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 #ifndef OPENSSL_HEADER_PQUEUE_H 58 #define OPENSSL_HEADER_PQUEUE_H 59 60 #include <openssl/base.h> 61 62 #if defined(__cplusplus) 63 extern "C" { 64 #endif 65 66 67 /* Priority queue. 68 * 69 * The priority queue maintains a linked-list of nodes, each with a unique, 70 * 64-bit priority, in ascending priority order. */ 71 72 typedef struct _pqueue *pqueue; 73 74 typedef struct _pitem { 75 uint8_t priority[8]; /* 64-bit value in big-endian encoding */ 76 void *data; 77 struct _pitem *next; 78 } pitem; 79 80 typedef struct _pitem *piterator; 81 82 83 /* Creating and freeing queues. */ 84 85 /* pqueue_new allocates a fresh, empty priority queue object and returns it, or 86 * NULL on error. */ 87 OPENSSL_EXPORT pqueue pqueue_new(void); 88 89 /* pqueue_free frees |pq| but not any of the items it points to. Thus |pq| must 90 * be empty or a memory leak will occur. */ 91 OPENSSL_EXPORT void pqueue_free(pqueue pq); 92 93 94 /* Creating and freeing items. */ 95 96 /* pitem_new allocates a fresh priority queue item that points at |data| and 97 * has a priority given by |prio64be|, which is a 64-bit, unsigned number 98 * expressed in big-endian form. It returns the fresh item, or NULL on 99 * error. */ 100 OPENSSL_EXPORT pitem *pitem_new(uint8_t prio64be[8], void *data); 101 102 /* pitem_free frees |item|, but not any data that it points to. */ 103 OPENSSL_EXPORT void pitem_free(pitem *item); 104 105 106 /* Queue accessor functions */ 107 108 /* pqueue_peek returns the item with the smallest priority from |pq|, or NULL 109 * if empty. */ 110 OPENSSL_EXPORT pitem *pqueue_peek(pqueue pq); 111 112 /* pqueue_find returns the item whose priority matches |prio64be| or NULL if no 113 * such item exists. */ 114 OPENSSL_EXPORT pitem *pqueue_find(pqueue pq, uint8_t *prio64be); 115 116 117 /* Queue mutation functions */ 118 119 /* pqueue_insert inserts |item| into |pq| and returns item. */ 120 OPENSSL_EXPORT pitem *pqueue_insert(pqueue pq, pitem *item); 121 122 /* pqueue_pop takes the item with the least priority from |pq| and returns it, 123 * or NULL if |pq| is empty. */ 124 OPENSSL_EXPORT pitem *pqueue_pop(pqueue pq); 125 126 /* pqueue_size returns the number of items in |pq|. */ 127 OPENSSL_EXPORT size_t pqueue_size(pqueue pq); 128 129 130 /* Iterating */ 131 132 /* pqueue_iterator returns an iterator that can be used to iterate over the 133 * contents of the queue. */ 134 OPENSSL_EXPORT piterator pqueue_iterator(pqueue pq); 135 136 /* pqueue_next returns the current value of |iter| and advances it to the next 137 * position. If the iterator has advanced over all the elements, it returns 138 * NULL. */ 139 OPENSSL_EXPORT pitem *pqueue_next(piterator *iter); 140 141 142 #if defined(__cplusplus) 143 } /* extern C */ 144 #endif 145 146 #endif /* OPENSSL_HEADER_PQUEUE_H */ 147
