xref: /openbsd/lib/libssl/pqueue.c (revision c3d6a26a)
1 /* $OpenBSD: pqueue.c,v 1.5 2014/06/12 15:49:31 deraadt Exp $ */
2 /*
3  * DTLS implementation written by Nagendra Modadugu
4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
5  */
6 /* ====================================================================
7  * Copyright (c) 1999-2005 The OpenSSL Project.  All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  *
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in
18  *    the documentation and/or other materials provided with the
19  *    distribution.
20  *
21  * 3. All advertising materials mentioning features or use of this
22  *    software must display the following acknowledgment:
23  *    "This product includes software developed by the OpenSSL Project
24  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25  *
26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27  *    endorse or promote products derived from this software without
28  *    prior written permission. For written permission, please contact
29  *    openssl-core@OpenSSL.org.
30  *
31  * 5. Products derived from this software may not be called "OpenSSL"
32  *    nor may "OpenSSL" appear in their names without prior written
33  *    permission of the OpenSSL Project.
34  *
35  * 6. Redistributions of any form whatsoever must retain the following
36  *    acknowledgment:
37  *    "This product includes software developed by the OpenSSL Project
38  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39  *
40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51  * OF THE POSSIBILITY OF SUCH DAMAGE.
52  * ====================================================================
53  *
54  * This product includes cryptographic software written by Eric Young
55  * (eay@cryptsoft.com).  This product includes software written by Tim
56  * Hudson (tjh@cryptsoft.com).
57  *
58  */
59 
60 #include <stdlib.h>
61 #include <string.h>
62 
63 #include "pqueue.h"
64 
65 typedef struct _pqueue {
66 	pitem *items;
67 	int count;
68 } pqueue_s;
69 
70 pitem *
pitem_new(unsigned char * prio64be,void * data)71 pitem_new(unsigned char *prio64be, void *data)
72 {
73 	pitem *item = malloc(sizeof(pitem));
74 
75 	if (item == NULL)
76 		return NULL;
77 
78 	memcpy(item->priority, prio64be, sizeof(item->priority));
79 
80 	item->data = data;
81 	item->next = NULL;
82 
83 	return item;
84 }
85 
86 void
pitem_free(pitem * item)87 pitem_free(pitem *item)
88 {
89 	free(item);
90 }
91 
92 pqueue_s *
pqueue_new(void)93 pqueue_new(void)
94 {
95 	return calloc(1, sizeof(pqueue_s));
96 }
97 
98 void
pqueue_free(pqueue_s * pq)99 pqueue_free(pqueue_s *pq)
100 {
101 	free(pq);
102 }
103 
104 pitem *
pqueue_insert(pqueue_s * pq,pitem * item)105 pqueue_insert(pqueue_s *pq, pitem *item)
106 {
107 	pitem *curr, *next;
108 
109 	if (pq->items == NULL) {
110 		pq->items = item;
111 		return item;
112 	}
113 
114 	for (curr = NULL, next = pq->items; next != NULL;
115 	    curr = next, next = next->next) {
116 		/* we can compare 64-bit value in big-endian encoding
117 		 * with memcmp:-) */
118 		int cmp = memcmp(next->priority, item->priority,
119 		    sizeof(item->priority));
120 		if (cmp > 0) {		/* next > item */
121 			item->next = next;
122 
123 			if (curr == NULL)
124 				pq->items = item;
125 			else
126 				curr->next = item;
127 
128 			return item;
129 		} else if (cmp == 0)	/* duplicates not allowed */
130 			return NULL;
131 	}
132 
133 	item->next = NULL;
134 	curr->next = item;
135 
136 	return item;
137 }
138 
139 pitem *
pqueue_peek(pqueue_s * pq)140 pqueue_peek(pqueue_s *pq)
141 {
142 	return pq->items;
143 }
144 
145 pitem *
pqueue_pop(pqueue_s * pq)146 pqueue_pop(pqueue_s *pq)
147 {
148 	pitem *item = pq->items;
149 
150 	if (pq->items != NULL)
151 		pq->items = pq->items->next;
152 
153 	return item;
154 }
155 
156 pitem *
pqueue_find(pqueue_s * pq,unsigned char * prio64be)157 pqueue_find(pqueue_s *pq, unsigned char *prio64be)
158 {
159 	pitem *next;
160 
161 	for (next = pq->items; next != NULL; next = next->next)
162 		if (memcmp(next->priority, prio64be,
163 		    sizeof(next->priority)) == 0)
164 			return next;
165 
166 	return NULL;
167 }
168 
169 pitem *
pqueue_iterator(pqueue_s * pq)170 pqueue_iterator(pqueue_s *pq)
171 {
172 	return pqueue_peek(pq);
173 }
174 
175 pitem *
pqueue_next(pitem ** item)176 pqueue_next(pitem **item)
177 {
178 	pitem *ret;
179 
180 	if (item == NULL || *item == NULL)
181 		return NULL;
182 
183 	/* *item != NULL */
184 	ret = *item;
185 	*item = (*item)->next;
186 
187 	return ret;
188 }
189 
190 int
pqueue_size(pqueue_s * pq)191 pqueue_size(pqueue_s *pq)
192 {
193 	pitem *item = pq->items;
194 	int count = 0;
195 
196 	while (item != NULL) {
197 		count++;
198 		item = item->next;
199 	}
200 	return count;
201 }
202