cosmopolitan/libc/calls/mkntpath.c

84 lines
4.0 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/internal.h"
#include "libc/calls/ntmagicpaths.internal.h"
#include "libc/str/oldutf16.internal.h"
#include "libc/str/str.h"
#include "libc/str/tpdecode.internal.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/errfuns.h"
textwindows static const char *FixNtMagicPath(const char *path,
unsigned flags) {
const struct NtMagicPaths *mp = &kNtMagicPaths;
asm("" : "+r"(mp));
if (path[0] != '/') return path;
if (strcmp(path, mp->devtty) == 0) {
if ((flags & O_ACCMODE) == O_RDONLY) {
return mp->conin;
} else if ((flags & O_ACCMODE) == O_WRONLY) {
return mp->conout;
}
}
if (strcmp(path, mp->devnull) == 0) return mp->nul;
if (strcmp(path, mp->devstdin) == 0) return mp->conin;
if (strcmp(path, mp->devstdout) == 0) return mp->conout;
return path;
}
textwindows int __mkntpath(const char *path,
char16_t path16[hasatleast PATH_MAX - 16]) {
return __mkntpath2(path, path16, -1);
}
/**
* Copies path for Windows NT.
*
* This entails (1) UTF-8 to UTF-16 conversion; (2) replacing
* forward-slashes with backslashes; and (3) remapping several
* well-known paths (e.g. /dev/null → NUL) for convenience.
*
* @param flags is used by open()
* @param path16 is shortened so caller can prefix, e.g. \\.\pipe\, and
* due to a plethora of special-cases throughout the Win32 API
* @return short count excluding NUL on success, or -1 w/ errno
* @error ENAMETOOLONG
*/
textwindows int __mkntpath2(const char *path,
char16_t path16[hasatleast PATH_MAX - 16],
int flags) {
/*
* 1. Reserve +1 for NUL-terminator
* 2. Reserve +1 for UTF-16 overflow
* 3. Reserve ≥2 for SetCurrentDirectory trailing slash requirement
* 4. Reserve ≥10 for CreateNamedPipe "\\.\pipe\" prefix requirement
* 5. Reserve ≥13 for mkdir() i.e. 1+8+3+1, e.g. "\\ffffffff.xxx\0"
*/
size_t i, n;
path = FixNtMagicPath(path, flags);
n = tprecode8to16(path16, PATH_MAX - 16, path).ax;
if (n == PATH_MAX - 16 - 1) return enametoolong();
for (i = 0; i < n; ++i) {
if (path16[i] == '/') {
path16[i] = '\\';
}
}
return n;
}