aboutsummaryrefslogtreecommitdiff
path: root/contrib/isc-dhcp/common/dispatch.c
blob: bd87675391ff134e4b319363b55559e33c4646e2 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
/* dispatch.c

   Network input dispatcher... */

/*
 * Copyright (c) 1995-2002 Internet Software Consortium.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of The Internet Software Consortium nor the names
 *    of its contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * This software has been written for the Internet Software Consortium
 * by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
 * To learn more about the Internet Software Consortium, see
 * ``http://www.isc.org/''.  To learn more about Vixie Enterprises,
 * see ``http://www.vix.com''.   To learn more about Nominum, Inc., see
 * ``http://www.nominum.com''.
 */

#ifndef lint
static char copyright[] =
"$Id: dispatch.c,v 1.63.2.3 2002/11/17 02:26:57 dhankins Exp $ Copyright (c) 1995-2002 The Internet Software Consortium.  All rights reserved.\n";
#endif /* not lint */

#include "dhcpd.h"

struct timeout *timeouts;
static struct timeout *free_timeouts;

void set_time (u_int32_t t)
{
	/* Do any outstanding timeouts. */
	if (cur_time != t) {
		cur_time = t;
		process_outstanding_timeouts ((struct timeval *)0);
	}
}

struct timeval *process_outstanding_timeouts (struct timeval *tvp)
{
	/* Call any expired timeouts, and then if there's
	   still a timeout registered, time out the select
	   call then. */
      another:
	if (timeouts) {
		struct timeout *t;
		if (timeouts -> when <= cur_time) {
			t = timeouts;
			timeouts = timeouts -> next;
			(*(t -> func)) (t -> what);
			if (t -> unref)
				(*t -> unref) (&t -> what, MDL);
			t -> next = free_timeouts;
			free_timeouts = t;
			goto another;
		}
		if (tvp) {
			tvp -> tv_sec = timeouts -> when;
			tvp -> tv_usec = 0;
		}
		return tvp;
	} else
		return (struct timeval *)0;
}

/* Wait for packets to come in using select().   When one does, call
   receive_packet to receive the packet and possibly strip hardware
   addressing information from it, and then call through the
   bootp_packet_handler hook to try to do something with it. */

void dispatch ()
{
	struct timeval tv, *tvp;
	isc_result_t status;

	/* Wait for a packet or a timeout... XXX */
	do {
		tvp = process_outstanding_timeouts (&tv);
		status = omapi_one_dispatch (0, tvp);
	} while (status == ISC_R_TIMEDOUT || status == ISC_R_SUCCESS);
	log_fatal ("omapi_one_dispatch failed: %s -- exiting.",
		   isc_result_totext (status));
}

void add_timeout (when, where, what, ref, unref)
	TIME when;
	void (*where) PROTO ((void *));
	void *what;
	tvref_t ref;
	tvunref_t unref;
{
	struct timeout *t, *q;

	/* See if this timeout supersedes an existing timeout. */
	t = (struct timeout *)0;
	for (q = timeouts; q; q = q -> next) {
		if ((where == NULL || q -> func == where) &&
		    q -> what == what) {
			if (t)
				t -> next = q -> next;
			else
				timeouts = q -> next;
			break;
		}
		t = q;
	}

	/* If we didn't supersede a timeout, allocate a timeout
	   structure now. */
	if (!q) {
		if (free_timeouts) {
			q = free_timeouts;
			free_timeouts = q -> next;
		} else {
			q = ((struct timeout *)
			     dmalloc (sizeof (struct timeout), MDL));
			if (!q)
				log_fatal ("add_timeout: no memory!");
		}
		memset (q, 0, sizeof *q);
		q -> func = where;
		q -> ref = ref;
		q -> unref = unref;
		if (q -> ref)
			(*q -> ref)(&q -> what, what, MDL);
		else
			q -> what = what;
	}

	q -> when = when;

	/* Now sort this timeout into the timeout list. */

	/* Beginning of list? */
	if (!timeouts || timeouts -> when > q -> when) {
		q -> next = timeouts;
		timeouts = q;
		return;
	}

	/* Middle of list? */
	for (t = timeouts; t -> next; t = t -> next) {
		if (t -> next -> when > q -> when) {
			q -> next = t -> next;
			t -> next = q;
			return;
		}
	}

	/* End of list. */
	t -> next = q;
	q -> next = (struct timeout *)0;
}

void cancel_timeout (where, what)
	void (*where) PROTO ((void *));
	void *what;
{
	struct timeout *t, *q;

	/* Look for this timeout on the list, and unlink it if we find it. */
	t = (struct timeout *)0;
	for (q = timeouts; q; q = q -> next) {
		if (q -> func == where && q -> what == what) {
			if (t)
				t -> next = q -> next;
			else
				timeouts = q -> next;
			break;
		}
		t = q;
	}

	/* If we found the timeout, put it on the free list. */
	if (q) {
		if (q -> unref)
			(*q -> unref) (&q -> what, MDL);
		q -> next = free_timeouts;
		free_timeouts = q;
	}
}

#if defined (DEBUG_MEMORY_LEAKAGE_ON_EXIT)
void cancel_all_timeouts ()
{
	struct timeout *t, *n;
	for (t = timeouts; t; t = n) {
		n = t -> next;
		if (t -> unref && t -> what)
			(*t -> unref) (&t -> what, MDL);
		t -> next = free_timeouts;
		free_timeouts = t;
	}
}

void relinquish_timeouts ()
{
	struct timeout *t, *n;
	for (t = free_timeouts; t; t = n) {
		n = t -> next;
		dfree (t, MDL);
	}
}
#endif