#include "dynamic-string.h"
#include "flow.h"
#include "hash.h"
+#include "cmap.h"
+#include "list.h"
#include "odp-util.h"
#include "ofp-util.h"
-#include "packets.h"
#include "ovs-thread.h"
+#include "packets.h"
+#include "pvector.h"
+#include "tag.h"
+#include "util.h"
+#include "vlog.h"
+
+VLOG_DEFINE_THIS_MODULE(classifier);
+
+struct trie_node;
+struct trie_ctx;
+
+/* Ports trie depends on both ports sharing the same ovs_be32. */
+#define TP_PORTS_OFS32 (offsetof(struct flow, tp_src) / 4)
+BUILD_ASSERT_DECL(TP_PORTS_OFS32 == offsetof(struct flow, tp_dst) / 4);
+
+typedef OVSRCU_TYPE(struct trie_node *) rcu_trie_ptr;
+
+/* Prefix trie for a 'field' */
+struct cls_trie {
+ const struct mf_field *field; /* Trie field, or NULL. */
+ rcu_trie_ptr root; /* NULL if none. */
+};
+
+enum {
+ CLS_MAX_INDICES = 3 /* Maximum number of lookup indices per subtable. */
+};
+
+struct cls_classifier {
+ struct ovs_mutex mutex;
+ int n_rules OVS_GUARDED; /* Total number of rules. */
+ uint8_t n_flow_segments;
+ uint8_t flow_segments[CLS_MAX_INDICES]; /* Flow segment boundaries to use
+ * for staged lookup. */
+ struct cmap subtables_map; /* Contains "struct cls_subtable"s. */
+ struct pvector subtables;
+ struct cmap partitions; /* Contains "struct cls_partition"s. */
+ struct cls_trie tries[CLS_MAX_TRIES]; /* Prefix tries. */
+ unsigned int n_tries;
+};
+
+/* A set of rules that all have the same fields wildcarded. */
+struct cls_subtable {
+ /* The fields are only used by writers and iterators. */
+ struct cmap_node cmap_node; /* Within struct cls_classifier
+ * 'subtables_map'. */
+
+ /* The fields are only used by writers. */
+ int n_rules OVS_GUARDED; /* Number of rules, including
+ * duplicates. */
+ unsigned int max_priority OVS_GUARDED; /* Max priority of any rule in
+ * the subtable. */
+ unsigned int max_count OVS_GUARDED; /* Count of max_priority rules. */
+
+ /* These fields are accessed by readers who care about wildcarding. */
+ tag_type tag; /* Tag generated from mask for partitioning (const). */
+ uint8_t n_indices; /* How many indices to use (const). */
+ uint8_t index_ofs[CLS_MAX_INDICES]; /* u32 segment boundaries (const). */
+ unsigned int trie_plen[CLS_MAX_TRIES]; /* Trie prefix length in 'mask'
+ * (runtime configurable). */
+ int ports_mask_len; /* (const) */
+ struct cmap indices[CLS_MAX_INDICES]; /* Staged lookup indices. */
+ rcu_trie_ptr ports_trie; /* NULL if none. */
+
+ /* These fields are accessed by all readers. */
+ struct cmap rules; /* Contains "struct cls_rule"s. */
+ struct minimask mask; /* Wildcards for fields (const). */
+ /* 'mask' must be the last field. */
+};
+
+/* Associates a metadata value (that is, a value of the OpenFlow 1.1+ metadata
+ * field) with tags for the "cls_subtable"s that contain rules that match that
+ * metadata value. */
+struct cls_partition {
+ struct cmap_node cmap_node; /* In struct cls_classifier's 'partitions'
+ * map. */
+ ovs_be64 metadata; /* metadata value for this partition. */
+ tag_type tags; /* OR of each flow's cls_subtable tag. */
+ struct tag_tracker tracker OVS_GUARDED; /* Tracks the bits in 'tags'. */
+};
+
+/* Internal representation of a rule in a "struct cls_subtable". */
+struct cls_match {
+ /* Accessed only by writers and iterators. */
+ struct list list OVS_GUARDED; /* List of identical, lower-priority rules. */
+
+ /* Accessed only by writers. */
+ struct cls_partition *partition OVS_GUARDED;
+
+ /* Accessed by readers interested in wildcarding. */
+ unsigned int priority; /* Larger numbers are higher priorities. */
+ struct cmap_node index_nodes[CLS_MAX_INDICES]; /* Within subtable's
+ * 'indices'. */
+ /* Accessed by all readers. */
+ struct cmap_node cmap_node; /* Within struct cls_subtable 'rules'. */
+ struct cls_rule *cls_rule;
+ struct miniflow flow; /* Matching rule. Mask is in the subtable. */
+ /* 'flow' must be the last field. */
+};
+
+static struct cls_match *
+cls_match_alloc(struct cls_rule *rule)
+{
+ int count = count_1bits(rule->match.flow.map);
-static struct cls_table *find_table(const struct classifier *,
- const struct minimask *);
-static struct cls_table *insert_table(struct classifier *,
- const struct minimask *);
-
-static void destroy_table(struct classifier *, struct cls_table *);
+ struct cls_match *cls_match
+ = xmalloc(sizeof *cls_match - sizeof cls_match->flow.inline_values
+ + MINIFLOW_VALUES_SIZE(count));
-static void update_tables_after_insertion(struct classifier *,
- struct cls_table *,
- unsigned int new_priority);
-static void update_tables_after_removal(struct classifier *,
- struct cls_table *,
- unsigned int del_priority);
+ cls_match->cls_rule = rule;
+ miniflow_clone_inline(&cls_match->flow, &rule->match.flow, count);
+ cls_match->priority = rule->priority;
+ rule->cls_match = cls_match;
-static struct cls_rule *find_match(const struct cls_table *,
- const struct flow *);
-static struct cls_rule *find_equal(struct cls_table *,
- const struct miniflow *, uint32_t hash);
-static struct cls_rule *insert_rule(struct classifier *,
- struct cls_table *, struct cls_rule *);
+ return cls_match;
+}
-/* Iterates RULE over HEAD and all of the cls_rules on HEAD->list. */
+static struct cls_subtable *find_subtable(const struct cls_classifier *cls,
+ const struct minimask *)
+ OVS_REQUIRES(cls->mutex);
+static struct cls_subtable *insert_subtable(struct cls_classifier *cls,
+ const struct minimask *)
+ OVS_REQUIRES(cls->mutex);
+static void destroy_subtable(struct cls_classifier *cls, struct cls_subtable *)
+ OVS_REQUIRES(cls->mutex);
+static struct cls_match *insert_rule(struct cls_classifier *cls,
+ struct cls_subtable *, struct cls_rule *)
+ OVS_REQUIRES(cls->mutex);
+
+static struct cls_match *find_match_wc(const struct cls_subtable *,
+ const struct flow *, struct trie_ctx *,
+ unsigned int n_tries,
+ struct flow_wildcards *);
+static struct cls_match *find_equal(struct cls_subtable *,
+ const struct miniflow *, uint32_t hash);
+
+/* Iterates RULE over HEAD and all of the cls_rules on HEAD->list.
+ * Classifier's mutex must be held while iterating, as the list is
+ * protoceted by it. */
#define FOR_EACH_RULE_IN_LIST(RULE, HEAD) \
for ((RULE) = (HEAD); (RULE) != NULL; (RULE) = next_rule_in_list(RULE))
#define FOR_EACH_RULE_IN_LIST_SAFE(RULE, NEXT, HEAD) \
(RULE) != NULL && ((NEXT) = next_rule_in_list(RULE), true); \
(RULE) = (NEXT))
-static struct cls_rule *next_rule_in_list__(struct cls_rule *);
-static struct cls_rule *next_rule_in_list(struct cls_rule *);
+static struct cls_match *next_rule_in_list__(struct cls_match *);
+static struct cls_match *next_rule_in_list(struct cls_match *);
+
+static unsigned int minimask_get_prefix_len(const struct minimask *,
+ const struct mf_field *);
+static void trie_init(struct cls_classifier *cls, int trie_idx,
+ const struct mf_field *)
+ OVS_REQUIRES(cls->mutex);
+static unsigned int trie_lookup(const struct cls_trie *, const struct flow *,
+ unsigned int *checkbits);
+static unsigned int trie_lookup_value(const rcu_trie_ptr *,
+ const ovs_be32 value[],
+ unsigned int value_bits,
+ unsigned int *checkbits);
+static void trie_destroy(rcu_trie_ptr *);
+static void trie_insert(struct cls_trie *, const struct cls_rule *, int mlen);
+static void trie_insert_prefix(rcu_trie_ptr *, const ovs_be32 *prefix,
+ int mlen);
+static void trie_remove(struct cls_trie *, const struct cls_rule *, int mlen);
+static void trie_remove_prefix(rcu_trie_ptr *, const ovs_be32 *prefix,
+ int mlen);
+static void mask_set_prefix_bits(struct flow_wildcards *, uint8_t be32ofs,
+ unsigned int n_bits);
+static bool mask_prefix_bits_set(const struct flow_wildcards *,
+ uint8_t be32ofs, unsigned int n_bits);
+\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 *mask_values = miniflow_get_u32_values(&mask->masks);
+ const uint32_t *flow_u32 = (const uint32_t *)flow;
+ const uint32_t *p = mask_values;
+ uint32_t hash;
+ uint64_t map;
+
+ hash = basis;
+ for (map = mask->masks.map; map; map = zero_rightmost_1bit(map)) {
+ hash = hash_add(hash, flow_u32[raw_ctz(map)] & *p++);
+ }
+
+ return hash_finish(hash, (p - mask_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 *mask_values = miniflow_get_u32_values(&mask->masks);
+ const uint32_t *p = mask_values;
+ uint32_t hash = basis;
+ uint32_t flow_u32;
+
+ MINIFLOW_FOR_EACH_IN_MAP(flow_u32, flow, mask->masks.map) {
+ hash = hash_add(hash, flow_u32 & *p++);
+ }
+
+ return hash_finish(hash, (p - mask_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 *mask_values = miniflow_get_u32_values(&mask->masks);
+ 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_values + offset;
+ uint32_t hash = *basis;
+
+ for (; map; map = zero_rightmost_1bit(map)) {
+ hash = hash_add(hash, flow_u32[raw_ctz(map)] & *p++);
+ }
+
+ *basis = hash; /* Allow continuation from the unfinished value. */
+ return hash_finish(hash, (p - mask_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 = miniflow_get_u32_values(&mask->masks) + 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 *values = miniflow_get_u32_values(flow);
+ const uint32_t *p = 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 = hash_add(hash, *p);
+ hash_map |= rightmost_1bit(map);
+ }
+ p++;
+ }
+ hash = hash_add(hash, hash_map);
+ hash = hash_add(hash, hash_map >> 32);
+
+ return hash_finish(hash, p - 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 = miniflow_get_u32_values(&match->mask.masks) + offset;
+ p = miniflow_get_u32_values(&match->flow) + offset;
+
+ for (i = 0; i < n; i++) {
+ hash = hash_add(hash, p[i] & q[i]);
+ }
+ *basis = hash; /* Allow continuation from the unfinished value. */
+ return hash_finish(hash, (offset + n) * 4);
+}
+
\f
/* cls_rule. */
{
minimatch_init(&rule->match, match);
rule->priority = priority;
+ rule->cls_match = NULL;
}
/* Same as cls_rule_init() for initialization from a "struct minimatch". */
{
minimatch_clone(&rule->match, match);
rule->priority = priority;
+ rule->cls_match = NULL;
}
/* Initializes 'dst' as a copy of 'src'.
{
minimatch_clone(&dst->match, &src->match);
dst->priority = src->priority;
+ dst->cls_match = NULL;
}
/* Initializes 'dst' with the data in 'src', destroying 'src'.
{
minimatch_move(&dst->match, &src->match);
dst->priority = src->priority;
+ dst->cls_match = NULL;
}
/* Frees memory referenced by 'rule'. Doesn't free 'rule' itself (it's
void
cls_rule_destroy(struct cls_rule *rule)
{
+ ovs_assert(!rule->cls_match);
minimatch_destroy(&rule->match);
}
/* 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)
+ OVS_EXCLUDED(cls_->cls->mutex)
{
+ struct cls_classifier *cls = xmalloc(sizeof *cls);
+
+ ovs_mutex_init(&cls->mutex);
+
+ ovs_mutex_lock(&cls->mutex);
+ cls_->cls = cls;
+
cls->n_rules = 0;
- hmap_init(&cls->tables);
- list_init(&cls->tables_priority);
- ovs_rwlock_init(&cls->rwlock);
+ cmap_init(&cls->subtables_map);
+ pvector_init(&cls->subtables);
+ cmap_init(&cls->partitions);
+ 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;
+ for (int i = 0; i < CLS_MAX_TRIES; i++) {
+ trie_init(cls, i, NULL);
+ }
+ ovs_mutex_unlock(&cls->mutex);
}
/* Destroys 'cls'. Rules within 'cls', if any, are not freed; this is the
- * caller's responsibility. */
+ * caller's responsibility.
+ * May only be called after all the readers have been terminated. */
void
-classifier_destroy(struct classifier *cls)
+classifier_destroy(struct classifier *cls_)
+ OVS_EXCLUDED(cls_->cls->mutex)
{
- if (cls) {
- struct cls_table *table, *next_table;
+ if (cls_) {
+ struct cls_classifier *cls = cls_->cls;
+ struct cls_partition *partition, *next_partition;
+ struct cls_subtable *subtable, *next_subtable;
+ int i;
+
+ if (!cls) {
+ return;
+ }
+
+ ovs_mutex_lock(&cls->mutex);
+ for (i = 0; i < cls->n_tries; i++) {
+ trie_destroy(&cls->tries[i].root);
+ }
- HMAP_FOR_EACH_SAFE (table, next_table, hmap_node, &cls->tables) {
- destroy_table(cls, table);
+ CMAP_FOR_EACH_SAFE (subtable, next_subtable, cmap_node,
+ &cls->subtables_map) {
+ destroy_subtable(cls, subtable);
}
- hmap_destroy(&cls->tables);
- ovs_rwlock_destroy(&cls->rwlock);
+ cmap_destroy(&cls->subtables_map);
+
+ CMAP_FOR_EACH_SAFE (partition, next_partition, cmap_node,
+ &cls->partitions) {
+ ovsrcu_postpone(free, partition);
+ }
+ cmap_destroy(&cls->partitions);
+
+ pvector_destroy(&cls->subtables);
+ ovs_mutex_unlock(&cls->mutex);
+ ovs_mutex_destroy(&cls->mutex);
+ free(cls);
}
}
-/* Returns true if 'cls' contains no classification rules, false otherwise. */
+/* 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. */
+bool
+classifier_set_prefix_fields(struct classifier *cls_,
+ const enum mf_field_id *trie_fields,
+ unsigned int n_fields)
+ OVS_EXCLUDED(cls_->cls->mutex)
+{
+ struct cls_classifier *cls = cls_->cls;
+ uint64_t fields = 0;
+ const struct mf_field * new_fields[CLS_MAX_TRIES];
+ int i, n_tries = 0;
+ bool changed = false;
+
+ ovs_mutex_lock(&cls->mutex);
+ for (i = 0; i < n_fields && n_tries < 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];
+
+ new_fields[n_tries] = NULL;
+ if (n_tries >= cls->n_tries || field != cls->tries[n_tries].field) {
+ new_fields[n_tries] = field;
+ changed = true;
+ }
+ n_tries++;
+ }
+
+ if (changed || n_tries < cls->n_tries) {
+ struct cls_subtable *subtable;
+
+ /* Trie configuration needs to change. Disable trie lookups
+ * for the tries that are changing and wait all the current readers
+ * with the old configuration to be done. */
+ changed = false;
+ CMAP_FOR_EACH (subtable, cmap_node, &cls->subtables_map) {
+ for (i = 0; i < cls->n_tries; i++) {
+ if ((i < n_tries && new_fields[i]) || i >= n_tries) {
+ if (subtable->trie_plen[i]) {
+ subtable->trie_plen[i] = 0;
+ changed = true;
+ }
+ }
+ }
+ }
+ /* Synchronize if any readers were using tries. The readers may
+ * temporarily function without the trie lookup based optimizations. */
+ if (changed) {
+ /* ovsrcu_synchronize() functions as a memory barrier, so it does
+ * not matter that subtable->trie_plen is not atomic. */
+ ovsrcu_synchronize();
+ }
+
+ /* Now set up the tries. */
+ for (i = 0; i < n_tries; i++) {
+ if (new_fields[i]) {
+ trie_init(cls, i, new_fields[i]);
+ }
+ }
+ /* Destroy the rest, if any. */
+ for (; i < cls->n_tries; i++) {
+ trie_init(cls, i, NULL);
+ }
+
+ cls->n_tries = n_tries;
+ ovs_mutex_unlock(&cls->mutex);
+ return true;
+ }
+
+ ovs_mutex_unlock(&cls->mutex);
+ return false; /* No change. */
+}
+
+static void
+trie_init(struct cls_classifier *cls, int trie_idx,
+ const struct mf_field *field)
+ OVS_REQUIRES(cls->mutex)
+{
+ struct cls_trie *trie = &cls->tries[trie_idx];
+ struct cls_subtable *subtable;
+
+ if (trie_idx < cls->n_tries) {
+ trie_destroy(&trie->root);
+ } else {
+ ovsrcu_set_hidden(&trie->root, NULL);
+ }
+ trie->field = field;
+
+ /* Add existing rules to the new trie. */
+ CMAP_FOR_EACH (subtable, cmap_node, &cls->subtables_map) {
+ unsigned int plen;
+
+ plen = field ? minimask_get_prefix_len(&subtable->mask, field) : 0;
+ if (plen) {
+ struct cls_match *head;
+
+ CMAP_FOR_EACH (head, cmap_node, &subtable->rules) {
+ struct cls_match *match;
+
+ FOR_EACH_RULE_IN_LIST (match, head) {
+ trie_insert(trie, match->cls_rule, plen);
+ }
+ }
+ }
+ /* Initialize subtable's prefix length on this field. This will
+ * allow readers to use the trie. */
+ atomic_thread_fence(memory_order_release);
+ subtable->trie_plen[trie_idx] = plen;
+ }
+}
+
+/* Returns true if 'cls' contains no classification rules, false otherwise.
+ * Checking the cmap requires no locking. */
bool
classifier_is_empty(const struct classifier *cls)
{
- return cls->n_rules == 0;
+ return cmap_is_empty(&cls->cls->subtables_map);
}
/* Returns the number of rules in 'cls'. */
int
classifier_count(const struct classifier *cls)
+ OVS_NO_THREAD_SAFETY_ANALYSIS
+{
+ /* n_rules is an int, so in the presence of concurrent writers this will
+ * return either the old or a new value. */
+ return cls->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 cls_classifier *cls, ovs_be64 metadata,
+ uint32_t hash)
+{
+ struct cls_partition *partition;
+
+ CMAP_FOR_EACH_WITH_HASH (partition, cmap_node, hash, &cls->partitions) {
+ if (partition->metadata == metadata) {
+ return partition;
+ }
+ }
+
+ return NULL;
+}
+
+static struct cls_partition *
+create_partition(struct cls_classifier *cls, struct cls_subtable *subtable,
+ ovs_be64 metadata)
+ OVS_REQUIRES(cls->mutex)
+{
+ 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);
+ cmap_insert(&cls->partitions, &partition->cmap_node, hash);
+ }
+ tag_tracker_add(&partition->tracker, &partition->tags, subtable->tag);
+ return partition;
+}
+
+static inline ovs_be32 minimatch_get_ports(const struct minimatch *match)
{
- return cls->n_rules;
+ /* Could optimize to use the same map if needed for fast path. */
+ return MINIFLOW_GET_BE32(&match->flow, tp_src)
+ & MINIFLOW_GET_BE32(&match->mask.masks, tp_src);
}
/* Inserts 'rule' into 'cls'. Until 'rule' is removed from 'cls', the caller
* rule, even rules that cannot have any effect because the new rule matches a
* superset of their flows and has higher priority. */
struct cls_rule *
-classifier_replace(struct classifier *cls, struct cls_rule *rule)
+classifier_replace(struct classifier *cls_, struct cls_rule *rule)
+ OVS_EXCLUDED(cls_->cls->mutex)
{
- struct cls_rule *old_rule;
- struct cls_table *table;
-
- table = find_table(cls, &rule->match.mask);
- if (!table) {
- table = insert_table(cls, &rule->match.mask);
+ struct cls_classifier *cls = cls_->cls;
+ struct cls_match *old_rule;
+ struct cls_subtable *subtable;
+ struct cls_rule *old_cls_rule = NULL;
+
+ ovs_mutex_lock(&cls->mutex);
+ subtable = find_subtable(cls, &rule->match.mask);
+ if (!subtable) {
+ subtable = insert_subtable(cls, &rule->match.mask);
}
- old_rule = insert_rule(cls, table, rule);
+ old_rule = insert_rule(cls, subtable, rule);
if (!old_rule) {
- table->n_table_rules++;
+ old_cls_rule = NULL;
+
+ rule->cls_match->partition = NULL;
+ if (minimask_get_metadata_mask(&rule->match.mask) == OVS_BE64_MAX) {
+ ovs_be64 metadata = miniflow_get_metadata(&rule->match.flow);
+ rule->cls_match->partition = create_partition(cls, subtable,
+ metadata);
+ }
+
cls->n_rules++;
+
+ for (int i = 0; i < cls->n_tries; i++) {
+ if (subtable->trie_plen[i]) {
+ trie_insert(&cls->tries[i], rule, subtable->trie_plen[i]);
+ }
+ }
+
+ /* Ports trie. */
+ if (subtable->ports_mask_len) {
+ /* We mask the value to be inserted to always have the wildcarded
+ * bits in known (zero) state, so we can include them in comparison
+ * and they will always match (== their original value does not
+ * matter). */
+ ovs_be32 masked_ports = minimatch_get_ports(&rule->match);
+
+ trie_insert_prefix(&subtable->ports_trie, &masked_ports,
+ subtable->ports_mask_len);
+ }
+ } else {
+ old_cls_rule = old_rule->cls_rule;
+ rule->cls_match->partition = old_rule->partition;
+ old_cls_rule->cls_match = NULL;
+
+ /* 'old_rule' contains a cmap_node, which may not be freed
+ * immediately. */
+ ovsrcu_postpone(free, old_rule);
}
- return old_rule;
+ ovs_mutex_unlock(&cls->mutex);
+ return old_cls_rule;
}
/* Inserts 'rule' into 'cls'. Until 'rule' is removed from 'cls', the caller
* 'rule' with cls_rule_destroy(), freeing the memory block in which 'rule'
* resides, etc., as necessary. */
void
-classifier_remove(struct classifier *cls, struct cls_rule *rule)
+classifier_remove(struct classifier *cls_, struct cls_rule *rule)
+ OVS_EXCLUDED(cls_->cls->mutex)
{
- struct cls_rule *head;
- struct cls_table *table;
+ struct cls_classifier *cls = cls_->cls;
+ struct cls_partition *partition;
+ struct cls_match *cls_match = rule->cls_match;
+ struct cls_match *head;
+ struct cls_subtable *subtable;
+ int i;
+ uint32_t basis = 0, hash, ihash[CLS_MAX_INDICES];
+ uint8_t prev_be32ofs = 0;
+
+ ovs_assert(cls_match);
+
+ ovs_mutex_lock(&cls->mutex);
+ subtable = find_subtable(cls, &rule->match.mask);
+ ovs_assert(subtable);
+
+ if (subtable->ports_mask_len) {
+ ovs_be32 masked_ports = minimatch_get_ports(&rule->match);
+
+ trie_remove_prefix(&subtable->ports_trie,
+ &masked_ports, subtable->ports_mask_len);
+ }
+ for (i = 0; i < cls->n_tries; i++) {
+ if (subtable->trie_plen[i]) {
+ trie_remove(&cls->tries[i], rule, subtable->trie_plen[i]);
+ }
+ }
+
+ /* Remove rule node from indices. */
+ for (i = 0; i < subtable->n_indices; i++) {
+ ihash[i] = minimatch_hash_range(&rule->match, prev_be32ofs,
+ subtable->index_ofs[i], &basis);
+ cmap_remove(&subtable->indices[i], &cls_match->index_nodes[i],
+ ihash[i]);
+ prev_be32ofs = subtable->index_ofs[i];
+ }
+ hash = minimatch_hash_range(&rule->match, prev_be32ofs, FLOW_U32S, &basis);
- table = find_table(cls, &rule->match.mask);
- head = find_equal(table, &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);
+ head = find_equal(subtable, &rule->match.flow, hash);
+ if (head != cls_match) {
+ list_remove(&cls_match->list);
+ } else if (list_is_empty(&cls_match->list)) {
+ cmap_remove(&subtable->rules, &cls_match->cmap_node, hash);
} else {
- struct cls_rule *next = CONTAINER_OF(rule->list.next,
- struct cls_rule, list);
+ struct cls_match *next = CONTAINER_OF(cls_match->list.next,
+ struct cls_match, list);
- list_remove(&rule->list);
- hmap_replace(&table->rules, &rule->hmap_node, &next->hmap_node);
+ list_remove(&cls_match->list);
+ cmap_replace(&subtable->rules, &cls_match->cmap_node,
+ &next->cmap_node, hash);
}
- if (--table->n_table_rules == 0) {
- destroy_table(cls, table);
- } else {
- update_tables_after_removal(cls, table, rule->priority);
+ partition = cls_match->partition;
+ if (partition) {
+ tag_tracker_subtract(&partition->tracker, &partition->tags,
+ subtable->tag);
+ if (!partition->tags) {
+ cmap_remove(&cls->partitions, &partition->cmap_node,
+ hash_metadata(partition->metadata));
+ ovsrcu_postpone(free, partition);
+ }
}
+
+ if (--subtable->n_rules == 0) {
+ destroy_subtable(cls, subtable);
+ } else if (subtable->max_priority == cls_match->priority
+ && --subtable->max_count == 0) {
+ /* Find the new 'max_priority' and 'max_count'. */
+ struct cls_match *head;
+ unsigned int max_priority = 0;
+
+ CMAP_FOR_EACH (head, cmap_node, &subtable->rules) {
+ if (head->priority > max_priority) {
+ max_priority = head->priority;
+ subtable->max_count = 1;
+ } else if (head->priority == max_priority) {
+ ++subtable->max_count;
+ }
+ }
+ subtable->max_priority = max_priority;
+ pvector_change_priority(&cls->subtables, subtable, max_priority);
+ }
+
cls->n_rules--;
+
+ rule->cls_match = NULL;
+ ovsrcu_postpone(free, cls_match);
+ ovs_mutex_unlock(&cls->mutex);
+}
+
+/* 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'.
* 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;
- struct cls_rule *best;
+ struct cls_classifier *cls = cls_->cls;
+ const struct cls_partition *partition;
+ tag_type tags;
+ int64_t best_priority = -1;
+ const struct cls_match *best;
+ struct trie_ctx trie_ctx[CLS_MAX_TRIES];
+ struct cls_subtable *subtable;
+
+ /* Synchronize for cls->n_tries and subtable->trie_plen. They can change
+ * when table configuration changes, which happens typically only on
+ * startup. */
+ atomic_thread_fence(memory_order_acquire);
+
+ /* 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 = (cmap_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 (int i = 0; i < cls->n_tries; i++) {
+ trie_ctx_init(&trie_ctx[i], &cls->tries[i]);
+ }
best = NULL;
- LIST_FOR_EACH (table, list_node, &cls->tables_priority) {
- struct cls_rule *rule = find_match(table, flow);
+ PVECTOR_FOR_EACH_PRIORITY(subtable, best_priority, 2,
+ sizeof(struct cls_subtable), &cls->subtables) {
+ struct cls_match *rule;
- if (wc) {
- flow_wildcards_fold_minimask(wc, &table->mask);
+ if (!tag_intersects(tags, subtable->tag)) {
+ continue;
}
- if (rule) {
+
+ rule = find_match_wc(subtable, flow, trie_ctx, cls->n_tries, wc);
+ if (rule && (int64_t)rule->priority > best_priority) {
+ best_priority = (int64_t)rule->priority;
best = rule;
- LIST_FOR_EACH_CONTINUE (table, list_node, &cls->tables_priority) {
- if (table->max_priority <= best->priority) {
- /* Tables in descending priority order,
- * can not find anything better. */
- return best;
- }
- rule = find_match(table, flow);
- if (wc) {
- flow_wildcards_fold_minimask(wc, &table->mask);
- }
- if (rule && rule->priority > best->priority) {
- best = rule;
- }
+ }
+ }
+
+ return best ? best->cls_rule : NULL;
+}
+
+/* Returns true if 'target' satisifies 'match', that is, if each bit for which
+ * 'match' specifies a particular value has the correct value in 'target'.
+ *
+ * 'flow' and 'mask' have the same mask! */
+static bool
+miniflow_and_mask_matches_miniflow(const struct miniflow *flow,
+ const struct minimask *mask,
+ const struct miniflow *target)
+{
+ const uint32_t *flowp = miniflow_get_u32_values(flow);
+ const uint32_t *maskp = miniflow_get_u32_values(&mask->masks);
+ uint32_t target_u32;
+
+ MINIFLOW_FOR_EACH_IN_MAP(target_u32, target, mask->masks.map) {
+ if ((*flowp++ ^ target_u32) & *maskp++) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+static inline struct cls_match *
+find_match_miniflow(const struct cls_subtable *subtable,
+ const struct miniflow *flow,
+ uint32_t hash)
+{
+ struct cls_match *rule;
+
+ CMAP_FOR_EACH_WITH_HASH (rule, cmap_node, hash, &subtable->rules) {
+ if (miniflow_and_mask_matches_miniflow(&rule->flow, &subtable->mask,
+ flow)) {
+ return rule;
+ }
+ }
+
+ return NULL;
+}
+
+/* For each miniflow in 'flows' performs a classifier lookup writing the result
+ * into the corresponding slot in 'rules'. If a particular entry in 'flows' is
+ * NULL it is skipped.
+ *
+ * This function is optimized for use in the userspace datapath and therefore
+ * does not implement a lot of features available in the standard
+ * classifier_lookup() function. Specifically, it does not implement
+ * priorities, instead returning any rule which matches the flow. */
+void
+classifier_lookup_miniflow_batch(const struct classifier *cls_,
+ const struct miniflow **flows,
+ struct cls_rule **rules, size_t len)
+{
+ struct cls_classifier *cls = cls_->cls;
+ struct cls_subtable *subtable;
+ size_t i, begin = 0;
+
+ memset(rules, 0, len * sizeof *rules);
+ PVECTOR_FOR_EACH (subtable, &cls->subtables) {
+ for (i = begin; i < len; i++) {
+ struct cls_match *match;
+ uint32_t hash;
+
+ if (OVS_UNLIKELY(rules[i] || !flows[i])) {
+ continue;
}
+
+ hash = miniflow_hash_in_minimask(flows[i], &subtable->mask, 0);
+ match = find_match_miniflow(subtable, flows[i], hash);
+ if (OVS_UNLIKELY(match)) {
+ rules[i] = match->cls_rule;
+ }
+ }
+
+ while (begin < len && (rules[begin] || !flows[begin])) {
+ begin++;
+ }
+ if (begin >= len) {
break;
}
}
- return best;
}
/* 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. */
struct cls_rule *
-classifier_find_rule_exactly(const struct classifier *cls,
+classifier_find_rule_exactly(const struct classifier *cls_,
const struct cls_rule *target)
+ OVS_EXCLUDED(cls_->cls->mutex)
{
- struct cls_rule *head, *rule;
- struct cls_table *table;
+ struct cls_classifier *cls = cls_->cls;
+ struct cls_match *head, *rule;
+ struct cls_subtable *subtable;
- table = find_table(cls, &target->match.mask);
- if (!table) {
- return NULL;
+ ovs_mutex_lock(&cls->mutex);
+ subtable = find_subtable(cls, &target->match.mask);
+ if (!subtable) {
+ goto out;
}
/* Skip if there is no hope. */
- if (target->priority > table->max_priority) {
- return NULL;
+ if (target->priority > subtable->max_priority) {
+ goto out;
}
- head = find_equal(table, &target->match.flow,
+ 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;
+ ovs_mutex_unlock(&cls->mutex);
+ return target->priority == rule->priority ? rule->cls_rule : NULL;
}
}
+out:
+ ovs_mutex_unlock(&cls->mutex);
return NULL;
}
* considered to overlap if both rules have the same priority and a packet
* could match both. */
bool
-classifier_rule_overlaps(const struct classifier *cls,
+classifier_rule_overlaps(const struct classifier *cls_,
const struct cls_rule *target)
+ OVS_EXCLUDED(cls_->cls->mutex)
{
- struct cls_table *table;
-
- /* Iterate tables in the descending max priority order. */
- LIST_FOR_EACH (table, list_node, &cls->tables_priority) {
+ struct cls_classifier *cls = cls_->cls;
+ struct cls_subtable *subtable;
+ int64_t stop_at_priority = (int64_t)target->priority - 1;
+
+ ovs_mutex_lock(&cls->mutex);
+ /* Iterate subtables in the descending max priority order. */
+ PVECTOR_FOR_EACH_PRIORITY (subtable, stop_at_priority, 2,
+ sizeof(struct cls_subtable), &cls->subtables) {
uint32_t storage[FLOW_U32S];
struct minimask mask;
- struct cls_rule *head;
-
- if (target->priority > table->max_priority) {
- break; /* Can skip this and the rest of the tables. */
- }
+ struct cls_match *head;
- minimask_combine(&mask, &target->match.mask, &table->mask, storage);
- HMAP_FOR_EACH (head, hmap_node, &table->rules) {
- struct cls_rule *rule;
+ minimask_combine(&mask, &target->match.mask, &subtable->mask, storage);
+ CMAP_FOR_EACH (head, cmap_node, &subtable->rules) {
+ struct cls_match *rule;
FOR_EACH_RULE_IN_LIST (rule, head) {
if (rule->priority < target->priority) {
}
if (rule->priority == target->priority
&& miniflow_equal_in_minimask(&target->match.flow,
- &rule->match.flow, &mask)) {
+ &rule->flow, &mask)) {
+ ovs_mutex_unlock(&cls->mutex);
return true;
}
}
}
}
+ ovs_mutex_unlock(&cls->mutex);
return false;
}
/* Iteration. */
static bool
-rule_matches(const struct cls_rule *rule, const struct cls_rule *target)
+rule_matches(const struct cls_match *rule, const struct cls_rule *target)
{
return (!target
- || miniflow_equal_in_minimask(&rule->match.flow,
+ || miniflow_equal_in_minimask(&rule->flow,
&target->match.flow,
&target->match.mask));
}
-static struct cls_rule *
-search_table(const struct cls_table *table, const struct cls_rule *target)
+static struct cls_match *
+search_subtable(const struct cls_subtable *subtable,
+ struct cls_cursor *cursor)
{
- if (!target || !minimask_has_extra(&table->mask, &target->match.mask)) {
- struct cls_rule *rule;
+ if (!cursor->target
+ || !minimask_has_extra(&subtable->mask, &cursor->target->match.mask)) {
+ struct cls_match *rule;
- HMAP_FOR_EACH (rule, hmap_node, &table->rules) {
- if (rule_matches(rule, target)) {
+ CMAP_CURSOR_FOR_EACH (rule, cmap_node, &cursor->rules,
+ &subtable->rules) {
+ if (rule_matches(rule, cursor->target)) {
return rule;
}
}
return NULL;
}
-/* Initializes 'cursor' for iterating through rules in 'cls':
+/* Initializes 'cursor' for iterating through rules in 'cls', and returns the
+ * first matching cls_rule via '*pnode', or NULL if there are no matches.
*
* - If 'target' is null, the cursor will visit every rule in 'cls'.
*
* such that cls_rule_is_loose_match(rule, target) returns true.
*
* Ignores target->priority. */
-void
-cls_cursor_init(struct cls_cursor *cursor, const struct classifier *cls,
- const struct cls_rule *target)
+struct cls_cursor cls_cursor_init(const struct classifier *cls,
+ const struct cls_rule *target,
+ void **pnode, const void *offset, bool safe)
+ OVS_NO_THREAD_SAFETY_ANALYSIS
{
- cursor->cls = cls;
- cursor->target = target && !cls_rule_is_catchall(target) ? target : NULL;
-}
+ struct cls_cursor cursor;
+ struct cls_subtable *subtable;
+ struct cls_rule *cls_rule = NULL;
-/* Returns the first matching cls_rule in 'cursor''s iteration, or a null
- * pointer if there are no matches. */
-struct cls_rule *
-cls_cursor_first(struct cls_cursor *cursor)
-{
- struct cls_table *table;
+ cursor.safe = safe;
+ cursor.cls = cls->cls;
+ cursor.target = target && !cls_rule_is_catchall(target) ? target : NULL;
+
+ /* Find first rule. */
+ ovs_mutex_lock(&cursor.cls->mutex);
+ CMAP_CURSOR_FOR_EACH (subtable, cmap_node, &cursor.subtables,
+ &cursor.cls->subtables_map) {
+ struct cls_match *rule = search_subtable(subtable, &cursor);
- HMAP_FOR_EACH (table, hmap_node, &cursor->cls->tables) {
- struct cls_rule *rule = search_table(table, cursor->target);
if (rule) {
- cursor->table = table;
- return rule;
+ cursor.subtable = subtable;
+ cls_rule = rule->cls_rule;
+ break;
}
}
+ *pnode = (char *)cls_rule + (ptrdiff_t)offset;
- return NULL;
+ /* Leave locked if requested and have a rule. */
+ if (safe || !cls_rule) {
+ ovs_mutex_unlock(&cursor.cls->mutex);
+ }
+ return cursor;
+}
+
+static void
+cls_cursor_next_unlock(struct cls_cursor *cursor, struct cls_rule *rule)
+ OVS_NO_THREAD_SAFETY_ANALYSIS
+{
+ /* Release the mutex if no rule, or 'safe' mode. */
+ if (!rule || cursor->safe) {
+ ovs_mutex_unlock(&cursor->cls->mutex);
+ }
}
/* 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_)
+ OVS_NO_THREAD_SAFETY_ANALYSIS
{
- const struct cls_table *table;
- struct cls_rule *next;
+ struct cls_match *rule = CONST_CAST(struct cls_match *, rule_->cls_match);
+ const struct cls_subtable *subtable;
+ struct cls_match *next;
+
+ /* Lock if not locked already. */
+ if (cursor->safe) {
+ ovs_mutex_lock(&cursor->cls->mutex);
+ }
next = next_rule_in_list__(rule);
if (next->priority < rule->priority) {
- return next;
+ cls_cursor_next_unlock(cursor, next->cls_rule);
+ return next->cls_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 map. (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) {
+ CMAP_CURSOR_FOR_EACH_CONTINUE (rule, cmap_node, &cursor->rules) {
if (rule_matches(rule, cursor->target)) {
- return rule;
+ cls_cursor_next_unlock(cursor, rule->cls_rule);
+ return rule->cls_rule;
}
}
- table = cursor->table;
- HMAP_FOR_EACH_CONTINUE (table, hmap_node, &cursor->cls->tables) {
- rule = search_table(table, cursor->target);
+ subtable = cursor->subtable;
+ CMAP_CURSOR_FOR_EACH_CONTINUE (subtable, cmap_node, &cursor->subtables) {
+ rule = search_subtable(subtable, cursor);
if (rule) {
- cursor->table = table;
- return rule;
+ cursor->subtable = subtable;
+ cls_cursor_next_unlock(cursor, rule->cls_rule);
+ return rule->cls_rule;
}
}
+ ovs_mutex_unlock(&cursor->cls->mutex);
return NULL;
}
\f
-static struct cls_table *
-find_table(const struct classifier *cls, const struct minimask *mask)
+static struct cls_subtable *
+find_subtable(const struct cls_classifier *cls, const struct minimask *mask)
+ OVS_REQUIRES(cls->mutex)
{
- struct cls_table *table;
+ struct cls_subtable *subtable;
- HMAP_FOR_EACH_IN_BUCKET (table, hmap_node, minimask_hash(mask, 0),
- &cls->tables) {
- if (minimask_equal(mask, &table->mask)) {
- return table;
+ CMAP_FOR_EACH_WITH_HASH (subtable, cmap_node, minimask_hash(mask, 0),
+ &cls->subtables_map) {
+ if (minimask_equal(mask, &subtable->mask)) {
+ return subtable;
}
}
return NULL;
}
-static struct cls_table *
-insert_table(struct classifier *cls, const struct minimask *mask)
+/* The new subtable will be visible to the readers only after this. */
+static struct cls_subtable *
+insert_subtable(struct cls_classifier *cls, const struct minimask *mask)
+ OVS_REQUIRES(cls->mutex)
{
- 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;
+ int count = count_1bits(mask->masks.map);
+
+ subtable = xzalloc(sizeof *subtable - sizeof mask->masks.inline_values
+ + MINIFLOW_VALUES_SIZE(count));
+ cmap_init(&subtable->rules);
+ miniflow_clone_inline(&subtable->mask.masks, &mask->masks, count);
+
+ /* 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)) {
+ cmap_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;
+ cmap_destroy(&subtable->indices[index]);
+ }
+ }
+ subtable->n_indices = index;
- table = xzalloc(sizeof *table);
- hmap_init(&table->rules);
- minimask_clone(&table->mask, mask);
- hmap_insert(&cls->tables, &table->hmap_node, minimask_hash(mask, 0));
- list_push_back(&cls->tables_priority, &table->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);
+ }
+
+ /* Ports trie. */
+ ovsrcu_set_hidden(&subtable->ports_trie, NULL);
+ subtable->ports_mask_len
+ = 32 - ctz32(ntohl(MINIFLOW_GET_BE32(&mask->masks, tp_src)));
+
+ cmap_insert(&cls->subtables_map, &subtable->cmap_node, hash);
+
+ return subtable;
}
static void
-destroy_table(struct classifier *cls, struct cls_table *table)
+destroy_subtable(struct cls_classifier *cls, struct cls_subtable *subtable)
+ OVS_REQUIRES(cls->mutex)
{
- minimask_destroy(&table->mask);
- hmap_remove(&cls->tables, &table->hmap_node);
- hmap_destroy(&table->rules);
- list_remove(&table->list_node);
- free(table);
+ int i;
+
+ pvector_remove(&cls->subtables, subtable);
+ trie_destroy(&subtable->ports_trie);
+
+ for (i = 0; i < subtable->n_indices; i++) {
+ cmap_destroy(&subtable->indices[i]);
+ }
+ cmap_remove(&cls->subtables_map, &subtable->cmap_node,
+ minimask_hash(&subtable->mask, 0));
+ minimask_destroy(&subtable->mask);
+ cmap_destroy(&subtable->rules);
+ ovsrcu_postpone(free, subtable);
}
-/* This function performs the following updates for 'table' in 'cls' following
- * the addition of a new rule with priority 'new_priority' to 'table':
- *
- * - Update 'table->max_priority' and 'table->max_count' if necessary.
- *
- * - Update 'table''s position in 'cls->tables_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_tables_after_insertion(struct classifier *cls, struct cls_table *table,
- unsigned int new_priority)
-{
- if (new_priority == table->max_priority) {
- ++table->max_count;
- } else if (new_priority > table->max_priority) {
- struct cls_table *iter;
-
- table->max_priority = new_priority;
- table->max_count = 1;
-
- /* Possibly move 'table' earlier in the priority list. If we break out
- * of the loop, then 'table' should be moved just after that 'iter'.
- * If the loop terminates normally, then 'iter' will be the list head
- * and we'll move table just after that (e.g. to the front of the
- * list). */
- iter = table;
- LIST_FOR_EACH_REVERSE_CONTINUE (iter, list_node,
- &cls->tables_priority) {
- if (iter->max_priority >= table->max_priority) {
- break;
+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;
+ }
+ }
}
}
-
- /* Move 'table' just after 'iter' (unless it's already there). */
- if (iter->list_node.next != &table->list_node) {
- list_splice(iter->list_node.next,
- &table->list_node, table->list_node.next);
- }
}
+ return false;
}
-/* This function performs the following updates for 'table' in 'cls' following
- * the deletion of a rule with priority 'del_priority' from 'table':
+/* Returns true if 'target' satisifies 'flow'/'mask', that is, if each bit
+ * for which 'flow', for which 'mask' has a bit set, specifies a particular
+ * value has the correct value in 'target'.
*
- * - Update 'table->max_priority' and 'table->max_count' if necessary.
- *
- * - Update 'table''s position in 'cls->tables_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_tables_after_removal(struct classifier *cls, struct cls_table *table,
- unsigned int del_priority)
+ * This function is equivalent to miniflow_equal_flow_in_minimask(flow,
+ * target, mask) but this is faster because of the invariant that
+ * flow->map and mask->masks.map are the same, and that this version
+ * takes the 'wc'. */
+static inline bool
+miniflow_and_mask_matches_flow(const struct miniflow *flow,
+ const struct minimask *mask,
+ const struct flow *target)
{
- struct cls_table *iter;
+ const uint32_t *flowp = miniflow_get_u32_values(flow);
+ const uint32_t *maskp = miniflow_get_u32_values(&mask->masks);
+ uint32_t idx;
- if (del_priority == table->max_priority && --table->max_count == 0) {
- struct cls_rule *head;
+ MAP_FOR_EACH_INDEX(idx, mask->masks.map) {
+ uint32_t diff = (*flowp++ ^ flow_u32_value(target, idx)) & *maskp++;
- table->max_priority = 0;
- HMAP_FOR_EACH (head, hmap_node, &table->rules) {
- if (head->priority > table->max_priority) {
- table->max_priority = head->priority;
- table->max_count = 1;
- } else if (head->priority == table->max_priority) {
- ++table->max_count;
- }
+ if (diff) {
+ return false;
}
+ }
- /* Possibly move 'table' later in the priority list. If we break out
- * of the loop, then 'table' should be moved just before that 'iter'.
- * If the loop terminates normally, then 'iter' will be the list head
- * and we'll move table just before that (e.g. to the back of the
- * list). */
- iter = table;
- LIST_FOR_EACH_CONTINUE (iter, list_node, &cls->tables_priority) {
- if (iter->max_priority <= table->max_priority) {
- break;
- }
+ return true;
+}
+
+static inline struct cls_match *
+find_match(const struct cls_subtable *subtable, const struct flow *flow,
+ uint32_t hash)
+{
+ struct cls_match *rule;
+
+ CMAP_FOR_EACH_WITH_HASH (rule, cmap_node, hash, &subtable->rules) {
+ if (miniflow_and_mask_matches_flow(&rule->flow, &subtable->mask,
+ flow)) {
+ return rule;
}
+ }
- /* Move 'table' just before 'iter' (unless it's already there). */
- if (iter->list_node.prev != &table->list_node) {
- list_splice(&iter->list_node,
- &table->list_node, table->list_node.next);
+ return NULL;
+}
+
+/* Returns true if 'target' satisifies 'flow'/'mask', that is, if each bit
+ * for which 'flow', for which 'mask' has a bit set, specifies a particular
+ * value has the correct value in 'target'.
+ *
+ * This function is equivalent to miniflow_and_mask_matches_flow() but this
+ * version fills in the mask bits in 'wc'. */
+static inline bool
+miniflow_and_mask_matches_flow_wc(const struct miniflow *flow,
+ const struct minimask *mask,
+ const struct flow *target,
+ struct flow_wildcards *wc)
+{
+ const uint32_t *flowp = miniflow_get_u32_values(flow);
+ const uint32_t *maskp = miniflow_get_u32_values(&mask->masks);
+ uint32_t idx;
+
+ MAP_FOR_EACH_INDEX(idx, mask->masks.map) {
+ uint32_t mask = *maskp++;
+ uint32_t diff = (*flowp++ ^ flow_u32_value(target, idx)) & mask;
+
+ if (diff) {
+ /* Only unwildcard if none of the differing bits is already
+ * exact-matched. */
+ if (!(flow_u32_value(&wc->masks, idx) & diff)) {
+ /* Keep one bit of the difference. */
+ *flow_u32_lvalue(&wc->masks, idx) |= rightmost_1bit(diff);
+ }
+ return false;
}
+ /* Fill in the bits that were looked at. */
+ *flow_u32_lvalue(&wc->masks, idx) |= mask;
+ }
+
+ return true;
+}
+
+/* Unwildcard the fields looked up so far, if any. */
+static void
+fill_range_wc(const struct cls_subtable *subtable, struct flow_wildcards *wc,
+ uint8_t to)
+{
+ if (to) {
+ flow_wildcards_fold_minimask_range(wc, &subtable->mask, 0, to);
}
}
-static struct cls_rule *
-find_match(const struct cls_table *table, const struct flow *flow)
+static struct cls_match *
+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 hash = flow_hash_in_minimask(flow, &table->mask, 0);
- struct cls_rule *rule;
+ uint32_t basis = 0, hash;
+ struct cls_match *rule;
+ int i;
+ struct range ofs;
+
+ if (OVS_UNLIKELY(!wc)) {
+ return find_match(subtable, flow,
+ flow_hash_in_minimask(flow, &subtable->mask, 0));
+ }
- HMAP_FOR_EACH_WITH_HASH (rule, hmap_node, hash, &table->rules) {
- if (miniflow_equal_flow_in_minimask(&rule->match.flow, flow,
- &table->mask)) {
- return rule;
+ ofs.start = 0;
+ /* Try to finish early by checking fields in segments. */
+ for (i = 0; i < subtable->n_indices; i++) {
+ struct cmap_node *inode;
+
+ ofs.end = subtable->index_ofs[i];
+
+ if (check_tries(trie_ctx, n_tries, subtable->trie_plen, ofs, flow,
+ wc)) {
+ /* 'wc' bits for the trie field set, now unwildcard the preceding
+ * bits used so far. */
+ fill_range_wc(subtable, wc, ofs.start);
+ return NULL;
+ }
+ hash = flow_hash_in_minimask_range(flow, &subtable->mask, ofs.start,
+ ofs.end, &basis);
+ inode = cmap_find(&subtable->indices[i], hash);
+ if (!inode) {
+ /* No match, can stop immediately, but must fold in the bits
+ * used in lookup so far. */
+ fill_range_wc(subtable, wc, ofs.end);
+ return NULL;
}
+
+ /* If we have narrowed down to a single rule already, check whether
+ * that rule matches. Either way, we're done.
+ *
+ * (Rare) hash collisions may cause us to miss the opportunity for this
+ * optimization. */
+ if (!cmap_node_next(inode)) {
+ ASSIGN_CONTAINER(rule, inode - i, index_nodes);
+ if (miniflow_and_mask_matches_flow_wc(&rule->flow, &subtable->mask,
+ flow, wc)) {
+ return rule;
+ }
+ return NULL;
+ }
+ ofs.start = ofs.end;
+ }
+ ofs.end = FLOW_U32S;
+ /* Trie check for the final range. */
+ if (check_tries(trie_ctx, n_tries, subtable->trie_plen, ofs, flow, wc)) {
+ fill_range_wc(subtable, wc, ofs.start);
+ return NULL;
+ }
+ hash = flow_hash_in_minimask_range(flow, &subtable->mask, ofs.start,
+ ofs.end, &basis);
+ rule = find_match(subtable, flow, hash);
+ if (!rule && subtable->ports_mask_len) {
+ /* Ports are always part of the final range, if any.
+ * No match was found for the ports. Use the ports trie to figure out
+ * which ports bits to unwildcard. */
+ unsigned int mbits;
+ ovs_be32 value, mask;
+
+ mask = MINIFLOW_GET_BE32(&subtable->mask.masks, tp_src);
+ value = ((OVS_FORCE ovs_be32 *)flow)[TP_PORTS_OFS32] & mask;
+ trie_lookup_value(&subtable->ports_trie, &value, 32, &mbits);
+
+ ((OVS_FORCE ovs_be32 *)&wc->masks)[TP_PORTS_OFS32] |=
+ mask & htonl(~0 << (32 - mbits));
+
+ /* Unwildcard all bits in the mask upto the ports, as they were used
+ * to determine there is no match. */
+ fill_range_wc(subtable, wc, TP_PORTS_OFS32);
+ return NULL;
}
- return NULL;
+ /* Must unwildcard all the fields, as they were looked at. */
+ flow_wildcards_fold_minimask(wc, &subtable->mask);
+ return rule;
}
-static struct cls_rule *
-find_equal(struct cls_table *table, const struct miniflow *flow, uint32_t hash)
+static struct cls_match *
+find_equal(struct cls_subtable *subtable, const struct miniflow *flow,
+ uint32_t hash)
{
- struct cls_rule *head;
+ struct cls_match *head;
- HMAP_FOR_EACH_WITH_HASH (head, hmap_node, hash, &table->rules) {
- if (miniflow_equal(&head->match.flow, flow)) {
+ CMAP_FOR_EACH_WITH_HASH (head, cmap_node, hash, &subtable->rules) {
+ if (miniflow_equal(&head->flow, flow)) {
return head;
}
}
return NULL;
}
-static struct cls_rule *
-insert_rule(struct classifier *cls,
- struct cls_table *table, struct cls_rule *new)
+/*
+ * As the readers are operating concurrently with the modifications, a
+ * concurrent reader may or may not see the new rule, depending on how
+ * the concurrent events overlap with each other. This is no
+ * different from the former locked behavior, but there the visibility
+ * of the new rule only depended on the timing of the locking
+ * functions.
+ *
+ * The new rule is first added to the segment indices, so the readers
+ * may find the rule in the indices before the rule is visible in the
+ * subtables 'rules' map. This may result in us losing the
+ * opportunity to quit lookups earlier, resulting in sub-optimal
+ * wildcarding. This will be fixed by forthcoming revalidation always
+ * scheduled after flow table changes.
+ *
+ * Similar behavior may happen due to us removing the overlapping rule
+ * (if any) from the indices only after the new rule has been added.
+ *
+ * The subtable's max priority is updated only after the rule is
+ * inserted, so the concurrent readers may not see the rule, as the
+ * updated priority ordered subtable list will only be visible after
+ * the subtable's max priority is updated.
+ *
+ * Similarly, the classifier's partitions for new rules are updated by
+ * the caller after this function, so the readers may keep skipping
+ * the subtable until they see the updated partitions.
+ */
+static struct cls_match *
+insert_rule(struct cls_classifier *cls, struct cls_subtable *subtable,
+ struct cls_rule *new_rule)
+ OVS_REQUIRES(cls->mutex)
{
- struct cls_rule *head;
- struct cls_rule *old = NULL;
-
- new->hmap_node.hash = miniflow_hash_in_minimask(&new->match.flow,
- &new->match.mask, 0);
-
- head = find_equal(table, &new->match.flow, new->hmap_node.hash);
+ struct cls_match *old = NULL;
+ struct cls_match *new = cls_match_alloc(new_rule);
+ struct cls_match *head;
+ int i;
+ uint32_t basis = 0, hash, ihash[CLS_MAX_INDICES];
+ uint8_t prev_be32ofs = 0;
+
+ /* Add new node to segment indices. */
+ for (i = 0; i < subtable->n_indices; i++) {
+ ihash[i] = minimatch_hash_range(&new_rule->match, prev_be32ofs,
+ subtable->index_ofs[i], &basis);
+ cmap_insert(&subtable->indices[i], &new->index_nodes[i], ihash[i]);
+ prev_be32ofs = subtable->index_ofs[i];
+ }
+ hash = minimatch_hash_range(&new_rule->match, prev_be32ofs, FLOW_U32S,
+ &basis);
+ head = find_equal(subtable, &new_rule->match.flow, hash);
if (!head) {
- hmap_insert(&table->rules, &new->hmap_node, new->hmap_node.hash);
+ cmap_insert(&subtable->rules, &new->cmap_node, hash);
list_init(&new->list);
goto out;
} else {
/* Scan the list for the insertion point that will keep the list in
* order of decreasing priority. */
- struct cls_rule *rule;
+ struct cls_match *rule;
+
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,
- &rule->hmap_node, &new->hmap_node);
+ cmap_replace(&subtable->rules, &rule->cmap_node,
+ &new->cmap_node, hash);
}
if (new->priority == rule->priority) {
list_replace(&new->list, &rule->list);
old = rule;
- goto out;
} else {
list_insert(&rule->list, &new->list);
- goto out;
}
+ goto out;
}
}
out:
if (!old) {
- update_tables_after_insertion(cls, table, new->priority);
+ subtable->n_rules++;
+
+ /* Rule was added, not replaced. Update 'subtable's 'max_priority'
+ * and 'max_count', if necessary. */
+ if (subtable->n_rules == 1) {
+ subtable->max_priority = new->priority;
+ subtable->max_count = 1;
+ pvector_insert(&cls->subtables, subtable, new->priority);
+ } else if (subtable->max_priority == new->priority) {
+ ++subtable->max_count;
+ } else if (new->priority > subtable->max_priority) {
+ subtable->max_priority = new->priority;
+ subtable->max_count = 1;
+ pvector_change_priority(&cls->subtables, subtable, new->priority);
+ }
+ } else {
+ /* Remove old node from indices. */
+ for (i = 0; i < subtable->n_indices; i++) {
+ cmap_remove(&subtable->indices[i], &old->index_nodes[i], ihash[i]);
+ }
}
return old;
}
-static struct cls_rule *
-next_rule_in_list__(struct cls_rule *rule)
+static struct cls_match *
+next_rule_in_list__(struct cls_match *rule)
+ OVS_NO_THREAD_SAFETY_ANALYSIS
{
- struct cls_rule *next = OBJECT_CONTAINING(rule->list.next, next, list);
+ struct cls_match *next = OBJECT_CONTAINING(rule->list.next, next, list);
return next;
}
-static struct cls_rule *
-next_rule_in_list(struct cls_rule *rule)
+static struct cls_match *
+next_rule_in_list(struct cls_match *rule)
{
- struct cls_rule *next = next_rule_in_list__(rule);
+ struct cls_match *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 n_bits; /* Never zero, except for the root node. */
+ unsigned int n_rules; /* Number of rules that have this prefix. */
+ rcu_trie_ptr 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 'n_bits' 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 n_bits, const ovs_be32 value[],
+ unsigned int ofs)
+{
+ uint64_t diff = prefix ^ raw_get_prefix(value, ofs, n_bits);
+ /* Set the bit after the relevant bits to limit the result. */
+ return raw_clz64(diff << 32 | UINT64_C(1) << (63 - n_bits));
+}
+
+/* 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->n_bits, 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->n_bits = plen;
+ ovsrcu_set_hidden(&node->edges[0], NULL);
+ ovsrcu_set_hidden(&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->n_bits = TRIE_PREFIX_BITS;
+ ovsrcu_set_hidden(&node->edges[bit], subnode);
+ ovsrcu_set_hidden(&node->edges[!bit], NULL);
+ node->n_rules = 0;
+ }
+ return node;
+}
+
+static void
+trie_node_destroy(const struct trie_node *node)
+{
+ ovsrcu_postpone(free, CONST_CAST(struct trie_node *, node));
+}
+
+/* Copy a trie node for modification and postpone delete the old one. */
+static struct trie_node *
+trie_node_rcu_realloc(const struct trie_node *node)
+{
+ struct trie_node *new_node = xmalloc(sizeof *node);
+
+ *new_node = *node;
+ trie_node_destroy(node);
+
+ return new_node;
+}
+
+/* May only be called while holding the cls_classifier mutex. */
+static void
+trie_destroy(rcu_trie_ptr *trie)
+{
+ struct trie_node *node = ovsrcu_get_protected(struct trie_node *, trie);
+
+ if (node) {
+ ovsrcu_set_hidden(trie, NULL);
+ trie_destroy(&node->edges[0]);
+ trie_destroy(&node->edges[1]);
+ trie_node_destroy(node);
+ }
+}
+
+static bool
+trie_is_leaf(const struct trie_node *trie)
+{
+ /* No children? */
+ return !ovsrcu_get(struct trie_node *, &trie->edges[0])
+ && !ovsrcu_get(struct trie_node *, &trie->edges[1]);
+}
+
+static void
+mask_set_prefix_bits(struct flow_wildcards *wc, uint8_t be32ofs,
+ unsigned int n_bits)
+{
+ ovs_be32 *mask = &((ovs_be32 *)&wc->masks)[be32ofs];
+ unsigned int i;
+
+ for (i = 0; i < n_bits / 32; i++) {
+ mask[i] = OVS_BE32_MAX;
+ }
+ if (n_bits % 32) {
+ mask[i] |= htonl(~0u << (32 - n_bits % 32));
+ }
+}
+
+static bool
+mask_prefix_bits_set(const struct flow_wildcards *wc, uint8_t be32ofs,
+ unsigned int n_bits)
+{
+ ovs_be32 *mask = &((ovs_be32 *)&wc->masks)[be32ofs];
+ unsigned int i;
+ ovs_be32 zeroes = 0;
+
+ for (i = 0; i < n_bits / 32; i++) {
+ zeroes |= ~mask[i];
+ }
+ if (n_bits % 32) {
+ zeroes |= ~mask[i] & htonl(~0u << (32 - n_bits % 32));
+ }
+
+ return !zeroes; /* All 'n_bits' bits set. */
+}
+
+static rcu_trie_ptr *
+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 ovsrcu_get(struct trie_node *,
+ &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 rcu_trie_ptr *trie, const ovs_be32 value[],
+ unsigned int n_bits, unsigned int *checkbits)
+{
+ const struct trie_node *node = ovsrcu_get(struct trie_node *, trie);
+ unsigned int ofs = 0, match_len = 0;
+ const struct trie_node *prev = NULL;
+
+ for (; node; prev = node, node = trie_next_node(node, value, ofs)) {
+ unsigned int eqbits;
+ /* Check if this edge can be followed. */
+ eqbits = prefix_equal_bits(node->prefix, node->n_bits, value, ofs);
+ ofs += eqbits;
+ if (eqbits < node->n_bits) { /* Mismatch, nothing more to be found. */
+ /* Bit at offset 'ofs' differed. */
+ *checkbits = ofs + 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 = ofs;
+ }
+ if (ofs >= n_bits) {
+ *checkbits = n_bits; /* Full prefix. */
+ return match_len;
+ }
+ }
+ /* node == NULL. Full match so far, but we came to a dead end.
+ * need to exclude the other branch if it exists. */
+ *checkbits = !prev || trie_is_leaf(prev) ? ofs : ofs + 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],
+ mf->n_bits, 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 n_bits = 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);
+ n_bits += 32 - mask_tz;
+ }
+ }
+
+ return n_bits;
+}
+
+/*
+ * 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 miniflow_get_be32_values(&match->flow) +
+ 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)
+{
+ trie_insert_prefix(&trie->root,
+ minimatch_get_prefix(&rule->match, trie->field), mlen);
+}
+
+static void
+trie_insert_prefix(rcu_trie_ptr *edge, const ovs_be32 *prefix, int mlen)
+{
+ struct trie_node *node;
+ int ofs = 0;
+
+ /* Walk the tree. */
+ for (; (node = ovsrcu_get_protected(struct trie_node *, edge));
+ edge = trie_next_edge(node, prefix, ofs)) {
+ unsigned int eqbits = trie_prefix_equal_bits(node, prefix, ofs, mlen);
+ ofs += eqbits;
+ if (eqbits < node->n_bits) {
+ /* Mismatch, new node needs to be inserted above. */
+ int old_branch = get_bit_at(node->prefix, eqbits);
+ struct trie_node *new_parent;
+
+ new_parent = trie_branch_create(prefix, ofs - eqbits, eqbits,
+ ofs == mlen ? 1 : 0);
+ /* Copy the node to modify it. */
+ node = trie_node_rcu_realloc(node);
+ /* Adjust the new node for its new position in the tree. */
+ node->prefix <<= eqbits;
+ node->n_bits -= eqbits;
+ ovsrcu_set_hidden(&new_parent->edges[old_branch], node);
+
+ /* Check if need a new branch for the new rule. */
+ if (ofs < mlen) {
+ ovsrcu_set_hidden(&new_parent->edges[!old_branch],
+ trie_branch_create(prefix, ofs, mlen - ofs,
+ 1));
+ }
+ ovsrcu_set(edge, new_parent); /* Publish changes. */
+ 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. */
+ ovsrcu_set(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)
+{
+ trie_remove_prefix(&trie->root,
+ minimatch_get_prefix(&rule->match, trie->field), mlen);
+}
+
+/* 'mlen' must be the (non-zero) CIDR prefix length of the 'trie->field' mask
+ * in 'rule'. */
+static void
+trie_remove_prefix(rcu_trie_ptr *root, const ovs_be32 *prefix, int mlen)
+{
+ struct trie_node *node;
+ rcu_trie_ptr *edges[sizeof(union mf_value) * 8];
+ int depth = 0, ofs = 0;
+
+ /* Walk the tree. */
+ for (edges[0] = root;
+ (node = ovsrcu_get_protected(struct trie_node *, edges[depth]));
+ edges[++depth] = trie_next_edge(node, prefix, ofs)) {
+ unsigned int eqbits = trie_prefix_equal_bits(node, prefix, ofs, mlen);
+
+ if (eqbits < node->n_bits) {
+ /* 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) {
+ struct trie_node *next,
+ *edge0 = ovsrcu_get_protected(struct trie_node *,
+ &node->edges[0]),
+ *edge1 = ovsrcu_get_protected(struct trie_node *,
+ &node->edges[1]);
+
+ if (edge0 && edge1) {
+ break; /* A branching point, cannot prune. */
+ }
+
+ /* Else have at most one child node, remove this node. */
+ next = edge0 ? edge0 : edge1;
+
+ if (next) {
+ if (node->n_bits + next->n_bits > TRIE_PREFIX_BITS) {
+ break; /* Cannot combine. */
+ }
+ next = trie_node_rcu_realloc(next); /* Modify. */
+
+ /* Combine node with next. */
+ next->prefix = node->prefix | next->prefix >> node->n_bits;
+ next->n_bits += node->n_bits;
+ }
+ /* Update the parent's edge. */
+ ovsrcu_set(edges[depth], next); /* Publish changes. */
+ trie_node_destroy(node);
+
+ if (next || !depth) {
+ /* Branch not pruned or at root, nothing more to do. */
+ break;
+ }
+ node = ovsrcu_get_protected(struct trie_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.");
+}
projects / cascardo / ovs.git / blobdiff