[PATCH net] vxlan: use nla_put_flag for ttl inherit

[Hangbin Liu]

Phil pointed out that there is a mismatch between vxlan and geneve ttl inherit.
We should define it as a flag and use nla_put_flag to export this opiton.

Fixes: 8fd780698745b ("vxlan: fill ttl inherit info")
Reported-by: Phil Sutter <p...@nwl.cc>
Signed-off-by: Hangbin Liu <liuhang...@gmail.com>
---
 drivers/net/vxlan.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 2b8da2b..479dda4 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -3539,7 +3539,7 @@ static size_t vxlan_get_size(const struct net_device *dev)
                nla_total_size(sizeof(__u32)) + /* IFLA_VXLAN_LINK */
                nla_total_size(sizeof(struct in6_addr)) + /* 
IFLA_VXLAN_LOCAL{6} */
                nla_total_size(sizeof(__u8)) +  /* IFLA_VXLAN_TTL */
-               nla_total_size(sizeof(__u8)) +  /* IFLA_VXLAN_TTL_INHERIT */
+               nla_total_size(0) +             /* IFLA_VXLAN_TTL_INHERIT */
                nla_total_size(sizeof(__u8)) +  /* IFLA_VXLAN_TOS */
                nla_total_size(sizeof(__be32)) + /* IFLA_VXLAN_LABEL */
                nla_total_size(sizeof(__u8)) +  /* IFLA_VXLAN_LEARNING */
@@ -3604,8 +3604,6 @@ static int vxlan_fill_info(struct sk_buff *skb, const 
struct net_device *dev)
        }
 
        if (nla_put_u8(skb, IFLA_VXLAN_TTL, vxlan->cfg.ttl) ||
-           nla_put_u8(skb, IFLA_VXLAN_TTL_INHERIT,
-                      !!(vxlan->cfg.flags & VXLAN_F_TTL_INHERIT)) ||
            nla_put_u8(skb, IFLA_VXLAN_TOS, vxlan->cfg.tos) ||
            nla_put_be32(skb, IFLA_VXLAN_LABEL, vxlan->cfg.label) ||
            nla_put_u8(skb, IFLA_VXLAN_LEARNING,
@@ -3650,6 +3648,10 @@ static int vxlan_fill_info(struct sk_buff *skb, const 
struct net_device *dev)
            nla_put_flag(skb, IFLA_VXLAN_REMCSUM_NOPARTIAL))
                goto nla_put_failure;
 
+       if (vxlan->cfg.flags & VXLAN_F_TTL_INHERIT &&
+           nla_put_flag(skb, IFLA_VXLAN_TTL_INHERIT))
+               goto nla_put_failure;
+
        return 0;
 
 nla_put_failure:
-- 
2.5.5