Home | History | Annotate | Download | only in pqueue
      1 /*
      2  * DTLS implementation written by Nagendra Modadugu
      3  * (nagendra (at) cs.stanford.edu) for the OpenSSL project 2005.
      4  */
      5 /* ====================================================================
      6  * Copyright (c) 1999-2005 The OpenSSL Project.  All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  *
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  *
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in
     17  *    the documentation and/or other materials provided with the
     18  *    distribution.
     19  *
     20  * 3. All advertising materials mentioning features or use of this
     21  *    software must display the following acknowledgment:
     22  *    "This product includes software developed by the OpenSSL Project
     23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
     24  *
     25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
     26  *    endorse or promote products derived from this software without
     27  *    prior written permission. For written permission, please contact
     28  *    openssl-core (at) OpenSSL.org.
     29  *
     30  * 5. Products derived from this software may not be called "OpenSSL"
     31  *    nor may "OpenSSL" appear in their names without prior written
     32  *    permission of the OpenSSL Project.
     33  *
     34  * 6. Redistributions of any form whatsoever must retain the following
     35  *    acknowledgment:
     36  *    "This product includes software developed by the OpenSSL Project
     37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
     38  *
     39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
     40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
     43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
     50  * OF THE POSSIBILITY OF SUCH DAMAGE.
     51  * ====================================================================
     52  *
     53  * This product includes cryptographic software written by Eric Young
     54  * (eay (at) cryptsoft.com).  This product includes software written by Tim
     55  * Hudson (tjh (at) cryptsoft.com). */
     56 
     57 #include <openssl/pqueue.h>
     58 
     59 #include <assert.h>
     60 #include <string.h>
     61 
     62 #include <openssl/mem.h>
     63 
     64 
     65 typedef struct _pqueue {
     66   pitem *items;
     67   unsigned count;
     68 } pqueue_s;
     69 
     70 
     71 pitem *pitem_new(uint8_t prio64be[8], void *data) {
     72   pitem *item = (pitem *)OPENSSL_malloc(sizeof(pitem));
     73   if (item == NULL) {
     74     return NULL;
     75   }
     76 
     77   memcpy(item->priority, prio64be, sizeof(item->priority));
     78 
     79   item->data = data;
     80   item->next = NULL;
     81 
     82   return item;
     83 }
     84 
     85 void pitem_free(pitem *item) {
     86   if (item == NULL) {
     87     return;
     88   }
     89 
     90   OPENSSL_free(item);
     91 }
     92 
     93 pqueue pqueue_new(void) {
     94   pqueue_s *pq = (pqueue_s *)OPENSSL_malloc(sizeof(pqueue_s));
     95   if (pq == NULL) {
     96     return NULL;
     97   }
     98 
     99   memset(pq, 0, sizeof(pqueue_s));
    100   return pq;
    101 }
    102 
    103 void pqueue_free(pqueue_s *pq) {
    104   if (pq == NULL) {
    105     return;
    106   }
    107 
    108   /* The queue must be empty. */
    109   assert(pq->items == NULL);
    110   OPENSSL_free(pq);
    111 }
    112 
    113 pitem *pqueue_peek(pqueue_s *pq) { return pq->items; }
    114 
    115 pitem *pqueue_find(pqueue_s *pq, uint8_t *prio64be) {
    116   pitem *curr;
    117 
    118   for (curr = pq->items; curr; curr = curr->next) {
    119     if (memcmp(curr->priority, prio64be, sizeof(curr->priority)) == 0) {
    120       return curr;
    121     }
    122   }
    123 
    124   return NULL;
    125 }
    126 
    127 size_t pqueue_size(pqueue_s *pq) {
    128   pitem *item = pq->items;
    129   size_t count = 0;
    130 
    131   while (item != NULL) {
    132     count++;
    133     item = item->next;
    134   }
    135   return count;
    136 }
    137 
    138 piterator pqueue_iterator(pqueue_s *pq) { return pq->items; }
    139 
    140 pitem *pqueue_next(piterator *item) {
    141   pitem *ret;
    142 
    143   if (item == NULL || *item == NULL) {
    144     return NULL;
    145   }
    146 
    147   ret = *item;
    148   *item = (*item)->next;
    149 
    150   return ret;
    151 }
    152 
    153 pitem *pqueue_insert(pqueue_s *pq, pitem *item) {
    154   pitem *curr, *next;
    155 
    156   if (pq->items == NULL) {
    157     pq->items = item;
    158     return item;
    159   }
    160 
    161   for (curr = NULL, next = pq->items; next != NULL;
    162        curr = next, next = next->next) {
    163     /* we can compare 64-bit value in big-endian encoding with memcmp. */
    164     int cmp = memcmp(next->priority, item->priority, sizeof(item->priority));
    165     if (cmp > 0) {
    166       /* next > item */
    167       item->next = next;
    168 
    169       if (curr == NULL) {
    170         pq->items = item;
    171       } else {
    172         curr->next = item;
    173       }
    174 
    175       return item;
    176     } else if (cmp == 0) {
    177       /* duplicates not allowed */
    178       return NULL;
    179     }
    180   }
    181 
    182   item->next = NULL;
    183   curr->next = item;
    184 
    185   return item;
    186 }
    187 
    188 
    189 pitem *pqueue_pop(pqueue_s *pq) {
    190   pitem *item = pq->items;
    191 
    192   if (pq->items != NULL) {
    193     pq->items = pq->items->next;
    194   }
    195 
    196   return item;
    197 }
    198