new module 'grantpt'

[Bruno Haible]

The next brick for building a portable openpty and forkpty is 'grantpt'.
I'm adding a port of the glibc implementation (based on the pt_chown program).


2010-03-21  Bruno Haible  <address@hidden>

        New module 'grantpt'.
        * lib/grantpt.c: New file, from glibc with modifications.
        * m4/grantpt.m4: New file.
        * modules/grantpt: New file.
        * lib/stdlib.in.h (grantpt): New declaration.
        * m4/stdlib_h.m4 (gl_STDLIB_H): Check whether grantpt is declared.
        (gl_STDLIB_H_DEFAULTS): Initialize GNULIB_GRANTPT, HAVE_GRANTPT.
        * modules/stdlib (Makefile.am): Substitute GNULIB_GRANTPT,
        HAVE_GRANTPT.
        * doc/posix-functions/grantpt.texi: Mention the new module.
        * tests/test-stdlib-c++.cc: Check GNULIB_NAMESPACE::grantpt.
        * config/srclist.txt: Add grantpt.c (commented).

================================ lib/grantpt.c ================================
/* Acquire ownership of the slave side of a pseudo-terminal.
   Copyright (C) 1998-2002, 2009-2010 Free Software Foundation, Inc.
   Contributed by Zack Weinberg <address@hidden>, 1998.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include <config.h>

#include <stdlib.h>

#include <assert.h>
#include <errno.h>
#include <string.h>
#include <sys/wait.h>
#include <unistd.h>

#if HAVE_SETRLIMIT
# include <sys/types.h>
# include <sys/time.h>
# include <sys/resource.h>
#endif

#include "configmake.h"
#include "pty-private.h"

#ifndef _LIBC
# define __builtin_expect(expr,val) (expr)
# define __set_errno(e) errno = (e)
# define __dup2 dup2
# define __fork fork
# define __setrlimit setrlimit
# define __waitpid waitpid
#endif

int
grantpt (int fd)
{
  /* This function is most often called from a process without 'root'
     credentials.  Use the helper program.  */
  int retval = -1;
  pid_t pid = __fork ();
  if (pid == -1)
    goto cleanup;
  else if (pid == 0)
    {
      /* This is executed in the child process.  */

#if HAVE_SETRLIMIT && defined RLIMIT_CORE
      /* Disable core dumps.  */
      struct rlimit rl = { 0, 0 };
      __setrlimit (RLIMIT_CORE, &rl);
#endif

      /* We pass the master pseudo terminal as file descriptor PTY_FILENO.  */
      if (fd != PTY_FILENO)
        if (__dup2 (fd, PTY_FILENO) < 0)
          _exit (FAIL_EBADF);

#ifdef CLOSE_ALL_FDS
      CLOSE_ALL_FDS ();
#endif

      execle (_PATH_PT_CHOWN, strrchr (_PATH_PT_CHOWN, '/') + 1, NULL, NULL);
      _exit (FAIL_EXEC);
    }
  else
    {
      int w;

      if (__waitpid (pid, &w, 0) == -1)
        goto cleanup;
      if (!WIFEXITED (w))
        __set_errno (ENOEXEC);
      else
        switch (WEXITSTATUS (w))
          {
          case 0:
            retval = 0;
            break;
          case FAIL_EBADF:
            __set_errno (EBADF);
            break;
          case FAIL_EINVAL:
            __set_errno (EINVAL);
            break;
          case FAIL_EACCES:
            __set_errno (EACCES);
            break;
          case FAIL_EXEC:
            __set_errno (ENOEXEC);
            break;
          case FAIL_ENOMEM:
            __set_errno (ENOMEM);
            break;

          default:
            assert(! "getpt: internal error: invalid exit code from pt_chown");
          }
    }

 cleanup:
  return retval;
}
================================ m4/grantpt.m4 ================================
# grantpt.m4 serial 1
dnl Copyright (C) 2010 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_GRANTPT],
[
  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])

  dnl Persuade glibc <stdlib.h> to declare grantpt().
  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])

  AC_CHECK_FUNCS([grantpt])
  if test $ac_cv_func_grantpt = no; then
    HAVE_GRANTPT=0
    AC_LIBOBJ([grantpt])
    gl_PREREQ_GRANTPT
  fi
])

# Prerequisites of lib/grantpt.c.
AC_DEFUN([gl_PREREQ_GRANTPT], [
  AC_CHECK_FUNCS([setrlimit])
])
=============================== modules/grantpt ===============================
Description:
grantpt() function: Acquire ownership of the slave side of a pseudo-terminal.

Files:
lib/grantpt.c
m4/grantpt.m4

Depends-on:
stdlib
extensions
pt_chown
configmake

configure.ac:
gl_FUNC_GRANTPT
gl_STDLIB_MODULE_INDICATOR([grantpt])

Makefile.am:

Include:
<stdlib.h>

License:
LGPL

Maintainer:
Bruno Haible
===============================================================================
--- lib/stdlib.in.h.orig        Sun Mar 21 20:06:55 2010
+++ lib/stdlib.in.h     Sun Mar 21 19:25:36 2010
@@ -201,6 +201,22 @@
 # endif
 #endif
 
+#if @GNULIB_GRANTPT@
+/* Change the ownership and access permission of the slave side of the
+   pseudo-terminal whose master side is specified by FD.  */
+# if address@hidden@
+_GL_FUNCDECL_SYS (grantpt, int, (int fd));
+# endif
+_GL_CXXALIAS_SYS (grantpt, int, (int fd));
+_GL_CXXALIASWARN (grantpt);
+#elif defined GNULIB_POSIXCHECK
+# undef grantpt
+# if HAVE_RAW_DECL_GRANTPT
+_GL_WARN_ON_USE (ptsname, "grantpt is not portable - "
+                 "use gnulib module grantpt for portability");
+# endif
+#endif
+
 #if @GNULIB_MALLOC_POSIX@
 # if address@hidden@
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
--- m4/stdlib_h.m4.orig Sun Mar 21 20:06:55 2010
+++ m4/stdlib_h.m4      Sun Mar 21 19:26:58 2010
@@ -1,4 +1,4 @@
-# stdlib_h.m4 serial 24
+# stdlib_h.m4 serial 25
 dnl Copyright (C) 2007-2010 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -33,7 +33,7 @@
 #if HAVE_RANDOM_H
 # include <random.h>
 #endif
-    ]], [atoll canonicalize_file_name getloadavg getsubopt mkdtemp
+    ]], [atoll canonicalize_file_name getloadavg getsubopt grantpt mkdtemp
     mkostemp mkostemps mkstemp mkstemps ptsname random_r initstat_r srandom_r
     setstate_r realpath rpmatch setenv strtod strtoll strtoull unsetenv])
 ])
@@ -54,6 +54,7 @@
   GNULIB_CANONICALIZE_FILE_NAME=0;  AC_SUBST([GNULIB_CANONICALIZE_FILE_NAME])
   GNULIB_GETLOADAVG=0;    AC_SUBST([GNULIB_GETLOADAVG])
   GNULIB_GETSUBOPT=0;     AC_SUBST([GNULIB_GETSUBOPT])
+  GNULIB_GRANTPT=0;       AC_SUBST([GNULIB_GRANTPT])
   GNULIB_MALLOC_POSIX=0;  AC_SUBST([GNULIB_MALLOC_POSIX])
   GNULIB_MKDTEMP=0;       AC_SUBST([GNULIB_MKDTEMP])
   GNULIB_MKOSTEMP=0;      AC_SUBST([GNULIB_MKOSTEMP])
@@ -77,6 +78,7 @@
   HAVE_CANONICALIZE_FILE_NAME=1;  AC_SUBST([HAVE_CANONICALIZE_FILE_NAME])
   HAVE_DECL_GETLOADAVG=1;    AC_SUBST([HAVE_DECL_GETLOADAVG])
   HAVE_GETSUBOPT=1;          AC_SUBST([HAVE_GETSUBOPT])
+  HAVE_GRANTPT=1;            AC_SUBST([HAVE_GRANTPT])
   HAVE_MALLOC_POSIX=1;       AC_SUBST([HAVE_MALLOC_POSIX])
   HAVE_MKDTEMP=1;            AC_SUBST([HAVE_MKDTEMP])
   HAVE_MKOSTEMP=1;           AC_SUBST([HAVE_MKOSTEMP])
--- modules/stdlib.orig Sun Mar 21 20:06:55 2010
+++ modules/stdlib      Sun Mar 21 19:26:16 2010
@@ -33,6 +33,7 @@
              -e 
's|@''GNULIB_CANONICALIZE_FILE_NAME''@|$(GNULIB_CANONICALIZE_FILE_NAME)|g' \
              -e 's|@''GNULIB_GETLOADAVG''@|$(GNULIB_GETLOADAVG)|g' \
              -e 's|@''GNULIB_GETSUBOPT''@|$(GNULIB_GETSUBOPT)|g' \
+             -e 's|@''GNULIB_GRANTPT''@|$(GNULIB_GRANTPT)|g' \
              -e 's|@''GNULIB_MALLOC_POSIX''@|$(GNULIB_MALLOC_POSIX)|g' \
              -e 's|@''GNULIB_MKDTEMP''@|$(GNULIB_MKDTEMP)|g' \
              -e 's|@''GNULIB_MKOSTEMP''@|$(GNULIB_MKOSTEMP)|g' \
@@ -55,6 +56,7 @@
              -e 
's|@''HAVE_CANONICALIZE_FILE_NAME''@|$(HAVE_CANONICALIZE_FILE_NAME)|g' \
              -e 's|@''HAVE_DECL_GETLOADAVG''@|$(HAVE_DECL_GETLOADAVG)|g' \
              -e 's|@''HAVE_GETSUBOPT''@|$(HAVE_GETSUBOPT)|g' \
+             -e 's|@''HAVE_GRANTPT''@|$(HAVE_GRANTPT)|g' \
              -e 's|@''HAVE_MALLOC_POSIX''@|$(HAVE_MALLOC_POSIX)|g' \
              -e 's|@''HAVE_MKDTEMP''@|$(HAVE_MKDTEMP)|g' \
              -e 's|@''HAVE_MKOSTEMP''@|$(HAVE_MKOSTEMP)|g' \
--- doc/posix-functions/grantpt.texi.orig       Sun Mar 21 20:06:55 2010
+++ doc/posix-functions/grantpt.texi    Sun Mar 21 19:18:58 2010
@@ -4,15 +4,15 @@
 
 POSIX specification: 
@url{http://www.opengroup.org/onlinepubs/9699919799/functions/grantpt.html}
 
-Gnulib module: ---
+Gnulib module: grantpt
 
 Portability problems fixed by Gnulib:
 @itemize
address@hidden
+This function is missing on some platforms:
+MacOS X 10.3, OpenBSD 3.8, mingw, BeOS.
 @end itemize
 
 Portability problems not fixed by Gnulib:
 @itemize
address@hidden
-This function is missing on some platforms:
-MacOS X 10.3, OpenBSD 3.8, mingw, BeOS.
 @end itemize
--- tests/test-stdlib-c++.cc.orig       Sun Mar 21 20:06:55 2010
+++ tests/test-stdlib-c++.cc    Sun Mar 21 19:53:14 2010
@@ -48,6 +48,10 @@
                  (char **, char *const *, char **));
 #endif
 
+#if GNULIB_GRANTPT
+SIGNATURE_CHECK (GNULIB_NAMESPACE::grantpt, int, (int));
+#endif
+
 #if GNULIB_MALLOC_POSIX
 SIGNATURE_CHECK (GNULIB_NAMESPACE::malloc, void *, (size_t));
 #endif
--- config/srclist.txt.orig     Sun Mar 21 20:06:55 2010
+++ config/srclist.txt  Sun Mar 21 19:54:32 2010
@@ -218,6 +218,7 @@
 #$LIBCSRC/sysdeps/unix/bsd/poll.c      lib gpl
 #$LIBCSRC/sysdeps/unix/bsd/ptsname.c   lib gpl
 #$LIBCSRC/sysdeps/unix/dirfd.c         lib gpl
+#$LIBCSRC/sysdeps/unix/grantpt.c       lib gpl
 #$LIBCSRC/sysdeps/unix/rmdir.c         lib gpl
 #$LIBCSRC/time/strftime.c              lib gpl
 # These are close, but we are using the gettext versions.