[XFRM]: beet: use IPOPT_NOP for option padding

draft-nikander-esp-beet-mode-07.txt states "The padding MUST be filled
with NOP options as defined in Internet Protocol [1] section 3.1
Internet header format.", so do that.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/ipv4/xfrm4_mode_beet.c b/net/ipv4/xfrm4_mode_beet.c
index 16efc66a7c3f..f8544b7f02de 100644
--- a/net/ipv4/xfrm4_mode_beet.c
+++ b/net/ipv4/xfrm4_mode_beet.c
@@ -54,6 +54,8 @@ static int xfrm4_beet_output(struct xfrm_state *x, struct sk_buff *skb)
                 ph->padlen = 4 - (optlen & 4);
                 ph->hdrlen = (optlen + ph->padlen + sizeof(*ph)) / 8;
                 ph->nexthdr = top_iph->protocol;
+                if (ph->padlen)
+                        memset(ph + 1, IPOPT_NOP, ph->padlen);
 
                 top_iph->protocol = IPPROTO_BEETPH;
                 top_iph->ihl = sizeof(struct iphdr) / 4;