unix, windows: add uv_fileno

Returns the platform specific file descriptor for handles that are
backed by one. The datatype is abstracted as uv_os_fd_t, which maps to
int on Unices and HANDLE on Windows.

Users can use this function to set specific socket options, for example,
in a non portable way.

This function is essentially a shotgun, you better be careful with
whatever you do with it, don't blame me if you used it to get the fd of
a stream, close it yourself and expect things to Just Work.

Makefile.am

@@ -142,6 +142,7 @@ test_run_tests_SOURCES = test/blackhole-server.c \
                          test/test-getaddrinfo.c \
                          test/test-getnameinfo.c \
                          test/test-getsockname.c \
+                         test/test-handle-fileno.c \
                          test/test-hrtime.c \
                          test/test-idle.c \
                          test/test-ip4-addr.c \

include/uv-unix.h

@@ -125,6 +125,7 @@ typedef struct uv_buf_t {
 
 typedef int uv_file;
 typedef int uv_os_sock_t;
+typedef int uv_os_fd_t;
 
 #define UV_ONCE_INIT PTHREAD_ONCE_INIT
 

include/uv-win.h

@@ -229,8 +229,8 @@ typedef struct uv_buf_t {
 } uv_buf_t;
 
 typedef int uv_file;
-
 typedef SOCKET uv_os_sock_t;
+typedef HANDLE uv_os_fd_t;
 
 typedef HANDLE uv_thread_t;
 

include/uv.h

@@ -615,6 +615,8 @@ UV_EXTERN void uv_close(uv_handle_t* handle, uv_close_cb close_cb);
  */
 UV_EXTERN int uv_recv_buffer_size(uv_handle_t* handle, int* value);
 
+UV_EXTERN int uv_fileno(const uv_handle_t* handle, uv_os_fd_t* fd);
+
 /*
  * Returns or sets the size of the send buffer that the operating
  * system uses for the socket.

src/unix/core.c

@@ -662,6 +662,36 @@ void uv_disable_stdio_inheritance(void) {
 }
 
 
+int uv_fileno(const uv_handle_t* handle, uv_os_fd_t* fd) {
+  int fd_out;
+
+  switch (handle->type) {
+  case UV_TCP:
+  case UV_NAMED_PIPE:
+  case UV_TTY:
+    fd_out = uv__stream_fd((uv_stream_t*) handle);
+    break;
+
+  case UV_UDP:
+    fd_out = ((uv_udp_t *) handle)->io_watcher.fd;
+    break;
+
+  case UV_POLL:
+    fd_out = ((uv_poll_t *) handle)->io_watcher.fd;
+    break;
+
+  default:
+    return -EINVAL;
+  }
+
+  if (uv__is_closing(handle) || fd_out == -1)
+    return -EBADF;
+
+  *fd = fd_out;
+  return 0;
+}
+
+
 static void uv__run_pending(uv_loop_t* loop) {
   QUEUE* q;
   uv__io_t* w;

src/win/core.c

@@ -429,6 +429,43 @@ int uv_run(uv_loop_t *loop, uv_run_mode mode) {
   return r;
 }
 
+
+int uv_fileno(const uv_handle_t* handle, uv_os_fd_t* fd) {
+  uv_os_fd_t fd_out;
+
+  switch (handle->type) {
+  case UV_TCP:
+    fd_out = (uv_os_fd_t)((uv_tcp_t*) handle)->socket;
+    break;
+
+  case UV_NAMED_PIPE:
+    fd_out = ((uv_pipe_t*) handle)->handle;
+    break;
+
+  case UV_TTY:
+    fd_out = ((uv_tty_t*) handle)->handle;
+    break;
+
+  case UV_UDP:
+    fd_out = (uv_os_fd_t)((uv_udp_t*) handle)->socket;
+    break;
+
+  case UV_POLL:
+    fd_out = (uv_os_fd_t)((uv_poll_t*) handle)->socket;
+    break;
+
+  default:
+    return UV_EINVAL;
+  }
+
+  if (uv_is_closing(handle) || fd_out == INVALID_HANDLE_VALUE)
+    return UV_EBADF;
+
+  *fd = fd_out;
+  return 0;
+}
+
+
 int uv__socket_sockopt(uv_handle_t* handle, int optname, int* value) {
   int r;
   int len;

test/test-handle-fileno.c

@@ -0,0 +1,120 @@
+/* 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"
+
+
+static int get_tty_fd(void) {
+  /* Make sure we have an FD that refers to a tty */
+#ifdef _WIN32
+  HANDLE handle;
+  handle = CreateFileA("conout$",
+                       GENERIC_READ | GENERIC_WRITE,
+                       FILE_SHARE_READ | FILE_SHARE_WRITE,
+                       NULL,
+                       OPEN_EXISTING,
+                       FILE_ATTRIBUTE_NORMAL,
+                       NULL);
+  if (handle == INVALID_HANDLE_VALUE)
+    return -1;
+  return _open_osfhandle((intptr_t) handle, 0);
+#else /* unix */
+  return open("/dev/tty", O_RDONLY, 0);
+#endif
+}
+
+
+TEST_IMPL(handle_fileno) {
+  int r;
+  int tty_fd;
+  struct sockaddr_in addr;
+  uv_os_fd_t fd;
+  uv_tcp_t tcp;
+  uv_udp_t udp;
+  uv_pipe_t pipe;
+  uv_tty_t tty;
+  uv_idle_t idle;
+  uv_loop_t* loop;
+
+  loop = uv_default_loop();
+  ASSERT(0 == uv_ip4_addr("127.0.0.1", TEST_PORT, &addr));
+
+  r = uv_idle_init(loop, &idle);
+  ASSERT(r == 0);
+  r = uv_fileno((uv_handle_t*) &idle, &fd);
+  ASSERT(r == UV_EINVAL);
+  uv_close((uv_handle_t*) &idle, NULL);
+
+  r = uv_tcp_init(loop, &tcp);
+  ASSERT(r == 0);
+  r = uv_fileno((uv_handle_t*) &tcp, &fd);
+  ASSERT(r == UV_EBADF);
+  r = uv_tcp_bind(&tcp, (const struct sockaddr*) &addr, 0);
+  ASSERT(r == 0);
+  r = uv_fileno((uv_handle_t*) &tcp, &fd);
+  ASSERT(r == 0);
+  uv_close((uv_handle_t*) &tcp, NULL);
+  r = uv_fileno((uv_handle_t*) &tcp, &fd);
+  ASSERT(r == UV_EBADF);
+
+  r = uv_udp_init(loop, &udp);
+  ASSERT(r == 0);
+  r = uv_fileno((uv_handle_t*) &udp, &fd);
+  ASSERT(r == UV_EBADF);
+  r = uv_udp_bind(&udp, (const struct sockaddr*) &addr, 0);
+  ASSERT(r == 0);
+  r = uv_fileno((uv_handle_t*) &udp, &fd);
+  ASSERT(r == 0);
+  uv_close((uv_handle_t*) &udp, NULL);
+  r = uv_fileno((uv_handle_t*) &udp, &fd);
+  ASSERT(r == UV_EBADF);
+
+  r = uv_pipe_init(loop, &pipe, 0);
+  ASSERT(r == 0);
+  r = uv_fileno((uv_handle_t*) &pipe, &fd);
+  ASSERT(r == UV_EBADF);
+  r = uv_pipe_bind(&pipe, TEST_PIPENAME);
+  ASSERT(r == 0);
+  r = uv_fileno((uv_handle_t*) &pipe, &fd);
+  ASSERT(r == 0);
+  uv_close((uv_handle_t*) &pipe, NULL);
+  r = uv_fileno((uv_handle_t*) &pipe, &fd);
+  ASSERT(r == UV_EBADF);
+
+  tty_fd = get_tty_fd();
+  if (tty_fd < 0) {
+    LOGF("Cannot open a TTY fd");
+  } else {
+    r = uv_tty_init(loop, &tty, tty_fd, 0);
+    ASSERT(r == 0);
+    r = uv_fileno((uv_handle_t*) &tty, &fd);
+    ASSERT(r == 0);
+    uv_close((uv_handle_t*) &tty, NULL);
+    r = uv_fileno((uv_handle_t*) &tty, &fd);
+    ASSERT(r == UV_EBADF);
+  }
+
+  uv_run(loop, UV_RUN_DEFAULT);
+
+  MAKE_VALGRIND_HAPPY();
+  return 0;
+}

test/test-list.h

@@ -172,6 +172,7 @@ TEST_DECLARE   (get_currentexe)
 TEST_DECLARE   (process_title)
 TEST_DECLARE   (cwd_and_chdir)
 TEST_DECLARE   (get_memory)
+TEST_DECLARE   (handle_fileno)
 TEST_DECLARE   (hrtime)
 TEST_DECLARE   (getaddrinfo_fail)
 TEST_DECLARE   (getaddrinfo_basic)
@@ -503,6 +504,8 @@ TASK_LIST_START
 
   TEST_ENTRY  (get_loadavg)
 
+  TEST_ENTRY  (handle_fileno)
+
   TEST_ENTRY  (hrtime)
 
   TEST_ENTRY_CUSTOM (getaddrinfo_fail, 0, 0, 10000)

uv.gyp

@@ -321,6 +321,7 @@
         'test/test-getaddrinfo.c',
         'test/test-getnameinfo.c',
         'test/test-getsockname.c',
+        'test/test-handle-fileno.c',
         'test/test-hrtime.c',
         'test/test-idle.c',
         'test/test-ip6-addr.c',