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authorPaolo Abeni <pabeni@redhat.com>2021-04-23 21:17:07 +0300
committerDavid S. Miller <davem@davemloft.net>2021-04-24 00:06:32 +0300
commit987858e5d026d355535b34f17c6ceeb1d71ccf75 (patch)
tree4e0f78464b3da95b115d4f74aac0d2ee5dd00c4b /net/mptcp
parentd976092ce1b04d634d408f475224347cfae81201 (diff)
downloadlinux-987858e5d026d355535b34f17c6ceeb1d71ccf75.tar.xz
mptcp: ignore unsupported msg flags
Currently mptcp_sendmsg() fails with EOPNOTSUPP if the user-space provides some unsupported flag. That is unexpected and may foul existing applications migrated to MPTCP, which expect a different behavior. Change the mentioned function to silently ignore the unsupported flags except MSG_FASTOPEN. This is the only flags currently not supported by MPTCP with user-space visible side-effects. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/162 Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mptcp')
-rw-r--r--net/mptcp/protocol.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index ae08c563c712..a996dd5bb0c2 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1614,9 +1614,13 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
int ret = 0;
long timeo;
- if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL))
+ /* we don't support FASTOPEN yet */
+ if (msg->msg_flags & MSG_FASTOPEN)
return -EOPNOTSUPP;
+ /* silently ignore everything else */
+ msg->msg_flags &= MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL;
+
mptcp_lock_sock(sk, __mptcp_wmem_reserve(sk, min_t(size_t, 1 << 20, len)));
timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
@@ -1951,9 +1955,6 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
if (unlikely(flags & MSG_ERRQUEUE))
return inet_recv_error(sk, msg, len, addr_len);
- if (msg->msg_flags & ~(MSG_WAITALL | MSG_DONTWAIT))
- return -EOPNOTSUPP;
-
mptcp_lock_sock(sk, __mptcp_splice_receive_queue(sk));
if (unlikely(sk->sk_state == TCP_LISTEN)) {
copied = -ENOTCONN;