/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2002, 2003 Gordon Tetlow
 * Copyright (c) 2006 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/disklabel.h>
#include <sys/malloc.h>
#include <sys/vnode.h>

#include <ufs/ufs/dinode.h>
#include <ufs/ffs/fs.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/extattr.h>
#include <ufs/ffs/ffs_extern.h>

#include <geom/geom.h>
#include <geom/geom_dbg.h>
#include <geom/label/g_label.h>

#define G_LABEL_UFS_VOLUME      0
#define G_LABEL_UFS_ID          1

/*
 * G_LABEL_UFS_CMP returns true if difference between provider mediasize
 * and filesystem size is less than G_LABEL_UFS_MAXDIFF sectors
 */
#define G_LABEL_UFS_CMP(prov, fsys, size)                                  \
        ( abs( ((fsys)->size) - ( (prov)->mediasize / (fsys)->fs_fsize ))  \
                                < G_LABEL_UFS_MAXDIFF )
#define G_LABEL_UFS_MAXDIFF     0x100

/*
 * For providers that look like disklabels we need to check if the file system
 * size is almost equal to the provider's size, because sysinstall(8) used to
 * bogusly put the first partition at offset 0 instead of 16, and glabel/ufs
 * would find a file system on the slice instead of the partition.
 *
 * In addition, media size can be a bit bigger than file system size. For
 * instance, mkuzip can append bytes to align data to large sector size (it
 * improves compression rates).
 */
static bool
g_label_ufs_ignore_bsdlabel_slice(struct g_consumer *cp,
    struct fs *fs)
{
        struct g_provider *pp;
        u_char *buf;
        uint32_t magic1, magic2;
        int error;

        pp = cp->provider;

        /*
         * If the expected provider size for the filesystem matches the
         * real provider size then don't ignore this filesystem.
         */
        if (G_LABEL_UFS_CMP(pp, fs, fs_providersize))
                return (false);

        /*
         * If the filesystem size matches the real provider size then
         * don't ignore this filesystem.
         */
        if (fs->fs_magic == FS_UFS1_MAGIC ?
            G_LABEL_UFS_CMP(pp, fs, fs_old_size) :
            G_LABEL_UFS_CMP(pp, fs, fs_size))
                return (false);

        /*
         * Provider is bigger than expected; probe to see if there's a
         * disklabel. Adapted from g_part_bsd_probe.
         */

        /* Check if the superblock overlaps where the disklabel lives. */
        if (fs->fs_sblockloc < pp->sectorsize * 2)
                return (false);

        /* Sanity-check the provider. */
        if (pp->sectorsize < sizeof(struct disklabel) ||
            pp->mediasize < BBSIZE)
                return (false);
        if (BBSIZE % pp->sectorsize)
                return (false);

        /* Check that there's a disklabel. */
        buf = g_read_data(cp, pp->sectorsize, pp->sectorsize, &error);
        if (buf == NULL)
                return (false);
        magic1 = le32dec(buf + 0);
        magic2 = le32dec(buf + 132);
        g_free(buf);
        if (magic1 == DISKMAGIC && magic2 == DISKMAGIC)
                return (true);

        return (false);
}

/*
 * Try to find a superblock on the provider. If successful, look for a volume
 * label and create an appropriate provider based on that.
 */
static void
g_label_ufs_taste_common(struct g_consumer *cp, char *label, size_t size, int what)
{
        struct g_provider *pp;
        struct fs *fs;

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

        fs = NULL;
        KASSERT(pp->sectorsize != 0, ("Tasting a disk with 0 sectorsize"));
        if (SBLOCKSIZE % pp->sectorsize != 0 || ffs_sbget(cp, &fs, UFS_STDSB,
            UFS_NOHASHFAIL | UFS_NOCSUM | UFS_NOMSG, M_GEOM, g_use_g_read_data)
            != 0) {
                KASSERT(fs == NULL,
                    ("g_label_ufs_taste_common: non-NULL fs %p\n", fs));
                return;
        }

        /* Check for magic. */
        if (fs->fs_magic == FS_UFS1_MAGIC && fs->fs_fsize > 0) {
                /* Valid UFS1. */
        } else if (fs->fs_magic == FS_UFS2_MAGIC && fs->fs_fsize > 0) {
                /* Valid UFS2. */
        } else {
                goto out;
        }
        /* Check if this should be ignored for compatibility. */
        if (g_label_ufs_ignore_bsdlabel_slice(cp, fs))
                goto out;
        G_LABEL_DEBUG(1, "%s file system detected on %s.",
            fs->fs_magic == FS_UFS1_MAGIC ? "UFS1" : "UFS2", pp->name);
        switch (what) {
        case G_LABEL_UFS_VOLUME:
                /* Check for volume label */
                if (fs->fs_volname[0] != '\0')
                        strlcpy(label, fs->fs_volname, size);
                break;
        case G_LABEL_UFS_ID:
                if (fs->fs_id[0] != 0 || fs->fs_id[1] != 0)
                        snprintf(label, size, "%08x%08x", fs->fs_id[0],
                            fs->fs_id[1]);
                break;
        }
out:
        g_free(fs);
}

static void
g_label_ufs_volume_taste(struct g_consumer *cp, char *label, size_t size)
{

        g_label_ufs_taste_common(cp, label, size, G_LABEL_UFS_VOLUME);
}

static void
g_label_ufs_id_taste(struct g_consumer *cp, char *label, size_t size)
{

        g_label_ufs_taste_common(cp, label, size, G_LABEL_UFS_ID);
}

struct g_label_desc g_label_ufs_volume = {
        .ld_taste = g_label_ufs_volume_taste,
        .ld_dirprefix = "ufs/",
        .ld_enabled = 1
};

struct g_label_desc g_label_ufs_id = {
        .ld_taste = g_label_ufs_id_taste,
        .ld_dirprefix = "ufsid/",
        .ld_enabled = 1
};

G_LABEL_INIT(ufsid, g_label_ufs_id, "Create device nodes for UFS file system IDs");
G_LABEL_INIT(ufs, g_label_ufs_volume, "Create device nodes for UFS volume names");

MODULE_DEPEND(g_label, ufs, 1, 1, 1);