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