xref: /illumos-gate/usr/src/cmd/cmd-inet/usr.lib/in.ripngd/timer.c (revision 2a8bcb4efb45d99ac41c94a75c396b362c414f7f)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 /*
31  * Portions of this source code were derived from Berkeley 4.3 BSD
32  * under license from the Regents of the University of California.
33  */
34 
35 /*
36  * Routing Table Management Daemon
37  */
38 #include "defs.h"
39 
40 int supplyinterval;			/* current supply interval */
41 
42 /*
43  * Timer routine.  Performs routing information supply
44  * duties and manages timers on routing table entries.
45  * Management of the RTS_CHANGED bit assumes that we multicast
46  * each time called.
47  */
48 void
timer(void)49 timer(void)
50 {
51 	struct rthash *rh;
52 	struct rt_entry *rt;
53 	boolean_t timetomulticast = _B_FALSE;
54 	int i;
55 	static int iftime;		/* interface timer */
56 	static int mtime;		/* periodic mcast supply timer */
57 	static int alarmtime = 0;	/* time elapsed since last call */
58 	int mintime;			/* tracks when next timer will expire */
59 
60 	/*
61 	 * On the initial call to timer(), the various times that are kept track
62 	 * of need to be initialized.  After initializing everything, "remember"
63 	 * (via a static) how long until the next timer expires.
64 	 */
65 	if (alarmtime == 0) {
66 		supplyinterval = GET_RANDOM(MIN_SUPPLY_TIME, MAX_SUPPLY_TIME);
67 		iftime = 0;
68 		mtime = supplyinterval;
69 		alarmtime = supplyinterval;
70 		(void) alarm(alarmtime);
71 		return;
72 	}
73 
74 	/*
75 	 * Initialize mintime to a suitable "large" value and then compare it to
76 	 * other times in the future to determine which event will occur next.
77 	 */
78 	mintime = INT_MAX;
79 	(void) sighold(SIGHUP);
80 	(void) sighold(SIGUSR1);
81 	(void) sighold(SIGUSR2);
82 
83 	iftime += alarmtime;
84 	if (iftime >= CHECK_INTERVAL) {
85 		initifs();
86 		iftime = 0;
87 	}
88 	mintime = min(mintime, CHECK_INTERVAL - iftime);
89 
90 	mtime += alarmtime;
91 	if (mtime >= supplyinterval) {
92 		if (supplier)
93 			timetomulticast = _B_TRUE;
94 		mtime = 0;
95 		supplyinterval = GET_RANDOM(MIN_SUPPLY_TIME, MAX_SUPPLY_TIME);
96 	}
97 	mintime = min(mintime, supplyinterval - mtime);
98 
99 	for (i = IPV6_ABITS; i >= 0; i--) {
100 		if (net_hashes[i] == NULL)
101 			continue;
102 
103 		for (rh = net_hashes[i];
104 		    rh < &net_hashes[i][ROUTEHASHSIZ]; rh++) {
105 			for (rt = rh->rt_forw; rt != (struct rt_entry *)rh;
106 			    rt = rt->rt_forw) {
107 				/*
108 				 * We don't advance time on a routing entry for
109 				 * an interface because we catch
110 				 * interfaces going up and down in initifs.
111 				 */
112 				rt->rt_state &= ~RTS_CHANGED;
113 				if ((rt->rt_state & RTS_INTERFACE) != 0)
114 					continue;
115 				rt->rt_timer += alarmtime;
116 				if (rt->rt_timer >= GARBAGE_TIME) {
117 					rt = rt->rt_back;
118 					rtdelete(rt->rt_forw);
119 					continue;
120 				}
121 				if (rt->rt_timer >= EXPIRE_TIME) {
122 					rtdown(rt);
123 					mintime = min(mintime,
124 					    GARBAGE_TIME - rt->rt_timer);
125 				} else {
126 					mintime = min(mintime,
127 					    EXPIRE_TIME - rt->rt_timer);
128 				}
129 			}
130 		}
131 	}
132 
133 	if (timetomulticast) {
134 		supplyall(&allrouters, 0, (struct interface *)NULL, _B_TRUE);
135 		(void) gettimeofday(&now, (struct timezone *)NULL);
136 		lastmcast = now;
137 		lastfullupdate = now;
138 		needupdate = _B_FALSE;	/* cancel any pending dynamic update */
139 		nextmcast.tv_sec = 0;
140 	}
141 	(void) sigrelse(SIGUSR2);
142 	(void) sigrelse(SIGUSR1);
143 	(void) sigrelse(SIGHUP);
144 
145 	/*
146 	 * "Remember" (via a static) how long until the next timer expires.
147 	 */
148 	alarmtime = mintime;
149 	(void) alarm(alarmtime);
150 }
151 
152 /*
153  * On SIGTERM, let everyone know we're going away.
154  */
155 void
term(void)156 term(void)
157 {
158 	struct rthash *rh;
159 	struct rt_entry *rt;
160 	int i;
161 
162 	if (!supplier)
163 		exit(EXIT_SUCCESS);
164 	for (i = IPV6_ABITS; i >= 0; i--) {
165 		if (net_hashes[i] == NULL)
166 			continue;
167 
168 		for (rh = net_hashes[i]; rh < &net_hashes[i][ROUTEHASHSIZ];
169 		    rh++) {
170 			for (rt = rh->rt_forw; rt != (struct rt_entry *)rh;
171 			    rt = rt->rt_forw) {
172 				rt->rt_metric = HOPCNT_INFINITY;
173 			}
174 		}
175 	}
176 	supplyall(&allrouters, 0, (struct interface *)NULL, _B_TRUE);
177 	(void) unlink(PATH_PID);
178 	exit(EXIT_SUCCESS);
179 }
180