/*
 * 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 (c) 2011, 2018 by Delphix. All rights reserved.
 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
 * Copyright (c) 2013, Joyent, Inc. All rights reserved.
 * Copyright (c) 2014, Nexenta Systems, Inc. All rights reserved.
 * Copyright (c) 2014 Integros [integros.com]
 * Copyright (c) 2017, Intel Corporation.
 */

#ifdef _KERNEL
#include <sys/systm.h>
#else
#include <errno.h>
#include <string.h>
#endif
#include <sys/debug.h>
#include <sys/fs/zfs.h>
#include <sys/inttypes.h>
#include <sys/types.h>
#include "zfeature_common.h"

/*
 * Set to disable all feature checks while opening pools, allowing pools with
 * unsupported features to be opened. Set for testing only.
 */
boolean_t zfeature_checks_disable = B_FALSE;

zfeature_info_t spa_feature_table[SPA_FEATURES];

/*
 * Valid characters for feature guids. This list is mainly for aesthetic
 * purposes and could be expanded in the future. There are different allowed
 * characters in the guids reverse dns portion (before the colon) and its
 * short name (after the colon).
 */
static int
valid_char(char c, boolean_t after_colon)
{
        return ((c >= 'a' && c <= 'z') ||
            (c >= '0' && c <= '9') ||
            (after_colon && c == '_') ||
            (!after_colon && (c == '.' || c == '-')));
}

/*
 * Every feature guid must contain exactly one colon which separates a reverse
 * dns organization name from the feature's "short" name (e.g.
 * "com.company:feature_name").
 */
boolean_t
zfeature_is_valid_guid(const char *name)
{
        int i;
        boolean_t has_colon = B_FALSE;

        i = 0;
        while (name[i] != '\0') {
                char c = name[i++];
                if (c == ':') {
                        if (has_colon)
                                return (B_FALSE);
                        has_colon = B_TRUE;
                        continue;
                }
                if (!valid_char(c, has_colon))
                        return (B_FALSE);
        }

        return (has_colon);
}

boolean_t
zfeature_is_supported(const char *guid)
{
        if (zfeature_checks_disable)
                return (B_TRUE);

        for (spa_feature_t i = 0; i < SPA_FEATURES; i++) {
                zfeature_info_t *feature = &spa_feature_table[i];
                if (strcmp(guid, feature->fi_guid) == 0)
                        return (B_TRUE);
        }
        return (B_FALSE);
}

int
zfeature_lookup_name(const char *name, spa_feature_t *res)
{
        for (spa_feature_t i = 0; i < SPA_FEATURES; i++) {
                zfeature_info_t *feature = &spa_feature_table[i];
                if (strcmp(name, feature->fi_uname) == 0) {
                        if (res != NULL)
                                *res = i;
                        return (0);
                }
        }

        return (ENOENT);
}

boolean_t
zfeature_depends_on(spa_feature_t fid, spa_feature_t check)
{
        zfeature_info_t *feature = &spa_feature_table[fid];

        for (int i = 0; feature->fi_depends[i] != SPA_FEATURE_NONE; i++) {
                if (feature->fi_depends[i] == check)
                        return (B_TRUE);
        }
        return (B_FALSE);
}

static boolean_t
deps_contains_feature(const spa_feature_t *deps, const spa_feature_t feature)
{
        for (int i = 0; deps[i] != SPA_FEATURE_NONE; i++)
                if (deps[i] == feature)
                        return (B_TRUE);

        return (B_FALSE);
}

static void
zfeature_register(spa_feature_t fid, const char *guid, const char *name,
    const char *desc, zfeature_flags_t flags, zfeature_type_t type,
    const spa_feature_t *deps)
{
        zfeature_info_t *feature = &spa_feature_table[fid];
        static spa_feature_t nodeps[] = { SPA_FEATURE_NONE };

        ASSERT(name != NULL);
        ASSERT(desc != NULL);
        ASSERT((flags & ZFEATURE_FLAG_READONLY_COMPAT) == 0 ||
            (flags & ZFEATURE_FLAG_MOS) == 0);
        ASSERT3U(fid, <, SPA_FEATURES);
        ASSERT(zfeature_is_valid_guid(guid));

        if (deps == NULL)
                deps = nodeps;

        VERIFY(((flags & ZFEATURE_FLAG_PER_DATASET) == 0) ||
            (deps_contains_feature(deps, SPA_FEATURE_EXTENSIBLE_DATASET)));

        feature->fi_feature = fid;
        feature->fi_guid = guid;
        feature->fi_uname = name;
        feature->fi_desc = desc;
        feature->fi_flags = flags;
        feature->fi_type = type;
        feature->fi_depends = deps;
}

void
zpool_feature_init(void)
{
        zfeature_register(SPA_FEATURE_ASYNC_DESTROY,
            "com.delphix:async_destroy", "async_destroy",
            "Destroy filesystems asynchronously.",
            ZFEATURE_FLAG_READONLY_COMPAT, ZFEATURE_TYPE_BOOLEAN, NULL);

        zfeature_register(SPA_FEATURE_EMPTY_BPOBJ,
            "com.delphix:empty_bpobj", "empty_bpobj",
            "Snapshots use less space.",
            ZFEATURE_FLAG_READONLY_COMPAT, ZFEATURE_TYPE_BOOLEAN, NULL);

        zfeature_register(SPA_FEATURE_LZ4_COMPRESS,
            "org.illumos:lz4_compress", "lz4_compress",
            "LZ4 compression algorithm support.",
            ZFEATURE_FLAG_ACTIVATE_ON_ENABLE, ZFEATURE_TYPE_BOOLEAN, NULL);

        zfeature_register(SPA_FEATURE_MULTI_VDEV_CRASH_DUMP,
            "com.joyent:multi_vdev_crash_dump", "multi_vdev_crash_dump",
            "Crash dumps to multiple vdev pools.",
            0, ZFEATURE_TYPE_BOOLEAN, NULL);

        zfeature_register(SPA_FEATURE_SPACEMAP_HISTOGRAM,
            "com.delphix:spacemap_histogram", "spacemap_histogram",
            "Spacemaps maintain space histograms.",
            ZFEATURE_FLAG_READONLY_COMPAT, ZFEATURE_TYPE_BOOLEAN, NULL);

        zfeature_register(SPA_FEATURE_ENABLED_TXG,
            "com.delphix:enabled_txg", "enabled_txg",
            "Record txg at which a feature is enabled",
            ZFEATURE_FLAG_READONLY_COMPAT, ZFEATURE_TYPE_BOOLEAN, NULL);

        {
                static spa_feature_t hole_birth_deps[] = {
                        SPA_FEATURE_ENABLED_TXG,
                        SPA_FEATURE_NONE
                };
                zfeature_register(SPA_FEATURE_HOLE_BIRTH,
                    "com.delphix:hole_birth", "hole_birth",
                    "Retain hole birth txg for more precise zfs send",
                    ZFEATURE_FLAG_MOS | ZFEATURE_FLAG_ACTIVATE_ON_ENABLE,
                    ZFEATURE_TYPE_BOOLEAN, hole_birth_deps);
        }

        zfeature_register(SPA_FEATURE_POOL_CHECKPOINT,
            "com.delphix:zpool_checkpoint", "zpool_checkpoint",
            "Pool state can be checkpointed, allowing rewind later.",
            ZFEATURE_FLAG_READONLY_COMPAT, ZFEATURE_TYPE_BOOLEAN, NULL);

        zfeature_register(SPA_FEATURE_SPACEMAP_V2,
            "com.delphix:spacemap_v2", "spacemap_v2",
            "Space maps representing large segments are more efficient.",
            ZFEATURE_FLAG_READONLY_COMPAT | ZFEATURE_FLAG_ACTIVATE_ON_ENABLE,
            ZFEATURE_TYPE_BOOLEAN, NULL);

        zfeature_register(SPA_FEATURE_EXTENSIBLE_DATASET,
            "com.delphix:extensible_dataset", "extensible_dataset",
            "Enhanced dataset functionality, used by other features.",
            0, ZFEATURE_TYPE_BOOLEAN, NULL);

        {
                static const spa_feature_t bookmarks_deps[] = {
                        SPA_FEATURE_EXTENSIBLE_DATASET,
                        SPA_FEATURE_NONE
                };
                zfeature_register(SPA_FEATURE_BOOKMARKS,
                    "com.delphix:bookmarks", "bookmarks",
                    "\"zfs bookmark\" command",
                    ZFEATURE_FLAG_READONLY_COMPAT, ZFEATURE_TYPE_BOOLEAN,
                    bookmarks_deps);
        }

        {
                static const spa_feature_t filesystem_limits_deps[] = {
                        SPA_FEATURE_EXTENSIBLE_DATASET,
                        SPA_FEATURE_NONE
                };
                zfeature_register(SPA_FEATURE_FS_SS_LIMIT,
                    "com.joyent:filesystem_limits", "filesystem_limits",
                    "Filesystem and snapshot limits.",
                    ZFEATURE_FLAG_READONLY_COMPAT, ZFEATURE_TYPE_BOOLEAN,
                    filesystem_limits_deps);
        }

        zfeature_register(SPA_FEATURE_EMBEDDED_DATA,
            "com.delphix:embedded_data", "embedded_data",
            "Blocks which compress very well use even less space.",
            ZFEATURE_FLAG_MOS | ZFEATURE_FLAG_ACTIVATE_ON_ENABLE,
            ZFEATURE_TYPE_BOOLEAN, NULL);

        /* Slot for SPA_FEATURE_LIVELIST */

        {
                static const spa_feature_t log_spacemap_deps[] = {
                        SPA_FEATURE_SPACEMAP_V2,
                        SPA_FEATURE_NONE
                };
                zfeature_register(SPA_FEATURE_LOG_SPACEMAP,
                    "com.delphix:log_spacemap", "log_spacemap",
                    "Log metaslab changes on a single spacemap and "
                    "flush them periodically.",
                    ZFEATURE_FLAG_READONLY_COMPAT, ZFEATURE_TYPE_BOOLEAN,
                    log_spacemap_deps);
        }

        {
                static const spa_feature_t large_blocks_deps[] = {
                        SPA_FEATURE_EXTENSIBLE_DATASET,
                        SPA_FEATURE_NONE
                };
                zfeature_register(SPA_FEATURE_LARGE_BLOCKS,
                    "org.open-zfs:large_blocks", "large_blocks",
                    "Support for blocks larger than 128KB.",
                    ZFEATURE_FLAG_PER_DATASET, ZFEATURE_TYPE_BOOLEAN,
                    large_blocks_deps);
        }

        {
                static const spa_feature_t large_dnode_deps[] = {
                        SPA_FEATURE_EXTENSIBLE_DATASET,
                        SPA_FEATURE_NONE
                };
                zfeature_register(SPA_FEATURE_LARGE_DNODE,
                    "org.zfsonlinux:large_dnode", "large_dnode",
                    "Variable on-disk size of dnodes.",
                    ZFEATURE_FLAG_PER_DATASET, ZFEATURE_TYPE_BOOLEAN,
                    large_dnode_deps);
        }

        {
                static const spa_feature_t sha512_deps[] = {
                        SPA_FEATURE_EXTENSIBLE_DATASET,
                        SPA_FEATURE_NONE
                };
                zfeature_register(SPA_FEATURE_SHA512,
                    "org.illumos:sha512", "sha512",
                    "SHA-512/256 hash algorithm.",
                    ZFEATURE_FLAG_PER_DATASET, ZFEATURE_TYPE_BOOLEAN,
                    sha512_deps);
        }

        {
                static const spa_feature_t skein_deps[] = {
                        SPA_FEATURE_EXTENSIBLE_DATASET,
                        SPA_FEATURE_NONE
                };
                zfeature_register(SPA_FEATURE_SKEIN,
                    "org.illumos:skein", "skein",
                    "Skein hash algorithm.",
                    ZFEATURE_FLAG_PER_DATASET, ZFEATURE_TYPE_BOOLEAN,
                    skein_deps);
        }

        {
                static const spa_feature_t edonr_deps[] = {
                        SPA_FEATURE_EXTENSIBLE_DATASET,
                        SPA_FEATURE_NONE
                };
                zfeature_register(SPA_FEATURE_EDONR,
                    "org.illumos:edonr", "edonr",
                    "Edon-R hash algorithm.",
                    ZFEATURE_FLAG_PER_DATASET, ZFEATURE_TYPE_BOOLEAN,
                    edonr_deps);
        }

        /* Slot for SPA_FEATURE_REDACTION_BOOKMARKS */

        /* Slot for SPA_FEATURE_REDACTED_DATASETS */

        /* Slot for SPA_FEATURE_BOOKMARK_WRITTEN */

        zfeature_register(SPA_FEATURE_DEVICE_REMOVAL,
            "com.delphix:device_removal", "device_removal",
            "Top-level vdevs can be removed, reducing logical pool size.",
            ZFEATURE_FLAG_MOS, ZFEATURE_TYPE_BOOLEAN, NULL);

        {
                static const spa_feature_t obsolete_counts_deps[] = {
                        SPA_FEATURE_EXTENSIBLE_DATASET,
                        SPA_FEATURE_DEVICE_REMOVAL,
                        SPA_FEATURE_NONE
                };
                zfeature_register(SPA_FEATURE_OBSOLETE_COUNTS,
                    "com.delphix:obsolete_counts", "obsolete_counts",
                    "Reduce memory used by removed devices when their "
                    "blocks are freed or remapped.",
                    ZFEATURE_FLAG_READONLY_COMPAT, ZFEATURE_TYPE_BOOLEAN,
                    obsolete_counts_deps);
        }

        {
                static const spa_feature_t userobj_accounting_deps[] = {
                        SPA_FEATURE_EXTENSIBLE_DATASET,
                        SPA_FEATURE_NONE
                };
                zfeature_register(SPA_FEATURE_USEROBJ_ACCOUNTING,
                    "org.zfsonlinux:userobj_accounting", "userobj_accounting",
                    "User/Group object accounting.",
                    ZFEATURE_FLAG_READONLY_COMPAT | ZFEATURE_FLAG_PER_DATASET,
                    ZFEATURE_TYPE_BOOLEAN, userobj_accounting_deps);
        }

        {
                static const spa_feature_t bookmark_v2_deps[] = {
                        SPA_FEATURE_EXTENSIBLE_DATASET,
                        SPA_FEATURE_BOOKMARKS,
                        SPA_FEATURE_NONE
                };
                zfeature_register(SPA_FEATURE_BOOKMARK_V2,
                    "com.datto:bookmark_v2", "bookmark_v2",
                    "Support for larger bookmarks",
                    0, ZFEATURE_TYPE_BOOLEAN, bookmark_v2_deps);
        }

        {
                static const spa_feature_t encryption_deps[] = {
                        SPA_FEATURE_EXTENSIBLE_DATASET,
                        SPA_FEATURE_BOOKMARK_V2,
                        SPA_FEATURE_NONE
                };
                zfeature_register(SPA_FEATURE_ENCRYPTION,
                    "com.datto:encryption", "encryption",
                    "Support for dataset level encryption",
                    ZFEATURE_FLAG_PER_DATASET, ZFEATURE_TYPE_BOOLEAN,
                    encryption_deps);
        }

        {
                static const spa_feature_t project_quota_deps[] = {
                        SPA_FEATURE_EXTENSIBLE_DATASET,
                        SPA_FEATURE_NONE
                };
                zfeature_register(SPA_FEATURE_PROJECT_QUOTA,
                    "org.zfsonlinux:project_quota", "project_quota",
                    "space/object accounting based on project ID.",
                    ZFEATURE_FLAG_READONLY_COMPAT | ZFEATURE_FLAG_PER_DATASET,
                    ZFEATURE_TYPE_BOOLEAN, project_quota_deps);
        }

        zfeature_register(SPA_FEATURE_ALLOCATION_CLASSES,
            "org.zfsonlinux:allocation_classes", "allocation_classes",
            "Support for separate allocation classes.",
            ZFEATURE_FLAG_READONLY_COMPAT, ZFEATURE_TYPE_BOOLEAN, NULL);

        zfeature_register(SPA_FEATURE_RESILVER_DEFER,
            "com.datto:resilver_defer", "resilver_defer",
            "Support for defering new resilvers when one is already running.",
            ZFEATURE_FLAG_READONLY_COMPAT, ZFEATURE_TYPE_BOOLEAN, NULL);

        /*
         * Slots for:
         * SPA_FEATURE_DEVICE_REBUILD
         * SPA_FEATURE_ZSTD_COMPRESS
         * SPA_FEATURE_DRAID
         * SPA_FEATURE_ZILSAXATTR
         * SPA_FEATURE_HEAD_ERRLOG
         * SPA_FEATURE_BLAKE3
         * SPA_FEATURE_BLOCK_CLONING
         * SPA_FEATURE_AVZ_V2
         * SPA_FEATURE_REDACTION_LIST_SPILL
         * SPA_FEATURE_RAIDZ_EXPANSION
         * SPA_FEATURE_FAST_DEDUP
         * SPA_FEATURE_LONGNAME
         * SPA_FEATURE_LARGE_MICROZAP
         */
}