xref: /freebsd/usr.sbin/ppp/probe.c (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
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 }
79