xref: /freebsd/crypto/openssl/ssl/pqueue.c (revision f7c32ed617858bcd22f8d1b03199099d50125721)
1 /*
2  * Copyright 2005-2018 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the OpenSSL license (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 #include "ssl_local.h"
11 #include <openssl/bn.h>
12 
13 struct pqueue_st {
14     pitem *items;
15     int count;
16 };
17 
18 pitem *pitem_new(unsigned char *prio64be, void *data)
19 {
20     pitem *item = OPENSSL_malloc(sizeof(*item));
21 
22     if (item == NULL) {
23         SSLerr(SSL_F_PITEM_NEW, ERR_R_MALLOC_FAILURE);
24         return NULL;
25     }
26 
27     memcpy(item->priority, prio64be, sizeof(item->priority));
28     item->data = data;
29     item->next = NULL;
30     return item;
31 }
32 
33 void pitem_free(pitem *item)
34 {
35     OPENSSL_free(item);
36 }
37 
38 pqueue *pqueue_new(void)
39 {
40     pqueue *pq = OPENSSL_zalloc(sizeof(*pq));
41 
42     if (pq == NULL)
43         SSLerr(SSL_F_PQUEUE_NEW, ERR_R_MALLOC_FAILURE);
44 
45     return pq;
46 }
47 
48 void pqueue_free(pqueue *pq)
49 {
50     OPENSSL_free(pq);
51 }
52 
53 pitem *pqueue_insert(pqueue *pq, pitem *item)
54 {
55     pitem *curr, *next;
56 
57     if (pq->items == NULL) {
58         pq->items = item;
59         return item;
60     }
61 
62     for (curr = NULL, next = pq->items;
63          next != NULL; curr = next, next = next->next) {
64         /*
65          * we can compare 64-bit value in big-endian encoding with memcmp:-)
66          */
67         int cmp = memcmp(next->priority, item->priority, 8);
68         if (cmp > 0) {          /* next > item */
69             item->next = next;
70 
71             if (curr == NULL)
72                 pq->items = item;
73             else
74                 curr->next = item;
75 
76             return item;
77         }
78 
79         else if (cmp == 0)      /* duplicates not allowed */
80             return NULL;
81     }
82 
83     item->next = NULL;
84     curr->next = item;
85 
86     return item;
87 }
88 
89 pitem *pqueue_peek(pqueue *pq)
90 {
91     return pq->items;
92 }
93 
94 pitem *pqueue_pop(pqueue *pq)
95 {
96     pitem *item = pq->items;
97 
98     if (pq->items != NULL)
99         pq->items = pq->items->next;
100 
101     return item;
102 }
103 
104 pitem *pqueue_find(pqueue *pq, unsigned char *prio64be)
105 {
106     pitem *next;
107     pitem *found = NULL;
108 
109     if (pq->items == NULL)
110         return NULL;
111 
112     for (next = pq->items; next->next != NULL; next = next->next) {
113         if (memcmp(next->priority, prio64be, 8) == 0) {
114             found = next;
115             break;
116         }
117     }
118 
119     /* check the one last node */
120     if (memcmp(next->priority, prio64be, 8) == 0)
121         found = next;
122 
123     if (!found)
124         return NULL;
125 
126     return found;
127 }
128 
129 pitem *pqueue_iterator(pqueue *pq)
130 {
131     return pqueue_peek(pq);
132 }
133 
134 pitem *pqueue_next(piterator *item)
135 {
136     pitem *ret;
137 
138     if (item == NULL || *item == NULL)
139         return NULL;
140 
141     /* *item != NULL */
142     ret = *item;
143     *item = (*item)->next;
144 
145     return ret;
146 }
147 
148 size_t pqueue_size(pqueue *pq)
149 {
150     pitem *item = pq->items;
151     size_t count = 0;
152 
153     while (item != NULL) {
154         count++;
155         item = item->next;
156     }
157     return count;
158 }
159