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