unix,win: introduce uv_accept_reject call

This call will immediately close the accepted fd and,
continue with the queued fds.

Fixes: https://github.com/libuv/libuv/issues/1754
Co-authored-by: Hüseyin Açacak <huseyin@janeasystems.com>
Signed-off-by: Juan José Arboleda <soyjuanarbol@gmail.com>

CMakeLists.txt

@@ -600,6 +600,7 @@ if(LIBUV_BUILD_TESTS)
        test/test-pipe-connect-prepare.c
        test/test-pipe-getsockname.c
        test/test-pipe-pending-instances.c
+       test/test-pipe-reject.c
        test/test-pipe-sendmsg.c
        test/test-pipe-server-close.c
        test/test-pipe-set-fchmod.c
@@ -637,6 +638,8 @@ if(LIBUV_BUILD_TESTS)
        test/test-tcp-bind-error.c
        test/test-tcp-bind6-error.c
        test/test-tcp-close-accept.c
+       test/test-tcp-reject.c
+       test/test-tcp-reject-accept.c
        test/test-tcp-close-after-read-timeout.c
        test/test-tcp-close-while-connecting.c
        test/test-tcp-close.c

Makefile.am

@@ -226,6 +226,7 @@ test_run_tests_SOURCES = test/blackhole-server.c \
                          test/test-pipe-connect-prepare.c \
                          test/test-pipe-getsockname.c \
                          test/test-pipe-pending-instances.c \
+                         test/test-pipe-reject.c \
                          test/test-pipe-sendmsg.c \
                          test/test-pipe-server-close.c \
                          test/test-pipe-close-stdout-read-stdin.c \
@@ -264,6 +265,8 @@ test_run_tests_SOURCES = test/blackhole-server.c \
                          test/test-tcp-bind-error.c \
                          test/test-tcp-bind6-error.c \
                          test/test-tcp-close-accept.c \
+                         test/test-tcp-reject.c \
+                         test/test-tcp-reject-accept.c \
                          test/test-tcp-close-while-connecting.c \
                          test/test-tcp-close-after-read-timeout.c \
                          test/test-tcp-close.c \

docs/src/stream.rst

@@ -133,6 +133,19 @@ API
     .. note::
         `server` and `client` must be handles running on the same loop.
 
+.. c:function:: int uv_reject(uv_stream_t* server)
+
+    This call is used in conjunction with :c:func:`uv_listen` to accept and
+    immediately discard incoming connections. Call this function after receiving
+    a :c:type:`uv_connection_cb`.
+
+    When the :c:type:`uv_connection_cb` callback is called it is guaranteed that
+    this function will complete successfully the first time. If you attempt to
+    use it more than once, it may fail. It is suggested to only call this
+    function once per :c:type:`uv_connection_cb` call. As :c:type:`uv_accept`.
+
+    .. versionadded:: REPLACEME
+
 .. c:function:: int uv_read_start(uv_stream_t* stream, uv_alloc_cb alloc_cb, uv_read_cb read_cb)
 
     Read data from an incoming stream. The :c:type:`uv_read_cb` callback will

include/uv.h

@@ -542,6 +542,7 @@ UV_EXTERN size_t uv_stream_get_write_queue_size(const uv_stream_t* stream);
 
 UV_EXTERN int uv_listen(uv_stream_t* stream, int backlog, uv_connection_cb cb);
 UV_EXTERN int uv_accept(uv_stream_t* server, uv_stream_t* client);
+UV_EXTERN int uv_reject(uv_stream_t* server);
 
 UV_EXTERN int uv_read_start(uv_stream_t*,
                             uv_alloc_cb alloc_cb,

src/unix/stream.c

@@ -533,6 +533,54 @@ void uv__server_io(uv_loop_t* loop, uv__io_t* w, unsigned int events) {
 }
 
 
+static void uv__process_queued_fds(uv_stream_t* server) {
+  /* Process queued fds */
+  uv__stream_queued_fds_t* queued_fds;
+
+  queued_fds = server->queued_fds;
+
+  /* Read first */
+  server->accepted_fd = queued_fds->fds[0];
+
+  /* All read, free */
+  assert(queued_fds->offset > 0);
+  if (--queued_fds->offset == 0) {
+    uv__free(queued_fds);
+    server->queued_fds = NULL;
+  } else {
+    /* Shift rest */
+    memmove(queued_fds->fds,
+            queued_fds->fds + 1,
+            queued_fds->offset * sizeof(*queued_fds->fds));
+  }
+}
+
+
+int uv_reject(uv_stream_t* server) {
+  if (server->accepted_fd == -1)
+    return UV_EAGAIN;
+
+  switch (server->type) {
+    case UV_NAMED_PIPE:
+    case UV_UDP:
+    case UV_TCP:
+      uv__close(server->accepted_fd); /* Simply close the fd */
+      break;
+    default:
+      return UV_EINVAL;
+  }
+
+  /* Process queued fds if needed */
+  if (server->queued_fds != NULL) {
+    uv__process_queued_fds(server);
+  } else {
+    server->accepted_fd = -1;
+    uv__io_start(server->loop, &server->io_watcher, POLLIN);
+  }
+
+  return 0;
+}
+
 int uv_accept(uv_stream_t* server, uv_stream_t* client) {
   int err;
 
@@ -569,30 +617,12 @@ int uv_accept(uv_stream_t* server, uv_stream_t* client) {
   client->flags |= UV_HANDLE_BOUND;
 
 done:
-  /* Process queued fds */
+  /* Process queued fds if needed */
   if (server->queued_fds != NULL) {
-    uv__stream_queued_fds_t* queued_fds;
-
-    queued_fds = server->queued_fds;
-
-    /* Read first */
-    server->accepted_fd = queued_fds->fds[0];
-
-    /* All read, free */
-    assert(queued_fds->offset > 0);
-    if (--queued_fds->offset == 0) {
-      uv__free(queued_fds);
-      server->queued_fds = NULL;
-    } else {
-      /* Shift rest */
-      memmove(queued_fds->fds,
-              queued_fds->fds + 1,
-              queued_fds->offset * sizeof(*queued_fds->fds));
-    }
+    uv__process_queued_fds(server);
   } else {
     server->accepted_fd = -1;
-    if (err == 0)
-      uv__io_start(server->loop, &server->io_watcher, POLLIN);
+    uv__io_start(server->loop, &server->io_watcher, POLLIN);
   }
   return err;
 }

src/win/stream.c

@@ -48,6 +48,48 @@ int uv_listen(uv_stream_t* stream, int backlog, uv_connection_cb cb) {
 }
 
 
+int uv_reject(uv_stream_t* client) {
+  int err = 0;
+  uv_pipe_t* pipe_client;
+  uv_tcp_accept_t* req;
+
+  if (client == NULL) {
+    return uv_translate_sys_error(ERROR_INVALID_PARAMETER);
+  }
+
+  switch (client->type) {
+    case UV_NAMED_PIPE:
+      pipe_client = (uv_pipe_t*)client;
+      if (pipe_client->u.fd == -1) {
+        CloseHandle(pipe_client->handle);
+      } else {
+        _close(pipe_client->u.fd);
+      }
+
+      pipe_client->u.fd = -1;
+      pipe_client->handle = INVALID_HANDLE_VALUE;
+      break;
+    case UV_TCP:
+      req = ((uv_tcp_t*)client)->tcp.serv.pending_accepts;
+
+      if (!req) {
+        err = WSAEWOULDBLOCK;
+      }
+
+      if (req->accept_socket == INVALID_SOCKET) {
+        err = WSAENOTCONN;
+      }
+
+      closesocket(req->accept_socket);
+      req->accept_socket = INVALID_SOCKET;
+      break;
+    default:
+      err = ERROR_INVALID_PARAMETER;
+  }
+  return uv_translate_sys_error(err);
+}
+
+
 int uv_accept(uv_stream_t* server, uv_stream_t* client) {
   int err;
 

test/test-list.h

@@ -153,6 +153,8 @@ TEST_DECLARE   (tcp_write_to_half_open_connection)
 TEST_DECLARE   (tcp_unexpected_read)
 TEST_DECLARE   (tcp_read_stop)
 TEST_DECLARE   (tcp_read_stop_start)
+TEST_DECLARE   (tcp_reject)
+TEST_DECLARE   (tcp_reject_accept)
 TEST_DECLARE   (tcp_reuseport)
 TEST_DECLARE   (tcp_rst)
 TEST_DECLARE   (tcp_bind6_error_addrinuse)
@@ -213,6 +215,7 @@ TEST_DECLARE   (pipe_getsockname_autobind)
 TEST_DECLARE   (pipe_getsockname_blocking)
 TEST_DECLARE   (pipe_pending_instances)
 TEST_DECLARE   (pipe_sendmsg)
+TEST_DECLARE   (pipe_reject)
 TEST_DECLARE   (pipe_server_close)
 TEST_DECLARE   (connection_fail)
 TEST_DECLARE   (connection_fail_doesnt_auto_close)
@@ -769,6 +772,8 @@ TASK_LIST_START
   TEST_ENTRY  (tcp_close_accept)
   TEST_ENTRY  (tcp_oob)
 #endif
+  TEST_ENTRY  (tcp_reject)
+  TEST_ENTRY  (tcp_reject_accept)
   TEST_ENTRY  (tcp_flags)
   TEST_ENTRY  (tcp_write_to_half_open_connection)
   TEST_ENTRY  (tcp_unexpected_read)
@@ -840,6 +845,7 @@ TASK_LIST_START
   TEST_ENTRY  (pipe_getsockname_blocking)
   TEST_ENTRY  (pipe_pending_instances)
   TEST_ENTRY  (pipe_sendmsg)
+  TEST_ENTRY  (pipe_reject)
 
   TEST_ENTRY  (connection_fail)
   TEST_ENTRY  (connection_fail_doesnt_auto_close)

test/test-pipe-reject.c

@@ -0,0 +1,71 @@
+/* Copyright libuv project and contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "task.h"
+#include "uv.h"
+
+typedef struct {
+  uv_pipe_t pipe_handle;
+  uv_connect_t conn_req;
+} client_t;
+static uv_pipe_t server_handle;
+static client_t client_handle;
+static int connect_cb_called;
+
+static void connect_cb(uv_connect_t* _, int status) {
+  ASSERT_OK(status);
+  connect_cb_called++;
+}
+
+static void connection_pipe_cb(uv_stream_t* server, int status) {
+  ASSERT_OK(uv_reject(server));
+  ASSERT_OK(status);
+  uv_close((uv_handle_t*) &server_handle, NULL);
+}
+
+TEST_IMPL(pipe_reject) {
+
+  int r;
+  uv_loop_t* loop;
+
+  loop = uv_default_loop();
+
+  r = uv_pipe_init(loop, &server_handle, 0);
+  ASSERT_OK(r);
+
+  r = uv_pipe_bind(&server_handle, TEST_PIPENAME);
+  ASSERT_OK(r);
+
+  r = uv_listen((uv_stream_t*)&server_handle, 128, connection_pipe_cb);
+  ASSERT_OK(r);
+
+  r = uv_pipe_init(loop, (uv_pipe_t*)&client_handle, 0);
+  ASSERT_OK(r);
+  uv_pipe_connect(&client_handle.conn_req,
+                  &client_handle.pipe_handle,
+                  TEST_PIPENAME,
+                  connect_cb);
+
+  uv_run(loop, UV_RUN_DEFAULT);
+
+  ASSERT(connect_cb_called == 1);
+  return 0;
+}

test/test-tcp-reject-accept.c

@@ -0,0 +1,137 @@
+/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "uv.h"
+#include "task.h"
+#include <stdio.h>
+#include <stdlib.h>
+
+static int connection_cb_called = 0;
+static int do_accept_called = 0;
+static int close_cb_called = 0;
+static int connect_cb_called = 0;
+uv_tcp_t* server;
+
+static void close_cb(uv_handle_t* handle) {
+  ASSERT_NOT_NULL(handle);
+  free(handle);
+  close_cb_called++;
+}
+
+static void connection_cb(uv_stream_t* tcp, int status) {
+  ASSERT_OK(status);
+
+  if (connection_cb_called == 0) {
+    ASSERT_OK(uv_reject(tcp));
+
+#ifdef _WIN32
+    ASSERT(server->tcp.serv.pending_accepts->accept_socket == INVALID_SOCKET);
+#else
+    ASSERT(server->accepted_fd == -1);
+#endif
+  } else {
+    uv_tcp_t* accepted_handle = (uv_tcp_t*)malloc(sizeof *accepted_handle);
+
+    ASSERT_NOT_NULL(accepted_handle);
+
+    int r = uv_tcp_init(uv_default_loop(), accepted_handle);
+    ASSERT_OK(r);
+
+    r = uv_accept((uv_stream_t*)tcp, (uv_stream_t*)accepted_handle);
+    ASSERT_OK(r);
+
+    do_accept_called++;
+
+    uv_close((uv_handle_t*)accepted_handle, close_cb);
+  }
+
+  /* After accepting the two clients close the server handle */
+  if (do_accept_called == 1) {
+    uv_close((uv_handle_t*)tcp, close_cb);
+  }
+
+  connection_cb_called++;
+}
+
+static void start_server(void) {
+  struct sockaddr_in addr;
+  server = (uv_tcp_t*)malloc(sizeof *server);
+  int r;
+
+  ASSERT_OK(uv_ip4_addr("0.0.0.0", TEST_PORT, &addr));
+  ASSERT_NOT_NULL(server);
+
+  r = uv_tcp_init(uv_default_loop(), server);
+  ASSERT_OK(r);
+  r = uv_tcp_bind(server, (const struct sockaddr*) &addr, 0);
+  ASSERT_OK(r);
+
+  r = uv_listen((uv_stream_t*)server, 128, connection_cb);
+  ASSERT_OK(r);
+}
+
+static void connect_cb(uv_connect_t* req, int status) {
+  ASSERT_NOT_NULL(req);
+  ASSERT_OK(status);
+  connect_cb_called++;
+  free(req);
+}
+
+static void client_connect(uv_tcp_t* client) {
+  struct sockaddr_in addr;
+  int r;
+  uv_connect_t* connect_req = malloc(sizeof *connect_req);
+
+  ASSERT_OK(uv_ip4_addr("127.0.0.1", TEST_PORT, &addr));
+  ASSERT_NOT_NULL(client);
+  ASSERT_NOT_NULL(connect_req);
+
+  ASSERT_OK(uv_tcp_init(uv_default_loop(), client));
+
+  r = uv_tcp_connect(connect_req,
+                     client,
+                     (const struct sockaddr*) &addr,
+                     connect_cb);
+  ASSERT_OK(r);
+}
+
+TEST_IMPL(tcp_reject_accept) {
+  uv_tcp_t client1;
+  uv_tcp_t client2;
+
+  start_server();
+
+  ASSERT_OK(uv_tcp_init(uv_default_loop(), &client1));
+  ASSERT_OK(uv_tcp_init(uv_default_loop(), &client2));
+
+  client_connect(&client1);
+  client_connect(&client2);
+
+  uv_run(uv_default_loop(), UV_RUN_DEFAULT);
+
+  ASSERT_EQ(2, connection_cb_called);
+  ASSERT_EQ(1, do_accept_called);
+  ASSERT_EQ(2, connect_cb_called);
+  ASSERT_EQ(2, close_cb_called);
+
+  MAKE_VALGRIND_HAPPY(uv_default_loop());
+  return 0;
+}

test/test-tcp-reject.c

@@ -0,0 +1,84 @@
+/* Copyright libuv project and contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "task.h"
+#include "uv.h"
+
+static uv_tcp_t server;
+static uv_tcp_t client;
+static int connection_cb_called;
+static int connect_cb_called;
+
+static void connect_cb(uv_connect_t* _, int status) {
+  ASSERT_OK(status);
+  connect_cb_called++;
+}
+
+static void connection_cb(uv_stream_t* tcp, int status) {
+  ASSERT_OK(status);
+  connection_cb_called++;
+
+  /* Reject the connection */
+  ASSERT_OK(uv_reject(tcp));
+
+  /* The server should not have accepted the connection */
+#ifdef _WIN32
+  ASSERT(server.tcp.serv.pending_accepts->accept_socket == INVALID_SOCKET);
+#else
+  ASSERT(server.accepted_fd == -1);
+#endif
+
+  /* Close the server */
+  uv_close((uv_handle_t*) &server, NULL);
+}
+
+static void start_server(void) {
+  struct sockaddr_in addr;
+
+  ASSERT_OK(uv_ip4_addr("0.0.0.0", TEST_PORT, &addr));
+
+  ASSERT_OK(uv_tcp_init(uv_default_loop(), &server));
+  ASSERT_OK(uv_tcp_bind(&server, (struct sockaddr*) &addr, 0));
+  ASSERT_OK(uv_listen((uv_stream_t*) &server, 128, connection_cb));
+}
+
+TEST_IMPL(tcp_reject) {
+  uv_connect_t connect_req;
+  struct sockaddr_in addr;
+
+  start_server();
+
+  ASSERT_OK(uv_ip4_addr("127.0.0.1", TEST_PORT, &addr));
+
+  ASSERT_OK(uv_tcp_init(uv_default_loop(), &client));
+  ASSERT_OK(uv_tcp_connect(&connect_req,
+                           &client,
+                           (struct sockaddr*) &addr,
+                           connect_cb));
+
+  ASSERT_OK(uv_run(uv_default_loop(), UV_RUN_DEFAULT));
+
+  ASSERT_EQ(1, connection_cb_called);
+  ASSERT_EQ(1, connect_cb_called);
+
+  MAKE_VALGRIND_HAPPY(uv_default_loop());
+  return 0;
+}