pintos-os.org Git - openvswitch/blob - datapath/table-linear.c

   1 /*
   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
   5  */
   6
   7 #include "table.h"
   8 #include "flow.h"
   9 #include "datapath.h"
  10
  11 #include <linux/rcupdate.h>
  12 #include <linux/slab.h>
  13 #include <linux/list.h>
  14
  15 struct sw_table_linear {
  16         struct sw_table swt;
  17
  18         unsigned int max_flows;
  19         atomic_t n_flows;
  20         struct list_head flows;
  21         struct list_head iter_flows;
  22         unsigned long int next_serial;
  23 };
  24
  25 static struct sw_flow *table_linear_lookup(struct sw_table *swt,
  26                                          const struct sw_flow_key *key)
  27 {
  28         struct sw_table_linear *tl = (struct sw_table_linear *) swt;
  29         struct sw_flow *flow;
  30         list_for_each_entry_rcu (flow, &tl->flows, node) {
  31                 if (flow_matches(&flow->key, key))
  32                         return flow;
  33         }
  34         return NULL;
  35 }
  36
  37 static int table_linear_insert(struct sw_table *swt, struct sw_flow *flow)
  38 {
  39         struct sw_table_linear *tl = (struct sw_table_linear *) swt;
  40         struct sw_flow *f;
  41
  42
  43         /* Loop through the existing list of entries.  New entries will
  44          * always be placed behind those with equal priority.  Just replace
  45          * any flows that match exactly.
  46          */
  47         list_for_each_entry (f, &tl->flows, node) {
  48                 if (f->priority == flow->priority
  49                                 && f->key.wildcards == flow->key.wildcards
  50                                 && flow_matches(&f->key, &flow->key)
  51                                 && flow_del(f)) {
  52                         flow->serial = f->serial;
  53                         list_replace_rcu(&f->node, &flow->node);
  54                         list_replace_rcu(&f->iter_node, &flow->iter_node);
  55                         flow_deferred_free(f);
  56                         return 1;
  57                 }
  58
  59                 if (f->priority < flow->priority)
  60                         break;
  61         }
  62
  63         /* Make sure there's room in the table. */
  64         if (atomic_read(&tl->n_flows) >= tl->max_flows) {
  65                 return 0;
  66         }
  67         atomic_inc(&tl->n_flows);
  68
  69         /* Insert the entry immediately in front of where we're pointing. */
  70         flow->serial = tl->next_serial++;
  71         list_add_tail_rcu(&flow->node, &f->node);
  72         list_add_rcu(&flow->iter_node, &tl->iter_flows);
  73         return 1;
  74 }
  75
  76 static int do_delete(struct sw_table *swt, struct sw_flow *flow)
  77 {
  78         if (flow_del(flow)) {
  79                 list_del_rcu(&flow->node);
  80                 list_del_rcu(&flow->iter_node);
  81                 flow_deferred_free(flow);
  82                 return 1;
  83         }
  84         return 0;
  85 }
  86
  87 static int table_linear_delete(struct sw_table *swt,
  88                                 const struct sw_flow_key *key, uint16_t priority, int strict)
  89 {
  90         struct sw_table_linear *tl = (struct sw_table_linear *) swt;
  91         struct sw_flow *flow;
  92         unsigned int count = 0;
  93
  94         list_for_each_entry (flow, &tl->flows, node) {
  95                 if (flow_del_matches(&flow->key, key, strict)
  96                                 && (!strict || (flow->priority == priority)))
  97                         count += do_delete(swt, flow);
  98         }
  99         if (count)
 100                 atomic_sub(count, &tl->n_flows);
 101         return count;
 102 }
 103
 104 static int table_linear_timeout(struct datapath *dp, struct sw_table *swt)
 105 {
 106         struct sw_table_linear *tl = (struct sw_table_linear *) swt;
 107         struct sw_flow *flow;
 108         int count = 0;
 109
 110         mutex_lock(&dp_mutex);
 111         list_for_each_entry (flow, &tl->flows, node) {
 112                 if (flow_timeout(flow)) {
 113                         count += do_delete(swt, flow);
 114                         if (dp->flags & OFPC_SEND_FLOW_EXP)
 115                                 dp_send_flow_expired(dp, flow);
 116                 }
 117         }
 118         mutex_unlock(&dp_mutex);
 119
 120         if (count)
 121                 atomic_sub(count, &tl->n_flows);
 122         return count;
 123 }
 124
 125 static void table_linear_destroy(struct sw_table *swt)
 126 {
 127         struct sw_table_linear *tl = (struct sw_table_linear *) swt;
 128
 129         while (!list_empty(&tl->flows)) {
 130                 struct sw_flow *flow = list_entry(tl->flows.next,
 131                                                   struct sw_flow, node);
 132                 list_del(&flow->node);
 133                 flow_free(flow);
 134         }
 135         kfree(tl);
 136 }
 137
 138 static int table_linear_iterate(struct sw_table *swt,
 139                                 const struct sw_flow_key *key,
 140                                 struct sw_table_position *position,
 141                                 int (*callback)(struct sw_flow *, void *),
 142                                 void *private)
 143 {
 144         struct sw_table_linear *tl = (struct sw_table_linear *) swt;
 145         struct sw_flow *flow;
 146         unsigned long start;
 147
 148         start = position->private[0];
 149         list_for_each_entry (flow, &tl->iter_flows, iter_node) {
 150                 if (flow->serial >= start && flow_matches(key, &flow->key)) {
 151                         int error = callback(flow, private);
 152                         if (error) {
 153                                 position->private[0] = flow->serial;
 154                                 return error;
 155                         }
 156                 }
 157         }
 158         return 0;
 159 }
 160
 161 static void table_linear_stats(struct sw_table *swt,
 162                                 struct sw_table_stats *stats)
 163 {
 164         struct sw_table_linear *tl = (struct sw_table_linear *) swt;
 165         stats->name = "linear";
 166         stats->n_flows = atomic_read(&tl->n_flows);
 167         stats->max_flows = tl->max_flows;
 168 }
 169
 170
 171 struct sw_table *table_linear_create(unsigned int max_flows)
 172 {
 173         struct sw_table_linear *tl;
 174         struct sw_table *swt;
 175
 176         tl = kzalloc(sizeof *tl, GFP_KERNEL);
 177         if (tl == NULL)
 178                 return NULL;
 179
 180         swt = &tl->swt;
 181         swt->lookup = table_linear_lookup;
 182         swt->insert = table_linear_insert;
 183         swt->delete = table_linear_delete;
 184         swt->timeout = table_linear_timeout;
 185         swt->destroy = table_linear_destroy;
 186         swt->iterate = table_linear_iterate;
 187         swt->stats = table_linear_stats;
 188
 189         tl->max_flows = max_flows;
 190         atomic_set(&tl->n_flows, 0);
 191         INIT_LIST_HEAD(&tl->flows);
 192         INIT_LIST_HEAD(&tl->iter_flows);
 193         tl->next_serial = 0;
 194
 195         return swt;
 196 }