vsock: notify server to shutdown when client has pending signal

The client's sk_state will be set to TCP_ESTABLISHED if the server
replay the client's connect request.

However, if the client has pending signal, its sk_state will be set
to TCP_CLOSE without notify the server, so the server will hold the
corrupt connection.

            client                        server

1. sk_state=TCP_SYN_SENT         |
2. call ->connect()              |
3. wait reply                    |
                                 | 4. sk_state=TCP_ESTABLISHED
                                 | 5. insert to connected list
                                 | 6. reply to the client
7. sk_state=TCP_ESTABLISHED      |
8. insert to connected list      |
9. *signal pending* <--------------------- the user kill client
10. sk_state=TCP_CLOSE           |
client is exiting...             |
11. call ->release()             |
     virtio_transport_close
      if (!(sk->sk_state == TCP_ESTABLISHED ||
	      sk->sk_state == TCP_CLOSING))
		return true; *return at here, the server cannot notice the connection is corrupt*

So the client should notify the peer in this case.

Cc: David S. Miller <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Jorgen Hansen <[email protected]>
Cc: Norbert Slusarek <[email protected]>
Cc: Andra Paraschiv <[email protected]>
Cc: Colin Ian King <[email protected]>
Cc: David Brazdil <[email protected]>
Cc: Alexander Popov <[email protected]>
Suggested-by: Stefano Garzarella <[email protected]>
Link: https://lkml.org/lkml/2021/5/17/418
Signed-off-by: lixianming <[email protected]>
Signed-off-by: Longpeng(Mike) <[email protected]>
Reviewed-by: Stefano Garzarella <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

0 files changed, 0 insertions, 0 deletions