bond_3ad.c

linux-2.6.15.6

}

/**
 * ad_rx_machine - handle a port's rx State Machine
 * @lacpdu: the lacpdu we've received
 * @port: the port we're looking at
 *
 * If lacpdu arrived, stop previous timer (if exists) and set the next state as
 * CURRENT. If timer expired set the state machine in the proper state.
 * In other cases, this function checks if we need to switch to other state.
 */
static void ad_rx_machine(struct lacpdu *lacpdu, struct port *port)
{
	rx_states_t last_state;

	// Lock to prevent 2 instances of this function to run simultaneously(rx interrupt and periodic machine callback)
	__get_rx_machine_lock(port);

	// keep current State Machine state to compare later if it was changed
	last_state = port->sm_rx_state;

	// check if state machine should change state
	// first, check if port was reinitialized
	if (port->sm_vars & AD_PORT_BEGIN) {
		port->sm_rx_state = AD_RX_INITIALIZE;		    // next state
	}
	// check if port is not enabled
	else if (!(port->sm_vars & AD_PORT_BEGIN) && !port->is_enabled && !(port->sm_vars & AD_PORT_MOVED)) {
		port->sm_rx_state = AD_RX_PORT_DISABLED;	    // next state
	}
	// check if new lacpdu arrived
	else if (lacpdu && ((port->sm_rx_state == AD_RX_EXPIRED) || (port->sm_rx_state == AD_RX_DEFAULTED) || (port->sm_rx_state == AD_RX_CURRENT))) {
		port->sm_rx_timer_counter = 0; // zero timer
		port->sm_rx_state = AD_RX_CURRENT;
	} else {
		// if timer is on, and if it is expired
		if (port->sm_rx_timer_counter && !(--port->sm_rx_timer_counter)) {
			switch (port->sm_rx_state) {
			case AD_RX_EXPIRED:
				port->sm_rx_state = AD_RX_DEFAULTED;		// next state
				break;
			case AD_RX_CURRENT:
				port->sm_rx_state = AD_RX_EXPIRED;	    // next state
				break;
			default:    //to silence the compiler
				break;
			}
		} else {
			// if no lacpdu arrived and no timer is on
			switch (port->sm_rx_state) {
			case AD_RX_PORT_DISABLED:
				if (port->sm_vars & AD_PORT_MOVED) {
					port->sm_rx_state = AD_RX_INITIALIZE;	    // next state
				} else if (port->is_enabled && (port->sm_vars & AD_PORT_LACP_ENABLED)) {
					port->sm_rx_state = AD_RX_EXPIRED;	// next state
				} else if (port->is_enabled && ((port->sm_vars & AD_PORT_LACP_ENABLED) == 0)) {
					port->sm_rx_state = AD_RX_LACP_DISABLED;    // next state
				}
				break;
			default:    //to silence the compiler
				break;

			}
		}
	}

	// check if the State machine was changed or new lacpdu arrived
	if ((port->sm_rx_state != last_state) || (lacpdu)) {
		dprintk("Rx Machine: Port=%d, Last State=%d, Curr State=%d\n", port->actor_port_number, last_state, port->sm_rx_state);
		switch (port->sm_rx_state) {
		case AD_RX_INITIALIZE:
			if (!(port->actor_oper_port_key & AD_DUPLEX_KEY_BITS)) {
				port->sm_vars &= ~AD_PORT_LACP_ENABLED;
			} else {
				port->sm_vars |= AD_PORT_LACP_ENABLED;
			}
			port->sm_vars &= ~AD_PORT_SELECTED;
			__record_default(port);
			port->actor_oper_port_state &= ~AD_STATE_EXPIRED;
			port->sm_vars &= ~AD_PORT_MOVED;
			port->sm_rx_state = AD_RX_PORT_DISABLED;	// next state

			/*- Fall Through -*/

		case AD_RX_PORT_DISABLED:
			port->sm_vars &= ~AD_PORT_MATCHED;
			break;
		case AD_RX_LACP_DISABLED:
			port->sm_vars &= ~AD_PORT_SELECTED;
			__record_default(port);
			port->partner_oper_port_state &= ~AD_STATE_AGGREGATION;
			port->sm_vars |= AD_PORT_MATCHED;
			port->actor_oper_port_state &= ~AD_STATE_EXPIRED;
			break;
		case AD_RX_EXPIRED:
			//Reset of the Synchronization flag. (Standard 43.4.12)
			//This reset cause to disable this port in the COLLECTING_DISTRIBUTING state of the
			//mux machine in case of EXPIRED even if LINK_DOWN didn't arrive for the port.
			port->partner_oper_port_state &= ~AD_STATE_SYNCHRONIZATION;
			port->sm_vars &= ~AD_PORT_MATCHED;
			port->partner_oper_port_state |= AD_SHORT_TIMEOUT;
			port->sm_rx_timer_counter = __ad_timer_to_ticks(AD_CURRENT_WHILE_TIMER, (u16)(AD_SHORT_TIMEOUT));
			port->actor_oper_port_state |= AD_STATE_EXPIRED;
			break;
		case AD_RX_DEFAULTED:
			__update_default_selected(port);
			__record_default(port);
			port->sm_vars |= AD_PORT_MATCHED;
			port->actor_oper_port_state &= ~AD_STATE_EXPIRED;
			break;
		case AD_RX_CURRENT:
			// detect loopback situation
			if (!MAC_ADDRESS_COMPARE(&(lacpdu->actor_system), &(port->actor_system))) {
				// INFO_RECEIVED_LOOPBACK_FRAMES
				printk(KERN_ERR DRV_NAME ": An illegal loopback occurred on adapter (%s)\n",
						port->slave->dev->name);
				printk(KERN_ERR "Check the configuration to verify that all Adapters "
						"are connected to 802.3ad compliant switch ports\n");
				__release_rx_machine_lock(port);
				return;
			}
			__update_selected(lacpdu, port);
			__update_ntt(lacpdu, port);
			__record_pdu(lacpdu, port);
			__choose_matched(lacpdu, port);
			port->sm_rx_timer_counter = __ad_timer_to_ticks(AD_CURRENT_WHILE_TIMER, (u16)(port->actor_oper_port_state & AD_STATE_LACP_TIMEOUT));
			port->actor_oper_port_state &= ~AD_STATE_EXPIRED;
			// verify that if the aggregator is enabled, the port is enabled too.
			//(because if the link goes down for a short time, the 802.3ad will not
			// catch it, and the port will continue to be disabled)
			if (port->aggregator && port->aggregator->is_active && !__port_is_enabled(port)) {
				__enable_port(port);
			}
			break;
		default:    //to silence the compiler
			break;
		}
	}
	__release_rx_machine_lock(port);
}

/**
 * ad_tx_machine - handle a port's tx state machine
 * @port: the port we're looking at
 *
 */
static void ad_tx_machine(struct port *port)
{
	// check if tx timer expired, to verify that we do not send more than 3 packets per second
	if (port->sm_tx_timer_counter && !(--port->sm_tx_timer_counter)) {
		// check if there is something to send
		if (port->ntt && (port->sm_vars & AD_PORT_LACP_ENABLED)) {
			__update_lacpdu_from_port(port);
			// send the lacpdu
			if (ad_lacpdu_send(port) >= 0) {
				dprintk("Sent LACPDU on port %d\n", port->actor_port_number);
				// mark ntt as false, so it will not be sent again until demanded
				port->ntt = 0;
			}
		}
		// restart tx timer(to verify that we will not exceed AD_MAX_TX_IN_SECOND
		port->sm_tx_timer_counter=ad_ticks_per_sec/AD_MAX_TX_IN_SECOND;
	}
}

/**
 * ad_periodic_machine - handle a port's periodic state machine
 * @port: the port we're looking at
 *
 * Turn ntt flag on priodically to perform periodic transmission of lacpdu's.
 */
static void ad_periodic_machine(struct port *port)
{
	periodic_states_t last_state;

	// keep current state machine state to compare later if it was changed
	last_state = port->sm_periodic_state;

	// check if port was reinitialized
	if (((port->sm_vars & AD_PORT_BEGIN) || !(port->sm_vars & AD_PORT_LACP_ENABLED) || !port->is_enabled) ||
	    (!(port->actor_oper_port_state & AD_STATE_LACP_ACTIVITY) && !(port->partner_oper_port_state & AD_STATE_LACP_ACTIVITY))
	   ) {
		port->sm_periodic_state = AD_NO_PERIODIC;	     // next state
	}
	// check if state machine should change state
	else if (port->sm_periodic_timer_counter) {
		// check if periodic state machine expired
		if (!(--port->sm_periodic_timer_counter)) {
			// if expired then do tx
			port->sm_periodic_state = AD_PERIODIC_TX;    // next state
		} else {
			// If not expired, check if there is some new timeout parameter from the partner state
			switch (port->sm_periodic_state) {
			case AD_FAST_PERIODIC:
				if (!(port->partner_oper_port_state & AD_STATE_LACP_TIMEOUT)) {
					port->sm_periodic_state = AD_SLOW_PERIODIC;  // next state
				}
				break;
			case AD_SLOW_PERIODIC:
				if ((port->partner_oper_port_state & AD_STATE_LACP_TIMEOUT)) {
					// stop current timer
					port->sm_periodic_timer_counter = 0;
					port->sm_periodic_state = AD_PERIODIC_TX;	 // next state
				}
				break;
			default:    //to silence the compiler
				break;
			}
		}
	} else {
		switch (port->sm_periodic_state) {
		case AD_NO_PERIODIC:
			port->sm_periodic_state = AD_FAST_PERIODIC;	 // next state
			break;
		case AD_PERIODIC_TX:
			if (!(port->partner_oper_port_state & AD_STATE_LACP_TIMEOUT)) {
				port->sm_periodic_state = AD_SLOW_PERIODIC;  // next state
			} else {
				port->sm_periodic_state = AD_FAST_PERIODIC;  // next state
			}
			break;
		default:    //to silence the compiler
			break;
		}
	}

	// check if the state machine was changed
	if (port->sm_periodic_state != last_state) {
		dprintk("Periodic Machine: Port=%d, Last State=%d, Curr State=%d\n", port->actor_port_number, last_state, port->sm_periodic_state);
		switch (port->sm_periodic_state) {
		case AD_NO_PERIODIC:
			port->sm_periodic_timer_counter = 0;	   // zero timer
			break;
		case AD_FAST_PERIODIC:
			port->sm_periodic_timer_counter = __ad_timer_to_ticks(AD_PERIODIC_TIMER, (u16)(AD_FAST_PERIODIC_TIME))-1; // decrement 1 tick we lost in the PERIODIC_TX cycle
			break;
		case AD_SLOW_PERIODIC:
			port->sm_periodic_timer_counter = __ad_timer_to_ticks(AD_PERIODIC_TIMER, (u16)(AD_SLOW_PERIODIC_TIME))-1; // decrement 1 tick we lost in the PERIODIC_TX cycle
			break;
		case AD_PERIODIC_TX:
			port->ntt = 1;
			break;
		default:    //to silence the compiler
			break;
		}
	}
}

/**
 * ad_port_selection_logic - select aggregation groups
 * @port: the port we're looking at
 *
 * Select aggregation groups, and assign each port for it's aggregetor. The
 * selection logic is called in the inititalization (after all the handshkes),
 * and after every lacpdu receive (if selected is off).
 */
static void ad_port_selection_logic(struct port *port)
{
	struct aggregator *aggregator, *free_aggregator = NULL, *temp_aggregator;
	struct port *last_port = NULL, *curr_port;
	int found = 0;

	// if the port is already Selected, do nothing
	if (port->sm_vars & AD_PORT_SELECTED) {
		return;
	}

	// if the port is connected to other aggregator, detach it
	if (port->aggregator) {
		// detach the port from its former aggregator
		temp_aggregator=port->aggregator;
		for (curr_port=temp_aggregator->lag_ports; curr_port; last_port=curr_port, curr_port=curr_port->next_port_in_aggregator) {
			if (curr_port == port) {
				temp_aggregator->num_of_ports--;
				if (!last_port) {// if it is the first port attached to the aggregator
					temp_aggregator->lag_ports=port->next_port_in_aggregator;
				} else {// not the first port attached to the aggregator
					last_port->next_port_in_aggregator=port->next_port_in_aggregator;
				}

				// clear the port's relations to this aggregator
				port->aggregator = NULL;
				port->next_port_in_aggregator=NULL;
				port->actor_port_aggregator_identifier=0;

				dprintk("Port %d left LAG %d\n", port->actor_port_number, temp_aggregator->aggregator_identifier);
				// if the aggregator is empty, clear its parameters, and set it ready to be attached
				if (!temp_aggregator->lag_ports) {
					ad_clear_agg(temp_aggregator);
				}
				break;
			}
		}
		if (!curr_port) { // meaning: the port was related to an aggregator but was not on the aggregator port list
			printk(KERN_WARNING DRV_NAME ": Warning: Port %d (on %s) was "
			       "related to aggregator %d but was not on its port list\n",
			       port->actor_port_number, port->slave->dev->name,
			       port->aggregator->aggregator_identifier);
		}
	}
	// search on all aggregators for a suitable aggregator for this port
	for (aggregator = __get_first_agg(port); aggregator;
	     aggregator = __get_next_agg(aggregator)) {

		// keep a free aggregator for later use(if needed)
		if (!aggregator->lag_ports) {
			if (!free_aggregator) {
				free_aggregator=aggregator;
			}
			continue;
		}
		// check if current aggregator suits us
		if (((aggregator->actor_oper_aggregator_key == port->actor_oper_port_key) && // if all parameters match AND
		     !MAC_ADDRESS_COMPARE(&(aggregator->partner_system), &(port->partner_oper_system)) &&
		     (aggregator->partner_system_priority == port->partner_oper_system_priority) &&
		     (aggregator->partner_oper_aggregator_key == port->partner_oper_key)
		    ) &&
		    ((MAC_ADDRESS_COMPARE(&(port->partner_oper_system), &(null_mac_addr)) && // partner answers
		      !aggregator->is_individual)  // but is not individual OR
		    )
		   ) {
			// attach to the founded aggregator
			port->aggregator = aggregator;
			port->actor_port_aggregator_identifier=port->aggregator->aggregator_identifier;
			port->next_port_in_aggregator=aggregator->lag_ports;
			port->aggregator->num_of_ports++;
			aggregator->lag_ports=port;
			dprintk("Port %d joined LAG %d(existing LAG)\n", port->actor_port_number, port->aggregator->aggregator_identifier);

			// mark this port as selected
			port->sm_vars |= AD_PORT_SELECTED;
			found = 1;
			break;
		}
	}

	// the port couldn't find an aggregator - attach it to a new aggregator
	if (!found) {
		if (free_aggregator) {
			// assign port a new aggregator
			port->aggregator = free_aggregator;
			port->actor_port_aggregator_identifier=port->aggregator->aggregator_identifier;

			// update the new aggregator's parameters
			// if port was responsed from the end-user
			if (port->actor_oper_port_key & AD_DUPLEX_KEY_BITS) {// if port is full duplex
				port->aggregator->is_individual = 0;
			} else {
				port->aggregator->is_individual = 1;
			}

			port->aggregator->actor_admin_aggregator_key = port->actor_admin_port_key;
			port->aggregator->actor_oper_aggregator_key = port->actor_oper_port_key;
			port->aggregator->partner_system=port->partner_oper_system;
			port->aggregator->partner_system_priority = port->partner_oper_system_priority;
			port->aggregator->partner_oper_aggregator_key = port->partner_oper_key;
			port->aggregator->receive_state = 1;
			port->aggregator->transmit_state = 1;
			port->aggregator->lag_ports = port;
			port->aggregator->num_of_ports++;

			// mark this port as selected