+/* Returns the effective vlan of a packet, taking into account both the
+ * 802.1Q header and implicitly tagged ports. A value of 0 indicates that
+ * the packet is untagged and -1 indicates it has an invalid header and
+ * should be dropped. */
+static int flow_get_vlan(struct bridge *br, const flow_t *flow,
+ struct port *in_port, bool have_packet)
+{
+ /* Note that dl_vlan of 0 and of OFP_VLAN_NONE both mean that the packet
+ * belongs to VLAN 0, so we should treat both cases identically. (In the
+ * former case, the packet has an 802.1Q header that specifies VLAN 0,
+ * presumably to allow a priority to be specified. In the latter case, the
+ * packet does not have any 802.1Q header.) */
+ int vlan = ntohs(flow->dl_vlan);
+ if (vlan == OFP_VLAN_NONE) {
+ vlan = 0;
+ }
+ if (in_port->vlan >= 0) {
+ if (vlan) {
+ /* XXX support double tagging? */
+ if (have_packet) {
+ static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
+ VLOG_WARN_RL(&rl, "bridge %s: dropping VLAN %"PRIu16" tagged "
+ "packet received on port %s configured with "
+ "implicit VLAN %"PRIu16,
+ br->name, ntohs(flow->dl_vlan),
+ in_port->name, in_port->vlan);
+ }
+ return -1;
+ }
+ vlan = in_port->vlan;
+ } else {
+ if (!port_includes_vlan(in_port, vlan)) {
+ if (have_packet) {
+ static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
+ VLOG_WARN_RL(&rl, "bridge %s: dropping VLAN %d tagged "
+ "packet received on port %s not configured for "
+ "trunking VLAN %d",
+ br->name, vlan, in_port->name, vlan);
+ }
+ return -1;
+ }
+ }
+
+ return vlan;
+}
+
+static void
+update_learning_table(struct bridge *br, const flow_t *flow, int vlan,
+ struct port *in_port)
+{
+ tag_type rev_tag = mac_learning_learn(br->ml, flow->dl_src,
+ vlan, in_port->port_idx);
+ if (rev_tag) {
+ /* The log messages here could actually be useful in debugging,
+ * so keep the rate limit relatively high. */
+ static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(30,
+ 300);
+ VLOG_DBG_RL(&rl, "bridge %s: learned that "ETH_ADDR_FMT" is "
+ "on port %s in VLAN %d",
+ br->name, ETH_ADDR_ARGS(flow->dl_src),
+ in_port->name, vlan);
+ ofproto_revalidate(br->ofproto, rev_tag);
+ }
+}
+