/*-*- 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/dce.h"
#include "libc/errno.h"
#include "libc/sock/internal.h"
#include "libc/sock/sock.h"

#define __NR_accept4_linux 0x0120 /* rhel5:enosysevil */

int sys_accept4(int server, void *addr, uint32_t *addrsize, int flags) {
  static bool once, demodernize;
  int olderr, client;
  if (!flags || demodernize) goto TriedAndTrue;
  olderr = errno;
  client = __sys_accept4(server, addr, addrsize, flags);
  if (client == -1 && errno == ENOSYS) {
    errno = olderr;
  TriedAndTrue:
    client = __fixupnewsockfd(__sys_accept(server, addr, addrsize, 0), flags);
  } else if (SupportsLinux() && !once) {
    once = true;
    if (client == __NR_accept4_linux) {
      demodernize = true;
      goto TriedAndTrue;
    }
  }
  if (client != -1 && IsBsd()) {
    sockaddr2linux(addr);
  }
  return client;
}