/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 * Copyright 2012 OmniTI Computer Consulting, Inc  All rights reserved.
 * Copyright 2020 Joyent, Inc.
 */

/*
 * IEEE 802.3ad Link Aggregation - Link Aggregation MAC ports.
 *
 * Implements the functions needed to manage the MAC ports that are
 * part of Link Aggregation groups.
 */

#include <sys/types.h>
#include <sys/sysmacros.h>
#include <sys/conf.h>
#include <sys/cmn_err.h>
#include <sys/id_space.h>
#include <sys/list.h>
#include <sys/ksynch.h>
#include <sys/kmem.h>
#include <sys/stream.h>
#include <sys/modctl.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/atomic.h>
#include <sys/stat.h>
#include <sys/sdt.h>
#include <sys/dlpi.h>
#include <sys/dls.h>
#include <sys/aggr.h>
#include <sys/aggr_impl.h>

static kmem_cache_t *aggr_port_cache;
static id_space_t *aggr_portids;

static void aggr_port_notify_cb(void *, mac_notify_type_t);

/*ARGSUSED*/
static int
aggr_port_constructor(void *buf, void *arg, int kmflag)
{
        bzero(buf, sizeof (aggr_port_t));
        return (0);
}

/*ARGSUSED*/
static void
aggr_port_destructor(void *buf, void *arg)
{
        aggr_port_t *port = buf;

        ASSERT3P(port->lp_mnh, ==, NULL);
        ASSERT(!port->lp_tx_grp_added);
        for (uint_t i = 0; i < MAX_GROUPS_PER_PORT; i++)
                ASSERT3P(port->lp_hwghs[i], ==, NULL);
}

void
aggr_port_init(void)
{
        aggr_port_cache = kmem_cache_create("aggr_port_cache",
            sizeof (aggr_port_t), 0, aggr_port_constructor,
            aggr_port_destructor, NULL, NULL, NULL, 0);

        /*
         * Allocate a id space to manage port identification. The range of
         * the arena will be from 1 to UINT16_MAX, because the LACP protocol
         * specifies 16-bit unique identification.
         */
        aggr_portids = id_space_create("aggr_portids", 1, UINT16_MAX);
        ASSERT(aggr_portids != NULL);
}

void
aggr_port_fini(void)
{
        /*
         * This function is called only after all groups have been
         * freed. This ensures that there are no remaining allocated
         * ports when this function is invoked.
         */
        kmem_cache_destroy(aggr_port_cache);
        id_space_destroy(aggr_portids);
}

/* ARGSUSED */
void
aggr_port_init_callbacks(aggr_port_t *port)
{
        /* add the port's receive callback */
        port->lp_mnh = mac_notify_add(port->lp_mh, aggr_port_notify_cb, port);
        /*
         * Hold a reference of the grp and the port and this reference will
         * be released when the thread exits.
         *
         * The reference on the port is used for aggr_port_delete() to
         * continue without waiting for the thread to exit; the reference
         * on the grp is used for aggr_grp_delete() to wait for the thread
         * to exit before calling mac_unregister().
         *
         * Note that these references will be released either in
         * aggr_port_delete() when mac_notify_remove() succeeds, or in
         * the aggr_port_notify_cb() callback when the port is deleted
         * (lp_closing is set).
         */
        aggr_grp_port_hold(port);
}

int
aggr_port_create(aggr_grp_t *grp, const datalink_id_t linkid, boolean_t force,
    aggr_port_t **pp)
{
        int err;
        mac_handle_t mh;
        mac_client_handle_t mch = NULL;
        aggr_port_t *port;
        uint16_t portid;
        uint_t i;
        boolean_t no_link_update = B_FALSE;
        const mac_info_t *mip;
        uint32_t note;
        uint32_t margin;
        char client_name[MAXNAMELEN];
        char aggr_name[MAXNAMELEN];
        char port_name[MAXNAMELEN];
        mac_diag_t diag;
        mac_unicast_handle_t mah;

        *pp = NULL;

        if ((err = mac_open_by_linkid(linkid, &mh)) != 0)
                return (err);

        mip = mac_info(mh);
        if (mip->mi_media != DL_ETHER || mip->mi_nativemedia != DL_ETHER) {
                err = EINVAL;
                goto fail;
        }

        /*
         * If the underlying MAC does not support link update notification, it
         * can only be aggregated if `force' is set.  This is because aggr
         * depends on link notifications to attach ports whose link is up.
         */
        note = mac_no_notification(mh);
        if ((note & (DL_NOTE_LINK_UP | DL_NOTE_LINK_DOWN)) != 0) {
                no_link_update = B_TRUE;
                if (!force) {
                        /*
                         * We borrow this error code to indicate that link
                         * notification is not supported.
                         */
                        err = ENETDOWN;
                        goto fail;
                }
        }

        if (((err = dls_mgmt_get_linkinfo(grp->lg_linkid,
            aggr_name, NULL, NULL, NULL)) != 0) ||
            ((err = dls_mgmt_get_linkinfo(linkid, port_name,
            NULL, NULL, NULL)) != 0)) {
                goto fail;
        }

        (void) snprintf(client_name, MAXNAMELEN, "%s-%s", aggr_name, port_name);
        if ((err = mac_client_open(mh, &mch, client_name,
            MAC_OPEN_FLAGS_IS_AGGR_PORT | MAC_OPEN_FLAGS_EXCLUSIVE)) != 0) {
                goto fail;
        }

        if ((portid = (uint16_t)id_alloc(aggr_portids)) == 0) {
                err = ENOMEM;
                goto fail;
        }

        /*
         * As the underlying MAC's current margin size is used to determine
         * the margin size of the aggregation itself, request the underlying
         * MAC not to change to a smaller size.
         */
        if ((err = mac_margin_add(mh, &margin, B_TRUE)) != 0) {
                id_free(aggr_portids, portid);
                goto fail;
        }

        if ((err = mac_unicast_add(mch, NULL, MAC_UNICAST_PRIMARY |
            MAC_UNICAST_DISABLE_TX_VID_CHECK, &mah, 0, &diag)) != 0) {
                VERIFY3S(mac_margin_remove(mh, margin), ==, 0);
                id_free(aggr_portids, portid);
                goto fail;
        }

        port = kmem_cache_alloc(aggr_port_cache, KM_SLEEP);

        port->lp_refs = 1;
        port->lp_next = NULL;
        port->lp_mh = mh;
        port->lp_mch = mch;
        port->lp_mip = mip;
        port->lp_linkid = linkid;
        port->lp_closing = B_FALSE;
        port->lp_mah = mah;

        /* get the port's original MAC address */
        mac_unicast_primary_get(port->lp_mh, port->lp_addr);

        /* initialize state */
        port->lp_state = AGGR_PORT_STATE_STANDBY;
        port->lp_link_state = LINK_STATE_UNKNOWN;
        port->lp_ifspeed = 0;
        port->lp_link_duplex = LINK_DUPLEX_UNKNOWN;
        port->lp_started = B_FALSE;
        port->lp_tx_enabled = B_FALSE;
        port->lp_promisc_on = B_FALSE;
        port->lp_no_link_update = no_link_update;
        port->lp_portid = portid;
        port->lp_margin = margin;
        port->lp_prom_addr = NULL;

        /*
         * Save the current statistics of the port. They will be used
         * later by aggr_m_stats() when aggregating the statistics of
         * the constituent ports.
         */
        for (i = 0; i < MAC_NSTAT; i++) {
                port->lp_stat[i] =
                    aggr_port_stat(port, i + MAC_STAT_MIN);
        }
        for (i = 0; i < ETHER_NSTAT; i++) {
                port->lp_ether_stat[i] =
                    aggr_port_stat(port, i + MACTYPE_STAT_MIN);
        }

        /* LACP related state */
        port->lp_collector_enabled = B_FALSE;

        *pp = port;
        return (0);

fail:
        if (mch != NULL)
                mac_client_close(mch, MAC_CLOSE_FLAGS_EXCLUSIVE);

        mac_close(mh);
        return (err);
}

void
aggr_port_delete(aggr_port_t *port)
{
        aggr_lacp_port_t *pl = &port->lp_lacp;

        ASSERT(!port->lp_promisc_on);
        port->lp_closing = B_TRUE;
        VERIFY0(mac_margin_remove(port->lp_mh, port->lp_margin));
        mac_client_clear_flow_cb(port->lp_mch);

        /*
         * If the notification callback is already in process and waiting for
         * the aggr grp's mac perimeter, don't wait (otherwise there would be
         * deadlock). Otherwise, if mac_notify_remove() succeeds, we can
         * release the reference held when mac_notify_add() is called.
         */
        if ((port->lp_mnh != NULL) &&
            (mac_notify_remove(port->lp_mnh, B_FALSE) == 0)) {
                aggr_grp_port_rele(port);
        }
        port->lp_mnh = NULL;

        /*
         * Inform the the port lacp timer thread to exit. Note that waiting
         * for the thread to exit may cause deadlock since that thread may
         * need to enter into the mac perimeter which we are currently in.
         * It is fine to continue without waiting though since that thread
         * is holding a reference of the port.
         */
        mutex_enter(&pl->lacp_timer_lock);
        pl->lacp_timer_bits |= LACP_THREAD_EXIT;
        cv_broadcast(&pl->lacp_timer_cv);
        mutex_exit(&pl->lacp_timer_lock);

        /*
         * Restore the port MAC address. Note it is called after the
         * port's notification callback being removed. This prevent
         * port's MAC_NOTE_UNICST notify callback function being called.
         */
        (void) mac_unicast_primary_set(port->lp_mh, port->lp_addr);

        if (port->lp_mah != NULL)
                (void) mac_unicast_remove(port->lp_mch, port->lp_mah);

        mac_client_close(port->lp_mch, MAC_CLOSE_FLAGS_EXCLUSIVE);
        mac_close(port->lp_mh);
        AGGR_PORT_REFRELE(port);
}

void
aggr_port_free(aggr_port_t *port)
{
        ASSERT(port->lp_refs == 0);
        if (port->lp_grp != NULL)
                AGGR_GRP_REFRELE(port->lp_grp);
        port->lp_grp = NULL;
        id_free(aggr_portids, port->lp_portid);
        port->lp_portid = 0;
        mutex_destroy(&port->lp_lacp.lacp_timer_lock);
        cv_destroy(&port->lp_lacp.lacp_timer_cv);
        kmem_cache_free(aggr_port_cache, port);
}

/*
 * Invoked upon receiving a MAC_NOTE_LINK notification for
 * one of the constituent ports.
 */
boolean_t
aggr_port_notify_link(aggr_grp_t *grp, aggr_port_t *port)
{
        boolean_t do_attach = B_FALSE;
        boolean_t do_detach = B_FALSE;
        boolean_t link_state_changed = B_TRUE;
        uint64_t ifspeed;
        link_state_t link_state;
        link_duplex_t link_duplex;
        mac_perim_handle_t mph;

        ASSERT(MAC_PERIM_HELD(grp->lg_mh));
        mac_perim_enter_by_mh(port->lp_mh, &mph);

        /*
         * link state change?  For links that do not support link state
         * notification, always assume the link is up.
         */
        link_state = port->lp_no_link_update ? LINK_STATE_UP :
            mac_link_get(port->lp_mh);
        if (port->lp_link_state != link_state) {
                if (link_state == LINK_STATE_UP)
                        do_attach = (port->lp_link_state != LINK_STATE_UP);
                else
                        do_detach = (port->lp_link_state == LINK_STATE_UP);
        }
        port->lp_link_state = link_state;

        /* link duplex change? */
        link_duplex = aggr_port_stat(port, ETHER_STAT_LINK_DUPLEX);
        if (port->lp_link_duplex != link_duplex) {
                if (link_duplex == LINK_DUPLEX_FULL)
                        do_attach |= (port->lp_link_duplex != LINK_DUPLEX_FULL);
                else
                        do_detach |= (port->lp_link_duplex == LINK_DUPLEX_FULL);
        }
        port->lp_link_duplex = link_duplex;

        /* link speed changes? */
        ifspeed = aggr_port_stat(port, MAC_STAT_IFSPEED);
        if (port->lp_ifspeed != ifspeed) {
                mutex_enter(&grp->lg_stat_lock);

                if (port->lp_state == AGGR_PORT_STATE_ATTACHED)
                        do_detach |= (ifspeed != grp->lg_ifspeed);
                else
                        do_attach |= (ifspeed == grp->lg_ifspeed);

                mutex_exit(&grp->lg_stat_lock);
        }
        port->lp_ifspeed = ifspeed;

        if (do_attach) {
                /* attempt to attach the port to the aggregation */
                link_state_changed = aggr_grp_attach_port(grp, port);
        } else if (do_detach) {
                /* detach the port from the aggregation */
                link_state_changed = aggr_grp_detach_port(grp, port);
        }

        mac_perim_exit(mph);
        return (link_state_changed);
}

/*
 * Invoked upon receiving a MAC_NOTE_UNICST for one of the constituent
 * ports of a group.
 */
static void
aggr_port_notify_unicst(aggr_grp_t *grp, aggr_port_t *port,
    boolean_t *mac_addr_changedp, boolean_t *link_state_changedp)
{
        boolean_t mac_addr_changed = B_FALSE;
        boolean_t link_state_changed = B_FALSE;
        uint8_t mac_addr[ETHERADDRL];
        mac_perim_handle_t mph;

        ASSERT(MAC_PERIM_HELD(grp->lg_mh));
        ASSERT(mac_addr_changedp != NULL);
        ASSERT(link_state_changedp != NULL);
        mac_perim_enter_by_mh(port->lp_mh, &mph);

        /*
         * If it is called when setting the MAC address to the
         * aggregation group MAC address, do nothing.
         */
        mac_unicast_primary_get(port->lp_mh, mac_addr);
        if (bcmp(mac_addr, grp->lg_addr, ETHERADDRL) == 0) {
                mac_perim_exit(mph);
                goto done;
        }

        /* save the new port MAC address */
        bcopy(mac_addr, port->lp_addr, ETHERADDRL);

        aggr_grp_port_mac_changed(grp, port, &mac_addr_changed,
            &link_state_changed);

        mac_perim_exit(mph);

        /*
         * If this port was used to determine the MAC address of
         * the group, update the MAC address of the constituent
         * ports.
         */
        if (mac_addr_changed && aggr_grp_update_ports_mac(grp))
                link_state_changed = B_TRUE;

done:
        *mac_addr_changedp = mac_addr_changed;
        *link_state_changedp = link_state_changed;
}

/*
 * Notification callback invoked by the MAC service module for
 * a particular MAC port.
 */
static void
aggr_port_notify_cb(void *arg, mac_notify_type_t type)
{
        aggr_port_t *port = arg;
        aggr_grp_t *grp = port->lp_grp;
        boolean_t mac_addr_changed, link_state_changed;
        mac_perim_handle_t mph;

        mac_perim_enter_by_mh(grp->lg_mh, &mph);
        if (port->lp_closing) {
                mac_perim_exit(mph);

                /*
                 * Release the reference so it is safe for aggr to call
                 * mac_unregister() now.
                 */
                aggr_grp_port_rele(port);
                return;
        }

        switch (type) {
        case MAC_NOTE_TX:
                mac_tx_update(grp->lg_mh);
                break;
        case MAC_NOTE_LINK:
                if (aggr_port_notify_link(grp, port))
                        mac_link_update(grp->lg_mh, grp->lg_link_state);
                break;
        case MAC_NOTE_UNICST:
                aggr_port_notify_unicst(grp, port, &mac_addr_changed,
                    &link_state_changed);
                if (mac_addr_changed)
                        mac_unicst_update(grp->lg_mh, grp->lg_addr);
                if (link_state_changed)
                        mac_link_update(grp->lg_mh, grp->lg_link_state);
                break;
        default:
                break;
        }

        mac_perim_exit(mph);
}

int
aggr_port_start(aggr_port_t *port)
{
        ASSERT(MAC_PERIM_HELD(port->lp_mh));

        if (port->lp_started)
                return (0);

        port->lp_started = B_TRUE;
        aggr_grp_multicst_port(port, B_TRUE);
        return (0);
}

void
aggr_port_stop(aggr_port_t *port)
{
        ASSERT(MAC_PERIM_HELD(port->lp_mh));

        if (!port->lp_started)
                return;

        aggr_grp_multicst_port(port, B_FALSE);

        /* update the port state */
        port->lp_started = B_FALSE;
}

/*
 * Set the promisc mode of the port. If the port is already in the
 * requested mode then do nothing.
 */
int
aggr_port_promisc(aggr_port_t *port, boolean_t on)
{
        int rc;

        ASSERT(MAC_PERIM_HELD(port->lp_mh));

        if (on == port->lp_promisc_on)
                return (0);

        rc = mac_set_promisc(port->lp_mh, on);

        if (rc == 0)
                port->lp_promisc_on = on;

        return (rc);
}

/*
 * Set the MAC address of a port.
 */
int
aggr_port_unicst(aggr_port_t *port)
{
        aggr_grp_t              *grp = port->lp_grp;

        ASSERT(MAC_PERIM_HELD(grp->lg_mh));
        ASSERT(MAC_PERIM_HELD(port->lp_mh));

        return (mac_unicast_primary_set(port->lp_mh, grp->lg_addr));
}

/*
 * Add or remove a multicast address to/from a port.
 */
int
aggr_port_multicst(void *arg, boolean_t add, const uint8_t *addrp)
{
        aggr_port_t *port = arg;

        if (add) {
                return (mac_multicast_add(port->lp_mch, addrp));
        } else {
                mac_multicast_remove(port->lp_mch, addrp);
                return (0);
        }
}

uint64_t
aggr_port_stat(aggr_port_t *port, uint_t stat)
{
        return (mac_stat_get(port->lp_mh, stat));
}

/*
 * Add a non-primary unicast address to the underlying port. If the
 * port supports HW Rx groups, then try to add the address filter to
 * the HW group first. If that fails, or if the port does not support
 * RINGS capab, then enable the port's promiscous mode.
 */
int
aggr_port_addmac(aggr_port_t *port, uint_t idx, const uint8_t *mac_addr)
{
        aggr_unicst_addr_t      *addr, **pprev;
        mac_perim_handle_t      pmph;
        int                     err;

        ASSERT(MAC_PERIM_HELD(port->lp_grp->lg_mh));
        ASSERT3U(idx, <, MAX_GROUPS_PER_PORT);
        mac_perim_enter_by_mh(port->lp_mh, &pmph);

        /*
         * If the port doesn't have a HW group to back the aggr's
         * pseudo group, then try using the port's default group and
         * let the aggr SW classify its traffic. This scenario happens
         * when mixing ports with a different number of HW groups.
         */
        if (port->lp_hwghs[idx] == NULL)
                idx = 0;

        /*
         * If there is an underlying HW Rx group, then try adding this
         * unicast address to it.
         */
        if ((port->lp_hwghs[idx] != NULL) &&
            ((mac_hwgroup_addmac(port->lp_hwghs[idx], mac_addr)) == 0)) {
                mac_perim_exit(pmph);
                return (0);
        }

        /*
         * If the port doesn't have HW groups, or we failed to add the
         * HW filter, then enable the port's promiscuous mode. We
         * enable promiscuous mode only if the port is already started.
         */
        if (port->lp_started &&
            ((err = aggr_port_promisc(port, B_TRUE)) != 0)) {
                mac_perim_exit(pmph);
                return (err);
        }

        /*
         * Walk through the unicast addresses that requires promiscous mode
         * enabled on this port, and add this address to the end of the list.
         */
        pprev = &port->lp_prom_addr;
        while ((addr = *pprev) != NULL) {
                ASSERT(bcmp(mac_addr, addr->aua_addr, ETHERADDRL) != 0);
                pprev = &addr->aua_next;
        }
        addr = kmem_alloc(sizeof (aggr_unicst_addr_t), KM_SLEEP);
        bcopy(mac_addr, addr->aua_addr, ETHERADDRL);
        addr->aua_next = NULL;
        *pprev = addr;
        mac_perim_exit(pmph);
        return (0);
}

/*
 * Remove a non-primary unicast address from the underlying port. This address
 * must has been added by aggr_port_addmac(). As a result, we probably need to
 * remove the address from the port's HW Rx group, or to disable the port's
 * promiscous mode.
 */
void
aggr_port_remmac(aggr_port_t *port, uint_t idx, const uint8_t *mac_addr)
{
        aggr_grp_t              *grp = port->lp_grp;
        aggr_unicst_addr_t      *addr, **pprev;
        mac_perim_handle_t      pmph;

        ASSERT(MAC_PERIM_HELD(grp->lg_mh));
        ASSERT3U(idx, <, MAX_GROUPS_PER_PORT);
        mac_perim_enter_by_mh(port->lp_mh, &pmph);

        /*
         * See whether this address is in the list of addresses that requires
         * the port being promiscous mode.
         */
        pprev = &port->lp_prom_addr;
        while ((addr = *pprev) != NULL) {
                if (bcmp(mac_addr, addr->aua_addr, ETHERADDRL) == 0)
                        break;
                pprev = &addr->aua_next;
        }

        if (addr != NULL) {
                /*
                 * This unicast address put the port into the promiscous mode,
                 * delete this address from the lp_prom_addr list. If this is
                 * the last address in that list, disable the promiscous mode
                 * if the aggregation is not in promiscous mode.
                 */
                *pprev = addr->aua_next;
                kmem_free(addr, sizeof (aggr_unicst_addr_t));
                if (port->lp_prom_addr == NULL && !grp->lg_promisc)
                        (void) aggr_port_promisc(port, B_FALSE);
        } else {
                /* See comment in aggr_port_addmac(). */
                if (port->lp_hwghs[idx] == NULL)
                        idx = 0;

                ASSERT3P(port->lp_hwghs[idx], !=, NULL);
                (void) mac_hwgroup_remmac(port->lp_hwghs[idx], mac_addr);
        }

        mac_perim_exit(pmph);
}

int
aggr_port_addvlan(aggr_port_t *port, uint_t idx, uint16_t vid)
{
        mac_perim_handle_t      pmph;
        int                     err;

        ASSERT(MAC_PERIM_HELD(port->lp_grp->lg_mh));
        ASSERT3U(idx, <, MAX_GROUPS_PER_PORT);
        mac_perim_enter_by_mh(port->lp_mh, &pmph);

        /* See comment in aggr_port_addmac(). */
        if (port->lp_hwghs[idx] == NULL)
                idx = 0;

        /*
         * Add the VLAN filter to the HW group if the port has a HW
         * group. If the port doesn't have a HW group, then it will
         * implicitly allow tagged traffic to pass and there is
         * nothing to do.
         */
        if (port->lp_hwghs[idx] == NULL)
                err = 0;
        else
                err = mac_hwgroup_addvlan(port->lp_hwghs[idx], vid);

        mac_perim_exit(pmph);
        return (err);
}

int
aggr_port_remvlan(aggr_port_t *port, uint_t idx, uint16_t vid)
{
        mac_perim_handle_t      pmph;
        int                     err;

        ASSERT(MAC_PERIM_HELD(port->lp_grp->lg_mh));
        ASSERT3U(idx, <, MAX_GROUPS_PER_PORT);
        mac_perim_enter_by_mh(port->lp_mh, &pmph);

        /* See comment in aggr_port_addmac(). */
        if (port->lp_hwghs[idx] == NULL)
                idx = 0;

        if (port->lp_hwghs[idx] == NULL)
                err = 0;
        else
                err = mac_hwgroup_remvlan(port->lp_hwghs[idx], vid);

        mac_perim_exit(pmph);
        return (err);
}