+
+#include <linux/module.h>
+#include <linux/rcupdate.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/delay.h>
+#include <linux/if_arp.h>
+
+#include "chain.h"
+#include "table.h"
+#include "flow.h"
+#include "datapath.h"
+
+
+/* Max number of flow entries supported by the hardware */
+#define DUMMY_MAX_FLOW 8192
+
+
+/* xxx Explain need for this separate list because of RCU */
+static spinlock_t pending_free_lock;
+static struct list_head pending_free_list;
+
+/* sw_flow private data for dummy table entries. */
+struct sw_flow_dummy {
+ struct list_head node;
+
+ /* xxx If per-entry data is needed, define it here. */
+};
+
+struct sw_table_dummy {
+ struct sw_table swt;
+
+ spinlock_t lock;
+ unsigned int max_flows;
+ atomic_t n_flows;
+ struct list_head flows;
+ struct list_head iter_flows;
+ unsigned long int next_serial;
+};
+
+
+static void table_dummy_sfw_destroy(struct sw_flow_dummy *sfw)
+{
+ /* xxx Remove the entry from hardware. If you need to do any other
+ * xxx clean-up associated with the entry, do it here.
+ */
+
+ kfree(sfw);
+}
+
+static void table_dummy_rcu_callback(struct rcu_head *rcu)
+{
+ struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
+
+ spin_lock(&pending_free_lock);
+ if (flow->private) {
+ struct sw_flow_dummy *sfw = flow->private;
+ list_add(&sfw->node, &pending_free_list);
+ flow->private = NULL;
+ }
+ spin_unlock(&pending_free_lock);
+ flow_free(flow);
+}
+
+static void table_dummy_flow_deferred_free(struct sw_flow *flow)
+{
+ call_rcu(&flow->rcu, table_dummy_rcu_callback);
+}
+
+static struct sw_flow *table_dummy_lookup(struct sw_table *swt,
+ const struct sw_flow_key *key)
+{
+ struct sw_table_dummy *td = (struct sw_table_dummy *) swt;
+ struct sw_flow *flow;
+ list_for_each_entry (flow, &td->flows, node) {
+ if (flow_matches(&flow->key, key)) {
+ printk("found!\n");
+ return flow;
+ }
+ }
+ return NULL;
+}
+
+static int table_dummy_insert(struct sw_table *swt, struct sw_flow *flow)
+{
+ /* xxx Use a data cache? */
+ flow->private = kzalloc(sizeof(struct sw_flow_dummy), GFP_ATOMIC);
+ if (flow->private == NULL)
+ return 0;
+
+ /* xxx Do whatever needs to be done to insert an entry in hardware.
+ * xxx If the entry can't be inserted, return 0. This stub code
+ * xxx doesn't do anything yet, so we're going to return 0...you
+ * xxx shouldn't.
+ */
+ kfree(flow->private);
+ return 0;
+}
+
+
+static int do_delete(struct sw_table *swt, struct sw_flow *flow)
+{
+ if (flow_del(flow)) {
+ list_del_rcu(&flow->node);
+ table_dummy_flow_deferred_free(flow);
+ return 1;
+ }
+ return 0;
+}
+
+static int table_dummy_delete(struct sw_table *swt,
+ const struct sw_flow_key *key, uint16_t priority, int strict)
+{
+ struct sw_table_dummy *td = (struct sw_table_dummy *) swt;
+ struct sw_flow *flow;
+ unsigned int count = 0;
+
+ list_for_each_entry_rcu (flow, &td->flows, node) {
+ if (flow_del_matches(&flow->key, key, strict)
+ && (!strict || (flow->priority == priority)))
+ count += do_delete(swt, flow);
+ }
+ if (count)
+ atomic_sub(count, &td->n_flows);
+ return count;
+}
+
+
+static int table_dummy_timeout(struct datapath *dp, struct sw_table *swt)
+{
+ struct sw_table_dummy *td = (struct sw_table_dummy *) swt;
+ struct sw_flow *flow;
+ struct sw_flow_dummy *sfw, *n;
+ int del_count = 0;
+ uint64_t packet_count = 0;
+ int i=0;
+
+ list_for_each_entry_rcu (flow, &td->flows, node) {
+ /* xxx Retrieve the packet count associated with this entry
+ * xxx and store it in "packet_count".
+ */
+
+ if ((packet_count > flow->packet_count)
+ && (flow->max_idle != OFP_FLOW_PERMANENT)) {
+ flow->packet_count = packet_count;
+ flow->timeout = jiffies + HZ * flow->max_idle;
+ }
+
+ if (flow_timeout(flow)) {
+ if (dp->flags & OFPC_SEND_FLOW_EXP) {
+ /* xxx Get byte count */
+ flow->byte_count = 0;
+ dp_send_flow_expired(dp, flow);
+ }
+ del_count += do_delete(swt, flow);
+ }
+ if ((i % 50) == 0) {
+ msleep_interruptible(1);
+ }
+ i++;
+ }
+
+ /* Remove any entries queued for removal */
+ spin_lock_bh(&pending_free_lock);
+ list_for_each_entry_safe (sfw, n, &pending_free_list, node) {
+ list_del(&sfw->node);
+ table_dummy_sfw_destroy(sfw);
+ }
+ spin_unlock_bh(&pending_free_lock);
+
+ if (del_count)
+ atomic_sub(del_count, &td->n_flows);
+ return del_count;
+}
+
+
+static void table_dummy_destroy(struct sw_table *swt)
+{
+ struct sw_table_dummy *td = (struct sw_table_dummy *)swt;
+
+
+ /* xxx This table is being destroyed, so free any data that you
+ * xxx don't want to leak.
+ */
+
+
+ if (td) {
+ while (!list_empty(&td->flows)) {
+ struct sw_flow *flow = list_entry(td->flows.next,
+ struct sw_flow, node);
+ list_del(&flow->node);
+ flow_free(flow);
+ }
+ kfree(td);
+ }
+}
+
+static int table_dummy_iterate(struct sw_table *swt,
+ const struct sw_flow_key *key,
+ struct sw_table_position *position,
+ int (*callback)(struct sw_flow *, void *),
+ void *private)
+{
+ struct sw_table_dummy *tl = (struct sw_table_dummy *) swt;
+ struct sw_flow *flow;
+ unsigned long start;
+
+ start = ~position->private[0];
+ list_for_each_entry_rcu (flow, &tl->iter_flows, iter_node) {
+ if (flow->serial <= start && flow_matches(key, &flow->key)) {
+ int error = callback(flow, private);
+ if (error) {
+ position->private[0] = ~flow->serial;
+ return error;
+ }
+ }
+ }
+ return 0;
+}
+
+static void table_dummy_stats(struct sw_table *swt,
+ struct sw_table_stats *stats)
+{
+ struct sw_table_dummy *td = (struct sw_table_dummy *) swt;
+ stats->name = "dummy";
+ stats->n_flows = atomic_read(&td->n_flows);
+ stats->max_flows = td->max_flows;
+}
+
+
+static struct sw_table *table_dummy_create(void)
+{
+ struct sw_table_dummy *td;
+ struct sw_table *swt;
+
+ td = kzalloc(sizeof *td, GFP_KERNEL);
+ if (td == NULL)
+ return NULL;
+
+ swt = &td->swt;
+ swt->lookup = table_dummy_lookup;
+ swt->insert = table_dummy_insert;
+ swt->delete = table_dummy_delete;
+ swt->timeout = table_dummy_timeout;
+ swt->destroy = table_dummy_destroy;
+ swt->iterate = table_dummy_iterate;
+ swt->stats = table_dummy_stats;
+
+ td->max_flows = DUMMY_MAX_FLOW;
+ atomic_set(&td->n_flows, 0);
+ INIT_LIST_HEAD(&td->flows);
+ spin_lock_init(&td->lock);
+
+ INIT_LIST_HEAD(&pending_free_list);
+ spin_lock_init(&pending_free_lock);
+
+ return swt;
+}
+
+static int __init dummy_init(void)
+{
+ return chain_set_hw_hook(table_dummy_create, THIS_MODULE);
+}
+module_init(dummy_init);
+
+static void dummy_cleanup(void)
+{
+ chain_clear_hw_hook();
+}
+module_exit(dummy_cleanup);
+
+MODULE_DESCRIPTION("Dummy hardware table driver");
+MODULE_AUTHOR("Copyright (c) 2007, 2008 The Board of Trustees of The Leland Stanford Junior University");
+MODULE_LICENSE("GPL");