source: MondoRescue/branches/3.0/mindi-busybox/util-linux/fdisk.c@ 3085

/* vi: set sw=4 ts=4: */
/* fdisk.c -- Partition table manipulator for Linux.
 *
 * Copyright (C) 1992  A. V. Le Blanc (LeBlanc@mcc.ac.uk)
 * Copyright (C) 2001,2002 Vladimir Oleynik <dzo@simtreas.ru> (initial bb port)
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

#ifndef _LARGEFILE64_SOURCE
/* For lseek64 */
# define _LARGEFILE64_SOURCE
#endif
#include <assert.h>             /* assert */
#include <sys/mount.h>
#if !defined(BLKSSZGET)
# define BLKSSZGET _IO(0x12, 104)
#endif
#if !defined(BLKGETSIZE64)
# define BLKGETSIZE64 _IOR(0x12,114,size_t)
#endif
#include "libbb.h"

#if BB_LITTLE_ENDIAN
# define inline_if_little_endian ALWAYS_INLINE
#else
# define inline_if_little_endian /* nothing */
#endif


/* Looks like someone forgot to add this to config system */
#ifndef ENABLE_FEATURE_FDISK_BLKSIZE
# define ENABLE_FEATURE_FDISK_BLKSIZE 0
# define IF_FEATURE_FDISK_BLKSIZE(a)
#endif

#define DEFAULT_SECTOR_SIZE      512
#define DEFAULT_SECTOR_SIZE_STR "512"
#define MAX_SECTOR_SIZE         2048
#define SECTOR_SIZE              512 /* still used in osf/sgi/sun code */
#define MAXIMUM_PARTS             60

#define ACTIVE_FLAG             0x80

#define EXTENDED                0x05
#define WIN98_EXTENDED          0x0f
#define LINUX_PARTITION         0x81
#define LINUX_SWAP              0x82
#define LINUX_NATIVE            0x83
#define LINUX_EXTENDED          0x85
#define LINUX_LVM               0x8e
#define LINUX_RAID              0xfd


enum {
    OPT_b = 1 << 0,
    OPT_C = 1 << 1,
    OPT_H = 1 << 2,
    OPT_l = 1 << 3,
    OPT_S = 1 << 4,
    OPT_u = 1 << 5,
    OPT_s = (1 << 6) * ENABLE_FEATURE_FDISK_BLKSIZE,
};


typedef unsigned long long ullong;
/* Used for sector numbers. Partition formats we know
 * do not support more than 2^32 sectors
 */
typedef uint32_t sector_t;
#if UINT_MAX == 4294967295
# define SECT_FMT ""
#elif ULONG_MAX == 4294967295
# define SECT_FMT "l"
#else
# error Cant detect sizeof(uint32_t)
#endif

struct hd_geometry {
    unsigned char heads;
    unsigned char sectors;
    unsigned short cylinders;
    unsigned long start;
};

#define HDIO_GETGEO     0x0301  /* get device geometry */

static const char msg_building_new_label[] ALIGN1 =
"Building a new %s. Changes will remain in memory only,\n"
"until you decide to write them. After that the previous content\n"
"won't be recoverable.\n\n";

static const char msg_part_already_defined[] ALIGN1 =
"Partition %u is already defined, delete it before re-adding\n";


struct partition {
    unsigned char boot_ind;         /* 0x80 - active */
    unsigned char head;             /* starting head */
    unsigned char sector;           /* starting sector */
    unsigned char cyl;              /* starting cylinder */
    unsigned char sys_ind;          /* what partition type */
    unsigned char end_head;         /* end head */
    unsigned char end_sector;       /* end sector */
    unsigned char end_cyl;          /* end cylinder */
    unsigned char start4[4];        /* starting sector counting from 0 */
    unsigned char size4[4];         /* nr of sectors in partition */
} PACKED;

/*
 * per partition table entry data
 *
 * The four primary partitions have the same sectorbuffer (MBRbuffer)
 * and have NULL ext_pointer.
 * Each logical partition table entry has two pointers, one for the
 * partition and one link to the next one.
 */
struct pte {
    struct partition *part_table;   /* points into sectorbuffer */
    struct partition *ext_pointer;  /* points into sectorbuffer */
    sector_t offset_from_dev_start; /* disk sector number */
    char *sectorbuffer;             /* disk sector contents */
#if ENABLE_FEATURE_FDISK_WRITABLE
    char changed;                   /* boolean */
#endif
};

#define unable_to_open "can't open '%s'"
#define unable_to_read "can't read from %s"
#define unable_to_seek "can't seek on %s"

enum label_type {
    LABEL_DOS, LABEL_SUN, LABEL_SGI, LABEL_AIX, LABEL_OSF, LABEL_GPT
};

#define LABEL_IS_DOS    (LABEL_DOS == current_label_type)

#if ENABLE_FEATURE_SUN_LABEL
#define LABEL_IS_SUN    (LABEL_SUN == current_label_type)
#define STATIC_SUN static
#else
#define LABEL_IS_SUN    0
#define STATIC_SUN extern
#endif

#if ENABLE_FEATURE_SGI_LABEL
#define LABEL_IS_SGI    (LABEL_SGI == current_label_type)
#define STATIC_SGI static
#else
#define LABEL_IS_SGI    0
#define STATIC_SGI extern
#endif

#if ENABLE_FEATURE_AIX_LABEL
#define LABEL_IS_AIX    (LABEL_AIX == current_label_type)
#define STATIC_AIX static
#else
#define LABEL_IS_AIX    0
#define STATIC_AIX extern
#endif

#if ENABLE_FEATURE_OSF_LABEL
#define LABEL_IS_OSF    (LABEL_OSF == current_label_type)
#define STATIC_OSF static
#else
#define LABEL_IS_OSF    0
#define STATIC_OSF extern
#endif

#if ENABLE_FEATURE_GPT_LABEL
#define LABEL_IS_GPT    (LABEL_GPT == current_label_type)
#define STATIC_GPT static
#else
#define LABEL_IS_GPT    0
#define STATIC_GPT extern
#endif

enum action { OPEN_MAIN, TRY_ONLY, CREATE_EMPTY_DOS, CREATE_EMPTY_SUN };

static void update_units(void);
#if ENABLE_FEATURE_FDISK_WRITABLE
static void change_units(void);
static void reread_partition_table(int leave);
static void delete_partition(int i);
static unsigned get_partition(int warn, unsigned max);
static void list_types(const char *const *sys);
static sector_t read_int(sector_t low, sector_t dflt, sector_t high, sector_t base, const char *mesg);
#endif
static const char *partition_type(unsigned char type);
static void get_geometry(void);
static void read_pte(struct pte *pe, sector_t offset);
#if ENABLE_FEATURE_SUN_LABEL || ENABLE_FEATURE_FDISK_WRITABLE
static int get_boot(enum action what);
#else
static int get_boot(void);
#endif

#define PLURAL   0
#define SINGULAR 1

static sector_t get_start_sect(const struct partition *p);
static sector_t get_nr_sects(const struct partition *p);

/* DOS partition types */

static const char *const i386_sys_types[] = {
    "\x00" "Empty",
    "\x01" "FAT12",
    "\x04" "FAT16 <32M",
    "\x05" "Extended",         /* DOS 3.3+ extended partition */
    "\x06" "FAT16",            /* DOS 16-bit >=32M */
    "\x07" "HPFS/NTFS",        /* OS/2 IFS, eg, HPFS or NTFS or QNX */
    "\x0a" "OS/2 Boot Manager",/* OS/2 Boot Manager */
    "\x0b" "Win95 FAT32",
    "\x0c" "Win95 FAT32 (LBA)",/* LBA really is 'Extended Int 13h' */
    "\x0e" "Win95 FAT16 (LBA)",
    "\x0f" "Win95 Ext'd (LBA)",
    "\x11" "Hidden FAT12",
    "\x12" "Compaq diagnostics",
    "\x14" "Hidden FAT16 <32M",
    "\x16" "Hidden FAT16",
    "\x17" "Hidden HPFS/NTFS",
    "\x1b" "Hidden Win95 FAT32",
    "\x1c" "Hidden W95 FAT32 (LBA)",
    "\x1e" "Hidden W95 FAT16 (LBA)",
    "\x3c" "Part.Magic recovery",
    "\x41" "PPC PReP Boot",
    "\x42" "SFS",
    "\x63" "GNU HURD or SysV", /* GNU HURD or Mach or Sys V/386 (such as ISC UNIX) */
    "\x80" "Old Minix",        /* Minix 1.4a and earlier */
    "\x81" "Minix / old Linux",/* Minix 1.4b and later */
    "\x82" "Linux swap",       /* also Solaris */
    "\x83" "Linux",
    "\x84" "OS/2 hidden C: drive",
    "\x85" "Linux extended",
    "\x86" "NTFS volume set",
    "\x87" "NTFS volume set",
    "\x8e" "Linux LVM",
    "\x9f" "BSD/OS",           /* BSDI */
    "\xa0" "Thinkpad hibernation",
    "\xa5" "FreeBSD",          /* various BSD flavours */
    "\xa6" "OpenBSD",
    "\xa8" "Darwin UFS",
    "\xa9" "NetBSD",
    "\xab" "Darwin boot",
    "\xb7" "BSDI fs",
    "\xb8" "BSDI swap",
    "\xbe" "Solaris boot",
    "\xeb" "BeOS fs",
    "\xee" "EFI GPT",                    /* Intel EFI GUID Partition Table */
    "\xef" "EFI (FAT-12/16/32)",         /* Intel EFI System Partition */
    "\xf0" "Linux/PA-RISC boot",         /* Linux/PA-RISC boot loader */
    "\xf2" "DOS secondary",              /* DOS 3.3+ secondary */
    "\xfd" "Linux raid autodetect",      /* New (2.2.x) raid partition with
                        autodetect using persistent
                        superblock */
#if 0 /* ENABLE_WEIRD_PARTITION_TYPES */
    "\x02" "XENIX root",
    "\x03" "XENIX usr",
    "\x08" "AIX",              /* AIX boot (AIX -- PS/2 port) or SplitDrive */
    "\x09" "AIX bootable",     /* AIX data or Coherent */
    "\x10" "OPUS",
    "\x18" "AST SmartSleep",
    "\x24" "NEC DOS",
    "\x39" "Plan 9",
    "\x40" "Venix 80286",
    "\x4d" "QNX4.x",
    "\x4e" "QNX4.x 2nd part",
    "\x4f" "QNX4.x 3rd part",
    "\x50" "OnTrack DM",
    "\x51" "OnTrack DM6 Aux1", /* (or Novell) */
    "\x52" "CP/M",             /* CP/M or Microport SysV/AT */
    "\x53" "OnTrack DM6 Aux3",
    "\x54" "OnTrackDM6",
    "\x55" "EZ-Drive",
    "\x56" "Golden Bow",
    "\x5c" "Priam Edisk",
    "\x61" "SpeedStor",
    "\x64" "Novell Netware 286",
    "\x65" "Novell Netware 386",
    "\x70" "DiskSecure Multi-Boot",
    "\x75" "PC/IX",
    "\x93" "Amoeba",
    "\x94" "Amoeba BBT",       /* (bad block table) */
    "\xa7" "NeXTSTEP",
    "\xbb" "Boot Wizard hidden",
    "\xc1" "DRDOS/sec (FAT-12)",
    "\xc4" "DRDOS/sec (FAT-16 < 32M)",
    "\xc6" "DRDOS/sec (FAT-16)",
    "\xc7" "Syrinx",
    "\xda" "Non-FS data",
    "\xdb" "CP/M / CTOS / ...",/* CP/M or Concurrent CP/M or
                                  Concurrent DOS or CTOS */
    "\xde" "Dell Utility",     /* Dell PowerEdge Server utilities */
    "\xdf" "BootIt",           /* BootIt EMBRM */
    "\xe1" "DOS access",       /* DOS access or SpeedStor 12-bit FAT
                                  extended partition */
    "\xe3" "DOS R/O",          /* DOS R/O or SpeedStor */
    "\xe4" "SpeedStor",        /* SpeedStor 16-bit FAT extended
                                  partition < 1024 cyl. */
    "\xf1" "SpeedStor",
    "\xf4" "SpeedStor",        /* SpeedStor large partition */
    "\xfe" "LANstep",          /* SpeedStor >1024 cyl. or LANstep */
    "\xff" "BBT",              /* Xenix Bad Block Table */
#endif
    NULL
};

enum {
    dev_fd = 3                  /* the disk */
};

/* Globals */
struct globals {
    char *line_ptr;

    const char *disk_device;
    int g_partitions; // = 4;       /* maximum partition + 1 */
    unsigned units_per_sector; // = 1;
    unsigned sector_size; // = DEFAULT_SECTOR_SIZE;
    unsigned user_set_sector_size;
    unsigned sector_offset; // = 1;
    unsigned g_heads, g_sectors, g_cylinders;
    smallint /* enum label_type */ current_label_type;
    smallint display_in_cyl_units; // = 1;
#if ENABLE_FEATURE_OSF_LABEL
    smallint possibly_osf_label;
#endif

    smallint listing;               /* no aborts for fdisk -l */
    smallint dos_compatible_flag; // = 1;
#if ENABLE_FEATURE_FDISK_WRITABLE
    //int dos_changed;
    smallint nowarn;                /* no warnings for fdisk -l/-s */
#endif
    int ext_index;                  /* the prime extended partition */
    unsigned user_cylinders, user_heads, user_sectors;
    unsigned pt_heads, pt_sectors;
    unsigned kern_heads, kern_sectors;
    sector_t extended_offset;       /* offset of link pointers */
    sector_t total_number_of_sectors;

    jmp_buf listingbuf;
    char line_buffer[80];
    char partname_buffer[80];
    /* Raw disk label. For DOS-type partition tables the MBR,
     * with descriptions of the primary partitions. */
    char MBRbuffer[MAX_SECTOR_SIZE];
    /* Partition tables */
    struct pte ptes[MAXIMUM_PARTS];
};
#define G (*ptr_to_globals)
#define line_ptr             (G.line_ptr            )
#define disk_device          (G.disk_device         )
#define g_partitions         (G.g_partitions        )
#define units_per_sector     (G.units_per_sector    )
#define sector_size          (G.sector_size         )
#define user_set_sector_size (G.user_set_sector_size)
#define sector_offset        (G.sector_offset       )
#define g_heads              (G.g_heads             )
#define g_sectors            (G.g_sectors           )
#define g_cylinders          (G.g_cylinders         )
#define current_label_type   (G.current_label_type  )
#define display_in_cyl_units (G.display_in_cyl_units)
#define possibly_osf_label   (G.possibly_osf_label  )
#define listing                 (G.listing                )
#define dos_compatible_flag     (G.dos_compatible_flag    )
#define nowarn                  (G.nowarn                 )
#define ext_index               (G.ext_index              )
#define user_cylinders          (G.user_cylinders         )
#define user_heads              (G.user_heads             )
#define user_sectors            (G.user_sectors           )
#define pt_heads                (G.pt_heads               )
#define pt_sectors              (G.pt_sectors             )
#define kern_heads              (G.kern_heads             )
#define kern_sectors            (G.kern_sectors           )
#define extended_offset         (G.extended_offset        )
#define total_number_of_sectors (G.total_number_of_sectors)
#define listingbuf      (G.listingbuf     )
#define line_buffer     (G.line_buffer    )
#define partname_buffer (G.partname_buffer)
#define MBRbuffer       (G.MBRbuffer      )
#define ptes            (G.ptes           )
#define INIT_G() do { \
    SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
    sector_size = DEFAULT_SECTOR_SIZE; \
    sector_offset = 1; \
    g_partitions = 4; \
    display_in_cyl_units = 1; \
    units_per_sector = 1; \
    dos_compatible_flag = 1; \
} while (0)


/* TODO: move to libbb? */
/* TODO: return unsigned long long, FEATURE_FDISK_BLKSIZE _can_ handle
 * disks > 2^32 sectors
 */
static sector_t bb_BLKGETSIZE_sectors(int fd)
{
    uint64_t v64;
    unsigned long longsectors;

    if (ioctl(fd, BLKGETSIZE64, &v64) == 0) {
        /* Got bytes, convert to 512 byte sectors */
        v64 >>= 9;
        if (v64 != (sector_t)v64) {
 ret_trunc:
            /* Not only DOS, but all other partition tables
             * we support can't record more than 32 bit
             * sector counts or offsets
             */
            bb_error_msg("device has more than 2^32 sectors, can't use all of them");
            v64 = (uint32_t)-1L;
        }
        return v64;
    }
    /* Needs temp of type long */
    if (ioctl(fd, BLKGETSIZE, &longsectors)) {
        /* Perhaps this is a disk image */
        off_t sz = lseek(fd, 0, SEEK_END);
        longsectors = 0;
        if (sz > 0)
            longsectors = (uoff_t)sz / sector_size;
        lseek(fd, 0, SEEK_SET);
    }
    if (sizeof(long) > sizeof(sector_t)
     && longsectors != (sector_t)longsectors
    ) {
        goto ret_trunc;
    }
    return longsectors;
}


#define IS_EXTENDED(i) \
    ((i) == EXTENDED || (i) == WIN98_EXTENDED || (i) == LINUX_EXTENDED)

#define cround(n)       (display_in_cyl_units ? ((n)/units_per_sector)+1 : (n))

#define scround(x)      (((x)+units_per_sector-1)/units_per_sector)

#define pt_offset(b, n) \
    ((struct partition *)((b) + 0x1be + (n) * sizeof(struct partition)))

#define sector(s)       ((s) & 0x3f)

#define cylinder(s, c)  ((c) | (((s) & 0xc0) << 2))

#define hsc2sector(h,s,c) \
    (sector(s) - 1 + sectors * ((h) + heads * cylinder(s,c)))

static void
close_dev_fd(void)
{
    /* Not really closing, but making sure it is open, and to harmless place */
    xmove_fd(xopen(bb_dev_null, O_RDONLY), dev_fd);
}

/*
 * Return partition name - uses static storage
 */
static const char *
partname(const char *dev, int pno, int lth)
{
    const char *p;
    int w, wp;
    int bufsiz;
    char *bufp;

    bufp = partname_buffer;
    bufsiz = sizeof(partname_buffer);

    w = strlen(dev);
    p = "";

    if (isdigit(dev[w-1]))
        p = "p";

    /* devfs kludge - note: fdisk partition names are not supposed
       to equal kernel names, so there is no reason to do this */
    if (strcmp(dev + w - 4, "disc") == 0) {
        w -= 4;
        p = "part";
    }

    wp = strlen(p);

    if (lth) {
        snprintf(bufp, bufsiz, "%*.*s%s%-2u",
            lth-wp-2, w, dev, p, pno);
    } else {
        snprintf(bufp, bufsiz, "%.*s%s%-2u", w, dev, p, pno);
    }
    return bufp;
}

static ALWAYS_INLINE struct partition *
get_part_table(int i)
{
    return ptes[i].part_table;
}

static const char *
str_units(int n)
{      /* n==1: use singular */
    if (n == 1)
        return display_in_cyl_units ? "cylinder" : "sector";
    return display_in_cyl_units ? "cylinders" : "sectors";
}

static int
valid_part_table_flag(const char *mbuffer)
{
    return (mbuffer[510] == 0x55 && (uint8_t)mbuffer[511] == 0xaa);
}

static void fdisk_fatal(const char *why)
{
    if (listing) {
        close_dev_fd();
        longjmp(listingbuf, 1);
    }
    bb_error_msg_and_die(why, disk_device);
}

static void
seek_sector(sector_t secno)
{
#if ENABLE_FDISK_SUPPORT_LARGE_DISKS
    off64_t off = (off64_t)secno * sector_size;
    if (lseek64(dev_fd, off, SEEK_SET) == (off64_t) -1)
        fdisk_fatal(unable_to_seek);
#else
    uint64_t off = (uint64_t)secno * sector_size;
    if (off > MAXINT(off_t)
     || lseek(dev_fd, (off_t)off, SEEK_SET) == (off_t) -1
    ) {
        fdisk_fatal(unable_to_seek);
    }
#endif
}

#if ENABLE_FEATURE_FDISK_WRITABLE
/* Read line; return 0 or first printable char */
static int
read_line(const char *prompt)
{
    int sz;

    sz = read_line_input(prompt, line_buffer, sizeof(line_buffer), NULL);
    if (sz <= 0)
        exit(EXIT_SUCCESS); /* Ctrl-D or Ctrl-C */

    if (line_buffer[sz-1] == '\n')
        line_buffer[--sz] = '\0';

    line_ptr = line_buffer;
    while (*line_ptr != '\0' && (unsigned char)*line_ptr <= ' ')
        line_ptr++;
    return *line_ptr;
}

static void
set_all_unchanged(void)
{
    int i;

    for (i = 0; i < MAXIMUM_PARTS; i++)
        ptes[i].changed = 0;
}

static ALWAYS_INLINE void
set_changed(int i)
{
    ptes[i].changed = 1;
}

static ALWAYS_INLINE void
write_part_table_flag(char *b)
{
    b[510] = 0x55;
    b[511] = 0xaa;
}

static char
read_nonempty(const char *mesg)
{
    while (!read_line(mesg))
        continue;
    return *line_ptr;
}

static char
read_maybe_empty(const char *mesg)
{
    if (!read_line(mesg)) {
        line_ptr = line_buffer;
        line_ptr[0] = '\n';
        line_ptr[1] = '\0';
    }
    return line_ptr[0];
}

static int
read_hex(const char *const *sys)
{
    unsigned long v;
    while (1) {
        read_nonempty("Hex code (type L to list codes): ");
        if ((line_ptr[0] | 0x20) == 'l') {
            list_types(sys);
            continue;
        }
        v = bb_strtoul(line_ptr, NULL, 16);
        if (v <= 0xff)
            return v;
    }
}

static void
write_sector(sector_t secno, const void *buf)
{
    seek_sector(secno);
    xwrite(dev_fd, buf, sector_size);
}
#endif /* FEATURE_FDISK_WRITABLE */


#include "fdisk_aix.c"

struct sun_partition {
    unsigned char info[128];   /* Informative text string */
    unsigned char spare0[14];
    struct sun_info {
        unsigned char spare1;
        unsigned char id;
        unsigned char spare2;
        unsigned char flags;
    } infos[8];
    unsigned char spare1[246]; /* Boot information etc. */
    unsigned short rspeed;     /* Disk rotational speed */
    unsigned short pcylcount;  /* Physical cylinder count */
    unsigned short sparecyl;   /* extra sects per cylinder */
    unsigned char spare2[4];   /* More magic... */
    unsigned short ilfact;     /* Interleave factor */
    unsigned short ncyl;       /* Data cylinder count */
    unsigned short nacyl;      /* Alt. cylinder count */
    unsigned short ntrks;      /* Tracks per cylinder */
    unsigned short nsect;      /* Sectors per track */
    unsigned char spare3[4];   /* Even more magic... */
    struct sun_partinfo {
        uint32_t start_cylinder;
        uint32_t num_sectors;
    } partitions[8];
    unsigned short magic;      /* Magic number */
    unsigned short csum;       /* Label xor'd checksum */
} FIX_ALIASING;
typedef struct sun_partition sun_partition;
#define sunlabel ((sun_partition *)MBRbuffer)
STATIC_OSF void bsd_select(void);
STATIC_OSF void xbsd_print_disklabel(int);
#include "fdisk_osf.c"

STATIC_GPT void gpt_list_table(int xtra);
#include "fdisk_gpt.c"

#if ENABLE_FEATURE_SGI_LABEL || ENABLE_FEATURE_SUN_LABEL
static uint16_t
fdisk_swap16(uint16_t x)
{
    return (x << 8) | (x >> 8);
}

static uint32_t
fdisk_swap32(uint32_t x)
{
    return (x << 24) |
           ((x & 0xFF00) << 8) |
           ((x & 0xFF0000) >> 8) |
           (x >> 24);
}
#endif

STATIC_SGI const char *const sgi_sys_types[];
STATIC_SGI unsigned sgi_get_num_sectors(int i);
STATIC_SGI int sgi_get_sysid(int i);
STATIC_SGI void sgi_delete_partition(int i);
STATIC_SGI void sgi_change_sysid(int i, int sys);
STATIC_SGI void sgi_list_table(int xtra);
#if ENABLE_FEATURE_FDISK_ADVANCED
STATIC_SGI void sgi_set_xcyl(void);
#endif
STATIC_SGI int verify_sgi(int verbose);
STATIC_SGI void sgi_add_partition(int n, int sys);
STATIC_SGI void sgi_set_swappartition(int i);
STATIC_SGI const char *sgi_get_bootfile(void);
STATIC_SGI void sgi_set_bootfile(const char* aFile);
STATIC_SGI void create_sgiinfo(void);
STATIC_SGI void sgi_write_table(void);
STATIC_SGI void sgi_set_bootpartition(int i);
#include "fdisk_sgi.c"

STATIC_SUN const char *const sun_sys_types[];
STATIC_SUN void sun_delete_partition(int i);
STATIC_SUN void sun_change_sysid(int i, int sys);
STATIC_SUN void sun_list_table(int xtra);
STATIC_SUN void add_sun_partition(int n, int sys);
#if ENABLE_FEATURE_FDISK_ADVANCED
STATIC_SUN void sun_set_alt_cyl(void);
STATIC_SUN void sun_set_ncyl(int cyl);
STATIC_SUN void sun_set_xcyl(void);
STATIC_SUN void sun_set_ilfact(void);
STATIC_SUN void sun_set_rspeed(void);
STATIC_SUN void sun_set_pcylcount(void);
#endif
STATIC_SUN void toggle_sunflags(int i, unsigned char mask);
STATIC_SUN void verify_sun(void);
STATIC_SUN void sun_write_table(void);
#include "fdisk_sun.c"


static inline_if_little_endian unsigned
read4_little_endian(const unsigned char *cp)
{
    uint32_t v;
    move_from_unaligned32(v, cp);
    return SWAP_LE32(v);
}

static sector_t
get_start_sect(const struct partition *p)
{
    return read4_little_endian(p->start4);
}

static sector_t
get_nr_sects(const struct partition *p)
{
    return read4_little_endian(p->size4);
}

#if ENABLE_FEATURE_FDISK_WRITABLE
/* start_sect and nr_sects are stored little endian on all machines */
/* moreover, they are not aligned correctly */
static inline_if_little_endian void
store4_little_endian(unsigned char *cp, unsigned val)
{
    uint32_t v = SWAP_LE32(val);
    move_to_unaligned32(cp, v);
}

static void
set_start_sect(struct partition *p, unsigned start_sect)
{
    store4_little_endian(p->start4, start_sect);
}

static void
set_nr_sects(struct partition *p, unsigned nr_sects)
{
    store4_little_endian(p->size4, nr_sects);
}
#endif

/* Allocate a buffer and read a partition table sector */
static void
read_pte(struct pte *pe, sector_t offset)
{
    pe->offset_from_dev_start = offset;
    pe->sectorbuffer = xzalloc(sector_size);
    seek_sector(offset);
    /* xread would make us abort - bad for fdisk -l */
    if (full_read(dev_fd, pe->sectorbuffer, sector_size) != sector_size)
        fdisk_fatal(unable_to_read);
#if ENABLE_FEATURE_FDISK_WRITABLE
    pe->changed = 0;
#endif
    pe->part_table = pe->ext_pointer = NULL;
}

static sector_t
get_partition_start_from_dev_start(const struct pte *pe)
{
    return pe->offset_from_dev_start + get_start_sect(pe->part_table);
}

#if ENABLE_FEATURE_FDISK_WRITABLE
/*
 * Avoid warning about DOS partitions when no DOS partition was changed.
 * Here a heuristic "is probably dos partition".
 * We might also do the opposite and warn in all cases except
 * for "is probably nondos partition".
 */
#ifdef UNUSED
static int
is_dos_partition(int t)
{
    return (t == 1 || t == 4 || t == 6 ||
        t == 0x0b || t == 0x0c || t == 0x0e ||
        t == 0x11 || t == 0x12 || t == 0x14 || t == 0x16 ||
        t == 0x1b || t == 0x1c || t == 0x1e || t == 0x24 ||
        t == 0xc1 || t == 0xc4 || t == 0xc6);
}
#endif

static void
menu(void)
{
    puts("Command Action");
    if (LABEL_IS_SUN) {
        puts("a\ttoggle a read only flag");           /* sun */
        puts("b\tedit bsd disklabel");
        puts("c\ttoggle the mountable flag");         /* sun */
        puts("d\tdelete a partition");
        puts("l\tlist known partition types");
        puts("n\tadd a new partition");
        puts("o\tcreate a new empty DOS partition table");
        puts("p\tprint the partition table");
        puts("q\tquit without saving changes");
        puts("s\tcreate a new empty Sun disklabel");  /* sun */
        puts("t\tchange a partition's system id");
        puts("u\tchange display/entry units");
        puts("v\tverify the partition table");
        puts("w\twrite table to disk and exit");
#if ENABLE_FEATURE_FDISK_ADVANCED
        puts("x\textra functionality (experts only)");
#endif
    } else if (LABEL_IS_SGI) {
        puts("a\tselect bootable partition");    /* sgi flavour */
        puts("b\tedit bootfile entry");          /* sgi */
        puts("c\tselect sgi swap partition");    /* sgi flavour */
        puts("d\tdelete a partition");
        puts("l\tlist known partition types");
        puts("n\tadd a new partition");
        puts("o\tcreate a new empty DOS partition table");
        puts("p\tprint the partition table");
        puts("q\tquit without saving changes");
        puts("s\tcreate a new empty Sun disklabel");  /* sun */
        puts("t\tchange a partition's system id");
        puts("u\tchange display/entry units");
        puts("v\tverify the partition table");
        puts("w\twrite table to disk and exit");
    } else if (LABEL_IS_AIX) {
        puts("o\tcreate a new empty DOS partition table");
        puts("q\tquit without saving changes");
        puts("s\tcreate a new empty Sun disklabel");  /* sun */
    } else if (LABEL_IS_GPT) {
        puts("o\tcreate a new empty DOS partition table");
        puts("p\tprint the partition table");
        puts("q\tquit without saving changes");
        puts("s\tcreate a new empty Sun disklabel");  /* sun */
    } else {
        puts("a\ttoggle a bootable flag");
        puts("b\tedit bsd disklabel");
        puts("c\ttoggle the dos compatibility flag");
        puts("d\tdelete a partition");
        puts("l\tlist known partition types");
        puts("n\tadd a new partition");
        puts("o\tcreate a new empty DOS partition table");
        puts("p\tprint the partition table");
        puts("q\tquit without saving changes");
        puts("s\tcreate a new empty Sun disklabel");  /* sun */
        puts("t\tchange a partition's system id");
        puts("u\tchange display/entry units");
        puts("v\tverify the partition table");
        puts("w\twrite table to disk and exit");
#if ENABLE_FEATURE_FDISK_ADVANCED
        puts("x\textra functionality (experts only)");
#endif
    }
}
#endif /* FEATURE_FDISK_WRITABLE */


#if ENABLE_FEATURE_FDISK_ADVANCED
static void
xmenu(void)
{
    puts("Command Action");
    if (LABEL_IS_SUN) {
        puts("a\tchange number of alternate cylinders");      /*sun*/
        puts("c\tchange number of cylinders");
        puts("d\tprint the raw data in the partition table");
        puts("e\tchange number of extra sectors per cylinder");/*sun*/
        puts("h\tchange number of heads");
        puts("i\tchange interleave factor");                  /*sun*/
        puts("o\tchange rotation speed (rpm)");               /*sun*/
        puts("p\tprint the partition table");
        puts("q\tquit without saving changes");
        puts("r\treturn to main menu");
        puts("s\tchange number of sectors/track");
        puts("v\tverify the partition table");
        puts("w\twrite table to disk and exit");
        puts("y\tchange number of physical cylinders");       /*sun*/
    } else if (LABEL_IS_SGI) {
        puts("b\tmove beginning of data in a partition"); /* !sun */
        puts("c\tchange number of cylinders");
        puts("d\tprint the raw data in the partition table");
        puts("e\tlist extended partitions");          /* !sun */
        puts("g\tcreate an IRIX (SGI) partition table");/* sgi */
        puts("h\tchange number of heads");
        puts("p\tprint the partition table");
        puts("q\tquit without saving changes");
        puts("r\treturn to main menu");
        puts("s\tchange number of sectors/track");
        puts("v\tverify the partition table");
        puts("w\twrite table to disk and exit");
    } else if (LABEL_IS_AIX) {
        puts("b\tmove beginning of data in a partition"); /* !sun */
        puts("c\tchange number of cylinders");
        puts("d\tprint the raw data in the partition table");
        puts("e\tlist extended partitions");          /* !sun */
        puts("g\tcreate an IRIX (SGI) partition table");/* sgi */
        puts("h\tchange number of heads");
        puts("p\tprint the partition table");
        puts("q\tquit without saving changes");
        puts("r\treturn to main menu");
        puts("s\tchange number of sectors/track");
        puts("v\tverify the partition table");
        puts("w\twrite table to disk and exit");
    } else {
        puts("b\tmove beginning of data in a partition"); /* !sun */
        puts("c\tchange number of cylinders");
        puts("d\tprint the raw data in the partition table");
        puts("e\tlist extended partitions");          /* !sun */
        puts("f\tfix partition order");               /* !sun, !aix, !sgi */
#if ENABLE_FEATURE_SGI_LABEL
        puts("g\tcreate an IRIX (SGI) partition table");/* sgi */
#endif
        puts("h\tchange number of heads");
        puts("p\tprint the partition table");
        puts("q\tquit without saving changes");
        puts("r\treturn to main menu");
        puts("s\tchange number of sectors/track");
        puts("v\tverify the partition table");
        puts("w\twrite table to disk and exit");
    }
}
#endif /* ADVANCED mode */

#if ENABLE_FEATURE_FDISK_WRITABLE
static const char *const *
get_sys_types(void)
{
    return (
        LABEL_IS_SUN ? sun_sys_types :
        LABEL_IS_SGI ? sgi_sys_types :
        i386_sys_types);
}
#else
#define get_sys_types() i386_sys_types
#endif

static const char *
partition_type(unsigned char type)
{
    int i;
    const char *const *types = get_sys_types();

    for (i = 0; types[i]; i++)
        if ((unsigned char)types[i][0] == type)
            return types[i] + 1;

    return "Unknown";
}

static int
is_cleared_partition(const struct partition *p)
{
    /* We consider partition "cleared" only if it has only zeros */
    const char *cp = (const char *)p;
    int cnt = sizeof(*p);
    char bits = 0;
    while (--cnt >= 0)
        bits |= *cp++;
    return (bits == 0);
}

static void
clear_partition(struct partition *p)
{
    if (p)
        memset(p, 0, sizeof(*p));
}

#if ENABLE_FEATURE_FDISK_WRITABLE
static int
get_sysid(int i)
{
    return LABEL_IS_SUN ? sunlabel->infos[i].id :
            (LABEL_IS_SGI ? sgi_get_sysid(i) :
                ptes[i].part_table->sys_ind);
}

static void
list_types(const char *const *sys)
{
    enum { COLS = 3 };

    unsigned last[COLS];
    unsigned done, next, size;
    int i;

    for (size = 0; sys[size]; size++)
        continue;

    done = 0;
    for (i = COLS-1; i >= 0; i--) {
        done += (size + i - done) / (i + 1);
        last[COLS-1 - i] = done;
    }

    i = done = next = 0;
    do {
        printf("%c%2x %-22.22s", i ? ' ' : '\n',
            (unsigned char)sys[next][0],
            sys[next] + 1);
        next = last[i++] + done;
        if (i >= COLS || next >= last[i]) {
            i = 0;
            next = ++done;
        }
    } while (done < last[0]);
    bb_putchar('\n');
}

#define set_hsc(h, s, c, sector) do \
{ \
    s = sector % g_sectors + 1;  \
    sector /= g_sectors;         \
    h = sector % g_heads;        \
    sector /= g_heads;           \
    c = sector & 0xff;           \
    s |= (sector >> 2) & 0xc0;   \
} while (0)

static void set_hsc_start_end(struct partition *p, sector_t start, sector_t stop)
{
    if (dos_compatible_flag && (start / (g_sectors * g_heads) > 1023))
        start = g_heads * g_sectors * 1024 - 1;
    set_hsc(p->head, p->sector, p->cyl, start);

    if (dos_compatible_flag && (stop / (g_sectors * g_heads) > 1023))
        stop = g_heads * g_sectors * 1024 - 1;
    set_hsc(p->end_head, p->end_sector, p->end_cyl, stop);
}

static void
set_partition(int i, int doext, sector_t start, sector_t stop, int sysid)
{
    struct partition *p;
    sector_t offset;

    if (doext) {
        p = ptes[i].ext_pointer;
        offset = extended_offset;
    } else {
        p = ptes[i].part_table;
        offset = ptes[i].offset_from_dev_start;
    }
    p->boot_ind = 0;
    p->sys_ind = sysid;
    set_start_sect(p, start - offset);
    set_nr_sects(p, stop - start + 1);
    set_hsc_start_end(p, start, stop);
    ptes[i].changed = 1;
}
#endif

static int
warn_geometry(void)
{
    if (g_heads && g_sectors && g_cylinders)
        return 0;

    printf("Unknown value(s) for:");
    if (!g_heads)
        printf(" heads");
    if (!g_sectors)
        printf(" sectors");
    if (!g_cylinders)
        printf(" cylinders");
    printf(
#if ENABLE_FEATURE_FDISK_WRITABLE
        " (settable in the extra functions menu)"
#endif
        "\n");
    return 1;
}

static void
update_units(void)
{
    int cyl_units = g_heads * g_sectors;

    if (display_in_cyl_units && cyl_units)
        units_per_sector = cyl_units;
    else
        units_per_sector = 1;   /* in sectors */
}

#if ENABLE_FEATURE_FDISK_WRITABLE
static void
warn_cylinders(void)
{
    if (LABEL_IS_DOS && g_cylinders > 1024 && !nowarn)
        printf("\n"
"The number of cylinders for this disk is set to %u.\n"
"There is nothing wrong with that, but this is larger than 1024,\n"
"and could in certain setups cause problems with:\n"
"1) software that runs at boot time (e.g., old versions of LILO)\n"
"2) booting and partitioning software from other OSs\n"
"   (e.g., DOS FDISK, OS/2 FDISK)\n",
            g_cylinders);
}
#endif

static void
read_extended(int ext)
{
    int i;
    struct pte *pex;
    struct partition *p, *q;

    ext_index = ext;
    pex = &ptes[ext];
    pex->ext_pointer = pex->part_table;

    p = pex->part_table;
    if (!get_start_sect(p)) {
        printf("Bad offset in primary extended partition\n");
        return;
    }

    while (IS_EXTENDED(p->sys_ind)) {
        struct pte *pe = &ptes[g_partitions];

        if (g_partitions >= MAXIMUM_PARTS) {
            /* This is not a Linux restriction, but
               this program uses arrays of size MAXIMUM_PARTS.
               Do not try to 'improve' this test. */
            struct pte *pre = &ptes[g_partitions - 1];
#if ENABLE_FEATURE_FDISK_WRITABLE
            printf("Warning: deleting partitions after %u\n",
                g_partitions);
            pre->changed = 1;
#endif
            clear_partition(pre->ext_pointer);
            return;
        }

        read_pte(pe, extended_offset + get_start_sect(p));

        if (!extended_offset)
            extended_offset = get_start_sect(p);

        q = p = pt_offset(pe->sectorbuffer, 0);
        for (i = 0; i < 4; i++, p++) if (get_nr_sects(p)) {
            if (IS_EXTENDED(p->sys_ind)) {
                if (pe->ext_pointer)
                    printf("Warning: extra link "
                        "pointer in partition table"
                        " %u\n", g_partitions + 1);
                else
                    pe->ext_pointer = p;
            } else if (p->sys_ind) {
                if (pe->part_table)
                    printf("Warning: ignoring extra "
                          "data in partition table"
                          " %u\n", g_partitions + 1);
                else
                    pe->part_table = p;
            }
        }

        /* very strange code here... */
        if (!pe->part_table) {
            if (q != pe->ext_pointer)
                pe->part_table = q;
            else
                pe->part_table = q + 1;
        }
        if (!pe->ext_pointer) {
            if (q != pe->part_table)
                pe->ext_pointer = q;
            else
                pe->ext_pointer = q + 1;
        }

        p = pe->ext_pointer;
        g_partitions++;
    }

#if ENABLE_FEATURE_FDISK_WRITABLE
    /* remove empty links */
 remove:
    for (i = 4; i < g_partitions; i++) {
        struct pte *pe = &ptes[i];

        if (!get_nr_sects(pe->part_table)
         && (g_partitions > 5 || ptes[4].part_table->sys_ind)
        ) {
            printf("Omitting empty partition (%u)\n", i+1);
            delete_partition(i);
            goto remove;    /* numbering changed */
        }
    }
#endif
}

#if ENABLE_FEATURE_FDISK_WRITABLE
static void
create_doslabel(void)
{
    printf(msg_building_new_label, "DOS disklabel");

    current_label_type = LABEL_DOS;
#if ENABLE_FEATURE_OSF_LABEL
    possibly_osf_label = 0;
#endif
    g_partitions = 4;

    memset(&MBRbuffer[510 - 4*16], 0, 4*16);
    write_part_table_flag(MBRbuffer);
    extended_offset = 0;
    set_all_unchanged();
    set_changed(0);
    get_boot(CREATE_EMPTY_DOS);
}
#endif

static void
get_sectorsize(void)
{
    if (!user_set_sector_size) {
        int arg;
        if (ioctl(dev_fd, BLKSSZGET, &arg) == 0)
            sector_size = arg;
        if (sector_size != DEFAULT_SECTOR_SIZE)
            printf("Note: sector size is %u "
                "(not " DEFAULT_SECTOR_SIZE_STR ")\n",
                sector_size);
    }
}

static void
get_kernel_geometry(void)
{
    struct hd_geometry geometry;

    if (!ioctl(dev_fd, HDIO_GETGEO, &geometry)) {
        kern_heads = geometry.heads;
        kern_sectors = geometry.sectors;
        /* never use geometry.cylinders - it is truncated */
    }
}

static void
get_partition_table_geometry(void)
{
    const unsigned char *bufp = (const unsigned char *)MBRbuffer;
    struct partition *p;
    int i, h, s, hh, ss;
    int first = 1;
    int bad = 0;

    if (!(valid_part_table_flag((char*)bufp)))
        return;

    hh = ss = 0;
    for (i = 0; i < 4; i++) {
        p = pt_offset(bufp, i);
        if (p->sys_ind != 0) {
            h = p->end_head + 1;
            s = (p->end_sector & 077);
            if (first) {
                hh = h;
                ss = s;
                first = 0;
            } else if (hh != h || ss != s)
                bad = 1;
        }
    }

    if (!first && !bad) {
        pt_heads = hh;
        pt_sectors = ss;
    }
}

static void
get_geometry(void)
{
    int sec_fac;

    get_sectorsize();
    sec_fac = sector_size / 512;
#if ENABLE_FEATURE_SUN_LABEL
    guess_device_type();
#endif
    g_heads = g_cylinders = g_sectors = 0;
    kern_heads = kern_sectors = 0;
    pt_heads = pt_sectors = 0;

    get_kernel_geometry();
    get_partition_table_geometry();

    g_heads = user_heads ? user_heads :
        pt_heads ? pt_heads :
        kern_heads ? kern_heads : 255;
    g_sectors = user_sectors ? user_sectors :
        pt_sectors ? pt_sectors :
        kern_sectors ? kern_sectors : 63;
    total_number_of_sectors = bb_BLKGETSIZE_sectors(dev_fd);

    sector_offset = 1;
    if (dos_compatible_flag)
        sector_offset = g_sectors;

    g_cylinders = total_number_of_sectors / (g_heads * g_sectors * sec_fac);
    if (!g_cylinders)
        g_cylinders = user_cylinders;
}

/*
 * Opens disk_device and optionally reads MBR.
 *    If what == OPEN_MAIN:
 *      Open device, read MBR.  Abort program on short read.  Create empty
 *      disklabel if the on-disk structure is invalid (WRITABLE mode).
 *    If what == TRY_ONLY:
 *      Open device, read MBR.  Return an error if anything is out of place.
 *      Do not create an empty disklabel.  This is used for the "list"
 *      operations: "fdisk -l /dev/sda" and "fdisk -l" (all devices).
 *    If what == CREATE_EMPTY_*:
 *      This means that get_boot() was called recursively from create_*label().
 *      Do not re-open the device; just set up the ptes array and print
 *      geometry warnings.
 *
 * Returns:
 *   -1: no 0xaa55 flag present (possibly entire disk BSD)
 *    0: found or created label
 *    1: I/O error
 */
#if ENABLE_FEATURE_SUN_LABEL || ENABLE_FEATURE_FDISK_WRITABLE
static int get_boot(enum action what)
#else
static int get_boot(void)
#define get_boot(what) get_boot()
#endif
{
    int i, fd;

    g_partitions = 4;
    for (i = 0; i < 4; i++) {
        struct pte *pe = &ptes[i];
        pe->part_table = pt_offset(MBRbuffer, i);
        pe->ext_pointer = NULL;
        pe->offset_from_dev_start = 0;
        pe->sectorbuffer = MBRbuffer;
#if ENABLE_FEATURE_FDISK_WRITABLE
        pe->changed = (what == CREATE_EMPTY_DOS);
#endif
    }

#if ENABLE_FEATURE_FDISK_WRITABLE
// ALERT! highly idiotic design!
// We end up here when we call get_boot() recursively
// via get_boot() [table is bad] -> create_doslabel() -> get_boot(CREATE_EMPTY_DOS).
// or get_boot() [table is bad] -> create_sunlabel() -> get_boot(CREATE_EMPTY_SUN).
// (just factor out re-init of ptes[0,1,2,3] in a separate fn instead?)
// So skip opening device _again_...
    if (what == CREATE_EMPTY_DOS  IF_FEATURE_SUN_LABEL(|| what == CREATE_EMPTY_SUN))
        goto created_table;

    fd = open(disk_device, (option_mask32 & OPT_l) ? O_RDONLY : O_RDWR);

    if (fd < 0) {
        fd = open(disk_device, O_RDONLY);
        if (fd < 0) {
            if (what == TRY_ONLY)
                return 1;
            fdisk_fatal(unable_to_open);
        }
        printf("'%s' is opened for read only\n", disk_device);
    }
    xmove_fd(fd, dev_fd);
    if (512 != full_read(dev_fd, MBRbuffer, 512)) {
        if (what == TRY_ONLY) {
            close_dev_fd();
            return 1;
        }
        fdisk_fatal(unable_to_read);
    }
#else
    fd = open(disk_device, O_RDONLY);
    if (fd < 0)
        return 1;
    if (512 != full_read(fd, MBRbuffer, 512)) {
        close(fd);
        return 1;
    }
    xmove_fd(fd, dev_fd);
#endif

    get_geometry();
    update_units();

#if ENABLE_FEATURE_SUN_LABEL
    if (check_sun_label())
        return 0;
#endif
#if ENABLE_FEATURE_SGI_LABEL
    if (check_sgi_label())
        return 0;
#endif
#if ENABLE_FEATURE_AIX_LABEL
    if (check_aix_label())
        return 0;
#endif
#if ENABLE_FEATURE_GPT_LABEL
    if (check_gpt_label())
        return 0;
#endif
#if ENABLE_FEATURE_OSF_LABEL
    if (check_osf_label()) {
        possibly_osf_label = 1;
        if (!valid_part_table_flag(MBRbuffer)) {
            current_label_type = LABEL_OSF;
            return 0;
        }
        printf("This disk has both DOS and BSD magic.\n"
             "Give the 'b' command to go to BSD mode.\n");
    }
#endif

#if !ENABLE_FEATURE_FDISK_WRITABLE
    if (!valid_part_table_flag(MBRbuffer))
        return -1;
#else
    if (!valid_part_table_flag(MBRbuffer)) {
        if (what == OPEN_MAIN) {
            printf("Device contains neither a valid DOS "
                  "partition table, nor Sun, SGI, OSF or GPT "
                  "disklabel\n");
#ifdef __sparc__
            IF_FEATURE_SUN_LABEL(create_sunlabel();)
#else
            create_doslabel();
#endif
            return 0;
        }
        /* TRY_ONLY: */
        return -1;
    }
 created_table:
#endif /* FEATURE_FDISK_WRITABLE */


    IF_FEATURE_FDISK_WRITABLE(warn_cylinders();)
    warn_geometry();

    for (i = 0; i < 4; i++) {
        if (IS_EXTENDED(ptes[i].part_table->sys_ind)) {
            if (g_partitions != 4)
                printf("Ignoring extra extended "
                    "partition %u\n", i + 1);
            else
                read_extended(i);
        }
    }

    for (i = 3; i < g_partitions; i++) {
        struct pte *pe = &ptes[i];
        if (!valid_part_table_flag(pe->sectorbuffer)) {
            printf("Warning: invalid flag 0x%02x,0x%02x of partition "
                "table %u will be corrected by w(rite)\n",
                pe->sectorbuffer[510],
                pe->sectorbuffer[511],
                i + 1);
            IF_FEATURE_FDISK_WRITABLE(pe->changed = 1;)
        }
    }

    return 0;
}

#if ENABLE_FEATURE_FDISK_WRITABLE
/*
 * Print the message MESG, then read an integer between LOW and HIGH (inclusive).
 * If the user hits Enter, DFLT is returned.
 * Answers like +10 are interpreted as offsets from BASE.
 *
 * There is no default if DFLT is not between LOW and HIGH.
 */
static sector_t
read_int(sector_t low, sector_t dflt, sector_t high, sector_t base, const char *mesg)
{
    sector_t value;
    int default_ok = 1;
    const char *fmt = "%s (%u-%u, default %u): ";

    if (dflt < low || dflt > high) {
        fmt = "%s (%u-%u): ";
        default_ok = 0;
    }

    while (1) {
        int use_default = default_ok;

        /* ask question and read answer */
        do {
            printf(fmt, mesg, low, high, dflt);
            read_maybe_empty("");
        } while (*line_ptr != '\n' && !isdigit(*line_ptr)
         && *line_ptr != '-' && *line_ptr != '+');

        if (*line_ptr == '+' || *line_ptr == '-') {
            int minus = (*line_ptr == '-');
            int absolute = 0;

            value = atoi(line_ptr + 1);

            /* (1) if 2nd char is digit, use_default = 0.
             * (2) move line_ptr to first non-digit. */
            while (isdigit(*++line_ptr))
                use_default = 0;

            switch (*line_ptr) {
            case 'c':
            case 'C':
                if (!display_in_cyl_units)
                    value *= g_heads * g_sectors;
                break;
            case 'K':
                absolute = 1024;
                break;
            case 'k':
                absolute = 1000;
                break;
            case 'm':
            case 'M':
                absolute = 1000000;
                break;
            case 'g':
            case 'G':
                absolute = 1000000000;
                break;
            default:
                break;
            }
            if (absolute) {
                ullong bytes;
                unsigned long unit;

                bytes = (ullong) value * absolute;
                unit = sector_size * units_per_sector;
                bytes += unit/2; /* round */
                bytes /= unit;
                value = bytes;
            }
            if (minus)
                value = -value;
            value += base;
        } else {
            value = atoi(line_ptr);
            while (isdigit(*line_ptr)) {
                line_ptr++;
                use_default = 0;
            }
        }
        if (use_default) {
            value = dflt;
            printf("Using default value %u\n", value);
        }
        if (value >= low && value <= high)
            break;
        printf("Value is out of range\n");
    }
    return value;
}

static unsigned
get_partition(int warn, unsigned max)
{
    struct pte *pe;
    unsigned i;

    i = read_int(1, 0, max, 0, "Partition number") - 1;
    pe = &ptes[i];

    if (warn) {
        if ((!LABEL_IS_SUN && !LABEL_IS_SGI && !pe->part_table->sys_ind)
         || (LABEL_IS_SUN && (!sunlabel->partitions[i].num_sectors || !sunlabel->infos[i].id))
         || (LABEL_IS_SGI && !sgi_get_num_sectors(i))
        ) {
            printf("Warning: partition %u has empty type\n", i+1);
        }
    }
    return i;
}

static int
get_existing_partition(int warn, unsigned max)
{
    int pno = -1;
    unsigned i;

    for (i = 0; i < max; i++) {
        struct pte *pe = &ptes[i];
        struct partition *p = pe->part_table;

        if (p && !is_cleared_partition(p)) {
            if (pno >= 0)
                goto not_unique;
            pno = i;
        }
    }
    if (pno >= 0) {
        printf("Selected partition %u\n", pno+1);
        return pno;
    }
    printf("No partition is defined yet!\n");
    return -1;

 not_unique:
    return get_partition(warn, max);
}

static int
get_nonexisting_partition(int warn, unsigned max)
{
    int pno = -1;
    unsigned i;

    for (i = 0; i < max; i++) {
        struct pte *pe = &ptes[i];
        struct partition *p = pe->part_table;

        if (p && is_cleared_partition(p)) {
            if (pno >= 0)
                goto not_unique;
            pno = i;
        }
    }
    if (pno >= 0) {
        printf("Selected partition %u\n", pno+1);
        return pno;
    }
    printf("All primary partitions have been defined already!\n");
    return -1;

 not_unique:
    return get_partition(warn, max);
}


static void
change_units(void)
{
    display_in_cyl_units = !display_in_cyl_units;
    update_units();
    printf("Changing display/entry units to %s\n",
        str_units(PLURAL));
}

static void
toggle_active(int i)
{
    struct pte *pe = &ptes[i];
    struct partition *p = pe->part_table;

    if (IS_EXTENDED(p->sys_ind) && !p->boot_ind)
        printf("WARNING: Partition %u is an extended partition\n", i + 1);
    p->boot_ind = (p->boot_ind ? 0 : ACTIVE_FLAG);
    pe->changed = 1;
}

static void
toggle_dos_compatibility_flag(void)
{
    dos_compatible_flag = 1 - dos_compatible_flag;
    if (dos_compatible_flag) {
        sector_offset = g_sectors;
        printf("DOS Compatibility flag is set\n");
    } else {
        sector_offset = 1;
        printf("DOS Compatibility flag is not set\n");
    }
}

static void
delete_partition(int i)
{
    struct pte *pe = &ptes[i];
    struct partition *p = pe->part_table;
    struct partition *q = pe->ext_pointer;

/* Note that for the fifth partition (i == 4) we don't actually
 * decrement partitions.
 */

    if (warn_geometry())
        return;         /* C/H/S not set */
    pe->changed = 1;

    if (LABEL_IS_SUN) {
        sun_delete_partition(i);
        return;
    }
    if (LABEL_IS_SGI) {
        sgi_delete_partition(i);
        return;
    }

    if (i < 4) {
        if (IS_EXTENDED(p->sys_ind) && i == ext_index) {
            g_partitions = 4;
            ptes[ext_index].ext_pointer = NULL;
            extended_offset = 0;
        }
        clear_partition(p);
        return;
    }

    if (!q->sys_ind && i > 4) {
        /* the last one in the chain - just delete */
        --g_partitions;
        --i;
        clear_partition(ptes[i].ext_pointer);
        ptes[i].changed = 1;
    } else {
        /* not the last one - further ones will be moved down */
        if (i > 4) {
            /* delete this link in the chain */
            p = ptes[i-1].ext_pointer;
            *p = *q;
            set_start_sect(p, get_start_sect(q));
            set_nr_sects(p, get_nr_sects(q));
            ptes[i-1].changed = 1;
        } else if (g_partitions > 5) {    /* 5 will be moved to 4 */
            /* the first logical in a longer chain */
            pe = &ptes[5];

            if (pe->part_table) /* prevent SEGFAULT */
                set_start_sect(pe->part_table,
                        get_partition_start_from_dev_start(pe) -
                        extended_offset);
            pe->offset_from_dev_start = extended_offset;
            pe->changed = 1;
        }

        if (g_partitions > 5) {
            g_partitions--;
            while (i < g_partitions) {
                ptes[i] = ptes[i+1];
                i++;
            }
        } else {
            /* the only logical: clear only */
            clear_partition(ptes[i].part_table);
        }
    }
}

static void
change_sysid(void)
{
    int i, sys, origsys;
    struct partition *p;

    /* If sgi_label then don't use get_existing_partition,
       let the user select a partition, since get_existing_partition()
       only works for Linux like partition tables. */
    if (!LABEL_IS_SGI) {
        i = get_existing_partition(0, g_partitions);
    } else {
        i = get_partition(0, g_partitions);
    }
    if (i == -1)
        return;
    p = ptes[i].part_table;
    origsys = sys = get_sysid(i);

    /* if changing types T to 0 is allowed, then
       the reverse change must be allowed, too */
    if (!sys && !LABEL_IS_SGI && !LABEL_IS_SUN && !get_nr_sects(p)) {
        printf("Partition %u does not exist yet!\n", i + 1);
        return;
    }
    while (1) {
        sys = read_hex(get_sys_types());

        if (!sys && !LABEL_IS_SGI && !LABEL_IS_SUN) {
            printf("Type 0 means free space to many systems\n"
                   "(but not to Linux). Having partitions of\n"
                   "type 0 is probably unwise.\n");
            /* break; */
        }

        if (!LABEL_IS_SUN && !LABEL_IS_SGI) {
            if (IS_EXTENDED(sys) != IS_EXTENDED(p->sys_ind)) {
                printf("You cannot change a partition into"
                       " an extended one or vice versa\n");
                break;
            }
        }

        if (sys < 256) {
#if ENABLE_FEATURE_SUN_LABEL
            if (LABEL_IS_SUN && i == 2 && sys != SUN_WHOLE_DISK)
                printf("Consider leaving partition 3 "
                       "as Whole disk (5),\n"
                       "as SunOS/Solaris expects it and "
                       "even Linux likes it\n\n");
#endif
#if ENABLE_FEATURE_SGI_LABEL
            if (LABEL_IS_SGI &&
                (
                    (i == 10 && sys != SGI_ENTIRE_DISK) ||
                    (i == 8 && sys != 0)
                )
            ) {
                printf("Consider leaving partition 9 "
                       "as volume header (0),\nand "
                       "partition 11 as entire volume (6)"
                       "as IRIX expects it\n\n");
            }
#endif
            if (sys == origsys)
                break;
            if (LABEL_IS_SUN) {
                sun_change_sysid(i, sys);
            } else if (LABEL_IS_SGI) {
                sgi_change_sysid(i, sys);
            } else
                p->sys_ind = sys;

            printf("Changed system type of partition %u "
                "to %x (%s)\n", i + 1, sys,
                partition_type(sys));
            ptes[i].changed = 1;
            //if (is_dos_partition(origsys) || is_dos_partition(sys))
            //  dos_changed = 1;
            break;
        }
    }
}
#endif /* FEATURE_FDISK_WRITABLE */


/* check_consistency() and linear2chs() added Sat Mar 6 12:28:16 1993,
 * faith@cs.unc.edu, based on code fragments from pfdisk by Gordon W. Ross,
 * Jan.  1990 (version 1.2.1 by Gordon W. Ross Aug. 1990; Modified by S.
 * Lubkin Oct.  1991). */

static void
linear2chs(unsigned ls, unsigned *c, unsigned *h, unsigned *s)
{
    int spc = g_heads * g_sectors;

    *c = ls / spc;
    ls = ls % spc;
    *h = ls / g_sectors;
    *s = ls % g_sectors + 1;  /* sectors count from 1 */
}

static void
check_consistency(const struct partition *p, int partition)
{
    unsigned pbc, pbh, pbs;          /* physical beginning c, h, s */
    unsigned pec, peh, pes;          /* physical ending c, h, s */
    unsigned lbc, lbh, lbs;          /* logical beginning c, h, s */
    unsigned lec, leh, les;          /* logical ending c, h, s */

    if (!g_heads || !g_sectors || (partition >= 4))
        return;         /* do not check extended partitions */

/* physical beginning c, h, s */
    pbc = (p->cyl & 0xff) | ((p->sector << 2) & 0x300);
    pbh = p->head;
    pbs = p->sector & 0x3f;

/* physical ending c, h, s */
    pec = (p->end_cyl & 0xff) | ((p->end_sector << 2) & 0x300);
    peh = p->end_head;
    pes = p->end_sector & 0x3f;

/* compute logical beginning (c, h, s) */
    linear2chs(get_start_sect(p), &lbc, &lbh, &lbs);

/* compute logical ending (c, h, s) */
    linear2chs(get_start_sect(p) + get_nr_sects(p) - 1, &lec, &leh, &les);

/* Same physical / logical beginning? */
    if (g_cylinders <= 1024 && (pbc != lbc || pbh != lbh || pbs != lbs)) {
        printf("Partition %u has different physical/logical "
            "beginnings (non-Linux?):\n", partition + 1);
        printf("     phys=(%u, %u, %u) ", pbc, pbh, pbs);
        printf("logical=(%u, %u, %u)\n", lbc, lbh, lbs);
    }

/* Same physical / logical ending? */
    if (g_cylinders <= 1024 && (pec != lec || peh != leh || pes != les)) {
        printf("Partition %u has different physical/logical "
            "endings:\n", partition + 1);
        printf("     phys=(%u, %u, %u) ", pec, peh, pes);
        printf("logical=(%u, %u, %u)\n", lec, leh, les);
    }

/* Ending on cylinder boundary? */
    if (peh != (g_heads - 1) || pes != g_sectors) {
        printf("Partition %u does not end on cylinder boundary\n",
            partition + 1);
    }
}

static void
list_disk_geometry(void)
{
    ullong bytes = ((ullong)total_number_of_sectors << 9);
    long megabytes = bytes / 1000000;

    if (megabytes < 10000)
        printf("\nDisk %s: %lu MB, %llu bytes\n",
            disk_device, megabytes, bytes);
    else
        printf("\nDisk %s: %lu.%lu GB, %llu bytes\n",
            disk_device, megabytes/1000, (megabytes/100)%10, bytes);
    printf("%u heads, %u sectors/track, %u cylinders",
           g_heads, g_sectors, g_cylinders);
    if (units_per_sector == 1)
        printf(", total %"SECT_FMT"u sectors",
            total_number_of_sectors / (sector_size/512));
    printf("\nUnits = %s of %u * %u = %u bytes\n\n",
        str_units(PLURAL),
        units_per_sector, sector_size, units_per_sector * sector_size);
}

/*
 * Check whether partition entries are ordered by their starting positions.
 * Return 0 if OK. Return i if partition i should have been earlier.
 * Two separate checks: primary and logical partitions.
 */
static int
wrong_p_order(int *prev)
{
    const struct pte *pe;
    const struct partition *p;
    sector_t last_p_start_pos = 0, p_start_pos;
    unsigned i, last_i = 0;

    for (i = 0; i < g_partitions; i++) {
        if (i == 4) {
            last_i = 4;
            last_p_start_pos = 0;
        }
        pe = &ptes[i];
        p = pe->part_table;
        if (p->sys_ind) {
            p_start_pos = get_partition_start_from_dev_start(pe);

            if (last_p_start_pos > p_start_pos) {
                if (prev)
                    *prev = last_i;
                return i;
            }

            last_p_start_pos = p_start_pos;
            last_i = i;
        }
    }
    return 0;
}

#if ENABLE_FEATURE_FDISK_ADVANCED
/*
 * Fix the chain of logicals.
 * extended_offset is unchanged, the set of sectors used is unchanged
 * The chain is sorted so that sectors increase, and so that
 * starting sectors increase.
 *
 * After this it may still be that cfdisk doesnt like the table.
 * (This is because cfdisk considers expanded parts, from link to
 * end of partition, and these may still overlap.)
 * Now
 *   sfdisk /dev/hda > ohda; sfdisk /dev/hda < ohda
 * may help.
 */
static void
fix_chain_of_logicals(void)
{
    int j, oj, ojj, sj, sjj;
    struct partition *pj,*pjj,tmp;

    /* Stage 1: sort sectors but leave sector of part 4 */
    /* (Its sector is the global extended_offset.) */
 stage1:
    for (j = 5; j < g_partitions - 1; j++) {
        oj = ptes[j].offset_from_dev_start;
        ojj = ptes[j+1].offset_from_dev_start;
        if (oj > ojj) {
            ptes[j].offset_from_dev_start = ojj;
            ptes[j+1].offset_from_dev_start = oj;
            pj = ptes[j].part_table;
            set_start_sect(pj, get_start_sect(pj)+oj-ojj);
            pjj = ptes[j+1].part_table;
            set_start_sect(pjj, get_start_sect(pjj)+ojj-oj);
            set_start_sect(ptes[j-1].ext_pointer,
                       ojj-extended_offset);
            set_start_sect(ptes[j].ext_pointer,
                       oj-extended_offset);
            goto stage1;
        }
    }

    /* Stage 2: sort starting sectors */
 stage2:
    for (j = 4; j < g_partitions - 1; j++) {
        pj = ptes[j].part_table;
        pjj = ptes[j+1].part_table;
        sj = get_start_sect(pj);
        sjj = get_start_sect(pjj);
        oj = ptes[j].offset_from_dev_start;
        ojj = ptes[j+1].offset_from_dev_start;
        if (oj+sj > ojj+sjj) {
            tmp = *pj;
            *pj = *pjj;
            *pjj = tmp;
            set_start_sect(pj, ojj+sjj-oj);
            set_start_sect(pjj, oj+sj-ojj);
            goto stage2;
        }
    }

    /* Probably something was changed */
    for (j = 4; j < g_partitions; j++)
        ptes[j].changed = 1;
}


static void
fix_partition_table_order(void)
{
    struct pte *pei, *pek;
    int i,k;

    if (!wrong_p_order(NULL)) {
        printf("Ordering is already correct\n\n");
        return;
    }

    while ((i = wrong_p_order(&k)) != 0 && i < 4) {
        /* partition i should have come earlier, move it */
        /* We have to move data in the MBR */
        struct partition *pi, *pk, *pe, pbuf;
        pei = &ptes[i];
        pek = &ptes[k];

        pe = pei->ext_pointer;
        pei->ext_pointer = pek->ext_pointer;
        pek->ext_pointer = pe;

        pi = pei->part_table;
        pk = pek->part_table;

        memmove(&pbuf, pi, sizeof(struct partition));
        memmove(pi, pk, sizeof(struct partition));
        memmove(pk, &pbuf, sizeof(struct partition));

        pei->changed = pek->changed = 1;
    }

    if (i)
        fix_chain_of_logicals();

    printf("Done.\n");
}
#endif

static void
list_table(int xtra)
{
    const struct partition *p;
    int i, w;

    if (LABEL_IS_SUN) {
        sun_list_table(xtra);
        return;
    }
    if (LABEL_IS_SGI) {
        sgi_list_table(xtra);
        return;
    }
    if (LABEL_IS_GPT) {
        gpt_list_table(xtra);
        return;
    }

    list_disk_geometry();

    if (LABEL_IS_OSF) {
        xbsd_print_disklabel(xtra);
        return;
    }

    /* Heuristic: we list partition 3 of /dev/foo as /dev/foo3,
       but if the device name ends in a digit, say /dev/foo1,
       then the partition is called /dev/foo1p3. */
    w = strlen(disk_device);
    if (w && isdigit(disk_device[w-1]))
        w++;
    if (w < 5)
        w = 5;

    //            1 12345678901 12345678901 12345678901  12
    printf("%*s Boot      Start         End      Blocks  Id System\n",
           w+1, "Device");

    for (i = 0; i < g_partitions; i++) {
        const struct pte *pe = &ptes[i];
        sector_t psects;
        sector_t pblocks;
        unsigned podd;

        p = pe->part_table;
        if (!p || is_cleared_partition(p))
            continue;

        psects = get_nr_sects(p);
        pblocks = psects;
        podd = 0;

        if (sector_size < 1024) {
            pblocks /= (1024 / sector_size);
            podd = psects % (1024 / sector_size);
        }
        if (sector_size > 1024)
            pblocks *= (sector_size / 1024);

        printf("%s  %c %11"SECT_FMT"u %11"SECT_FMT"u %11"SECT_FMT"u%c %2x %s\n",
            partname(disk_device, i+1, w+2),
            !p->boot_ind ? ' ' : p->boot_ind == ACTIVE_FLAG /* boot flag */
                ? '*' : '?',
            cround(get_partition_start_from_dev_start(pe)),           /* start */
            cround(get_partition_start_from_dev_start(pe) + psects    /* end */
                - (psects ? 1 : 0)),
            pblocks, podd ? '+' : ' ', /* odd flag on end */
            p->sys_ind,                                     /* type id */
            partition_type(p->sys_ind));                    /* type name */

        check_consistency(p, i);
    }

    /* Is partition table in disk order? It need not be, but... */
    /* partition table entries are not checked for correct order
     * if this is a sgi, sun or aix labeled disk... */
    if (LABEL_IS_DOS && wrong_p_order(NULL)) {
        /* FIXME */
        printf("\nPartition table entries are not in disk order\n");
    }
}

#if ENABLE_FEATURE_FDISK_ADVANCED
static void
x_list_table(int extend)
{
    const struct pte *pe;
    const struct partition *p;
    int i;

    printf("\nDisk %s: %u heads, %u sectors, %u cylinders\n\n",
        disk_device, g_heads, g_sectors, g_cylinders);
    printf("Nr AF  Hd Sec  Cyl  Hd Sec  Cyl      Start       Size ID\n");
    for (i = 0; i < g_partitions; i++) {
        pe = &ptes[i];
        p = (extend ? pe->ext_pointer : pe->part_table);
        if (p != NULL) {
            printf("%2u %02x%4u%4u%5u%4u%4u%5u%11"SECT_FMT"u%11"SECT_FMT"u %02x\n",
                i + 1, p->boot_ind, p->head,
                sector(p->sector),
                cylinder(p->sector, p->cyl), p->end_head,
                sector(p->end_sector),
                cylinder(p->end_sector, p->end_cyl),
                get_start_sect(p), get_nr_sects(p),
                p->sys_ind);
            if (p->sys_ind)
                check_consistency(p, i);
        }
    }
}
#endif

#if ENABLE_FEATURE_FDISK_WRITABLE
static void
fill_bounds(sector_t *first, sector_t *last)
{
    unsigned i;
    const struct pte *pe = &ptes[0];
    const struct partition *p;

    for (i = 0; i < g_partitions; pe++,i++) {
        p = pe->part_table;
        if (!p->sys_ind || IS_EXTENDED(p->sys_ind)) {
            first[i] = 0xffffffff;
            last[i] = 0;
        } else {
            first[i] = get_partition_start_from_dev_start(pe);
            last[i] = first[i] + get_nr_sects(p) - 1;
        }
    }
}

static void
check(int n, unsigned h, unsigned s, unsigned c, sector_t start)
{
    sector_t total, real_s, real_c;

    real_s = sector(s) - 1;
    real_c = cylinder(s, c);
    total = (real_c * g_sectors + real_s) * g_heads + h;
    if (!total)
        printf("Partition %u contains sector 0\n", n);
    if (h >= g_heads)
        printf("Partition %u: head %u greater than maximum %u\n",
            n, h + 1, g_heads);
    if (real_s >= g_sectors)
        printf("Partition %u: sector %u greater than "
            "maximum %u\n", n, s, g_sectors);
    if (real_c >= g_cylinders)
        printf("Partition %u: cylinder %"SECT_FMT"u greater than "
            "maximum %u\n", n, real_c + 1, g_cylinders);
    if (g_cylinders <= 1024 && start != total)
        printf("Partition %u: previous sectors %"SECT_FMT"u disagrees with "
            "total %"SECT_FMT"u\n", n, start, total);
}

static void
verify(void)
{
    int i, j;
    sector_t total = 1;
    sector_t first[g_partitions], last[g_partitions];
    struct partition *p;

    if (warn_geometry())
        return;

    if (LABEL_IS_SUN) {
        verify_sun();
        return;
    }
    if (LABEL_IS_SGI) {
        verify_sgi(1);
        return;
    }

    fill_bounds(first, last);
    for (i = 0; i < g_partitions; i++) {
        struct pte *pe = &ptes[i];

        p = pe->part_table;
        if (p->sys_ind && !IS_EXTENDED(p->sys_ind)) {
            check_consistency(p, i);
            if (get_partition_start_from_dev_start(pe) < first[i])
                printf("Warning: bad start-of-data in "
                    "partition %u\n", i + 1);
            check(i + 1, p->end_head, p->end_sector, p->end_cyl,
                last[i]);
            total += last[i] + 1 - first[i];
            for (j = 0; j < i; j++) {
                if ((first[i] >= first[j] && first[i] <= last[j])
                 || ((last[i] <= last[j] && last[i] >= first[j]))) {
                    printf("Warning: partition %u overlaps "
                        "partition %u\n", j + 1, i + 1);
                    total += first[i] >= first[j] ?
                        first[i] : first[j];
                    total -= last[i] <= last[j] ?
                        last[i] : last[j];
                }
            }
        }
    }

    if (extended_offset) {
        struct pte *pex = &ptes[ext_index];
        sector_t e_last = get_start_sect(pex->part_table) +
            get_nr_sects(pex->part_table) - 1;

        for (i = 4; i < g_partitions; i++) {
            total++;
            p = ptes[i].part_table;
            if (!p->sys_ind) {
                if (i != 4 || i + 1 < g_partitions)
                    printf("Warning: partition %u "
                        "is empty\n", i + 1);
            } else if (first[i] < extended_offset || last[i] > e_last) {
                printf("Logical partition %u not entirely in "
                    "partition %u\n", i + 1, ext_index + 1);
            }
        }
    }

    if (total > g_heads * g_sectors * g_cylinders)
        printf("Total allocated sectors %u greater than the maximum "
            "%u\n", total, g_heads * g_sectors * g_cylinders);
    else {
        total = g_heads * g_sectors * g_cylinders - total;
        if (total != 0)
            printf("%"SECT_FMT"u unallocated sectors\n", total);
    }
}

static void
add_partition(int n, int sys)
{
    char mesg[256];         /* 48 does not suffice in Japanese */
    int i, num_read = 0;
    struct partition *p = ptes[n].part_table;
    struct partition *q = ptes[ext_index].part_table;
    sector_t limit, temp;
    sector_t start, stop = 0;
    sector_t first[g_partitions], last[g_partitions];

    if (p && p->sys_ind) {
        printf(msg_part_already_defined, n + 1);
        return;
    }
    fill_bounds(first, last);
    if (n < 4) {
        start = sector_offset;
        if (display_in_cyl_units || !total_number_of_sectors)
            limit = (sector_t) g_heads * g_sectors * g_cylinders - 1;
        else
            limit = total_number_of_sectors - 1;
        if (extended_offset) {
            first[ext_index] = extended_offset;
            last[ext_index] = get_start_sect(q) +
                get_nr_sects(q) - 1;
        }
    } else {
        start = extended_offset + sector_offset;
        limit = get_start_sect(q) + get_nr_sects(q) - 1;
    }
    if (display_in_cyl_units)
        for (i = 0; i < g_partitions; i++)
            first[i] = (cround(first[i]) - 1) * units_per_sector;

    snprintf(mesg, sizeof(mesg), "First %s", str_units(SINGULAR));
    do {
        temp = start;
        for (i = 0; i < g_partitions; i++) {
            int lastplusoff;

            if (start == ptes[i].offset_from_dev_start)
                start += sector_offset;
            lastplusoff = last[i] + ((n < 4) ? 0 : sector_offset);
            if (start >= first[i] && start <= lastplusoff)
                start = lastplusoff + 1;
        }
        if (start > limit)
            break;
        if (start >= temp+units_per_sector && num_read) {
            printf("Sector %"SECT_FMT"u is already allocated\n", temp);
            temp = start;
            num_read = 0;
        }
        if (!num_read && start == temp) {
            sector_t saved_start;

            saved_start = start;
            start = read_int(cround(saved_start), cround(saved_start), cround(limit), 0, mesg);
            if (display_in_cyl_units) {
                start = (start - 1) * units_per_sector;
                if (start < saved_start)
                    start = saved_start;
            }
            num_read = 1;
        }
    } while (start != temp || !num_read);
    if (n > 4) {                    /* NOT for fifth partition */
        struct pte *pe = &ptes[n];

        pe->offset_from_dev_start = start - sector_offset;
        if (pe->offset_from_dev_start == extended_offset) { /* must be corrected */
            pe->offset_from_dev_start++;
            if (sector_offset == 1)
                start++;
        }
    }

    for (i = 0; i < g_partitions; i++) {
        struct pte *pe = &ptes[i];

        if (start < pe->offset_from_dev_start && limit >= pe->offset_from_dev_start)
            limit = pe->offset_from_dev_start - 1;
        if (start < first[i] && limit >= first[i])
            limit = first[i] - 1;
    }
    if (start > limit) {
        printf("No free sectors available\n");
        if (n > 4)
            g_partitions--;
        return;
    }
    if (cround(start) == cround(limit)) {
        stop = limit;
    } else {
        snprintf(mesg, sizeof(mesg),
             "Last %s or +size or +sizeM or +sizeK",
             str_units(SINGULAR));
        stop = read_int(cround(start), cround(limit), cround(limit), cround(start), mesg);
        if (display_in_cyl_units) {
            stop = stop * units_per_sector - 1;
            if (stop >limit)
                stop = limit;
        }
    }

    set_partition(n, 0, start, stop, sys);
    if (n > 4)
        set_partition(n - 1, 1, ptes[n].offset_from_dev_start, stop, EXTENDED);

    if (IS_EXTENDED(sys)) {
        struct pte *pe4 = &ptes[4];
        struct pte *pen = &ptes[n];

        ext_index = n;
        pen->ext_pointer = p;
        pe4->offset_from_dev_start = extended_offset = start;
        pe4->sectorbuffer = xzalloc(sector_size);
        pe4->part_table = pt_offset(pe4->sectorbuffer, 0);
        pe4->ext_pointer = pe4->part_table + 1;
        pe4->changed = 1;
        g_partitions = 5;
    }
}

static void
add_logical(void)
{
    if (g_partitions > 5 || ptes[4].part_table->sys_ind) {
        struct pte *pe = &ptes[g_partitions];

        pe->sectorbuffer = xzalloc(sector_size);
        pe->part_table = pt_offset(pe->sectorbuffer, 0);
        pe->ext_pointer = pe->part_table + 1;
        pe->offset_from_dev_start = 0;
        pe->changed = 1;
        g_partitions++;
    }
    add_partition(g_partitions - 1, LINUX_NATIVE);
}

static void
new_partition(void)
{
    int i, free_primary = 0;

    if (warn_geometry())
        return;

    if (LABEL_IS_SUN) {
        add_sun_partition(get_partition(0, g_partitions), LINUX_NATIVE);
        return;
    }
    if (LABEL_IS_SGI) {
        sgi_add_partition(get_partition(0, g_partitions), LINUX_NATIVE);
        return;
    }
    if (LABEL_IS_AIX) {
        printf("Sorry - this fdisk cannot handle AIX disk labels.\n"
"If you want to add DOS-type partitions, create a new empty DOS partition\n"
"table first (use 'o'). This will destroy the present disk contents.\n");
        return;
    }

    for (i = 0; i < 4; i++)
        free_primary += !ptes[i].part_table->sys_ind;

    if (!free_primary && g_partitions >= MAXIMUM_PARTS) {
        printf("The maximum number of partitions has been created\n");
        return;
    }

    if (!free_primary) {
        if (extended_offset)
            add_logical();
        else
            printf("You must delete some partition and add "
                 "an extended partition first\n");
    } else {
        char c, line[80];
        snprintf(line, sizeof(line),
            "Command action\n"
            "   %s\n"
            "   p   primary partition (1-4)\n",
            (extended_offset ?
            "l   logical (5 or over)" : "e   extended"));
        while (1) {
            c = read_nonempty(line);
            if ((c | 0x20) == 'p') {
                i = get_nonexisting_partition(0, 4);
                if (i >= 0)
                    add_partition(i, LINUX_NATIVE);
                return;
            }
            if (c == 'l' && extended_offset) {
                add_logical();
                return;
            }
            if (c == 'e' && !extended_offset) {
                i = get_nonexisting_partition(0, 4);
                if (i >= 0)
                    add_partition(i, EXTENDED);
                return;
            }
            printf("Invalid partition number "
                     "for type '%c'\n", c);
        }
    }
}

static void
write_table(void)
{
    int i;

    if (LABEL_IS_DOS) {
        for (i = 0; i < 3; i++)
            if (ptes[i].changed)
                ptes[3].changed = 1;
        for (i = 3; i < g_partitions; i++) {
            struct pte *pe = &ptes[i];

            if (pe->changed) {
                write_part_table_flag(pe->sectorbuffer);
                write_sector(pe->offset_from_dev_start, pe->sectorbuffer);
            }
        }
    }
    else if (LABEL_IS_SGI) {
        /* no test on change? the printf below might be mistaken */
        sgi_write_table();
    }
    else if (LABEL_IS_SUN) {
        int needw = 0;

        for (i = 0; i < 8; i++)
            if (ptes[i].changed)
                needw = 1;
        if (needw)
            sun_write_table();
    }

    printf("The partition table has been altered!\n\n");
    reread_partition_table(1);
}

static void
reread_partition_table(int leave)
{
    int i;

    printf("Calling ioctl() to re-read partition table\n");
    sync();
    /* sleep(2); Huh? */
    i = ioctl_or_perror(dev_fd, BLKRRPART, NULL,
            "WARNING: rereading partition table "
            "failed, kernel still uses old table");
#if 0
    if (dos_changed)
        printf(
        "\nWARNING: If you have created or modified any DOS 6.x\n"
        "partitions, please see the fdisk manual page for additional\n"
        "information\n");
#endif

    if (leave) {
        if (ENABLE_FEATURE_CLEAN_UP)
            close_dev_fd();
        exit(i != 0);
    }
}
#endif /* FEATURE_FDISK_WRITABLE */

#if ENABLE_FEATURE_FDISK_ADVANCED
#define MAX_PER_LINE    16
static void
print_buffer(char *pbuffer)
{
    int i,l;

    for (i = 0, l = 0; i < sector_size; i++, l++) {
        if (l == 0)
            printf("0x%03X:", i);
        printf(" %02X", (unsigned char) pbuffer[i]);
        if (l == MAX_PER_LINE - 1) {
            bb_putchar('\n');
            l = -1;
        }
    }
    if (l > 0)
        bb_putchar('\n');
    bb_putchar('\n');
}

static void
print_raw(void)
{
    int i;

    printf("Device: %s\n", disk_device);
    if (LABEL_IS_SGI || LABEL_IS_SUN)
        print_buffer(MBRbuffer);
    else {
        for (i = 3; i < g_partitions; i++)
            print_buffer(ptes[i].sectorbuffer);
    }
}

static void
move_begin(unsigned i)
{
    struct pte *pe = &ptes[i];
    struct partition *p = pe->part_table;
    sector_t new, first, nr_sects;

    if (warn_geometry())
        return;
    nr_sects = get_nr_sects(p);
    if (!p->sys_ind || !nr_sects || IS_EXTENDED(p->sys_ind)) {
        printf("Partition %u has no data area\n", i + 1);
        return;
    }
    first = get_partition_start_from_dev_start(pe); /* == pe->offset_from_dev_start + get_start_sect(p) */
    new = read_int(0 /*was:first*/, first, first + nr_sects - 1, first, "New beginning of data");
    if (new != first) {
        sector_t new_relative = new - pe->offset_from_dev_start;
        nr_sects += (get_start_sect(p) - new_relative);
        set_start_sect(p, new_relative);
        set_nr_sects(p, nr_sects);
        read_nonempty("Recalculate C/H/S values? (Y/N): ");
        if ((line_ptr[0] | 0x20) == 'y')
            set_hsc_start_end(p, new, new + nr_sects - 1);
        pe->changed = 1;
    }
}

static void
xselect(void)
{
    char c;

    while (1) {
        bb_putchar('\n');
        c = 0x20 | read_nonempty("Expert command (m for help): ");
        switch (c) {
        case 'a':
            if (LABEL_IS_SUN)
                sun_set_alt_cyl();
            break;
        case 'b':
            if (LABEL_IS_DOS)
                move_begin(get_partition(0, g_partitions));
            break;
        case 'c':
            user_cylinders = g_cylinders =
                read_int(1, g_cylinders, 1048576, 0,
                    "Number of cylinders");
            if (LABEL_IS_SUN)
                sun_set_ncyl(g_cylinders);
            if (LABEL_IS_DOS)
                warn_cylinders();
            break;
        case 'd':
            print_raw();
            break;
        case 'e':
            if (LABEL_IS_SGI)
                sgi_set_xcyl();
            else if (LABEL_IS_SUN)
                sun_set_xcyl();
            else if (LABEL_IS_DOS)
                x_list_table(1);
            break;
        case 'f':
            if (LABEL_IS_DOS)
                fix_partition_table_order();
            break;
        case 'g':
#if ENABLE_FEATURE_SGI_LABEL
            create_sgilabel();
#endif
            break;
        case 'h':
            user_heads = g_heads = read_int(1, g_heads, 256, 0, "Number of heads");
            update_units();
            break;
        case 'i':
            if (LABEL_IS_SUN)
                sun_set_ilfact();
            break;
        case 'o':
            if (LABEL_IS_SUN)
                sun_set_rspeed();
            break;
        case 'p':
            if (LABEL_IS_SUN)
                list_table(1);
            else
                x_list_table(0);
            break;
        case 'q':
            if (ENABLE_FEATURE_CLEAN_UP)
                close_dev_fd();
            bb_putchar('\n');
            exit(EXIT_SUCCESS);
        case 'r':
            return;
        case 's':
            user_sectors = g_sectors = read_int(1, g_sectors, 63, 0, "Number of sectors");
            if (dos_compatible_flag) {
                sector_offset = g_sectors;
                printf("Warning: setting sector offset for DOS "
                    "compatiblity\n");
            }
            update_units();
            break;
        case 'v':
            verify();
            break;
        case 'w':
            write_table();  /* does not return */
            break;
        case 'y':
            if (LABEL_IS_SUN)
                sun_set_pcylcount();
            break;
        default:
            xmenu();
        }
    }
}
#endif /* ADVANCED mode */

static int
is_ide_cdrom_or_tape(const char *device)
{
    FILE *procf;
    char buf[100];
    struct stat statbuf;
    int is_ide = 0;

    /* No device was given explicitly, and we are trying some
       likely things.  But opening /dev/hdc may produce errors like
       "hdc: tray open or drive not ready"
       if it happens to be a CD-ROM drive. It even happens that
       the process hangs on the attempt to read a music CD.
       So try to be careful. This only works since 2.1.73. */

    if (strncmp("/dev/hd", device, 7))
        return 0;

    snprintf(buf, sizeof(buf), "/proc/ide/%s/media", device+5);
    procf = fopen_for_read(buf);
    if (procf != NULL && fgets(buf, sizeof(buf), procf))
        is_ide = (!strncmp(buf, "cdrom", 5) ||
              !strncmp(buf, "tape", 4));
    else
        /* Now when this proc file does not exist, skip the
           device when it is read-only. */
        if (stat(device, &statbuf) == 0)
            is_ide = ((statbuf.st_mode & 0222) == 0);

    if (procf)
        fclose(procf);
    return is_ide;
}


static void
open_list_and_close(const char *device, int user_specified)
{
    int gb;

    disk_device = device;
    if (setjmp(listingbuf))
        return;
    if (!user_specified)
        if (is_ide_cdrom_or_tape(device))
            return;

    /* Open disk_device, save file descriptor to dev_fd */
    errno = 0;
    gb = get_boot(TRY_ONLY);
    if (gb > 0) {   /* I/O error */
        /* Ignore other errors, since we try IDE
           and SCSI hard disks which may not be
           installed on the system. */
        if (user_specified || errno == EACCES)
            bb_perror_msg("can't open '%s'", device);
        return;
    }

    if (gb < 0) { /* no DOS signature */
        list_disk_geometry();
        if (LABEL_IS_AIX)
            goto ret;
#if ENABLE_FEATURE_OSF_LABEL
        if (bsd_trydev(device) < 0)
#endif
            printf("Disk %s doesn't contain a valid "
                "partition table\n", device);
    } else {
        list_table(0);
#if ENABLE_FEATURE_FDISK_WRITABLE
        if (!LABEL_IS_SUN && g_partitions > 4) {
            delete_partition(ext_index);
        }
#endif
    }
 ret:
    close_dev_fd();
}

/* for fdisk -l: try all things in /proc/partitions
   that look like a partition name (do not end in a digit) */
static void
list_devs_in_proc_partititons(void)
{
    FILE *procpt;
    char line[100], ptname[100], devname[120], *s;
    int ma, mi, sz;

    procpt = fopen_or_warn("/proc/partitions", "r");

    while (fgets(line, sizeof(line), procpt)) {
        if (sscanf(line, " %u %u %u %[^\n ]",
                &ma, &mi, &sz, ptname) != 4)
            continue;
        for (s = ptname; *s; s++)
            continue;
        /* note: excluding '0': e.g. mmcblk0 is not a partition name! */
        if (s[-1] >= '1' && s[-1] <= '9')
            continue;
        sprintf(devname, "/dev/%s", ptname);
        open_list_and_close(devname, 0);
    }
#if ENABLE_FEATURE_CLEAN_UP
    fclose(procpt);
#endif
}

#if ENABLE_FEATURE_FDISK_WRITABLE
static void
unknown_command(int c)
{
    printf("%c: unknown command\n", c);
}
#endif

int fdisk_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int fdisk_main(int argc UNUSED_PARAM, char **argv)
{
    unsigned opt;
    /*
     *  fdisk -v
     *  fdisk -l [-b sectorsize] [-u] device ...
     *  fdisk -s [partition] ...
     *  fdisk [-b sectorsize] [-u] device
     *
     * Options -C, -H, -S set the geometry.
     */
    INIT_G();

    close_dev_fd(); /* needed: fd 3 must not stay closed */

    opt_complementary = "b+:C+:H+:S+"; /* numeric params */
    opt = getopt32(argv, "b:C:H:lS:u" IF_FEATURE_FDISK_BLKSIZE("s"),
                &sector_size, &user_cylinders, &user_heads, &user_sectors);
    argv += optind;
    if (opt & OPT_b) {
        /* Ugly: this sector size is really per device,
         * so cannot be combined with multiple disks,
         * and the same goes for the C/H/S options.
         */
        if (sector_size < 512
         || sector_size > 0x10000
         || (sector_size & (sector_size-1)) /* not power of 2 */
        ) {
            bb_show_usage();
        }
        sector_offset = 2;
        user_set_sector_size = 1;
    }
    if (user_heads <= 0 || user_heads >= 256)
        user_heads = 0;
    if (user_sectors <= 0 || user_sectors >= 64)
        user_sectors = 0;
    if (opt & OPT_u)
        display_in_cyl_units = 0; // -u

#if ENABLE_FEATURE_FDISK_WRITABLE
    if (opt & OPT_l) {
        nowarn = 1;
#endif
        if (*argv) {
            listing = 1;
            do {
                open_list_and_close(*argv, 1);
            } while (*++argv);
        } else {
            /* we don't have device names, */
            /* use /proc/partitions instead */
            list_devs_in_proc_partititons();
        }
        return 0;
#if ENABLE_FEATURE_FDISK_WRITABLE
    }
#endif

#if ENABLE_FEATURE_FDISK_BLKSIZE
    if (opt & OPT_s) {
        int j;

        nowarn = 1;
        if (!argv[0])
            bb_show_usage();
        for (j = 0; argv[j]; j++) {
            unsigned long long size;
            fd = xopen(argv[j], O_RDONLY);
            size = bb_BLKGETSIZE_sectors(fd) / 2;
            close(fd);
            if (argv[1])
                printf("%llu\n", size);
            else
                printf("%s: %llu\n", argv[j], size);
        }
        return 0;
    }
#endif

#if ENABLE_FEATURE_FDISK_WRITABLE
    if (!argv[0] || argv[1])
        bb_show_usage();

    disk_device = argv[0];
    get_boot(OPEN_MAIN);

    if (LABEL_IS_OSF) {
        /* OSF label, and no DOS label */
        printf("Detected an OSF/1 disklabel on %s, entering "
            "disklabel mode\n", disk_device);
        bsd_select();
        /*Why do we do this?  It seems to be counter-intuitive*/
        current_label_type = LABEL_DOS;
        /* If we return we may want to make an empty DOS label? */
    }

    while (1) {
        int c;
        bb_putchar('\n');
        c = 0x20 | read_nonempty("Command (m for help): ");
        switch (c) {
        case 'a':
            if (LABEL_IS_DOS)
                toggle_active(get_partition(1, g_partitions));
            else if (LABEL_IS_SUN)
                toggle_sunflags(get_partition(1, g_partitions),
                        0x01);
            else if (LABEL_IS_SGI)
                sgi_set_bootpartition(
                    get_partition(1, g_partitions));
            else
                unknown_command(c);
            break;
        case 'b':
            if (LABEL_IS_SGI) {
                printf("\nThe current boot file is: %s\n",
                    sgi_get_bootfile());
                if (read_maybe_empty("Please enter the name of the "
                           "new boot file: ") == '\n')
                    printf("Boot file unchanged\n");
                else
                    sgi_set_bootfile(line_ptr);
            }
#if ENABLE_FEATURE_OSF_LABEL
            else
                bsd_select();
#endif
            break;
        case 'c':
            if (LABEL_IS_DOS)
                toggle_dos_compatibility_flag();
            else if (LABEL_IS_SUN)
                toggle_sunflags(get_partition(1, g_partitions),
                        0x10);
            else if (LABEL_IS_SGI)
                sgi_set_swappartition(
                        get_partition(1, g_partitions));
            else
                unknown_command(c);
            break;
        case 'd':
            {
                int j;
            /* If sgi_label then don't use get_existing_partition,
               let the user select a partition, since
               get_existing_partition() only works for Linux-like
               partition tables */
                if (!LABEL_IS_SGI) {
                    j = get_existing_partition(1, g_partitions);
                } else {
                    j = get_partition(1, g_partitions);
                }
                if (j >= 0)
                    delete_partition(j);
            }
            break;
        case 'i':
            if (LABEL_IS_SGI)
                create_sgiinfo();
            else
                unknown_command(c);
        case 'l':
            list_types(get_sys_types());
            break;
        case 'm':
            menu();
            break;
        case 'n':
            new_partition();
            break;
        case 'o':
            create_doslabel();
            break;
        case 'p':
            list_table(0);
            break;
        case 'q':
            if (ENABLE_FEATURE_CLEAN_UP)
                close_dev_fd();
            bb_putchar('\n');
            return 0;
        case 's':
#if ENABLE_FEATURE_SUN_LABEL
            create_sunlabel();
#endif
            break;
        case 't':
            change_sysid();
            break;
        case 'u':
            change_units();
            break;
        case 'v':
            verify();
            break;
        case 'w':
            write_table();          /* does not return */
            break;
#if ENABLE_FEATURE_FDISK_ADVANCED
        case 'x':
            if (LABEL_IS_SGI) {
                printf("\n\tSorry, no experts menu for SGI "
                    "partition tables available\n\n");
            } else
                xselect();
            break;
#endif
        default:
            unknown_command(c);
            menu();
        }
    }
    return 0;
#endif /* FEATURE_FDISK_WRITABLE */
}