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
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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
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24 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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38 #include "switch-flow.h"
41 #define THIS_MODULE VLM_chain
44 /* Set of tables chained together in sequence from cheap to expensive. */
45 #define CHAIN_MAX_TABLES 4
48 struct sw_table *tables[CHAIN_MAX_TABLES];
51 /* Attempts to append 'table' to the set of tables in 'chain'. Returns 0 or
52 * negative error. If 'table' is null it is assumed that table creation failed
53 * due to out-of-memory. */
54 static int add_table(struct sw_chain *chain, struct sw_table *table)
58 if (chain->n_tables >= CHAIN_MAX_TABLES) {
59 VLOG_ERR("too many tables in chain\n");
60 table->destroy(table);
63 chain->tables[chain->n_tables++] = table;
67 /* Creates and returns a new chain. Returns NULL if the chain cannot be
69 struct sw_chain *chain_create(void)
71 struct sw_chain *chain = calloc(1, sizeof *chain);
75 if (add_table(chain, table_mac_create(TABLE_MAC_NUM_BUCKETS,
77 || add_table(chain, table_hash2_create(0x1EDC6F41, TABLE_HASH_MAX_FLOWS,
78 0x741B8CD7, TABLE_HASH_MAX_FLOWS))
79 || add_table(chain, table_linear_create(TABLE_LINEAR_MAX_FLOWS))) {
87 /* Searches 'chain' for a flow matching 'key', which must not have any wildcard
88 * fields. Returns the flow if successful, otherwise a null pointer. */
90 chain_lookup(struct sw_chain *chain, const struct sw_flow_key *key)
94 assert(!key->wildcards);
95 for (i = 0; i < chain->n_tables; i++) {
96 struct sw_table *t = chain->tables[i];
97 struct sw_flow *flow = t->lookup(t, key);
104 /* Inserts 'flow' into 'chain', replacing any duplicate flow. Returns 0 if
105 * successful or a negative error.
107 * If successful, 'flow' becomes owned by the chain, otherwise it is retained
110 chain_insert(struct sw_chain *chain, struct sw_flow *flow)
114 for (i = 0; i < chain->n_tables; i++) {
115 struct sw_table *t = chain->tables[i];
116 if (t->insert(t, flow))
123 /* Deletes from 'chain' any and all flows that match 'key'. Returns the number
124 * of flows that were deleted.
126 * Expensive in the general case as currently implemented, since it requires
127 * iterating through the entire contents of each table for keys that contain
128 * wildcards. Relatively cheap for fully specified keys. */
130 chain_delete(struct sw_chain *chain, const struct sw_flow_key *key, int strict)
135 for (i = 0; i < chain->n_tables; i++) {
136 struct sw_table *t = chain->tables[i];
137 count += t->delete(t, key, strict);
144 /* Deletes timed-out flow entries from all the tables in 'chain' and appends
145 * the deleted flows to 'deleted'.
147 * Expensive as currently implemented, since it iterates through the entire
148 * contents of each table. */
150 chain_timeout(struct sw_chain *chain, struct list *deleted)
154 for (i = 0; i < chain->n_tables; i++) {
155 struct sw_table *t = chain->tables[i];
156 t->timeout(t, deleted);
160 /* Destroys 'chain', which must not have any users. */
162 chain_destroy(struct sw_chain *chain)
166 for (i = 0; i < chain->n_tables; i++) {
167 struct sw_table *t = chain->tables[i];
173 /* Prints statistics for each of the tables in 'chain'. */
175 chain_print_stats(struct sw_chain *chain)
180 for (i = 0; i < chain->n_tables; i++) {
181 struct sw_table *t = chain->tables[i];
182 struct sw_table_stats stats;
184 printf("%s: %lu/%lu flows\n",
185 stats.name, stats.n_flows, stats.max_flows);