/*
- * Copyright (c) 2009, 2010, 2011, 2012 Nicira, Inc.
+ * Copyright (c) 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <config.h>
#include "classifier.h"
-#include <assert.h>
#include <errno.h>
#include <netinet/in.h>
#include "byte-order.h"
#include "hash.h"
#include "odp-util.h"
#include "ofp-util.h"
+#include "ovs-thread.h"
#include "packets.h"
-
-static struct cls_table *find_table(const struct classifier *,
- const struct flow_wildcards *);
-static struct cls_table *insert_table(struct classifier *,
- const struct flow_wildcards *);
-
-static void destroy_table(struct classifier *, struct cls_table *);
-
-static struct cls_rule *find_match(const struct cls_table *,
- const struct flow *);
-static struct cls_rule *find_equal(struct cls_table *, const struct flow *,
- uint32_t hash);
-static struct cls_rule *insert_rule(struct cls_table *, struct cls_rule *);
+#include "vlog.h"
+
+VLOG_DEFINE_THIS_MODULE(classifier);
+
+struct trie_ctx;
+static struct cls_subtable *find_subtable(const struct classifier *,
+ const struct minimask *);
+static struct cls_subtable *insert_subtable(struct classifier *,
+ const struct minimask *);
+
+static void destroy_subtable(struct classifier *, struct cls_subtable *);
+
+static void update_subtables_after_insertion(struct classifier *,
+ struct cls_subtable *,
+ unsigned int new_priority);
+static void update_subtables_after_removal(struct classifier *,
+ struct cls_subtable *,
+ unsigned int del_priority);
+
+static struct cls_rule *find_match_wc(const struct cls_subtable *,
+ const struct flow *, struct trie_ctx *,
+ unsigned int n_tries,
+ struct flow_wildcards *);
+static struct cls_rule *find_equal(struct cls_subtable *,
+ const struct miniflow *, uint32_t hash);
+static struct cls_rule *insert_rule(struct classifier *,
+ struct cls_subtable *, struct cls_rule *);
/* Iterates RULE over HEAD and all of the cls_rules on HEAD->list. */
#define FOR_EACH_RULE_IN_LIST(RULE, HEAD) \
static struct cls_rule *next_rule_in_list__(struct cls_rule *);
static struct cls_rule *next_rule_in_list(struct cls_rule *);
+
+static unsigned int minimask_get_prefix_len(const struct minimask *,
+ const struct mf_field *);
+static void trie_init(struct classifier *, int trie_idx,
+ const struct mf_field *);
+static unsigned int trie_lookup(const struct cls_trie *, const struct flow *,
+ unsigned int *checkbits);
+
+static void trie_destroy(struct trie_node *);
+static void trie_insert(struct cls_trie *, const struct cls_rule *, int mlen);
+static void trie_remove(struct cls_trie *, const struct cls_rule *, int mlen);
+static void mask_set_prefix_bits(struct flow_wildcards *, uint8_t be32ofs,
+ unsigned int nbits);
+static bool mask_prefix_bits_set(const struct flow_wildcards *,
+ uint8_t be32ofs, unsigned int nbits);
+\f
+/* flow/miniflow/minimask/minimatch utilities.
+ * These are only used by the classifier, so place them here to allow
+ * for better optimization. */
+
+static inline uint64_t
+miniflow_get_map_in_range(const struct miniflow *miniflow,
+ uint8_t start, uint8_t end, unsigned int *offset)
+{
+ uint64_t map = miniflow->map;
+ *offset = 0;
+
+ if (start > 0) {
+ uint64_t msk = (UINT64_C(1) << start) - 1; /* 'start' LSBs set */
+ *offset = count_1bits(map & msk);
+ map &= ~msk;
+ }
+ if (end < FLOW_U32S) {
+ uint64_t msk = (UINT64_C(1) << end) - 1; /* 'end' LSBs set */
+ map &= msk;
+ }
+ return map;
+}
+
+/* Returns a hash value for the bits of 'flow' where there are 1-bits in
+ * 'mask', given 'basis'.
+ *
+ * The hash values returned by this function are the same as those returned by
+ * miniflow_hash_in_minimask(), only the form of the arguments differ. */
+static inline uint32_t
+flow_hash_in_minimask(const struct flow *flow, const struct minimask *mask,
+ uint32_t basis)
+{
+ const uint32_t *flow_u32 = (const uint32_t *)flow;
+ const uint32_t *p = mask->masks.values;
+ uint32_t hash;
+ uint64_t map;
+
+ hash = basis;
+ for (map = mask->masks.map; map; map = zero_rightmost_1bit(map)) {
+ hash = mhash_add(hash, flow_u32[raw_ctz(map)] & *p++);
+ }
+
+ return mhash_finish(hash, (p - mask->masks.values) * 4);
+}
+
+/* Returns a hash value for the bits of 'flow' where there are 1-bits in
+ * 'mask', given 'basis'.
+ *
+ * The hash values returned by this function are the same as those returned by
+ * flow_hash_in_minimask(), only the form of the arguments differ. */
+static inline uint32_t
+miniflow_hash_in_minimask(const struct miniflow *flow,
+ const struct minimask *mask, uint32_t basis)
+{
+ const uint32_t *p = mask->masks.values;
+ uint32_t hash = basis;
+ uint32_t flow_u32;
+
+ MINIFLOW_FOR_EACH_IN_MAP(flow_u32, flow, mask->masks.map) {
+ hash = mhash_add(hash, flow_u32 & *p++);
+ }
+
+ return mhash_finish(hash, (p - mask->masks.values) * 4);
+}
+
+/* Returns a hash value for the bits of range [start, end) in 'flow',
+ * where there are 1-bits in 'mask', given 'hash'.
+ *
+ * The hash values returned by this function are the same as those returned by
+ * minimatch_hash_range(), only the form of the arguments differ. */
+static inline uint32_t
+flow_hash_in_minimask_range(const struct flow *flow,
+ const struct minimask *mask,
+ uint8_t start, uint8_t end, uint32_t *basis)
+{
+ const uint32_t *flow_u32 = (const uint32_t *)flow;
+ unsigned int offset;
+ uint64_t map = miniflow_get_map_in_range(&mask->masks, start, end,
+ &offset);
+ const uint32_t *p = mask->masks.values + offset;
+ uint32_t hash = *basis;
+
+ for (; map; map = zero_rightmost_1bit(map)) {
+ hash = mhash_add(hash, flow_u32[raw_ctz(map)] & *p++);
+ }
+
+ *basis = hash; /* Allow continuation from the unfinished value. */
+ return mhash_finish(hash, (p - mask->masks.values) * 4);
+}
+
+/* Fold minimask 'mask''s wildcard mask into 'wc's wildcard mask. */
+static inline void
+flow_wildcards_fold_minimask(struct flow_wildcards *wc,
+ const struct minimask *mask)
+{
+ flow_union_with_miniflow(&wc->masks, &mask->masks);
+}
+
+/* Fold minimask 'mask''s wildcard mask into 'wc's wildcard mask
+ * in range [start, end). */
+static inline void
+flow_wildcards_fold_minimask_range(struct flow_wildcards *wc,
+ const struct minimask *mask,
+ uint8_t start, uint8_t end)
+{
+ uint32_t *dst_u32 = (uint32_t *)&wc->masks;
+ unsigned int offset;
+ uint64_t map = miniflow_get_map_in_range(&mask->masks, start, end,
+ &offset);
+ const uint32_t *p = mask->masks.values + offset;
+
+ for (; map; map = zero_rightmost_1bit(map)) {
+ dst_u32[raw_ctz(map)] |= *p++;
+ }
+}
+
+/* Returns a hash value for 'flow', given 'basis'. */
+static inline uint32_t
+miniflow_hash(const struct miniflow *flow, uint32_t basis)
+{
+ const uint32_t *p = flow->values;
+ uint32_t hash = basis;
+ uint64_t hash_map = 0;
+ uint64_t map;
+
+ for (map = flow->map; map; map = zero_rightmost_1bit(map)) {
+ if (*p) {
+ hash = mhash_add(hash, *p);
+ hash_map |= rightmost_1bit(map);
+ }
+ p++;
+ }
+ hash = mhash_add(hash, hash_map);
+ hash = mhash_add(hash, hash_map >> 32);
+
+ return mhash_finish(hash, p - flow->values);
+}
+
+/* Returns a hash value for 'mask', given 'basis'. */
+static inline uint32_t
+minimask_hash(const struct minimask *mask, uint32_t basis)
+{
+ return miniflow_hash(&mask->masks, basis);
+}
+
+/* Returns a hash value for 'match', given 'basis'. */
+static inline uint32_t
+minimatch_hash(const struct minimatch *match, uint32_t basis)
+{
+ return miniflow_hash(&match->flow, minimask_hash(&match->mask, basis));
+}
+
+/* Returns a hash value for the bits of range [start, end) in 'minimatch',
+ * given 'basis'.
+ *
+ * The hash values returned by this function are the same as those returned by
+ * flow_hash_in_minimask_range(), only the form of the arguments differ. */
+static inline uint32_t
+minimatch_hash_range(const struct minimatch *match, uint8_t start, uint8_t end,
+ uint32_t *basis)
+{
+ unsigned int offset;
+ const uint32_t *p, *q;
+ uint32_t hash = *basis;
+ int n, i;
+
+ n = count_1bits(miniflow_get_map_in_range(&match->mask.masks, start, end,
+ &offset));
+ q = match->mask.masks.values + offset;
+ p = match->flow.values + offset;
+
+ for (i = 0; i < n; i++) {
+ hash = mhash_add(hash, p[i] & q[i]);
+ }
+ *basis = hash; /* Allow continuation from the unfinished value. */
+ return mhash_finish(hash, (offset + n) * 4);
+}
+
\f
/* cls_rule. */
/* Initializes 'rule' to match packets specified by 'match' at the given
- * 'priority'.
+ * 'priority'. 'match' must satisfy the invariant described in the comment at
+ * the definition of struct match.
*
* The caller must eventually destroy 'rule' with cls_rule_destroy().
*
- * 'match' must satisfy the invariant described in the comment at the
- * definition of struct match.
- *
* (OpenFlow uses priorities between 0 and UINT16_MAX, inclusive, but
* internally Open vSwitch supports a wider range.) */
void
cls_rule_init(struct cls_rule *rule,
const struct match *match, unsigned int priority)
{
- rule->match = *match;
+ minimatch_init(&rule->match, match);
+ rule->priority = priority;
+}
+
+/* Same as cls_rule_init() for initialization from a "struct minimatch". */
+void
+cls_rule_init_from_minimatch(struct cls_rule *rule,
+ const struct minimatch *match,
+ unsigned int priority)
+{
+ minimatch_clone(&rule->match, match);
rule->priority = priority;
}
/* Initializes 'dst' as a copy of 'src'.
*
- * The caller must eventually destroy 'rule' with cls_rule_destroy(). */
+ * The caller must eventually destroy 'dst' with cls_rule_destroy(). */
void
cls_rule_clone(struct cls_rule *dst, const struct cls_rule *src)
{
- *dst = *src;
+ minimatch_clone(&dst->match, &src->match);
+ dst->priority = src->priority;
+}
+
+/* Initializes 'dst' with the data in 'src', destroying 'src'.
+ *
+ * The caller must eventually destroy 'dst' with cls_rule_destroy(). */
+void
+cls_rule_move(struct cls_rule *dst, struct cls_rule *src)
+{
+ minimatch_move(&dst->match, &src->match);
+ dst->priority = src->priority;
}
/* Frees memory referenced by 'rule'. Doesn't free 'rule' itself (it's
*
* ('rule' must not currently be in a classifier.) */
void
-cls_rule_destroy(struct cls_rule *rule OVS_UNUSED)
+cls_rule_destroy(struct cls_rule *rule)
{
- /* Nothing to do yet. */
+ minimatch_destroy(&rule->match);
}
/* Returns true if 'a' and 'b' match the same packets at the same priority,
bool
cls_rule_equal(const struct cls_rule *a, const struct cls_rule *b)
{
- return a->priority == b->priority && match_equal(&a->match, &b->match);
+ return a->priority == b->priority && minimatch_equal(&a->match, &b->match);
}
/* Returns a hash value for 'rule', folding in 'basis'. */
uint32_t
cls_rule_hash(const struct cls_rule *rule, uint32_t basis)
{
- return match_hash(&rule->match, hash_int(rule->priority, basis));
+ return minimatch_hash(&rule->match, hash_int(rule->priority, basis));
}
/* Appends a string describing 'rule' to 's'. */
void
cls_rule_format(const struct cls_rule *rule, struct ds *s)
{
- match_format(&rule->match, s, rule->priority);
+ minimatch_format(&rule->match, s, rule->priority);
+}
+
+/* Returns true if 'rule' matches every packet, false otherwise. */
+bool
+cls_rule_is_catchall(const struct cls_rule *rule)
+{
+ return minimask_is_catchall(&rule->match.mask);
}
\f
/* Initializes 'cls' as a classifier that initially contains no classification
* rules. */
void
-classifier_init(struct classifier *cls)
+classifier_init(struct classifier *cls, const uint8_t *flow_segments)
{
cls->n_rules = 0;
- hmap_init(&cls->tables);
+ hmap_init(&cls->subtables);
+ list_init(&cls->subtables_priority);
+ hmap_init(&cls->partitions);
+ fat_rwlock_init(&cls->rwlock);
+ cls->n_flow_segments = 0;
+ if (flow_segments) {
+ while (cls->n_flow_segments < CLS_MAX_INDICES
+ && *flow_segments < FLOW_U32S) {
+ cls->flow_segments[cls->n_flow_segments++] = *flow_segments++;
+ }
+ }
+ cls->n_tries = 0;
}
/* Destroys 'cls'. Rules within 'cls', if any, are not freed; this is the
classifier_destroy(struct classifier *cls)
{
if (cls) {
- struct cls_table *table, *next_table;
+ struct cls_subtable *partition, *next_partition;
+ struct cls_subtable *subtable, *next_subtable;
+ int i;
- HMAP_FOR_EACH_SAFE (table, next_table, hmap_node, &cls->tables) {
- hmap_destroy(&table->rules);
- hmap_remove(&cls->tables, &table->hmap_node);
- free(table);
+ for (i = 0; i < cls->n_tries; i++) {
+ trie_destroy(cls->tries[i].root);
+ }
+
+ HMAP_FOR_EACH_SAFE (subtable, next_subtable, hmap_node,
+ &cls->subtables) {
+ destroy_subtable(cls, subtable);
+ }
+ hmap_destroy(&cls->subtables);
+
+ HMAP_FOR_EACH_SAFE (partition, next_partition, hmap_node,
+ &cls->partitions) {
+ hmap_remove(&cls->partitions, &partition->hmap_node);
+ free(partition);
+ }
+ hmap_destroy(&cls->partitions);
+ fat_rwlock_destroy(&cls->rwlock);
+ }
+}
+
+/* We use uint64_t as a set for the fields below. */
+BUILD_ASSERT_DECL(MFF_N_IDS <= 64);
+
+/* Set the fields for which prefix lookup should be performed. */
+void
+classifier_set_prefix_fields(struct classifier *cls,
+ const enum mf_field_id *trie_fields,
+ unsigned int n_fields)
+{
+ uint64_t fields = 0;
+ int i, trie;
+
+ for (i = 0, trie = 0; i < n_fields && trie < CLS_MAX_TRIES; i++) {
+ const struct mf_field *field = mf_from_id(trie_fields[i]);
+ if (field->flow_be32ofs < 0 || field->n_bits % 32) {
+ /* Incompatible field. This is the only place where we
+ * enforce these requirements, but the rest of the trie code
+ * depends on the flow_be32ofs to be non-negative and the
+ * field length to be a multiple of 32 bits. */
+ continue;
+ }
+
+ if (fields & (UINT64_C(1) << trie_fields[i])) {
+ /* Duplicate field, there is no need to build more than
+ * one index for any one field. */
+ continue;
+ }
+ fields |= UINT64_C(1) << trie_fields[i];
+
+ if (trie >= cls->n_tries || field != cls->tries[trie].field) {
+ trie_init(cls, trie, field);
+ }
+ trie++;
+ }
+
+ /* Destroy the rest. */
+ for (i = trie; i < cls->n_tries; i++) {
+ trie_init(cls, i, NULL);
+ }
+ cls->n_tries = trie;
+}
+
+static void
+trie_init(struct classifier *cls, int trie_idx,
+ const struct mf_field *field)
+{
+ struct cls_trie *trie = &cls->tries[trie_idx];
+ struct cls_subtable *subtable;
+
+ if (trie_idx < cls->n_tries) {
+ trie_destroy(trie->root);
+ }
+ trie->root = NULL;
+ trie->field = field;
+
+ /* Add existing rules to the trie. */
+ LIST_FOR_EACH (subtable, list_node, &cls->subtables_priority) {
+ unsigned int plen;
+
+ plen = field ? minimask_get_prefix_len(&subtable->mask, field) : 0;
+ /* Initialize subtable's prefix length on this field. */
+ subtable->trie_plen[trie_idx] = plen;
+
+ if (plen) {
+ struct cls_rule *head;
+
+ HMAP_FOR_EACH (head, hmap_node, &subtable->rules) {
+ struct cls_rule *rule;
+
+ FOR_EACH_RULE_IN_LIST (rule, head) {
+ trie_insert(trie, rule, plen);
+ }
+ }
}
- hmap_destroy(&cls->tables);
}
}
return cls->n_rules;
}
+static uint32_t
+hash_metadata(ovs_be64 metadata_)
+{
+ uint64_t metadata = (OVS_FORCE uint64_t) metadata_;
+ return hash_uint64(metadata);
+}
+
+static struct cls_partition *
+find_partition(const struct classifier *cls, ovs_be64 metadata, uint32_t hash)
+{
+ struct cls_partition *partition;
+
+ HMAP_FOR_EACH_IN_BUCKET (partition, hmap_node, hash, &cls->partitions) {
+ if (partition->metadata == metadata) {
+ return partition;
+ }
+ }
+
+ return NULL;
+}
+
+static struct cls_partition *
+create_partition(struct classifier *cls, struct cls_subtable *subtable,
+ ovs_be64 metadata)
+{
+ uint32_t hash = hash_metadata(metadata);
+ struct cls_partition *partition = find_partition(cls, metadata, hash);
+ if (!partition) {
+ partition = xmalloc(sizeof *partition);
+ partition->metadata = metadata;
+ partition->tags = 0;
+ tag_tracker_init(&partition->tracker);
+ hmap_insert(&cls->partitions, &partition->hmap_node, hash);
+ }
+ tag_tracker_add(&partition->tracker, &partition->tags, subtable->tag);
+ return partition;
+}
+
/* Inserts 'rule' into 'cls'. Until 'rule' is removed from 'cls', the caller
* must not modify or free it.
*
classifier_replace(struct classifier *cls, struct cls_rule *rule)
{
struct cls_rule *old_rule;
- struct cls_table *table;
+ struct cls_subtable *subtable;
- table = find_table(cls, &rule->match.wc);
- if (!table) {
- table = insert_table(cls, &rule->match.wc);
+ subtable = find_subtable(cls, &rule->match.mask);
+ if (!subtable) {
+ subtable = insert_subtable(cls, &rule->match.mask);
}
- old_rule = insert_rule(table, rule);
+ old_rule = insert_rule(cls, subtable, rule);
if (!old_rule) {
- table->n_table_rules++;
+ int i;
+
+ if (minimask_get_metadata_mask(&rule->match.mask) == OVS_BE64_MAX) {
+ ovs_be64 metadata = miniflow_get_metadata(&rule->match.flow);
+ rule->partition = create_partition(cls, subtable, metadata);
+ } else {
+ rule->partition = NULL;
+ }
+
+ subtable->n_rules++;
cls->n_rules++;
+
+ for (i = 0; i < cls->n_tries; i++) {
+ if (subtable->trie_plen[i]) {
+ trie_insert(&cls->tries[i], rule, subtable->trie_plen[i]);
+ }
+ }
+ } else {
+ rule->partition = old_rule->partition;
}
return old_rule;
}
classifier_insert(struct classifier *cls, struct cls_rule *rule)
{
struct cls_rule *displaced_rule = classifier_replace(cls, rule);
- assert(!displaced_rule);
+ ovs_assert(!displaced_rule);
}
/* Removes 'rule' from 'cls'. It is the caller's responsibility to destroy
void
classifier_remove(struct classifier *cls, struct cls_rule *rule)
{
+ struct cls_partition *partition;
struct cls_rule *head;
- struct cls_table *table;
+ struct cls_subtable *subtable;
+ int i;
+
+ subtable = find_subtable(cls, &rule->match.mask);
+
+ for (i = 0; i < cls->n_tries; i++) {
+ if (subtable->trie_plen[i]) {
+ trie_remove(&cls->tries[i], rule, subtable->trie_plen[i]);
+ }
+ }
- table = find_table(cls, &rule->match.wc);
- head = find_equal(table, &rule->match.flow, rule->hmap_node.hash);
+ /* Remove rule node from indices. */
+ for (i = 0; i < subtable->n_indices; i++) {
+ hindex_remove(&subtable->indices[i], &rule->index_nodes[i]);
+ }
+
+ head = find_equal(subtable, &rule->match.flow, rule->hmap_node.hash);
if (head != rule) {
list_remove(&rule->list);
} else if (list_is_empty(&rule->list)) {
- hmap_remove(&table->rules, &rule->hmap_node);
+ hmap_remove(&subtable->rules, &rule->hmap_node);
} else {
struct cls_rule *next = CONTAINER_OF(rule->list.next,
struct cls_rule, list);
list_remove(&rule->list);
- hmap_replace(&table->rules, &rule->hmap_node, &next->hmap_node);
+ hmap_replace(&subtable->rules, &rule->hmap_node, &next->hmap_node);
+ }
+
+ partition = rule->partition;
+ if (partition) {
+ tag_tracker_subtract(&partition->tracker, &partition->tags,
+ subtable->tag);
+ if (!partition->tags) {
+ hmap_remove(&cls->partitions, &partition->hmap_node);
+ free(partition);
+ }
}
- if (--table->n_table_rules == 0) {
- destroy_table(cls, table);
+ if (--subtable->n_rules == 0) {
+ destroy_subtable(cls, subtable);
+ } else {
+ update_subtables_after_removal(cls, subtable, rule->priority);
}
cls->n_rules--;
}
+/* Prefix tree context. Valid when 'lookup_done' is true. Can skip all
+ * subtables which have more than 'match_plen' bits in their corresponding
+ * field at offset 'be32ofs'. If skipped, 'maskbits' prefix bits should be
+ * unwildcarded to quarantee datapath flow matches only packets it should. */
+struct trie_ctx {
+ const struct cls_trie *trie;
+ bool lookup_done; /* Status of the lookup. */
+ uint8_t be32ofs; /* U32 offset of the field in question. */
+ unsigned int match_plen; /* Longest prefix than could possibly match. */
+ unsigned int maskbits; /* Prefix length needed to avoid false matches. */
+};
+
+static void
+trie_ctx_init(struct trie_ctx *ctx, const struct cls_trie *trie)
+{
+ ctx->trie = trie;
+ ctx->be32ofs = trie->field->flow_be32ofs;
+ ctx->lookup_done = false;
+}
+
/* Finds and returns the highest-priority rule in 'cls' that matches 'flow'.
* Returns a null pointer if no rules in 'cls' match 'flow'. If multiple rules
- * of equal priority match 'flow', returns one arbitrarily. */
+ * of equal priority match 'flow', returns one arbitrarily.
+ *
+ * If a rule is found and 'wc' is non-null, bitwise-OR's 'wc' with the
+ * set of bits that were significant in the lookup. At some point
+ * earlier, 'wc' should have been initialized (e.g., by
+ * flow_wildcards_init_catchall()). */
struct cls_rule *
-classifier_lookup(const struct classifier *cls, const struct flow *flow)
+classifier_lookup(const struct classifier *cls, const struct flow *flow,
+ struct flow_wildcards *wc)
{
- struct cls_table *table;
+ const struct cls_partition *partition;
+ struct cls_subtable *subtable;
struct cls_rule *best;
-
+ tag_type tags;
+ struct trie_ctx trie_ctx[CLS_MAX_TRIES];
+ int i;
+
+ /* Determine 'tags' such that, if 'subtable->tag' doesn't intersect them,
+ * then 'flow' cannot possibly match in 'subtable':
+ *
+ * - If flow->metadata maps to a given 'partition', then we can use
+ * 'tags' for 'partition->tags'.
+ *
+ * - If flow->metadata has no partition, then no rule in 'cls' has an
+ * exact-match for flow->metadata. That means that we don't need to
+ * search any subtable that includes flow->metadata in its mask.
+ *
+ * In either case, we always need to search any cls_subtables that do not
+ * include flow->metadata in its mask. One way to do that would be to
+ * check the "cls_subtable"s explicitly for that, but that would require an
+ * extra branch per subtable. Instead, we mark such a cls_subtable's
+ * 'tags' as TAG_ALL and make sure that 'tags' is never empty. This means
+ * that 'tags' always intersects such a cls_subtable's 'tags', so we don't
+ * need a special case.
+ */
+ partition = (hmap_is_empty(&cls->partitions)
+ ? NULL
+ : find_partition(cls, flow->metadata,
+ hash_metadata(flow->metadata)));
+ tags = partition ? partition->tags : TAG_ARBITRARY;
+
+ /* Initialize trie contexts for match_find_wc(). */
+ for (i = 0; i < cls->n_tries; i++) {
+ trie_ctx_init(&trie_ctx[i], &cls->tries[i]);
+ }
best = NULL;
- HMAP_FOR_EACH (table, hmap_node, &cls->tables) {
- struct cls_rule *rule = find_match(table, flow);
- if (rule && (!best || rule->priority > best->priority)) {
+ LIST_FOR_EACH (subtable, list_node, &cls->subtables_priority) {
+ struct cls_rule *rule;
+
+ if (!tag_intersects(tags, subtable->tag)) {
+ continue;
+ }
+
+ rule = find_match_wc(subtable, flow, trie_ctx, cls->n_tries, wc);
+ if (rule) {
best = rule;
+ LIST_FOR_EACH_CONTINUE (subtable, list_node,
+ &cls->subtables_priority) {
+ if (subtable->max_priority <= best->priority) {
+ /* Subtables are in descending priority order,
+ * can not find anything better. */
+ return best;
+ }
+ if (!tag_intersects(tags, subtable->tag)) {
+ continue;
+ }
+
+ rule = find_match_wc(subtable, flow, trie_ctx, cls->n_tries,
+ wc);
+ if (rule && rule->priority > best->priority) {
+ best = rule;
+ }
+ }
+ break;
}
}
+
return best;
}
+/* Returns true if 'target' satisifies 'match', that is, if each bit for which
+ * 'match' specifies a particular value has the correct value in 'target'. */
+static bool
+minimatch_matches_miniflow(const struct minimatch *match,
+ const struct miniflow *target)
+{
+ const uint32_t *flowp = (const uint32_t *)match->flow.values;
+ const uint32_t *maskp = (const uint32_t *)match->mask.masks.values;
+ uint32_t target_u32;
+
+ MINIFLOW_FOR_EACH_IN_MAP(target_u32, target, match->mask.masks.map) {
+ if ((*flowp++ ^ target_u32) & *maskp++) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+static inline struct cls_rule *
+find_match_miniflow(const struct cls_subtable *subtable,
+ const struct miniflow *flow,
+ uint32_t hash)
+{
+ struct cls_rule *rule;
+
+ HMAP_FOR_EACH_WITH_HASH (rule, hmap_node, hash, &subtable->rules) {
+ if (minimatch_matches_miniflow(&rule->match, flow)) {
+ return rule;
+ }
+ }
+
+ return NULL;
+}
+
+/* Finds and returns the highest-priority rule in 'cls' that matches
+ * 'miniflow'. Returns a null pointer if no rules in 'cls' match 'flow'.
+ * If multiple rules of equal priority match 'flow', returns one arbitrarily.
+ *
+ * This function is optimized for the userspace datapath, which only ever has
+ * one priority value for it's flows!
+ */
+struct cls_rule *classifier_lookup_miniflow_first(const struct classifier *cls,
+ const struct miniflow *flow)
+{
+ struct cls_subtable *subtable;
+
+ LIST_FOR_EACH (subtable, list_node, &cls->subtables_priority) {
+ struct cls_rule *rule;
+
+ rule = find_match_miniflow(subtable, flow,
+ miniflow_hash_in_minimask(flow,
+ &subtable->mask,
+ 0));
+ if (rule) {
+ return rule;
+ }
+ }
+
+ return NULL;
+}
+
/* Finds and returns a rule in 'cls' with exactly the same priority and
* matching criteria as 'target'. Returns a null pointer if 'cls' doesn't
* contain an exact match. */
const struct cls_rule *target)
{
struct cls_rule *head, *rule;
- struct cls_table *table;
+ struct cls_subtable *subtable;
+
+ subtable = find_subtable(cls, &target->match.mask);
+ if (!subtable) {
+ return NULL;
+ }
- table = find_table(cls, &target->match.wc);
- if (!table) {
+ /* Skip if there is no hope. */
+ if (target->priority > subtable->max_priority) {
return NULL;
}
- head = find_equal(table, &target->match.flow,
- flow_hash(&target->match.flow, 0));
+ head = find_equal(subtable, &target->match.flow,
+ miniflow_hash_in_minimask(&target->match.flow,
+ &target->match.mask, 0));
FOR_EACH_RULE_IN_LIST (rule, head) {
if (target->priority >= rule->priority) {
return target->priority == rule->priority ? rule : NULL;
classifier_rule_overlaps(const struct classifier *cls,
const struct cls_rule *target)
{
- struct cls_table *table;
+ struct cls_subtable *subtable;
- HMAP_FOR_EACH (table, hmap_node, &cls->tables) {
- struct flow_wildcards wc;
+ /* Iterate subtables in the descending max priority order. */
+ LIST_FOR_EACH (subtable, list_node, &cls->subtables_priority) {
+ uint32_t storage[FLOW_U32S];
+ struct minimask mask;
struct cls_rule *head;
- flow_wildcards_combine(&wc, &target->match.wc, &table->wc);
- HMAP_FOR_EACH (head, hmap_node, &table->rules) {
+ if (target->priority > subtable->max_priority) {
+ break; /* Can skip this and the rest of the subtables. */
+ }
+
+ minimask_combine(&mask, &target->match.mask, &subtable->mask, storage);
+ HMAP_FOR_EACH (head, hmap_node, &subtable->rules) {
struct cls_rule *rule;
FOR_EACH_RULE_IN_LIST (rule, head) {
+ if (rule->priority < target->priority) {
+ break; /* Rules in descending priority order. */
+ }
if (rule->priority == target->priority
- && flow_equal_except(&target->match.flow,
- &rule->match.flow, &wc)) {
+ && miniflow_equal_in_minimask(&target->match.flow,
+ &rule->match.flow, &mask)) {
return true;
}
}
* Ignores rule->priority. */
bool
cls_rule_is_loose_match(const struct cls_rule *rule,
- const struct match *criteria)
+ const struct minimatch *criteria)
{
- return (!flow_wildcards_has_extra(&rule->match.wc, &criteria->wc)
- && flow_equal_except(&rule->match.flow, &criteria->flow,
- &criteria->wc));
+ return (!minimask_has_extra(&rule->match.mask, &criteria->mask)
+ && miniflow_equal_in_minimask(&rule->match.flow, &criteria->flow,
+ &criteria->mask));
}
\f
/* Iteration. */
rule_matches(const struct cls_rule *rule, const struct cls_rule *target)
{
return (!target
- || flow_equal_except(&rule->match.flow, &target->match.flow,
- &target->match.wc));
+ || miniflow_equal_in_minimask(&rule->match.flow,
+ &target->match.flow,
+ &target->match.mask));
}
static struct cls_rule *
-search_table(const struct cls_table *table, const struct cls_rule *target)
+search_subtable(const struct cls_subtable *subtable,
+ const struct cls_rule *target)
{
- if (!target || !flow_wildcards_has_extra(&table->wc, &target->match.wc)) {
+ if (!target || !minimask_has_extra(&subtable->mask, &target->match.mask)) {
struct cls_rule *rule;
- HMAP_FOR_EACH (rule, hmap_node, &table->rules) {
+ HMAP_FOR_EACH (rule, hmap_node, &subtable->rules) {
if (rule_matches(rule, target)) {
return rule;
}
const struct cls_rule *target)
{
cursor->cls = cls;
- cursor->target = target;
+ cursor->target = target && !cls_rule_is_catchall(target) ? target : NULL;
}
/* Returns the first matching cls_rule in 'cursor''s iteration, or a null
struct cls_rule *
cls_cursor_first(struct cls_cursor *cursor)
{
- struct cls_table *table;
+ struct cls_subtable *subtable;
- HMAP_FOR_EACH (table, hmap_node, &cursor->cls->tables) {
- struct cls_rule *rule = search_table(table, cursor->target);
+ HMAP_FOR_EACH (subtable, hmap_node, &cursor->cls->subtables) {
+ struct cls_rule *rule = search_subtable(subtable, cursor->target);
if (rule) {
- cursor->table = table;
+ cursor->subtable = subtable;
return rule;
}
}
/* Returns the next matching cls_rule in 'cursor''s iteration, or a null
* pointer if there are no more matches. */
struct cls_rule *
-cls_cursor_next(struct cls_cursor *cursor, struct cls_rule *rule)
+cls_cursor_next(struct cls_cursor *cursor, const struct cls_rule *rule_)
{
- const struct cls_table *table;
+ struct cls_rule *rule = CONST_CAST(struct cls_rule *, rule_);
+ const struct cls_subtable *subtable;
struct cls_rule *next;
next = next_rule_in_list__(rule);
}
/* 'next' is the head of the list, that is, the rule that is included in
- * the table's hmap. (This is important when the classifier contains rules
- * that differ only in priority.) */
+ * the subtable's hmap. (This is important when the classifier contains
+ * rules that differ only in priority.) */
rule = next;
- HMAP_FOR_EACH_CONTINUE (rule, hmap_node, &cursor->table->rules) {
+ HMAP_FOR_EACH_CONTINUE (rule, hmap_node, &cursor->subtable->rules) {
if (rule_matches(rule, cursor->target)) {
return rule;
}
}
- table = cursor->table;
- HMAP_FOR_EACH_CONTINUE (table, hmap_node, &cursor->cls->tables) {
- rule = search_table(table, cursor->target);
+ subtable = cursor->subtable;
+ HMAP_FOR_EACH_CONTINUE (subtable, hmap_node, &cursor->cls->subtables) {
+ rule = search_subtable(subtable, cursor->target);
if (rule) {
- cursor->table = table;
+ cursor->subtable = subtable;
return rule;
}
}
return NULL;
}
\f
-static struct cls_table *
-find_table(const struct classifier *cls, const struct flow_wildcards *wc)
+static struct cls_subtable *
+find_subtable(const struct classifier *cls, const struct minimask *mask)
{
- struct cls_table *table;
+ struct cls_subtable *subtable;
- HMAP_FOR_EACH_IN_BUCKET (table, hmap_node, flow_wildcards_hash(wc, 0),
- &cls->tables) {
- if (flow_wildcards_equal(wc, &table->wc)) {
- return table;
+ HMAP_FOR_EACH_IN_BUCKET (subtable, hmap_node, minimask_hash(mask, 0),
+ &cls->subtables) {
+ if (minimask_equal(mask, &subtable->mask)) {
+ return subtable;
}
}
return NULL;
}
-static struct cls_table *
-insert_table(struct classifier *cls, const struct flow_wildcards *wc)
+static struct cls_subtable *
+insert_subtable(struct classifier *cls, const struct minimask *mask)
{
- struct cls_table *table;
+ uint32_t hash = minimask_hash(mask, 0);
+ struct cls_subtable *subtable;
+ int i, index = 0;
+ struct flow_wildcards old, new;
+ uint8_t prev;
+
+ subtable = xzalloc(sizeof *subtable);
+ hmap_init(&subtable->rules);
+ minimask_clone(&subtable->mask, mask);
+
+ /* Init indices for segmented lookup, if any. */
+ flow_wildcards_init_catchall(&new);
+ old = new;
+ prev = 0;
+ for (i = 0; i < cls->n_flow_segments; i++) {
+ flow_wildcards_fold_minimask_range(&new, mask, prev,
+ cls->flow_segments[i]);
+ /* Add an index if it adds mask bits. */
+ if (!flow_wildcards_equal(&new, &old)) {
+ hindex_init(&subtable->indices[index]);
+ subtable->index_ofs[index] = cls->flow_segments[i];
+ index++;
+ old = new;
+ }
+ prev = cls->flow_segments[i];
+ }
+ /* Check if the rest of the subtable's mask adds any bits,
+ * and remove the last index if it doesn't. */
+ if (index > 0) {
+ flow_wildcards_fold_minimask_range(&new, mask, prev, FLOW_U32S);
+ if (flow_wildcards_equal(&new, &old)) {
+ --index;
+ subtable->index_ofs[index] = 0;
+ hindex_destroy(&subtable->indices[index]);
+ }
+ }
+ subtable->n_indices = index;
- table = xzalloc(sizeof *table);
- hmap_init(&table->rules);
- table->wc = *wc;
- table->is_catchall = flow_wildcards_is_catchall(&table->wc);
- hmap_insert(&cls->tables, &table->hmap_node, flow_wildcards_hash(wc, 0));
+ hmap_insert(&cls->subtables, &subtable->hmap_node, hash);
+ list_push_back(&cls->subtables_priority, &subtable->list_node);
+ subtable->tag = (minimask_get_metadata_mask(mask) == OVS_BE64_MAX
+ ? tag_create_deterministic(hash)
+ : TAG_ALL);
- return table;
+ for (i = 0; i < cls->n_tries; i++) {
+ subtable->trie_plen[i] = minimask_get_prefix_len(mask,
+ cls->tries[i].field);
+ }
+
+ return subtable;
}
static void
-destroy_table(struct classifier *cls, struct cls_table *table)
+destroy_subtable(struct classifier *cls, struct cls_subtable *subtable)
{
- hmap_remove(&cls->tables, &table->hmap_node);
- hmap_destroy(&table->rules);
- free(table);
+ int i;
+
+ for (i = 0; i < subtable->n_indices; i++) {
+ hindex_destroy(&subtable->indices[i]);
+ }
+ minimask_destroy(&subtable->mask);
+ hmap_remove(&cls->subtables, &subtable->hmap_node);
+ hmap_destroy(&subtable->rules);
+ list_remove(&subtable->list_node);
+ free(subtable);
}
-static struct cls_rule *
-find_match(const struct cls_table *table, const struct flow *flow)
+/* This function performs the following updates for 'subtable' in 'cls'
+ * following the addition of a new rule with priority 'new_priority' to
+ * 'subtable':
+ *
+ * - Update 'subtable->max_priority' and 'subtable->max_count' if necessary.
+ *
+ * - Update 'subtable''s position in 'cls->subtables_priority' if necessary.
+ *
+ * This function should only be called after adding a new rule, not after
+ * replacing a rule by an identical one or modifying a rule in-place. */
+static void
+update_subtables_after_insertion(struct classifier *cls,
+ struct cls_subtable *subtable,
+ unsigned int new_priority)
+{
+ if (new_priority == subtable->max_priority) {
+ ++subtable->max_count;
+ } else if (new_priority > subtable->max_priority) {
+ struct cls_subtable *iter;
+
+ subtable->max_priority = new_priority;
+ subtable->max_count = 1;
+
+ /* Possibly move 'subtable' earlier in the priority list. If we break
+ * out of the loop, then 'subtable' should be moved just after that
+ * 'iter'. If the loop terminates normally, then 'iter' will be the
+ * list head and we'll move subtable just after that (e.g. to the front
+ * of the list). */
+ iter = subtable;
+ LIST_FOR_EACH_REVERSE_CONTINUE (iter, list_node,
+ &cls->subtables_priority) {
+ if (iter->max_priority >= subtable->max_priority) {
+ break;
+ }
+ }
+
+ /* Move 'subtable' just after 'iter' (unless it's already there). */
+ if (iter->list_node.next != &subtable->list_node) {
+ list_splice(iter->list_node.next,
+ &subtable->list_node, subtable->list_node.next);
+ }
+ }
+}
+
+/* This function performs the following updates for 'subtable' in 'cls'
+ * following the deletion of a rule with priority 'del_priority' from
+ * 'subtable':
+ *
+ * - Update 'subtable->max_priority' and 'subtable->max_count' if necessary.
+ *
+ * - Update 'subtable''s position in 'cls->subtables_priority' if necessary.
+ *
+ * This function should only be called after removing a rule, not after
+ * replacing a rule by an identical one or modifying a rule in-place. */
+static void
+update_subtables_after_removal(struct classifier *cls,
+ struct cls_subtable *subtable,
+ unsigned int del_priority)
+{
+ struct cls_subtable *iter;
+
+ if (del_priority == subtable->max_priority && --subtable->max_count == 0) {
+ struct cls_rule *head;
+
+ subtable->max_priority = 0;
+ HMAP_FOR_EACH (head, hmap_node, &subtable->rules) {
+ if (head->priority > subtable->max_priority) {
+ subtable->max_priority = head->priority;
+ subtable->max_count = 1;
+ } else if (head->priority == subtable->max_priority) {
+ ++subtable->max_count;
+ }
+ }
+
+ /* Possibly move 'subtable' later in the priority list. If we break
+ * out of the loop, then 'subtable' should be moved just before that
+ * 'iter'. If the loop terminates normally, then 'iter' will be the
+ * list head and we'll move subtable just before that (e.g. to the back
+ * of the list). */
+ iter = subtable;
+ LIST_FOR_EACH_CONTINUE (iter, list_node, &cls->subtables_priority) {
+ if (iter->max_priority <= subtable->max_priority) {
+ break;
+ }
+ }
+
+ /* Move 'subtable' just before 'iter' (unless it's already there). */
+ if (iter->list_node.prev != &subtable->list_node) {
+ list_splice(&iter->list_node,
+ &subtable->list_node, subtable->list_node.next);
+ }
+ }
+}
+
+struct range {
+ uint8_t start;
+ uint8_t end;
+};
+
+/* Return 'true' if can skip rest of the subtable based on the prefix trie
+ * lookup results. */
+static inline bool
+check_tries(struct trie_ctx trie_ctx[CLS_MAX_TRIES], unsigned int n_tries,
+ const unsigned int field_plen[CLS_MAX_TRIES],
+ const struct range ofs, const struct flow *flow,
+ struct flow_wildcards *wc)
+{
+ int j;
+
+ /* Check if we could avoid fully unwildcarding the next level of
+ * fields using the prefix tries. The trie checks are done only as
+ * needed to avoid folding in additional bits to the wildcards mask. */
+ for (j = 0; j < n_tries; j++) {
+ /* Is the trie field relevant for this subtable? */
+ if (field_plen[j]) {
+ struct trie_ctx *ctx = &trie_ctx[j];
+ uint8_t be32ofs = ctx->be32ofs;
+
+ /* Is the trie field within the current range of fields? */
+ if (be32ofs >= ofs.start && be32ofs < ofs.end) {
+ /* On-demand trie lookup. */
+ if (!ctx->lookup_done) {
+ ctx->match_plen = trie_lookup(ctx->trie, flow,
+ &ctx->maskbits);
+ ctx->lookup_done = true;
+ }
+ /* Possible to skip the rest of the subtable if subtable's
+ * prefix on the field is longer than what is known to match
+ * based on the trie lookup. */
+ if (field_plen[j] > ctx->match_plen) {
+ /* RFC: We want the trie lookup to never result in
+ * unwildcarding any bits that would not be unwildcarded
+ * otherwise. Since the trie is shared by the whole
+ * classifier, it is possible that the 'maskbits' contain
+ * bits that are irrelevant for the partition of the
+ * classifier relevant for the current flow. */
+
+ /* Can skip if the field is already unwildcarded. */
+ if (mask_prefix_bits_set(wc, be32ofs, ctx->maskbits)) {
+ return true;
+ }
+ /* Check that the trie result will not unwildcard more bits
+ * than this stage will. */
+ if (ctx->maskbits <= field_plen[j]) {
+ /* Unwildcard the bits and skip the rest. */
+ mask_set_prefix_bits(wc, be32ofs, ctx->maskbits);
+ /* Note: Prerequisite already unwildcarded, as the only
+ * prerequisite of the supported trie lookup fields is
+ * the ethertype, which is currently always
+ * unwildcarded.
+ */
+ return true;
+ }
+ }
+ }
+ }
+ }
+ return false;
+}
+
+static inline struct cls_rule *
+find_match(const struct cls_subtable *subtable, const struct flow *flow,
+ uint32_t hash)
{
struct cls_rule *rule;
- if (table->is_catchall) {
- HMAP_FOR_EACH (rule, hmap_node, &table->rules) {
+ HMAP_FOR_EACH_WITH_HASH (rule, hmap_node, hash, &subtable->rules) {
+ if (minimatch_matches_flow(&rule->match, flow)) {
return rule;
}
- } else {
- struct flow f;
+ }
- f = *flow;
- flow_zero_wildcards(&f, &table->wc);
- HMAP_FOR_EACH_WITH_HASH (rule, hmap_node, flow_hash(&f, 0),
- &table->rules) {
- if (flow_equal(&f, &rule->match.flow)) {
- return rule;
+ return NULL;
+}
+
+static struct cls_rule *
+find_match_wc(const struct cls_subtable *subtable, const struct flow *flow,
+ struct trie_ctx trie_ctx[CLS_MAX_TRIES], unsigned int n_tries,
+ struct flow_wildcards *wc)
+{
+ uint32_t basis = 0, hash;
+ struct cls_rule *rule = NULL;
+ int i;
+ struct range ofs;
+
+ if (!wc) {
+ return find_match(subtable, flow,
+ flow_hash_in_minimask(flow, &subtable->mask, 0));
+ }
+
+ ofs.start = 0;
+ /* Try to finish early by checking fields in segments. */
+ for (i = 0; i < subtable->n_indices; i++) {
+ struct hindex_node *inode;
+ ofs.end = subtable->index_ofs[i];
+
+ if (check_tries(trie_ctx, n_tries, subtable->trie_plen, ofs, flow,
+ wc)) {
+ goto range_out;
+ }
+ hash = flow_hash_in_minimask_range(flow, &subtable->mask, ofs.start,
+ ofs.end, &basis);
+ ofs.start = ofs.end;
+ inode = hindex_node_with_hash(&subtable->indices[i], hash);
+ if (!inode) {
+ /* No match, can stop immediately, but must fold in the mask
+ * covered so far. */
+ goto range_out;
+ }
+
+ /* If we have narrowed down to a single rule already, check whether
+ * that rule matches. If it does match, then we're done. If it does
+ * not match, then we know that we will never get a match, but we do
+ * not yet know how many wildcards we need to fold into 'wc' so we
+ * continue iterating through indices to find that out. (We won't
+ * waste time calling minimatch_matches_flow() again because we've set
+ * 'rule' nonnull.)
+ *
+ * This check shows a measurable benefit with non-trivial flow tables.
+ *
+ * (Rare) hash collisions may cause us to miss the opportunity for this
+ * optimization. */
+ if (!inode->s && !rule) {
+ ASSIGN_CONTAINER(rule, inode - i, index_nodes);
+ if (minimatch_matches_flow(&rule->match, flow)) {
+ goto out;
}
}
}
-
+ ofs.end = FLOW_U32S;
+ /* Trie check for the final range. */
+ if (check_tries(trie_ctx, n_tries, subtable->trie_plen, ofs, flow, wc)) {
+ goto range_out;
+ }
+ if (!rule) {
+ /* Multiple potential matches exist, look for one. */
+ hash = flow_hash_in_minimask_range(flow, &subtable->mask, ofs.start,
+ ofs.end, &basis);
+ rule = find_match(subtable, flow, hash);
+ } else {
+ /* We already narrowed the matching candidates down to just 'rule',
+ * but it didn't match. */
+ rule = NULL;
+ }
+ out:
+ /* Must unwildcard all the fields, as they were looked at. */
+ flow_wildcards_fold_minimask(wc, &subtable->mask);
+ return rule;
+
+ range_out:
+ /* Must unwildcard the fields looked up so far, if any. */
+ if (ofs.start) {
+ flow_wildcards_fold_minimask_range(wc, &subtable->mask, 0, ofs.start);
+ }
return NULL;
}
static struct cls_rule *
-find_equal(struct cls_table *table, const struct flow *flow, uint32_t hash)
+find_equal(struct cls_subtable *subtable, const struct miniflow *flow,
+ uint32_t hash)
{
struct cls_rule *head;
- HMAP_FOR_EACH_WITH_HASH (head, hmap_node, hash, &table->rules) {
- if (flow_equal(&head->match.flow, flow)) {
+ HMAP_FOR_EACH_WITH_HASH (head, hmap_node, hash, &subtable->rules) {
+ if (miniflow_equal(&head->match.flow, flow)) {
return head;
}
}
}
static struct cls_rule *
-insert_rule(struct cls_table *table, struct cls_rule *new)
+insert_rule(struct classifier *cls, struct cls_subtable *subtable,
+ struct cls_rule *new)
{
struct cls_rule *head;
-
- new->hmap_node.hash = flow_hash(&new->match.flow, 0);
-
- head = find_equal(table, &new->match.flow, new->hmap_node.hash);
+ struct cls_rule *old = NULL;
+ int i;
+ uint32_t basis = 0, hash;
+ uint8_t prev_be32ofs = 0;
+
+ /* Add new node to segment indices. */
+ for (i = 0; i < subtable->n_indices; i++) {
+ hash = minimatch_hash_range(&new->match, prev_be32ofs,
+ subtable->index_ofs[i], &basis);
+ hindex_insert(&subtable->indices[i], &new->index_nodes[i], hash);
+ prev_be32ofs = subtable->index_ofs[i];
+ }
+ hash = minimatch_hash_range(&new->match, prev_be32ofs, FLOW_U32S, &basis);
+ head = find_equal(subtable, &new->match.flow, hash);
if (!head) {
- hmap_insert(&table->rules, &new->hmap_node, new->hmap_node.hash);
+ hmap_insert(&subtable->rules, &new->hmap_node, hash);
list_init(&new->list);
- return NULL;
+ goto out;
} else {
/* Scan the list for the insertion point that will keep the list in
* order of decreasing priority. */
struct cls_rule *rule;
+
+ new->hmap_node.hash = hash; /* Otherwise done by hmap_insert. */
+
FOR_EACH_RULE_IN_LIST (rule, head) {
if (new->priority >= rule->priority) {
if (rule == head) {
/* 'new' is the new highest-priority flow in the list. */
- hmap_replace(&table->rules,
+ hmap_replace(&subtable->rules,
&rule->hmap_node, &new->hmap_node);
}
if (new->priority == rule->priority) {
list_replace(&new->list, &rule->list);
- return rule;
+ old = rule;
+ goto out;
} else {
list_insert(&rule->list, &new->list);
- return NULL;
+ goto out;
}
}
}
/* Insert 'new' at the end of the list. */
list_push_back(&head->list, &new->list);
- return NULL;
}
+
+ out:
+ if (!old) {
+ update_subtables_after_insertion(cls, subtable, new->priority);
+ } else {
+ /* Remove old node from indices. */
+ for (i = 0; i < subtable->n_indices; i++) {
+ hindex_remove(&subtable->indices[i], &old->index_nodes[i]);
+ }
+ }
+ return old;
}
static struct cls_rule *
struct cls_rule *next = next_rule_in_list__(rule);
return next->priority < rule->priority ? next : NULL;
}
+\f
+/* A longest-prefix match tree. */
+struct trie_node {
+ uint32_t prefix; /* Prefix bits for this node, MSB first. */
+ uint8_t nbits; /* Never zero, except for the root node. */
+ unsigned int n_rules; /* Number of rules that have this prefix. */
+ struct trie_node *edges[2]; /* Both NULL if leaf. */
+};
+
+/* Max bits per node. Must fit in struct trie_node's 'prefix'.
+ * Also tested with 16, 8, and 5 to stress the implementation. */
+#define TRIE_PREFIX_BITS 32
+
+/* Return at least 'plen' bits of the 'prefix', starting at bit offset 'ofs'.
+ * Prefixes are in the network byte order, and the offset 0 corresponds to
+ * the most significant bit of the first byte. The offset can be read as
+ * "how many bits to skip from the start of the prefix starting at 'pr'". */
+static uint32_t
+raw_get_prefix(const ovs_be32 pr[], unsigned int ofs, unsigned int plen)
+{
+ uint32_t prefix;
+
+ pr += ofs / 32; /* Where to start. */
+ ofs %= 32; /* How many bits to skip at 'pr'. */
+
+ prefix = ntohl(*pr) << ofs; /* Get the first 32 - ofs bits. */
+ if (plen > 32 - ofs) { /* Need more than we have already? */
+ prefix |= ntohl(*++pr) >> (32 - ofs);
+ }
+ /* Return with possible unwanted bits at the end. */
+ return prefix;
+}
+
+/* Return min(TRIE_PREFIX_BITS, plen) bits of the 'prefix', starting at bit
+ * offset 'ofs'. Prefixes are in the network byte order, and the offset 0
+ * corresponds to the most significant bit of the first byte. The offset can
+ * be read as "how many bits to skip from the start of the prefix starting at
+ * 'pr'". */
+static uint32_t
+trie_get_prefix(const ovs_be32 pr[], unsigned int ofs, unsigned int plen)
+{
+ if (!plen) {
+ return 0;
+ }
+ if (plen > TRIE_PREFIX_BITS) {
+ plen = TRIE_PREFIX_BITS; /* Get at most TRIE_PREFIX_BITS. */
+ }
+ /* Return with unwanted bits cleared. */
+ return raw_get_prefix(pr, ofs, plen) & ~0u << (32 - plen);
+}
+
+/* Return the number of equal bits in 'nbits' of 'prefix's MSBs and a 'value'
+ * starting at "MSB 0"-based offset 'ofs'. */
+static unsigned int
+prefix_equal_bits(uint32_t prefix, unsigned int nbits, const ovs_be32 value[],
+ unsigned int ofs)
+{
+ uint64_t diff = prefix ^ raw_get_prefix(value, ofs, nbits);
+ /* Set the bit after the relevant bits to limit the result. */
+ return raw_clz64(diff << 32 | UINT64_C(1) << (63 - nbits));
+}
+
+/* Return the number of equal bits in 'node' prefix and a 'prefix' of length
+ * 'plen', starting at "MSB 0"-based offset 'ofs'. */
+static unsigned int
+trie_prefix_equal_bits(const struct trie_node *node, const ovs_be32 prefix[],
+ unsigned int ofs, unsigned int plen)
+{
+ return prefix_equal_bits(node->prefix, MIN(node->nbits, plen - ofs),
+ prefix, ofs);
+}
+
+/* Return the bit at ("MSB 0"-based) offset 'ofs' as an int. 'ofs' can
+ * be greater than 31. */
+static unsigned int
+be_get_bit_at(const ovs_be32 value[], unsigned int ofs)
+{
+ return (((const uint8_t *)value)[ofs / 8] >> (7 - ofs % 8)) & 1u;
+}
+
+/* Return the bit at ("MSB 0"-based) offset 'ofs' as an int. 'ofs' must
+ * be between 0 and 31, inclusive. */
+static unsigned int
+get_bit_at(const uint32_t prefix, unsigned int ofs)
+{
+ return (prefix >> (31 - ofs)) & 1u;
+}
+
+/* Create new branch. */
+static struct trie_node *
+trie_branch_create(const ovs_be32 *prefix, unsigned int ofs, unsigned int plen,
+ unsigned int n_rules)
+{
+ struct trie_node *node = xmalloc(sizeof *node);
+
+ node->prefix = trie_get_prefix(prefix, ofs, plen);
+
+ if (plen <= TRIE_PREFIX_BITS) {
+ node->nbits = plen;
+ node->edges[0] = NULL;
+ node->edges[1] = NULL;
+ node->n_rules = n_rules;
+ } else { /* Need intermediate nodes. */
+ struct trie_node *subnode = trie_branch_create(prefix,
+ ofs + TRIE_PREFIX_BITS,
+ plen - TRIE_PREFIX_BITS,
+ n_rules);
+ int bit = get_bit_at(subnode->prefix, 0);
+ node->nbits = TRIE_PREFIX_BITS;
+ node->edges[bit] = subnode;
+ node->edges[!bit] = NULL;
+ node->n_rules = 0;
+ }
+ return node;
+}
+
+static void
+trie_node_destroy(struct trie_node *node)
+{
+ free(node);
+}
+
+static void
+trie_destroy(struct trie_node *node)
+{
+ if (node) {
+ trie_destroy(node->edges[0]);
+ trie_destroy(node->edges[1]);
+ free(node);
+ }
+}
+
+static bool
+trie_is_leaf(const struct trie_node *trie)
+{
+ return !trie->edges[0] && !trie->edges[1]; /* No children. */
+}
+
+static void
+mask_set_prefix_bits(struct flow_wildcards *wc, uint8_t be32ofs,
+ unsigned int nbits)
+{
+ ovs_be32 *mask = &((ovs_be32 *)&wc->masks)[be32ofs];
+ unsigned int i;
+
+ for (i = 0; i < nbits / 32; i++) {
+ mask[i] = OVS_BE32_MAX;
+ }
+ if (nbits % 32) {
+ mask[i] |= htonl(~0u << (32 - nbits % 32));
+ }
+}
+
+static bool
+mask_prefix_bits_set(const struct flow_wildcards *wc, uint8_t be32ofs,
+ unsigned int nbits)
+{
+ ovs_be32 *mask = &((ovs_be32 *)&wc->masks)[be32ofs];
+ unsigned int i;
+ ovs_be32 zeroes = 0;
+
+ for (i = 0; i < nbits / 32; i++) {
+ zeroes |= ~mask[i];
+ }
+ if (nbits % 32) {
+ zeroes |= ~mask[i] & htonl(~0u << (32 - nbits % 32));
+ }
+
+ return !zeroes; /* All 'nbits' bits set. */
+}
+
+static struct trie_node **
+trie_next_edge(struct trie_node *node, const ovs_be32 value[],
+ unsigned int ofs)
+{
+ return node->edges + be_get_bit_at(value, ofs);
+}
+
+static const struct trie_node *
+trie_next_node(const struct trie_node *node, const ovs_be32 value[],
+ unsigned int ofs)
+{
+ return node->edges[be_get_bit_at(value, ofs)];
+}
+
+/* Return the prefix mask length necessary to find the longest-prefix match for
+ * the '*value' in the prefix tree 'node'.
+ * '*checkbits' is set to the number of bits in the prefix mask necessary to
+ * determine a mismatch, in case there are longer prefixes in the tree below
+ * the one that matched.
+ */
+static unsigned int
+trie_lookup_value(const struct trie_node *node, const ovs_be32 value[],
+ unsigned int *checkbits)
+{
+ unsigned int plen = 0, match_len = 0;
+ const struct trie_node *prev = NULL;
+
+ for (; node; prev = node, node = trie_next_node(node, value, plen)) {
+ unsigned int eqbits;
+ /* Check if this edge can be followed. */
+ eqbits = prefix_equal_bits(node->prefix, node->nbits, value, plen);
+ plen += eqbits;
+ if (eqbits < node->nbits) { /* Mismatch, nothing more to be found. */
+ /* Bit at offset 'plen' differed. */
+ *checkbits = plen + 1; /* Includes the first mismatching bit. */
+ return match_len;
+ }
+ /* Full match, check if rules exist at this prefix length. */
+ if (node->n_rules > 0) {
+ match_len = plen;
+ }
+ }
+ /* Dead end, exclude the other branch if it exists. */
+ *checkbits = !prev || trie_is_leaf(prev) ? plen : plen + 1;
+ return match_len;
+}
+
+static unsigned int
+trie_lookup(const struct cls_trie *trie, const struct flow *flow,
+ unsigned int *checkbits)
+{
+ const struct mf_field *mf = trie->field;
+
+ /* Check that current flow matches the prerequisites for the trie
+ * field. Some match fields are used for multiple purposes, so we
+ * must check that the trie is relevant for this flow. */
+ if (mf_are_prereqs_ok(mf, flow)) {
+ return trie_lookup_value(trie->root,
+ &((ovs_be32 *)flow)[mf->flow_be32ofs],
+ checkbits);
+ }
+ *checkbits = 0; /* Value not used in this case. */
+ return UINT_MAX;
+}
+
+/* Returns the length of a prefix match mask for the field 'mf' in 'minimask'.
+ * Returns the u32 offset to the miniflow data in '*miniflow_index', if
+ * 'miniflow_index' is not NULL. */
+static unsigned int
+minimask_get_prefix_len(const struct minimask *minimask,
+ const struct mf_field *mf)
+{
+ unsigned int nbits = 0, mask_tz = 0; /* Non-zero when end of mask seen. */
+ uint8_t u32_ofs = mf->flow_be32ofs;
+ uint8_t u32_end = u32_ofs + mf->n_bytes / 4;
+
+ for (; u32_ofs < u32_end; ++u32_ofs) {
+ uint32_t mask;
+ mask = ntohl((OVS_FORCE ovs_be32)minimask_get(minimask, u32_ofs));
+
+ /* Validate mask, count the mask length. */
+ if (mask_tz) {
+ if (mask) {
+ return 0; /* No bits allowed after mask ended. */
+ }
+ } else {
+ if (~mask & (~mask + 1)) {
+ return 0; /* Mask not contiguous. */
+ }
+ mask_tz = ctz32(mask);
+ nbits += 32 - mask_tz;
+ }
+ }
+
+ return nbits;
+}
+
+/*
+ * This is called only when mask prefix is known to be CIDR and non-zero.
+ * Relies on the fact that the flow and mask have the same map, and since
+ * the mask is CIDR, the storage for the flow field exists even if it
+ * happened to be zeros.
+ */
+static const ovs_be32 *
+minimatch_get_prefix(const struct minimatch *match, const struct mf_field *mf)
+{
+ return match->flow.values +
+ count_1bits(match->flow.map & ((UINT64_C(1) << mf->flow_be32ofs) - 1));
+}
+
+/* Insert rule in to the prefix tree.
+ * 'mlen' must be the (non-zero) CIDR prefix length of the 'trie->field' mask
+ * in 'rule'. */
+static void
+trie_insert(struct cls_trie *trie, const struct cls_rule *rule, int mlen)
+{
+ const ovs_be32 *prefix = minimatch_get_prefix(&rule->match, trie->field);
+ struct trie_node *node;
+ struct trie_node **edge;
+ int ofs = 0;
+
+ /* Walk the tree. */
+ for (edge = &trie->root;
+ (node = *edge) != NULL;
+ edge = trie_next_edge(node, prefix, ofs)) {
+ unsigned int eqbits = trie_prefix_equal_bits(node, prefix, ofs, mlen);
+ ofs += eqbits;
+ if (eqbits < node->nbits) {
+ /* Mismatch, new node needs to be inserted above. */
+ int old_branch = get_bit_at(node->prefix, eqbits);
+
+ /* New parent node. */
+ *edge = trie_branch_create(prefix, ofs - eqbits, eqbits,
+ ofs == mlen ? 1 : 0);
+
+ /* Adjust old node for its new position in the tree. */
+ node->prefix <<= eqbits;
+ node->nbits -= eqbits;
+ (*edge)->edges[old_branch] = node;
+
+ /* Check if need a new branch for the new rule. */
+ if (ofs < mlen) {
+ (*edge)->edges[!old_branch]
+ = trie_branch_create(prefix, ofs, mlen - ofs, 1);
+ }
+ return;
+ }
+ /* Full match so far. */
+
+ if (ofs == mlen) {
+ /* Full match at the current node, rule needs to be added here. */
+ node->n_rules++;
+ return;
+ }
+ }
+ /* Must insert a new tree branch for the new rule. */
+ *edge = trie_branch_create(prefix, ofs, mlen - ofs, 1);
+}
+
+/* 'mlen' must be the (non-zero) CIDR prefix length of the 'trie->field' mask
+ * in 'rule'. */
+static void
+trie_remove(struct cls_trie *trie, const struct cls_rule *rule, int mlen)
+{
+ const ovs_be32 *prefix = minimatch_get_prefix(&rule->match, trie->field);
+ struct trie_node *node;
+ struct trie_node **edges[sizeof(union mf_value) * 8];
+ int depth = 0, ofs = 0;
+
+ /* Walk the tree. */
+ for (edges[depth] = &trie->root;
+ (node = *edges[depth]) != NULL;
+ edges[++depth] = trie_next_edge(node, prefix, ofs)) {
+ unsigned int eqbits = trie_prefix_equal_bits(node, prefix, ofs, mlen);
+ if (eqbits < node->nbits) {
+ /* Mismatch, nothing to be removed. This should never happen, as
+ * only rules in the classifier are ever removed. */
+ break; /* Log a warning. */
+ }
+ /* Full match so far. */
+ ofs += eqbits;
+
+ if (ofs == mlen) {
+ /* Full prefix match at the current node, remove rule here. */
+ if (!node->n_rules) {
+ break; /* Log a warning. */
+ }
+ node->n_rules--;
+
+ /* Check if can prune the tree. */
+ while (!node->n_rules && !(node->edges[0] && node->edges[1])) {
+ /* No rules and at most one child node, remove this node. */
+ struct trie_node *next;
+ next = node->edges[0] ? node->edges[0] : node->edges[1];
+
+ if (next) {
+ if (node->nbits + next->nbits > TRIE_PREFIX_BITS) {
+ break; /* Cannot combine. */
+ }
+ /* Combine node with next. */
+ next->prefix = node->prefix | next->prefix >> node->nbits;
+ next->nbits += node->nbits;
+ }
+ trie_node_destroy(node);
+ /* Update the parent's edge. */
+ *edges[depth] = next;
+ if (next || !depth) {
+ /* Branch not pruned or at root, nothing more to do. */
+ break;
+ }
+ node = *edges[--depth];
+ }
+ return;
+ }
+ }
+ /* Cannot go deeper. This should never happen, since only rules
+ * that actually exist in the classifier are ever removed. */
+ VLOG_WARN("Trying to remove non-existing rule from a prefix trie.");
+}
git://git.onelab.eu / sliver-openvswitch.git / blobdiff