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
, cls_version_t version
,
91 const struct cls_conjunction conj
[], size_t n
)
93 size_t count
= miniflow_n_values(rule
->match
.flow
);
95 struct cls_match
*cls_match
96 = xmalloc(sizeof *cls_match
+ MINIFLOW_VALUES_SIZE(count
));
98 ovsrcu_init(&cls_match
->next
, NULL
);
99 *CONST_CAST(const struct cls_rule
**, &cls_match
->cls_rule
) = rule
;
100 *CONST_CAST(int *, &cls_match
->priority
) = rule
->priority
;
101 *CONST_CAST(cls_version_t
*, &cls_match
->add_version
) = version
;
102 atomic_init(&cls_match
->remove_version
, version
); /* Initially
104 miniflow_clone(CONST_CAST(struct miniflow
*, &cls_match
->flow
),
105 rule
->match
.flow
, count
);
106 ovsrcu_set_hidden(&cls_match
->conj_set
,
107 cls_conjunction_set_alloc(cls_match
, conj
, n
));
112 static struct cls_subtable
*find_subtable(const struct classifier
*cls
,
113 const struct minimask
*);
114 static struct cls_subtable
*insert_subtable(struct classifier
*cls
,
115 const struct minimask
*);
116 static void destroy_subtable(struct classifier
*cls
, struct cls_subtable
*);
118 static const struct cls_match
*find_match_wc(const struct cls_subtable
*,
119 cls_version_t version
,
122 unsigned int n_tries
,
123 struct flow_wildcards
*);
124 static struct cls_match
*find_equal(const struct cls_subtable
*,
125 const struct miniflow
*, uint32_t hash
);
127 /* Return the next visible (lower-priority) rule in the list. Multiple
128 * identical rules with the same priority may exist transitionally, but when
129 * versioning is used at most one of them is ever visible for lookups on any
130 * given 'version'. */
131 static inline const struct cls_match
*
132 next_visible_rule_in_list(const struct cls_match
*rule
, cls_version_t version
)
135 rule
= cls_match_next(rule
);
136 } while (rule
&& !cls_match_visible_in_version(rule
, version
));
141 /* Type with maximum supported prefix length. */
143 struct in6_addr ipv6
; /* For sizing. */
144 ovs_be32 be32
; /* For access. */
147 static unsigned int minimask_get_prefix_len(const struct minimask
*,
148 const struct mf_field
*);
149 static void trie_init(struct classifier
*cls
, int trie_idx
,
150 const struct mf_field
*);
151 static unsigned int trie_lookup(const struct cls_trie
*, const struct flow
*,
152 union trie_prefix
*plens
);
153 static unsigned int trie_lookup_value(const rcu_trie_ptr
*,
154 const ovs_be32 value
[], ovs_be32 plens
[],
155 unsigned int value_bits
);
156 static void trie_destroy(rcu_trie_ptr
*);
157 static void trie_insert(struct cls_trie
*, const struct cls_rule
*, int mlen
);
158 static void trie_insert_prefix(rcu_trie_ptr
*, const ovs_be32
*prefix
,
160 static void trie_remove(struct cls_trie
*, const struct cls_rule
*, int mlen
);
161 static void trie_remove_prefix(rcu_trie_ptr
*, const ovs_be32
*prefix
,
163 static void mask_set_prefix_bits(struct flow_wildcards
*, uint8_t be32ofs
,
164 unsigned int n_bits
);
165 static bool mask_prefix_bits_set(const struct flow_wildcards
*,
166 uint8_t be32ofs
, unsigned int n_bits
);
171 cls_rule_init__(struct cls_rule
*rule
, unsigned int priority
)
173 rculist_init(&rule
->node
);
174 *CONST_CAST(int *, &rule
->priority
) = priority
;
175 rule
->cls_match
= NULL
;
178 /* Initializes 'rule' to match packets specified by 'match' at the given
179 * 'priority'. 'match' must satisfy the invariant described in the comment at
180 * the definition of struct match.
182 * The caller must eventually destroy 'rule' with cls_rule_destroy().
184 * Clients should not use priority INT_MIN. (OpenFlow uses priorities between
185 * 0 and UINT16_MAX, inclusive.) */
187 cls_rule_init(struct cls_rule
*rule
, const struct match
*match
, int priority
)
189 cls_rule_init__(rule
, priority
);
190 minimatch_init(CONST_CAST(struct minimatch
*, &rule
->match
), match
);
193 /* Same as cls_rule_init() for initialization from a "struct minimatch". */
195 cls_rule_init_from_minimatch(struct cls_rule
*rule
,
196 const struct minimatch
*match
, int priority
)
198 cls_rule_init__(rule
, priority
);
199 minimatch_clone(CONST_CAST(struct minimatch
*, &rule
->match
), match
);
202 /* Initializes 'dst' as a copy of 'src'.
204 * The caller must eventually destroy 'dst' with cls_rule_destroy(). */
206 cls_rule_clone(struct cls_rule
*dst
, const struct cls_rule
*src
)
208 cls_rule_init__(dst
, src
->priority
);
209 minimatch_clone(CONST_CAST(struct minimatch
*, &dst
->match
), &src
->match
);
212 /* Initializes 'dst' with the data in 'src', destroying 'src'.
214 * 'src' must be a cls_rule NOT in a classifier.
216 * The caller must eventually destroy 'dst' with cls_rule_destroy(). */
218 cls_rule_move(struct cls_rule
*dst
, struct cls_rule
*src
)
220 cls_rule_init__(dst
, src
->priority
);
221 minimatch_move(CONST_CAST(struct minimatch
*, &dst
->match
),
222 CONST_CAST(struct minimatch
*, &src
->match
));
225 /* Frees memory referenced by 'rule'. Doesn't free 'rule' itself (it's
226 * normally embedded into a larger structure).
228 * ('rule' must not currently be in a classifier.) */
230 cls_rule_destroy(struct cls_rule
*rule
)
231 OVS_NO_THREAD_SAFETY_ANALYSIS
233 ovs_assert(!rule
->cls_match
); /* Must not be in a classifier. */
235 /* Check that the rule has been properly removed from the classifier. */
236 ovs_assert(rule
->node
.prev
== RCULIST_POISON
237 || rculist_is_empty(&rule
->node
));
238 rculist_poison__(&rule
->node
); /* Poisons also the next pointer. */
240 minimatch_destroy(CONST_CAST(struct minimatch
*, &rule
->match
));
244 cls_rule_set_conjunctions(struct cls_rule
*cr
,
245 const struct cls_conjunction
*conj
, size_t n
)
247 struct cls_match
*match
= cr
->cls_match
;
248 struct cls_conjunction_set
*old
249 = ovsrcu_get_protected(struct cls_conjunction_set
*, &match
->conj_set
);
250 struct cls_conjunction
*old_conj
= old
? old
->conj
: NULL
;
251 unsigned int old_n
= old
? old
->n
: 0;
253 if (old_n
!= n
|| (n
&& memcmp(old_conj
, conj
, n
* sizeof *conj
))) {
255 ovsrcu_postpone(free
, old
);
257 ovsrcu_set(&match
->conj_set
,
258 cls_conjunction_set_alloc(match
, conj
, n
));
263 /* Returns true if 'a' and 'b' match the same packets at the same priority,
264 * false if they differ in some way. */
266 cls_rule_equal(const struct cls_rule
*a
, const struct cls_rule
*b
)
268 return a
->priority
== b
->priority
&& minimatch_equal(&a
->match
, &b
->match
);
271 /* Appends a string describing 'rule' to 's'. */
273 cls_rule_format(const struct cls_rule
*rule
, struct ds
*s
)
275 minimatch_format(&rule
->match
, s
, rule
->priority
);
278 /* Returns true if 'rule' matches every packet, false otherwise. */
280 cls_rule_is_catchall(const struct cls_rule
*rule
)
282 return minimask_is_catchall(rule
->match
.mask
);
285 /* Makes 'rule' invisible in 'remove_version'. Once that version is used in
286 * lookups, the caller should remove 'rule' via ovsrcu_postpone().
288 * 'rule' must be in a classifier. */
290 cls_rule_make_invisible_in_version(const struct cls_rule
*rule
,
291 cls_version_t remove_version
)
293 ovs_assert(remove_version
>= rule
->cls_match
->add_version
);
295 cls_match_set_remove_version(rule
->cls_match
, remove_version
);
298 /* This undoes the change made by cls_rule_make_invisible_in_version().
300 * 'rule' must be in a classifier. */
302 cls_rule_restore_visibility(const struct cls_rule
*rule
)
304 cls_match_set_remove_version(rule
->cls_match
, CLS_NOT_REMOVED_VERSION
);
307 /* Return true if 'rule' is visible in 'version'.
309 * 'rule' must be in a classifier. */
311 cls_rule_visible_in_version(const struct cls_rule
*rule
, cls_version_t version
)
313 return cls_match_visible_in_version(rule
->cls_match
, version
);
316 /* Initializes 'cls' as a classifier that initially contains no classification
319 classifier_init(struct classifier
*cls
, const uint8_t *flow_segments
)
322 cmap_init(&cls
->subtables_map
);
323 pvector_init(&cls
->subtables
);
324 cmap_init(&cls
->partitions
);
325 cls
->n_flow_segments
= 0;
327 while (cls
->n_flow_segments
< CLS_MAX_INDICES
328 && *flow_segments
< FLOW_U64S
) {
329 cls
->flow_segments
[cls
->n_flow_segments
++] = *flow_segments
++;
333 for (int i
= 0; i
< CLS_MAX_TRIES
; i
++) {
334 trie_init(cls
, i
, NULL
);
339 /* Destroys 'cls'. Rules within 'cls', if any, are not freed; this is the
340 * caller's responsibility.
341 * May only be called after all the readers have been terminated. */
343 classifier_destroy(struct classifier
*cls
)
346 struct cls_partition
*partition
;
347 struct cls_subtable
*subtable
;
350 for (i
= 0; i
< cls
->n_tries
; i
++) {
351 trie_destroy(&cls
->tries
[i
].root
);
354 CMAP_FOR_EACH (subtable
, cmap_node
, &cls
->subtables_map
) {
355 destroy_subtable(cls
, subtable
);
357 cmap_destroy(&cls
->subtables_map
);
359 CMAP_FOR_EACH (partition
, cmap_node
, &cls
->partitions
) {
360 ovsrcu_postpone(free
, partition
);
362 cmap_destroy(&cls
->partitions
);
364 pvector_destroy(&cls
->subtables
);
368 /* Set the fields for which prefix lookup should be performed. */
370 classifier_set_prefix_fields(struct classifier
*cls
,
371 const enum mf_field_id
*trie_fields
,
372 unsigned int n_fields
)
374 const struct mf_field
* new_fields
[CLS_MAX_TRIES
];
375 struct mf_bitmap fields
= MF_BITMAP_INITIALIZER
;
377 bool changed
= false;
379 for (i
= 0; i
< n_fields
&& n_tries
< CLS_MAX_TRIES
; i
++) {
380 const struct mf_field
*field
= mf_from_id(trie_fields
[i
]);
381 if (field
->flow_be32ofs
< 0 || field
->n_bits
% 32) {
382 /* Incompatible field. This is the only place where we
383 * enforce these requirements, but the rest of the trie code
384 * depends on the flow_be32ofs to be non-negative and the
385 * field length to be a multiple of 32 bits. */
389 if (bitmap_is_set(fields
.bm
, trie_fields
[i
])) {
390 /* Duplicate field, there is no need to build more than
391 * one index for any one field. */
394 bitmap_set1(fields
.bm
, trie_fields
[i
]);
396 new_fields
[n_tries
] = NULL
;
397 if (n_tries
>= cls
->n_tries
|| field
!= cls
->tries
[n_tries
].field
) {
398 new_fields
[n_tries
] = field
;
404 if (changed
|| n_tries
< cls
->n_tries
) {
405 struct cls_subtable
*subtable
;
407 /* Trie configuration needs to change. Disable trie lookups
408 * for the tries that are changing and wait all the current readers
409 * with the old configuration to be done. */
411 CMAP_FOR_EACH (subtable
, cmap_node
, &cls
->subtables_map
) {
412 for (i
= 0; i
< cls
->n_tries
; i
++) {
413 if ((i
< n_tries
&& new_fields
[i
]) || i
>= n_tries
) {
414 if (subtable
->trie_plen
[i
]) {
415 subtable
->trie_plen
[i
] = 0;
421 /* Synchronize if any readers were using tries. The readers may
422 * temporarily function without the trie lookup based optimizations. */
424 /* ovsrcu_synchronize() functions as a memory barrier, so it does
425 * not matter that subtable->trie_plen is not atomic. */
426 ovsrcu_synchronize();
429 /* Now set up the tries. */
430 for (i
= 0; i
< n_tries
; i
++) {
432 trie_init(cls
, i
, new_fields
[i
]);
435 /* Destroy the rest, if any. */
436 for (; i
< cls
->n_tries
; i
++) {
437 trie_init(cls
, i
, NULL
);
440 cls
->n_tries
= n_tries
;
444 return false; /* No change. */
448 trie_init(struct classifier
*cls
, int trie_idx
, const struct mf_field
*field
)
450 struct cls_trie
*trie
= &cls
->tries
[trie_idx
];
451 struct cls_subtable
*subtable
;
453 if (trie_idx
< cls
->n_tries
) {
454 trie_destroy(&trie
->root
);
456 ovsrcu_set_hidden(&trie
->root
, NULL
);
460 /* Add existing rules to the new trie. */
461 CMAP_FOR_EACH (subtable
, cmap_node
, &cls
->subtables_map
) {
464 plen
= field
? minimask_get_prefix_len(&subtable
->mask
, field
) : 0;
466 struct cls_match
*head
;
468 CMAP_FOR_EACH (head
, cmap_node
, &subtable
->rules
) {
469 trie_insert(trie
, head
->cls_rule
, plen
);
472 /* Initialize subtable's prefix length on this field. This will
473 * allow readers to use the trie. */
474 atomic_thread_fence(memory_order_release
);
475 subtable
->trie_plen
[trie_idx
] = plen
;
479 /* Returns true if 'cls' contains no classification rules, false otherwise.
480 * Checking the cmap requires no locking. */
482 classifier_is_empty(const struct classifier
*cls
)
484 return cmap_is_empty(&cls
->subtables_map
);
487 /* Returns the number of rules in 'cls'. */
489 classifier_count(const struct classifier
*cls
)
491 /* n_rules is an int, so in the presence of concurrent writers this will
492 * return either the old or a new value. */
497 hash_metadata(ovs_be64 metadata
)
499 return hash_uint64((OVS_FORCE
uint64_t) metadata
);
502 static struct cls_partition
*
503 find_partition(const struct classifier
*cls
, ovs_be64 metadata
, uint32_t hash
)
505 struct cls_partition
*partition
;
507 CMAP_FOR_EACH_WITH_HASH (partition
, cmap_node
, hash
, &cls
->partitions
) {
508 if (partition
->metadata
== metadata
) {
516 static struct cls_partition
*
517 create_partition(struct classifier
*cls
, struct cls_subtable
*subtable
,
520 uint32_t hash
= hash_metadata(metadata
);
521 struct cls_partition
*partition
= find_partition(cls
, metadata
, hash
);
523 partition
= xmalloc(sizeof *partition
);
524 partition
->metadata
= metadata
;
526 tag_tracker_init(&partition
->tracker
);
527 cmap_insert(&cls
->partitions
, &partition
->cmap_node
, hash
);
529 tag_tracker_add(&partition
->tracker
, &partition
->tags
, subtable
->tag
);
533 static inline ovs_be32
minimatch_get_ports(const struct minimatch
*match
)
535 /* Could optimize to use the same map if needed for fast path. */
536 return MINIFLOW_GET_BE32(match
->flow
, tp_src
)
537 & MINIFLOW_GET_BE32(&match
->mask
->masks
, tp_src
);
541 subtable_replace_head_rule(struct classifier
*cls OVS_UNUSED
,
542 struct cls_subtable
*subtable
,
543 struct cls_match
*head
, struct cls_match
*new,
544 uint32_t hash
, uint32_t ihash
[CLS_MAX_INDICES
])
546 /* Rule's data is already in the tries. */
548 new->partition
= head
->partition
; /* Steal partition, if any. */
549 head
->partition
= NULL
;
551 for (int i
= 0; i
< subtable
->n_indices
; i
++) {
552 cmap_replace(&subtable
->indices
[i
], &head
->index_nodes
[i
],
553 &new->index_nodes
[i
], ihash
[i
]);
555 cmap_replace(&subtable
->rules
, &head
->cmap_node
, &new->cmap_node
, hash
);
558 /* Inserts 'rule' into 'cls' in 'version'. Until 'rule' is removed from 'cls',
559 * the caller must not modify or free it.
561 * If 'cls' already contains an identical rule (including wildcards, values of
562 * fixed fields, and priority) that is visible in 'version', replaces the old
563 * rule by 'rule' and returns the rule that was replaced. The caller takes
564 * ownership of the returned rule and is thus responsible for destroying it
565 * with cls_rule_destroy(), after RCU grace period has passed (see
566 * ovsrcu_postpone()).
568 * Returns NULL if 'cls' does not contain a rule with an identical key, after
569 * inserting the new rule. In this case, no rules are displaced by the new
570 * rule, even rules that cannot have any effect because the new rule matches a
571 * superset of their flows and has higher priority.
573 const struct cls_rule
*
574 classifier_replace(struct classifier
*cls
, const struct cls_rule
*rule
,
575 cls_version_t version
,
576 const struct cls_conjunction
*conjs
, size_t n_conjs
)
578 struct cls_match
*new;
579 struct cls_subtable
*subtable
;
580 uint32_t ihash
[CLS_MAX_INDICES
];
581 struct cls_match
*head
;
582 unsigned int mask_offset
;
588 /* 'new' is initially invisible to lookups. */
589 new = cls_match_alloc(rule
, version
, conjs
, n_conjs
);
591 CONST_CAST(struct cls_rule
*, rule
)->cls_match
= new;
593 subtable
= find_subtable(cls
, rule
->match
.mask
);
595 subtable
= insert_subtable(cls
, rule
->match
.mask
);
598 /* Compute hashes in segments. */
601 for (i
= 0; i
< subtable
->n_indices
; i
++) {
602 ihash
[i
] = minimatch_hash_range(&rule
->match
, &subtable
->index_maps
[i
],
603 &mask_offset
, &basis
);
605 hash
= minimatch_hash_range(&rule
->match
, &subtable
->index_maps
[i
],
606 &mask_offset
, &basis
);
608 head
= find_equal(subtable
, rule
->match
.flow
, hash
);
610 /* Add rule to tries.
612 * Concurrent readers might miss seeing the rule until this update,
613 * which might require being fixed up by revalidation later. */
614 for (i
= 0; i
< cls
->n_tries
; i
++) {
615 if (subtable
->trie_plen
[i
]) {
616 trie_insert(&cls
->tries
[i
], rule
, subtable
->trie_plen
[i
]);
620 /* Add rule to ports trie. */
621 if (subtable
->ports_mask_len
) {
622 /* We mask the value to be inserted to always have the wildcarded
623 * bits in known (zero) state, so we can include them in comparison
624 * and they will always match (== their original value does not
626 ovs_be32 masked_ports
= minimatch_get_ports(&rule
->match
);
628 trie_insert_prefix(&subtable
->ports_trie
, &masked_ports
,
629 subtable
->ports_mask_len
);
632 /* Add rule to partitions.
634 * Concurrent readers might miss seeing the rule until this update,
635 * which might require being fixed up by revalidation later. */
636 new->partition
= NULL
;
637 if (minimask_get_metadata_mask(rule
->match
.mask
) == OVS_BE64_MAX
) {
638 ovs_be64 metadata
= miniflow_get_metadata(rule
->match
.flow
);
640 new->partition
= create_partition(cls
, subtable
, metadata
);
643 /* Add new node to segment indices.
645 * Readers may find the rule in the indices before the rule is visible
646 * in the subtables 'rules' map. This may result in us losing the
647 * opportunity to quit lookups earlier, resulting in sub-optimal
648 * wildcarding. This will be fixed later by revalidation (always
649 * scheduled after flow table changes). */
650 for (i
= 0; i
< subtable
->n_indices
; i
++) {
651 cmap_insert(&subtable
->indices
[i
], &new->index_nodes
[i
], ihash
[i
]);
653 n_rules
= cmap_insert(&subtable
->rules
, &new->cmap_node
, hash
);
654 } else { /* Equal rules exist in the classifier already. */
655 struct cls_match
*prev
, *iter
;
657 /* Scan the list for the insertion point that will keep the list in
658 * order of decreasing priority. Insert after rules marked invisible
659 * in any version of the same priority. */
660 FOR_EACH_RULE_IN_LIST_PROTECTED (iter
, prev
, head
) {
661 if (rule
->priority
> iter
->priority
662 || (rule
->priority
== iter
->priority
663 && !cls_match_is_eventually_invisible(iter
))) {
668 /* Replace 'iter' with 'new' or insert 'new' between 'prev' and
671 struct cls_rule
*old
;
673 if (rule
->priority
== iter
->priority
) {
674 cls_match_replace(prev
, iter
, new);
675 old
= CONST_CAST(struct cls_rule
*, iter
->cls_rule
);
677 cls_match_insert(prev
, iter
, new);
681 /* Replace the existing head in data structures, if rule is the new
684 subtable_replace_head_rule(cls
, subtable
, head
, new, hash
,
689 struct cls_conjunction_set
*conj_set
;
691 conj_set
= ovsrcu_get_protected(struct cls_conjunction_set
*,
694 ovsrcu_postpone(free
, conj_set
);
697 ovsrcu_postpone(cls_match_free_cb
, iter
);
698 old
->cls_match
= NULL
;
700 /* No change in subtable's max priority or max count. */
702 /* Make 'new' visible to lookups in the appropriate version. */
703 cls_match_set_remove_version(new, CLS_NOT_REMOVED_VERSION
);
705 /* Make rule visible to iterators (immediately). */
706 rculist_replace(CONST_CAST(struct rculist
*, &rule
->node
),
709 /* Return displaced rule. Caller is responsible for keeping it
710 * around until all threads quiesce. */
714 /* 'new' is new node after 'prev' */
715 cls_match_insert(prev
, iter
, new);
719 /* Make 'new' visible to lookups in the appropriate version. */
720 cls_match_set_remove_version(new, CLS_NOT_REMOVED_VERSION
);
722 /* Make rule visible to iterators (immediately). */
723 rculist_push_back(&subtable
->rules_list
,
724 CONST_CAST(struct rculist
*, &rule
->node
));
726 /* Rule was added, not replaced. Update 'subtable's 'max_priority' and
727 * 'max_count', if necessary.
729 * The rule was already inserted, but concurrent readers may not see the
730 * rule yet as the subtables vector is not updated yet. This will have to
731 * be fixed by revalidation later. */
733 subtable
->max_priority
= rule
->priority
;
734 subtable
->max_count
= 1;
735 pvector_insert(&cls
->subtables
, subtable
, rule
->priority
);
736 } else if (rule
->priority
== subtable
->max_priority
) {
737 ++subtable
->max_count
;
738 } else if (rule
->priority
> subtable
->max_priority
) {
739 subtable
->max_priority
= rule
->priority
;
740 subtable
->max_count
= 1;
741 pvector_change_priority(&cls
->subtables
, subtable
, rule
->priority
);
744 /* Nothing was replaced. */
748 pvector_publish(&cls
->subtables
);
754 /* Inserts 'rule' into 'cls'. Until 'rule' is removed from 'cls', the caller
755 * must not modify or free it.
757 * 'cls' must not contain an identical rule (including wildcards, values of
758 * fixed fields, and priority). Use classifier_find_rule_exactly() to find
761 classifier_insert(struct classifier
*cls
, const struct cls_rule
*rule
,
762 cls_version_t version
, const struct cls_conjunction conj
[],
765 const struct cls_rule
*displaced_rule
766 = classifier_replace(cls
, rule
, version
, conj
, n_conj
);
767 ovs_assert(!displaced_rule
);
770 /* Removes 'rule' from 'cls'. It is the caller's responsibility to destroy
771 * 'rule' with cls_rule_destroy(), freeing the memory block in which 'rule'
772 * resides, etc., as necessary.
774 * Does nothing if 'rule' has been already removed, or was never inserted.
776 * Returns the removed rule, or NULL, if it was already removed.
778 const struct cls_rule
*
779 classifier_remove(struct classifier
*cls
, const struct cls_rule
*cls_rule
)
781 struct cls_match
*rule
, *prev
, *next
, *head
;
782 struct cls_partition
*partition
;
783 struct cls_conjunction_set
*conj_set
;
784 struct cls_subtable
*subtable
;
785 uint32_t basis
= 0, hash
, ihash
[CLS_MAX_INDICES
];
786 unsigned int mask_offset
;
790 rule
= cls_rule
->cls_match
;
794 /* Mark as removed. */
795 CONST_CAST(struct cls_rule
*, cls_rule
)->cls_match
= NULL
;
797 /* Remove 'cls_rule' from the subtable's rules list. */
798 rculist_remove(CONST_CAST(struct rculist
*, &cls_rule
->node
));
800 subtable
= find_subtable(cls
, cls_rule
->match
.mask
);
801 ovs_assert(subtable
);
804 for (i
= 0; i
< subtable
->n_indices
; i
++) {
805 ihash
[i
] = minimatch_hash_range(&cls_rule
->match
,
806 &subtable
->index_maps
[i
],
807 &mask_offset
, &basis
);
809 hash
= minimatch_hash_range(&cls_rule
->match
, &subtable
->index_maps
[i
],
810 &mask_offset
, &basis
);
812 head
= find_equal(subtable
, cls_rule
->match
.flow
, hash
);
814 /* Check if the rule is not the head rule. */
816 struct cls_match
*iter
;
818 /* Not the head rule, but potentially one with the same priority. */
819 /* Remove from the list of equal rules. */
820 FOR_EACH_RULE_IN_LIST_PROTECTED (iter
, prev
, head
) {
825 ovs_assert(iter
== rule
);
827 cls_match_remove(prev
, rule
);
832 /* 'rule' is the head rule. Check if there is another rule to
833 * replace 'rule' in the data structures. */
834 next
= cls_match_next_protected(rule
);
836 subtable_replace_head_rule(cls
, subtable
, rule
, next
, hash
, ihash
);
840 /* 'rule' is last of the kind in the classifier, must remove from all the
841 * data structures. */
843 if (subtable
->ports_mask_len
) {
844 ovs_be32 masked_ports
= minimatch_get_ports(&cls_rule
->match
);
846 trie_remove_prefix(&subtable
->ports_trie
,
847 &masked_ports
, subtable
->ports_mask_len
);
849 for (i
= 0; i
< cls
->n_tries
; i
++) {
850 if (subtable
->trie_plen
[i
]) {
851 trie_remove(&cls
->tries
[i
], cls_rule
, subtable
->trie_plen
[i
]);
855 /* Remove rule node from indices. */
856 for (i
= 0; i
< subtable
->n_indices
; i
++) {
857 cmap_remove(&subtable
->indices
[i
], &rule
->index_nodes
[i
], ihash
[i
]);
859 n_rules
= cmap_remove(&subtable
->rules
, &rule
->cmap_node
, hash
);
861 partition
= rule
->partition
;
863 tag_tracker_subtract(&partition
->tracker
, &partition
->tags
,
865 if (!partition
->tags
) {
866 cmap_remove(&cls
->partitions
, &partition
->cmap_node
,
867 hash_metadata(partition
->metadata
));
868 ovsrcu_postpone(free
, partition
);
873 destroy_subtable(cls
, subtable
);
876 if (subtable
->max_priority
== rule
->priority
877 && --subtable
->max_count
== 0) {
878 /* Find the new 'max_priority' and 'max_count'. */
879 int max_priority
= INT_MIN
;
880 struct cls_match
*head
;
882 CMAP_FOR_EACH (head
, cmap_node
, &subtable
->rules
) {
883 if (head
->priority
> max_priority
) {
884 max_priority
= head
->priority
;
885 subtable
->max_count
= 1;
886 } else if (head
->priority
== max_priority
) {
887 ++subtable
->max_count
;
890 subtable
->max_priority
= max_priority
;
891 pvector_change_priority(&cls
->subtables
, subtable
, max_priority
);
896 pvector_publish(&cls
->subtables
);
900 conj_set
= ovsrcu_get_protected(struct cls_conjunction_set
*,
903 ovsrcu_postpone(free
, conj_set
);
905 ovsrcu_postpone(cls_match_free_cb
, rule
);
911 /* Prefix tree context. Valid when 'lookup_done' is true. Can skip all
912 * subtables which have a prefix match on the trie field, but whose prefix
913 * length is not indicated in 'match_plens'. For example, a subtable that
914 * has a 8-bit trie field prefix match can be skipped if
915 * !be_get_bit_at(&match_plens, 8 - 1). If skipped, 'maskbits' prefix bits
916 * must be unwildcarded to make datapath flow only match packets it should. */
918 const struct cls_trie
*trie
;
919 bool lookup_done
; /* Status of the lookup. */
920 uint8_t be32ofs
; /* U32 offset of the field in question. */
921 unsigned int maskbits
; /* Prefix length needed to avoid false matches. */
922 union trie_prefix match_plens
; /* Bitmask of prefix lengths with possible
927 trie_ctx_init(struct trie_ctx
*ctx
, const struct cls_trie
*trie
)
930 ctx
->be32ofs
= trie
->field
->flow_be32ofs
;
931 ctx
->lookup_done
= false;
934 struct conjunctive_match
{
935 struct hmap_node hmap_node
;
940 static struct conjunctive_match
*
941 find_conjunctive_match__(struct hmap
*matches
, uint64_t id
, uint32_t hash
)
943 struct conjunctive_match
*m
;
945 HMAP_FOR_EACH_IN_BUCKET (m
, hmap_node
, hash
, matches
) {
954 find_conjunctive_match(const struct cls_conjunction_set
*set
,
955 unsigned int max_n_clauses
, struct hmap
*matches
,
956 struct conjunctive_match
*cm_stubs
, size_t n_cm_stubs
,
959 const struct cls_conjunction
*c
;
961 if (max_n_clauses
< set
->min_n_clauses
) {
965 for (c
= set
->conj
; c
< &set
->conj
[set
->n
]; c
++) {
966 struct conjunctive_match
*cm
;
969 if (c
->n_clauses
> max_n_clauses
) {
973 hash
= hash_int(c
->id
, 0);
974 cm
= find_conjunctive_match__(matches
, c
->id
, hash
);
976 size_t n
= hmap_count(matches
);
978 cm
= n
< n_cm_stubs
? &cm_stubs
[n
] : xmalloc(sizeof *cm
);
979 hmap_insert(matches
, &cm
->hmap_node
, hash
);
981 cm
->clauses
= UINT64_MAX
<< (c
->n_clauses
& 63);
983 cm
->clauses
|= UINT64_C(1) << c
->clause
;
984 if (cm
->clauses
== UINT64_MAX
) {
993 free_conjunctive_matches(struct hmap
*matches
,
994 struct conjunctive_match
*cm_stubs
, size_t n_cm_stubs
)
996 if (hmap_count(matches
) > n_cm_stubs
) {
997 struct conjunctive_match
*cm
, *next
;
999 HMAP_FOR_EACH_SAFE (cm
, next
, hmap_node
, matches
) {
1000 if (!(cm
>= cm_stubs
&& cm
< &cm_stubs
[n_cm_stubs
])) {
1005 hmap_destroy(matches
);
1008 /* Like classifier_lookup(), except that support for conjunctive matches can be
1009 * configured with 'allow_conjunctive_matches'. That feature is not exposed
1010 * externally because turning off conjunctive matches is only useful to avoid
1011 * recursion within this function itself.
1013 * 'flow' is non-const to allow for temporary modifications during the lookup.
1014 * Any changes are restored before returning. */
1015 static const struct cls_rule
*
1016 classifier_lookup__(const struct classifier
*cls
, cls_version_t version
,
1017 struct flow
*flow
, struct flow_wildcards
*wc
,
1018 bool allow_conjunctive_matches
)
1020 const struct cls_partition
*partition
;
1021 struct trie_ctx trie_ctx
[CLS_MAX_TRIES
];
1022 const struct cls_match
*match
;
1025 /* Highest-priority flow in 'cls' that certainly matches 'flow'. */
1026 const struct cls_match
*hard
= NULL
;
1027 int hard_pri
= INT_MIN
; /* hard ? hard->priority : INT_MIN. */
1029 /* Highest-priority conjunctive flows in 'cls' matching 'flow'. Since
1030 * these are (components of) conjunctive flows, we can only know whether
1031 * the full conjunctive flow matches after seeing multiple of them. Thus,
1032 * we refer to these as "soft matches". */
1033 struct cls_conjunction_set
*soft_stub
[64];
1034 struct cls_conjunction_set
**soft
= soft_stub
;
1035 size_t n_soft
= 0, allocated_soft
= ARRAY_SIZE(soft_stub
);
1036 int soft_pri
= INT_MIN
; /* n_soft ? MAX(soft[*]->priority) : INT_MIN. */
1038 /* Synchronize for cls->n_tries and subtable->trie_plen. They can change
1039 * when table configuration changes, which happens typically only on
1041 atomic_thread_fence(memory_order_acquire
);
1043 /* Determine 'tags' such that, if 'subtable->tag' doesn't intersect them,
1044 * then 'flow' cannot possibly match in 'subtable':
1046 * - If flow->metadata maps to a given 'partition', then we can use
1047 * 'tags' for 'partition->tags'.
1049 * - If flow->metadata has no partition, then no rule in 'cls' has an
1050 * exact-match for flow->metadata. That means that we don't need to
1051 * search any subtable that includes flow->metadata in its mask.
1053 * In either case, we always need to search any cls_subtables that do not
1054 * include flow->metadata in its mask. One way to do that would be to
1055 * check the "cls_subtable"s explicitly for that, but that would require an
1056 * extra branch per subtable. Instead, we mark such a cls_subtable's
1057 * 'tags' as TAG_ALL and make sure that 'tags' is never empty. This means
1058 * that 'tags' always intersects such a cls_subtable's 'tags', so we don't
1059 * need a special case.
1061 partition
= (cmap_is_empty(&cls
->partitions
)
1063 : find_partition(cls
, flow
->metadata
,
1064 hash_metadata(flow
->metadata
)));
1065 tags
= partition
? partition
->tags
: TAG_ARBITRARY
;
1067 /* Initialize trie contexts for find_match_wc(). */
1068 for (int i
= 0; i
< cls
->n_tries
; i
++) {
1069 trie_ctx_init(&trie_ctx
[i
], &cls
->tries
[i
]);
1073 struct cls_subtable
*subtable
;
1074 PVECTOR_FOR_EACH_PRIORITY (subtable
, hard_pri
, 2, sizeof *subtable
,
1076 struct cls_conjunction_set
*conj_set
;
1078 /* Skip subtables not in our partition. */
1079 if (!tag_intersects(tags
, subtable
->tag
)) {
1083 /* Skip subtables with no match, or where the match is lower-priority
1084 * than some certain match we've already found. */
1085 match
= find_match_wc(subtable
, version
, flow
, trie_ctx
, cls
->n_tries
,
1087 if (!match
|| match
->priority
<= hard_pri
) {
1091 conj_set
= ovsrcu_get(struct cls_conjunction_set
*, &match
->conj_set
);
1093 /* 'match' isn't part of a conjunctive match. It's the best
1094 * certain match we've got so far, since we know that it's
1095 * higher-priority than hard_pri.
1097 * (There might be a higher-priority conjunctive match. We can't
1100 hard_pri
= hard
->priority
;
1101 } else if (allow_conjunctive_matches
) {
1102 /* 'match' is part of a conjunctive match. Add it to the list. */
1103 if (OVS_UNLIKELY(n_soft
>= allocated_soft
)) {
1104 struct cls_conjunction_set
**old_soft
= soft
;
1106 allocated_soft
*= 2;
1107 soft
= xmalloc(allocated_soft
* sizeof *soft
);
1108 memcpy(soft
, old_soft
, n_soft
* sizeof *soft
);
1109 if (old_soft
!= soft_stub
) {
1113 soft
[n_soft
++] = conj_set
;
1115 /* Keep track of the highest-priority soft match. */
1116 if (soft_pri
< match
->priority
) {
1117 soft_pri
= match
->priority
;
1122 /* In the common case, at this point we have no soft matches and we can
1123 * return immediately. (We do the same thing if we have potential soft
1124 * matches but none of them are higher-priority than our hard match.) */
1125 if (hard_pri
>= soft_pri
) {
1126 if (soft
!= soft_stub
) {
1129 return hard
? hard
->cls_rule
: NULL
;
1132 /* At this point, we have some soft matches. We might also have a hard
1133 * match; if so, its priority is lower than the highest-priority soft
1138 * Check whether soft matches are real matches. */
1140 /* Delete soft matches that are null. This only happens in second and
1141 * subsequent iterations of the soft match loop, when we drop back from
1142 * a high-priority soft match to a lower-priority one.
1144 * Also, delete soft matches whose priority is less than or equal to
1145 * the hard match's priority. In the first iteration of the soft
1146 * match, these can be in 'soft' because the earlier main loop found
1147 * the soft match before the hard match. In second and later iteration
1148 * of the soft match loop, these can be in 'soft' because we dropped
1149 * back from a high-priority soft match to a lower-priority soft match.
1151 * It is tempting to delete soft matches that cannot be satisfied
1152 * because there are fewer soft matches than required to satisfy any of
1153 * their conjunctions, but we cannot do that because there might be
1154 * lower priority soft or hard matches with otherwise identical
1155 * matches. (We could special case those here, but there's no
1156 * need--we'll do so at the bottom of the soft match loop anyway and
1157 * this duplicates less code.)
1159 * It's also tempting to break out of the soft match loop if 'n_soft ==
1160 * 1' but that would also miss lower-priority hard matches. We could
1161 * special case that also but again there's no need. */
1162 for (int i
= 0; i
< n_soft
; ) {
1163 if (!soft
[i
] || soft
[i
]->priority
<= hard_pri
) {
1164 soft
[i
] = soft
[--n_soft
];
1173 /* Find the highest priority among the soft matches. (We know this
1174 * must be higher than the hard match's priority; otherwise we would
1175 * have deleted all of the soft matches in the previous loop.) Count
1176 * the number of soft matches that have that priority. */
1179 for (int i
= 0; i
< n_soft
; i
++) {
1180 if (soft
[i
]->priority
> soft_pri
) {
1181 soft_pri
= soft
[i
]->priority
;
1183 } else if (soft
[i
]->priority
== soft_pri
) {
1187 ovs_assert(soft_pri
> hard_pri
);
1189 /* Look for a real match among the highest-priority soft matches.
1191 * It's unusual to have many conjunctive matches, so we use stubs to
1192 * avoid calling malloc() in the common case. An hmap has a built-in
1193 * stub for up to 2 hmap_nodes; possibly, we would benefit a variant
1194 * with a bigger stub. */
1195 struct conjunctive_match cm_stubs
[16];
1196 struct hmap matches
;
1198 hmap_init(&matches
);
1199 for (int i
= 0; i
< n_soft
; i
++) {
1202 if (soft
[i
]->priority
== soft_pri
1203 && find_conjunctive_match(soft
[i
], n_soft_pri
, &matches
,
1204 cm_stubs
, ARRAY_SIZE(cm_stubs
),
1206 uint32_t saved_conj_id
= flow
->conj_id
;
1207 const struct cls_rule
*rule
;
1210 rule
= classifier_lookup__(cls
, version
, flow
, wc
, false);
1211 flow
->conj_id
= saved_conj_id
;
1214 free_conjunctive_matches(&matches
,
1215 cm_stubs
, ARRAY_SIZE(cm_stubs
));
1216 if (soft
!= soft_stub
) {
1223 free_conjunctive_matches(&matches
, cm_stubs
, ARRAY_SIZE(cm_stubs
));
1225 /* There's no real match among the highest-priority soft matches.
1226 * However, if any of those soft matches has a lower-priority but
1227 * otherwise identical flow match, then we need to consider those for
1228 * soft or hard matches.
1230 * The next iteration of the soft match loop will delete any null
1231 * pointers we put into 'soft' (and some others too). */
1232 for (int i
= 0; i
< n_soft
; i
++) {
1233 if (soft
[i
]->priority
!= soft_pri
) {
1237 /* Find next-lower-priority flow with identical flow match. */
1238 match
= next_visible_rule_in_list(soft
[i
]->match
, version
);
1240 soft
[i
] = ovsrcu_get(struct cls_conjunction_set
*,
1243 /* The flow is a hard match; don't treat as a soft
1245 if (match
->priority
> hard_pri
) {
1247 hard_pri
= hard
->priority
;
1251 /* No such lower-priority flow (probably the common case). */
1257 if (soft
!= soft_stub
) {
1260 return hard
? hard
->cls_rule
: NULL
;
1263 /* Finds and returns the highest-priority rule in 'cls' that matches 'flow' and
1264 * that is visible in 'version'. Returns a null pointer if no rules in 'cls'
1265 * match 'flow'. If multiple rules of equal priority match 'flow', returns one
1268 * If a rule is found and 'wc' is non-null, bitwise-OR's 'wc' with the
1269 * set of bits that were significant in the lookup. At some point
1270 * earlier, 'wc' should have been initialized (e.g., by
1271 * flow_wildcards_init_catchall()).
1273 * 'flow' is non-const to allow for temporary modifications during the lookup.
1274 * Any changes are restored before returning. */
1275 const struct cls_rule
*
1276 classifier_lookup(const struct classifier
*cls
, cls_version_t version
,
1277 struct flow
*flow
, struct flow_wildcards
*wc
)
1279 return classifier_lookup__(cls
, version
, flow
, wc
, true);
1282 /* Finds and returns a rule in 'cls' with exactly the same priority and
1283 * matching criteria as 'target', and that is visible in 'version'.
1284 * Only one such rule may ever exist. Returns a null pointer if 'cls' doesn't
1285 * contain an exact match. */
1286 const struct cls_rule
*
1287 classifier_find_rule_exactly(const struct classifier
*cls
,
1288 const struct cls_rule
*target
,
1289 cls_version_t version
)
1291 const struct cls_match
*head
, *rule
;
1292 const struct cls_subtable
*subtable
;
1294 subtable
= find_subtable(cls
, target
->match
.mask
);
1299 head
= find_equal(subtable
, target
->match
.flow
,
1300 miniflow_hash_in_minimask(target
->match
.flow
,
1301 target
->match
.mask
, 0));
1305 CLS_MATCH_FOR_EACH (rule
, head
) {
1306 if (rule
->priority
< target
->priority
) {
1307 break; /* Not found. */
1309 if (rule
->priority
== target
->priority
1310 && cls_match_visible_in_version(rule
, version
)) {
1311 return rule
->cls_rule
;
1317 /* Finds and returns a rule in 'cls' with priority 'priority' and exactly the
1318 * same matching criteria as 'target', and that is visible in 'version'.
1319 * Returns a null pointer if 'cls' doesn't contain an exact match visible in
1321 const struct cls_rule
*
1322 classifier_find_match_exactly(const struct classifier
*cls
,
1323 const struct match
*target
, int priority
,
1324 cls_version_t version
)
1326 const struct cls_rule
*retval
;
1329 cls_rule_init(&cr
, target
, priority
);
1330 retval
= classifier_find_rule_exactly(cls
, &cr
, version
);
1331 cls_rule_destroy(&cr
);
1336 /* Checks if 'target' would overlap any other rule in 'cls' in 'version'. Two
1337 * rules are considered to overlap if both rules have the same priority and a
1338 * packet could match both, and if both rules are visible in the same version.
1340 * A trivial example of overlapping rules is two rules matching disjoint sets
1341 * of fields. E.g., if one rule matches only on port number, while another only
1342 * on dl_type, any packet from that specific port and with that specific
1343 * dl_type could match both, if the rules also have the same priority. */
1345 classifier_rule_overlaps(const struct classifier
*cls
,
1346 const struct cls_rule
*target
, cls_version_t version
)
1348 struct cls_subtable
*subtable
;
1350 /* Iterate subtables in the descending max priority order. */
1351 PVECTOR_FOR_EACH_PRIORITY (subtable
, target
->priority
- 1, 2,
1352 sizeof(struct cls_subtable
), &cls
->subtables
) {
1354 struct minimask mask
;
1355 uint64_t storage
[FLOW_U64S
];
1357 const struct cls_rule
*rule
;
1359 minimask_combine(&m
.mask
, target
->match
.mask
, &subtable
->mask
,
1362 RCULIST_FOR_EACH (rule
, node
, &subtable
->rules_list
) {
1363 if (rule
->priority
== target
->priority
1364 && miniflow_equal_in_minimask(target
->match
.flow
,
1365 rule
->match
.flow
, &m
.mask
)
1366 && cls_match_visible_in_version(rule
->cls_match
, version
)) {
1374 /* Returns true if 'rule' exactly matches 'criteria' or if 'rule' is more
1375 * specific than 'criteria'. That is, 'rule' matches 'criteria' and this
1376 * function returns true if, for every field:
1378 * - 'criteria' and 'rule' specify the same (non-wildcarded) value for the
1381 * - 'criteria' wildcards the field,
1383 * Conversely, 'rule' does not match 'criteria' and this function returns false
1384 * if, for at least one field:
1386 * - 'criteria' and 'rule' specify different values for the field, or
1388 * - 'criteria' specifies a value for the field but 'rule' wildcards it.
1390 * Equivalently, the truth table for whether a field matches is:
1395 * r +---------+---------+
1396 * i wild | yes | yes |
1398 * e +---------+---------+
1399 * r exact | no |if values|
1401 * a +---------+---------+
1403 * This is the matching rule used by OpenFlow 1.0 non-strict OFPT_FLOW_MOD
1404 * commands and by OpenFlow 1.0 aggregate and flow stats.
1406 * Ignores rule->priority. */
1408 cls_rule_is_loose_match(const struct cls_rule
*rule
,
1409 const struct minimatch
*criteria
)
1411 return (!minimask_has_extra(rule
->match
.mask
, criteria
->mask
)
1412 && miniflow_equal_in_minimask(rule
->match
.flow
, criteria
->flow
,
1419 rule_matches(const struct cls_rule
*rule
, const struct cls_rule
*target
,
1420 cls_version_t version
)
1422 /* Rule may only match a target if it is visible in target's version. */
1423 return cls_match_visible_in_version(rule
->cls_match
, version
)
1424 && (!target
|| miniflow_equal_in_minimask(rule
->match
.flow
,
1426 target
->match
.mask
));
1429 static const struct cls_rule
*
1430 search_subtable(const struct cls_subtable
*subtable
,
1431 struct cls_cursor
*cursor
)
1434 || !minimask_has_extra(&subtable
->mask
, cursor
->target
->match
.mask
)) {
1435 const struct cls_rule
*rule
;
1437 RCULIST_FOR_EACH (rule
, node
, &subtable
->rules_list
) {
1438 if (rule_matches(rule
, cursor
->target
, cursor
->version
)) {
1446 /* Initializes 'cursor' for iterating through rules in 'cls', and returns the
1449 * - If 'target' is null, or if the 'target' is a catchall target, the
1450 * cursor will visit every rule in 'cls' that is visible in 'version'.
1452 * - If 'target' is nonnull, the cursor will visit each 'rule' in 'cls'
1453 * such that cls_rule_is_loose_match(rule, target) returns true and that
1454 * the rule is visible in 'version'.
1456 * Ignores target->priority. */
1458 cls_cursor_start(const struct classifier
*cls
, const struct cls_rule
*target
,
1459 cls_version_t version
)
1461 struct cls_cursor cursor
;
1462 struct cls_subtable
*subtable
;
1465 cursor
.target
= target
&& !cls_rule_is_catchall(target
) ? target
: NULL
;
1466 cursor
.version
= version
;
1469 /* Find first rule. */
1470 PVECTOR_CURSOR_FOR_EACH (subtable
, &cursor
.subtables
,
1471 &cursor
.cls
->subtables
) {
1472 const struct cls_rule
*rule
= search_subtable(subtable
, &cursor
);
1475 cursor
.subtable
= subtable
;
1484 static const struct cls_rule
*
1485 cls_cursor_next(struct cls_cursor
*cursor
)
1487 const struct cls_rule
*rule
;
1488 const struct cls_subtable
*subtable
;
1490 rule
= cursor
->rule
;
1491 subtable
= cursor
->subtable
;
1492 RCULIST_FOR_EACH_CONTINUE (rule
, node
, &subtable
->rules_list
) {
1493 if (rule_matches(rule
, cursor
->target
, cursor
->version
)) {
1498 PVECTOR_CURSOR_FOR_EACH_CONTINUE (subtable
, &cursor
->subtables
) {
1499 rule
= search_subtable(subtable
, cursor
);
1501 cursor
->subtable
= subtable
;
1509 /* Sets 'cursor->rule' to the next matching cls_rule in 'cursor''s iteration,
1510 * or to null if all matching rules have been visited. */
1512 cls_cursor_advance(struct cls_cursor
*cursor
)
1514 cursor
->rule
= cls_cursor_next(cursor
);
1517 static struct cls_subtable
*
1518 find_subtable(const struct classifier
*cls
, const struct minimask
*mask
)
1520 struct cls_subtable
*subtable
;
1522 CMAP_FOR_EACH_WITH_HASH (subtable
, cmap_node
, minimask_hash(mask
, 0),
1523 &cls
->subtables_map
) {
1524 if (minimask_equal(mask
, &subtable
->mask
)) {
1531 /* Initializes 'map' with a subset of 'miniflow''s maps that includes only the
1532 * portions with u64-offset 'i' such that 'start' <= i < 'end'. Does not copy
1533 * any data from 'miniflow' to 'map'. */
1535 miniflow_get_map_in_range(const struct miniflow
*miniflow
,
1536 uint8_t start
, uint8_t end
, struct miniflow
*map
)
1538 *map
= *miniflow
; /* Copy maps. */
1540 if (start
>= FLOW_TNL_U64S
) {
1542 if (start
> FLOW_TNL_U64S
) {
1543 /* Clear 'start - FLOW_TNL_U64S' LSBs from pkt_map. */
1544 start
-= FLOW_TNL_U64S
;
1545 uint64_t msk
= (UINT64_C(1) << start
) - 1;
1547 map
->pkt_map
&= ~msk
;
1549 } else if (start
> 0) {
1550 /* Clear 'start' LSBs from tnl_map. */
1551 uint64_t msk
= (UINT64_C(1) << start
) - 1;
1553 map
->tnl_map
&= ~msk
;
1556 if (end
<= FLOW_TNL_U64S
) {
1558 if (end
< FLOW_TNL_U64S
) {
1559 /* Keep 'end' LSBs in tnl_map. */
1560 map
->tnl_map
&= (UINT64_C(1) << end
) - 1;
1563 if (end
< FLOW_U64S
) {
1564 /* Keep 'end - FLOW_TNL_U64S' LSBs in pkt_map. */
1565 map
->pkt_map
&= (UINT64_C(1) << (end
- FLOW_TNL_U64S
)) - 1;
1570 /* The new subtable will be visible to the readers only after this. */
1571 static struct cls_subtable
*
1572 insert_subtable(struct classifier
*cls
, const struct minimask
*mask
)
1574 uint32_t hash
= minimask_hash(mask
, 0);
1575 struct cls_subtable
*subtable
;
1577 struct minimask stage_mask
;
1579 size_t count
= miniflow_n_values(&mask
->masks
);
1581 subtable
= xzalloc(sizeof *subtable
+ MINIFLOW_VALUES_SIZE(count
));
1582 cmap_init(&subtable
->rules
);
1583 miniflow_clone(CONST_CAST(struct miniflow
*, &subtable
->mask
.masks
),
1584 &mask
->masks
, count
);
1586 /* Init indices for segmented lookup, if any. */
1588 for (i
= 0; i
< cls
->n_flow_segments
; i
++) {
1589 miniflow_get_map_in_range(&mask
->masks
, prev
, cls
->flow_segments
[i
],
1591 /* Add an index if it adds mask bits. */
1592 if (!minimask_is_catchall(&stage_mask
)) {
1593 cmap_init(&subtable
->indices
[index
]);
1594 *CONST_CAST(struct miniflow
*, &subtable
->index_maps
[index
])
1598 prev
= cls
->flow_segments
[i
];
1600 /* Map for the final stage. */
1601 miniflow_get_map_in_range(
1602 &mask
->masks
, prev
, FLOW_U64S
,
1603 CONST_CAST(struct miniflow
*, &subtable
->index_maps
[index
]));
1604 /* Check if the final stage adds any bits,
1605 * and remove the last index if it doesn't. */
1607 if (miniflow_equal_maps(&subtable
->index_maps
[index
],
1608 &subtable
->index_maps
[index
- 1])) {
1610 cmap_destroy(&subtable
->indices
[index
]);
1613 *CONST_CAST(uint8_t *, &subtable
->n_indices
) = index
;
1615 *CONST_CAST(tag_type
*, &subtable
->tag
) =
1616 (minimask_get_metadata_mask(mask
) == OVS_BE64_MAX
1617 ? tag_create_deterministic(hash
)
1620 for (i
= 0; i
< cls
->n_tries
; i
++) {
1621 subtable
->trie_plen
[i
] = minimask_get_prefix_len(mask
,
1622 cls
->tries
[i
].field
);
1626 ovsrcu_set_hidden(&subtable
->ports_trie
, NULL
);
1627 *CONST_CAST(int *, &subtable
->ports_mask_len
)
1628 = 32 - ctz32(ntohl(MINIFLOW_GET_BE32(&mask
->masks
, tp_src
)));
1630 /* List of rules. */
1631 rculist_init(&subtable
->rules_list
);
1633 cmap_insert(&cls
->subtables_map
, &subtable
->cmap_node
, hash
);
1638 /* RCU readers may still access the subtable before it is actually freed. */
1640 destroy_subtable(struct classifier
*cls
, struct cls_subtable
*subtable
)
1644 pvector_remove(&cls
->subtables
, subtable
);
1645 cmap_remove(&cls
->subtables_map
, &subtable
->cmap_node
,
1646 minimask_hash(&subtable
->mask
, 0));
1648 ovs_assert(ovsrcu_get_protected(struct trie_node
*, &subtable
->ports_trie
)
1650 ovs_assert(cmap_is_empty(&subtable
->rules
));
1651 ovs_assert(rculist_is_empty(&subtable
->rules_list
));
1653 for (i
= 0; i
< subtable
->n_indices
; i
++) {
1654 cmap_destroy(&subtable
->indices
[i
]);
1656 cmap_destroy(&subtable
->rules
);
1657 ovsrcu_postpone(free
, subtable
);
1660 static unsigned int be_get_bit_at(const ovs_be32 value
[], unsigned int ofs
);
1662 /* Return 'true' if can skip rest of the subtable based on the prefix trie
1663 * lookup results. */
1665 check_tries(struct trie_ctx trie_ctx
[CLS_MAX_TRIES
], unsigned int n_tries
,
1666 const unsigned int field_plen
[CLS_MAX_TRIES
],
1667 const struct miniflow
*range_map
, const struct flow
*flow
,
1668 struct flow_wildcards
*wc
)
1672 /* Check if we could avoid fully unwildcarding the next level of
1673 * fields using the prefix tries. The trie checks are done only as
1674 * needed to avoid folding in additional bits to the wildcards mask. */
1675 for (j
= 0; j
< n_tries
; j
++) {
1676 /* Is the trie field relevant for this subtable? */
1677 if (field_plen
[j
]) {
1678 struct trie_ctx
*ctx
= &trie_ctx
[j
];
1679 uint8_t be32ofs
= ctx
->be32ofs
;
1680 uint8_t be64ofs
= be32ofs
/ 2;
1682 /* Is the trie field within the current range of fields? */
1683 if (MINIFLOW_IN_MAP(range_map
, be64ofs
)) {
1684 /* On-demand trie lookup. */
1685 if (!ctx
->lookup_done
) {
1686 memset(&ctx
->match_plens
, 0, sizeof ctx
->match_plens
);
1687 ctx
->maskbits
= trie_lookup(ctx
->trie
, flow
,
1689 ctx
->lookup_done
= true;
1691 /* Possible to skip the rest of the subtable if subtable's
1692 * prefix on the field is not included in the lookup result. */
1693 if (!be_get_bit_at(&ctx
->match_plens
.be32
, field_plen
[j
] - 1)) {
1694 /* We want the trie lookup to never result in unwildcarding
1695 * any bits that would not be unwildcarded otherwise.
1696 * Since the trie is shared by the whole classifier, it is
1697 * possible that the 'maskbits' contain bits that are
1698 * irrelevant for the partition relevant for the current
1699 * packet. Hence the checks below. */
1701 /* Check that the trie result will not unwildcard more bits
1702 * than this subtable would otherwise. */
1703 if (ctx
->maskbits
<= field_plen
[j
]) {
1704 /* Unwildcard the bits and skip the rest. */
1705 mask_set_prefix_bits(wc
, be32ofs
, ctx
->maskbits
);
1706 /* Note: Prerequisite already unwildcarded, as the only
1707 * prerequisite of the supported trie lookup fields is
1708 * the ethertype, which is always unwildcarded. */
1711 /* Can skip if the field is already unwildcarded. */
1712 if (mask_prefix_bits_set(wc
, be32ofs
, ctx
->maskbits
)) {
1722 /* Returns true if 'target' satisifies 'flow'/'mask', that is, if each bit
1723 * for which 'flow', for which 'mask' has a bit set, specifies a particular
1724 * value has the correct value in 'target'.
1726 * This function is equivalent to miniflow_equal_flow_in_minimask(flow,
1727 * target, mask) but this is faster because of the invariant that
1728 * flow->map and mask->masks.map are the same, and that this version
1729 * takes the 'wc'. */
1731 miniflow_and_mask_matches_flow(const struct miniflow
*flow
,
1732 const struct minimask
*mask
,
1733 const struct flow
*target
)
1735 const uint64_t *flowp
= miniflow_get_values(flow
);
1736 const uint64_t *maskp
= miniflow_get_values(&mask
->masks
);
1737 const uint64_t *target_u64
= (const uint64_t *)target
;
1740 MAP_FOR_EACH_INDEX(idx
, mask
->masks
.tnl_map
) {
1741 if ((*flowp
++ ^ target_u64
[idx
]) & *maskp
++) {
1745 target_u64
+= FLOW_TNL_U64S
;
1746 MAP_FOR_EACH_INDEX(idx
, mask
->masks
.pkt_map
) {
1747 if ((*flowp
++ ^ target_u64
[idx
]) & *maskp
++) {
1755 static inline const struct cls_match
*
1756 find_match(const struct cls_subtable
*subtable
, cls_version_t version
,
1757 const struct flow
*flow
, uint32_t hash
)
1759 const struct cls_match
*head
, *rule
;
1761 CMAP_FOR_EACH_WITH_HASH (head
, cmap_node
, hash
, &subtable
->rules
) {
1762 if (OVS_LIKELY(miniflow_and_mask_matches_flow(&head
->flow
,
1765 /* Return highest priority rule that is visible. */
1766 CLS_MATCH_FOR_EACH (rule
, head
) {
1767 if (OVS_LIKELY(cls_match_visible_in_version(rule
, version
))) {
1777 /* Returns true if 'target' satisifies 'flow'/'mask', that is, if each bit
1778 * for which 'flow', for which 'mask' has a bit set, specifies a particular
1779 * value has the correct value in 'target'.
1781 * This function is equivalent to miniflow_and_mask_matches_flow() but this
1782 * version fills in the mask bits in 'wc'. */
1784 miniflow_and_mask_matches_flow_wc(const struct miniflow
*flow
,
1785 const struct minimask
*mask
,
1786 const struct flow
*target
,
1787 struct flow_wildcards
*wc
)
1789 const uint64_t *flowp
= miniflow_get_values(flow
);
1790 const uint64_t *maskp
= miniflow_get_values(&mask
->masks
);
1791 const uint64_t *target_u64
= (const uint64_t *)target
;
1792 uint64_t *wc_u64
= (uint64_t *)&wc
->masks
;
1796 MAP_FOR_EACH_INDEX(idx
, mask
->masks
.tnl_map
) {
1797 uint64_t msk
= *maskp
++;
1799 diff
= (*flowp
++ ^ target_u64
[idx
]) & msk
;
1804 /* Fill in the bits that were looked at. */
1807 target_u64
+= FLOW_TNL_U64S
;
1808 wc_u64
+= FLOW_TNL_U64S
;
1809 MAP_FOR_EACH_INDEX(idx
, mask
->masks
.pkt_map
) {
1810 uint64_t msk
= *maskp
++;
1812 diff
= (*flowp
++ ^ target_u64
[idx
]) & msk
;
1817 /* Fill in the bits that were looked at. */
1824 /* Only unwildcard if none of the differing bits is already
1826 if (!(wc_u64
[idx
] & diff
)) {
1827 /* Keep one bit of the difference. The selected bit may be
1828 * different in big-endian v.s. little-endian systems. */
1829 wc_u64
[idx
] |= rightmost_1bit(diff
);
1834 static const struct cls_match
*
1835 find_match_wc(const struct cls_subtable
*subtable
, cls_version_t version
,
1836 const struct flow
*flow
, struct trie_ctx trie_ctx
[CLS_MAX_TRIES
],
1837 unsigned int n_tries
, struct flow_wildcards
*wc
)
1839 uint32_t basis
= 0, hash
;
1840 const struct cls_match
*rule
= NULL
;
1842 struct miniflow stages_map
;
1843 unsigned int mask_offset
= 0;
1845 if (OVS_UNLIKELY(!wc
)) {
1846 return find_match(subtable
, version
, flow
,
1847 flow_hash_in_minimask(flow
, &subtable
->mask
, 0));
1850 memset(&stages_map
, 0, sizeof stages_map
);
1851 /* Try to finish early by checking fields in segments. */
1852 for (i
= 0; i
< subtable
->n_indices
; i
++) {
1853 const struct cmap_node
*inode
;
1855 if (check_tries(trie_ctx
, n_tries
, subtable
->trie_plen
,
1856 &subtable
->index_maps
[i
], flow
, wc
)) {
1857 /* 'wc' bits for the trie field set, now unwildcard the preceding
1858 * bits used so far. */
1862 /* Accumulate the map used so far. */
1863 stages_map
.tnl_map
|= subtable
->index_maps
[i
].tnl_map
;
1864 stages_map
.pkt_map
|= subtable
->index_maps
[i
].pkt_map
;
1866 hash
= flow_hash_in_minimask_range(flow
, &subtable
->mask
,
1867 &subtable
->index_maps
[i
],
1868 &mask_offset
, &basis
);
1870 inode
= cmap_find(&subtable
->indices
[i
], hash
);
1875 /* If we have narrowed down to a single rule already, check whether
1876 * that rule matches. Either way, we're done.
1878 * (Rare) hash collisions may cause us to miss the opportunity for this
1880 if (!cmap_node_next(inode
)) {
1881 const struct cls_match
*head
;
1883 ASSIGN_CONTAINER(head
, inode
- i
, index_nodes
);
1884 if (miniflow_and_mask_matches_flow_wc(&head
->flow
, &subtable
->mask
,
1886 /* Return highest priority rule that is visible. */
1887 CLS_MATCH_FOR_EACH (rule
, head
) {
1888 if (OVS_LIKELY(cls_match_visible_in_version(rule
,
1897 /* Trie check for the final range. */
1898 if (check_tries(trie_ctx
, n_tries
, subtable
->trie_plen
,
1899 &subtable
->index_maps
[i
], flow
, wc
)) {
1902 hash
= flow_hash_in_minimask_range(flow
, &subtable
->mask
,
1903 &subtable
->index_maps
[i
],
1904 &mask_offset
, &basis
);
1905 rule
= find_match(subtable
, version
, flow
, hash
);
1906 if (!rule
&& subtable
->ports_mask_len
) {
1907 /* The final stage had ports, but there was no match. Instead of
1908 * unwildcarding all the ports bits, use the ports trie to figure out a
1909 * smaller set of bits to unwildcard. */
1911 ovs_be32 value
, plens
, mask
;
1913 mask
= MINIFLOW_GET_BE32(&subtable
->mask
.masks
, tp_src
);
1914 value
= ((OVS_FORCE ovs_be32
*)flow
)[TP_PORTS_OFS32
] & mask
;
1915 mbits
= trie_lookup_value(&subtable
->ports_trie
, &value
, &plens
, 32);
1917 ((OVS_FORCE ovs_be32
*)&wc
->masks
)[TP_PORTS_OFS32
] |=
1918 mask
& be32_prefix_mask(mbits
);
1923 /* Must unwildcard all the fields, as they were looked at. */
1924 flow_wildcards_fold_minimask(wc
, &subtable
->mask
);
1928 /* Unwildcard the bits in stages so far, as they were used in determining
1929 * there is no match. */
1930 flow_wildcards_fold_minimask_in_map(wc
, &subtable
->mask
, &stages_map
);
1934 static struct cls_match
*
1935 find_equal(const struct cls_subtable
*subtable
, const struct miniflow
*flow
,
1938 struct cls_match
*head
;
1940 CMAP_FOR_EACH_WITH_HASH (head
, cmap_node
, hash
, &subtable
->rules
) {
1941 if (miniflow_equal(&head
->flow
, flow
)) {
1948 /* A longest-prefix match tree. */
1950 /* Return at least 'plen' bits of the 'prefix', starting at bit offset 'ofs'.
1951 * Prefixes are in the network byte order, and the offset 0 corresponds to
1952 * the most significant bit of the first byte. The offset can be read as
1953 * "how many bits to skip from the start of the prefix starting at 'pr'". */
1955 raw_get_prefix(const ovs_be32 pr
[], unsigned int ofs
, unsigned int plen
)
1959 pr
+= ofs
/ 32; /* Where to start. */
1960 ofs
%= 32; /* How many bits to skip at 'pr'. */
1962 prefix
= ntohl(*pr
) << ofs
; /* Get the first 32 - ofs bits. */
1963 if (plen
> 32 - ofs
) { /* Need more than we have already? */
1964 prefix
|= ntohl(*++pr
) >> (32 - ofs
);
1966 /* Return with possible unwanted bits at the end. */
1970 /* Return min(TRIE_PREFIX_BITS, plen) bits of the 'prefix', starting at bit
1971 * offset 'ofs'. Prefixes are in the network byte order, and the offset 0
1972 * corresponds to the most significant bit of the first byte. The offset can
1973 * be read as "how many bits to skip from the start of the prefix starting at
1976 trie_get_prefix(const ovs_be32 pr
[], unsigned int ofs
, unsigned int plen
)
1981 if (plen
> TRIE_PREFIX_BITS
) {
1982 plen
= TRIE_PREFIX_BITS
; /* Get at most TRIE_PREFIX_BITS. */
1984 /* Return with unwanted bits cleared. */
1985 return raw_get_prefix(pr
, ofs
, plen
) & ~0u << (32 - plen
);
1988 /* Return the number of equal bits in 'n_bits' of 'prefix's MSBs and a 'value'
1989 * starting at "MSB 0"-based offset 'ofs'. */
1991 prefix_equal_bits(uint32_t prefix
, unsigned int n_bits
, const ovs_be32 value
[],
1994 uint64_t diff
= prefix
^ raw_get_prefix(value
, ofs
, n_bits
);
1995 /* Set the bit after the relevant bits to limit the result. */
1996 return raw_clz64(diff
<< 32 | UINT64_C(1) << (63 - n_bits
));
1999 /* Return the number of equal bits in 'node' prefix and a 'prefix' of length
2000 * 'plen', starting at "MSB 0"-based offset 'ofs'. */
2002 trie_prefix_equal_bits(const struct trie_node
*node
, const ovs_be32 prefix
[],
2003 unsigned int ofs
, unsigned int plen
)
2005 return prefix_equal_bits(node
->prefix
, MIN(node
->n_bits
, plen
- ofs
),
2009 /* Return the bit at ("MSB 0"-based) offset 'ofs' as an int. 'ofs' can
2010 * be greater than 31. */
2012 be_get_bit_at(const ovs_be32 value
[], unsigned int ofs
)
2014 return (((const uint8_t *)value
)[ofs
/ 8] >> (7 - ofs
% 8)) & 1u;
2017 /* Return the bit at ("MSB 0"-based) offset 'ofs' as an int. 'ofs' must
2018 * be between 0 and 31, inclusive. */
2020 get_bit_at(const uint32_t prefix
, unsigned int ofs
)
2022 return (prefix
>> (31 - ofs
)) & 1u;
2025 /* Create new branch. */
2026 static struct trie_node
*
2027 trie_branch_create(const ovs_be32
*prefix
, unsigned int ofs
, unsigned int plen
,
2028 unsigned int n_rules
)
2030 struct trie_node
*node
= xmalloc(sizeof *node
);
2032 node
->prefix
= trie_get_prefix(prefix
, ofs
, plen
);
2034 if (plen
<= TRIE_PREFIX_BITS
) {
2035 node
->n_bits
= plen
;
2036 ovsrcu_set_hidden(&node
->edges
[0], NULL
);
2037 ovsrcu_set_hidden(&node
->edges
[1], NULL
);
2038 node
->n_rules
= n_rules
;
2039 } else { /* Need intermediate nodes. */
2040 struct trie_node
*subnode
= trie_branch_create(prefix
,
2041 ofs
+ TRIE_PREFIX_BITS
,
2042 plen
- TRIE_PREFIX_BITS
,
2044 int bit
= get_bit_at(subnode
->prefix
, 0);
2045 node
->n_bits
= TRIE_PREFIX_BITS
;
2046 ovsrcu_set_hidden(&node
->edges
[bit
], subnode
);
2047 ovsrcu_set_hidden(&node
->edges
[!bit
], NULL
);
2054 trie_node_destroy(const struct trie_node
*node
)
2056 ovsrcu_postpone(free
, CONST_CAST(struct trie_node
*, node
));
2059 /* Copy a trie node for modification and postpone delete the old one. */
2060 static struct trie_node
*
2061 trie_node_rcu_realloc(const struct trie_node
*node
)
2063 struct trie_node
*new_node
= xmalloc(sizeof *node
);
2066 trie_node_destroy(node
);
2072 trie_destroy(rcu_trie_ptr
*trie
)
2074 struct trie_node
*node
= ovsrcu_get_protected(struct trie_node
*, trie
);
2077 ovsrcu_set_hidden(trie
, NULL
);
2078 trie_destroy(&node
->edges
[0]);
2079 trie_destroy(&node
->edges
[1]);
2080 trie_node_destroy(node
);
2085 trie_is_leaf(const struct trie_node
*trie
)
2088 return !ovsrcu_get(struct trie_node
*, &trie
->edges
[0])
2089 && !ovsrcu_get(struct trie_node
*, &trie
->edges
[1]);
2093 mask_set_prefix_bits(struct flow_wildcards
*wc
, uint8_t be32ofs
,
2094 unsigned int n_bits
)
2096 ovs_be32
*mask
= &((ovs_be32
*)&wc
->masks
)[be32ofs
];
2099 for (i
= 0; i
< n_bits
/ 32; i
++) {
2100 mask
[i
] = OVS_BE32_MAX
;
2103 mask
[i
] |= htonl(~0u << (32 - n_bits
% 32));
2108 mask_prefix_bits_set(const struct flow_wildcards
*wc
, uint8_t be32ofs
,
2109 unsigned int n_bits
)
2111 ovs_be32
*mask
= &((ovs_be32
*)&wc
->masks
)[be32ofs
];
2113 ovs_be32 zeroes
= 0;
2115 for (i
= 0; i
< n_bits
/ 32; i
++) {
2119 zeroes
|= ~mask
[i
] & htonl(~0u << (32 - n_bits
% 32));
2122 return !zeroes
; /* All 'n_bits' bits set. */
2125 static rcu_trie_ptr
*
2126 trie_next_edge(struct trie_node
*node
, const ovs_be32 value
[],
2129 return node
->edges
+ be_get_bit_at(value
, ofs
);
2132 static const struct trie_node
*
2133 trie_next_node(const struct trie_node
*node
, const ovs_be32 value
[],
2136 return ovsrcu_get(struct trie_node
*,
2137 &node
->edges
[be_get_bit_at(value
, ofs
)]);
2140 /* Set the bit at ("MSB 0"-based) offset 'ofs'. 'ofs' can be greater than 31.
2143 be_set_bit_at(ovs_be32 value
[], unsigned int ofs
)
2145 ((uint8_t *)value
)[ofs
/ 8] |= 1u << (7 - ofs
% 8);
2148 /* Returns the number of bits in the prefix mask necessary to determine a
2149 * mismatch, in case there are longer prefixes in the tree below the one that
2151 * '*plens' will have a bit set for each prefix length that may have matching
2152 * rules. The caller is responsible for clearing the '*plens' prior to
2156 trie_lookup_value(const rcu_trie_ptr
*trie
, const ovs_be32 value
[],
2157 ovs_be32 plens
[], unsigned int n_bits
)
2159 const struct trie_node
*prev
= NULL
;
2160 const struct trie_node
*node
= ovsrcu_get(struct trie_node
*, trie
);
2161 unsigned int match_len
= 0; /* Number of matching bits. */
2163 for (; node
; prev
= node
, node
= trie_next_node(node
, value
, match_len
)) {
2164 unsigned int eqbits
;
2165 /* Check if this edge can be followed. */
2166 eqbits
= prefix_equal_bits(node
->prefix
, node
->n_bits
, value
,
2168 match_len
+= eqbits
;
2169 if (eqbits
< node
->n_bits
) { /* Mismatch, nothing more to be found. */
2170 /* Bit at offset 'match_len' differed. */
2171 return match_len
+ 1; /* Includes the first mismatching bit. */
2173 /* Full match, check if rules exist at this prefix length. */
2174 if (node
->n_rules
> 0) {
2175 be_set_bit_at(plens
, match_len
- 1);
2177 if (match_len
>= n_bits
) {
2178 return n_bits
; /* Full prefix. */
2181 /* node == NULL. Full match so far, but we tried to follow an
2182 * non-existing branch. Need to exclude the other branch if it exists
2183 * (it does not if we were called on an empty trie or 'prev' is a leaf
2185 return !prev
|| trie_is_leaf(prev
) ? match_len
: match_len
+ 1;
2189 trie_lookup(const struct cls_trie
*trie
, const struct flow
*flow
,
2190 union trie_prefix
*plens
)
2192 const struct mf_field
*mf
= trie
->field
;
2194 /* Check that current flow matches the prerequisites for the trie
2195 * field. Some match fields are used for multiple purposes, so we
2196 * must check that the trie is relevant for this flow. */
2197 if (mf_are_prereqs_ok(mf
, flow
)) {
2198 return trie_lookup_value(&trie
->root
,
2199 &((ovs_be32
*)flow
)[mf
->flow_be32ofs
],
2200 &plens
->be32
, mf
->n_bits
);
2202 memset(plens
, 0xff, sizeof *plens
); /* All prefixes, no skipping. */
2203 return 0; /* Value not used in this case. */
2206 /* Returns the length of a prefix match mask for the field 'mf' in 'minimask'.
2207 * Returns the u32 offset to the miniflow data in '*miniflow_index', if
2208 * 'miniflow_index' is not NULL. */
2210 minimask_get_prefix_len(const struct minimask
*minimask
,
2211 const struct mf_field
*mf
)
2213 unsigned int n_bits
= 0, mask_tz
= 0; /* Non-zero when end of mask seen. */
2214 uint8_t be32_ofs
= mf
->flow_be32ofs
;
2215 uint8_t be32_end
= be32_ofs
+ mf
->n_bytes
/ 4;
2217 for (; be32_ofs
< be32_end
; ++be32_ofs
) {
2218 uint32_t mask
= ntohl(minimask_get_be32(minimask
, be32_ofs
));
2220 /* Validate mask, count the mask length. */
2223 return 0; /* No bits allowed after mask ended. */
2226 if (~mask
& (~mask
+ 1)) {
2227 return 0; /* Mask not contiguous. */
2229 mask_tz
= ctz32(mask
);
2230 n_bits
+= 32 - mask_tz
;
2238 * This is called only when mask prefix is known to be CIDR and non-zero.
2239 * Relies on the fact that the flow and mask have the same map, and since
2240 * the mask is CIDR, the storage for the flow field exists even if it
2241 * happened to be zeros.
2243 static const ovs_be32
*
2244 minimatch_get_prefix(const struct minimatch
*match
, const struct mf_field
*mf
)
2246 size_t u64_ofs
= mf
->flow_be32ofs
/ 2;
2248 return (OVS_FORCE
const ovs_be32
*)miniflow_get__(match
->flow
, u64_ofs
)
2249 + (mf
->flow_be32ofs
& 1);
2252 /* Insert rule in to the prefix tree.
2253 * 'mlen' must be the (non-zero) CIDR prefix length of the 'trie->field' mask
2256 trie_insert(struct cls_trie
*trie
, const struct cls_rule
*rule
, int mlen
)
2258 trie_insert_prefix(&trie
->root
,
2259 minimatch_get_prefix(&rule
->match
, trie
->field
), mlen
);
2263 trie_insert_prefix(rcu_trie_ptr
*edge
, const ovs_be32
*prefix
, int mlen
)
2265 struct trie_node
*node
;
2268 /* Walk the tree. */
2269 for (; (node
= ovsrcu_get_protected(struct trie_node
*, edge
));
2270 edge
= trie_next_edge(node
, prefix
, ofs
)) {
2271 unsigned int eqbits
= trie_prefix_equal_bits(node
, prefix
, ofs
, mlen
);
2273 if (eqbits
< node
->n_bits
) {
2274 /* Mismatch, new node needs to be inserted above. */
2275 int old_branch
= get_bit_at(node
->prefix
, eqbits
);
2276 struct trie_node
*new_parent
;
2278 new_parent
= trie_branch_create(prefix
, ofs
- eqbits
, eqbits
,
2279 ofs
== mlen
? 1 : 0);
2280 /* Copy the node to modify it. */
2281 node
= trie_node_rcu_realloc(node
);
2282 /* Adjust the new node for its new position in the tree. */
2283 node
->prefix
<<= eqbits
;
2284 node
->n_bits
-= eqbits
;
2285 ovsrcu_set_hidden(&new_parent
->edges
[old_branch
], node
);
2287 /* Check if need a new branch for the new rule. */
2289 ovsrcu_set_hidden(&new_parent
->edges
[!old_branch
],
2290 trie_branch_create(prefix
, ofs
, mlen
- ofs
,
2293 ovsrcu_set(edge
, new_parent
); /* Publish changes. */
2296 /* Full match so far. */
2299 /* Full match at the current node, rule needs to be added here. */
2304 /* Must insert a new tree branch for the new rule. */
2305 ovsrcu_set(edge
, trie_branch_create(prefix
, ofs
, mlen
- ofs
, 1));
2308 /* 'mlen' must be the (non-zero) CIDR prefix length of the 'trie->field' mask
2311 trie_remove(struct cls_trie
*trie
, const struct cls_rule
*rule
, int mlen
)
2313 trie_remove_prefix(&trie
->root
,
2314 minimatch_get_prefix(&rule
->match
, trie
->field
), mlen
);
2317 /* 'mlen' must be the (non-zero) CIDR prefix length of the 'trie->field' mask
2320 trie_remove_prefix(rcu_trie_ptr
*root
, const ovs_be32
*prefix
, int mlen
)
2322 struct trie_node
*node
;
2323 rcu_trie_ptr
*edges
[sizeof(union trie_prefix
) * CHAR_BIT
];
2324 int depth
= 0, ofs
= 0;
2326 /* Walk the tree. */
2327 for (edges
[0] = root
;
2328 (node
= ovsrcu_get_protected(struct trie_node
*, edges
[depth
]));
2329 edges
[++depth
] = trie_next_edge(node
, prefix
, ofs
)) {
2330 unsigned int eqbits
= trie_prefix_equal_bits(node
, prefix
, ofs
, mlen
);
2332 if (eqbits
< node
->n_bits
) {
2333 /* Mismatch, nothing to be removed. This should never happen, as
2334 * only rules in the classifier are ever removed. */
2335 break; /* Log a warning. */
2337 /* Full match so far. */
2341 /* Full prefix match at the current node, remove rule here. */
2342 if (!node
->n_rules
) {
2343 break; /* Log a warning. */
2347 /* Check if can prune the tree. */
2348 while (!node
->n_rules
) {
2349 struct trie_node
*next
,
2350 *edge0
= ovsrcu_get_protected(struct trie_node
*,
2352 *edge1
= ovsrcu_get_protected(struct trie_node
*,
2355 if (edge0
&& edge1
) {
2356 break; /* A branching point, cannot prune. */
2359 /* Else have at most one child node, remove this node. */
2360 next
= edge0
? edge0
: edge1
;
2363 if (node
->n_bits
+ next
->n_bits
> TRIE_PREFIX_BITS
) {
2364 break; /* Cannot combine. */
2366 next
= trie_node_rcu_realloc(next
); /* Modify. */
2368 /* Combine node with next. */
2369 next
->prefix
= node
->prefix
| next
->prefix
>> node
->n_bits
;
2370 next
->n_bits
+= node
->n_bits
;
2372 /* Update the parent's edge. */
2373 ovsrcu_set(edges
[depth
], next
); /* Publish changes. */
2374 trie_node_destroy(node
);
2376 if (next
|| !depth
) {
2377 /* Branch not pruned or at root, nothing more to do. */
2380 node
= ovsrcu_get_protected(struct trie_node
*,
2386 /* Cannot go deeper. This should never happen, since only rules
2387 * that actually exist in the classifier are ever removed. */
2388 VLOG_WARN("Trying to remove non-existing rule from a prefix trie.");
2392 #define CLS_MATCH_POISON (struct cls_match *)(UINTPTR_MAX / 0xf * 0xb)
2395 cls_match_free_cb(struct cls_match
*rule
)
2397 ovsrcu_set_hidden(&rule
->next
, CLS_MATCH_POISON
);