+ wc->wildcards = 0;
+ wc->nw_src_mask = htonl(UINT32_MAX);
+ wc->nw_dst_mask = htonl(UINT32_MAX);
+ memset(wc->reg_masks, 0xff, sizeof wc->reg_masks);
+}
+
+static inline uint32_t
+combine_nw_bits(uint32_t wb1, uint32_t wb2, int shift)
+{
+ uint32_t sb1 = (wb1 >> shift) & 0x3f;
+ uint32_t sb2 = (wb2 >> shift) & 0x3f;
+ return MAX(sb1, sb2) << shift;
+}
+
+/* Initializes 'dst' as the combination of wildcards in 'src1' and 'src2'.
+ * That is, a bit or a field is wildcarded in 'dst' if it is wildcarded in
+ * 'src1' or 'src2' or both. */
+void
+flow_wildcards_combine(struct flow_wildcards *dst,
+ const struct flow_wildcards *src1,
+ const struct flow_wildcards *src2)
+{
+ uint32_t wb1 = src1->wildcards;
+ uint32_t wb2 = src2->wildcards;
+ int i;
+
+ dst->wildcards = (wb1 | wb2) & ~(OFPFW_NW_SRC_MASK | OFPFW_NW_DST_MASK);
+ dst->wildcards |= combine_nw_bits(wb1, wb2, OFPFW_NW_SRC_SHIFT);
+ dst->wildcards |= combine_nw_bits(wb1, wb2, OFPFW_NW_DST_SHIFT);
+ dst->nw_src_mask = src1->nw_src_mask & src2->nw_src_mask;
+ dst->nw_dst_mask = src1->nw_dst_mask & src2->nw_dst_mask;
+ for (i = 0; i < FLOW_N_REGS; i++) {
+ dst->reg_masks[i] = src1->reg_masks[i] & src2->reg_masks[i];
+ }
+}
+
+/* Returns a hash of the wildcards in 'wc'. */
+uint32_t
+flow_wildcards_hash(const struct flow_wildcards *wc)
+{
+ /* There is no need to include nw_src_mask or nw_dst_mask because they do
+ * not add any information (they can be computed from wc->wildcards). */
+ BUILD_ASSERT_DECL(sizeof wc->wildcards == 4);
+ BUILD_ASSERT_DECL(sizeof wc->reg_masks == 4 * FLOW_N_REGS);
+ BUILD_ASSERT_DECL(offsetof(struct flow_wildcards, wildcards) == 0);
+ BUILD_ASSERT_DECL(offsetof(struct flow_wildcards, reg_masks) == 4);
+ return hash_words((const uint32_t *) wc, 1 + FLOW_N_REGS, 0);
+}
+
+/* Returns true if 'a' and 'b' represent the same wildcards, false if they are
+ * different. */
+bool
+flow_wildcards_equal(const struct flow_wildcards *a,
+ const struct flow_wildcards *b)
+{
+ int i;
+
+ if (a->wildcards != b->wildcards) {
+ return false;
+ }
+
+ for (i = 0; i < FLOW_N_REGS; i++) {
+ if (a->reg_masks[i] != b->reg_masks[i]) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+/* Returns true if at least one bit or field is wildcarded in 'a' but not in
+ * 'b', false otherwise. */
+bool
+flow_wildcards_has_extra(const struct flow_wildcards *a,
+ const struct flow_wildcards *b)
+{
+ int i;
+
+ for (i = 0; i < FLOW_N_REGS; i++) {
+ if ((a->reg_masks[i] & b->reg_masks[i]) != b->reg_masks[i]) {
+ return true;
+ }
+ }
+
+#define OFPFW_NW_MASK (OFPFW_NW_SRC_MASK | OFPFW_NW_DST_MASK)
+ return ((a->wildcards & ~(b->wildcards | OFPFW_NW_MASK))
+ || (a->nw_src_mask & b->nw_src_mask) != b->nw_src_mask
+ || (a->nw_dst_mask & b->nw_dst_mask) != b->nw_dst_mask);