[PATCH 6.1.y] mptcp: sockopt: fix getting freebind & transparent

["Matthieu Baerts (NGI0)" <matttbe@kernel.org>]

commit e2f4ac7bab2205d3c4dd9464e6ffd82502177c51 upstream.

When adding a socket option support in MPTCP, both the get and set parts
are supposed to be implemented.

IP(V6)_FREEBIND and IP(V6)_TRANSPARENT support for the setsockopt part
has been added a while ago, but it looks like the get part got
forgotten. It should have been present as a way to verify a setting has
been set as expected, and not to act differently from TCP or any other
socket types.

Everything was in place to expose it, just the last step was missing.
Only new code is added to cover these specific getsockopt(), that seems
safe.

Fixes: c9406a23c116 ("mptcp: sockopt: add SOL_IP freebind & transparent options")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250314-net-mptcp-fix-data-stream-corr-sockopt-v1-3-122dbb249db3@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
[ Conflict in sockopt.c due to commit e08d0b3d1723 ("inet: implement
  lockless IP_TOS") not being in this version. The conflict is in the
  context and the modification can still be applied in
  mptcp_getsockopt_v4() after the IP_TOS case.
  Also, get the values without 'inet_test_bit()' like it was done in
  this version. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 net/mptcp/sockopt.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index 362ef7c9b940..129c9e9ee396 100644
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -1266,6 +1266,12 @@ static int mptcp_getsockopt_v4(struct mptcp_sock *msk, int optname,
 	switch (optname) {
 	case IP_TOS:
 		return mptcp_put_int_option(msk, optval, optlen, inet_sk(sk)->tos);
+	case IP_FREEBIND:
+		return mptcp_put_int_option(msk, optval, optlen,
+					    inet_sk(sk)->freebind);
+	case IP_TRANSPARENT:
+		return mptcp_put_int_option(msk, optval, optlen,
+					    inet_sk(sk)->transparent);
 	}
 
 	return -EOPNOTSUPP;
@@ -1280,6 +1286,12 @@ static int mptcp_getsockopt_v6(struct mptcp_sock *msk, int optname,
 	case IPV6_V6ONLY:
 		return mptcp_put_int_option(msk, optval, optlen,
 					    sk->sk_ipv6only);
+	case IPV6_TRANSPARENT:
+		return mptcp_put_int_option(msk, optval, optlen,
+					    inet_sk(sk)->transparent);
+	case IPV6_FREEBIND:
+		return mptcp_put_int_option(msk, optval, optlen,
+					    inet_sk(sk)->freebind);
 	}
 
 	return -EOPNOTSUPP;
-- 
2.48.1