2 * Distributed under the terms of the GNU GPL version 2.
3 * Copyright (c) 2007, 2008 The Board of Trustees of The Leland
4 * Stanford Junior University
11 #include <linux/rcupdate.h>
12 #include <linux/slab.h>
13 #include <linux/list.h>
15 struct sw_table_linear {
19 unsigned int max_flows;
21 struct list_head flows;
22 struct list_head iter_flows;
23 unsigned long int next_serial;
26 static struct sw_flow *table_linear_lookup(struct sw_table *swt,
27 const struct sw_flow_key *key)
29 struct sw_table_linear *tl = (struct sw_table_linear *) swt;
31 list_for_each_entry_rcu (flow, &tl->flows, node) {
32 if (flow_matches(&flow->key, key))
38 static int table_linear_insert(struct sw_table *swt, struct sw_flow *flow)
40 struct sw_table_linear *tl = (struct sw_table_linear *) swt;
41 unsigned long int flags;
45 /* Loop through the existing list of entries. New entries will
46 * always be placed behind those with equal priority. Just replace
47 * any flows that match exactly.
49 spin_lock_irqsave(&tl->lock, flags);
50 list_for_each_entry_rcu (f, &tl->flows, node) {
51 if (f->priority == flow->priority
52 && f->key.wildcards == flow->key.wildcards
53 && flow_matches(&f->key, &flow->key)
55 flow->serial = f->serial;
56 list_replace_rcu(&f->node, &flow->node);
57 list_replace_rcu(&f->iter_node, &flow->iter_node);
58 spin_unlock_irqrestore(&tl->lock, flags);
59 flow_deferred_free(f);
63 if (f->priority < flow->priority)
67 /* Make sure there's room in the table. */
68 if (atomic_read(&tl->n_flows) >= tl->max_flows) {
69 spin_unlock_irqrestore(&tl->lock, flags);
72 atomic_inc(&tl->n_flows);
74 /* Insert the entry immediately in front of where we're pointing. */
75 list_add_tail_rcu(&flow->node, &f->node);
76 list_add_rcu(&flow->iter_node, &tl->iter_flows);
77 spin_unlock_irqrestore(&tl->lock, flags);
81 static int do_delete(struct sw_table *swt, struct sw_flow *flow)
84 list_del_rcu(&flow->node);
85 list_del_rcu(&flow->iter_node);
86 flow_deferred_free(flow);
92 static int table_linear_delete(struct sw_table *swt,
93 const struct sw_flow_key *key, int strict)
95 struct sw_table_linear *tl = (struct sw_table_linear *) swt;
96 struct list_head *pos, *n;
97 unsigned int count = 0;
99 list_for_each_safe_rcu (pos, n, &tl->flows) {
100 struct sw_flow *flow = list_entry(pos, struct sw_flow, node);
101 if (flow_del_matches(&flow->key, key, strict))
102 count += do_delete(swt, flow);
105 atomic_sub(count, &tl->n_flows);
109 static int table_linear_timeout(struct datapath *dp, struct sw_table *swt)
111 struct sw_table_linear *tl = (struct sw_table_linear *) swt;
112 struct list_head *pos, *n;
115 list_for_each_safe_rcu (pos, n, &tl->flows) {
116 struct sw_flow *flow = list_entry(pos, struct sw_flow, node);
117 if (flow_timeout(flow)) {
118 count += do_delete(swt, flow);
119 if (dp->flags & OFPC_SEND_FLOW_EXP)
120 dp_send_flow_expired(dp, flow);
124 atomic_sub(count, &tl->n_flows);
128 static void table_linear_destroy(struct sw_table *swt)
130 struct sw_table_linear *tl = (struct sw_table_linear *) swt;
132 while (!list_empty(&tl->flows)) {
133 struct sw_flow *flow = list_entry(tl->flows.next,
134 struct sw_flow, node);
135 list_del(&flow->node);
141 static int table_linear_iterate(struct sw_table *swt,
142 const struct sw_flow_key *key,
143 struct sw_table_position *position,
144 int (*callback)(struct sw_flow *, void *),
147 struct sw_table_linear *tl = (struct sw_table_linear *) swt;
148 struct sw_flow *flow;
151 start = ~position->private[0];
152 list_for_each_entry_rcu (flow, &tl->iter_flows, iter_node) {
153 if (flow->serial <= start && flow_matches(key, &flow->key)) {
154 int error = callback(flow, private);
156 position->private[0] = ~(flow->serial - 1);
164 static void table_linear_stats(struct sw_table *swt,
165 struct sw_table_stats *stats)
167 struct sw_table_linear *tl = (struct sw_table_linear *) swt;
168 stats->name = "linear";
169 stats->n_flows = atomic_read(&tl->n_flows);
170 stats->max_flows = tl->max_flows;
174 struct sw_table *table_linear_create(unsigned int max_flows)
176 struct sw_table_linear *tl;
177 struct sw_table *swt;
179 tl = kzalloc(sizeof *tl, GFP_KERNEL);
184 swt->lookup = table_linear_lookup;
185 swt->insert = table_linear_insert;
186 swt->delete = table_linear_delete;
187 swt->timeout = table_linear_timeout;
188 swt->destroy = table_linear_destroy;
189 swt->iterate = table_linear_iterate;
190 swt->stats = table_linear_stats;
192 tl->max_flows = max_flows;
193 atomic_set(&tl->n_flows, 0);
194 INIT_LIST_HEAD(&tl->flows);
195 INIT_LIST_HEAD(&tl->iter_flows);
196 spin_lock_init(&tl->lock);