bonding: export slave's partner_oper_port_state via sysfs and netlink

Export the partner_oper_port_state of each port via sysfs and netlink.
In 802.3ad mode it is valuable for the user to be able to check the
partner_oper state, it is already exported via bond's proc entry.

Signed-off-by: Nikolay Aleksandrov <[e-mail]>
Signed-off-by: Andy Gospodarek <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/bonding/bond_netlink.c

···
 		nla_total_size(sizeof(u16)) +	/* IFLA_BOND_SLAVE_QUEUE_ID */
 		nla_total_size(sizeof(u16)) +	/* IFLA_BOND_SLAVE_AD_AGGREGATOR_ID */
 		nla_total_size(sizeof(u8)) +	/* IFLA_BOND_SLAVE_AD_ACTOR_OPER_PORT_STATE */
+		nla_total_size(sizeof(u16)) +	/* IFLA_BOND_SLAVE_AD_PARTNER_OPER_PORT_STATE */
 		0;
 }
 
···
 			if (nla_put_u8(skb,
 				       IFLA_BOND_SLAVE_AD_ACTOR_OPER_PORT_STATE,
 				       ad_port->actor_oper_port_state))
+				goto nla_put_failure;
+			if (nla_put_u16(skb,
+					IFLA_BOND_SLAVE_AD_PARTNER_OPER_PORT_STATE,
+					ad_port->partner_oper.port_state))
 				goto nla_put_failure;
 		}
 	}

drivers/net/bonding/bond_sysfs_slave.c

···
 }
 static SLAVE_ATTR_RO(ad_actor_oper_port_state);
 
+static ssize_t ad_partner_oper_port_state_show(struct slave *slave, char *buf)
+{
+	const struct port *ad_port;
+
+	if (BOND_MODE(slave->bond) == BOND_MODE_8023AD) {
+		ad_port = &SLAVE_AD_INFO(slave)->port;
+		if (ad_port->aggregator)
+			return sprintf(buf, "%u\n",
+				       ad_port->partner_oper.port_state);
+	}
+
+	return sprintf(buf, "N/A\n");
+}
+static SLAVE_ATTR_RO(ad_partner_oper_port_state);
+
 static const struct slave_attribute *slave_attrs[] = {
 	&slave_attr_state,
 	&slave_attr_mii_status,
···
 	&slave_attr_queue_id,
 	&slave_attr_ad_aggregator_id,
 	&slave_attr_ad_actor_oper_port_state,
+	&slave_attr_ad_partner_oper_port_state,
 	NULL
 };
 

include/uapi/linux/if_link.h

···
 	IFLA_BOND_SLAVE_QUEUE_ID,
 	IFLA_BOND_SLAVE_AD_AGGREGATOR_ID,
 	IFLA_BOND_SLAVE_AD_ACTOR_OPER_PORT_STATE,
+	IFLA_BOND_SLAVE_AD_PARTNER_OPER_PORT_STATE,
 	__IFLA_BOND_SLAVE_MAX,
 };