mptcp: __mptcp_tcp_fallback() returns a struct sock

Currently __mptcp_tcp_fallback() always return NULL
on incoming connections, because MPTCP does not create
the additional socket for the first subflow.
Since the previous commit no __mptcp_tcp_fallback()
caller needs a struct socket, so let __mptcp_tcp_fallback()
return the first subflow sock and cope correctly even with
incoming connections.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index ad619bd..f2b2bd3 100644 (file)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -76,14 +76,14 @@ static bool mptcp_is_tcpsk(struct sock *sk)
        return false;
 }
 
-static struct socket *__mptcp_tcp_fallback(struct mptcp_sock *msk)
+static struct sock *__mptcp_tcp_fallback(struct mptcp_sock *msk)
 {
        sock_owned_by_me((const struct sock *)msk);
 
        if (likely(!__mptcp_check_fallback(msk)))
                return NULL;
 
-       return msk->subflow;
+       return msk->first;
 }
 
 static int __mptcp_socket_create(struct mptcp_sock *msk)
@@ -1498,7 +1498,7 @@ static int mptcp_setsockopt(struct sock *sk, int level, int optname,
                            char __user *optval, unsigned int optlen)
 {
        struct mptcp_sock *msk = mptcp_sk(sk);
-       struct socket *ssock;
+       struct sock *ssk;
 
        pr_debug("msk=%p", msk);
 
@@ -1509,11 +1509,10 @@ static int mptcp_setsockopt(struct sock *sk, int level, int optname,
         * to the one remaining subflow.
         */
        lock_sock(sk);
-       ssock = __mptcp_tcp_fallback(msk);
+       ssk = __mptcp_tcp_fallback(msk);
        release_sock(sk);
-       if (ssock)
-               return tcp_setsockopt(ssock->sk, level, optname, optval,
-                                     optlen);
+       if (ssk)
+               return tcp_setsockopt(ssk, level, optname, optval, optlen);
 
        return -EOPNOTSUPP;
 }
@@ -1522,7 +1521,7 @@ static int mptcp_getsockopt(struct sock *sk, int level, int optname,
                            char __user *optval, int __user *option)
 {
        struct mptcp_sock *msk = mptcp_sk(sk);
-       struct socket *ssock;
+       struct sock *ssk;
 
        pr_debug("msk=%p", msk);
 
@@ -1533,11 +1532,10 @@ static int mptcp_getsockopt(struct sock *sk, int level, int optname,
         * to the one remaining subflow.
         */
        lock_sock(sk);
-       ssock = __mptcp_tcp_fallback(msk);
+       ssk = __mptcp_tcp_fallback(msk);
        release_sock(sk);
-       if (ssock)
-               return tcp_getsockopt(ssock->sk, level, optname, optval,
-                                     option);
+       if (ssk)
+               return tcp_getsockopt(ssk, level, optname, optval, option);
 
        return -EOPNOTSUPP;
 }