ofp-actions: Refactor ofpact_get_mf_dst().

This function finds the mf destination field for any ofpact, returning
NULL if not applicable. It will be used by the next patch to properly
reject OpenFlow flows with conntrack actions when conntrack is
unsupported by the datapath.

Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>

diff --git a/lib/ofp-actions.c b/lib/ofp-actions.c
index 8050fe4..354c768 100644 (file)
--- a/lib/ofp-actions.c
+++ b/lib/ofp-actions.c
@@ -6730,16 +6730,20 @@ ofpacts_check_consistency(struct ofpact ofpacts[], size_t ofpacts_len,
             : 0);
 }
 
-static const struct mf_field *
-ofpact_get_mf_field(enum ofpact_type type, const void *ofpact)
+/* Returns the destination field that 'ofpact' would write to, or NULL
+ * if the action would not write to an mf_field. */
+const struct mf_field *
+ofpact_get_mf_dst(const struct ofpact *ofpact)
 {
-    if (type == OFPACT_SET_FIELD) {
-        const struct ofpact_set_field *orl = ofpact;
+    if (ofpact->type == OFPACT_SET_FIELD) {
+        const struct ofpact_set_field *orl;
 
+        orl = CONTAINER_OF(ofpact, struct ofpact_set_field, ofpact);
         return orl->field;
-    } else if (type == OFPACT_REG_MOVE) {
-        const struct ofpact_reg_move *orm = ofpact;
+    } else if (ofpact->type == OFPACT_REG_MOVE) {
+        const struct ofpact_reg_move *orm;
 
+        orm = CONTAINER_OF(ofpact, struct ofpact_reg_move, ofpact);
         return orm->dst.field;
     }
 
@@ -6764,7 +6768,7 @@ field_requires_ct(enum mf_field_id field)
 static enum ofperr
 ofpacts_verify_nested(const struct ofpact *a, enum ofpact_type outer_action)
 {
-    const struct mf_field *field = ofpact_get_mf_field(a->type, a);
+    const struct mf_field *field = ofpact_get_mf_dst(a);
 
     if (field && field_requires_ct(field->id) && outer_action != OFPACT_CT) {
         VLOG_WARN("cannot set CT fields outside of ct action");

diff --git a/lib/ofp-actions.h b/lib/ofp-actions.h
index a07fb3f..18c7395 100644 (file)
--- a/lib/ofp-actions.h
+++ b/lib/ofp-actions.h
@@ -874,6 +874,7 @@ bool ofpacts_output_to_group(const struct ofpact[], size_t ofpacts_len,
                              uint32_t group_id);
 bool ofpacts_equal(const struct ofpact a[], size_t a_len,
                    const struct ofpact b[], size_t b_len);
+const struct mf_field *ofpact_get_mf_dst(const struct ofpact *ofpact);
 uint32_t ofpacts_get_meter(const struct ofpact[], size_t ofpacts_len);
 
 /* Formatting and parsing ofpacts. */