[PATCH mptcp-next v5 05/11] mptcp: skip ip6 options on v4-mapped clone

From: Geliang Tang <[email protected]>

v4-mapped IPv6 destinations carry no IPv6-specific options, so skip
mptcp_copy_ip6_options() when sk_v6_daddr is in ::ffff:0:0/96. Native
IPv6 subflows are unchanged.

Signed-off-by: Geliang Tang <[email protected]>
---
 net/mptcp/protocol.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index c2762d74f29d..f19777c04d32 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -3750,7 +3750,8 @@ struct sock *mptcp_sk_clone_init(const struct sock *sk,
 	__mptcp_init_sock(nsk);
 
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
-	if (nsk->sk_family == AF_INET6)
+	if (nsk->sk_family == AF_INET6 &&
+	    !ipv6_addr_v4mapped(&nsk->sk_v6_daddr))
 		mptcp_copy_ip6_options(nsk, sk);
 	else
 #endif
-- 
2.53.0