bonding: add support for per-port LACP actor priority

Introduce a new netlink attribute 'actor_port_prio' to allow setting
the LACP actor port priority on a per-slave basis. This extends the
existing bonding infrastructure to support more granular control over
LACP negotiations.

The priority value is embedded in LACPDU packets and will be used by
subsequent patches to influence aggregator selection policies.

Signed-off-by: Hangbin Liu <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Paolo Abeni <[e-mail]>

Documentation/networking/bonding.rst

···
 	This parameter has effect only in 802.3ad mode and is available through
 	SysFs interface.
 
+actor_port_prio
+
+	In an AD system, this specifies the port priority. The allowed range
+	is 1 - 65535. If the value is not specified, it takes 255 as the
+	default value.
+
+	This parameter has effect only in 802.3ad mode and is available through
+	netlink interface.
+
 ad_actor_system
 
 	In an AD system, this specifies the mac-address for the actor in

drivers/net/bonding/bond_3ad.c

···
 
 	port->actor_system = BOND_AD_INFO(bond).system.sys_mac_addr;
 	port->actor_system_priority = BOND_AD_INFO(bond).system.sys_priority;
+	port->actor_port_priority = SLAVE_AD_INFO(port->slave)->port_priority;
 }
 
 /* Conversions */
···
 		port = &(SLAVE_AD_INFO(slave)->port);
 
 		ad_initialize_port(port, &bond->params);
+
+		/* Port priority is initialized. Update it to slave's ad info */
+		SLAVE_AD_INFO(slave)->port_priority = port->actor_port_priority;
 
 		port->slave = slave;
 		port->actor_port_number = SLAVE_AD_INFO(slave)->id;

drivers/net/bonding/bond_netlink.c

···
 		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 */
 		nla_total_size(sizeof(s32)) +	/* IFLA_BOND_SLAVE_PRIO */
+		nla_total_size(sizeof(u16)) +	/* IFLA_BOND_SLAVE_ACTOR_PORT_PRIO */
 		0;
 }
 
···
 					ad_port->partner_oper.port_state))
 				goto nla_put_failure;
 		}
+
+		if (nla_put_u16(skb, IFLA_BOND_SLAVE_ACTOR_PORT_PRIO,
+				SLAVE_AD_INFO(slave)->port_priority))
+			goto nla_put_failure;
 	}
 
 	return 0;
···
 static const struct nla_policy bond_slave_policy[IFLA_BOND_SLAVE_MAX + 1] = {
 	[IFLA_BOND_SLAVE_QUEUE_ID]	= { .type = NLA_U16 },
 	[IFLA_BOND_SLAVE_PRIO]		= { .type = NLA_S32 },
+	[IFLA_BOND_SLAVE_ACTOR_PORT_PRIO]	= { .type = NLA_U16 },
 };
 
 static int bond_validate(struct nlattr *tb[], struct nlattr *data[],
···
 		bond_opt_slave_initval(&newval, &slave_dev, prio);
 		err = __bond_opt_set(bond, BOND_OPT_PRIO, &newval,
 				     data[IFLA_BOND_SLAVE_PRIO], extack);
+		if (err)
+			return err;
+	}
+
+	if (data[IFLA_BOND_SLAVE_ACTOR_PORT_PRIO]) {
+		u16 ad_prio = nla_get_u16(data[IFLA_BOND_SLAVE_ACTOR_PORT_PRIO]);
+
+		bond_opt_slave_initval(&newval, &slave_dev, ad_prio);
+		err = __bond_opt_set(bond, BOND_OPT_ACTOR_PORT_PRIO, &newval,
+				     data[IFLA_BOND_SLAVE_ACTOR_PORT_PRIO], extack);
 		if (err)
 			return err;
 	}

drivers/net/bonding/bond_options.c

···
 				  const struct bond_opt_value *newval);
 static int bond_option_ad_actor_sys_prio_set(struct bonding *bond,
 					     const struct bond_opt_value *newval);
+static int bond_option_actor_port_prio_set(struct bonding *bond,
+					   const struct bond_opt_value *newval);
 static int bond_option_ad_actor_system_set(struct bonding *bond,
 					   const struct bond_opt_value *newval);
 static int bond_option_ad_user_port_key_set(struct bonding *bond,
···
 static const struct bond_opt_value bond_ad_actor_sys_prio_tbl[] = {
 	{ "minval",  1,     BOND_VALFLAG_MIN},
 	{ "maxval",  65535, BOND_VALFLAG_MAX | BOND_VALFLAG_DEFAULT},
+	{ NULL,      -1,    0},
+};
+
+static const struct bond_opt_value bond_actor_port_prio_tbl[] = {
+	{ "minval",  0,     BOND_VALFLAG_MIN},
+	{ "maxval",  65535, BOND_VALFLAG_MAX},
+	{ "default", 255,   BOND_VALFLAG_DEFAULT},
 	{ NULL,      -1,    0},
 };
 
···
 		.unsuppmodes = BOND_MODE_ALL_EX(BIT(BOND_MODE_8023AD)),
 		.values = bond_ad_actor_sys_prio_tbl,
 		.set = bond_option_ad_actor_sys_prio_set,
+	},
+	[BOND_OPT_ACTOR_PORT_PRIO] = {
+		.id = BOND_OPT_ACTOR_PORT_PRIO,
+		.name = "actor_port_prio",
+		.unsuppmodes = BOND_MODE_ALL_EX(BIT(BOND_MODE_8023AD)),
+		.values = bond_actor_port_prio_tbl,
+		.set = bond_option_actor_port_prio_set,
 	},
 	[BOND_OPT_AD_ACTOR_SYSTEM] = {
 		.id = BOND_OPT_AD_ACTOR_SYSTEM,
···
 		   newval->value);
 
 	bond->params.ad_actor_sys_prio = newval->value;
+	bond_3ad_update_ad_actor_settings(bond);
+
+	return 0;
+}
+
+static int bond_option_actor_port_prio_set(struct bonding *bond,
+					   const struct bond_opt_value *newval)
+{
+	struct slave *slave;
+
+	slave = bond_slave_get_rtnl(newval->slave_dev);
+	if (!slave) {
+		netdev_dbg(bond->dev, "%s called on NULL slave\n", __func__);
+		return -ENODEV;
+	}
+
+	netdev_dbg(newval->slave_dev, "Setting actor_port_prio to %llu\n",
+		   newval->value);
+
+	SLAVE_AD_INFO(slave)->port_priority = newval->value;
 	bond_3ad_update_ad_actor_settings(bond);
 
 	return 0;

include/net/bond_3ad.h

···
 	struct port port;		/* 802.3ad port structure */
 	struct bond_3ad_stats stats;
 	u16 id;
+	u16 port_priority;
 };
 
 static inline const char *bond_3ad_churn_desc(churn_state_t state)

include/net/bond_options.h

···
 	BOND_OPT_PRIO,
 	BOND_OPT_COUPLED_CONTROL,
 	BOND_OPT_BROADCAST_NEIGH,
+	BOND_OPT_ACTOR_PORT_PRIO,
 	BOND_OPT_LAST
 };
 

include/uapi/linux/if_link.h

···
 	IFLA_BOND_SLAVE_AD_ACTOR_OPER_PORT_STATE,
 	IFLA_BOND_SLAVE_AD_PARTNER_OPER_PORT_STATE,
 	IFLA_BOND_SLAVE_PRIO,
+	IFLA_BOND_SLAVE_ACTOR_PORT_PRIO,
 	__IFLA_BOND_SLAVE_MAX,
 };