crypto/libressl/ssl/pqueue.c

   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 *
  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
  87 pitem_free(pitem *item)
  88 {
  89         free(item);
  90 }
  91
  92 pqueue_s *
  93 pqueue_new(void)
  94 {
  95         return calloc(1, sizeof(pqueue_s));
  96 }
  97
  98 void
  99 pqueue_free(pqueue_s *pq)
 100 {
 101         free(pq);
 102 }
 103
 104 pitem *
 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 *
 140 pqueue_peek(pqueue_s *pq)
 141 {
 142         return pq->items;
 143 }
 144
 145 pitem *
 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 *
 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 *
 170 pqueue_iterator(pqueue_s *pq)
 171 {
 172         return pqueue_peek(pq);
 173 }
 174
 175 pitem *
 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
 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 }