/* Flow classifier.
*
- * This flow classifier assumes that we can arrange the fields in a flow in an
- * order such that the set of wildcarded fields in a rule tend to fall toward
- * the end of the ordering. That is, if field F is wildcarded, then all the
- * fields after F tend to be wildcarded as well. If this assumption is
- * violated, then the classifier will still classify flows correctly, but its
- * performance will suffer.
- *
- * The classifier uses a collection of CLS_N_FIELDS hash tables for wildcarded
- * flows. Each of these tables contains the flows that wildcard a given field
- * and do not wildcard any of the fields that precede F in the ordering. The
- * key for each hash table is the value of the fields preceding F that are not
- * wildcarded. All the flows that fall within a table and have the same key
- * are kept as a linked list ordered from highest to lowest priority.
- *
- * The classifier also maintains a separate hash table of exact-match flows.
- *
- * To search the classifier we first search the table of exact-match flows,
- * since exact-match flows always have highest priority. If there is a match,
- * we're done. Otherwise, we search each of the CLS_N_FIELDS hash tables in
- * turn, looking for the highest-priority match, and return it (if any).
+ * A classifier is a "struct classifier",
+ * a hash map from a set of wildcards to a "struct cls_table",
+ * a hash map from fixed field values to "struct cls_rule",
+ * which can contain a list of otherwise identical rules
+ * with lower priorities.
*/
#include "flow.h"
#include "openflow/nicira-ext.h"
#include "openflow/openflow.h"
-/* Number of bytes of fields in a rule. */
-#define CLS_N_BYTES 37
-
-/* Fields in a rule.
- *
- * This definition sets the ordering of fields, which is important for
- * performance (see above). To adjust the ordering, change the order of the
- * lines. */
-#define CLS_FIELDS \
- /* struct flow all-caps */ \
- /* wildcard bit(s) member name name */ \
- /* ----------------- ----------- -------- */ \
- CLS_FIELD(OFPFW_IN_PORT, in_port, IN_PORT) \
- CLS_FIELD(NXFW_TUN_ID, tun_id, TUN_ID) \
- CLS_FIELD(OFPFW_DL_VLAN, dl_vlan, DL_VLAN) \
- CLS_FIELD(OFPFW_DL_VLAN_PCP, dl_vlan_pcp, DL_VLAN_PCP) \
- CLS_FIELD(OFPFW_DL_SRC, dl_src, DL_SRC) \
- CLS_FIELD(OFPFW_DL_DST, dl_dst, DL_DST) \
- CLS_FIELD(OFPFW_DL_TYPE, dl_type, DL_TYPE) \
- CLS_FIELD(OFPFW_NW_SRC_MASK, nw_src, NW_SRC) \
- CLS_FIELD(OFPFW_NW_DST_MASK, nw_dst, NW_DST) \
- CLS_FIELD(OFPFW_NW_PROTO, nw_proto, NW_PROTO) \
- CLS_FIELD(OFPFW_NW_TOS, nw_tos, NW_TOS) \
- CLS_FIELD(OFPFW_TP_SRC, tp_src, TP_SRC) \
- CLS_FIELD(OFPFW_TP_DST, tp_dst, TP_DST)
-
-/* Field indexes.
- *
- * (These are also indexed into struct classifier's 'tables' array.) */
-enum {
-#define CLS_FIELD(WILDCARDS, MEMBER, NAME) CLS_F_IDX_##NAME,
- CLS_FIELDS
-#undef CLS_FIELD
- CLS_F_IDX_EXACT, /* Exact-match table. */
- CLS_N_FIELDS = CLS_F_IDX_EXACT
-};
-
-/* Field information. */
-struct cls_field {
- int ofs; /* Offset in struct flow. */
- int len; /* Length in bytes. */
- uint32_t wildcards; /* OFPFW_* bit or bits for this field. */
- const char *name; /* Name (for debugging). */
-};
-extern const struct cls_field cls_fields[CLS_N_FIELDS + 1];
-
/* A flow classifier. */
struct classifier {
- int n_rules; /* Sum of hmap_count() over tables[]. */
- struct hmap tables[CLS_N_FIELDS]; /* Contain cls_bucket elements. */
- struct hmap exact_table; /* Contain cls_rule elements. */
+ int n_rules; /* Total number of rules. */
+ struct hmap tables; /* Contains "struct cls_table"s. */
};
-/* A group of rules with the same fixed values for initial fields. */
-struct cls_bucket {
- struct hmap_node hmap_node; /* Within struct classifier 'tables'. */
- struct list rules; /* In order from highest to lowest priority. */
- struct flow fixed; /* Values for fixed fields. */
+/* A set of rules that all have the same fields wildcarded. */
+struct cls_table {
+ struct hmap_node hmap_node; /* Within struct classifier 'wctables'. */
+ struct hmap rules; /* Contains "struct cls_rule"s. */
+ struct flow_wildcards wc; /* Wildcards for fields. */
+ int n_table_rules; /* Number of rules, including duplicates. */
+ int n_refs; /* Reference count used during iteration. */
};
/* A flow classification rule.
*
- * Use cls_rule_from_flow() or cls_rule_from_match() to initialize a cls_rule
- * or you will almost certainly not initialize 'table_idx' correctly, with
- * disastrous results! */
+ * Use one of the cls_rule_*() functions to initialize a cls_rule.
+ *
+ * The cls_rule_*() functions below maintain the following important
+ * invariant that the classifier depends on:
+ *
+ * - If a bit or a field is wildcarded in 'wc', then the corresponding bit or
+ * field in 'flow' is set to all-0-bits. (The cls_rule_zero_wildcards()
+ * function can be used to restore this invariant after adding wildcards.)
+ */
struct cls_rule {
- union {
- struct list list; /* Within struct cls_bucket 'rules'. */
- struct hmap_node hmap; /* Within struct classifier 'exact_table'. */
- } node;
+ struct hmap_node hmap_node; /* Within struct cls_table 'rules'. */
+ struct list list; /* List of identical, lower-priority rules. */
struct flow flow; /* All field values. */
struct flow_wildcards wc; /* Wildcards for fields. */
unsigned int priority; /* Larger numbers are higher priorities. */
- unsigned int table_idx; /* Index into struct classifier 'tables'. */
};
enum {
void cls_rule_from_match(const struct ofp_match *, unsigned int priority,
bool tun_id_from_cookie, uint64_t cookie,
struct cls_rule *);
+
+void cls_rule_zero_wildcards(struct cls_rule *);
+
char *cls_rule_to_string(const struct cls_rule *);
void cls_rule_print(const struct cls_rule *);
struct cls_rule *classifier_find_rule_exactly(const struct classifier *,
const struct cls_rule *);
-#define CLASSIFIER_FOR_EACH_EXACT_RULE(RULE, MEMBER, CLS) \
- HMAP_FOR_EACH (RULE, MEMBER.node.hmap, &(CLS)->exact_table)
+/* Iteration shorthands. */
+
+struct cls_table *classifier_exact_table(const struct classifier *);
+struct cls_rule *cls_table_first_rule(const struct cls_table *);
+struct cls_rule *cls_table_next_rule(const struct cls_table *,
+ const struct cls_rule *);
+
+#define CLS_TABLE_FOR_EACH_RULE(RULE, MEMBER, TABLE) \
+ for ((RULE) = OBJECT_CONTAINING(cls_table_first_rule(TABLE), \
+ RULE, MEMBER); \
+ &(RULE)->MEMBER != NULL; \
+ (RULE) = OBJECT_CONTAINING(cls_table_next_rule(TABLE, \
+ &(RULE)->MEMBER), \
+ RULE, MEMBER))
-#define CLASSIFIER_FOR_EACH_EXACT_RULE_SAFE(RULE, NEXT, MEMBER, CLS) \
- HMAP_FOR_EACH_SAFE (RULE, NEXT, MEMBER.node.hmap, &(CLS)->exact_table)
+#define CLASSIFIER_FOR_EACH_EXACT_RULE(RULE, MEMBER, CLS) \
+ CLS_TABLE_FOR_EACH_RULE (RULE, MEMBER, classifier_exact_table(CLS))
#endif /* classifier.h */
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