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// Copyright (c) 2015-2016 Nuxi, https://nuxi.nl/
//
// SPDX-License-Identifier: BSD-2-Clause
#include <assert.h>
#include <wasi/api.h>
#include <wasi/libc.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
static_assert(O_APPEND == __WASI_FDFLAGS_APPEND, "Value mismatch");
static_assert(O_DSYNC == __WASI_FDFLAGS_DSYNC, "Value mismatch");
static_assert(O_NONBLOCK == __WASI_FDFLAGS_NONBLOCK, "Value mismatch");
static_assert(O_RSYNC == __WASI_FDFLAGS_RSYNC, "Value mismatch");
static_assert(O_SYNC == __WASI_FDFLAGS_SYNC, "Value mismatch");
static_assert(O_CREAT >> 12 == __WASI_OFLAGS_CREAT, "Value mismatch");
static_assert(O_DIRECTORY >> 12 == __WASI_OFLAGS_DIRECTORY, "Value mismatch");
static_assert(O_EXCL >> 12 == __WASI_OFLAGS_EXCL, "Value mismatch");
static_assert(O_TRUNC >> 12 == __WASI_OFLAGS_TRUNC, "Value mismatch");
int __wasilibc_nocwd_openat_nomode(int fd, const char *path, int oflag) {
// Compute rights corresponding with the access modes provided.
// Attempt to obtain all rights, except the ones that contradict the
// access mode provided to openat().
__wasi_rights_t max =
~(__WASI_RIGHTS_FD_DATASYNC | __WASI_RIGHTS_FD_READ |
__WASI_RIGHTS_FD_WRITE | __WASI_RIGHTS_FD_ALLOCATE |
__WASI_RIGHTS_FD_READDIR | __WASI_RIGHTS_FD_FILESTAT_SET_SIZE);
switch (oflag & O_ACCMODE) {
case O_RDONLY:
case O_RDWR:
case O_WRONLY:
if ((oflag & O_RDONLY) != 0) {
max |= __WASI_RIGHTS_FD_READ | __WASI_RIGHTS_FD_READDIR;
}
if ((oflag & O_WRONLY) != 0) {
max |= __WASI_RIGHTS_FD_DATASYNC | __WASI_RIGHTS_FD_WRITE |
__WASI_RIGHTS_FD_ALLOCATE |
__WASI_RIGHTS_FD_FILESTAT_SET_SIZE;
}
break;
case O_EXEC:
break;
case O_SEARCH:
break;
default:
errno = EINVAL;
return -1;
}
// Ensure that we can actually obtain the minimal rights needed.
__wasi_fdstat_t fsb_cur;
__wasi_errno_t error = __wasi_fd_fdstat_get(fd, &fsb_cur);
if (error != 0) {
errno = error;
return -1;
}
// Path lookup properties.
__wasi_lookupflags_t lookup_flags = 0;
if ((oflag & O_NOFOLLOW) == 0)
lookup_flags |= __WASI_LOOKUPFLAGS_SYMLINK_FOLLOW;
// Open file with appropriate rights.
__wasi_fdflags_t fs_flags = oflag & 0xfff;
__wasi_rights_t fs_rights_base = max & fsb_cur.fs_rights_inheriting;
__wasi_rights_t fs_rights_inheriting = fsb_cur.fs_rights_inheriting;
__wasi_fd_t newfd;
error = __wasi_path_open(fd, lookup_flags, path,
(oflag >> 12) & 0xfff,
fs_rights_base, fs_rights_inheriting, fs_flags,
&newfd);
if (error != 0) {
errno = error;
return -1;
}
return newfd;
}
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