path: root/common/estream.c

/* estream.c - Extended Stream I/O Library
 * Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010 g10 Code GmbH
 *
 * This file is part of Libestream.
 *
 * Libestream 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 of the License,
 * or (at your option) any later version.
 *
 * Libestream 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 Libestream; if not, see <http://www.gnu.org/licenses/>.
 *
 * ALTERNATIVELY, Libestream may be distributed under the terms of the
 * following license, in which case the provisions of this license are
 * required INSTEAD OF the GNU General Public License. If you wish to
 * allow use of your version of this file only under the terms of the
 * GNU General Public License, and not to allow others to use your
 * version of this file under the terms of the following license,
 * indicate your decision by deleting this paragraph and the license
 * below.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, and the entire permission notice in its entirety,
 *    including the disclaimer of warranties.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote
 *    products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifdef USE_ESTREAM_SUPPORT_H
# include <estream-support.h>
#endif

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#if defined(_WIN32) && !defined(HAVE_W32_SYSTEM)
# define HAVE_W32_SYSTEM 1
# if defined(__MINGW32CE__) && !defined (HAVE_W32CE_SYSTEM)
#  define HAVE_W32CE_SYSTEM
# endif
#endif

#include <sys/types.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdarg.h>
#include <fcntl.h>
#include <errno.h>
#include <stddef.h>
#include <assert.h>
#ifdef HAVE_W32_SYSTEM
# include <windows.h>
#endif
#ifdef HAVE_W32CE_SYSTEM
# include <gpg-error.h> /* ERRNO replacement.  */
#endif

#ifdef WITHOUT_GNU_PTH /* Give the Makefile a chance to build without Pth.  */
# undef HAVE_PTH
# undef USE_GNU_PTH
#endif

#ifdef HAVE_PTH
# include <pth.h>
#endif

/* This is for the special hack to use estream.c in GnuPG.  */
#ifdef GNUPG_MAJOR_VERSION
# include "../common/util.h"
#endif

#ifndef HAVE_MKSTEMP
int mkstemp (char *template);
#endif

#ifndef HAVE_MEMRCHR
void *memrchr (const void *block, int c, size_t size);
#endif

#include <estream.h>
#include <estream-printf.h>



#ifndef O_BINARY
#define O_BINARY 0
#endif

#ifdef HAVE_W32CE_SYSTEM
# define _set_errno(a)  gpg_err_set_errno ((a))
/* Setmode is missing in cegcc but available since CE 5.0.  */
int _setmode (int handle, int mode);
# define setmode(a,b)   _setmode ((a),(b))
#else
# define _set_errno(a)  do { errno = (a); } while (0)
#endif

#ifdef HAVE_W32_SYSTEM
# define IS_INVALID_FD(a) ((void*)(a) == (void*)(-1))
#else
# define IS_INVALID_FD(a) ((a) == -1)
#endif


/* Generally used types.  */

typedef void *(*func_realloc_t) (void *mem, size_t size);
typedef void (*func_free_t) (void *mem);




/* Buffer management layer.  */

#define BUFFER_BLOCK_SIZE  BUFSIZ
#define BUFFER_UNREAD_SIZE 16



/* Locking.  */

#ifdef HAVE_PTH
typedef pth_mutex_t estream_mutex_t;
#else /*!HAVE_PTH*/
typedef void *estream_mutex_t;
#endif /*!HAVE_PTH*/

static inline void
dummy_mutex_call_void (estream_mutex_t mutex)
{
  (void)mutex;
}

static inline int
dummy_mutex_call_int (estream_mutex_t mutex)
{
  (void)mutex;
  return 0;
}


#ifdef HAVE_PTH

static int estream_pth_killed;

# define ESTREAM_MUTEX_INITIALIZER PTH_MUTEX_INIT
# define ESTREAM_MUTEX_LOCK(mutex)                              \
  (estream_pth_killed ? dummy_mutex_call_void ((mutex))         \
   : pth_mutex_acquire (&(mutex), 0, NULL))
# define ESTREAM_MUTEX_UNLOCK(mutex)                            \
  (estream_pth_killed ? dummy_mutex_call_void ((mutex))         \
   : pth_mutex_release (&(mutex)))
# define ESTREAM_MUTEX_TRYLOCK(mutex)                                   \
  (estream_pth_killed ? dummy_mutex_call_int ((mutex))                  \
   : ((pth_mutex_acquire (&(mutex), 1, NULL) == TRUE)? 0:-1))
# define ESTREAM_MUTEX_INITIALIZE(mutex)                        \
  (estream_pth_killed ? dummy_mutex_call_void ((mutex))         \
   : pth_mutex_init (&(mutex)))

#else /*!HAVE_PTH*/

# define ESTREAM_MUTEX_INITIALIZER NULL
# define ESTREAM_MUTEX_LOCK(mutex) dummy_mutex_call_void ((mutex))
# define ESTREAM_MUTEX_UNLOCK(mutex) dummy_mutex_call_void ((mutex))
# define ESTREAM_MUTEX_TRYLOCK(mutex) dummy_mutex_call_int ((mutex))
# define ESTREAM_MUTEX_INITIALIZE(mutex) dummy_mutex_call_void ((mutex))

#endif /*!HAVE_PTH*/

/* Primitive system I/O.  */

#ifdef HAVE_PTH
# define ESTREAM_SYS_READ  es_pth_read
# define ESTREAM_SYS_WRITE es_pth_write
# define ESTREAM_SYS_YIELD() \
  do { if (!estream_pth_killed) pth_yield (NULL); } while (0)
#else
# define ESTREAM_SYS_READ  read
# define ESTREAM_SYS_WRITE write
# define ESTREAM_SYS_YIELD() do { } while (0)
#endif

/* Misc definitions.  */

#define ES_DEFAULT_OPEN_MODE (S_IRUSR | S_IWUSR)

/* An internal stream object.  */

struct estream_internal
{
  unsigned char buffer[BUFFER_BLOCK_SIZE];
  unsigned char unread_buffer[BUFFER_UNREAD_SIZE];
  estream_mutex_t lock;		 /* Lock. */
  void *cookie;			 /* Cookie.                */
  void *opaque;			 /* Opaque data.           */
  unsigned int modeflags;	 /* Flags for the backend. */
  char *printable_fname;         /* Malloced filename for es_fname_get.  */
  off_t offset;
  es_cookie_read_function_t func_read;
  es_cookie_write_function_t func_write;
  es_cookie_seek_function_t func_seek;
  es_cookie_close_function_t func_close;
  int strategy;
  int fd;
  struct
  {
    unsigned int err: 1;
    unsigned int eof: 1;
  } indicators;
  unsigned int deallocate_buffer: 1;
  unsigned int is_stdstream:1;   /* This is a standard stream.  */
  unsigned int stdstream_fd:2;   /* 0, 1 or 2 for a standard stream.  */
  unsigned int print_err: 1;     /* Error in print_fun_writer.  */
  unsigned int printable_fname_inuse: 1;  /* es_fname_get has been used.  */
  int print_errno;               /* Errno from print_fun_writer.  */
  size_t print_ntotal;           /* Bytes written from in print_fun_writer. */
  FILE *print_fp;                /* Stdio stream used by print_fun_writer.  */
};


typedef struct estream_internal *estream_internal_t;

#define ESTREAM_LOCK(stream) ESTREAM_MUTEX_LOCK (stream->intern->lock)
#define ESTREAM_UNLOCK(stream) ESTREAM_MUTEX_UNLOCK (stream->intern->lock)
#define ESTREAM_TRYLOCK(stream) ESTREAM_MUTEX_TRYLOCK (stream->intern->lock)

/* Stream list.  */

typedef struct estream_list *estream_list_t;

struct estream_list
{
  estream_t car;
  estream_list_t cdr;
  estream_list_t *prev_cdr;
};

static estream_list_t estream_list;
static estream_mutex_t estream_list_lock;

#define ESTREAM_LIST_LOCK   ESTREAM_MUTEX_LOCK   (estream_list_lock)
#define ESTREAM_LIST_UNLOCK ESTREAM_MUTEX_UNLOCK (estream_list_lock)

/* File descriptors registered to be used as the standard file handles. */
static int custom_std_fds[3];
static unsigned char custom_std_fds_valid[3];


#ifndef EOPNOTSUPP
# define EOPNOTSUPP ENOSYS
#endif


/* Local prototypes.  */
static void fname_set_internal (estream_t stream, const char *fname, int quote);




/* Macros.  */

/* Calculate array dimension.  */
#ifndef DIM
#define DIM(array) (sizeof (array) / sizeof (*array))
#endif

#define tohex(n) ((n) < 10 ? ((n) + '0') : (((n) - 10) + 'A'))


/* Evaluate EXPRESSION, setting VARIABLE to the return code, if
   VARIABLE is zero.  */
#define SET_UNLESS_NONZERO(variable, tmp_variable, expression) \
  do                                                           \
    {                                                          \
      tmp_variable = expression;                               \
      if ((! variable) && tmp_variable)                        \
        variable = tmp_variable;                               \
    }                                                          \
  while (0)


/* Malloc wrappers to overcome problems on some older OSes.  */
static void *
mem_alloc (size_t n)
{
  if (!n)
    n++;
  return malloc (n);
}

static void *
mem_realloc (void *p, size_t n)
{
  if (!p)
    return mem_alloc (n);
  return realloc (p, n);
}

static void
mem_free (void *p)
{
  if (p)
    free (p);
}



/*
 * List manipulation.
 */

/* Add STREAM to the list of registered stream objects.  If
   WITH_LOCKED_LIST is true we assumed that the list of streams is
   already locked.  */
static int
es_list_add (estream_t stream, int with_locked_list)
{
  estream_list_t list_obj;
  int ret;

  list_obj = mem_alloc (sizeof (*list_obj));
  if (! list_obj)
    ret = -1;
  else
    {
      if (!with_locked_list)
        ESTREAM_LIST_LOCK;
      list_obj->car = stream;
      list_obj->cdr = estream_list;
      list_obj->prev_cdr = &estream_list;
      if (estream_list)
	estream_list->prev_cdr = &list_obj->cdr;
      estream_list = list_obj;
      if (!with_locked_list)
        ESTREAM_LIST_UNLOCK;
      ret = 0;
    }

  return ret;
}

/* Remove STREAM from the list of registered stream objects.  */
static void
es_list_remove (estream_t stream, int with_locked_list)
{
  estream_list_t list_obj;

  if (!with_locked_list)
    ESTREAM_LIST_LOCK;
  for (list_obj = estream_list; list_obj; list_obj = list_obj->cdr)
    if (list_obj->car == stream)
      {
	*list_obj->prev_cdr = list_obj->cdr;
	if (list_obj->cdr)
	  list_obj->cdr->prev_cdr = list_obj->prev_cdr;
	mem_free (list_obj);
	break;
      }
  if (!with_locked_list)
    ESTREAM_LIST_UNLOCK;
}

/* Type of an stream-iterator-function.  */
typedef int (*estream_iterator_t) (estream_t stream);

/* Iterate over list of registered streams, calling ITERATOR for each
   of them.  */
static int
es_list_iterate (estream_iterator_t iterator)
{
  estream_list_t list_obj;
  int ret = 0;

  ESTREAM_LIST_LOCK;
  for (list_obj = estream_list; list_obj; list_obj = list_obj->cdr)
    ret |= (*iterator) (list_obj->car);
  ESTREAM_LIST_UNLOCK;

  return ret;
}



/*
 * I/O Helper
 *
 * Unfortunately our Pth emulation for Windows expects system handles
 * for pth_read and pth_write.  We use a simple approach to fix this:
 * If the function returns an error we fall back to a vanilla read or
 * write, assuming that we do I/O on a plain file where the operation
 * can't block.
 */
#ifdef HAVE_PTH
static int
es_pth_read (int fd, void *buffer, size_t size)
{
  if (estream_pth_killed)
    return read (fd, buffer, size);
  else
    {
# ifdef HAVE_W32_SYSTEM
      int rc = pth_read (fd, buffer, size);
      if (rc == -1 && errno == EINVAL)
        rc = read (fd, buffer, size);
      return rc;
# else /*!HAVE_W32_SYSTEM*/
      return pth_read (fd, buffer, size);
# endif /* !HAVE_W32_SYSTEM*/
    }
}

static int
es_pth_write (int fd, const void *buffer, size_t size)
{
  if (estream_pth_killed)
    return write (fd, buffer, size);
  else
    {
# ifdef HAVE_W32_SYSTEM
      int rc = pth_write (fd, buffer, size);
      if (rc == -1 && errno == EINVAL)
        rc = write (fd, buffer, size);
      return rc;
# else /*!HAVE_W32_SYSTEM*/
      return pth_write (fd, buffer, size);
# endif /* !HAVE_W32_SYSTEM*/
    }
}
#endif /*HAVE_PTH*/



static void
es_deinit (void)
{
  /* Flush all streams. */
  es_fflush (NULL);
}


/* A replacement for pth_kill.  The reason we need this is that after
   a pth_kill all our pth functions may not be used anymore.  Thus
   applications using estream and pth need to use this function
   instead of a plain pth_kill.  */
int
es_pth_kill (void)
{
#ifdef HAVE_PTH
  int rc;

  rc = pth_kill ();
  if (rc)
    estream_pth_killed = 1;
  return rc;
#else /*!HAVE_PTH*/
  return 0;
#endif /*!HAVE_PTH*/
}


/*
 * Initialization.
 */

static int
es_init_do (void)
{
  static int initialized;

  if (!initialized)
    {
#ifdef HAVE_PTH
      if (estream_pth_killed)
        initialized = 1;
      else
        {
          if (!pth_init () && errno != EPERM )
            return -1;
          if (pth_mutex_init (&estream_list_lock))
            initialized = 1;
        }
#else
      initialized = 1;
#endif
      atexit (es_deinit);
    }
  return 0;
}



/*
 * I/O methods.
 */

/* Implementation of Memory I/O.  */

/* Cookie for memory objects.  */
typedef struct estream_cookie_mem
{
  unsigned int modeflags;	/* Open flags.  */
  unsigned char *memory;	/* Allocated data buffer.  */
  size_t memory_size;		/* Allocated size of MEMORY.  */
  size_t memory_limit;          /* Caller supplied maximum allowed
                                   allocation size or 0 for no limit.  */
  size_t offset;		/* Current offset in MEMORY.  */
  size_t data_len;		/* Used length of data in MEMORY.  */
  size_t block_size;		/* Block size.  */
  struct {
    unsigned int grow: 1;	/* MEMORY is allowed to grow.  */
  } flags;
  func_realloc_t func_realloc;
  func_free_t func_free;
} *estream_cookie_mem_t;


/* Create function for memory objects.  DATA is either NULL or a user
   supplied buffer with the initial content of the memory buffer.  If
   DATA is NULL, DATA_N and DATA_LEN need to be 0 as well.  If DATA is
   not NULL, DATA_N gives the allocated size of DATA and DATA_LEN the
   used length in DATA.  */
static int
es_func_mem_create (void *ES__RESTRICT *ES__RESTRICT cookie,
		    unsigned char *ES__RESTRICT data, size_t data_n,
		    size_t data_len,
		    size_t block_size, unsigned int grow,
		    func_realloc_t func_realloc, func_free_t func_free,
		    unsigned int modeflags,
                    size_t memory_limit)
{
  estream_cookie_mem_t mem_cookie;
  int err;

  if (!data && (data_n || data_len))
    {
      _set_errno (EINVAL);
      return -1;
    }

  mem_cookie = mem_alloc (sizeof (*mem_cookie));
  if (!mem_cookie)
    err = -1;
  else
    {
      mem_cookie->modeflags = modeflags;
      mem_cookie->memory = data;
      mem_cookie->memory_size = data_n;
      mem_cookie->memory_limit = memory_limit;
      mem_cookie->offset = 0;
      mem_cookie->data_len = data_len;
      mem_cookie->block_size = block_size;
      mem_cookie->flags.grow = !!grow;
      mem_cookie->func_realloc = func_realloc ? func_realloc : mem_realloc;
      mem_cookie->func_free = func_free ? func_free : mem_free;
      *cookie = mem_cookie;
      err = 0;
    }

  return err;
}


/* Read function for memory objects.  */
static ssize_t
es_func_mem_read (void *cookie, void *buffer, size_t size)
{
  estream_cookie_mem_t mem_cookie = cookie;
  ssize_t ret;

  if (size > mem_cookie->data_len - mem_cookie->offset)
    size = mem_cookie->data_len - mem_cookie->offset;

  if (size)
    {
      memcpy (buffer, mem_cookie->memory + mem_cookie->offset, size);
      mem_cookie->offset += size;
    }

  ret = size;
  return ret;
}


/* Write function for memory objects.  */
static ssize_t
es_func_mem_write (void *cookie, const void *buffer, size_t size)
{
  estream_cookie_mem_t mem_cookie = cookie;
  ssize_t ret;
  size_t nleft;

  if (!size)
    return 0;  /* A flush is a NOP for memory objects.  */

  if (mem_cookie->modeflags & O_APPEND)
    {
      /* Append to data.  */
      mem_cookie->offset = mem_cookie->data_len;
    }

  assert (mem_cookie->memory_size >= mem_cookie->offset);
  nleft = mem_cookie->memory_size - mem_cookie->offset;

  /* If we are not allowed to grow limit the size to the left space.  */
  if (!mem_cookie->flags.grow && size > nleft)
    size = nleft;

  /* Enlarge the memory buffer if needed.  */
  if (size > nleft)
    {
      unsigned char *newbuf;
      size_t newsize;

      if (!mem_cookie->memory_size)
        newsize = size;  /* Not yet allocated.  */
      else
        newsize = mem_cookie->memory_size + (size - nleft);
      if (newsize < mem_cookie->offset)
        {
          _set_errno (EINVAL);
          return -1;
        }

      /* Round up to the next block length.  BLOCK_SIZE should always
         be set; we check anyway.  */
      if (mem_cookie->block_size)
        {
          newsize += mem_cookie->block_size - 1;
          if (newsize < mem_cookie->offset)
            {
              _set_errno (EINVAL);
              return -1;
            }
          newsize /= mem_cookie->block_size;
          newsize *= mem_cookie->block_size;
        }

      /* Check for a total limit.  */
      if (mem_cookie->memory_limit && newsize > mem_cookie->memory_limit)
        {
          _set_errno (ENOSPC);
          return -1;
        }

      newbuf = mem_cookie->func_realloc (mem_cookie->memory, newsize);
      if (!newbuf)
        return -1;

      mem_cookie->memory = newbuf;
      mem_cookie->memory_size = newsize;

      assert (mem_cookie->memory_size >= mem_cookie->offset);
      nleft = mem_cookie->memory_size - mem_cookie->offset;

      assert (size <= nleft);
    }

  memcpy (mem_cookie->memory + mem_cookie->offset, buffer, size);
  if (mem_cookie->offset + size > mem_cookie->data_len)
    mem_cookie->data_len = mem_cookie->offset + size;
  mem_cookie->offset += size;

  ret = size;
  return ret;
}


/* Seek function for memory objects.  */
static int
es_func_mem_seek (void *cookie, off_t *offset, int whence)
{
  estream_cookie_mem_t mem_cookie = cookie;
  off_t pos_new;

  switch (whence)
    {
    case SEEK_SET:
      pos_new = *offset;
      break;

    case SEEK_CUR:
      pos_new = mem_cookie->offset += *offset;
      break;

    case SEEK_END:
      pos_new = mem_cookie->data_len += *offset;
      break;

    default:
      _set_errno (EINVAL);
      return -1;
    }

  if (pos_new > mem_cookie->memory_size)
    {
      size_t newsize;
      void *newbuf;

      if (!mem_cookie->flags.grow)
	{
	  _set_errno (ENOSPC);
	  return -1;
        }

      newsize = pos_new + mem_cookie->block_size - 1;
      if (newsize < pos_new)
        {
          _set_errno (EINVAL);
          return -1;
        }
      newsize /= mem_cookie->block_size;
      newsize *= mem_cookie->block_size;

      if (mem_cookie->memory_limit && newsize > mem_cookie->memory_limit)
        {
          _set_errno (ENOSPC);
          return -1;
        }

      newbuf = mem_cookie->func_realloc (mem_cookie->memory, newsize);
      if (!newbuf)
        return -1;

      mem_cookie->memory = newbuf;
      mem_cookie->memory_size = newsize;
    }

  if (pos_new > mem_cookie->data_len)
    {
      /* Fill spare space with zeroes.  */
      memset (mem_cookie->memory + mem_cookie->data_len,
              0, pos_new - mem_cookie->data_len);
      mem_cookie->data_len = pos_new;
    }

  mem_cookie->offset = pos_new;
  *offset = pos_new;

  return 0;
}


/* Destroy function for memory objects.  */
static int
es_func_mem_destroy (void *cookie)
{
  estream_cookie_mem_t mem_cookie = cookie;

  if (cookie)
    {
      mem_cookie->func_free (mem_cookie->memory);
      mem_free (mem_cookie);
    }
  return 0;
}


static es_cookie_io_functions_t estream_functions_mem =
  {
    es_func_mem_read,
    es_func_mem_write,
    es_func_mem_seek,
    es_func_mem_destroy
  };



/* Implementation of fd I/O.  */

/* Cookie for fd objects.  */
typedef struct estream_cookie_fd
{
  int fd;        /* The file descriptor we are using for actual output.  */
  int no_close;  /* If set we won't close the file descriptor.  */
} *estream_cookie_fd_t;

/* Create function for fd objects.  */
static int
es_func_fd_create (void **cookie, int fd, unsigned int modeflags, int no_close)
{
  estream_cookie_fd_t fd_cookie;
  int err;

  fd_cookie = mem_alloc (sizeof (*fd_cookie));
  if (! fd_cookie)
    err = -1;
  else
    {
#ifdef HAVE_DOSISH_SYSTEM
      /* Make sure it is in binary mode if requested.  */
      if ( (modeflags & O_BINARY) )
        setmode (fd, O_BINARY);
#else
      (void)modeflags;
#endif
      fd_cookie->fd = fd;
      fd_cookie->no_close = no_close;
      *cookie = fd_cookie;
      err = 0;
    }

  return err;
}

/* Read function for fd objects.  */
static ssize_t
es_func_fd_read (void *cookie, void *buffer, size_t size)

{
  estream_cookie_fd_t file_cookie = cookie;
  ssize_t bytes_read;

  if (IS_INVALID_FD (file_cookie->fd))
    {
      ESTREAM_SYS_YIELD ();
      bytes_read = 0;
    }
  else
    {
      do
        bytes_read = ESTREAM_SYS_READ (file_cookie->fd, buffer, size);
      while (bytes_read == -1 && errno == EINTR);
    }

  return bytes_read;
}

/* Write function for fd objects.  */
static ssize_t
es_func_fd_write (void *cookie, const void *buffer, size_t size)
{
  estream_cookie_fd_t file_cookie = cookie;
  ssize_t bytes_written;

  if (IS_INVALID_FD (file_cookie->fd))
    {
      ESTREAM_SYS_YIELD ();
      bytes_written = size; /* Yeah:  Success writing to the bit bucket.  */
    }
  else
    {
      do
        bytes_written = ESTREAM_SYS_WRITE (file_cookie->fd, buffer, size);
      while (bytes_written == -1 && errno == EINTR);
    }

  return bytes_written;
}

/* Seek function for fd objects.  */
static int
es_func_fd_seek (void *cookie, off_t *offset, int whence)
{
  estream_cookie_fd_t file_cookie = cookie;
  off_t offset_new;
  int err;

  if (IS_INVALID_FD (file_cookie->fd))
    {
      _set_errno (ESPIPE);
      err = -1;
    }
  else
    {
      offset_new = lseek (file_cookie->fd, *offset, whence);
      if (offset_new == -1)
        err = -1;
      else
        {
          *offset = offset_new;
          err = 0;
        }
    }

  return err;
}

/* Destroy function for fd objects.  */
static int
es_func_fd_destroy (void *cookie)
{
  estream_cookie_fd_t fd_cookie = cookie;
  int err;

  if (fd_cookie)
    {
      if (IS_INVALID_FD (fd_cookie->fd))
        err = 0;
      else
        err = fd_cookie->no_close? 0 : close (fd_cookie->fd);
      mem_free (fd_cookie);
    }
  else
    err = 0;

  return err;
}


static es_cookie_io_functions_t estream_functions_fd =
  {
    es_func_fd_read,
    es_func_fd_write,
    es_func_fd_seek,
    es_func_fd_destroy
  };




/* Implementation of FILE* I/O.  */

/* Cookie for fp objects.  */
typedef struct estream_cookie_fp
{
  FILE *fp;      /* The file pointer we are using for actual output.  */
  int no_close;  /* If set we won't close the file pointer.  */
} *estream_cookie_fp_t;

/* Create function for fd objects.  */
static int
es_func_fp_create (void **cookie, FILE *fp,
                   unsigned int modeflags, int no_close)
{
  estream_cookie_fp_t fp_cookie;
  int err;

  fp_cookie = mem_alloc (sizeof *fp_cookie);
  if (!fp_cookie)
    err = -1;
  else
    {
#ifdef HAVE_DOSISH_SYSTEM
      /* Make sure it is in binary mode if requested.  */
      if ( (modeflags & O_BINARY) )
        setmode (fileno (fp), O_BINARY);
#else
      (void)modeflags;
#endif
      fp_cookie->fp = fp;
      fp_cookie->no_close = no_close;
      *cookie = fp_cookie;
      err = 0;
    }

  return err;
}

/* Read function for FILE* objects.  */
static ssize_t
es_func_fp_read (void *cookie, void *buffer, size_t size)

{
  estream_cookie_fp_t file_cookie = cookie;
  ssize_t bytes_read;

  if (file_cookie->fp)
    bytes_read = fread (buffer, 1, size, file_cookie->fp);
  else
    bytes_read = 0;
  if (!bytes_read && ferror (file_cookie->fp))
    return -1;
  return bytes_read;
}

/* Write function for FILE* objects.  */
static ssize_t
es_func_fp_write (void *cookie, const void *buffer, size_t size)

{
  estream_cookie_fp_t file_cookie = cookie;
  size_t bytes_written;


  if (file_cookie->fp)
    bytes_written = fwrite (buffer, 1, size, file_cookie->fp);
  else
    bytes_written = size; /* Successfully written to the bit bucket.  */
  if (bytes_written != size)
    return -1;
  return bytes_written;
}

/* Seek function for FILE* objects.  */
static int
es_func_fp_seek (void *cookie, off_t *offset, int whence)
{
  estream_cookie_fp_t file_cookie = cookie;
  long int offset_new;

  if (!file_cookie->fp)
    {
      _set_errno (ESPIPE);
      return -1;
    }

  if ( fseek (file_cookie->fp, (long int)*offset, whence) )
    {
      /* fprintf (stderr, "\nfseek failed: errno=%d (%s)\n", */
      /*          errno,strerror (errno)); */
      return -1;
    }

  offset_new = ftell (file_cookie->fp);
  if (offset_new == -1)
    {
      /* fprintf (stderr, "\nftell failed: errno=%d (%s)\n",  */
      /*          errno,strerror (errno)); */
      return -1;
    }
  *offset = offset_new;
  return 0;
}

/* Destroy function for FILE* objects.  */
static int
es_func_fp_destroy (void *cookie)
{
  estream_cookie_fp_t fp_cookie = cookie;
  int err;

  if (fp_cookie)
    {
      if (fp_cookie->fp)
        {
          fflush (fp_cookie->fp);
          err = fp_cookie->no_close? 0 : fclose (fp_cookie->fp);
        }
      else
        err = 0;
      mem_free (fp_cookie);
    }
  else
    err = 0;

  return err;
}


static es_cookie_io_functions_t estream_functions_fp =
  {
    es_func_fp_read,
    es_func_fp_write,
    es_func_fp_seek,
    es_func_fp_destroy
  };




/* Implementation of file I/O.  */

/* Create function for file objects.  */
static int
es_func_file_create (void **cookie, int *filedes,
		     const char *path, unsigned int modeflags)
{
  estream_cookie_fd_t file_cookie;
  int err;
  int fd;

  err = 0;
  fd = -1;

  file_cookie = mem_alloc (sizeof (*file_cookie));
  if (! file_cookie)
    {
      err = -1;
      goto out;
    }

  fd = open (path, modeflags, ES_DEFAULT_OPEN_MODE);
  if (fd == -1)
    {
      err = -1;
      goto out;
    }
#ifdef HAVE_DOSISH_SYSTEM
  /* Make sure it is in binary mode if requested.  */
  if ( (modeflags & O_BINARY) )
    setmode (fd, O_BINARY);
#endif

  file_cookie->fd = fd;
  file_cookie->no_close = 0;
  *cookie = file_cookie;
  *filedes = fd;

 out:

  if (err)
    mem_free (file_cookie);

  return err;
}


static int
es_convert_mode (const char *mode, unsigned int *modeflags)
{
  unsigned int omode, oflags;

  switch (*mode)
    {
    case 'r':
      omode = O_RDONLY;
      oflags = 0;
      break;
    case 'w':
      omode = O_WRONLY;
      oflags = O_TRUNC | O_CREAT;
      break;
    case 'a':
      omode = O_WRONLY;
      oflags = O_APPEND | O_CREAT;
      break;
    default:
      _set_errno (EINVAL);
      return -1;
    }
  for (mode++; *mode; mode++)
    {
      switch (*mode)
        {
        case '+':
          omode = O_RDWR;
          break;
        case 'b':
          oflags |= O_BINARY;
          break;
        case 'x':
          oflags |= O_EXCL;
          break;
        default: /* Ignore unknown flags.  */
          break;
        }
    }

  *modeflags = (omode | oflags);
  return 0;
}



/*
 * Low level stream functionality.
 */

static int
es_fill (estream_t stream)
{
  size_t bytes_read = 0;
  int err;

  if (!stream->intern->func_read)
    {
      _set_errno (EOPNOTSUPP);
      err = -1;
    }
  else
    {
      es_cookie_read_function_t func_read = stream->intern->func_read;
      ssize_t ret;

      ret = (*func_read) (stream->intern->cookie,
			  stream->buffer, stream->buffer_size);
      if (ret == -1)
	{
	  bytes_read = 0;
	  err = -1;
	}
      else
	{
	  bytes_read = ret;
	  err = 0;
	}
    }

  if (err)
    stream->intern->indicators.err = 1;
  else if (!bytes_read)
    stream->intern->indicators.eof = 1;

  stream->intern->offset += stream->data_len;
  stream->data_len = bytes_read;
  stream->data_offset = 0;

  return err;
}

static int
es_flush (estream_t stream)
{
  es_cookie_write_function_t func_write = stream->intern->func_write;
  int err;

  assert (stream->flags.writing);

  if (stream->data_offset)
    {
      size_t bytes_written;
      size_t data_flushed;
      ssize_t ret;

      if (! func_write)
	{
	  err = EOPNOTSUPP;
	  goto out;
	}

      /* Note: to prevent an endless loop caused by user-provided
	 write-functions that pretend to have written more bytes than
	 they were asked to write, we have to check for
	 "(stream->data_offset - data_flushed) > 0" instead of
	 "stream->data_offset - data_flushed".  */

      data_flushed = 0;
      err = 0;

      while ((((ssize_t) (stream->data_offset - data_flushed)) > 0) && (! err))
	{
	  ret = (*func_write) (stream->intern->cookie,
			       stream->buffer + data_flushed,
			       stream->data_offset - data_flushed);
	  if (ret == -1)
	    {
	      bytes_written = 0;
	      err = -1;
	    }
	  else
	    bytes_written = ret;

	  data_flushed += bytes_written;
	  if (err)
	    break;
	}

      stream->data_flushed += data_flushed;
      if (stream->data_offset == data_flushed)
	{
	  stream->intern->offset += stream->data_offset;
	  stream->data_offset = 0;
	  stream->data_flushed = 0;

	  /* Propagate flush event.  */
	  (*func_write) (stream->intern->cookie, NULL, 0);
	}
    }
  else
    err = 0;

 out:

  if (err)
    stream->intern->indicators.err = 1;

  return err;
}

/* Discard buffered data for STREAM.  */
static void
es_empty (estream_t stream)
{
  assert (!stream->flags.writing);
  stream->data_len = 0;
  stream->data_offset = 0;
  stream->unread_data_len = 0;
}

/* Initialize STREAM.  */
static void
es_initialize (estream_t stream,
	       void *cookie, int fd, es_cookie_io_functions_t functions,
               unsigned int modeflags)
{
  stream->intern->cookie = cookie;
  stream->intern->opaque = NULL;
  stream->intern->offset = 0;
  stream->intern->func_read = functions.func_read;
  stream->intern->func_write = functions.func_write;
  stream->intern->func_seek = functions.func_seek;
  stream->intern->func_close = functions.func_close;
  stream->intern->strategy = _IOFBF;
  stream->intern->fd = fd;
  stream->intern->print_err = 0;
  stream->intern->print_errno = 0;
  stream->intern->print_ntotal = 0;
  stream->intern->print_fp = NULL;
  stream->intern->indicators.err = 0;
  stream->intern->indicators.eof = 0;
  stream->intern->is_stdstream = 0;
  stream->intern->stdstream_fd = 0;
  stream->intern->deallocate_buffer = 0;
  stream->intern->printable_fname = NULL;
  stream->intern->printable_fname_inuse = 0;

  stream->data_len = 0;
  stream->data_offset = 0;
  stream->data_flushed = 0;
  stream->unread_data_len = 0;
  /* Depending on the modeflags we set whether we start in writing or
     reading mode.  This is required in case we are working on a
     stream which is not seeekable (like stdout).  Without this
     pre-initialization we would do a seek at the first write call and
     as this will fail no utput will be delivered. */
  if ((modeflags & O_WRONLY) || (modeflags & O_RDWR) )
    stream->flags.writing = 1;
  else
    stream->flags.writing = 0;
}

/* Deinitialize STREAM.  */
static int
es_deinitialize (estream_t stream)
{
  es_cookie_close_function_t func_close;
  int err, tmp_err;

  if (stream->intern->print_fp)
    {
      int save_errno = errno;
      fclose (stream->intern->print_fp);
      stream->intern->print_fp = NULL;
      _set_errno (save_errno);
    }

  func_close = stream->intern->func_close;

  err = 0;
  if (stream->flags.writing)
    SET_UNLESS_NONZERO (err, tmp_err, es_flush (stream));
  if (func_close)
    SET_UNLESS_NONZERO (err, tmp_err, (*func_close) (stream->intern->cookie));

  mem_free (stream->intern->printable_fname);
  stream->intern->printable_fname = NULL;
  stream->intern->printable_fname_inuse = 0;

  return err;
}

/* Create a new stream object, initialize it.  */
static int
es_create (estream_t *stream, void *cookie, int fd,
	   es_cookie_io_functions_t functions, unsigned int modeflags,
           int with_locked_list)
{
  estream_internal_t stream_internal_new;
  estream_t stream_new;
  int err;

  stream_new = NULL;
  stream_internal_new = NULL;

  stream_new = mem_alloc (sizeof (*stream_new));
  if (! stream_new)
    {
      err = -1;
      goto out;
    }

  stream_internal_new = mem_alloc (sizeof (*stream_internal_new));
  if (! stream_internal_new)
    {
      err = -1;
      goto out;
    }

  stream_new->buffer = stream_internal_new->buffer;
  stream_new->buffer_size = sizeof (stream_internal_new->buffer);
  stream_new->unread_buffer = stream_internal_new->unread_buffer;
  stream_new->unread_buffer_size = sizeof (stream_internal_new->unread_buffer);
  stream_new->intern = stream_internal_new;

  ESTREAM_MUTEX_INITIALIZE (stream_new->intern->lock);
  es_initialize (stream_new, cookie, fd, functions, modeflags);

  err = es_list_add (stream_new, with_locked_list);
  if (err)
    goto out;

  *stream = stream_new;

 out:

  if (err)
    {
      if (stream_new)
	{
	  es_deinitialize (stream_new);
	  mem_free (stream_new);
	}
    }

  return err;
}

/* Deinitialize a stream object and destroy it.  */
static int
es_destroy (estream_t stream, int with_locked_list)
{
  int err = 0;

  if (stream)
    {
      es_list_remove (stream, with_locked_list);
      err = es_deinitialize (stream);
      mem_free (stream->intern);
      mem_free (stream);
    }

  return err;
}

/* Try to read BYTES_TO_READ bytes FROM STREAM into BUFFER in
   unbuffered-mode, storing the amount of bytes read in
   *BYTES_READ.  */
static int
es_read_nbf (estream_t ES__RESTRICT stream,
	     unsigned char *ES__RESTRICT buffer,
	     size_t bytes_to_read, size_t *ES__RESTRICT bytes_read)
{
  es_cookie_read_function_t func_read = stream->intern->func_read;
  size_t data_read;
  ssize_t ret;
  int err;

  data_read = 0;
  err = 0;

  while (bytes_to_read - data_read)
    {
      ret = (*func_read) (stream->intern->cookie,
			  buffer + data_read, bytes_to_read - data_read);
      if (ret == -1)
	{
	  err = -1;
	  break;
	}
      else if (ret)
	data_read += ret;
      else
	break;
    }

  stream->intern->offset += data_read;
  *bytes_read = data_read;

  return err;
}

/* Try to read BYTES_TO_READ bytes FROM STREAM into BUFFER in
   fully-buffered-mode, storing the amount of bytes read in
   *BYTES_READ.  */
static int
es_read_fbf (estream_t ES__RESTRICT stream,
	     unsigned char *ES__RESTRICT buffer,
	     size_t bytes_to_read, size_t *ES__RESTRICT bytes_read)
{
  size_t data_available;
  size_t data_to_read;
  size_t data_read;
  int err;

  data_read = 0;
  err = 0;

  while ((bytes_to_read - data_read) && (! err))
    {
      if (stream->data_offset == stream->data_len)
	{
	  /* Nothing more to read in current container, try to
	     fill container with new data.  */
	  err = es_fill (stream);
	  if (! err)
	    if (! stream->data_len)
	      /* Filling did not result in any data read.  */
	      break;
	}

      if (! err)
	{
	  /* Filling resulted in some new data.  */

	  data_to_read = bytes_to_read - data_read;
	  data_available = stream->data_len - stream->data_offset;
	  if (data_to_read > data_available)
	    data_to_read = data_available;

	  memcpy (buffer + data_read,
		  stream->buffer + stream->data_offset, data_to_read);
	  stream->data_offset += data_to_read;
	  data_read += data_to_read;
	}
    }

  *bytes_read = data_read;

  return err;
}

/* Try to read BYTES_TO_READ bytes FROM STREAM into BUFFER in
   line-buffered-mode, storing the amount of bytes read in
   *BYTES_READ.  */
static int
es_read_lbf (estream_t ES__RESTRICT stream,
	     unsigned char *ES__RESTRICT buffer,
	     size_t bytes_to_read, size_t *ES__RESTRICT bytes_read)
{
  int err;

  err = es_read_fbf (stream, buffer, bytes_to_read, bytes_read);

  return err;
}

/* Try to read BYTES_TO_READ bytes FROM STREAM into BUFFER, storing
   *the amount of bytes read in BYTES_READ.  */
static int
es_readn (estream_t ES__RESTRICT stream,
	  void *ES__RESTRICT buffer_arg,
	  size_t bytes_to_read, size_t *ES__RESTRICT bytes_read)
{
  unsigned char *buffer = (unsigned char *)buffer_arg;
  size_t data_read_unread, data_read;
  int err;

  data_read_unread = 0;
  data_read = 0;
  err = 0;

  if (stream->flags.writing)
    {
      /* Switching to reading mode -> flush output.  */
      err = es_flush (stream);
      if (err)
	goto out;
      stream->flags.writing = 0;
    }

  /* Read unread data first.  */
  while ((bytes_to_read - data_read_unread) && stream->unread_data_len)
    {
      buffer[data_read_unread]
	= stream->unread_buffer[stream->unread_data_len - 1];
      stream->unread_data_len--;
      data_read_unread++;
    }

  switch (stream->intern->strategy)
    {
    case _IONBF:
      err = es_read_nbf (stream,
			 buffer + data_read_unread,
			 bytes_to_read - data_read_unread, &data_read);
      break;
    case _IOLBF:
      err = es_read_lbf (stream,
			 buffer + data_read_unread,
			 bytes_to_read - data_read_unread, &data_read);
      break;
    case _IOFBF:
      err = es_read_fbf (stream,
			 buffer + data_read_unread,
			 bytes_to_read - data_read_unread, &data_read);
      break;
    }

 out:

  if (bytes_read)
    *bytes_read = data_read_unread + data_read;

  return err;
}

/* Try to unread DATA_N bytes from DATA into STREAM, storing the
   amount of bytes successfully unread in *BYTES_UNREAD.  */
static void
es_unreadn (estream_t ES__RESTRICT stream,
	    const unsigned char *ES__RESTRICT data, size_t data_n,
	    size_t *ES__RESTRICT bytes_unread)
{
  size_t space_left;

  space_left = stream->unread_buffer_size - stream->unread_data_len;

  if (data_n > space_left)
    data_n = space_left;

  if (! data_n)
    goto out;

  memcpy (stream->unread_buffer + stream->unread_data_len, data, data_n);
  stream->unread_data_len += data_n;
  stream->intern->indicators.eof = 0;

 out:

  if (bytes_unread)
    *bytes_unread = data_n;
}

/* Seek in STREAM.  */
static int
es_seek (estream_t ES__RESTRICT stream, off_t offset, int whence,
	 off_t *ES__RESTRICT offset_new)
{
  es_cookie_seek_function_t func_seek = stream->intern->func_seek;
  int err, ret;
  off_t off;

  if (! func_seek)
    {
      _set_errno (EOPNOTSUPP);
      err = -1;
      goto out;
    }

  if (stream->flags.writing)
    {
      /* Flush data first in order to prevent flushing it to the wrong
	 offset.  */
      err = es_flush (stream);
      if (err)
	goto out;
      stream->flags.writing = 0;
    }

  off = offset;
  if (whence == SEEK_CUR)
    {
      off = off - stream->data_len + stream->data_offset;
      off -= stream->unread_data_len;
    }

  ret = (*func_seek) (stream->intern->cookie, &off, whence);
  if (ret == -1)
    {
      err = -1;
      goto out;
    }

  err = 0;
  es_empty (stream);

  if (offset_new)
    *offset_new = off;

  stream->intern->indicators.eof = 0;
  stream->intern->offset = off;

 out:

  if (err)
    stream->intern->indicators.err = 1;

  return err;
}

/* Write BYTES_TO_WRITE bytes from BUFFER into STREAM in
   unbuffered-mode, storing the amount of bytes written in
   *BYTES_WRITTEN.  */
static int
es_write_nbf (estream_t ES__RESTRICT stream,
	      const unsigned char *ES__RESTRICT buffer,
	      size_t bytes_to_write, size_t *ES__RESTRICT bytes_written)
{
  es_cookie_write_function_t func_write = stream->intern->func_write;
  size_t data_written;
  ssize_t ret;
  int err;

  if (bytes_to_write && (! func_write))
    {
      err = EOPNOTSUPP;
      goto out;
    }

  data_written = 0;
  err = 0;

  while (bytes_to_write - data_written)
    {
      ret = (*func_write) (stream->intern->cookie,
			   buffer + data_written,
			   bytes_to_write - data_written);
      if (ret == -1)
	{
	  err = -1;
	  break;
	}
      else
	data_written += ret;
    }

  stream->intern->offset += data_written;
  *bytes_written = data_written;

 out:

  return err;
}

/* Write BYTES_TO_WRITE bytes from BUFFER into STREAM in
   fully-buffered-mode, storing the amount of bytes written in
   *BYTES_WRITTEN.  */
static int
es_write_fbf (estream_t ES__RESTRICT stream,
	      const unsigned char *ES__RESTRICT buffer,
	      size_t bytes_to_write, size_t *ES__RESTRICT bytes_written)
{
  size_t space_available;
  size_t data_to_write;
  size_t data_written;
  int err;

  data_written = 0;
  err = 0;

  while ((bytes_to_write - data_written) && (! err))
    {
      if (stream->data_offset == stream->buffer_size)
	/* Container full, flush buffer.  */
	err = es_flush (stream);

      if (! err)
	{
	  /* Flushing resulted in empty container.  */

	  data_to_write = bytes_to_write - data_written;
	  space_available = stream->buffer_size - stream->data_offset;
	  if (data_to_write > space_available)
	    data_to_write = space_available;

	  memcpy (stream->buffer + stream->data_offset,
		  buffer + data_written, data_to_write);
	  stream->data_offset += data_to_write;
	  data_written += data_to_write;
	}
    }

  *bytes_written = data_written;

  return err;
}


/* Write BYTES_TO_WRITE bytes from BUFFER into STREAM in
   line-buffered-mode, storing the amount of bytes written in
   *BYTES_WRITTEN.  */
static int
es_write_lbf (estream_t ES__RESTRICT stream,
	      const unsigned char *ES__RESTRICT buffer,
	      size_t bytes_to_write, size_t *ES__RESTRICT bytes_written)
{
  size_t data_flushed = 0;
  size_t data_buffered = 0;
  unsigned char *nlp;
  int err = 0;

  nlp = memrchr (buffer, '\n', bytes_to_write);
  if (nlp)
    {
      /* Found a newline, directly write up to (including) this
	 character.  */
      err = es_flush (stream);
      if (!err)
	err = es_write_nbf (stream, buffer, nlp - buffer + 1, &data_flushed);
    }

  if (!err)
    {
      /* Write remaining data fully buffered.  */
      err = es_write_fbf (stream, buffer + data_flushed,
			  bytes_to_write - data_flushed, &data_buffered);
    }

  *bytes_written = data_flushed + data_buffered;
  return err;
}


/* Write BYTES_TO_WRITE bytes from BUFFER into STREAM in, storing the
   amount of bytes written in BYTES_WRITTEN.  */
static int
es_writen (estream_t ES__RESTRICT stream,
	   const void *ES__RESTRICT buffer,
	   size_t bytes_to_write, size_t *ES__RESTRICT bytes_written)
{
  size_t data_written;
  int err;

  data_written = 0;
  err = 0;

  if (!stream->flags.writing)
    {
      /* Switching to writing mode -> discard input data and seek to
	 position at which reading has stopped.  We can do this only
	 if a seek function has been registered. */
      if (stream->intern->func_seek)
        {
          err = es_seek (stream, 0, SEEK_CUR, NULL);
          if (err)
            {
              if (errno == ESPIPE)
                err = 0;
              else
                goto out;
            }
        }
    }

  switch (stream->intern->strategy)
    {
    case _IONBF:
      err = es_write_nbf (stream, buffer, bytes_to_write, &data_written);
      break;

    case _IOLBF:
      err = es_write_lbf (stream, buffer, bytes_to_write, &data_written);
      break;

    case _IOFBF:
      err = es_write_fbf (stream, buffer, bytes_to_write, &data_written);
      break;
    }

 out:

  if (bytes_written)
    *bytes_written = data_written;
  if (data_written)
    if (!stream->flags.writing)
      stream->flags.writing = 1;

  return err;
}


static int
es_peek (estream_t ES__RESTRICT stream, unsigned char **ES__RESTRICT data,
	 size_t *ES__RESTRICT data_len)
{
  int err;

  if (stream->flags.writing)
    {
      /* Switching to reading mode -> flush output.  */
      err = es_flush (stream);
      if (err)
	goto out;
      stream->flags.writing = 0;
    }

  if (stream->data_offset == stream->data_len)
    {
      /* Refill container.  */
      err = es_fill (stream);
      if (err)
	goto out;
    }

  if (data)
    *data = stream->buffer + stream->data_offset;
  if (data_len)
    *data_len = stream->data_len - stream->data_offset;
  err = 0;

 out:

  return err;
}


/* Skip SIZE bytes of input data contained in buffer.  */
static int
es_skip (estream_t stream, size_t size)
{
  int err;

  if (stream->data_offset + size > stream->data_len)
    {
      _set_errno (EINVAL);
      err = -1;
    }
  else
    {
      stream->data_offset += size;
      err = 0;
    }

  return err;
}


static int
doreadline (estream_t ES__RESTRICT stream, size_t max_length,
            char *ES__RESTRICT *ES__RESTRICT line,
            size_t *ES__RESTRICT line_length)
{
  size_t space_left;
  size_t line_size;
  estream_t line_stream;
  char *line_new;
  void *line_stream_cookie;
  char *newline;
  unsigned char *data;
  size_t data_len;
  int err;

  line_new = NULL;
  line_stream = NULL;
  line_stream_cookie = NULL;

  err = es_func_mem_create (&line_stream_cookie, NULL, 0, 0,
                            BUFFER_BLOCK_SIZE, 1,
                            mem_realloc, mem_free,
                            O_RDWR,
                            0);
  if (err)
    goto out;

  err = es_create (&line_stream, line_stream_cookie, -1,
		   estream_functions_mem, O_RDWR, 0);
  if (err)
    goto out;

  space_left = max_length;
  line_size = 0;
  while (1)
    {
      if (max_length && (space_left == 1))
	break;

      err = es_peek (stream, &data, &data_len);
      if (err || (! data_len))
	break;

      if (data_len > (space_left - 1))
	data_len = space_left - 1;

      newline = memchr (data, '\n', data_len);
      if (newline)
	{
	  data_len = (newline - (char *) data) + 1;
	  err = es_write (line_stream, data, data_len, NULL);
	  if (! err)
	    {
	      space_left -= data_len;
	      line_size += data_len;
	      es_skip (stream, data_len);
	      break;
	    }
	}
      else
	{
	  err = es_write (line_stream, data, data_len, NULL);
	  if (! err)
	    {
	      space_left -= data_len;
	      line_size += data_len;
	      es_skip (stream, data_len);
	    }
	}
      if (err)
	break;
    }
  if (err)
    goto out;

  /* Complete line has been written to line_stream.  */

  if ((max_length > 1) && (! line_size))
    {
      stream->intern->indicators.eof = 1;
      goto out;
    }

  err = es_seek (line_stream, 0, SEEK_SET, NULL);
  if (err)
    goto out;

  if (! *line)
    {
      line_new = mem_alloc (line_size + 1);
      if (! line_new)
	{
	  err = -1;
	  goto out;
	}
    }
  else
    line_new = *line;

  err = es_read (line_stream, line_new, line_size, NULL);
  if (err)
    goto out;

  line_new[line_size] = '\0';

  if (! *line)
    *line = line_new;
  if (line_length)
    *line_length = line_size;

 out:

  if (line_stream)
    es_destroy (line_stream, 0);
  else if (line_stream_cookie)
    es_func_mem_destroy (line_stream_cookie);

  if (err)
    {
      if (! *line)
	mem_free (line_new);
      stream->intern->indicators.err = 1;
    }

  return err;
}


/* Output fucntion used for estream_format.  */
static int
print_writer (void *outfncarg, const char *buf, size_t buflen)
{
  estream_t stream = outfncarg;
  size_t nwritten;
  int rc;

  nwritten = 0;
  rc = es_writen (stream, buf, buflen, &nwritten);
  stream->intern->print_ntotal += nwritten;
  return rc;
}


/* The core of our printf function.  This is called in locked state. */
static int
es_print (estream_t ES__RESTRICT stream,
	  const char *ES__RESTRICT format, va_list ap)
{
  int rc;

  stream->intern->print_ntotal = 0;
  rc = estream_format (print_writer, stream, format, ap);
  if (rc)
    return -1;
  return (int)stream->intern->print_ntotal;
}


static void
es_set_indicators (estream_t stream, int ind_err, int ind_eof)
{
  if (ind_err != -1)
    stream->intern->indicators.err = ind_err ? 1 : 0;
  if (ind_eof != -1)
    stream->intern->indicators.eof = ind_eof ? 1 : 0;
}


static int
es_get_indicator (estream_t stream, int ind_err, int ind_eof)
{
  int ret = 0;

  if (ind_err)
    ret = stream->intern->indicators.err;
  else if (ind_eof)
    ret = stream->intern->indicators.eof;

  return ret;
}


static int
es_set_buffering (estream_t ES__RESTRICT stream,
		  char *ES__RESTRICT buffer, int mode, size_t size)
{
  int err;

  /* Flush or empty buffer depending on mode.  */
  if (stream->flags.writing)
    {
      err = es_flush (stream);
      if (err)
	goto out;
    }
  else
    es_empty (stream);

  es_set_indicators (stream, -1, 0);

  /* Free old buffer in case that was allocated by this function.  */
  if (stream->intern->deallocate_buffer)
    {
      stream->intern->deallocate_buffer = 0;
      mem_free (stream->buffer);
      stream->buffer = NULL;
    }

  if (mode == _IONBF)
    stream->buffer_size = 0;
  else
    {
      void *buffer_new;

      if (buffer)
	buffer_new = buffer;
      else
	{
          if (!size)
            size = BUFSIZ;
	  buffer_new = mem_alloc (size);
	  if (! buffer_new)
	    {
	      err = -1;
	      goto out;
	    }
	}

      stream->buffer = buffer_new;
      stream->buffer_size = size;
      if (! buffer)
	stream->intern->deallocate_buffer = 1;
    }
  stream->intern->strategy = mode;
  err = 0;

 out:

  return err;
}


static off_t
es_offset_calculate (estream_t stream)
{
  off_t offset;

  offset = stream->intern->offset + stream->data_offset;
  if (offset < stream->unread_data_len)
    /* Offset undefined.  */
    offset = 0;
  else
    offset -= stream->unread_data_len;

  return offset;
}


static void
es_opaque_ctrl (estream_t ES__RESTRICT stream, void *ES__RESTRICT opaque_new,
		void **ES__RESTRICT opaque_old)
{
  if (opaque_old)
    *opaque_old = stream->intern->opaque;
  if (opaque_new)
    stream->intern->opaque = opaque_new;
}


static int
es_get_fd (estream_t stream)
{
  return stream->intern->fd;
}



/* API.  */

int
es_init (void)
{
  int err;

  err = es_init_do ();

  return err;
}

estream_t
es_fopen (const char *ES__RESTRICT path, const char *ES__RESTRICT mode)
{
  unsigned int modeflags;
  int create_called;
  estream_t stream;
  void *cookie;
  int err;
  int fd;

  stream = NULL;
  cookie = NULL;
  create_called = 0;

  err = es_convert_mode (mode, &modeflags);
  if (err)
    goto out;

  err = es_func_file_create (&cookie, &fd, path, modeflags);
  if (err)
    goto out;

  create_called = 1;
  err = es_create (&stream, cookie, fd, estream_functions_fd, modeflags, 0);
  if (err)
    goto out;

  if (stream && path)
    fname_set_internal (stream, path, 1);

 out:

  if (err && create_called)
    (*estream_functions_fd.func_close) (cookie);

  return stream;
}


estream_t
es_mopen (unsigned char *ES__RESTRICT data, size_t data_n, size_t data_len,
	  unsigned int grow,
	  func_realloc_t func_realloc, func_free_t func_free,
	  const char *ES__RESTRICT mode)
{
  unsigned int modeflags;
  int create_called;
  estream_t stream;
  void *cookie;
  int err;

  cookie = 0;
  stream = NULL;
  create_called = 0;

  err = es_convert_mode (mode, &modeflags);
  if (err)
    goto out;

  err = es_func_mem_create (&cookie, data, data_n, data_len,
			    BUFFER_BLOCK_SIZE, grow,
			    func_realloc, func_free, modeflags, 0);
  if (err)
    goto out;

  create_called = 1;
  err = es_create (&stream, cookie, -1, estream_functions_mem, modeflags, 0);

 out:

  if (err && create_called)
    (*estream_functions_mem.func_close) (cookie);

  return stream;
}


estream_t
es_fopenmem (size_t memlimit, const char *ES__RESTRICT mode)
{
  unsigned int modeflags;
  estream_t stream = NULL;
  void *cookie = NULL;

  /* Memory streams are always read/write.  We use MODE only to get
     the append flag.  */
  if (es_convert_mode (mode, &modeflags))
    return NULL;
  modeflags |= O_RDWR;


  if (es_func_mem_create (&cookie, NULL, 0, 0,
                          BUFFER_BLOCK_SIZE, 1,
                          mem_realloc, mem_free, modeflags,
                          memlimit))
    return NULL;

  if (es_create (&stream, cookie, -1, estream_functions_mem, modeflags, 0))
    (*estream_functions_mem.func_close) (cookie);

  return stream;
}



estream_t
es_fopencookie (void *ES__RESTRICT cookie,
		const char *ES__RESTRICT mode,
		es_cookie_io_functions_t functions)
{
  unsigned int modeflags;
  estream_t stream;
  int err;

  stream = NULL;
  modeflags = 0;

  err = es_convert_mode (mode, &modeflags);
  if (err)
    goto out;

  err = es_create (&stream, cookie, -1, functions, modeflags, 0);
  if (err)
    goto out;

 out:

  return stream;
}


estream_t
do_fdopen (int filedes, const char *mode, int no_close, int with_locked_list)
{
  unsigned int modeflags;
  int create_called;
  estream_t stream;
  void *cookie;
  int err;

  stream = NULL;
  cookie = NULL;
  create_called = 0;

  err = es_convert_mode (mode, &modeflags);
  if (err)
    goto out;

  err = es_func_fd_create (&cookie, filedes, modeflags, no_close);
  if (err)
    goto out;

  create_called = 1;
  err = es_create (&stream, cookie, filedes, estream_functions_fd,
                   modeflags, with_locked_list);

 out:

  if (err && create_called)
    (*estream_functions_fd.func_close) (cookie);

  return stream;
}

estream_t
es_fdopen (int filedes, const char *mode)
{
  return do_fdopen (filedes, mode, 0, 0);
}

/* A variant of es_fdopen which does not close FILEDES at the end.  */
estream_t
es_fdopen_nc (int filedes, const char *mode)
{
  return do_fdopen (filedes, mode, 1, 0);
}


estream_t
do_fpopen (FILE *fp, const char *mode, int no_close, int with_locked_list)
{
  unsigned int modeflags;
  int create_called;
  estream_t stream;
  void *cookie;
  int err;

  stream = NULL;
  cookie = NULL;
  create_called = 0;

  err = es_convert_mode (mode, &modeflags);
  if (err)
    goto out;

  if (fp)
    fflush (fp);
  err = es_func_fp_create (&cookie, fp, modeflags, no_close);
  if (err)
    goto out;

  create_called = 1;
  err = es_create (&stream, cookie, fp? fileno (fp):-1, estream_functions_fp,
                   modeflags, with_locked_list);

 out:

  if (err && create_called)
    (*estream_functions_fp.func_close) (cookie);

  return stream;
}


/* Create an estream from the stdio stream FP.  This mechanism is
   useful in case the stdio streams have special properties and may
   not be mixed with fd based functions.  This is for example the case
   under Windows where the 3 standard streams are associated with the
   console whereas a duped and fd-opened stream of one of this stream
   won't be associated with the console.  As this messes things up it
   is easier to keep on using the standard I/O stream as a backend for
   estream. */
estream_t
es_fpopen (FILE *fp, const char *mode)
{
  return do_fpopen (fp, mode, 0, 0);
}


/* Same as es_fpopen but does not close  FP at the end.  */
estream_t
es_fpopen_nc (FILE *fp, const char *mode)
{
  return do_fpopen (fp, mode, 1, 0);
}


/* Set custom standard descriptors to be used for stdin, stdout and
   stderr.  This function needs to be called before any of the
   standard streams are accessed.  */
void
_es_set_std_fd (int no, int fd)
{
  ESTREAM_LIST_LOCK;
  if (no >= 0 && no < 3 && !custom_std_fds_valid[no])
    {
      custom_std_fds[no] = fd;
      custom_std_fds_valid[no] = 1;
    }
  ESTREAM_LIST_UNLOCK;
}


/* Return the stream used for stdin, stdout or stderr.  */
estream_t
_es_get_std_stream (int fd)
{
  estream_list_t list_obj;
  estream_t stream = NULL;

  fd %= 3; /* We only allow 0, 1 or 2 but we don't want to return an error. */
  ESTREAM_LIST_LOCK;
  for (list_obj = estream_list; list_obj; list_obj = list_obj->cdr)
    if (list_obj->car->intern->is_stdstream
        && list_obj->car->intern->stdstream_fd == fd)
      {
	stream = list_obj->car;
	break;
      }
  if (!stream)
    {
      /* Standard stream not yet created.  We first try to create them
         from registered file descriptors.  */
      if (!fd && custom_std_fds_valid[0])
        stream = do_fdopen (custom_std_fds[0], "r", 1, 1);
      else if (fd == 1 && custom_std_fds_valid[1])
        stream = do_fdopen (custom_std_fds[1], "a", 1, 1);
      else if (custom_std_fds_valid[2])
        stream = do_fdopen (custom_std_fds[2], "a", 1, 1);

      if (!stream)
        {
          /* Second try is to use the standard C streams.  */
          if (!fd)
            stream = do_fpopen (stdin, "r", 1, 1);
          else if (fd == 1)
            stream = do_fpopen (stdout, "a", 1, 1);
          else
            stream = do_fpopen (stderr, "a", 1, 1);
        }

      if (!stream)
        {
          /* Last try: Create a bit bucket.  */
          stream = do_fpopen (NULL, fd? "a":"r", 0, 1);
          if (!stream)
            {
              fprintf (stderr, "fatal: error creating a dummy estream"
                       " for %d: %s\n", fd, strerror (errno));
              abort();
            }
        }

      stream->intern->is_stdstream = 1;
      stream->intern->stdstream_fd = fd;
      if (fd == 2)
        es_set_buffering (stream, NULL, _IOLBF, 0);
      fname_set_internal (stream,
                          fd == 0? "[stdin]" :
                          fd == 1? "[stdout]" : "[stderr]", 0);
    }
  ESTREAM_LIST_UNLOCK;
  return stream;
}


estream_t
es_freopen (const char *ES__RESTRICT path, const char *ES__RESTRICT mode,
	    estream_t ES__RESTRICT stream)
{
  int err;

  if (path)
    {
      unsigned int modeflags;
      int create_called;
      void *cookie;
      int fd;

      cookie = NULL;
      create_called = 0;

      ESTREAM_LOCK (stream);

      es_deinitialize (stream);

      err = es_convert_mode (mode, &modeflags);
      if (err)
	goto leave;

      err = es_func_file_create (&cookie, &fd, path, modeflags);
      if (err)
	goto leave;

      create_called = 1;
      es_initialize (stream, cookie, fd, estream_functions_fd, modeflags);

    leave:

      if (err)
	{
	  if (create_called)
	    es_func_fd_destroy (cookie);

	  es_destroy (stream, 0);
	  stream = NULL;
	}
      else
        {
          if (stream && path)
            fname_set_internal (stream, path, 1);
          ESTREAM_UNLOCK (stream);
        }
    }
  else
    {
      /* FIXME?  We don't support re-opening at the moment.  */
      _set_errno (EINVAL);
      es_deinitialize (stream);
      es_destroy (stream, 0);
      stream = NULL;
    }

  return stream;
}


int
es_fclose (estream_t stream)
{
  int err;

  err = es_destroy (stream, 0);

  return err;
}

int
es_fileno_unlocked (estream_t stream)
{
  return es_get_fd (stream);
}


void
es_flockfile (estream_t stream)
{
  ESTREAM_LOCK (stream);
}


int
es_ftrylockfile (estream_t stream)
{
  return ESTREAM_TRYLOCK (stream);
}


void
es_funlockfile (estream_t stream)
{
  ESTREAM_UNLOCK (stream);
}


int
es_fileno (estream_t stream)
{
  int ret;

  ESTREAM_LOCK (stream);
  ret = es_fileno_unlocked (stream);
  ESTREAM_UNLOCK (stream);

  return ret;
}


int
es_feof_unlocked (estream_t stream)
{
  return es_get_indicator (stream, 0, 1);
}


int
es_feof (estream_t stream)
{
  int ret;

  ESTREAM_LOCK (stream);
  ret = es_feof_unlocked (stream);
  ESTREAM_UNLOCK (stream);

  return ret;
}


int
es_ferror_unlocked (estream_t stream)
{
  return es_get_indicator (stream, 1, 0);
}


int
es_ferror (estream_t stream)
{
  int ret;

  ESTREAM_LOCK (stream);
  ret = es_ferror_unlocked (stream);
  ESTREAM_UNLOCK (stream);

  return ret;
}


void
es_clearerr_unlocked (estream_t stream)
{
  es_set_indicators (stream, 0, 0);
}


void
es_clearerr (estream_t stream)
{
  ESTREAM_LOCK (stream);
  es_clearerr_unlocked (stream);
  ESTREAM_UNLOCK (stream);
}


static int
do_fflush (estream_t stream)
{
  int err;

  if (stream->flags.writing)
    err = es_flush (stream);
  else
    {
      es_empty (stream);
      err = 0;
    }

  return err;
}


int
es_fflush (estream_t stream)
{
  int err;

  if (stream)
    {
      ESTREAM_LOCK (stream);
      err = do_fflush (stream);
      ESTREAM_UNLOCK (stream);
    }
  else
    err = es_list_iterate (do_fflush);

  return err ? EOF : 0;
}


int
es_fseek (estream_t stream, long int offset, int whence)
{
  int err;

  ESTREAM_LOCK (stream);
  err = es_seek (stream, offset, whence, NULL);
  ESTREAM_UNLOCK (stream);

  return err;
}


int
es_fseeko (estream_t stream, off_t offset, int whence)
{
  int err;

  ESTREAM_LOCK (stream);
  err = es_seek (stream, offset, whence, NULL);
  ESTREAM_UNLOCK (stream);

  return err;
}


long int
es_ftell (estream_t stream)
{
  long int ret;

  ESTREAM_LOCK (stream);
  ret = es_offset_calculate (stream);
  ESTREAM_UNLOCK (stream);

  return ret;
}


off_t
es_ftello (estream_t stream)
{
  off_t ret = -1;

  ESTREAM_LOCK (stream);
  ret = es_offset_calculate (stream);
  ESTREAM_UNLOCK (stream);

  return ret;
}


void
es_rewind (estream_t stream)
{
  ESTREAM_LOCK (stream);
  es_seek (stream, 0L, SEEK_SET, NULL);
  es_set_indicators (stream, 0, -1);
  ESTREAM_UNLOCK (stream);
}


int
_es_getc_underflow (estream_t stream)
{
  int err;
  unsigned char c;
  size_t bytes_read;

  err = es_readn (stream, &c, 1, &bytes_read);

  return (err || (! bytes_read)) ? EOF : c;
}


int
_es_putc_overflow (int c, estream_t stream)
{
  unsigned char d = c;
  int err;

  err = es_writen (stream, &d, 1, NULL);

  return err ? EOF : c;
}


int
es_fgetc (estream_t stream)
{
  int ret;

  ESTREAM_LOCK (stream);
  ret = es_getc_unlocked (stream);
  ESTREAM_UNLOCK (stream);

  return ret;
}


int
es_fputc (int c, estream_t stream)
{
  int ret;

  ESTREAM_LOCK (stream);
  ret = es_putc_unlocked (c, stream);
  ESTREAM_UNLOCK (stream);

  return ret;
}


int
es_ungetc (int c, estream_t stream)
{
  unsigned char data = (unsigned char) c;
  size_t data_unread;

  ESTREAM_LOCK (stream);
  es_unreadn (stream, &data, 1, &data_unread);
  ESTREAM_UNLOCK (stream);

  return data_unread ? c : EOF;
}


int
es_read (estream_t ES__RESTRICT stream,
	 void *ES__RESTRICT buffer, size_t bytes_to_read,
	 size_t *ES__RESTRICT bytes_read)
{
  int err;

  if (bytes_to_read)
    {
      ESTREAM_LOCK (stream);
      err = es_readn (stream, buffer, bytes_to_read, bytes_read);
      ESTREAM_UNLOCK (stream);
    }
  else
    err = 0;

  return err;
}


int
es_write (estream_t ES__RESTRICT stream,
	  const void *ES__RESTRICT buffer, size_t bytes_to_write,
	  size_t *ES__RESTRICT bytes_written)
{
  int err;

  if (bytes_to_write)
    {
      ESTREAM_LOCK (stream);
      err = es_writen (stream, buffer, bytes_to_write, bytes_written);
      ESTREAM_UNLOCK (stream);
    }
  else
    err = 0;

  return err;
}


size_t
es_fread (void *ES__RESTRICT ptr, size_t size, size_t nitems,
	  estream_t ES__RESTRICT stream)
{
  size_t ret, bytes;

  if (size * nitems)
    {
      ESTREAM_LOCK (stream);
      es_readn (stream, ptr, size * nitems, &bytes);
      ESTREAM_UNLOCK (stream);

      ret = bytes / size;
    }
  else
    ret = 0;

  return ret;
}


size_t
es_fwrite (const void *ES__RESTRICT ptr, size_t size, size_t nitems,
	   estream_t ES__RESTRICT stream)
{
  size_t ret, bytes;

  if (size * nitems)
    {
      ESTREAM_LOCK (stream);
      es_writen (stream, ptr, size * nitems, &bytes);
      ESTREAM_UNLOCK (stream);

      ret = bytes / size;
    }
  else
    ret = 0;

  return ret;
}


char *
es_fgets (char *ES__RESTRICT buffer, int length, estream_t ES__RESTRICT stream)
{
  unsigned char *s = (unsigned char*)buffer;
  int c;

  if (!length)
    return NULL;

  c = EOF;
  ESTREAM_LOCK (stream);
  while (length > 1 && (c = es_getc_unlocked (stream)) != EOF && c != '\n')
    {
      *s++ = c;
      length--;
    }
  ESTREAM_UNLOCK (stream);

  if (c == EOF && s == (unsigned char*)buffer)
    return NULL; /* Nothing read.  */

  if (c != EOF && length > 1)
    *s++ = c;

  *s = 0;
  return buffer;
}


int
es_fputs_unlocked (const char *ES__RESTRICT s, estream_t ES__RESTRICT stream)
{
  size_t length;
  int err;

  length = strlen (s);
  err = es_writen (stream, s, length, NULL);
  return err ? EOF : 0;
}

int
es_fputs (const char *ES__RESTRICT s, estream_t ES__RESTRICT stream)
{
  size_t length;
  int err;

  length = strlen (s);
  ESTREAM_LOCK (stream);
  err = es_writen (stream, s, length, NULL);
  ESTREAM_UNLOCK (stream);

  return err ? EOF : 0;
}


ssize_t
es_getline (char *ES__RESTRICT *ES__RESTRICT lineptr, size_t *ES__RESTRICT n,
	    estream_t ES__RESTRICT stream)
{
  char *line = NULL;
  size_t line_n = 0;
  int err;

  ESTREAM_LOCK (stream);
  err = doreadline (stream, 0, &line, &line_n);
  ESTREAM_UNLOCK (stream);
  if (err)
    goto out;

  if (*n)
    {
      /* Caller wants us to use his buffer.  */

      if (*n < (line_n + 1))
	{
	  /* Provided buffer is too small -> resize.  */

	  void *p;

	  p = mem_realloc (*lineptr, line_n + 1);
	  if (! p)
	    err = -1;
	  else
	    {
	      if (*lineptr != p)
		*lineptr = p;
	    }
	}

      if (! err)
	{
	  memcpy (*lineptr, line, line_n + 1);
	  if (*n != line_n)
	    *n = line_n;
	}
      mem_free (line);
    }
  else
    {
      /* Caller wants new buffers.  */
      *lineptr = line;
      *n = line_n;
    }

 out:

  return err ? err : (ssize_t)line_n;
}



/* Same as fgets() but if the provided buffer is too short a larger
   one will be allocated.  This is similar to getline. A line is
   considered a byte stream ending in a LF.

   If MAX_LENGTH is not NULL, it shall point to a value with the
   maximum allowed allocation.

   Returns the length of the line. EOF is indicated by a line of
   length zero. A truncated line is indicated my setting the value at
   MAX_LENGTH to 0.  If the returned value is less then 0 not enough
   memory was enable or another error occurred; ERRNO is then set
   accordingly.

   If a line has been truncated, the file pointer is moved forward to
   the end of the line so that the next read starts with the next
   line.  Note that MAX_LENGTH must be re-initialzied in this case.

   The caller initially needs to provide the address of a variable,
   initialized to NULL, at ADDR_OF_BUFFER and don't change this value
   anymore with the following invocations.  LENGTH_OF_BUFFER should be
   the address of a variable, initialized to 0, which is also
   maintained by this function.  Thus, both paramaters should be
   considered the state of this function.

   Note: The returned buffer is allocated with enough extra space to
   allow the caller to append a CR,LF,Nul.  The buffer should be
   released using es_free.
 */
ssize_t
es_read_line (estream_t stream,
              char **addr_of_buffer, size_t *length_of_buffer,
              size_t *max_length)
{
  int c;
  char  *buffer = *addr_of_buffer;
  size_t length = *length_of_buffer;
  size_t nbytes = 0;
  size_t maxlen = max_length? *max_length : 0;
  char *p;

  if (!buffer)
    {
      /* No buffer given - allocate a new one. */
      length = 256;
      buffer = mem_alloc (length);
      *addr_of_buffer = buffer;
      if (!buffer)
        {
          *length_of_buffer = 0;
          if (max_length)
            *max_length = 0;
          return -1;
        }
      *length_of_buffer = length;
    }

  if (length < 4)
    {
      /* This should never happen. If it does, the function has been
         called with wrong arguments. */
      _set_errno (EINVAL);
      return -1;
    }
  length -= 3; /* Reserve 3 bytes for CR,LF,EOL. */

  ESTREAM_LOCK (stream);
  p = buffer;
  while  ((c = es_getc_unlocked (stream)) != EOF)
    {
      if (nbytes == length)
        {
          /* Enlarge the buffer. */
          if (maxlen && length > maxlen)
            {
              /* We are beyond our limit: Skip the rest of the line. */
              while (c != '\n' && (c=es_getc_unlocked (stream)) != EOF)
                ;
              *p++ = '\n'; /* Always append a LF (we reserved some space). */
              nbytes++;
              if (max_length)
                *max_length = 0; /* Indicate truncation. */
              break; /* the while loop. */
            }
          length += 3; /* Adjust for the reserved bytes. */
          length += length < 1024? 256 : 1024;
          *addr_of_buffer = mem_realloc (buffer, length);
          if (!*addr_of_buffer)
            {
              int save_errno = errno;
              mem_free (buffer);
              *length_of_buffer = 0;
              if (max_length)
                *max_length = 0;
              ESTREAM_UNLOCK (stream);
              _set_errno (save_errno);
              return -1;
            }
          buffer = *addr_of_buffer;
          *length_of_buffer = length;
          length -= 3;
          p = buffer + nbytes;
	}
      *p++ = c;
      nbytes++;
      if (c == '\n')
        break;
    }
  *p = 0; /* Make sure the line is a string. */
  ESTREAM_UNLOCK (stream);

  return nbytes;
}

/* Wrapper around free() to match the memory allocation system used
   by estream.  Should be used for all buffers returned to the caller
   by libestream. */
void
es_free (void *a)
{
  mem_free (a);
}


int
es_vfprintf_unlocked (estream_t ES__RESTRICT stream,
                      const char *ES__RESTRICT format,
                      va_list ap)
{
  return es_print (stream, format, ap);
}


int
es_vfprintf (estream_t ES__RESTRICT stream, const char *ES__RESTRICT format,
	     va_list ap)
{
  int ret;

  ESTREAM_LOCK (stream);
  ret = es_print (stream, format, ap);
  ESTREAM_UNLOCK (stream);

  return ret;
}


int
es_fprintf_unlocked (estream_t ES__RESTRICT stream,
                     const char *ES__RESTRICT format, ...)
{
  int ret;

  va_list ap;
  va_start (ap, format);
  ret = es_print (stream, format, ap);
  va_end (ap);

  return ret;
}


int
es_fprintf (estream_t ES__RESTRICT stream,
	    const char *ES__RESTRICT format, ...)
{
  int ret;

  va_list ap;
  va_start (ap, format);
  ESTREAM_LOCK (stream);
  ret = es_print (stream, format, ap);
  ESTREAM_UNLOCK (stream);
  va_end (ap);

  return ret;
}

/* A variant of asprintf.  The function returns the allocated buffer
   or NULL on error; ERRNO is set in the error case.  The caller
   should use es_free to release the buffer.  This function actually
   belongs into estream-printf but we put it here as a convenience
   and because es_free is required anyway.  */
char *
es_asprintf (const char *ES__RESTRICT format, ...)
{
  int rc;
  va_list ap;
  char *buf;

  va_start (ap, format);
  rc = estream_vasprintf (&buf, format, ap);
  va_end (ap);
  if (rc < 0)
    return NULL;
  return buf;
}


/* A variant of vasprintf.  The function returns the allocated buffer
   or NULL on error; ERRNO is set in the error case.  The caller
   should use es_free to release the buffer.  This function actually
   belongs into estream-printf but we put it here as a convenience
   and because es_free is required anyway.  */
char *
es_vasprintf (const char *ES__RESTRICT format, va_list ap)
{
  int rc;
  char *buf;

  rc = estream_vasprintf (&buf, format, ap);
  if (rc < 0)
    return NULL;
  return buf;
}


static int
tmpfd (void)
{
#ifdef HAVE_W32_SYSTEM
  int attempts, n;
#ifdef HAVE_W32CE_SYSTEM
  wchar_t buffer[MAX_PATH+9+12+1];
# define mystrlen(a) wcslen (a)
  wchar_t *name, *p;
#else
  char buffer[MAX_PATH+9+12+1];
# define mystrlen(a) strlen (a)
  char *name, *p;
#endif
  HANDLE file;
  int pid = GetCurrentProcessId ();
  unsigned int value;
  int i;

  n = GetTempPath (MAX_PATH+1, buffer);
  if (!n || n > MAX_PATH || mystrlen (buffer) > MAX_PATH)
    {
      _set_errno (ENOENT);
      return -1;
    }
  p = buffer + mystrlen (buffer);
#ifdef HAVE_W32CE_SYSTEM
  wcscpy (p, L"_estream");
#else
  strcpy (p, "_estream");
#endif
  p += 8;
  /* We try to create the directory but don't care about an error as
     it may already exist and the CreateFile would throw an error
     anyway.  */
  CreateDirectory (buffer, NULL);
  *p++ = '\\';
  name = p;
  for (attempts=0; attempts < 10; attempts++)
    {
      p = name;
      value = (GetTickCount () ^ ((pid<<16) & 0xffff0000));
      for (i=0; i < 8; i++)
        {
          *p++ = tohex (((value >> 28) & 0x0f));
          value <<= 4;
        }
#ifdef HAVE_W32CE_SYSTEM
      wcscpy (p, L".tmp");
#else
      strcpy (p, ".tmp");
#endif
      file = CreateFile (buffer,
                         GENERIC_READ | GENERIC_WRITE,
                         0,
                         NULL,
                         CREATE_NEW,
                         FILE_ATTRIBUTE_TEMPORARY | FILE_FLAG_DELETE_ON_CLOSE,
                         NULL);
      if (file != INVALID_HANDLE_VALUE)
        {
#ifdef HAVE_W32CE_SYSTEM
          int fd = (int)file;
#else
          int fd = _open_osfhandle ((long)file, 0);
          if (fd == -1)
            {
              CloseHandle (file);
              return -1;
            }
#endif
          return fd;
        }
      Sleep (1); /* One ms as this is the granularity of GetTickCount.  */
    }
  _set_errno (ENOENT);
  return -1;
#else /*!HAVE_W32_SYSTEM*/
  FILE *fp;
  int fp_fd;
  int fd;

  fp = NULL;
  fd = -1;

  fp = tmpfile ();
  if (! fp)
    goto out;

  fp_fd = fileno (fp);
  fd = dup (fp_fd);

 out:

  if (fp)
    fclose (fp);

  return fd;
#endif /*!HAVE_W32_SYSTEM*/
}

estream_t
es_tmpfile (void)
{
  unsigned int modeflags;
  int create_called;
  estream_t stream;
  void *cookie;
  int err;
  int fd;

  create_called = 0;
  stream = NULL;
  modeflags = O_RDWR | O_TRUNC | O_CREAT;
  cookie = NULL;

  fd = tmpfd ();
  if (fd == -1)
    {
      err = -1;
      goto out;
    }

  err = es_func_fd_create (&cookie, fd, modeflags, 0);
  if (err)
    goto out;

  create_called = 1;
  err = es_create (&stream, cookie, fd, estream_functions_fd, modeflags, 0);

 out:

  if (err)
    {
      if (create_called)
	es_func_fd_destroy (cookie);
      else if (fd != -1)
	close (fd);
      stream = NULL;
    }

  return stream;
}


int
es_setvbuf (estream_t ES__RESTRICT stream,
	    char *ES__RESTRICT buf, int type, size_t size)
{
  int err;

  if ((type == _IOFBF || type == _IOLBF || type == _IONBF)
      && (!buf || size || type == _IONBF))
    {
      ESTREAM_LOCK (stream);
      err = es_set_buffering (stream, buf, type, size);
      ESTREAM_UNLOCK (stream);
    }
  else
    {
      _set_errno (EINVAL);
      err = -1;
    }

  return err;
}


void
es_setbuf (estream_t ES__RESTRICT stream, char *ES__RESTRICT buf)
{
  ESTREAM_LOCK (stream);
  es_set_buffering (stream, buf, buf ? _IOFBF : _IONBF, BUFSIZ);
  ESTREAM_UNLOCK (stream);
}

void
es_opaque_set (estream_t stream, void *opaque)
{
  ESTREAM_LOCK (stream);
  es_opaque_ctrl (stream, opaque, NULL);
  ESTREAM_UNLOCK (stream);
}


void *
es_opaque_get (estream_t stream)
{
  void *opaque;

  ESTREAM_LOCK (stream);
  es_opaque_ctrl (stream, NULL, &opaque);
  ESTREAM_UNLOCK (stream);

  return opaque;
}


static void
fname_set_internal (estream_t stream, const char *fname, int quote)
{
  if (stream->intern->printable_fname
      && !stream->intern->printable_fname_inuse)
    {
      mem_free (stream->intern->printable_fname);
      stream->intern->printable_fname = NULL;
    }
  if (stream->intern->printable_fname)
    return; /* Can't change because it is in use.  */

  if (*fname != '[')
    quote = 0;
  else
    quote = !!quote;

  stream->intern->printable_fname = mem_alloc (strlen (fname) + quote + 1);
  if (fname)
    {
      if (quote)
        stream->intern->printable_fname[0] = '\\';
      strcpy (stream->intern->printable_fname+quote, fname);
    }
}


/* Set the filename attribute of STREAM.  There is no error return.
   as long as STREAM is valid.  This function is called internally by
   functions which open a filename.  */
void
es_fname_set (estream_t stream, const char *fname)
{
  if (fname)
    {
      ESTREAM_LOCK (stream);
      fname_set_internal (stream, fname, 1);
      ESTREAM_UNLOCK (stream);
    }
}


/* Return the filename attribute of STREAM.  In case no filename has
   been set, "[?]" will be returned.  The returned file name is valid
   as long as STREAM is valid.  */
const char *
es_fname_get (estream_t stream)
{
  const char *fname;

  ESTREAM_LOCK (stream);
  fname = stream->intern->printable_fname;
  if (fname)
    stream->intern->printable_fname_inuse = 1;
  ESTREAM_UNLOCK (stream);
  if (!fname)
    fname = "[?]";
  return fname;
}


/* Print a BUFFER to STREAM while replacing all control characters and
   the characters in DELIMITERS by standard C escape sequences.
   Returns 0 on success or -1 on error.  If BYTES_WRITTEN is not NULL
   the number of bytes actually written are stored at this
   address.  */
int
es_write_sanitized (estream_t ES__RESTRICT stream,
                    const void * ES__RESTRICT buffer, size_t length,
                    const char * delimiters,
                    size_t * ES__RESTRICT bytes_written)
{
  const unsigned char *p = buffer;
  size_t count = 0;
  int ret;

  ESTREAM_LOCK (stream);
  for (; length; length--, p++, count++)
    {
      if (*p < 0x20
          || *p == 0x7f
          || (delimiters
              && (strchr (delimiters, *p) || *p == '\\')))
        {
          es_putc_unlocked ('\\', stream);
          count++;
          if (*p == '\n')
            {
              es_putc_unlocked ('n', stream);
              count++;
            }
          else if (*p == '\r')
            {
              es_putc_unlocked ('r', stream);
              count++;
            }
          else if (*p == '\f')
            {
              es_putc_unlocked ('f', stream);
              count++;
            }
          else if (*p == '\v')
            {
              es_putc_unlocked ('v', stream);
              count++;
            }
          else if (*p == '\b')
            {
              es_putc_unlocked ('b', stream);
              count++;
            }
          else if (!*p)
            {
              es_putc_unlocked('0', stream);
              count++;
            }
          else
            {
              es_fprintf_unlocked (stream, "x%02x", *p);
              count += 3;
            }
	}
      else
        {
          es_putc_unlocked (*p, stream);
          count++;
        }
    }

  if (bytes_written)
    *bytes_written = count;
  ret =  es_ferror_unlocked (stream)? -1 : 0;
  ESTREAM_UNLOCK (stream);

  return ret;
}


/* Write LENGTH bytes of BUFFER to STREAM as a hex encoded string.
   RESERVED must be 0.  Returns 0 on success or -1 on error.  If
   BYTES_WRITTEN is not NULL the number of bytes actually written are
   stored at this address.  */
int
es_write_hexstring (estream_t ES__RESTRICT stream,
                    const void *ES__RESTRICT buffer, size_t length,
                    int reserved, size_t *ES__RESTRICT bytes_written )
{
  int ret;
  const unsigned char *s;
  size_t count = 0;

  (void)reserved;

#define tohex(n) ((n) < 10 ? ((n) + '0') : (((n) - 10) + 'A'))

  if (!length)
    return 0;

  ESTREAM_LOCK (stream);

  for (s = buffer; length; s++, length--)
    {
      es_putc_unlocked ( tohex ((*s>>4)&15), stream);
      es_putc_unlocked ( tohex (*s&15), stream);
      count += 2;
    }

  if (bytes_written)
    *bytes_written = count;
  ret = es_ferror_unlocked (stream)? -1 : 0;

  ESTREAM_UNLOCK (stream);

  return ret;

#undef tohex
}



#ifdef GNUPG_MAJOR_VERSION
/* Special estream function to print an UTF8 string in the native
   encoding.  The interface is the same as es_write_sanitized, however
   only one delimiter may be supported.

   THIS IS NOT A STANDARD ESTREAM FUNCTION AND ONLY USED BY GNUPG!. */
int
es_write_sanitized_utf8_buffer (estream_t stream,
                                const void *buffer, size_t length,
                                const char *delimiters, size_t *bytes_written)
{
  const char *p = buffer;
  size_t i;

  /* We can handle plain ascii simpler, so check for it first. */
  for (i=0; i < length; i++ )
    {
      if ( (p[i] & 0x80) )
        break;
    }
  if (i < length)
    {
      int delim = delimiters? *delimiters : 0;
      char *buf;
      int ret;

      /*(utf8 conversion already does the control character quoting). */
      buf = utf8_to_native (p, length, delim);
      if (bytes_written)
        *bytes_written = strlen (buf);
      ret = es_fputs (buf, stream);
      xfree (buf);
      return ret == EOF? ret : (int)i;
    }
  else
    return es_write_sanitized (stream, p, length, delimiters, bytes_written);
}
#endif /*GNUPG_MAJOR_VERSION*/