Function bstp_decode_bpdu

freebsd/net/bridgestp.c:267–338

}

static void
bstp_decode_bpdu(struct bstp_port *bp, struct bstp_cbpdu *cpdu,
    struct bstp_config_unit *cu)
{
	int flags;

	cu->cu_pv.pv_root_id =
	    (((uint64_t)ntohs(cpdu->cbu_rootpri)) << 48) |
	    (((uint64_t)cpdu->cbu_rootaddr[0]) << 40) |
	    (((uint64_t)cpdu->cbu_rootaddr[1]) << 32) |
	    (((uint64_t)cpdu->cbu_rootaddr[2]) << 24) |
	    (((uint64_t)cpdu->cbu_rootaddr[3]) << 16) |
	    (((uint64_t)cpdu->cbu_rootaddr[4]) << 8) |
	    (((uint64_t)cpdu->cbu_rootaddr[5]) << 0);

	cu->cu_pv.pv_dbridge_id =
	    (((uint64_t)ntohs(cpdu->cbu_bridgepri)) << 48) |
	    (((uint64_t)cpdu->cbu_bridgeaddr[0]) << 40) |
	    (((uint64_t)cpdu->cbu_bridgeaddr[1]) << 32) |
	    (((uint64_t)cpdu->cbu_bridgeaddr[2]) << 24) |
	    (((uint64_t)cpdu->cbu_bridgeaddr[3]) << 16) |
	    (((uint64_t)cpdu->cbu_bridgeaddr[4]) << 8) |
	    (((uint64_t)cpdu->cbu_bridgeaddr[5]) << 0);

	cu->cu_pv.pv_cost = ntohl(cpdu->cbu_rootpathcost);
	cu->cu_message_age = ntohs(cpdu->cbu_messageage);
	cu->cu_max_age = ntohs(cpdu->cbu_maxage);
	cu->cu_hello_time = ntohs(cpdu->cbu_hellotime);
	cu->cu_forward_delay = ntohs(cpdu->cbu_forwarddelay);
	cu->cu_pv.pv_dport_id = ntohs(cpdu->cbu_portid);
	cu->cu_pv.pv_port_id = bp->bp_port_id;
	cu->cu_message_type = cpdu->cbu_bpdutype;

	/* Strip off unused flags in STP mode */
	flags = cpdu->cbu_flags;
	switch (cpdu->cbu_protover) {
		case BSTP_PROTO_STP:
			flags &= BSTP_PDU_STPMASK;
			/* A STP BPDU explicitly conveys a Designated Port */
			cu->cu_role = BSTP_ROLE_DESIGNATED;
			break;

		case BSTP_PROTO_RSTP:
			flags &= BSTP_PDU_RSTPMASK;
			break;
	}

	cu->cu_topology_change_ack =
		(flags & BSTP_PDU_F_TCA) ? 1 : 0;
	cu->cu_proposal =
		(flags & BSTP_PDU_F_P) ? 1 : 0;
	cu->cu_agree =
		(flags & BSTP_PDU_F_A) ? 1 : 0;
	cu->cu_learning =
		(flags & BSTP_PDU_F_L) ? 1 : 0;
	cu->cu_forwarding =
		(flags & BSTP_PDU_F_F) ? 1 : 0;
	cu->cu_topology_change =