I’ll review the v3 when ready,
Jarno
On Dec 30, 2014, at 4:30 PM, Ben Pfaff <b...@nicira.com> wrote:
> A "conjunctive match" allows higher-level matches in the flow table, such
> as set membership matches, without causing a cross-product explosion for
> multidimensional matches. Please refer to the documentation that this
> commit adds to ovs-ofctl(8) for a better explanation, including an example.
>
> Issues:
>
> - Until now the conceptual model of a cls_rule has been that it is
> immutable while it is in a classifier. This commit adds a "conjunctive
> match" (optional) to each cls_rule, and makes the new member safely
> mutable while it is in a classifier. This might be a conceptual failing
> bad enough to need fixing; I am not sure.
>
> - Needs some real tests; you can run the "test-conjunction" script inside
> "make sandbox", for now.
>
> - The code needs some more comments.
> ---
> v1->v2:
> - Use 1-based dimension numbers in formatted syntax, e.g. 1/2 and 2/2,
> not 0/2 and 1/2.
> - Add new conj_id field instead of overwriting reg0.
> - Since priority is now an 'int', get rid of awkward +1s and comparisons
> on priorities in classifier_lookup().
> - Fix memory leak in classifier_replace().
> - Modify conj_id in-place in classifier_lookup() instead of copying
> entire flow.
> - Remove prototype for nonexistent cls_rule_init_conjunction().
> - Fix memory leak in classifier_lookup(), and eliminate memory allocation
> in the common case of few conjunctive matches.
>
> v2->v2.1:
> - Rebase.
> ---
> NEWS | 4 +
> lib/classifier-private.h | 3 +-
> lib/classifier.c | 396 +++++++++++++++++++++++++++++++++++++++---
> lib/classifier.h | 10 ++
> lib/flow.c | 1 +
> lib/flow.h | 3 +-
> lib/match.c | 11 ++
> lib/match.h | 3 +-
> lib/meta-flow.c | 17 ++
> lib/meta-flow.h | 14 ++
> lib/nx-match.c | 4 +
> lib/ofp-actions.c | 112 +++++++++++-
> lib/ofp-actions.h | 12 ++
> lib/ofp-errors.h | 8 +
> ofproto/ofproto-dpif-xlate.c | 4 +
> ofproto/ofproto.c | 41 +++++
> tests/automake.mk | 2 +
> tests/ofproto.at | 3 +-
> tests/test-conjunction | 22 +++
> utilities/ovs-ofctl.8.in | 185 ++++++++++++++++++++
> 20 files changed, 825 insertions(+), 30 deletions(-)
> create mode 100755 tests/test-conjunction
>
> diff --git a/NEWS b/NEWS
> index f2fceb5..0bbe6f7 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -1,5 +1,9 @@
> Post-v2.3.0
> ---------------------
> + - New support for a "conjunctive match" OpenFlow extension, which
> + allows constructing OpenFlow matches of the form "field1 in
> + {a,b,c...} AND field2 in {d,e,f...}" and generalizations. For details,
> + see documentation fo the "conjunction" action in ovs-ofctl(8).
> - Add bash command-line completion support for ovs-appctl/ovs-dpctl/
> ovs-ofctl/ovsdb-tool commands. Please check
> utilities/ovs-command-compgen.INSTALL.md for how to use.
> diff --git a/lib/classifier-private.h b/lib/classifier-private.h
> index 2522e91..2230286 100644
> --- a/lib/classifier-private.h
> +++ b/lib/classifier-private.h
> @@ -68,7 +68,7 @@ struct cls_partition {
> /* Internal representation of a rule in a "struct cls_subtable". */
> struct cls_match {
> /* Accessed by everybody. */
> - struct rculist list; /* Identical, lower-priority rules. */
> + struct rculist list; /* Identical, lower-priority "cls_match"es. */
>
> /* Accessed only by writers. */
> struct cls_partition *partition;
> @@ -80,6 +80,7 @@ struct cls_match {
> /* Accessed by all readers. */
> struct cmap_node cmap_node; /* Within struct cls_subtable 'rules'. */
> const struct cls_rule *cls_rule;
> + OVSRCU_TYPE(struct cls_conjunction_set *) conj_set;
> const struct miniflow flow; /* Matching rule. Mask is in the subtable. */
> /* 'flow' must be the last field. */
> };
> diff --git a/lib/classifier.c b/lib/classifier.c
> index dd60cc7..36194d2 100644
> --- a/lib/classifier.c
> +++ b/lib/classifier.c
> @@ -31,6 +31,33 @@ VLOG_DEFINE_THIS_MODULE(classifier);
>
> struct trie_ctx;
>
> +/* A collection of "struct cls_conjunction"s currently embedded into a
> + * cls_match. */
> +struct cls_conjunction_set {
> + /* Link back to the cls_match.
> + *
> + * cls_conjunction_set is mostly used during classifier lookup, and, in
> + * turn, during classifier lookup the most used member of
> + * cls_conjunction_set is the rule's priority, so we cache it here for
> fast
> + * access. */
> + struct cls_match *match;
> + int priority; /* Cached copy of match->priority. */
> +
> + /* Conjunction information.
> + *
> + * 'min_n_clauses' allows some optimization during classifier lookup. */
> + unsigned int n; /* Number of elements in 'conj'. */
> + unsigned int min_n_clauses; /* Smallest 'n' among elements of 'conj'. */
> + struct cls_conjunction conj[];
> +};
> +
> +static inline size_t
> +cls_conjunction_set_size(size_t n)
> +{
> + return (sizeof(struct cls_conjunction_set)
> + + n * sizeof(struct cls_conjunction));
> +}
> +
> /* 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);
> @@ -49,6 +76,7 @@ cls_match_alloc(const struct cls_rule *rule)
> *CONST_CAST(int *, &cls_match->priority) = rule->priority;
> miniflow_clone_inline(CONST_CAST(struct miniflow *, &cls_match->flow),
> &rule->match.flow, count);
> + ovsrcu_set_hidden(&cls_match->conj_set, NULL);
>
> return cls_match;
> }
> @@ -199,6 +227,42 @@ cls_rule_destroy(struct cls_rule *rule)
> minimatch_destroy(&rule->match);
> }
>
> +void
> +cls_rule_set_conjunctions(struct cls_rule *cr,
> + const struct cls_conjunction *conj, size_t n)
> +{
> + struct cls_match *match = cr->cls_match;
> + struct cls_conjunction_set *old = ovsrcu_get_protected(struct
> cls_conjunction_set *, &match->conj_set);
> + struct cls_conjunction *old_conj = old ? old->conj : NULL;
> + unsigned int old_n = old ? old->n : 0;
> +
> + if (old_n != n || (n && memcmp(old_conj, conj, n * sizeof *conj))) {
> + struct cls_conjunction_set *new;
> +
> + if (old) {
> + ovsrcu_postpone(free, old);
> + }
> +
> + if (n) {
> + size_t min_n_clauses = conj[0].n_clauses;
> + for (size_t i = 1; i < n; i++) {
> + min_n_clauses = MIN(min_n_clauses, conj[i].n_clauses);
> + }
> +
> + new = xmalloc(cls_conjunction_set_size(n));
> + new->match = match;
> + new->priority = match->priority;
> + new->n = n;
> + new->min_n_clauses = min_n_clauses;
> + memcpy(new->conj, conj, n * sizeof *conj);
> + } else {
> + new = NULL;
> + }
> + ovsrcu_set(&match->conj_set, new);
> + }
> +}
> +
> +
> /* Returns true if 'a' and 'b' match the same packets at the same priority,
> * false if they differ in some way. */
> bool
> @@ -593,6 +657,14 @@ classifier_replace(struct classifier *cls, const struct
> cls_rule *rule)
> }
>
> if (old) {
> + struct cls_conjunction_set *conj_set;
> +
> + conj_set = ovsrcu_get_protected(struct cls_conjunction_set *,
> + &iter->conj_set);
> + if (conj_set) {
> + ovsrcu_postpone(free, conj_set);
> + }
> +
> ovsrcu_postpone(free, iter);
> old->cls_match = NULL;
>
> @@ -669,6 +741,7 @@ classifier_remove(struct classifier *cls, const struct
> cls_rule *rule)
> {
> 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;
> @@ -779,6 +852,11 @@ check_priority:
> }
>
> free:
> + conj_set = ovsrcu_get_protected(struct cls_conjunction_set *,
> + &cls_match->conj_set);
> + if (conj_set) {
> + ovsrcu_postpone(free, conj_set);
> + }
> ovsrcu_postpone(free, cls_match);
> cls->n_rules--;
>
> @@ -808,27 +886,107 @@ trie_ctx_init(struct trie_ctx *ctx, const struct
> cls_trie *trie)
> 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.
> - *
> - * 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 conjunctive_match {
> + struct hmap_node hmap_node;
> + uint64_t id;
> + uint64_t clauses;
> +};
> +
> +static struct conjunctive_match *
> +find_conjunctive_match__(struct hmap *matches, uint64_t id, uint32_t hash)
> +{
> + struct conjunctive_match *m;
> +
> + HMAP_FOR_EACH_IN_BUCKET (m, hmap_node, hash, matches) {
> + if (m->id == id) {
> + return m;
> + }
> + }
> + return NULL;
> +}
> +
> +static bool
> +find_conjunctive_match(const struct cls_conjunction_set *set,
> + unsigned int max_n_clauses, struct hmap *matches,
> + struct conjunctive_match *cm_stubs, size_t n_cm_stubs,
> + uint32_t *idp)
> +{
> + const struct cls_conjunction *c;
> +
> + if (max_n_clauses > set->min_n_clauses) {
> + return false;
> + }
> +
> + for (c = set->conj; c < &set->conj[set->n]; c++) {
> + uint32_t hash = hash_int(c->id, 0);
> + struct conjunctive_match *cm;
> +
> + if (c->n_clauses > max_n_clauses) {
> + continue;
> + }
> +
> + cm = find_conjunctive_match__(matches, c->id, hash);
> + if (!cm) {
> + size_t n = hmap_count(matches);
> + cm = n < n_cm_stubs ? &cm_stubs[n++] : xmalloc(sizeof *cm);
> + hmap_insert(matches, &cm->hmap_node, hash);
> + cm->id = c->id;
> + cm->clauses = UINT64_MAX << (c->n_clauses & 63);
> + }
> + cm->clauses |= UINT64_C(1) << c->clause;
> + if (cm->clauses == UINT64_MAX) {
> + *idp = cm->id;
> + return true;
> + }
> + }
> + return false;
> +}
> +
> +static void
> +free_conjunctive_matches(struct hmap *matches,
> + struct conjunctive_match *cm_stubs, size_t
> n_cm_stubs)
> +{
> + if (hmap_count(matches) > n_cm_stubs) {
> + struct conjunctive_match *cm, *next;
> +
> + HMAP_FOR_EACH_SAFE (cm, next, hmap_node, matches) {
> + if (!(cm >= cm_stubs && cm < &cm_stubs[n_cm_stubs])) {
> + hmap_remove(matches, &cm->hmap_node);
> + free(cm);
> + }
> + }
> + }
> + hmap_destroy(matches);
> +}
> +
> +/* Like classifier_lookup(), except that support for conjunctive matches can
> be
> + * configured with 'allow_conjunctive_matches'. That feature is not exposed
> + * externally because turning off conjunctive matches is only useful to avoid
> + * recursion within this function itself.
> *
> * 'flow' is non-const to allow for temporary modifications during the lookup.
> * Any changes are restored before returning. */
> -const struct cls_rule *
> -classifier_lookup(const struct classifier *cls, struct flow *flow,
> - struct flow_wildcards *wc)
> +static const struct cls_rule *
> +classifier_lookup__(const struct classifier *cls, struct flow *flow,
> + struct flow_wildcards *wc, bool
> allow_conjunctive_matches)
> {
> const struct cls_partition *partition;
> - tag_type tags;
> - int best_priority = INT_MIN;
> - const struct cls_match *best;
> struct trie_ctx trie_ctx[CLS_MAX_TRIES];
> - struct cls_subtable *subtable;
> + const struct cls_match *match;
> + tag_type tags;
> +
> + /* Highest-priority flow in 'cls' that certainly matches 'flow'. */
> + const struct cls_match *hard = NULL;
> + int hard_pri = INT_MIN; /* hard ? hard->priority : INT_MIN. */
> +
> + /* Highest-priority conjunctive flows in 'cls' matching 'flow'. Since
> + * these are (components of) conjunctive flows, we can only know whether
> + * the full conjunctive flow matches after seeing multiple of them.
> Thus,
> + * we refer to these as "soft matches". */
> + struct cls_conjunction_set *soft_stub[64];
> + struct cls_conjunction_set **soft = soft_stub;
> + size_t n_soft = 0, allocated_soft = ARRAY_SIZE(soft_stub);
> + int soft_pri = INT_MIN; /* n_soft ? MAX(soft[*]->priority) : INT_MIN.
> */
>
> /* Synchronize for cls->n_tries and subtable->trie_plen. They can change
> * when table configuration changes, which happens typically only on
> @@ -864,23 +1022,213 @@ classifier_lookup(const struct classifier *cls,
> struct flow *flow,
> trie_ctx_init(&trie_ctx[i], &cls->tries[i]);
> }
>
> - best = NULL;
> - PVECTOR_FOR_EACH_PRIORITY(subtable, best_priority, 2,
> - sizeof(struct cls_subtable), &cls->subtables) {
> - const struct cls_match *rule;
> + /* Main loop. */
> + struct cls_subtable *subtable;
> + PVECTOR_FOR_EACH_PRIORITY (subtable, hard_pri, 2, sizeof *subtable,
> + &cls->subtables) {
> + struct cls_conjunction_set *conj_set;
>
> + /* Skip subtables not in our partition. */
> 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_priority = rule->priority;
> - best = rule;
> + /* Skip subtables with no match, or where the match is lower-priority
> + * than some certain match we've already found. */
> + match = find_match_wc(subtable, flow, trie_ctx, cls->n_tries, wc);
> + if (!match || match->priority <= hard_pri) {
> + continue;
> + }
> +
> + conj_set = ovsrcu_get(struct cls_conjunction_set *,
> &match->conj_set);
> + if (!conj_set) {
> + /* 'match' isn't part of a conjunctive match. It's the best
> + * certain match we've got so far, since we know that it's
> + * higher-priority than hard_pri.
> + *
> + * (There might be a higher-priority conjunctive match. We can't
> + * tell yet.) */
> + hard = match;
> + hard_pri = hard->priority;
> + } else if (allow_conjunctive_matches) {
> + /* 'match' is part of a conjunctive match. Add it to the list.
> */
> + if (OVS_UNLIKELY(n_soft >= allocated_soft)) {
> + struct cls_conjunction_set **old_soft = soft;
> +
> + allocated_soft *= 2;
> + soft = xmalloc(allocated_soft * sizeof *soft);
> + memcpy(soft, old_soft, n_soft * sizeof *soft);
> + if (old_soft != soft_stub) {
> + free(old_soft);
> + }
> + }
> + soft[n_soft++] = conj_set;
> +
> + /* Keep track of the highest-priority soft match. */
> + if (soft_pri < match->priority) {
> + soft_pri = match->priority;
> + }
> }
> }
>
> - return best ? best->cls_rule : NULL;
> + /* In the common case, at this point we have no soft matches and we can
> + * return immediately. (We do the same thing if we have potential soft
> + * matches but none of them are higher-priority than our hard match.)*/
> + if (hard_pri >= soft_pri) {
> + if (soft != soft_stub) {
> + free(soft);
> + }
> + return hard ? hard->cls_rule : NULL;
> + }
> +
> + /* At this point, we have some soft matches. We might also have a hard
> + * match; if so, its priority is lower than the highest-priority soft
> + * match. */
> +
> + /* Soft match loop.
> + *
> + * Check whether soft matches are real matches. */
> + for (;;) {
> + /* Delete soft matches that are null. This only happens in second
> and
> + * subsequent iterations of the soft match loop, when we drop back
> from
> + * a high-priority soft match to a lower-priority one.
> + *
> + * Also, delete soft matches whose priority is less than or equal to
> + * the hard match's priority. In the first iteration of the soft
> + * match, these can be in 'soft' because the earlier main loop found
> + * the soft match before the hard match. In second and later
> iteration
> + * of the soft match loop, these can be in 'soft' because we dropped
> + * back from a high-priority soft match to a lower-priority soft
> match.
> + *
> + * Also, delete soft matches that cannot be satisfied because there
> are
> + * fewer soft matches than required to satisfy any of their
> + * conjunctions. Since deleting soft matches can cause this
> condition
> + * to become true for new soft matches, we iterate until we've
> deleted
> + * as many as possible. */
> + bool deleted;
> + do {
> + deleted = false;
> + for (int i = 0; i < n_soft; ) {
> + if (!soft[i]
> + || soft[i]->priority <= hard_pri
> + || n_soft < soft[i]->min_n_clauses) {
> + deleted = true;
> + soft[i] = soft[--n_soft];
> + } else {
> + i++;
> + }
> + }
> + } while (deleted);
> + if (n_soft < 2) {
> + break;
> + }
> +
> + /* Find the highest priority among the soft matches. (We know this
> + * must be higher than the hard match's priority; otherwise we would
> + * have deleted all of the soft matches in the previous loop.) Count
> + * the number of soft matches that have that priority. */
> + soft_pri = INT_MIN;
> + int n_soft_pri = 0;
> + for (int i = 0; i < n_soft; i++) {
> + if (soft[i]->priority > soft_pri) {
> + soft_pri = soft[i]->priority;
> + n_soft_pri = 1;
> + } else if (soft[i]->priority == soft_pri) {
> + n_soft_pri++;
> + }
> + }
> + ovs_assert(soft_pri > hard_pri);
> +
> + /* Look for a real match among the highest-priority soft matches.
> + *
> + * It's unusual to have many conjunctive matches, so we use stubs to
> + * avoid calling malloc() in the common case. An hmap has a built-in
> + * stub for up to 2 hmap_nodes; possibly, we would benefit a variant
> + * with a bigger stub. */
> + struct conjunctive_match cm_stubs[16];
> + struct hmap matches;
> +
> + hmap_init(&matches);
> + for (int i = 0; i < n_soft; i++) {
> + uint32_t id;
> +
> + if (soft[i]->priority == soft_pri
> + && find_conjunctive_match(soft[i], n_soft_pri, &matches,
> + cm_stubs, ARRAY_SIZE(cm_stubs),
> + &id)) {
> + uint32_t saved_conj_id = flow->conj_id;
> + const struct cls_rule *rule;
> +
> + flow->conj_id = id;
> + rule = classifier_lookup__(cls, flow, wc, false);
> + flow->conj_id = saved_conj_id;
> +
> + if (rule) {
> + free_conjunctive_matches(&matches,
> + cm_stubs, ARRAY_SIZE(cm_stubs));
> + if (soft != soft_stub) {
> + free(soft);
> + }
> + return rule;
> + }
> + }
> + }
> + free_conjunctive_matches(&matches, cm_stubs, ARRAY_SIZE(cm_stubs));
> +
> + /* There's no real match among the highest-priority soft matches.
> + * However, if any of those soft matches has a lower-priority but
> + * otherwise identical flow match, then we need to consider those for
> + * soft or hard matches.
> + *
> + * The next iteration of the soft match loop will delete any null
> + * pointers we put into 'soft' (and some others too). */
> + for (int i = 0; i < n_soft; i++) {
> + if (soft[i]->priority != soft_pri) {
> + continue;
> + }
> +
> + /* Find next-lower-priority flow with identical flow match. */
> + match = next_rule_in_list(soft[i]->match);
> + if (match) {
> + soft[i] = ovsrcu_get(struct cls_conjunction_set *,
> + &match->conj_set);
> + if (!soft[i]) {
> + /* The flow is a hard match; don't treat as a soft
> + * match. */
> + if (match->priority > hard_pri) {
> + hard = match;
> + hard_pri = hard->priority;
> + }
> + }
> + } else {
> + /* No such lower-priority flow (probably the common case). */
> + soft[i] = NULL;
> + }
> + }
> + }
> +
> + if (soft != soft_stub) {
> + free(soft);
> + }
> + return hard ? hard->cls_rule : NULL;
> +}
> +
> +/* 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.
> + *
> + * 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()).
> + *
> + * 'flow' is non-const to allow for temporary modifications during the
> lookup.
> + * Any changes are restored before returning. */
> +const struct cls_rule *
> +classifier_lookup(const struct classifier *cls, struct flow *flow,
> + struct flow_wildcards *wc)
> +{
> + return classifier_lookup__(cls, flow, wc, true);
> }
>
> /* Finds and returns a rule in 'cls' with exactly the same priority and
> diff --git a/lib/classifier.h b/lib/classifier.h
> index 9ebc506..a0335a1 100644
> --- a/lib/classifier.h
> +++ b/lib/classifier.h
> @@ -255,6 +255,12 @@ struct classifier {
> bool publish; /* Make changes visible to lookups? */
> };
>
> +struct cls_conjunction {
> + uint32_t id;
> + uint8_t clause;
> + uint8_t n_clauses;
> +};
> +
> /* A rule to be inserted to the classifier. */
> struct cls_rule {
> struct rculist node; /* In struct cls_subtable 'rules_list'. */
> @@ -269,6 +275,10 @@ void cls_rule_init_from_minimatch(struct cls_rule *,
> const struct minimatch *,
> void cls_rule_clone(struct cls_rule *, const struct cls_rule *);
> void cls_rule_move(struct cls_rule *dst, struct cls_rule *src);
> void cls_rule_destroy(struct cls_rule *);
> +
> +void cls_rule_set_conjunctions(struct cls_rule *,
> + const struct cls_conjunction *, size_t n);
> +
> bool cls_rule_equal(const struct cls_rule *, const struct cls_rule *);
> uint32_t cls_rule_hash(const struct cls_rule *, uint32_t basis);
> void cls_rule_format(const struct cls_rule *, struct ds *);
> diff --git a/lib/flow.c b/lib/flow.c
> index eb7fdf1..f30f3b6 100644
> --- a/lib/flow.c
> +++ b/lib/flow.c
> @@ -990,6 +990,7 @@ flow_wildcards_clear_non_packet_fields(struct
> flow_wildcards *wc)
> memset(&wc->masks.metadata, 0, sizeof wc->masks.metadata);
> memset(&wc->masks.regs, 0, sizeof wc->masks.regs);
> wc->masks.actset_output = 0;
> + wc->masks.conj_id = 0;
> }
>
> /* Returns true if 'wc' matches every packet, false if 'wc' fixes any bits or
> diff --git a/lib/flow.h b/lib/flow.h
> index 8e56d05..1ca3b6e 100644
> --- a/lib/flow.h
> +++ b/lib/flow.h
> @@ -101,6 +101,7 @@ struct flow {
> uint32_t skb_priority; /* Packet priority for QoS. */
> uint32_t pkt_mark; /* Packet mark. */
> uint32_t recirc_id; /* Must be exact match. */
> + uint32_t conj_id; /* Conjunction ID. */
> union flow_in_port in_port; /* Input port.*/
> ofp_port_t actset_output; /* Output port in action set. */
> ovs_be16 pad1; /* Pad to 32 bits. */
> @@ -156,7 +157,7 @@ BUILD_ASSERT_DECL(sizeof(struct flow) % 4 == 0);
>
> /* Remember to update FLOW_WC_SEQ when changing 'struct flow'. */
> BUILD_ASSERT_DECL(offsetof(struct flow, dp_hash) + sizeof(uint32_t)
> - == sizeof(struct flow_tnl) + 180
> + == sizeof(struct flow_tnl) + 184
> && FLOW_WC_SEQ == 28);
>
> /* Incremental points at which flow classification may be performed in
> diff --git a/lib/match.c b/lib/match.c
> index 480b972..acfb2b3 100644
> --- a/lib/match.c
> +++ b/lib/match.c
> @@ -89,6 +89,13 @@ match_set_recirc_id(struct match *match, uint32_t value)
> }
>
> void
> +match_set_conj_id(struct match *match, uint32_t value)
> +{
> + match->flow.conj_id = value;
> + match->wc.masks.conj_id = UINT32_MAX;
> +}
> +
> +void
> match_set_reg(struct match *match, unsigned int reg_idx, uint32_t value)
> {
> match_set_reg_masked(match, reg_idx, value, UINT32_MAX);
> @@ -888,6 +895,10 @@ match_format(const struct match *match, struct ds *s,
> int priority)
> wc->masks.dp_hash);
> }
>
> + if (wc->masks.conj_id) {
> + ds_put_format(s, "conj_id=%"PRIu32",", f->conj_id);
> + }
> +
> if (wc->masks.skb_priority) {
> ds_put_format(s, "skb_priority=%#"PRIx32",", f->skb_priority);
> }
> diff --git a/lib/match.h b/lib/match.h
> index a245bcf..452b5e7 100644
> --- a/lib/match.h
> +++ b/lib/match.h
> @@ -46,7 +46,8 @@ void match_set_dp_hash(struct match *, uint32_t value);
> void match_set_dp_hash_masked(struct match *, uint32_t value, uint32_t mask);
>
> void match_set_recirc_id(struct match *, uint32_t value);
> -void match_set_recirc_id_masked(struct match *, uint32_t value, uint32_t
> mask);
> +
> +void match_set_conj_id(struct match *, uint32_t value);
>
> void match_set_reg(struct match *, unsigned int reg_idx, uint32_t value);
> void match_set_reg_masked(struct match *, unsigned int reg_idx,
> diff --git a/lib/meta-flow.c b/lib/meta-flow.c
> index 90dd27c..67115b2 100644
> --- a/lib/meta-flow.c
> +++ b/lib/meta-flow.c
> @@ -108,6 +108,8 @@ mf_is_all_wild(const struct mf_field *mf, const struct
> flow_wildcards *wc)
> return !wc->masks.dp_hash;
> case MFF_RECIRC_ID:
> return !wc->masks.recirc_id;
> + case MFF_CONJ_ID:
> + return !wc->masks.conj_id;
> case MFF_TUN_SRC:
> return !wc->masks.tunnel.ip_src;
> case MFF_TUN_DST:
> @@ -363,6 +365,7 @@ mf_is_value_valid(const struct mf_field *mf, const union
> mf_value *value)
> switch (mf->id) {
> case MFF_DP_HASH:
> case MFF_RECIRC_ID:
> + case MFF_CONJ_ID:
> case MFF_TUN_ID:
> case MFF_TUN_SRC:
> case MFF_TUN_DST:
> @@ -464,6 +467,9 @@ mf_get_value(const struct mf_field *mf, const struct flow
> *flow,
> case MFF_RECIRC_ID:
> value->be32 = htonl(flow->recirc_id);
> break;
> + case MFF_CONJ_ID:
> + value->be32 = htonl(flow->conj_id);
> + break;
> case MFF_TUN_ID:
> value->be64 = flow->tunnel.tun_id;
> break;
> @@ -669,6 +675,9 @@ mf_set_value(const struct mf_field *mf,
> case MFF_RECIRC_ID:
> match_set_recirc_id(match, ntohl(value->be32));
> break;
> + case MFF_CONJ_ID:
> + match_set_conj_id(match, ntohl(value->be32));
> + break;
> case MFF_TUN_ID:
> match_set_tun_id(match, value->be64);
> break;
> @@ -898,6 +907,9 @@ mf_set_flow_value(const struct mf_field *mf,
> case MFF_RECIRC_ID:
> flow->recirc_id = ntohl(value->be32);
> break;
> + case MFF_CONJ_ID:
> + flow->conj_id = ntohl(value->be32);
> + break;
> case MFF_TUN_ID:
> flow->tunnel.tun_id = value->be64;
> break;
> @@ -1152,6 +1164,10 @@ mf_set_wild(const struct mf_field *mf, struct match
> *match)
> match->flow.recirc_id = 0;
> match->wc.masks.recirc_id = 0;
> break;
> + case MFF_CONJ_ID:
> + match->flow.conj_id = 0;
> + match->wc.masks.conj_id = 0;
> + break;
> case MFF_TUN_ID:
> match_set_tun_id_masked(match, htonll(0), htonll(0));
> break;
> @@ -1373,6 +1389,7 @@ mf_set(const struct mf_field *mf,
>
> switch (mf->id) {
> case MFF_RECIRC_ID:
> + case MFF_CONJ_ID:
> case MFF_IN_PORT:
> case MFF_IN_PORT_OXM:
> case MFF_ACTSET_OUTPUT:
> diff --git a/lib/meta-flow.h b/lib/meta-flow.h
> index 62e9c79..1ee5c75 100644
> --- a/lib/meta-flow.h
> +++ b/lib/meta-flow.h
> @@ -299,6 +299,20 @@ enum OVS_PACKED_ENUM mf_field_id {
> */
> MFF_RECIRC_ID,
>
> + /* "conj_id".
> + *
> + * ID for "conjunction" actions. Please refer to ovs-ofctl(8)
> + * documentation of "conjunction" for details.
> + *
> + * Type: be32.
> + * Maskable: no.
> + * Formatting: decimal.
> + * Prerequisites: none.
> + * Access: read-only.
> + * NXM: NXM_NX_CONJ_ID(37) since v2.4.
> + * OXM: none. */
> + MFF_CONJ_ID,
> +
> /* "tun_id" (aka "tunnel_id").
> *
> * The "key" or "tunnel ID" or "VNI" in a packet received via a keyed
> diff --git a/lib/nx-match.c b/lib/nx-match.c
> index 2ad3cf2..8644787 100644
> --- a/lib/nx-match.c
> +++ b/lib/nx-match.c
> @@ -829,6 +829,10 @@ nx_put_raw(struct ofpbuf *b, enum ofp_version oxm, const
> struct match *match,
> nxm_put_32(b, MFF_RECIRC_ID, oxm, htonl(flow->recirc_id));
> }
>
> + if (match->wc.masks.conj_id) {
> + nxm_put_32(b, MFF_CONJ_ID, oxm, htonl(flow->conj_id));
> + }
> +
> if (match->wc.masks.in_port.ofp_port) {
> ofp_port_t in_port = flow->in_port.ofp_port;
> if (oxm) {
> diff --git a/lib/ofp-actions.c b/lib/ofp-actions.c
> index 4680d81..e694fd9 100644
> --- a/lib/ofp-actions.c
> +++ b/lib/ofp-actions.c
> @@ -281,6 +281,9 @@ enum ofp_raw_action_type {
>
> /* NX1.0+(29): struct nx_action_sample. */
> NXAST_RAW_SAMPLE,
> +
> + /* NX1.0+(34): struct nx_action_conjunction. */
> + NXAST_RAW_CONJUNCTION,
> };
>
> /* OpenFlow actions are always a multiple of 8 bytes in length. */
> @@ -3898,6 +3901,89 @@ format_LEARN(const struct ofpact_learn *a, struct ds
> *s)
> learn_format(a, s);
> }
>
> +/* Action structure for NXAST_CONJUNCTION. */
> +struct nx_action_conjunction {
> + ovs_be16 type; /* OFPAT_VENDOR. */
> + ovs_be16 len; /* At least 16. */
> + ovs_be32 vendor; /* NX_VENDOR_ID. */
> + ovs_be16 subtype; /* See enum ofp_raw_action_type. */
> + uint8_t clause;
> + uint8_t n_clauses;
> + ovs_be32 id;
> +};
> +OFP_ASSERT(sizeof(struct nx_action_conjunction) == 16);
> +
> +static void
> +add_conjunction(struct ofpbuf *out,
> + uint32_t id, uint8_t clause, uint8_t n_clauses)
> +{
> + struct ofpact_conjunction *oc;
> +
> + oc = ofpact_put_CONJUNCTION(out);
> + oc->id = id;
> + oc->clause = clause;
> + oc->n_clauses = n_clauses;
> +}
> +
> +static enum ofperr
> +decode_NXAST_RAW_CONJUNCTION(const struct nx_action_conjunction *nac,
> + struct ofpbuf *out)
> +{
> + if (nac->n_clauses < 2 || nac->n_clauses > 64
> + || nac->clause >= nac->n_clauses) {
> + return OFPERR_NXBAC_BAD_CONJUNCTION;
> + } else {
> + add_conjunction(out, ntohl(nac->id), nac->clause, nac->n_clauses);
> + return 0;
> + }
> +}
> +
> +static void
> +encode_CONJUNCTION(const struct ofpact_conjunction *oc,
> + enum ofp_version ofp_version OVS_UNUSED, struct ofpbuf
> *out)
> +{
> + struct nx_action_conjunction *nac = put_NXAST_CONJUNCTION(out);
> + nac->clause = oc->clause;
> + nac->n_clauses = oc->n_clauses;
> + nac->id = htonl(oc->id);
> +}
> +
> +static void
> +format_CONJUNCTION(const struct ofpact_conjunction *oc, struct ds *s)
> +{
> + ds_put_format(s, "conjunction(%"PRIu32",%"PRIu8"/%"PRIu8")",
> + oc->id, oc->clause + 1, oc->n_clauses);
> +}
> +
> +static char * OVS_WARN_UNUSED_RESULT
> +parse_CONJUNCTION(const char *arg, struct ofpbuf *ofpacts,
> + enum ofputil_protocol *usable_protocols OVS_UNUSED)
> +{
> + uint8_t n_clauses;
> + uint8_t clause;
> + uint32_t id;
> + int n;
> +
> + if (!ovs_scan(arg, "%"SCNi32" , %"SCNu8" / %"SCNu8" %n",
> + &id, &clause, &n_clauses, &n) || n != strlen(arg)) {
> + return xstrdup("\"conjunction\" syntax is \"conjunction(id,i/n)\"");
> + }
> +
> + if (n_clauses < 2) {
> + return xstrdup("conjunction must have at least 2 clauses");
> + } else if (n_clauses > 64) {
> + return xstrdup("conjunction must have at most 64 clauses");
> + } else if (clause < 1) {
> + return xstrdup("clause index must be positive");
> + } else if (clause > n_clauses) {
> + return xstrdup("clause index must be less than or equal to "
> + "number of clauses");
> + }
> +
> + add_conjunction(ofpacts, id, clause - 1, n_clauses);
> + return NULL;
> +}
> +
> /* Action structure for NXAST_MULTIPATH.
> *
> * This action performs the following steps in sequence:
> @@ -4644,6 +4730,7 @@ ofpact_is_set_or_move_action(const struct ofpact *a)
> case OFPACT_GOTO_TABLE:
> case OFPACT_GROUP:
> case OFPACT_LEARN:
> + case OFPACT_CONJUNCTION:
> case OFPACT_METER:
> case OFPACT_MULTIPATH:
> case OFPACT_NOTE:
> @@ -4710,6 +4797,7 @@ ofpact_is_allowed_in_actions_set(const struct ofpact *a)
> case OFPACT_EXIT:
> case OFPACT_FIN_TIMEOUT:
> case OFPACT_LEARN:
> + case OFPACT_CONJUNCTION:
> case OFPACT_MULTIPATH:
> case OFPACT_NOTE:
> case OFPACT_OUTPUT_REG:
> @@ -4925,6 +5013,7 @@ ovs_instruction_type_from_ofpact_type(enum ofpact_type
> type)
> case OFPACT_FIN_TIMEOUT:
> case OFPACT_RESUBMIT:
> case OFPACT_LEARN:
> + case OFPACT_CONJUNCTION:
> case OFPACT_MULTIPATH:
> case OFPACT_NOTE:
> case OFPACT_EXIT:
> @@ -5455,6 +5544,9 @@ ofpact_check__(enum ofputil_protocol *usable_protocols,
> struct ofpact *a,
> case OFPACT_LEARN:
> return learn_check(ofpact_get_LEARN(a), flow);
>
> + case OFPACT_CONJUNCTION:
> + return 0;
> +
> case OFPACT_MULTIPATH:
> return multipath_check(ofpact_get_MULTIPATH(a), flow);
>
> @@ -5576,8 +5668,12 @@ ofpacts_check_consistency(struct ofpact ofpacts[],
> size_t ofpacts_len,
> : 0);
> }
>
> -/* Verifies that the 'ofpacts_len' bytes of actions in 'ofpacts' are
> - * in the appropriate order as defined by the OpenFlow spec. */
> +/* Verifies that the 'ofpacts_len' bytes of actions in 'ofpacts' are in the
> + * appropriate order as defined by the OpenFlow spec and as required by Open
> + * vSwitch.
> + *
> + * 'allowed_ovsinsts' is a bitmap of OVSINST_* values, in which 1-bits
> indicate
> + * instructions that are allowed within 'ofpacts[]'. */
> static enum ofperr
> ofpacts_verify(const struct ofpact ofpacts[], size_t ofpacts_len,
> uint32_t allowed_ovsinsts)
> @@ -5589,6 +5685,17 @@ ofpacts_verify(const struct ofpact ofpacts[], size_t
> ofpacts_len,
> OFPACT_FOR_EACH (a, ofpacts, ofpacts_len) {
> enum ovs_instruction_type next;
>
> + if (a->type == OFPACT_CONJUNCTION) {
> + OFPACT_FOR_EACH (a, ofpacts, ofpacts_len) {
> + if (a->type != OFPACT_CONJUNCTION) {
> + VLOG_WARN("when %s action is present, it must be the
> only "
> + "kind of action used", ofpact_name(a->type));
> + return OFPERR_NXBAC_BAD_CONJUNCTION;
> + }
> + }
> + return 0;
> + }
> +
> next = ovs_instruction_type_from_ofpact_type(a->type);
> if (a > ofpacts
> && (inst == OVSINST_OFPIT11_APPLY_ACTIONS
> @@ -5887,6 +5994,7 @@ ofpact_outputs_to_port(const struct ofpact *ofpact,
> ofp_port_t port)
> case OFPACT_FIN_TIMEOUT:
> case OFPACT_RESUBMIT:
> case OFPACT_LEARN:
> + case OFPACT_CONJUNCTION:
> case OFPACT_MULTIPATH:
> case OFPACT_NOTE:
> case OFPACT_EXIT:
> diff --git a/lib/ofp-actions.h b/lib/ofp-actions.h
> index 8362aa8..5458583 100644
> --- a/lib/ofp-actions.h
> +++ b/lib/ofp-actions.h
> @@ -19,6 +19,7 @@
>
> #include <stddef.h>
> #include <stdint.h>
> +#include "classifier.h"
> #include "meta-flow.h"
> #include "ofp-errors.h"
> #include "ofp-util.h"
> @@ -96,6 +97,7 @@
> /* Flow table interaction. */ \
> OFPACT(RESUBMIT, ofpact_resubmit, ofpact, "resubmit") \
> OFPACT(LEARN, ofpact_learn, specs, "learn") \
> + OFPACT(CONJUNCTION, ofpact_conjunction, ofpact, "conjunction") \
> \
> /* Arithmetic. */ \
> OFPACT(MULTIPATH, ofpact_multipath, ofpact, "multipath") \
> @@ -611,6 +613,16 @@ enum nx_mp_algorithm {
> NX_MP_ALG_ITER_HASH = 3,
> };
>
> +/* OFPACT_CONJUNCTION.
> + *
> + * Used for NXAST_CONJUNCTION. */
> +struct ofpact_conjunction {
> + struct ofpact ofpact;
> + uint8_t clause;
> + uint8_t n_clauses;
> + uint32_t id;
> +};
> +
> /* OFPACT_MULTIPATH.
> *
> * Used for NXAST_MULTIPATH. */
> diff --git a/lib/ofp-errors.h b/lib/ofp-errors.h
> index 238fded..56b7652 100644
> --- a/lib/ofp-errors.h
> +++ b/lib/ofp-errors.h
> @@ -230,6 +230,14 @@ enum ofperr {
> * value. */
> OFPERR_NXBAC_MUST_BE_ZERO,
>
> + /* NX1.0-1.1(2,526), NX1.2+(15). Conjunction action must be only action
> + * present. Conjunction action must have at least one clause. */
> + OFPERR_NXBAC_BAD_CONJUNCTION,
> +
> + /* NX1.0-1.1(2,527), NX1.2+(16). Conjunction actions may not be
> modified.
> + * (Instead, remove the flow and add a new one in its place.) */
> + OFPERR_NXBAC_READONLY_CONJUNCTION,
> +
> /* ## --------------------- ## */
> /* ## OFPET_BAD_INSTRUCTION ## */
> /* ## --------------------- ## */
> diff --git a/ofproto/ofproto-dpif-xlate.c b/ofproto/ofproto-dpif-xlate.c
> index ba0c0d8..283df27 100644
> --- a/ofproto/ofproto-dpif-xlate.c
> +++ b/ofproto/ofproto-dpif-xlate.c
> @@ -3742,6 +3742,7 @@ ofpact_needs_recirculation_after_mpls(const struct
> ofpact *a, struct xlate_ctx *
> case OFPACT_SET_TUNNEL:
> case OFPACT_SET_QUEUE:
> case OFPACT_POP_QUEUE:
> + case OFPACT_CONJUNCTION:
> case OFPACT_NOTE:
> case OFPACT_OUTPUT_REG:
> case OFPACT_EXIT:
> @@ -4055,6 +4056,9 @@ do_xlate_actions(const struct ofpact *ofpacts, size_t
> ofpacts_len,
> xlate_learn_action(ctx, ofpact_get_LEARN(a));
> break;
>
> + case OFPACT_CONJUNCTION:
> + break;
> +
> case OFPACT_EXIT:
> ctx->exit = true;
> break;
> diff --git a/ofproto/ofproto.c b/ofproto/ofproto.c
> index dc7b551..1881c0b 100644
> --- a/ofproto/ofproto.c
> +++ b/ofproto/ofproto.c
> @@ -4138,6 +4138,45 @@ evict_rules_from_table(struct oftable *table, unsigned
> int extra_space)
> return error;
> }
>
> +static bool
> +is_conjunction(const struct ofpact *ofpacts, size_t ofpacts_len)
> +{
> + return ofpacts_len > 0 && ofpacts->type == OFPACT_CONJUNCTION;
> +}
> +
> +static void
> +set_conjunction(struct rule *rule)
> + OVS_REQUIRES(ofproto_mutex)
> +{
> + struct cls_rule *cr = CONST_CAST(struct cls_rule *, &rule->cr);
> + const struct rule_actions *actions = rule_get_actions(rule);
> + if (is_conjunction(actions->ofpacts, actions->ofpacts_len)) {
> + struct cls_conjunction *conjs;
> + const struct ofpact *ofpact;
> + int n_conjs;
> + int i;
> +
> + n_conjs = 0;
> + OFPACT_FOR_EACH (ofpact, actions->ofpacts, actions->ofpacts_len) {
> + n_conjs++;
> + }
> +
> + conjs = xzalloc(n_conjs * sizeof *conjs);
> + i = 0;
> + OFPACT_FOR_EACH (ofpact, actions->ofpacts, actions->ofpacts_len) {
> + struct ofpact_conjunction *oc = ofpact_get_CONJUNCTION(ofpact);
> + conjs[i].clause = oc->clause;
> + conjs[i].n_clauses = oc->n_clauses;
> + conjs[i].id = oc->id;
> + i++;
> + }
> + cls_rule_set_conjunctions(cr, conjs, n_conjs);
> + free(conjs);
> + } else {
> + cls_rule_set_conjunctions(cr, NULL, 0);
> + }
> +}
> +
> /* Implements OFPFC_ADD and the cases for OFPFC_MODIFY and OFPFC_MODIFY_STRICT
> * in which no matching flow already exists in the flow table.
> *
> @@ -4285,6 +4324,7 @@ add_flow(struct ofproto *ofproto, struct
> ofputil_flow_mod *fm,
>
> classifier_defer(&table->cls);
> classifier_insert(&table->cls, &rule->cr);
> + set_conjunction(rule);
>
> error = ofproto->ofproto_class->rule_insert(rule);
> if (error) {
> @@ -4398,6 +4438,7 @@ modify_flows__(struct ofproto *ofproto, struct
> ofputil_flow_mod *fm,
> if (change_actions) {
> ovsrcu_set(&rule->actions, rule_actions_create(fm->ofpacts,
> fm->ofpacts_len));
> + set_conjunction(rule);
> }
>
> if (change_actions || reset_counters) {
> diff --git a/tests/automake.mk b/tests/automake.mk
> index 33502bc..35ccf9e 100644
> --- a/tests/automake.mk
> +++ b/tests/automake.mk
> @@ -322,3 +322,5 @@ clean-pki:
> rm -f tests/pki/stamp
> rm -rf tests/pki
> endif
> +
> +EXTRA_DIST += tests/test-conjunction
> diff --git a/tests/ofproto.at b/tests/ofproto.at
> index 8cfecc6..9e7b1bf 100644
> --- a/tests/ofproto.at
> +++ b/tests/ofproto.at
> @@ -1405,6 +1405,7 @@ OVS_VSWITCHD_START
> matching:
> dp_hash: arbitrary mask
> recirc_id: exact match or wildcard
> + conj_id: exact match or wildcard
> tun_id: arbitrary mask
> tun_src: arbitrary mask
> tun_dst: arbitrary mask
> @@ -1482,7 +1483,7 @@ AT_CHECK(
> # Check that the configuration was updated.
> mv expout orig-expout
> sed 's/classifier/main/
> -74s/1000000/1024/' < orig-expout > expout
> +75s/1000000/1024/' < orig-expout > expout
> AT_CHECK([ovs-ofctl -O OpenFlow13 dump-table-features br0 | sed '/^$/d
> /^OFPST_TABLE_FEATURES/d'], [0], [expout])
> OVS_VSWITCHD_STOP
> diff --git a/tests/test-conjunction b/tests/test-conjunction
> new file mode 100755
> index 0000000..83dbe37
> --- /dev/null
> +++ b/tests/test-conjunction
> @@ -0,0 +1,22 @@
> +#! /bin/sh
> +ovs-vsctl --may-exist add-br br0
> +ovs-ofctl del-flows br0
> +ovs-ofctl add-flows br0 - <<EOF
> +conj_id=1,ip,actions=mod_dl_src:00:11:22:33:44:55,local
> +ip,ip_src=10.0.0.1,actions=conjunction(1,1/2)
> +ip,ip_src=10.0.0.4,actions=conjunction(1,1/2)
> +ip,ip_src=10.0.0.6,actions=conjunction(1,1/2)
> +ip,ip_src=10.0.0.7,actions=conjunction(1,1/2)
> +ip,ip_dst=10.0.0.2,actions=conjunction(1,2/2)
> +ip,ip_dst=10.0.0.5,actions=conjunction(1,2/2)
> +ip,ip_dst=10.0.0.7,actions=conjunction(1,2/2)
> +ip,ip_dst=10.0.0.8,actions=conjunction(1,2/2)
> +EOF
> +
> +# This should match the conjunctive flow and thus change the Ethernet
> +# source address and output to local.
> +ovs-appctl ofproto/trace br0 tcp,ip_src=10.0.0.1,ip_dst=10.0.0.5
> +printf "%s\n\n"
> '------------------------------------------------------------'
> +
> +# This should not match anything and thus get dropped.
> +ovs-appctl ofproto/trace br0 tcp,ip_src=10.0.0.2,ip_dst=10.0.0.5
> diff --git a/utilities/ovs-ofctl.8.in b/utilities/ovs-ofctl.8.in
> index 7ffbeaa..1e8727a 100644
> --- a/utilities/ovs-ofctl.8.in
> +++ b/utilities/ovs-ofctl.8.in
> @@ -1141,6 +1141,11 @@ output group in the OpenFlow action set), then the
> value will be
> .IP
> This field was introduced in Open vSwitch 2.4 to conform with the
> OpenFlow 1.5 (draft) specification.
> +.
> +.IP \fBconj_id=\fIvalue\fR
> +Matches the given 32-bit \fIvalue\fR against the conjunction ID. This
> +is used only with the \fBconjunction\fR action, documented later.
> +.
> .PP
> Defining IPv6 flows (those with \fBdl_type\fR equal to 0x86dd) requires
> support for NXM. The following shorthand notations are available for
> @@ -1783,6 +1788,186 @@ unaffected. Any further actions, including those
> which may be in
> other tables, or different levels of the \fBresubmit\fR call stack,
> are ignored. Actions in the action set is still executed (specify
> \fBclear_actions\fR before \fBexit\fR to discard them).
> +.
> +.IP "\fBconjunction(\fIid\fB, \fIk\fB/\fIn\fR\fB)\fR"
> +An individual OpenFlow flow can match only a single value for each
> +field. However, situations often arise where one wants to match one
> +of a set of values within a field or fields. For matching a single
> +field against a set, it is straightforward and efficient to add
> +multiple flows to the flow table, one for each value in the set. For
> +example, one might use the following flows to send packets with IP
> +source address \fIa\fR, \fIb\fR, \fIc\fR, or \fId\fR to the OpenFlow
> +controller:
> +.RS +1in
> +.br
> +\fBip,ip_src=\fIa\fB actions=controller\fR
> +.br
> +\fBip,ip_src=\fIb\fB actions=controller\fR
> +.br
> +\fBip,ip_src=\fIc\fB actions=controller\fR
> +.br
> +\fBip,ip_src=\fId\fB actions=controller\fR
> +.br
> +.RE
> +.IP
> +Similarly, these flows send packets with IP destination address
> +\fIe\fR, \fIf\fR, \fIg\fR, or \fIh\fR to the OpenFlow controller:
> +.RS +1in
> +.br
> +\fBip,ip_dst=\fIe\fB actions=controller\fR
> +.br
> +\fBip,ip_dst=\fIf\fB actions=controller\fR
> +.br
> +\fBip,ip_dst=\fIg\fB actions=controller\fR
> +.br
> +\fBip,ip_dst=\fIh\fB actions=controller\fR
> +.br
> +.RE
> +.IP
> +Installing all of the above flows in a single flow table yields a
> +disjunctive effect: a packet is sent to the controller if \fBip_src\fR
> +\[mo] {\fIa\fR,\fIb\fR,\fIc\fR,\fId\fR} or \fBip_dst\fR \[mo]
> +{\fIe\fR,\fIf\fR,\fIg\fR,\fIh\fR} (or both). (Pedantically, if both
> +of the above sets of flows are present in the flow table, they should
> +have different priorities, because OpenFlow says that the results are
> +undefined when two flows with same priority can both match a single
> +packet.)
> +.IP
> +Suppose, on the other hand, one wishes to match conjunctively, that
> +is, to send a packet to the controller only if both \fBip_src\fR \[mo]
> +{\fIa\fR,\fIb\fR,\fIc\fR,\fId\fR} and \fBip_dst\fR \[mo]
> +{\fIe\fR,\fIf\fR,\fIg\fR,\fIh\fR}. This requires 4 \[mu] 4 = 16
> +flows, one for each possible pairing of \fBip_src\fR and \fBip_dst\fR.
> +That is acceptable for our small example, but it does not gracefully
> +extend to larger sets or greater numbers of dimensions.
> +.IP
> +The \fBconjunction\fR action is a solution for conjunctive matches
> +that is built into Open vSwitch. A \fBconjunction\fR action ties
> +groups of individual OpenFlow flows into higher-level ``conjunctive
> +flows''. Each group corresponds to one dimension, and each flow
> +within the group matches one possible value for the dimension. A
> +packet that matches one flow from each group matches the conjunctive
> +flow.
> +.IP
> +To implement a conjunctive flow with \Bconjunction\fR, assign the
> +conjunctive flow a 32-bit \fIid\fR, which must be unique within an
> +OpenFlow table. Assign each of the \fIn\fR \[>=] 2 dimensions a
> +unique number from 1 to \fIn\fR; the ordering is unimportant. Add one
> +flow to the OpenFlow flow table for each possible value of each
> +dimension with \fBconjunction(\fIid, \fIk\fB/\fIn\fB)\fR as the flow's
> +actions, where \fIk\fR is the number assigned to the flow's dimension.
> +Together, these flows specify the conjunctive flow's match condition.
> +When the conjunctive match condition is met, Open vSwitch looks up one
> +more flow that specifies the conjunctive flow's actions and receives
> +its statistics. This flow is found by setting \fBconj_id\fR to the
> +specified \fIid\fR and then again searching the flow table.
> +.IP
> +The following flows provide an example. Whenever the IP source is one
> +of the values in the flows that match on the IP source (dimension 1 of
> +2), \fIand\fR the IP destination is one of the values in the flows
> +that match on IP destination (dimension 2 of 2), Open vSwitch searches
> +for a flow that matches \fBconj_id\fR against the conjunction ID
> +(1234), finding the first flow listed below.
> +.RS +1in
> +.br
> +.B "conj_id=1234 actions=controller"
> +.br
> +.B "ip,ip_src=10.0.0.1 actions=conjunction(1234, 1/2)"
> +.br
> +.B "ip,ip_src=10.0.0.4 actions=conjunction(1234, 1/2)"
> +.br
> +.B "ip,ip_src=10.0.0.6 actions=conjunction(1234, 1/2)"
> +.br
> +.B "ip,ip_src=10.0.0.7 actions=conjunction(1234, 1/2)"
> +.br
> +.B "ip,ip_dst=10.0.0.2 actions=conjunction(1234, 2/2)"
> +.br
> +.B "ip,ip_dst=10.0.0.5 actions=conjunction(1234, 2/2)"
> +.br
> +.B "ip,ip_dst=10.0.0.7 actions=conjunction(1234, 2/2)"
> +.br
> +.B "ip,ip_dst=10.0.0.8 actions=conjunction(1234, 2/2)"
> +.RE
> +.IP
> +Many subtleties exist:
> +.RS
> +.IP \(bu
> +In the example above, every flow in a single dimension has the same
> +form, that is, dimension 1 matches on \fBip_src\fR, dimension 2 on
> +\fBip_dst\fR, but this is not a requirement. Different flows within a
> +dimension may match on different bits within a field (e.g. IP network
> +prefixes of different lengths, or TCP/UDP port ranges as bitwise
> +matches), or even on entirely different fields (e.g. to match packets
> +for TCP source port 80 or TCP destination port 80).
> +.IP \(bu
> +The flows within a dimension can vary their matches across more than
> +one field, e.g. to match only specific pairs of IP source and
> +destination addresses or L4 port numbers.
> +.IP \(bu
> +A flow may have multiple \fBconjunction\fR actions, with different
> +\fIid\fR values. This is useful for multiple conjunctive flows with
> +overlapping sets. If one conjunctive flow matches packets with both
> +\fBip_src\fR \[mo] {\fIa\fR,\fIb\fR} and \fBip_dst\fR \[mo]
> +{\fId\fR,\fIe\fR} and a second conjunctive flow matches \fBip_src\fR
> +\[mo] {\fIb\fR,\fIc\fR} and \fBip_dst\fR \[mo] {\fIf\fR,\fIg\fR}, for
> +example, then the flow that matches \fBip_src=\fIb\fR would have two
> +\fBconjunction\fR actions, one for each conjunctive flow. The order
> +of \fBconjunction\fR actions within a list of actions is not
> +significant.
> +.IP \(bu
> +A flow with \fBconjunction\fR actions may not have any other actions.
> +(It would not be useful.)
> +.IP \(bu
> +All of the flows that constitute a conjunctive flow with a given
> +\fIid\fR must have the same priority. (Flows with the same \fIid\fR
> +but different priorities are currently treated as different
> +conjunctive flows, that is, currently \fIid\fR values need only be
> +unique within an OpenFlow table at a given priority. This behavior
> +isn't guaranteed to stay the same in later releases, so please use
> +\fIid\fR values unique within an OpenFlow table.)
> +.IP \(bu
> +Conjunctive flows must not overlap with each other, at a given
> +priority, that is, any given packet must be able to match at most one
> +conjunctive flow at a given priority. Overlapping conjunctive flows
> +yield unpredictable results.
> +.IP \(bu
> +Following a conjunctive flow match, the search for the flow with
> +\fBconj_id=\fIid\fR is done in the same general-purpose way as other flow
> +table searches, so one can use flows with \fBconj_id=\fIid\fR to act
> +differently depending on circumstances. (One exception is that the
> +search for the \fBconj_id=\fIid\fR flow itself ignores conjunctive flows,
> +to avoid recursion.) If the search with \fBconj_id=\fIid\fR fails, Open
> +vSwitch acts as if the conjunctive flow had not matched at all, and
> +continues searching the flow table for other matching flows.
> +.IP \(bu
> +OpenFlow prerequisite checking occurs for the flow with
> +\fBconj_id=\fIid\fR in the same way as any other flow, e.g. in an
> +OpenFlow 1.1+ context, putting a \fBmod_nw_src\fR action into the
> +example above would require adding an \fBip\fR match, like this:
> +.RS +1in
> +.br
> +.B "conj_id=1234,ip actions=mod_nw_src:1.2.3.4,controller"
> +.br
> +.RE
> +.IP \(bu
> +The flows that constitute a conjunctive flow do not have useful
> +statistics. They are never updated with byte or packet counts, and so
> +on. (For such a flow, therefore, the idle and hard timeouts work much
> +the same way.)
> +.IP \(bu
> +Conjunctive flows can be a useful building block for negation, that
> +is, inequality matches like \fBtcp_src\fR \[!=] 80. To implement an
> +inequality match, convert it to a pair of range matches, e.g. 0 \[<=]
> +\fBtcp_src\ < 80 and 80 < \fBtcp_src\fR \[<=] 65535, then convert each
> +of the range matches into a collection of bitwise matches as explained
> +above in the description of \fBtcp_src\fR.
> +.IP \(bu
> +A conjunctive match must have \fIn\fR \[>=] 2 dimensions (otherwise a
> +conjunctive match is not necessary). Open vSwitch enforces this.
> +.IP \(bu
> +Each dimension within a conjunctive match should ordinarily have more
> +than one flow. Open vSwitch does not enforce this.
> +.RE
> .RE
> .
> .PP
> --
> 1.7.10.4
>
> _______________________________________________
> dev mailing list
> dev@openvswitch.org
> http://openvswitch.org/mailman/listinfo/dev
_______________________________________________
dev mailing list
dev@openvswitch.org
http://openvswitch.org/mailman/listinfo/dev
