OpenFlow 1.4 bundles are easier to implement when it is possible to
mark a rule as 'to_be_removed' and then insert a new, identical rule
with the same priority.
All but one out of the identical rules must be marked as
'to_be_removed', and the one rule that is not 'to_be_removed' must
have been inserted last.
Signed-off-by: Jarno Rajahalme <jrajaha...@nicira.com>
---
lib/classifier.c | 145 +++++++++++++++++++++++++++++++++---------------------
lib/classifier.h | 1 +
2 files changed, 90 insertions(+), 56 deletions(-)
diff --git a/lib/classifier.c b/lib/classifier.c
index 0cf42f6..9016aba 100644
--- a/lib/classifier.c
+++ b/lib/classifier.c
@@ -131,21 +131,30 @@ next_rule_in_list__(const struct cls_match *rule)
}
static inline const struct cls_match *
-next_rule_in_list(const struct cls_match *rule)
+next_rule_in_list(const struct cls_match *rule, const struct cls_match *head)
{
const struct cls_match *next = next_rule_in_list__(rule);
- return next->priority < rule->priority ? next : NULL;
+ return next != head ? next : NULL;
}
-/* Return the next lower-priority rule in the list that is visible. */
+/* Return the next lower-priority rule in the list that is visible. Multiple
+ * identical rules with the same priority may exist transitionally. In that
+ * case the first rule of a given priority has been marked as 'to_be_removed',
+ * and the later rules are marked as '!visible'. This gets a bit complex if
+ * there are two rules of the same priority in the list, as in that case the
+ * head and tail of the list will have the same priority. */
static inline const struct cls_match *
next_visible_rule_in_list(const struct cls_match *rule)
{
const struct cls_match *next = rule;
do {
- next = next_rule_in_list(next);
- } while (next && !next->visible);
+ next = next_rule_in_list__(next);
+ if (next->priority > rule->priority || next == rule) {
+ /* We have reached the head of the list, stop. */
+ return NULL;
+ }
+ } while (!next->visible);
return next;
}
@@ -159,18 +168,19 @@ next_rule_in_list_protected__(struct cls_match *rule)
}
static inline struct cls_match *
-next_rule_in_list_protected(struct cls_match *rule)
+next_rule_in_list_protected(struct cls_match *rule, struct cls_match *head)
{
struct cls_match *next = next_rule_in_list_protected__(rule);
- return next->priority < rule->priority ? next : NULL;
+ return next != head ? next : NULL;
}
/* Iterates RULE over HEAD and all of the cls_rules on HEAD->list. */
-#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_PROTECTED(RULE, HEAD) \
- for ((RULE) = (HEAD); (RULE) != NULL; \
- (RULE) = next_rule_in_list_protected(RULE))
+#define FOR_EACH_RULE_IN_LIST(RULE, HEAD) \
+ for ((RULE) = (HEAD); (RULE) != NULL; \
+ (RULE) = next_rule_in_list(RULE, HEAD))
+#define FOR_EACH_RULE_IN_LIST_PROTECTED(RULE, HEAD) \
+ for ((RULE) = (HEAD); (RULE) != NULL; \
+ (RULE) = next_rule_in_list_protected(RULE, HEAD))
static unsigned int minimask_get_prefix_len(const struct minimask *,
const struct mf_field *);
@@ -200,6 +210,7 @@ cls_rule_init__(struct cls_rule *rule, unsigned int
priority)
{
rculist_init(&rule->node);
rule->priority = priority;
+ rule->to_be_removed = false;
rule->cls_match = NULL;
}
@@ -663,14 +674,17 @@ classifier_replace(struct classifier *cls, const struct
cls_rule *rule,
struct cls_match *iter;
/* Scan the list for the insertion point that will keep the list in
- * order of decreasing priority. */
+ * order of decreasing priority.
+ * Insert after 'to_be_removed' rules of the same priority. */
FOR_EACH_RULE_IN_LIST_PROTECTED (iter, head) {
- if (rule->priority >= iter->priority) {
+ if (rule->priority > iter->priority
+ || (rule->priority == iter->priority
+ && !iter->cls_rule->to_be_removed)) {
break;
}
}
- /* 'iter' now at the insertion point or NULL it at end. */
+ /* 'iter' now at the insertion point or NULL if at end. */
if (iter) {
struct cls_rule *old;
@@ -778,57 +792,62 @@ classifier_insert(struct classifier *cls, const struct
cls_rule *rule,
* Returns the removed rule, or NULL, if it was already removed.
*/
const struct cls_rule *
-classifier_remove(struct classifier *cls, const struct cls_rule *rule)
+classifier_remove(struct classifier *cls, const struct cls_rule *cls_rule)
{
+ struct cls_match *rule, *prev, *next;
struct cls_partition *partition;
- struct cls_match *cls_match;
struct cls_conjunction_set *conj_set;
struct cls_subtable *subtable;
- struct cls_match *prev;
- struct cls_match *next;
int i;
uint32_t basis = 0, hash, ihash[CLS_MAX_INDICES];
uint8_t prev_be64ofs = 0;
size_t n_rules;
- cls_match = rule->cls_match;
- if (!cls_match) {
+ rule = cls_rule->cls_match;
+ if (!rule) {
return NULL;
}
/* Mark as removed. */
- CONST_CAST(struct cls_rule *, rule)->cls_match = NULL;
+ CONST_CAST(struct cls_rule *, cls_rule)->cls_match = NULL;
- /* Remove 'rule' from the subtable's rules list. */
- rculist_remove(CONST_CAST(struct rculist *, &rule->node));
+ /* Remove 'cls_rule' from the subtable's rules list. */
+ rculist_remove(CONST_CAST(struct rculist *, &cls_rule->node));
- INIT_CONTAINER(prev, rculist_back_protected(&cls_match->list), list);
- INIT_CONTAINER(next, rculist_next(&cls_match->list), list);
+ INIT_CONTAINER(prev, rculist_back_protected(&rule->list), list);
+ INIT_CONTAINER(next, rculist_next(&rule->list), list);
/* Remove from the list of equal rules. */
- rculist_remove(&cls_match->list);
+ rculist_remove(&rule->list);
- /* Check if this is NOT a head rule. */
+ /* Cheap check for a non-head rule. */
if (prev->priority > rule->priority) {
/* Not the highest priority rule, no need to check subtable's
* 'max_priority'. */
goto free;
}
- subtable = find_subtable(cls, &rule->match.mask);
+ subtable = find_subtable(cls, &cls_rule->match.mask);
ovs_assert(subtable);
for (i = 0; i < subtable->n_indices; i++) {
- ihash[i] = minimatch_hash_range(&rule->match, prev_be64ofs,
+ ihash[i] = minimatch_hash_range(&cls_rule->match, prev_be64ofs,
subtable->index_ofs[i], &basis);
prev_be64ofs = subtable->index_ofs[i];
}
- hash = minimatch_hash_range(&rule->match, prev_be64ofs, FLOW_U64S, &basis);
+ hash = minimatch_hash_range(&cls_rule->match, prev_be64ofs, FLOW_U64S,
+ &basis);
+
+ /* Check if the rule is not the head rule. */
+ if (rule != prev &&
+ rule != find_equal(subtable, &cls_rule->match.flow, hash)) {
+ /* Not the head rule, but potentially one with the same priority. */
+ goto check_priority;
+ }
- /* Head rule. Check if 'next' is an identical, lower-priority rule that
- * will replace 'rule' in the data structures. */
- if (next->priority < rule->priority) {
- subtable_replace_head_rule(cls, subtable, cls_match, next, hash,
- ihash);
+ /* 'rule' is the head rule. Check if there is another rule to
+ * replace 'rule' in the data structures. */
+ if (next != rule) {
+ subtable_replace_head_rule(cls, subtable, rule, next, hash, ihash);
goto check_priority;
}
@@ -836,25 +855,24 @@ classifier_remove(struct classifier *cls, const struct
cls_rule *rule)
* data structures. */
if (subtable->ports_mask_len) {
- ovs_be32 masked_ports = minimatch_get_ports(&rule->match);
+ ovs_be32 masked_ports = minimatch_get_ports(&cls_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]);
+ trie_remove(&cls->tries[i], cls_rule, subtable->trie_plen[i]);
}
}
/* Remove rule node from indices. */
for (i = 0; i < subtable->n_indices; i++) {
- cmap_remove(&subtable->indices[i], &cls_match->index_nodes[i],
- ihash[i]);
+ cmap_remove(&subtable->indices[i], &rule->index_nodes[i], ihash[i]);
}
- n_rules = cmap_remove(&subtable->rules, &cls_match->cmap_node, hash);
+ n_rules = cmap_remove(&subtable->rules, &rule->cmap_node, hash);
- partition = cls_match->partition;
+ partition = rule->partition;
if (partition) {
tag_tracker_subtract(&partition->tracker, &partition->tags,
subtable->tag);
@@ -872,8 +890,8 @@ check_priority:
if (subtable->max_priority == rule->priority
&& --subtable->max_count == 0) {
/* Find the new 'max_priority' and 'max_count'. */
- struct cls_match *head;
int max_priority = INT_MIN;
+ struct cls_match *head;
CMAP_FOR_EACH (head, cmap_node, &subtable->rules) {
if (head->priority > max_priority) {
@@ -894,14 +912,14 @@ check_priority:
free:
conj_set = ovsrcu_get_protected(struct cls_conjunction_set *,
- &cls_match->conj_set);
+ &rule->conj_set);
if (conj_set) {
ovsrcu_postpone(free, conj_set);
}
- ovsrcu_postpone(free, cls_match);
+ ovsrcu_postpone(free, rule);
cls->n_rules--;
- return rule;
+ return cls_rule;
}
/* Prefix tree context. Valid when 'lookup_done' is true. Can skip all
@@ -1274,7 +1292,10 @@ classifier_lookup(const struct classifier *cls, struct
flow *flow,
/* 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. */
+ * contain an exact match.
+ *
+ * Returns the first matching rule that is not 'to_be_removed'. Only one such
+ * rule may exist. */
const struct cls_rule *
classifier_find_rule_exactly(const struct classifier *cls,
const struct cls_rule *target)
@@ -1294,8 +1315,12 @@ classifier_find_rule_exactly(const struct classifier
*cls,
return NULL;
}
FOR_EACH_RULE_IN_LIST (rule, head) {
- if (target->priority >= rule->priority) {
- return target->priority == rule->priority ? rule->cls_rule : NULL;
+ if (rule->priority < target->priority) {
+ break; /* Not found. */
+ }
+ if (rule->priority == target->priority
+ && !rule->cls_rule->to_be_removed) {
+ return rule->cls_rule;
}
}
return NULL;
@@ -1325,7 +1350,11 @@ classifier_find_match_exactly(const struct classifier
*cls,
* A trivial example of overlapping rules is two rules matching disjoint sets
* of fields. E.g., if one rule matches only on port number, while another only
* on dl_type, any packet from that specific port and with that specific
- * dl_type could match both, if the rules also have the same priority. */
+ * dl_type could match both, if the rules also have the same priority.
+ *
+ * 'target' is not considered to overlap with a rule that has been marked
+ * as 'to_be_removed'.
+ */
bool
classifier_rule_overlaps(const struct classifier *cls,
const struct cls_rule *target)
@@ -1343,6 +1372,7 @@ classifier_rule_overlaps(const struct classifier *cls,
RCULIST_FOR_EACH (rule, node, &subtable->rules_list) {
if (rule->priority == target->priority
+ && !rule->to_be_removed
&& miniflow_equal_in_minimask(&target->match.flow,
&rule->match.flow, &mask)) {
return true;
@@ -1399,10 +1429,13 @@ cls_rule_is_loose_match(const struct cls_rule *rule,
static bool
rule_matches(const struct cls_rule *rule, const struct cls_rule *target)
{
- return (!target
- || miniflow_equal_in_minimask(&rule->match.flow,
- &target->match.flow,
- &target->match.mask));
+ /* Iterators never see rules that have been marked for removal.
+ * This allows them to be oblivious of duplicate rules. */
+ return (!rule->to_be_removed &&
+ (!target
+ || miniflow_equal_in_minimask(&rule->match.flow,
+ &target->match.flow,
+ &target->match.mask)));
}
static const struct cls_rule *
@@ -1431,8 +1464,8 @@ search_subtable(const struct cls_subtable *subtable,
* such that cls_rule_is_loose_match(rule, target) returns true.
*
* Ignores target->priority. */
-struct cls_cursor cls_cursor_start(const struct classifier *cls,
- const struct cls_rule *target)
+struct cls_cursor
+cls_cursor_start(const struct classifier *cls, const struct cls_rule *target)
{
struct cls_cursor cursor;
struct cls_subtable *subtable;
diff --git a/lib/classifier.h b/lib/classifier.h
index 77c4458..50cc9f8 100644
--- a/lib/classifier.h
+++ b/lib/classifier.h
@@ -265,6 +265,7 @@ struct cls_conjunction {
struct cls_rule {
struct rculist node; /* In struct cls_subtable 'rules_list'. */
int priority; /* Larger numbers are higher priorities. */
+ bool to_be_removed; /* Rule will be deleted. */
struct cls_match *cls_match; /* NULL if not in a classifier. */
struct minimatch match; /* Matching rule. */
};
--
1.7.10.4
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