mptcp: handle defer connect in mptcp_sendmsg

When TCP_FASTOPEN_CONNECT has been set on the socket before a connect,
the defer flag is set and must be handled when sendmsg is called.

This is similar to what is done in tcp_sendmsg_locked().

Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Co-developed-by: Benjamin Hesmans <benjamin.hesmans@tessares.net>
Signed-off-by: Benjamin Hesmans <benjamin.hesmans@tessares.net>
Signed-off-by: Dmytro Shytyi <dmytro@shytyi.net>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 866dfad..fc75389 100644 (file)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1677,6 +1677,7 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 {
        struct mptcp_sock *msk = mptcp_sk(sk);
        struct page_frag *pfrag;
+       struct socket *ssock;
        size_t copied = 0;
        int ret = 0;
        long timeo;
@@ -1690,6 +1691,27 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 
        lock_sock(sk);
 
+       ssock = __mptcp_nmpc_socket(msk);
+       if (unlikely(ssock && inet_sk(ssock->sk)->defer_connect)) {
+               struct sock *ssk = ssock->sk;
+               int copied_syn = 0;
+
+               lock_sock(ssk);
+
+               ret = tcp_sendmsg_fastopen(ssk, msg, &copied_syn, len, NULL);
+               copied += copied_syn;
+               if (ret == -EINPROGRESS && copied_syn > 0) {
+                       /* reflect the new state on the MPTCP socket */
+                       inet_sk_state_store(sk, inet_sk_state_load(ssk));
+                       release_sock(ssk);
+                       goto out;
+               } else if (ret) {
+                       release_sock(ssk);
+                       goto out;
+               }
+               release_sock(ssk);
+       }
+
        timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 
        if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) {