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/rculist.h>
  14
  15 struct sw_table_linear {
  16         struct sw_table swt;
  17
  18         unsigned int max_flows;
  19         unsigned int 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_1wild(key, &flow->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_2wild(&f->key, &flow->key)) {
  51                         /* Keep stats from the original flow */
  52                         flow->init_time = f->init_time;
  53                         flow->packet_count = f->packet_count;
  54                         flow->byte_count = f->byte_count;
  55
  56                         flow->serial = f->serial;
  57                         list_replace_rcu(&f->node, &flow->node);
  58                         list_replace_rcu(&f->iter_node, &flow->iter_node);
  59                         flow_deferred_free(f);
  60                         return 1;
  61                 }
  62
  63                 if (f->priority < flow->priority)
  64                         break;
  65         }
  66
  67         /* Make sure there's room in the table. */
  68         if (tl->n_flows >= tl->max_flows) {
  69                 return 0;
  70         }
  71         tl->n_flows++;
  72
  73         /* Insert the entry immediately in front of where we're pointing. */
  74         flow->serial = tl->next_serial++;
  75         list_add_tail_rcu(&flow->node, &f->node);
  76         list_add_rcu(&flow->iter_node, &tl->iter_flows);
  77         return 1;
  78 }
  79
  80 static int table_linear_modify(struct sw_table *swt,
  81                                 const struct sw_flow_key *key,
  82                                 const struct ofp_action *actions, int n_actions)
  83 {
  84         struct sw_table_linear *tl = (struct sw_table_linear *) swt;
  85         struct sw_flow *flow;
  86         unsigned int count = 0;
  87
  88         list_for_each_entry (flow, &tl->flows, node) {
  89                 if (flow_matches_1wild(&flow->key, key)) {
  90                         flow_replace_acts(flow, actions, n_actions);
  91                         count++;
  92                 }
  93         }
  94         return count;
  95 }
  96
  97 static int do_delete(struct sw_table *swt, struct sw_flow *flow)
  98 {
  99         list_del_rcu(&flow->node);
 100         list_del_rcu(&flow->iter_node);
 101         flow_deferred_free(flow);
 102         return 1;
 103 }
 104
 105 static int table_linear_delete(struct sw_table *swt,
 106                                 const struct sw_flow_key *key, uint16_t priority, int strict)
 107 {
 108         struct sw_table_linear *tl = (struct sw_table_linear *) swt;
 109         struct sw_flow *flow;
 110         unsigned int count = 0;
 111
 112         list_for_each_entry (flow, &tl->flows, node) {
 113                 if (flow_del_matches(&flow->key, key, strict)
 114                                 && (!strict || (flow->priority == priority)))
 115                         count += do_delete(swt, flow);
 116         }
 117         tl->n_flows -= count;
 118         return count;
 119 }
 120
 121 static int table_linear_timeout(struct datapath *dp, struct sw_table *swt)
 122 {
 123         struct sw_table_linear *tl = (struct sw_table_linear *) swt;
 124         struct sw_flow *flow;
 125         int count = 0;
 126
 127         mutex_lock(&dp_mutex);
 128         list_for_each_entry (flow, &tl->flows, node) {
 129                 int reason = flow_timeout(flow);
 130                 if (reason >= 0) {
 131                         count += do_delete(swt, flow);
 132                         dp_send_flow_expired(dp, flow, reason);
 133                 }
 134         }
 135         tl->n_flows -= count;
 136         mutex_unlock(&dp_mutex);
 137         return count;
 138 }
 139
 140 static void table_linear_destroy(struct sw_table *swt)
 141 {
 142         struct sw_table_linear *tl = (struct sw_table_linear *) swt;
 143
 144         while (!list_empty(&tl->flows)) {
 145                 struct sw_flow *flow = list_entry(tl->flows.next,
 146                                                   struct sw_flow, node);
 147                 list_del(&flow->node);
 148                 flow_free(flow);
 149         }
 150         kfree(tl);
 151 }
 152
 153 static int table_linear_iterate(struct sw_table *swt,
 154                                 const struct sw_flow_key *key,
 155                                 struct sw_table_position *position,
 156                                 int (*callback)(struct sw_flow *, void *),
 157                                 void *private)
 158 {
 159         struct sw_table_linear *tl = (struct sw_table_linear *) swt;
 160         struct sw_flow *flow;
 161         unsigned long start;
 162
 163         start = position->private[0];
 164         list_for_each_entry (flow, &tl->iter_flows, iter_node) {
 165                 if (flow->serial >= start
 166                     && flow_matches_2wild(key, &flow->key)) {
 167                         int error = callback(flow, private);
 168                         if (error) {
 169                                 position->private[0] = flow->serial;
 170                                 return error;
 171                         }
 172                 }
 173         }
 174         return 0;
 175 }
 176
 177 static void table_linear_stats(struct sw_table *swt,
 178                                 struct sw_table_stats *stats)
 179 {
 180         struct sw_table_linear *tl = (struct sw_table_linear *) swt;
 181         stats->name = "linear";
 182         stats->wildcards = OFPFW_ALL;
 183         stats->n_flows   = tl->n_flows;
 184         stats->max_flows = tl->max_flows;
 185         stats->n_matched = swt->n_matched;
 186 }
 187
 188
 189 struct sw_table *table_linear_create(unsigned int max_flows)
 190 {
 191         struct sw_table_linear *tl;
 192         struct sw_table *swt;
 193
 194         tl = kzalloc(sizeof *tl, GFP_KERNEL);
 195         if (tl == NULL)
 196                 return NULL;
 197
 198         swt = &tl->swt;
 199         swt->lookup = table_linear_lookup;
 200         swt->insert = table_linear_insert;
 201         swt->modify = table_linear_modify;
 202         swt->delete = table_linear_delete;
 203         swt->timeout = table_linear_timeout;
 204         swt->destroy = table_linear_destroy;
 205         swt->iterate = table_linear_iterate;
 206         swt->stats = table_linear_stats;
 207
 208         tl->max_flows = max_flows;
 209         tl->n_flows = 0;
 210         INIT_LIST_HEAD(&tl->flows);
 211         INIT_LIST_HEAD(&tl->iter_flows);
 212         tl->next_serial = 0;
 213
 214         return swt;
 215 }