net: l2tp: netlink: l2tp_nl_tunnel_send: set UDP6 checksum flags

This patch causes the proper attribute flags to be set,
in the case that IPv6 UDP checksums are disabled, so that
userspace ie. `ip l2tp show tunnel` knows about it.

Signed-off-by: Asbjoern Sloth Toennesen <asbjorn@asbjorn.st>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c
index 2abd100b83954fc3eaa1a1314d6ae79bd96f53e3..494910d84602558a820fb2c573303aa8cb524105 100644 (file)
--- a/net/l2tp/l2tp_netlink.c
+++ b/net/l2tp/l2tp_netlink.c
@@ -384,6 +384,16 @@ static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int fla
                        if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
                                goto nla_put_failure;
                        break;
+#if IS_ENABLED(CONFIG_IPV6)
+               case AF_INET6:
+                       if (udp_get_no_check6_tx(sk) &&
+                           nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX))
+                               goto nla_put_failure;
+                       if (udp_get_no_check6_rx(sk) &&
+                           nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX))
+                               goto nla_put_failure;
+                       break;
+#endif
                }
                if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
                    nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))