:
  - remove skb_transport_offset(), as it will always return 0
    in xfrm6_beet_gso_segment(), thank Sabrina's check.

Fixes: 7f9e40eb18a9 ("esp6: add gso_segment for esp6 beet mode")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

diff --git a/net/ipv6/esp6_offload.c b/net/ipv6/esp6_offload.c
index b92372b..9c03460 100644 (file)
--- a/net/ipv6/esp6_offload.c
+++ b/net/ipv6/esp6_offload.c
@@ -171,7 +171,7 @@ static struct sk_buff *xfrm6_beet_gso_segment(struct xfrm_state *x,
        struct xfrm_offload *xo = xfrm_offload(skb);
        struct sk_buff *segs = ERR_PTR(-EINVAL);
        const struct net_offload *ops;
-       int proto = xo->proto;
+       u8 proto = xo->proto;
 
        skb->transport_header += x->props.header_len;
 
@@ -182,7 +182,12 @@ static struct sk_buff *xfrm6_beet_gso_segment(struct xfrm_state *x,
                proto = ph->nexthdr;
        }
 
-       if (x->sel.family != AF_INET6) {
+       if (x->sel.family == AF_INET6) {
+               __be16 frag;
+
+               skb->transport_header +=
+                       ipv6_skip_exthdr(skb, 0, &proto, &frag);
+       } else {
                skb->transport_header -=
                        (sizeof(struct ipv6hdr) - sizeof(struct iphdr));