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.
34 #include <linux/module.h>
35 #include <linux/rcupdate.h>
36 #include <linux/slab.h>
37 #include <linux/list.h>
38 #include <linux/delay.h>
39 #include <linux/if_arp.h>
47 /* Max number of flow entries supported by the hardware */
48 #define DUMMY_MAX_FLOW 8192
51 /* xxx Explain need for this separate list because of RCU */
52 static spinlock_t pending_free_lock;
53 static struct list_head pending_free_list;
55 /* sw_flow private data for dummy table entries. */
56 struct sw_flow_dummy {
57 struct list_head node;
59 /* xxx If per-entry data is needed, define it here. */
62 struct sw_table_dummy {
65 unsigned int max_flows;
67 struct list_head flows;
68 struct list_head iter_flows;
69 unsigned long int next_serial;
73 static void table_dummy_sfw_destroy(struct sw_flow_dummy *sfw)
75 /* xxx Remove the entry from hardware. If you need to do any other
76 * xxx clean-up associated with the entry, do it here.
82 static void table_dummy_rcu_callback(struct rcu_head *rcu)
84 struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
86 spin_lock(&pending_free_lock);
88 struct sw_flow_dummy *sfw = flow->private;
89 list_add(&sfw->node, &pending_free_list);
92 spin_unlock(&pending_free_lock);
96 static void table_dummy_flow_deferred_free(struct sw_flow *flow)
98 call_rcu(&flow->rcu, table_dummy_rcu_callback);
101 static struct sw_flow *table_dummy_lookup(struct sw_table *swt,
102 const struct sw_flow_key *key)
104 struct sw_table_dummy *td = (struct sw_table_dummy *) swt;
105 struct sw_flow *flow;
106 list_for_each_entry (flow, &td->flows, node) {
107 if (flow_matches(&flow->key, key)) {
114 static int table_dummy_insert(struct sw_table *swt, struct sw_flow *flow)
116 /* xxx Use a data cache? */
117 flow->private = kzalloc(sizeof(struct sw_flow_dummy), GFP_ATOMIC);
118 if (flow->private == NULL)
121 /* xxx Do whatever needs to be done to insert an entry in hardware.
122 * xxx If the entry can't be inserted, return 0. This stub code
123 * xxx doesn't do anything yet, so we're going to return 0...you
126 kfree(flow->private);
131 static int do_delete(struct sw_table *swt, struct sw_flow *flow)
133 if (flow_del(flow)) {
134 list_del_rcu(&flow->node);
135 list_del_rcu(&flow->iter_node);
136 table_dummy_flow_deferred_free(flow);
142 static int table_dummy_delete(struct sw_table *swt,
143 const struct sw_flow_key *key, uint16_t priority, int strict)
145 struct sw_table_dummy *td = (struct sw_table_dummy *) swt;
146 struct sw_flow *flow;
147 unsigned int count = 0;
149 list_for_each_entry (flow, &td->flows, node) {
150 if (flow_del_matches(&flow->key, key, strict)
151 && (!strict || (flow->priority == priority)))
152 count += do_delete(swt, flow);
154 td->n_flows -= count;
159 static int table_dummy_timeout(struct datapath *dp, struct sw_table *swt)
161 struct sw_table_dummy *td = (struct sw_table_dummy *) swt;
162 struct sw_flow *flow;
163 struct sw_flow_dummy *sfw, *n;
165 uint64_t packet_count = 0;
168 mutex_lock(&dp_mutex);
169 list_for_each_entry (flow, &td->flows, node) {
170 /* xxx Retrieve the packet count associated with this entry
171 * xxx and store it in "packet_count".
174 if ((packet_count > flow->packet_count)
175 && (flow->max_idle != OFP_FLOW_PERMANENT)) {
176 flow->packet_count = packet_count;
177 flow->timeout = jiffies + HZ * flow->max_idle;
180 if (flow_timeout(flow)) {
181 if (dp->flags & OFPC_SEND_FLOW_EXP) {
182 /* xxx Get byte count */
183 flow->byte_count = 0;
184 dp_send_flow_expired(dp, flow);
186 del_count += do_delete(swt, flow);
189 msleep_interruptible(1);
194 /* Remove any entries queued for removal */
195 spin_lock_bh(&pending_free_lock);
196 list_for_each_entry_safe (sfw, n, &pending_free_list, node) {
197 list_del(&sfw->node);
198 table_dummy_sfw_destroy(sfw);
200 spin_unlock_bh(&pending_free_lock);
201 mutex_unlock(&dp_mutex);
203 td->n_flows -= del_count;
208 static void table_dummy_destroy(struct sw_table *swt)
210 struct sw_table_dummy *td = (struct sw_table_dummy *)swt;
213 /* xxx This table is being destroyed, so free any data that you
214 * xxx don't want to leak.
219 while (!list_empty(&td->flows)) {
220 struct sw_flow *flow = list_entry(td->flows.next,
221 struct sw_flow, node);
222 list_del(&flow->node);
229 static int table_dummy_iterate(struct sw_table *swt,
230 const struct sw_flow_key *key,
231 struct sw_table_position *position,
232 int (*callback)(struct sw_flow *, void *),
235 struct sw_table_dummy *tl = (struct sw_table_dummy *) swt;
236 struct sw_flow *flow;
239 start = ~position->private[0];
240 list_for_each_entry (flow, &tl->iter_flows, iter_node) {
241 if (flow->serial <= start && flow_matches(key, &flow->key)) {
242 int error = callback(flow, private);
244 position->private[0] = ~flow->serial;
252 static void table_dummy_stats(struct sw_table *swt,
253 struct sw_table_stats *stats)
255 struct sw_table_dummy *td = (struct sw_table_dummy *) swt;
256 stats->name = "dummy";
257 stats->n_flows = td->n_flows;
258 stats->max_flows = td->max_flows;
262 static struct sw_table *table_dummy_create(void)
264 struct sw_table_dummy *td;
265 struct sw_table *swt;
267 td = kzalloc(sizeof *td, GFP_KERNEL);
272 swt->lookup = table_dummy_lookup;
273 swt->insert = table_dummy_insert;
274 swt->delete = table_dummy_delete;
275 swt->timeout = table_dummy_timeout;
276 swt->destroy = table_dummy_destroy;
277 swt->iterate = table_dummy_iterate;
278 swt->stats = table_dummy_stats;
280 td->max_flows = DUMMY_MAX_FLOW;
282 INIT_LIST_HEAD(&td->flows);
283 INIT_LIST_HEAD(&td->iter_flows);
286 INIT_LIST_HEAD(&pending_free_list);
287 spin_lock_init(&pending_free_lock);
292 static int __init dummy_init(void)
294 return chain_set_hw_hook(table_dummy_create, THIS_MODULE);
296 module_init(dummy_init);
298 static void dummy_cleanup(void)
300 chain_clear_hw_hook();
302 module_exit(dummy_cleanup);
304 MODULE_DESCRIPTION("Dummy hardware table driver");
305 MODULE_AUTHOR("Copyright (c) 2008 The Board of Trustees of The Leland Stanford Junior University");
306 MODULE_LICENSE("Stanford License");