1 files changed, 111 insertions, 0 deletions
diff --git a/sysdeps/unix/grantpt.c b/sysdeps/unix/grantpt.c
new file mode 100644
index 0000000000..4837a7a128
--- /dev/null
+++ b/sysdeps/unix/grantpt.c
@@ -0,0 +1,111 @@
+/* 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.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/resource.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include <assert.h>
+
+#include "pty-internal.h"
+
+/* Given a fd on a master pseudoterminal, chown the file associated
+   with the slave to the calling process, and set its group and
+   mode appropriately.  Note that this is an unprivileged operation. */
+
+/* This "generic Unix" implementation works because we provide the program
+   /usr/libexec/pt_chown, and it only depends on ptsname() working. */
+static const char helper[] = LIBEXECDIR "/pt_chown";
+static const char *argv[] = { "pt_chown", NULL };
+
+int
+grantpt (fd)
+     int fd;
+{
+  struct stat st;
+  int w, pid;
+  char namebuf[PTYNAMELEN];
+
+  /* Some systems do it for us.  */
+  if (ptsname_r (fd, namebuf, PTYNAMELEN) == NULL)
+    return -1;
+  if (stat (namebuf, &st))
+    return -1;
+
+  if (st.st_uid == getuid ())
+    return 0;
+
+  /* We have to do it in user space.  */
+
+  pid = fork ();
+  if (pid == -1)
+    return -1;
+  else if (pid == 0)
+    {
+      /* Disable core dumps in the child.  */
+      struct rlimit off = { 0, 0 };
+      setrlimit (RLIMIT_CORE, &off);
+
+      /* The helper does its thing on fd PTY_FD.  */
+      if (fd != PTY_FD)
+	if (dup2 (fd, PTY_FD) == -1)
+	  _exit (FAIL_EBADF);
+
+      execve (helper, (char *const *) argv, 0);
+      _exit (FAIL_EXEC);
+    }
+  else
+    {
+      if (waitpid (pid, &w, 0) == -1)
+	return -1;
+      if (!WIFEXITED (w))
+	{
+	  __set_errno (ENOEXEC);
+	  return -1;
+	}
+      else
+	switch (WEXITSTATUS(w))
+	  {
+	  case 0:
+	    break;
+	  case FAIL_EBADF:
+	    __set_errno (EBADF);
+	    return -1;
+	  case FAIL_EINVAL:
+	    __set_errno (EINVAL);
+	    return -1;
+	  case FAIL_EACCES:
+	    __set_errno (EACCES);
+	    return -1;
+	  case FAIL_EXEC:
+	    __set_errno (ENOEXEC);
+	    return -1;
+
+	  default:
+	    assert(! "getpt: internal error: invalid exit code from pt_chown");
+	  }
+    }
+
+  /* Success.  */
+  return 0;
+}