cosmopolitan/libc/calls/dup3-sysv.c

47 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 │
│ │
│ 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/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;
}