+{
+ size_t tag_size = strlen(tag) + 1;
+ char *payload;
+
+ payload = snap_compose(b, eth_addr_broadcast, eth_src, 0x002320, snap_type,
+ tag_size + ETH_ADDR_LEN);
+ memcpy(payload, tag, tag_size);
+ memcpy(payload + tag_size, eth_src, ETH_ADDR_LEN);
+}
+
+/* Modify the TCI field of 'packet', whose data must begin with an Ethernet
+ * header. If a VLAN tag is present, its TCI field is replaced by 'tci'. If a
+ * VLAN tag is not present, one is added with the TCI field set to 'tci'.
+ *
+ * Also sets 'packet->l2' to point to the new Ethernet header. */
+void
+eth_set_vlan_tci(struct ofpbuf *packet, ovs_be16 tci)
+{
+ struct eth_header *eh = packet->data;
+ struct vlan_eth_header *veh;
+
+ if (packet->size >= sizeof(struct vlan_eth_header)
+ && eh->eth_type == htons(ETH_TYPE_VLAN)) {
+ veh = packet->data;
+ veh->veth_tci = tci;
+ } else {
+ /* Insert new 802.1Q header. */
+ struct vlan_eth_header tmp;
+ memcpy(tmp.veth_dst, eh->eth_dst, ETH_ADDR_LEN);
+ memcpy(tmp.veth_src, eh->eth_src, ETH_ADDR_LEN);
+ tmp.veth_type = htons(ETH_TYPE_VLAN);
+ tmp.veth_tci = tci;
+ tmp.veth_next_type = eh->eth_type;
+
+ veh = ofpbuf_push_uninit(packet, VLAN_HEADER_LEN);
+ memcpy(veh, &tmp, sizeof tmp);
+ }
+ packet->l2 = packet->data;
+}
+
+/* Stores the string representation of the IPv6 address 'addr' into the
+ * character array 'addr_str', which must be at least INET6_ADDRSTRLEN
+ * bytes long. */
+void
+format_ipv6_addr(char *addr_str, const struct in6_addr *addr)
+{
+ inet_ntop(AF_INET6, addr, addr_str, INET6_ADDRSTRLEN);
+}
+
+void
+print_ipv6_addr(struct ds *string, const struct in6_addr *addr)
+{
+ char addr_str[INET6_ADDRSTRLEN];
+
+ format_ipv6_addr(addr_str, addr);
+ ds_put_format(string, "%s", addr_str);
+}
+
+struct in6_addr ipv6_addr_bitand(const struct in6_addr *a,
+ const struct in6_addr *b)
+{
+ int i;
+ struct in6_addr dst;
+
+#ifdef s6_addr32
+ for (i=0; i<4; i++) {
+ dst.s6_addr32[i] = a->s6_addr32[i] & b->s6_addr32[i];
+ }
+#else
+ for (i=0; i<16; i++) {
+ dst.s6_addr[i] = a->s6_addr[i] & b->s6_addr[i];
+ }
+#endif
+
+ return dst;
+}
+
+/* Returns an in6_addr consisting of 'mask' high-order 1-bits and 128-N
+ * low-order 0-bits. */
+struct in6_addr
+ipv6_create_mask(int mask)
+{
+ struct in6_addr netmask;
+ uint8_t *netmaskp = &netmask.s6_addr[0];
+
+ memset(&netmask, 0, sizeof netmask);
+ while (mask > 8) {
+ *netmaskp = 0xff;
+ netmaskp++;
+ mask -= 8;
+ }
+
+ if (mask) {
+ *netmaskp = 0xff << (8 - mask);
+ }
+
+ return netmask;
+}
+
+/* Given the IPv6 netmask 'netmask', returns the number of bits of the
+ * IPv6 address that it wildcards. 'netmask' must be a CIDR netmask (see
+ * ipv6_is_cidr()). */
+int
+ipv6_count_cidr_bits(const struct in6_addr *netmask)
+{
+ int i;
+ int count = 0;
+ const uint8_t *netmaskp = &netmask->s6_addr[0];
+
+ assert(ipv6_is_cidr(netmask));
+
+ for (i=0; i<16; i++) {
+ if (netmaskp[i] == 0xff) {
+ count += 8;
+ } else {
+ uint8_t nm;
+
+ for(nm = netmaskp[i]; nm; nm <<= 1) {
+ count++;
+ }
+ break;
+ }
+
+ }
+
+ return count;
+}
+
+/* Returns true if 'netmask' is a CIDR netmask, that is, if it consists of N
+ * high-order 1-bits and 128-N low-order 0-bits. */
+bool
+ipv6_is_cidr(const struct in6_addr *netmask)
+{
+ const uint8_t *netmaskp = &netmask->s6_addr[0];
+ int i;
+
+ for (i=0; i<16; i++) {
+ if (netmaskp[i] != 0xff) {
+ uint8_t x = ~netmaskp[i];
+ if (x & (x + 1)) {
+ return false;
+ }
+ while (++i < 16) {
+ if (netmaskp[i]) {
+ return false;
+ }
+ }
+ }
+ }
+
+ return true;
+}
+
+/* Populates 'b' with an Ethernet II packet headed with the given 'eth_dst',
+ * 'eth_src' and 'eth_type' parameters. A payload of 'size' bytes is allocated
+ * in 'b' and returned. This payload may be populated with appropriate
+ * information by the caller.
+ *
+ * The returned packet has enough headroom to insert an 802.1Q VLAN header if
+ * desired. */
+void *
+eth_compose(struct ofpbuf *b, const uint8_t eth_dst[ETH_ADDR_LEN],
+ const uint8_t eth_src[ETH_ADDR_LEN], uint16_t eth_type,
+ size_t size)
+{
+ void *data;
+ struct eth_header *eth;
+
+ ofpbuf_clear(b);
+
+ ofpbuf_prealloc_tailroom(b, ETH_HEADER_LEN + VLAN_HEADER_LEN + size);
+ ofpbuf_reserve(b, VLAN_HEADER_LEN);
+ eth = ofpbuf_put_uninit(b, ETH_HEADER_LEN);
+ data = ofpbuf_put_uninit(b, size);
+
+ memcpy(eth->eth_dst, eth_dst, ETH_ADDR_LEN);
+ memcpy(eth->eth_src, eth_src, ETH_ADDR_LEN);
+ eth->eth_type = htons(eth_type);
+
+ return data;
+}
+
+/* Populates 'b' with an Ethernet LLC+SNAP packet headed with the given
+ * 'eth_dst', 'eth_src', 'snap_org', and 'snap_type'. A payload of 'size'
+ * bytes is allocated in 'b' and returned. This payload may be populated with
+ * appropriate information by the caller.
+ *
+ * The returned packet has enough headroom to insert an 802.1Q VLAN header if
+ * desired. */
+void *
+snap_compose(struct ofpbuf *b, const uint8_t eth_dst[ETH_ADDR_LEN],
+ const uint8_t eth_src[ETH_ADDR_LEN],
+ unsigned int oui, uint16_t snap_type, size_t size)