1 /* NetBSD: status.c,v 1.3 2008/05/04 13:30:54 martin Exp */
2
3 /*
4 * status.c - pppd plugin to implement an `lcpstatus' option.
5 * This is intended as more of an example than perfected feature,
6 * but this code has been in use on my local network for a year and
7 * is quite useful as is (with a bit of external help, at any rate).
8 *
9 * Written January 2003 by John F. Woods, jfw@funhouse.com
10 */
11
12 /*
13 * Copyright (c) 2004 The NetBSD Foundation, Inc.
14 * All rights reserved.
15 *
16 * This code is derived from software contributed to The NetBSD Foundation
17 * by John F. Woods, jfw@funhouse.com.
18 *
19 * Redistribution and use in source and binary forms, with or without
20 * modification, are permitted provided that the following conditions
21 * are met:
22 * 1. Redistributions of source code must retain the above copyright
23 * notice, this list of conditions and the following disclaimer.
24 * 2. Redistributions in binary form must reproduce the above copyright
25 * notice, this list of conditions and the following disclaimer in the
26 * documentation and/or other materials provided with the distribution.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
29 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
30 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
31 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
32 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
33 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
34 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
35 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
36 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
37 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38 * POSSIBILITY OF SUCH DAMAGE.
39 */
40 #include <stddef.h>
41 #include <time.h>
42 #include <stdio.h>
43 #include "pppd.h"
44
45 /* this version string will be checked against pppd's version string when
46 * this plugin is loaded.
47 */
48 char pppd_version[] = VERSION;
49
50 /*
51 * Usage: to use this status plug as-is, add the lines:
52 plugin status
53 lcpstatus /var/run/ppp0.status
54 * to your PPP options file (or add the appropriate options to your
55 * pppd command line), where /var/run/ppp0.status can vary to taste.
56 * This plugin will then proceed to create the lcp status file and
57 * write one of four strings to the file based on the most recent LCP
58 * event: "up", "down", "?", or "!", representing LCP up, LCP down,
59 * LCP echo not received, and received-our-own-LCP-echo (probably
60 * indicating a loopback or a disconnected modem echoing back characters).
61 * On my system, I have a separate program which reads that file every
62 * second and sends a UDP broadcast packet on my ethernet with the contents
63 * of the file; each of the other computers on my ethernet (all Macs) have
64 * a tiny little program which listens for that UDP broadcast packet and
65 * updates a menubar status indicator; the end result is that when PPP
66 * shuts down, users on my LAN immediately know without having to go look
67 * at the modem. (Or without demanding that *I* go look at the modem...)
68 *
69 * If you want to modify this plugin, other ways you could use and display
70 * the data generated by the transitions would include:
71 * + directly broadcasting the results from inside the pppd task (rather
72 * than having a separate process do it)
73 * + store the ppp state in an SNMP database so it could be displayed with
74 * a standard form of client rather than a goofy little Mac OS X menubar
75 * widget.
76 */
77
78 static char *statusfilename = 0;
79 static char *laststatus = 0;
80 static char UP[] = "up";
81 static char DOWN[] = "down";
82 static char MISS[] = "?";
83 static char MINE[] = "!";
84
85 static option_t status_options[] = {
86 { "lcpstatus", o_string, &statusfilename,
87 "Name of file to which LCP status string will be written" },
88 { NULL }
89 };
90
91 /* status should be one of the canned constants above. */
writestatus(char * status)92 static void writestatus(char *status)
93 {
94 FILE *statusfile;
95 if (status == laststatus) return; /* we knew that already */
96 statusfile = fopen(statusfilename, "w");
97 if (!statusfile) {
98 warn("can't write %s to log LCP status", statusfilename);
99 free(statusfilename);
100 statusfilename = 0;
101 return;
102 }
103 fprintf(statusfile, "%s\n", status);
104 fclose(statusfile);
105 laststatus = status;
106 }
107
status_lcp_up(void)108 static void status_lcp_up(void)
109 {
110 if (!statusfilename) return; /* not enabled */
111 writestatus(UP);
112 }
113
status_lcp_down(void)114 static void status_lcp_down(void)
115 {
116 if (!statusfilename) return; /* not enabled */
117 writestatus(DOWN);
118 }
119
status_lcp_echo(int pending)120 static void status_lcp_echo(int pending)
121 {
122 if (!statusfilename) return; /* not enabled */
123 if (pending == 0)
124 writestatus(UP);
125 else if (laststatus != MINE)
126 writestatus(MISS);
127 }
128
status_lcp_echoreply(int mine)129 static void status_lcp_echoreply(int mine)
130 {
131 if (!statusfilename) return; /* not enabled */
132 if (mine == 0)
133 writestatus(UP);
134 else
135 writestatus(MINE);
136 }
137
plugin_init(void)138 void plugin_init(void)
139 {
140 info("Initialize PPP status plugin.");
141 add_options(status_options);
142 lcp_up_hook = status_lcp_up;
143 lcp_down_hook = status_lcp_down;
144 lcp_echo_hook = status_lcp_echo;
145 lcp_echoreply_hook = status_lcp_echoreply;
146 }
147