cosmopolitan/libc/calls/mkntpath.ncabi.c

97 lines
4.2 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 │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/ntmagicpaths.internal.h"
#include "libc/nexgen32e/tinystrcmp.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 (tinystrcmp(path, mp->devtty) == 0) {
if ((flags & O_ACCMODE) == O_RDONLY) {
return mp->conin;
} else if ((flags & O_ACCMODE) == O_WRONLY) {
return mp->conout;
}
}
if (tinystrcmp(path, mp->devnull) == 0) return mp->nul;
if (tinystrcmp(path, mp->devstdin) == 0) return mp->conin;
if (tinystrcmp(path, mp->devstdout) == 0) return mp->conout;
return path;
}
/**
* 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
*/
forcealignargpointer textwindows int mkntpath(
const char *path, unsigned flags,
char16_t path16[hasatleast PATH_MAX - 16]) {
/*
* 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"
*/
int rc;
wint_t wc;
size_t i, j;
path = FixNtMagicPath(path, flags);
i = 0;
j = 0;
for (;;) {
if ((rc = tpdecode(&path[i], &wc)) == -1) {
path16[0] = u'\0';
return -1;
}
if (!wc) break;
i += (size_t)rc;
if (wc == '/') wc = '\\';
if (j + 1 /* utf-16 */ + 1 /* chdir() */ + 1 /* NUL */ < PATH_MAX - 16) {
if ((rc = pututf16(&path16[j], 2, wc, false)) == -1) {
path16[0] = u'\0';
return -1;
}
j += (size_t)rc;
} else {
path16[0] = u'\0';
return enametoolong();
}
}
path16[j] = u'\0';
return j;
}