libc-bottom-half/cloudlibc/src/libc/sys/stat/stat_impl.h

   1 // Copyright (c) 2015-2017 Nuxi, https://nuxi.nl/
   2 //
   3 // SPDX-License-Identifier: BSD-2-Clause
   4
   5 #ifndef SYS_STAT_STAT_IMPL_H
   6 #define SYS_STAT_STAT_IMPL_H
   7
   8 #include <common/time.h>
   9
  10 #include <sys/stat.h>
  11
  12 #include <assert.h>
  13 #include <wasi/api.h>
  14 #include <stdbool.h>
  15
  16 static_assert(S_ISBLK(S_IFBLK), "Value mismatch");
  17 static_assert(S_ISCHR(S_IFCHR), "Value mismatch");
  18 static_assert(S_ISDIR(S_IFDIR), "Value mismatch");
  19 static_assert(S_ISFIFO(S_IFIFO), "Value mismatch");
  20 static_assert(S_ISLNK(S_IFLNK), "Value mismatch");
  21 static_assert(S_ISREG(S_IFREG), "Value mismatch");
  22 static_assert(S_ISSOCK(S_IFSOCK), "Value mismatch");
  23
  24 static inline void to_public_stat(const __wasi_filestat_t *in,
  25                                   struct stat *out) {
  26   // Ensure that we don't truncate any values.
  27   static_assert(sizeof(in->dev) == sizeof(out->st_dev), "Size mismatch");
  28   static_assert(sizeof(in->ino) == sizeof(out->st_ino), "Size mismatch");
  29   /*
  30    * The non-standard __st_filetype field appears to only be used for shared
  31    * memory, which we don't currently support.
  32    */
  33   /* nlink_t is 64-bit on wasm32, following the x32 ABI. */
  34   static_assert(sizeof(in->nlink) <= sizeof(out->st_nlink), "Size shortfall");
  35   static_assert(sizeof(in->size) == sizeof(out->st_size), "Size mismatch");
  36
  37   *out = (struct stat){
  38       .st_dev = in->dev,
  39       .st_ino = in->ino,
  40       .st_nlink = in->nlink,
  41       .st_size = in->size,
  42       .st_atim = timestamp_to_timespec(in->atim),
  43       .st_mtim = timestamp_to_timespec(in->mtim),
  44       .st_ctim = timestamp_to_timespec(in->ctim),
  45   };
  46
  47   // Convert file type to legacy types encoded in st_mode.
  48   switch (in->filetype) {
  49     case __WASI_FILETYPE_BLOCK_DEVICE:
  50       out->st_mode |= S_IFBLK;
  51       break;
  52     case __WASI_FILETYPE_CHARACTER_DEVICE:
  53       out->st_mode |= S_IFCHR;
  54       break;
  55     case __WASI_FILETYPE_DIRECTORY:
  56       out->st_mode |= S_IFDIR;
  57       break;
  58     case __WASI_FILETYPE_REGULAR_FILE:
  59       out->st_mode |= S_IFREG;
  60       break;
  61     case __WASI_FILETYPE_SOCKET_DGRAM:
  62     case __WASI_FILETYPE_SOCKET_STREAM:
  63       out->st_mode |= S_IFSOCK;
  64       break;
  65     case __WASI_FILETYPE_SYMBOLIC_LINK:
  66       out->st_mode |= S_IFLNK;
  67       break;
  68   }
  69 }
  70
  71 static inline bool utimens_get_timestamps(const struct timespec *times,
  72                                           __wasi_timestamp_t *st_atim,
  73                                           __wasi_timestamp_t *st_mtim,
  74                                           __wasi_fstflags_t *flags) {
  75   if (times == NULL) {
  76     // Update both timestamps.
  77     *flags = __WASI_FSTFLAGS_ATIM_NOW | __WASI_FSTFLAGS_MTIM_NOW;
  78     *st_atim = (__wasi_timestamp_t) { 0 };
  79     *st_mtim = (__wasi_timestamp_t) { 0 };
  80   } else {
  81     // Set individual timestamps.
  82     *flags = 0;
  83     switch (times[0].tv_nsec) {
  84       case UTIME_NOW:
  85         *flags |= __WASI_FSTFLAGS_ATIM_NOW;
  86         *st_atim = (__wasi_timestamp_t) { 0 };
  87         break;
  88       case UTIME_OMIT:
  89         *st_atim = (__wasi_timestamp_t) { 0 };
  90         break;
  91       default:
  92         *flags |= __WASI_FSTFLAGS_ATIM;
  93         if (!timespec_to_timestamp_exact(&times[0], st_atim))
  94           return false;
  95         break;
  96     }
  97
  98     switch (times[1].tv_nsec) {
  99       case UTIME_NOW:
 100         *flags |= __WASI_FSTFLAGS_MTIM_NOW;
 101         *st_mtim = (__wasi_timestamp_t) { 0 };
 102         break;
 103       case UTIME_OMIT:
 104         *st_mtim = (__wasi_timestamp_t) { 0 };
 105         break;
 106       default:
 107         *flags |= __WASI_FSTFLAGS_MTIM;
 108         if (!timespec_to_timestamp_exact(&times[1], st_mtim))
 109           return false;
 110         break;
 111     }
 112   }
 113   return true;
 114 }
 115
 116 #endif