/*
 * 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 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Copyright 2019, Joyent, Inc.
 * Copyright 2022 Garrett D'Amore
 */

#include <sys/types.h>
#include <inet/common.h>
#include <sys/stropts.h>
#include <sys/modctl.h>
#include <sys/dld.h>
#include <sys/softmac_impl.h>

dev_info_t              *softmac_dip = NULL;
static kmem_cache_t     *softmac_upper_cachep;

/*
 * This function is a generic open(9E) entry point into the softmac for
 * both the softmac module and the softmac driver.
 */
static int softmac_cmn_open(queue_t *, dev_t *, int, int, cred_t *);

/*
 * The following softmac_mod_xxx() functions are (9E) entry point functions for
 * the softmac module.
 */
static int softmac_mod_close(queue_t *, int, cred_t *);
static int softmac_mod_rput(queue_t *, mblk_t *);
static int softmac_mod_wput(queue_t *, mblk_t *);
static int softmac_mod_wsrv(queue_t *);

/*
 * The following softmac_drv_xxx() functions are (9E) entry point functions for
 * the softmac driver.
 */
static int softmac_drv_open(queue_t *, dev_t *, int, int, cred_t *);
static int softmac_drv_close(queue_t *, int, cred_t *);
static int softmac_drv_wput(queue_t *, mblk_t *);
static int softmac_drv_wsrv(queue_t *);

static int softmac_attach(dev_info_t *, ddi_attach_cmd_t);
static int softmac_detach(dev_info_t *, ddi_detach_cmd_t);
static int softmac_info(dev_info_t *, ddi_info_cmd_t, void *, void **);

static struct module_info softmac_modinfo = {
        0,
        SOFTMAC_DEV_NAME,
        0,
        INFPSZ,
        65536,
        1024
};

/*
 * hi-water mark is 1 because of the flow control mechanism implemented in
 * dld.  Refer to the comments in dld_str.c for details.
 */
static struct module_info softmac_dld_modinfo = {
        0,
        SOFTMAC_DEV_NAME,
        0,
        INFPSZ,
        1,
        0
};

static struct qinit softmac_urinit = {
        softmac_mod_rput,               /* qi_putp */
        NULL,                           /* qi_srvp */
        softmac_cmn_open,               /* qi_qopen */
        softmac_mod_close,              /* qi_qclose */
        NULL,                           /* qi_qadmin */
        &softmac_modinfo                /* qi_minfo */
};

static struct qinit softmac_uwinit = {
        softmac_mod_wput,               /* qi_putp */
        softmac_mod_wsrv,               /* qi_srvp */
        NULL,                           /* qi_qopen */
        NULL,                           /* qi_qclose */
        NULL,                           /* qi_qadmin */
        &softmac_modinfo                /* qi_minfo */
};

static struct streamtab softmac_tab = {
        &softmac_urinit,        /* st_rdinit */
        &softmac_uwinit         /* st_wrinit */
};

DDI_DEFINE_STREAM_OPS(softmac_ops, nulldev, nulldev, softmac_attach,
    softmac_detach, nodev, softmac_info, D_MP, &softmac_tab,
    ddi_quiesce_not_supported);

static struct qinit softmac_dld_r_qinit = {
        NULL, NULL, softmac_drv_open, softmac_drv_close, NULL,
        &softmac_dld_modinfo
};

static struct qinit softmac_dld_w_qinit = {
        softmac_drv_wput, softmac_drv_wsrv, NULL, NULL, NULL,
        &softmac_dld_modinfo
};

static struct fmodsw softmac_fmodsw = {
        SOFTMAC_DEV_NAME,
        &softmac_tab,
        D_MP
};

static struct modldrv softmac_modldrv = {
        &mod_driverops,
        "softmac driver",
        &softmac_ops
};

static struct modlstrmod softmac_modlstrmod = {
        &mod_strmodops,
        "softmac module",
        &softmac_fmodsw
};

static struct modlinkage softmac_modlinkage = {
        MODREV_1,
        &softmac_modlstrmod,
        &softmac_modldrv,
        NULL
};

static void softmac_dedicated_rx(void *, mac_resource_handle_t, mblk_t *,
    mac_header_info_t *);

/*ARGSUSED*/
static int
softmac_upper_constructor(void *buf, void *arg, int kmflag)
{
        softmac_upper_t *sup = buf;

        bzero(buf, sizeof (softmac_upper_t));

        mutex_init(&sup->su_mutex, NULL, MUTEX_DEFAULT, NULL);
        cv_init(&sup->su_cv, NULL, CV_DEFAULT, NULL);
        mutex_init(&sup->su_disp_mutex, NULL, MUTEX_DEFAULT, NULL);
        cv_init(&sup->su_disp_cv, NULL, CV_DEFAULT, NULL);
        list_create(&sup->su_req_list, sizeof (softmac_switch_req_t),
            offsetof(softmac_switch_req_t, ssq_req_list_node));
        return (0);
}

/*ARGSUSED*/
static void
softmac_upper_destructor(void *buf, void *arg)
{
        softmac_upper_t *sup = buf;

        ASSERT(sup->su_slp == NULL);
        ASSERT(sup->su_pending_head == NULL && sup->su_pending_tail == NULL);
        ASSERT(!sup->su_dlpi_pending);
        ASSERT(!sup->su_active);
        ASSERT(!sup->su_closing);
        ASSERT(sup->su_tx_flow_mp == NULL);
        ASSERT(sup->su_tx_inprocess == 0);
        ASSERT(sup->su_mode == SOFTMAC_UNKNOWN);
        ASSERT(!sup->su_tx_busy);
        ASSERT(!sup->su_bound);
        ASSERT(!sup->su_taskq_scheduled);
        ASSERT(sup->su_tx_notify_func == NULL);
        ASSERT(sup->su_tx_notify_arg == NULL);
        ASSERT(list_is_empty(&sup->su_req_list));

        list_destroy(&sup->su_req_list);
        mutex_destroy(&sup->su_mutex);
        cv_destroy(&sup->su_cv);
        mutex_destroy(&sup->su_disp_mutex);
        cv_destroy(&sup->su_disp_cv);
}

int
_init(void)
{
        int     err;

        mac_init_ops(NULL, SOFTMAC_DEV_NAME);
        softmac_init();

        softmac_upper_cachep = kmem_cache_create("softmac_upper_cache",
            sizeof (softmac_upper_t), 0, softmac_upper_constructor,
            softmac_upper_destructor, NULL, NULL, NULL, 0);
        ASSERT(softmac_upper_cachep != NULL);

        if ((err = mod_install(&softmac_modlinkage)) != 0) {
                softmac_fini();
                return (err);
        }

        return (0);
}

int
_fini(void)
{
        int err;

        if (softmac_busy())
                return (EBUSY);

        if ((err = mod_remove(&softmac_modlinkage)) != 0)
                return (err);

        kmem_cache_destroy(softmac_upper_cachep);
        softmac_fini();

        return (0);
}

int
_info(struct modinfo *modinfop)
{
        return (mod_info(&softmac_modlinkage, modinfop));
}

static int
softmac_cmn_open(queue_t *rq, dev_t *devp, int flag, int sflag, cred_t *credp)
{
        softmac_lower_t *slp;
        /*
         * This is a self-cloning driver so that each queue should only
         * get opened once.
         */
        if (rq->q_ptr != NULL)
                return (EBUSY);

        if (sflag == MODOPEN) {
                /*
                 * This is the softmac module pushed over an underlying
                 * legacy device.  Initialize the lower structure.
                 */
                if ((slp = kmem_zalloc(sizeof (*slp), KM_NOSLEEP)) == NULL)
                        return (ENOMEM);

                slp->sl_wq = WR(rq);
                cv_init(&slp->sl_cv, NULL, CV_DRIVER, NULL);
                mutex_init(&slp->sl_mutex, NULL, MUTEX_DRIVER, NULL);
                slp->sl_pending_prim = DL_PRIM_INVAL;
                rq->q_ptr = WR(rq)->q_ptr = slp;
                qprocson(rq);
                return (0);
        }

        /*
         * Regular device open of a softmac DLPI node.  We modify
         * the queues' q_qinfo pointer such that all future STREAMS
         * operations will go through another set of entry points
         */
        rq->q_qinfo = &softmac_dld_r_qinit;
        WR(rq)->q_qinfo = &softmac_dld_w_qinit;
        return (softmac_drv_open(rq, devp, flag, sflag, credp));
}

/* ARGSUSED */
static int
softmac_mod_close(queue_t *rq, int flags __unused, cred_t *credp __unused)
{
        softmac_lower_t *slp = rq->q_ptr;

        /*
         * Call the appropriate delete routine depending on whether this is
         * a module or device.
         */
        ASSERT(WR(rq)->q_next != NULL);

        qprocsoff(rq);

        slp->sl_softmac = NULL;
        slp->sl_lh = NULL;

        ASSERT(slp->sl_ack_mp == NULL);
        ASSERT(slp->sl_pending_prim == DL_PRIM_INVAL);
        ASSERT(slp->sl_pending_ioctl == B_FALSE);

        cv_destroy(&slp->sl_cv);
        mutex_destroy(&slp->sl_mutex);

        kmem_free(slp, sizeof (*slp));
        return (0);
}

static int
softmac_mod_rput(queue_t *rq, mblk_t *mp)
{
        softmac_lower_t         *slp = rq->q_ptr;
        softmac_lower_rxinfo_t  *rxinfo;
        union DL_primitives     *dlp;

        /*
         * This is the softmac module.
         */
        ASSERT(WR(rq)->q_next != NULL);
        ASSERT((mp->b_next == NULL) && (mp->b_prev == NULL));

        switch (DB_TYPE(mp)) {
        case M_DATA: {

                /*
                 * If sl_rxinfo is non-NULL. This is dedicated-lower-stream
                 * created for fastpath. Directly call the rx callback.
                 */
                if ((rxinfo = slp->sl_rxinfo) != NULL) {
                        rxinfo->slr_rx(rxinfo->slr_arg, NULL, mp, NULL);
                        break;
                }

                /*
                 * A shared-lower-stream. Some driver starts to send up
                 * packets even it not in the DL_IDLE state, where
                 * sl_softmac is not set yet. Drop the packet in this case.
                 */
                if (slp->sl_softmac == NULL) {
                        freemsg(mp);
                        return (0);
                }

                /*
                 * If this message is looped back from the legacy devices,
                 * drop it as the Nemo framework will be responsible for
                 * looping it back by the mac_txloop() function.
                 */
                if (mp->b_flag & MSGNOLOOP) {
                        freemsg(mp);
                        return (0);
                }

                /*
                 * This is the most common case.
                 */
                if (DB_REF(mp) == 1) {
                        ASSERT(slp->sl_softmac != NULL);
                        mac_rx(slp->sl_softmac->smac_mh, NULL, mp);
                        return (0);
                } else {
                        softmac_rput_process_data(slp, mp);
                }
                break;
        }
        case M_PROTO:
        case M_PCPROTO:
                if (MBLKL(mp) < sizeof (dlp->dl_primitive)) {
                        freemsg(mp);
                        break;
                }
                dlp = (union DL_primitives *)mp->b_rptr;
                if (dlp->dl_primitive == DL_UNITDATA_IND) {

                        if ((rxinfo = slp->sl_rxinfo) != NULL) {
                                softmac_dedicated_rx(slp->sl_sup, NULL, mp,
                                    NULL);
                                break;
                        }

                        cmn_err(CE_WARN, "got unexpected %s message",
                            dl_primstr(DL_UNITDATA_IND));
                        freemsg(mp);
                        break;
                }
                /*FALLTHROUGH*/
        default:
                softmac_rput_process_notdata(rq, slp->sl_sup, mp);
                break;
        }
        return (0);
}

static int
softmac_mod_wput(queue_t *wq, mblk_t *mp)
{
        /*
         * This is the softmac module
         */
        ASSERT(wq->q_next != NULL);

        switch (DB_TYPE(mp)) {
        case M_IOCTL: {
                struct iocblk           *ioc = (struct iocblk *)mp->b_rptr;

                switch (ioc->ioc_cmd) {
                case SMAC_IOC_START: {
                        softmac_lower_t         *slp = wq->q_ptr;
                        smac_ioc_start_t        *arg;

                        if (ioc->ioc_count != sizeof (*arg)) {
                                miocnak(wq, mp, 0, EINVAL);
                                break;
                        }

                        /*
                         * Assign the devname and perstream handle of the
                         * specific lower stream and return it as a part
                         * of the ioctl.
                         */
                        arg = (smac_ioc_start_t *)mp->b_cont->b_rptr;
                        arg->si_slp = slp;
                        miocack(wq, mp, sizeof (*arg), 0);
                        break;
                }
                default:
                        miocnak(wq, mp, 0, EINVAL);
                        break;
                }
                break;
        }
        default:
                freemsg(mp);
                break;
        }
        return (0);
}

static int
softmac_mod_wsrv(queue_t *wq)
{
        softmac_lower_t *slp = wq->q_ptr;

        /*
         * This is the softmac module
         */
        ASSERT(wq->q_next != NULL);

        /*
         * Inform that the tx resource is available; mac_tx_update() will
         * inform all the upper streams sharing this lower stream.
         */
        if (slp->sl_sup != NULL)
                qenable(slp->sl_sup->su_wq);
        else if (slp->sl_softmac != NULL)
                mac_tx_update(slp->sl_softmac->smac_mh);
        return (0);
}

static int
softmac_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
{
        ASSERT(ddi_get_instance(dip) == 0);

        if (cmd != DDI_ATTACH)
                return (DDI_FAILURE);

        softmac_dip = dip;

        return (DDI_SUCCESS);
}

/* ARGSUSED */
static int
softmac_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
{
        if (cmd != DDI_DETACH)
                return (DDI_FAILURE);

        softmac_dip = NULL;
        return (DDI_SUCCESS);
}

/* ARGSUSED */
static int
softmac_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
{
        switch (infocmd) {
        case DDI_INFO_DEVT2DEVINFO:
                if (softmac_dip != NULL) {
                        *result = softmac_dip;
                        return (DDI_SUCCESS);
                }
                break;

        case DDI_INFO_DEVT2INSTANCE:
                *result = NULL;
                return (DDI_SUCCESS);

        }

        return (DDI_FAILURE);
}

/*ARGSUSED*/
static void
softmac_dedicated_rx(void *arg, mac_resource_handle_t mrh, mblk_t *mp,
    mac_header_info_t *mhip)
{
        queue_t *rq = ((softmac_upper_t *)arg)->su_rq;

        if (canputnext(rq))
                putnext(rq, mp);
        else
                freemsg(mp);
}

/*ARGSUSED*/
static int
softmac_drv_open(queue_t *rq, dev_t *devp, int flag, int sflag, cred_t *credp)
{
        softmac_upper_t *sup = NULL;
        softmac_t       *softmac;
        int             err = 0;

        /*
         * This is a softmac device created for a legacy device, find the
         * associated softmac and initialize the softmac_upper_t structure.
         */
        if ((err = softmac_hold(*devp, &softmac)) != 0)
                return (err);

        sup = kmem_cache_alloc(softmac_upper_cachep, KM_NOSLEEP);
        if (sup == NULL) {
                err = ENOMEM;
                goto fail;
        }

        ASSERT(list_is_empty(&sup->su_req_list));

        if ((sup->su_tx_flow_mp = allocb(1, BPRI_HI)) == NULL) {
                err = ENOMEM;
                goto fail;
        }

        sup->su_rq = rq;
        sup->su_wq = WR(rq);
        sup->su_softmac = softmac;
        sup->su_mode = SOFTMAC_UNKNOWN;

        sup->su_rxinfo.slr_arg = sup;
        sup->su_rxinfo.slr_rx = softmac_dedicated_rx;
        sup->su_direct_rxinfo.slr_arg = sup;
        sup->su_direct_rxinfo.slr_rx = softmac_dedicated_rx;

        if ((err = dld_str_open(rq, devp, sup)) != 0) {
                freeb(sup->su_tx_flow_mp);
                sup->su_tx_flow_mp = NULL;
                goto fail;
        }

        return (0);

fail:
        if (sup != NULL)
                kmem_cache_free(softmac_upper_cachep, sup);
        softmac_rele(softmac);
        return (err);
}

/* ARGSUSED */
static int
softmac_drv_close(queue_t *rq, int flags __unused, cred_t *credp __unused)
{
        softmac_upper_t *sup = dld_str_private(rq);
        softmac_t       *softmac = sup->su_softmac;

        ASSERT(WR(rq)->q_next == NULL);

        qprocsoff(rq);

        ASSERT(sup->su_tx_inprocess == 0);

        /*
         * Wait until the pending request are processed by the worker thread.
         */
        mutex_enter(&sup->su_disp_mutex);
        sup->su_closing = B_TRUE;
        while (sup->su_dlpi_pending)
                cv_wait(&sup->su_disp_cv, &sup->su_disp_mutex);
        mutex_exit(&sup->su_disp_mutex);

        softmac_upperstream_close(sup);

        if (sup->su_tx_flow_mp != NULL) {
                freeb(sup->su_tx_flow_mp);
                sup->su_tx_flow_mp = NULL;
        }

        if (sup->su_active) {
                mutex_enter(&softmac->smac_active_mutex);
                softmac->smac_nactive--;
                mutex_exit(&softmac->smac_active_mutex);
                sup->su_active = B_FALSE;
        }

        sup->su_bound = B_FALSE;
        sup->su_softmac = NULL;
        sup->su_closing = B_FALSE;

        kmem_cache_free(softmac_upper_cachep, sup);

        softmac_rele(softmac);
        return (dld_str_close(rq));
}

static int
softmac_drv_wput(queue_t *wq, mblk_t *mp)
{
        softmac_upper_t *sup = dld_str_private(wq);
        t_uscalar_t     prim;

        ASSERT(wq->q_next == NULL);

        switch (DB_TYPE(mp)) {
        case M_DATA:
                softmac_wput_data(sup, mp);
                break;
        case M_PROTO:
        case M_PCPROTO:

                if (MBLKL(mp) < sizeof (t_uscalar_t)) {
                        freemsg(mp);
                        return (0);
                }

                prim = ((union DL_primitives *)mp->b_rptr)->dl_primitive;
                if (prim == DL_UNITDATA_REQ) {
                        softmac_wput_data(sup, mp);
                        return (0);
                }

                softmac_wput_nondata(sup, mp);
                break;
        default:
                softmac_wput_nondata(sup, mp);
                break;
        }
        return (0);
}

static int
softmac_drv_wsrv(queue_t *wq)
{
        softmac_upper_t *sup = dld_str_private(wq);

        ASSERT(wq->q_next == NULL);

        mutex_enter(&sup->su_mutex);
        if (sup->su_mode != SOFTMAC_FASTPATH) {
                /*
                 * Bump su_tx_inprocess so that su_mode won't change.
                 */
                sup->su_tx_inprocess++;
                mutex_exit(&sup->su_mutex);
                (void) dld_wsrv(wq);
                mutex_enter(&sup->su_mutex);
                if (--sup->su_tx_inprocess == 0)
                        cv_signal(&sup->su_cv);
        } else if (sup->su_tx_busy && SOFTMAC_CANPUTNEXT(sup->su_slp->sl_wq)) {
                /*
                 * The flow-conctol of the dedicated-lower-stream is
                 * relieved. If DLD_CAPAB_DIRECT is enabled, call tx_notify
                 * callback to relieve the flow-control of the specific client,
                 * otherwise relieve the flow-control of all the upper-stream
                 * using the traditional STREAM mechanism.
                 */
                if (sup->su_tx_notify_func != NULL) {
                        sup->su_tx_inprocess++;
                        mutex_exit(&sup->su_mutex);
                        sup->su_tx_notify_func(sup->su_tx_notify_arg,
                            (mac_tx_cookie_t)sup);
                        mutex_enter(&sup->su_mutex);
                        if (--sup->su_tx_inprocess == 0)
                                cv_signal(&sup->su_cv);
                }
                ASSERT(sup->su_tx_flow_mp == NULL);
                VERIFY((sup->su_tx_flow_mp = getq(wq)) != NULL);
                sup->su_tx_busy = B_FALSE;
        }
        mutex_exit(&sup->su_mutex);
        return (0);
}