1 /* Copyright (c) 2008 The Board of Trustees of The Leland Stanford
4 * We are making the OpenFlow specification and associated documentation
5 * (Software) available for public use and benefit with the expectation
6 * that others will use, modify and enhance the Software and contribute
7 * those enhancements back to the community. However, since we would
8 * like to make the Software available for broadest use, with as few
9 * restrictions as possible permission is hereby granted, free of
10 * charge, to any person obtaining a copy of this Software to deal in
11 * the Software under the copyrights without restriction, including
12 * without limitation the rights to use, copy, modify, merge, publish,
13 * distribute, sublicense, and/or sell copies of the Software, and to
14 * permit persons to whom the Software is furnished to do so, subject to
15 * the following conditions:
17 * The above copyright notice and this permission notice shall be
18 * included in all copies or substantial portions of the Software.
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
21 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
22 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
23 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
24 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
25 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
26 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
29 * The name and trademarks of copyright holder(s) may NOT be used in
30 * advertising or publicity pertaining to the Software or any
31 * derivatives without specific, written prior permission.
42 struct sw_table_hash {
46 unsigned int bucket_mask; /* Number of buckets minus 1. */
47 struct sw_flow **buckets;
50 static struct sw_flow **find_bucket(struct sw_table *swt,
51 const struct sw_flow_key *key)
53 struct sw_table_hash *th = (struct sw_table_hash *) swt;
54 unsigned int crc = crc32_calculate(&th->crc32, key, sizeof *key);
55 return &th->buckets[crc & th->bucket_mask];
58 static struct sw_flow *table_hash_lookup(struct sw_table *swt,
59 const struct sw_flow_key *key)
61 struct sw_flow *flow = *find_bucket(swt, key);
62 return flow && !memcmp(&flow->key, key, sizeof *key) ? flow : NULL;
65 static int table_hash_insert(struct sw_table *swt, struct sw_flow *flow)
67 struct sw_table_hash *th = (struct sw_table_hash *) swt;
68 struct sw_flow **bucket;
71 if (flow->key.wildcards != 0)
74 bucket = find_bucket(swt, &flow->key);
75 if (*bucket == NULL) {
80 struct sw_flow *old_flow = *bucket;
81 if (!memcmp(&old_flow->key, &flow->key, sizeof flow->key)) {
92 /* Caller must update n_flows. */
94 do_delete(struct sw_flow **bucket)
100 /* Returns number of deleted flows. We can igonre the priority
101 * argument, since all exact-match entries are the same (highest)
103 static int table_hash_delete(struct sw_table *swt,
104 const struct sw_flow_key *key,
105 uint16_t priority, int strict)
107 struct sw_table_hash *th = (struct sw_table_hash *) swt;
108 unsigned int count = 0;
110 if (key->wildcards == 0) {
111 struct sw_flow **bucket = find_bucket(swt, key);
112 struct sw_flow *flow = *bucket;
113 if (flow && !memcmp(&flow->key, key, sizeof *key)) {
120 for (i = 0; i <= th->bucket_mask; i++) {
121 struct sw_flow **bucket = &th->buckets[i];
122 struct sw_flow *flow = *bucket;
123 if (flow && flow_del_matches(&flow->key, key, strict)) {
129 th->n_flows -= count;
133 static void table_hash_timeout(struct sw_table *swt, struct list *deleted)
135 struct sw_table_hash *th = (struct sw_table_hash *) swt;
138 for (i = 0; i <= th->bucket_mask; i++) {
139 struct sw_flow **bucket = &th->buckets[i];
140 struct sw_flow *flow = *bucket;
141 if (flow && flow_timeout(flow)) {
142 list_push_back(deleted, &flow->node);
149 static void table_hash_destroy(struct sw_table *swt)
151 struct sw_table_hash *th = (struct sw_table_hash *) swt;
153 for (i = 0; i <= th->bucket_mask; i++) {
154 if (th->buckets[i]) {
155 flow_free(th->buckets[i]);
162 static int table_hash_iterate(struct sw_table *swt,
163 const struct sw_flow_key *key,
164 struct sw_table_position *position,
165 int (*callback)(struct sw_flow *, void *private),
168 struct sw_table_hash *th = (struct sw_table_hash *) swt;
170 if (position->private[0] > th->bucket_mask)
173 if (key->wildcards == 0) {
174 struct sw_flow *flow = table_hash_lookup(swt, key);
175 position->private[0] = -1;
176 return flow ? callback(flow, private) : 0;
180 for (i = position->private[0]; i <= th->bucket_mask; i++) {
181 struct sw_flow *flow = th->buckets[i];
182 if (flow && flow_matches(key, &flow->key)) {
183 int error = callback(flow, private);
185 position->private[0] = i + 1;
194 static void table_hash_stats(struct sw_table *swt,
195 struct sw_table_stats *stats)
197 struct sw_table_hash *th = (struct sw_table_hash *) swt;
198 stats->name = "hash";
199 stats->n_flows = th->n_flows;
200 stats->max_flows = th->bucket_mask + 1;
203 struct sw_table *table_hash_create(unsigned int polynomial,
204 unsigned int n_buckets)
206 struct sw_table_hash *th;
207 struct sw_table *swt;
209 th = malloc(sizeof *th);
213 assert(!(n_buckets & (n_buckets - 1)));
214 th->buckets = calloc(n_buckets, sizeof *th->buckets);
215 if (th->buckets == NULL) {
216 printf("failed to allocate %u buckets\n", n_buckets);
221 th->bucket_mask = n_buckets - 1;
224 swt->lookup = table_hash_lookup;
225 swt->insert = table_hash_insert;
226 swt->delete = table_hash_delete;
227 swt->timeout = table_hash_timeout;
228 swt->destroy = table_hash_destroy;
229 swt->iterate = table_hash_iterate;
230 swt->stats = table_hash_stats;
232 crc32_init(&th->crc32, polynomial);
237 /* Double-hashing table. */
239 struct sw_table_hash2 {
241 struct sw_table *subtable[2];
244 static struct sw_flow *table_hash2_lookup(struct sw_table *swt,
245 const struct sw_flow_key *key)
247 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
250 for (i = 0; i < 2; i++) {
251 struct sw_flow *flow = *find_bucket(t2->subtable[i], key);
252 if (flow && !memcmp(&flow->key, key, sizeof *key))
258 static int table_hash2_insert(struct sw_table *swt, struct sw_flow *flow)
260 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
262 if (table_hash_insert(t2->subtable[0], flow))
264 return table_hash_insert(t2->subtable[1], flow);
267 static int table_hash2_delete(struct sw_table *swt,
268 const struct sw_flow_key *key,
269 uint16_t priority, int strict)
271 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
272 return (table_hash_delete(t2->subtable[0], key, priority, strict)
273 + table_hash_delete(t2->subtable[1], key, priority, strict));
276 static void table_hash2_timeout(struct sw_table *swt, struct list *deleted)
278 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
279 table_hash_timeout(t2->subtable[0], deleted);
280 table_hash_timeout(t2->subtable[1], deleted);
283 static void table_hash2_destroy(struct sw_table *swt)
285 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
286 table_hash_destroy(t2->subtable[0]);
287 table_hash_destroy(t2->subtable[1]);
291 static int table_hash2_iterate(struct sw_table *swt,
292 const struct sw_flow_key *key,
293 struct sw_table_position *position,
294 int (*callback)(struct sw_flow *, void *),
297 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
300 for (i = position->private[1]; i < 2; i++) {
301 int error = table_hash_iterate(t2->subtable[i], key, position,
306 position->private[0] = 0;
307 position->private[1]++;
312 static void table_hash2_stats(struct sw_table *swt,
313 struct sw_table_stats *stats)
315 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
316 struct sw_table_stats substats[2];
319 for (i = 0; i < 2; i++)
320 table_hash_stats(t2->subtable[i], &substats[i]);
321 stats->name = "hash2";
322 stats->n_flows = substats[0].n_flows + substats[1].n_flows;
323 stats->max_flows = substats[0].max_flows + substats[1].max_flows;
326 struct sw_table *table_hash2_create(unsigned int poly0, unsigned int buckets0,
327 unsigned int poly1, unsigned int buckets1)
330 struct sw_table_hash2 *t2;
331 struct sw_table *swt;
333 t2 = malloc(sizeof *t2);
337 t2->subtable[0] = table_hash_create(poly0, buckets0);
338 if (t2->subtable[0] == NULL)
341 t2->subtable[1] = table_hash_create(poly1, buckets1);
342 if (t2->subtable[1] == NULL)
343 goto out_free_subtable0;
346 swt->lookup = table_hash2_lookup;
347 swt->insert = table_hash2_insert;
348 swt->delete = table_hash2_delete;
349 swt->timeout = table_hash2_timeout;
350 swt->destroy = table_hash2_destroy;
351 swt->iterate = table_hash2_iterate;
352 swt->stats = table_hash2_stats;
357 table_hash_destroy(t2->subtable[0]);