lib/classifier.h

   1 /*
   2  * Copyright (c) 2009, 2010, 2011, 2012 Nicira, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #ifndef CLASSIFIER_H
  18 #define CLASSIFIER_H 1
  19
  20 /* Flow classifier.
  21  *
  22  * A classifier is a "struct classifier",
  23  *      a hash map from a set of wildcards to a "struct cls_table",
  24  *              a hash map from fixed field values to "struct cls_rule",
  25  *                      which can contain a list of otherwise identical rules
  26  *                      with lower priorities.
  27  */
  28
  29 #include "flow.h"
  30 #include "hmap.h"
  31 #include "list.h"
  32 #include "match.h"
  33 #include "openflow/nicira-ext.h"
  34 #include "openflow/openflow.h"
  35
  36 #ifdef __cplusplus
  37 extern "C" {
  38 #endif
  39
  40 /* A flow classifier. */
  41 struct classifier {
  42     int n_rules;                /* Total number of rules. */
  43     struct hmap tables;         /* Contains "struct cls_table"s.  */
  44 };
  45
  46 /* A set of rules that all have the same fields wildcarded. */
  47 struct cls_table {
  48     struct hmap_node hmap_node; /* Within struct classifier 'tables' hmap. */
  49     struct hmap rules;          /* Contains "struct cls_rule"s. */
  50     struct minimask mask;       /* Wildcards for fields. */
  51     int n_table_rules;          /* Number of rules, including duplicates. */
  52 };
  53
  54 /* Returns true if 'table' is a "catch-all" table that will match every
  55  * packet (if there is no higher-priority match). */
  56 static inline bool
  57 cls_table_is_catchall(const struct cls_table *table)
  58 {
  59     return minimask_is_catchall(&table->mask);
  60 }
  61
  62 /* A rule in a "struct classifier". */
  63 struct cls_rule {
  64     struct hmap_node hmap_node; /* Within struct cls_table 'rules'. */
  65     struct list list;           /* List of identical, lower-priority rules. */
  66     struct minimatch match;     /* Matching rule. */
  67     unsigned int priority;      /* Larger numbers are higher priorities. */
  68 };
  69
  70 void cls_rule_init(struct cls_rule *, const struct match *,
  71                    unsigned int priority);
  72 void cls_rule_init_from_minimatch(struct cls_rule *, const struct minimatch *,
  73                                   unsigned int priority);
  74 void cls_rule_clone(struct cls_rule *, const struct cls_rule *);
  75 void cls_rule_destroy(struct cls_rule *);
  76
  77 bool cls_rule_equal(const struct cls_rule *, const struct cls_rule *);
  78 uint32_t cls_rule_hash(const struct cls_rule *, uint32_t basis);
  79
  80 void cls_rule_format(const struct cls_rule *, struct ds *);
  81
  82 bool cls_rule_is_catchall(const struct cls_rule *);
  83
  84 bool cls_rule_is_loose_match(const struct cls_rule *rule,
  85                              const struct minimatch *criteria);
  86
  87 void classifier_init(struct classifier *);
  88 void classifier_destroy(struct classifier *);
  89 bool classifier_is_empty(const struct classifier *);
  90 int classifier_count(const struct classifier *);
  91 void classifier_insert(struct classifier *, struct cls_rule *);
  92 struct cls_rule *classifier_replace(struct classifier *, struct cls_rule *);
  93 void classifier_remove(struct classifier *, struct cls_rule *);
  94 struct cls_rule *classifier_lookup(const struct classifier *,
  95                                    const struct flow *);
  96 bool classifier_rule_overlaps(const struct classifier *,
  97                               const struct cls_rule *);
  98
  99 typedef void cls_cb_func(struct cls_rule *, void *aux);
 100
 101 struct cls_rule *classifier_find_rule_exactly(const struct classifier *,
 102                                               const struct cls_rule *);
 103 struct cls_rule *classifier_find_match_exactly(const struct classifier *,
 104                                                const struct match *,
 105                                                unsigned int priority);
 106 \f
 107 /* Iteration. */
 108
 109 struct cls_cursor {
 110     const struct classifier *cls;
 111     const struct cls_table *table;
 112     const struct cls_rule *target;
 113 };
 114
 115 void cls_cursor_init(struct cls_cursor *, const struct classifier *,
 116                      const struct cls_rule *match);
 117 struct cls_rule *cls_cursor_first(struct cls_cursor *);
 118 struct cls_rule *cls_cursor_next(struct cls_cursor *, struct cls_rule *);
 119
 120 #define CLS_CURSOR_FOR_EACH(RULE, MEMBER, CURSOR)                       \
 121     for (ASSIGN_CONTAINER(RULE, cls_cursor_first(CURSOR), MEMBER);      \
 122          &(RULE)->MEMBER != NULL;                                       \
 123          ASSIGN_CONTAINER(RULE, cls_cursor_next(CURSOR, &(RULE)->MEMBER), \
 124                           MEMBER))
 125
 126 #define CLS_CURSOR_FOR_EACH_SAFE(RULE, NEXT, MEMBER, CURSOR)            \
 127     for (ASSIGN_CONTAINER(RULE, cls_cursor_first(CURSOR), MEMBER);      \
 128          (&(RULE)->MEMBER != NULL                                       \
 129           ? ASSIGN_CONTAINER(NEXT, cls_cursor_next(CURSOR, &(RULE)->MEMBER), \
 130                              MEMBER)                                    \
 131           : 0);                                                         \
 132          (RULE) = (NEXT))
 133
 134 #ifdef __cplusplus
 135 }
 136 #endif
 137
 138 #endif /* classifier.h */