mirror of
https://github.com/openvswitch/ovs
synced 2025-08-22 18:07:40 +00:00
cb22974d77
This is a straight search-and-replace, except that I also removed #include <assert.h> from each file where there were no assert calls left. Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Ethan Jackson <ethan@nicira.com>
593 lines
18 KiB
C
593 lines
18 KiB
C
/*
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* Copyright (c) 2009, 2010, 2011, 2012 Nicira, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <config.h>
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#include "classifier.h"
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#include <errno.h>
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#include <netinet/in.h>
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#include "byte-order.h"
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#include "dynamic-string.h"
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#include "flow.h"
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#include "hash.h"
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#include "odp-util.h"
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#include "ofp-util.h"
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#include "packets.h"
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static struct cls_table *find_table(const struct classifier *,
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const struct minimask *);
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static struct cls_table *insert_table(struct classifier *,
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const struct minimask *);
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static void destroy_table(struct classifier *, struct cls_table *);
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static struct cls_rule *find_match(const struct cls_table *,
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const struct flow *);
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static struct cls_rule *find_equal(struct cls_table *,
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const struct miniflow *, uint32_t hash);
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static struct cls_rule *insert_rule(struct cls_table *, struct cls_rule *);
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/* Iterates RULE over HEAD and all of the cls_rules on HEAD->list. */
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#define FOR_EACH_RULE_IN_LIST(RULE, HEAD) \
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for ((RULE) = (HEAD); (RULE) != NULL; (RULE) = next_rule_in_list(RULE))
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#define FOR_EACH_RULE_IN_LIST_SAFE(RULE, NEXT, HEAD) \
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for ((RULE) = (HEAD); \
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(RULE) != NULL && ((NEXT) = next_rule_in_list(RULE), true); \
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(RULE) = (NEXT))
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static struct cls_rule *next_rule_in_list__(struct cls_rule *);
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static struct cls_rule *next_rule_in_list(struct cls_rule *);
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/* cls_rule. */
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/* Initializes 'rule' to match packets specified by 'match' at the given
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* 'priority'. 'match' must satisfy the invariant described in the comment at
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* the definition of struct match.
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*
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* The caller must eventually destroy 'rule' with cls_rule_destroy().
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*
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* (OpenFlow uses priorities between 0 and UINT16_MAX, inclusive, but
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* internally Open vSwitch supports a wider range.) */
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void
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cls_rule_init(struct cls_rule *rule,
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const struct match *match, unsigned int priority)
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{
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minimatch_init(&rule->match, match);
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rule->priority = priority;
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}
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/* Same as cls_rule_init() for initialization from a "struct minimatch". */
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void
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cls_rule_init_from_minimatch(struct cls_rule *rule,
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const struct minimatch *match,
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unsigned int priority)
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{
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minimatch_clone(&rule->match, match);
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rule->priority = priority;
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}
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/* Initializes 'dst' as a copy of 'src'.
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*
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* The caller must eventually destroy 'rule' with cls_rule_destroy(). */
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void
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cls_rule_clone(struct cls_rule *dst, const struct cls_rule *src)
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{
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minimatch_clone(&dst->match, &src->match);
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dst->priority = src->priority;
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}
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/* Frees memory referenced by 'rule'. Doesn't free 'rule' itself (it's
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* normally embedded into a larger structure).
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*
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* ('rule' must not currently be in a classifier.) */
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void
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cls_rule_destroy(struct cls_rule *rule)
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{
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minimatch_destroy(&rule->match);
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}
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/* Returns true if 'a' and 'b' match the same packets at the same priority,
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* false if they differ in some way. */
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bool
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cls_rule_equal(const struct cls_rule *a, const struct cls_rule *b)
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{
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return a->priority == b->priority && minimatch_equal(&a->match, &b->match);
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}
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/* Returns a hash value for 'rule', folding in 'basis'. */
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uint32_t
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cls_rule_hash(const struct cls_rule *rule, uint32_t basis)
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{
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return minimatch_hash(&rule->match, hash_int(rule->priority, basis));
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}
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/* Appends a string describing 'rule' to 's'. */
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void
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cls_rule_format(const struct cls_rule *rule, struct ds *s)
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{
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minimatch_format(&rule->match, s, rule->priority);
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}
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/* Returns true if 'rule' matches every packet, false otherwise. */
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bool
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cls_rule_is_catchall(const struct cls_rule *rule)
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{
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return minimask_is_catchall(&rule->match.mask);
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}
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/* Initializes 'cls' as a classifier that initially contains no classification
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* rules. */
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void
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classifier_init(struct classifier *cls)
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{
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cls->n_rules = 0;
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hmap_init(&cls->tables);
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}
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/* Destroys 'cls'. Rules within 'cls', if any, are not freed; this is the
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* caller's responsibility. */
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void
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classifier_destroy(struct classifier *cls)
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{
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if (cls) {
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struct cls_table *table, *next_table;
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HMAP_FOR_EACH_SAFE (table, next_table, hmap_node, &cls->tables) {
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destroy_table(cls, table);
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}
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hmap_destroy(&cls->tables);
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}
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}
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/* Returns true if 'cls' contains no classification rules, false otherwise. */
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bool
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classifier_is_empty(const struct classifier *cls)
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{
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return cls->n_rules == 0;
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}
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/* Returns the number of rules in 'cls'. */
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int
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classifier_count(const struct classifier *cls)
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{
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return cls->n_rules;
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}
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/* Inserts 'rule' into 'cls'. Until 'rule' is removed from 'cls', the caller
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* must not modify or free it.
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*
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* If 'cls' already contains an identical rule (including wildcards, values of
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* fixed fields, and priority), replaces the old rule by 'rule' and returns the
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* rule that was replaced. The caller takes ownership of the returned rule and
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* is thus responsible for destroying it with cls_rule_destroy(), freeing the
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* memory block in which it resides, etc., as necessary.
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*
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* Returns NULL if 'cls' does not contain a rule with an identical key, after
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* inserting the new rule. In this case, no rules are displaced by the new
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* rule, even rules that cannot have any effect because the new rule matches a
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* superset of their flows and has higher priority. */
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struct cls_rule *
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classifier_replace(struct classifier *cls, struct cls_rule *rule)
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{
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struct cls_rule *old_rule;
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struct cls_table *table;
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table = find_table(cls, &rule->match.mask);
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if (!table) {
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table = insert_table(cls, &rule->match.mask);
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}
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old_rule = insert_rule(table, rule);
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if (!old_rule) {
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table->n_table_rules++;
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cls->n_rules++;
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}
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return old_rule;
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}
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/* Inserts 'rule' into 'cls'. Until 'rule' is removed from 'cls', the caller
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* must not modify or free it.
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*
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* 'cls' must not contain an identical rule (including wildcards, values of
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* fixed fields, and priority). Use classifier_find_rule_exactly() to find
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* such a rule. */
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void
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classifier_insert(struct classifier *cls, struct cls_rule *rule)
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{
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struct cls_rule *displaced_rule = classifier_replace(cls, rule);
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ovs_assert(!displaced_rule);
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}
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/* Removes 'rule' from 'cls'. It is the caller's responsibility to destroy
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* 'rule' with cls_rule_destroy(), freeing the memory block in which 'rule'
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* resides, etc., as necessary. */
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void
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classifier_remove(struct classifier *cls, struct cls_rule *rule)
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{
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struct cls_rule *head;
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struct cls_table *table;
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table = find_table(cls, &rule->match.mask);
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head = find_equal(table, &rule->match.flow, rule->hmap_node.hash);
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if (head != rule) {
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list_remove(&rule->list);
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} else if (list_is_empty(&rule->list)) {
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hmap_remove(&table->rules, &rule->hmap_node);
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} else {
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struct cls_rule *next = CONTAINER_OF(rule->list.next,
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struct cls_rule, list);
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list_remove(&rule->list);
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hmap_replace(&table->rules, &rule->hmap_node, &next->hmap_node);
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}
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if (--table->n_table_rules == 0) {
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destroy_table(cls, table);
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}
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cls->n_rules--;
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}
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/* Finds and returns the highest-priority rule in 'cls' that matches 'flow'.
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* Returns a null pointer if no rules in 'cls' match 'flow'. If multiple rules
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* of equal priority match 'flow', returns one arbitrarily. */
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struct cls_rule *
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classifier_lookup(const struct classifier *cls, const struct flow *flow)
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{
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struct cls_table *table;
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struct cls_rule *best;
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best = NULL;
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HMAP_FOR_EACH (table, hmap_node, &cls->tables) {
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struct cls_rule *rule = find_match(table, flow);
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if (rule && (!best || rule->priority > best->priority)) {
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best = rule;
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}
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}
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return best;
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}
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/* Finds and returns a rule in 'cls' with exactly the same priority and
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* matching criteria as 'target'. Returns a null pointer if 'cls' doesn't
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* contain an exact match. */
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struct cls_rule *
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classifier_find_rule_exactly(const struct classifier *cls,
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const struct cls_rule *target)
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{
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struct cls_rule *head, *rule;
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struct cls_table *table;
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table = find_table(cls, &target->match.mask);
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if (!table) {
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return NULL;
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}
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head = find_equal(table, &target->match.flow,
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miniflow_hash_in_minimask(&target->match.flow,
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&target->match.mask, 0));
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FOR_EACH_RULE_IN_LIST (rule, head) {
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if (target->priority >= rule->priority) {
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return target->priority == rule->priority ? rule : NULL;
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}
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}
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return NULL;
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}
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/* Finds and returns a rule in 'cls' with priority 'priority' and exactly the
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* same matching criteria as 'target'. Returns a null pointer if 'cls' doesn't
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* contain an exact match. */
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struct cls_rule *
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classifier_find_match_exactly(const struct classifier *cls,
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const struct match *target,
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unsigned int priority)
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{
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struct cls_rule *retval;
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struct cls_rule cr;
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cls_rule_init(&cr, target, priority);
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retval = classifier_find_rule_exactly(cls, &cr);
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cls_rule_destroy(&cr);
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return retval;
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}
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/* Checks if 'target' would overlap any other rule in 'cls'. Two rules are
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* considered to overlap if both rules have the same priority and a packet
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* could match both. */
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bool
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classifier_rule_overlaps(const struct classifier *cls,
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const struct cls_rule *target)
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{
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struct cls_table *table;
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HMAP_FOR_EACH (table, hmap_node, &cls->tables) {
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uint32_t storage[FLOW_U32S];
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struct minimask mask;
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struct cls_rule *head;
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minimask_combine(&mask, &target->match.mask, &table->mask, storage);
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HMAP_FOR_EACH (head, hmap_node, &table->rules) {
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struct cls_rule *rule;
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FOR_EACH_RULE_IN_LIST (rule, head) {
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if (rule->priority == target->priority
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&& miniflow_equal_in_minimask(&target->match.flow,
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&rule->match.flow, &mask)) {
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return true;
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}
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}
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}
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}
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return false;
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}
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/* Returns true if 'rule' exactly matches 'criteria' or if 'rule' is more
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* specific than 'criteria'. That is, 'rule' matches 'criteria' and this
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* function returns true if, for every field:
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*
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* - 'criteria' and 'rule' specify the same (non-wildcarded) value for the
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* field, or
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*
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* - 'criteria' wildcards the field,
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*
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* Conversely, 'rule' does not match 'criteria' and this function returns false
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* if, for at least one field:
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*
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* - 'criteria' and 'rule' specify different values for the field, or
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*
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* - 'criteria' specifies a value for the field but 'rule' wildcards it.
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*
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* Equivalently, the truth table for whether a field matches is:
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*
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* rule
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*
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* c wildcard exact
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* r +---------+---------+
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* i wild | yes | yes |
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* t card | | |
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* e +---------+---------+
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* r exact | no |if values|
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* i | |are equal|
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* a +---------+---------+
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*
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* This is the matching rule used by OpenFlow 1.0 non-strict OFPT_FLOW_MOD
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* commands and by OpenFlow 1.0 aggregate and flow stats.
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*
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* Ignores rule->priority. */
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bool
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cls_rule_is_loose_match(const struct cls_rule *rule,
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const struct minimatch *criteria)
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{
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return (!minimask_has_extra(&rule->match.mask, &criteria->mask)
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&& miniflow_equal_in_minimask(&rule->match.flow, &criteria->flow,
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&criteria->mask));
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}
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/* Iteration. */
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static bool
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rule_matches(const struct cls_rule *rule, const struct cls_rule *target)
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{
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return (!target
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|| miniflow_equal_in_minimask(&rule->match.flow,
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&target->match.flow,
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&target->match.mask));
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}
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static struct cls_rule *
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search_table(const struct cls_table *table, const struct cls_rule *target)
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{
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if (!target || !minimask_has_extra(&table->mask, &target->match.mask)) {
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struct cls_rule *rule;
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HMAP_FOR_EACH (rule, hmap_node, &table->rules) {
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if (rule_matches(rule, target)) {
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return rule;
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}
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}
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}
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return NULL;
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}
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/* Initializes 'cursor' for iterating through rules in 'cls':
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*
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* - If 'target' is null, the cursor will visit every rule in 'cls'.
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*
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* - If 'target' is nonnull, the cursor will visit each 'rule' in 'cls'
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* such that cls_rule_is_loose_match(rule, target) returns true.
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*
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* Ignores target->priority. */
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void
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cls_cursor_init(struct cls_cursor *cursor, const struct classifier *cls,
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const struct cls_rule *target)
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{
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cursor->cls = cls;
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cursor->target = target && !cls_rule_is_catchall(target) ? target : NULL;
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}
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/* Returns the first matching cls_rule in 'cursor''s iteration, or a null
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* pointer if there are no matches. */
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struct cls_rule *
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cls_cursor_first(struct cls_cursor *cursor)
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{
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struct cls_table *table;
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HMAP_FOR_EACH (table, hmap_node, &cursor->cls->tables) {
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struct cls_rule *rule = search_table(table, cursor->target);
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if (rule) {
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cursor->table = table;
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return rule;
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}
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}
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return NULL;
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}
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/* Returns the next matching cls_rule in 'cursor''s iteration, or a null
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* pointer if there are no more matches. */
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struct cls_rule *
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cls_cursor_next(struct cls_cursor *cursor, struct cls_rule *rule)
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{
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const struct cls_table *table;
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struct cls_rule *next;
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next = next_rule_in_list__(rule);
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if (next->priority < rule->priority) {
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return next;
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}
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/* 'next' is the head of the list, that is, the rule that is included in
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* the table's hmap. (This is important when the classifier contains rules
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* that differ only in priority.) */
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rule = next;
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HMAP_FOR_EACH_CONTINUE (rule, hmap_node, &cursor->table->rules) {
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if (rule_matches(rule, cursor->target)) {
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return rule;
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}
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}
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table = cursor->table;
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HMAP_FOR_EACH_CONTINUE (table, hmap_node, &cursor->cls->tables) {
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rule = search_table(table, cursor->target);
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if (rule) {
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cursor->table = table;
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return rule;
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}
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}
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return NULL;
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}
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static struct cls_table *
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find_table(const struct classifier *cls, const struct minimask *mask)
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{
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struct cls_table *table;
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HMAP_FOR_EACH_IN_BUCKET (table, hmap_node, minimask_hash(mask, 0),
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&cls->tables) {
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if (minimask_equal(mask, &table->mask)) {
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return table;
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}
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}
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return NULL;
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}
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static struct cls_table *
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insert_table(struct classifier *cls, const struct minimask *mask)
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{
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struct cls_table *table;
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table = xzalloc(sizeof *table);
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hmap_init(&table->rules);
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minimask_clone(&table->mask, mask);
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hmap_insert(&cls->tables, &table->hmap_node, minimask_hash(mask, 0));
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return table;
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}
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static void
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destroy_table(struct classifier *cls, struct cls_table *table)
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{
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minimask_destroy(&table->mask);
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hmap_remove(&cls->tables, &table->hmap_node);
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hmap_destroy(&table->rules);
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free(table);
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}
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|
||
static struct cls_rule *
|
||
find_match(const struct cls_table *table, const struct flow *flow)
|
||
{
|
||
uint32_t hash = flow_hash_in_minimask(flow, &table->mask, 0);
|
||
struct cls_rule *rule;
|
||
|
||
HMAP_FOR_EACH_WITH_HASH (rule, hmap_node, hash, &table->rules) {
|
||
if (miniflow_equal_flow_in_minimask(&rule->match.flow, flow,
|
||
&table->mask)) {
|
||
return rule;
|
||
}
|
||
}
|
||
|
||
return NULL;
|
||
}
|
||
|
||
static struct cls_rule *
|
||
find_equal(struct cls_table *table, const struct miniflow *flow, uint32_t hash)
|
||
{
|
||
struct cls_rule *head;
|
||
|
||
HMAP_FOR_EACH_WITH_HASH (head, hmap_node, hash, &table->rules) {
|
||
if (miniflow_equal(&head->match.flow, flow)) {
|
||
return head;
|
||
}
|
||
}
|
||
return NULL;
|
||
}
|
||
|
||
static struct cls_rule *
|
||
insert_rule(struct cls_table *table, struct cls_rule *new)
|
||
{
|
||
struct cls_rule *head;
|
||
|
||
new->hmap_node.hash = miniflow_hash_in_minimask(&new->match.flow,
|
||
&new->match.mask, 0);
|
||
|
||
head = find_equal(table, &new->match.flow, new->hmap_node.hash);
|
||
if (!head) {
|
||
hmap_insert(&table->rules, &new->hmap_node, new->hmap_node.hash);
|
||
list_init(&new->list);
|
||
return NULL;
|
||
} else {
|
||
/* Scan the list for the insertion point that will keep the list in
|
||
* order of decreasing priority. */
|
||
struct cls_rule *rule;
|
||
FOR_EACH_RULE_IN_LIST (rule, head) {
|
||
if (new->priority >= rule->priority) {
|
||
if (rule == head) {
|
||
/* 'new' is the new highest-priority flow in the list. */
|
||
hmap_replace(&table->rules,
|
||
&rule->hmap_node, &new->hmap_node);
|
||
}
|
||
|
||
if (new->priority == rule->priority) {
|
||
list_replace(&new->list, &rule->list);
|
||
return rule;
|
||
} else {
|
||
list_insert(&rule->list, &new->list);
|
||
return NULL;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Insert 'new' at the end of the list. */
|
||
list_push_back(&head->list, &new->list);
|
||
return NULL;
|
||
}
|
||
}
|
||
|
||
static struct cls_rule *
|
||
next_rule_in_list__(struct cls_rule *rule)
|
||
{
|
||
struct cls_rule *next = OBJECT_CONTAINING(rule->list.next, next, list);
|
||
return next;
|
||
}
|
||
|
||
static struct cls_rule *
|
||
next_rule_in_list(struct cls_rule *rule)
|
||
{
|
||
struct cls_rule *next = next_rule_in_list__(rule);
|
||
return next->priority < rule->priority ? next : NULL;
|
||
}
|