2 * Copyright (c) 2009, 2010 Nicira Networks.
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:
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
18 #include "classifier.h"
21 #include <netinet/in.h>
22 #include "dynamic-string.h"
26 const struct cls_field cls_fields[CLS_N_FIELDS + 1] = {
27 #define CLS_FIELD(WILDCARDS, MEMBER, NAME) \
28 { offsetof(flow_t, MEMBER), \
29 sizeof ((flow_t *)0)->MEMBER, \
34 { sizeof(flow_t), 0, 0, "exact" },
37 static uint32_t hash_fields(const flow_t *, int table_idx);
38 static bool equal_fields(const flow_t *, const flow_t *, int table_idx);
40 static int table_idx_from_wildcards(uint32_t wildcards);
41 static struct cls_rule *table_insert(struct hmap *, struct cls_rule *);
42 static struct cls_rule *insert_exact_rule(struct classifier *,
44 static struct cls_bucket *find_bucket(struct hmap *, size_t hash,
45 const struct cls_rule *);
46 static struct cls_rule *search_table(const struct hmap *table, int field_idx,
47 const struct cls_rule *);
48 static struct cls_rule *search_exact_table(const struct classifier *,
49 size_t hash, const flow_t *);
50 static bool rules_match_1wild(const struct cls_rule *fixed,
51 const struct cls_rule *wild, int field_idx);
52 static bool rules_match_2wild(const struct cls_rule *wild1,
53 const struct cls_rule *wild2, int field_idx);
55 /* Converts the flow in 'flow' into a cls_rule in 'rule', with the given
56 * 'wildcards' and 'priority'.*/
58 cls_rule_from_flow(const flow_t *flow, uint32_t wildcards,
59 unsigned int priority, struct cls_rule *rule)
62 flow_wildcards_init(&rule->wc, wildcards);
63 rule->priority = priority;
64 rule->table_idx = table_idx_from_wildcards(rule->wc.wildcards);
67 /* Converts the ofp_match in 'match' into a cls_rule in 'rule', with the given
68 * 'priority'. If 'tun_id_from_cookie' is set then the upper 32 bits of
69 * 'cookie' are stored in the rule as the tunnel ID. */
71 cls_rule_from_match(const struct ofp_match *match, unsigned int priority,
72 bool tun_id_from_cookie, uint64_t cookie,
73 struct cls_rule *rule)
76 flow_from_match(match, tun_id_from_cookie, cookie, &rule->flow, &wildcards);
77 flow_wildcards_init(&rule->wc, wildcards);
78 rule->priority = rule->wc.wildcards ? priority : UINT16_MAX;
79 rule->table_idx = table_idx_from_wildcards(rule->wc.wildcards);
82 /* Converts 'rule' to a string and returns the string. The caller must free
83 * the string (with free()). */
85 cls_rule_to_string(const struct cls_rule *rule)
87 struct ds s = DS_EMPTY_INITIALIZER;
88 ds_put_format(&s, "wildcards=%x priority=%u ",
89 rule->wc.wildcards, rule->priority);
90 flow_format(&s, &rule->flow);
94 /* Prints cls_rule 'rule', for debugging.
96 * (The output could be improved and expanded, but this was good enough to
97 * debug the classifier.) */
99 cls_rule_print(const struct cls_rule *rule)
101 printf("wildcards=%x priority=%u ", rule->wc.wildcards, rule->priority);
102 flow_print(stdout, &rule->flow);
106 /* Adjusts pointers around 'old', which must be in classifier 'cls', to
107 * compensate for it having been moved in memory to 'new' (e.g. due to
110 * This function cannot be realized in all possible flow classifier
111 * implementations, so we will probably have to change the interface if we
112 * change the implementation. Shouldn't be a big deal though. */
114 cls_rule_moved(struct classifier *cls, struct cls_rule *old,
115 struct cls_rule *new)
118 if (new->wc.wildcards) {
119 list_moved(&new->node.list);
121 hmap_node_moved(&cls->exact_table,
122 &old->node.hmap, &new->node.hmap);
127 /* Replaces 'old', which must be in classifier 'cls', by 'new' (e.g. due to
128 * realloc()); that is, after calling this function 'new' will be in 'cls' in
131 * 'new' and 'old' must be exactly the same: wildcard the same fields, have the
132 * same fixed values for non-wildcarded fields, and have the same priority.
134 * The caller takes ownership of 'old' and is thus responsible for freeing it,
135 * etc., as necessary.
137 * This function cannot be realized in all possible flow classifier
138 * implementations, so we will probably have to change the interface if we
139 * change the implementation. Shouldn't be a big deal though. */
141 cls_rule_replace(struct classifier *cls, const struct cls_rule *old,
142 struct cls_rule *new)
145 assert(old->wc.wildcards == new->wc.wildcards);
146 assert(old->priority == new->priority);
148 if (new->wc.wildcards) {
149 list_replace(&new->node.list, &old->node.list);
151 hmap_replace(&cls->exact_table, &old->node.hmap, &new->node.hmap);
155 /* Initializes 'cls' as a classifier that initially contains no classification
158 classifier_init(struct classifier *cls)
163 for (i = 0; i < ARRAY_SIZE(cls->tables); i++) {
164 hmap_init(&cls->tables[i]);
166 hmap_init(&cls->exact_table);
169 /* Destroys 'cls'. Rules within 'cls', if any, are not freed; this is the
170 * caller's responsibility. */
172 classifier_destroy(struct classifier *cls)
175 struct cls_bucket *bucket, *next_bucket;
178 for (tbl = &cls->tables[0]; tbl < &cls->tables[CLS_N_FIELDS]; tbl++) {
179 HMAP_FOR_EACH_SAFE (bucket, next_bucket, hmap_node, tbl) {
184 hmap_destroy(&cls->exact_table);
188 /* Returns true if 'cls' does not contain any classification rules, false
191 classifier_is_empty(const struct classifier *cls)
193 return cls->n_rules == 0;
196 /* Returns the number of rules in 'classifier'. */
198 classifier_count(const struct classifier *cls)
203 /* Returns the number of rules in 'classifier' that have no wildcards. */
205 classifier_count_exact(const struct classifier *cls)
207 return hmap_count(&cls->exact_table);
210 /* Inserts 'rule' into 'cls'. Transfers ownership of 'rule' to 'cls'.
212 * If 'cls' already contains an identical rule (including wildcards, values of
213 * fixed fields, and priority), replaces the old rule by 'rule' and returns the
214 * rule that was replaced. The caller takes ownership of the returned rule and
215 * is thus responsible for freeing it, etc., as necessary.
217 * Returns NULL if 'cls' does not contain a rule with an identical key, after
218 * inserting the new rule. In this case, no rules are displaced by the new
219 * rule, even rules that cannot have any effect because the new rule matches a
220 * superset of their flows and has higher priority. */
222 classifier_insert(struct classifier *cls, struct cls_rule *rule)
224 struct cls_rule *old;
225 assert((rule->wc.wildcards == 0) == (rule->table_idx == CLS_F_IDX_EXACT));
226 old = (rule->wc.wildcards
227 ? table_insert(&cls->tables[rule->table_idx], rule)
228 : insert_exact_rule(cls, rule));
235 /* Inserts 'rule' into 'cls'. Transfers ownership of 'rule' to 'cls'.
237 * 'rule' must be an exact-match rule (rule->wc.wildcards must be 0) and 'cls'
238 * must not contain any rule with an identical key. */
240 classifier_insert_exact(struct classifier *cls, struct cls_rule *rule)
242 hmap_insert(&cls->exact_table, &rule->node.hmap,
243 flow_hash(&rule->flow, 0));
247 /* Removes 'rule' from 'cls'. It is caller's responsibility to free 'rule', if
248 * this is desirable. */
250 classifier_remove(struct classifier *cls, struct cls_rule *rule)
252 if (rule->wc.wildcards) {
253 /* Remove 'rule' from bucket. If that empties the bucket, remove the
254 * bucket from its table. */
255 struct hmap *table = &cls->tables[rule->table_idx];
256 struct list *rules = list_remove(&rule->node.list);
257 if (list_is_empty(rules)) {
258 /* This code is a little tricky. list_remove() returns the list
259 * element just after the one removed. Since the list is now
260 * empty, this will be the address of the 'rules' member of the
261 * bucket that was just emptied, so pointer arithmetic (via
262 * CONTAINER_OF) can find that bucket. */
263 struct cls_bucket *bucket;
264 bucket = CONTAINER_OF(rules, struct cls_bucket, rules);
265 hmap_remove(table, &bucket->hmap_node);
269 /* Remove 'rule' from cls->exact_table. */
270 hmap_remove(&cls->exact_table, &rule->node.hmap);
275 /* Finds and returns the highest-priority rule in 'cls' that matches 'flow'.
276 * Returns a null pointer if no rules in 'cls' match 'flow'. If multiple rules
277 * of equal priority match 'flow', returns one arbitrarily.
279 * (When multiple rules of equal priority happen to fall into the same bucket,
280 * rules added more recently take priority over rules added less recently, but
281 * this is subject to change and should not be depended upon.) */
283 classifier_lookup(const struct classifier *cls, const flow_t *flow)
285 struct cls_rule *rule = classifier_lookup_exact(cls, flow);
287 rule = classifier_lookup_wild(cls, flow);
293 classifier_lookup_exact(const struct classifier *cls, const flow_t *flow)
295 return (!hmap_is_empty(&cls->exact_table)
296 ? search_exact_table(cls, flow_hash(flow, 0), flow)
301 classifier_lookup_wild(const struct classifier *cls, const flow_t *flow)
303 struct cls_rule *best = NULL;
304 if (cls->n_rules > hmap_count(&cls->exact_table)) {
305 struct cls_rule target;
308 cls_rule_from_flow(flow, 0, 0, &target);
309 for (i = 0; i < CLS_N_FIELDS; i++) {
310 struct cls_rule *rule = search_table(&cls->tables[i], i, &target);
311 if (rule && (!best || rule->priority > best->priority)) {
320 classifier_find_rule_exactly(const struct classifier *cls,
321 const flow_t *target, uint32_t wildcards,
322 unsigned int priority)
324 struct cls_bucket *bucket;
329 /* Ignores 'priority'. */
330 return search_exact_table(cls, flow_hash(target, 0), target);
333 assert(wildcards == (wildcards & OVSFW_ALL));
334 table_idx = table_idx_from_wildcards(wildcards);
335 hash = hash_fields(target, table_idx);
336 HMAP_FOR_EACH_WITH_HASH (bucket, hmap_node, hash,
337 &cls->tables[table_idx]) {
338 if (equal_fields(&bucket->fixed, target, table_idx)) {
339 struct cls_rule *pos;
340 LIST_FOR_EACH (pos, node.list, &bucket->rules) {
341 if (pos->priority < priority) {
343 } else if (pos->priority == priority &&
344 pos->wc.wildcards == wildcards &&
345 flow_equal(target, &pos->flow)) {
354 /* Checks if the flow defined by 'target' with 'wildcards' at 'priority'
355 * overlaps with any other rule at the same priority in the classifier.
356 * Two rules are considered overlapping if a packet could match both. */
358 classifier_rule_overlaps(const struct classifier *cls,
359 const flow_t *target, uint32_t wildcards,
360 unsigned int priority)
362 struct cls_rule target_rule;
363 const struct hmap *tbl;
366 return search_exact_table(cls, flow_hash(target, 0), target) ?
370 cls_rule_from_flow(target, wildcards, priority, &target_rule);
372 for (tbl = &cls->tables[0]; tbl < &cls->tables[CLS_N_FIELDS]; tbl++) {
373 struct cls_bucket *bucket;
375 HMAP_FOR_EACH (bucket, hmap_node, tbl) {
376 struct cls_rule *rule;
378 LIST_FOR_EACH (rule, node.list, &bucket->rules) {
379 if (rule->priority == priority
380 && rules_match_2wild(rule, &target_rule, 0)) {
390 /* Ignores target->priority.
392 * 'callback' is allowed to delete the rule that is passed as its argument, but
393 * it must not delete (or move) any other rules in 'cls' that are in the same
394 * table as the argument rule. Two rules are in the same table if their
395 * cls_rule structs have the same table_idx; as a special case, a rule with
396 * wildcards and an exact-match rule will never be in the same table. */
398 classifier_for_each_match(const struct classifier *cls,
399 const struct cls_rule *target,
400 int include, cls_cb_func *callback, void *aux)
402 if (include & CLS_INC_WILD) {
403 const struct hmap *table;
405 for (table = &cls->tables[0]; table < &cls->tables[CLS_N_FIELDS];
407 struct cls_bucket *bucket, *next_bucket;
409 HMAP_FOR_EACH_SAFE (bucket, next_bucket, hmap_node, table) {
410 /* XXX there is a bit of room for optimization here based on
411 * rejecting entire buckets on their fixed fields, but it will
412 * only be worthwhile for big buckets (which we hope we won't
413 * get anyway, but...) */
414 struct cls_rule *prev_rule, *rule;
416 /* We can't just use LIST_FOR_EACH_SAFE here because, if the
417 * callback deletes the last rule in the bucket, then the
418 * bucket itself will be destroyed. The bucket contains the
419 * list head so that's a use-after-free error. */
421 LIST_FOR_EACH (rule, node.list, &bucket->rules) {
422 if (rules_match_1wild(rule, target, 0)) {
424 callback(prev_rule, aux);
430 callback(prev_rule, aux);
436 if (include & CLS_INC_EXACT) {
437 if (target->wc.wildcards) {
438 struct cls_rule *rule, *next_rule;
440 HMAP_FOR_EACH_SAFE (rule, next_rule, node.hmap,
442 if (rules_match_1wild(rule, target, 0)) {
447 /* Optimization: there can be at most one match in the exact
449 size_t hash = flow_hash(&target->flow, 0);
450 struct cls_rule *rule = search_exact_table(cls, hash,
459 /* 'callback' is allowed to delete the rule that is passed as its argument, but
460 * it must not delete (or move) any other rules in 'cls' that are in the same
461 * table as the argument rule. Two rules are in the same table if their
462 * cls_rule structs have the same table_idx; as a special case, a rule with
463 * wildcards and an exact-match rule will never be in the same table.
465 * If 'include' is CLS_INC_EXACT then CLASSIFIER_FOR_EACH_EXACT_RULE(_SAFE) is
466 * probably easier to use. */
468 classifier_for_each(const struct classifier *cls, int include,
469 void (*callback)(struct cls_rule *, void *aux),
472 if (include & CLS_INC_WILD) {
473 const struct hmap *tbl;
475 for (tbl = &cls->tables[0]; tbl < &cls->tables[CLS_N_FIELDS]; tbl++) {
476 struct cls_bucket *bucket, *next_bucket;
478 HMAP_FOR_EACH_SAFE (bucket, next_bucket, hmap_node, tbl) {
479 struct cls_rule *prev_rule, *rule;
481 /* We can't just use LIST_FOR_EACH_SAFE here because, if the
482 * callback deletes the last rule in the bucket, then the
483 * bucket itself will be destroyed. The bucket contains the
484 * list head so that's a use-after-free error. */
486 LIST_FOR_EACH (rule, node.list, &bucket->rules) {
488 callback(prev_rule, aux);
493 callback(prev_rule, aux);
499 if (include & CLS_INC_EXACT) {
500 struct cls_rule *rule, *next_rule;
502 HMAP_FOR_EACH_SAFE (rule, next_rule, node.hmap, &cls->exact_table) {
508 static struct cls_bucket *create_bucket(struct hmap *, size_t hash,
509 const flow_t *fixed);
510 static struct cls_rule *bucket_insert(struct cls_bucket *, struct cls_rule *);
512 static inline bool equal_bytes(const void *, const void *, size_t n);
514 /* Returns a hash computed across the fields in 'flow' whose field indexes
515 * (CLS_F_IDX_*) are less than 'table_idx'. (If 'table_idx' is
516 * CLS_F_IDX_EXACT, hashes all the fields in 'flow'). */
518 hash_fields(const flow_t *flow, int table_idx)
520 /* I just know I'm going to hell for writing code this way.
522 * GCC generates pretty good code here, with only a single taken
523 * conditional jump per execution. Now the question is, would we be better
524 * off marking this function ALWAYS_INLINE and writing a wrapper that
525 * switches on the value of 'table_idx' to get rid of all the conditional
526 * jumps entirely (except for one in the wrapper)? Honestly I really,
527 * really hope that it doesn't matter in practice.
529 * We could do better by calculating hashes incrementally, instead of
530 * starting over from the top each time. But that would be even uglier. */
535 a = b = c = 0xdeadbeef + table_idx;
538 #define CLS_FIELD(WILDCARDS, MEMBER, NAME) \
539 if (table_idx == CLS_F_IDX_##NAME) { \
541 memset((uint8_t *) tmp + n, 0, sizeof tmp - n); \
544 const size_t size = sizeof flow->MEMBER; \
545 const uint8_t *p1 = (const uint8_t *) &flow->MEMBER; \
546 const size_t p1_size = MIN(sizeof tmp - n, size); \
547 const uint8_t *p2 = p1 + p1_size; \
548 const size_t p2_size = size - p1_size; \
550 /* Append to 'tmp' as much data as will fit. */ \
551 memcpy((uint8_t *) tmp + n, p1, p1_size); \
554 /* If 'tmp' is full, mix. */ \
555 if (n == sizeof tmp) { \
563 /* Append to 'tmp' any data that didn't fit. */ \
564 memcpy(tmp, p2, p2_size); \
578 /* Compares the fields in 'a' and 'b' whose field indexes (CLS_F_IDX_*) are
579 * less than 'table_idx'. (If 'table_idx' is CLS_F_IDX_EXACT, compares all the
580 * fields in 'a' and 'b').
582 * Returns true if all the compared fields are equal, false otherwise. */
584 equal_fields(const flow_t *a, const flow_t *b, int table_idx)
586 /* XXX The generated code could be better here. */
587 #define CLS_FIELD(WILDCARDS, MEMBER, NAME) \
588 if (table_idx == CLS_F_IDX_##NAME) { \
590 } else if (!equal_bytes(&a->MEMBER, &b->MEMBER, sizeof a->MEMBER)) { \
600 table_idx_from_wildcards(uint32_t wildcards)
603 return CLS_F_IDX_EXACT;
605 #define CLS_FIELD(WILDCARDS, MEMBER, NAME) \
606 if (wildcards & WILDCARDS) { \
607 return CLS_F_IDX_##NAME; \
614 /* Inserts 'rule' into 'table'. Returns the rule, if any, that was displaced
615 * in favor of 'rule'. */
616 static struct cls_rule *
617 table_insert(struct hmap *table, struct cls_rule *rule)
619 struct cls_bucket *bucket;
622 hash = hash_fields(&rule->flow, rule->table_idx);
623 bucket = find_bucket(table, hash, rule);
625 bucket = create_bucket(table, hash, &rule->flow);
628 return bucket_insert(bucket, rule);
631 /* Inserts 'rule' into 'bucket', given that 'field' is the first wildcarded
634 * Returns the rule, if any, that was displaced in favor of 'rule'. */
635 static struct cls_rule *
636 bucket_insert(struct cls_bucket *bucket, struct cls_rule *rule)
638 struct cls_rule *pos;
639 LIST_FOR_EACH (pos, node.list, &bucket->rules) {
640 if (pos->priority == rule->priority) {
641 if (pos->wc.wildcards == rule->wc.wildcards
642 && rules_match_1wild(pos, rule, rule->table_idx))
644 list_replace(&rule->node.list, &pos->node.list);
647 } else if (pos->priority < rule->priority) {
651 list_insert(&pos->node.list, &rule->node.list);
655 static struct cls_rule *
656 insert_exact_rule(struct classifier *cls, struct cls_rule *rule)
658 struct cls_rule *old_rule;
661 hash = flow_hash(&rule->flow, 0);
662 old_rule = search_exact_table(cls, hash, &rule->flow);
664 hmap_remove(&cls->exact_table, &old_rule->node.hmap);
666 hmap_insert(&cls->exact_table, &rule->node.hmap, hash);
670 /* Returns the bucket in 'table' that has the given 'hash' and the same fields
671 * as 'rule->flow' (up to 'rule->table_idx'), or a null pointer if no bucket
673 static struct cls_bucket *
674 find_bucket(struct hmap *table, size_t hash, const struct cls_rule *rule)
676 struct cls_bucket *bucket;
677 HMAP_FOR_EACH_WITH_HASH (bucket, hmap_node, hash, table) {
678 if (equal_fields(&bucket->fixed, &rule->flow, rule->table_idx)) {
685 /* Creates a bucket and inserts it in 'table' with the given 'hash' and 'fixed'
686 * values. Returns the new bucket. */
687 static struct cls_bucket *
688 create_bucket(struct hmap *table, size_t hash, const flow_t *fixed)
690 struct cls_bucket *bucket = xmalloc(sizeof *bucket);
691 list_init(&bucket->rules);
692 bucket->fixed = *fixed;
693 hmap_insert(table, &bucket->hmap_node, hash);
697 /* Returns true if the 'n' bytes in 'a' and 'b' are equal, false otherwise. */
698 static inline bool ALWAYS_INLINE
699 equal_bytes(const void *a, const void *b, size_t n)
702 /* For some reason GCC generates stupid code for memcmp() of small
703 * constant integer lengths. Help it out.
705 * This function is always inlined, and it is always called with 'n' as a
706 * compile-time constant, so the switch statement gets optimized out and
707 * this whole function just expands to an instruction or two. */
710 return *(uint8_t *) a == *(uint8_t *) b;
713 return *(uint16_t *) a == *(uint16_t *) b;
716 return *(uint32_t *) a == *(uint32_t *) b;
719 return (*(uint32_t *) a == *(uint32_t *) b
720 && ((uint16_t *) a)[2] == ((uint16_t *) b)[2]);
726 /* I hope GCC is smarter on your platform. */
727 return !memcmp(a, b, n);
731 /* Returns the 32-bit unsigned integer at 'p'. */
732 static inline uint32_t
733 read_uint32(const void *p)
735 /* GCC optimizes this into a single machine instruction on x86. */
737 memcpy(&x, p, sizeof x);
741 /* Compares the specified field in 'a' and 'b'. Returns true if the fields are
742 * equal, or if the ofp_match wildcard bits in 'wildcards' are set such that
743 * non-equal values may be ignored. 'nw_src_mask' and 'nw_dst_mask' must be
744 * those that would be set for 'wildcards' by cls_rule_set_masks().
746 * The compared field is the one with wildcard bit or bits 'field_wc', offset
747 * 'rule_ofs' within cls_rule's "fields" member, and length 'len', in bytes. */
748 static inline bool ALWAYS_INLINE
749 field_matches(const flow_t *a_, const flow_t *b_,
750 uint32_t wildcards, uint32_t nw_src_mask, uint32_t nw_dst_mask,
751 uint32_t field_wc, int ofs, int len)
753 /* This function is always inlined, and it is always called with 'field_wc'
754 * as a compile-time constant, so the "if" conditionals here generate no
756 const void *a = (const uint8_t *) a_ + ofs;
757 const void *b = (const uint8_t *) b_ + ofs;
758 if (!(field_wc & (field_wc - 1))) {
759 /* Handle all the single-bit wildcard cases. */
760 return wildcards & field_wc || equal_bytes(a, b, len);
761 } else if (field_wc == OFPFW_NW_SRC_MASK ||
762 field_wc == OFPFW_NW_DST_MASK) {
763 uint32_t a_ip = read_uint32(a);
764 uint32_t b_ip = read_uint32(b);
765 uint32_t mask = (field_wc == OFPFW_NW_SRC_MASK
766 ? nw_src_mask : nw_dst_mask);
767 return ((a_ip ^ b_ip) & mask) == 0;
773 /* Returns true if 'a' and 'b' match, ignoring fields for which the wildcards
774 * in 'wildcards' are set. 'nw_src_mask' and 'nw_dst_mask' must be those that
775 * would be set for 'wildcards' by cls_rule_set_masks(). 'field_idx' is the
776 * index of the first field to be compared; fields before 'field_idx' are
777 * assumed to match. (Always returns true if 'field_idx' is CLS_N_FIELDS.) */
779 rules_match(const struct cls_rule *a, const struct cls_rule *b,
780 uint32_t wildcards, uint32_t nw_src_mask, uint32_t nw_dst_mask,
783 /* This is related to Duff's device (see
784 * http://en.wikipedia.org/wiki/Duff's_device). */
786 #define CLS_FIELD(WILDCARDS, MEMBER, NAME) \
787 case CLS_F_IDX_##NAME: \
788 if (!field_matches(&a->flow, &b->flow, \
789 wildcards, nw_src_mask, nw_dst_mask, \
790 WILDCARDS, offsetof(flow_t, MEMBER), \
791 sizeof a->flow.MEMBER)) { \
801 /* Returns true if 'fixed' and 'wild' match. All fields in 'fixed' must have
802 * fixed values; 'wild' may contain wildcards.
804 * 'field_idx' is the index of the first field to be compared; fields before
805 * 'field_idx' are assumed to match. Always returns true if 'field_idx' is
808 rules_match_1wild(const struct cls_rule *fixed, const struct cls_rule *wild,
811 return rules_match(fixed, wild, wild->wc.wildcards, wild->wc.nw_src_mask,
812 wild->wc.nw_dst_mask, field_idx);
815 /* Returns true if 'wild1' and 'wild2' match, that is, if their fields
816 * are equal modulo wildcards in 'wild1' or 'wild2'.
818 * 'field_idx' is the index of the first field to be compared; fields before
819 * 'field_idx' are assumed to match. Always returns true if 'field_idx' is
822 rules_match_2wild(const struct cls_rule *wild1, const struct cls_rule *wild2,
825 return rules_match(wild1, wild2,
826 wild1->wc.wildcards | wild2->wc.wildcards,
827 wild1->wc.nw_src_mask & wild2->wc.nw_src_mask,
828 wild1->wc.nw_dst_mask & wild2->wc.nw_dst_mask,
832 /* Searches 'bucket' for a rule that matches 'target'. Returns the
833 * highest-priority match, if one is found, or a null pointer if there is no
836 * 'field_idx' must be the index of the first wildcarded field in 'bucket'. */
837 static struct cls_rule *
838 search_bucket(struct cls_bucket *bucket, int field_idx,
839 const struct cls_rule *target)
841 struct cls_rule *pos;
843 if (!equal_fields(&bucket->fixed, &target->flow, field_idx)) {
847 LIST_FOR_EACH (pos, node.list, &bucket->rules) {
848 if (rules_match_1wild(target, pos, field_idx)) {
855 /* Searches 'table' for a rule that matches 'target'. Returns the
856 * highest-priority match, if one is found, or a null pointer if there is no
859 * 'field_idx' must be the index of the first wildcarded field in 'table'. */
860 static struct cls_rule *
861 search_table(const struct hmap *table, int field_idx,
862 const struct cls_rule *target)
864 struct cls_bucket *bucket;
866 switch (hmap_count(table)) {
867 /* In these special cases there's no need to hash. */
871 bucket = CONTAINER_OF(hmap_first(table), struct cls_bucket, hmap_node);
872 return search_bucket(bucket, field_idx, target);
875 HMAP_FOR_EACH_WITH_HASH (bucket, hmap_node,
876 hash_fields(&target->flow, field_idx), table) {
877 struct cls_rule *rule = search_bucket(bucket, field_idx, target);
885 static struct cls_rule *
886 search_exact_table(const struct classifier *cls, size_t hash,
887 const flow_t *target)
889 struct cls_rule *rule;
891 HMAP_FOR_EACH_WITH_HASH (rule, node.hmap, hash, &cls->exact_table) {
892 if (flow_equal(&rule->flow, target)) {