bonding: Add independent control state machine
authorAahil Awatramani <aahila@google.com>
Fri, 2 Feb 2024 17:58:58 +0000 (17:58 +0000)
committerPaolo Abeni <pabeni@redhat.com>
Tue, 6 Feb 2024 12:17:54 +0000 (13:17 +0100)
Add support for the independent control state machine per IEEE
802.1AX-2008 5.4.15 in addition to the existing implementation of the
coupled control state machine.

Introduces two new states, AD_MUX_COLLECTING and AD_MUX_DISTRIBUTING in
the LACP MUX state machine for separated handling of an initial
Collecting state before the Collecting and Distributing state. This
enables a port to be in a state where it can receive incoming packets
while not still distributing. This is useful for reducing packet loss when
a port begins distributing before its partner is able to collect.

Added new functions such as bond_set_slave_tx_disabled_flags and
bond_set_slave_rx_enabled_flags to precisely manage the port's collecting
and distributing states. Previously, there was no dedicated method to
disable TX while keeping RX enabled, which this patch addresses.

Note that the regular flow process in the kernel's bonding driver remains
unaffected by this patch. The extension requires explicit opt-in by the
user (in order to ensure no disruptions for existing setups) via netlink
support using the new bonding parameter coupled_control. The default value
for coupled_control is set to 1 so as to preserve existing behaviour.

Signed-off-by: Aahil Awatramani <aahila@google.com>
Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20240202175858.1573852-1-aahila@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Documentation/networking/bonding.rst
drivers/net/bonding/bond_3ad.c
drivers/net/bonding/bond_main.c
drivers/net/bonding/bond_netlink.c
drivers/net/bonding/bond_options.c
include/net/bond_3ad.h
include/net/bond_options.h
include/net/bonding.h
include/uapi/linux/if_link.h
tools/include/uapi/linux/if_link.h

index f7a73421eb76a1e358650592f767a24e46ca01ac..e774b48de9f5118be7035f9b96c7226c2679e185 100644 (file)
@@ -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
index c99ffe6c683a3853c67225f0828bfbadafe938db..f2942e8c6c91b42bac2aa31582d5f1485753f826 100644 (file)
@@ -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
index 4e0600c7b050f21c82a8862e224bb055e95d5039..ae9d32c0faf40ca32884f3c7e69b320e1e02c8d0 100644 (file)
@@ -6306,6 +6306,7 @@ 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);
index cfa74cf8bb1a95b1eb36f1135e39c256a220fec0..29b4c3d1b9b6ff873fe067e80bedf7cb681d18f1 100644 (file)
@@ -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;
 
index f3f27f0bd2a6cdd52d8c97e10a9b047af9f2da00..4cdbc7e084f4b4cb3b150656aa765531806d8ad9 100644 (file)
@@ -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;
+}
index c5e57c6bd8736759086f8cc263f9028796850f12..9ce5ac2bfbad9e9777f6baef9ec2aab016144544 100644 (file)
@@ -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;
 
index 69292ecc03257f066f4f614b3f4a5982a3b9a5f1..473a0147769eb9c7cc33ccbc72e74425442a0e14 100644 (file)
@@ -76,6 +76,7 @@ enum {
        BOND_OPT_MISSED_MAX,
        BOND_OPT_NS_TARGETS,
        BOND_OPT_PRIO,
+       BOND_OPT_COUPLED_CONTROL,
        BOND_OPT_LAST
 };
 
index 5b8b1b644a2dbf542695c874e27e0b2b3222cef6..b61fb1aa3a56b5e6b27b2f74a6f25bdcf09418f1 100644 (file)
@@ -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;
index ab9bcff96e4da10bdc22b8e2345d4103f1598bc6..ffa637b38c93bc4f13e68bcaa2b84bc577cb9c81 100644 (file)
@@ -1505,6 +1505,7 @@ enum {
        IFLA_BOND_AD_LACP_ACTIVE,
        IFLA_BOND_MISSED_MAX,
        IFLA_BOND_NS_IP6_TARGET,
+       IFLA_BOND_COUPLED_CONTROL,
        __IFLA_BOND_MAX,
 };
 
index a0aa05a28cf29c435b272e4d77e8677417b559e1..f0d71b2a3f1e1a3d0945bc3a0efe31cd95940f72 100644 (file)
@@ -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,
 };