libc-bottom-half/cloudlibc/src/libc/dirent/fdopendir.c

   1 // Copyright (c) 2015-2016 Nuxi, https://nuxi.nl/
   2 //
   3 // SPDX-License-Identifier: BSD-2-Clause
   4
   5 #include <common/errno.h>
   6
   7 #include <wasi/api.h>
   8 #include <dirent.h>
   9 #include <errno.h>
  10 #include <stdlib.h>
  11
  12 #include "dirent_impl.h"
  13
  14 DIR *fdopendir(int fd) {
  15   // Allocate new directory object and read buffer.
  16   DIR *dirp = malloc(sizeof(*dirp));
  17   if (dirp == NULL)
  18     return NULL;
  19   dirp->buffer = malloc(DIRENT_DEFAULT_BUFFER_SIZE);
  20   if (dirp->buffer == NULL) {
  21     free(dirp);
  22     return NULL;
  23   }
  24
  25   // Ensure that this is really a directory by already loading the first
  26   // chunk of data.
  27   __wasi_errno_t error =
  28 #ifdef __wasilibc_unmodified_upstream
  29       __wasi_file_readdir(fd, dirp->buffer, DIRENT_DEFAULT_BUFFER_SIZE,
  30 #else
  31       // TODO: Remove the cast on `dirp->buffer` once the witx is updated with char8 support.
  32       __wasi_fd_readdir(fd, (uint8_t *)dirp->buffer, DIRENT_DEFAULT_BUFFER_SIZE,
  33 #endif
  34                                 __WASI_DIRCOOKIE_START, &dirp->buffer_used);
  35   if (error != 0) {
  36     free(dirp->buffer);
  37     free(dirp);
  38     errno = errno_fixup_directory(fd, error);
  39     return NULL;
  40   }
  41
  42   // Initialize other members.
  43   dirp->fd = fd;
  44   dirp->cookie = __WASI_DIRCOOKIE_START;
  45   dirp->buffer_processed = 0;
  46   dirp->buffer_size = DIRENT_DEFAULT_BUFFER_SIZE;
  47   dirp->dirent = NULL;
  48   dirp->dirent_size = 1;
  49   return dirp;
  50 }