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  * $FreeBSD$
  27  */
  28
  29 #include <sys/time.h>
  30 #include <sys/socket.h>
  31
  32 #include <stdio.h>
  33 #include <unistd.h>
  34
  35 #include "probe.h"
  36 #include "log.h"
  37 #include "id.h"
  38
  39 struct probe probe;
  40
  41 /* Does select() alter the passed time value ? */
  42 static int
  43 select_changes_time(void)
  44 {
  45   struct timeval t;
  46
  47   t.tv_sec = 0;
  48   t.tv_usec = 100000;
  49   select(0, NULL, NULL, NULL, &t);
  50   return t.tv_usec != 100000;
  51 }
  52
  53 #ifndef NOINET6
  54 static int
  55 ipv6_available(void)
  56 {
  57   int s;
  58
  59   if ((s = ID0socket(PF_INET6, SOCK_DGRAM, 0)) == -1)
  60     return 0;
  61
  62   close(s);
  63   return 1;
  64 }
  65 #endif
  66
  67 void
  68 probe_Init()
  69 {
  70   probe.select_changes_time = select_changes_time() ? 1 : 0;
  71   log_Printf(LogDEBUG, "Select changes time: %s\n",
  72              probe.select_changes_time ? "yes" : "no");
  73 #ifndef NOINET6
  74   probe.ipv6_available = ipv6_available() ? 1 : 0;
  75   log_Printf(LogDEBUG, "IPv6 available: %s\n",
  76              probe.ipv6_available ? "yes" : "no");
  77 #endif
  78 }