/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2004-2005 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/cdefs.h>
#include "opt_geom.h"

#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/ctype.h>
#include <sys/malloc.h>
#include <sys/libkern.h>
#include <sys/sbuf.h>
#include <sys/stddef.h>
#include <sys/sysctl.h>
#include <geom/geom.h>
#include <geom/geom_dbg.h>
#include <geom/geom_slice.h>
#include <geom/label/g_label.h>

FEATURE(geom_label, "GEOM labeling support");

SYSCTL_DECL(_kern_geom);
SYSCTL_NODE(_kern_geom, OID_AUTO, label, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "GEOM_LABEL stuff");
u_int g_label_debug = 0;
SYSCTL_UINT(_kern_geom_label, OID_AUTO, debug, CTLFLAG_RWTUN, &g_label_debug, 0,
    "Debug level");

static int g_label_destroy_geom(struct gctl_req *req, struct g_class *mp,
    struct g_geom *gp);
static int g_label_destroy(struct g_geom *gp, boolean_t force);
static struct g_geom *g_label_taste(struct g_class *mp, struct g_provider *pp,
    int flags __unused);
static void g_label_generic_taste(struct g_consumer *, char *, size_t);
static void g_label_config(struct gctl_req *req, struct g_class *mp,
    const char *verb);

#define G_LABEL_DIRPREFIX       "label/"

struct g_class g_label_class = {
        .name = G_LABEL_CLASS_NAME,
        .version = G_VERSION,
        .ctlreq = g_label_config,
        .taste = g_label_taste,
        .destroy_geom = g_label_destroy_geom
};

static struct g_label_desc g_label_generic = {
        .ld_taste = g_label_generic_taste,
        .ld_dirprefix = G_LABEL_DIRPREFIX,
        .ld_enabled = 1
};

/*
 * To add a new file system where you want to look for volume labels,
 * you have to:
 * 1. Add a file g_label_<file system>.c which implements labels recognition.
 * 2. Add an 'extern const struct g_label_desc g_label_<file system>;' into
 *    g_label.h file.
 * 3. Add an element to the table below '&g_label_<file system>,'.
 * 4. Add your file to sys/conf/files.
 * 5. Add your file to sys/modules/geom/geom_label/Makefile.
 * 6. Add your file system to manual page sbin/geom/class/label/glabel.8.
 */
const struct g_label_desc *g_labels[] = {
        &g_label_gpt,
        &g_label_gpt_uuid,
#ifdef GEOM_LABEL
        &g_label_ufs_id,
        &g_label_ufs_volume,
        &g_label_iso9660,
        &g_label_msdosfs,
        &g_label_ext2fs,
        &g_label_ntfs,
        &g_label_disk_ident,
        &g_label_flashmap,
        &g_label_swaplinux,
#endif
        &g_label_generic,
        NULL
};

void
g_label_rtrim(char *label, size_t size)
{
        ptrdiff_t i;

        for (i = size - 1; i >= 0; i--) {
                if (label[i] == '\0')
                        continue;
                else if (label[i] == ' ')
                        label[i] = '\0';
                else
                        break;
        }
}

static int
g_label_destroy_geom(struct gctl_req *req __unused, struct g_class *mp,
    struct g_geom *gp __unused)
{

        /*
         * XXX: Unloading a class which is using geom_slice:1.56 is currently
         * XXX: broken, so we deny unloading when we have geoms.
         */
        return (EOPNOTSUPP);
}

static void
g_label_orphan(struct g_consumer *cp)
{

        G_LABEL_DEBUG(1, "Label %s removed.",
            LIST_FIRST(&cp->geom->provider)->name);
        g_slice_orphan(cp);
}

static void
g_label_spoiled(struct g_consumer *cp)
{

        G_LABEL_DEBUG(1, "Label %s removed.",
            LIST_FIRST(&cp->geom->provider)->name);
        g_slice_spoiled(cp);
}

static void
g_label_resize(struct g_consumer *cp)
{

        G_LABEL_DEBUG(1, "Label %s resized.",
            LIST_FIRST(&cp->geom->provider)->name);

        g_slice_config(cp->geom, 0, G_SLICE_CONFIG_FORCE, (off_t)0,
            cp->provider->mediasize, cp->provider->sectorsize, "notused");
}

static int
g_label_is_name_ok(const char *label)
{
        const char *s;

        /* Check if the label starts from ../ */
        if (strncmp(label, "../", 3) == 0)
                return (0);
        /* Check if the label contains /../ */
        if (strstr(label, "/../") != NULL)
                return (0);
        /* Check if the label ends at ../ */
        if ((s = strstr(label, "/..")) != NULL && s[3] == '\0')
                return (0);
        return (1);
}

static void
g_label_mangle_name(char *label, size_t size)
{
        struct sbuf *sb;
        const u_char *c;
        size_t len, i;

        /* Trim trailing whitespace. */
        len = strlen(label);
        for (i = len; i > 0; i--) {
                if (isspace(label[i - 1]))
                        label[i - 1] = '\0';
                else
                        break;
        }
        if (*label == '\0')
                return;

        sb = sbuf_new(NULL, NULL, size, SBUF_FIXEDLEN);
        for (c = label; *c != '\0'; c++) {
                /* Trim leading whitespace. */
                if (isspace(*c) && sbuf_len(sb) == 0)
                        continue;
                if (!isprint(*c) || isspace(*c) || *c =='"' || *c == '%')
                        sbuf_printf(sb, "%%%02X", *c);
                else
                        sbuf_putc(sb, *c);
        }
        if (sbuf_finish(sb) != 0)
                label[0] = '\0';
        else
                strlcpy(label, sbuf_data(sb), size);
        sbuf_delete(sb);
}

static struct g_geom *
g_label_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp,
    const char *label, const char *dirprefix, off_t mediasize)
{
        struct g_geom *gp;
        struct g_provider *pp2;
        struct g_consumer *cp;
        char name[64];

        g_topology_assert();

        if (!g_label_is_name_ok(label)) {
                G_LABEL_DEBUG(0, "%s contains suspicious label, skipping.",
                    pp->name);
                G_LABEL_DEBUG(1, "%s suspicious label is: %s", pp->name, label);
                if (req != NULL)
                        gctl_error(req, "Label name %s is invalid.", label);
                return (NULL);
        }
        gp = NULL;
        cp = NULL;
        if (snprintf(name, sizeof(name), "%s%s", dirprefix, label) >= sizeof(name)) {
                if (req != NULL)
                        gctl_error(req, "Label name %s is too long.", label);
                return (NULL);
        }
        LIST_FOREACH(gp, &mp->geom, geom) {
                pp2 = LIST_FIRST(&gp->provider);
                if (pp2 == NULL)
                        continue;
                if ((pp2->flags & G_PF_ORPHAN) != 0)
                        continue;
                if (strcmp(pp2->name, name) == 0) {
                        G_LABEL_DEBUG(1, "Label %s(%s) already exists (%s).",
                            label, name, pp->name);
                        if (req != NULL) {
                                gctl_error(req, "Provider %s already exists.",
                                    name);
                        }
                        return (NULL);
                }
        }
        gp = g_slice_new(mp, 1, pp, &cp, NULL, 0, NULL);
        if (gp == NULL) {
                G_LABEL_DEBUG(0, "Cannot create slice %s.", label);
                if (req != NULL)
                        gctl_error(req, "Cannot create slice %s.", label);
                return (NULL);
        }
        gp->orphan = g_label_orphan;
        gp->spoiled = g_label_spoiled;
        gp->resize = g_label_resize;
        g_access(cp, -1, 0, 0);
        g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t)0, mediasize,
            pp->sectorsize, "%s", name);
        G_LABEL_DEBUG(1, "Label for provider %s is %s.", pp->name, name);
        return (gp);
}

static int
g_label_destroy(struct g_geom *gp, boolean_t force)
{
        struct g_provider *pp;

        g_topology_assert();
        pp = LIST_FIRST(&gp->provider);
        if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
                if (force) {
                        G_LABEL_DEBUG(0, "Provider %s is still open, so it "
                            "can't be definitely removed.", pp->name);
                } else {
                        G_LABEL_DEBUG(1,
                            "Provider %s is still open (r%dw%de%d).", pp->name,
                            pp->acr, pp->acw, pp->ace);
                        return (EBUSY);
                }
        } else if (pp != NULL)
                G_LABEL_DEBUG(1, "Label %s removed.", pp->name);
        g_slice_spoiled(LIST_FIRST(&gp->consumer));
        return (0);
}

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

        pp = cp->provider;
        if (pp->sectorsize < sizeof(*md))
                return (EINVAL);
        buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
            &error);
        if (buf == NULL)
                return (error);
        /* Decode metadata. */
        label_metadata_decode(buf, md);
        g_free(buf);

        return (0);
}

static void
g_label_orphan_taste(struct g_consumer *cp __unused)
{

        KASSERT(1 == 0, ("%s called?", __func__));
}

static void
g_label_start_taste(struct bio *bp __unused)
{

        KASSERT(1 == 0, ("%s called?", __func__));
}

static int
g_label_access_taste(struct g_provider *pp __unused, int dr __unused,
    int dw __unused, int de __unused)
{

        KASSERT(1 == 0, ("%s called", __func__));
        return (EOPNOTSUPP);
}

static void
g_label_generic_taste(struct g_consumer *cp, char *label, size_t size)
{
        struct g_provider *pp;
        struct g_label_metadata md;

        g_topology_assert_not();
        label[0] = '\0';
        pp = cp->provider;

        if (g_label_read_metadata(cp, &md) != 0)
                return;

        if (strcmp(md.md_magic, G_LABEL_MAGIC) != 0)
                return;

        if (md.md_version > G_LABEL_VERSION) {
                printf("geom_label.ko module is too old to handle %s.\n",
                        pp->name);
                return;
        }
        /*
         * Backward compatibility: there was no md_provsize field in
         * earlier versions of metadata, so only check if we have it.
         */
        if (md.md_version >= 2 && md.md_provsize != pp->mediasize)
                return;

        strlcpy(label, md.md_label, size);
}

static struct g_geom *
g_label_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
{
        struct g_consumer *cp;
        struct g_geom *gp;
        off_t mediasize;
        int i;

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

        G_LABEL_DEBUG(2, "Tasting %s.", pp->name);

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

        /* Skip broken disks that don't set their sector size */
        if (pp->sectorsize == 0)
                return (NULL);

        if (strcmp(pp->geom->class->name, mp->name) == 0)
                return (NULL);

        gp = g_new_geom(mp, "label:taste");
        gp->start = g_label_start_taste;
        gp->access = g_label_access_taste;
        gp->orphan = g_label_orphan_taste;
        cp = g_new_consumer(gp);
        cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
        if (g_attach(cp, pp) != 0)
                goto end2;
        if (g_access(cp, 1, 0, 0) != 0)
                goto end;
        for (i = 0; g_labels[i] != NULL; i++) {
                char label[128];

                if (g_labels[i]->ld_enabled == 0)
                        continue;
                g_topology_unlock();
                g_labels[i]->ld_taste(cp, label, sizeof(label));
                g_label_mangle_name(label, sizeof(label));
                g_topology_lock();
                if (label[0] == '\0')
                        continue;
                if (g_labels[i] != &g_label_generic) {
                        mediasize = pp->mediasize;
                } else {
                        mediasize = pp->mediasize - pp->sectorsize;
                }
                g_label_create(NULL, mp, pp, label,
                    g_labels[i]->ld_dirprefix, mediasize);
        }
        g_access(cp, -1, 0, 0);
end:
        g_detach(cp);
end2:
        g_destroy_consumer(cp);
        g_destroy_geom(gp);
        return (NULL);
}

static void
g_label_ctl_create(struct gctl_req *req, struct g_class *mp)
{
        struct g_provider *pp;
        const char *name;
        int *nargs;

        g_topology_assert();

        nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
        if (nargs == NULL) {
                gctl_error(req, "No '%s' argument", "nargs");
                return;
        }
        if (*nargs != 2) {
                gctl_error(req, "Invalid number of arguments.");
                return;
        }
        /*
         * arg1 is the name of provider.
         */
        pp = gctl_get_provider(req, "arg1");
        if (pp == NULL)
                return;
        /*
         * arg0 is the label.
         */
        name = gctl_get_asciiparam(req, "arg0");
        if (name == NULL) {
                gctl_error(req, "No 'arg%d' argument", 0);
                return;
        }
        g_label_create(req, mp, pp, name, G_LABEL_DIRPREFIX, pp->mediasize);
}

static const char *
g_label_skip_dir(const char *name)
{
        u_int i;

        if (strncmp(name, _PATH_DEV, strlen(_PATH_DEV)) == 0)
                name += strlen(_PATH_DEV);
        for (i = 0; g_labels[i] != NULL; i++) {
                if (strncmp(name, g_labels[i]->ld_dirprefix,
                    strlen(g_labels[i]->ld_dirprefix)) == 0) {
                        name += strlen(g_labels[i]->ld_dirprefix);
                        break;
                }
        }
        return (name);
}

static struct g_geom *
g_label_find_geom(struct g_class *mp, const char *name)
{
        struct g_geom *gp;
        struct g_provider *pp;
        const char *pname;

        name = g_label_skip_dir(name);
        LIST_FOREACH(gp, &mp->geom, geom) {
                pp = LIST_FIRST(&gp->provider);
                pname = g_label_skip_dir(pp->name);
                if (strcmp(pname, name) == 0)
                        return (gp);
        }
        return (NULL);
}

static void
g_label_ctl_destroy(struct gctl_req *req, struct g_class *mp)
{
        int *nargs, *force, error, i;
        struct g_geom *gp;
        const char *name;
        char param[16];

        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 'force' argument");
                return;
        }

        for (i = 0; i < *nargs; i++) {
                snprintf(param, sizeof(param), "arg%d", i);
                name = gctl_get_asciiparam(req, param);
                if (name == NULL) {
                        gctl_error(req, "No 'arg%d' argument", i);
                        return;
                }
                gp = g_label_find_geom(mp, name);
                if (gp == NULL) {
                        G_LABEL_DEBUG(1, "Label %s is invalid.", name);
                        gctl_error(req, "Label %s is invalid.", name);
                        return;
                }
                error = g_label_destroy(gp, *force);
                if (error != 0) {
                        gctl_error(req, "Cannot destroy label %s (error=%d).",
                            LIST_FIRST(&gp->provider)->name, error);
                        return;
                }
        }
}

static void
g_label_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_LABEL_VERSION) {
                gctl_error(req, "Userland and kernel parts are out of sync.");
                return;
        }

        if (strcmp(verb, "create") == 0) {
                g_label_ctl_create(req, mp);
                return;
        } else if (strcmp(verb, "destroy") == 0 ||
            strcmp(verb, "stop") == 0) {
                g_label_ctl_destroy(req, mp);
                return;
        }

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

DECLARE_GEOM_CLASS(g_label_class, g_label);
MODULE_VERSION(geom_label, 0);