bpo-44011: New asyncio ssl implementation (#31275)

* bpo-44011: New asyncio ssl implementation

Co-Authored-By: Andrew Svetlov <andrew.svetlov@gmail.com>

* fix warning

* fix typo

Co-authored-by: Andrew Svetlov <andrew.svetlov@gmail.com>

Lib/asyncio/base_events.py

@@ -269,7 +269,7 @@ async def restore(self):
 class Server(events.AbstractServer):
 
     def __init__(self, loop, sockets, protocol_factory, ssl_context, backlog,
-                 ssl_handshake_timeout):
+                 ssl_handshake_timeout, ssl_shutdown_timeout=None):
         self._loop = loop
         self._sockets = sockets
         self._active_count = 0
@@ -278,6 +278,7 @@ def __init__(self, loop, sockets, protocol_factory, ssl_context, backlog,
         self._backlog = backlog
         self._ssl_context = ssl_context
         self._ssl_handshake_timeout = ssl_handshake_timeout
+        self._ssl_shutdown_timeout = ssl_shutdown_timeout
         self._serving = False
         self._serving_forever_fut = None
 
@@ -309,7 +310,8 @@ def _start_serving(self):
             sock.listen(self._backlog)
             self._loop._start_serving(
                 self._protocol_factory, sock, self._ssl_context,
-                self, self._backlog, self._ssl_handshake_timeout)
+                self, self._backlog, self._ssl_handshake_timeout,
+                self._ssl_shutdown_timeout)
 
     def get_loop(self):
         return self._loop
@@ -463,6 +465,7 @@ def _make_ssl_transport(
             *, server_side=False, server_hostname=None,
             extra=None, server=None,
             ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None,
             call_connection_made=True):
         """Create SSL transport."""
         raise NotImplementedError
@@ -965,6 +968,7 @@ async def create_connection(
             proto=0, flags=0, sock=None,
             local_addr=None, server_hostname=None,
             ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None,
             happy_eyeballs_delay=None, interleave=None):
         """Connect to a TCP server.
 
@@ -1000,6 +1004,10 @@ async def create_connection(
             raise ValueError(
                 'ssl_handshake_timeout is only meaningful with ssl')
 
+        if ssl_shutdown_timeout is not None and not ssl:
+            raise ValueError(
+                'ssl_shutdown_timeout is only meaningful with ssl')
+
         if happy_eyeballs_delay is not None and interleave is None:
             # If using happy eyeballs, default to interleave addresses by family
             interleave = 1
@@ -1075,7 +1083,8 @@ async def create_connection(
 
         transport, protocol = await self._create_connection_transport(
             sock, protocol_factory, ssl, server_hostname,
-            ssl_handshake_timeout=ssl_handshake_timeout)
+            ssl_handshake_timeout=ssl_handshake_timeout,
+            ssl_shutdown_timeout=ssl_shutdown_timeout)
         if self._debug:
             # Get the socket from the transport because SSL transport closes
             # the old socket and creates a new SSL socket
@@ -1087,7 +1096,8 @@ async def create_connection(
     async def _create_connection_transport(
             self, sock, protocol_factory, ssl,
             server_hostname, server_side=False,
-            ssl_handshake_timeout=None):
+            ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None):
 
         sock.setblocking(False)
 
@@ -1098,7 +1108,8 @@ async def _create_connection_transport(
             transport = self._make_ssl_transport(
                 sock, protocol, sslcontext, waiter,
                 server_side=server_side, server_hostname=server_hostname,
-                ssl_handshake_timeout=ssl_handshake_timeout)
+                ssl_handshake_timeout=ssl_handshake_timeout,
+                ssl_shutdown_timeout=ssl_shutdown_timeout)
         else:
             transport = self._make_socket_transport(sock, protocol, waiter)
 
@@ -1189,7 +1200,8 @@ async def _sendfile_fallback(self, transp, file, offset, count):
     async def start_tls(self, transport, protocol, sslcontext, *,
                         server_side=False,
                         server_hostname=None,
-                        ssl_handshake_timeout=None):
+                        ssl_handshake_timeout=None,
+                        ssl_shutdown_timeout=None):
         """Upgrade transport to TLS.
 
         Return a new transport that *protocol* should start using
@@ -1212,6 +1224,7 @@ async def start_tls(self, transport, protocol, sslcontext, *,
             self, protocol, sslcontext, waiter,
             server_side, server_hostname,
             ssl_handshake_timeout=ssl_handshake_timeout,
+            ssl_shutdown_timeout=ssl_shutdown_timeout,
             call_connection_made=False)
 
         # Pause early so that "ssl_protocol.data_received()" doesn't
@@ -1397,6 +1410,7 @@ async def create_server(
             reuse_address=None,
             reuse_port=None,
             ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None,
             start_serving=True):
         """Create a TCP server.
 
@@ -1420,6 +1434,10 @@ async def create_server(
             raise ValueError(
                 'ssl_handshake_timeout is only meaningful with ssl')
 
+        if ssl_shutdown_timeout is not None and ssl is None:
+            raise ValueError(
+                'ssl_shutdown_timeout is only meaningful with ssl')
+
         if host is not None or port is not None:
             if sock is not None:
                 raise ValueError(
@@ -1492,7 +1510,8 @@ async def create_server(
             sock.setblocking(False)
 
         server = Server(self, sockets, protocol_factory,
-                        ssl, backlog, ssl_handshake_timeout)
+                        ssl, backlog, ssl_handshake_timeout,
+                        ssl_shutdown_timeout)
         if start_serving:
             server._start_serving()
             # Skip one loop iteration so that all 'loop.add_reader'
@@ -1506,17 +1525,23 @@ async def create_server(
     async def connect_accepted_socket(
             self, protocol_factory, sock,
             *, ssl=None,
-            ssl_handshake_timeout=None):
+            ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None):
         if sock.type != socket.SOCK_STREAM:
             raise ValueError(f'A Stream Socket was expected, got {sock!r}')
 
         if ssl_handshake_timeout is not None and not ssl:
             raise ValueError(
                 'ssl_handshake_timeout is only meaningful with ssl')
 
+        if ssl_shutdown_timeout is not None and not ssl:
+            raise ValueError(
+                'ssl_shutdown_timeout is only meaningful with ssl')
+
         transport, protocol = await self._create_connection_transport(
             sock, protocol_factory, ssl, '', server_side=True,
-            ssl_handshake_timeout=ssl_handshake_timeout)
+            ssl_handshake_timeout=ssl_handshake_timeout,
+            ssl_shutdown_timeout=ssl_shutdown_timeout)
         if self._debug:
             # Get the socket from the transport because SSL transport closes
             # the old socket and creates a new SSL socket

Lib/asyncio/constants.py

@@ -15,10 +15,17 @@
 # The default timeout matches that of Nginx.
 SSL_HANDSHAKE_TIMEOUT = 60.0
 
+# Number of seconds to wait for SSL shutdown to complete
+# The default timeout mimics lingering_time
+SSL_SHUTDOWN_TIMEOUT = 30.0
+
 # Used in sendfile fallback code.  We use fallback for platforms
 # that don't support sendfile, or for TLS connections.
 SENDFILE_FALLBACK_READBUFFER_SIZE = 1024 * 256
 
+FLOW_CONTROL_HIGH_WATER_SSL_READ = 256  # KiB
+FLOW_CONTROL_HIGH_WATER_SSL_WRITE = 512  # KiB
+
 # The enum should be here to break circular dependencies between
 # base_events and sslproto
 class _SendfileMode(enum.Enum):

Lib/asyncio/events.py

@@ -303,6 +303,7 @@ async def create_connection(
             flags=0, sock=None, local_addr=None,
             server_hostname=None,
             ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None,
             happy_eyeballs_delay=None, interleave=None):
         raise NotImplementedError
 
@@ -312,6 +313,7 @@ async def create_server(
             flags=socket.AI_PASSIVE, sock=None, backlog=100,
             ssl=None, reuse_address=None, reuse_port=None,
             ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None,
             start_serving=True):
         """A coroutine which creates a TCP server bound to host and port.
 
@@ -352,6 +354,10 @@ async def create_server(
         will wait for completion of the SSL handshake before aborting the
         connection. Default is 60s.
 
+        ssl_shutdown_timeout is the time in seconds that an SSL server
+        will wait for completion of the SSL shutdown procedure
+        before aborting the connection. Default is 30s.
+
         start_serving set to True (default) causes the created server
         to start accepting connections immediately.  When set to False,
         the user should await Server.start_serving() or Server.serve_forever()
@@ -370,7 +376,8 @@ async def sendfile(self, transport, file, offset=0, count=None,
     async def start_tls(self, transport, protocol, sslcontext, *,
                         server_side=False,
                         server_hostname=None,
-                        ssl_handshake_timeout=None):
+                        ssl_handshake_timeout=None,
+                        ssl_shutdown_timeout=None):
         """Upgrade a transport to TLS.
 
         Return a new transport that *protocol* should start using
@@ -382,13 +389,15 @@ async def create_unix_connection(
             self, protocol_factory, path=None, *,
             ssl=None, sock=None,
             server_hostname=None,
-            ssl_handshake_timeout=None):
+            ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None):
         raise NotImplementedError
 
     async def create_unix_server(
             self, protocol_factory, path=None, *,
             sock=None, backlog=100, ssl=None,
             ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None,
             start_serving=True):
         """A coroutine which creates a UNIX Domain Socket server.
 
@@ -410,6 +419,9 @@ async def create_unix_server(
         ssl_handshake_timeout is the time in seconds that an SSL server
         will wait for the SSL handshake to complete (defaults to 60s).
 
+        ssl_shutdown_timeout is the time in seconds that an SSL server
+        will wait for the SSL shutdown to finish (defaults to 30s).
+
         start_serving set to True (default) causes the created server
         to start accepting connections immediately.  When set to False,
         the user should await Server.start_serving() or Server.serve_forever()
@@ -420,7 +432,8 @@ async def create_unix_server(
     async def connect_accepted_socket(
             self, protocol_factory, sock,
             *, ssl=None,
-            ssl_handshake_timeout=None):
+            ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None):
         """Handle an accepted connection.
 
         This is used by servers that accept connections outside of

Lib/asyncio/proactor_events.py

@@ -642,11 +642,13 @@ def _make_ssl_transport(
             self, rawsock, protocol, sslcontext, waiter=None,
             *, server_side=False, server_hostname=None,
             extra=None, server=None,
-            ssl_handshake_timeout=None):
+            ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None):
         ssl_protocol = sslproto.SSLProtocol(
                 self, protocol, sslcontext, waiter,
                 server_side, server_hostname,
-                ssl_handshake_timeout=ssl_handshake_timeout)
+                ssl_handshake_timeout=ssl_handshake_timeout,
+                ssl_shutdown_timeout=ssl_shutdown_timeout)
         _ProactorSocketTransport(self, rawsock, ssl_protocol,
                                  extra=extra, server=server)
         return ssl_protocol._app_transport
@@ -812,7 +814,8 @@ def _write_to_self(self):
 
     def _start_serving(self, protocol_factory, sock,
                        sslcontext=None, server=None, backlog=100,
-                       ssl_handshake_timeout=None):
+                       ssl_handshake_timeout=None,
+                       ssl_shutdown_timeout=None):
 
         def loop(f=None):
             try:
@@ -826,7 +829,8 @@ def loop(f=None):
                         self._make_ssl_transport(
                             conn, protocol, sslcontext, server_side=True,
                             extra={'peername': addr}, server=server,
-                            ssl_handshake_timeout=ssl_handshake_timeout)
+                            ssl_handshake_timeout=ssl_handshake_timeout,
+                            ssl_shutdown_timeout=ssl_shutdown_timeout)
                     else:
                         self._make_socket_transport(
                             conn, protocol,

Lib/asyncio/selector_events.py

@@ -70,11 +70,15 @@ def _make_ssl_transport(
             self, rawsock, protocol, sslcontext, waiter=None,
             *, server_side=False, server_hostname=None,
             extra=None, server=None,
-            ssl_handshake_timeout=constants.SSL_HANDSHAKE_TIMEOUT):
+            ssl_handshake_timeout=constants.SSL_HANDSHAKE_TIMEOUT,
+            ssl_shutdown_timeout=constants.SSL_SHUTDOWN_TIMEOUT,
+    ):
         ssl_protocol = sslproto.SSLProtocol(
-                self, protocol, sslcontext, waiter,
-                server_side, server_hostname,
-                ssl_handshake_timeout=ssl_handshake_timeout)
+            self, protocol, sslcontext, waiter,
+            server_side, server_hostname,
+            ssl_handshake_timeout=ssl_handshake_timeout,
+            ssl_shutdown_timeout=ssl_shutdown_timeout
+        )
         _SelectorSocketTransport(self, rawsock, ssl_protocol,
                                  extra=extra, server=server)
         return ssl_protocol._app_transport
@@ -146,15 +150,17 @@ def _write_to_self(self):
 
     def _start_serving(self, protocol_factory, sock,
                        sslcontext=None, server=None, backlog=100,
-                       ssl_handshake_timeout=constants.SSL_HANDSHAKE_TIMEOUT):
+                       ssl_handshake_timeout=constants.SSL_HANDSHAKE_TIMEOUT,
+                       ssl_shutdown_timeout=constants.SSL_SHUTDOWN_TIMEOUT):
         self._add_reader(sock.fileno(), self._accept_connection,
                          protocol_factory, sock, sslcontext, server, backlog,
-                         ssl_handshake_timeout)
+                         ssl_handshake_timeout, ssl_shutdown_timeout)
 
     def _accept_connection(
             self, protocol_factory, sock,
             sslcontext=None, server=None, backlog=100,
-            ssl_handshake_timeout=constants.SSL_HANDSHAKE_TIMEOUT):
+            ssl_handshake_timeout=constants.SSL_HANDSHAKE_TIMEOUT,
+            ssl_shutdown_timeout=constants.SSL_SHUTDOWN_TIMEOUT):
         # This method is only called once for each event loop tick where the
         # listening socket has triggered an EVENT_READ. There may be multiple
         # connections waiting for an .accept() so it is called in a loop.
@@ -185,20 +191,22 @@ def _accept_connection(
                     self.call_later(constants.ACCEPT_RETRY_DELAY,
                                     self._start_serving,
                                     protocol_factory, sock, sslcontext, server,
-                                    backlog, ssl_handshake_timeout)
+                                    backlog, ssl_handshake_timeout,
+                                    ssl_shutdown_timeout)
                 else:
                     raise  # The event loop will catch, log and ignore it.
             else:
                 extra = {'peername': addr}
                 accept = self._accept_connection2(
                     protocol_factory, conn, extra, sslcontext, server,
-                    ssl_handshake_timeout)
+                    ssl_handshake_timeout, ssl_shutdown_timeout)
                 self.create_task(accept)
 
     async def _accept_connection2(
             self, protocol_factory, conn, extra,
             sslcontext=None, server=None,
-            ssl_handshake_timeout=constants.SSL_HANDSHAKE_TIMEOUT):
+            ssl_handshake_timeout=constants.SSL_HANDSHAKE_TIMEOUT,
+            ssl_shutdown_timeout=constants.SSL_SHUTDOWN_TIMEOUT):
         protocol = None
         transport = None
         try:
@@ -208,7 +216,8 @@ async def _accept_connection2(
                 transport = self._make_ssl_transport(
                     conn, protocol, sslcontext, waiter=waiter,
                     server_side=True, extra=extra, server=server,
-                    ssl_handshake_timeout=ssl_handshake_timeout)
+                    ssl_handshake_timeout=ssl_handshake_timeout,
+                    ssl_shutdown_timeout=ssl_shutdown_timeout)
             else:
                 transport = self._make_socket_transport(
                     conn, protocol, waiter=waiter, extra=extra,