# \[PATCH bpf-next 01/10\] bpf: Use ipv6\_only\_sock in bpf\_tcp\_gen\_syncookie

- From: Maxim Mikityanskiy \<hidden\>
- Date: 2021-10-19 14:47:42 
- List: netdev
- Page: https://ratatoskr.run/netdev/2021/10/7782603
- Thread: https://ratatoskr.run/netdev/2021/10/7782602/t.md

```text
Instead of querying the sk_ipv6only field directly, use the dedicated
ipv6_only_sock helper.

Signed-off-by: Maxim Mikityanskiy <redacted>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
---
 net/core/filter.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/filter.c b/net/core/filter.c
index 4bace37a6a44..d830055d477c 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -6788,7 +6788,7 @@ BPF_CALL_5(bpf_tcp_gen_syncookie, struct sock *, sk, void *, iph, u32, iph_len,
 	 */
 	switch (((struct iphdr *)iph)->version) {
 	case 4:
-		if (sk->sk_family == AF_INET6 && sk->sk_ipv6only)
+		if (sk->sk_family == AF_INET6 && ipv6_only_sock(sk))
 			return -EINVAL;
 
 		mss = tcp_v4_get_syncookie(sk, iph, th, &cookie);
-- 
2.30.2

```