cosmopolitan/libc/intrin/createfile.c
Justine Tunney 39e7f24947
Fix handling of paths with dirfd on Windows
This change fixes an issue with all system calls ending with *at(), when
the caller passes `dirfd != AT_FDCWD` and an absolute path. It's because
the old code was turning paths like C:\bin\ls into \\C:\bin\ls\C:\bin\ls
after being converted from paths like /C/bin/ls. I noticed this when the
Emacs dired mode stopped working. It's unclear if it's a regression with
Cosmopolitan Libc or if this was introduced by the Emacs v29 upgrade. It
also impacted posix_spawn() for which a newly minted example now exists.
2024-09-01 17:52:30 -07:00

94 lines
4.8 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 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/nt/createfile.h"
#include "libc/calls/sig.internal.h"
#include "libc/calls/syscall_support-nt.internal.h"
#include "libc/intrin/describeflags.h"
#include "libc/intrin/strace.h"
#include "libc/nt/enum/accessmask.h"
#include "libc/nt/enum/creationdisposition.h"
#include "libc/nt/errors.h"
#include "libc/nt/runtime.h"
#include "libc/nt/synchronization.h"
#include "libc/nt/thunk/msabi.h"
__msabi extern typeof(CreateFile) *const __imp_CreateFileW;
__msabi extern typeof(GetLastError) *const __imp_GetLastError;
__msabi extern typeof(Sleep) *const __imp_Sleep;
/**
* Opens file on the New Technology.
*
* @return handle, or -1 on failure w/ `errno` set appropriately
* @note this wrapper takes care of ABI, STRACE(), and __winerr()
*/
textwindows int64_t
CreateFile(const char16_t *lpFileName, //
uint32_t dwDesiredAccess, //
uint32_t dwShareMode, //
const struct NtSecurityAttributes *opt_lpSecurity, //
int dwCreationDisposition, //
uint32_t dwFlagsAndAttributes, //
int64_t opt_hTemplateFile) {
int64_t hHandle;
uint32_t micros = 1;
char buf_accessflags[512];
char buf_shareflags[64];
char buf_secattr[32];
char buf_flagattr[256];
TryAgain:
hHandle = __imp_CreateFileW(lpFileName, dwDesiredAccess, dwShareMode,
opt_lpSecurity, dwCreationDisposition,
dwFlagsAndAttributes, opt_hTemplateFile);
NTTRACE("CreateFile(%#!hs, %s, %s, %s, %s, %s, %ld) → {%ld, %d}", lpFileName,
_DescribeNtFileAccessFlags(buf_accessflags, dwDesiredAccess),
_DescribeNtFileShareFlags(buf_shareflags, dwShareMode),
_DescribeNtSecurityAttributes(buf_secattr, opt_lpSecurity),
_DescribeNtCreationDisposition(dwCreationDisposition),
_DescribeNtFileFlagAttr(buf_flagattr, dwFlagsAndAttributes),
opt_hTemplateFile, hHandle, __imp_GetLastError());
if (hHandle == -1) {
switch (__imp_GetLastError()) {
case kNtErrorPipeBusy:
if (micros >= 1024)
__imp_Sleep(micros / 1024);
if (micros < 1024 * 1024)
micros <<= 1;
goto TryAgain;
case kNtErrorAccessDenied:
// GetNtOpenFlags() always greedily requests execute permissions
// because the POSIX flag O_EXEC doesn't mean the same thing. It
// seems however this causes the opening of certain files to not
// work, possibly due to Windows Defender or some security thing
// In that case, we'll cross our fingers the file isn't a binary
if ((dwDesiredAccess & kNtGenericExecute) &&
(dwCreationDisposition == kNtOpenExisting ||
dwCreationDisposition == kNtTruncateExisting)) {
NTTRACE("CreateFile removed kNtGenericExecute");
dwDesiredAccess &= ~kNtGenericExecute;
goto TryAgain;
}
break;
default:
break;
}
__winerr();
}
return hHandle;
}