Add in libutil, based on Cory Visi's variant of Michael Shmulevich's libutil

port.  I have reworked the code quite a bit so that the stuff that is supposed
to be in libc is in libc, and I added a bunch of missing stuff so the libutil
interface matches that of glibc's libutil.  The only caveat is that
libutil/login.c is currently a stub.
 -Erik

1 files changed, 197 insertions, 0 deletions

diff --git a/libc/stdlib/unix_grantpt.c b/libc/stdlib/unix_grantpt.c
new file mode 100644
index 000000000..eb6ce0b35
--- /dev/null
+++ b/libc/stdlib/unix_grantpt.c
@@ -0,0 +1,197 @@
+/* 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 <assert.h>
+#include <errno.h>
+#include <grp.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/resource.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "pty-private.h"
+
+extern int ptsname_r (int fd, char *buf, size_t buflen);
+
+/* Return the result of ptsname_r in the buffer pointed to by PTS,
+   which should be of length BUF_LEN.  If it is too long to fit in
+   this buffer, a sufficiently long buffer is allocated using malloc,
+   and returned in PTS.  0 is returned upon success, -1 otherwise.  */
+static int
+pts_name (int fd, char **pts, size_t buf_len)
+{
+  int rv;
+  char *buf = *pts;
+
+  for (;;)
+    {
+      char *new_buf;
+
+      if (buf_len)
+	{
+	  rv = ptsname_r (fd, buf, buf_len);
+
+	  if (rv != 0 || memchr (buf, '\0', buf_len))
+	    /* We either got an error, or we succeeded and the
+	       returned name fit in the buffer.  */
+	    break;
+
+	  /* Try again with a longer buffer.  */
+	  buf_len += buf_len;	/* Double it */
+	}
+      else
+	/* No initial buffer; start out by mallocing one.  */
+	buf_len = 128;		/* First time guess.  */
+
+      if (buf != *pts)
+	/* We've already malloced another buffer at least once.  */
+	new_buf = realloc (buf, buf_len);
+      else
+	new_buf = malloc (buf_len);
+      if (! new_buf)
+	{
+	  rv = -1;
+	  errno = ENOMEM;
+	  break;
+	}
+      buf = new_buf;
+    }
+
+  if (rv == 0)
+    *pts = buf;		/* Return buffer to the user.  */
+  else if (buf != *pts)
+    free (buf);		/* Free what we malloced when returning an error.  */
+
+  return rv;
+}
+
+/* Change the ownership and access permission of the slave pseudo
+   terminal associated with the master pseudo terminal specified
+   by FD.  */
+int
+grantpt (int fd)
+{
+  int retval = -1;
+#ifdef PATH_MAX
+  char _buf[PATH_MAX];
+#else
+  char _buf[512];
+#endif
+  char *buf = _buf;
+  struct stat st;
+  uid_t uid;
+  gid_t gid;
+  pid_t pid;
+
+  if (pts_name (fd, &buf, sizeof (_buf)))
+    return -1;
+
+  if (_xstat (_STAT_VER, buf, &st) < 0)
+    goto cleanup;
+
+  /* Make sure that we own the device.  */
+  uid = getuid ();
+  if (st.st_uid != uid)
+    {
+      if (chown (buf, uid, st.st_gid) < 0)
+	goto helper;
+    }
+
+  gid = getgid ();
+
+  /* Make sure the group of the device is that special group.  */
+  if (st.st_gid != gid)
+    {
+      if (chown (buf, uid, gid) < 0)
+	goto helper;
+    }
+
+  /* Make sure the permission mode is set to readable and writable by
+     the owner, and writable by the group.  */
+  if ((st.st_mode & ACCESSPERMS) != (S_IRUSR|S_IWUSR|S_IWGRP))
+    {
+      if (chmod (buf, S_IRUSR|S_IWUSR|S_IWGRP) < 0)
+	goto helper;
+    }
+
+  retval = 0;
+  goto cleanup;
+
+  /* We have to use the helper program.  */
+ helper:
+
+  pid = fork ();
+  if (pid == -1)
+    goto cleanup;
+  else if (pid == 0)
+    {
+      /* Disable core dumps.  */
+      struct rlimit rl = { 0, 0 };
+      setrlimit (RLIMIT_CORE, &rl);
+
+      /* We pase the master pseudo terminal as file descriptor PTY_FILENO.  */
+      if (fd != PTY_FILENO)
+	if (dup2 (fd, PTY_FILENO) < 0)
+	  exit (FAIL_EBADF);
+
+      execle (_PATH_PT_CHOWN, _PATH_PT_CHOWN, NULL, NULL);
+      exit (FAIL_EXEC);
+    }
+  else
+    {
+      int w;
+
+      if (waitpid (pid, &w, 0) == -1)
+	goto cleanup;
+      if (!WIFEXITED (w))
+	errno = ENOEXEC;
+      else
+	switch (WEXITSTATUS(w))
+	  {
+	  case 0:
+	    retval = 0;
+	    break;
+	  case FAIL_EBADF:
+	    errno = EBADF;
+	    break;
+	  case FAIL_EINVAL:
+	    errno = EINVAL;
+	    break;
+	  case FAIL_EACCES:
+	    errno = EACCES;
+	    break;
+	  case FAIL_EXEC:
+	    errno = ENOEXEC;
+	    break;
+
+	  default:
+	    assert(! "getpt: internal error: invalid exit code from pt_chown");
+	  }
+    }
+
+ cleanup:
+  if (buf != _buf)
+    free (buf);
+
+  return retval;
+}