/*

 * libwebsockets - small server side websockets and web server implementation

 *

 * Copyright (C) 2010 - 2019 Andy Green <andy@warmcat.com>

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to

 * deal in the Software without restriction, including without limitation the

 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or

 * sell copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS

 * IN THE SOFTWARE.

 */

#if !defined(_GNU_SOURCE)

#define _GNU_SOURCE

#endif

#include "private-lib-core.h"

#include <pwd.h>

#include <grp.h>

#ifdef LWS_WITH_PLUGINS

#include <dlfcn.h>

#endif

#include <dirent.h>

int lws_plat_apply_FD_CLOEXEC(int n)

{

  if (n == -1)

    return 0;

  return fcntl(n, F_SETFD, FD_CLOEXEC);

}

int

lws_plat_write_file(const char *filename, void *buf, size_t len)

{

  ssize_t m;

  int fd;

  fd = lws_open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);

  if (fd == -1)

    return 1;

  m = write(fd, buf, len);

  close(fd);

  if (m < 0)

    return 1;

  return (size_t)m != len;

}

int

lws_plat_read_file(const char *filename, void *buf, size_t len)

{

  int fd = lws_open(filename, O_RDONLY);

  ssize_t n;

  if (fd == -1)

    return -1;

  n = read(fd, buf, len);

  close(fd);

  return (int)n;

}

lws_fop_fd_t

_lws_plat_file_open(const struct lws_plat_file_ops *fops_own,

        const struct lws_plat_file_ops *fops, const char *filename,

        const char *vpath, lws_fop_flags_t *flags)

{

  struct stat stat_buf;

  int ret = lws_open(filename, (int)((*flags) & LWS_FOP_FLAGS_MASK), 0664);

  lws_fop_fd_t fop_fd;

  if (ret < 0)

    return NULL;

  if (fstat(ret, &stat_buf) < 0)

    goto bail;

  fop_fd = malloc(sizeof(*fop_fd));

  if (!fop_fd)

    goto bail;

  fop_fd->fops = fops;

  fop_fd->flags = *flags;

  fop_fd->fd = ret;

  fop_fd->filesystem_priv = NULL; /* we don't use it */

  fop_fd->len = (lws_filepos_t)stat_buf.st_size;

  fop_fd->pos = 0;

  return fop_fd;

bail:

  close(ret);

  return NULL;

}

int

_lws_plat_file_close(lws_fop_fd_t *fop_fd)

{

  int fd = (*fop_fd)->fd;

  free(*fop_fd);

  *fop_fd = NULL;

  return close(fd);

}

lws_fileofs_t

_lws_plat_file_seek_cur(lws_fop_fd_t fop_fd, lws_fileofs_t offset)

{

  lws_fileofs_t r;

  if (offset > 0 &&

      offset > (lws_fileofs_t)fop_fd->len - (lws_fileofs_t)fop_fd->pos)

    offset = (lws_fileofs_t)(fop_fd->len - fop_fd->pos);

  if ((lws_fileofs_t)fop_fd->pos + offset < 0)

    offset = (lws_fileofs_t)(-fop_fd->pos);

  r = lseek(fop_fd->fd, (off_t)offset, SEEK_CUR);

  if (r >= 0)

    fop_fd->pos = (lws_filepos_t)r;

  else

    lwsl_err("error seeking from cur %ld, offset %ld\n",

                        (long)fop_fd->pos, (long)offset);

  return r;

}

int

_lws_plat_file_read(lws_fop_fd_t fop_fd, lws_filepos_t *amount,

        uint8_t *buf, lws_filepos_t len)

{

  ssize_t n;

  n = read((int)fop_fd->fd, buf, (size_t)len);

  if (n == -1l) {

    *amount = 0;

    return -1;

  }

  fop_fd->pos = (lws_filepos_t)(fop_fd->pos + (lws_filepos_t)n);

  lwsl_debug("%s: read %ld of req %ld, pos %ld, len %ld\n", __func__,

      (long)n, (long)len, (long)fop_fd->pos,

      (long)fop_fd->len);

  *amount = (lws_filepos_t)n;

  return 0;

}

int

_lws_plat_file_write(lws_fop_fd_t fop_fd, lws_filepos_t *amount,

         uint8_t *buf, lws_filepos_t len)

{

  ssize_t n;

  n = write((int)fop_fd->fd, buf, (size_t)len);

  if (n == -1) {

    *amount = 0;

    return -1;

  }

  fop_fd->pos = (lws_filepos_t)(fop_fd->pos + (lws_filepos_t)n);

  *amount = (lws_filepos_t)n;

  return 0;

}