cosmopolitan/libc/calls/dup3-sysv.c

48 lines
2.5 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/internal.h"
#include "libc/errno.h"
#define __NR_dup3_linux 0x0124 /*RHEL5:CVE-2010-3301*/
int32_t dup3$sysv(int32_t oldfd, int32_t newfd, int flags) {
static bool once, demodernize;
int olderr, fd;
if (!once) {
once = true;
olderr = errno;
fd = __dup3$sysv(oldfd, newfd, flags);
if ((fd == -1 && errno == ENOSYS) || fd == __NR_dup3_linux) {
demodernize = true;
errno = olderr;
goto OldSkool;
}
} else if (demodernize) {
goto OldSkool;
} else {
fd = __dup3$sysv(oldfd, newfd, flags);
}
return fd;
OldSkool:
fd = dup2$sysv(oldfd, newfd);
if (flags) fd = fixupnewfd$sysv(fd, flags);
return fd;
}