usr.sbin/ppp/probe.c

   1 /*-
   2  * Copyright (c) 1998 Brian Somers <brian@Awfulhak.org>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $FreeBSD: src/usr.sbin/ppp/probe.c,v 1.3.2.1 2002/09/01 02:12:31 brian Exp $
  27  * $DragonFly: src/usr.sbin/ppp/probe.c,v 1.3 2005/11/24 23:42:54 swildner Exp $
  28  */
  29
  30 #include <sys/time.h>
  31 #include <sys/socket.h>
  32
  33 #include <stdio.h>
  34 #include <unistd.h>
  35
  36 #include "probe.h"
  37 #include "log.h"
  38 #include "id.h"
  39
  40 struct probe probe;
  41
  42 /* Does select() alter the passed time value ? */
  43 static int
  44 select_changes_time(void)
  45 {
  46   struct timeval t;
  47
  48   t.tv_sec = 0;
  49   t.tv_usec = 100000;
  50   select(0, NULL, NULL, NULL, &t);
  51   return t.tv_usec != 100000;
  52 }
  53
  54 #ifndef NOINET6
  55 static int
  56 ipv6_available(void)
  57 {
  58   int s;
  59
  60   if ((s = ID0socket(PF_INET6, SOCK_DGRAM, 0)) == -1)
  61     return 0;
  62
  63   close(s);
  64   return 1;
  65 }
  66 #endif
  67
  68 void
  69 probe_Init(void)
  70 {
  71   probe.select_changes_time = select_changes_time() ? 1 : 0;
  72   log_Printf(LogDEBUG, "Select changes time: %s\n",
  73              probe.select_changes_time ? "yes" : "no");
  74 #ifndef NOINET6
  75   probe.ipv6_available = ipv6_available() ? 1 : 0;
  76   log_Printf(LogDEBUG, "IPv6 available: %s\n",
  77              probe.ipv6_available ? "yes" : "no");
  78 #endif
  79 }