OT_WEAK void dll_activate(void) {
/// Do session creation
/// 1. Block DLL Idle-time tasks: they get reactivated by dll_idle()
/// 2. Get top session
/// 3. Associated Applet can construct packet, or control parameters
/// 4. Session is terminated if "SCRAP" bit is 1
/// 5. Session is processed otherwise
m2session* s_active;
ot_app s_applet;
dll_block_idletasks();
//dll.idle_state = sub_default_idle();
s_active = session_top();
s_applet = (s_active->applet == NULL) ? \
&dll_response_applet : s_active->applet;
s_active->applet = NULL;
s_applet(s_active);
if (s_active->netstate & M2_NETSTATE_SCRAP) {
session_pop();
dll_idle();
}
else if (s_active->netstate & M2_NETSTATE_RX) {
dll_init_rx(s_active);
}
else {
dll_init_tx(s_active->netstate & (M2_NETFLAG_BG | M2_NETFLAG_STREAM));
}
}
m2session* otapi_task_advertise(advert_tmpl* adv_tmpl, session_tmpl* s_tmpl, ot_app applet) {
/// This is a more complicated process than the others, because it actually
/// creates two sessions: one for the flood and one for the request.
# define _FLOOD_NETSTATE (M2_NETFLAG_FLOOD | M2_NETSTATE_INIT | M2_NETSTATE_REQTX)
ot_u8 scratch;
m2session* session;
/// 1. Clear any sessions between now and the request, and push the
/// request session onto the stack. If the push failed, exit. If the
/// advertising is 0, also exit and do this session without flood.
session_crop(adv_tmpl->duration);
session = sub_newtask(s_tmpl, applet, adv_tmpl->duration);
if ((session == NULL) || (adv_tmpl->duration == 0))
return NULL;
/// 2. Flood duty cycling is not supported at this time. All floods
/// are implemented as 100% duty cycle.
/// 3. Push the Advertising session onto the stack, for immediate running.
/// <LI> Use the same subnet for the advertising as for the request. </LI>
/// <LI> For basic flooding, the applet can be empty </LI>
scratch = session->subnet;
session = session_new(&otutils_applet_null, 0, _FLOOD_NETSTATE, adv_tmpl->channel);
if (session == NULL) {
session_pop(); //pop the request session from above
return NULL;
}
session->subnet = scratch;
return session;
}
OT_WEAK void dll_beacon_applet(m2session* active) {
/// Beaconing is a Request-TX operation, and the value for Tc is the amount of
/// time to spend in CSMA before quitting the beacon.
ot_queue beacon_queue;
ot_u8 b_params;
ot_u8 cmd_ext;
ot_u8 cmd_code;
b_params = active->extra;
active->extra = 0;
/// Start building the beacon packet:
/// <LI> Calling m2np_header() will write most of the front of the frame </LI>
/// <LI> Add the command byte and optional command-extension byte </LI>
m2np_header(active, M2RT_BROADCAST, M2FI_FRDIALOG);
cmd_ext = (b_params & 0x06); // Normal extension bits
cmd_ext |= (dll.netconf.btemp[2] == 0) << 6; // Announcement No-File bit
cmd_code = 0x20 | (b_params & 1) | ((cmd_ext!=0) << 7);
q_writebyte(&txq, cmd_code);
if (cmd_code) {
q_writebyte(&txq, cmd_ext);
}
/// Setup the comm parameters, if the channel is available:
/// <LI> dll.comm values tx_eirp, cs_rssi, and cca_rssi must be set by the
/// radio module during the CSMA-CA process -- don't set them here.
/// The DASH7 spec requires it to happen in this order. </LI>
/// <LI> Set CSMA-CA parameters, which are used by the radio module </LI>
/// <LI> Set number of redundant TX's we would like to transmit </LI>
/// <LI> Set rx_timeout for Default-Tg or 0, if beacon has no response </LI>
dll_set_defaults(active);
dll.comm.tc = TI2CLK(M2_PARAM_BEACON_TCA);
dll.comm.rx_timeout = (b_params & 0x02) ? \
0 : rm2_default_tgd(active->channel);
dll.comm.csmaca_params |= (b_params & 0x04) | M2_CSMACA_NA2P | M2_CSMACA_MACCA;
dll.comm.redundants = dll.netconf.b_attempts;
q_writebyte(&txq, (ot_u8)dll.comm.rx_timeout);
/// Add the announcement file data if the specified return data != 0 bytes.
/// If the beacon data is missing or otherwise not accessible by the GUEST
/// user, dump the session (thus killing the beacon) and go back to idle.
if (dll.netconf.btemp[2] != 0) {
q_init(&beacon_queue, &dll.netconf.btemp[2], 4);
if (m2qp_isf_call((b_params & 1), &beacon_queue, AUTH_GUEST) < 0) {
session_pop();
dll_idle();
return;
}
}
/// Final step to any packet generation: add footer
m2np_footer();
}
void dll_processing(void) {
/// This is the task for processing a DASH7 packet which has been received.
/// If the packet is a valid request, this task will put the DLL into HOLD.
/// If the listen bit is high, additionally, this task will clone the session
/// to be re-visited at a later time.
m2session* active;
ot_int proc_score;
sys.task_RFA.event = 0; // Only run processing once
active = session_top();
active->counter = 0;
proc_score = network_route_ff(active);
/// Response is prepared already, so setup holdstate and flow control.
/// proc_score is always negative after parsing a response.
if (proc_score >= 0) {
sub_fceval(proc_score);
sys.task_HSS.cursor = 0;
dll.counter = dll.netconf.hold_limit;
dll.idle_state = M2_DLLIDLE_HOLD;
/// If the Listen flag is high, clone the session to a time in the
/// future, when it will listen again.
/// <LI> dll.comm.tc has just been assigned by the request. It is the
/// response contention period (Tc). </LI>
/// <LI> This device should listen again after Tc ends, so the session
/// is cloned & scheduled for Tc </LI>
/// <LI> The current session is popped after response, or on next kernel
/// loop (immediately) if no response </LI>
if (active->flags & M2_FLAG_LISTEN) {
network_cont_session(active->applet, M2_NETSTATE_REQRX, 0);
}
}
/// Bad score, plus session indicates no listening or sending response.
/// Scrap the session.
else if ((active->netstate & M2_NETSTATE_RESP) == 0) {
goto dll_processing_SCRAP;
}
/// A protocol parser has scrapped the session, or possibly the above
/// condition branched here directly.
if (active->netstate & M2_NETSTATE_SCRAP) {
dll_processing_SCRAP:
session_pop();
dll_idle();
}
}