/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2013 Chelsio Communications, Inc.
 * All rights reserved.
 * Written by: Navdeep Parhar <np@FreeBSD.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#include "opt_inet.h"
#include "opt_inet6.h"

#include <sys/param.h>
#include <sys/eventhandler.h>
#include <sys/lock.h>
#include <sys/types.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sx.h>
#include <net/bpf.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_clone.h>
#include <net/if_types.h>

#include "common/common.h"
#include "common/t4_msg.h"
#include "common/t4_regs.h"
#include "t4_ioctl.h"

/*
 * Locking notes
 * =============
 *
 * An interface cloner is registered during mod_load and it can be used to
 * create or destroy the tracing ifnet for an adapter at any time.  It is
 * possible for the cloned interface to outlive the adapter (adapter disappears
 * in t4_detach but the tracing ifnet may live till mod_unload when removal of
 * the cloner finally destroys any remaining cloned interfaces).  When tracing
 * filters are active, this ifnet is also receiving data.  There are potential
 * bad races between ifnet create, ifnet destroy, ifnet rx, ifnet ioctl,
 * cxgbe_detach/t4_detach, mod_unload.
 *
 * a) The driver selects an iq for tracing (sc->traceq) inside a synch op.  The
 *    iq is destroyed inside a synch op too (and sc->traceq updated).
 * b) The cloner looks for an adapter that matches the name of the ifnet it's
 *    been asked to create, starts a synch op on that adapter, and proceeds only
 *    if the adapter has a tracing iq.
 * c) The cloned ifnet and the adapter are coupled to each other via
 *    ifp->if_softc and sc->ifp.  These can be modified only with the global
 *    t4_trace_lock sx as well as the sc->ifp_lock mutex held.  Holding either
 *    of these will prevent any change.
 *
 * The order in which all the locks involved should be acquired are:
 * t4_list_lock
 * adapter lock
 * (begin synch op and let go of the above two)
 * t4_trace_lock
 * sc->ifp_lock
 */

static struct sx t4_trace_lock;
static const char *t4_cloner_name = "tXnex";
static struct if_clone *t4_cloner;

/* tracer ifnet routines.  mostly no-ops. */
static void tracer_init(void *);
static int tracer_ioctl(if_t, unsigned long, caddr_t);
static int tracer_transmit(if_t, struct mbuf *);
static void tracer_qflush(if_t);
static int tracer_media_change(if_t);
static void tracer_media_status(if_t, struct ifmediareq *);

/* match name (request/response) */
struct match_rr {
        const char *name;
        int lock;       /* set to 1 to returned sc locked. */
        struct adapter *sc;
        int rc;
};

static void
match_name(struct adapter *sc, void *arg)
{
        struct match_rr *mrr = arg;

        if (strcmp(device_get_nameunit(sc->dev), mrr->name) != 0)
                return;

        KASSERT(mrr->sc == NULL, ("%s: multiple matches (%p, %p) for %s",
            __func__, mrr->sc, sc, mrr->name));

        mrr->sc = sc;
        if (mrr->lock)
                mrr->rc = begin_synchronized_op(mrr->sc, NULL, 0, "t4clon");
        else
                mrr->rc = 0;
}

static int
t4_cloner_match(struct if_clone *ifc, const char *name)
{

        if (strncmp(name, "t4nex", 5) != 0 && strncmp(name, "t5nex", 5) != 0 &&
            strncmp(name, "t6nex", 5) != 0 && strncmp(name, "chnex", 5) != 0)
                return (0);
        if (name[5] < '0' || name[5] > '9')
                return (0);
        return (1);
}

static int
t4_cloner_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
{
        struct match_rr mrr;
        struct adapter *sc;
        if_t ifp;
        int rc;
        const uint8_t lla[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};

        mrr.name = name;
        mrr.lock = 1;
        mrr.sc = NULL;
        mrr.rc = ENOENT;
        t4_iterate(match_name, &mrr);

        if (mrr.rc != 0)
                return (mrr.rc);
        sc = mrr.sc;

        KASSERT(sc != NULL, ("%s: name (%s) matched but softc is NULL",
            __func__, name));
        ASSERT_SYNCHRONIZED_OP(sc);

        sx_xlock(&t4_trace_lock);

        if (sc->ifp != NULL) {
                rc = EEXIST;
                goto done;
        }
        if (sc->traceq < 0) {
                rc = EAGAIN;
                goto done;
        }

        ifp = if_alloc(IFT_ETHER);
        /* Note that if_xname is identical to the nexus nameunit */
        if_initname(ifp, name, -1);
        if_setdname(ifp, t4_cloner_name);
        if_setinitfn(ifp, tracer_init);
        if_setflags(ifp, IFF_SIMPLEX | IFF_DRV_RUNNING);
        if_setioctlfn(ifp, tracer_ioctl);
        if_settransmitfn(ifp, tracer_transmit);
        if_setqflushfn(ifp, tracer_qflush);
        if_setcapabilities(ifp, IFCAP_JUMBO_MTU | IFCAP_VLAN_MTU);
        ifmedia_init(&sc->media, IFM_IMASK, tracer_media_change,
            tracer_media_status);
        ifmedia_add(&sc->media, IFM_ETHER | IFM_FDX | IFM_NONE, 0, NULL);
        ifmedia_set(&sc->media, IFM_ETHER | IFM_FDX | IFM_NONE);
        sx_xunlock(&t4_trace_lock);
        ether_ifattach(ifp, lla);
        sx_xlock(&t4_trace_lock);
        mtx_lock(&sc->ifp_lock);
        if_setsoftc(ifp, sc);
        sc->ifp = ifp;
        mtx_unlock(&sc->ifp_lock);
        rc = 0;
done:
        sx_xunlock(&t4_trace_lock);
        end_synchronized_op(sc, 0);
        return (rc);
}

static int
t4_cloner_destroy(struct if_clone *ifc, if_t ifp)
{
        struct adapter *sc;

        sx_xlock(&t4_trace_lock);
        sc = if_getsoftc(ifp);
        if (sc != NULL) {
                mtx_lock(&sc->ifp_lock);
                sc->ifp = NULL;
                if_setsoftc(ifp, NULL);
                mtx_unlock(&sc->ifp_lock);
                ifmedia_removeall(&sc->media);
        }
        sx_xunlock(&t4_trace_lock);
        ether_ifdetach(ifp);
        if_free(ifp);

        return (0);
}

void
t4_tracer_modload(void)
{

        sx_init(&t4_trace_lock, "T4/T5 tracer lock");
        t4_cloner = if_clone_advanced(t4_cloner_name, 0, t4_cloner_match,
            t4_cloner_create, t4_cloner_destroy);
}

void
t4_tracer_modunload(void)
{

        if (t4_cloner != NULL) {
                /*
                 * The module is being unloaded so the nexus drivers have
                 * detached.  The tracing interfaces can not outlive the nexus
                 * (ifp->if_softc is the nexus) and must have been destroyed
                 * already.  XXX: but if_clone is opaque to us and we can't
                 * assert LIST_EMPTY(&t4_cloner->ifc_iflist) at this time.
                 */
                if_clone_detach(t4_cloner);
        }
        sx_destroy(&t4_trace_lock);
}

void
t4_tracer_port_detach(struct adapter *sc)
{

        sx_xlock(&t4_trace_lock);
        if (sc->ifp != NULL) {
                mtx_lock(&sc->ifp_lock);
                if_setsoftc(sc->ifp, NULL);
                sc->ifp = NULL;
                mtx_unlock(&sc->ifp_lock);
        }
        ifmedia_removeall(&sc->media);
        sx_xunlock(&t4_trace_lock);
}

int
t4_get_tracer(struct adapter *sc, struct t4_tracer *t)
{
        int rc, i, enabled;
        struct trace_params tp;

        if (t->idx >= NTRACE) {
                t->idx = 0xff;
                t->enabled = 0;
                t->valid = 0;
                return (0);
        }

        rc = begin_synchronized_op(sc, NULL, HOLD_LOCK | SLEEP_OK | INTR_OK,
            "t4gett");
        if (rc)
                return (rc);

        if (hw_off_limits(sc)) {
                rc = ENXIO;
                goto done;
        }

        for (i = t->idx; i < NTRACE; i++) {
                if (isset(&sc->tracer_valid, t->idx)) {
                        t4_get_trace_filter(sc, &tp, i, &enabled);
                        t->idx = i;
                        t->enabled = enabled;
                        t->valid = 1;
                        memcpy(&t->tp.data[0], &tp.data[0], sizeof(t->tp.data));
                        memcpy(&t->tp.mask[0], &tp.mask[0], sizeof(t->tp.mask));
                        t->tp.snap_len = tp.snap_len;
                        t->tp.min_len = tp.min_len;
                        t->tp.skip_ofst = tp.skip_ofst;
                        t->tp.skip_len = tp.skip_len;
                        t->tp.invert = tp.invert;

                        /* convert channel to port iff 0 <= port < 8. */
                        if (tp.port < 4)
                                t->tp.port = sc->chan_map[tp.port];
                        else if (tp.port < 8)
                                t->tp.port = sc->chan_map[tp.port - 4] + 4;
                        else
                                t->tp.port = tp.port;

                        goto done;
                }
        }

        t->idx = 0xff;
        t->enabled = 0;
        t->valid = 0;
done:
        end_synchronized_op(sc, LOCK_HELD);

        return (rc);
}

int
t4_set_tracer(struct adapter *sc, struct t4_tracer *t)
{
        int rc;
        struct trace_params tp, *tpp;

        if (t->idx >= NTRACE)
                return (EINVAL);

        rc = begin_synchronized_op(sc, NULL, HOLD_LOCK | SLEEP_OK | INTR_OK,
            "t4sett");
        if (rc)
                return (rc);

        if (hw_off_limits(sc)) {
                rc = ENXIO;
                goto done;
        }

        /*
         * If no tracing filter is specified this time then check if the filter
         * at the index is valid anyway because it was set previously.  If so
         * then this is a legitimate enable/disable operation.
         */
        if (t->valid == 0) {
                if (isset(&sc->tracer_valid, t->idx))
                        tpp = NULL;
                else
                        rc = EINVAL;
                goto done;
        }

        if (t->tp.port > 19 || t->tp.snap_len > 9600 ||
            t->tp.min_len > M_TFMINPKTSIZE || t->tp.skip_len > M_TFLENGTH ||
            t->tp.skip_ofst > M_TFOFFSET) {
                rc = EINVAL;
                goto done;
        }

        memcpy(&tp.data[0], &t->tp.data[0], sizeof(tp.data));
        memcpy(&tp.mask[0], &t->tp.mask[0], sizeof(tp.mask));
        tp.snap_len = t->tp.snap_len;
        tp.min_len = t->tp.min_len;
        tp.skip_ofst = t->tp.skip_ofst;
        tp.skip_len = t->tp.skip_len;
        tp.invert = !!t->tp.invert;

        /* convert port to channel iff 0 <= port < 8. */
        if (t->tp.port < 4) {
                if (sc->port[t->tp.port] == NULL) {
                        rc = EINVAL;
                        goto done;
                }
                tp.port = sc->port[t->tp.port]->tx_chan;
        } else if (t->tp.port < 8) {
                if (sc->port[t->tp.port - 4] == NULL) {
                        rc = EINVAL;
                        goto done;
                }
                tp.port = sc->port[t->tp.port - 4]->tx_chan + 4;
        } else
                tp.port = t->tp.port;
        tpp = &tp;
done:
        if (rc == 0) {
                rc = -t4_set_trace_filter(sc, tpp, t->idx, t->enabled);
                if (rc == 0) {
                        if (t->enabled) {
                                setbit(&sc->tracer_valid, t->idx);
                                if (sc->tracer_enabled == 0) {
                                        t4_set_reg_field(sc, A_MPS_TRC_CFG,
                                            F_TRCEN, F_TRCEN);
                                }
                                setbit(&sc->tracer_enabled, t->idx);
                        } else {
                                clrbit(&sc->tracer_enabled, t->idx);
                                if (sc->tracer_enabled == 0) {
                                        t4_set_reg_field(sc, A_MPS_TRC_CFG,
                                            F_TRCEN, 0);
                                }
                        }
                }
        }
        end_synchronized_op(sc, LOCK_HELD);

        return (rc);
}

int
t4_trace_pkt(struct sge_iq *iq, const struct rss_header *rss, struct mbuf *m)
{
        struct adapter *sc = iq->adapter;
        if_t ifp;

        KASSERT(m != NULL, ("%s: no payload with opcode %02x", __func__,
            rss->opcode));

        mtx_lock(&sc->ifp_lock);
        ifp = sc->ifp;
        if (sc->ifp) {
                m_adj(m, sizeof(struct cpl_trace_pkt));
                m->m_pkthdr.rcvif = ifp;
                ETHER_BPF_MTAP(ifp, m);
        }
        mtx_unlock(&sc->ifp_lock);
        m_freem(m);

        return (0);
}

int
t5_trace_pkt(struct sge_iq *iq, const struct rss_header *rss, struct mbuf *m)
{
        struct adapter *sc = iq->adapter;
        if_t ifp;

        KASSERT(m != NULL, ("%s: no payload with opcode %02x", __func__,
            rss->opcode));

        mtx_lock(&sc->ifp_lock);
        ifp = sc->ifp;
        if (ifp != NULL) {
                m_adj(m, sizeof(struct cpl_t5_trace_pkt));
                m->m_pkthdr.rcvif = ifp;
                ETHER_BPF_MTAP(ifp, m);
        }
        mtx_unlock(&sc->ifp_lock);
        m_freem(m);

        return (0);
}


static void
tracer_init(void *arg)
{

        return;
}

static int
tracer_ioctl(if_t ifp, unsigned long cmd, caddr_t data)
{
        int rc = 0;
        struct adapter *sc;
        struct ifreq *ifr = (struct ifreq *)data;

        switch (cmd) {
        case SIOCSIFMTU:
        case SIOCSIFFLAGS:
        case SIOCADDMULTI:
        case SIOCDELMULTI:
        case SIOCSIFCAP:
                break;
        case SIOCSIFMEDIA:
        case SIOCGIFMEDIA:
        case SIOCGIFXMEDIA:
                sx_xlock(&t4_trace_lock);
                sc = if_getsoftc(ifp);
                if (sc == NULL)
                        rc = EIO;
                else
                        rc = ifmedia_ioctl(ifp, ifr, &sc->media, cmd);
                sx_xunlock(&t4_trace_lock);
                break;
        default:
                rc = ether_ioctl(ifp, cmd, data);
        }

        return (rc);
}

static int
tracer_transmit(if_t ifp, struct mbuf *m)
{

        m_freem(m);
        return (0);
}

static void
tracer_qflush(if_t ifp)
{

        return;
}

static int
tracer_media_change(if_t ifp)
{

        return (EOPNOTSUPP);
}

static void
tracer_media_status(if_t ifp, struct ifmediareq *ifmr)
{

        ifmr->ifm_status = IFM_AVALID | IFM_ACTIVE;

        return;
}