streams: add explicit stop functions

This allows us to explicitly stop streams, dialers, and listeners,
before we start tearing down things. This hopefully will be useful
in resolving use-after-free bugs in http, tls, and websockets.

The new functions are not yet documented, but they are
nng_stream_stop, nng_stream_dialer_stop, and nng_stream_listener_stop.
They should be called after close, and before free.  The close
functions now close without blocking, but the stop function is
allowed to block.

1 files changed, 7 insertions, 0 deletions

diff --git a/src/core/sockfd.c b/src/core/sockfd.c
index cedd7436..787a0783 100644
--- a/src/core/sockfd.c
+++ b/src/core/sockfd.c
@@ -63,6 +63,12 @@ sfd_listener_close(void *arg)
 	nni_mtx_unlock(&l->mtx);
 }
 
+static void
+sfd_listener_stop(void *arg)
+{
+	sfd_listener_close(arg);
+}
+
 static int
 sfd_listener_listen(void *arg)
 {
@@ -222,6 +228,7 @@ nni_sfd_listener_alloc(nng_stream_listener **lp, const nng_url *url)
 
 	l->ops.sl_free   = sfd_listener_free;
 	l->ops.sl_close  = sfd_listener_close;
+	l->ops.sl_stop   = sfd_listener_stop;
 	l->ops.sl_listen = sfd_listener_listen;
 	l->ops.sl_accept = sfd_listener_accept;
 	l->ops.sl_get    = sfd_listener_get;