/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2005 Pawel Jakub Dawidek <pjd@FreeBSD.org>
 * All rights reserved.
 *
 * 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 AUTHORS 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 AUTHORS 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/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/bio.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <vm/uma.h>
#include <geom/geom.h>
#include <geom/geom_dbg.h>
#include <geom/shsec/g_shsec.h>

FEATURE(geom_shsec, "GEOM shared secret device support");

static MALLOC_DEFINE(M_SHSEC, "shsec_data", "GEOM_SHSEC Data");

static uma_zone_t g_shsec_zone;

static int g_shsec_destroy(struct g_shsec_softc *sc, boolean_t force);
static int g_shsec_destroy_geom(struct gctl_req *req, struct g_class *mp,
    struct g_geom *gp);

static g_taste_t g_shsec_taste;
static g_ctl_req_t g_shsec_config;
static g_dumpconf_t g_shsec_dumpconf;
static g_init_t g_shsec_init;
static g_fini_t g_shsec_fini;

struct g_class g_shsec_class = {
        .name = G_SHSEC_CLASS_NAME,
        .version = G_VERSION,
        .ctlreq = g_shsec_config,
        .taste = g_shsec_taste,
        .destroy_geom = g_shsec_destroy_geom,
        .init = g_shsec_init,
        .fini = g_shsec_fini
};

SYSCTL_DECL(_kern_geom);
static SYSCTL_NODE(_kern_geom, OID_AUTO, shsec, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "GEOM_SHSEC stuff");
static u_int g_shsec_debug;
SYSCTL_UINT(_kern_geom_shsec, OID_AUTO, debug, CTLFLAG_RWTUN, &g_shsec_debug, 0,
    "Debug level");
static u_long g_shsec_maxmem;
SYSCTL_ULONG(_kern_geom_shsec, OID_AUTO, maxmem,
    CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &g_shsec_maxmem,
    0, "Maximum memory that can be allocated for I/O (in bytes)");
static u_int g_shsec_alloc_failed = 0;
SYSCTL_UINT(_kern_geom_shsec, OID_AUTO, alloc_failed, CTLFLAG_RD,
    &g_shsec_alloc_failed, 0, "How many times I/O allocation failed");

/*
 * Greatest Common Divisor.
 */
static u_int
gcd(u_int a, u_int b)
{
        u_int c;

        while (b != 0) {
                c = a;
                a = b;
                b = (c % b);
        }
        return (a);
}

/*
 * Least Common Multiple.
 */
static u_int
lcm(u_int a, u_int b)
{

        return ((a * b) / gcd(a, b));
}

static void
g_shsec_init(struct g_class *mp __unused)
{

        g_shsec_maxmem = maxphys * 100;
        TUNABLE_ULONG_FETCH("kern.geom.shsec.maxmem,", &g_shsec_maxmem);
        g_shsec_zone = uma_zcreate("g_shsec_zone", maxphys, NULL, NULL, NULL,
            NULL, 0, 0);
        g_shsec_maxmem -= g_shsec_maxmem % maxphys;
        uma_zone_set_max(g_shsec_zone, g_shsec_maxmem / maxphys);
}

static void
g_shsec_fini(struct g_class *mp __unused)
{

        uma_zdestroy(g_shsec_zone);
}

/*
 * Return the number of valid disks.
 */
static u_int
g_shsec_nvalid(struct g_shsec_softc *sc)
{
        u_int i, no;

        no = 0;
        for (i = 0; i < sc->sc_ndisks; i++) {
                if (sc->sc_disks[i] != NULL)
                        no++;
        }

        return (no);
}

static void
g_shsec_remove_disk(struct g_consumer *cp)
{
        struct g_shsec_softc *sc;
        u_int no;

        KASSERT(cp != NULL, ("Non-valid disk in %s.", __func__));
        sc = (struct g_shsec_softc *)cp->private;
        KASSERT(sc != NULL, ("NULL sc in %s.", __func__));
        no = cp->index;

        G_SHSEC_DEBUG(0, "Disk %s removed from %s.", cp->provider->name,
            sc->sc_name);

        sc->sc_disks[no] = NULL;
        if (sc->sc_provider != NULL) {
                g_wither_provider(sc->sc_provider, ENXIO);
                sc->sc_provider = NULL;
                G_SHSEC_DEBUG(0, "Device %s removed.", sc->sc_name);
        }

        if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
                return;
        g_detach(cp);
        g_destroy_consumer(cp);
}

static void
g_shsec_orphan(struct g_consumer *cp)
{
        struct g_shsec_softc *sc;
        struct g_geom *gp;

        g_topology_assert();
        gp = cp->geom;
        sc = gp->softc;
        if (sc == NULL)
                return;

        g_shsec_remove_disk(cp);
        /* If there are no valid disks anymore, remove device. */
        if (LIST_EMPTY(&gp->consumer))
                g_shsec_destroy(sc, 1);
}

static int
g_shsec_access(struct g_provider *pp, int dr, int dw, int de)
{
        struct g_consumer *cp1, *cp2, *tmp;
        struct g_shsec_softc *sc;
        struct g_geom *gp;
        int error;

        gp = pp->geom;
        sc = gp->softc;

        /* On first open, grab an extra "exclusive" bit */
        if (pp->acr == 0 && pp->acw == 0 && pp->ace == 0)
                de++;
        /* ... and let go of it on last close */
        if ((pp->acr + dr) == 0 && (pp->acw + dw) == 0 && (pp->ace + de) == 0)
                de--;

        error = ENXIO;
        LIST_FOREACH_SAFE(cp1, &gp->consumer, consumer, tmp) {
                error = g_access(cp1, dr, dw, de);
                if (error != 0)
                        goto fail;
                if (cp1->acr == 0 && cp1->acw == 0 && cp1->ace == 0 &&
                    cp1->flags & G_CF_ORPHAN) {
                        g_detach(cp1);
                        g_destroy_consumer(cp1);
                }
        }

        /* If there are no valid disks anymore, remove device. */
        if (LIST_EMPTY(&gp->consumer))
                g_shsec_destroy(sc, 1);

        return (error);

fail:
        /* If we fail here, backout all previous changes. */
        LIST_FOREACH(cp2, &gp->consumer, consumer) {
                if (cp1 == cp2)
                        break;
                g_access(cp2, -dr, -dw, -de);
        }
        return (error);
}

static void
g_shsec_xor1(uint32_t *src, uint32_t *dst, ssize_t len)
{

        for (; len > 0; len -= sizeof(uint32_t), dst++)
                *dst = *dst ^ *src++;
        KASSERT(len == 0, ("len != 0 (len=%zd)", len));
}

static void
g_shsec_done(struct bio *bp)
{
        struct bio *pbp;

        pbp = bp->bio_parent;
        if (bp->bio_error == 0)
                G_SHSEC_LOGREQ(2, bp, "Request done.");
        else {
                G_SHSEC_LOGREQ(0, bp, "Request failed (error=%d).",
                    bp->bio_error);
                if (pbp->bio_error == 0)
                        pbp->bio_error = bp->bio_error;
        }
        if (pbp->bio_cmd == BIO_READ) {
                if ((pbp->bio_pflags & G_SHSEC_BFLAG_FIRST) != 0) {
                        bcopy(bp->bio_data, pbp->bio_data, pbp->bio_length);
                        pbp->bio_pflags = 0;
                } else {
                        g_shsec_xor1((uint32_t *)bp->bio_data,
                            (uint32_t *)pbp->bio_data,
                            (ssize_t)pbp->bio_length);
                }
        }
        if (bp->bio_data != NULL) {
                explicit_bzero(bp->bio_data, bp->bio_length);
                uma_zfree(g_shsec_zone, bp->bio_data);
        }
        g_destroy_bio(bp);
        pbp->bio_inbed++;
        if (pbp->bio_children == pbp->bio_inbed) {
                pbp->bio_completed = pbp->bio_length;
                g_io_deliver(pbp, pbp->bio_error);
        }
}

static void
g_shsec_xor2(uint32_t *rand, uint32_t *dst, ssize_t len)
{

        for (; len > 0; len -= sizeof(uint32_t), dst++) {
                *rand = arc4random();
                *dst = *dst ^ *rand++;
        }
        KASSERT(len == 0, ("len != 0 (len=%zd)", len));
}

static void
g_shsec_start(struct bio *bp)
{
        TAILQ_HEAD(, bio) queue = TAILQ_HEAD_INITIALIZER(queue);
        struct g_shsec_softc *sc;
        struct bio *cbp;
        uint32_t *dst;
        ssize_t len;
        u_int no;
        int error;

        sc = bp->bio_to->geom->softc;
        /*
         * If sc == NULL, provider's error should be set and g_shsec_start()
         * should not be called at all.
         */
        KASSERT(sc != NULL,
            ("Provider's error should be set (error=%d)(device=%s).",
            bp->bio_to->error, bp->bio_to->name));

        G_SHSEC_LOGREQ(2, bp, "Request received.");

        switch (bp->bio_cmd) {
        case BIO_READ:
        case BIO_WRITE:
        case BIO_FLUSH:
        case BIO_SPEEDUP:
                /*
                 * Only those requests are supported.
                 */
                break;
        case BIO_DELETE:
        case BIO_GETATTR:
                /* To which provider it should be delivered? */
        default:
                g_io_deliver(bp, EOPNOTSUPP);
                return;
        }

        /*
         * Allocate all bios first and calculate XOR.
         */
        dst = NULL;
        len = bp->bio_length;
        if (bp->bio_cmd == BIO_READ)
                bp->bio_pflags = G_SHSEC_BFLAG_FIRST;
        for (no = 0; no < sc->sc_ndisks; no++) {
                cbp = g_clone_bio(bp);
                if (cbp == NULL) {
                        error = ENOMEM;
                        goto failure;
                }
                TAILQ_INSERT_TAIL(&queue, cbp, bio_queue);

                /*
                 * Fill in the component buf structure.
                 */
                cbp->bio_done = g_shsec_done;
                cbp->bio_caller2 = sc->sc_disks[no];
                if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) {
                        cbp->bio_data = uma_zalloc(g_shsec_zone, M_NOWAIT);
                        if (cbp->bio_data == NULL) {
                                g_shsec_alloc_failed++;
                                error = ENOMEM;
                                goto failure;
                        }
                        if (bp->bio_cmd == BIO_WRITE) {
                                if (no == 0) {
                                        dst = (uint32_t *)cbp->bio_data;
                                        bcopy(bp->bio_data, dst, len);
                                } else {
                                        g_shsec_xor2((uint32_t *)cbp->bio_data,
                                            dst, len);
                                }
                        }
                }
        }
        /*
         * Fire off all allocated requests!
         */
        while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
                struct g_consumer *cp;

                TAILQ_REMOVE(&queue, cbp, bio_queue);
                cp = cbp->bio_caller2;
                cbp->bio_caller2 = NULL;
                cbp->bio_to = cp->provider;
                G_SHSEC_LOGREQ(2, cbp, "Sending request.");
                g_io_request(cbp, cp);
        }
        return;
failure:
        while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
                TAILQ_REMOVE(&queue, cbp, bio_queue);
                bp->bio_children--;
                if (cbp->bio_data != NULL) {
                        explicit_bzero(cbp->bio_data, cbp->bio_length);
                        uma_zfree(g_shsec_zone, cbp->bio_data);
                }
                g_destroy_bio(cbp);
        }
        if (bp->bio_error == 0)
                bp->bio_error = error;
        g_io_deliver(bp, bp->bio_error);
}

static void
g_shsec_check_and_run(struct g_shsec_softc *sc)
{
        off_t mediasize, ms;
        u_int no, sectorsize = 0;

        if (g_shsec_nvalid(sc) != sc->sc_ndisks)
                return;

        sc->sc_provider = g_new_providerf(sc->sc_geom, "shsec/%s", sc->sc_name);
        /*
         * Find the smallest disk.
         */
        mediasize = sc->sc_disks[0]->provider->mediasize;
        mediasize -= sc->sc_disks[0]->provider->sectorsize;
        sectorsize = sc->sc_disks[0]->provider->sectorsize;
        for (no = 1; no < sc->sc_ndisks; no++) {
                ms = sc->sc_disks[no]->provider->mediasize;
                ms -= sc->sc_disks[no]->provider->sectorsize;
                if (ms < mediasize)
                        mediasize = ms;
                sectorsize = lcm(sectorsize,
                    sc->sc_disks[no]->provider->sectorsize);
        }
        sc->sc_provider->sectorsize = sectorsize;
        sc->sc_provider->mediasize = mediasize;
        g_error_provider(sc->sc_provider, 0);

        G_SHSEC_DEBUG(0, "Device %s activated.", sc->sc_name);
}

static int
g_shsec_read_metadata(struct g_consumer *cp, struct g_shsec_metadata *md)
{
        struct g_provider *pp;
        u_char *buf;
        int error;

        g_topology_assert();

        error = g_access(cp, 1, 0, 0);
        if (error != 0)
                return (error);
        pp = cp->provider;
        g_topology_unlock();
        buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
            &error);
        g_topology_lock();
        g_access(cp, -1, 0, 0);
        if (buf == NULL)
                return (error);

        /* Decode metadata. */
        shsec_metadata_decode(buf, md);
        g_free(buf);

        return (0);
}

/*
 * Add disk to given device.
 */
static int
g_shsec_add_disk(struct g_shsec_softc *sc, struct g_provider *pp, u_int no)
{
        struct g_consumer *cp, *fcp;
        struct g_geom *gp;
        struct g_shsec_metadata md;
        int error;

        /* Metadata corrupted? */
        if (no >= sc->sc_ndisks)
                return (EINVAL);

        /* Check if disk is not already attached. */
        if (sc->sc_disks[no] != NULL)
                return (EEXIST);

        gp = sc->sc_geom;
        fcp = LIST_FIRST(&gp->consumer);

        cp = g_new_consumer(gp);
        error = g_attach(cp, pp);
        if (error != 0) {
                g_destroy_consumer(cp);
                return (error);
        }

        if (fcp != NULL && (fcp->acr > 0 || fcp->acw > 0 || fcp->ace > 0)) {
                error = g_access(cp, fcp->acr, fcp->acw, fcp->ace);
                if (error != 0) {
                        g_detach(cp);
                        g_destroy_consumer(cp);
                        return (error);
                }
        }

        /* Reread metadata. */
        error = g_shsec_read_metadata(cp, &md);
        if (error != 0)
                goto fail;

        if (strcmp(md.md_magic, G_SHSEC_MAGIC) != 0 ||
            strcmp(md.md_name, sc->sc_name) != 0 || md.md_id != sc->sc_id) {
                G_SHSEC_DEBUG(0, "Metadata on %s changed.", pp->name);
                goto fail;
        }

        cp->private = sc;
        cp->index = no;
        sc->sc_disks[no] = cp;

        G_SHSEC_DEBUG(0, "Disk %s attached to %s.", pp->name, sc->sc_name);

        g_shsec_check_and_run(sc);

        return (0);
fail:
        if (fcp != NULL && (fcp->acr > 0 || fcp->acw > 0 || fcp->ace > 0))
                g_access(cp, -fcp->acr, -fcp->acw, -fcp->ace);
        g_detach(cp);
        g_destroy_consumer(cp);
        return (error);
}

static struct g_geom *
g_shsec_create(struct g_class *mp, const struct g_shsec_metadata *md)
{
        struct g_shsec_softc *sc;
        struct g_geom *gp;
        u_int no;

        G_SHSEC_DEBUG(1, "Creating device %s (id=%u).", md->md_name, md->md_id);

        /* Two disks is minimum. */
        if (md->md_all < 2) {
                G_SHSEC_DEBUG(0, "Too few disks defined for %s.", md->md_name);
                return (NULL);
        }

        /* Check for duplicate unit */
        LIST_FOREACH(gp, &mp->geom, geom) {
                sc = gp->softc;
                if (sc != NULL && strcmp(sc->sc_name, md->md_name) == 0) {
                        G_SHSEC_DEBUG(0, "Device %s already configured.",
                            sc->sc_name);
                        return (NULL);
                }
        }
        gp = g_new_geom(mp, md->md_name);
        sc = malloc(sizeof(*sc), M_SHSEC, M_WAITOK | M_ZERO);
        gp->start = g_shsec_start;
        gp->spoiled = g_shsec_orphan;
        gp->orphan = g_shsec_orphan;
        gp->access = g_shsec_access;
        gp->dumpconf = g_shsec_dumpconf;

        sc->sc_id = md->md_id;
        sc->sc_ndisks = md->md_all;
        sc->sc_disks = malloc(sizeof(struct g_consumer *) * sc->sc_ndisks,
            M_SHSEC, M_WAITOK | M_ZERO);
        for (no = 0; no < sc->sc_ndisks; no++)
                sc->sc_disks[no] = NULL;

        gp->softc = sc;
        sc->sc_geom = gp;
        sc->sc_provider = NULL;

        G_SHSEC_DEBUG(0, "Device %s created (id=%u).", sc->sc_name, sc->sc_id);

        return (gp);
}

static int
g_shsec_destroy(struct g_shsec_softc *sc, boolean_t force)
{
        struct g_provider *pp;
        struct g_geom *gp;
        u_int no;

        g_topology_assert();

        if (sc == NULL)
                return (ENXIO);

        pp = sc->sc_provider;
        if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
                if (force) {
                        G_SHSEC_DEBUG(0, "Device %s is still open, so it "
                            "can't be definitely removed.", pp->name);
                } else {
                        G_SHSEC_DEBUG(1,
                            "Device %s is still open (r%dw%de%d).", pp->name,
                            pp->acr, pp->acw, pp->ace);
                        return (EBUSY);
                }
        }

        for (no = 0; no < sc->sc_ndisks; no++) {
                if (sc->sc_disks[no] != NULL)
                        g_shsec_remove_disk(sc->sc_disks[no]);
        }

        gp = sc->sc_geom;
        gp->softc = NULL;
        KASSERT(sc->sc_provider == NULL, ("Provider still exists? (device=%s)",
            gp->name));
        free(sc->sc_disks, M_SHSEC);
        free(sc, M_SHSEC);

        pp = LIST_FIRST(&gp->provider);
        if (pp == NULL || (pp->acr == 0 && pp->acw == 0 && pp->ace == 0))
                G_SHSEC_DEBUG(0, "Device %s destroyed.", gp->name);

        g_wither_geom(gp, ENXIO);

        return (0);
}

static int
g_shsec_destroy_geom(struct gctl_req *req __unused, struct g_class *mp __unused,
    struct g_geom *gp)
{
        struct g_shsec_softc *sc;

        sc = gp->softc;
        return (g_shsec_destroy(sc, 0));
}

static struct g_geom *
g_shsec_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
{
        struct g_shsec_metadata md;
        struct g_shsec_softc *sc;
        struct g_consumer *cp;
        struct g_geom *gp;
        int error;

        g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
        g_topology_assert();

        /* Skip providers that are already open for writing. */
        if (pp->acw > 0)
                return (NULL);

        G_SHSEC_DEBUG(3, "Tasting %s.", pp->name);

        gp = g_new_geom(mp, "shsec:taste");
        gp->start = g_shsec_start;
        gp->access = g_shsec_access;
        gp->orphan = g_shsec_orphan;
        cp = g_new_consumer(gp);
        cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
        error = g_attach(cp, pp);
        if (error == 0) {
                error = g_shsec_read_metadata(cp, &md);
                g_detach(cp);
        }
        g_destroy_consumer(cp);
        g_destroy_geom(gp);
        if (error != 0)
                return (NULL);
        gp = NULL;

        if (strcmp(md.md_magic, G_SHSEC_MAGIC) != 0)
                return (NULL);
        if (md.md_version > G_SHSEC_VERSION) {
                G_SHSEC_DEBUG(0, "Kernel module is too old to handle %s.\n",
                    pp->name);
                return (NULL);
        }
        /*
         * Backward compatibility:
         */
        /* There was no md_provsize field in earlier versions of metadata. */
        if (md.md_version < 1)
                md.md_provsize = pp->mediasize;

        if (md.md_provider[0] != '\0' &&
            !g_compare_names(md.md_provider, pp->name))
                return (NULL);
        if (md.md_provsize != pp->mediasize)
                return (NULL);

        /*
         * Let's check if device already exists.
         */
        sc = NULL;
        LIST_FOREACH(gp, &mp->geom, geom) {
                sc = gp->softc;
                if (sc == NULL)
                        continue;
                if (strcmp(md.md_name, sc->sc_name) != 0)
                        continue;
                if (md.md_id != sc->sc_id)
                        continue;
                break;
        }
        if (gp != NULL) {
                G_SHSEC_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
                error = g_shsec_add_disk(sc, pp, md.md_no);
                if (error != 0) {
                        G_SHSEC_DEBUG(0, "Cannot add disk %s to %s (error=%d).",
                            pp->name, gp->name, error);
                        return (NULL);
                }
        } else {
                gp = g_shsec_create(mp, &md);
                if (gp == NULL) {
                        G_SHSEC_DEBUG(0, "Cannot create device %s.", md.md_name);
                        return (NULL);
                }
                sc = gp->softc;
                G_SHSEC_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
                error = g_shsec_add_disk(sc, pp, md.md_no);
                if (error != 0) {
                        G_SHSEC_DEBUG(0, "Cannot add disk %s to %s (error=%d).",
                            pp->name, gp->name, error);
                        g_shsec_destroy(sc, 1);
                        return (NULL);
                }
        }
        return (gp);
}

static struct g_shsec_softc *
g_shsec_find_device(struct g_class *mp, const char *name)
{
        struct g_shsec_softc *sc;
        struct g_geom *gp;

        LIST_FOREACH(gp, &mp->geom, geom) {
                sc = gp->softc;
                if (sc == NULL)
                        continue;
                if (strcmp(sc->sc_name, name) == 0)
                        return (sc);
        }
        return (NULL);
}

static void
g_shsec_ctl_destroy(struct gctl_req *req, struct g_class *mp)
{
        struct g_shsec_softc *sc;
        int *force, *nargs, error;
        const char *name;
        char param[16];
        u_int i;

        g_topology_assert();

        nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
        if (nargs == NULL) {
                gctl_error(req, "No '%s' argument.", "nargs");
                return;
        }
        if (*nargs <= 0) {
                gctl_error(req, "Missing device(s).");
                return;
        }
        force = gctl_get_paraml(req, "force", sizeof(*force));
        if (force == NULL) {
                gctl_error(req, "No '%s' argument.", "force");
                return;
        }

        for (i = 0; i < (u_int)*nargs; i++) {
                snprintf(param, sizeof(param), "arg%u", i);
                name = gctl_get_asciiparam(req, param);
                if (name == NULL) {
                        gctl_error(req, "No 'arg%u' argument.", i);
                        return;
                }
                sc = g_shsec_find_device(mp, name);
                if (sc == NULL) {
                        gctl_error(req, "No such device: %s.", name);
                        return;
                }
                error = g_shsec_destroy(sc, *force);
                if (error != 0) {
                        gctl_error(req, "Cannot destroy device %s (error=%d).",
                            sc->sc_name, error);
                        return;
                }
        }
}

static void
g_shsec_config(struct gctl_req *req, struct g_class *mp, const char *verb)
{
        uint32_t *version;

        g_topology_assert();

        version = gctl_get_paraml(req, "version", sizeof(*version));
        if (version == NULL) {
                gctl_error(req, "No '%s' argument.", "version");
                return;
        }
        if (*version != G_SHSEC_VERSION) {
                gctl_error(req, "Userland and kernel parts are out of sync.");
                return;
        }

        if (strcmp(verb, "stop") == 0) {
                g_shsec_ctl_destroy(req, mp);
                return;
        }

        gctl_error(req, "Unknown verb.");
}

static void
g_shsec_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
    struct g_consumer *cp, struct g_provider *pp)
{
        struct g_shsec_softc *sc;

        sc = gp->softc;
        if (sc == NULL)
                return;
        if (pp != NULL) {
                /* Nothing here. */
        } else if (cp != NULL) {
                sbuf_printf(sb, "%s<Number>%u</Number>\n", indent,
                    (u_int)cp->index);
        } else {
                sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)sc->sc_id);
                sbuf_printf(sb, "%s<Status>Total=%u, Online=%u</Status>\n",
                    indent, sc->sc_ndisks, g_shsec_nvalid(sc));
                sbuf_printf(sb, "%s<State>", indent);
                if (sc->sc_provider != NULL && sc->sc_provider->error == 0)
                        sbuf_printf(sb, "UP");
                else
                        sbuf_printf(sb, "DOWN");
                sbuf_printf(sb, "</State>\n");
        }
}

DECLARE_GEOM_CLASS(g_shsec_class, g_shsec);
MODULE_VERSION(geom_shsec, 0);