2 files changed, 121 insertions, 55 deletions

diff --git a/login/programs/pt_chown.c b/login/programs/pt_chown.c
index dbf79fc..6ed8e82 100644
--- a/login/programs/pt_chown.c
+++ b/login/programs/pt_chown.c
@@ -1,4 +1,5 @@
-/* Copyright (C) 1998 Free Software Foundation, Inc.
+/* pt_chmod - helper program for `grantpt'.
+   Copyright (C) 1998 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by C. Scott Ananian <cananian@alumni.princeton.edu>, 1998.
 
@@ -17,72 +18,136 @@
    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    Boston, MA 02111-1307, USA.  */
 
-/* pt_chmod.c ... securely implement grantpt in user-land.  */
-
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <stdlib.h>
-#include <unistd.h>
+#include <argp.h>
 #include <errno.h>
-#include <stdio.h>
+#include <error.h>
 #include <grp.h>
+#include <libintl.h>
+#include <locale.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "pty-private.h"
 
-#include "pty-internal.h"
-#define Str(x) _Str(x)
-#define _Str(x) #x
+/* Get libc version number.  */
+#include "../version.h"
 
-void
-usage (void)
+#define PACKAGE _libc_intl_domainname
+
+/* Name and version of program.  */
+static void print_version (FILE *stream, struct argp_state *state);
+void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;
+
+/* Function to print some extra text in the help message.  */
+static char *more_help (int key, const char *text, void *input);
+
+/* Data structure to communicate with argp functions.  */
+static struct argp argp =
 {
-  fprintf (stderr, _("usage: pt_chown FD>&%s\n"
-		     "This program is used internally by grantpt(3).\n"),
-	   Str (PTY_FD));
-  exit (0);
+  NULL, NULL, NULL, NULL, NULL, more_help
+};
+
+
+/* Print the version information.  */
+static void
+print_version (FILE *stream, struct argp_state *state)
+{
+  fprintf (stream, "pt_chmod (GNU %s) %s\n", PACKAGE, VERSION);
+  fprintf (stream, gettext ("\
+Copyright (C) %s Free Software Foundation, Inc.\n\
+This is free software; see the source for copying conditions.  There is NO\n\
+warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
+"), "1998");
 }
 
-void
-bad_installation (void)
+static char *
+more_help (int key, const char *text, void *input)
 {
-  fputs (_("pt_chown: installation problem: "
-	   "This program needs to be setuid root.\n"), stderr);
-  exit (FAIL_EXEC);
+  char *cp;
+  
+  switch (key)
+    {
+    case ARGP_KEY_HELP_PRE_DOC:
+      asprintf (&cp, gettext ("\
+Set the owner, group and access permission of the terminal passed on\
+ file descriptor `%d'.  This is the helper program for the `grantpt'\
+ function.  It is not intended to be run directly from the command\
+ line.\n"),
+		PTY_FILENO);
+      return cp;
+    case ARGP_KEY_HELP_EXTRA:
+      /* We print some extra information.  */
+      asprintf (&cp, gettext ("\
+The owner is set to the current user, the group is set to `%s',\
+ and the access permission is set to `%o'.\n\n\
+%s"),
+		TTY_GROUP, S_IRUSR|S_IWUSR|S_IWGRP, gettext ("\
+Report bugs using the `glibcbug' script to <bugs@gnu.org>.\n"));
+      return cp;
+    default:
+      break;
+    }
+  return (char *) text;
 }
 
 int
-main (int argc, char **argv)
+main (int argc, char *argv[])
 {
-  struct group *grp;
-  struct stat s;
   char *pty;
+  int remaining;
+  struct stat st;
+  struct group *p;
   gid_t gid;
-  uid_t uid;
 
-  if (argc != 1)
-    usage ();
+  /* Set locale via LC_ALL.  */
+  setlocale (LC_ALL, "");
+
+  /* Set the text message domain.  */
+  textdomain (PACKAGE);
+
+  /* parse and process arguments.  */
+  argp_parse (&argp, argc, argv, 0, &remaining, NULL);
+
+  if (remaining < argc)
+    {
+      /* We should not be called with any non-option parameters.  */
+      error (0, 0, gettext ("too many arguments"));
+      argp_help (&argp, stdout, ARGP_HELP_SEE | ARGP_HELP_EXIT_ERR,
+		 program_invocation_short_name);
+      exit (EXIT_FAILURE);
+    }
+  
+  /* Check if we are properly installed.  */
   if (geteuid () != 0)
-    bad_installation ();
-
-  grp = getgrnam (TTY_GROUP);
-  gid = grp ? grp->gr_gid : getgid ();
-  uid = getuid ();
+    error (FAIL_EXEC, 0, gettext ("needs to be installed setuid `root'"));
 
-  /* Check that fd is a valid pty master -- call ptsname().  */
-  pty = ptsname (PTY_FD);
+  /* Check that PTY_FILENO is a valid master pseudo terminal.  */
+  pty = ptsname (PTY_FILENO);
   if (pty == NULL)
     return errno == EBADF ? FAIL_EBADF : FAIL_EINVAL;
-  close (PTY_FD);
+  close (PTY_FILENO);
 
-  /* Check that target file is a character device.  */
-  if (stat (pty, &s))
-    return FAIL_EINVAL; /* This should only fail if pty doesn't exist.  */
-  if (!S_ISCHR (s.st_mode))
+  /* Check that the returned slave pseudo terminal is a
+     character device.  */
+  if (stat (pty, &st) < 0 || !S_ISCHR(st.st_mode))
     return FAIL_EINVAL;
 
-  if (chmod (pty, 0620))
-    return FAIL_EACCES;  /* XXX: Probably not true. */
+  /* Get the group ID of the special `tty' group.  */
+  p = getgrnam (TTY_GROUP);
+  gid = p ? p->gr_gid : getgid ();
+
+  /* Set the owner to the real user ID, and the group to that special
+     group ID.  */
+  if (chown (pty, getuid (), gid) < 0)
+    return FAIL_EACCES;
 
-  if (chown (pty, uid, gid))
+  /* Set the permission mode to readable and writable by the owner,
+     and writable by the group.  */
+  if (chmod (pty, S_IRUSR|S_IWUSR|S_IWGRP) < 0)
     return FAIL_EACCES;
 
-  return 0;
+  exit (EXIT_SUCCESS);
 }
diff --git a/login/pty-internal.h b/login/pty-private.h
index c185886..b20fd0e 100644
--- a/login/pty-internal.h
+++ b/login/pty-private.h
@@ -1,4 +1,5 @@
-/* Copyright (C) 1998 Free Software Foundation, Inc.
+/* Internal defenitions and declarations for pseudo terminal functions.
+   Copyright (C) 1998 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1998.
 
@@ -17,19 +18,19 @@
    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    Boston, MA 02111-1307, USA.  */
 
-/* Internal constants used by the pseudoterminal handling code. */
+#ifndef _PTY_PRIVATE_H
+#define _PTY_PRIVATE_H 1
 
-#ifndef _PTY_INTERNAL_H
-#define _PTY_INTERNAL_H	1
+/* The group slave pseudo terminals belong to.  */
+#define TTY_GROUP "tty"
 
-/* Length of a buffer to hold a pty name. */
-#define PTYNAMELEN 15   /* "/dev/pts/65535$" */
+/* The file descriptor connected to the master pseudo terminal.  */
+#define PTY_FILENO 3
 
-/* Which group should pty slaves belong to: */
-#define TTY_GROUP "tty"
+/* Path to the helper program that implements `grantpt' in user space.  */
+#define _PATH_PT_CHOWN LIBEXECDIR "/pt_chown"
 
-/* Communication between grantpt and pt_chown. */
-#define PTY_FD 3
+/* Exit codes for the helper program.  */
 enum  /* failure modes */
 {
   FAIL_EBADF = 1,
@@ -38,4 +39,4 @@ enum  /* failure modes */
   FAIL_EXEC
 };
 
-#endif
+#endif /* pty-private.h  */