mptcp: sockopt: add TCP_DEFER_ACCEPT support

Support this via passthrough to the underlying tcp listener socket.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/271
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index 826b0c1..423d382 100644 (file)
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -756,6 +756,18 @@ static int mptcp_setsockopt_v4(struct mptcp_sock *msk, int optname,
        return -EOPNOTSUPP;
 }
 
+static int mptcp_setsockopt_sol_tcp_defer(struct mptcp_sock *msk, sockptr_t optval,
+                                         unsigned int optlen)
+{
+       struct socket *listener;
+
+       listener = __mptcp_nmpc_socket(msk);
+       if (!listener)
+               return 0; /* TCP_DEFER_ACCEPT does not fail */
+
+       return tcp_setsockopt(listener->sk, SOL_TCP, TCP_DEFER_ACCEPT, optval, optlen);
+}
+
 static int mptcp_setsockopt_sol_tcp(struct mptcp_sock *msk, int optname,
                                    sockptr_t optval, unsigned int optlen)
 {
@@ -782,6 +794,8 @@ static int mptcp_setsockopt_sol_tcp(struct mptcp_sock *msk, int optname,
                return mptcp_setsockopt_sol_tcp_cork(msk, optval, optlen);
        case TCP_NODELAY:
                return mptcp_setsockopt_sol_tcp_nodelay(msk, optval, optlen);
+       case TCP_DEFER_ACCEPT:
+               return mptcp_setsockopt_sol_tcp_defer(msk, optval, optlen);
        }
 
        return -EOPNOTSUPP;
@@ -1142,6 +1156,7 @@ static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname,
        case TCP_CONGESTION:
        case TCP_INFO:
        case TCP_CC_INFO:
+       case TCP_DEFER_ACCEPT:
                return mptcp_getsockopt_first_sf_only(msk, SOL_TCP, optname,
                                                      optval, optlen);
        case TCP_INQ: