gnulib: import select

A few sims use this to emulate the syscall & provide network
functionality.

20 files changed, 2402 insertions, 26 deletions

diff --git a/gnulib/ChangeLog b/gnulib/ChangeLog
index 9d74f1d..223b663 100644
--- a/gnulib/ChangeLog
+++ b/gnulib/ChangeLog
@@ -1,6 +1,16 @@
 2021-06-08  Mike Frysinger  <vapier@gentoo.org>
 
 	* update-gnulib.sh (IMPORTED_GNULIB_MODULES): Add netdb.
+	* aclocal.m4, config.in, configure, Makefile.gnulib.inc.in,
+	Makefile.in, import/Makefile.am, import/Makefile.in,
+	import/m4/gnulib-cache.m4, import/m4/gnulib-comp.m4: Regenerate.
+	* import/m4/select.m4, import/m4/socketlib.m4, import/m4/sockets.m4,
+	import/m4/sys_select_h.m4, import/select.c, import/sockets.c,
+	import/sockets.h, import/sys_select.in.h, import/w32sock.h: New files.
+
+2021-06-08  Mike Frysinger  <vapier@gentoo.org>
+
+	* update-gnulib.sh (IMPORTED_GNULIB_MODULES): Add netdb.
 	* aclocal.m4, configure, Makefile.in, import/Makefile.am,
 	import/Makefile.in, import/m4/gnulib-cache.m4,
 	import/m4/gnulib-comp.m4: Regenerate.
diff --git a/gnulib/Makefile.gnulib.inc.in b/gnulib/Makefile.gnulib.inc.in
index 8cac19f..822f892 100644
--- a/gnulib/Makefile.gnulib.inc.in
+++ b/gnulib/Makefile.gnulib.inc.in
@@ -40,5 +40,5 @@ LIBGNU = $(GNULIB_BUILDDIR)/import/libgnu.a
 LIBGNU_EXTRA_LIBS = @FREXPL_LIBM@ @FREXP_LIBM@ @INET_NTOP_LIB@ \
                     @LIBTHREAD@ @LIB_GETLOGIN@ @LIB_GETRANDOM@ \
                     @LIB_HARD_LOCALE@ @LIB_MBRTOWC@ \
-                    @LIB_SETLOCALE_NULL@ @LIBINTL@
+                    @LIB_SETLOCALE_NULL@ @LIBINTL@ @LIB_SELECT@ @LIBSOCKET@
 INCGNU = -I$(srcdir)/../gnulib/import -I$(GNULIB_BUILDDIR)/import
diff --git a/gnulib/Makefile.in b/gnulib/Makefile.in
index be15472..e1b9b34 100644
--- a/gnulib/Makefile.in
+++ b/gnulib/Makefile.in
@@ -231,9 +231,12 @@ am__aclocal_m4_deps = $(top_srcdir)/../config/depstand.m4 \
 	$(top_srcdir)/import/m4/rewinddir.m4 \
 	$(top_srcdir)/import/m4/rmdir.m4 \
 	$(top_srcdir)/import/m4/save-cwd.m4 \
+	$(top_srcdir)/import/m4/select.m4 \
 	$(top_srcdir)/import/m4/setenv.m4 \
 	$(top_srcdir)/import/m4/setlocale_null.m4 \
 	$(top_srcdir)/import/m4/signal_h.m4 \
+	$(top_srcdir)/import/m4/socketlib.m4 \
+	$(top_srcdir)/import/m4/sockets.m4 \
 	$(top_srcdir)/import/m4/socklen.m4 \
 	$(top_srcdir)/import/m4/sockpfaf.m4 \
 	$(top_srcdir)/import/m4/ssize_t.m4 \
@@ -256,6 +259,7 @@ am__aclocal_m4_deps = $(top_srcdir)/../config/depstand.m4 \
 	$(top_srcdir)/import/m4/strstr.m4 \
 	$(top_srcdir)/import/m4/strtok_r.m4 \
 	$(top_srcdir)/import/m4/sys_random_h.m4 \
+	$(top_srcdir)/import/m4/sys_select_h.m4 \
 	$(top_srcdir)/import/m4/sys_socket_h.m4 \
 	$(top_srcdir)/import/m4/sys_stat_h.m4 \
 	$(top_srcdir)/import/m4/sys_time_h.m4 \
@@ -680,6 +684,7 @@ GNULIB_POWF = @GNULIB_POWF@
 GNULIB_PREAD = @GNULIB_PREAD@
 GNULIB_PRINTF = @GNULIB_PRINTF@
 GNULIB_PRINTF_POSIX = @GNULIB_PRINTF_POSIX@
+GNULIB_PSELECT = @GNULIB_PSELECT@
 GNULIB_PTHREAD_SIGMASK = @GNULIB_PTHREAD_SIGMASK@
 GNULIB_PTSNAME = @GNULIB_PTSNAME@
 GNULIB_PTSNAME_R = @GNULIB_PTSNAME_R@
@@ -720,6 +725,7 @@ GNULIB_RPMATCH = @GNULIB_RPMATCH@
 GNULIB_SCANDIR = @GNULIB_SCANDIR@
 GNULIB_SCANF = @GNULIB_SCANF@
 GNULIB_SECURE_GETENV = @GNULIB_SECURE_GETENV@
+GNULIB_SELECT = @GNULIB_SELECT@
 GNULIB_SEND = @GNULIB_SEND@
 GNULIB_SENDTO = @GNULIB_SENDTO@
 GNULIB_SETENV = @GNULIB_SETENV@
@@ -1088,6 +1094,7 @@ HAVE_POSIX_OPENPT = @HAVE_POSIX_OPENPT@
 HAVE_POSIX_SIGNALBLOCKING = @HAVE_POSIX_SIGNALBLOCKING@
 HAVE_POWF = @HAVE_POWF@
 HAVE_PREAD = @HAVE_PREAD@
+HAVE_PSELECT = @HAVE_PSELECT@
 HAVE_PTHREAD_SIGMASK = @HAVE_PTHREAD_SIGMASK@
 HAVE_PTSNAME = @HAVE_PTSNAME@
 HAVE_PTSNAME_R = @HAVE_PTSNAME_R@
@@ -1161,6 +1168,7 @@ HAVE_SYS_INTTYPES_H = @HAVE_SYS_INTTYPES_H@
 HAVE_SYS_LOADAVG_H = @HAVE_SYS_LOADAVG_H@
 HAVE_SYS_PARAM_H = @HAVE_SYS_PARAM_H@
 HAVE_SYS_RANDOM_H = @HAVE_SYS_RANDOM_H@
+HAVE_SYS_SELECT_H = @HAVE_SYS_SELECT_H@
 HAVE_SYS_SOCKET_H = @HAVE_SYS_SOCKET_H@
 HAVE_SYS_TIME_H = @HAVE_SYS_TIME_H@
 HAVE_SYS_TYPES_H = @HAVE_SYS_TYPES_H@
@@ -1244,6 +1252,7 @@ LIBOBJS = @LIBOBJS@
 LIBPMULTITHREAD = @LIBPMULTITHREAD@
 LIBPTHREAD = @LIBPTHREAD@
 LIBS = @LIBS@
+LIBSOCKET = @LIBSOCKET@
 LIBSTDTHREAD = @LIBSTDTHREAD@
 LIBTHREAD = @LIBTHREAD@
 LIB_CLOCK_GETTIME = @LIB_CLOCK_GETTIME@
@@ -1252,6 +1261,7 @@ LIB_GETRANDOM = @LIB_GETRANDOM@
 LIB_HARD_LOCALE = @LIB_HARD_LOCALE@
 LIB_MBRTOWC = @LIB_MBRTOWC@
 LIB_SCHED_YIELD = @LIB_SCHED_YIELD@
+LIB_SELECT = @LIB_SELECT@
 LIB_SETLOCALE_NULL = @LIB_SETLOCALE_NULL@
 LIMITS_H = @LIMITS_H@
 LN_S = @LN_S@
@@ -1291,6 +1301,7 @@ NEXT_AS_FIRST_DIRECTIVE_STDLIB_H = @NEXT_AS_FIRST_DIRECTIVE_STDLIB_H@
 NEXT_AS_FIRST_DIRECTIVE_STRINGS_H = @NEXT_AS_FIRST_DIRECTIVE_STRINGS_H@
 NEXT_AS_FIRST_DIRECTIVE_STRING_H = @NEXT_AS_FIRST_DIRECTIVE_STRING_H@
 NEXT_AS_FIRST_DIRECTIVE_SYS_RANDOM_H = @NEXT_AS_FIRST_DIRECTIVE_SYS_RANDOM_H@
+NEXT_AS_FIRST_DIRECTIVE_SYS_SELECT_H = @NEXT_AS_FIRST_DIRECTIVE_SYS_SELECT_H@
 NEXT_AS_FIRST_DIRECTIVE_SYS_SOCKET_H = @NEXT_AS_FIRST_DIRECTIVE_SYS_SOCKET_H@
 NEXT_AS_FIRST_DIRECTIVE_SYS_STAT_H = @NEXT_AS_FIRST_DIRECTIVE_SYS_STAT_H@
 NEXT_AS_FIRST_DIRECTIVE_SYS_TIME_H = @NEXT_AS_FIRST_DIRECTIVE_SYS_TIME_H@
@@ -1321,6 +1332,7 @@ NEXT_STDLIB_H = @NEXT_STDLIB_H@
 NEXT_STRINGS_H = @NEXT_STRINGS_H@
 NEXT_STRING_H = @NEXT_STRING_H@
 NEXT_SYS_RANDOM_H = @NEXT_SYS_RANDOM_H@
+NEXT_SYS_SELECT_H = @NEXT_SYS_SELECT_H@
 NEXT_SYS_SOCKET_H = @NEXT_SYS_SOCKET_H@
 NEXT_SYS_STAT_H = @NEXT_SYS_STAT_H@
 NEXT_SYS_TIME_H = @NEXT_SYS_TIME_H@
@@ -1514,6 +1526,7 @@ REPLACE_POPEN = @REPLACE_POPEN@
 REPLACE_POSIX_MEMALIGN = @REPLACE_POSIX_MEMALIGN@
 REPLACE_PREAD = @REPLACE_PREAD@
 REPLACE_PRINTF = @REPLACE_PRINTF@
+REPLACE_PSELECT = @REPLACE_PSELECT@
 REPLACE_PTHREAD_SIGMASK = @REPLACE_PTHREAD_SIGMASK@
 REPLACE_PTSNAME = @REPLACE_PTSNAME@
 REPLACE_PTSNAME_R = @REPLACE_PTSNAME_R@
@@ -1539,6 +1552,7 @@ REPLACE_RMDIR = @REPLACE_RMDIR@
 REPLACE_ROUND = @REPLACE_ROUND@
 REPLACE_ROUNDF = @REPLACE_ROUNDF@
 REPLACE_ROUNDL = @REPLACE_ROUNDL@
+REPLACE_SELECT = @REPLACE_SELECT@
 REPLACE_SETENV = @REPLACE_SETENV@
 REPLACE_SETLOCALE = @REPLACE_SETLOCALE@
 REPLACE_SETSTATE = @REPLACE_SETSTATE@
diff --git a/gnulib/aclocal.m4 b/gnulib/aclocal.m4
index 96f7dc6..83780b6 100644
--- a/gnulib/aclocal.m4
+++ b/gnulib/aclocal.m4
@@ -1304,9 +1304,12 @@ m4_include([import/m4/rename.m4])
 m4_include([import/m4/rewinddir.m4])
 m4_include([import/m4/rmdir.m4])
 m4_include([import/m4/save-cwd.m4])
+m4_include([import/m4/select.m4])
 m4_include([import/m4/setenv.m4])
 m4_include([import/m4/setlocale_null.m4])
 m4_include([import/m4/signal_h.m4])
+m4_include([import/m4/socketlib.m4])
+m4_include([import/m4/sockets.m4])
 m4_include([import/m4/socklen.m4])
 m4_include([import/m4/sockpfaf.m4])
 m4_include([import/m4/ssize_t.m4])
@@ -1329,6 +1332,7 @@ m4_include([import/m4/strnlen.m4])
 m4_include([import/m4/strstr.m4])
 m4_include([import/m4/strtok_r.m4])
 m4_include([import/m4/sys_random_h.m4])
+m4_include([import/m4/sys_select_h.m4])
 m4_include([import/m4/sys_socket_h.m4])
 m4_include([import/m4/sys_stat_h.m4])
 m4_include([import/m4/sys_time_h.m4])
diff --git a/gnulib/config.in b/gnulib/config.in
index 15abb17..a90ddd6 100644
--- a/gnulib/config.in
+++ b/gnulib/config.in
@@ -303,6 +303,9 @@
 /* Define to 1 when the gnulib module rmdir should be tested. */
 #undef GNULIB_TEST_RMDIR
 
+/* Define to 1 when the gnulib module select should be tested. */
+#undef GNULIB_TEST_SELECT
+
 /* Define to 1 when the gnulib module setenv should be tested. */
 #undef GNULIB_TEST_SETENV
 
@@ -880,6 +883,9 @@
 /* Define to 1 if you have the <sys/random.h> header file. */
 #undef HAVE_SYS_RANDOM_H
 
+/* Define to 1 if you have the <sys/select.h> header file. */
+#undef HAVE_SYS_SELECT_H
+
 /* Define to 1 if you have the <sys/socket.h> header file. */
 #undef HAVE_SYS_SOCKET_H
 
@@ -1252,6 +1258,9 @@
    'wchar_t'. */
 #undef WCHAR_T_SUFFIX
 
+/* Define if WSAStartup is needed. */
+#undef WINDOWS_SOCKETS
+
 /* Define to l, ll, u, ul, ull, etc., as suitable for constants of type
    'wint_t'. */
 #undef WINT_T_SUFFIX
diff --git a/gnulib/configure b/gnulib/configure
index d447121..73a3808 100644
--- a/gnulib/configure
+++ b/gnulib/configure
@@ -776,6 +776,16 @@ GNULIB_SIGPROCMASK
 GNULIB_SIGNAL_H_SIGPIPE
 GNULIB_RAISE
 GNULIB_PTHREAD_SIGMASK
+LIB_SELECT
+LIBSOCKET
+HAVE_SYS_SELECT_H
+NEXT_AS_FIRST_DIRECTIVE_SYS_SELECT_H
+NEXT_SYS_SELECT_H
+REPLACE_SELECT
+REPLACE_PSELECT
+HAVE_PSELECT
+GNULIB_SELECT
+GNULIB_PSELECT
 GL_GENERATE_NETINET_IN_H_FALSE
 GL_GENERATE_NETINET_IN_H_TRUE
 NETINET_IN_H
@@ -3783,6 +3793,7 @@ as_fn_append ac_func_list " openat"
 as_fn_append ac_func_list " pipe"
 as_fn_append ac_func_list " readlink"
 as_fn_append ac_func_list " link"
+as_fn_append ac_header_list " sys/select.h"
 as_fn_append ac_func_list " setenv"
 as_fn_append ac_func_list " strerror_r"
 as_fn_append ac_func_list " __xpg_strerror_r"
@@ -6813,6 +6824,7 @@ fi
   # Code from module same-inode:
   # Code from module save-cwd:
   # Code from module scratch_buffer:
+  # Code from module select:
   # Code from module setenv:
   # Code from module setlocale-null:
   # Code from module signal-h:
@@ -6820,6 +6832,8 @@ fi
   # Code from module snippet/arg-nonnull:
   # Code from module snippet/c++defs:
   # Code from module snippet/warn-on-use:
+  # Code from module socketlib:
+  # Code from module sockets:
   # Code from module socklen:
   # Code from module ssize_t:
   # Code from module stat:
@@ -6845,6 +6859,7 @@ fi
   # Code from module strstr-simple:
   # Code from module strtok_r:
   # Code from module sys_random:
+  # Code from module sys_select:
   # Code from module sys_socket:
   # Code from module sys_stat:
   # Code from module sys_time:
@@ -16475,6 +16490,409 @@ _ACEOF
 
 
 
+
+  GNULIB_PSELECT=0;
+  GNULIB_SELECT=0;
+    HAVE_PSELECT=1;
+  REPLACE_PSELECT=0;
+  REPLACE_SELECT=0;
+
+
+
+
+
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether <sys/select.h> is self-contained" >&5
+$as_echo_n "checking whether <sys/select.h> is self-contained... " >&6; }
+if ${gl_cv_header_sys_select_h_selfcontained+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+                                    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <sys/select.h>
+int
+main ()
+{
+struct timeval b;
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  gl_cv_header_sys_select_h_selfcontained=yes
+else
+  gl_cv_header_sys_select_h_selfcontained=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+                        if test $gl_cv_header_sys_select_h_selfcontained = yes; then
+        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <sys/select.h>
+int
+main ()
+{
+int memset; int bzero;
+  ;
+  return 0;
+}
+
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <sys/select.h>
+int
+main ()
+{
+
+                  #undef memset
+                  #define memset nonexistent_memset
+                  extern
+                  #ifdef __cplusplus
+                  "C"
+                  #endif
+                  void *memset (void *, int, unsigned long);
+                  #undef bzero
+                  #define bzero nonexistent_bzero
+                  extern
+                  #ifdef __cplusplus
+                  "C"
+                  #endif
+                  void bzero (void *, unsigned long);
+                  fd_set fds;
+                  FD_ZERO (&fds);
+
+  ;
+  return 0;
+}
+
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+
+else
+  gl_cv_header_sys_select_h_selfcontained=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+      fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gl_cv_header_sys_select_h_selfcontained" >&5
+$as_echo "$gl_cv_header_sys_select_h_selfcontained" >&6; }
+
+
+
+
+
+
+
+
+
+     if test $gl_cv_have_include_next = yes; then
+       gl_cv_next_sys_select_h='<'sys/select.h'>'
+     else
+       { $as_echo "$as_me:${as_lineno-$LINENO}: checking absolute name of <sys/select.h>" >&5
+$as_echo_n "checking absolute name of <sys/select.h>... " >&6; }
+if ${gl_cv_next_sys_select_h+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+             if test $ac_cv_header_sys_select_h = yes; then
+
+
+
+
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <sys/select.h>
+_ACEOF
+                case "$host_os" in
+    aix*) gl_absname_cpp="$ac_cpp -C" ;;
+    *)    gl_absname_cpp="$ac_cpp" ;;
+  esac
+
+  case "$host_os" in
+    mingw*)
+                                          gl_dirsep_regex='[/\\]'
+      ;;
+    *)
+      gl_dirsep_regex='\/'
+      ;;
+  esac
+      gl_make_literal_regex_sed='s,[]$^\\.*/[],\\&,g'
+  gl_header_literal_regex=`echo 'sys/select.h' \
+                           | sed -e "$gl_make_literal_regex_sed"`
+  gl_absolute_header_sed="/${gl_dirsep_regex}${gl_header_literal_regex}/"'{
+      s/.*"\(.*'"${gl_dirsep_regex}${gl_header_literal_regex}"'\)".*/\1/
+      s|^/[^/]|//&|
+      p
+      q
+    }'
+
+        gl_cv_absolute_sys_select_h=`(eval "$gl_absname_cpp conftest.$ac_ext") 2>&5 |
+  sed -n "$gl_absolute_header_sed"`
+
+           gl_header=$gl_cv_absolute_sys_select_h
+           gl_cv_next_sys_select_h='"'$gl_header'"'
+          else
+               gl_cv_next_sys_select_h='<'sys/select.h'>'
+             fi
+
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gl_cv_next_sys_select_h" >&5
+$as_echo "$gl_cv_next_sys_select_h" >&6; }
+     fi
+     NEXT_SYS_SELECT_H=$gl_cv_next_sys_select_h
+
+     if test $gl_cv_have_include_next = yes || test $gl_cv_have_include_next = buggy; then
+       # INCLUDE_NEXT_AS_FIRST_DIRECTIVE='include_next'
+       gl_next_as_first_directive='<'sys/select.h'>'
+     else
+       # INCLUDE_NEXT_AS_FIRST_DIRECTIVE='include'
+       gl_next_as_first_directive=$gl_cv_next_sys_select_h
+     fi
+     NEXT_AS_FIRST_DIRECTIVE_SYS_SELECT_H=$gl_next_as_first_directive
+
+
+
+
+  if test $ac_cv_header_sys_select_h = yes; then
+    HAVE_SYS_SELECT_H=1
+  else
+    HAVE_SYS_SELECT_H=0
+  fi
+
+
+
+
+
+  if test $ac_cv_header_sys_socket_h != yes; then
+                    for ac_header in winsock2.h
+do :
+  ac_fn_c_check_header_mongrel "$LINENO" "winsock2.h" "ac_cv_header_winsock2_h" "$ac_includes_default"
+if test "x$ac_cv_header_winsock2_h" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_WINSOCK2_H 1
+_ACEOF
+
+fi
+
+done
+
+  fi
+  if test "$ac_cv_header_winsock2_h" = yes; then
+    HAVE_WINSOCK2_H=1
+    UNISTD_H_HAVE_WINSOCK2_H=1
+    SYS_IOCTL_H_HAVE_WINSOCK2_H=1
+  else
+    HAVE_WINSOCK2_H=0
+  fi
+
+
+
+
+
+
+
+
+
+
+
+
+  if test $ac_cv_header_sys_socket_h != yes; then
+                    for ac_header in winsock2.h
+do :
+  ac_fn_c_check_header_mongrel "$LINENO" "winsock2.h" "ac_cv_header_winsock2_h" "$ac_includes_default"
+if test "x$ac_cv_header_winsock2_h" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_WINSOCK2_H 1
+_ACEOF
+
+fi
+
+done
+
+  fi
+  if test "$ac_cv_header_winsock2_h" = yes; then
+    HAVE_WINSOCK2_H=1
+    UNISTD_H_HAVE_WINSOCK2_H=1
+    SYS_IOCTL_H_HAVE_WINSOCK2_H=1
+  else
+    HAVE_WINSOCK2_H=0
+  fi
+
+   LIBSOCKET=
+  if test $HAVE_WINSOCK2_H = 1; then
+                { $as_echo "$as_me:${as_lineno-$LINENO}: checking for WSAStartup" >&5
+$as_echo_n "checking for WSAStartup... " >&6; }
+if ${gl_cv_func_wsastartup+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+       gl_save_LIBS="$LIBS"
+       LIBS="$LIBS -lws2_32"
+       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#ifdef HAVE_WINSOCK2_H
+# include <winsock2.h>
+#endif
+int
+main ()
+{
+
+            WORD wVersionRequested = MAKEWORD(1, 1);
+            WSADATA wsaData;
+            int err = WSAStartup(wVersionRequested, &wsaData);
+            WSACleanup ();
+
+  ;
+  return 0;
+}
+
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  gl_cv_func_wsastartup=yes
+else
+  gl_cv_func_wsastartup=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+       LIBS="$gl_save_LIBS"
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gl_cv_func_wsastartup" >&5
+$as_echo "$gl_cv_func_wsastartup" >&6; }
+    if test "$gl_cv_func_wsastartup" = "yes"; then
+
+$as_echo "#define WINDOWS_SOCKETS 1" >>confdefs.h
+
+      LIBSOCKET='-lws2_32'
+    fi
+  else
+                                    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing setsockopt" >&5
+$as_echo_n "checking for library containing setsockopt... " >&6; }
+if ${gl_cv_lib_socket+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+      gl_cv_lib_socket=
+      cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+extern
+#ifdef __cplusplus
+"C"
+#endif
+char setsockopt();
+int
+main ()
+{
+setsockopt();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+
+else
+  gl_save_LIBS="$LIBS"
+         LIBS="$gl_save_LIBS -lsocket"
+         cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+extern
+#ifdef __cplusplus
+"C"
+#endif
+char setsockopt();
+int
+main ()
+{
+setsockopt();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  gl_cv_lib_socket="-lsocket"
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+         if test -z "$gl_cv_lib_socket"; then
+           LIBS="$gl_save_LIBS -lnetwork"
+           cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+extern
+#ifdef __cplusplus
+"C"
+#endif
+char setsockopt();
+int
+main ()
+{
+setsockopt();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  gl_cv_lib_socket="-lnetwork"
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+           if test -z "$gl_cv_lib_socket"; then
+             LIBS="$gl_save_LIBS -lnet"
+             cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+extern
+#ifdef __cplusplus
+"C"
+#endif
+char setsockopt();
+int
+main ()
+{
+setsockopt();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  gl_cv_lib_socket="-lnet"
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+           fi
+         fi
+         LIBS="$gl_save_LIBS"
+
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+      if test -z "$gl_cv_lib_socket"; then
+        gl_cv_lib_socket="none needed"
+      fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gl_cv_lib_socket" >&5
+$as_echo "$gl_cv_lib_socket" >&6; }
+    if test "$gl_cv_lib_socket" != "none needed"; then
+      LIBSOCKET="$gl_cv_lib_socket"
+    fi
+  fi
+
+
+
+
+
+
+  :
+
+
 ac_fn_c_check_decl "$LINENO" "setenv" "ac_cv_have_decl_setenv" "$ac_includes_default"
 if test "x$ac_cv_have_decl_setenv" = xyes; then :
   ac_have_decl=1
@@ -27598,6 +28016,188 @@ $as_echo "#define GNULIB_TEST_RMDIR 1" >>confdefs.h
 
 
 
+
+
+  if test "$ac_cv_header_winsock2_h" = yes; then
+    REPLACE_SELECT=1
+  else
+
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether select supports a 0 argument" >&5
+$as_echo_n "checking whether select supports a 0 argument... " >&6; }
+if ${gl_cv_func_select_supports0+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+        if test "$cross_compiling" = yes; then :
+
+           case "$host_os" in
+                       # Guess no on Interix.
+             interix*) gl_cv_func_select_supports0="guessing no";;
+                       # Guess yes otherwise.
+             *)        gl_cv_func_select_supports0="guessing yes";;
+           esac
+
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#include <sys/types.h>
+#include <sys/time.h>
+#if HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+int main ()
+{
+  struct timeval timeout;
+  timeout.tv_sec = 0;
+  timeout.tv_usec = 5;
+  return select (0, (fd_set *)0, (fd_set *)0, (fd_set *)0, &timeout) < 0;
+}
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  gl_cv_func_select_supports0=yes
+else
+  gl_cv_func_select_supports0=no
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gl_cv_func_select_supports0" >&5
+$as_echo "$gl_cv_func_select_supports0" >&6; }
+    case "$gl_cv_func_select_supports0" in
+      *yes) ;;
+      *) REPLACE_SELECT=1 ;;
+    esac
+
+        { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether select detects invalid fds" >&5
+$as_echo_n "checking whether select detects invalid fds... " >&6; }
+if ${gl_cv_func_select_detects_ebadf+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+        if test "$cross_compiling" = yes; then :
+
+           case "$host_os" in
+                             # Guess yes on Linux systems.
+            linux-* | linux) gl_cv_func_select_detects_ebadf="guessing yes" ;;
+                             # Guess yes on glibc systems.
+            *-gnu* | gnu*)   gl_cv_func_select_detects_ebadf="guessing yes" ;;
+                             # If we don't know, obey --enable-cross-guesses.
+            *)               gl_cv_func_select_detects_ebadf="$gl_cross_guess_normal" ;;
+           esac
+
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#include <sys/types.h>
+#include <sys/time.h>
+#if HAVE_SYS_SELECT_H
+# include <sys/select.h>
+#endif
+#include <unistd.h>
+#include <errno.h>
+
+
+$gl_mda_defines
+
+int
+main ()
+{
+
+  fd_set set;
+  dup2(0, 16);
+  FD_ZERO(&set);
+  FD_SET(16, &set);
+  close(16);
+  struct timeval timeout;
+  timeout.tv_sec = 0;
+  timeout.tv_usec = 5;
+  return select (17, &set, NULL, NULL, &timeout) != -1 || errno != EBADF;
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  gl_cv_func_select_detects_ebadf=yes
+else
+  gl_cv_func_select_detects_ebadf=no
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gl_cv_func_select_detects_ebadf" >&5
+$as_echo "$gl_cv_func_select_detects_ebadf" >&6; }
+    case $gl_cv_func_select_detects_ebadf in
+      *yes) ;;
+      *) REPLACE_SELECT=1 ;;
+    esac
+  fi
+
+    LIB_SELECT="$LIBSOCKET"
+  if test $REPLACE_SELECT = 1; then
+    case "$host_os" in
+      mingw*)
+                                cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+int
+main ()
+{
+  MsgWaitForMultipleObjects (0, NULL, 0, 0, 0);
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+
+else
+  LIB_SELECT="$LIB_SELECT -luser32"
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+        ;;
+    esac
+  fi
+
+
+  if test $REPLACE_SELECT = 1; then
+
+
+
+
+
+
+
+
+  gl_LIBOBJS="$gl_LIBOBJS select.$ac_objext"
+
+  fi
+
+
+
+
+
+          GNULIB_SELECT=1
+
+
+
+
+
+$as_echo "#define GNULIB_TEST_SELECT 1" >>confdefs.h
+
+
+
+
+
      if test $ac_cv_func_setenv = no; then
     HAVE_SETENV=0
   else
@@ -28113,6 +28713,8 @@ fi
 
 
 
+
+
      ac_fn_c_check_type "$LINENO" "socklen_t" "ac_cv_type_socklen_t" "
 /* <sys/types.h> is not needed according to POSIX, but the
    <sys/socket.h> in i386-unknown-freebsd4.10 and
@@ -29921,6 +30523,8 @@ $as_echo "$gl_cv_next_sys_random_h" >&6; }
 
 
 
+
+
      if test $gl_cv_have_include_next = yes; then
        gl_cv_next_sys_stat_h='<'sys/stat.h'>'
      else
diff --git a/gnulib/import/Makefile.am b/gnulib/import/Makefile.am
index 2a11acc..1ae25ac 100644
--- a/gnulib/import/Makefile.am
+++ b/gnulib/import/Makefile.am
@@ -63,6 +63,7 @@
 #  rawmemchr \
 #  readlink \
 #  rename \
+#  select \
 #  setenv \
 #  signal-h \
 #  strchrnul \
@@ -1701,6 +1702,15 @@ EXTRA_DIST += malloc/scratch_buffer.h scratch_buffer.h
 
 ## end   gnulib module scratch_buffer
 
+## begin gnulib module select
+
+
+EXTRA_DIST += select.c
+
+EXTRA_libgnu_a_SOURCES += select.c
+
+## end   gnulib module select
+
 ## begin gnulib module setenv
 
 
@@ -1810,6 +1820,14 @@ EXTRA_DIST += warn-on-use.h
 
 ## end   gnulib module snippet/warn-on-use
 
+## begin gnulib module sockets
+
+libgnu_a_SOURCES += sockets.h sockets.c
+
+EXTRA_DIST += w32sock.h
+
+## end   gnulib module sockets
+
 ## begin gnulib module stat
 
 
@@ -2492,6 +2510,40 @@ EXTRA_DIST += sys_random.in.h
 
 ## end   gnulib module sys_random
 
+## begin gnulib module sys_select
+
+BUILT_SOURCES += sys/select.h
+
+# We need the following in order to create <sys/select.h> when the system
+# doesn't have one that works with the given compiler.
+sys/select.h: sys_select.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(WARN_ON_USE_H)
+	$(AM_V_at)$(MKDIR_P) sys
+	$(AM_V_GEN)rm -f $@-t $@ && \
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+	  sed -e 's|@''GUARD_PREFIX''@|GL|g' \
+	      -e 's|@''INCLUDE_NEXT''@|$(INCLUDE_NEXT)|g' \
+	      -e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
+	      -e 's|@''PRAGMA_COLUMNS''@|@PRAGMA_COLUMNS@|g' \
+	      -e 's|@''NEXT_SYS_SELECT_H''@|$(NEXT_SYS_SELECT_H)|g' \
+	      -e 's|@''HAVE_SYS_SELECT_H''@|$(HAVE_SYS_SELECT_H)|g' \
+	      -e 's/@''GNULIB_PSELECT''@/$(GNULIB_PSELECT)/g' \
+	      -e 's/@''GNULIB_SELECT''@/$(GNULIB_SELECT)/g' \
+	      -e 's|@''HAVE_WINSOCK2_H''@|$(HAVE_WINSOCK2_H)|g' \
+	      -e 's|@''HAVE_PSELECT''@|$(HAVE_PSELECT)|g' \
+	      -e 's|@''REPLACE_PSELECT''@|$(REPLACE_PSELECT)|g' \
+	      -e 's|@''REPLACE_SELECT''@|$(REPLACE_SELECT)|g' \
+	      -e '/definitions of _GL_FUNCDECL_RPL/r $(CXXDEFS_H)' \
+	      -e '/definition of _GL_WARN_ON_USE/r $(WARN_ON_USE_H)' \
+	      < $(srcdir)/sys_select.in.h; \
+	} > $@-t && \
+	mv $@-t $@
+MOSTLYCLEANFILES += sys/select.h sys/select.h-t
+MOSTLYCLEANDIRS += sys
+
+EXTRA_DIST += sys_select.in.h
+
+## end   gnulib module sys_select
+
 ## begin gnulib module sys_socket
 
 BUILT_SOURCES += sys/socket.h
diff --git a/gnulib/import/Makefile.in b/gnulib/import/Makefile.in
index 96606cf..e9b52a7 100644
--- a/gnulib/import/Makefile.in
+++ b/gnulib/import/Makefile.in
@@ -77,6 +77,7 @@
 #  rawmemchr \
 #  readlink \
 #  rename \
+#  select \
 #  setenv \
 #  signal-h \
 #  strchrnul \
@@ -294,9 +295,12 @@ am__aclocal_m4_deps = $(top_srcdir)/../config/depstand.m4 \
 	$(top_srcdir)/import/m4/rewinddir.m4 \
 	$(top_srcdir)/import/m4/rmdir.m4 \
 	$(top_srcdir)/import/m4/save-cwd.m4 \
+	$(top_srcdir)/import/m4/select.m4 \
 	$(top_srcdir)/import/m4/setenv.m4 \
 	$(top_srcdir)/import/m4/setlocale_null.m4 \
 	$(top_srcdir)/import/m4/signal_h.m4 \
+	$(top_srcdir)/import/m4/socketlib.m4 \
+	$(top_srcdir)/import/m4/sockets.m4 \
 	$(top_srcdir)/import/m4/socklen.m4 \
 	$(top_srcdir)/import/m4/sockpfaf.m4 \
 	$(top_srcdir)/import/m4/ssize_t.m4 \
@@ -319,6 +323,7 @@ am__aclocal_m4_deps = $(top_srcdir)/../config/depstand.m4 \
 	$(top_srcdir)/import/m4/strstr.m4 \
 	$(top_srcdir)/import/m4/strtok_r.m4 \
 	$(top_srcdir)/import/m4/sys_random_h.m4 \
+	$(top_srcdir)/import/m4/sys_select_h.m4 \
 	$(top_srcdir)/import/m4/sys_socket_h.m4 \
 	$(top_srcdir)/import/m4/sys_stat_h.m4 \
 	$(top_srcdir)/import/m4/sys_time_h.m4 \
@@ -366,7 +371,7 @@ am_libgnu_a_OBJECTS = openat-proc.$(OBJEXT) basename-lgpl.$(OBJEXT) \
 	malloc/scratch_buffer_grow.$(OBJEXT) \
 	malloc/scratch_buffer_grow_preserve.$(OBJEXT) \
 	malloc/scratch_buffer_set_array_size.$(OBJEXT) \
-	setlocale_null.$(OBJEXT) stat-time.$(OBJEXT) \
+	setlocale_null.$(OBJEXT) sockets.$(OBJEXT) stat-time.$(OBJEXT) \
 	strnlen1.$(OBJEXT) sys_socket.$(OBJEXT) tempname.$(OBJEXT) \
 	glthread/threadlib.$(OBJEXT) unistd.$(OBJEXT) \
 	dup-safer.$(OBJEXT) fd-safer.$(OBJEXT) pipe-safer.$(OBJEXT) \
@@ -781,6 +786,7 @@ GNULIB_POWF = @GNULIB_POWF@
 GNULIB_PREAD = @GNULIB_PREAD@
 GNULIB_PRINTF = @GNULIB_PRINTF@
 GNULIB_PRINTF_POSIX = @GNULIB_PRINTF_POSIX@
+GNULIB_PSELECT = @GNULIB_PSELECT@
 GNULIB_PTHREAD_SIGMASK = @GNULIB_PTHREAD_SIGMASK@
 GNULIB_PTSNAME = @GNULIB_PTSNAME@
 GNULIB_PTSNAME_R = @GNULIB_PTSNAME_R@
@@ -821,6 +827,7 @@ GNULIB_RPMATCH = @GNULIB_RPMATCH@
 GNULIB_SCANDIR = @GNULIB_SCANDIR@
 GNULIB_SCANF = @GNULIB_SCANF@
 GNULIB_SECURE_GETENV = @GNULIB_SECURE_GETENV@
+GNULIB_SELECT = @GNULIB_SELECT@
 GNULIB_SEND = @GNULIB_SEND@
 GNULIB_SENDTO = @GNULIB_SENDTO@
 GNULIB_SETENV = @GNULIB_SETENV@
@@ -1189,6 +1196,7 @@ HAVE_POSIX_OPENPT = @HAVE_POSIX_OPENPT@
 HAVE_POSIX_SIGNALBLOCKING = @HAVE_POSIX_SIGNALBLOCKING@
 HAVE_POWF = @HAVE_POWF@
 HAVE_PREAD = @HAVE_PREAD@
+HAVE_PSELECT = @HAVE_PSELECT@
 HAVE_PTHREAD_SIGMASK = @HAVE_PTHREAD_SIGMASK@
 HAVE_PTSNAME = @HAVE_PTSNAME@
 HAVE_PTSNAME_R = @HAVE_PTSNAME_R@
@@ -1262,6 +1270,7 @@ HAVE_SYS_INTTYPES_H = @HAVE_SYS_INTTYPES_H@
 HAVE_SYS_LOADAVG_H = @HAVE_SYS_LOADAVG_H@
 HAVE_SYS_PARAM_H = @HAVE_SYS_PARAM_H@
 HAVE_SYS_RANDOM_H = @HAVE_SYS_RANDOM_H@
+HAVE_SYS_SELECT_H = @HAVE_SYS_SELECT_H@
 HAVE_SYS_SOCKET_H = @HAVE_SYS_SOCKET_H@
 HAVE_SYS_TIME_H = @HAVE_SYS_TIME_H@
 HAVE_SYS_TYPES_H = @HAVE_SYS_TYPES_H@
@@ -1345,6 +1354,7 @@ LIBOBJS = @LIBOBJS@
 LIBPMULTITHREAD = @LIBPMULTITHREAD@
 LIBPTHREAD = @LIBPTHREAD@
 LIBS = @LIBS@
+LIBSOCKET = @LIBSOCKET@
 LIBSTDTHREAD = @LIBSTDTHREAD@
 LIBTHREAD = @LIBTHREAD@
 LIB_CLOCK_GETTIME = @LIB_CLOCK_GETTIME@
@@ -1353,6 +1363,7 @@ LIB_GETRANDOM = @LIB_GETRANDOM@
 LIB_HARD_LOCALE = @LIB_HARD_LOCALE@
 LIB_MBRTOWC = @LIB_MBRTOWC@
 LIB_SCHED_YIELD = @LIB_SCHED_YIELD@
+LIB_SELECT = @LIB_SELECT@
 LIB_SETLOCALE_NULL = @LIB_SETLOCALE_NULL@
 LIMITS_H = @LIMITS_H@
 LN_S = @LN_S@
@@ -1392,6 +1403,7 @@ NEXT_AS_FIRST_DIRECTIVE_STDLIB_H = @NEXT_AS_FIRST_DIRECTIVE_STDLIB_H@
 NEXT_AS_FIRST_DIRECTIVE_STRINGS_H = @NEXT_AS_FIRST_DIRECTIVE_STRINGS_H@
 NEXT_AS_FIRST_DIRECTIVE_STRING_H = @NEXT_AS_FIRST_DIRECTIVE_STRING_H@
 NEXT_AS_FIRST_DIRECTIVE_SYS_RANDOM_H = @NEXT_AS_FIRST_DIRECTIVE_SYS_RANDOM_H@
+NEXT_AS_FIRST_DIRECTIVE_SYS_SELECT_H = @NEXT_AS_FIRST_DIRECTIVE_SYS_SELECT_H@
 NEXT_AS_FIRST_DIRECTIVE_SYS_SOCKET_H = @NEXT_AS_FIRST_DIRECTIVE_SYS_SOCKET_H@
 NEXT_AS_FIRST_DIRECTIVE_SYS_STAT_H = @NEXT_AS_FIRST_DIRECTIVE_SYS_STAT_H@
 NEXT_AS_FIRST_DIRECTIVE_SYS_TIME_H = @NEXT_AS_FIRST_DIRECTIVE_SYS_TIME_H@
@@ -1422,6 +1434,7 @@ NEXT_STDLIB_H = @NEXT_STDLIB_H@
 NEXT_STRINGS_H = @NEXT_STRINGS_H@
 NEXT_STRING_H = @NEXT_STRING_H@
 NEXT_SYS_RANDOM_H = @NEXT_SYS_RANDOM_H@
+NEXT_SYS_SELECT_H = @NEXT_SYS_SELECT_H@
 NEXT_SYS_SOCKET_H = @NEXT_SYS_SOCKET_H@
 NEXT_SYS_STAT_H = @NEXT_SYS_STAT_H@
 NEXT_SYS_TIME_H = @NEXT_SYS_TIME_H@
@@ -1615,6 +1628,7 @@ REPLACE_POPEN = @REPLACE_POPEN@
 REPLACE_POSIX_MEMALIGN = @REPLACE_POSIX_MEMALIGN@
 REPLACE_PREAD = @REPLACE_PREAD@
 REPLACE_PRINTF = @REPLACE_PRINTF@
+REPLACE_PSELECT = @REPLACE_PSELECT@
 REPLACE_PTHREAD_SIGMASK = @REPLACE_PTHREAD_SIGMASK@
 REPLACE_PTSNAME = @REPLACE_PTSNAME@
 REPLACE_PTSNAME_R = @REPLACE_PTSNAME_R@
@@ -1640,6 +1654,7 @@ REPLACE_RMDIR = @REPLACE_RMDIR@
 REPLACE_ROUND = @REPLACE_ROUND@
 REPLACE_ROUNDF = @REPLACE_ROUNDF@
 REPLACE_ROUNDL = @REPLACE_ROUNDL@
+REPLACE_SELECT = @REPLACE_SELECT@
 REPLACE_SETENV = @REPLACE_SETENV@
 REPLACE_SETLOCALE = @REPLACE_SETLOCALE@
 REPLACE_SETSTATE = @REPLACE_SETSTATE@
@@ -1831,14 +1846,15 @@ EXTRA_DIST = m4/gnulib-cache.m4 alloca.c alloca.in.h arpa_inet.in.h \
 	rawmemchr.c rawmemchr.valgrind dirent-private.h readdir.c \
 	readlink.c realloc.c rename.c dirent-private.h rewinddir.c \
 	rmdir.c same-inode.h save-cwd.h malloc/scratch_buffer.h \
-	scratch_buffer.h setenv.c setlocale-lock.c setlocale_null.h \
-	windows-initguard.h signal.in.h _Noreturn.h arg-nonnull.h \
-	c++defs.h warn-on-use.h stat-w32.c stat-w32.h stat.c \
-	stat-time.h stdalign.in.h stdbool.in.h stddef.in.h stdint.in.h \
-	stdio.in.h stdlib.in.h strchrnul.c strchrnul.valgrind strdup.c \
-	streq.h strerror.c strerror-override.c strerror-override.h \
-	strerror_r.c string.in.h strings.in.h strnlen.c strstr.c \
-	str-two-way.h strstr.c strtok_r.c sys_random.in.h \
+	scratch_buffer.h select.c setenv.c setlocale-lock.c \
+	setlocale_null.h windows-initguard.h signal.in.h _Noreturn.h \
+	arg-nonnull.h c++defs.h warn-on-use.h w32sock.h stat-w32.c \
+	stat-w32.h stat.c stat-time.h stdalign.in.h stdbool.in.h \
+	stddef.in.h stdint.in.h stdio.in.h stdlib.in.h strchrnul.c \
+	strchrnul.valgrind strdup.c streq.h strerror.c \
+	strerror-override.c strerror-override.h strerror_r.c \
+	string.in.h strings.in.h strnlen.c strstr.c str-two-way.h \
+	strstr.c strtok_r.c sys_random.in.h sys_select.in.h \
 	sys_socket.in.h sys_stat.in.h sys_time.in.h sys_types.in.h \
 	sys_uio.in.h tempname.h time.in.h time_r.c unistd.in.h \
 	unistd--.h unistd-safer.h unsetenv.c \
@@ -1852,9 +1868,9 @@ BUILT_SOURCES = $(ALLOCA_H) arpa/inet.h ctype.h dirent.h $(ERRNO_H) \
 	fcntl.h $(FLOAT_H) $(FNMATCH_H) $(GLOB_H) inttypes.h \
 	$(LIMITS_H) locale.h math.h netdb.h $(NETINET_IN_H) signal.h \
 	$(STDALIGN_H) $(STDBOOL_H) $(STDDEF_H) $(STDINT_H) stdio.h \
-	stdlib.h string.h strings.h sys/random.h sys/socket.h \
-	sys/stat.h sys/time.h sys/types.h sys/uio.h time.h unistd.h \
-	wchar.h wctype.h
+	stdlib.h string.h strings.h sys/random.h sys/select.h \
+	sys/socket.h sys/stat.h sys/time.h sys/types.h sys/uio.h \
+	time.h unistd.h wchar.h wctype.h
 SUFFIXES = 
 MOSTLYCLEANFILES = core *.stackdump alloca.h alloca.h-t arpa/inet.h \
 	arpa/inet.h-t ctype.h ctype.h-t dirent.h dirent.h-t errno.h \
@@ -1865,11 +1881,12 @@ MOSTLYCLEANFILES = core *.stackdump alloca.h alloca.h-t arpa/inet.h \
 	stdalign.h stdalign.h-t stdbool.h stdbool.h-t stddef.h \
 	stddef.h-t stdint.h stdint.h-t stdio.h stdio.h-t stdlib.h \
 	stdlib.h-t string.h string.h-t strings.h strings.h-t \
-	sys/random.h sys/random.h-t sys/socket.h sys/socket.h-t \
-	sys/stat.h sys/stat.h-t sys/time.h sys/time.h-t sys/types.h \
-	sys/types.h-t sys/uio.h sys/uio.h-t time.h time.h-t unistd.h \
-	unistd.h-t wchar.h wchar.h-t wctype.h wctype.h-t
-MOSTLYCLEANDIRS = arpa netinet sys sys sys sys
+	sys/random.h sys/random.h-t sys/select.h sys/select.h-t \
+	sys/socket.h sys/socket.h-t sys/stat.h sys/stat.h-t sys/time.h \
+	sys/time.h-t sys/types.h sys/types.h-t sys/uio.h sys/uio.h-t \
+	time.h time.h-t unistd.h unistd.h-t wchar.h wchar.h-t wctype.h \
+	wctype.h-t
+MOSTLYCLEANDIRS = arpa netinet sys sys sys sys sys
 CLEANFILES = 
 DISTCLEANFILES = 
 MAINTAINERCLEANFILES = 
@@ -1885,9 +1902,9 @@ libgnu_a_SOURCES = openat-priv.h openat-proc.c basename-lgpl.c \
 	malloc/scratch_buffer_grow.c \
 	malloc/scratch_buffer_grow_preserve.c \
 	malloc/scratch_buffer_set_array_size.c setlocale_null.c \
-	stat-time.c strnlen1.h strnlen1.c sys_socket.c tempname.c \
-	glthread/threadlib.c unistd.c dup-safer.c fd-safer.c \
-	pipe-safer.c wctype-h.c
+	sockets.h sockets.c stat-time.c strnlen1.h strnlen1.c \
+	sys_socket.c tempname.c glthread/threadlib.c unistd.c \
+	dup-safer.c fd-safer.c pipe-safer.c wctype-h.c
 libgnu_a_LIBADD = $(gl_LIBOBJS) @ALLOCA@
 libgnu_a_DEPENDENCIES = $(gl_LIBOBJS) @ALLOCA@
 EXTRA_libgnu_a_SOURCES = alloca.c btowc.c canonicalize-lgpl.c \
@@ -1904,11 +1921,11 @@ EXTRA_libgnu_a_SOURCES = alloca.c btowc.c canonicalize-lgpl.c \
 	memmem.c mempcpy.c memrchr.c mkdir.c mkdtemp.c mkostemp.c \
 	msvc-inval.c msvc-nothrow.c open.c openat.c opendir.c pipe.c \
 	rawmemchr.c readdir.c readlink.c realloc.c rename.c \
-	rewinddir.c rmdir.c setenv.c setlocale-lock.c stat-w32.c \
-	stat.c strchrnul.c strdup.c strerror.c strerror-override.c \
-	strerror_r.c strnlen.c strstr.c strstr.c strtok_r.c time_r.c \
-	unsetenv.c windows-mutex.c windows-once.c windows-recmutex.c \
-	windows-rwlock.c wmemchr.c wmempcpy.c
+	rewinddir.c rmdir.c select.c setenv.c setlocale-lock.c \
+	stat-w32.c stat.c strchrnul.c strdup.c strerror.c \
+	strerror-override.c strerror_r.c strnlen.c strstr.c strstr.c \
+	strtok_r.c time_r.c unsetenv.c windows-mutex.c windows-once.c \
+	windows-recmutex.c windows-rwlock.c wmemchr.c wmempcpy.c
 
 # Use this preprocessor expression to decide whether #include_next works.
 # Do not rely on a 'configure'-time test for this, since the expression
@@ -2111,9 +2128,11 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/rewinddir.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/rmdir.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/save-cwd.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/select.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/setenv.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/setlocale-lock.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/setlocale_null.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sockets.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/stat-time.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/stat-w32.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/stat.Po@am__quote@
@@ -3539,6 +3558,30 @@ sys/random.h: sys_random.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_N
 	} > $@-t && \
 	mv -f $@-t $@
 
+# We need the following in order to create <sys/select.h> when the system
+# doesn't have one that works with the given compiler.
+sys/select.h: sys_select.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(WARN_ON_USE_H)
+	$(AM_V_at)$(MKDIR_P) sys
+	$(AM_V_GEN)rm -f $@-t $@ && \
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+	  sed -e 's|@''GUARD_PREFIX''@|GL|g' \
+	      -e 's|@''INCLUDE_NEXT''@|$(INCLUDE_NEXT)|g' \
+	      -e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
+	      -e 's|@''PRAGMA_COLUMNS''@|@PRAGMA_COLUMNS@|g' \
+	      -e 's|@''NEXT_SYS_SELECT_H''@|$(NEXT_SYS_SELECT_H)|g' \
+	      -e 's|@''HAVE_SYS_SELECT_H''@|$(HAVE_SYS_SELECT_H)|g' \
+	      -e 's/@''GNULIB_PSELECT''@/$(GNULIB_PSELECT)/g' \
+	      -e 's/@''GNULIB_SELECT''@/$(GNULIB_SELECT)/g' \
+	      -e 's|@''HAVE_WINSOCK2_H''@|$(HAVE_WINSOCK2_H)|g' \
+	      -e 's|@''HAVE_PSELECT''@|$(HAVE_PSELECT)|g' \
+	      -e 's|@''REPLACE_PSELECT''@|$(REPLACE_PSELECT)|g' \
+	      -e 's|@''REPLACE_SELECT''@|$(REPLACE_SELECT)|g' \
+	      -e '/definitions of _GL_FUNCDECL_RPL/r $(CXXDEFS_H)' \
+	      -e '/definition of _GL_WARN_ON_USE/r $(WARN_ON_USE_H)' \
+	      < $(srcdir)/sys_select.in.h; \
+	} > $@-t && \
+	mv $@-t $@
+
 # We need the following in order to create <sys/socket.h> when the system
 # doesn't have one that works with the given compiler.
 sys/socket.h: sys_socket.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(WARN_ON_USE_H) $(ARG_NONNULL_H)
diff --git a/gnulib/import/m4/gnulib-cache.m4 b/gnulib/import/m4/gnulib-cache.m4
index 54ee8ca..689ebd3 100644
--- a/gnulib/import/m4/gnulib-cache.m4
+++ b/gnulib/import/m4/gnulib-cache.m4
@@ -68,6 +68,7 @@
 #  rawmemchr \
 #  readlink \
 #  rename \
+#  select \
 #  setenv \
 #  signal-h \
 #  strchrnul \
@@ -115,6 +116,7 @@ gl_MODULES([
   rawmemchr
   readlink
   rename
+  select
   setenv
   signal-h
   strchrnul
diff --git a/gnulib/import/m4/gnulib-comp.m4 b/gnulib/import/m4/gnulib-comp.m4
index 0bf0d17..03eff90 100644
--- a/gnulib/import/m4/gnulib-comp.m4
+++ b/gnulib/import/m4/gnulib-comp.m4
@@ -172,6 +172,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module same-inode:
   # Code from module save-cwd:
   # Code from module scratch_buffer:
+  # Code from module select:
   # Code from module setenv:
   # Code from module setlocale-null:
   # Code from module signal-h:
@@ -179,6 +180,8 @@ AC_DEFUN([gl_EARLY],
   # Code from module snippet/arg-nonnull:
   # Code from module snippet/c++defs:
   # Code from module snippet/warn-on-use:
+  # Code from module socketlib:
+  # Code from module sockets:
   # Code from module socklen:
   # Code from module ssize_t:
   # Code from module stat:
@@ -204,6 +207,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module strstr-simple:
   # Code from module strtok_r:
   # Code from module sys_random:
+  # Code from module sys_select:
   # Code from module sys_socket:
   # Code from module sys_stat:
   # Code from module sys_time:
@@ -664,6 +668,11 @@ AC_DEFUN([gl_INIT],
   fi
   gl_UNISTD_MODULE_INDICATOR([rmdir])
   gl_SAVE_CWD
+  gl_FUNC_SELECT
+  if test $REPLACE_SELECT = 1; then
+    AC_LIBOBJ([select])
+  fi
+  gl_SYS_SELECT_MODULE_INDICATOR([select])
   gl_FUNC_SETENV
   if test $HAVE_SETENV = 0 || test $REPLACE_SETENV = 1; then
     AC_LIBOBJ([setenv])
@@ -676,6 +685,8 @@ AC_DEFUN([gl_INIT],
   fi
   gl_LOCALE_MODULE_INDICATOR([setlocale_null])
   gl_SIGNAL_H
+  AC_REQUIRE([gl_SOCKETLIB])
+  AC_REQUIRE([gl_SOCKETS])
   gl_TYPE_SOCKLEN_T
   gt_TYPE_SSIZE_T
   gl_FUNC_STAT
@@ -754,6 +765,8 @@ AC_DEFUN([gl_INIT],
   gl_STRING_MODULE_INDICATOR([strtok_r])
   gl_HEADER_SYS_RANDOM
   AC_PROG_MKDIR_P
+  AC_REQUIRE([gl_HEADER_SYS_SELECT])
+  AC_PROG_MKDIR_P
   AC_REQUIRE([gl_HEADER_SYS_SOCKET])
   AC_PROG_MKDIR_P
   gl_HEADER_SYS_STAT_H
@@ -1127,11 +1140,14 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/save-cwd.c
   lib/save-cwd.h
   lib/scratch_buffer.h
+  lib/select.c
   lib/setenv.c
   lib/setlocale-lock.c
   lib/setlocale_null.c
   lib/setlocale_null.h
   lib/signal.in.h
+  lib/sockets.c
+  lib/sockets.h
   lib/stat-time.c
   lib/stat-time.h
   lib/stat-w32.c
@@ -1161,6 +1177,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/strstr.c
   lib/strtok_r.c
   lib/sys_random.in.h
+  lib/sys_select.in.h
   lib/sys_socket.c
   lib/sys_socket.in.h
   lib/sys_stat.in.h
@@ -1177,6 +1194,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/unistd.in.h
   lib/unsetenv.c
   lib/verify.h
+  lib/w32sock.h
   lib/warn-on-use.h
   lib/wchar.in.h
   lib/wctype-h.c
@@ -1313,9 +1331,12 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/rewinddir.m4
   m4/rmdir.m4
   m4/save-cwd.m4
+  m4/select.m4
   m4/setenv.m4
   m4/setlocale_null.m4
   m4/signal_h.m4
+  m4/socketlib.m4
+  m4/sockets.m4
   m4/socklen.m4
   m4/sockpfaf.m4
   m4/ssize_t.m4
@@ -1338,6 +1359,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/strstr.m4
   m4/strtok_r.m4
   m4/sys_random_h.m4
+  m4/sys_select_h.m4
   m4/sys_socket_h.m4
   m4/sys_stat_h.m4
   m4/sys_time_h.m4
diff --git a/gnulib/import/m4/select.m4 b/gnulib/import/m4/select.m4
new file mode 100644
index 0000000..c7409d2
--- /dev/null
+++ b/gnulib/import/m4/select.m4
@@ -0,0 +1,117 @@
+# select.m4 serial 12
+dnl Copyright (C) 2009-2021 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_SELECT],
+[
+  AC_REQUIRE([gl_HEADER_SYS_SELECT])
+  AC_REQUIRE([AC_C_RESTRICT])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_REQUIRE([gl_SOCKETS])
+  if test "$ac_cv_header_winsock2_h" = yes; then
+    REPLACE_SELECT=1
+  else
+    dnl On Interix 3.5, select(0, NULL, NULL, NULL, timeout) fails with error
+    dnl EFAULT.
+    AC_CHECK_HEADERS_ONCE([sys/select.h])
+    AC_CACHE_CHECK([whether select supports a 0 argument],
+      [gl_cv_func_select_supports0],
+      [
+        AC_RUN_IFELSE([AC_LANG_SOURCE([[
+#include <sys/types.h>
+#include <sys/time.h>
+#if HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+int main ()
+{
+  struct timeval timeout;
+  timeout.tv_sec = 0;
+  timeout.tv_usec = 5;
+  return select (0, (fd_set *)0, (fd_set *)0, (fd_set *)0, &timeout) < 0;
+}]])], [gl_cv_func_select_supports0=yes], [gl_cv_func_select_supports0=no],
+          [
+changequote(,)dnl
+           case "$host_os" in
+                       # Guess no on Interix.
+             interix*) gl_cv_func_select_supports0="guessing no";;
+                       # Guess yes otherwise.
+             *)        gl_cv_func_select_supports0="guessing yes";;
+           esac
+changequote([,])dnl
+          ])
+      ])
+    case "$gl_cv_func_select_supports0" in
+      *yes) ;;
+      *) REPLACE_SELECT=1 ;;
+    esac
+
+    dnl On FreeBSD 8.2, select() doesn't always reject bad fds.
+    AC_CACHE_CHECK([whether select detects invalid fds],
+      [gl_cv_func_select_detects_ebadf],
+      [
+        AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <sys/time.h>
+#if HAVE_SYS_SELECT_H
+# include <sys/select.h>
+#endif
+#include <unistd.h>
+#include <errno.h>
+]GL_MDA_DEFINES],
+[[
+  fd_set set;
+  dup2(0, 16);
+  FD_ZERO(&set);
+  FD_SET(16, &set);
+  close(16);
+  struct timeval timeout;
+  timeout.tv_sec = 0;
+  timeout.tv_usec = 5;
+  return select (17, &set, NULL, NULL, &timeout) != -1 || errno != EBADF;
+]])], [gl_cv_func_select_detects_ebadf=yes],
+      [gl_cv_func_select_detects_ebadf=no],
+          [
+           case "$host_os" in
+                             # Guess yes on Linux systems.
+            linux-* | linux) gl_cv_func_select_detects_ebadf="guessing yes" ;;
+                             # Guess yes on glibc systems.
+            *-gnu* | gnu*)   gl_cv_func_select_detects_ebadf="guessing yes" ;;
+                             # If we don't know, obey --enable-cross-guesses.
+            *)               gl_cv_func_select_detects_ebadf="$gl_cross_guess_normal" ;;
+           esac
+          ])
+      ])
+    case $gl_cv_func_select_detects_ebadf in
+      *yes) ;;
+      *) REPLACE_SELECT=1 ;;
+    esac
+  fi
+
+  dnl Determine the needed libraries.
+  LIB_SELECT="$LIBSOCKET"
+  if test $REPLACE_SELECT = 1; then
+    case "$host_os" in
+      mingw*)
+        dnl On the MSVC platform, the function MsgWaitForMultipleObjects
+        dnl (used in lib/select.c) requires linking with -luser32. On mingw,
+        dnl it is implicit.
+        AC_LINK_IFELSE(
+          [AC_LANG_SOURCE([[
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+int
+main ()
+{
+  MsgWaitForMultipleObjects (0, NULL, 0, 0, 0);
+  return 0;
+}]])],
+          [],
+          [LIB_SELECT="$LIB_SELECT -luser32"])
+        ;;
+    esac
+  fi
+  AC_SUBST([LIB_SELECT])
+])
diff --git a/gnulib/import/m4/socketlib.m4 b/gnulib/import/m4/socketlib.m4
new file mode 100644
index 0000000..0f8a082
--- /dev/null
+++ b/gnulib/import/m4/socketlib.m4
@@ -0,0 +1,96 @@
+# socketlib.m4 serial 3
+dnl Copyright (C) 2008-2021 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl gl_SOCKETLIB
+dnl Determines the library to use for socket functions.
+dnl Sets and AC_SUBSTs LIBSOCKET.
+
+AC_DEFUN([gl_SOCKETLIB],
+[
+  gl_PREREQ_SYS_H_WINSOCK2 dnl for HAVE_WINSOCK2_H
+  LIBSOCKET=
+  if test $HAVE_WINSOCK2_H = 1; then
+    dnl Native Windows API (not Cygwin).
+    dnl If the function WSAStartup exists (declared in <winsock2.h> and
+    dnl defined through -lws2_32), we need to call it.
+    AC_CACHE_CHECK([for WSAStartup],
+      [gl_cv_func_wsastartup], [
+       gl_save_LIBS="$LIBS"
+       LIBS="$LIBS -lws2_32"
+       AC_LINK_IFELSE(
+         [AC_LANG_PROGRAM([[
+#ifdef HAVE_WINSOCK2_H
+# include <winsock2.h>
+#endif]], [[
+            WORD wVersionRequested = MAKEWORD(1, 1);
+            WSADATA wsaData;
+            int err = WSAStartup(wVersionRequested, &wsaData);
+            WSACleanup ();
+            ]])
+         ],
+         [gl_cv_func_wsastartup=yes],
+         [gl_cv_func_wsastartup=no])
+       LIBS="$gl_save_LIBS"
+      ])
+    if test "$gl_cv_func_wsastartup" = "yes"; then
+      AC_DEFINE([WINDOWS_SOCKETS], [1], [Define if WSAStartup is needed.])
+      LIBSOCKET='-lws2_32'
+    fi
+  else
+    dnl Unix API.
+    dnl Solaris has most socket functions in libsocket.
+    dnl Haiku has most socket functions in libnetwork.
+    dnl BeOS has most socket functions in libnet.
+    dnl On HP-UX, do NOT link with libxnet, because in 64-bit mode this would
+    dnl break code (e.g. in libraries) that invokes accept(), getpeername(),
+    dnl getsockname(), getsockopt(), or recvfrom() with a 32-bit addrlen. See
+    dnl "man xopen_networking" for details.
+    AC_CACHE_CHECK([for library containing setsockopt], [gl_cv_lib_socket], [
+      gl_cv_lib_socket=
+      AC_LINK_IFELSE([AC_LANG_PROGRAM([[extern
+#ifdef __cplusplus
+"C"
+#endif
+char setsockopt();]], [[setsockopt();]])],
+        [],
+        [gl_save_LIBS="$LIBS"
+         LIBS="$gl_save_LIBS -lsocket"
+         AC_LINK_IFELSE([AC_LANG_PROGRAM([[extern
+#ifdef __cplusplus
+"C"
+#endif
+char setsockopt();]], [[setsockopt();]])],
+           [gl_cv_lib_socket="-lsocket"])
+         if test -z "$gl_cv_lib_socket"; then
+           LIBS="$gl_save_LIBS -lnetwork"
+           AC_LINK_IFELSE([AC_LANG_PROGRAM([[extern
+#ifdef __cplusplus
+"C"
+#endif
+char setsockopt();]], [[setsockopt();]])],
+             [gl_cv_lib_socket="-lnetwork"])
+           if test -z "$gl_cv_lib_socket"; then
+             LIBS="$gl_save_LIBS -lnet"
+             AC_LINK_IFELSE([AC_LANG_PROGRAM([[extern
+#ifdef __cplusplus
+"C"
+#endif
+char setsockopt();]], [[setsockopt();]])],
+               [gl_cv_lib_socket="-lnet"])
+           fi
+         fi
+         LIBS="$gl_save_LIBS"
+        ])
+      if test -z "$gl_cv_lib_socket"; then
+        gl_cv_lib_socket="none needed"
+      fi
+    ])
+    if test "$gl_cv_lib_socket" != "none needed"; then
+      LIBSOCKET="$gl_cv_lib_socket"
+    fi
+  fi
+  AC_SUBST([LIBSOCKET])
+])
diff --git a/gnulib/import/m4/sockets.m4 b/gnulib/import/m4/sockets.m4
new file mode 100644
index 0000000..02b43b6
--- /dev/null
+++ b/gnulib/import/m4/sockets.m4
@@ -0,0 +1,17 @@
+# sockets.m4 serial 7
+dnl Copyright (C) 2008-2021 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_SOCKETS],
+[
+  AC_REQUIRE([AC_C_INLINE])
+  AC_REQUIRE([gl_SOCKETLIB])
+  gl_PREREQ_SOCKETS
+])
+
+# Prerequisites of lib/sockets.c.
+AC_DEFUN([gl_PREREQ_SOCKETS], [
+  :
+])
diff --git a/gnulib/import/m4/sys_select_h.m4 b/gnulib/import/m4/sys_select_h.m4
new file mode 100644
index 0000000..4b33d31
--- /dev/null
+++ b/gnulib/import/m4/sys_select_h.m4
@@ -0,0 +1,95 @@
+# sys_select_h.m4 serial 20
+dnl Copyright (C) 2006-2021 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_HEADER_SYS_SELECT],
+[
+  AC_REQUIRE([AC_C_RESTRICT])
+  AC_REQUIRE([gl_SYS_SELECT_H_DEFAULTS])
+  AC_CACHE_CHECK([whether <sys/select.h> is self-contained],
+    [gl_cv_header_sys_select_h_selfcontained],
+    [
+      dnl Test against two bugs:
+      dnl 1. On many platforms, <sys/select.h> assumes prior inclusion of
+      dnl    <sys/types.h>.
+      dnl 2. On OSF/1 4.0, <sys/select.h> provides only a forward declaration
+      dnl    of 'struct timeval', and no definition of this type.
+      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/select.h>]],
+                                         [[struct timeval b;]])],
+        [gl_cv_header_sys_select_h_selfcontained=yes],
+        [gl_cv_header_sys_select_h_selfcontained=no])
+      dnl Test against another bug:
+      dnl 3. On Solaris 10, <sys/select.h> provides an FD_ZERO implementation
+      dnl    that relies on memset(), but without including <string.h>.
+      if test $gl_cv_header_sys_select_h_selfcontained = yes; then
+        AC_COMPILE_IFELSE(
+          [AC_LANG_PROGRAM([[#include <sys/select.h>]],
+                           [[int memset; int bzero;]])
+          ],
+          [AC_LINK_IFELSE(
+             [AC_LANG_PROGRAM([[#include <sys/select.h>]], [[
+                  #undef memset
+                  #define memset nonexistent_memset
+                  extern
+                  #ifdef __cplusplus
+                  "C"
+                  #endif
+                  void *memset (void *, int, unsigned long);
+                  #undef bzero
+                  #define bzero nonexistent_bzero
+                  extern
+                  #ifdef __cplusplus
+                  "C"
+                  #endif
+                  void bzero (void *, unsigned long);
+                  fd_set fds;
+                  FD_ZERO (&fds);
+                ]])
+             ],
+             [],
+             [gl_cv_header_sys_select_h_selfcontained=no])
+          ])
+      fi
+    ])
+  dnl <sys/select.h> is always overridden, because of GNULIB_POSIXCHECK.
+  gl_CHECK_NEXT_HEADERS([sys/select.h])
+  if test $ac_cv_header_sys_select_h = yes; then
+    HAVE_SYS_SELECT_H=1
+  else
+    HAVE_SYS_SELECT_H=0
+  fi
+  AC_SUBST([HAVE_SYS_SELECT_H])
+  gl_PREREQ_SYS_H_WINSOCK2
+
+  dnl Check for declarations of anything we want to poison if the
+  dnl corresponding gnulib module is not in use.
+  gl_WARN_ON_USE_PREPARE([[
+/* Some systems require prerequisite headers.  */
+#include <sys/types.h>
+#if !(defined __GLIBC__ && !defined __UCLIBC__) && HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+#include <sys/select.h>
+    ]], [pselect select])
+])
+
+AC_DEFUN([gl_SYS_SELECT_MODULE_INDICATOR],
+[
+  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
+  AC_REQUIRE([gl_SYS_SELECT_H_DEFAULTS])
+  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
+  dnl Define it also as a C macro, for the benefit of the unit tests.
+  gl_MODULE_INDICATOR_FOR_TESTS([$1])
+])
+
+AC_DEFUN([gl_SYS_SELECT_H_DEFAULTS],
+[
+  GNULIB_PSELECT=0; AC_SUBST([GNULIB_PSELECT])
+  GNULIB_SELECT=0; AC_SUBST([GNULIB_SELECT])
+  dnl Assume proper GNU behavior unless another module says otherwise.
+  HAVE_PSELECT=1; AC_SUBST([HAVE_PSELECT])
+  REPLACE_PSELECT=0; AC_SUBST([REPLACE_PSELECT])
+  REPLACE_SELECT=0; AC_SUBST([REPLACE_SELECT])
+])
diff --git a/gnulib/import/select.c b/gnulib/import/select.c
new file mode 100644
index 0000000..56ac8bb
--- /dev/null
+++ b/gnulib/import/select.c
@@ -0,0 +1,597 @@
+/* Emulation for select(2)
+   Contributed by Paolo Bonzini.
+
+   Copyright 2008-2021 Free Software Foundation, Inc.
+
+   This file is part of gnulib.
+
+   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, 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 <https://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <sys/select.h>
+
+#if defined _WIN32 && ! defined __CYGWIN__
+/* Native Windows.  */
+
+#include <alloca.h>
+#include <assert.h>
+#include <sys/types.h>
+#include <errno.h>
+#include <limits.h>
+
+#include <winsock2.h>
+#include <windows.h>
+#include <io.h>
+#include <stdio.h>
+#include <conio.h>
+#include <time.h>
+
+/* Get the overridden 'struct timeval'.  */
+#include <sys/time.h>
+
+#if GNULIB_MSVC_NOTHROW
+# include "msvc-nothrow.h"
+#else
+# include <io.h>
+#endif
+
+#undef select
+
+/* Don't assume that UNICODE is not defined.  */
+#undef GetModuleHandle
+#define GetModuleHandle GetModuleHandleA
+#undef PeekConsoleInput
+#define PeekConsoleInput PeekConsoleInputA
+#undef CreateEvent
+#define CreateEvent CreateEventA
+#undef PeekMessage
+#define PeekMessage PeekMessageA
+#undef DispatchMessage
+#define DispatchMessage DispatchMessageA
+
+/* Avoid warnings from gcc -Wcast-function-type.  */
+#define GetProcAddress \
+  (void *) GetProcAddress
+
+struct bitset {
+  unsigned char in[FD_SETSIZE / CHAR_BIT];
+  unsigned char out[FD_SETSIZE / CHAR_BIT];
+};
+
+/* Declare data structures for ntdll functions.  */
+typedef struct _FILE_PIPE_LOCAL_INFORMATION {
+  ULONG NamedPipeType;
+  ULONG NamedPipeConfiguration;
+  ULONG MaximumInstances;
+  ULONG CurrentInstances;
+  ULONG InboundQuota;
+  ULONG ReadDataAvailable;
+  ULONG OutboundQuota;
+  ULONG WriteQuotaAvailable;
+  ULONG NamedPipeState;
+  ULONG NamedPipeEnd;
+} FILE_PIPE_LOCAL_INFORMATION, *PFILE_PIPE_LOCAL_INFORMATION;
+
+typedef struct _IO_STATUS_BLOCK
+{
+  union {
+    DWORD Status;
+    PVOID Pointer;
+  } u;
+  ULONG_PTR Information;
+} IO_STATUS_BLOCK, *PIO_STATUS_BLOCK;
+
+typedef enum _FILE_INFORMATION_CLASS {
+  FilePipeLocalInformation = 24
+} FILE_INFORMATION_CLASS, *PFILE_INFORMATION_CLASS;
+
+typedef DWORD (WINAPI *PNtQueryInformationFile)
+         (HANDLE, IO_STATUS_BLOCK *, VOID *, ULONG, FILE_INFORMATION_CLASS);
+
+#ifndef PIPE_BUF
+#define PIPE_BUF        512
+#endif
+
+static BOOL IsConsoleHandle (HANDLE h)
+{
+  DWORD mode;
+  return GetConsoleMode (h, &mode) != 0;
+}
+
+static BOOL
+IsSocketHandle (HANDLE h)
+{
+  WSANETWORKEVENTS ev;
+
+  if (IsConsoleHandle (h))
+    return FALSE;
+
+  /* Under Wine, it seems that getsockopt returns 0 for pipes too.
+     WSAEnumNetworkEvents instead distinguishes the two correctly.  */
+  ev.lNetworkEvents = 0xDEADBEEF;
+  WSAEnumNetworkEvents ((SOCKET) h, NULL, &ev);
+  return ev.lNetworkEvents != 0xDEADBEEF;
+}
+
+/* Compute output fd_sets for libc descriptor FD (whose Windows handle is
+   H).  */
+
+static int
+windows_poll_handle (HANDLE h, int fd,
+                     struct bitset *rbits,
+                     struct bitset *wbits,
+                     struct bitset *xbits)
+{
+  BOOL read, write, except;
+  int i, ret;
+  INPUT_RECORD *irbuffer;
+  DWORD avail, nbuffer;
+  BOOL bRet;
+  IO_STATUS_BLOCK iosb;
+  FILE_PIPE_LOCAL_INFORMATION fpli;
+  static PNtQueryInformationFile NtQueryInformationFile;
+  static BOOL once_only;
+
+  read = write = except = FALSE;
+  switch (GetFileType (h))
+    {
+    case FILE_TYPE_DISK:
+      read = TRUE;
+      write = TRUE;
+      break;
+
+    case FILE_TYPE_PIPE:
+      if (!once_only)
+        {
+          NtQueryInformationFile = (PNtQueryInformationFile)
+            GetProcAddress (GetModuleHandle ("ntdll.dll"),
+                            "NtQueryInformationFile");
+          once_only = TRUE;
+        }
+
+      if (PeekNamedPipe (h, NULL, 0, NULL, &avail, NULL) != 0)
+        {
+          if (avail)
+            read = TRUE;
+        }
+      else if (GetLastError () == ERROR_BROKEN_PIPE)
+        ;
+
+      else
+        {
+          /* It was the write-end of the pipe.  Check if it is writable.
+             If NtQueryInformationFile fails, optimistically assume the pipe is
+             writable.  This could happen on Windows 9x, where
+             NtQueryInformationFile is not available, or if we inherit a pipe
+             that doesn't permit FILE_READ_ATTRIBUTES access on the write end
+             (I think this should not happen since Windows XP SP2; WINE seems
+             fine too).  Otherwise, ensure that enough space is available for
+             atomic writes.  */
+          memset (&iosb, 0, sizeof (iosb));
+          memset (&fpli, 0, sizeof (fpli));
+
+          if (!NtQueryInformationFile
+              || NtQueryInformationFile (h, &iosb, &fpli, sizeof (fpli),
+                                         FilePipeLocalInformation)
+              || fpli.WriteQuotaAvailable >= PIPE_BUF
+              || (fpli.OutboundQuota < PIPE_BUF &&
+                  fpli.WriteQuotaAvailable == fpli.OutboundQuota))
+            write = TRUE;
+        }
+      break;
+
+    case FILE_TYPE_CHAR:
+      write = TRUE;
+      if (!(rbits->in[fd / CHAR_BIT] & (1 << (fd & (CHAR_BIT - 1)))))
+        break;
+
+      ret = WaitForSingleObject (h, 0);
+      if (ret == WAIT_OBJECT_0)
+        {
+          if (!IsConsoleHandle (h))
+            {
+              read = TRUE;
+              break;
+            }
+
+          nbuffer = avail = 0;
+          bRet = GetNumberOfConsoleInputEvents (h, &nbuffer);
+
+          /* Screen buffers handles are filtered earlier.  */
+          assert (bRet);
+          if (nbuffer == 0)
+            {
+              except = TRUE;
+              break;
+            }
+
+          irbuffer = (INPUT_RECORD *) alloca (nbuffer * sizeof (INPUT_RECORD));
+          bRet = PeekConsoleInput (h, irbuffer, nbuffer, &avail);
+          if (!bRet || avail == 0)
+            {
+              except = TRUE;
+              break;
+            }
+
+          for (i = 0; i < avail; i++)
+            if (irbuffer[i].EventType == KEY_EVENT)
+              read = TRUE;
+        }
+      break;
+
+    default:
+      ret = WaitForSingleObject (h, 0);
+      write = TRUE;
+      if (ret == WAIT_OBJECT_0)
+        read = TRUE;
+
+      break;
+    }
+
+  ret = 0;
+  if (read && (rbits->in[fd / CHAR_BIT] & (1 << (fd & (CHAR_BIT - 1)))))
+    {
+      rbits->out[fd / CHAR_BIT] |= (1 << (fd & (CHAR_BIT - 1)));
+      ret++;
+    }
+
+  if (write && (wbits->in[fd / CHAR_BIT] & (1 << (fd & (CHAR_BIT - 1)))))
+    {
+      wbits->out[fd / CHAR_BIT] |= (1 << (fd & (CHAR_BIT - 1)));
+      ret++;
+    }
+
+  if (except && (xbits->in[fd / CHAR_BIT] & (1 << (fd & (CHAR_BIT - 1)))))
+    {
+      xbits->out[fd / CHAR_BIT] |= (1 << (fd & (CHAR_BIT - 1)));
+      ret++;
+    }
+
+  return ret;
+}
+
+int
+rpl_select (int nfds, fd_set *rfds, fd_set *wfds, fd_set *xfds,
+            struct timeval *timeout)
+#undef timeval
+{
+  static struct timeval tv0;
+  static HANDLE hEvent;
+  HANDLE h, handle_array[FD_SETSIZE + 2];
+  fd_set handle_rfds, handle_wfds, handle_xfds;
+  struct bitset rbits, wbits, xbits;
+  unsigned char anyfds_in[FD_SETSIZE / CHAR_BIT];
+  DWORD ret, wait_timeout, nhandles, nsock, nbuffer;
+  MSG msg;
+  int i, fd, rc;
+  clock_t tend;
+
+  if (nfds > FD_SETSIZE)
+    nfds = FD_SETSIZE;
+
+  if (!timeout)
+    wait_timeout = INFINITE;
+  else
+    {
+      wait_timeout = timeout->tv_sec * 1000 + timeout->tv_usec / 1000;
+
+      /* select is also used as a portable usleep.  */
+      if (!rfds && !wfds && !xfds)
+        {
+          Sleep (wait_timeout);
+          return 0;
+        }
+    }
+
+  if (!hEvent)
+    hEvent = CreateEvent (NULL, FALSE, FALSE, NULL);
+
+  handle_array[0] = hEvent;
+  nhandles = 1;
+  nsock = 0;
+
+  /* Copy descriptors to bitsets.  At the same time, eliminate
+     bits in the "wrong" direction for console input buffers
+     and screen buffers, because screen buffers are waitable
+     and they will block until a character is available.  */
+  memset (&rbits, 0, sizeof (rbits));
+  memset (&wbits, 0, sizeof (wbits));
+  memset (&xbits, 0, sizeof (xbits));
+  memset (anyfds_in, 0, sizeof (anyfds_in));
+  if (rfds)
+    for (i = 0; i < rfds->fd_count; i++)
+      {
+        fd = rfds->fd_array[i];
+        h = (HANDLE) _get_osfhandle (fd);
+        if (IsConsoleHandle (h)
+            && !GetNumberOfConsoleInputEvents (h, &nbuffer))
+          continue;
+
+        rbits.in[fd / CHAR_BIT] |= 1 << (fd & (CHAR_BIT - 1));
+        anyfds_in[fd / CHAR_BIT] |= 1 << (fd & (CHAR_BIT - 1));
+      }
+  else
+    rfds = (fd_set *) alloca (sizeof (fd_set));
+
+  if (wfds)
+    for (i = 0; i < wfds->fd_count; i++)
+      {
+        fd = wfds->fd_array[i];
+        h = (HANDLE) _get_osfhandle (fd);
+        if (IsConsoleHandle (h)
+            && GetNumberOfConsoleInputEvents (h, &nbuffer))
+          continue;
+
+        wbits.in[fd / CHAR_BIT] |= 1 << (fd & (CHAR_BIT - 1));
+        anyfds_in[fd / CHAR_BIT] |= 1 << (fd & (CHAR_BIT - 1));
+      }
+  else
+    wfds = (fd_set *) alloca (sizeof (fd_set));
+
+  if (xfds)
+    for (i = 0; i < xfds->fd_count; i++)
+      {
+        fd = xfds->fd_array[i];
+        xbits.in[fd / CHAR_BIT] |= 1 << (fd & (CHAR_BIT - 1));
+        anyfds_in[fd / CHAR_BIT] |= 1 << (fd & (CHAR_BIT - 1));
+      }
+  else
+    xfds = (fd_set *) alloca (sizeof (fd_set));
+
+  /* Zero all the fd_sets, including the application's.  */
+  FD_ZERO (rfds);
+  FD_ZERO (wfds);
+  FD_ZERO (xfds);
+  FD_ZERO (&handle_rfds);
+  FD_ZERO (&handle_wfds);
+  FD_ZERO (&handle_xfds);
+
+  /* Classify handles.  Create fd sets for sockets, poll the others. */
+  for (i = 0; i < nfds; i++)
+    {
+      if ((anyfds_in[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1)))) == 0)
+        continue;
+
+      h = (HANDLE) _get_osfhandle (i);
+      if (!h)
+        {
+          errno = EBADF;
+          return -1;
+        }
+
+      if (IsSocketHandle (h))
+        {
+          int requested = FD_CLOSE;
+
+          /* See above; socket handles are mapped onto select, but we
+             need to map descriptors to handles.  */
+          if (rbits.in[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+            {
+              requested |= FD_READ | FD_ACCEPT;
+              FD_SET ((SOCKET) h, rfds);
+              FD_SET ((SOCKET) h, &handle_rfds);
+            }
+          if (wbits.in[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+            {
+              requested |= FD_WRITE | FD_CONNECT;
+              FD_SET ((SOCKET) h, wfds);
+              FD_SET ((SOCKET) h, &handle_wfds);
+            }
+          if (xbits.in[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+            {
+              requested |= FD_OOB;
+              FD_SET ((SOCKET) h, xfds);
+              FD_SET ((SOCKET) h, &handle_xfds);
+            }
+
+          WSAEventSelect ((SOCKET) h, hEvent, requested);
+          nsock++;
+        }
+      else
+        {
+          handle_array[nhandles++] = h;
+
+          /* Poll now.  If we get an event, do not wait below.  */
+          if (wait_timeout != 0
+              && windows_poll_handle (h, i, &rbits, &wbits, &xbits))
+            wait_timeout = 0;
+        }
+    }
+
+  /* Place a sentinel at the end of the array.  */
+  handle_array[nhandles] = NULL;
+
+  /* When will the waiting period expire?  */
+  if (wait_timeout != INFINITE)
+    tend = clock () + wait_timeout;
+
+restart:
+  if (wait_timeout == 0 || nsock == 0)
+    rc = 0;
+  else
+    {
+      /* See if we need to wait in the loop below.  If any select is ready,
+         do MsgWaitForMultipleObjects anyway to dispatch messages, but
+         no need to call select again.  */
+      rc = select (0, &handle_rfds, &handle_wfds, &handle_xfds, &tv0);
+      if (rc == 0)
+        {
+          /* Restore the fd_sets for the other select we do below.  */
+          memcpy (&handle_rfds, rfds, sizeof (fd_set));
+          memcpy (&handle_wfds, wfds, sizeof (fd_set));
+          memcpy (&handle_xfds, xfds, sizeof (fd_set));
+        }
+      else
+        wait_timeout = 0;
+    }
+
+  /* How much is left to wait?  */
+  if (wait_timeout != INFINITE)
+    {
+      clock_t tnow = clock ();
+      if (tend >= tnow)
+        wait_timeout = tend - tnow;
+      else
+        wait_timeout = 0;
+    }
+
+  for (;;)
+    {
+      ret = MsgWaitForMultipleObjects (nhandles, handle_array, FALSE,
+                                       wait_timeout, QS_ALLINPUT);
+
+      if (ret == WAIT_OBJECT_0 + nhandles)
+        {
+          /* new input of some other kind */
+          BOOL bRet;
+          while ((bRet = PeekMessage (&msg, NULL, 0, 0, PM_REMOVE)) != 0)
+            {
+              TranslateMessage (&msg);
+              DispatchMessage (&msg);
+            }
+        }
+      else
+        break;
+    }
+
+  /* If we haven't done it yet, check the status of the sockets.  */
+  if (rc == 0 && nsock > 0)
+    rc = select (0, &handle_rfds, &handle_wfds, &handle_xfds, &tv0);
+
+  if (nhandles > 1)
+    {
+      /* Count results that are not counted in the return value of select.  */
+      nhandles = 1;
+      for (i = 0; i < nfds; i++)
+        {
+          if ((anyfds_in[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1)))) == 0)
+            continue;
+
+          h = (HANDLE) _get_osfhandle (i);
+          if (h == handle_array[nhandles])
+            {
+              /* Not a socket.  */
+              nhandles++;
+              windows_poll_handle (h, i, &rbits, &wbits, &xbits);
+              if (rbits.out[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1)))
+                  || wbits.out[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1)))
+                  || xbits.out[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+                rc++;
+            }
+        }
+
+      if (rc == 0
+          && (wait_timeout == INFINITE
+              /* If NHANDLES > 1, but no bits are set, it means we've
+                 been told incorrectly that some handle was signaled.
+                 This happens with anonymous pipes, which always cause
+                 MsgWaitForMultipleObjects to exit immediately, but no
+                 data is found ready to be read by windows_poll_handle.
+                 To avoid a total failure (whereby we return zero and
+                 don't wait at all), let's poll in a more busy loop.  */
+              || (wait_timeout != 0 && nhandles > 1)))
+        {
+          /* Sleep 1 millisecond to avoid busy wait and retry with the
+             original fd_sets.  */
+          memcpy (&handle_rfds, rfds, sizeof (fd_set));
+          memcpy (&handle_wfds, wfds, sizeof (fd_set));
+          memcpy (&handle_xfds, xfds, sizeof (fd_set));
+          SleepEx (1, TRUE);
+          goto restart;
+        }
+      if (timeout && wait_timeout == 0 && rc == 0)
+        timeout->tv_sec = timeout->tv_usec = 0;
+    }
+
+  /* Now fill in the results.  */
+  FD_ZERO (rfds);
+  FD_ZERO (wfds);
+  FD_ZERO (xfds);
+  nhandles = 1;
+  for (i = 0; i < nfds; i++)
+    {
+      if ((anyfds_in[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1)))) == 0)
+        continue;
+
+      h = (HANDLE) _get_osfhandle (i);
+      if (h != handle_array[nhandles])
+        {
+          /* Perform handle->descriptor mapping.  */
+          WSAEventSelect ((SOCKET) h, NULL, 0);
+          if (FD_ISSET (h, &handle_rfds))
+            FD_SET (i, rfds);
+          if (FD_ISSET (h, &handle_wfds))
+            FD_SET (i, wfds);
+          if (FD_ISSET (h, &handle_xfds))
+            FD_SET (i, xfds);
+        }
+      else
+        {
+          /* Not a socket.  */
+          nhandles++;
+          if (rbits.out[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+            FD_SET (i, rfds);
+          if (wbits.out[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+            FD_SET (i, wfds);
+          if (xbits.out[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+            FD_SET (i, xfds);
+        }
+    }
+
+  return rc;
+}
+
+#else /* ! Native Windows.  */
+
+#include <stddef.h> /* NULL */
+#include <errno.h>
+#include <unistd.h>
+
+#undef select
+
+int
+rpl_select (int nfds, fd_set *rfds, fd_set *wfds, fd_set *xfds,
+            struct timeval *timeout)
+{
+  int i;
+
+  /* FreeBSD 8.2 has a bug: it does not always detect invalid fds.  */
+  if (nfds < 0 || nfds > FD_SETSIZE)
+    {
+      errno = EINVAL;
+      return -1;
+    }
+  for (i = 0; i < nfds; i++)
+    {
+      if (((rfds && FD_ISSET (i, rfds))
+           || (wfds && FD_ISSET (i, wfds))
+           || (xfds && FD_ISSET (i, xfds)))
+          && dup2 (i, i) != i)
+        return -1;
+    }
+
+  /* Interix 3.5 has a bug: it does not support nfds == 0.  */
+  if (nfds == 0)
+    {
+      nfds = 1;
+      rfds = NULL;
+      wfds = NULL;
+      xfds = NULL;
+    }
+  return select (nfds, rfds, wfds, xfds, timeout);
+}
+
+#endif
diff --git a/gnulib/import/sockets.c b/gnulib/import/sockets.c
new file mode 100644
index 0000000..2de48d2
--- /dev/null
+++ b/gnulib/import/sockets.c
@@ -0,0 +1,161 @@
+/* sockets.c --- wrappers for Windows socket functions
+
+   Copyright (C) 2008-2021 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 <https://www.gnu.org/licenses/>.  */
+
+/* Written by Simon Josefsson */
+
+#include <config.h>
+
+/* Specification.  */
+#include "sockets.h"
+
+#if WINDOWS_SOCKETS
+
+/* This includes winsock2.h on MinGW. */
+# include <sys/socket.h>
+
+# include "fd-hook.h"
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
+
+/* Get set_winsock_errno, FD_TO_SOCKET etc. */
+# include "w32sock.h"
+
+static int
+close_fd_maybe_socket (const struct fd_hook *remaining_list,
+                       gl_close_fn primary,
+                       int fd)
+{
+  /* Note about multithread-safety: There is a race condition where, between
+     our calls to closesocket() and the primary close(), some other thread
+     could make system calls that allocate precisely the same HANDLE value
+     as sock; then the primary close() would call CloseHandle() on it.  */
+  SOCKET sock;
+  WSANETWORKEVENTS ev;
+
+  /* Test whether fd refers to a socket.  */
+  sock = FD_TO_SOCKET (fd);
+  ev.lNetworkEvents = 0xDEADBEEF;
+  WSAEnumNetworkEvents (sock, NULL, &ev);
+  if (ev.lNetworkEvents != 0xDEADBEEF)
+    {
+      /* fd refers to a socket.  */
+      /* FIXME: other applications, like squid, use an undocumented
+         _free_osfhnd free function.  But this is not enough: The 'osfile'
+         flags for fd also needs to be cleared, but it is hard to access it.
+         Instead, here we just close twice the file descriptor.  */
+      if (closesocket (sock))
+        {
+          set_winsock_errno ();
+          return -1;
+        }
+      else
+        {
+          /* This call frees the file descriptor and does a
+             CloseHandle ((HANDLE) _get_osfhandle (fd)), which fails.  */
+          _close (fd);
+          return 0;
+        }
+    }
+  else
+    /* Some other type of file descriptor.  */
+    return execute_close_hooks (remaining_list, primary, fd);
+}
+
+static int
+ioctl_fd_maybe_socket (const struct fd_hook *remaining_list,
+                       gl_ioctl_fn primary,
+                       int fd, int request, void *arg)
+{
+  SOCKET sock;
+  WSANETWORKEVENTS ev;
+
+  /* Test whether fd refers to a socket.  */
+  sock = FD_TO_SOCKET (fd);
+  ev.lNetworkEvents = 0xDEADBEEF;
+  WSAEnumNetworkEvents (sock, NULL, &ev);
+  if (ev.lNetworkEvents != 0xDEADBEEF)
+    {
+      /* fd refers to a socket.  */
+      if (ioctlsocket (sock, request, arg) < 0)
+        {
+          set_winsock_errno ();
+          return -1;
+        }
+      else
+        return 0;
+    }
+  else
+    /* Some other type of file descriptor.  */
+    return execute_ioctl_hooks (remaining_list, primary, fd, request, arg);
+}
+
+static struct fd_hook fd_sockets_hook;
+
+static int initialized_sockets_version /* = 0 */;
+
+#endif /* WINDOWS_SOCKETS */
+
+int
+gl_sockets_startup (int version _GL_UNUSED)
+{
+#if WINDOWS_SOCKETS
+  if (version > initialized_sockets_version)
+    {
+      WSADATA data;
+      int err;
+
+      err = WSAStartup (version, &data);
+      if (err != 0)
+        return 1;
+
+      if (data.wVersion != version)
+        {
+          WSACleanup ();
+          return 2;
+        }
+
+      if (initialized_sockets_version == 0)
+        register_fd_hook (close_fd_maybe_socket, ioctl_fd_maybe_socket,
+                          &fd_sockets_hook);
+
+      initialized_sockets_version = version;
+    }
+#endif
+
+  return 0;
+}
+
+int
+gl_sockets_cleanup (void)
+{
+#if WINDOWS_SOCKETS
+  int err;
+
+  initialized_sockets_version = 0;
+
+  unregister_fd_hook (&fd_sockets_hook);
+
+  err = WSACleanup ();
+  if (err != 0)
+    return 1;
+#endif
+
+  return 0;
+}
diff --git a/gnulib/import/sockets.h b/gnulib/import/sockets.h
new file mode 100644
index 0000000..e0729c2
--- /dev/null
+++ b/gnulib/import/sockets.h
@@ -0,0 +1,66 @@
+/* sockets.h - wrappers for Windows socket functions
+
+   Copyright (C) 2008-2021 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 <https://www.gnu.org/licenses/>.  */
+
+/* Written by Simon Josefsson */
+
+#ifndef SOCKETS_H
+#define SOCKETS_H 1
+
+#define SOCKETS_1_0 0x0001
+#define SOCKETS_1_1 0x0101
+#define SOCKETS_2_0 0x0002
+#define SOCKETS_2_1 0x0102
+#define SOCKETS_2_2 0x0202
+
+int gl_sockets_startup (int version)
+#ifndef WINDOWS_SOCKETS
+  _GL_ATTRIBUTE_CONST
+#endif
+  ;
+
+int gl_sockets_cleanup (void)
+#ifndef WINDOWS_SOCKETS
+  _GL_ATTRIBUTE_CONST
+#endif
+  ;
+
+/* This function is useful it you create a socket using gnulib's
+   Winsock wrappers but needs to pass on the socket handle to some
+   other library that only accepts sockets. */
+#ifdef WINDOWS_SOCKETS
+
+# include <sys/socket.h>
+
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
+
+static inline SOCKET
+gl_fd_to_handle (int fd)
+{
+  return _get_osfhandle (fd);
+}
+
+#else
+
+# define gl_fd_to_handle(x) (x)
+
+#endif /* WINDOWS_SOCKETS */
+
+#endif /* SOCKETS_H */
diff --git a/gnulib/import/sys_select.in.h b/gnulib/import/sys_select.in.h
new file mode 100644
index 0000000..1dacb21
--- /dev/null
+++ b/gnulib/import/sys_select.in.h
@@ -0,0 +1,326 @@
+/* Substitute for <sys/select.h>.
+   Copyright (C) 2007-2021 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, 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 <https://www.gnu.org/licenses/>.  */
+
+# if __GNUC__ >= 3
+@PRAGMA_SYSTEM_HEADER@
+# endif
+@PRAGMA_COLUMNS@
+
+/* On OSF/1 and Solaris 2.6, <sys/types.h> and <sys/time.h>
+   both include <sys/select.h>.
+   On Cygwin, <sys/time.h> includes <sys/select.h>.
+   Simply delegate to the system's header in this case.  */
+#if (@HAVE_SYS_SELECT_H@                                                \
+     && !defined _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TYPES_H             \
+     && ((defined __osf__ && defined _SYS_TYPES_H_                      \
+          && defined _OSF_SOURCE)                                       \
+         || (defined __sun && defined _SYS_TYPES_H                      \
+             && (! (defined _XOPEN_SOURCE || defined _POSIX_C_SOURCE)   \
+                 || defined __EXTENSIONS__))))
+
+# define _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TYPES_H
+# @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
+
+#elif (@HAVE_SYS_SELECT_H@                                              \
+       && (defined _CYGWIN_SYS_TIME_H                                   \
+           || (!defined _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TIME_H       \
+               && ((defined __osf__ && defined _SYS_TIME_H_             \
+                    && defined _OSF_SOURCE)                             \
+                   || (defined __sun && defined _SYS_TIME_H             \
+                       && (! (defined _XOPEN_SOURCE                     \
+                              || defined _POSIX_C_SOURCE)               \
+                           || defined __EXTENSIONS__))))))
+
+# define _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TIME_H
+# @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
+
+/* On IRIX 6.5, <sys/timespec.h> includes <sys/types.h>, which includes
+   <sys/bsd_types.h>, which includes <sys/select.h>.  At this point we cannot
+   include <signal.h>, because that includes <internal/signal_core.h>, which
+   gives a syntax error because <sys/timespec.h> has not been completely
+   processed.  Simply delegate to the system's header in this case.  */
+#elif @HAVE_SYS_SELECT_H@ && defined __sgi && (defined _SYS_BSD_TYPES_H && !defined _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_BSD_TYPES_H)
+
+# define _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_BSD_TYPES_H
+# @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
+
+/* On OpenBSD 5.0, <pthread.h> includes <sys/types.h>, which includes
+   <sys/select.h>.  At this point we cannot include <signal.h>, because that
+   includes gnulib's pthread.h override, which gives a syntax error because
+   /usr/include/pthread.h has not been completely processed.  Simply delegate
+   to the system's header in this case.  */
+#elif @HAVE_SYS_SELECT_H@ && defined __OpenBSD__ && (defined _PTHREAD_H_ && !defined PTHREAD_MUTEX_INITIALIZER)
+
+# @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
+
+#else
+
+#ifndef _@GUARD_PREFIX@_SYS_SELECT_H
+
+/* On many platforms, <sys/select.h> assumes prior inclusion of
+   <sys/types.h>.  Also, mingw defines sigset_t there, instead of
+   in <signal.h> where it belongs.  */
+#include <sys/types.h>
+
+#if @HAVE_SYS_SELECT_H@
+
+/* On OSF/1 4.0, <sys/select.h> provides only a forward declaration
+   of 'struct timeval', and no definition of this type.
+   Also, Mac OS X, AIX, HP-UX, IRIX, Solaris, Interix declare select()
+   in <sys/time.h>.
+   But avoid namespace pollution on glibc systems and "unknown type
+   name" problems on Cygwin.  */
+# if !(defined __GLIBC__ || defined __CYGWIN__)
+#  include <sys/time.h>
+# endif
+
+/* On AIX 7 and Solaris 10, <sys/select.h> provides an FD_ZERO implementation
+   that relies on memset(), but without including <string.h>.
+   But in any case avoid namespace pollution on glibc systems.  */
+# if (defined __OpenBSD__ || defined _AIX || defined __sun || defined __osf__ || defined __BEOS__) \
+     && ! defined __GLIBC__
+#  include <string.h>
+# endif
+
+/* The include_next requires a split double-inclusion guard.  */
+# @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
+
+#endif
+
+/* Get definition of 'sigset_t'.
+   But avoid namespace pollution on glibc systems and "unknown type
+   name" problems on Cygwin.
+   On OS/2 kLIBC, sigset_t is defined in <sys/select.h>, too. In addition,
+   if <sys/param.h> is included, <types.h> -> <sys/types.h> -> <sys/select.h>
+   are included. Then <signal.h> -> <pthread.h> are included by GNULIB. By the
+   way, <pthread.h> requires PAGE_SIZE defined in <sys/param.h>. However,
+   <sys/param.h> has not been processed, yet. As a result, 'PAGE_SIZE'
+   undeclared error occurs in <pthread.h>.
+   Do this after the include_next (for the sake of OpenBSD 5.0) but before
+   the split double-inclusion guard (for the sake of Solaris).  */
+#if !((defined __GLIBC__ || defined __CYGWIN__ || defined __KLIBC__) \
+      && !defined __UCLIBC__)
+# include <signal.h>
+#endif
+
+#ifndef _@GUARD_PREFIX@_SYS_SELECT_H
+#define _@GUARD_PREFIX@_SYS_SELECT_H
+
+#if !@HAVE_SYS_SELECT_H@
+/* A platform that lacks <sys/select.h>.  */
+/* Get the 'struct timeval' and 'fd_set' types and the FD_* macros
+   on most platforms.  */
+# include <sys/time.h>
+/* On HP-UX 11, <sys/time.h> provides an FD_ZERO implementation
+   that relies on memset(), but without including <string.h>.  */
+# if defined __hpux
+#  include <string.h>
+# endif
+/* On native Windows platforms:
+   Get the 'fd_set' type.
+   Get the close() declaration before we override it.  */
+# if @HAVE_WINSOCK2_H@
+#  if !defined _GL_INCLUDING_WINSOCK2_H
+#   define _GL_INCLUDING_WINSOCK2_H
+#   include <winsock2.h>
+#   undef _GL_INCLUDING_WINSOCK2_H
+#  endif
+#  include <io.h>
+# endif
+#endif
+
+/* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
+
+/* The definition of _GL_WARN_ON_USE is copied here.  */
+
+
+/* Fix some definitions from <winsock2.h>.  */
+
+#if @HAVE_WINSOCK2_H@
+
+# if !GNULIB_defined_rpl_fd_isset
+
+/* Re-define FD_ISSET to avoid a WSA call while we are not using
+   network sockets.  */
+static int
+rpl_fd_isset (SOCKET fd, fd_set * set)
+{
+  u_int i;
+  if (set == NULL)
+    return 0;
+
+  for (i = 0; i < set->fd_count; i++)
+    if (set->fd_array[i] == fd)
+      return 1;
+
+  return 0;
+}
+
+#  define GNULIB_defined_rpl_fd_isset 1
+# endif
+
+# undef FD_ISSET
+# define FD_ISSET(fd, set) rpl_fd_isset(fd, set)
+
+#endif
+
+/* Hide some function declarations from <winsock2.h>.  */
+
+#if @HAVE_WINSOCK2_H@
+# if !defined _@GUARD_PREFIX@_UNISTD_H
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef close
+#   define close close_used_without_including_unistd_h
+#  elif !defined __clang__
+    _GL_WARN_ON_USE (close,
+                     "close() used without including <unistd.h>");
+#  endif
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef gethostname
+#   define gethostname gethostname_used_without_including_unistd_h
+#  elif !defined __clang__
+    _GL_WARN_ON_USE (gethostname,
+                     "gethostname() used without including <unistd.h>");
+#  endif
+# endif
+# if !defined _@GUARD_PREFIX@_SYS_SOCKET_H
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef socket
+#   define socket              socket_used_without_including_sys_socket_h
+#   undef connect
+#   define connect             connect_used_without_including_sys_socket_h
+#   undef accept
+#   define accept              accept_used_without_including_sys_socket_h
+#   undef bind
+#   define bind                bind_used_without_including_sys_socket_h
+#   undef getpeername
+#   define getpeername         getpeername_used_without_including_sys_socket_h
+#   undef getsockname
+#   define getsockname         getsockname_used_without_including_sys_socket_h
+#   undef getsockopt
+#   define getsockopt          getsockopt_used_without_including_sys_socket_h
+#   undef listen
+#   define listen              listen_used_without_including_sys_socket_h
+#   undef recv
+#   define recv                recv_used_without_including_sys_socket_h
+#   undef send
+#   define send                send_used_without_including_sys_socket_h
+#   undef recvfrom
+#   define recvfrom            recvfrom_used_without_including_sys_socket_h
+#   undef sendto
+#   define sendto              sendto_used_without_including_sys_socket_h
+#   undef setsockopt
+#   define setsockopt          setsockopt_used_without_including_sys_socket_h
+#   undef shutdown
+#   define shutdown            shutdown_used_without_including_sys_socket_h
+#  elif !defined __clang__
+    _GL_WARN_ON_USE (socket,
+                     "socket() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (connect,
+                     "connect() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (accept,
+                     "accept() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (bind,
+                     "bind() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (getpeername,
+                     "getpeername() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (getsockname,
+                     "getsockname() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (getsockopt,
+                     "getsockopt() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (listen,
+                     "listen() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (recv,
+                     "recv() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (send,
+                     "send() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (recvfrom,
+                     "recvfrom() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (sendto,
+                     "sendto() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (setsockopt,
+                     "setsockopt() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (shutdown,
+                     "shutdown() used without including <sys/socket.h>");
+#  endif
+# endif
+#endif
+
+
+#if @GNULIB_PSELECT@
+# if @REPLACE_PSELECT@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef pselect
+#   define pselect rpl_pselect
+#  endif
+_GL_FUNCDECL_RPL (pselect, int,
+                  (int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
+                   struct timespec const *restrict, const sigset_t *restrict));
+_GL_CXXALIAS_RPL (pselect, int,
+                  (int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
+                   struct timespec const *restrict, const sigset_t *restrict));
+# else
+#  if !@HAVE_PSELECT@
+_GL_FUNCDECL_SYS (pselect, int,
+                  (int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
+                   struct timespec const *restrict, const sigset_t *restrict));
+#  endif
+_GL_CXXALIAS_SYS (pselect, int,
+                  (int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
+                   struct timespec const *restrict, const sigset_t *restrict));
+# endif
+_GL_CXXALIASWARN (pselect);
+#elif defined GNULIB_POSIXCHECK
+# undef pselect
+# if HAVE_RAW_DECL_PSELECT
+_GL_WARN_ON_USE (pselect, "pselect is not portable - "
+                 "use gnulib module pselect for portability");
+# endif
+#endif
+
+#if @GNULIB_SELECT@
+# if @REPLACE_SELECT@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef select
+#   define select rpl_select
+#  endif
+_GL_FUNCDECL_RPL (select, int,
+                  (int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
+                   struct timeval *restrict));
+_GL_CXXALIAS_RPL (select, int,
+                  (int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
+                   timeval *restrict));
+# else
+_GL_CXXALIAS_SYS (select, int,
+                  (int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
+                   timeval *restrict));
+# endif
+_GL_CXXALIASWARN (select);
+#elif @HAVE_WINSOCK2_H@
+# undef select
+# define select select_used_without_requesting_gnulib_module_select
+#elif defined GNULIB_POSIXCHECK
+# undef select
+# if HAVE_RAW_DECL_SELECT
+_GL_WARN_ON_USE (select, "select is not always POSIX compliant - "
+                 "use gnulib module select for portability");
+# endif
+#endif
+
+
+#endif /* _@GUARD_PREFIX@_SYS_SELECT_H */
+#endif /* _@GUARD_PREFIX@_SYS_SELECT_H */
+#endif /* OSF/1 */
diff --git a/gnulib/import/w32sock.h b/gnulib/import/w32sock.h
new file mode 100644
index 0000000..f731188
--- /dev/null
+++ b/gnulib/import/w32sock.h
@@ -0,0 +1,140 @@
+/* w32sock.h --- internal auxiliary functions for Windows socket functions
+
+   Copyright (C) 2008-2021 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 <https://www.gnu.org/licenses/>.  */
+
+/* Written by Paolo Bonzini */
+
+#include <errno.h>
+
+/* Get O_RDWR and O_BINARY.  */
+#include <fcntl.h>
+
+/* Get _open_osfhandle().  */
+#include <io.h>
+
+/* Get _get_osfhandle().  */
+#if GNULIB_MSVC_NOTHROW
+# include "msvc-nothrow.h"
+#else
+# include <io.h>
+#endif
+
+#define FD_TO_SOCKET(fd)   ((SOCKET) _get_osfhandle ((fd)))
+#define SOCKET_TO_FD(fh)   (_open_osfhandle ((intptr_t) (fh), O_RDWR | O_BINARY))
+
+static inline void
+set_winsock_errno (void)
+{
+  int err = WSAGetLastError ();
+
+  /* Map some WSAE* errors to the runtime library's error codes.  */
+  switch (err)
+    {
+    case WSA_INVALID_HANDLE:
+      errno = EBADF;
+      break;
+    case WSA_NOT_ENOUGH_MEMORY:
+      errno = ENOMEM;
+      break;
+    case WSA_INVALID_PARAMETER:
+      errno = EINVAL;
+      break;
+    case WSAENAMETOOLONG:
+      errno = ENAMETOOLONG;
+      break;
+    case WSAENOTEMPTY:
+      errno = ENOTEMPTY;
+      break;
+    case WSAEWOULDBLOCK:
+      errno = EWOULDBLOCK;
+      break;
+    case WSAEINPROGRESS:
+      errno = EINPROGRESS;
+      break;
+    case WSAEALREADY:
+      errno = EALREADY;
+      break;
+    case WSAENOTSOCK:
+      errno = ENOTSOCK;
+      break;
+    case WSAEDESTADDRREQ:
+      errno = EDESTADDRREQ;
+      break;
+    case WSAEMSGSIZE:
+      errno = EMSGSIZE;
+      break;
+    case WSAEPROTOTYPE:
+      errno = EPROTOTYPE;
+      break;
+    case WSAENOPROTOOPT:
+      errno = ENOPROTOOPT;
+      break;
+    case WSAEPROTONOSUPPORT:
+      errno = EPROTONOSUPPORT;
+      break;
+    case WSAEOPNOTSUPP:
+      errno = EOPNOTSUPP;
+      break;
+    case WSAEAFNOSUPPORT:
+      errno = EAFNOSUPPORT;
+      break;
+    case WSAEADDRINUSE:
+      errno = EADDRINUSE;
+      break;
+    case WSAEADDRNOTAVAIL:
+      errno = EADDRNOTAVAIL;
+      break;
+    case WSAENETDOWN:
+      errno = ENETDOWN;
+      break;
+    case WSAENETUNREACH:
+      errno = ENETUNREACH;
+      break;
+    case WSAENETRESET:
+      errno = ENETRESET;
+      break;
+    case WSAECONNABORTED:
+      errno = ECONNABORTED;
+      break;
+    case WSAECONNRESET:
+      errno = ECONNRESET;
+      break;
+    case WSAENOBUFS:
+      errno = ENOBUFS;
+      break;
+    case WSAEISCONN:
+      errno = EISCONN;
+      break;
+    case WSAENOTCONN:
+      errno = ENOTCONN;
+      break;
+    case WSAETIMEDOUT:
+      errno = ETIMEDOUT;
+      break;
+    case WSAECONNREFUSED:
+      errno = ECONNREFUSED;
+      break;
+    case WSAELOOP:
+      errno = ELOOP;
+      break;
+    case WSAEHOSTUNREACH:
+      errno = EHOSTUNREACH;
+      break;
+    default:
+      errno = (err > 10000 && err < 10025) ? err - 10000 : err;
+      break;
+    }
+}
diff --git a/gnulib/update-gnulib.sh b/gnulib/update-gnulib.sh
index 252f163..08c43fc 100755
--- a/gnulib/update-gnulib.sh
+++ b/gnulib/update-gnulib.sh
@@ -60,6 +60,7 @@ IMPORTED_GNULIB_MODULES="\
     rawmemchr \
     readlink \
     rename \
+    select \
     setenv \
     signal-h \
     strchrnul \