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+/* Test of select() substitute.
+   Copyright (C) 2008 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Paolo Bonzini, 2008.  */
+
+#include <config.h>
+
+#include <sys/select.h>
+
+#include <stdio.h>
+#include <string.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <errno.h>
+#include "sockets.h"
+
+enum { SEL_IN = 1, SEL_OUT = 2, SEL_EXC = 4 };
+
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+# define WIN32_NATIVE
+#endif
+
+#ifdef WIN32_NATIVE
+#include <io.h>
+#define pipe(x) _pipe(x, 256, O_BINARY)
+#endif
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_SYS_WAIT_H
+#include <sys/wait.h>
+#endif
+
+#ifndef SO_REUSEPORT
+#define SO_REUSEPORT    SO_REUSEADDR
+#endif
+
+#define TEST_PORT	12345
+
+
+/* Minimal testing infrastructure.  */
+
+static int failures;
+
+static void
+failed (const char *reason)
+{
+  if (++failures > 1)
+    printf ("  ");
+  printf ("failed (%s)\n", reason);
+}
+
+static int
+test (void (*fn) (void), const char *msg)
+{
+  failures = 0;
+  printf ("%s... ", msg);
+  fflush (stdout);
+  fn ();
+
+  if (!failures)
+    printf ("passed\n");
+
+  return failures;
+}
+
+
+/* Funny socket code.  */
+
+static int
+open_server_socket ()
+{
+  int s, x;
+  struct sockaddr_in ia;
+
+  s = socket (AF_INET, SOCK_STREAM, 0);
+
+  memset (&ia, 0, sizeof (ia));
+  ia.sin_family = AF_INET;
+  inet_pton (AF_INET, "127.0.0.1", &ia.sin_addr);
+  ia.sin_port = htons (TEST_PORT);
+  if (bind (s, (struct sockaddr *) &ia, sizeof (ia)) < 0)
+    {
+      perror ("bind");
+      exit (77);
+    }
+
+  x = 1;
+  setsockopt (s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof (x));
+
+  if (listen (s, 1) < 0)
+    {
+      perror ("listen");
+      exit (77);
+    }
+
+  return s;
+}
+
+static int
+connect_to_socket (int blocking)
+{
+  int s;
+  struct sockaddr_in ia;
+
+  s = socket (AF_INET, SOCK_STREAM, 0);
+
+  memset (&ia, 0, sizeof (ia));
+  ia.sin_family = AF_INET;
+  inet_pton (AF_INET, "127.0.0.1", &ia.sin_addr);
+  ia.sin_port = htons (TEST_PORT);
+
+  if (!blocking)
+    {
+#ifdef WIN32_NATIVE
+      unsigned long iMode = 1;
+      ioctl (s, FIONBIO, (char *) &iMode);
+
+#elif defined F_GETFL
+      int oldflags = fcntl (s, F_GETFL, NULL);
+
+      if (!(oldflags & O_NONBLOCK))
+        fcntl (s, F_SETFL, oldflags | O_NONBLOCK);
+#endif
+    }
+
+  if (connect (s, (struct sockaddr *) &ia, sizeof (ia)) < 0
+      && (blocking || errno != EINPROGRESS))
+    {
+      perror ("connect");
+      exit (77);
+    }
+
+  return s;
+}
+
+
+/* A slightly more convenient interface to select(2).  */
+
+static int
+do_select (int fd, int ev, struct timeval *tv)
+{
+  fd_set rfds, wfds, xfds;
+  int r, rev;
+
+  FD_ZERO (&rfds);
+  FD_ZERO (&wfds);
+  FD_ZERO (&xfds);
+  if (ev & SEL_IN)
+    FD_SET (fd, &rfds);
+  if (ev & SEL_OUT)
+    FD_SET (fd, &wfds);
+  if (ev & SEL_EXC)
+    FD_SET (fd, &xfds);
+  r = select (fd + 1, &rfds, &wfds, &xfds, tv);
+  if (r < 0)
+    return r;
+
+  rev = 0;
+  if (FD_ISSET (fd, &rfds))
+    rev |= SEL_IN;
+  if (FD_ISSET (fd, &wfds))
+    rev |= SEL_OUT;
+  if (FD_ISSET (fd, &xfds))
+    rev |= SEL_EXC;
+  if (rev && r == 0)
+    failed ("select returned 0");
+  if (rev & ~ev)
+    failed ("select returned unrequested events");
+
+  return rev;
+}
+
+static int
+do_select_nowait (int fd, int ev)
+{
+  static struct timeval tv0;
+  return do_select (fd, ev, &tv0);
+}
+
+static int
+do_select_wait (int fd, int ev)
+{
+  return do_select (fd, ev, NULL);
+}
+
+
+/* Test poll(2) for TTYs.  */
+
+#ifdef INTERACTIVE
+static void
+test_tty (void)
+{
+  if (do_select_nowait (0, SEL_IN) != 0)
+    failed ("can read");
+  if (do_select_nowait (0, SEL_OUT) == 0)
+    failed ("cannot write");
+
+  if (do_select_wait (0, SEL_IN) == 0)
+    failed ("return with infinite timeout");
+
+  getchar ();
+  if (do_select_nowait (0, SEL_IN) != 0)
+    failed ("can read after getc");
+}
+#endif
+
+
+/* Test poll(2) for unconnected nonblocking sockets.  */
+
+static void
+test_connect_first (void)
+{
+  int s = open_server_socket ();
+  struct sockaddr_in ia;
+  socklen_t addrlen;
+
+  int c1, c2;
+
+  if (do_select_nowait (s, SEL_IN | SEL_EXC) != 0)
+    failed ("can read, socket not connected");
+
+  c1 = connect_to_socket (false);
+
+  if (do_select_wait (s, SEL_IN | SEL_EXC) != SEL_IN)
+    failed ("expecting readability on passive socket");
+  if (do_select_nowait (s, SEL_IN | SEL_EXC) != SEL_IN)
+    failed ("expecting readability on passive socket");
+
+  addrlen = sizeof (ia);
+  c2 = accept (s, (struct sockaddr *) &ia, &addrlen);
+  close (s);
+  close (c1);
+  close (c2);
+}
+
+
+/* Test poll(2) for unconnected blocking sockets.  */
+
+static void
+test_accept_first (void)
+{
+#ifndef WIN32_NATIVE
+  int s = open_server_socket ();
+  struct sockaddr_in ia;
+  socklen_t addrlen;
+  char buf[3];
+  int c, pid;
+
+  pid = fork ();
+  if (pid < 0)
+    return;
+
+  if (pid == 0)
+    {
+      addrlen = sizeof (ia);
+      c = accept (s, (struct sockaddr *) &ia, &addrlen);
+      close (s);
+      write (c, "foo", 3);
+      read (c, buf, 3);
+      shutdown (c, SHUT_RD);
+      close (c);
+      exit (0);
+    }
+  else
+    {
+      close (s);
+      c = connect_to_socket (true);
+      if (do_select_nowait (c, SEL_OUT) != SEL_OUT)
+        failed ("cannot write after blocking connect");
+      write (c, "foo", 3);
+      wait (&pid);
+      if (do_select_wait (c, SEL_IN) != SEL_IN)
+        failed ("cannot read data left in the socket by closed process");
+      read (c, buf, 3);
+      write (c, "foo", 3);
+      close (c);
+    }
+#endif
+}
+
+
+/* Common code for pipes and connected sockets.  */
+
+static void
+test_pair (int rd, int wd)
+{
+  char buf[3];
+  if (do_select_wait (wd, SEL_IN | SEL_OUT | SEL_EXC) != SEL_OUT)
+    failed ("expecting writability before writing");
+  if (do_select_nowait (wd, SEL_IN | SEL_OUT | SEL_EXC) != SEL_OUT)
+    failed ("expecting writability before writing");
+
+  write (wd, "foo", 3);
+  if (do_select_wait (rd, SEL_IN) != SEL_IN)
+    failed ("expecting readability after writing");
+  if (do_select_nowait (rd, SEL_IN) != SEL_IN)
+    failed ("expecting readability after writing");
+
+  read (rd, buf, 3);
+}
+
+
+/* Test poll(2) on connected sockets.  */
+
+static void
+test_socket_pair (void)
+{
+  struct sockaddr_in ia;
+
+  socklen_t addrlen = sizeof (ia);
+  int s = open_server_socket ();
+  int c1 = connect_to_socket (false);
+  int c2 = accept (s, (struct sockaddr *) &ia, &addrlen);
+
+  close (s);
+
+  test_pair (c1, c2);
+  close (c1);
+  write (c2, "foo", 3);
+  close (c2);
+}
+
+
+/* Test poll(2) on pipes.  */
+
+static void
+test_pipe (void)
+{
+  int fd[2];
+
+  pipe (fd);
+  test_pair (fd[0], fd[1]);
+  close (fd[0]);
+  close (fd[1]);
+}
+
+
+/* Do them all.  */
+
+int
+main ()
+{
+  int result;
+
+  gl_sockets_startup (SOCKETS_1_1);
+
+#ifdef INTERACTIVE
+  printf ("Please press Enter\n");
+  test (test_tty, "TTY");
+#endif
+
+  result = test (test_connect_first, "Unconnected socket test");
+  result += test (test_socket_pair, "Connected sockets test");
+  result += test (test_accept_first, "General socket test with fork");
+  result += test (test_pipe, "Pipe test");
+
+  exit (result);
+}