/*
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1998 Robert Nordier
 * 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(S) ``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(S) 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>
#ifdef MAKEFS
/* In the makefs case we only want struct disklabel */
#include <sys/disk/bsd.h>
#else
#include <sys/fdcio.h>
#include <sys/disk.h>
#include <sys/disklabel.h>
#include <sys/mount.h>
#endif
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/time.h>

#include <assert.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <paths.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "mkfs_msdos.h"

#define MAXU16    0xffff        /* maximum unsigned 16-bit quantity */
#define BPN       4             /* bits per nibble */
#define NPB       2             /* nibbles per byte */

#define DOSMAGIC  0xaa55        /* DOS magic number */
#define MINBPS    512           /* minimum bytes per sector */
#define MAXBPS    4096          /* maximum bytes per sector */
#define MAXSPC    128           /* maximum sectors per cluster */
#define MAXNFT    16            /* maximum number of FATs */
#define DEFBLK    4096          /* default block size */
#define DEFBLK16  2048          /* default block size FAT16 */
#define DEFRDE    512           /* default root directory entries */
#define RESFTE    2             /* reserved FAT entries */
#define MINCLS12  1U            /* minimum FAT12 clusters */
#define MINCLS16  0xff5U        /* minimum FAT16 clusters */
#define MINCLS32  0xfff5U       /* minimum FAT32 clusters */
#define MAXCLS12  0xff4U        /* maximum FAT12 clusters */
#define MAXCLS16  0xfff4U       /* maximum FAT16 clusters */
#define MAXCLS32  0xffffff4U    /* maximum FAT32 clusters */

#define mincls(fat)  ((fat) == 12 ? MINCLS12 :  \
                      (fat) == 16 ? MINCLS16 :  \
                                    MINCLS32)

#define maxcls(fat)  ((fat) == 12 ? MAXCLS12 :  \
                      (fat) == 16 ? MAXCLS16 :  \
                                    MAXCLS32)

#define mk1(p, x)                               \
    (p) = (u_int8_t)(x)

#define mk2(p, x)                               \
    (p)[0] = (u_int8_t)(x),                     \
    (p)[1] = (u_int8_t)((x) >> 010)

#define mk4(p, x)                               \
    (p)[0] = (u_int8_t)(x),                     \
    (p)[1] = (u_int8_t)((x) >> 010),            \
    (p)[2] = (u_int8_t)((x) >> 020),            \
    (p)[3] = (u_int8_t)((x) >> 030)

struct bs {
    u_int8_t bsJump[3];                 /* bootstrap entry point */
    u_int8_t bsOemName[8];              /* OEM name and version */
} __packed;

struct bsbpb {
    u_int8_t bpbBytesPerSec[2];         /* bytes per sector */
    u_int8_t bpbSecPerClust;            /* sectors per cluster */
    u_int8_t bpbResSectors[2];          /* reserved sectors */
    u_int8_t bpbFATs;                   /* number of FATs */
    u_int8_t bpbRootDirEnts[2];         /* root directory entries */
    u_int8_t bpbSectors[2];             /* total sectors */
    u_int8_t bpbMedia;                  /* media descriptor */
    u_int8_t bpbFATsecs[2];             /* sectors per FAT */
    u_int8_t bpbSecPerTrack[2];         /* sectors per track */
    u_int8_t bpbHeads[2];               /* drive heads */
    u_int8_t bpbHiddenSecs[4];          /* hidden sectors */
    u_int8_t bpbHugeSectors[4];         /* big total sectors */
} __packed;

struct bsxbpb {
    u_int8_t bpbBigFATsecs[4];          /* big sectors per FAT */
    u_int8_t bpbExtFlags[2];            /* FAT control flags */
    u_int8_t bpbFSVers[2];              /* file system version */
    u_int8_t bpbRootClust[4];           /* root directory start cluster */
    u_int8_t bpbFSInfo[2];              /* file system info sector */
    u_int8_t bpbBackup[2];              /* backup boot sector */
    u_int8_t bpbReserved[12];           /* reserved */
} __packed;

struct bsx {
    u_int8_t exDriveNumber;             /* drive number */
    u_int8_t exReserved1;               /* reserved */
    u_int8_t exBootSignature;           /* extended boot signature */
    u_int8_t exVolumeID[4];             /* volume ID number */
    u_int8_t exVolumeLabel[11];         /* volume label */
    u_int8_t exFileSysType[8];          /* file system type */
} __packed;

struct de {
    u_int8_t deName[11];                /* name and extension */
    u_int8_t deAttributes;              /* attributes */
    u_int8_t rsvd[10];                  /* reserved */
    u_int8_t deMTime[2];                /* last-modified time */
    u_int8_t deMDate[2];                /* last-modified date */
    u_int8_t deStartCluster[2];         /* starting cluster */
    u_int8_t deFileSize[4];             /* size */
} __packed;

struct bpb {
    u_int bpbBytesPerSec;               /* bytes per sector */
    u_int bpbSecPerClust;               /* sectors per cluster */
    u_int bpbResSectors;                /* reserved sectors */
    u_int bpbFATs;                      /* number of FATs */
    u_int bpbRootDirEnts;               /* root directory entries */
    u_int bpbSectors;                   /* total sectors */
    u_int bpbMedia;                     /* media descriptor */
    u_int bpbFATsecs;                   /* sectors per FAT */
    u_int bpbSecPerTrack;               /* sectors per track */
    u_int bpbHeads;                     /* drive heads */
    u_int bpbHiddenSecs;                /* hidden sectors */
    u_int bpbHugeSectors;               /* big total sectors */
    u_int bpbBigFATsecs;                /* big sectors per FAT */
    u_int bpbRootClust;                 /* root directory start cluster */
    u_int bpbFSInfo;                    /* file system info sector */
    u_int bpbBackup;                    /* backup boot sector */
};

#define BPBGAP 0, 0, 0, 0, 0, 0

static struct {
    const char *name;
    struct bpb bpb;
} const stdfmt[] = {
    {"160",  {512, 1, 1, 2,  64,  320, 0xfe, 1,  8, 1, BPBGAP}},
    {"180",  {512, 1, 1, 2,  64,  360, 0xfc, 2,  9, 1, BPBGAP}},
    {"320",  {512, 2, 1, 2, 112,  640, 0xff, 1,  8, 2, BPBGAP}},
    {"360",  {512, 2, 1, 2, 112,  720, 0xfd, 2,  9, 2, BPBGAP}},
    {"640",  {512, 2, 1, 2, 112, 1280, 0xfb, 2,  8, 2, BPBGAP}},
    {"720",  {512, 2, 1, 2, 112, 1440, 0xf9, 3,  9, 2, BPBGAP}},
    {"1200", {512, 1, 1, 2, 224, 2400, 0xf9, 7, 15, 2, BPBGAP}},
    {"1232", {1024,1, 1, 2, 192, 1232, 0xfe, 2,  8, 2, BPBGAP}},
    {"1440", {512, 1, 1, 2, 224, 2880, 0xf0, 9, 18, 2, BPBGAP}},
    {"2880", {512, 2, 1, 2, 240, 5760, 0xf0, 9, 36, 2, BPBGAP}}
};

static const u_int8_t bootcode[] = {
    0xfa,                       /* cli              */
    0x31, 0xc0,                 /* xor     ax,ax    */
    0x8e, 0xd0,                 /* mov     ss,ax    */
    0xbc, 0x00, 0x7c,           /* mov     sp,7c00h */
    0xfb,                       /* sti              */
    0x8e, 0xd8,                 /* mov     ds,ax    */
    0xe8, 0x00, 0x00,           /* call    $ + 3    */
    0x5e,                       /* pop     si       */
    0x83, 0xc6, 0x19,           /* add     si,+19h  */
    0xbb, 0x07, 0x00,           /* mov     bx,0007h */
    0xfc,                       /* cld              */
    0xac,                       /* lodsb            */
    0x84, 0xc0,                 /* test    al,al    */
    0x74, 0x06,                 /* jz      $ + 8    */
    0xb4, 0x0e,                 /* mov     ah,0eh   */
    0xcd, 0x10,                 /* int     10h      */
    0xeb, 0xf5,                 /* jmp     $ - 9    */
    0x30, 0xe4,                 /* xor     ah,ah    */
    0xcd, 0x16,                 /* int     16h      */
    0xcd, 0x19,                 /* int     19h      */
    0x0d, 0x0a,
    'N', 'o', 'n', '-', 's', 'y', 's', 't',
    'e', 'm', ' ', 'd', 'i', 's', 'k',
    0x0d, 0x0a,
    'P', 'r', 'e', 's', 's', ' ', 'a', 'n',
    'y', ' ', 'k', 'e', 'y', ' ', 't', 'o',
    ' ', 'r', 'e', 'b', 'o', 'o', 't',
    0x0d, 0x0a,
    0
};

static volatile sig_atomic_t got_siginfo;
static void infohandler(int);

#ifndef MAKEFS
static int check_mounted(const char *, mode_t);
#endif
static ssize_t getchunksize(void);
static int getstdfmt(const char *, struct bpb *);
static int getdiskinfo(int, const char *, const char *, int, struct bpb *);
static void print_bpb(struct bpb *);
static int ckgeom(const char *, u_int, const char *);
static void mklabel(u_int8_t *, const char *);
static int oklabel(const char *);
static void setstr(u_int8_t *, const char *, size_t);

int
mkfs_msdos(const char *fname, const char *dtype, const struct msdos_options *op)
{
    char buf[MAXPATHLEN];
    struct sigaction si_sa;
    struct stat sb;
    struct timeval tv;
    struct bpb bpb;
    struct tm *tm;
    struct bs *bs;
    struct bsbpb *bsbpb;
    struct bsxbpb *bsxbpb;
    struct bsx *bsx;
    struct de *de;
    u_int8_t *img;
    u_int8_t *physbuf, *physbuf_end;
    const char *bname;
    ssize_t n;
    time_t now;
    u_int fat, bss, rds, cls, dir, lsn, x, x1, x2;
    u_int extra_res, alignment, alignto, saved_x, attempts=0;
    bool set_res, set_spf, set_spc;
    int fd, fd1, rv;
    struct msdos_options o = *op;
    ssize_t chunksize;

    physbuf = NULL;
    rv = -1;
    fd = fd1 = -1;

    if (o.block_size && o.sectors_per_cluster) {
        warnx("Cannot specify both block size and sectors per cluster");
        goto done;
    }
    if (o.OEM_string && strlen(o.OEM_string) > 8) {
        warnx("%s: OEM string too long", o.OEM_string);
        goto done;
    }
    if (o.create_size) {
        if (o.no_create) {
            warnx("create (-C) is incompatible with -N");
            goto done;
        }
        fd = open(fname, O_RDWR | O_CREAT | O_TRUNC, 0644);
        if (fd == -1) {
            warn("failed to create %s", fname);
            goto done;
        }
        if (ftruncate(fd, o.create_size)) {
            warn("failed to initialize %jd bytes", (intmax_t)o.create_size);
            goto done;
        }
    } else if ((fd = open(fname, o.no_create ? O_RDONLY : O_RDWR)) == -1) {
        warn("%s", fname);
        goto done;
    }
    if (fstat(fd, &sb)) {
        warn("%s", fname);
        goto done;
    }
    if (o.create_size) {
        if (!S_ISREG(sb.st_mode))
            warnx("warning, %s is not a regular file", fname);
    } else {
#ifdef MAKEFS
        errx(1, "o.create_size must be set!");
#else
        if (!S_ISCHR(sb.st_mode))
            warnx("warning, %s is not a character device", fname);
#endif
    }
#ifndef MAKEFS
    if (!o.no_create)
        if (check_mounted(fname, sb.st_mode) == -1)
            goto done;
#endif
    if (o.offset && o.offset != lseek(fd, o.offset, SEEK_SET)) {
        warnx("cannot seek to %jd", (intmax_t)o.offset);
        goto done;
    }
    memset(&bpb, 0, sizeof(bpb));
    if (o.floppy) {
        if (getstdfmt(o.floppy, &bpb) == -1)
            goto done;
        bpb.bpbHugeSectors = bpb.bpbSectors;
        bpb.bpbSectors = 0;
        bpb.bpbBigFATsecs = bpb.bpbFATsecs;
        bpb.bpbFATsecs = 0;
    }
    if (o.drive_heads)
        bpb.bpbHeads = o.drive_heads;
    if (o.sectors_per_track)
        bpb.bpbSecPerTrack = o.sectors_per_track;
    if (o.bytes_per_sector)
        bpb.bpbBytesPerSec = o.bytes_per_sector;
    if (o.size)
        bpb.bpbHugeSectors = o.size;
    if (o.hidden_sectors_set)
        bpb.bpbHiddenSecs = o.hidden_sectors;
    if (!(o.floppy || (o.drive_heads && o.sectors_per_track &&
        o.bytes_per_sector && o.size && o.hidden_sectors_set))) {
        if (getdiskinfo(fd, fname, dtype, o.hidden_sectors_set, &bpb) == -1)
                goto done;
        bpb.bpbHugeSectors -= (o.offset / bpb.bpbBytesPerSec);
        if (bpb.bpbSecPerClust == 0) {  /* set defaults */
            if (bpb.bpbHugeSectors <= 6000)     /* about 3MB -> 512 bytes */
                bpb.bpbSecPerClust = 1;
            else if (bpb.bpbHugeSectors <= (1<<17)) /* 64M -> 4k */
                bpb.bpbSecPerClust = 8;
            else if (bpb.bpbHugeSectors <= (1<<19)) /* 256M -> 8k */
                bpb.bpbSecPerClust = 16;
            else if (bpb.bpbHugeSectors <= (1<<21)) /* 1G -> 16k */
                bpb.bpbSecPerClust = 32;
            else
                bpb.bpbSecPerClust = 64;                /* otherwise 32k */
        }
    }
    if (bpb.bpbBytesPerSec < MINBPS ||
        bpb.bpbBytesPerSec > MAXBPS ||
        !powerof2(bpb.bpbBytesPerSec)) {
        warnx("Invalid bytes/sector (%u): must be 512, 1024, 2048 or 4096",
            bpb.bpbBytesPerSec);
        goto done;
    }

    if (o.volume_label && !oklabel(o.volume_label)) {
        warnx("%s: bad volume label", o.volume_label);
        goto done;
    }
    if (!(fat = o.fat_type)) {
        if (o.floppy)
            fat = 12;
        else if (!o.directory_entries && (o.info_sector || o.backup_sector))
            fat = 32;
    }
    if ((fat == 32 && o.directory_entries) || (fat != 32 && (o.info_sector || o.backup_sector))) {
        warnx("-%c is not a legal FAT%s option",
             fat == 32 ? 'e' : o.info_sector ? 'i' : 'k',
             fat == 32 ? "32" : "12/16");
        goto done;
    }
    if (o.floppy && fat == 32)
        bpb.bpbRootDirEnts = 0;
    if (fat != 0 && fat != 12 && fat != 16 && fat != 32) {
        warnx("%d: bad FAT type", fat);
        goto done;
    }

    if (o.block_size) {
        if (!powerof2(o.block_size)) {
            warnx("block size (%u) is not a power of 2", o.block_size);
            goto done;
        }
        if (o.block_size < bpb.bpbBytesPerSec) {
            warnx("block size (%u) is too small; minimum is %u",
                 o.block_size, bpb.bpbBytesPerSec);
            goto done;
        }
        if (o.block_size > bpb.bpbBytesPerSec * MAXSPC) {
            warnx("block size (%u) is too large; maximum is %u",
                 o.block_size, bpb.bpbBytesPerSec * MAXSPC);
            goto done;
        }
        bpb.bpbSecPerClust = o.block_size / bpb.bpbBytesPerSec;
    }
    if (o.sectors_per_cluster) {
        if (!powerof2(o.sectors_per_cluster)) {
            warnx("sectors/cluster (%u) is not a power of 2",
                o.sectors_per_cluster);
            goto done;
        }
        bpb.bpbSecPerClust = o.sectors_per_cluster;
    }
    if (o.reserved_sectors)
        bpb.bpbResSectors = o.reserved_sectors;
    if (o.num_FAT) {
        if (o.num_FAT > MAXNFT) {
            warnx("number of FATs (%u) is too large; maximum is %u",
                 o.num_FAT, MAXNFT);
            goto done;
        }
        bpb.bpbFATs = o.num_FAT;
    }
    if (o.directory_entries) {
        bpb.bpbRootDirEnts = roundup(o.directory_entries,
            bpb.bpbBytesPerSec / sizeof(struct de));
        if (bpb.bpbBytesPerSec == 0 || o.directory_entries >= MAXU16)
            bpb.bpbRootDirEnts = MAXU16;
    }
    if (o.media_descriptor_set) {
        if (o.media_descriptor < 0xf0) {
            warnx("illegal media descriptor (%#x)", o.media_descriptor);
            goto done;
        }
        bpb.bpbMedia = o.media_descriptor;
    }
    if (o.sectors_per_fat)
        bpb.bpbBigFATsecs = o.sectors_per_fat;
    if (o.info_sector)
        bpb.bpbFSInfo = o.info_sector;
    if (o.backup_sector)
        bpb.bpbBackup = o.backup_sector;
    bss = 1;
    bname = NULL;
    fd1 = -1;
    if (o.bootstrap) {
        bname = o.bootstrap;
        if (!strchr(bname, '/')) {
            snprintf(buf, sizeof(buf), "/boot/%s", bname);
            bname = buf;
        }
        if ((fd1 = open(bname, O_RDONLY)) == -1 || fstat(fd1, &sb)) {
            warn("%s", bname);
            goto done;
        }
        if (!S_ISREG(sb.st_mode) || sb.st_size % bpb.bpbBytesPerSec ||
            sb.st_size < bpb.bpbBytesPerSec ||
            sb.st_size > bpb.bpbBytesPerSec * MAXU16) {
            warnx("%s: inappropriate file type or format", bname);
            goto done;
        }
        bss = sb.st_size / bpb.bpbBytesPerSec;
    }
    if (!bpb.bpbFATs)
        bpb.bpbFATs = 2;
    if (!fat) {
        if (bpb.bpbHugeSectors < (bpb.bpbResSectors ? bpb.bpbResSectors : bss) +
            howmany((RESFTE + (bpb.bpbSecPerClust ? MINCLS16 : MAXCLS12 + 1)) *
                (bpb.bpbSecPerClust ? 16 : 12) / BPN,
                bpb.bpbBytesPerSec * NPB) *
            bpb.bpbFATs +
            howmany(bpb.bpbRootDirEnts ? bpb.bpbRootDirEnts : DEFRDE,
                    bpb.bpbBytesPerSec / sizeof(struct de)) +
            (bpb.bpbSecPerClust ? MINCLS16 : MAXCLS12 + 1) *
            (bpb.bpbSecPerClust ? bpb.bpbSecPerClust :
             howmany(DEFBLK, bpb.bpbBytesPerSec)))
            fat = 12;
        else if (bpb.bpbRootDirEnts || bpb.bpbHugeSectors <
                 (bpb.bpbResSectors ? bpb.bpbResSectors : bss) +
                 howmany((RESFTE + MAXCLS16) * 2, bpb.bpbBytesPerSec) *
                 bpb.bpbFATs +
                 howmany(DEFRDE, bpb.bpbBytesPerSec / sizeof(struct de)) +
                 (MAXCLS16 + 1) *
                 (bpb.bpbSecPerClust ? bpb.bpbSecPerClust :
                  howmany(8192, bpb.bpbBytesPerSec)))
            fat = 16;
        else
            fat = 32;
    }
    x = bss;
    if (fat == 32) {
        if (!bpb.bpbFSInfo) {
            if (x == MAXU16 || x == bpb.bpbBackup) {
                warnx("no room for info sector");
                goto done;
            }
            bpb.bpbFSInfo = x;
        }
        if (bpb.bpbFSInfo != MAXU16 && x <= bpb.bpbFSInfo)
            x = bpb.bpbFSInfo + 1;
        if (!bpb.bpbBackup) {
            if (x == MAXU16) {
                warnx("no room for backup sector");
                goto done;
            }
            bpb.bpbBackup = x;
        } else if (bpb.bpbBackup != MAXU16 && bpb.bpbBackup == bpb.bpbFSInfo) {
            warnx("backup sector would overwrite info sector");
            goto done;
        }
        if (bpb.bpbBackup != MAXU16 && x <= bpb.bpbBackup)
            x = bpb.bpbBackup + 1;
    }

    extra_res = 0;
    alignment = 0;
    set_res = (bpb.bpbResSectors == 0);
    set_spf = (bpb.bpbBigFATsecs == 0);
    set_spc = (bpb.bpbSecPerClust == 0);
    saved_x = x;

    /*
     * Attempt to align the root directory to cluster if o.align is set.
     * This is done by padding with reserved blocks. Note that this can
     * cause other factors to change, which can in turn change the alignment.
     * This should take at most 2 iterations, as increasing the reserved
     * amount may cause the FAT size to decrease by 1, requiring another
     * bpbFATs reserved blocks. If bpbSecPerClust changes, it will
     * be half of its previous size, and thus will not throw off alignment.
     */
    do {
        x = saved_x;
        if (set_res)
            bpb.bpbResSectors = ((fat == 32) ?
                MAX(x, MAX(16384 / bpb.bpbBytesPerSec, 4)) : x) + extra_res;
        else if (bpb.bpbResSectors < x) {
            warnx("too few reserved sectors (need %d have %d)", x,
                bpb.bpbResSectors);
            goto done;
        }
        if (fat != 32 && !bpb.bpbRootDirEnts)
            bpb.bpbRootDirEnts = DEFRDE;
        rds = howmany(bpb.bpbRootDirEnts,
            bpb.bpbBytesPerSec / sizeof(struct de));
        if (set_spc) {
            for (bpb.bpbSecPerClust = howmany(fat == 16 ? DEFBLK16 :
                    DEFBLK, bpb.bpbBytesPerSec);
                bpb.bpbSecPerClust < MAXSPC && (bpb.bpbResSectors +
                    howmany((RESFTE + maxcls(fat)) * (fat / BPN),
                        bpb.bpbBytesPerSec * NPB) * bpb.bpbFATs +
                    rds +
                    (u_int64_t) (maxcls(fat) + 1) * bpb.bpbSecPerClust) <=
                    bpb.bpbHugeSectors;
                bpb.bpbSecPerClust <<= 1)
                    continue;

        }
        if (fat != 32 && bpb.bpbBigFATsecs > MAXU16) {
            warnx("too many sectors/FAT for FAT12/16");
            goto done;
        }
        x1 = bpb.bpbResSectors + rds;
        x = bpb.bpbBigFATsecs ? bpb.bpbBigFATsecs : 1;
        if (x1 + (u_int64_t)x * bpb.bpbFATs > bpb.bpbHugeSectors) {
            warnx("meta data exceeds file system size");
            goto done;
        }
        x1 += x * bpb.bpbFATs;
        x = (u_int64_t)(bpb.bpbHugeSectors - x1) * bpb.bpbBytesPerSec * NPB /
            (bpb.bpbSecPerClust * bpb.bpbBytesPerSec * NPB +
            fat / BPN * bpb.bpbFATs);
        x2 = howmany((RESFTE + MIN(x, maxcls(fat))) * (fat / BPN),
            bpb.bpbBytesPerSec * NPB);
        if (set_spf) {
            if (bpb.bpbBigFATsecs == 0)
                bpb.bpbBigFATsecs = x2;
            x1 += (bpb.bpbBigFATsecs - 1) * bpb.bpbFATs;
        }
        if (set_res) {
            alignto = bpb.bpbSecPerClust;
            if (alignto > 1) {
                /* align data clusters */
                alignment = (bpb.bpbResSectors + bpb.bpbBigFATsecs * bpb.bpbFATs + rds) %
                    alignto;
                if (alignment != 0)
                    extra_res += alignto - alignment;
            }
        }
        attempts++;
    } while (alignment != 0 && attempts < 2);
    if (o.align && alignment != 0)
        warnx("warning: Alignment failed.");

    cls = (bpb.bpbHugeSectors - x1) / bpb.bpbSecPerClust;
    x = (u_int64_t)bpb.bpbBigFATsecs * bpb.bpbBytesPerSec * NPB / (fat / BPN) -
        RESFTE;
    if (cls > x)
        cls = x;
    if (bpb.bpbBigFATsecs < x2)
        warnx("warning: sectors/FAT limits file system to %u clusters",
              cls);
    if (cls < mincls(fat)) {
        warnx("%u clusters too few clusters for FAT%u, need %u", cls, fat,
            mincls(fat));
        goto done;
    }
    if (cls > maxcls(fat)) {
        cls = maxcls(fat);
        bpb.bpbHugeSectors = x1 + (cls + 1) * bpb.bpbSecPerClust - 1;
        warnx("warning: FAT type limits file system to %u sectors",
              bpb.bpbHugeSectors);
    }
    printf("%s: %u sector%s in %u FAT%u cluster%s "
           "(%u bytes/cluster)\n", fname, cls * bpb.bpbSecPerClust,
           cls * bpb.bpbSecPerClust == 1 ? "" : "s", cls, fat,
           cls == 1 ? "" : "s", bpb.bpbBytesPerSec * bpb.bpbSecPerClust);
    if (!bpb.bpbMedia)
        bpb.bpbMedia = !bpb.bpbHiddenSecs ? 0xf0 : 0xf8;
    if (fat == 32)
        bpb.bpbRootClust = RESFTE;
    if (bpb.bpbHugeSectors <= MAXU16) {
        bpb.bpbSectors = bpb.bpbHugeSectors;
        bpb.bpbHugeSectors = 0;
    }
    if (fat != 32) {
        bpb.bpbFATsecs = bpb.bpbBigFATsecs;
        bpb.bpbBigFATsecs = 0;
    }
    print_bpb(&bpb);
    if (!o.no_create) {
        if (o.timestamp_set) {
            tv.tv_sec = now = o.timestamp;
            tv.tv_usec = 0;
            tm = gmtime(&now);
        } else {
            gettimeofday(&tv, NULL);
            now = tv.tv_sec;
            tm = localtime(&now);
        }

        chunksize = getchunksize();
        physbuf = malloc(chunksize);
        if (physbuf == NULL) {
            warn(NULL);
            goto done;
        }
        physbuf_end = physbuf + chunksize;
        img = physbuf;

        dir = bpb.bpbResSectors + (bpb.bpbFATsecs ? bpb.bpbFATsecs :
                                   bpb.bpbBigFATsecs) * bpb.bpbFATs;
        memset(&si_sa, 0, sizeof(si_sa));
        si_sa.sa_handler = infohandler;
#ifdef SIGINFO
        if (sigaction(SIGINFO, &si_sa, NULL) == -1) {
            warn("sigaction SIGINFO");
            goto done;
        }
#endif
        for (lsn = 0; lsn < dir + (fat == 32 ? bpb.bpbSecPerClust : rds); lsn++) {
            if (got_siginfo) {
                    fprintf(stderr,"%s: writing sector %u of %u (%u%%)\n",
                        fname, lsn,
                        (dir + (fat == 32 ? bpb.bpbSecPerClust: rds)),
                        (lsn * 100) / (dir +
                            (fat == 32 ? bpb.bpbSecPerClust: rds)));
                    got_siginfo = 0;
            }
            x = lsn;
            if (o.bootstrap &&
                fat == 32 && bpb.bpbBackup != MAXU16 &&
                bss <= bpb.bpbBackup && x >= bpb.bpbBackup) {
                x -= bpb.bpbBackup;
                if (!x && lseek(fd1, o.offset, SEEK_SET)) {
                    warn("%s", bname);
                    goto done;
                }
            }
            if (o.bootstrap && x < bss) {
                if ((n = read(fd1, img, bpb.bpbBytesPerSec)) == -1) {
                    warn("%s", bname);
                    goto done;
                }
                if ((unsigned)n != bpb.bpbBytesPerSec) {
                    warnx("%s: can't read sector %u", bname, x);
                    goto done;
                }
            } else
                memset(img, 0, bpb.bpbBytesPerSec);
            if (!lsn ||
                (fat == 32 && bpb.bpbBackup != MAXU16 &&
                 lsn == bpb.bpbBackup)) {
                x1 = sizeof(struct bs);
                bsbpb = (struct bsbpb *)(img + x1);
                mk2(bsbpb->bpbBytesPerSec, bpb.bpbBytesPerSec);
                mk1(bsbpb->bpbSecPerClust, bpb.bpbSecPerClust);
                mk2(bsbpb->bpbResSectors, bpb.bpbResSectors);
                mk1(bsbpb->bpbFATs, bpb.bpbFATs);
                mk2(bsbpb->bpbRootDirEnts, bpb.bpbRootDirEnts);
                mk2(bsbpb->bpbSectors, bpb.bpbSectors);
                mk1(bsbpb->bpbMedia, bpb.bpbMedia);
                mk2(bsbpb->bpbFATsecs, bpb.bpbFATsecs);
                mk2(bsbpb->bpbSecPerTrack, bpb.bpbSecPerTrack);
                mk2(bsbpb->bpbHeads, bpb.bpbHeads);
                mk4(bsbpb->bpbHiddenSecs, bpb.bpbHiddenSecs);
                mk4(bsbpb->bpbHugeSectors, bpb.bpbHugeSectors);
                x1 += sizeof(struct bsbpb);
                if (fat == 32) {
                    bsxbpb = (struct bsxbpb *)(img + x1);
                    mk4(bsxbpb->bpbBigFATsecs, bpb.bpbBigFATsecs);
                    mk2(bsxbpb->bpbExtFlags, 0);
                    mk2(bsxbpb->bpbFSVers, 0);
                    mk4(bsxbpb->bpbRootClust, bpb.bpbRootClust);
                    mk2(bsxbpb->bpbFSInfo, bpb.bpbFSInfo);
                    mk2(bsxbpb->bpbBackup, bpb.bpbBackup);
                    x1 += sizeof(struct bsxbpb);
                }
                bsx = (struct bsx *)(img + x1);
                mk1(bsx->exBootSignature, 0x29);
                if (o.volume_id_set)
                    x = o.volume_id;
                else
                    x = (((u_int)(1 + tm->tm_mon) << 8 |
                          (u_int)tm->tm_mday) +
                         ((u_int)tm->tm_sec << 8 |
                          (u_int)(tv.tv_usec / 10))) << 16 |
                        ((u_int)(1900 + tm->tm_year) +
                         ((u_int)tm->tm_hour << 8 |
                          (u_int)tm->tm_min));
                mk4(bsx->exVolumeID, x);
                mklabel(bsx->exVolumeLabel, o.volume_label ? o.volume_label : "NO NAME");
                snprintf(buf, sizeof(buf), "FAT%u", fat);
                setstr(bsx->exFileSysType, buf, sizeof(bsx->exFileSysType));
                if (!o.bootstrap) {
                    x1 += sizeof(struct bsx);
                    bs = (struct bs *)img;
                    mk1(bs->bsJump[0], 0xeb);
                    mk1(bs->bsJump[1], x1 - 2);
                    mk1(bs->bsJump[2], 0x90);
                    setstr(bs->bsOemName, o.OEM_string ? o.OEM_string : "BSD4.4  ",
                           sizeof(bs->bsOemName));
                    memcpy(img + x1, bootcode, sizeof(bootcode));
                    mk2(img + MINBPS - 2, DOSMAGIC);
                }
            } else if (fat == 32 && bpb.bpbFSInfo != MAXU16 &&
                       (lsn == bpb.bpbFSInfo ||
                        (bpb.bpbBackup != MAXU16 &&
                         lsn == bpb.bpbBackup + bpb.bpbFSInfo))) {
                mk4(img, 0x41615252);
                mk4(img + MINBPS - 28, 0x61417272);
                mk4(img + MINBPS - 24, 0xffffffff);
                mk4(img + MINBPS - 20, 0xffffffff);
                mk2(img + MINBPS - 2, DOSMAGIC);
            } else if (lsn >= bpb.bpbResSectors && lsn < dir &&
                       !((lsn - bpb.bpbResSectors) %
                         (bpb.bpbFATsecs ? bpb.bpbFATsecs :
                          bpb.bpbBigFATsecs))) {
                mk1(img[0], bpb.bpbMedia);
                for (x = 1; x < fat * (fat == 32 ? 3 : 2) / 8; x++)
                    mk1(img[x], fat == 32 && x % 4 == 3 ? 0x0f : 0xff);
            } else if (lsn == dir && o.volume_label) {
                de = (struct de *)img;
                mklabel(de->deName, o.volume_label);
                mk1(de->deAttributes, 050);
                x = (u_int)tm->tm_hour << 11 |
                    (u_int)tm->tm_min << 5 |
                    (u_int)tm->tm_sec >> 1;
                mk2(de->deMTime, x);
                x = (u_int)(tm->tm_year - 80) << 9 |
                    (u_int)(tm->tm_mon + 1) << 5 |
                    (u_int)tm->tm_mday;
                mk2(de->deMDate, x);
            }
            /*
             * Issue a write of chunksize once we have collected
             * enough sectors.
             */
            img += bpb.bpbBytesPerSec;
            if (img >= physbuf_end) {
                n = write(fd, physbuf, chunksize);
                if (n != chunksize) {
                    warnx("%s: can't write sector %u", fname, lsn);
                    goto done;
                }
                img = physbuf;
            }
        }
        /*
         * Write remaining sectors, if the last write didn't end
         * up filling a whole chunk.
         */
        if (img != physbuf) {
                ssize_t tailsize = img - physbuf;

                n = write(fd, physbuf, tailsize);
                if (n != tailsize) {
                    warnx("%s: can't write sector %u", fname, lsn);
                    goto done;
                }
        }
    }
    rv = 0;
done:
    free(physbuf);
    if (fd != -1)
            close(fd);
    if (fd1 != -1)
            close(fd1);

    return rv;
}

/*
 * return -1 with error if file system is mounted.
 */
#ifndef MAKEFS
static int
check_mounted(const char *fname, mode_t mode)
{
/*
 * If getmntinfo() is not available (e.g. Linux) don't check. This should
 * not be a problem since we will only be using makefs to create images.
 */
    struct statfs *mp;
    const char *s1, *s2;
    size_t len;
    int n, r;

    if (!(n = getmntinfo(&mp, MNT_NOWAIT))) {
        warn("getmntinfo");
        return -1;
    }
    len = strlen(_PATH_DEV);
    s1 = fname;
    if (!strncmp(s1, _PATH_DEV, len))
        s1 += len;
    r = S_ISCHR(mode) && s1 != fname && *s1 == 'r';
    for (; n--; mp++) {
        s2 = mp->f_mntfromname;
        if (!strncmp(s2, _PATH_DEV, len))
            s2 += len;
        if ((r && s2 != mp->f_mntfromname && !strcmp(s1 + 1, s2)) ||
            !strcmp(s1, s2)) {
            warnx("%s is mounted on %s", fname, mp->f_mntonname);
            return -1;
        }
    }
    return 0;
}
#endif

/*
 * Get optimal I/O size
 */
static ssize_t
getchunksize(void)
{
        static ssize_t chunksize;

        if (chunksize != 0)
                return (chunksize);

#ifdef  KERN_MAXPHYS
        int mib[2];
        size_t len;

        mib[0] = CTL_KERN;
        mib[1] = KERN_MAXPHYS;
        len = sizeof(chunksize);

        if (sysctl(mib, 2, &chunksize, &len, NULL, 0) == -1) {
                warn("sysctl: KERN_MAXPHYS, using %zu", (size_t)MAXPHYS);
                chunksize = 0;
        }
#endif
        if (chunksize == 0)
                chunksize = MAXPHYS;

        /*
         * For better performance, we want to write larger chunks instead of
         * individual sectors (the size can only be 512, 1024, 2048 or 4096
         * bytes). Assert that chunksize can always hold an integer number of
         * sectors by asserting that both are power of two numbers and the
         * chunksize is greater than MAXBPS.
         */
        static_assert(powerof2(MAXBPS), "MAXBPS is not power of 2");
        assert(powerof2(chunksize));
        assert(chunksize > MAXBPS);

        return (chunksize);
}

/*
 * Get a standard format.
 */
static int
getstdfmt(const char *fmt, struct bpb *bpb)
{
    u_int x, i;

    x = nitems(stdfmt);
    for (i = 0; i < x && strcmp(fmt, stdfmt[i].name); i++);
    if (i == x) {
        warnx("%s: unknown standard format", fmt);
        return -1;
    }
    *bpb = stdfmt[i].bpb;
    return 0;
}

static void
compute_geometry_from_file(int fd, const char *fname, struct disklabel *lp)
{
        struct stat st;
        off_t ms;

        if (fstat(fd, &st))
                err(1, "cannot get disk size");
        if (!S_ISREG(st.st_mode))
                errx(1, "%s is not a regular file", fname);
        ms = st.st_size;
        lp->d_secsize = 512;
        lp->d_nsectors = 63;
        lp->d_ntracks = 255;
        lp->d_secperunit = ms / lp->d_secsize;
}

/*
 * Get disk slice, partition, and geometry information.
 */
static int
getdiskinfo(int fd, const char *fname, const char *dtype, __unused int oflag,
            struct bpb *bpb)
{
    struct disklabel *lp, dlp;
    off_t hs = 0;
#ifndef MAKEFS
    off_t ms;
    struct fd_type type;

    lp = NULL;

    /* If the user specified a disk type, try to use that */
    if (dtype != NULL) {
        lp = getdiskbyname(dtype);
    }

    /* Maybe it's a floppy drive */
    if (lp == NULL) {
        if (ioctl(fd, DIOCGMEDIASIZE, &ms) == -1) {
            /* create a fake geometry for a file image */
            compute_geometry_from_file(fd, fname, &dlp);
            lp = &dlp;
        } else if (ioctl(fd, FD_GTYPE, &type) != -1) {
            dlp.d_secsize = 128 << type.secsize;
            dlp.d_nsectors = type.sectrac;
            dlp.d_ntracks = type.heads;
            dlp.d_secperunit = ms / dlp.d_secsize;
            lp = &dlp;
        }
    }

    /* Maybe it's a fixed drive */
    if (lp == NULL) {
        if (bpb->bpbBytesPerSec)
            dlp.d_secsize = bpb->bpbBytesPerSec;
        if (bpb->bpbBytesPerSec == 0 && ioctl(fd, DIOCGSECTORSIZE,
                                              &dlp.d_secsize) == -1)
            err(1, "cannot get sector size");

        dlp.d_secperunit = ms / dlp.d_secsize;

        if (bpb->bpbSecPerTrack == 0 && ioctl(fd, DIOCGFWSECTORS,
                                              &dlp.d_nsectors) == -1) {
            warn("cannot get number of sectors per track");
            dlp.d_nsectors = 63;
        }
        if (bpb->bpbHeads == 0 &&
            ioctl(fd, DIOCGFWHEADS, &dlp.d_ntracks) == -1) {
            warn("cannot get number of heads");
            if (dlp.d_secperunit <= 63*1*1024)
                dlp.d_ntracks = 1;
            else if (dlp.d_secperunit <= 63*16*1024)
                dlp.d_ntracks = 16;
            else
                dlp.d_ntracks = 255;
        }

        hs = (ms / dlp.d_secsize) - dlp.d_secperunit;
        lp = &dlp;
    }
#else
    (void)dtype;
    /* In the makefs case we only support image files: */
    compute_geometry_from_file(fd, fname, &dlp);
    lp = &dlp;
#endif

    if (bpb->bpbBytesPerSec == 0) {
        if (ckgeom(fname, lp->d_secsize, "bytes/sector") == -1)
            return -1;
        bpb->bpbBytesPerSec = lp->d_secsize;
    }
    if (bpb->bpbSecPerTrack == 0) {
        if (ckgeom(fname, lp->d_nsectors, "sectors/track") == -1)
            return -1;
        bpb->bpbSecPerTrack = lp->d_nsectors;
    }
    if (bpb->bpbHeads == 0) {
        if (ckgeom(fname, lp->d_ntracks, "drive heads") == -1)
            return -1;
        bpb->bpbHeads = lp->d_ntracks;
    }
    if (bpb->bpbHugeSectors == 0)
        bpb->bpbHugeSectors = lp->d_secperunit;
    if (bpb->bpbHiddenSecs == 0)
        bpb->bpbHiddenSecs = hs;
    return 0;
}

/*
 * Print out BPB values.
 */
static void
print_bpb(struct bpb *bpb)
{
    printf("BytesPerSec=%u SecPerClust=%u ResSectors=%u FATs=%u",
           bpb->bpbBytesPerSec, bpb->bpbSecPerClust, bpb->bpbResSectors,
           bpb->bpbFATs);
    if (bpb->bpbRootDirEnts)
        printf(" RootDirEnts=%u", bpb->bpbRootDirEnts);
    if (bpb->bpbSectors)
        printf(" Sectors=%u", bpb->bpbSectors);
    printf(" Media=%#x", bpb->bpbMedia);
    if (bpb->bpbFATsecs)
        printf(" FATsecs=%u", bpb->bpbFATsecs);
    printf(" SecPerTrack=%u Heads=%u HiddenSecs=%u", bpb->bpbSecPerTrack,
           bpb->bpbHeads, bpb->bpbHiddenSecs);
    if (bpb->bpbHugeSectors)
        printf(" HugeSectors=%u", bpb->bpbHugeSectors);
    if (!bpb->bpbFATsecs) {
        printf(" FATsecs=%u RootCluster=%u", bpb->bpbBigFATsecs,
               bpb->bpbRootClust);
        printf(" FSInfo=");
        printf(bpb->bpbFSInfo == MAXU16 ? "%#x" : "%u", bpb->bpbFSInfo);
        printf(" Backup=");
        printf(bpb->bpbBackup == MAXU16 ? "%#x" : "%u", bpb->bpbBackup);
    }
    printf("\n");
}

/*
 * Check a disk geometry value.
 */
static int
ckgeom(const char *fname, u_int val, const char *msg)
{
    if (!val) {
        warnx("%s: no default %s", fname, msg);
        return -1;
    }
    if (val > MAXU16) {
        warnx("%s: illegal %s %d", fname, msg, val);
        return -1;
    }
    return 0;
}

/*
 * Check a volume label.
 */
static int
oklabel(const char *src)
{
    int c, i;

    for (i = 0; i <= 11; i++) {
        c = (u_char)*src++;
        if (c < ' ' + !i || strchr("\"*+,./:;<=>?[\\]|", c))
            break;
    }
    return i && !c;
}

/*
 * Make a volume label.
 */
static void
mklabel(u_int8_t *dest, const char *src)
{
    int c, i;

    for (i = 0; i < 11; i++) {
        c = *src ? toupper(*src++) : ' ';
        *dest++ = !i && c == '\xe5' ? 5 : c;
    }
}

/*
 * Copy string, padding with spaces.
 */
static void
setstr(u_int8_t *dest, const char *src, size_t len)
{
    while (len--)
        *dest++ = *src ? *src++ : ' ';
}

static void
infohandler(int sig __unused)
{

        got_siginfo = 1;
}