[net-next,v6] bonding: Add independent control state machine

diff --git a/Documentation/networking/bonding.rst b/Documentation/networking/bonding.rst
index f7a73421eb76..e774b48de9f5 100644
--- a/Documentation/networking/bonding.rst
+++ b/Documentation/networking/bonding.rst
@@ -444,6 +444,18 @@  arp_missed_max
 
 	The default value is 2, and the allowable range is 1 - 255.
 
+coupled_control
+
+    Specifies whether the LACP state machine's MUX in the 802.3ad mode
+    should have separate Collecting and Distributing states.
+
+    This is by implementing the independent control state machine per
+    IEEE 802.1AX-2008 5.4.15 in addition to the existing coupled control
+    state machine.
+
+    The default value is 1. This setting does not separate the Collecting
+    and Distributing states, maintaining the bond in coupled control.
+
 downdelay
 
 	Specifies the time, in milliseconds, to wait before disabling
diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c
index c99ffe6c683a..f2942e8c6c91 100644
--- a/drivers/net/bonding/bond_3ad.c
+++ b/drivers/net/bonding/bond_3ad.c
@@ -106,6 +106,9 @@  static void ad_agg_selection_logic(struct aggregator *aggregator,
 static void ad_clear_agg(struct aggregator *aggregator);
 static void ad_initialize_agg(struct aggregator *aggregator);
 static void ad_initialize_port(struct port *port, int lacp_fast);
+static void ad_enable_collecting(struct port *port);
+static void ad_disable_distributing(struct port *port,
+				    bool *update_slave_arr);
 static void ad_enable_collecting_distributing(struct port *port,
 					      bool *update_slave_arr);
 static void ad_disable_collecting_distributing(struct port *port,
@@ -171,9 +174,38 @@  static inline int __agg_has_partner(struct aggregator *agg)
 	return !is_zero_ether_addr(agg->partner_system.mac_addr_value);
 }
 
+/**
+ * __disable_distributing_port - disable the port's slave for distributing.
+ * Port will still be able to collect.
+ * @port: the port we're looking at
+ *
+ * This will disable only distributing on the port's slave.
+ */
+static void __disable_distributing_port(struct port *port)
+{
+	bond_set_slave_tx_disabled_flags(port->slave, BOND_SLAVE_NOTIFY_LATER);
+}
+
+/**
+ * __enable_collecting_port - enable the port's slave for collecting,
+ * if it's up
+ * @port: the port we're looking at
+ *
+ * This will enable only collecting on the port's slave.
+ */
+static void __enable_collecting_port(struct port *port)
+{
+	struct slave *slave = port->slave;
+
+	if (slave->link == BOND_LINK_UP && bond_slave_is_up(slave))
+		bond_set_slave_rx_enabled_flags(slave, BOND_SLAVE_NOTIFY_LATER);
+}
+
 /**
  * __disable_port - disable the port's slave
  * @port: the port we're looking at
+ *
+ * This will disable both collecting and distributing on the port's slave.
  */
 static inline void __disable_port(struct port *port)
 {
@@ -183,6 +215,8 @@  static inline void __disable_port(struct port *port)
 /**
  * __enable_port - enable the port's slave, if it's up
  * @port: the port we're looking at
+ *
+ * This will enable both collecting and distributing on the port's slave.
  */
 static inline void __enable_port(struct port *port)
 {
@@ -193,10 +227,27 @@  static inline void __enable_port(struct port *port)
 }
 
 /**
- * __port_is_enabled - check if the port's slave is in active state
+ * __port_move_to_attached_state - check if port should transition back to attached
+ * state.
+ * @port: the port we're looking at
+ */
+static bool __port_move_to_attached_state(struct port *port)
+{
+	if (!(port->sm_vars & AD_PORT_SELECTED) ||
+	    (port->sm_vars & AD_PORT_STANDBY) ||
+	    !(port->partner_oper.port_state & LACP_STATE_SYNCHRONIZATION) ||
+	    !(port->actor_oper_port_state & LACP_STATE_SYNCHRONIZATION))
+		port->sm_mux_state = AD_MUX_ATTACHED;
+
+	return port->sm_mux_state == AD_MUX_ATTACHED;
+}
+
+/**
+ * __port_is_collecting_distributing - check if the port's slave is in the
+ * combined collecting/distributing state
  * @port: the port we're looking at
  */
-static inline int __port_is_enabled(struct port *port)
+static int __port_is_collecting_distributing(struct port *port)
 {
 	return bond_is_active_slave(port->slave);
 }
@@ -942,6 +993,7 @@  static int ad_marker_send(struct port *port, struct bond_marker *marker)
  */
 static void ad_mux_machine(struct port *port, bool *update_slave_arr)
 {
+	struct bonding *bond = __get_bond_by_port(port);
 	mux_states_t last_state;
 
 	/* keep current State Machine state to compare later if it was
@@ -999,9 +1051,13 @@  static void ad_mux_machine(struct port *port, bool *update_slave_arr)
 			if ((port->sm_vars & AD_PORT_SELECTED) &&
 			    (port->partner_oper.port_state & LACP_STATE_SYNCHRONIZATION) &&
 			    !__check_agg_selection_timer(port)) {
-				if (port->aggregator->is_active)
-					port->sm_mux_state =
-					    AD_MUX_COLLECTING_DISTRIBUTING;
+				if (port->aggregator->is_active) {
+					int state = AD_MUX_COLLECTING_DISTRIBUTING;
+
+					if (!bond->params.coupled_control)
+						state = AD_MUX_COLLECTING;
+					port->sm_mux_state = state;
+				}
 			} else if (!(port->sm_vars & AD_PORT_SELECTED) ||
 				   (port->sm_vars & AD_PORT_STANDBY)) {
 				/* if UNSELECTED or STANDBY */
@@ -1019,11 +1075,45 @@  static void ad_mux_machine(struct port *port, bool *update_slave_arr)
 			}
 			break;
 		case AD_MUX_COLLECTING_DISTRIBUTING:
+			if (!__port_move_to_attached_state(port)) {
+				/* if port state hasn't changed make
+				 * sure that a collecting distributing
+				 * port in an active aggregator is enabled
+				 */
+				if (port->aggregator->is_active &&
+				    !__port_is_collecting_distributing(port)) {
+					__enable_port(port);
+					*update_slave_arr = true;
+				}
+			}
+			break;
+		case AD_MUX_COLLECTING:
+			if (!__port_move_to_attached_state(port)) {
+				if ((port->sm_vars & AD_PORT_SELECTED) &&
+				    (port->partner_oper.port_state & LACP_STATE_SYNCHRONIZATION) &&
+				    (port->partner_oper.port_state & LACP_STATE_COLLECTING)) {
+					port->sm_mux_state = AD_MUX_DISTRIBUTING;
+				} else {
+					/* If port state hasn't changed, make sure that a collecting
+					 * port is enabled for an active aggregator.
+					 */
+					struct slave *slave = port->slave;
+
+					if (port->aggregator->is_active &&
+					    bond_is_slave_rx_disabled(slave)) {
+						ad_enable_collecting(port);
+						*update_slave_arr = true;
+					}
+				}
+			}
+			break;
+		case AD_MUX_DISTRIBUTING:
 			if (!(port->sm_vars & AD_PORT_SELECTED) ||
 			    (port->sm_vars & AD_PORT_STANDBY) ||
+			    !(port->partner_oper.port_state & LACP_STATE_COLLECTING) ||
 			    !(port->partner_oper.port_state & LACP_STATE_SYNCHRONIZATION) ||
 			    !(port->actor_oper_port_state & LACP_STATE_SYNCHRONIZATION)) {
-				port->sm_mux_state = AD_MUX_ATTACHED;
+				port->sm_mux_state = AD_MUX_COLLECTING;
 			} else {
 				/* if port state hasn't changed make
 				 * sure that a collecting distributing
@@ -1031,7 +1121,7 @@  static void ad_mux_machine(struct port *port, bool *update_slave_arr)
 				 */
 				if (port->aggregator &&
 				    port->aggregator->is_active &&
-				    !__port_is_enabled(port)) {
+				    !__port_is_collecting_distributing(port)) {
 					__enable_port(port);
 					*update_slave_arr = true;
 				}
@@ -1082,6 +1172,20 @@  static void ad_mux_machine(struct port *port, bool *update_slave_arr)
 							  update_slave_arr);
 			port->ntt = true;
 			break;
+		case AD_MUX_COLLECTING:
+			port->actor_oper_port_state |= LACP_STATE_COLLECTING;
+			port->actor_oper_port_state &= ~LACP_STATE_DISTRIBUTING;
+			port->actor_oper_port_state |= LACP_STATE_SYNCHRONIZATION;
+			ad_enable_collecting(port);
+			ad_disable_distributing(port, update_slave_arr);
+			port->ntt = true;
+			break;
+		case AD_MUX_DISTRIBUTING:
+			port->actor_oper_port_state |= LACP_STATE_DISTRIBUTING;
+			port->actor_oper_port_state |= LACP_STATE_SYNCHRONIZATION;
+			ad_enable_collecting_distributing(port,
+							  update_slave_arr);
+			break;
 		default:
 			break;
 		}
@@ -1906,6 +2010,45 @@  static void ad_initialize_port(struct port *port, int lacp_fast)
 	}
 }
 
+/**
+ * ad_enable_collecting - enable a port's receive
+ * @port: the port we're looking at
+ *
+ * Enable @port if it's in an active aggregator
+ */
+static void ad_enable_collecting(struct port *port)
+{
+	if (port->aggregator->is_active) {
+		struct slave *slave = port->slave;
+
+		slave_dbg(slave->bond->dev, slave->dev,
+			  "Enabling collecting on port %d (LAG %d)\n",
+			  port->actor_port_number,
+			  port->aggregator->aggregator_identifier);
+		__enable_collecting_port(port);
+	}
+}
+
+/**
+ * ad_disable_distributing - disable a port's transmit
+ * @port: the port we're looking at
+ * @update_slave_arr: Does slave array need update?
+ */
+static void ad_disable_distributing(struct port *port, bool *update_slave_arr)
+{
+	if (port->aggregator &&
+	    !MAC_ADDRESS_EQUAL(&port->aggregator->partner_system,
+			       &(null_mac_addr))) {
+		slave_dbg(port->slave->bond->dev, port->slave->dev,
+			  "Disabling distributing on port %d (LAG %d)\n",
+			  port->actor_port_number,
+			  port->aggregator->aggregator_identifier);
+		__disable_distributing_port(port);
+		/* Slave array needs an update */
+		*update_slave_arr = true;
+	}
+}
+
 /**
  * ad_enable_collecting_distributing - enable a port's transmit/receive
  * @port: the port we're looking at
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 8e6cc0e133b7..30f4b0ff01c0 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -6331,6 +6331,7 @@  static int __init bond_check_params(struct bond_params *params)
 	params->ad_actor_sys_prio = ad_actor_sys_prio;
 	eth_zero_addr(params->ad_actor_system);
 	params->ad_user_port_key = ad_user_port_key;
+	params->coupled_control = 1;
 	if (packets_per_slave > 0) {
 		params->reciprocal_packets_per_slave =
 			reciprocal_value(packets_per_slave);
diff --git a/drivers/net/bonding/bond_netlink.c b/drivers/net/bonding/bond_netlink.c
index cfa74cf8bb1a..29b4c3d1b9b6 100644
--- a/drivers/net/bonding/bond_netlink.c
+++ b/drivers/net/bonding/bond_netlink.c
@@ -122,6 +122,7 @@  static const struct nla_policy bond_policy[IFLA_BOND_MAX + 1] = {
 	[IFLA_BOND_PEER_NOTIF_DELAY]    = NLA_POLICY_FULL_RANGE(NLA_U32, &delay_range),
 	[IFLA_BOND_MISSED_MAX]		= { .type = NLA_U8 },
 	[IFLA_BOND_NS_IP6_TARGET]	= { .type = NLA_NESTED },
+	[IFLA_BOND_COUPLED_CONTROL]	= { .type = NLA_U8 },
 };
 
 static const struct nla_policy bond_slave_policy[IFLA_BOND_SLAVE_MAX + 1] = {
@@ -549,6 +550,16 @@  static int bond_changelink(struct net_device *bond_dev, struct nlattr *tb[],
 			return err;
 	}
 
+	if (data[IFLA_BOND_COUPLED_CONTROL]) {
+		int coupled_control = nla_get_u8(data[IFLA_BOND_COUPLED_CONTROL]);
+
+		bond_opt_initval(&newval, coupled_control);
+		err = __bond_opt_set(bond, BOND_OPT_COUPLED_CONTROL, &newval,
+				     data[IFLA_BOND_COUPLED_CONTROL], extack);
+		if (err)
+			return err;
+	}
+
 	return 0;
 }
 
@@ -615,6 +626,7 @@  static size_t bond_get_size(const struct net_device *bond_dev)
 						/* IFLA_BOND_NS_IP6_TARGET */
 		nla_total_size(sizeof(struct nlattr)) +
 		nla_total_size(sizeof(struct in6_addr)) * BOND_MAX_NS_TARGETS +
+		nla_total_size(sizeof(u8)) +	/* IFLA_BOND_COUPLED_CONTROL */
 		0;
 }
 
@@ -774,6 +786,10 @@  static int bond_fill_info(struct sk_buff *skb,
 		       bond->params.missed_max))
 		goto nla_put_failure;
 
+	if (nla_put_u8(skb, IFLA_BOND_COUPLED_CONTROL,
+		       bond->params.coupled_control))
+		goto nla_put_failure;
+
 	if (BOND_MODE(bond) == BOND_MODE_8023AD) {
 		struct ad_info info;
 
diff --git a/drivers/net/bonding/bond_options.c b/drivers/net/bonding/bond_options.c
index f3f27f0bd2a6..4cdbc7e084f4 100644
--- a/drivers/net/bonding/bond_options.c
+++ b/drivers/net/bonding/bond_options.c
@@ -84,7 +84,8 @@  static int bond_option_ad_user_port_key_set(struct bonding *bond,
 					    const struct bond_opt_value *newval);
 static int bond_option_missed_max_set(struct bonding *bond,
 				      const struct bond_opt_value *newval);
-
+static int bond_option_coupled_control_set(struct bonding *bond,
+					   const struct bond_opt_value *newval);
 
 static const struct bond_opt_value bond_mode_tbl[] = {
 	{ "balance-rr",    BOND_MODE_ROUNDROBIN,   BOND_VALFLAG_DEFAULT},
@@ -232,6 +233,12 @@  static const struct bond_opt_value bond_missed_max_tbl[] = {
 	{ NULL,		-1,	0},
 };
 
+static const struct bond_opt_value bond_coupled_control_tbl[] = {
+	{ "on",  1,  BOND_VALFLAG_DEFAULT},
+	{ "off", 0,  0},
+	{ NULL,  -1, 0},
+};
+
 static const struct bond_option bond_opts[BOND_OPT_LAST] = {
 	[BOND_OPT_MODE] = {
 		.id = BOND_OPT_MODE,
@@ -496,6 +503,15 @@  static const struct bond_option bond_opts[BOND_OPT_LAST] = {
 		.desc = "Delay between each peer notification on failover event, in milliseconds",
 		.values = bond_peer_notif_delay_tbl,
 		.set = bond_option_peer_notif_delay_set
+	},
+	[BOND_OPT_COUPLED_CONTROL] = {
+		.id = BOND_OPT_COUPLED_CONTROL,
+		.name = "coupled_control",
+		.desc = "Opt into using coupled control MUX for LACP states",
+		.unsuppmodes = BOND_MODE_ALL_EX(BIT(BOND_MODE_8023AD)),
+		.flags = BOND_OPTFLAG_IFDOWN,
+		.values = bond_coupled_control_tbl,
+		.set = bond_option_coupled_control_set,
 	}
 };
 
@@ -1692,3 +1708,13 @@  static int bond_option_ad_user_port_key_set(struct bonding *bond,
 	bond->params.ad_user_port_key = newval->value;
 	return 0;
 }
+
+static int bond_option_coupled_control_set(struct bonding *bond,
+					   const struct bond_opt_value *newval)
+{
+	netdev_info(bond->dev, "Setting coupled_control to %s (%llu)\n",
+		    newval->string, newval->value);
+
+	bond->params.coupled_control = newval->value;
+	return 0;
+}
diff --git a/drivers/net/bonding/bond_procfs.c b/drivers/net/bonding/bond_procfs.c
index 43be458422b3..95d88df94756 100644
--- a/drivers/net/bonding/bond_procfs.c
+++ b/drivers/net/bonding/bond_procfs.c
@@ -154,6 +154,8 @@  static void bond_info_show_master(struct seq_file *seq)
 			   (bond->params.lacp_active) ? "on" : "off");
 		seq_printf(seq, "LACP rate: %s\n",
 			   (bond->params.lacp_fast) ? "fast" : "slow");
+		seq_printf(seq, "LACP coupled_control: %s\n",
+			   (bond->params.coupled_control) ? "on" : "off");
 		seq_printf(seq, "Min links: %d\n", bond->params.min_links);
 		optval = bond_opt_get_val(BOND_OPT_AD_SELECT,
 					  bond->params.ad_select);
diff --git a/include/net/bond_3ad.h b/include/net/bond_3ad.h
index c5e57c6bd873..9ce5ac2bfbad 100644
--- a/include/net/bond_3ad.h
+++ b/include/net/bond_3ad.h
@@ -54,6 +54,8 @@  typedef enum {
 	AD_MUX_DETACHED,	/* mux machine */
 	AD_MUX_WAITING,		/* mux machine */
 	AD_MUX_ATTACHED,	/* mux machine */
+	AD_MUX_COLLECTING,	/* mux machine */
+	AD_MUX_DISTRIBUTING,	/* mux machine */
 	AD_MUX_COLLECTING_DISTRIBUTING	/* mux machine */
 } mux_states_t;
 
diff --git a/include/net/bond_options.h b/include/net/bond_options.h
index 69292ecc0325..473a0147769e 100644
--- a/include/net/bond_options.h
+++ b/include/net/bond_options.h
@@ -76,6 +76,7 @@  enum {
 	BOND_OPT_MISSED_MAX,
 	BOND_OPT_NS_TARGETS,
 	BOND_OPT_PRIO,
+	BOND_OPT_COUPLED_CONTROL,
 	BOND_OPT_LAST
 };
 
diff --git a/include/net/bonding.h b/include/net/bonding.h
index 5b8b1b644a2d..b61fb1aa3a56 100644
--- a/include/net/bonding.h
+++ b/include/net/bonding.h
@@ -148,6 +148,7 @@  struct bond_params {
 #if IS_ENABLED(CONFIG_IPV6)
 	struct in6_addr ns_targets[BOND_MAX_NS_TARGETS];
 #endif
+	int coupled_control;
 
 	/* 2 bytes of padding : see ether_addr_equal_64bits() */
 	u8 ad_actor_system[ETH_ALEN + 2];
@@ -167,6 +168,7 @@  struct slave {
 	u8     backup:1,   /* indicates backup slave. Value corresponds with
 			      BOND_STATE_ACTIVE and BOND_STATE_BACKUP */
 	       inactive:1, /* indicates inactive slave */
+	       rx_disabled:1, /* indicates whether slave's Rx is disabled */
 	       should_notify:1, /* indicates whether the state changed */
 	       should_notify_link:1; /* indicates whether the link changed */
 	u8     duplex;
@@ -568,6 +570,14 @@  static inline void bond_set_slave_inactive_flags(struct slave *slave,
 		bond_set_slave_state(slave, BOND_STATE_BACKUP, notify);
 	if (!slave->bond->params.all_slaves_active)
 		slave->inactive = 1;
+	if (BOND_MODE(slave->bond) == BOND_MODE_8023AD)
+		slave->rx_disabled = 1;
+}
+
+static inline void bond_set_slave_tx_disabled_flags(struct slave *slave,
+						 bool notify)
+{
+	bond_set_slave_state(slave, BOND_STATE_BACKUP, notify);
 }
 
 static inline void bond_set_slave_active_flags(struct slave *slave,
@@ -575,6 +585,14 @@  static inline void bond_set_slave_active_flags(struct slave *slave,
 {
 	bond_set_slave_state(slave, BOND_STATE_ACTIVE, notify);
 	slave->inactive = 0;
+	if (BOND_MODE(slave->bond) == BOND_MODE_8023AD)
+		slave->rx_disabled = 0;
+}
+
+static inline void bond_set_slave_rx_enabled_flags(struct slave *slave,
+					       bool notify)
+{
+	slave->rx_disabled = 0;
 }
 
 static inline bool bond_is_slave_inactive(struct slave *slave)
@@ -582,6 +600,11 @@  static inline bool bond_is_slave_inactive(struct slave *slave)
 	return slave->inactive;
 }
 
+static inline bool bond_is_slave_rx_disabled(struct slave *slave)
+{
+	return slave->rx_disabled;
+}
+
 static inline void bond_propose_link_state(struct slave *slave, int state)
 {
 	slave->link_new_state = state;
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 29ff80da2775..7a54fcff2eec 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -976,6 +976,7 @@  enum {
 	IFLA_BOND_AD_LACP_ACTIVE,
 	IFLA_BOND_MISSED_MAX,
 	IFLA_BOND_NS_IP6_TARGET,
+	IFLA_BOND_COUPLED_CONTROL,
 	__IFLA_BOND_MAX,
 };
 
diff --git a/tools/include/uapi/linux/if_link.h b/tools/include/uapi/linux/if_link.h
index a0aa05a28cf2..f0d71b2a3f1e 100644
--- a/tools/include/uapi/linux/if_link.h
+++ b/tools/include/uapi/linux/if_link.h
@@ -974,6 +974,7 @@  enum {
 	IFLA_BOND_AD_LACP_ACTIVE,
 	IFLA_BOND_MISSED_MAX,
 	IFLA_BOND_NS_IP6_TARGET,
+	IFLA_BOND_COUPLED_CONTROL,
 	__IFLA_BOND_MAX,
 };