[ovs-dev] [flow monitor v2 04/12] classifier: New function cls_rule_is_loose_match().
Ben Pfaff
blp at nicira.com
Fri Jul 6 21:49:36 UTC 2012
This function will be useful in an upcoming commit.
Signed-off-by: Ben Pfaff <blp at nicira.com>
---
lib/classifier.c | 76 ++++++++++++++++++++++++++++++++----------------------
lib/classifier.h | 3 ++
2 files changed, 48 insertions(+), 31 deletions(-)
diff --git a/lib/classifier.c b/lib/classifier.c
index 6e8f4d2..0c51df1 100644
--- a/lib/classifier.c
+++ b/lib/classifier.c
@@ -934,6 +934,46 @@ classifier_rule_overlaps(const struct classifier *cls,
return false;
}
+
+/* Returns true if 'rule' exactly matches 'criteria' or are more specific than
+ * 'criteria'. That is, 'rule' matches 'criteria' and this function returns
+ * true if, for every field:
+ *
+ * - 'criteria' and 'rule' specify the same (non-wildcarded) value for the
+ * field, or
+ *
+ * - 'criteria' wildcards the field,
+ *
+ * but not if:
+ *
+ * - 'criteria' and 'rule' specify different values for the field, or
+ *
+ * - 'criteria' specifies a value for the field but 'rule' wildcards it.
+ *
+ * Equivalently, the truth table for whether a field matches is:
+ *
+ * rule
+ *
+ * wildcard exact
+ * +---------+---------+
+ * t wild | yes | yes |
+ * a card | | |
+ * r +---------+---------+
+ * g exact | no |if values|
+ * e | |are equal|
+ * t +---------+---------+
+ *
+ * This is the matching rule used by OpenFlow 1.0 non-strict OFPT_FLOW_MOD
+ * commands and by OpenFlow 1.0 aggregate and flow stats.
+ *
+ * Ignores rule->priority and criteria->priority. */
+bool
+cls_rule_is_loose_match(const struct cls_rule *rule,
+ const struct cls_rule *criteria)
+{
+ return (!flow_wildcards_has_extra(&rule->wc, &criteria->wc)
+ && flow_equal_except(&rule->flow, &criteria->flow, &criteria->wc));
+}
/* Iteration. */
@@ -959,40 +999,14 @@ search_table(const struct cls_table *table, const struct cls_rule *target)
return NULL;
}
-/* Initializes 'cursor' for iterating through 'cls' rules that exactly match
- * 'target' or are more specific than 'target'. That is, a given 'rule'
- * matches 'target' if, for every field:
+/* Initializes 'cursor' for iterating through rules in 'cls':
*
- * - 'target' and 'rule' specify the same (non-wildcarded) value for the
- * field, or
- *
- * - 'target' wildcards the field,
- *
- * but not if:
- *
- * - 'target' and 'rule' specify different values for the field, or
- *
- * - 'target' specifies a value for the field but 'rule' wildcards it.
- *
- * Equivalently, the truth table for whether a field matches is:
- *
- * rule
- *
- * wildcard exact
- * +---------+---------+
- * t wild | yes | yes |
- * a card | | |
- * r +---------+---------+
- * g exact | no |if values|
- * e | |are equal|
- * t +---------+---------+
- *
- * This is the matching rule used by OpenFlow 1.0 non-strict OFPT_FLOW_MOD
- * commands and by OpenFlow 1.0 aggregate and flow stats.
+ * - If 'target' is null, the cursor will visit every rule in 'cls'.
*
- * Ignores target->priority.
+ * - If 'target' is nonnull, the cursor will visit each 'rule' in 'cls'
+ * such that cls_rule_is_loose_match(rule, target) returns true.
*
- * 'target' may be NULL to iterate over every rule in 'cls'. */
+ * Ignores target->priority. */
void
cls_cursor_init(struct cls_cursor *cursor, const struct classifier *cls,
const struct cls_rule *target)
diff --git a/lib/classifier.h b/lib/classifier.h
index ec7316c..b154899 100644
--- a/lib/classifier.h
+++ b/lib/classifier.h
@@ -87,6 +87,9 @@ void cls_rule_init_catchall(struct cls_rule *, unsigned int priority);
void cls_rule_zero_wildcarded_fields(struct cls_rule *);
+bool cls_rule_is_loose_match(const struct cls_rule *rule,
+ const struct cls_rule *criteria);
+
void cls_rule_set_reg(struct cls_rule *, unsigned int reg_idx, uint32_t value);
void cls_rule_set_reg_masked(struct cls_rule *, unsigned int reg_idx,
uint32_t value, uint32_t mask);
--
1.7.2.5
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