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064af421 | 1 | /* |
78c8df12 | 2 | * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2014 Nicira, Inc. |
064af421 | 3 | * |
a14bc59f BP |
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: | |
064af421 | 7 | * |
a14bc59f BP |
8 | * http://www.apache.org/licenses/LICENSE-2.0 |
9 | * | |
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. | |
064af421 BP |
15 | */ |
16 | ||
17 | #include <config.h> | |
18 | #include "classifier.h" | |
064af421 BP |
19 | #include <errno.h> |
20 | #include <netinet/in.h> | |
844dff32 | 21 | #include "byte-order.h" |
68d1c8c3 | 22 | #include "dynamic-string.h" |
064af421 BP |
23 | #include "flow.h" |
24 | #include "hash.h" | |
f2c21402 | 25 | #include "cmap.h" |
52054c15 | 26 | #include "list.h" |
07b37e8f | 27 | #include "odp-util.h" |
d8ae4d67 | 28 | #include "ofp-util.h" |
13751fd8 | 29 | #include "packets.h" |
52054c15 JR |
30 | #include "tag.h" |
31 | #include "util.h" | |
13751fd8 JR |
32 | #include "vlog.h" |
33 | ||
34 | VLOG_DEFINE_THIS_MODULE(classifier); | |
064af421 | 35 | |
69d6040e JR |
36 | struct trie_ctx; |
37 | ||
38 | /* Ports trie depends on both ports sharing the same ovs_be32. */ | |
39 | #define TP_PORTS_OFS32 (offsetof(struct flow, tp_src) / 4) | |
40 | BUILD_ASSERT_DECL(TP_PORTS_OFS32 == offsetof(struct flow, tp_dst) / 4); | |
cabd4c43 | 41 | |
cabd4c43 JR |
42 | /* A set of rules that all have the same fields wildcarded. */ |
43 | struct cls_subtable { | |
e65413ab | 44 | /* The fields are only used by writers and iterators. */ |
e48eccd1 | 45 | struct cmap_node cmap_node; /* Within struct classifier 'subtables_map'. */ |
e65413ab JR |
46 | |
47 | /* The fields are only used by writers. */ | |
48 | int n_rules OVS_GUARDED; /* Number of rules, including | |
49 | * duplicates. */ | |
50 | unsigned int max_priority OVS_GUARDED; /* Max priority of any rule in | |
51 | * the subtable. */ | |
52 | unsigned int max_count OVS_GUARDED; /* Count of max_priority rules. */ | |
53 | ||
54 | /* These fields are accessed by readers who care about wildcarding. */ | |
55 | tag_type tag; /* Tag generated from mask for partitioning (const). */ | |
56 | uint8_t n_indices; /* How many indices to use (const). */ | |
57 | uint8_t index_ofs[CLS_MAX_INDICES]; /* u32 segment boundaries (const). */ | |
58 | unsigned int trie_plen[CLS_MAX_TRIES]; /* Trie prefix length in 'mask' | |
59 | * (runtime configurable). */ | |
60 | int ports_mask_len; /* (const) */ | |
61 | struct cmap indices[CLS_MAX_INDICES]; /* Staged lookup indices. */ | |
f358a2cb | 62 | rcu_trie_ptr ports_trie; /* NULL if none. */ |
e65413ab JR |
63 | |
64 | /* These fields are accessed by all readers. */ | |
65 | struct cmap rules; /* Contains "struct cls_rule"s. */ | |
66 | struct minimask mask; /* Wildcards for fields (const). */ | |
3016f3e4 | 67 | /* 'mask' must be the last field. */ |
cabd4c43 JR |
68 | }; |
69 | ||
70 | /* Associates a metadata value (that is, a value of the OpenFlow 1.1+ metadata | |
71 | * field) with tags for the "cls_subtable"s that contain rules that match that | |
72 | * metadata value. */ | |
73 | struct cls_partition { | |
e48eccd1 | 74 | struct cmap_node cmap_node; /* In struct classifier's 'partitions' map. */ |
cabd4c43 JR |
75 | ovs_be64 metadata; /* metadata value for this partition. */ |
76 | tag_type tags; /* OR of each flow's cls_subtable tag. */ | |
e65413ab | 77 | struct tag_tracker tracker OVS_GUARDED; /* Tracks the bits in 'tags'. */ |
cabd4c43 JR |
78 | }; |
79 | ||
627fb667 JR |
80 | /* Internal representation of a rule in a "struct cls_subtable". */ |
81 | struct cls_match { | |
e65413ab JR |
82 | /* Accessed only by writers and iterators. */ |
83 | struct list list OVS_GUARDED; /* List of identical, lower-priority rules. */ | |
84 | ||
85 | /* Accessed only by writers. */ | |
86 | struct cls_partition *partition OVS_GUARDED; | |
87 | ||
88 | /* Accessed by readers interested in wildcarding. */ | |
89 | unsigned int priority; /* Larger numbers are higher priorities. */ | |
f2c21402 JR |
90 | struct cmap_node index_nodes[CLS_MAX_INDICES]; /* Within subtable's |
91 | * 'indices'. */ | |
e65413ab | 92 | /* Accessed by all readers. */ |
f2c21402 | 93 | struct cmap_node cmap_node; /* Within struct cls_subtable 'rules'. */ |
e65413ab | 94 | struct cls_rule *cls_rule; |
3016f3e4 JR |
95 | struct miniflow flow; /* Matching rule. Mask is in the subtable. */ |
96 | /* 'flow' must be the last field. */ | |
627fb667 | 97 | }; |
cabd4c43 | 98 | |
627fb667 JR |
99 | static struct cls_match * |
100 | cls_match_alloc(struct cls_rule *rule) | |
101 | { | |
3016f3e4 JR |
102 | int count = count_1bits(rule->match.flow.map); |
103 | ||
104 | struct cls_match *cls_match | |
105 | = xmalloc(sizeof *cls_match - sizeof cls_match->flow.inline_values | |
106 | + MINIFLOW_VALUES_SIZE(count)); | |
627fb667 JR |
107 | |
108 | cls_match->cls_rule = rule; | |
3016f3e4 | 109 | miniflow_clone_inline(&cls_match->flow, &rule->match.flow, count); |
627fb667 JR |
110 | cls_match->priority = rule->priority; |
111 | rule->cls_match = cls_match; | |
112 | ||
113 | return cls_match; | |
114 | } | |
cabd4c43 | 115 | |
e48eccd1 | 116 | static struct cls_subtable *find_subtable(const struct classifier *cls, |
e65413ab JR |
117 | const struct minimask *) |
118 | OVS_REQUIRES(cls->mutex); | |
e48eccd1 | 119 | static struct cls_subtable *insert_subtable(struct classifier *cls, |
e65413ab JR |
120 | const struct minimask *) |
121 | OVS_REQUIRES(cls->mutex); | |
e48eccd1 | 122 | static void destroy_subtable(struct classifier *cls, struct cls_subtable *) |
e65413ab | 123 | OVS_REQUIRES(cls->mutex); |
e48eccd1 | 124 | static struct cls_match *insert_rule(struct classifier *cls, |
e65413ab JR |
125 | struct cls_subtable *, struct cls_rule *) |
126 | OVS_REQUIRES(cls->mutex); | |
b5d97350 | 127 | |
627fb667 JR |
128 | static struct cls_match *find_match_wc(const struct cls_subtable *, |
129 | const struct flow *, struct trie_ctx *, | |
130 | unsigned int n_tries, | |
131 | struct flow_wildcards *); | |
132 | static struct cls_match *find_equal(struct cls_subtable *, | |
133 | const struct miniflow *, uint32_t hash); | |
b5d97350 | 134 | |
e65413ab JR |
135 | /* Iterates RULE over HEAD and all of the cls_rules on HEAD->list. |
136 | * Classifier's mutex must be held while iterating, as the list is | |
137 | * protoceted by it. */ | |
b5d97350 BP |
138 | #define FOR_EACH_RULE_IN_LIST(RULE, HEAD) \ |
139 | for ((RULE) = (HEAD); (RULE) != NULL; (RULE) = next_rule_in_list(RULE)) | |
140 | #define FOR_EACH_RULE_IN_LIST_SAFE(RULE, NEXT, HEAD) \ | |
141 | for ((RULE) = (HEAD); \ | |
142 | (RULE) != NULL && ((NEXT) = next_rule_in_list(RULE), true); \ | |
143 | (RULE) = (NEXT)) | |
144 | ||
627fb667 JR |
145 | static struct cls_match *next_rule_in_list__(struct cls_match *); |
146 | static struct cls_match *next_rule_in_list(struct cls_match *); | |
13751fd8 JR |
147 | |
148 | static unsigned int minimask_get_prefix_len(const struct minimask *, | |
149 | const struct mf_field *); | |
e48eccd1 | 150 | static void trie_init(struct classifier *cls, int trie_idx, |
e65413ab JR |
151 | const struct mf_field *) |
152 | OVS_REQUIRES(cls->mutex); | |
13751fd8 | 153 | static unsigned int trie_lookup(const struct cls_trie *, const struct flow *, |
c0bfb650 | 154 | union mf_value *plens); |
f358a2cb | 155 | static unsigned int trie_lookup_value(const rcu_trie_ptr *, |
c0bfb650 JR |
156 | const ovs_be32 value[], ovs_be32 plens[], |
157 | unsigned int value_bits); | |
f358a2cb | 158 | static void trie_destroy(rcu_trie_ptr *); |
13751fd8 | 159 | static void trie_insert(struct cls_trie *, const struct cls_rule *, int mlen); |
f358a2cb | 160 | static void trie_insert_prefix(rcu_trie_ptr *, const ovs_be32 *prefix, |
69d6040e | 161 | int mlen); |
13751fd8 | 162 | static void trie_remove(struct cls_trie *, const struct cls_rule *, int mlen); |
f358a2cb | 163 | static void trie_remove_prefix(rcu_trie_ptr *, const ovs_be32 *prefix, |
69d6040e | 164 | int mlen); |
13751fd8 | 165 | static void mask_set_prefix_bits(struct flow_wildcards *, uint8_t be32ofs, |
c30cfa6b | 166 | unsigned int n_bits); |
13751fd8 | 167 | static bool mask_prefix_bits_set(const struct flow_wildcards *, |
c30cfa6b | 168 | uint8_t be32ofs, unsigned int n_bits); |
3d91d909 JR |
169 | \f |
170 | /* flow/miniflow/minimask/minimatch utilities. | |
171 | * These are only used by the classifier, so place them here to allow | |
172 | * for better optimization. */ | |
173 | ||
174 | static inline uint64_t | |
175 | miniflow_get_map_in_range(const struct miniflow *miniflow, | |
176 | uint8_t start, uint8_t end, unsigned int *offset) | |
177 | { | |
178 | uint64_t map = miniflow->map; | |
179 | *offset = 0; | |
180 | ||
181 | if (start > 0) { | |
182 | uint64_t msk = (UINT64_C(1) << start) - 1; /* 'start' LSBs set */ | |
183 | *offset = count_1bits(map & msk); | |
184 | map &= ~msk; | |
185 | } | |
186 | if (end < FLOW_U32S) { | |
187 | uint64_t msk = (UINT64_C(1) << end) - 1; /* 'end' LSBs set */ | |
188 | map &= msk; | |
189 | } | |
190 | return map; | |
191 | } | |
192 | ||
193 | /* Returns a hash value for the bits of 'flow' where there are 1-bits in | |
194 | * 'mask', given 'basis'. | |
195 | * | |
196 | * The hash values returned by this function are the same as those returned by | |
197 | * miniflow_hash_in_minimask(), only the form of the arguments differ. */ | |
198 | static inline uint32_t | |
199 | flow_hash_in_minimask(const struct flow *flow, const struct minimask *mask, | |
200 | uint32_t basis) | |
201 | { | |
27bbe15d | 202 | const uint32_t *mask_values = miniflow_get_u32_values(&mask->masks); |
3d91d909 | 203 | const uint32_t *flow_u32 = (const uint32_t *)flow; |
27bbe15d | 204 | const uint32_t *p = mask_values; |
3d91d909 JR |
205 | uint32_t hash; |
206 | uint64_t map; | |
207 | ||
208 | hash = basis; | |
209 | for (map = mask->masks.map; map; map = zero_rightmost_1bit(map)) { | |
33c6a1b9 | 210 | hash = hash_add(hash, flow_u32[raw_ctz(map)] & *p++); |
3d91d909 JR |
211 | } |
212 | ||
33c6a1b9 | 213 | return hash_finish(hash, (p - mask_values) * 4); |
3d91d909 JR |
214 | } |
215 | ||
216 | /* Returns a hash value for the bits of 'flow' where there are 1-bits in | |
217 | * 'mask', given 'basis'. | |
218 | * | |
219 | * The hash values returned by this function are the same as those returned by | |
220 | * flow_hash_in_minimask(), only the form of the arguments differ. */ | |
221 | static inline uint32_t | |
222 | miniflow_hash_in_minimask(const struct miniflow *flow, | |
223 | const struct minimask *mask, uint32_t basis) | |
224 | { | |
27bbe15d JR |
225 | const uint32_t *mask_values = miniflow_get_u32_values(&mask->masks); |
226 | const uint32_t *p = mask_values; | |
3d91d909 JR |
227 | uint32_t hash = basis; |
228 | uint32_t flow_u32; | |
229 | ||
230 | MINIFLOW_FOR_EACH_IN_MAP(flow_u32, flow, mask->masks.map) { | |
33c6a1b9 | 231 | hash = hash_add(hash, flow_u32 & *p++); |
3d91d909 JR |
232 | } |
233 | ||
33c6a1b9 | 234 | return hash_finish(hash, (p - mask_values) * 4); |
3d91d909 JR |
235 | } |
236 | ||
237 | /* Returns a hash value for the bits of range [start, end) in 'flow', | |
238 | * where there are 1-bits in 'mask', given 'hash'. | |
239 | * | |
240 | * The hash values returned by this function are the same as those returned by | |
241 | * minimatch_hash_range(), only the form of the arguments differ. */ | |
242 | static inline uint32_t | |
243 | flow_hash_in_minimask_range(const struct flow *flow, | |
244 | const struct minimask *mask, | |
245 | uint8_t start, uint8_t end, uint32_t *basis) | |
246 | { | |
27bbe15d | 247 | const uint32_t *mask_values = miniflow_get_u32_values(&mask->masks); |
3d91d909 JR |
248 | const uint32_t *flow_u32 = (const uint32_t *)flow; |
249 | unsigned int offset; | |
250 | uint64_t map = miniflow_get_map_in_range(&mask->masks, start, end, | |
251 | &offset); | |
27bbe15d | 252 | const uint32_t *p = mask_values + offset; |
3d91d909 JR |
253 | uint32_t hash = *basis; |
254 | ||
255 | for (; map; map = zero_rightmost_1bit(map)) { | |
33c6a1b9 | 256 | hash = hash_add(hash, flow_u32[raw_ctz(map)] & *p++); |
3d91d909 JR |
257 | } |
258 | ||
259 | *basis = hash; /* Allow continuation from the unfinished value. */ | |
33c6a1b9 | 260 | return hash_finish(hash, (p - mask_values) * 4); |
3d91d909 JR |
261 | } |
262 | ||
263 | /* Fold minimask 'mask''s wildcard mask into 'wc's wildcard mask. */ | |
264 | static inline void | |
265 | flow_wildcards_fold_minimask(struct flow_wildcards *wc, | |
266 | const struct minimask *mask) | |
267 | { | |
268 | flow_union_with_miniflow(&wc->masks, &mask->masks); | |
269 | } | |
270 | ||
271 | /* Fold minimask 'mask''s wildcard mask into 'wc's wildcard mask | |
272 | * in range [start, end). */ | |
273 | static inline void | |
274 | flow_wildcards_fold_minimask_range(struct flow_wildcards *wc, | |
275 | const struct minimask *mask, | |
276 | uint8_t start, uint8_t end) | |
277 | { | |
278 | uint32_t *dst_u32 = (uint32_t *)&wc->masks; | |
279 | unsigned int offset; | |
280 | uint64_t map = miniflow_get_map_in_range(&mask->masks, start, end, | |
281 | &offset); | |
27bbe15d | 282 | const uint32_t *p = miniflow_get_u32_values(&mask->masks) + offset; |
3d91d909 JR |
283 | |
284 | for (; map; map = zero_rightmost_1bit(map)) { | |
285 | dst_u32[raw_ctz(map)] |= *p++; | |
286 | } | |
287 | } | |
288 | ||
289 | /* Returns a hash value for 'flow', given 'basis'. */ | |
290 | static inline uint32_t | |
291 | miniflow_hash(const struct miniflow *flow, uint32_t basis) | |
292 | { | |
27bbe15d JR |
293 | const uint32_t *values = miniflow_get_u32_values(flow); |
294 | const uint32_t *p = values; | |
3d91d909 JR |
295 | uint32_t hash = basis; |
296 | uint64_t hash_map = 0; | |
297 | uint64_t map; | |
298 | ||
299 | for (map = flow->map; map; map = zero_rightmost_1bit(map)) { | |
300 | if (*p) { | |
33c6a1b9 | 301 | hash = hash_add(hash, *p); |
3d91d909 JR |
302 | hash_map |= rightmost_1bit(map); |
303 | } | |
304 | p++; | |
305 | } | |
33c6a1b9 JR |
306 | hash = hash_add(hash, hash_map); |
307 | hash = hash_add(hash, hash_map >> 32); | |
3d91d909 | 308 | |
33c6a1b9 | 309 | return hash_finish(hash, p - values); |
3d91d909 JR |
310 | } |
311 | ||
312 | /* Returns a hash value for 'mask', given 'basis'. */ | |
313 | static inline uint32_t | |
314 | minimask_hash(const struct minimask *mask, uint32_t basis) | |
315 | { | |
316 | return miniflow_hash(&mask->masks, basis); | |
317 | } | |
318 | ||
319 | /* Returns a hash value for 'match', given 'basis'. */ | |
320 | static inline uint32_t | |
321 | minimatch_hash(const struct minimatch *match, uint32_t basis) | |
322 | { | |
323 | return miniflow_hash(&match->flow, minimask_hash(&match->mask, basis)); | |
324 | } | |
325 | ||
326 | /* Returns a hash value for the bits of range [start, end) in 'minimatch', | |
327 | * given 'basis'. | |
328 | * | |
329 | * The hash values returned by this function are the same as those returned by | |
330 | * flow_hash_in_minimask_range(), only the form of the arguments differ. */ | |
331 | static inline uint32_t | |
332 | minimatch_hash_range(const struct minimatch *match, uint8_t start, uint8_t end, | |
333 | uint32_t *basis) | |
334 | { | |
335 | unsigned int offset; | |
336 | const uint32_t *p, *q; | |
337 | uint32_t hash = *basis; | |
338 | int n, i; | |
339 | ||
340 | n = count_1bits(miniflow_get_map_in_range(&match->mask.masks, start, end, | |
341 | &offset)); | |
27bbe15d JR |
342 | q = miniflow_get_u32_values(&match->mask.masks) + offset; |
343 | p = miniflow_get_u32_values(&match->flow) + offset; | |
3d91d909 JR |
344 | |
345 | for (i = 0; i < n; i++) { | |
33c6a1b9 | 346 | hash = hash_add(hash, p[i] & q[i]); |
3d91d909 JR |
347 | } |
348 | *basis = hash; /* Allow continuation from the unfinished value. */ | |
33c6a1b9 | 349 | return hash_finish(hash, (offset + n) * 4); |
3d91d909 JR |
350 | } |
351 | ||
81a76618 BP |
352 | \f |
353 | /* cls_rule. */ | |
b5d97350 | 354 | |
81a76618 | 355 | /* Initializes 'rule' to match packets specified by 'match' at the given |
5cb7a798 BP |
356 | * 'priority'. 'match' must satisfy the invariant described in the comment at |
357 | * the definition of struct match. | |
66642cb4 | 358 | * |
48d28ac1 BP |
359 | * The caller must eventually destroy 'rule' with cls_rule_destroy(). |
360 | * | |
81a76618 BP |
361 | * (OpenFlow uses priorities between 0 and UINT16_MAX, inclusive, but |
362 | * internally Open vSwitch supports a wider range.) */ | |
47284b1f | 363 | void |
81a76618 BP |
364 | cls_rule_init(struct cls_rule *rule, |
365 | const struct match *match, unsigned int priority) | |
47284b1f | 366 | { |
5cb7a798 BP |
367 | minimatch_init(&rule->match, match); |
368 | rule->priority = priority; | |
627fb667 | 369 | rule->cls_match = NULL; |
5cb7a798 BP |
370 | } |
371 | ||
372 | /* Same as cls_rule_init() for initialization from a "struct minimatch". */ | |
373 | void | |
374 | cls_rule_init_from_minimatch(struct cls_rule *rule, | |
375 | const struct minimatch *match, | |
376 | unsigned int priority) | |
377 | { | |
378 | minimatch_clone(&rule->match, match); | |
81a76618 | 379 | rule->priority = priority; |
627fb667 | 380 | rule->cls_match = NULL; |
685a51a5 JP |
381 | } |
382 | ||
48d28ac1 BP |
383 | /* Initializes 'dst' as a copy of 'src'. |
384 | * | |
b2c1f00b | 385 | * The caller must eventually destroy 'dst' with cls_rule_destroy(). */ |
48d28ac1 BP |
386 | void |
387 | cls_rule_clone(struct cls_rule *dst, const struct cls_rule *src) | |
388 | { | |
5cb7a798 BP |
389 | minimatch_clone(&dst->match, &src->match); |
390 | dst->priority = src->priority; | |
627fb667 | 391 | dst->cls_match = NULL; |
48d28ac1 BP |
392 | } |
393 | ||
b2c1f00b BP |
394 | /* Initializes 'dst' with the data in 'src', destroying 'src'. |
395 | * | |
396 | * The caller must eventually destroy 'dst' with cls_rule_destroy(). */ | |
397 | void | |
398 | cls_rule_move(struct cls_rule *dst, struct cls_rule *src) | |
399 | { | |
400 | minimatch_move(&dst->match, &src->match); | |
401 | dst->priority = src->priority; | |
627fb667 | 402 | dst->cls_match = NULL; |
b2c1f00b BP |
403 | } |
404 | ||
48d28ac1 BP |
405 | /* Frees memory referenced by 'rule'. Doesn't free 'rule' itself (it's |
406 | * normally embedded into a larger structure). | |
407 | * | |
408 | * ('rule' must not currently be in a classifier.) */ | |
409 | void | |
5cb7a798 | 410 | cls_rule_destroy(struct cls_rule *rule) |
48d28ac1 | 411 | { |
627fb667 | 412 | ovs_assert(!rule->cls_match); |
5cb7a798 | 413 | minimatch_destroy(&rule->match); |
48d28ac1 BP |
414 | } |
415 | ||
81a76618 BP |
416 | /* Returns true if 'a' and 'b' match the same packets at the same priority, |
417 | * false if they differ in some way. */ | |
193eb874 BP |
418 | bool |
419 | cls_rule_equal(const struct cls_rule *a, const struct cls_rule *b) | |
420 | { | |
5cb7a798 | 421 | return a->priority == b->priority && minimatch_equal(&a->match, &b->match); |
193eb874 BP |
422 | } |
423 | ||
81a76618 | 424 | /* Returns a hash value for 'rule', folding in 'basis'. */ |
57452fdc BP |
425 | uint32_t |
426 | cls_rule_hash(const struct cls_rule *rule, uint32_t basis) | |
427 | { | |
5cb7a798 | 428 | return minimatch_hash(&rule->match, hash_int(rule->priority, basis)); |
73f33563 BP |
429 | } |
430 | ||
81a76618 | 431 | /* Appends a string describing 'rule' to 's'. */ |
07b37e8f BP |
432 | void |
433 | cls_rule_format(const struct cls_rule *rule, struct ds *s) | |
434 | { | |
5cb7a798 | 435 | minimatch_format(&rule->match, s, rule->priority); |
064af421 | 436 | } |
3ca1de08 BP |
437 | |
438 | /* Returns true if 'rule' matches every packet, false otherwise. */ | |
439 | bool | |
440 | cls_rule_is_catchall(const struct cls_rule *rule) | |
441 | { | |
5cb7a798 | 442 | return minimask_is_catchall(&rule->match.mask); |
3ca1de08 | 443 | } |
064af421 BP |
444 | \f |
445 | /* Initializes 'cls' as a classifier that initially contains no classification | |
446 | * rules. */ | |
447 | void | |
e48eccd1 JR |
448 | classifier_init(struct classifier *cls, const uint8_t *flow_segments) |
449 | OVS_EXCLUDED(cls->mutex) | |
064af421 | 450 | { |
e65413ab | 451 | ovs_mutex_init(&cls->mutex); |
e65413ab | 452 | ovs_mutex_lock(&cls->mutex); |
064af421 | 453 | cls->n_rules = 0; |
f2c21402 | 454 | cmap_init(&cls->subtables_map); |
fe7cfa5c | 455 | pvector_init(&cls->subtables); |
f2c21402 | 456 | cmap_init(&cls->partitions); |
476f36e8 JR |
457 | cls->n_flow_segments = 0; |
458 | if (flow_segments) { | |
459 | while (cls->n_flow_segments < CLS_MAX_INDICES | |
460 | && *flow_segments < FLOW_U32S) { | |
461 | cls->flow_segments[cls->n_flow_segments++] = *flow_segments++; | |
462 | } | |
463 | } | |
13751fd8 | 464 | cls->n_tries = 0; |
e65413ab JR |
465 | for (int i = 0; i < CLS_MAX_TRIES; i++) { |
466 | trie_init(cls, i, NULL); | |
467 | } | |
468 | ovs_mutex_unlock(&cls->mutex); | |
064af421 BP |
469 | } |
470 | ||
471 | /* Destroys 'cls'. Rules within 'cls', if any, are not freed; this is the | |
afae68b1 JR |
472 | * caller's responsibility. |
473 | * May only be called after all the readers have been terminated. */ | |
064af421 | 474 | void |
e48eccd1 JR |
475 | classifier_destroy(struct classifier *cls) |
476 | OVS_EXCLUDED(cls->mutex) | |
064af421 | 477 | { |
e48eccd1 | 478 | if (cls) { |
78c8df12 BP |
479 | struct cls_partition *partition; |
480 | struct cls_subtable *subtable; | |
13751fd8 JR |
481 | int i; |
482 | ||
e65413ab | 483 | ovs_mutex_lock(&cls->mutex); |
13751fd8 | 484 | for (i = 0; i < cls->n_tries; i++) { |
f358a2cb | 485 | trie_destroy(&cls->tries[i].root); |
13751fd8 | 486 | } |
064af421 | 487 | |
78c8df12 | 488 | CMAP_FOR_EACH_SAFE (subtable, cmap_node, &cls->subtables_map) { |
03868246 | 489 | destroy_subtable(cls, subtable); |
064af421 | 490 | } |
f2c21402 | 491 | cmap_destroy(&cls->subtables_map); |
c906cedf | 492 | |
78c8df12 | 493 | CMAP_FOR_EACH_SAFE (partition, cmap_node, &cls->partitions) { |
f2c21402 | 494 | ovsrcu_postpone(free, partition); |
c906cedf | 495 | } |
f2c21402 | 496 | cmap_destroy(&cls->partitions); |
cabd4c43 | 497 | |
fe7cfa5c | 498 | pvector_destroy(&cls->subtables); |
e65413ab JR |
499 | ovs_mutex_unlock(&cls->mutex); |
500 | ovs_mutex_destroy(&cls->mutex); | |
064af421 BP |
501 | } |
502 | } | |
503 | ||
13751fd8 JR |
504 | /* We use uint64_t as a set for the fields below. */ |
505 | BUILD_ASSERT_DECL(MFF_N_IDS <= 64); | |
506 | ||
507 | /* Set the fields for which prefix lookup should be performed. */ | |
f358a2cb | 508 | bool |
e48eccd1 | 509 | classifier_set_prefix_fields(struct classifier *cls, |
13751fd8 JR |
510 | const enum mf_field_id *trie_fields, |
511 | unsigned int n_fields) | |
e48eccd1 | 512 | OVS_EXCLUDED(cls->mutex) |
13751fd8 JR |
513 | { |
514 | uint64_t fields = 0; | |
f358a2cb JR |
515 | const struct mf_field * new_fields[CLS_MAX_TRIES]; |
516 | int i, n_tries = 0; | |
517 | bool changed = false; | |
13751fd8 | 518 | |
e65413ab | 519 | ovs_mutex_lock(&cls->mutex); |
f358a2cb | 520 | for (i = 0; i < n_fields && n_tries < CLS_MAX_TRIES; i++) { |
13751fd8 JR |
521 | const struct mf_field *field = mf_from_id(trie_fields[i]); |
522 | if (field->flow_be32ofs < 0 || field->n_bits % 32) { | |
523 | /* Incompatible field. This is the only place where we | |
524 | * enforce these requirements, but the rest of the trie code | |
525 | * depends on the flow_be32ofs to be non-negative and the | |
526 | * field length to be a multiple of 32 bits. */ | |
527 | continue; | |
528 | } | |
529 | ||
530 | if (fields & (UINT64_C(1) << trie_fields[i])) { | |
531 | /* Duplicate field, there is no need to build more than | |
532 | * one index for any one field. */ | |
533 | continue; | |
534 | } | |
535 | fields |= UINT64_C(1) << trie_fields[i]; | |
536 | ||
f358a2cb JR |
537 | new_fields[n_tries] = NULL; |
538 | if (n_tries >= cls->n_tries || field != cls->tries[n_tries].field) { | |
539 | new_fields[n_tries] = field; | |
540 | changed = true; | |
541 | } | |
542 | n_tries++; | |
543 | } | |
544 | ||
545 | if (changed || n_tries < cls->n_tries) { | |
546 | struct cls_subtable *subtable; | |
547 | ||
548 | /* Trie configuration needs to change. Disable trie lookups | |
549 | * for the tries that are changing and wait all the current readers | |
550 | * with the old configuration to be done. */ | |
551 | changed = false; | |
552 | CMAP_FOR_EACH (subtable, cmap_node, &cls->subtables_map) { | |
553 | for (i = 0; i < cls->n_tries; i++) { | |
554 | if ((i < n_tries && new_fields[i]) || i >= n_tries) { | |
555 | if (subtable->trie_plen[i]) { | |
556 | subtable->trie_plen[i] = 0; | |
557 | changed = true; | |
558 | } | |
559 | } | |
560 | } | |
561 | } | |
562 | /* Synchronize if any readers were using tries. The readers may | |
563 | * temporarily function without the trie lookup based optimizations. */ | |
564 | if (changed) { | |
565 | /* ovsrcu_synchronize() functions as a memory barrier, so it does | |
566 | * not matter that subtable->trie_plen is not atomic. */ | |
567 | ovsrcu_synchronize(); | |
13751fd8 | 568 | } |
13751fd8 | 569 | |
f358a2cb JR |
570 | /* Now set up the tries. */ |
571 | for (i = 0; i < n_tries; i++) { | |
572 | if (new_fields[i]) { | |
573 | trie_init(cls, i, new_fields[i]); | |
574 | } | |
575 | } | |
576 | /* Destroy the rest, if any. */ | |
577 | for (; i < cls->n_tries; i++) { | |
578 | trie_init(cls, i, NULL); | |
579 | } | |
580 | ||
581 | cls->n_tries = n_tries; | |
582 | ovs_mutex_unlock(&cls->mutex); | |
583 | return true; | |
13751fd8 | 584 | } |
f358a2cb | 585 | |
e65413ab | 586 | ovs_mutex_unlock(&cls->mutex); |
f358a2cb | 587 | return false; /* No change. */ |
13751fd8 JR |
588 | } |
589 | ||
590 | static void | |
e48eccd1 | 591 | trie_init(struct classifier *cls, int trie_idx, const struct mf_field *field) |
e65413ab | 592 | OVS_REQUIRES(cls->mutex) |
13751fd8 JR |
593 | { |
594 | struct cls_trie *trie = &cls->tries[trie_idx]; | |
595 | struct cls_subtable *subtable; | |
596 | ||
597 | if (trie_idx < cls->n_tries) { | |
f358a2cb JR |
598 | trie_destroy(&trie->root); |
599 | } else { | |
600 | ovsrcu_set_hidden(&trie->root, NULL); | |
13751fd8 | 601 | } |
13751fd8 JR |
602 | trie->field = field; |
603 | ||
f358a2cb | 604 | /* Add existing rules to the new trie. */ |
f2c21402 | 605 | CMAP_FOR_EACH (subtable, cmap_node, &cls->subtables_map) { |
13751fd8 JR |
606 | unsigned int plen; |
607 | ||
608 | plen = field ? minimask_get_prefix_len(&subtable->mask, field) : 0; | |
13751fd8 | 609 | if (plen) { |
627fb667 | 610 | struct cls_match *head; |
13751fd8 | 611 | |
f2c21402 | 612 | CMAP_FOR_EACH (head, cmap_node, &subtable->rules) { |
627fb667 | 613 | struct cls_match *match; |
13751fd8 | 614 | |
627fb667 JR |
615 | FOR_EACH_RULE_IN_LIST (match, head) { |
616 | trie_insert(trie, match->cls_rule, plen); | |
13751fd8 JR |
617 | } |
618 | } | |
619 | } | |
f358a2cb JR |
620 | /* Initialize subtable's prefix length on this field. This will |
621 | * allow readers to use the trie. */ | |
622 | atomic_thread_fence(memory_order_release); | |
623 | subtable->trie_plen[trie_idx] = plen; | |
13751fd8 JR |
624 | } |
625 | } | |
626 | ||
5f0476ce JR |
627 | /* Returns true if 'cls' contains no classification rules, false otherwise. |
628 | * Checking the cmap requires no locking. */ | |
064af421 BP |
629 | bool |
630 | classifier_is_empty(const struct classifier *cls) | |
631 | { | |
e48eccd1 | 632 | return cmap_is_empty(&cls->subtables_map); |
064af421 BP |
633 | } |
634 | ||
dbda2960 | 635 | /* Returns the number of rules in 'cls'. */ |
064af421 BP |
636 | int |
637 | classifier_count(const struct classifier *cls) | |
afae68b1 | 638 | OVS_NO_THREAD_SAFETY_ANALYSIS |
064af421 | 639 | { |
afae68b1 JR |
640 | /* n_rules is an int, so in the presence of concurrent writers this will |
641 | * return either the old or a new value. */ | |
e48eccd1 | 642 | return cls->n_rules; |
064af421 BP |
643 | } |
644 | ||
c906cedf BP |
645 | static uint32_t |
646 | hash_metadata(ovs_be64 metadata_) | |
647 | { | |
648 | uint64_t metadata = (OVS_FORCE uint64_t) metadata_; | |
965607c8 | 649 | return hash_uint64(metadata); |
c906cedf BP |
650 | } |
651 | ||
652 | static struct cls_partition * | |
e48eccd1 | 653 | find_partition(const struct classifier *cls, ovs_be64 metadata, uint32_t hash) |
c906cedf BP |
654 | { |
655 | struct cls_partition *partition; | |
656 | ||
f2c21402 | 657 | CMAP_FOR_EACH_WITH_HASH (partition, cmap_node, hash, &cls->partitions) { |
c906cedf BP |
658 | if (partition->metadata == metadata) { |
659 | return partition; | |
660 | } | |
661 | } | |
662 | ||
663 | return NULL; | |
664 | } | |
665 | ||
666 | static struct cls_partition * | |
e48eccd1 | 667 | create_partition(struct classifier *cls, struct cls_subtable *subtable, |
c906cedf | 668 | ovs_be64 metadata) |
e65413ab | 669 | OVS_REQUIRES(cls->mutex) |
c906cedf BP |
670 | { |
671 | uint32_t hash = hash_metadata(metadata); | |
672 | struct cls_partition *partition = find_partition(cls, metadata, hash); | |
673 | if (!partition) { | |
674 | partition = xmalloc(sizeof *partition); | |
675 | partition->metadata = metadata; | |
676 | partition->tags = 0; | |
183126a1 | 677 | tag_tracker_init(&partition->tracker); |
f2c21402 | 678 | cmap_insert(&cls->partitions, &partition->cmap_node, hash); |
c906cedf | 679 | } |
03868246 | 680 | tag_tracker_add(&partition->tracker, &partition->tags, subtable->tag); |
c906cedf BP |
681 | return partition; |
682 | } | |
683 | ||
69d6040e JR |
684 | static inline ovs_be32 minimatch_get_ports(const struct minimatch *match) |
685 | { | |
686 | /* Could optimize to use the same map if needed for fast path. */ | |
687 | return MINIFLOW_GET_BE32(&match->flow, tp_src) | |
688 | & MINIFLOW_GET_BE32(&match->mask.masks, tp_src); | |
689 | } | |
690 | ||
b5d97350 BP |
691 | /* Inserts 'rule' into 'cls'. Until 'rule' is removed from 'cls', the caller |
692 | * must not modify or free it. | |
064af421 BP |
693 | * |
694 | * If 'cls' already contains an identical rule (including wildcards, values of | |
695 | * fixed fields, and priority), replaces the old rule by 'rule' and returns the | |
696 | * rule that was replaced. The caller takes ownership of the returned rule and | |
48d28ac1 BP |
697 | * is thus responsible for destroying it with cls_rule_destroy(), freeing the |
698 | * memory block in which it resides, etc., as necessary. | |
064af421 BP |
699 | * |
700 | * Returns NULL if 'cls' does not contain a rule with an identical key, after | |
701 | * inserting the new rule. In this case, no rules are displaced by the new | |
702 | * rule, even rules that cannot have any effect because the new rule matches a | |
703 | * superset of their flows and has higher priority. */ | |
704 | struct cls_rule * | |
e48eccd1 JR |
705 | classifier_replace(struct classifier *cls, struct cls_rule *rule) |
706 | OVS_EXCLUDED(cls->mutex) | |
064af421 | 707 | { |
627fb667 | 708 | struct cls_match *old_rule; |
03868246 | 709 | struct cls_subtable *subtable; |
e65413ab | 710 | struct cls_rule *old_cls_rule = NULL; |
b5d97350 | 711 | |
e65413ab | 712 | ovs_mutex_lock(&cls->mutex); |
03868246 JR |
713 | subtable = find_subtable(cls, &rule->match.mask); |
714 | if (!subtable) { | |
715 | subtable = insert_subtable(cls, &rule->match.mask); | |
b5d97350 BP |
716 | } |
717 | ||
03868246 | 718 | old_rule = insert_rule(cls, subtable, rule); |
b5d97350 | 719 | if (!old_rule) { |
e65413ab | 720 | old_cls_rule = NULL; |
13751fd8 | 721 | |
627fb667 | 722 | rule->cls_match->partition = NULL; |
c906cedf BP |
723 | if (minimask_get_metadata_mask(&rule->match.mask) == OVS_BE64_MAX) { |
724 | ovs_be64 metadata = miniflow_get_metadata(&rule->match.flow); | |
627fb667 JR |
725 | rule->cls_match->partition = create_partition(cls, subtable, |
726 | metadata); | |
c906cedf BP |
727 | } |
728 | ||
064af421 | 729 | cls->n_rules++; |
13751fd8 | 730 | |
e65413ab | 731 | for (int i = 0; i < cls->n_tries; i++) { |
13751fd8 JR |
732 | if (subtable->trie_plen[i]) { |
733 | trie_insert(&cls->tries[i], rule, subtable->trie_plen[i]); | |
734 | } | |
735 | } | |
69d6040e JR |
736 | |
737 | /* Ports trie. */ | |
738 | if (subtable->ports_mask_len) { | |
739 | /* We mask the value to be inserted to always have the wildcarded | |
740 | * bits in known (zero) state, so we can include them in comparison | |
741 | * and they will always match (== their original value does not | |
742 | * matter). */ | |
743 | ovs_be32 masked_ports = minimatch_get_ports(&rule->match); | |
744 | ||
745 | trie_insert_prefix(&subtable->ports_trie, &masked_ports, | |
746 | subtable->ports_mask_len); | |
747 | } | |
c906cedf | 748 | } else { |
e65413ab | 749 | old_cls_rule = old_rule->cls_rule; |
627fb667 JR |
750 | rule->cls_match->partition = old_rule->partition; |
751 | old_cls_rule->cls_match = NULL; | |
f2c21402 JR |
752 | |
753 | /* 'old_rule' contains a cmap_node, which may not be freed | |
754 | * immediately. */ | |
755 | ovsrcu_postpone(free, old_rule); | |
064af421 | 756 | } |
e65413ab JR |
757 | ovs_mutex_unlock(&cls->mutex); |
758 | return old_cls_rule; | |
064af421 BP |
759 | } |
760 | ||
08944c1d BP |
761 | /* Inserts 'rule' into 'cls'. Until 'rule' is removed from 'cls', the caller |
762 | * must not modify or free it. | |
763 | * | |
764 | * 'cls' must not contain an identical rule (including wildcards, values of | |
765 | * fixed fields, and priority). Use classifier_find_rule_exactly() to find | |
766 | * such a rule. */ | |
767 | void | |
768 | classifier_insert(struct classifier *cls, struct cls_rule *rule) | |
769 | { | |
770 | struct cls_rule *displaced_rule = classifier_replace(cls, rule); | |
cb22974d | 771 | ovs_assert(!displaced_rule); |
08944c1d BP |
772 | } |
773 | ||
48d28ac1 BP |
774 | /* Removes 'rule' from 'cls'. It is the caller's responsibility to destroy |
775 | * 'rule' with cls_rule_destroy(), freeing the memory block in which 'rule' | |
776 | * resides, etc., as necessary. */ | |
064af421 | 777 | void |
e48eccd1 JR |
778 | classifier_remove(struct classifier *cls, struct cls_rule *rule) |
779 | OVS_EXCLUDED(cls->mutex) | |
064af421 | 780 | { |
c906cedf | 781 | struct cls_partition *partition; |
627fb667 JR |
782 | struct cls_match *cls_match = rule->cls_match; |
783 | struct cls_match *head; | |
03868246 | 784 | struct cls_subtable *subtable; |
476f36e8 | 785 | int i; |
f2c21402 JR |
786 | uint32_t basis = 0, hash, ihash[CLS_MAX_INDICES]; |
787 | uint8_t prev_be32ofs = 0; | |
064af421 | 788 | |
627fb667 JR |
789 | ovs_assert(cls_match); |
790 | ||
e65413ab | 791 | ovs_mutex_lock(&cls->mutex); |
03868246 | 792 | subtable = find_subtable(cls, &rule->match.mask); |
627fb667 JR |
793 | ovs_assert(subtable); |
794 | ||
69d6040e JR |
795 | if (subtable->ports_mask_len) { |
796 | ovs_be32 masked_ports = minimatch_get_ports(&rule->match); | |
797 | ||
798 | trie_remove_prefix(&subtable->ports_trie, | |
799 | &masked_ports, subtable->ports_mask_len); | |
800 | } | |
13751fd8 JR |
801 | for (i = 0; i < cls->n_tries; i++) { |
802 | if (subtable->trie_plen[i]) { | |
803 | trie_remove(&cls->tries[i], rule, subtable->trie_plen[i]); | |
804 | } | |
805 | } | |
806 | ||
476f36e8 JR |
807 | /* Remove rule node from indices. */ |
808 | for (i = 0; i < subtable->n_indices; i++) { | |
f2c21402 JR |
809 | ihash[i] = minimatch_hash_range(&rule->match, prev_be32ofs, |
810 | subtable->index_ofs[i], &basis); | |
811 | cmap_remove(&subtable->indices[i], &cls_match->index_nodes[i], | |
812 | ihash[i]); | |
813 | prev_be32ofs = subtable->index_ofs[i]; | |
476f36e8 | 814 | } |
f2c21402 | 815 | hash = minimatch_hash_range(&rule->match, prev_be32ofs, FLOW_U32S, &basis); |
476f36e8 | 816 | |
f2c21402 | 817 | head = find_equal(subtable, &rule->match.flow, hash); |
627fb667 JR |
818 | if (head != cls_match) { |
819 | list_remove(&cls_match->list); | |
820 | } else if (list_is_empty(&cls_match->list)) { | |
f2c21402 | 821 | cmap_remove(&subtable->rules, &cls_match->cmap_node, hash); |
b5d97350 | 822 | } else { |
627fb667 JR |
823 | struct cls_match *next = CONTAINER_OF(cls_match->list.next, |
824 | struct cls_match, list); | |
064af421 | 825 | |
627fb667 | 826 | list_remove(&cls_match->list); |
f2c21402 JR |
827 | cmap_replace(&subtable->rules, &cls_match->cmap_node, |
828 | &next->cmap_node, hash); | |
b5d97350 | 829 | } |
064af421 | 830 | |
627fb667 | 831 | partition = cls_match->partition; |
183126a1 BP |
832 | if (partition) { |
833 | tag_tracker_subtract(&partition->tracker, &partition->tags, | |
03868246 | 834 | subtable->tag); |
183126a1 | 835 | if (!partition->tags) { |
f2c21402 JR |
836 | cmap_remove(&cls->partitions, &partition->cmap_node, |
837 | hash_metadata(partition->metadata)); | |
838 | ovsrcu_postpone(free, partition); | |
183126a1 | 839 | } |
c906cedf BP |
840 | } |
841 | ||
03868246 JR |
842 | if (--subtable->n_rules == 0) { |
843 | destroy_subtable(cls, subtable); | |
fe7cfa5c JR |
844 | } else if (subtable->max_priority == cls_match->priority |
845 | && --subtable->max_count == 0) { | |
846 | /* Find the new 'max_priority' and 'max_count'. */ | |
847 | struct cls_match *head; | |
848 | unsigned int max_priority = 0; | |
849 | ||
f2c21402 | 850 | CMAP_FOR_EACH (head, cmap_node, &subtable->rules) { |
fe7cfa5c JR |
851 | if (head->priority > max_priority) { |
852 | max_priority = head->priority; | |
853 | subtable->max_count = 1; | |
854 | } else if (head->priority == max_priority) { | |
855 | ++subtable->max_count; | |
856 | } | |
857 | } | |
858 | subtable->max_priority = max_priority; | |
859 | pvector_change_priority(&cls->subtables, subtable, max_priority); | |
4d935a6b | 860 | } |
13751fd8 | 861 | |
b5d97350 | 862 | cls->n_rules--; |
627fb667 JR |
863 | |
864 | rule->cls_match = NULL; | |
f2c21402 | 865 | ovsrcu_postpone(free, cls_match); |
e65413ab | 866 | ovs_mutex_unlock(&cls->mutex); |
064af421 BP |
867 | } |
868 | ||
13751fd8 | 869 | /* Prefix tree context. Valid when 'lookup_done' is true. Can skip all |
c0bfb650 JR |
870 | * subtables which have a prefix match on the trie field, but whose prefix |
871 | * length is not indicated in 'match_plens'. For example, a subtable that | |
872 | * has a 8-bit trie field prefix match can be skipped if | |
873 | * !be_get_bit_at(&match_plens, 8 - 1). If skipped, 'maskbits' prefix bits | |
874 | * must be unwildcarded to make datapath flow only match packets it should. */ | |
13751fd8 JR |
875 | struct trie_ctx { |
876 | const struct cls_trie *trie; | |
877 | bool lookup_done; /* Status of the lookup. */ | |
878 | uint8_t be32ofs; /* U32 offset of the field in question. */ | |
13751fd8 | 879 | unsigned int maskbits; /* Prefix length needed to avoid false matches. */ |
c0bfb650 JR |
880 | union mf_value match_plens; /* Bitmask of prefix lengths with possible |
881 | * matches. */ | |
13751fd8 JR |
882 | }; |
883 | ||
884 | static void | |
885 | trie_ctx_init(struct trie_ctx *ctx, const struct cls_trie *trie) | |
886 | { | |
887 | ctx->trie = trie; | |
888 | ctx->be32ofs = trie->field->flow_be32ofs; | |
889 | ctx->lookup_done = false; | |
890 | } | |
891 | ||
48c3de13 BP |
892 | /* Finds and returns the highest-priority rule in 'cls' that matches 'flow'. |
893 | * Returns a null pointer if no rules in 'cls' match 'flow'. If multiple rules | |
74f74083 EJ |
894 | * of equal priority match 'flow', returns one arbitrarily. |
895 | * | |
896 | * If a rule is found and 'wc' is non-null, bitwise-OR's 'wc' with the | |
897 | * set of bits that were significant in the lookup. At some point | |
898 | * earlier, 'wc' should have been initialized (e.g., by | |
899 | * flow_wildcards_init_catchall()). */ | |
48c3de13 | 900 | struct cls_rule * |
e48eccd1 | 901 | classifier_lookup(const struct classifier *cls, const struct flow *flow, |
74f74083 | 902 | struct flow_wildcards *wc) |
48c3de13 | 903 | { |
c906cedf | 904 | const struct cls_partition *partition; |
c906cedf | 905 | tag_type tags; |
ec988646 | 906 | int64_t best_priority = -1; |
fe7cfa5c JR |
907 | const struct cls_match *best; |
908 | struct trie_ctx trie_ctx[CLS_MAX_TRIES]; | |
909 | struct cls_subtable *subtable; | |
c906cedf | 910 | |
f358a2cb JR |
911 | /* Synchronize for cls->n_tries and subtable->trie_plen. They can change |
912 | * when table configuration changes, which happens typically only on | |
913 | * startup. */ | |
914 | atomic_thread_fence(memory_order_acquire); | |
915 | ||
03868246 JR |
916 | /* Determine 'tags' such that, if 'subtable->tag' doesn't intersect them, |
917 | * then 'flow' cannot possibly match in 'subtable': | |
c906cedf BP |
918 | * |
919 | * - If flow->metadata maps to a given 'partition', then we can use | |
920 | * 'tags' for 'partition->tags'. | |
921 | * | |
922 | * - If flow->metadata has no partition, then no rule in 'cls' has an | |
923 | * exact-match for flow->metadata. That means that we don't need to | |
03868246 | 924 | * search any subtable that includes flow->metadata in its mask. |
c906cedf | 925 | * |
03868246 | 926 | * In either case, we always need to search any cls_subtables that do not |
c906cedf | 927 | * include flow->metadata in its mask. One way to do that would be to |
03868246 JR |
928 | * check the "cls_subtable"s explicitly for that, but that would require an |
929 | * extra branch per subtable. Instead, we mark such a cls_subtable's | |
930 | * 'tags' as TAG_ALL and make sure that 'tags' is never empty. This means | |
931 | * that 'tags' always intersects such a cls_subtable's 'tags', so we don't | |
932 | * need a special case. | |
c906cedf | 933 | */ |
f2c21402 | 934 | partition = (cmap_is_empty(&cls->partitions) |
c906cedf BP |
935 | ? NULL |
936 | : find_partition(cls, flow->metadata, | |
937 | hash_metadata(flow->metadata))); | |
938 | tags = partition ? partition->tags : TAG_ARBITRARY; | |
48c3de13 | 939 | |
13751fd8 | 940 | /* Initialize trie contexts for match_find_wc(). */ |
fe7cfa5c | 941 | for (int i = 0; i < cls->n_tries; i++) { |
13751fd8 JR |
942 | trie_ctx_init(&trie_ctx[i], &cls->tries[i]); |
943 | } | |
ec988646 | 944 | |
b5d97350 | 945 | best = NULL; |
fe7cfa5c JR |
946 | PVECTOR_FOR_EACH_PRIORITY(subtable, best_priority, 2, |
947 | sizeof(struct cls_subtable), &cls->subtables) { | |
627fb667 | 948 | struct cls_match *rule; |
c906cedf | 949 | |
fe7cfa5c | 950 | if (!tag_intersects(tags, subtable->tag)) { |
c906cedf BP |
951 | continue; |
952 | } | |
74f74083 | 953 | |
fe7cfa5c | 954 | rule = find_match_wc(subtable, flow, trie_ctx, cls->n_tries, wc); |
ec988646 JR |
955 | if (rule && (int64_t)rule->priority > best_priority) { |
956 | best_priority = (int64_t)rule->priority; | |
1f3c5efc | 957 | best = rule; |
b5d97350 | 958 | } |
48c3de13 | 959 | } |
13751fd8 | 960 | |
627fb667 | 961 | return best ? best->cls_rule : NULL; |
48c3de13 BP |
962 | } |
963 | ||
2abf78ff | 964 | /* Returns true if 'target' satisifies 'match', that is, if each bit for which |
3016f3e4 JR |
965 | * 'match' specifies a particular value has the correct value in 'target'. |
966 | * | |
967 | * 'flow' and 'mask' have the same mask! */ | |
2abf78ff | 968 | static bool |
3016f3e4 JR |
969 | miniflow_and_mask_matches_miniflow(const struct miniflow *flow, |
970 | const struct minimask *mask, | |
971 | const struct miniflow *target) | |
2abf78ff | 972 | { |
3016f3e4 JR |
973 | const uint32_t *flowp = miniflow_get_u32_values(flow); |
974 | const uint32_t *maskp = miniflow_get_u32_values(&mask->masks); | |
2abf78ff JR |
975 | uint32_t target_u32; |
976 | ||
3016f3e4 | 977 | MINIFLOW_FOR_EACH_IN_MAP(target_u32, target, mask->masks.map) { |
2abf78ff JR |
978 | if ((*flowp++ ^ target_u32) & *maskp++) { |
979 | return false; | |
980 | } | |
981 | } | |
982 | ||
983 | return true; | |
984 | } | |
985 | ||
627fb667 | 986 | static inline struct cls_match * |
2abf78ff JR |
987 | find_match_miniflow(const struct cls_subtable *subtable, |
988 | const struct miniflow *flow, | |
989 | uint32_t hash) | |
990 | { | |
627fb667 | 991 | struct cls_match *rule; |
2abf78ff | 992 | |
f2c21402 | 993 | CMAP_FOR_EACH_WITH_HASH (rule, cmap_node, hash, &subtable->rules) { |
3016f3e4 JR |
994 | if (miniflow_and_mask_matches_miniflow(&rule->flow, &subtable->mask, |
995 | flow)) { | |
2abf78ff JR |
996 | return rule; |
997 | } | |
998 | } | |
999 | ||
1000 | return NULL; | |
1001 | } | |
1002 | ||
b7648634 EJ |
1003 | /* For each miniflow in 'flows' performs a classifier lookup writing the result |
1004 | * into the corresponding slot in 'rules'. If a particular entry in 'flows' is | |
1005 | * NULL it is skipped. | |
2abf78ff | 1006 | * |
b7648634 EJ |
1007 | * This function is optimized for use in the userspace datapath and therefore |
1008 | * does not implement a lot of features available in the standard | |
1009 | * classifier_lookup() function. Specifically, it does not implement | |
1010 | * priorities, instead returning any rule which matches the flow. */ | |
1011 | void | |
e48eccd1 | 1012 | classifier_lookup_miniflow_batch(const struct classifier *cls, |
b7648634 EJ |
1013 | const struct miniflow **flows, |
1014 | struct cls_rule **rules, size_t len) | |
2abf78ff JR |
1015 | { |
1016 | struct cls_subtable *subtable; | |
b7648634 | 1017 | size_t i, begin = 0; |
2abf78ff | 1018 | |
b7648634 | 1019 | memset(rules, 0, len * sizeof *rules); |
fe7cfa5c | 1020 | PVECTOR_FOR_EACH (subtable, &cls->subtables) { |
b7648634 EJ |
1021 | for (i = begin; i < len; i++) { |
1022 | struct cls_match *match; | |
1023 | uint32_t hash; | |
2abf78ff | 1024 | |
b7648634 EJ |
1025 | if (OVS_UNLIKELY(rules[i] || !flows[i])) { |
1026 | continue; | |
1027 | } | |
1028 | ||
1029 | hash = miniflow_hash_in_minimask(flows[i], &subtable->mask, 0); | |
1030 | match = find_match_miniflow(subtable, flows[i], hash); | |
1031 | if (OVS_UNLIKELY(match)) { | |
1032 | rules[i] = match->cls_rule; | |
1033 | } | |
2abf78ff | 1034 | } |
2abf78ff | 1035 | |
b7648634 EJ |
1036 | while (begin < len && (rules[begin] || !flows[begin])) { |
1037 | begin++; | |
1038 | } | |
1039 | if (begin >= len) { | |
1040 | break; | |
1041 | } | |
1042 | } | |
2abf78ff JR |
1043 | } |
1044 | ||
b5d97350 BP |
1045 | /* Finds and returns a rule in 'cls' with exactly the same priority and |
1046 | * matching criteria as 'target'. Returns a null pointer if 'cls' doesn't | |
c084ce1d | 1047 | * contain an exact match. */ |
064af421 | 1048 | struct cls_rule * |
e48eccd1 | 1049 | classifier_find_rule_exactly(const struct classifier *cls, |
76ecc721 | 1050 | const struct cls_rule *target) |
e48eccd1 | 1051 | OVS_EXCLUDED(cls->mutex) |
064af421 | 1052 | { |
627fb667 | 1053 | struct cls_match *head, *rule; |
03868246 | 1054 | struct cls_subtable *subtable; |
064af421 | 1055 | |
e65413ab | 1056 | ovs_mutex_lock(&cls->mutex); |
03868246 JR |
1057 | subtable = find_subtable(cls, &target->match.mask); |
1058 | if (!subtable) { | |
e65413ab | 1059 | goto out; |
064af421 BP |
1060 | } |
1061 | ||
4d935a6b | 1062 | /* Skip if there is no hope. */ |
03868246 | 1063 | if (target->priority > subtable->max_priority) { |
e65413ab | 1064 | goto out; |
4d935a6b JR |
1065 | } |
1066 | ||
03868246 | 1067 | head = find_equal(subtable, &target->match.flow, |
5cb7a798 BP |
1068 | miniflow_hash_in_minimask(&target->match.flow, |
1069 | &target->match.mask, 0)); | |
b5d97350 BP |
1070 | FOR_EACH_RULE_IN_LIST (rule, head) { |
1071 | if (target->priority >= rule->priority) { | |
e65413ab | 1072 | ovs_mutex_unlock(&cls->mutex); |
627fb667 | 1073 | return target->priority == rule->priority ? rule->cls_rule : NULL; |
064af421 BP |
1074 | } |
1075 | } | |
e65413ab JR |
1076 | out: |
1077 | ovs_mutex_unlock(&cls->mutex); | |
064af421 BP |
1078 | return NULL; |
1079 | } | |
1080 | ||
81a76618 BP |
1081 | /* Finds and returns a rule in 'cls' with priority 'priority' and exactly the |
1082 | * same matching criteria as 'target'. Returns a null pointer if 'cls' doesn't | |
1083 | * contain an exact match. */ | |
1084 | struct cls_rule * | |
1085 | classifier_find_match_exactly(const struct classifier *cls, | |
1086 | const struct match *target, | |
1087 | unsigned int priority) | |
1088 | { | |
1089 | struct cls_rule *retval; | |
1090 | struct cls_rule cr; | |
1091 | ||
1092 | cls_rule_init(&cr, target, priority); | |
1093 | retval = classifier_find_rule_exactly(cls, &cr); | |
48d28ac1 | 1094 | cls_rule_destroy(&cr); |
81a76618 BP |
1095 | |
1096 | return retval; | |
1097 | } | |
1098 | ||
faa50f40 BP |
1099 | /* Checks if 'target' would overlap any other rule in 'cls'. Two rules are |
1100 | * considered to overlap if both rules have the same priority and a packet | |
1101 | * could match both. */ | |
49bdc010 | 1102 | bool |
e48eccd1 | 1103 | classifier_rule_overlaps(const struct classifier *cls, |
faa50f40 | 1104 | const struct cls_rule *target) |
e48eccd1 | 1105 | OVS_EXCLUDED(cls->mutex) |
49bdc010 | 1106 | { |
03868246 | 1107 | struct cls_subtable *subtable; |
fe7cfa5c | 1108 | int64_t stop_at_priority = (int64_t)target->priority - 1; |
49bdc010 | 1109 | |
e65413ab | 1110 | ovs_mutex_lock(&cls->mutex); |
03868246 | 1111 | /* Iterate subtables in the descending max priority order. */ |
fe7cfa5c JR |
1112 | PVECTOR_FOR_EACH_PRIORITY (subtable, stop_at_priority, 2, |
1113 | sizeof(struct cls_subtable), &cls->subtables) { | |
5cb7a798 BP |
1114 | uint32_t storage[FLOW_U32S]; |
1115 | struct minimask mask; | |
627fb667 | 1116 | struct cls_match *head; |
49bdc010 | 1117 | |
03868246 | 1118 | minimask_combine(&mask, &target->match.mask, &subtable->mask, storage); |
f2c21402 | 1119 | CMAP_FOR_EACH (head, cmap_node, &subtable->rules) { |
627fb667 | 1120 | struct cls_match *rule; |
49bdc010 | 1121 | |
b5d97350 | 1122 | FOR_EACH_RULE_IN_LIST (rule, head) { |
4d935a6b JR |
1123 | if (rule->priority < target->priority) { |
1124 | break; /* Rules in descending priority order. */ | |
1125 | } | |
faa50f40 | 1126 | if (rule->priority == target->priority |
5cb7a798 | 1127 | && miniflow_equal_in_minimask(&target->match.flow, |
3016f3e4 | 1128 | &rule->flow, &mask)) { |
e65413ab | 1129 | ovs_mutex_unlock(&cls->mutex); |
49bdc010 JP |
1130 | return true; |
1131 | } | |
1132 | } | |
1133 | } | |
1134 | } | |
1135 | ||
e65413ab | 1136 | ovs_mutex_unlock(&cls->mutex); |
49bdc010 JP |
1137 | return false; |
1138 | } | |
6ceeaa92 BP |
1139 | |
1140 | /* Returns true if 'rule' exactly matches 'criteria' or if 'rule' is more | |
1141 | * specific than 'criteria'. That is, 'rule' matches 'criteria' and this | |
1142 | * function returns true if, for every field: | |
1143 | * | |
1144 | * - 'criteria' and 'rule' specify the same (non-wildcarded) value for the | |
1145 | * field, or | |
1146 | * | |
1147 | * - 'criteria' wildcards the field, | |
1148 | * | |
1149 | * Conversely, 'rule' does not match 'criteria' and this function returns false | |
1150 | * if, for at least one field: | |
1151 | * | |
1152 | * - 'criteria' and 'rule' specify different values for the field, or | |
1153 | * | |
1154 | * - 'criteria' specifies a value for the field but 'rule' wildcards it. | |
1155 | * | |
1156 | * Equivalently, the truth table for whether a field matches is: | |
1157 | * | |
1158 | * rule | |
1159 | * | |
1160 | * c wildcard exact | |
1161 | * r +---------+---------+ | |
1162 | * i wild | yes | yes | | |
1163 | * t card | | | | |
1164 | * e +---------+---------+ | |
1165 | * r exact | no |if values| | |
1166 | * i | |are equal| | |
1167 | * a +---------+---------+ | |
1168 | * | |
1169 | * This is the matching rule used by OpenFlow 1.0 non-strict OFPT_FLOW_MOD | |
1170 | * commands and by OpenFlow 1.0 aggregate and flow stats. | |
1171 | * | |
81a76618 | 1172 | * Ignores rule->priority. */ |
6ceeaa92 BP |
1173 | bool |
1174 | cls_rule_is_loose_match(const struct cls_rule *rule, | |
5cb7a798 | 1175 | const struct minimatch *criteria) |
6ceeaa92 | 1176 | { |
5cb7a798 BP |
1177 | return (!minimask_has_extra(&rule->match.mask, &criteria->mask) |
1178 | && miniflow_equal_in_minimask(&rule->match.flow, &criteria->flow, | |
1179 | &criteria->mask)); | |
6ceeaa92 | 1180 | } |
b5d97350 | 1181 | \f |
5ecc9d81 BP |
1182 | /* Iteration. */ |
1183 | ||
1184 | static bool | |
627fb667 | 1185 | rule_matches(const struct cls_match *rule, const struct cls_rule *target) |
5ecc9d81 BP |
1186 | { |
1187 | return (!target | |
3016f3e4 | 1188 | || miniflow_equal_in_minimask(&rule->flow, |
5cb7a798 BP |
1189 | &target->match.flow, |
1190 | &target->match.mask)); | |
5ecc9d81 BP |
1191 | } |
1192 | ||
627fb667 | 1193 | static struct cls_match * |
03868246 | 1194 | search_subtable(const struct cls_subtable *subtable, |
f2c21402 | 1195 | struct cls_cursor *cursor) |
5ecc9d81 | 1196 | { |
f2c21402 JR |
1197 | if (!cursor->target |
1198 | || !minimask_has_extra(&subtable->mask, &cursor->target->match.mask)) { | |
627fb667 | 1199 | struct cls_match *rule; |
5ecc9d81 | 1200 | |
f2c21402 JR |
1201 | CMAP_CURSOR_FOR_EACH (rule, cmap_node, &cursor->rules, |
1202 | &subtable->rules) { | |
1203 | if (rule_matches(rule, cursor->target)) { | |
5ecc9d81 BP |
1204 | return rule; |
1205 | } | |
1206 | } | |
1207 | } | |
1208 | return NULL; | |
1209 | } | |
1210 | ||
5f0476ce JR |
1211 | /* Initializes 'cursor' for iterating through rules in 'cls', and returns the |
1212 | * first matching cls_rule via '*pnode', or NULL if there are no matches. | |
5ecc9d81 | 1213 | * |
6ceeaa92 | 1214 | * - If 'target' is null, the cursor will visit every rule in 'cls'. |
5ecc9d81 | 1215 | * |
6ceeaa92 BP |
1216 | * - If 'target' is nonnull, the cursor will visit each 'rule' in 'cls' |
1217 | * such that cls_rule_is_loose_match(rule, target) returns true. | |
5ecc9d81 | 1218 | * |
6ceeaa92 | 1219 | * Ignores target->priority. */ |
78c8df12 BP |
1220 | struct cls_cursor cls_cursor_start(const struct classifier *cls, |
1221 | const struct cls_rule *target, | |
1222 | bool safe) | |
5f0476ce | 1223 | OVS_NO_THREAD_SAFETY_ANALYSIS |
5ecc9d81 | 1224 | { |
5f0476ce | 1225 | struct cls_cursor cursor; |
03868246 | 1226 | struct cls_subtable *subtable; |
5ecc9d81 | 1227 | |
5f0476ce | 1228 | cursor.safe = safe; |
e48eccd1 | 1229 | cursor.cls = cls; |
5f0476ce | 1230 | cursor.target = target && !cls_rule_is_catchall(target) ? target : NULL; |
78c8df12 | 1231 | cursor.rule = NULL; |
5f0476ce JR |
1232 | |
1233 | /* Find first rule. */ | |
e65413ab | 1234 | ovs_mutex_lock(&cursor.cls->mutex); |
5f0476ce | 1235 | CMAP_CURSOR_FOR_EACH (subtable, cmap_node, &cursor.subtables, |
e65413ab | 1236 | &cursor.cls->subtables_map) { |
5f0476ce | 1237 | struct cls_match *rule = search_subtable(subtable, &cursor); |
f2c21402 | 1238 | |
5ecc9d81 | 1239 | if (rule) { |
5f0476ce | 1240 | cursor.subtable = subtable; |
78c8df12 | 1241 | cursor.rule = rule->cls_rule; |
5f0476ce | 1242 | break; |
5ecc9d81 BP |
1243 | } |
1244 | } | |
1245 | ||
5f0476ce | 1246 | /* Leave locked if requested and have a rule. */ |
78c8df12 | 1247 | if (safe || !cursor.rule) { |
e65413ab | 1248 | ovs_mutex_unlock(&cursor.cls->mutex); |
5f0476ce JR |
1249 | } |
1250 | return cursor; | |
1251 | } | |
1252 | ||
1253 | static void | |
1254 | cls_cursor_next_unlock(struct cls_cursor *cursor, struct cls_rule *rule) | |
1255 | OVS_NO_THREAD_SAFETY_ANALYSIS | |
1256 | { | |
e65413ab | 1257 | /* Release the mutex if no rule, or 'safe' mode. */ |
78c8df12 | 1258 | cursor->rule = rule; |
5f0476ce | 1259 | if (!rule || cursor->safe) { |
e65413ab | 1260 | ovs_mutex_unlock(&cursor->cls->mutex); |
5f0476ce | 1261 | } |
5ecc9d81 BP |
1262 | } |
1263 | ||
78c8df12 BP |
1264 | /* Sets 'cursor->rule' to the next matching cls_rule in 'cursor''s iteration, |
1265 | * or to null if all matching rules have been visited. */ | |
1266 | void | |
1267 | cls_cursor_advance(struct cls_cursor *cursor) | |
5f0476ce | 1268 | OVS_NO_THREAD_SAFETY_ANALYSIS |
5ecc9d81 | 1269 | { |
78c8df12 | 1270 | struct cls_match *rule = cursor->rule->cls_match; |
03868246 | 1271 | const struct cls_subtable *subtable; |
627fb667 | 1272 | struct cls_match *next; |
5ecc9d81 | 1273 | |
5f0476ce JR |
1274 | /* Lock if not locked already. */ |
1275 | if (cursor->safe) { | |
e65413ab | 1276 | ovs_mutex_lock(&cursor->cls->mutex); |
5f0476ce JR |
1277 | } |
1278 | ||
955f579d BP |
1279 | next = next_rule_in_list__(rule); |
1280 | if (next->priority < rule->priority) { | |
5f0476ce | 1281 | cls_cursor_next_unlock(cursor, next->cls_rule); |
78c8df12 | 1282 | return; |
5ecc9d81 BP |
1283 | } |
1284 | ||
955f579d | 1285 | /* 'next' is the head of the list, that is, the rule that is included in |
f2c21402 | 1286 | * the subtable's map. (This is important when the classifier contains |
03868246 | 1287 | * rules that differ only in priority.) */ |
955f579d | 1288 | rule = next; |
f2c21402 | 1289 | CMAP_CURSOR_FOR_EACH_CONTINUE (rule, cmap_node, &cursor->rules) { |
5ecc9d81 | 1290 | if (rule_matches(rule, cursor->target)) { |
5f0476ce | 1291 | cls_cursor_next_unlock(cursor, rule->cls_rule); |
78c8df12 | 1292 | return; |
5ecc9d81 BP |
1293 | } |
1294 | } | |
1295 | ||
03868246 | 1296 | subtable = cursor->subtable; |
f2c21402 JR |
1297 | CMAP_CURSOR_FOR_EACH_CONTINUE (subtable, cmap_node, &cursor->subtables) { |
1298 | rule = search_subtable(subtable, cursor); | |
5ecc9d81 | 1299 | if (rule) { |
03868246 | 1300 | cursor->subtable = subtable; |
5f0476ce | 1301 | cls_cursor_next_unlock(cursor, rule->cls_rule); |
78c8df12 | 1302 | return; |
5ecc9d81 BP |
1303 | } |
1304 | } | |
1305 | ||
e65413ab | 1306 | ovs_mutex_unlock(&cursor->cls->mutex); |
78c8df12 | 1307 | cursor->rule = NULL; |
5ecc9d81 BP |
1308 | } |
1309 | \f | |
03868246 | 1310 | static struct cls_subtable * |
e48eccd1 | 1311 | find_subtable(const struct classifier *cls, const struct minimask *mask) |
e65413ab | 1312 | OVS_REQUIRES(cls->mutex) |
b5d97350 | 1313 | { |
03868246 | 1314 | struct cls_subtable *subtable; |
064af421 | 1315 | |
f2c21402 | 1316 | CMAP_FOR_EACH_WITH_HASH (subtable, cmap_node, minimask_hash(mask, 0), |
5a87054c | 1317 | &cls->subtables_map) { |
03868246 JR |
1318 | if (minimask_equal(mask, &subtable->mask)) { |
1319 | return subtable; | |
064af421 BP |
1320 | } |
1321 | } | |
b5d97350 | 1322 | return NULL; |
064af421 | 1323 | } |
064af421 | 1324 | |
e65413ab | 1325 | /* The new subtable will be visible to the readers only after this. */ |
03868246 | 1326 | static struct cls_subtable * |
e48eccd1 | 1327 | insert_subtable(struct classifier *cls, const struct minimask *mask) |
e65413ab | 1328 | OVS_REQUIRES(cls->mutex) |
b5d97350 | 1329 | { |
c906cedf | 1330 | uint32_t hash = minimask_hash(mask, 0); |
03868246 | 1331 | struct cls_subtable *subtable; |
476f36e8 JR |
1332 | int i, index = 0; |
1333 | struct flow_wildcards old, new; | |
1334 | uint8_t prev; | |
3016f3e4 | 1335 | int count = count_1bits(mask->masks.map); |
064af421 | 1336 | |
3016f3e4 JR |
1337 | subtable = xzalloc(sizeof *subtable - sizeof mask->masks.inline_values |
1338 | + MINIFLOW_VALUES_SIZE(count)); | |
f2c21402 | 1339 | cmap_init(&subtable->rules); |
3016f3e4 | 1340 | miniflow_clone_inline(&subtable->mask.masks, &mask->masks, count); |
476f36e8 JR |
1341 | |
1342 | /* Init indices for segmented lookup, if any. */ | |
1343 | flow_wildcards_init_catchall(&new); | |
1344 | old = new; | |
1345 | prev = 0; | |
1346 | for (i = 0; i < cls->n_flow_segments; i++) { | |
1347 | flow_wildcards_fold_minimask_range(&new, mask, prev, | |
1348 | cls->flow_segments[i]); | |
1349 | /* Add an index if it adds mask bits. */ | |
1350 | if (!flow_wildcards_equal(&new, &old)) { | |
f2c21402 | 1351 | cmap_init(&subtable->indices[index]); |
476f36e8 JR |
1352 | subtable->index_ofs[index] = cls->flow_segments[i]; |
1353 | index++; | |
1354 | old = new; | |
1355 | } | |
1356 | prev = cls->flow_segments[i]; | |
1357 | } | |
1358 | /* Check if the rest of the subtable's mask adds any bits, | |
1359 | * and remove the last index if it doesn't. */ | |
1360 | if (index > 0) { | |
1361 | flow_wildcards_fold_minimask_range(&new, mask, prev, FLOW_U32S); | |
1362 | if (flow_wildcards_equal(&new, &old)) { | |
1363 | --index; | |
1364 | subtable->index_ofs[index] = 0; | |
f2c21402 | 1365 | cmap_destroy(&subtable->indices[index]); |
476f36e8 JR |
1366 | } |
1367 | } | |
1368 | subtable->n_indices = index; | |
1369 | ||
03868246 JR |
1370 | subtable->tag = (minimask_get_metadata_mask(mask) == OVS_BE64_MAX |
1371 | ? tag_create_deterministic(hash) | |
1372 | : TAG_ALL); | |
064af421 | 1373 | |
13751fd8 JR |
1374 | for (i = 0; i < cls->n_tries; i++) { |
1375 | subtable->trie_plen[i] = minimask_get_prefix_len(mask, | |
1376 | cls->tries[i].field); | |
1377 | } | |
1378 | ||
69d6040e | 1379 | /* Ports trie. */ |
f358a2cb | 1380 | ovsrcu_set_hidden(&subtable->ports_trie, NULL); |
69d6040e JR |
1381 | subtable->ports_mask_len |
1382 | = 32 - ctz32(ntohl(MINIFLOW_GET_BE32(&mask->masks, tp_src))); | |
1383 | ||
f2c21402 | 1384 | cmap_insert(&cls->subtables_map, &subtable->cmap_node, hash); |
ec988646 | 1385 | |
03868246 | 1386 | return subtable; |
064af421 BP |
1387 | } |
1388 | ||
b5d97350 | 1389 | static void |
e48eccd1 | 1390 | destroy_subtable(struct classifier *cls, struct cls_subtable *subtable) |
e65413ab | 1391 | OVS_REQUIRES(cls->mutex) |
b5d97350 | 1392 | { |
476f36e8 JR |
1393 | int i; |
1394 | ||
fe7cfa5c | 1395 | pvector_remove(&cls->subtables, subtable); |
f358a2cb | 1396 | trie_destroy(&subtable->ports_trie); |
69d6040e | 1397 | |
476f36e8 | 1398 | for (i = 0; i < subtable->n_indices; i++) { |
f2c21402 | 1399 | cmap_destroy(&subtable->indices[i]); |
476f36e8 | 1400 | } |
f2c21402 JR |
1401 | cmap_remove(&cls->subtables_map, &subtable->cmap_node, |
1402 | minimask_hash(&subtable->mask, 0)); | |
fe7cfa5c | 1403 | minimask_destroy(&subtable->mask); |
f2c21402 | 1404 | cmap_destroy(&subtable->rules); |
fe7cfa5c | 1405 | ovsrcu_postpone(free, subtable); |
4aacd02d BP |
1406 | } |
1407 | ||
13751fd8 JR |
1408 | struct range { |
1409 | uint8_t start; | |
1410 | uint8_t end; | |
1411 | }; | |
1412 | ||
c0bfb650 JR |
1413 | static unsigned int be_get_bit_at(const ovs_be32 value[], unsigned int ofs); |
1414 | ||
13751fd8 JR |
1415 | /* Return 'true' if can skip rest of the subtable based on the prefix trie |
1416 | * lookup results. */ | |
1417 | static inline bool | |
1418 | check_tries(struct trie_ctx trie_ctx[CLS_MAX_TRIES], unsigned int n_tries, | |
1419 | const unsigned int field_plen[CLS_MAX_TRIES], | |
1420 | const struct range ofs, const struct flow *flow, | |
1421 | struct flow_wildcards *wc) | |
1422 | { | |
1423 | int j; | |
1424 | ||
1425 | /* Check if we could avoid fully unwildcarding the next level of | |
1426 | * fields using the prefix tries. The trie checks are done only as | |
1427 | * needed to avoid folding in additional bits to the wildcards mask. */ | |
1428 | for (j = 0; j < n_tries; j++) { | |
1429 | /* Is the trie field relevant for this subtable? */ | |
1430 | if (field_plen[j]) { | |
1431 | struct trie_ctx *ctx = &trie_ctx[j]; | |
1432 | uint8_t be32ofs = ctx->be32ofs; | |
1433 | ||
1434 | /* Is the trie field within the current range of fields? */ | |
1435 | if (be32ofs >= ofs.start && be32ofs < ofs.end) { | |
1436 | /* On-demand trie lookup. */ | |
1437 | if (!ctx->lookup_done) { | |
c0bfb650 JR |
1438 | memset(&ctx->match_plens, 0, sizeof ctx->match_plens); |
1439 | ctx->maskbits = trie_lookup(ctx->trie, flow, | |
1440 | &ctx->match_plens); | |
13751fd8 JR |
1441 | ctx->lookup_done = true; |
1442 | } | |
1443 | /* Possible to skip the rest of the subtable if subtable's | |
c0bfb650 JR |
1444 | * prefix on the field is not included in the lookup result. */ |
1445 | if (!be_get_bit_at(&ctx->match_plens.be32, field_plen[j] - 1)) { | |
1817dcea JR |
1446 | /* We want the trie lookup to never result in unwildcarding |
1447 | * any bits that would not be unwildcarded otherwise. | |
1448 | * Since the trie is shared by the whole classifier, it is | |
1449 | * possible that the 'maskbits' contain bits that are | |
1450 | * irrelevant for the partition relevant for the current | |
1451 | * packet. Hence the checks below. */ | |
13751fd8 | 1452 | |
13751fd8 | 1453 | /* Check that the trie result will not unwildcard more bits |
1817dcea | 1454 | * than this subtable would otherwise. */ |
13751fd8 JR |
1455 | if (ctx->maskbits <= field_plen[j]) { |
1456 | /* Unwildcard the bits and skip the rest. */ | |
1457 | mask_set_prefix_bits(wc, be32ofs, ctx->maskbits); | |
1458 | /* Note: Prerequisite already unwildcarded, as the only | |
1459 | * prerequisite of the supported trie lookup fields is | |
1817dcea JR |
1460 | * the ethertype, which is always unwildcarded. */ |
1461 | return true; | |
1462 | } | |
1463 | /* Can skip if the field is already unwildcarded. */ | |
1464 | if (mask_prefix_bits_set(wc, be32ofs, ctx->maskbits)) { | |
13751fd8 JR |
1465 | return true; |
1466 | } | |
1467 | } | |
1468 | } | |
1469 | } | |
1470 | } | |
1471 | return false; | |
1472 | } | |
1473 | ||
3016f3e4 JR |
1474 | /* Returns true if 'target' satisifies 'flow'/'mask', that is, if each bit |
1475 | * for which 'flow', for which 'mask' has a bit set, specifies a particular | |
1476 | * value has the correct value in 'target'. | |
1477 | * | |
1478 | * This function is equivalent to miniflow_equal_flow_in_minimask(flow, | |
a64759f0 JR |
1479 | * target, mask) but this is faster because of the invariant that |
1480 | * flow->map and mask->masks.map are the same, and that this version | |
1481 | * takes the 'wc'. */ | |
3016f3e4 JR |
1482 | static inline bool |
1483 | miniflow_and_mask_matches_flow(const struct miniflow *flow, | |
1484 | const struct minimask *mask, | |
e9319757 | 1485 | const struct flow *target) |
3016f3e4 JR |
1486 | { |
1487 | const uint32_t *flowp = miniflow_get_u32_values(flow); | |
1488 | const uint32_t *maskp = miniflow_get_u32_values(&mask->masks); | |
a64759f0 | 1489 | uint32_t idx; |
3016f3e4 | 1490 | |
a64759f0 JR |
1491 | MAP_FOR_EACH_INDEX(idx, mask->masks.map) { |
1492 | uint32_t diff = (*flowp++ ^ flow_u32_value(target, idx)) & *maskp++; | |
1493 | ||
1494 | if (diff) { | |
3016f3e4 JR |
1495 | return false; |
1496 | } | |
1497 | } | |
1498 | ||
1499 | return true; | |
1500 | } | |
1501 | ||
627fb667 | 1502 | static inline struct cls_match * |
476f36e8 JR |
1503 | find_match(const struct cls_subtable *subtable, const struct flow *flow, |
1504 | uint32_t hash) | |
b5d97350 | 1505 | { |
627fb667 | 1506 | struct cls_match *rule; |
b5d97350 | 1507 | |
f2c21402 | 1508 | CMAP_FOR_EACH_WITH_HASH (rule, cmap_node, hash, &subtable->rules) { |
3016f3e4 | 1509 | if (miniflow_and_mask_matches_flow(&rule->flow, &subtable->mask, |
e9319757 | 1510 | flow)) { |
b5d97350 | 1511 | return rule; |
064af421 BP |
1512 | } |
1513 | } | |
c23740be | 1514 | |
064af421 BP |
1515 | return NULL; |
1516 | } | |
1517 | ||
e9319757 JR |
1518 | /* Returns true if 'target' satisifies 'flow'/'mask', that is, if each bit |
1519 | * for which 'flow', for which 'mask' has a bit set, specifies a particular | |
1520 | * value has the correct value in 'target'. | |
1521 | * | |
1522 | * This function is equivalent to miniflow_and_mask_matches_flow() but this | |
1523 | * version fills in the mask bits in 'wc'. */ | |
1524 | static inline bool | |
1525 | miniflow_and_mask_matches_flow_wc(const struct miniflow *flow, | |
1526 | const struct minimask *mask, | |
1527 | const struct flow *target, | |
1528 | struct flow_wildcards *wc) | |
1529 | { | |
1530 | const uint32_t *flowp = miniflow_get_u32_values(flow); | |
1531 | const uint32_t *maskp = miniflow_get_u32_values(&mask->masks); | |
1532 | uint32_t idx; | |
1533 | ||
1534 | MAP_FOR_EACH_INDEX(idx, mask->masks.map) { | |
1535 | uint32_t mask = *maskp++; | |
1536 | uint32_t diff = (*flowp++ ^ flow_u32_value(target, idx)) & mask; | |
1537 | ||
1538 | if (diff) { | |
1539 | /* Only unwildcard if none of the differing bits is already | |
1540 | * exact-matched. */ | |
1541 | if (!(flow_u32_value(&wc->masks, idx) & diff)) { | |
1542 | /* Keep one bit of the difference. */ | |
1543 | *flow_u32_lvalue(&wc->masks, idx) |= rightmost_1bit(diff); | |
1544 | } | |
1545 | return false; | |
1546 | } | |
1547 | /* Fill in the bits that were looked at. */ | |
1548 | *flow_u32_lvalue(&wc->masks, idx) |= mask; | |
1549 | } | |
1550 | ||
1551 | return true; | |
1552 | } | |
1553 | ||
386cb9f7 JR |
1554 | /* Unwildcard the fields looked up so far, if any. */ |
1555 | static void | |
1556 | fill_range_wc(const struct cls_subtable *subtable, struct flow_wildcards *wc, | |
1557 | uint8_t to) | |
1558 | { | |
1559 | if (to) { | |
1560 | flow_wildcards_fold_minimask_range(wc, &subtable->mask, 0, to); | |
1561 | } | |
1562 | } | |
1563 | ||
627fb667 | 1564 | static struct cls_match * |
476f36e8 | 1565 | find_match_wc(const struct cls_subtable *subtable, const struct flow *flow, |
13751fd8 JR |
1566 | struct trie_ctx trie_ctx[CLS_MAX_TRIES], unsigned int n_tries, |
1567 | struct flow_wildcards *wc) | |
476f36e8 JR |
1568 | { |
1569 | uint32_t basis = 0, hash; | |
a64759f0 | 1570 | struct cls_match *rule; |
476f36e8 | 1571 | int i; |
13751fd8 | 1572 | struct range ofs; |
476f36e8 | 1573 | |
ec988646 | 1574 | if (OVS_UNLIKELY(!wc)) { |
476f36e8 JR |
1575 | return find_match(subtable, flow, |
1576 | flow_hash_in_minimask(flow, &subtable->mask, 0)); | |
1577 | } | |
1578 | ||
13751fd8 | 1579 | ofs.start = 0; |
476f36e8 JR |
1580 | /* Try to finish early by checking fields in segments. */ |
1581 | for (i = 0; i < subtable->n_indices; i++) { | |
f2c21402 JR |
1582 | struct cmap_node *inode; |
1583 | ||
13751fd8 | 1584 | ofs.end = subtable->index_ofs[i]; |
476f36e8 | 1585 | |
13751fd8 JR |
1586 | if (check_tries(trie_ctx, n_tries, subtable->trie_plen, ofs, flow, |
1587 | wc)) { | |
386cb9f7 JR |
1588 | /* 'wc' bits for the trie field set, now unwildcard the preceding |
1589 | * bits used so far. */ | |
1590 | fill_range_wc(subtable, wc, ofs.start); | |
1591 | return NULL; | |
13751fd8 JR |
1592 | } |
1593 | hash = flow_hash_in_minimask_range(flow, &subtable->mask, ofs.start, | |
1594 | ofs.end, &basis); | |
f2c21402 | 1595 | inode = cmap_find(&subtable->indices[i], hash); |
476f36e8 | 1596 | if (!inode) { |
386cb9f7 JR |
1597 | /* No match, can stop immediately, but must fold in the bits |
1598 | * used in lookup so far. */ | |
1599 | fill_range_wc(subtable, wc, ofs.end); | |
1600 | return NULL; | |
476f36e8 JR |
1601 | } |
1602 | ||
1603 | /* If we have narrowed down to a single rule already, check whether | |
a64759f0 | 1604 | * that rule matches. Either way, we're done. |
476f36e8 JR |
1605 | * |
1606 | * (Rare) hash collisions may cause us to miss the opportunity for this | |
1607 | * optimization. */ | |
f2c21402 | 1608 | if (!cmap_node_next(inode)) { |
476f36e8 | 1609 | ASSIGN_CONTAINER(rule, inode - i, index_nodes); |
e9319757 JR |
1610 | if (miniflow_and_mask_matches_flow_wc(&rule->flow, &subtable->mask, |
1611 | flow, wc)) { | |
1612 | return rule; | |
476f36e8 | 1613 | } |
e9319757 | 1614 | return NULL; |
476f36e8 | 1615 | } |
386cb9f7 | 1616 | ofs.start = ofs.end; |
476f36e8 | 1617 | } |
13751fd8 JR |
1618 | ofs.end = FLOW_U32S; |
1619 | /* Trie check for the final range. */ | |
1620 | if (check_tries(trie_ctx, n_tries, subtable->trie_plen, ofs, flow, wc)) { | |
386cb9f7 JR |
1621 | fill_range_wc(subtable, wc, ofs.start); |
1622 | return NULL; | |
13751fd8 | 1623 | } |
a64759f0 JR |
1624 | hash = flow_hash_in_minimask_range(flow, &subtable->mask, ofs.start, |
1625 | ofs.end, &basis); | |
1626 | rule = find_match(subtable, flow, hash); | |
69d6040e JR |
1627 | if (!rule && subtable->ports_mask_len) { |
1628 | /* Ports are always part of the final range, if any. | |
1629 | * No match was found for the ports. Use the ports trie to figure out | |
1630 | * which ports bits to unwildcard. */ | |
1631 | unsigned int mbits; | |
c0bfb650 | 1632 | ovs_be32 value, plens, mask; |
69d6040e JR |
1633 | |
1634 | mask = MINIFLOW_GET_BE32(&subtable->mask.masks, tp_src); | |
1635 | value = ((OVS_FORCE ovs_be32 *)flow)[TP_PORTS_OFS32] & mask; | |
c0bfb650 | 1636 | mbits = trie_lookup_value(&subtable->ports_trie, &value, &plens, 32); |
69d6040e JR |
1637 | |
1638 | ((OVS_FORCE ovs_be32 *)&wc->masks)[TP_PORTS_OFS32] |= | |
1639 | mask & htonl(~0 << (32 - mbits)); | |
1640 | ||
386cb9f7 JR |
1641 | /* Unwildcard all bits in the mask upto the ports, as they were used |
1642 | * to determine there is no match. */ | |
1643 | fill_range_wc(subtable, wc, TP_PORTS_OFS32); | |
1644 | return NULL; | |
69d6040e | 1645 | } |
e9319757 | 1646 | |
13751fd8 | 1647 | /* Must unwildcard all the fields, as they were looked at. */ |
476f36e8 JR |
1648 | flow_wildcards_fold_minimask(wc, &subtable->mask); |
1649 | return rule; | |
1650 | } | |
1651 | ||
627fb667 | 1652 | static struct cls_match * |
03868246 JR |
1653 | find_equal(struct cls_subtable *subtable, const struct miniflow *flow, |
1654 | uint32_t hash) | |
064af421 | 1655 | { |
627fb667 | 1656 | struct cls_match *head; |
064af421 | 1657 | |
f2c21402 | 1658 | CMAP_FOR_EACH_WITH_HASH (head, cmap_node, hash, &subtable->rules) { |
3016f3e4 | 1659 | if (miniflow_equal(&head->flow, flow)) { |
b5d97350 | 1660 | return head; |
064af421 BP |
1661 | } |
1662 | } | |
1663 | return NULL; | |
1664 | } | |
1665 | ||
afae68b1 JR |
1666 | /* |
1667 | * As the readers are operating concurrently with the modifications, a | |
1668 | * concurrent reader may or may not see the new rule, depending on how | |
1669 | * the concurrent events overlap with each other. This is no | |
1670 | * different from the former locked behavior, but there the visibility | |
1671 | * of the new rule only depended on the timing of the locking | |
1672 | * functions. | |
1673 | * | |
1674 | * The new rule is first added to the segment indices, so the readers | |
1675 | * may find the rule in the indices before the rule is visible in the | |
1676 | * subtables 'rules' map. This may result in us losing the | |
1677 | * opportunity to quit lookups earlier, resulting in sub-optimal | |
1678 | * wildcarding. This will be fixed by forthcoming revalidation always | |
1679 | * scheduled after flow table changes. | |
1680 | * | |
1681 | * Similar behavior may happen due to us removing the overlapping rule | |
1682 | * (if any) from the indices only after the new rule has been added. | |
1683 | * | |
1684 | * The subtable's max priority is updated only after the rule is | |
1685 | * inserted, so the concurrent readers may not see the rule, as the | |
1686 | * updated priority ordered subtable list will only be visible after | |
1687 | * the subtable's max priority is updated. | |
1688 | * | |
1689 | * Similarly, the classifier's partitions for new rules are updated by | |
1690 | * the caller after this function, so the readers may keep skipping | |
1691 | * the subtable until they see the updated partitions. | |
1692 | */ | |
627fb667 | 1693 | static struct cls_match * |
e48eccd1 | 1694 | insert_rule(struct classifier *cls, struct cls_subtable *subtable, |
f2c21402 | 1695 | struct cls_rule *new_rule) |
e65413ab | 1696 | OVS_REQUIRES(cls->mutex) |
064af421 | 1697 | { |
627fb667 | 1698 | struct cls_match *old = NULL; |
f2c21402 JR |
1699 | struct cls_match *new = cls_match_alloc(new_rule); |
1700 | struct cls_match *head; | |
476f36e8 | 1701 | int i; |
f2c21402 | 1702 | uint32_t basis = 0, hash, ihash[CLS_MAX_INDICES]; |
13751fd8 | 1703 | uint8_t prev_be32ofs = 0; |
476f36e8 JR |
1704 | |
1705 | /* Add new node to segment indices. */ | |
1706 | for (i = 0; i < subtable->n_indices; i++) { | |
f2c21402 JR |
1707 | ihash[i] = minimatch_hash_range(&new_rule->match, prev_be32ofs, |
1708 | subtable->index_ofs[i], &basis); | |
1709 | cmap_insert(&subtable->indices[i], &new->index_nodes[i], ihash[i]); | |
13751fd8 | 1710 | prev_be32ofs = subtable->index_ofs[i]; |
476f36e8 | 1711 | } |
f2c21402 JR |
1712 | hash = minimatch_hash_range(&new_rule->match, prev_be32ofs, FLOW_U32S, |
1713 | &basis); | |
1714 | head = find_equal(subtable, &new_rule->match.flow, hash); | |
b5d97350 | 1715 | if (!head) { |
f2c21402 JR |
1716 | cmap_insert(&subtable->rules, &new->cmap_node, hash); |
1717 | list_init(&new->list); | |
4aacd02d | 1718 | goto out; |
b5d97350 BP |
1719 | } else { |
1720 | /* Scan the list for the insertion point that will keep the list in | |
1721 | * order of decreasing priority. */ | |
627fb667 | 1722 | struct cls_match *rule; |
476f36e8 | 1723 | |
b5d97350 | 1724 | FOR_EACH_RULE_IN_LIST (rule, head) { |
f2c21402 | 1725 | if (new->priority >= rule->priority) { |
b5d97350 | 1726 | if (rule == head) { |
f2c21402 JR |
1727 | /* 'new' is the new highest-priority flow in the list. */ |
1728 | cmap_replace(&subtable->rules, &rule->cmap_node, | |
1729 | &new->cmap_node, hash); | |
b5d97350 | 1730 | } |
064af421 | 1731 | |
f2c21402 JR |
1732 | if (new->priority == rule->priority) { |
1733 | list_replace(&new->list, &rule->list); | |
4aacd02d | 1734 | old = rule; |
b5d97350 | 1735 | } else { |
f2c21402 | 1736 | list_insert(&rule->list, &new->list); |
b5d97350 | 1737 | } |
fe7cfa5c | 1738 | goto out; |
b5d97350 BP |
1739 | } |
1740 | } | |
064af421 | 1741 | |
b5d97350 | 1742 | /* Insert 'new' at the end of the list. */ |
f2c21402 | 1743 | list_push_back(&head->list, &new->list); |
064af421 | 1744 | } |
4aacd02d BP |
1745 | |
1746 | out: | |
1747 | if (!old) { | |
fe7cfa5c JR |
1748 | subtable->n_rules++; |
1749 | ||
1750 | /* Rule was added, not replaced. Update 'subtable's 'max_priority' | |
1751 | * and 'max_count', if necessary. */ | |
1752 | if (subtable->n_rules == 1) { | |
f2c21402 | 1753 | subtable->max_priority = new->priority; |
fe7cfa5c | 1754 | subtable->max_count = 1; |
f2c21402 JR |
1755 | pvector_insert(&cls->subtables, subtable, new->priority); |
1756 | } else if (subtable->max_priority == new->priority) { | |
fe7cfa5c | 1757 | ++subtable->max_count; |
f2c21402 JR |
1758 | } else if (new->priority > subtable->max_priority) { |
1759 | subtable->max_priority = new->priority; | |
fe7cfa5c | 1760 | subtable->max_count = 1; |
f2c21402 | 1761 | pvector_change_priority(&cls->subtables, subtable, new->priority); |
fe7cfa5c | 1762 | } |
476f36e8 JR |
1763 | } else { |
1764 | /* Remove old node from indices. */ | |
1765 | for (i = 0; i < subtable->n_indices; i++) { | |
f2c21402 | 1766 | cmap_remove(&subtable->indices[i], &old->index_nodes[i], ihash[i]); |
476f36e8 | 1767 | } |
4aacd02d BP |
1768 | } |
1769 | return old; | |
064af421 BP |
1770 | } |
1771 | ||
627fb667 JR |
1772 | static struct cls_match * |
1773 | next_rule_in_list__(struct cls_match *rule) | |
e65413ab | 1774 | OVS_NO_THREAD_SAFETY_ANALYSIS |
064af421 | 1775 | { |
627fb667 | 1776 | struct cls_match *next = OBJECT_CONTAINING(rule->list.next, next, list); |
955f579d BP |
1777 | return next; |
1778 | } | |
1779 | ||
627fb667 JR |
1780 | static struct cls_match * |
1781 | next_rule_in_list(struct cls_match *rule) | |
955f579d | 1782 | { |
627fb667 | 1783 | struct cls_match *next = next_rule_in_list__(rule); |
b5d97350 | 1784 | return next->priority < rule->priority ? next : NULL; |
064af421 | 1785 | } |
13751fd8 JR |
1786 | \f |
1787 | /* A longest-prefix match tree. */ | |
1788 | struct trie_node { | |
1789 | uint32_t prefix; /* Prefix bits for this node, MSB first. */ | |
c30cfa6b | 1790 | uint8_t n_bits; /* Never zero, except for the root node. */ |
13751fd8 | 1791 | unsigned int n_rules; /* Number of rules that have this prefix. */ |
f358a2cb | 1792 | rcu_trie_ptr edges[2]; /* Both NULL if leaf. */ |
13751fd8 JR |
1793 | }; |
1794 | ||
1795 | /* Max bits per node. Must fit in struct trie_node's 'prefix'. | |
1796 | * Also tested with 16, 8, and 5 to stress the implementation. */ | |
1797 | #define TRIE_PREFIX_BITS 32 | |
1798 | ||
1799 | /* Return at least 'plen' bits of the 'prefix', starting at bit offset 'ofs'. | |
1800 | * Prefixes are in the network byte order, and the offset 0 corresponds to | |
1801 | * the most significant bit of the first byte. The offset can be read as | |
1802 | * "how many bits to skip from the start of the prefix starting at 'pr'". */ | |
1803 | static uint32_t | |
1804 | raw_get_prefix(const ovs_be32 pr[], unsigned int ofs, unsigned int plen) | |
1805 | { | |
1806 | uint32_t prefix; | |
1807 | ||
1808 | pr += ofs / 32; /* Where to start. */ | |
1809 | ofs %= 32; /* How many bits to skip at 'pr'. */ | |
1810 | ||
1811 | prefix = ntohl(*pr) << ofs; /* Get the first 32 - ofs bits. */ | |
1812 | if (plen > 32 - ofs) { /* Need more than we have already? */ | |
1813 | prefix |= ntohl(*++pr) >> (32 - ofs); | |
1814 | } | |
1815 | /* Return with possible unwanted bits at the end. */ | |
1816 | return prefix; | |
1817 | } | |
1818 | ||
1819 | /* Return min(TRIE_PREFIX_BITS, plen) bits of the 'prefix', starting at bit | |
1820 | * offset 'ofs'. Prefixes are in the network byte order, and the offset 0 | |
1821 | * corresponds to the most significant bit of the first byte. The offset can | |
1822 | * be read as "how many bits to skip from the start of the prefix starting at | |
1823 | * 'pr'". */ | |
1824 | static uint32_t | |
1825 | trie_get_prefix(const ovs_be32 pr[], unsigned int ofs, unsigned int plen) | |
1826 | { | |
1827 | if (!plen) { | |
1828 | return 0; | |
1829 | } | |
1830 | if (plen > TRIE_PREFIX_BITS) { | |
1831 | plen = TRIE_PREFIX_BITS; /* Get at most TRIE_PREFIX_BITS. */ | |
1832 | } | |
1833 | /* Return with unwanted bits cleared. */ | |
1834 | return raw_get_prefix(pr, ofs, plen) & ~0u << (32 - plen); | |
1835 | } | |
1836 | ||
c30cfa6b | 1837 | /* Return the number of equal bits in 'n_bits' of 'prefix's MSBs and a 'value' |
13751fd8 JR |
1838 | * starting at "MSB 0"-based offset 'ofs'. */ |
1839 | static unsigned int | |
c30cfa6b | 1840 | prefix_equal_bits(uint32_t prefix, unsigned int n_bits, const ovs_be32 value[], |
13751fd8 JR |
1841 | unsigned int ofs) |
1842 | { | |
c30cfa6b | 1843 | uint64_t diff = prefix ^ raw_get_prefix(value, ofs, n_bits); |
13751fd8 | 1844 | /* Set the bit after the relevant bits to limit the result. */ |
c30cfa6b | 1845 | return raw_clz64(diff << 32 | UINT64_C(1) << (63 - n_bits)); |
13751fd8 JR |
1846 | } |
1847 | ||
1848 | /* Return the number of equal bits in 'node' prefix and a 'prefix' of length | |
1849 | * 'plen', starting at "MSB 0"-based offset 'ofs'. */ | |
1850 | static unsigned int | |
1851 | trie_prefix_equal_bits(const struct trie_node *node, const ovs_be32 prefix[], | |
1852 | unsigned int ofs, unsigned int plen) | |
1853 | { | |
c30cfa6b | 1854 | return prefix_equal_bits(node->prefix, MIN(node->n_bits, plen - ofs), |
13751fd8 JR |
1855 | prefix, ofs); |
1856 | } | |
1857 | ||
1858 | /* Return the bit at ("MSB 0"-based) offset 'ofs' as an int. 'ofs' can | |
1859 | * be greater than 31. */ | |
1860 | static unsigned int | |
1861 | be_get_bit_at(const ovs_be32 value[], unsigned int ofs) | |
1862 | { | |
1863 | return (((const uint8_t *)value)[ofs / 8] >> (7 - ofs % 8)) & 1u; | |
1864 | } | |
1865 | ||
1866 | /* Return the bit at ("MSB 0"-based) offset 'ofs' as an int. 'ofs' must | |
1867 | * be between 0 and 31, inclusive. */ | |
1868 | static unsigned int | |
1869 | get_bit_at(const uint32_t prefix, unsigned int ofs) | |
1870 | { | |
1871 | return (prefix >> (31 - ofs)) & 1u; | |
1872 | } | |
1873 | ||
1874 | /* Create new branch. */ | |
1875 | static struct trie_node * | |
1876 | trie_branch_create(const ovs_be32 *prefix, unsigned int ofs, unsigned int plen, | |
1877 | unsigned int n_rules) | |
1878 | { | |
1879 | struct trie_node *node = xmalloc(sizeof *node); | |
1880 | ||
1881 | node->prefix = trie_get_prefix(prefix, ofs, plen); | |
1882 | ||
1883 | if (plen <= TRIE_PREFIX_BITS) { | |
c30cfa6b | 1884 | node->n_bits = plen; |
f358a2cb JR |
1885 | ovsrcu_set_hidden(&node->edges[0], NULL); |
1886 | ovsrcu_set_hidden(&node->edges[1], NULL); | |
13751fd8 JR |
1887 | node->n_rules = n_rules; |
1888 | } else { /* Need intermediate nodes. */ | |
1889 | struct trie_node *subnode = trie_branch_create(prefix, | |
1890 | ofs + TRIE_PREFIX_BITS, | |
1891 | plen - TRIE_PREFIX_BITS, | |
1892 | n_rules); | |
1893 | int bit = get_bit_at(subnode->prefix, 0); | |
c30cfa6b | 1894 | node->n_bits = TRIE_PREFIX_BITS; |
f358a2cb JR |
1895 | ovsrcu_set_hidden(&node->edges[bit], subnode); |
1896 | ovsrcu_set_hidden(&node->edges[!bit], NULL); | |
13751fd8 JR |
1897 | node->n_rules = 0; |
1898 | } | |
1899 | return node; | |
1900 | } | |
1901 | ||
1902 | static void | |
f358a2cb | 1903 | trie_node_destroy(const struct trie_node *node) |
13751fd8 | 1904 | { |
f358a2cb JR |
1905 | ovsrcu_postpone(free, CONST_CAST(struct trie_node *, node)); |
1906 | } | |
1907 | ||
1908 | /* Copy a trie node for modification and postpone delete the old one. */ | |
1909 | static struct trie_node * | |
1910 | trie_node_rcu_realloc(const struct trie_node *node) | |
1911 | { | |
1912 | struct trie_node *new_node = xmalloc(sizeof *node); | |
1913 | ||
1914 | *new_node = *node; | |
1915 | trie_node_destroy(node); | |
1916 | ||
1917 | return new_node; | |
13751fd8 JR |
1918 | } |
1919 | ||
e48eccd1 | 1920 | /* May only be called while holding the classifier mutex. */ |
13751fd8 | 1921 | static void |
f358a2cb | 1922 | trie_destroy(rcu_trie_ptr *trie) |
13751fd8 | 1923 | { |
f358a2cb JR |
1924 | struct trie_node *node = ovsrcu_get_protected(struct trie_node *, trie); |
1925 | ||
13751fd8 | 1926 | if (node) { |
f358a2cb JR |
1927 | ovsrcu_set_hidden(trie, NULL); |
1928 | trie_destroy(&node->edges[0]); | |
1929 | trie_destroy(&node->edges[1]); | |
1930 | trie_node_destroy(node); | |
13751fd8 JR |
1931 | } |
1932 | } | |
1933 | ||
1934 | static bool | |
1935 | trie_is_leaf(const struct trie_node *trie) | |
1936 | { | |
f358a2cb JR |
1937 | /* No children? */ |
1938 | return !ovsrcu_get(struct trie_node *, &trie->edges[0]) | |
1939 | && !ovsrcu_get(struct trie_node *, &trie->edges[1]); | |
13751fd8 JR |
1940 | } |
1941 | ||
1942 | static void | |
1943 | mask_set_prefix_bits(struct flow_wildcards *wc, uint8_t be32ofs, | |
c30cfa6b | 1944 | unsigned int n_bits) |
13751fd8 JR |
1945 | { |
1946 | ovs_be32 *mask = &((ovs_be32 *)&wc->masks)[be32ofs]; | |
1947 | unsigned int i; | |
1948 | ||
c30cfa6b | 1949 | for (i = 0; i < n_bits / 32; i++) { |
13751fd8 JR |
1950 | mask[i] = OVS_BE32_MAX; |
1951 | } | |
c30cfa6b JR |
1952 | if (n_bits % 32) { |
1953 | mask[i] |= htonl(~0u << (32 - n_bits % 32)); | |
13751fd8 JR |
1954 | } |
1955 | } | |
1956 | ||
1957 | static bool | |
1958 | mask_prefix_bits_set(const struct flow_wildcards *wc, uint8_t be32ofs, | |
c30cfa6b | 1959 | unsigned int n_bits) |
13751fd8 JR |
1960 | { |
1961 | ovs_be32 *mask = &((ovs_be32 *)&wc->masks)[be32ofs]; | |
1962 | unsigned int i; | |
1963 | ovs_be32 zeroes = 0; | |
1964 | ||
c30cfa6b | 1965 | for (i = 0; i < n_bits / 32; i++) { |
13751fd8 JR |
1966 | zeroes |= ~mask[i]; |
1967 | } | |
c30cfa6b JR |
1968 | if (n_bits % 32) { |
1969 | zeroes |= ~mask[i] & htonl(~0u << (32 - n_bits % 32)); | |
13751fd8 JR |
1970 | } |
1971 | ||
c30cfa6b | 1972 | return !zeroes; /* All 'n_bits' bits set. */ |
13751fd8 JR |
1973 | } |
1974 | ||
f358a2cb | 1975 | static rcu_trie_ptr * |
13751fd8 JR |
1976 | trie_next_edge(struct trie_node *node, const ovs_be32 value[], |
1977 | unsigned int ofs) | |
1978 | { | |
1979 | return node->edges + be_get_bit_at(value, ofs); | |
1980 | } | |
1981 | ||
1982 | static const struct trie_node * | |
1983 | trie_next_node(const struct trie_node *node, const ovs_be32 value[], | |
1984 | unsigned int ofs) | |
1985 | { | |
f358a2cb JR |
1986 | return ovsrcu_get(struct trie_node *, |
1987 | &node->edges[be_get_bit_at(value, ofs)]); | |
13751fd8 JR |
1988 | } |
1989 | ||
c0bfb650 JR |
1990 | /* Set the bit at ("MSB 0"-based) offset 'ofs'. 'ofs' can be greater than 31. |
1991 | */ | |
1992 | static void | |
1993 | be_set_bit_at(ovs_be32 value[], unsigned int ofs) | |
1994 | { | |
1995 | ((uint8_t *)value)[ofs / 8] |= 1u << (7 - ofs % 8); | |
1996 | } | |
1997 | ||
1998 | /* Returns the number of bits in the prefix mask necessary to determine a | |
1999 | * mismatch, in case there are longer prefixes in the tree below the one that | |
2000 | * matched. | |
2001 | * '*plens' will have a bit set for each prefix length that may have matching | |
2002 | * rules. The caller is responsible for clearing the '*plens' prior to | |
2003 | * calling this. | |
13751fd8 JR |
2004 | */ |
2005 | static unsigned int | |
f358a2cb | 2006 | trie_lookup_value(const rcu_trie_ptr *trie, const ovs_be32 value[], |
c0bfb650 | 2007 | ovs_be32 plens[], unsigned int n_bits) |
13751fd8 | 2008 | { |
13751fd8 | 2009 | const struct trie_node *prev = NULL; |
c0bfb650 JR |
2010 | const struct trie_node *node = ovsrcu_get(struct trie_node *, trie); |
2011 | unsigned int match_len = 0; /* Number of matching bits. */ | |
13751fd8 | 2012 | |
27ce650f | 2013 | for (; node; prev = node, node = trie_next_node(node, value, match_len)) { |
13751fd8 JR |
2014 | unsigned int eqbits; |
2015 | /* Check if this edge can be followed. */ | |
27ce650f JR |
2016 | eqbits = prefix_equal_bits(node->prefix, node->n_bits, value, |
2017 | match_len); | |
2018 | match_len += eqbits; | |
c30cfa6b | 2019 | if (eqbits < node->n_bits) { /* Mismatch, nothing more to be found. */ |
27ce650f | 2020 | /* Bit at offset 'match_len' differed. */ |
c0bfb650 | 2021 | return match_len + 1; /* Includes the first mismatching bit. */ |
13751fd8 JR |
2022 | } |
2023 | /* Full match, check if rules exist at this prefix length. */ | |
2024 | if (node->n_rules > 0) { | |
c0bfb650 | 2025 | be_set_bit_at(plens, match_len - 1); |
13751fd8 | 2026 | } |
27ce650f | 2027 | if (match_len >= n_bits) { |
c0bfb650 | 2028 | return n_bits; /* Full prefix. */ |
f0e5aa11 | 2029 | } |
13751fd8 | 2030 | } |
c0bfb650 JR |
2031 | /* node == NULL. Full match so far, but we tried to follow an |
2032 | * non-existing branch. Need to exclude the other branch if it exists | |
2033 | * (it does not if we were called on an empty trie or 'prev' is a leaf | |
2034 | * node). */ | |
2035 | return !prev || trie_is_leaf(prev) ? match_len : match_len + 1; | |
13751fd8 JR |
2036 | } |
2037 | ||
2038 | static unsigned int | |
2039 | trie_lookup(const struct cls_trie *trie, const struct flow *flow, | |
c0bfb650 | 2040 | union mf_value *plens) |
13751fd8 JR |
2041 | { |
2042 | const struct mf_field *mf = trie->field; | |
2043 | ||
2044 | /* Check that current flow matches the prerequisites for the trie | |
2045 | * field. Some match fields are used for multiple purposes, so we | |
2046 | * must check that the trie is relevant for this flow. */ | |
2047 | if (mf_are_prereqs_ok(mf, flow)) { | |
f358a2cb | 2048 | return trie_lookup_value(&trie->root, |
13751fd8 | 2049 | &((ovs_be32 *)flow)[mf->flow_be32ofs], |
c0bfb650 | 2050 | &plens->be32, mf->n_bits); |
13751fd8 | 2051 | } |
c0bfb650 JR |
2052 | memset(plens, 0xff, sizeof *plens); /* All prefixes, no skipping. */ |
2053 | return 0; /* Value not used in this case. */ | |
13751fd8 JR |
2054 | } |
2055 | ||
2056 | /* Returns the length of a prefix match mask for the field 'mf' in 'minimask'. | |
2057 | * Returns the u32 offset to the miniflow data in '*miniflow_index', if | |
2058 | * 'miniflow_index' is not NULL. */ | |
2059 | static unsigned int | |
2060 | minimask_get_prefix_len(const struct minimask *minimask, | |
2061 | const struct mf_field *mf) | |
2062 | { | |
c30cfa6b | 2063 | unsigned int n_bits = 0, mask_tz = 0; /* Non-zero when end of mask seen. */ |
13751fd8 JR |
2064 | uint8_t u32_ofs = mf->flow_be32ofs; |
2065 | uint8_t u32_end = u32_ofs + mf->n_bytes / 4; | |
2066 | ||
2067 | for (; u32_ofs < u32_end; ++u32_ofs) { | |
2068 | uint32_t mask; | |
2069 | mask = ntohl((OVS_FORCE ovs_be32)minimask_get(minimask, u32_ofs)); | |
2070 | ||
2071 | /* Validate mask, count the mask length. */ | |
2072 | if (mask_tz) { | |
2073 | if (mask) { | |
2074 | return 0; /* No bits allowed after mask ended. */ | |
2075 | } | |
2076 | } else { | |
2077 | if (~mask & (~mask + 1)) { | |
2078 | return 0; /* Mask not contiguous. */ | |
2079 | } | |
2080 | mask_tz = ctz32(mask); | |
c30cfa6b | 2081 | n_bits += 32 - mask_tz; |
13751fd8 JR |
2082 | } |
2083 | } | |
2084 | ||
c30cfa6b | 2085 | return n_bits; |
13751fd8 JR |
2086 | } |
2087 | ||
2088 | /* | |
2089 | * This is called only when mask prefix is known to be CIDR and non-zero. | |
2090 | * Relies on the fact that the flow and mask have the same map, and since | |
2091 | * the mask is CIDR, the storage for the flow field exists even if it | |
2092 | * happened to be zeros. | |
2093 | */ | |
2094 | static const ovs_be32 * | |
2095 | minimatch_get_prefix(const struct minimatch *match, const struct mf_field *mf) | |
2096 | { | |
27bbe15d | 2097 | return miniflow_get_be32_values(&match->flow) + |
13751fd8 JR |
2098 | count_1bits(match->flow.map & ((UINT64_C(1) << mf->flow_be32ofs) - 1)); |
2099 | } | |
2100 | ||
2101 | /* Insert rule in to the prefix tree. | |
2102 | * 'mlen' must be the (non-zero) CIDR prefix length of the 'trie->field' mask | |
2103 | * in 'rule'. */ | |
2104 | static void | |
2105 | trie_insert(struct cls_trie *trie, const struct cls_rule *rule, int mlen) | |
2106 | { | |
69d6040e JR |
2107 | trie_insert_prefix(&trie->root, |
2108 | minimatch_get_prefix(&rule->match, trie->field), mlen); | |
2109 | } | |
2110 | ||
2111 | static void | |
f358a2cb | 2112 | trie_insert_prefix(rcu_trie_ptr *edge, const ovs_be32 *prefix, int mlen) |
69d6040e | 2113 | { |
13751fd8 | 2114 | struct trie_node *node; |
13751fd8 JR |
2115 | int ofs = 0; |
2116 | ||
2117 | /* Walk the tree. */ | |
f358a2cb | 2118 | for (; (node = ovsrcu_get_protected(struct trie_node *, edge)); |
13751fd8 JR |
2119 | edge = trie_next_edge(node, prefix, ofs)) { |
2120 | unsigned int eqbits = trie_prefix_equal_bits(node, prefix, ofs, mlen); | |
2121 | ofs += eqbits; | |
c30cfa6b | 2122 | if (eqbits < node->n_bits) { |
13751fd8 JR |
2123 | /* Mismatch, new node needs to be inserted above. */ |
2124 | int old_branch = get_bit_at(node->prefix, eqbits); | |
f358a2cb | 2125 | struct trie_node *new_parent; |
13751fd8 | 2126 | |
f358a2cb JR |
2127 | new_parent = trie_branch_create(prefix, ofs - eqbits, eqbits, |
2128 | ofs == mlen ? 1 : 0); | |
2129 | /* Copy the node to modify it. */ | |
2130 | node = trie_node_rcu_realloc(node); | |
2131 | /* Adjust the new node for its new position in the tree. */ | |
13751fd8 | 2132 | node->prefix <<= eqbits; |
c30cfa6b | 2133 | node->n_bits -= eqbits; |
f358a2cb | 2134 | ovsrcu_set_hidden(&new_parent->edges[old_branch], node); |
13751fd8 JR |
2135 | |
2136 | /* Check if need a new branch for the new rule. */ | |
2137 | if (ofs < mlen) { | |
f358a2cb JR |
2138 | ovsrcu_set_hidden(&new_parent->edges[!old_branch], |
2139 | trie_branch_create(prefix, ofs, mlen - ofs, | |
2140 | 1)); | |
13751fd8 | 2141 | } |
f358a2cb | 2142 | ovsrcu_set(edge, new_parent); /* Publish changes. */ |
13751fd8 JR |
2143 | return; |
2144 | } | |
2145 | /* Full match so far. */ | |
2146 | ||
2147 | if (ofs == mlen) { | |
2148 | /* Full match at the current node, rule needs to be added here. */ | |
2149 | node->n_rules++; | |
2150 | return; | |
2151 | } | |
2152 | } | |
2153 | /* Must insert a new tree branch for the new rule. */ | |
f358a2cb | 2154 | ovsrcu_set(edge, trie_branch_create(prefix, ofs, mlen - ofs, 1)); |
13751fd8 JR |
2155 | } |
2156 | ||
2157 | /* 'mlen' must be the (non-zero) CIDR prefix length of the 'trie->field' mask | |
2158 | * in 'rule'. */ | |
2159 | static void | |
2160 | trie_remove(struct cls_trie *trie, const struct cls_rule *rule, int mlen) | |
2161 | { | |
69d6040e JR |
2162 | trie_remove_prefix(&trie->root, |
2163 | minimatch_get_prefix(&rule->match, trie->field), mlen); | |
2164 | } | |
2165 | ||
2166 | /* 'mlen' must be the (non-zero) CIDR prefix length of the 'trie->field' mask | |
2167 | * in 'rule'. */ | |
2168 | static void | |
f358a2cb | 2169 | trie_remove_prefix(rcu_trie_ptr *root, const ovs_be32 *prefix, int mlen) |
69d6040e | 2170 | { |
13751fd8 | 2171 | struct trie_node *node; |
f358a2cb | 2172 | rcu_trie_ptr *edges[sizeof(union mf_value) * 8]; |
13751fd8 JR |
2173 | int depth = 0, ofs = 0; |
2174 | ||
2175 | /* Walk the tree. */ | |
69d6040e | 2176 | for (edges[0] = root; |
f358a2cb | 2177 | (node = ovsrcu_get_protected(struct trie_node *, edges[depth])); |
13751fd8 JR |
2178 | edges[++depth] = trie_next_edge(node, prefix, ofs)) { |
2179 | unsigned int eqbits = trie_prefix_equal_bits(node, prefix, ofs, mlen); | |
69d6040e | 2180 | |
c30cfa6b | 2181 | if (eqbits < node->n_bits) { |
13751fd8 JR |
2182 | /* Mismatch, nothing to be removed. This should never happen, as |
2183 | * only rules in the classifier are ever removed. */ | |
2184 | break; /* Log a warning. */ | |
2185 | } | |
2186 | /* Full match so far. */ | |
2187 | ofs += eqbits; | |
2188 | ||
2189 | if (ofs == mlen) { | |
2190 | /* Full prefix match at the current node, remove rule here. */ | |
2191 | if (!node->n_rules) { | |
2192 | break; /* Log a warning. */ | |
2193 | } | |
2194 | node->n_rules--; | |
2195 | ||
2196 | /* Check if can prune the tree. */ | |
f358a2cb JR |
2197 | while (!node->n_rules) { |
2198 | struct trie_node *next, | |
2199 | *edge0 = ovsrcu_get_protected(struct trie_node *, | |
2200 | &node->edges[0]), | |
2201 | *edge1 = ovsrcu_get_protected(struct trie_node *, | |
2202 | &node->edges[1]); | |
2203 | ||
2204 | if (edge0 && edge1) { | |
2205 | break; /* A branching point, cannot prune. */ | |
2206 | } | |
2207 | ||
2208 | /* Else have at most one child node, remove this node. */ | |
2209 | next = edge0 ? edge0 : edge1; | |
13751fd8 JR |
2210 | |
2211 | if (next) { | |
c30cfa6b | 2212 | if (node->n_bits + next->n_bits > TRIE_PREFIX_BITS) { |
13751fd8 JR |
2213 | break; /* Cannot combine. */ |
2214 | } | |
f358a2cb JR |
2215 | next = trie_node_rcu_realloc(next); /* Modify. */ |
2216 | ||
13751fd8 | 2217 | /* Combine node with next. */ |
c30cfa6b JR |
2218 | next->prefix = node->prefix | next->prefix >> node->n_bits; |
2219 | next->n_bits += node->n_bits; | |
13751fd8 | 2220 | } |
13751fd8 | 2221 | /* Update the parent's edge. */ |
f358a2cb JR |
2222 | ovsrcu_set(edges[depth], next); /* Publish changes. */ |
2223 | trie_node_destroy(node); | |
2224 | ||
13751fd8 JR |
2225 | if (next || !depth) { |
2226 | /* Branch not pruned or at root, nothing more to do. */ | |
2227 | break; | |
2228 | } | |
f358a2cb JR |
2229 | node = ovsrcu_get_protected(struct trie_node *, |
2230 | edges[--depth]); | |
13751fd8 JR |
2231 | } |
2232 | return; | |
2233 | } | |
2234 | } | |
2235 | /* Cannot go deeper. This should never happen, since only rules | |
2236 | * that actually exist in the classifier are ever removed. */ | |
2237 | VLOG_WARN("Trying to remove non-existing rule from a prefix trie."); | |
2238 | } |