1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2020 Alexander V. Chernikov
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #ifndef _NET_ROUTE_NHOP_UTILS_H_
29 #define _NET_ROUTE_NHOP_UTILS_H_
30
31 /* Chained hash table */
32 struct _cht_head {
33 uint32_t hash_size;
34 uint32_t items_count;
35 void **ptr;
36 };
37
38 static inline uint32_t
_cht_get_resize_size(const struct _cht_head * head)39 _cht_get_resize_size(const struct _cht_head *head)
40 {
41 uint32_t new_size = 0;
42
43 if ((head->items_count * 2 > head->hash_size) && (head->hash_size < 65536))
44 new_size = head->hash_size * 2;
45 else if ((head->items_count * 4 < head->hash_size) && head->hash_size > 16)
46 new_size = head->hash_size / 2;
47
48 return (new_size);
49 }
50
51 static inline int
_cht_need_resize(const struct _cht_head * head)52 _cht_need_resize(const struct _cht_head *head)
53 {
54
55 return (_cht_get_resize_size(head) > 0);
56 }
57
58 #ifndef typeof
59 #define typeof __typeof
60 #endif
61
62 #define CHT_SLIST_NEED_RESIZE(_head) \
63 _cht_need_resize((const struct _cht_head *)(_head))
64 #define CHT_SLIST_GET_RESIZE_BUCKETS(_head) \
65 _cht_get_resize_size((const struct _cht_head *)(_head))
66 #define CHT_SLIST_GET_RESIZE_SIZE(_buckets) ((_buckets) * sizeof(void *))
67
68 #define CHT_SLIST_DEFINE(_HNAME, _ITEM_TYPE) \
69 struct _HNAME##_head { \
70 uint32_t hash_size; \
71 uint32_t items_count; \
72 _ITEM_TYPE **ptr; \
73 }
74
75 #define CHT_SLIST_INIT(_head, _ptr, _num_buckets) \
76 (_head)->hash_size = _num_buckets; \
77 (_head)->items_count = 0; \
78 (_head)->ptr = _ptr;
79
80 /* Default hash method for constant-size keys */
81
82 #define CHT_GET_BUCK(_head, _PX, _key) _PX##_hash_key(_key) & ((_head)->hash_size - 1)
83 #define CHT_GET_BUCK_OBJ(_head, _PX, _obj) _PX##_hash_obj(_obj) & ((_head)->hash_size - 1)
84
85 #define CHT_FIRST(_head, idx) _CHT_FIRST((_head)->ptr, idx)
86 #define _CHT_FIRST(_ptr, idx) (_ptr)[idx]
87
88 #define CHT_SLIST_FIND(_head, _PX, _key, _ret) do { \
89 uint32_t _buck = CHT_GET_BUCK(_head, _PX, _key); \
90 _ret = CHT_FIRST(_head, _buck); \
91 for ( ; _ret != NULL; _ret = _PX##_next(_ret)) { \
92 if (_PX##_cmp(_key, (_ret))) \
93 break; \
94 } \
95 } while(0)
96
97 /*
98 * hash_obj, nhop_cmp
99 */
100 #define CHT_SLIST_FIND_BYOBJ(_head, _PX, _obj, _ret) do { \
101 uint32_t _buck = CHT_GET_BUCK_OBJ(_head, _PX, _obj); \
102 _ret = CHT_FIRST(_head, _buck); \
103 for ( ; _ret != NULL; _ret = _PX##_next(_ret)) { \
104 if (_PX##_cmp(_obj, _ret)) \
105 break; \
106 } \
107 } while(0)
108
109 #define CHT_SLIST_INSERT_HEAD(_head, _PX, _obj) do { \
110 uint32_t _buck = CHT_GET_BUCK_OBJ(_head, _PX, _obj); \
111 _PX##_next(_obj) = CHT_FIRST(_head, _buck); \
112 CHT_FIRST(_head, _buck) = _obj; \
113 (_head)->items_count++; \
114 } while(0)
115
116 #define CHT_SLIST_REMOVE(_head, _PX, _obj, _ret) do { \
117 typeof(*(_head)->ptr) _tmp; \
118 uint32_t _buck = CHT_GET_BUCK_OBJ(_head, _PX, _obj); \
119 _ret = CHT_FIRST(_head, _buck); \
120 _tmp = NULL; \
121 for ( ; _ret != NULL; _tmp = _ret, _ret = _PX##_next(_ret)) { \
122 if (_obj == _ret) \
123 break; \
124 } \
125 if (_ret != NULL) { \
126 if (_tmp == NULL) \
127 CHT_FIRST(_head, _buck) = _PX##_next(_ret); \
128 else \
129 _PX##_next(_tmp) = _PX##_next(_ret); \
130 (_head)->items_count--; \
131 } \
132 } while(0)
133 #define CHT_SLIST_REMOVE_BYOBJ CHT_SLIST_REMOVE
134
135 #define CHT_SLIST_FOREACH(_head, _PX, _x) \
136 for (uint32_t _i = 0; _i < (_head)->hash_size; _i++) { \
137 for (_x = CHT_FIRST(_head, _i); _x; _x = _PX##_next(_x))
138 #define CHT_SLIST_FOREACH_END }
139
140 #define CHT_SLIST_FOREACH_SAFE(_head, _PX, _x, _tmp) \
141 for (uint32_t _i = 0; _i < (_head)->hash_size; _i++) { \
142 for (_x = CHT_FIRST(_head, _i); (_tmp = _PX##_next(_x), _x); _x = _tmp)
143 #define CHT_SLIST_FOREACH_SAFE_END }
144
145 #define CHT_SLIST_RESIZE(_head, _PX, _new_void_ptr, _new_hsize) \
146 uint32_t _new_idx; \
147 typeof((_head)->ptr) _new_ptr = (void *)_new_void_ptr; \
148 typeof(*(_head)->ptr) _x, _y; \
149 for (uint32_t _old_idx = 0; _old_idx < (_head)->hash_size; _old_idx++) {\
150 _x = CHT_FIRST(_head, _old_idx); \
151 _y = _x; \
152 while (_y != NULL) { \
153 _y = _PX##_next(_x); \
154 _new_idx = _PX##_hash_obj(_x) & (_new_hsize - 1);\
155 _PX##_next(_x) = _CHT_FIRST(_new_ptr, _new_idx);\
156 _CHT_FIRST(_new_ptr, _new_idx) = _x; \
157 _x = _y; \
158 } \
159 } \
160 (_head)->hash_size = _new_hsize; \
161 _new_void_ptr = (void *)(_head)->ptr; \
162 (_head)->ptr = _new_ptr;
163
164 /* bitmasks */
165
166 struct bitmask_head {
167 uint16_t free_off; /* index of the first potentially free block */
168 uint16_t blocks; /* number of 4/8-byte blocks in the index */
169 uint32_t items_count; /* total number of items */
170 u_long *idx;
171 };
172
173 size_t bitmask_get_size(uint32_t items);
174 uint32_t bitmask_get_resize_items(const struct bitmask_head *nh);
175 int bitmask_should_resize(const struct bitmask_head *bh);
176 void bitmask_swap(struct bitmask_head *bh, void *new_idx, uint32_t new_items, void **pidx);
177 void bitmask_init(struct bitmask_head *bh, void *idx, uint32_t num_items);
178 int bitmask_copy(const struct bitmask_head *bi, void *new_idx, uint32_t new_items);
179 int bitmask_alloc_idx(struct bitmask_head *bi, uint16_t *pidx);
180 int bitmask_free_idx(struct bitmask_head *bi, uint16_t idx);
181
182 #endif
183