2 * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2014, 2015 Nicira, Inc.
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"
19 #include "classifier-private.h"
21 #include <netinet/in.h>
22 #include "byte-order.h"
23 #include "dynamic-string.h"
28 #include "openvswitch/vlog.h"
30 VLOG_DEFINE_THIS_MODULE(classifier);
34 /* A collection of "struct cls_conjunction"s currently embedded into a
36 struct cls_conjunction_set {
37 /* Link back to the cls_match.
39 * cls_conjunction_set is mostly used during classifier lookup, and, in
40 * turn, during classifier lookup the most used member of
41 * cls_conjunction_set is the rule's priority, so we cache it here for fast
43 struct cls_match *match;
44 int priority; /* Cached copy of match->priority. */
46 /* Conjunction information.
48 * 'min_n_clauses' allows some optimization during classifier lookup. */
49 unsigned int n; /* Number of elements in 'conj'. */
50 unsigned int min_n_clauses; /* Smallest 'n' among elements of 'conj'. */
51 struct cls_conjunction conj[];
54 /* Ports trie depends on both ports sharing the same ovs_be32. */
55 #define TP_PORTS_OFS32 (offsetof(struct flow, tp_src) / 4)
56 BUILD_ASSERT_DECL(TP_PORTS_OFS32 == offsetof(struct flow, tp_dst) / 4);
57 BUILD_ASSERT_DECL(TP_PORTS_OFS32 % 2 == 0);
58 #define TP_PORTS_OFS64 (TP_PORTS_OFS32 / 2)
61 cls_conjunction_set_size(size_t n)
63 return (sizeof(struct cls_conjunction_set)
64 + n * sizeof(struct cls_conjunction));
67 static struct cls_conjunction_set *
68 cls_conjunction_set_alloc(struct cls_match *match,
69 const struct cls_conjunction conj[], size_t n)
72 size_t min_n_clauses = conj[0].n_clauses;
73 for (size_t i = 1; i < n; i++) {
74 min_n_clauses = MIN(min_n_clauses, conj[i].n_clauses);
77 struct cls_conjunction_set *set = xmalloc(cls_conjunction_set_size(n));
79 set->priority = match->priority;
81 set->min_n_clauses = min_n_clauses;
82 memcpy(set->conj, conj, n * sizeof *conj);
89 static struct cls_match *
90 cls_match_alloc(const struct cls_rule *rule,
91 const struct cls_conjunction conj[], size_t n)
93 int count = count_1bits(rule->match.flow.map);
95 struct cls_match *cls_match
96 = xmalloc(sizeof *cls_match - sizeof cls_match->flow.inline_values
97 + MINIFLOW_VALUES_SIZE(count));
99 ovsrcu_init(&cls_match->next, NULL);
100 *CONST_CAST(const struct cls_rule **, &cls_match->cls_rule) = rule;
101 *CONST_CAST(int *, &cls_match->priority) = rule->priority;
102 atomic_init(&cls_match->visibility, 0); /* Initially invisible. */
103 miniflow_clone_inline(CONST_CAST(struct miniflow *, &cls_match->flow),
104 &rule->match.flow, count);
105 ovsrcu_set_hidden(&cls_match->conj_set,
106 cls_conjunction_set_alloc(cls_match, conj, n));
111 static struct cls_subtable *find_subtable(const struct classifier *cls,
112 const struct minimask *);
113 static struct cls_subtable *insert_subtable(struct classifier *cls,
114 const struct minimask *);
115 static void destroy_subtable(struct classifier *cls, struct cls_subtable *);
117 static const struct cls_match *find_match_wc(const struct cls_subtable *,
121 unsigned int n_tries,
122 struct flow_wildcards *);
123 static struct cls_match *find_equal(const struct cls_subtable *,
124 const struct miniflow *, uint32_t hash);
126 /* Return the next visible (lower-priority) rule in the list. Multiple
127 * identical rules with the same priority may exist transitionally, but when
128 * versioning is used at most one of them is ever visible for lookups on any
129 * given 'version'. */
130 static inline const struct cls_match *
131 next_visible_rule_in_list(const struct cls_match *rule, long long version)
134 rule = cls_match_next(rule);
136 /* We have reached the head of the list, stop. */
139 } while (!cls_match_visible_in_version(rule, version));
144 static unsigned int minimask_get_prefix_len(const struct minimask *,
145 const struct mf_field *);
146 static void trie_init(struct classifier *cls, int trie_idx,
147 const struct mf_field *);
148 static unsigned int trie_lookup(const struct cls_trie *, const struct flow *,
149 union mf_value *plens);
150 static unsigned int trie_lookup_value(const rcu_trie_ptr *,
151 const ovs_be32 value[], ovs_be32 plens[],
152 unsigned int value_bits);
153 static void trie_destroy(rcu_trie_ptr *);
154 static void trie_insert(struct cls_trie *, const struct cls_rule *, int mlen);
155 static void trie_insert_prefix(rcu_trie_ptr *, const ovs_be32 *prefix,
157 static void trie_remove(struct cls_trie *, const struct cls_rule *, int mlen);
158 static void trie_remove_prefix(rcu_trie_ptr *, const ovs_be32 *prefix,
160 static void mask_set_prefix_bits(struct flow_wildcards *, uint8_t be32ofs,
161 unsigned int n_bits);
162 static bool mask_prefix_bits_set(const struct flow_wildcards *,
163 uint8_t be32ofs, unsigned int n_bits);
168 cls_rule_init__(struct cls_rule *rule, unsigned int priority,
171 ovs_assert(version > 0);
173 rculist_init(&rule->node);
174 *CONST_CAST(int *, &rule->priority) = priority;
175 *CONST_CAST(long long *, &rule->version) = version;
176 rule->cls_match = NULL;
179 /* Initializes 'rule' to match packets specified by 'match' at the given
180 * 'priority'. 'match' must satisfy the invariant described in the comment at
181 * the definition of struct match.
183 * The caller must eventually destroy 'rule' with cls_rule_destroy().
185 * Clients should not use priority INT_MIN. (OpenFlow uses priorities between
186 * 0 and UINT16_MAX, inclusive.) */
188 cls_rule_init(struct cls_rule *rule, const struct match *match, int priority,
191 cls_rule_init__(rule, priority, version);
192 minimatch_init(CONST_CAST(struct minimatch *, &rule->match), match);
195 /* Same as cls_rule_init() for initialization from a "struct minimatch". */
197 cls_rule_init_from_minimatch(struct cls_rule *rule,
198 const struct minimatch *match, int priority,
201 cls_rule_init__(rule, priority, version);
202 minimatch_clone(CONST_CAST(struct minimatch *, &rule->match), match);
205 /* Initializes 'dst' as a copy of 'src'.
207 * The caller must eventually destroy 'dst' with cls_rule_destroy(). */
209 cls_rule_clone(struct cls_rule *dst, const struct cls_rule *src)
211 cls_rule_init__(dst, src->priority, src->version);
212 minimatch_clone(CONST_CAST(struct minimatch *, &dst->match), &src->match);
215 /* Initializes 'dst' with the data in 'src', destroying 'src'.
217 * 'src' must be a cls_rule NOT in a classifier.
219 * The caller must eventually destroy 'dst' with cls_rule_destroy(). */
221 cls_rule_move(struct cls_rule *dst, struct cls_rule *src)
223 cls_rule_init__(dst, src->priority, src->version);
224 minimatch_move(CONST_CAST(struct minimatch *, &dst->match),
225 CONST_CAST(struct minimatch *, &src->match));
228 /* Frees memory referenced by 'rule'. Doesn't free 'rule' itself (it's
229 * normally embedded into a larger structure).
231 * ('rule' must not currently be in a classifier.) */
233 cls_rule_destroy(struct cls_rule *rule)
235 ovs_assert(!rule->cls_match); /* Must not be in a classifier. */
237 /* Check that the rule has been properly removed from the classifier and
238 * that the destruction only happens after the RCU grace period, or that
239 * the rule was never inserted to the classifier in the first place. */
240 ovs_assert(rculist_next_protected(&rule->node) == RCULIST_POISON
241 || rculist_is_empty(&rule->node));
243 minimatch_destroy(CONST_CAST(struct minimatch *, &rule->match));
247 cls_rule_set_conjunctions(struct cls_rule *cr,
248 const struct cls_conjunction *conj, size_t n)
250 struct cls_match *match = cr->cls_match;
251 struct cls_conjunction_set *old
252 = ovsrcu_get_protected(struct cls_conjunction_set *, &match->conj_set);
253 struct cls_conjunction *old_conj = old ? old->conj : NULL;
254 unsigned int old_n = old ? old->n : 0;
256 if (old_n != n || (n && memcmp(old_conj, conj, n * sizeof *conj))) {
258 ovsrcu_postpone(free, old);
260 ovsrcu_set(&match->conj_set,
261 cls_conjunction_set_alloc(match, conj, n));
266 /* Returns true if 'a' and 'b' match the same packets at the same priority,
267 * false if they differ in some way. */
269 cls_rule_equal(const struct cls_rule *a, const struct cls_rule *b)
271 return a->priority == b->priority && minimatch_equal(&a->match, &b->match);
274 /* Returns a hash value for 'rule', folding in 'basis'. */
276 cls_rule_hash(const struct cls_rule *rule, uint32_t basis)
278 return minimatch_hash(&rule->match, hash_int(rule->priority, basis));
281 /* Appends a string describing 'rule' to 's'. */
283 cls_rule_format(const struct cls_rule *rule, struct ds *s)
285 minimatch_format(&rule->match, s, rule->priority);
288 /* Returns true if 'rule' matches every packet, false otherwise. */
290 cls_rule_is_catchall(const struct cls_rule *rule)
292 return minimask_is_catchall(&rule->match.mask);
295 /* Makes rule invisible after 'version'. Once that version is made invisible
296 * (by changing the version parameter used in lookups), the rule should be
297 * actually removed via ovsrcu_postpone().
299 * 'rule_' must be in a classifier. */
301 cls_rule_make_invisible_in_version(const struct cls_rule *rule_,
302 long long version, long long lookup_version)
304 struct cls_match *rule = rule_->cls_match;
306 /* XXX: Adjust when versioning is actually used. */
307 ovs_assert(version >= rule_->version && version >= lookup_version);
309 /* Normally, we call this when deleting a rule that is already visible to
310 * lookups. However, sometimes a bundle transaction will add a rule and
311 * then delete it before the rule has ever become visible. If we set such
312 * a rule to become invisible in a future 'version', it would become
313 * visible to all prior versions. So, in this case we must set the rule
314 * visibility to 0 (== never visible). */
315 if (cls_match_visible_in_version(rule, lookup_version)) {
316 /* Make invisible starting at 'version'. */
317 atomic_store_relaxed(&rule->visibility, -version);
319 /* Rule has not yet been visible to lookups, make invisible in all
321 atomic_store_relaxed(&rule->visibility, 0);
325 /* This undoes the change made by cls_rule_make_invisible_after_version().
327 * 'rule' must be in a classifier. */
329 cls_rule_restore_visibility(const struct cls_rule *rule)
331 atomic_store_relaxed(&rule->cls_match->visibility, rule->version);
334 /* Return true if 'rule' is visible in 'version'.
336 * 'rule' must be in a classifier. */
338 cls_rule_visible_in_version(const struct cls_rule *rule, long long version)
340 return cls_match_visible_in_version(rule->cls_match, version);
343 /* Initializes 'cls' as a classifier that initially contains no classification
346 classifier_init(struct classifier *cls, const uint8_t *flow_segments)
349 cmap_init(&cls->subtables_map);
350 pvector_init(&cls->subtables);
351 cmap_init(&cls->partitions);
352 cls->n_flow_segments = 0;
354 while (cls->n_flow_segments < CLS_MAX_INDICES
355 && *flow_segments < FLOW_U64S) {
356 cls->flow_segments[cls->n_flow_segments++] = *flow_segments++;
360 for (int i = 0; i < CLS_MAX_TRIES; i++) {
361 trie_init(cls, i, NULL);
366 /* Destroys 'cls'. Rules within 'cls', if any, are not freed; this is the
367 * caller's responsibility.
368 * May only be called after all the readers have been terminated. */
370 classifier_destroy(struct classifier *cls)
373 struct cls_partition *partition;
374 struct cls_subtable *subtable;
377 for (i = 0; i < cls->n_tries; i++) {
378 trie_destroy(&cls->tries[i].root);
381 CMAP_FOR_EACH (subtable, cmap_node, &cls->subtables_map) {
382 destroy_subtable(cls, subtable);
384 cmap_destroy(&cls->subtables_map);
386 CMAP_FOR_EACH (partition, cmap_node, &cls->partitions) {
387 ovsrcu_postpone(free, partition);
389 cmap_destroy(&cls->partitions);
391 pvector_destroy(&cls->subtables);
395 /* Set the fields for which prefix lookup should be performed. */
397 classifier_set_prefix_fields(struct classifier *cls,
398 const enum mf_field_id *trie_fields,
399 unsigned int n_fields)
401 const struct mf_field * new_fields[CLS_MAX_TRIES];
402 struct mf_bitmap fields = MF_BITMAP_INITIALIZER;
404 bool changed = false;
406 for (i = 0; i < n_fields && n_tries < CLS_MAX_TRIES; i++) {
407 const struct mf_field *field = mf_from_id(trie_fields[i]);
408 if (field->flow_be32ofs < 0 || field->n_bits % 32) {
409 /* Incompatible field. This is the only place where we
410 * enforce these requirements, but the rest of the trie code
411 * depends on the flow_be32ofs to be non-negative and the
412 * field length to be a multiple of 32 bits. */
416 if (bitmap_is_set(fields.bm, trie_fields[i])) {
417 /* Duplicate field, there is no need to build more than
418 * one index for any one field. */
421 bitmap_set1(fields.bm, trie_fields[i]);
423 new_fields[n_tries] = NULL;
424 if (n_tries >= cls->n_tries || field != cls->tries[n_tries].field) {
425 new_fields[n_tries] = field;
431 if (changed || n_tries < cls->n_tries) {
432 struct cls_subtable *subtable;
434 /* Trie configuration needs to change. Disable trie lookups
435 * for the tries that are changing and wait all the current readers
436 * with the old configuration to be done. */
438 CMAP_FOR_EACH (subtable, cmap_node, &cls->subtables_map) {
439 for (i = 0; i < cls->n_tries; i++) {
440 if ((i < n_tries && new_fields[i]) || i >= n_tries) {
441 if (subtable->trie_plen[i]) {
442 subtable->trie_plen[i] = 0;
448 /* Synchronize if any readers were using tries. The readers may
449 * temporarily function without the trie lookup based optimizations. */
451 /* ovsrcu_synchronize() functions as a memory barrier, so it does
452 * not matter that subtable->trie_plen is not atomic. */
453 ovsrcu_synchronize();
456 /* Now set up the tries. */
457 for (i = 0; i < n_tries; i++) {
459 trie_init(cls, i, new_fields[i]);
462 /* Destroy the rest, if any. */
463 for (; i < cls->n_tries; i++) {
464 trie_init(cls, i, NULL);
467 cls->n_tries = n_tries;
471 return false; /* No change. */
475 trie_init(struct classifier *cls, int trie_idx, const struct mf_field *field)
477 struct cls_trie *trie = &cls->tries[trie_idx];
478 struct cls_subtable *subtable;
480 if (trie_idx < cls->n_tries) {
481 trie_destroy(&trie->root);
483 ovsrcu_set_hidden(&trie->root, NULL);
487 /* Add existing rules to the new trie. */
488 CMAP_FOR_EACH (subtable, cmap_node, &cls->subtables_map) {
491 plen = field ? minimask_get_prefix_len(&subtable->mask, field) : 0;
493 struct cls_match *head;
495 CMAP_FOR_EACH (head, cmap_node, &subtable->rules) {
496 trie_insert(trie, head->cls_rule, plen);
499 /* Initialize subtable's prefix length on this field. This will
500 * allow readers to use the trie. */
501 atomic_thread_fence(memory_order_release);
502 subtable->trie_plen[trie_idx] = plen;
506 /* Returns true if 'cls' contains no classification rules, false otherwise.
507 * Checking the cmap requires no locking. */
509 classifier_is_empty(const struct classifier *cls)
511 return cmap_is_empty(&cls->subtables_map);
514 /* Returns the number of rules in 'cls'. */
516 classifier_count(const struct classifier *cls)
518 /* n_rules is an int, so in the presence of concurrent writers this will
519 * return either the old or a new value. */
524 hash_metadata(ovs_be64 metadata)
526 return hash_uint64((OVS_FORCE uint64_t) metadata);
529 static struct cls_partition *
530 find_partition(const struct classifier *cls, ovs_be64 metadata, uint32_t hash)
532 struct cls_partition *partition;
534 CMAP_FOR_EACH_WITH_HASH (partition, cmap_node, hash, &cls->partitions) {
535 if (partition->metadata == metadata) {
543 static struct cls_partition *
544 create_partition(struct classifier *cls, struct cls_subtable *subtable,
547 uint32_t hash = hash_metadata(metadata);
548 struct cls_partition *partition = find_partition(cls, metadata, hash);
550 partition = xmalloc(sizeof *partition);
551 partition->metadata = metadata;
553 tag_tracker_init(&partition->tracker);
554 cmap_insert(&cls->partitions, &partition->cmap_node, hash);
556 tag_tracker_add(&partition->tracker, &partition->tags, subtable->tag);
560 static inline ovs_be32 minimatch_get_ports(const struct minimatch *match)
562 /* Could optimize to use the same map if needed for fast path. */
563 return MINIFLOW_GET_BE32(&match->flow, tp_src)
564 & MINIFLOW_GET_BE32(&match->mask.masks, tp_src);
568 subtable_replace_head_rule(struct classifier *cls OVS_UNUSED,
569 struct cls_subtable *subtable,
570 struct cls_match *head, struct cls_match *new,
571 uint32_t hash, uint32_t ihash[CLS_MAX_INDICES])
573 /* Rule's data is already in the tries. */
575 new->partition = head->partition; /* Steal partition, if any. */
576 head->partition = NULL;
578 for (int i = 0; i < subtable->n_indices; i++) {
579 cmap_replace(&subtable->indices[i], &head->index_nodes[i],
580 &new->index_nodes[i], ihash[i]);
582 cmap_replace(&subtable->rules, &head->cmap_node, &new->cmap_node, hash);
585 /* Inserts 'rule' into 'cls'. Until 'rule' is removed from 'cls', the caller
586 * must not modify or free it.
588 * If 'cls' already contains an identical rule (including wildcards, values of
589 * fixed fields, and priority), replaces the old rule by 'rule' and returns the
590 * rule that was replaced. The caller takes ownership of the returned rule and
591 * is thus responsible for destroying it with cls_rule_destroy(), after RCU
592 * grace period has passed (see ovsrcu_postpone()).
594 * Returns NULL if 'cls' does not contain a rule with an identical key, after
595 * inserting the new rule. In this case, no rules are displaced by the new
596 * rule, even rules that cannot have any effect because the new rule matches a
597 * superset of their flows and has higher priority.
599 const struct cls_rule *
600 classifier_replace(struct classifier *cls, const struct cls_rule *rule,
601 const struct cls_conjunction *conjs, size_t n_conjs)
603 struct cls_match *new;
604 struct cls_subtable *subtable;
605 uint32_t ihash[CLS_MAX_INDICES];
606 uint8_t prev_be64ofs = 0;
607 struct cls_match *head;
613 ovs_assert(rule->version > 0);
615 /* 'new' is initially invisible to lookups. */
616 new = cls_match_alloc(rule, conjs, n_conjs);
618 CONST_CAST(struct cls_rule *, rule)->cls_match = new;
620 subtable = find_subtable(cls, &rule->match.mask);
622 subtable = insert_subtable(cls, &rule->match.mask);
625 /* Compute hashes in segments. */
627 for (i = 0; i < subtable->n_indices; i++) {
628 ihash[i] = minimatch_hash_range(&rule->match, prev_be64ofs,
629 subtable->index_ofs[i], &basis);
630 prev_be64ofs = subtable->index_ofs[i];
632 hash = minimatch_hash_range(&rule->match, prev_be64ofs, FLOW_U64S, &basis);
634 head = find_equal(subtable, &rule->match.flow, hash);
636 /* Add rule to tries.
638 * Concurrent readers might miss seeing the rule until this update,
639 * which might require being fixed up by revalidation later. */
640 for (i = 0; i < cls->n_tries; i++) {
641 if (subtable->trie_plen[i]) {
642 trie_insert(&cls->tries[i], rule, subtable->trie_plen[i]);
646 /* Add rule to ports trie. */
647 if (subtable->ports_mask_len) {
648 /* We mask the value to be inserted to always have the wildcarded
649 * bits in known (zero) state, so we can include them in comparison
650 * and they will always match (== their original value does not
652 ovs_be32 masked_ports = minimatch_get_ports(&rule->match);
654 trie_insert_prefix(&subtable->ports_trie, &masked_ports,
655 subtable->ports_mask_len);
658 /* Add rule to partitions.
660 * Concurrent readers might miss seeing the rule until this update,
661 * which might require being fixed up by revalidation later. */
662 new->partition = NULL;
663 if (minimask_get_metadata_mask(&rule->match.mask) == OVS_BE64_MAX) {
664 ovs_be64 metadata = miniflow_get_metadata(&rule->match.flow);
666 new->partition = create_partition(cls, subtable, metadata);
669 /* Add new node to segment indices.
671 * Readers may find the rule in the indices before the rule is visible
672 * in the subtables 'rules' map. This may result in us losing the
673 * opportunity to quit lookups earlier, resulting in sub-optimal
674 * wildcarding. This will be fixed later by revalidation (always
675 * scheduled after flow table changes). */
676 for (i = 0; i < subtable->n_indices; i++) {
677 cmap_insert(&subtable->indices[i], &new->index_nodes[i], ihash[i]);
679 n_rules = cmap_insert(&subtable->rules, &new->cmap_node, hash);
680 } else { /* Equal rules exist in the classifier already. */
681 struct cls_match *prev, *iter;
683 /* Scan the list for the insertion point that will keep the list in
684 * order of decreasing priority. Insert after rules marked invisible
685 * in any version of the same priority. */
686 FOR_EACH_RULE_IN_LIST_PROTECTED (iter, prev, head) {
687 if (rule->priority > iter->priority
688 || (rule->priority == iter->priority
689 && !cls_match_is_eventually_invisible(iter))) {
694 /* Replace 'iter' with 'new' or insert 'new' between 'prev' and
697 struct cls_rule *old;
699 if (rule->priority == iter->priority) {
700 cls_match_replace(prev, iter, new);
701 old = CONST_CAST(struct cls_rule *, iter->cls_rule);
703 cls_match_insert(prev, iter, new);
707 /* Replace the existing head in data structures, if rule is the new
710 subtable_replace_head_rule(cls, subtable, head, new, hash,
715 struct cls_conjunction_set *conj_set;
717 conj_set = ovsrcu_get_protected(struct cls_conjunction_set *,
720 ovsrcu_postpone(free, conj_set);
723 ovsrcu_postpone(cls_match_free_cb, iter);
724 old->cls_match = NULL;
726 /* No change in subtable's max priority or max count. */
728 /* Make 'new' visible to lookups in the appropriate version. */
729 cls_match_set_visibility(new, rule->version);
731 /* Make rule visible to iterators (immediately). */
732 rculist_replace(CONST_CAST(struct rculist *, &rule->node),
735 /* Return displaced rule. Caller is responsible for keeping it
736 * around until all threads quiesce. */
740 /* 'new' is new node after 'prev' */
741 cls_match_insert(prev, iter, new);
745 /* Make 'new' visible to lookups in the appropriate version. */
746 cls_match_set_visibility(new, rule->version);
748 /* Make rule visible to iterators (immediately). */
749 rculist_push_back(&subtable->rules_list,
750 CONST_CAST(struct rculist *, &rule->node));
752 /* Rule was added, not replaced. Update 'subtable's 'max_priority' and
753 * 'max_count', if necessary.
755 * The rule was already inserted, but concurrent readers may not see the
756 * rule yet as the subtables vector is not updated yet. This will have to
757 * be fixed by revalidation later. */
759 subtable->max_priority = rule->priority;
760 subtable->max_count = 1;
761 pvector_insert(&cls->subtables, subtable, rule->priority);
762 } else if (rule->priority == subtable->max_priority) {
763 ++subtable->max_count;
764 } else if (rule->priority > subtable->max_priority) {
765 subtable->max_priority = rule->priority;
766 subtable->max_count = 1;
767 pvector_change_priority(&cls->subtables, subtable, rule->priority);
770 /* Nothing was replaced. */
774 pvector_publish(&cls->subtables);
780 /* Inserts 'rule' into 'cls'. Until 'rule' is removed from 'cls', the caller
781 * must not modify or free it.
783 * 'cls' must not contain an identical rule (including wildcards, values of
784 * fixed fields, and priority). Use classifier_find_rule_exactly() to find
787 classifier_insert(struct classifier *cls, const struct cls_rule *rule,
788 const struct cls_conjunction conj[], size_t n_conj)
790 const struct cls_rule *displaced_rule
791 = classifier_replace(cls, rule, conj, n_conj);
792 ovs_assert(!displaced_rule);
795 /* Removes 'rule' from 'cls'. It is the caller's responsibility to destroy
796 * 'rule' with cls_rule_destroy(), freeing the memory block in which 'rule'
797 * resides, etc., as necessary.
799 * Does nothing if 'rule' has been already removed, or was never inserted.
801 * Returns the removed rule, or NULL, if it was already removed.
803 const struct cls_rule *
804 classifier_remove(struct classifier *cls, const struct cls_rule *cls_rule)
806 struct cls_match *rule, *prev, *next, *head;
807 struct cls_partition *partition;
808 struct cls_conjunction_set *conj_set;
809 struct cls_subtable *subtable;
811 uint32_t basis = 0, hash, ihash[CLS_MAX_INDICES];
812 uint8_t prev_be64ofs = 0;
815 rule = cls_rule->cls_match;
819 /* Mark as removed. */
820 CONST_CAST(struct cls_rule *, cls_rule)->cls_match = NULL;
822 /* Remove 'cls_rule' from the subtable's rules list. */
823 rculist_remove(CONST_CAST(struct rculist *, &cls_rule->node));
825 subtable = find_subtable(cls, &cls_rule->match.mask);
826 ovs_assert(subtable);
828 for (i = 0; i < subtable->n_indices; i++) {
829 ihash[i] = minimatch_hash_range(&cls_rule->match, prev_be64ofs,
830 subtable->index_ofs[i], &basis);
831 prev_be64ofs = subtable->index_ofs[i];
833 hash = minimatch_hash_range(&cls_rule->match, prev_be64ofs, FLOW_U64S,
836 head = find_equal(subtable, &cls_rule->match.flow, hash);
838 /* Check if the rule is not the head rule. */
840 struct cls_match *iter;
842 /* Not the head rule, but potentially one with the same priority. */
843 /* Remove from the list of equal rules. */
844 FOR_EACH_RULE_IN_LIST_PROTECTED (iter, prev, head) {
849 ovs_assert(iter == rule);
851 cls_match_remove(prev, rule);
856 /* 'rule' is the head rule. Check if there is another rule to
857 * replace 'rule' in the data structures. */
858 next = cls_match_next_protected(rule);
860 subtable_replace_head_rule(cls, subtable, rule, next, hash, ihash);
864 /* 'rule' is last of the kind in the classifier, must remove from all the
865 * data structures. */
867 if (subtable->ports_mask_len) {
868 ovs_be32 masked_ports = minimatch_get_ports(&cls_rule->match);
870 trie_remove_prefix(&subtable->ports_trie,
871 &masked_ports, subtable->ports_mask_len);
873 for (i = 0; i < cls->n_tries; i++) {
874 if (subtable->trie_plen[i]) {
875 trie_remove(&cls->tries[i], cls_rule, subtable->trie_plen[i]);
879 /* Remove rule node from indices. */
880 for (i = 0; i < subtable->n_indices; i++) {
881 cmap_remove(&subtable->indices[i], &rule->index_nodes[i], ihash[i]);
883 n_rules = cmap_remove(&subtable->rules, &rule->cmap_node, hash);
885 partition = rule->partition;
887 tag_tracker_subtract(&partition->tracker, &partition->tags,
889 if (!partition->tags) {
890 cmap_remove(&cls->partitions, &partition->cmap_node,
891 hash_metadata(partition->metadata));
892 ovsrcu_postpone(free, partition);
897 destroy_subtable(cls, subtable);
900 if (subtable->max_priority == rule->priority
901 && --subtable->max_count == 0) {
902 /* Find the new 'max_priority' and 'max_count'. */
903 int max_priority = INT_MIN;
904 struct cls_match *head;
906 CMAP_FOR_EACH (head, cmap_node, &subtable->rules) {
907 if (head->priority > max_priority) {
908 max_priority = head->priority;
909 subtable->max_count = 1;
910 } else if (head->priority == max_priority) {
911 ++subtable->max_count;
914 subtable->max_priority = max_priority;
915 pvector_change_priority(&cls->subtables, subtable, max_priority);
920 pvector_publish(&cls->subtables);
924 conj_set = ovsrcu_get_protected(struct cls_conjunction_set *,
927 ovsrcu_postpone(free, conj_set);
929 ovsrcu_postpone(cls_match_free_cb, rule);
935 /* Prefix tree context. Valid when 'lookup_done' is true. Can skip all
936 * subtables which have a prefix match on the trie field, but whose prefix
937 * length is not indicated in 'match_plens'. For example, a subtable that
938 * has a 8-bit trie field prefix match can be skipped if
939 * !be_get_bit_at(&match_plens, 8 - 1). If skipped, 'maskbits' prefix bits
940 * must be unwildcarded to make datapath flow only match packets it should. */
942 const struct cls_trie *trie;
943 bool lookup_done; /* Status of the lookup. */
944 uint8_t be32ofs; /* U32 offset of the field in question. */
945 unsigned int maskbits; /* Prefix length needed to avoid false matches. */
946 union mf_value match_plens; /* Bitmask of prefix lengths with possible
951 trie_ctx_init(struct trie_ctx *ctx, const struct cls_trie *trie)
954 ctx->be32ofs = trie->field->flow_be32ofs;
955 ctx->lookup_done = false;
958 struct conjunctive_match {
959 struct hmap_node hmap_node;
964 static struct conjunctive_match *
965 find_conjunctive_match__(struct hmap *matches, uint64_t id, uint32_t hash)
967 struct conjunctive_match *m;
969 HMAP_FOR_EACH_IN_BUCKET (m, hmap_node, hash, matches) {
978 find_conjunctive_match(const struct cls_conjunction_set *set,
979 unsigned int max_n_clauses, struct hmap *matches,
980 struct conjunctive_match *cm_stubs, size_t n_cm_stubs,
983 const struct cls_conjunction *c;
985 if (max_n_clauses < set->min_n_clauses) {
989 for (c = set->conj; c < &set->conj[set->n]; c++) {
990 struct conjunctive_match *cm;
993 if (c->n_clauses > max_n_clauses) {
997 hash = hash_int(c->id, 0);
998 cm = find_conjunctive_match__(matches, c->id, hash);
1000 size_t n = hmap_count(matches);
1002 cm = n < n_cm_stubs ? &cm_stubs[n] : xmalloc(sizeof *cm);
1003 hmap_insert(matches, &cm->hmap_node, hash);
1005 cm->clauses = UINT64_MAX << (c->n_clauses & 63);
1007 cm->clauses |= UINT64_C(1) << c->clause;
1008 if (cm->clauses == UINT64_MAX) {
1017 free_conjunctive_matches(struct hmap *matches,
1018 struct conjunctive_match *cm_stubs, size_t n_cm_stubs)
1020 if (hmap_count(matches) > n_cm_stubs) {
1021 struct conjunctive_match *cm, *next;
1023 HMAP_FOR_EACH_SAFE (cm, next, hmap_node, matches) {
1024 if (!(cm >= cm_stubs && cm < &cm_stubs[n_cm_stubs])) {
1029 hmap_destroy(matches);
1032 /* Like classifier_lookup(), except that support for conjunctive matches can be
1033 * configured with 'allow_conjunctive_matches'. That feature is not exposed
1034 * externally because turning off conjunctive matches is only useful to avoid
1035 * recursion within this function itself.
1037 * 'flow' is non-const to allow for temporary modifications during the lookup.
1038 * Any changes are restored before returning. */
1039 static const struct cls_rule *
1040 classifier_lookup__(const struct classifier *cls, long long version,
1041 struct flow *flow, struct flow_wildcards *wc,
1042 bool allow_conjunctive_matches)
1044 const struct cls_partition *partition;
1045 struct trie_ctx trie_ctx[CLS_MAX_TRIES];
1046 const struct cls_match *match;
1049 /* Highest-priority flow in 'cls' that certainly matches 'flow'. */
1050 const struct cls_match *hard = NULL;
1051 int hard_pri = INT_MIN; /* hard ? hard->priority : INT_MIN. */
1053 /* Highest-priority conjunctive flows in 'cls' matching 'flow'. Since
1054 * these are (components of) conjunctive flows, we can only know whether
1055 * the full conjunctive flow matches after seeing multiple of them. Thus,
1056 * we refer to these as "soft matches". */
1057 struct cls_conjunction_set *soft_stub[64];
1058 struct cls_conjunction_set **soft = soft_stub;
1059 size_t n_soft = 0, allocated_soft = ARRAY_SIZE(soft_stub);
1060 int soft_pri = INT_MIN; /* n_soft ? MAX(soft[*]->priority) : INT_MIN. */
1062 /* Synchronize for cls->n_tries and subtable->trie_plen. They can change
1063 * when table configuration changes, which happens typically only on
1065 atomic_thread_fence(memory_order_acquire);
1067 /* Determine 'tags' such that, if 'subtable->tag' doesn't intersect them,
1068 * then 'flow' cannot possibly match in 'subtable':
1070 * - If flow->metadata maps to a given 'partition', then we can use
1071 * 'tags' for 'partition->tags'.
1073 * - If flow->metadata has no partition, then no rule in 'cls' has an
1074 * exact-match for flow->metadata. That means that we don't need to
1075 * search any subtable that includes flow->metadata in its mask.
1077 * In either case, we always need to search any cls_subtables that do not
1078 * include flow->metadata in its mask. One way to do that would be to
1079 * check the "cls_subtable"s explicitly for that, but that would require an
1080 * extra branch per subtable. Instead, we mark such a cls_subtable's
1081 * 'tags' as TAG_ALL and make sure that 'tags' is never empty. This means
1082 * that 'tags' always intersects such a cls_subtable's 'tags', so we don't
1083 * need a special case.
1085 partition = (cmap_is_empty(&cls->partitions)
1087 : find_partition(cls, flow->metadata,
1088 hash_metadata(flow->metadata)));
1089 tags = partition ? partition->tags : TAG_ARBITRARY;
1091 /* Initialize trie contexts for find_match_wc(). */
1092 for (int i = 0; i < cls->n_tries; i++) {
1093 trie_ctx_init(&trie_ctx[i], &cls->tries[i]);
1097 struct cls_subtable *subtable;
1098 PVECTOR_FOR_EACH_PRIORITY (subtable, hard_pri, 2, sizeof *subtable,
1100 struct cls_conjunction_set *conj_set;
1102 /* Skip subtables not in our partition. */
1103 if (!tag_intersects(tags, subtable->tag)) {
1107 /* Skip subtables with no match, or where the match is lower-priority
1108 * than some certain match we've already found. */
1109 match = find_match_wc(subtable, version, flow, trie_ctx, cls->n_tries,
1111 if (!match || match->priority <= hard_pri) {
1115 conj_set = ovsrcu_get(struct cls_conjunction_set *, &match->conj_set);
1117 /* 'match' isn't part of a conjunctive match. It's the best
1118 * certain match we've got so far, since we know that it's
1119 * higher-priority than hard_pri.
1121 * (There might be a higher-priority conjunctive match. We can't
1124 hard_pri = hard->priority;
1125 } else if (allow_conjunctive_matches) {
1126 /* 'match' is part of a conjunctive match. Add it to the list. */
1127 if (OVS_UNLIKELY(n_soft >= allocated_soft)) {
1128 struct cls_conjunction_set **old_soft = soft;
1130 allocated_soft *= 2;
1131 soft = xmalloc(allocated_soft * sizeof *soft);
1132 memcpy(soft, old_soft, n_soft * sizeof *soft);
1133 if (old_soft != soft_stub) {
1137 soft[n_soft++] = conj_set;
1139 /* Keep track of the highest-priority soft match. */
1140 if (soft_pri < match->priority) {
1141 soft_pri = match->priority;
1146 /* In the common case, at this point we have no soft matches and we can
1147 * return immediately. (We do the same thing if we have potential soft
1148 * matches but none of them are higher-priority than our hard match.) */
1149 if (hard_pri >= soft_pri) {
1150 if (soft != soft_stub) {
1153 return hard ? hard->cls_rule : NULL;
1156 /* At this point, we have some soft matches. We might also have a hard
1157 * match; if so, its priority is lower than the highest-priority soft
1162 * Check whether soft matches are real matches. */
1164 /* Delete soft matches that are null. This only happens in second and
1165 * subsequent iterations of the soft match loop, when we drop back from
1166 * a high-priority soft match to a lower-priority one.
1168 * Also, delete soft matches whose priority is less than or equal to
1169 * the hard match's priority. In the first iteration of the soft
1170 * match, these can be in 'soft' because the earlier main loop found
1171 * the soft match before the hard match. In second and later iteration
1172 * of the soft match loop, these can be in 'soft' because we dropped
1173 * back from a high-priority soft match to a lower-priority soft match.
1175 * It is tempting to delete soft matches that cannot be satisfied
1176 * because there are fewer soft matches than required to satisfy any of
1177 * their conjunctions, but we cannot do that because there might be
1178 * lower priority soft or hard matches with otherwise identical
1179 * matches. (We could special case those here, but there's no
1180 * need--we'll do so at the bottom of the soft match loop anyway and
1181 * this duplicates less code.)
1183 * It's also tempting to break out of the soft match loop if 'n_soft ==
1184 * 1' but that would also miss lower-priority hard matches. We could
1185 * special case that also but again there's no need. */
1186 for (int i = 0; i < n_soft; ) {
1187 if (!soft[i] || soft[i]->priority <= hard_pri) {
1188 soft[i] = soft[--n_soft];
1197 /* Find the highest priority among the soft matches. (We know this
1198 * must be higher than the hard match's priority; otherwise we would
1199 * have deleted all of the soft matches in the previous loop.) Count
1200 * the number of soft matches that have that priority. */
1203 for (int i = 0; i < n_soft; i++) {
1204 if (soft[i]->priority > soft_pri) {
1205 soft_pri = soft[i]->priority;
1207 } else if (soft[i]->priority == soft_pri) {
1211 ovs_assert(soft_pri > hard_pri);
1213 /* Look for a real match among the highest-priority soft matches.
1215 * It's unusual to have many conjunctive matches, so we use stubs to
1216 * avoid calling malloc() in the common case. An hmap has a built-in
1217 * stub for up to 2 hmap_nodes; possibly, we would benefit a variant
1218 * with a bigger stub. */
1219 struct conjunctive_match cm_stubs[16];
1220 struct hmap matches;
1222 hmap_init(&matches);
1223 for (int i = 0; i < n_soft; i++) {
1226 if (soft[i]->priority == soft_pri
1227 && find_conjunctive_match(soft[i], n_soft_pri, &matches,
1228 cm_stubs, ARRAY_SIZE(cm_stubs),
1230 uint32_t saved_conj_id = flow->conj_id;
1231 const struct cls_rule *rule;
1234 rule = classifier_lookup__(cls, version, flow, wc, false);
1235 flow->conj_id = saved_conj_id;
1238 free_conjunctive_matches(&matches,
1239 cm_stubs, ARRAY_SIZE(cm_stubs));
1240 if (soft != soft_stub) {
1247 free_conjunctive_matches(&matches, cm_stubs, ARRAY_SIZE(cm_stubs));
1249 /* There's no real match among the highest-priority soft matches.
1250 * However, if any of those soft matches has a lower-priority but
1251 * otherwise identical flow match, then we need to consider those for
1252 * soft or hard matches.
1254 * The next iteration of the soft match loop will delete any null
1255 * pointers we put into 'soft' (and some others too). */
1256 for (int i = 0; i < n_soft; i++) {
1257 if (soft[i]->priority != soft_pri) {
1261 /* Find next-lower-priority flow with identical flow match. */
1262 match = next_visible_rule_in_list(soft[i]->match, version);
1264 soft[i] = ovsrcu_get(struct cls_conjunction_set *,
1267 /* The flow is a hard match; don't treat as a soft
1269 if (match->priority > hard_pri) {
1271 hard_pri = hard->priority;
1275 /* No such lower-priority flow (probably the common case). */
1281 if (soft != soft_stub) {
1284 return hard ? hard->cls_rule : NULL;
1287 /* Finds and returns the highest-priority rule in 'cls' that matches 'flow' and
1288 * that is visible in 'version'. Returns a null pointer if no rules in 'cls'
1289 * match 'flow'. If multiple rules of equal priority match 'flow', returns one
1292 * If a rule is found and 'wc' is non-null, bitwise-OR's 'wc' with the
1293 * set of bits that were significant in the lookup. At some point
1294 * earlier, 'wc' should have been initialized (e.g., by
1295 * flow_wildcards_init_catchall()).
1297 * 'flow' is non-const to allow for temporary modifications during the lookup.
1298 * Any changes are restored before returning. */
1299 const struct cls_rule *
1300 classifier_lookup(const struct classifier *cls, long long version,
1301 struct flow *flow, struct flow_wildcards *wc)
1303 return classifier_lookup__(cls, version, flow, wc, true);
1306 /* Finds and returns a rule in 'cls' with exactly the same priority and
1307 * matching criteria as 'target', and that is visible in 'target->version.
1308 * Only one such rule may ever exist. Returns a null pointer if 'cls' doesn't
1309 * contain an exact match. */
1310 const struct cls_rule *
1311 classifier_find_rule_exactly(const struct classifier *cls,
1312 const struct cls_rule *target)
1314 const struct cls_match *head, *rule;
1315 const struct cls_subtable *subtable;
1317 subtable = find_subtable(cls, &target->match.mask);
1322 head = find_equal(subtable, &target->match.flow,
1323 miniflow_hash_in_minimask(&target->match.flow,
1324 &target->match.mask, 0));
1328 CLS_MATCH_FOR_EACH (rule, head) {
1329 if (rule->priority < target->priority) {
1330 break; /* Not found. */
1332 if (rule->priority == target->priority
1333 && cls_match_visible_in_version(rule, target->version)) {
1334 return rule->cls_rule;
1340 /* Finds and returns a rule in 'cls' with priority 'priority' and exactly the
1341 * same matching criteria as 'target', and that is visible in 'version'.
1342 * Returns a null pointer if 'cls' doesn't contain an exact match visible in
1344 const struct cls_rule *
1345 classifier_find_match_exactly(const struct classifier *cls,
1346 const struct match *target, int priority,
1349 const struct cls_rule *retval;
1352 cls_rule_init(&cr, target, priority, version);
1353 retval = classifier_find_rule_exactly(cls, &cr);
1354 cls_rule_destroy(&cr);
1359 /* Checks if 'target' would overlap any other rule in 'cls'. Two rules are
1360 * considered to overlap if both rules have the same priority and a packet
1361 * could match both, and if both rules are visible in the same version.
1363 * A trivial example of overlapping rules is two rules matching disjoint sets
1364 * of fields. E.g., if one rule matches only on port number, while another only
1365 * on dl_type, any packet from that specific port and with that specific
1366 * dl_type could match both, if the rules also have the same priority. */
1368 classifier_rule_overlaps(const struct classifier *cls,
1369 const struct cls_rule *target)
1371 struct cls_subtable *subtable;
1373 /* Iterate subtables in the descending max priority order. */
1374 PVECTOR_FOR_EACH_PRIORITY (subtable, target->priority - 1, 2,
1375 sizeof(struct cls_subtable), &cls->subtables) {
1376 uint64_t storage[FLOW_U64S];
1377 struct minimask mask;
1378 const struct cls_rule *rule;
1380 minimask_combine(&mask, &target->match.mask, &subtable->mask, storage);
1382 RCULIST_FOR_EACH (rule, node, &subtable->rules_list) {
1383 if (rule->priority == target->priority
1384 && miniflow_equal_in_minimask(&target->match.flow,
1385 &rule->match.flow, &mask)
1386 && cls_match_visible_in_version(rule->cls_match,
1395 /* Returns true if 'rule' exactly matches 'criteria' or if 'rule' is more
1396 * specific than 'criteria'. That is, 'rule' matches 'criteria' and this
1397 * function returns true if, for every field:
1399 * - 'criteria' and 'rule' specify the same (non-wildcarded) value for the
1402 * - 'criteria' wildcards the field,
1404 * Conversely, 'rule' does not match 'criteria' and this function returns false
1405 * if, for at least one field:
1407 * - 'criteria' and 'rule' specify different values for the field, or
1409 * - 'criteria' specifies a value for the field but 'rule' wildcards it.
1411 * Equivalently, the truth table for whether a field matches is:
1416 * r +---------+---------+
1417 * i wild | yes | yes |
1419 * e +---------+---------+
1420 * r exact | no |if values|
1422 * a +---------+---------+
1424 * This is the matching rule used by OpenFlow 1.0 non-strict OFPT_FLOW_MOD
1425 * commands and by OpenFlow 1.0 aggregate and flow stats.
1427 * Ignores rule->priority. */
1429 cls_rule_is_loose_match(const struct cls_rule *rule,
1430 const struct minimatch *criteria)
1432 return (!minimask_has_extra(&rule->match.mask, &criteria->mask)
1433 && miniflow_equal_in_minimask(&rule->match.flow, &criteria->flow,
1439 /* Rule may only match a target if it is visible in target's version. For NULL
1440 * target we only return rules that are not invisible in any version. */
1442 rule_matches(const struct cls_rule *rule, const struct cls_rule *target)
1444 /* Iterators never see duplicate rules with the same priority. */
1446 ? (miniflow_equal_in_minimask(&rule->match.flow, &target->match.flow,
1447 &target->match.mask)
1448 && cls_match_visible_in_version(rule->cls_match, target->version))
1449 : !cls_match_is_eventually_invisible(rule->cls_match);
1452 static const struct cls_rule *
1453 search_subtable(const struct cls_subtable *subtable,
1454 struct cls_cursor *cursor)
1457 || !minimask_has_extra(&subtable->mask, &cursor->target->match.mask)) {
1458 const struct cls_rule *rule;
1460 RCULIST_FOR_EACH (rule, node, &subtable->rules_list) {
1461 if (rule_matches(rule, cursor->target)) {
1469 /* Initializes 'cursor' for iterating through rules in 'cls', and returns the
1470 * first matching cls_rule via '*pnode', or NULL if there are no matches.
1472 * - If 'target' is null, or if the 'target' is a catchall target and the
1473 * target's version is CLS_NO_VERSION, the cursor will visit every rule
1474 * in 'cls' that is not invisible in any version.
1476 * - If 'target' is nonnull, the cursor will visit each 'rule' in 'cls'
1477 * such that cls_rule_is_loose_match(rule, target) returns true and that
1478 * the rule is visible in 'target->version'.
1480 * Ignores target->priority. */
1482 cls_cursor_start(const struct classifier *cls, const struct cls_rule *target)
1484 struct cls_cursor cursor;
1485 struct cls_subtable *subtable;
1488 cursor.target = target && (!cls_rule_is_catchall(target)
1489 || target->version != CLS_MAX_VERSION)
1493 /* Find first rule. */
1494 PVECTOR_CURSOR_FOR_EACH (subtable, &cursor.subtables,
1495 &cursor.cls->subtables) {
1496 const struct cls_rule *rule = search_subtable(subtable, &cursor);
1499 cursor.subtable = subtable;
1508 static const struct cls_rule *
1509 cls_cursor_next(struct cls_cursor *cursor)
1511 const struct cls_rule *rule;
1512 const struct cls_subtable *subtable;
1514 rule = cursor->rule;
1515 subtable = cursor->subtable;
1516 RCULIST_FOR_EACH_CONTINUE (rule, node, &subtable->rules_list) {
1517 if (rule_matches(rule, cursor->target)) {
1522 PVECTOR_CURSOR_FOR_EACH_CONTINUE (subtable, &cursor->subtables) {
1523 rule = search_subtable(subtable, cursor);
1525 cursor->subtable = subtable;
1533 /* Sets 'cursor->rule' to the next matching cls_rule in 'cursor''s iteration,
1534 * or to null if all matching rules have been visited. */
1536 cls_cursor_advance(struct cls_cursor *cursor)
1538 cursor->rule = cls_cursor_next(cursor);
1541 static struct cls_subtable *
1542 find_subtable(const struct classifier *cls, const struct minimask *mask)
1544 struct cls_subtable *subtable;
1546 CMAP_FOR_EACH_WITH_HASH (subtable, cmap_node, minimask_hash(mask, 0),
1547 &cls->subtables_map) {
1548 if (minimask_equal(mask, &subtable->mask)) {
1555 /* The new subtable will be visible to the readers only after this. */
1556 static struct cls_subtable *
1557 insert_subtable(struct classifier *cls, const struct minimask *mask)
1559 uint32_t hash = minimask_hash(mask, 0);
1560 struct cls_subtable *subtable;
1562 struct flow_wildcards old, new;
1564 int count = count_1bits(mask->masks.map);
1566 subtable = xzalloc(sizeof *subtable - sizeof mask->masks.inline_values
1567 + MINIFLOW_VALUES_SIZE(count));
1568 cmap_init(&subtable->rules);
1569 miniflow_clone_inline(CONST_CAST(struct miniflow *, &subtable->mask.masks),
1570 &mask->masks, count);
1572 /* Init indices for segmented lookup, if any. */
1573 flow_wildcards_init_catchall(&new);
1576 for (i = 0; i < cls->n_flow_segments; i++) {
1577 flow_wildcards_fold_minimask_range(&new, mask, prev,
1578 cls->flow_segments[i]);
1579 /* Add an index if it adds mask bits. */
1580 if (!flow_wildcards_equal(&new, &old)) {
1581 cmap_init(&subtable->indices[index]);
1582 *CONST_CAST(uint8_t *, &subtable->index_ofs[index])
1583 = cls->flow_segments[i];
1587 prev = cls->flow_segments[i];
1589 /* Check if the rest of the subtable's mask adds any bits,
1590 * and remove the last index if it doesn't. */
1592 flow_wildcards_fold_minimask_range(&new, mask, prev, FLOW_U64S);
1593 if (flow_wildcards_equal(&new, &old)) {
1595 *CONST_CAST(uint8_t *, &subtable->index_ofs[index]) = 0;
1596 cmap_destroy(&subtable->indices[index]);
1599 *CONST_CAST(uint8_t *, &subtable->n_indices) = index;
1601 *CONST_CAST(tag_type *, &subtable->tag) =
1602 (minimask_get_metadata_mask(mask) == OVS_BE64_MAX
1603 ? tag_create_deterministic(hash)
1606 for (i = 0; i < cls->n_tries; i++) {
1607 subtable->trie_plen[i] = minimask_get_prefix_len(mask,
1608 cls->tries[i].field);
1612 ovsrcu_set_hidden(&subtable->ports_trie, NULL);
1613 *CONST_CAST(int *, &subtable->ports_mask_len)
1614 = 32 - ctz32(ntohl(MINIFLOW_GET_BE32(&mask->masks, tp_src)));
1616 /* List of rules. */
1617 rculist_init(&subtable->rules_list);
1619 cmap_insert(&cls->subtables_map, &subtable->cmap_node, hash);
1624 /* RCU readers may still access the subtable before it is actually freed. */
1626 destroy_subtable(struct classifier *cls, struct cls_subtable *subtable)
1630 pvector_remove(&cls->subtables, subtable);
1631 cmap_remove(&cls->subtables_map, &subtable->cmap_node,
1632 minimask_hash(&subtable->mask, 0));
1634 ovs_assert(ovsrcu_get_protected(struct trie_node *, &subtable->ports_trie)
1636 ovs_assert(cmap_is_empty(&subtable->rules));
1637 ovs_assert(rculist_is_empty(&subtable->rules_list));
1639 for (i = 0; i < subtable->n_indices; i++) {
1640 cmap_destroy(&subtable->indices[i]);
1642 cmap_destroy(&subtable->rules);
1643 ovsrcu_postpone(free, subtable);
1651 static unsigned int be_get_bit_at(const ovs_be32 value[], unsigned int ofs);
1653 /* Return 'true' if can skip rest of the subtable based on the prefix trie
1654 * lookup results. */
1656 check_tries(struct trie_ctx trie_ctx[CLS_MAX_TRIES], unsigned int n_tries,
1657 const unsigned int field_plen[CLS_MAX_TRIES],
1658 const struct range ofs, const struct flow *flow,
1659 struct flow_wildcards *wc)
1663 /* Check if we could avoid fully unwildcarding the next level of
1664 * fields using the prefix tries. The trie checks are done only as
1665 * needed to avoid folding in additional bits to the wildcards mask. */
1666 for (j = 0; j < n_tries; j++) {
1667 /* Is the trie field relevant for this subtable? */
1668 if (field_plen[j]) {
1669 struct trie_ctx *ctx = &trie_ctx[j];
1670 uint8_t be32ofs = ctx->be32ofs;
1671 uint8_t be64ofs = be32ofs / 2;
1673 /* Is the trie field within the current range of fields? */
1674 if (be64ofs >= ofs.start && be64ofs < ofs.end) {
1675 /* On-demand trie lookup. */
1676 if (!ctx->lookup_done) {
1677 memset(&ctx->match_plens, 0, sizeof ctx->match_plens);
1678 ctx->maskbits = trie_lookup(ctx->trie, flow,
1680 ctx->lookup_done = true;
1682 /* Possible to skip the rest of the subtable if subtable's
1683 * prefix on the field is not included in the lookup result. */
1684 if (!be_get_bit_at(&ctx->match_plens.be32, field_plen[j] - 1)) {
1685 /* We want the trie lookup to never result in unwildcarding
1686 * any bits that would not be unwildcarded otherwise.
1687 * Since the trie is shared by the whole classifier, it is
1688 * possible that the 'maskbits' contain bits that are
1689 * irrelevant for the partition relevant for the current
1690 * packet. Hence the checks below. */
1692 /* Check that the trie result will not unwildcard more bits
1693 * than this subtable would otherwise. */
1694 if (ctx->maskbits <= field_plen[j]) {
1695 /* Unwildcard the bits and skip the rest. */
1696 mask_set_prefix_bits(wc, be32ofs, ctx->maskbits);
1697 /* Note: Prerequisite already unwildcarded, as the only
1698 * prerequisite of the supported trie lookup fields is
1699 * the ethertype, which is always unwildcarded. */
1702 /* Can skip if the field is already unwildcarded. */
1703 if (mask_prefix_bits_set(wc, be32ofs, ctx->maskbits)) {
1713 /* Returns true if 'target' satisifies 'flow'/'mask', that is, if each bit
1714 * for which 'flow', for which 'mask' has a bit set, specifies a particular
1715 * value has the correct value in 'target'.
1717 * This function is equivalent to miniflow_equal_flow_in_minimask(flow,
1718 * target, mask) but this is faster because of the invariant that
1719 * flow->map and mask->masks.map are the same, and that this version
1720 * takes the 'wc'. */
1722 miniflow_and_mask_matches_flow(const struct miniflow *flow,
1723 const struct minimask *mask,
1724 const struct flow *target)
1726 const uint64_t *flowp = miniflow_get_values(flow);
1727 const uint64_t *maskp = miniflow_get_values(&mask->masks);
1730 MAP_FOR_EACH_INDEX(idx, mask->masks.map) {
1731 uint64_t diff = (*flowp++ ^ flow_u64_value(target, idx)) & *maskp++;
1741 static inline const struct cls_match *
1742 find_match(const struct cls_subtable *subtable, long long version,
1743 const struct flow *flow, uint32_t hash)
1745 const struct cls_match *head, *rule;
1747 CMAP_FOR_EACH_WITH_HASH (head, cmap_node, hash, &subtable->rules) {
1748 if (OVS_LIKELY(miniflow_and_mask_matches_flow(&head->flow,
1751 /* Return highest priority rule that is visible. */
1752 CLS_MATCH_FOR_EACH (rule, head) {
1753 if (OVS_LIKELY(cls_match_visible_in_version(rule, version))) {
1763 /* Returns true if 'target' satisifies 'flow'/'mask', that is, if each bit
1764 * for which 'flow', for which 'mask' has a bit set, specifies a particular
1765 * value has the correct value in 'target'.
1767 * This function is equivalent to miniflow_and_mask_matches_flow() but this
1768 * version fills in the mask bits in 'wc'. */
1770 miniflow_and_mask_matches_flow_wc(const struct miniflow *flow,
1771 const struct minimask *mask,
1772 const struct flow *target,
1773 struct flow_wildcards *wc)
1775 const uint64_t *flowp = miniflow_get_values(flow);
1776 const uint64_t *maskp = miniflow_get_values(&mask->masks);
1779 MAP_FOR_EACH_INDEX(idx, mask->masks.map) {
1780 uint64_t mask = *maskp++;
1781 uint64_t diff = (*flowp++ ^ flow_u64_value(target, idx)) & mask;
1784 /* Only unwildcard if none of the differing bits is already
1786 if (!(flow_u64_value(&wc->masks, idx) & diff)) {
1787 /* Keep one bit of the difference. The selected bit may be
1788 * different in big-endian v.s. little-endian systems. */
1789 *flow_u64_lvalue(&wc->masks, idx) |= rightmost_1bit(diff);
1793 /* Fill in the bits that were looked at. */
1794 *flow_u64_lvalue(&wc->masks, idx) |= mask;
1800 /* Unwildcard the fields looked up so far, if any. */
1802 fill_range_wc(const struct cls_subtable *subtable, struct flow_wildcards *wc,
1806 flow_wildcards_fold_minimask_range(wc, &subtable->mask, 0, to);
1810 static const struct cls_match *
1811 find_match_wc(const struct cls_subtable *subtable, long long version,
1812 const struct flow *flow, struct trie_ctx trie_ctx[CLS_MAX_TRIES],
1813 unsigned int n_tries, struct flow_wildcards *wc)
1815 uint32_t basis = 0, hash;
1816 const struct cls_match *rule = NULL;
1820 if (OVS_UNLIKELY(!wc)) {
1821 return find_match(subtable, version, flow,
1822 flow_hash_in_minimask(flow, &subtable->mask, 0));
1826 /* Try to finish early by checking fields in segments. */
1827 for (i = 0; i < subtable->n_indices; i++) {
1828 const struct cmap_node *inode;
1830 ofs.end = subtable->index_ofs[i];
1832 if (check_tries(trie_ctx, n_tries, subtable->trie_plen, ofs, flow,
1834 /* 'wc' bits for the trie field set, now unwildcard the preceding
1835 * bits used so far. */
1836 fill_range_wc(subtable, wc, ofs.start);
1839 hash = flow_hash_in_minimask_range(flow, &subtable->mask, ofs.start,
1841 inode = cmap_find(&subtable->indices[i], hash);
1843 /* No match, can stop immediately, but must fold in the bits
1844 * used in lookup so far. */
1845 fill_range_wc(subtable, wc, ofs.end);
1849 /* If we have narrowed down to a single rule already, check whether
1850 * that rule matches. Either way, we're done.
1852 * (Rare) hash collisions may cause us to miss the opportunity for this
1854 if (!cmap_node_next(inode)) {
1855 const struct cls_match *head;
1857 ASSIGN_CONTAINER(head, inode - i, index_nodes);
1858 if (miniflow_and_mask_matches_flow_wc(&head->flow, &subtable->mask,
1860 /* Return highest priority rule that is visible. */
1861 CLS_MATCH_FOR_EACH (rule, head) {
1862 if (OVS_LIKELY(cls_match_visible_in_version(rule,
1870 ofs.start = ofs.end;
1872 ofs.end = FLOW_U64S;
1873 /* Trie check for the final range. */
1874 if (check_tries(trie_ctx, n_tries, subtable->trie_plen, ofs, flow, wc)) {
1875 fill_range_wc(subtable, wc, ofs.start);
1878 hash = flow_hash_in_minimask_range(flow, &subtable->mask, ofs.start,
1880 rule = find_match(subtable, version, flow, hash);
1881 if (!rule && subtable->ports_mask_len) {
1882 /* Ports are always part of the final range, if any.
1883 * No match was found for the ports. Use the ports trie to figure out
1884 * which ports bits to unwildcard. */
1886 ovs_be32 value, plens, mask;
1888 mask = MINIFLOW_GET_BE32(&subtable->mask.masks, tp_src);
1889 value = ((OVS_FORCE ovs_be32 *)flow)[TP_PORTS_OFS32] & mask;
1890 mbits = trie_lookup_value(&subtable->ports_trie, &value, &plens, 32);
1892 ((OVS_FORCE ovs_be32 *)&wc->masks)[TP_PORTS_OFS32] |=
1893 mask & be32_prefix_mask(mbits);
1895 /* Unwildcard all bits in the mask upto the ports, as they were used
1896 * to determine there is no match. */
1897 fill_range_wc(subtable, wc, TP_PORTS_OFS64);
1901 /* Must unwildcard all the fields, as they were looked at. */
1902 flow_wildcards_fold_minimask(wc, &subtable->mask);
1906 static struct cls_match *
1907 find_equal(const struct cls_subtable *subtable, const struct miniflow *flow,
1910 struct cls_match *head;
1912 CMAP_FOR_EACH_WITH_HASH (head, cmap_node, hash, &subtable->rules) {
1913 if (miniflow_equal(&head->flow, flow)) {
1920 /* A longest-prefix match tree. */
1922 /* Return at least 'plen' bits of the 'prefix', starting at bit offset 'ofs'.
1923 * Prefixes are in the network byte order, and the offset 0 corresponds to
1924 * the most significant bit of the first byte. The offset can be read as
1925 * "how many bits to skip from the start of the prefix starting at 'pr'". */
1927 raw_get_prefix(const ovs_be32 pr[], unsigned int ofs, unsigned int plen)
1931 pr += ofs / 32; /* Where to start. */
1932 ofs %= 32; /* How many bits to skip at 'pr'. */
1934 prefix = ntohl(*pr) << ofs; /* Get the first 32 - ofs bits. */
1935 if (plen > 32 - ofs) { /* Need more than we have already? */
1936 prefix |= ntohl(*++pr) >> (32 - ofs);
1938 /* Return with possible unwanted bits at the end. */
1942 /* Return min(TRIE_PREFIX_BITS, plen) bits of the 'prefix', starting at bit
1943 * offset 'ofs'. Prefixes are in the network byte order, and the offset 0
1944 * corresponds to the most significant bit of the first byte. The offset can
1945 * be read as "how many bits to skip from the start of the prefix starting at
1948 trie_get_prefix(const ovs_be32 pr[], unsigned int ofs, unsigned int plen)
1953 if (plen > TRIE_PREFIX_BITS) {
1954 plen = TRIE_PREFIX_BITS; /* Get at most TRIE_PREFIX_BITS. */
1956 /* Return with unwanted bits cleared. */
1957 return raw_get_prefix(pr, ofs, plen) & ~0u << (32 - plen);
1960 /* Return the number of equal bits in 'n_bits' of 'prefix's MSBs and a 'value'
1961 * starting at "MSB 0"-based offset 'ofs'. */
1963 prefix_equal_bits(uint32_t prefix, unsigned int n_bits, const ovs_be32 value[],
1966 uint64_t diff = prefix ^ raw_get_prefix(value, ofs, n_bits);
1967 /* Set the bit after the relevant bits to limit the result. */
1968 return raw_clz64(diff << 32 | UINT64_C(1) << (63 - n_bits));
1971 /* Return the number of equal bits in 'node' prefix and a 'prefix' of length
1972 * 'plen', starting at "MSB 0"-based offset 'ofs'. */
1974 trie_prefix_equal_bits(const struct trie_node *node, const ovs_be32 prefix[],
1975 unsigned int ofs, unsigned int plen)
1977 return prefix_equal_bits(node->prefix, MIN(node->n_bits, plen - ofs),
1981 /* Return the bit at ("MSB 0"-based) offset 'ofs' as an int. 'ofs' can
1982 * be greater than 31. */
1984 be_get_bit_at(const ovs_be32 value[], unsigned int ofs)
1986 return (((const uint8_t *)value)[ofs / 8] >> (7 - ofs % 8)) & 1u;
1989 /* Return the bit at ("MSB 0"-based) offset 'ofs' as an int. 'ofs' must
1990 * be between 0 and 31, inclusive. */
1992 get_bit_at(const uint32_t prefix, unsigned int ofs)
1994 return (prefix >> (31 - ofs)) & 1u;
1997 /* Create new branch. */
1998 static struct trie_node *
1999 trie_branch_create(const ovs_be32 *prefix, unsigned int ofs, unsigned int plen,
2000 unsigned int n_rules)
2002 struct trie_node *node = xmalloc(sizeof *node);
2004 node->prefix = trie_get_prefix(prefix, ofs, plen);
2006 if (plen <= TRIE_PREFIX_BITS) {
2007 node->n_bits = plen;
2008 ovsrcu_set_hidden(&node->edges[0], NULL);
2009 ovsrcu_set_hidden(&node->edges[1], NULL);
2010 node->n_rules = n_rules;
2011 } else { /* Need intermediate nodes. */
2012 struct trie_node *subnode = trie_branch_create(prefix,
2013 ofs + TRIE_PREFIX_BITS,
2014 plen - TRIE_PREFIX_BITS,
2016 int bit = get_bit_at(subnode->prefix, 0);
2017 node->n_bits = TRIE_PREFIX_BITS;
2018 ovsrcu_set_hidden(&node->edges[bit], subnode);
2019 ovsrcu_set_hidden(&node->edges[!bit], NULL);
2026 trie_node_destroy(const struct trie_node *node)
2028 ovsrcu_postpone(free, CONST_CAST(struct trie_node *, node));
2031 /* Copy a trie node for modification and postpone delete the old one. */
2032 static struct trie_node *
2033 trie_node_rcu_realloc(const struct trie_node *node)
2035 struct trie_node *new_node = xmalloc(sizeof *node);
2038 trie_node_destroy(node);
2044 trie_destroy(rcu_trie_ptr *trie)
2046 struct trie_node *node = ovsrcu_get_protected(struct trie_node *, trie);
2049 ovsrcu_set_hidden(trie, NULL);
2050 trie_destroy(&node->edges[0]);
2051 trie_destroy(&node->edges[1]);
2052 trie_node_destroy(node);
2057 trie_is_leaf(const struct trie_node *trie)
2060 return !ovsrcu_get(struct trie_node *, &trie->edges[0])
2061 && !ovsrcu_get(struct trie_node *, &trie->edges[1]);
2065 mask_set_prefix_bits(struct flow_wildcards *wc, uint8_t be32ofs,
2066 unsigned int n_bits)
2068 ovs_be32 *mask = &((ovs_be32 *)&wc->masks)[be32ofs];
2071 for (i = 0; i < n_bits / 32; i++) {
2072 mask[i] = OVS_BE32_MAX;
2075 mask[i] |= htonl(~0u << (32 - n_bits % 32));
2080 mask_prefix_bits_set(const struct flow_wildcards *wc, uint8_t be32ofs,
2081 unsigned int n_bits)
2083 ovs_be32 *mask = &((ovs_be32 *)&wc->masks)[be32ofs];
2085 ovs_be32 zeroes = 0;
2087 for (i = 0; i < n_bits / 32; i++) {
2091 zeroes |= ~mask[i] & htonl(~0u << (32 - n_bits % 32));
2094 return !zeroes; /* All 'n_bits' bits set. */
2097 static rcu_trie_ptr *
2098 trie_next_edge(struct trie_node *node, const ovs_be32 value[],
2101 return node->edges + be_get_bit_at(value, ofs);
2104 static const struct trie_node *
2105 trie_next_node(const struct trie_node *node, const ovs_be32 value[],
2108 return ovsrcu_get(struct trie_node *,
2109 &node->edges[be_get_bit_at(value, ofs)]);
2112 /* Set the bit at ("MSB 0"-based) offset 'ofs'. 'ofs' can be greater than 31.
2115 be_set_bit_at(ovs_be32 value[], unsigned int ofs)
2117 ((uint8_t *)value)[ofs / 8] |= 1u << (7 - ofs % 8);
2120 /* Returns the number of bits in the prefix mask necessary to determine a
2121 * mismatch, in case there are longer prefixes in the tree below the one that
2123 * '*plens' will have a bit set for each prefix length that may have matching
2124 * rules. The caller is responsible for clearing the '*plens' prior to
2128 trie_lookup_value(const rcu_trie_ptr *trie, const ovs_be32 value[],
2129 ovs_be32 plens[], unsigned int n_bits)
2131 const struct trie_node *prev = NULL;
2132 const struct trie_node *node = ovsrcu_get(struct trie_node *, trie);
2133 unsigned int match_len = 0; /* Number of matching bits. */
2135 for (; node; prev = node, node = trie_next_node(node, value, match_len)) {
2136 unsigned int eqbits;
2137 /* Check if this edge can be followed. */
2138 eqbits = prefix_equal_bits(node->prefix, node->n_bits, value,
2140 match_len += eqbits;
2141 if (eqbits < node->n_bits) { /* Mismatch, nothing more to be found. */
2142 /* Bit at offset 'match_len' differed. */
2143 return match_len + 1; /* Includes the first mismatching bit. */
2145 /* Full match, check if rules exist at this prefix length. */
2146 if (node->n_rules > 0) {
2147 be_set_bit_at(plens, match_len - 1);
2149 if (match_len >= n_bits) {
2150 return n_bits; /* Full prefix. */
2153 /* node == NULL. Full match so far, but we tried to follow an
2154 * non-existing branch. Need to exclude the other branch if it exists
2155 * (it does not if we were called on an empty trie or 'prev' is a leaf
2157 return !prev || trie_is_leaf(prev) ? match_len : match_len + 1;
2161 trie_lookup(const struct cls_trie *trie, const struct flow *flow,
2162 union mf_value *plens)
2164 const struct mf_field *mf = trie->field;
2166 /* Check that current flow matches the prerequisites for the trie
2167 * field. Some match fields are used for multiple purposes, so we
2168 * must check that the trie is relevant for this flow. */
2169 if (mf_are_prereqs_ok(mf, flow)) {
2170 return trie_lookup_value(&trie->root,
2171 &((ovs_be32 *)flow)[mf->flow_be32ofs],
2172 &plens->be32, mf->n_bits);
2174 memset(plens, 0xff, sizeof *plens); /* All prefixes, no skipping. */
2175 return 0; /* Value not used in this case. */
2178 /* Returns the length of a prefix match mask for the field 'mf' in 'minimask'.
2179 * Returns the u32 offset to the miniflow data in '*miniflow_index', if
2180 * 'miniflow_index' is not NULL. */
2182 minimask_get_prefix_len(const struct minimask *minimask,
2183 const struct mf_field *mf)
2185 unsigned int n_bits = 0, mask_tz = 0; /* Non-zero when end of mask seen. */
2186 uint8_t be32_ofs = mf->flow_be32ofs;
2187 uint8_t be32_end = be32_ofs + mf->n_bytes / 4;
2189 for (; be32_ofs < be32_end; ++be32_ofs) {
2190 uint32_t mask = ntohl(minimask_get_be32(minimask, be32_ofs));
2192 /* Validate mask, count the mask length. */
2195 return 0; /* No bits allowed after mask ended. */
2198 if (~mask & (~mask + 1)) {
2199 return 0; /* Mask not contiguous. */
2201 mask_tz = ctz32(mask);
2202 n_bits += 32 - mask_tz;
2210 * This is called only when mask prefix is known to be CIDR and non-zero.
2211 * Relies on the fact that the flow and mask have the same map, and since
2212 * the mask is CIDR, the storage for the flow field exists even if it
2213 * happened to be zeros.
2215 static const ovs_be32 *
2216 minimatch_get_prefix(const struct minimatch *match, const struct mf_field *mf)
2218 return (OVS_FORCE const ovs_be32 *)
2219 (miniflow_get_values(&match->flow)
2220 + count_1bits(match->flow.map &
2221 ((UINT64_C(1) << mf->flow_be32ofs / 2) - 1)))
2222 + (mf->flow_be32ofs & 1);
2225 /* Insert rule in to the prefix tree.
2226 * 'mlen' must be the (non-zero) CIDR prefix length of the 'trie->field' mask
2229 trie_insert(struct cls_trie *trie, const struct cls_rule *rule, int mlen)
2231 trie_insert_prefix(&trie->root,
2232 minimatch_get_prefix(&rule->match, trie->field), mlen);
2236 trie_insert_prefix(rcu_trie_ptr *edge, const ovs_be32 *prefix, int mlen)
2238 struct trie_node *node;
2241 /* Walk the tree. */
2242 for (; (node = ovsrcu_get_protected(struct trie_node *, edge));
2243 edge = trie_next_edge(node, prefix, ofs)) {
2244 unsigned int eqbits = trie_prefix_equal_bits(node, prefix, ofs, mlen);
2246 if (eqbits < node->n_bits) {
2247 /* Mismatch, new node needs to be inserted above. */
2248 int old_branch = get_bit_at(node->prefix, eqbits);
2249 struct trie_node *new_parent;
2251 new_parent = trie_branch_create(prefix, ofs - eqbits, eqbits,
2252 ofs == mlen ? 1 : 0);
2253 /* Copy the node to modify it. */
2254 node = trie_node_rcu_realloc(node);
2255 /* Adjust the new node for its new position in the tree. */
2256 node->prefix <<= eqbits;
2257 node->n_bits -= eqbits;
2258 ovsrcu_set_hidden(&new_parent->edges[old_branch], node);
2260 /* Check if need a new branch for the new rule. */
2262 ovsrcu_set_hidden(&new_parent->edges[!old_branch],
2263 trie_branch_create(prefix, ofs, mlen - ofs,
2266 ovsrcu_set(edge, new_parent); /* Publish changes. */
2269 /* Full match so far. */
2272 /* Full match at the current node, rule needs to be added here. */
2277 /* Must insert a new tree branch for the new rule. */
2278 ovsrcu_set(edge, trie_branch_create(prefix, ofs, mlen - ofs, 1));
2281 /* 'mlen' must be the (non-zero) CIDR prefix length of the 'trie->field' mask
2284 trie_remove(struct cls_trie *trie, const struct cls_rule *rule, int mlen)
2286 trie_remove_prefix(&trie->root,
2287 minimatch_get_prefix(&rule->match, trie->field), mlen);
2290 /* 'mlen' must be the (non-zero) CIDR prefix length of the 'trie->field' mask
2293 trie_remove_prefix(rcu_trie_ptr *root, const ovs_be32 *prefix, int mlen)
2295 struct trie_node *node;
2296 rcu_trie_ptr *edges[sizeof(union mf_value) * 8];
2297 int depth = 0, ofs = 0;
2299 /* Walk the tree. */
2300 for (edges[0] = root;
2301 (node = ovsrcu_get_protected(struct trie_node *, edges[depth]));
2302 edges[++depth] = trie_next_edge(node, prefix, ofs)) {
2303 unsigned int eqbits = trie_prefix_equal_bits(node, prefix, ofs, mlen);
2305 if (eqbits < node->n_bits) {
2306 /* Mismatch, nothing to be removed. This should never happen, as
2307 * only rules in the classifier are ever removed. */
2308 break; /* Log a warning. */
2310 /* Full match so far. */
2314 /* Full prefix match at the current node, remove rule here. */
2315 if (!node->n_rules) {
2316 break; /* Log a warning. */
2320 /* Check if can prune the tree. */
2321 while (!node->n_rules) {
2322 struct trie_node *next,
2323 *edge0 = ovsrcu_get_protected(struct trie_node *,
2325 *edge1 = ovsrcu_get_protected(struct trie_node *,
2328 if (edge0 && edge1) {
2329 break; /* A branching point, cannot prune. */
2332 /* Else have at most one child node, remove this node. */
2333 next = edge0 ? edge0 : edge1;
2336 if (node->n_bits + next->n_bits > TRIE_PREFIX_BITS) {
2337 break; /* Cannot combine. */
2339 next = trie_node_rcu_realloc(next); /* Modify. */
2341 /* Combine node with next. */
2342 next->prefix = node->prefix | next->prefix >> node->n_bits;
2343 next->n_bits += node->n_bits;
2345 /* Update the parent's edge. */
2346 ovsrcu_set(edges[depth], next); /* Publish changes. */
2347 trie_node_destroy(node);
2349 if (next || !depth) {
2350 /* Branch not pruned or at root, nothing more to do. */
2353 node = ovsrcu_get_protected(struct trie_node *,
2359 /* Cannot go deeper. This should never happen, since only rules
2360 * that actually exist in the classifier are ever removed. */
2361 VLOG_WARN("Trying to remove non-existing rule from a prefix trie.");
2365 #define CLS_MATCH_POISON (struct cls_match *)(UINTPTR_MAX / 0xf * 0xb)
2368 cls_match_free_cb(struct cls_match *rule)
2370 ovsrcu_set_hidden(&rule->next, CLS_MATCH_POISON);