/*-
 * Copyright (c) 2002 Marcel Moolenaar
 * 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 AUTHOR ``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 AUTHOR 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.
 *
 * $FreeBSD: src/sbin/gpt/recover.c,v 1.8 2005/08/31 01:47:19 marcel Exp $
 */

#include <sys/types.h>

#include <err.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "gpt.h"

static void
usage_recover(void)
{
        fprintf(stderr, "usage: %s device ...\n", getprogname());
        exit(1);
}

static void
recover(int fd)
{
        off_t last;
        map_t *gpt, *tpg;
        map_t *tbl, *lbt;
        struct gpt_hdr *hdr;

        if (map_find(MAP_TYPE_MBR) != NULL) {
                warnx("%s: error: device contains a MBR", device_name);
                return;
        }

        gpt = map_find(MAP_TYPE_GPT_PRI_HDR);
        tpg = map_find(MAP_TYPE_GPT_SEC_HDR);
        tbl = map_find(MAP_TYPE_GPT_PRI_TBL);
        lbt = map_find(MAP_TYPE_GPT_SEC_TBL);

        if (gpt == NULL && tpg == NULL) {
                warnx("%s: no primary or secondary GPT headers, can't recover",
                    device_name);
                return;
        }
        if (tbl == NULL && lbt == NULL) {
                warnx("%s: no primary or secondary GPT tables, can't recover",
                    device_name);
                return;
        }

        last = mediasz / secsz - 1LL;

        if (tbl != NULL && lbt == NULL) {
                lbt = map_add(last - tbl->map_size, tbl->map_size,
                    MAP_TYPE_GPT_SEC_TBL, tbl->map_data);
                if (lbt == NULL) {
                        warnx("%s: adding secondary GPT table failed",
                            device_name);
                        return;
                }
                gpt_write(fd, lbt);
                warnx("%s: recovered secondary GPT table from primary",
                    device_name);
        } else if (tbl == NULL && lbt != NULL) {
                tbl = map_add(2LL, lbt->map_size, MAP_TYPE_GPT_PRI_TBL,
                    lbt->map_data);
                if (tbl == NULL) {
                        warnx("%s: adding primary GPT table failed",
                            device_name);
                        return;
                }
                gpt_write(fd, tbl);
                warnx("%s: recovered primary GPT table from secondary",
                    device_name);
        }

        if (gpt != NULL && tpg == NULL) {
                tpg = map_add(last, 1LL, MAP_TYPE_GPT_SEC_HDR,
                    calloc(1, secsz));
                if (tpg == NULL) {
                        warnx("%s: adding secondary GPT header failed",
                            device_name);
                        return;
                }
                memcpy(tpg->map_data, gpt->map_data, secsz);
                hdr = tpg->map_data;
                hdr->hdr_lba_self = htole64(tpg->map_start);
                hdr->hdr_lba_alt = htole64(gpt->map_start);
                hdr->hdr_lba_table = htole64(lbt->map_start);
                hdr->hdr_crc_self = 0;
                hdr->hdr_crc_self = htole32(crc32(hdr, le32toh(hdr->hdr_size)));
                gpt_write(fd, tpg);
                warnx("%s: recovered secondary GPT header from primary",
                    device_name);
        } else if (gpt == NULL && tpg != NULL) {
                gpt = map_add(1LL, 1LL, MAP_TYPE_GPT_PRI_HDR,
                    calloc(1, secsz));
                if (gpt == NULL) {
                        warnx("%s: adding primary GPT header failed",
                            device_name);
                        return;
                }
                memcpy(gpt->map_data, tpg->map_data, secsz);
                hdr = gpt->map_data;
                hdr->hdr_lba_self = htole64(gpt->map_start);
                hdr->hdr_lba_alt = htole64(tpg->map_start);
                hdr->hdr_lba_table = htole64(tbl->map_start);
                hdr->hdr_crc_self = 0;
                hdr->hdr_crc_self = htole32(crc32(hdr, le32toh(hdr->hdr_size)));
                gpt_write(fd, gpt);
                warnx("%s: recovered primary GPT header from secondary",
                    device_name);
        }

        /* Create PMBR if missing. */
        if (map_find(MAP_TYPE_PMBR) == NULL) {
                map_t *map;
                struct mbr *mbr;

                if (map_free(0LL) == 0) {
                        warnx("%s: error: no room for the PMBR", device_name);
                        return;
                }

                mbr = gpt_read(fd, 0LL, 1);
                if (mbr == NULL) {
                        warnx("%s: error: reading PMBR failed", device_name);
                        return;
                }

                bzero(mbr, sizeof(*mbr));
                mbr->mbr_sig = htole16(DOSMAGIC);
                mbr->mbr_part[0].dp_shd = 0xff;
                mbr->mbr_part[0].dp_ssect = 0xff;
                mbr->mbr_part[0].dp_scyl = 0xff;
                mbr->mbr_part[0].dp_typ = DOSPTYP_PMBR;
                mbr->mbr_part[0].dp_ehd = 0xff;
                mbr->mbr_part[0].dp_esect = 0xff;
                mbr->mbr_part[0].dp_ecyl = 0xff;
                mbr->mbr_part[0].dp_start = htole32(1U);
                if (last > 0xffffffff)
                        mbr->mbr_part[0].dp_size = htole32(0xffffffffU);
                else
                        mbr->mbr_part[0].dp_size = htole32((uint32_t)last);
                map = map_add(0LL, 1LL, MAP_TYPE_PMBR, mbr);
                gpt_write(fd, map);
                warnx("%s: recreated PMBR", device_name);
        }
}

int
cmd_recover(int argc, char *argv[])
{
        int ch, fd;

        while ((ch = getopt(argc, argv, "h")) != -1) {
                switch(ch) {
                case 'h':
                default:
                        usage_recover();
                }
        }

        if (argc == optind)
                usage_recover();

        while (optind < argc) {
                fd = gpt_open(argv[optind++]);
                if (fd == -1) {
                        warn("unable to open device '%s'", device_name);
                        continue;
                }

                recover(fd);

                gpt_close(fd);
        }

        return (0);
}