[PATCH] teamd: lacp: update port state according to partner's sync bit

[Hangbin Liu]

1) According to 6.4.12 of IEEE 802.1AX-2008, Figure 6-18, if the partner's sync
bit is not set, the lacp port state should be set to EXPIRED.

Function lacpdu_recv() makes the state of the lacp port to PORT_STATE_CURRENT
when the teamd receives any valid lacp packet. Fix it by checking the parter's
sync bit.

2) According to 6.4.15 of IEEE 802.1AX-2008, Figure 6-22, the state that the
port is selected moves MUX state from DETACHED to ATTACHED.

But ATTACHED sate does not mean that the port can send and receive user frames.
COLLECTING_DISTRIBUTION state is the sate that the port can send and receive
user frames. To move MUX state from ATTACHED to COLLECTING_DISTRIBUTION, the
partner state should be sync as well as the port selected.

In function lacp_port_actor_update(), only INFO_STATE_SYNCHRONIZATION should
be set to the actor.state when the port is selected. INFO_STATE_COLLECTING and
INFO_STATE_DISTRIBUTING should be set to false with ATTACHED mode and set to
true when INFO_STATE_SYNCHRONIZATION of partner.state is set.

In function lacp_port_should_be_{enabled, disabled}(), we also need to check
the INFO_STATE_SYNCHRONIZATION bit of partner.state.

Reported-by: Cisco Systems
Signed-off-by: Hangbin Liu <liuhangbin(a)gmail.com&gt;
---
 teamd/teamd_runner_lacp.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/teamd/teamd_runner_lacp.c b/teamd/teamd_runner_lacp.c
index 7b8f0a7..5e763ad 100644
--- a/teamd/teamd_runner_lacp.c
+++ b/teamd/teamd_runner_lacp.c
@@ -333,7 +333,8 @@ static int lacp_port_should_be_enabled(struct lacp_port *lacp_port)
 	struct lacp *lacp = lacp_port->lacp;
 
 	if (lacp_port_selected(lacp_port) &&
-	    lacp_port->agg_lead == lacp->selected_agg_lead)
+	    lacp_port->agg_lead == lacp->selected_agg_lead &&
+	    lacp_port->partner.state & INFO_STATE_SYNCHRONIZATION)
 		return true;
 	return false;
 }
@@ -343,7 +344,8 @@ static int lacp_port_should_be_disabled(struct lacp_port *lacp_port)
 	struct lacp *lacp = lacp_port->lacp;
 
 	if (!lacp_port_selected(lacp_port) ||
-	    lacp_port->agg_lead != lacp->selected_agg_lead)
+	    lacp_port->agg_lead != lacp->selected_agg_lead ||
+	    !(lacp_port->partner.state & INFO_STATE_SYNCHRONIZATION))
 		return true;
 	return false;
 }
@@ -914,9 +916,13 @@ static void lacp_port_actor_update(struct lacp_port *lacp_port)
 	if (lacp_port->lacp->cfg.fast_rate)
 		state |= INFO_STATE_LACP_TIMEOUT;
 	if (lacp_port_selected(lacp_port) &&
-	    lacp_port_agg_selected(lacp_port))
-		state |= INFO_STATE_SYNCHRONIZATION |
-			 INFO_STATE_COLLECTING | INFO_STATE_DISTRIBUTING;
+	    lacp_port_agg_selected(lacp_port)) {
+		state |= INFO_STATE_SYNCHRONIZATION;
+		state &= ~(INFO_STATE_COLLECTING | INFO_STATE_DISTRIBUTING);
+		if (lacp_port->partner.state & INFO_STATE_SYNCHRONIZATION)
+			state |= INFO_STATE_COLLECTING |
+				 INFO_STATE_DISTRIBUTING;
+	}
 	if (lacp_port->state == PORT_STATE_EXPIRED)
 		state |= INFO_STATE_EXPIRED;
 	if (lacp_port->state == PORT_STATE_DEFAULTED)
@@ -1095,7 +1101,10 @@ static int lacpdu_recv(struct lacp_port *lacp_port)
 			return err;
 	}
 
-	err = lacp_port_set_state(lacp_port, PORT_STATE_CURRENT);
+	if (lacp_port->partner.state & INFO_STATE_SYNCHRONIZATION)
+		err = lacp_port_set_state(lacp_port, PORT_STATE_CURRENT);
+	else
+		err = lacp_port_set_state(lacp_port, PORT_STATE_EXPIRED);
 	if (err)
 		return err;
 
-- 
2.19.2