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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
36 
37 /*
38  * Routing Table Management Daemon
39  */
40 #include "defs.h"
41 
42 int supplyinterval;			/* current supply interval */
43 
44 /*
45  * Timer routine.  Performs routing information supply
46  * duties and manages timers on routing table entries.
47  * Management of the RTS_CHANGED bit assumes that we multicast
48  * each time called.
49  */
50 void
timer(void)51 timer(void)
52 {
53 	struct rthash *rh;
54 	struct rt_entry *rt;
55 	boolean_t timetomulticast = _B_FALSE;
56 	int i;
57 	static int iftime;		/* interface timer */
58 	static int mtime;		/* periodic mcast supply timer */
59 	static int alarmtime = 0;	/* time elapsed since last call */
60 	int mintime;			/* tracks when next timer will expire */
61 
62 	/*
63 	 * On the initial call to timer(), the various times that are kept track
64 	 * of need to be initialized.  After initializing everything, "remember"
65 	 * (via a static) how long until the next timer expires.
66 	 */
67 	if (alarmtime == 0) {
68 		supplyinterval = GET_RANDOM(MIN_SUPPLY_TIME, MAX_SUPPLY_TIME);
69 		iftime = 0;
70 		mtime = supplyinterval;
71 		alarmtime = supplyinterval;
72 		(void) alarm(alarmtime);
73 		return;
74 	}
75 
76 	/*
77 	 * Initialize mintime to a suitable "large" value and then compare it to
78 	 * other times in the future to determine which event will occur next.
79 	 */
80 	mintime = INT_MAX;
81 	(void) sighold(SIGHUP);
82 	(void) sighold(SIGUSR1);
83 	(void) sighold(SIGUSR2);
84 
85 	iftime += alarmtime;
86 	if (iftime >= CHECK_INTERVAL) {
87 		initifs();
88 		iftime = 0;
89 	}
90 	mintime = min(mintime, CHECK_INTERVAL - iftime);
91 
92 	mtime += alarmtime;
93 	if (mtime >= supplyinterval) {
94 		if (supplier)
95 			timetomulticast = _B_TRUE;
96 		mtime = 0;
97 		supplyinterval = GET_RANDOM(MIN_SUPPLY_TIME, MAX_SUPPLY_TIME);
98 	}
99 	mintime = min(mintime, supplyinterval - mtime);
100 
101 	for (i = IPV6_ABITS; i >= 0; i--) {
102 		if (net_hashes[i] == NULL)
103 			continue;
104 
105 		for (rh = net_hashes[i];
106 		    rh < &net_hashes[i][ROUTEHASHSIZ]; rh++) {
107 			for (rt = rh->rt_forw; rt != (struct rt_entry *)rh;
108 			    rt = rt->rt_forw) {
109 				/*
110 				 * We don't advance time on a routing entry for
111 				 * an interface because we catch
112 				 * interfaces going up and down in initifs.
113 				 */
114 				rt->rt_state &= ~RTS_CHANGED;
115 				if ((rt->rt_state & RTS_INTERFACE) != 0)
116 					continue;
117 				rt->rt_timer += alarmtime;
118 				if (rt->rt_timer >= GARBAGE_TIME) {
119 					rt = rt->rt_back;
120 					rtdelete(rt->rt_forw);
121 					continue;
122 				}
123 				if (rt->rt_timer >= EXPIRE_TIME) {
124 					rtdown(rt);
125 					mintime = min(mintime,
126 					    GARBAGE_TIME - rt->rt_timer);
127 				} else {
128 					mintime = min(mintime,
129 					    EXPIRE_TIME - rt->rt_timer);
130 				}
131 			}
132 		}
133 	}
134 
135 	if (timetomulticast) {
136 		supplyall(&allrouters, 0, (struct interface *)NULL, _B_TRUE);
137 		(void) gettimeofday(&now, (struct timezone *)NULL);
138 		lastmcast = now;
139 		lastfullupdate = now;
140 		needupdate = _B_FALSE;	/* cancel any pending dynamic update */
141 		nextmcast.tv_sec = 0;
142 	}
143 	(void) sigrelse(SIGUSR2);
144 	(void) sigrelse(SIGUSR1);
145 	(void) sigrelse(SIGHUP);
146 
147 	/*
148 	 * "Remember" (via a static) how long until the next timer expires.
149 	 */
150 	alarmtime = mintime;
151 	(void) alarm(alarmtime);
152 }
153 
154 /*
155  * On SIGTERM, let everyone know we're going away.
156  */
157 void
term(void)158 term(void)
159 {
160 	struct rthash *rh;
161 	struct rt_entry *rt;
162 	int i;
163 
164 	if (!supplier)
165 		exit(EXIT_SUCCESS);
166 	for (i = IPV6_ABITS; i >= 0; i--) {
167 		if (net_hashes[i] == NULL)
168 			continue;
169 
170 		for (rh = net_hashes[i]; rh < &net_hashes[i][ROUTEHASHSIZ];
171 		    rh++) {
172 			for (rt = rh->rt_forw; rt != (struct rt_entry *)rh;
173 			    rt = rt->rt_forw) {
174 				rt->rt_metric = HOPCNT_INFINITY;
175 			}
176 		}
177 	}
178 	supplyall(&allrouters, 0, (struct interface *)NULL, _B_TRUE);
179 	(void) unlink(PATH_PID);
180 	exit(EXIT_SUCCESS);
181 }
182