/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2005 Ivan Voras <ivoras@freebsd.org>
 *
 * 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 <errno.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <strings.h>
#include <fcntl.h>
#include <unistd.h>
#include <libgeom.h>
#include <err.h>
#include <assert.h>

#include <core/geom.h>
#include <misc/subr.h>

#include <geom/virstor/g_virstor_md.h>
#include <geom/virstor/g_virstor.h>

uint32_t lib_version = G_LIB_VERSION;
uint32_t version = G_VIRSTOR_VERSION;

#define GVIRSTOR_CHUNK_SIZE     "4M"
#define GVIRSTOR_VIR_SIZE       "2T"

#if G_LIB_VERSION == 1
/* Support RELENG_6 */
#define G_TYPE_BOOL G_TYPE_NONE
#endif

/*
 * virstor_main gets called by the geom(8) utility
 */
static void virstor_main(struct gctl_req *req, unsigned flags);

struct g_command class_commands[] = {
        { "clear", G_FLAG_VERBOSE, virstor_main, G_NULL_OPTS,
            "[-v] prov ..."
        },
        { "dump", 0, virstor_main, G_NULL_OPTS,
            "prov ..."
        },
        { "label", G_FLAG_VERBOSE | G_FLAG_LOADKLD, virstor_main,
            {
                { 'h', "hardcode", NULL, G_TYPE_BOOL},
                { 'm', "chunk_size", GVIRSTOR_CHUNK_SIZE, G_TYPE_NUMBER},
                { 's', "vir_size", GVIRSTOR_VIR_SIZE, G_TYPE_NUMBER},
                G_OPT_SENTINEL
            },
            "[-h] [-v] [-m chunk_size] [-s vir_size] name provider0 [provider1 ...]"
        },
        { "destroy", G_FLAG_VERBOSE, NULL,
            {
                { 'f', "force", NULL, G_TYPE_BOOL},
                G_OPT_SENTINEL
            },
            "[-fv] name ..."
        },
        { "stop", G_FLAG_VERBOSE, NULL,
            {
                { 'f', "force", NULL, G_TYPE_BOOL},
                G_OPT_SENTINEL
            },
            "[-fv] name ... (alias for \"destroy\")"
        },
        { "add", G_FLAG_VERBOSE, NULL,
            {
                { 'h', "hardcode", NULL, G_TYPE_BOOL},
                G_OPT_SENTINEL
            },
            "[-vh] name prov [prov ...]"
        },
        { "remove", G_FLAG_VERBOSE, NULL, G_NULL_OPTS,
            "[-v] name ..."
        },
        G_CMD_SENTINEL
};

static int verbose = 0;

/* Helper functions' declarations */
static void virstor_clear(struct gctl_req *req);
static void virstor_dump(struct gctl_req *req);
static void virstor_label(struct gctl_req *req);

/* Dispatcher function (no real work done here, only verbose flag recorder) */
static void
virstor_main(struct gctl_req *req, unsigned flags)
{
        const char *name;

        if ((flags & G_FLAG_VERBOSE) != 0)
                verbose = 1;

        name = gctl_get_ascii(req, "verb");
        if (name == NULL) {
                gctl_error(req, "No '%s' argument.", "verb");
                return;
        }
        if (strcmp(name, "label") == 0)
                virstor_label(req);
        else if (strcmp(name, "clear") == 0)
                virstor_clear(req);
        else if (strcmp(name, "dump") == 0)
                virstor_dump(req);
        else
                gctl_error(req, "%s: Unknown command: %s.", __func__, name);

        /* No CTASSERT in userland
        CTASSERT(VIRSTOR_MAP_BLOCK_ENTRIES*VIRSTOR_MAP_ENTRY_SIZE == MAXPHYS);
        */
}

/*
 * Labels a new geom Meaning: parses and checks the parameters, calculates &
 * writes metadata to the relevant providers so when the next round of
 * "tasting" comes (which will be just after the provider(s) are closed) geom
 * can be instantiated with the tasted metadata.
 */
static void
virstor_label(struct gctl_req *req)
{
        struct g_virstor_metadata md;
        off_t msize;
        unsigned char *sect;
        unsigned int i;
        size_t ssize, secsize;
        const char *name;
        char param[32];
        int hardcode, nargs, error;
        struct virstor_map_entry *map;
        size_t total_chunks, write_max_map_entries;
        unsigned int map_chunks; /* Chunks needed by the map (map size). */
        size_t map_size;        /* In bytes. */
        ssize_t written;
        int fd;

        nargs = gctl_get_int(req, "nargs");
        if (nargs < 2) {
                gctl_error(req, "Too few arguments (%d): expecting: name "
                    "provider0 [provider1 ...]", nargs);
                return;
        }

        hardcode = gctl_get_int(req, "hardcode");

        /*
         * Initialize constant parts of metadata: magic signature, version,
         * name.
         */
        bzero(&md, sizeof(md));
        strlcpy(md.md_magic, G_VIRSTOR_MAGIC, sizeof(md.md_magic));
        md.md_version = G_VIRSTOR_VERSION;
        name = gctl_get_ascii(req, "arg0");
        if (name == NULL) {
                gctl_error(req, "No 'arg%u' argument.", 0);
                return;
        }
        strlcpy(md.md_name, name, sizeof(md.md_name));

        md.md_virsize = (off_t)gctl_get_intmax(req, "vir_size");
        md.md_chunk_size = gctl_get_intmax(req, "chunk_size");
        md.md_count = nargs - 1;

        if (md.md_virsize == 0 || md.md_chunk_size == 0) {
                gctl_error(req, "Virtual size and chunk size must be non-zero");
                return;
        }

        msize = secsize = 0;
        for (i = 1; i < (unsigned)nargs; i++) {
                snprintf(param, sizeof(param), "arg%u", i);
                name = gctl_get_ascii(req, "%s", param);
                ssize = g_get_sectorsize(name);
                if (ssize == 0)
                        fprintf(stderr, "%s for %s\n", strerror(errno), name);
                msize += g_get_mediasize(name);
                if (secsize == 0)
                        secsize = ssize;
                else if (secsize != ssize) {
                        gctl_error(req, "Devices need to have same sector size "
                            "(%u on %s needs to be %u).",
                            (u_int)ssize, name, (u_int)secsize);
                        return;
                }
        }

        if (secsize == 0) {
                gctl_error(req, "Device not specified");
                return;
        }

        if (md.md_chunk_size % secsize != 0) {
                size_t new_size = roundup(md.md_chunk_size, secsize);
                fprintf(stderr, "Resizing chunk size to be a multiple of "
                    "sector size (%zu bytes).\n", secsize);
                fprintf(stderr, "New chunk size: %zu kB\n", new_size / 1024);
                md.md_chunk_size = new_size;
        }

        if (md.md_virsize % md.md_chunk_size != 0) {
                off_t chunk_count = md.md_virsize / md.md_chunk_size;
                md.md_virsize = chunk_count * md.md_chunk_size;
                fprintf(stderr, "Resizing virtual size to be a multiple of "
                    "chunk size.\n");
                fprintf(stderr, "New virtual size: %zu MB\n",
                    (size_t)(md.md_virsize / (1024 * 1024)));
        }

        total_chunks = md.md_virsize / md.md_chunk_size;
        map_size = total_chunks * sizeof(*map);
        assert(md.md_virsize % md.md_chunk_size == 0);

        ssize = map_size % secsize;
        if (ssize != 0) {
                size_t add_chunks = (secsize - ssize) / sizeof(*map);
                total_chunks += add_chunks;
                md.md_virsize = (off_t)total_chunks * (off_t)md.md_chunk_size;
                map_size = total_chunks * sizeof(*map);
                fprintf(stderr, "Resizing virtual size to fit virstor "
                    "structures.\n");
                fprintf(stderr, "New virtual size: %ju MB (%zu new chunks)\n",
                    (uintmax_t)(md.md_virsize / (1024 * 1024)), add_chunks);
        }

        if (verbose)
                printf("Total virtual chunks: %zu (%zu MB each), %ju MB total "
                    "virtual size.\n",
                    total_chunks, (size_t)(md.md_chunk_size / (1024 * 1024)),
                    md.md_virsize/(1024 * 1024));

        if ((off_t)md.md_virsize < msize)
                fprintf(stderr, "WARNING: Virtual storage size < Physical "
                    "available storage (%ju < %ju)\n", md.md_virsize, msize);

        /* Clear last sector first to spoil all components if device exists. */
        if (verbose)
                printf("Clearing metadata on");

        for (i = 1; i < (unsigned)nargs; i++) {
                snprintf(param, sizeof(param), "arg%u", i);
                name = gctl_get_ascii(req, "%s", param);

                if (verbose)
                        printf(" %s", name);

                msize = g_get_mediasize(name);
                ssize = g_get_sectorsize(name);
                if (msize == 0 || ssize == 0) {
                        gctl_error(req, "Can't retrieve information about "
                            "%s: %s.", name, strerror(errno));
                        return;
                }
                if (msize < (off_t) MAX(md.md_chunk_size*4, map_size))
                        gctl_error(req, "Device %s is too small", name);
                error = g_metadata_clear(name, NULL);
                if (error != 0) {
                        gctl_error(req, "Can't clear metadata on %s: %s.", name,
                            strerror(error));
                        return;
                }
        }


        /* Write allocation table to the first provider - this needs to be done
         * before metadata is written because when kernel tastes it it's too
         * late */
        name = gctl_get_ascii(req, "arg1"); /* device with metadata */
        if (verbose)
                printf(".\nWriting allocation table to %s...", name);

        /* How many chunks does the map occupy? */
        map_chunks = map_size/md.md_chunk_size;
        if (map_size % md.md_chunk_size != 0)
                map_chunks++;
        if (verbose) {
                printf(" (%zu MB, %d chunks) ", map_size/(1024*1024), map_chunks);
                fflush(stdout);
        }

        if (strncmp(name, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
                fd = open(name, O_RDWR);
        else {
                sprintf(param, "%s%s", _PATH_DEV, name);
                fd = open(param, O_RDWR);
        }
        if (fd < 0) {
                gctl_error(req, "Cannot open provider %s to write map", name);
                return;
        }

        /*
         * Initialize and write the map.  Don't malloc the whole map at once,
         * in case it's large.  Use calloc because there might be a need to set
         * up chunk flags in the future.
         */
        write_max_map_entries = 1024 * 1024 / sizeof(*map);
        if (write_max_map_entries > total_chunks)
                write_max_map_entries = total_chunks;
        map = calloc(write_max_map_entries, sizeof(*map));
        if (map == NULL) {
                gctl_error(req,
                    "Out of memory (need %zu bytes for allocation map)",
                    write_max_map_entries * sizeof(*map));
                close(fd);
                return;
        }
        for (size_t chunk = 0; chunk < total_chunks;
            chunk += write_max_map_entries) {
                size_t bytes_to_write, entries_to_write;

                entries_to_write = total_chunks - chunk;
                if (entries_to_write > write_max_map_entries)
                        entries_to_write = write_max_map_entries;
                bytes_to_write = entries_to_write * sizeof(*map);
                for (size_t off = 0; off < bytes_to_write; off += written) {
                        written = write(fd, ((char *)map) + off,
                            bytes_to_write - off);
                        if (written < 0) {
                                if (verbose) {
                                        fprintf(stderr,
                                            "\nError writing map at offset "
                                            "%zu of %zu: %s\n",
                                            chunk * sizeof(*map) + off,
                                            map_size, strerror(errno));
                                }
                                gctl_error(req,
                                    "Error writing out allocation map!");
                                free(map);
                                close(fd);
                                return;
                        }
                }
        }
        free(map);
        map = NULL;
        close (fd);

        if (verbose)
                printf("\nStoring metadata on ");

        /*
         * ID is randomly generated, unique for a geom. This is used to
         * recognize all providers belonging to one geom.
         */
        md.md_id = arc4random();

        /* Ok, store metadata. */
        for (i = 1; i < (unsigned)nargs; i++) {
                snprintf(param, sizeof(param), "arg%u", i);
                name = gctl_get_ascii(req, "%s", param);

                msize = g_get_mediasize(name);
                ssize = g_get_sectorsize(name);

                if (verbose)
                        printf("%s ", name);

                /* this provider's position/type in geom */
                md.no = i - 1;
                /* this provider's size */
                md.provsize = msize;
                /* chunk allocation info */
                md.chunk_count = md.provsize / md.md_chunk_size;
                if (verbose)
                        printf("(%u chunks) ", md.chunk_count);
                /* Check to make sure last sector is unused */
                if ((off_t)(md.chunk_count * md.md_chunk_size) > (off_t)(msize-ssize))
                    md.chunk_count--;
                md.chunk_next = 0;
                if (i != 1) {
                        md.chunk_reserved = 0;
                        md.flags = 0;
                } else {
                        md.chunk_reserved = map_chunks * 2;
                        md.flags = VIRSTOR_PROVIDER_ALLOCATED |
                            VIRSTOR_PROVIDER_CURRENT;
                        md.chunk_next = md.chunk_reserved;
                        if (verbose)
                                printf("(%u reserved) ", md.chunk_reserved);
                }

                if (!hardcode)
                        bzero(md.provider, sizeof(md.provider));
                else {
                        /* convert "/dev/something" to "something" */
                        if (strncmp(name, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0) {
                                strlcpy(md.provider, name + sizeof(_PATH_DEV) - 1,
                                    sizeof(md.provider));
                        } else
                                strlcpy(md.provider, name, sizeof(md.provider));
                }
                sect = calloc(ssize, sizeof(unsigned char));
                if (sect == NULL)
                        err(1, "Cannot allocate sector of %zu bytes", ssize);
                virstor_metadata_encode(&md, sect);
                error = g_metadata_store(name, sect, ssize);
                free(sect);
                if (error != 0) {
                        if (verbose)
                                printf("\n");
                        fprintf(stderr, "Can't store metadata on %s: %s.\n",
                            name, strerror(error));
                        gctl_error(req,
                            "Not fully done (error storing metadata).");
                        return;
                }
        }
#if 0
        if (verbose)
                printf("\n");
#endif
}

/* Clears metadata on given provider(s) IF it's owned by us */
static void
virstor_clear(struct gctl_req *req)
{
        const char *name;
        char param[32];
        unsigned i;
        int nargs, error;
        int fd;

        nargs = gctl_get_int(req, "nargs");
        if (nargs < 1) {
                gctl_error(req, "Too few arguments.");
                return;
        }
        for (i = 0; i < (unsigned)nargs; i++) {
                snprintf(param, sizeof(param), "arg%u", i);
                name = gctl_get_ascii(req, "%s", param);

                error = g_metadata_clear(name, G_VIRSTOR_MAGIC);
                if (error != 0) {
                        fprintf(stderr, "Can't clear metadata on %s: %s "
                            "(do I own it?)\n", name, strerror(error));
                        gctl_error(req,
                            "Not fully done (can't clear metadata).");
                        continue;
                }
                if (strncmp(name, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
                        fd = open(name, O_RDWR);
                else {
                        sprintf(param, "%s%s", _PATH_DEV, name);
                        fd = open(param, O_RDWR);
                }
                if (fd < 0) {
                        gctl_error(req, "Cannot clear header sector for %s",
                            name);
                        continue;
                }
                if (verbose)
                        printf("Metadata cleared on %s.\n", name);
        }
}

/* Print some metadata information */
static void
virstor_metadata_dump(const struct g_virstor_metadata *md)
{
        printf("          Magic string: %s\n", md->md_magic);
        printf("      Metadata version: %u\n", (u_int) md->md_version);
        printf("           Device name: %s\n", md->md_name);
        printf("             Device ID: %u\n", (u_int) md->md_id);
        printf("        Provider index: %u\n", (u_int) md->no);
        printf("      Active providers: %u\n", (u_int) md->md_count);
        printf("    Hardcoded provider: %s\n",
            md->provider[0] != '\0' ? md->provider : "(not hardcoded)");
        printf("          Virtual size: %u MB\n",
            (unsigned int)(md->md_virsize/(1024 * 1024)));
        printf("            Chunk size: %u kB\n", md->md_chunk_size / 1024);
        printf("    Chunks on provider: %u\n", md->chunk_count);
        printf("           Chunks free: %u\n", md->chunk_count - md->chunk_next);
        printf("       Reserved chunks: %u\n", md->chunk_reserved);
}

/* Called by geom(8) via gvirstor_main() to dump metadata information */
static void
virstor_dump(struct gctl_req *req)
{
        struct g_virstor_metadata md;
        u_char tmpmd[512];      /* temporary buffer */
        const char *name;
        char param[16];
        int nargs, error, i;

        assert(sizeof(tmpmd) >= sizeof(md));

        nargs = gctl_get_int(req, "nargs");
        if (nargs < 1) {
                gctl_error(req, "Too few arguments.");
                return;
        }
        for (i = 0; i < nargs; i++) {
                snprintf(param, sizeof(param), "arg%u", i);
                name = gctl_get_ascii(req, "%s", param);

                error = g_metadata_read(name, (u_char *) & tmpmd, sizeof(tmpmd),
                    G_VIRSTOR_MAGIC);
                if (error != 0) {
                        fprintf(stderr, "Can't read metadata from %s: %s.\n",
                            name, strerror(error));
                        gctl_error(req,
                            "Not fully done (error reading metadata).");
                        continue;
                }
                virstor_metadata_decode((u_char *) & tmpmd, &md);
                printf("Metadata on %s:\n", name);
                virstor_metadata_dump(&md);
                printf("\n");
        }
}