/*
 * 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) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2012, 2020 by Delphix. All rights reserved.
 */

#include <libzfs.h>

#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <sys/file.h>
#include <sys/mntent.h>
#include <sys/mnttab.h>
#include <sys/param.h>
#include <sys/stat.h>

#include <sys/dmu.h>
#include <sys/dmu_objset.h>
#include <sys/dnode.h>
#include <sys/vdev_impl.h>

#include <sys/mkdev.h>

#include "zinject.h"

static int debug;

static void
ziprintf(const char *fmt, ...)
{
        va_list ap;

        if (!debug)
                return;

        va_start(ap, fmt);
        (void) vprintf(fmt, ap);
        va_end(ap);
}

static void
compress_slashes(const char *src, char *dest)
{
        while (*src != '\0') {
                *dest = *src++;
                while (*dest == '/' && *src == '/')
                        ++src;
                ++dest;
        }
        *dest = '\0';
}

/*
 * Given a full path to a file, translate into a dataset name and a relative
 * path within the dataset.  'dataset' must be at least MAXNAMELEN characters,
 * and 'relpath' must be at least MAXPATHLEN characters.  We also pass a stat64
 * buffer, which we need later to get the object ID.
 */
static int
parse_pathname(const char *inpath, char *dataset, char *relpath,
    struct stat64 *statbuf)
{
        struct extmnttab mp;
        FILE *fp;
        int match;
        const char *rel;
        char fullpath[MAXPATHLEN];

        compress_slashes(inpath, fullpath);

        if (fullpath[0] != '/') {
                (void) fprintf(stderr, "invalid object '%s': must be full "
                    "path\n", fullpath);
                usage();
                return (-1);
        }

        if (strlen(fullpath) >= MAXPATHLEN) {
                (void) fprintf(stderr, "invalid object; pathname too long\n");
                return (-1);
        }

        if (stat64(fullpath, statbuf) != 0) {
                (void) fprintf(stderr, "cannot open '%s': %s\n",
                    fullpath, strerror(errno));
                return (-1);
        }

        if ((fp = fopen(MNTTAB, "r")) == NULL) {
                (void) fprintf(stderr, "cannot open /etc/mnttab\n");
                return (-1);
        }

        match = 0;
        while (getextmntent(fp, &mp, sizeof (mp)) == 0) {
                if (makedev(mp.mnt_major, mp.mnt_minor) == statbuf->st_dev) {
                        match = 1;
                        break;
                }
        }

        if (!match) {
                (void) fprintf(stderr, "cannot find mountpoint for '%s'\n",
                    fullpath);
                return (-1);
        }

        if (strcmp(mp.mnt_fstype, MNTTYPE_ZFS) != 0) {
                (void) fprintf(stderr, "invalid path '%s': not a ZFS "
                    "filesystem\n", fullpath);
                return (-1);
        }

        if (strncmp(fullpath, mp.mnt_mountp, strlen(mp.mnt_mountp)) != 0) {
                (void) fprintf(stderr, "invalid path '%s': mountpoint "
                    "doesn't match path\n", fullpath);
                return (-1);
        }

        (void) strcpy(dataset, mp.mnt_special);

        rel = fullpath + strlen(mp.mnt_mountp);
        if (rel[0] == '/')
                rel++;
        (void) strcpy(relpath, rel);

        return (0);
}

/*
 * Convert from a dataset to a objset id. Note that
 * we grab the object number from the inode number.
 */
static int
object_from_path(const char *dataset, uint64_t object, zinject_record_t *record)
{
        zfs_handle_t *zhp;

        if ((zhp = zfs_open(g_zfs, dataset, ZFS_TYPE_DATASET)) == NULL)
                return (-1);

        record->zi_objset = zfs_prop_get_int(zhp, ZFS_PROP_OBJSETID);
        record->zi_object = object;

        zfs_close(zhp);

        return (0);
}

/*
 * Initialize the range based on the type, level, and range given.
 */
static int
initialize_range(err_type_t type, int level, char *range,
    zinject_record_t *record)
{
        /*
         * Determine the numeric range from the string.
         */
        if (range == NULL) {
                /*
                 * If range is unspecified, set the range to [0,-1], which
                 * indicates that the whole object should be treated as an
                 * error.
                 */
                record->zi_start = 0;
                record->zi_end = -1ULL;
        } else {
                char *end;

                /* XXX add support for suffixes */
                record->zi_start = strtoull(range, &end, 10);


                if (*end == '\0')
                        record->zi_end = record->zi_start + 1;
                else if (*end == ',')
                        record->zi_end = strtoull(end + 1, &end, 10);

                if (*end != '\0') {
                        (void) fprintf(stderr, "invalid range '%s': must be "
                            "a numeric range of the form 'start[,end]'\n",
                            range);
                        return (-1);
                }
        }

        switch (type) {
        case TYPE_DATA:
                break;

        case TYPE_DNODE:
                /*
                 * If this is a request to inject faults into the dnode, then we
                 * must translate the current (objset,object) pair into an
                 * offset within the metadnode for the objset.  Specifying any
                 * kind of range with type 'dnode' is illegal.
                 */
                if (range != NULL) {
                        (void) fprintf(stderr, "range cannot be specified when "
                            "type is 'dnode'\n");
                        return (-1);
                }

                record->zi_start = record->zi_object * sizeof (dnode_phys_t);
                record->zi_end = record->zi_start + sizeof (dnode_phys_t);
                record->zi_object = 0;
                break;
        }

        record->zi_level = level;

        return (0);
}

int
translate_record(err_type_t type, const char *object, const char *range,
    int level, zinject_record_t *record, char *poolname, char *dataset)
{
        char path[MAXPATHLEN];
        char *slash;
        struct stat64 statbuf;
        int ret = -1;

        debug = (getenv("ZINJECT_DEBUG") != NULL);

        ziprintf("translating: %s\n", object);

        if (MOS_TYPE(type)) {
                /*
                 * MOS objects are treated specially.
                 */
                switch (type) {
                case TYPE_MOS:
                        record->zi_type = 0;
                        break;
                case TYPE_MOSDIR:
                        record->zi_type = DMU_OT_OBJECT_DIRECTORY;
                        break;
                case TYPE_METASLAB:
                        record->zi_type = DMU_OT_OBJECT_ARRAY;
                        break;
                case TYPE_CONFIG:
                        record->zi_type = DMU_OT_PACKED_NVLIST;
                        break;
                case TYPE_BPOBJ:
                        record->zi_type = DMU_OT_BPOBJ;
                        break;
                case TYPE_SPACEMAP:
                        record->zi_type = DMU_OT_SPACE_MAP;
                        break;
                case TYPE_ERRLOG:
                        record->zi_type = DMU_OT_ERROR_LOG;
                        break;
                }

                dataset[0] = '\0';
                (void) strcpy(poolname, object);
                return (0);
        }

        /*
         * Convert a full path into a (dataset, file) pair.
         */
        if (parse_pathname(object, dataset, path, &statbuf) != 0)
                goto err;

        ziprintf("   dataset: %s\n", dataset);
        ziprintf("      path: %s\n", path);

        /*
         * Convert (dataset, file) into (objset, object)
         */
        if (object_from_path(dataset, statbuf.st_ino, record) != 0)
                goto err;

        ziprintf("raw objset: %llu\n", record->zi_objset);
        ziprintf("raw object: %llu\n", record->zi_object);

        /*
         * For the given object, initialize the range in bytes
         */
        if (initialize_range(type, level, (char *)range, record) != 0)
                goto err;

        ziprintf("    objset: %llu\n", record->zi_objset);
        ziprintf("    object: %llu\n", record->zi_object);
        if (record->zi_start == 0 &&
            record->zi_end == -1ULL)
                ziprintf("     range: all\n");
        else
                ziprintf("     range: [%llu, %llu]\n", record->zi_start,
                    record->zi_end);

        /*
         * Copy the pool name
         */
        (void) strcpy(poolname, dataset);
        if ((slash = strchr(poolname, '/')) != NULL)
                *slash = '\0';

        ret = 0;

err:
        return (ret);
}

int
translate_raw(const char *str, zinject_record_t *record)
{
        /*
         * A raw bookmark of the form objset:object:level:blkid, where each
         * number is a hexidecimal value.
         */
        if (sscanf(str, "%llx:%llx:%x:%llx", (u_longlong_t *)&record->zi_objset,
            (u_longlong_t *)&record->zi_object, &record->zi_level,
            (u_longlong_t *)&record->zi_start) != 4) {
                (void) fprintf(stderr, "bad raw spec '%s': must be of the form "
                    "'objset:object:level:blkid'\n", str);
                return (-1);
        }

        record->zi_end = record->zi_start;

        return (0);
}

int
translate_device(const char *pool, const char *device, err_type_t label_type,
    zinject_record_t *record)
{
        char *end;
        zpool_handle_t *zhp;
        nvlist_t *tgt;
        boolean_t isspare, iscache;

        /*
         * Given a device name or GUID, create an appropriate injection record
         * with zi_guid set.
         */
        if ((zhp = zpool_open(g_zfs, pool)) == NULL)
                return (-1);

        record->zi_guid = strtoull(device, &end, 16);
        if (record->zi_guid == 0 || *end != '\0') {
                tgt = zpool_find_vdev(zhp, device, &isspare, &iscache, NULL);

                if (tgt == NULL) {
                        (void) fprintf(stderr, "cannot find device '%s' in "
                            "pool '%s'\n", device, pool);
                        return (-1);
                }

                verify(nvlist_lookup_uint64(tgt, ZPOOL_CONFIG_GUID,
                    &record->zi_guid) == 0);
        }

        /*
         * Device faults can take on three different forms:
         * 1). delayed or hanging I/O
         * 2). zfs label faults
         * 3). generic disk faults
         */
        if (record->zi_timer != 0) {
                record->zi_cmd = ZINJECT_DELAY_IO;
        } else if (label_type != TYPE_INVAL) {
                record->zi_cmd = ZINJECT_LABEL_FAULT;
        } else {
                record->zi_cmd = ZINJECT_DEVICE_FAULT;
        }

        switch (label_type) {
        case TYPE_LABEL_UBERBLOCK:
                record->zi_start = offsetof(vdev_label_t, vl_uberblock[0]);
                record->zi_end = record->zi_start + VDEV_UBERBLOCK_RING - 1;
                break;
        case TYPE_LABEL_NVLIST:
                record->zi_start = offsetof(vdev_label_t, vl_vdev_phys);
                record->zi_end = record->zi_start + VDEV_PHYS_SIZE - 1;
                break;
        case TYPE_LABEL_PAD1:
                record->zi_start = offsetof(vdev_label_t, vl_pad1);
                record->zi_end = record->zi_start + VDEV_PAD_SIZE - 1;
                break;
        case TYPE_LABEL_PAD2:
                record->zi_start = offsetof(vdev_label_t, vl_be);
                record->zi_end = record->zi_start + VDEV_PAD_SIZE - 1;
                break;
        }
        return (0);
}