Signed-off-by: Ben Pfaff <[email protected]>
---
ovn/expr.c | 115 ++++++++++++++++++++++++++++++++++++++++++-------------
ovn/expr.h | 6 ++-
tests/test-ovn.c | 6 +--
3 files changed, 95 insertions(+), 32 deletions(-)
diff --git a/ovn/expr.c b/ovn/expr.c
index cd6f729..83fd866 100644
--- a/ovn/expr.c
+++ b/ovn/expr.c
@@ -21,6 +21,7 @@
#include "lex.h"
#include "match.h"
#include "shash.h"
+#include "simap.h"
#include "openvswitch/vlog.h"
VLOG_DEFINE_THIS_MODULE(expr);
@@ -1136,9 +1137,14 @@ expr_symtab_add_subfield(struct shash *symtab, const
char *name,
* 'prereqs'. */
struct expr_symbol *
expr_symtab_add_string(struct shash *symtab, const char *name,
- const char *prereqs)
+ enum mf_field_id id, const char *prereqs)
{
- return add_symbol(symtab, name, 0, prereqs, EXPR_L_NOMINAL, false);
+ const struct mf_field *field = mf_from_id(id);
+ struct expr_symbol *symbol;
+
+ symbol = add_symbol(symtab, name, 0, prereqs, EXPR_L_NOMINAL, false);
+ symbol->field = field;
+ return symbol;
}
static enum expr_level
@@ -2101,33 +2107,59 @@ expr_match_add(struct hmap *matches, struct expr_match
*match)
hmap_insert(matches, &match->hmap_node, hash);
}
-static void
-constrain_match(const struct expr *expr, struct match *m)
+static bool
+constrain_match(const struct expr *expr, const struct simap *ports,
+ struct match *m)
{
ovs_assert(expr->type == EXPR_T_CMP);
- ovs_assert(expr->cmp.symbol->width);
- mf_mask_subfield(expr->cmp.symbol->field, &expr->cmp.value,
- &expr->cmp.mask, m);
+ if (expr->cmp.symbol->width) {
+ mf_mask_subfield(expr->cmp.symbol->field, &expr->cmp.value,
+ &expr->cmp.mask, m);
+ } else {
+ const struct simap_node *node;
+ node = ports ? simap_find(ports, expr->cmp.string) : NULL;
+ if (!node) {
+ return false;
+ }
+
+ struct mf_subfield sf;
+ sf.field = expr->cmp.symbol->field;
+ sf.ofs = 0;
+ sf.n_bits = expr->cmp.symbol->field->n_bits;
+
+ union mf_subvalue x;
+ memset(&x, 0, sizeof x);
+ x.integer = htonll(node->data);
+
+ mf_write_subfield(&sf, &x, m);
+ }
+ return true;
}
-static void
-add_disjunction(const struct expr *or, struct match *m, uint8_t clause,
- uint8_t n_clauses, uint32_t conj_id, struct hmap *matches)
+static bool
+add_disjunction(const struct expr *or, const struct simap *ports,
+ struct match *m, uint8_t clause, uint8_t n_clauses,
+ uint32_t conj_id, struct hmap *matches)
{
struct expr *sub;
+ int n = 0;
ovs_assert(or->type == EXPR_T_OR);
LIST_FOR_EACH (sub, node, &or->andor) {
struct expr_match *match = expr_match_new(m, clause, n_clauses,
conj_id);
- constrain_match(sub, &match->match);
+ n += constrain_match(sub, ports, &match->match);
expr_match_add(matches, match);
}
+
+ /* If n == 1, then this didn't really need to be a disjunction. Oh well,
+ * that shouldn't happen much. */
+ return n > 0;
}
static void
-add_conjunction(const struct expr *and, uint32_t *n_conjsp,
- struct hmap *matches)
+add_conjunction(const struct expr *and, const struct simap *ports,
+ uint32_t *n_conjsp, struct hmap *matches)
{
struct match match;
int n_clauses = 0;
@@ -2139,7 +2171,9 @@ add_conjunction(const struct expr *and, uint32_t
*n_conjsp,
LIST_FOR_EACH (sub, node, &and->andor) {
switch (sub->type) {
case EXPR_T_CMP:
- constrain_match(sub, &match);
+ if (!constrain_match(sub, ports, &match)) {
+ return;
+ }
break;
case EXPR_T_OR:
n_clauses++;
@@ -2155,7 +2189,7 @@ add_conjunction(const struct expr *and, uint32_t
*n_conjsp,
} else if (n_clauses == 1) {
LIST_FOR_EACH (sub, node, &and->andor) {
if (sub->type == EXPR_T_OR) {
- add_disjunction(sub, &match, 0, 0, 0, matches);
+ add_disjunction(sub, ports, &match, 0, 0, 0, matches);
}
}
} else {
@@ -2163,38 +2197,65 @@ add_conjunction(const struct expr *and, uint32_t
*n_conjsp,
(*n_conjsp)++;
LIST_FOR_EACH (sub, node, &and->andor) {
if (sub->type == EXPR_T_OR) {
- add_disjunction(sub, &match, clause++, n_clauses, *n_conjsp,
- matches);
+ if (!add_disjunction(sub, ports, &match, clause++,
+ n_clauses, *n_conjsp, matches)) {
+ /* This clause can't ever match, so we might as well skip
+ * adding the other clauses--the overall disjunctive flow
+ * can't ever match. Ideally we would also back out all of
+ * the clauses we already added, but that seems like a lot
+ * of trouble for a case that might never occur in
+ * practice. */
+ return;
+ }
}
}
}
}
static void
-add_cmp_flow(const struct expr *cmp, struct hmap *matches)
+add_cmp_flow(const struct expr *cmp, const struct simap *ports,
+ struct hmap *matches)
{
struct expr_match *m = expr_match_new(NULL, 0, 0, 0);
match_init_catchall(&m->match);
- constrain_match(cmp, &m->match);
- expr_match_add(matches, m);
+ if (constrain_match(cmp, ports, &m->match)) {
+ expr_match_add(matches, m);
+ } else {
+ free(m);
+ }
}
/* Converts 'expr', which must be in the form returned by expr_normalize(), to
* a collection of Open vSwitch flows in 'matches', which this function
- * initializes to an hmap of "struct expr_match" structures. */
+ * initializes to an hmap of "struct expr_match" structures. Returns the
+ * number of conjunctive match IDs consumed by 'matches', which uses
+ * conjunctive match IDs beginning with 0; the caller must offset or remap them
+ * into the desired range as necessary.
+ *
+ * 'ports' must be a map from strings (presumably names of ports) to integers.
+ * Any comparisons against string fields in 'expr' are translated into integers
+ * through this map. A comparison against a string that is not in 'ports' acts
+ * like a Boolean "false"; that is, it will always fail to match. For a simple
+ * expression, this means that the overall expression always fails to match,
+ * but an expression with a disjunction on the string field might still match
+ * on other port names.
+ *
+ * (This treatment of string fields might be too simplistic in general, but it
+ * seems reasonable for now when string fields are used only for ports.) */
uint32_t
-expr_to_matches(const struct expr *expr, struct hmap *matches)
+expr_to_matches(const struct expr *expr, const struct simap *ports,
+ struct hmap *matches)
{
uint32_t n_conjs = 0;
hmap_init(matches);
switch (expr->type) {
case EXPR_T_CMP:
- add_cmp_flow(expr, matches);
+ add_cmp_flow(expr, ports, matches);
break;
case EXPR_T_AND:
- add_conjunction(expr, &n_conjs, matches);
+ add_conjunction(expr, ports, &n_conjs, matches);
break;
case EXPR_T_OR:
@@ -2202,16 +2263,16 @@ expr_to_matches(const struct expr *expr, struct hmap
*matches)
struct expr *sub;
LIST_FOR_EACH (sub, node, &expr->andor) {
- add_cmp_flow(sub, matches);
+ add_cmp_flow(sub, ports, matches);
}
} else {
struct expr *sub;
LIST_FOR_EACH (sub, node, &expr->andor) {
if (sub->type == EXPR_T_AND) {
- add_conjunction(sub, &n_conjs, matches);
+ add_conjunction(sub, ports, &n_conjs, matches);
} else {
- add_cmp_flow(sub, matches);
+ add_cmp_flow(sub, ports, matches);
}
}
}
diff --git a/ovn/expr.h b/ovn/expr.h
index ab13c1b..f42d752 100644
--- a/ovn/expr.h
+++ b/ovn/expr.h
@@ -61,6 +61,7 @@
struct ds;
struct shash;
+struct simap;
/* "Measurement level" of a field. See "Level of Measurement" in the large
* comment on struct expr_symbol below for more information. */
@@ -255,7 +256,7 @@ struct expr_symbol *expr_symtab_add_subfield(struct shash
*symtab,
const char *prereqs,
const char *subfield);
struct expr_symbol *expr_symtab_add_string(struct shash *symtab,
- const char *name,
+ const char *name, enum mf_field_id,
const char *prereqs);
struct expr_symbol *expr_symtab_add_predicate(struct shash *symtab,
const char *name,
@@ -362,6 +363,7 @@ struct expr_match {
size_t n, allocated;
};
-uint32_t expr_to_matches(const struct expr *, struct hmap *);
+uint32_t expr_to_matches(const struct expr *, const struct simap *ports,
+ struct hmap *matches);
#endif /* ovn/expr.h */
diff --git a/tests/test-ovn.c b/tests/test-ovn.c
index aef4e45..8048e08 100644
--- a/tests/test-ovn.c
+++ b/tests/test-ovn.c
@@ -130,8 +130,8 @@ create_symtab(struct shash *symtab)
{
shash_init(symtab);
- expr_symtab_add_string(symtab, "inport", NULL);
- expr_symtab_add_string(symtab, "outport", NULL);
+ expr_symtab_add_string(symtab, "inport", MFF_IN_PORT, NULL);
+ expr_symtab_add_string(symtab, "outport", MFF_ACTSET_OUTPUT, NULL);
expr_symtab_add_field(symtab, "xreg0", MFF_XREG0, NULL, false);
expr_symtab_add_field(symtab, "xreg1", MFF_XREG1, NULL, false);
@@ -858,7 +858,7 @@ test_tree_shape_exhaustively(struct expr *expr, struct
shash *symtab,
struct test_rule *test_rule;
uint32_t n_conjs;
- n_conjs = expr_to_matches(modified, &matches);
+ n_conjs = expr_to_matches(modified, NULL, &matches);
classifier_init(&cls, NULL);
HMAP_FOR_EACH (m, hmap_node, &matches) {
--
2.1.3
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