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         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(&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 (tl->n_flows >= tl->max_flows) {
  65                 return 0;
  66         }
  67         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         tl->n_flows -= count;
 100         return count;
 101 }
 102
 103 static int table_linear_timeout(struct datapath *dp, struct sw_table *swt)
 104 {
 105         struct sw_table_linear *tl = (struct sw_table_linear *) swt;
 106         struct sw_flow *flow;
 107         int count = 0;
 108
 109         mutex_lock(&dp_mutex);
 110         list_for_each_entry (flow, &tl->flows, node) {
 111                 if (flow_timeout(flow)) {
 112                         count += do_delete(swt, flow);
 113                         if (dp->flags & OFPC_SEND_FLOW_EXP)
 114                                 dp_send_flow_expired(dp, flow);
 115                 }
 116         }
 117         tl->n_flows -= count;
 118         mutex_unlock(&dp_mutex);
 119         return count;
 120 }
 121
 122 static void table_linear_destroy(struct sw_table *swt)
 123 {
 124         struct sw_table_linear *tl = (struct sw_table_linear *) swt;
 125
 126         while (!list_empty(&tl->flows)) {
 127                 struct sw_flow *flow = list_entry(tl->flows.next,
 128                                                   struct sw_flow, node);
 129                 list_del(&flow->node);
 130                 flow_free(flow);
 131         }
 132         kfree(tl);
 133 }
 134
 135 static int table_linear_iterate(struct sw_table *swt,
 136                                 const struct sw_flow_key *key,
 137                                 struct sw_table_position *position,
 138                                 int (*callback)(struct sw_flow *, void *),
 139                                 void *private)
 140 {
 141         struct sw_table_linear *tl = (struct sw_table_linear *) swt;
 142         struct sw_flow *flow;
 143         unsigned long start;
 144
 145         start = position->private[0];
 146         list_for_each_entry (flow, &tl->iter_flows, iter_node) {
 147                 if (flow->serial >= start && flow_matches(key, &flow->key)) {
 148                         int error = callback(flow, private);
 149                         if (error) {
 150                                 position->private[0] = flow->serial;
 151                                 return error;
 152                         }
 153                 }
 154         }
 155         return 0;
 156 }
 157
 158 static void table_linear_stats(struct sw_table *swt,
 159                                 struct sw_table_stats *stats)
 160 {
 161         struct sw_table_linear *tl = (struct sw_table_linear *) swt;
 162         stats->name = "linear";
 163         stats->n_flows = tl->n_flows;
 164         stats->max_flows = tl->max_flows;
 165 }
 166
 167
 168 struct sw_table *table_linear_create(unsigned int max_flows)
 169 {
 170         struct sw_table_linear *tl;
 171         struct sw_table *swt;
 172
 173         tl = kzalloc(sizeof *tl, GFP_KERNEL);
 174         if (tl == NULL)
 175                 return NULL;
 176
 177         swt = &tl->swt;
 178         swt->lookup = table_linear_lookup;
 179         swt->insert = table_linear_insert;
 180         swt->delete = table_linear_delete;
 181         swt->timeout = table_linear_timeout;
 182         swt->destroy = table_linear_destroy;
 183         swt->iterate = table_linear_iterate;
 184         swt->stats = table_linear_stats;
 185
 186         tl->max_flows = max_flows;
 187         tl->n_flows = 0;
 188         INIT_LIST_HEAD(&tl->flows);
 189         INIT_LIST_HEAD(&tl->iter_flows);
 190         tl->next_serial = 0;
 191
 192         return swt;
 193 }