/*
   Copyright (C) 1996, 1999, 2000, 2008 Free Software Foundation, Inc.
   Written by Michael I. Bushnell, p/BSG.

   This file is part of the GNU Hurd.

   The GNU Hurd 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 2, or (at
   your option) any later version.

   The GNU Hurd 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, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */

#include <string.h>
#include <stdio.h>
#include <hurd/paths.h>
#include "netfs.h"
#include "fs_S.h"
#include <sys/mman.h>
#include <sys/sysmacros.h>

kern_return_t
netfs_S_file_get_translator (struct protid *user,
			     data_t *trans,
			     mach_msg_type_number_t *translen)
{
  struct node *np;
  error_t err;

  if (!user)
    return EOPNOTSUPP;

  np = user->po->np;
  pthread_mutex_lock (&np->lock);
  err = netfs_validate_stat (np, user->user);

  if (err)
    {
      pthread_mutex_unlock (&np->lock);
      return err;
    }

  if (np->nn_translated & S_IPTRANS)
    {
      char *string = NULL;
      mach_msg_type_number_t len = 0;
      err = netfs_get_translator (np, &string, &len);
      if (!err)
	{
	  if (len > *translen)
	    {
	      void *buf = mmap (0, len, PROT_READ|PROT_WRITE, MAP_ANON, 0, 0);
	      if (buf == MAP_FAILED)
		{
		  pthread_mutex_unlock (&np->lock);
		  return errno;
		}

	      *trans = buf;
	    }
	  memcpy (*trans, string, len);
	  *translen = len;
	  free (string);
	}
    }
  else if (S_ISLNK (np->nn_stat.st_mode))
    {
      unsigned int len = sizeof _HURD_SYMLINK + np->nn_stat.st_size + 1;

      if (len  > *translen)
	{
	  void *buf = mmap (0, len, PROT_READ|PROT_WRITE, MAP_ANON, 0, 0);
	  if (buf == MAP_FAILED)
	    {
	      pthread_mutex_unlock (&np->lock);
	      return errno;
	    }

	  *trans = buf;
	}
      memcpy (*trans, _HURD_SYMLINK, sizeof _HURD_SYMLINK);

      err = netfs_attempt_readlink (user->user, np,
				    *trans + sizeof _HURD_SYMLINK);
      if (!err)
	{
	  (*trans)[sizeof _HURD_SYMLINK + np->nn_stat.st_size] = '\0';
	  *translen = len;
	}
      else
	if (len > *translen)
	  munmap (*trans, len);
    }
  else if (S_ISCHR (np->nn_stat.st_mode) || S_ISBLK (np->nn_stat.st_mode))
    {
      char *buf;
      int buflen;

      buflen = asprintf (&buf, "%s%c%d%c%d",
			 (S_ISCHR (np->nn_stat.st_mode)
			  ? _HURD_CHRDEV
			  : _HURD_BLKDEV),
			 '\0', gnu_dev_major (np->nn_stat.st_rdev),
			 '\0', gnu_dev_minor (np->nn_stat.st_rdev));
      if (buflen < 0)
	err = ENOMEM;
      else
	{
	  buflen++;			/* terminating nul */

	  if (buflen > *translen)
	    {
	      void *buf = mmap (0, buflen, PROT_READ|PROT_WRITE,
				MAP_ANON, 0, 0);
	      if (buf == MAP_FAILED)
		{
		  pthread_mutex_unlock (&np->lock);
		  return errno;
		}

	      *trans = buf;
	    }
	  memcpy (*trans, buf, buflen);
	  free (buf);
	  *translen = buflen;
	  err = 0;
	}
    }
  else if (S_ISFIFO (np->nn_stat.st_mode))
    {
      unsigned int len;

      len = sizeof _HURD_FIFO;
      if (len > *translen)
	{
	  void *buf = mmap (0, len, PROT_READ|PROT_WRITE, MAP_ANON, 0, 0);
	  if (buf == MAP_FAILED)
	    {
	      pthread_mutex_unlock (&np->lock);
	      return errno;
	    }

	  *trans = buf;
	}
      memcpy (*trans, _HURD_FIFO, sizeof _HURD_FIFO);
      *translen = len;
      err = 0;
    }
  else if (S_ISSOCK (np->nn_stat.st_mode))
    {
      unsigned int len;

      len = sizeof _HURD_IFSOCK;
      if (len > *translen)
	{
	  void *buf = mmap (0, len, PROT_READ|PROT_WRITE, MAP_ANON, 0, 0);
	  if (buf == MAP_FAILED)
	    {
	      pthread_mutex_unlock (&np->lock);
	      return errno;
	    }

	  *trans = buf;
	}
      memcpy (*trans, _HURD_IFSOCK, sizeof _HURD_IFSOCK);
      *translen = len;
      err = 0;
    }
  else
    err = EINVAL;

  pthread_mutex_unlock (&np->lock);

  return err;
}
