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#include "sm_l.h"

typedef struct{
	LIST_ITEM entry;	
	uint64 timestamp;
} sm_flap_event_t;

typedef struct {
	Popo_t *popop;
	uint64	NodeGUID;
	STL_LID lid;
} flapping_context_t;

void
sm_flap_gc(PopoPort_t *poportp)
{
	QUICK_LIST *list = (QUICK_LIST*)poportp->quarantine.longTermData.data;
	LIST_ITEM * li, * next;
	for (li = QListHead(list); li; li = next) {
		next = QListNext(list, li);
		QListRemoveItem(list, li);
		sm_flap_event_t *event = PARENT_STRUCT(li, sm_flap_event_t, entry);
		vs_pool_free(&sm_pool, event);
	}
	vs_pool_free(&sm_pool, poportp->quarantine.longTermData.data);
}


static void
_sm_flap_age_out_events(QUICK_LIST *list, uint64_t window_start)
{
	LIST_ITEM * li, * next;
	for (li = QListHead(list); li; li = next) {
		next = QListNext(list, li);
		sm_flap_event_t *event = PARENT_STRUCT(li, sm_flap_event_t, entry);

		//age out old events.
		if(event->timestamp < window_start) {
			QListRemoveItem(list, li);
			vs_pool_free(&sm_pool, event);
		} else{
			break;
		}
	}
}

/*
 * sm_flap_state_handler is called periodically by monitor thread.
 * Makes decisions about the following possible state transitions:
 * Monitored -> Quarantined
 * Quarantined -> Monitored
 * Monitored -> Unmonitored
 *
 * This function is called with popo lock held.
 */
void
sm_flap_state_handler(Popo_t *popop, PopoPort_t *poportp)
{
	uint64_t current_time, window_start, window_size;
	vs_time_get(&current_time);
	window_size = sm_config.port_quarantine.flapping.window_size*60*1000000;//convert mins to us
	window_start = current_time - window_size;

	int high_thresh = sm_config.port_quarantine.flapping.high_thresh;
	int low_thresh = sm_config.port_quarantine.flapping.low_thresh;

	QUICK_LIST *list = (QUICK_LIST *)poportp->quarantine.longTermData.data;

	//Remove events from list that occurred outside of sliding window period
	_sm_flap_age_out_events(list, window_start);
	int event_count = QListCount(list);
	

	if(poportp->quarantine.monitored){
		if(event_count >= high_thresh) {
			/* TRANSITION Monitor -> Quarantine */
			//add to long term quarantine
			PopoQuarantineType_t prevType = poportp->quarantine.type;
			if(prevType == POPO_QUARANTINE_SHORT)
				QListRemoveItem(&popop->quarantine.shortTerm, &poportp->quarantine.quarantineEntry);
			poportp->quarantine.type = POPO_QUARANTINE_LONG;
			QListInsertTail(&popop->quarantine.longTerm, &poportp->quarantine.quarantineEntry);
			vs_time_get(&poportp->quarantine.longTermData.quarantinedTime);
			//remove from monitor
			poportp->quarantine.monitored = 0;
			QListRemoveItem(&popop->quarantine.monitored, &poportp->quarantine.monitorEntry);
			IB_LOG_WARN_FMT(__func__, "Port Quarantined for flapping! Guid: " FMT_U64 " PortIndex: %d", 
				poportp->ponodep->info.guid, poportp->portNum);

		} else if (event_count <= low_thresh) {

			if(window_start >= poportp->quarantine.longTermData.monitoredTime) {
				/* TRANSITION: Monitored -> Unmonitored */
				//remove from monitor
				poportp->quarantine.monitored = 0;
				QListRemoveItem(&popop->quarantine.monitored, &poportp->quarantine.monitorEntry);
				//IB_LOG_WARN_FMT(__func__, "Port unmonitored for flapping! Guid: " FMT_U64 " PortIndex: %d", 
					//poportp->ponodep->info.guid, poportp->portNum); //, debugging
				//garbage collect
				poportp->quarantine.longTermData.reason = POPO_LONGTERM_NONE;
				sm_flap_gc(poportp);
			}
		}

	} else if (poportp->quarantine.type == POPO_QUARANTINE_LONG) {

		if (event_count <= low_thresh) {
			if(window_start >= poportp->quarantine.longTermData.quarantinedTime) {
				/* Transition Quarantine -> Monitored */
				//remove from quarantine
				QListRemoveItem(&popop->quarantine.longTerm, &poportp->quarantine.quarantineEntry);
				poportp->quarantine.type = POPO_QUARANTINE_NONE;
				//add to monitor				
				poportp->quarantine.monitored = 1;
				vs_time_get(&poportp->quarantine.longTermData.monitoredTime);
				QListInsertTail(&popop->quarantine.monitored, &poportp->quarantine.monitorEntry);
				IB_LOG_WARN_FMT(__func__, "Port Unquarantined for flapping. Guid: " FMT_U64 " PortIndex: %d", 
					poportp->ponodep->info.guid, poportp->portNum);
			}
		}
	}
	return;
}

static boolean
_sm_flap_does_node_have_flapping(Popo_t *popop, Node_t *nodep)
{
	
	PopoNode_t *ponodep = nodep->ponodep;
	int i;
	sm_popo_lock(popop);
	for (i = 0; i <= ponodep->info.numPorts; ++i) {
		PopoPort_t * poportp = ponodep->ports + i;

		if(poportp->quarantine.type != POPO_QUARANTINE_LONG &&
			!poportp->quarantine.monitored)
			continue;

		if(poportp->quarantine.longTermData.reason != POPO_LONGTERM_FLAPPING)
			continue;
	
		sm_popo_unlock(popop);
		return TRUE;
	}

	sm_popo_unlock(popop);
	return FALSE;	
}


static 
void _sm_flap_log_event(Popo_t *popop, Port_t *portp){

	sm_flap_event_t *event;
	vs_pool_alloc(&sm_pool, sizeof(sm_flap_event_t), (void**) &event);
    vs_time_get(&event->timestamp);
	QListInsertTail(portp->poportp->quarantine.longTermData.data, &event->entry);
}


//_sm_flap_compare_psi compares a fresh Get(PortStateInfo) for a node against
//the last known port states recorded in the Node->Port->PortStates structure
//
static
boolean _sm_flap_compare_psi(Popo_t *popop, Node_t *nodep, STL_PORT_STATE_INFO *psi)
{
	boolean discovery_needed = 0;
	boolean state_change_found = 0;
	Port_t *portp;

	STL_PORT_STATES *newState;
	STL_PORT_STATES lastState;
	sm_popo_lock(popop);
	for_all_physical_ports(nodep, portp) {

		if(!portp){
			discovery_needed = 1;
			continue;
		}

		lastState = portp->poportp->portStates;
		newState = &psi[portp->index].PortStates;

		//if logical portState regressed it indicates this port bounced	
		if(newState->s.PortState < lastState.s.PortState) {
			state_change_found = 1;
			if(sm_popo_is_port_monitored_unsafe(&sm_popo, portp)) {
				if(sm_popo_get_quarantine_reason_unsafe(&sm_popo, portp) == POPO_LONGTERM_FLAPPING)
					_sm_flap_log_event(&sm_popo, portp);
				discovery_needed = 1;
				continue;
			}
			if(!sm_popo_is_port_quarantined_unsafe(&sm_popo, portp)) {
				discovery_needed = 1;
				continue;
			}
			if(sm_popo_get_quarantine_reason_unsafe(&sm_popo, portp) == POPO_LONGTERM_FLAPPING) {
				_sm_flap_log_event(&sm_popo, portp);
				//no discovery needed
				continue;
			}
		}

		//If port state moved forward in state machine,
		//and this is a quarantined port, block discovery sweep
		if(newState->s.PortState > lastState.s.PortState) {
			if(sm_popo_is_port_quarantined_unsafe(&sm_popo, portp)) {
				state_change_found = 1;
				continue;
			}
		}

		//if physical portState regressed it indicates this port bounced or 
		//is having trouble completing LNI
		if((lastState.s.PortPhysicalState == IB_PORT_PHYS_TRAINING) &&
			(newState->s.PortPhysicalState < IB_PORT_PHYS_TRAINING)) {
			state_change_found = 1;
			if(sm_popo_is_port_monitored_unsafe(&sm_popo, portp)) {
				if(sm_popo_get_quarantine_reason_unsafe(&sm_popo, portp) == POPO_LONGTERM_FLAPPING)
					_sm_flap_log_event(&sm_popo, portp);
				discovery_needed = 1;
				continue;
			}
			if(!sm_popo_is_port_quarantined_unsafe(&sm_popo, portp)) {
				discovery_needed = 1;
				continue;
			}
			if(sm_popo_get_quarantine_reason_unsafe(&sm_popo, portp) == POPO_LONGTERM_FLAPPING) {
				_sm_flap_log_event(&sm_popo, portp);
				//no discovery needed
				continue;
			}
		}

		//if IsSMConfigurationStarted was cleared it indicates this port bounced
		if(newState->s.IsSMConfigurationStarted == 0 &&
			lastState.s.IsSMConfigurationStarted == 1) {
			state_change_found = 1;
			if(sm_popo_is_port_monitored_unsafe(&sm_popo, portp)) {
				if(sm_popo_get_quarantine_reason_unsafe(&sm_popo, portp) == POPO_LONGTERM_FLAPPING)
					_sm_flap_log_event(&sm_popo, portp);
				discovery_needed = 1;
				continue;
			}
			if(!sm_popo_is_port_quarantined_unsafe(&sm_popo, portp)) {
				discovery_needed = 1;
				continue;
			}
			if(sm_popo_get_quarantine_reason_unsafe(&sm_popo, portp) == POPO_LONGTERM_FLAPPING) {
				_sm_flap_log_event(&sm_popo, portp);
				//no discovery needed
				continue;
			}
		}
	}

	if(!state_change_found){
		discovery_needed = 1;
	}

	sm_popo_unlock(popop);
	return discovery_needed;
}


static 
void _trap_psi_callback(cntxt_entry_t *cntxt, Status_t status, void *data, Mai_t *mad)
{

	flapping_context_t *ctx = (flapping_context_t *) data;
	boolean discovery_needed = 0;

	vs_rdlock(&old_topology_lock); 
	Node_t *nodep = sm_find_guid(&old_topology, ctx->NodeGUID);
	if(!nodep){
		discovery_needed = 1;
		goto cleanup;
	}

	if(!sm_callback_check(cntxt, status, nodep, NULL, mad)) {
		discovery_needed = 1;
		goto cleanup;
	}

	STL_PORT_STATE_INFO * psi = (STL_PORT_STATE_INFO *)stl_mai_get_smp_data(mad);
    BSWAP_STL_PORT_STATE_INFO(psi, nodep->nodeInfo.NumPorts +1);
	discovery_needed = _sm_flap_compare_psi(ctx->popop, nodep, psi);
	sm_popo_update_node_port_states(ctx->popop, nodep, psi);

cleanup:
	vs_unlock(&old_topology_lock);
	if(discovery_needed) {
		//Callbacks are currently done on async thread. Async thread is
		//the only caller of sm_discovery_needed, which modifies shared globals
		//IF callbacks are taken off async thread locks will probably be needed here. 
		sm_discovery_needed("Port State Change Trap", ctx->lid);
	}
	vs_pool_free(&sm_pool, ctx);
	return;
}


boolean
sm_flap_report_port_change_trap(Popo_t *popop, Node_t *nodep)
{

	if(!nodep)
		return TRUE;

	if(!_sm_flap_does_node_have_flapping(popop, nodep))
		return TRUE;

	Port_t *portp = sm_get_node_end_port(nodep);
	if(!portp)
		return TRUE;

	SmpAddr_t addr = SMP_ADDR_CREATE_LR(sm_lid, portp->portData->lid);
	uint32_t amod = (nodep->nodeInfo.NumPorts + 1) << 24;
	flapping_context_t *ctx;
	vs_pool_alloc(&sm_pool, sizeof(flapping_context_t), (void**) &ctx);
	ctx->NodeGUID = nodep->nodeInfo.NodeGUID; 
	ctx->lid = portp->portData->lid;
	ctx->popop = popop;

	SM_Get_PortStateInfo_Dispatch(fd_flapping_port, amod, &addr, nodep,
		&sm_asyncDispatch, _trap_psi_callback, ctx); 

	return FALSE; //Don't trigger a resweep just yet
}