+/* Given the wildcard bit count in the least-significant 6 of 'wcbits', returns
+ * an IP netmask with a 1 in each bit that must match and a 0 in each bit that
+ * is wildcarded.
+ *
+ * The bits in 'wcbits' are in the format used in enum ofp_flow_wildcards: 0
+ * is exact match, 1 ignores the LSB, 2 ignores the 2 least-significant bits,
+ * ..., 32 and higher wildcard the entire field. This is the *opposite* of the
+ * usual convention where e.g. /24 indicates that 8 bits (not 24 bits) are
+ * wildcarded. */
+ovs_be32
+ofputil_wcbits_to_netmask(int wcbits)
+{
+ wcbits &= 0x3f;
+ return wcbits < 32 ? htonl(~((1u << wcbits) - 1)) : 0;
+}
+
+/* Given the IP netmask 'netmask', returns the number of bits of the IP address
+ * that it wildcards. 'netmask' must be a CIDR netmask (see ip_is_cidr()). */
+int
+ofputil_netmask_to_wcbits(ovs_be32 netmask)
+{
+ assert(ip_is_cidr(netmask));
+#if __GNUC__ >= 4
+ return netmask == htonl(0) ? 32 : __builtin_ctz(ntohl(netmask));
+#else
+ int wcbits;
+
+ for (wcbits = 32; netmask; wcbits--) {
+ netmask &= netmask - 1;
+ }
+
+ return wcbits;
+#endif
+}
+
+/* A list of the FWW_* and OFPFW_ bits that have the same value, meaning, and
+ * name. */
+#define WC_INVARIANT_LIST \
+ WC_INVARIANT_BIT(IN_PORT) \
+ WC_INVARIANT_BIT(DL_SRC) \
+ WC_INVARIANT_BIT(DL_DST) \
+ WC_INVARIANT_BIT(DL_TYPE) \
+ WC_INVARIANT_BIT(NW_PROTO) \
+ WC_INVARIANT_BIT(TP_SRC) \
+ WC_INVARIANT_BIT(TP_DST)
+
+/* Verify that all of the invariant bits (as defined on WC_INVARIANT_LIST)
+ * actually have the same names and values. */
+#define WC_INVARIANT_BIT(NAME) BUILD_ASSERT_DECL(FWW_##NAME == OFPFW_##NAME);
+ WC_INVARIANT_LIST
+#undef WC_INVARIANT_BIT
+
+/* WC_INVARIANTS is the invariant bits (as defined on WC_INVARIANT_LIST) all
+ * OR'd together. */
+enum {
+ WC_INVARIANTS = 0
+#define WC_INVARIANT_BIT(NAME) | FWW_##NAME
+ WC_INVARIANT_LIST
+#undef WC_INVARIANT_BIT
+};
+
+/* Converts the ofp_match in 'match' into a cls_rule in 'rule', with the given
+ * 'priority'.
+ *
+ * 'flow_format' must either NXFF_OPENFLOW10 or NXFF_TUN_ID_FROM_COOKIE. In
+ * the latter case only, 'flow''s tun_id field will be taken from the high bits
+ * of 'cookie', if 'match''s wildcards do not indicate that tun_id is
+ * wildcarded. */
+void
+ofputil_cls_rule_from_match(const struct ofp_match *match,
+ unsigned int priority,
+ enum nx_flow_format flow_format,
+ uint64_t cookie, struct cls_rule *rule)
+{
+ struct flow_wildcards *wc = &rule->wc;
+ unsigned int ofpfw;
+ ovs_be16 vid, pcp;
+
+ /* Initialize rule->priority. */
+ ofpfw = ntohl(match->wildcards);
+ ofpfw &= flow_format == NXFF_TUN_ID_FROM_COOKIE ? OVSFW_ALL : OFPFW_ALL;
+ rule->priority = !ofpfw ? UINT16_MAX : priority;
+
+ /* Initialize most of rule->wc. */
+ wc->wildcards = ofpfw & WC_INVARIANTS;
+ if (ofpfw & OFPFW_NW_TOS) {
+ wc->wildcards |= FWW_NW_TOS;
+ }
+ memset(wc->reg_masks, 0, sizeof wc->reg_masks);
+ wc->nw_src_mask = ofputil_wcbits_to_netmask(ofpfw >> OFPFW_NW_SRC_SHIFT);
+ wc->nw_dst_mask = ofputil_wcbits_to_netmask(ofpfw >> OFPFW_NW_DST_SHIFT);
+
+ if (flow_format == NXFF_TUN_ID_FROM_COOKIE && !(ofpfw & NXFW_TUN_ID)) {
+ rule->flow.tun_id = htonl(ntohll(cookie) >> 32);
+ } else {
+ wc->wildcards |= FWW_TUN_ID;
+ rule->flow.tun_id = 0;
+ }
+
+ if (ofpfw & OFPFW_DL_DST) {
+ /* OpenFlow 1.0 OFPFW_DL_DST covers the whole Ethernet destination, but
+ * Open vSwitch breaks the Ethernet destination into bits as FWW_DL_DST
+ * and FWW_ETH_MCAST. */
+ wc->wildcards |= FWW_ETH_MCAST;
+ }
+
+ /* Initialize most of rule->flow. */
+ rule->flow.nw_src = match->nw_src;
+ rule->flow.nw_dst = match->nw_dst;
+ rule->flow.in_port = (match->in_port == htons(OFPP_LOCAL) ? ODPP_LOCAL
+ : ntohs(match->in_port));
+ rule->flow.dl_type = match->dl_type;
+ rule->flow.tp_src = match->tp_src;
+ rule->flow.tp_dst = match->tp_dst;
+ memcpy(rule->flow.dl_src, match->dl_src, ETH_ADDR_LEN);
+ memcpy(rule->flow.dl_dst, match->dl_dst, ETH_ADDR_LEN);
+ rule->flow.nw_tos = match->nw_tos;
+ rule->flow.nw_proto = match->nw_proto;
+
+ /* Translate VLANs. */
+ vid = match->dl_vlan & htons(VLAN_VID_MASK);
+ pcp = htons((match->dl_vlan_pcp << VLAN_PCP_SHIFT) & VLAN_PCP_MASK);
+ switch (ofpfw & (OFPFW_DL_VLAN | OFPFW_DL_VLAN_PCP)) {
+ case OFPFW_DL_VLAN | OFPFW_DL_VLAN_PCP:
+ /* Wildcard everything. */
+ rule->flow.vlan_tci = htons(0);
+ rule->wc.vlan_tci_mask = htons(0);
+ break;
+
+ case OFPFW_DL_VLAN_PCP:
+ if (match->dl_vlan == htons(OFP_VLAN_NONE)) {
+ /* Match only packets without 802.1Q header. */
+ rule->flow.vlan_tci = htons(0);
+ rule->wc.vlan_tci_mask = htons(0xffff);
+ } else {
+ /* Wildcard PCP, specific VID. */
+ rule->flow.vlan_tci = vid | htons(VLAN_CFI);
+ rule->wc.vlan_tci_mask = htons(VLAN_VID_MASK | VLAN_CFI);
+ }
+ break;
+
+ case OFPFW_DL_VLAN:
+ /* Wildcard VID, specific PCP. */
+ rule->flow.vlan_tci = pcp | htons(VLAN_CFI);
+ rule->wc.vlan_tci_mask = htons(VLAN_PCP_MASK | VLAN_CFI);
+ break;
+
+ case 0:
+ if (match->dl_vlan == htons(OFP_VLAN_NONE)) {
+ /* This case is odd, since we can't have a specific PCP without an
+ * 802.1Q header. However, older versions of OVS treated this as
+ * matching packets withut an 802.1Q header, so we do here too. */
+ rule->flow.vlan_tci = htons(0);
+ rule->wc.vlan_tci_mask = htons(0xffff);
+ } else {
+ /* Specific VID and PCP. */
+ rule->flow.vlan_tci = vid | pcp | htons(VLAN_CFI);
+ rule->wc.vlan_tci_mask = htons(0xffff);
+ }
+ break;
+ }
+
+ /* Clean up. */
+ cls_rule_zero_wildcarded_fields(rule);
+}
+
+/* Extract 'flow' with 'wildcards' into the OpenFlow match structure
+ * 'match'.
+ *
+ * 'flow_format' must either NXFF_OPENFLOW10 or NXFF_TUN_ID_FROM_COOKIE. In
+ * the latter case only, 'match''s NXFW_TUN_ID bit will be filled in; otherwise
+ * it is always set to 0. */
+void
+ofputil_cls_rule_to_match(const struct cls_rule *rule,
+ enum nx_flow_format flow_format,
+ struct ofp_match *match)
+{
+ const struct flow_wildcards *wc = &rule->wc;
+ unsigned int ofpfw;
+
+ /* Figure out most OpenFlow wildcards. */
+ ofpfw = wc->wildcards & WC_INVARIANTS;
+ ofpfw |= ofputil_netmask_to_wcbits(wc->nw_src_mask) << OFPFW_NW_SRC_SHIFT;
+ ofpfw |= ofputil_netmask_to_wcbits(wc->nw_dst_mask) << OFPFW_NW_DST_SHIFT;
+ if (wc->wildcards & FWW_NW_TOS) {
+ ofpfw |= OFPFW_NW_TOS;
+ }
+ if (flow_format == NXFF_TUN_ID_FROM_COOKIE && wc->wildcards & FWW_TUN_ID) {
+ ofpfw |= NXFW_TUN_ID;
+ }
+
+ /* Translate VLANs. */
+ match->dl_vlan = htons(0);
+ match->dl_vlan_pcp = 0;
+ if (rule->wc.vlan_tci_mask == htons(0)) {
+ ofpfw |= OFPFW_DL_VLAN | OFPFW_DL_VLAN_PCP;
+ } else if (rule->wc.vlan_tci_mask & htons(VLAN_CFI)
+ && !(rule->flow.vlan_tci & htons(VLAN_CFI))) {
+ match->dl_vlan = htons(OFP_VLAN_NONE);
+ } else {
+ if (!(rule->wc.vlan_tci_mask & htons(VLAN_VID_MASK))) {
+ ofpfw |= OFPFW_DL_VLAN;
+ } else {
+ match->dl_vlan = htons(vlan_tci_to_vid(rule->flow.vlan_tci));
+ }
+
+ if (!(rule->wc.vlan_tci_mask & htons(VLAN_PCP_MASK))) {
+ ofpfw |= OFPFW_DL_VLAN_PCP;
+ } else {
+ match->dl_vlan_pcp = vlan_tci_to_pcp(rule->flow.vlan_tci);
+ }
+ }
+
+ /* Compose most of the match structure. */
+ match->wildcards = htonl(ofpfw);
+ match->in_port = htons(rule->flow.in_port == ODPP_LOCAL ? OFPP_LOCAL
+ : rule->flow.in_port);
+ memcpy(match->dl_src, rule->flow.dl_src, ETH_ADDR_LEN);
+ memcpy(match->dl_dst, rule->flow.dl_dst, ETH_ADDR_LEN);
+ match->dl_type = rule->flow.dl_type;
+ match->nw_src = rule->flow.nw_src;
+ match->nw_dst = rule->flow.nw_dst;
+ match->nw_tos = rule->flow.nw_tos;
+ match->nw_proto = rule->flow.nw_proto;
+ match->tp_src = rule->flow.tp_src;
+ match->tp_dst = rule->flow.tp_dst;
+ memset(match->pad1, '\0', sizeof match->pad1);
+ memset(match->pad2, '\0', sizeof match->pad2);
+}
+