97 lines
4.1 KiB
C
97 lines
4.1 KiB
C
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/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ This program is free software; you can redistribute it and/or modify │
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│ it under the terms of the GNU General Public License as published by │
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│ the Free Software Foundation; version 2 of the License. │
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│ │
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│ This program is distributed in the hope that it will be useful, but │
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│ WITHOUT ANY WARRANTY; without even the implied warranty of │
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│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
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│ General Public License for more details. │
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│ │
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│ You should have received a copy of the GNU General Public License │
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│ along with this program; if not, write to the Free Software │
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│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
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│ 02110-1301 USA │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/assert.h"
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#include "libc/calls/calls.h"
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#include "libc/calls/internal.h"
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#include "libc/conv/conv.h"
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#include "libc/conv/isslash.h"
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#include "libc/conv/itoa.h"
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#include "libc/dce.h"
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#include "libc/nt/createfile.h"
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#include "libc/nt/enum/creationdisposition.h"
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#include "libc/nt/enum/fileflagandattributes.h"
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#include "libc/str/str.h"
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#include "libc/sysv/consts/at.h"
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#include "libc/sysv/consts/o.h"
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static struct OpenAnon { int count; } g_openanon;
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static void openanon$genpath(const char *name, struct OpenAnon *state,
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char pathbuf[hasatleast PATH_MAX]) {
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char c;
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size_t i;
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char *p, *pe;
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p = stpcpy(pathbuf, kTmpPath);
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pe = pathbuf + PATH_MAX - 8 - 10 - 1 - 10 - 1;
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if (!name) name = "openanon";
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for (i = 0; p < pe; ++i) {
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if (!(c = name[i])) break;
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if (isslash(c)) c = '_';
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*p++ = c;
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}
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*p++ = '.';
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p += uint64toarray_radix10(getpid(), p);
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*p++ = '.';
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p += uint64toarray_radix10(++state->count, p);
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*p = '\0';
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assert(p < pe);
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}
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static int openanon$impl(const char *name, unsigned flags,
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struct OpenAnon *state,
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char pathbuf[hasatleast PATH_MAX]) {
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int fd;
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openanon$genpath(name, state, pathbuf);
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if (!IsWindows()) {
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flags |= O_RDWR | O_CREAT | O_EXCL | O_TRUNC;
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if ((fd = openat$sysv(AT_FDCWD, pathbuf, flags, 0600)) != -1) {
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unlink(pathbuf);
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}
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return fd;
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} else {
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if ((fd = createfd()) != -1 &&
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(g_fds.p[fd].handle = CreateFileA(
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pathbuf, kNtGenericRead | kNtGenericWrite, kNtFileShareExclusive,
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(flags & O_CLOEXEC) ? &kNtIsInheritable : NULL, kNtCreateAlways,
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(kNtFileAttributeNotContentIndexed | kNtFileAttributeNormal |
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kNtFileAttributeTemporary | kNtFileFlagDeleteOnClose),
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0)) != -1) {
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g_fds.p[fd].kind = kFdFile;
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return fd;
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} else {
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return winerr();
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}
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}
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}
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/**
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* Creates anonymous file.
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*
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* @param name is purely informative
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* @param flags can have O_CLOEXEC
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* @return fd of file with no name, needing close(), or -1 w/ errno
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* @see memfd_create() if disk-paranoid
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* @see mkostempsm() for named files
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*/
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int openanon(char *name, unsigned flags) {
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char pathbuf[PATH_MAX];
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return openanon$impl(name, flags, &g_openanon, pathbuf);
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}
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