mpartition.c

   1 /*  Copyright 1997-2003,2005-2007,2009 Alain Knaff.
   2  *  This file is part of mtools.
   3  *
   4  *  Mtools is free software: you can redistribute it and/or modify
   5  *  it under the terms of the GNU General Public License as published by
   6  *  the Free Software Foundation, either version 3 of the License, or
   7  *  (at your option) any later version.
   8  *
   9  *  Mtools is distributed in the hope that it will be useful,
  10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *  GNU General Public License for more details.
  13  *
  14  *  You should have received a copy of the GNU General Public License
  15  *  along with Mtools.  If not, see <http://www.gnu.org/licenses/>.
  16  *
  17  * mformat.c
  18  */
  19 #define DONT_NEED_WAIT
  20
  21 #include "sysincludes.h"
  22 #include "msdos.h"
  23 #include "mtools.h"
  24 #include "mainloop.h"
  25 #include "fsP.h"
  26 #include "file.h"
  27 #include "plain_io.h"
  28 #include "nameclash.h"
  29 #include "buffer.h"
  30 #include "partition.h"
  31 #include "open_image.h"
  32 #include "lba.h"
  33
  34 #ifdef OS_linux
  35 #include "linux/hdreg.h"
  36 #include "linux/fs.h"
  37 #endif
  38
  39 static void set_offset(hsc *h, unsigned long offset,
  40                        uint16_t heads, uint16_t sectors)
  41 {
  42         uint16_t head, sector;
  43         unsigned int cyl;
  44
  45         if(! heads || !sectors)
  46                 head = sector = cyl = 0; /* linear mode */
  47         else {
  48                 sector = offset % sectors;
  49                 offset = offset / sectors;
  50
  51                 head = offset % heads;
  52                 offset = offset / heads;
  53                 if(offset > 1023)
  54                         cyl = 1023;
  55                 else
  56                         cyl = (uint16_t) offset;
  57         }
  58         if(head > UINT8_MAX) {
  59                 /* sector or head out of range => linear mode */
  60                 head = sector = cyl = 0;
  61         }
  62         h->head = (uint8_t) head;
  63         h->sector = ((sector+1) & 0x3f) | ((cyl & 0x300)>>2);
  64         h->cyl = cyl & 0xff;
  65 }
  66
  67 void setBeginEnd(struct partition *partTable,
  68                  uint32_t begin, uint32_t end,
  69                  uint16_t iheads, uint16_t isectors,
  70                  int activate, uint8_t type, unsigned int fat_bits)
  71 {
  72         uint8_t heads, sectors;
  73
  74         if(iheads > UINT8_MAX) {
  75                 fprintf(stderr,
  76                         "Too many heads for partition: %d\n",
  77                         iheads);
  78                 exit(1);
  79         }
  80         heads=(uint8_t) iheads;
  81         if(isectors > UINT8_MAX) {
  82                 fprintf(stderr,
  83                         "Too many sectors for partition: %d\n",
  84                         isectors);
  85                 exit(1);
  86         }
  87         sectors=(uint8_t) isectors;
  88
  89         set_offset(&partTable->start, begin, heads, sectors);
  90         set_offset(&partTable->end, end-1, heads, sectors);
  91         set_dword(partTable->start_sect, begin);
  92         set_dword(partTable->nr_sects, end-begin);
  93         if(activate)
  94                 partTable->boot_ind = 0x80;
  95         else
  96                 partTable->boot_ind = 0;
  97         if(!type) {
  98                 if (fat_bits == 0) {
  99                         /**
 100                          * Fat bits unknown / not specified. We look
 101                          * at size to get a rough estimate what FAT
 102                          * bits are used.  Note: this is only an
 103                          * estimate, the precise calculation would
 104                          * involve the number of clusters, which is
 105                          * not necessarily known here.
 106                          */
 107                         /* cc977219 would have a cutoff number of 32680,
 108                          * corresponding to a FAT12 partition with 4K
 109                          * clusters, however other information hints that
 110                          * only partitions with less than 4096 sectors are
 111                          * considered */
 112                         if(end-begin < 4096)
 113                                 fat_bits = 12;
 114                         else
 115                                 fat_bits = 16;
 116                 }
 117
 118                 /* Description of various partition types in
 119                  * https://en.wikipedia.org/wiki/Partition_type#List_of_partition_IDs
 120                  * and
 121                  * https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-2000-server/cc977219(v=technet.10)
 122                  */
 123                 if (fat_bits == 32)
 124                         /* FAT 32 partition. For now, we disregard the
 125                          * possibility of FAT 32 CHS partitions */
 126                         type = 0x0C; /* Win95 FAT32, LBA */
 127                 else if (end < 65536) {
 128                         /* FAT 12 or FAT 16 partitions which fit entirely below
 129                            the 32M mark */
 130                         /* The 32M restriction doesn't apply to logical
 131                            partitions within an extended partition, but for the
 132                            moment mpartition only makes primary partitions */
 133                         if(fat_bits == 12)
 134                                 /* FAT 12 partition */
 135                                 type = 0x01; /* DOS FAT12, CHS */
 136                         else if (fat_bits == 16)
 137                                 /* FAT 16 partition */
 138                                 type = 0x04; /* DOS FAT16, CHS */
 139                 } else if (end <  sectors * heads * 1024u)
 140                         /* FAT 12 or FAT16 partition above the 32M
 141                          * mark but below the 1024 cylinder mark.
 142                          * Indeed, there can be no CHS partition
 143                          * beyond 1024 cylinders */
 144                         type = 0x06; /* DOS BIG FAT16 or FAT12, CHS */
 145                 else
 146                         type = 0x0E; /* Win95 BIG FAT16, LBA */
 147         }
 148         partTable->sys_ind = type;
 149 }
 150
 151
 152 /* setsize function.  Determines scsicam mapping if this cannot be inferred from
 153  * any existing partitions. Shamelessly snarfed from the Linux kernel ;-) */
 154
 155 /*
 156  * Function : static int setsize(unsigned long capacity,unsigned int *cyls,
 157  *      unsigned int *hds, unsigned int *secs);
 158  *
 159  * Purpose : to determine a near-optimal int 0x13 mapping for a
 160  *      SCSI disk in terms of lost space of size capacity, storing
 161  *      the results in *cyls, *hds, and *secs.
 162  *
 163  * Returns : -1 on failure, 0 on success.
 164  *
 165  * Extracted from
 166  *
 167  * WORKING                                                    X3T9.2
 168  * DRAFT                                                        792D
 169  *
 170  *
 171  *                                                        Revision 6
 172  *                                                         10-MAR-94
 173  * Information technology -
 174  * SCSI-2 Common access method
 175  * transport and SCSI interface module
 176  *
 177  * ANNEX A :
 178  *
 179  * setsize() converts a read capacity value to int 13h
 180  * head-cylinder-sector requirements. It minimizes the value for
 181  * number of heads and maximizes the number of cylinders. This
 182  * will support rather large disks before the number of heads
 183  * will not fit in 4 bits (or 6 bits). This algorithm also
 184  * minimizes the number of sectors that will be unused at the end
 185  * of the disk while allowing for very large disks to be
 186  * accommodated. This algorithm does not use physical geometry.
 187  */
 188
 189 static int setsize(unsigned long capacity,unsigned int *cyls,
 190                    uint16_t *hds,  uint16_t *secs) {
 191     int rv = 0;
 192     unsigned long heads, sectors, cylinders, temp;
 193
 194     cylinders = 1024L;                  /* Set number of cylinders to max */
 195     sectors = 62L;                      /* Maximize sectors per track */
 196
 197     temp = cylinders * sectors;         /* Compute divisor for heads */
 198     heads = capacity / temp;            /* Compute value for number of heads */
 199     if (capacity % temp) {              /* If no remainder, done! */
 200         heads++;                        /* Else, increment number of heads */
 201         temp = cylinders * heads;       /* Compute divisor for sectors */
 202         sectors = capacity / temp;      /* Compute value for sectors per
 203                                                track */
 204         if (capacity % temp) {          /* If no remainder, done! */
 205             sectors++;                  /* Else, increment number of sectors */
 206             temp = heads * sectors;     /* Compute divisor for cylinders */
 207             cylinders = capacity / temp;/* Compute number of cylinders */
 208         }
 209     }
 210     if (cylinders == 0) rv=-1;/* Give error if 0 cylinders */
 211
 212     *cyls = (unsigned int) cylinders;   /* Stuff return values */
 213     *secs = (uint16_t) sectors;
 214     *hds  = (uint16_t) heads;
 215     return(rv);
 216 }
 217
 218 static void setsize0(uint32_t capacity,unsigned int *cyls,
 219                      uint16_t *hds, uint16_t *secs)
 220 {
 221         int r;
 222
 223         /* 1. First try "Megabyte" sizes */
 224         if(capacity < 1024 * 2048 && !(capacity % 1024)) {
 225                 *cyls = capacity >> 11;
 226                 *hds  = 64;
 227                 *secs = 32;
 228                 return;
 229         }
 230
 231         /* then try scsicam's size */
 232         r = setsize(capacity,cyls,hds,secs);
 233         if(r || *hds > 255 || *secs > 63) {
 234                 /* scsicam failed. Do megabytes anyways */
 235                 *cyls = capacity >> 11;
 236                 *hds  = 64;
 237                 *secs = 32;
 238                 return;
 239         }
 240 }
 241
 242
 243 static void usage(int ret) NORETURN;
 244 static void usage(int ret)
 245 {
 246         fprintf(stderr,
 247                 "Mtools version %s, dated %s\n", mversion, mdate);
 248         fprintf(stderr,
 249                 "Usage: %s [-pradcv] [-I] [-B bootsect-template] [-s sectors] "
 250                         "[-t cylinders] "
 251                 "[-h heads] [-T type] [-b begin] [-l length] "
 252                 "drive\n", progname);
 253         exit(ret);
 254 }
 255
 256 void mpartition(int argc, char **argv, int dummy UNUSEDP) NORETURN;
 257 void mpartition(int argc, char **argv, int dummy UNUSEDP)
 258 {
 259         Stream_t *Stream;
 260         unsigned int dummy2;
 261
 262         unsigned int i;
 263
 264         uint16_t sec_per_cyl;
 265         int doprint = 0;
 266         int verbose = 0;
 267         int create = 0;
 268         int force = 0;
 269         unsigned int length = 0;
 270         int do_remove = 0;
 271         int initialize = 0;
 272
 273         uint32_t tot_sectors=0;
 274         /* Needs to be long due to BLKGETSIZE ioctl */
 275
 276         uint8_t type = 0;
 277         int begin_set = 0;
 278         int size_set = 0;
 279         int end_set = 0;
 280         int activate = 0;
 281         int has_activated = 0;
 282         int inconsistency=0;
 283         unsigned int begin=0;
 284         unsigned int end=0;
 285         int dirty = 0;
 286         int open2flags = 0;
 287
 288         int c;
 289         struct device used_dev;
 290         unsigned int argtracks;
 291         uint16_t argheads, argsectors;
 292
 293         char drive, name[EXPAND_BUF];
 294         unsigned char buf[512];
 295         struct partition *partTable=(struct partition *)(buf+ 0x1ae);
 296         struct device *dev;
 297         char errmsg[2100];
 298         char *bootSector=0;
 299         struct partition *tpartition;
 300
 301         argtracks = 0;
 302         argheads = 0;
 303         argsectors = 0;
 304
 305         /* get command line options */
 306         if(helpFlag(argc, argv))
 307                 usage(0);
 308         while ((c = getopt(argc, argv, "i:adprcIT:t:h:s:fvpb:l:S:B:")) != EOF) {
 309                 char *endptr=NULL;
 310                 errno=0;
 311                 switch (c) {
 312                         case 'i':
 313                                 set_cmd_line_image(optarg);
 314                                 break;
 315                         case 'B':
 316                                 bootSector = optarg;
 317                                 break;
 318                         case 'a':
 319                                 /* no privs, as it could be abused to
 320                                  * make other partitions unbootable, or
 321                                  * to boot a rogue kernel from this one */
 322                                 open2flags |= NO_PRIV;
 323                                 activate = 1;
 324                                 dirty = 1;
 325                                 break;
 326                         case 'd':
 327                                 activate = -1;
 328                                 dirty = 1;
 329                                 break;
 330                         case 'p':
 331                                 doprint = 1;
 332                                 break;
 333                         case 'r':
 334                                 do_remove = 1;
 335                                 dirty = 1;
 336                                 break;
 337                         case 'I':
 338                                 /* could be abused to nuke all other
 339                                  * partitions */
 340                                 open2flags |= NO_PRIV;
 341                                 initialize = 1;
 342                                 dirty = 1;
 343                                 break;
 344                         case 'c':
 345                                 create = 1;
 346                                 dirty = 1;
 347                                 break;
 348
 349                         case 'T':
 350                                 /* could be abused to "manually" create
 351                                  * extended partitions */
 352                                 open2flags |= NO_PRIV;
 353                                 type = strtou8(optarg, &endptr, 0);
 354                                 break;
 355
 356                         case 't':
 357                                 argtracks = atoui(optarg);
 358                                 break;
 359                         case 'h':
 360                                 argheads = atou16(optarg);
 361                                 break;
 362                         case 's':
 363                                 argsectors = atou16(optarg);
 364                                 break;
 365
 366                         case 'f':
 367                                 /* could be abused by creating overlapping
 368                                  * partitions and other such Snafu */
 369                                 open2flags |= NO_PRIV;
 370                                 force = 1;
 371                                 break;
 372
 373                         case 'v':
 374                                 verbose++;
 375                                 break;
 376                         case 'b':
 377                                 begin_set = 1;
 378                                 begin = strtoui(optarg, &endptr, 0);
 379                                 break;
 380                         case 'l':
 381                                 size_set = 1;
 382                                 length = parseSize(optarg);
 383                                 break;
 384
 385                         default:
 386                                 usage(1);
 387                 }
 388                 check_number_parse_errno((char)c, optarg, endptr);
 389         }
 390
 391         if (argc - optind != 1 ||
 392             !argv[optind][0] || argv[optind][1] != ':')
 393                 usage(1);
 394
 395         drive = ch_toupper(argv[optind][0]);
 396
 397         /* check out a drive whose letter and parameters match */
 398         sprintf(errmsg, "Drive '%c:' not supported", drive);
 399         Stream = 0;
 400         for(dev=devices;dev->drive;dev++) {
 401                 int mode ;
 402
 403                 FREE(&(Stream));
 404                 /* drive letter */
 405                 if (dev->drive != drive)
 406                         continue;
 407                 if (dev->partition < 1 || dev->partition > 4) {
 408                         sprintf(errmsg,
 409                                 "Drive '%c:' is not a partition",
 410                                 drive);
 411                         continue;
 412                 }
 413                 used_dev = *dev;
 414
 415                 SET_INT(used_dev.tracks, argtracks);
 416                 SET_INT(used_dev.heads, argheads);
 417                 SET_INT(used_dev.sectors, argsectors);
 418
 419                 expand(dev->name, name);
 420
 421                 mode = dirty ? O_RDWR : O_RDONLY;
 422                 if(initialize)
 423                         mode |= O_CREAT;
 424
 425 #ifdef USING_NEW_VOLD
 426                 strcpy(name, getVoldName(dev, name));
 427 #endif
 428                 Stream = OpenImage(&used_dev, dev, name, mode, errmsg,
 429                                    open2flags | SKIP_PARTITION | ALWAYS_GET_GEOMETRY,
 430                                    mode, NULL, NULL, NULL);
 431
 432                 if (!Stream) {
 433 #ifdef HAVE_SNPRINTF
 434                         snprintf(errmsg,sizeof(errmsg)-1,
 435                                  "init: open: %s", strerror(errno));
 436 #else
 437                         sprintf(errmsg,"init: open: %s", strerror(errno));
 438 #endif
 439                         continue;
 440                 }
 441
 442                 tot_sectors = used_dev.tot_sectors;
 443
 444                 /* read the partition table */
 445                 if (PREADS(Stream, (char *) buf, 0, 512) != 512 && !initialize){
 446 #ifdef HAVE_SNPRINTF
 447                         snprintf(errmsg, sizeof(errmsg)-1,
 448                                 "Error reading from '%s', wrong parameters?",
 449                                 name);
 450 #else
 451                         sprintf(errmsg,
 452                                 "Error reading from '%s', wrong parameters?",
 453                                 name);
 454 #endif
 455                         continue;
 456                 }
 457                 if(verbose>=2)
 458                         print_sector("Read sector", buf, 512);
 459                 break;
 460         }
 461
 462         /* print error msg if needed */
 463         if ( dev->drive == 0 ){
 464                 FREE(&Stream);
 465                 fprintf(stderr,"%s: %s\n", argv[0],errmsg);
 466                 exit(1);
 467         }
 468
 469         if((used_dev.sectors || used_dev.heads) &&
 470            (!used_dev.sectors || !used_dev.heads)) {
 471                 fprintf(stderr,"You should either indicate both the number of sectors and the number of heads,\n");
 472                 fprintf(stderr," or none of them\n");
 473                 exit(1);
 474         }
 475
 476         if(initialize) {
 477                 if (bootSector) {
 478                         int fd;
 479                         fd = open(bootSector, O_RDONLY | O_BINARY | O_LARGEFILE);
 480                         if (fd < 0) {
 481                                 perror("open MBR");
 482                                 exit(1);
 483                         }
 484                         if(read(fd, (char *) buf, 512) < 512) {
 485                                 perror("read MBR");
 486                                 exit(1);
 487                         }
 488                 }
 489                 memset((char *)(partTable+1), 0, 4*sizeof(*partTable));
 490                 set_word(((unsigned char*)buf)+510, 0xaa55);
 491         }
 492
 493         /* check for boot signature, and place it if needed */
 494         if((buf[510] != 0x55) || (buf[511] != 0xaa)) {
 495                 fprintf(stderr,"Boot signature not set\n");
 496                 fprintf(stderr,
 497                         "Use the -I flag to initialize the partition table, and set the boot signature\n");
 498                 inconsistency = 1;
 499         }
 500
 501         tpartition=&partTable[dev->partition];
 502         if(do_remove){
 503                 if(!tpartition->sys_ind)
 504                         fprintf(stderr,
 505                                 "Partition for drive %c: does not exist\n",
 506                                 drive);
 507                 if((tpartition->sys_ind & 0x3f) == 5) {
 508                         fprintf(stderr,
 509                                 "Partition for drive %c: may be an extended partition\n",
 510                                 drive);
 511                         fprintf(stderr,
 512                                 "Use the -f flag to remove it anyways\n");
 513                         inconsistency = 1;
 514                 }
 515                 memset(tpartition, 0, sizeof(*tpartition));
 516         }
 517
 518         if(create && tpartition->sys_ind) {
 519                 fprintf(stderr,
 520                         "Partition for drive %c: already exists\n", drive);
 521                 fprintf(stderr,
 522                         "Use the -r flag to remove it before attempting to recreate it\n");
 523         }
 524
 525         /* if number of heads and sectors not known yet, set "reasonable"
 526          * defaults */
 527         compute_lba_geom_from_tot_sectors(&used_dev);
 528
 529         /* find out whether there is any activated partition. Moreover
 530          * if no offset of a partition to be created have been
 531          * specificed, find out whether it may be placed between the
 532          * preceding and following partition already existing */
 533         has_activated = 0;
 534         for(i=1; i<5; i++){
 535                 struct partition *partition=&partTable[i];
 536                 if(!partition->sys_ind)
 537                         continue;
 538
 539                 if(partition->boot_ind)
 540                         has_activated++;
 541
 542                 if(i<dev->partition && !begin_set)
 543                         begin = END(partition);
 544                 if(i>dev->partition && !end_set && !size_set) {
 545                         end = BEGIN(partition);
 546                         end_set = 1;
 547                 }
 548         }
 549
 550         if(!used_dev.sectors && !used_dev.heads) {
 551                 if(tot_sectors) {
 552                         setsize0((uint32_t)tot_sectors,&dummy2,&used_dev.heads,
 553                                  &used_dev.sectors);
 554                 } else {
 555                         used_dev.heads = 64;
 556                         used_dev.sectors = 32;
 557                 }
 558         }
 559
 560         if(verbose)
 561                 fprintf(stderr,"sectors: %d heads: %d %u\n",
 562                         used_dev.sectors, used_dev.heads, tot_sectors);
 563
 564         sec_per_cyl = used_dev.sectors * used_dev.heads;
 565         if(create) {
 566                 unsigned int overlap;
 567                 if(!end_set && !size_set && tot_sectors) {
 568                         end = tot_sectors - tot_sectors % sec_per_cyl;
 569                         end_set = 1;
 570                 }
 571
 572                 /* if the partition starts right at the beginning of
 573                  * the disk, keep one track unused to allow place for
 574                  * the master boot record */
 575                 if(!begin && !begin_set)
 576                         begin = used_dev.sectors ? used_dev.sectors : 2048;
 577
 578                 /* Do not try to align  partitions (other than first) on track
 579                  * boundaries here: apparently this was a thing of the past */
 580
 581                 if(size_set) {
 582                         end = begin + length;
 583                 } else if(!end_set) {
 584                         fprintf(stderr,"Unknown size\n");
 585                         exit(1);
 586                 }
 587
 588                 /* Make sure partition boundaries are correctly ordered
 589                  * (end > begin) */
 590                 if(begin >= end) {
 591                         fprintf(stderr, "Begin larger than end\n");
 592                         exit(1);
 593                 }
 594
 595                 /* Check whether new partition doesn't overlap with
 596                  * any of those already in place */
 597                 if((overlap=findOverlap(partTable, 4, begin, end))) {
 598                         fprintf(stderr,
 599                                 "Partition would overlap with partition %d\n",
 600                                 overlap);
 601                         exit(1);
 602                 }
 603
 604                 setBeginEnd(tpartition, begin, end,
 605                             used_dev.heads, used_dev.sectors,
 606                             !has_activated, type,
 607                             abs(dev->fat_bits));
 608         }
 609
 610         if(activate) {
 611                 if(!tpartition->sys_ind) {
 612                         fprintf(stderr,
 613                                 "Partition for drive %c: does not exist\n",
 614                                 drive);
 615                 } else {
 616                         switch(activate) {
 617                                 case 1:
 618                                         tpartition->boot_ind=0x80;
 619                                         break;
 620                                 case -1:
 621                                         tpartition->boot_ind=0x00;
 622                                         break;
 623                         }
 624                 }
 625         }
 626
 627         inconsistency |= consistencyCheck(partTable, doprint, verbose,
 628                                           &has_activated, tot_sectors,
 629                                           &used_dev, dev->partition);
 630
 631         switch(has_activated) {
 632                 case 0:
 633                         fprintf(stderr,
 634                                 "Warning: no active (bootable) partition present\n");
 635                         break;
 636                 case 1:
 637                         break;
 638                 default:
 639                         fprintf(stderr,
 640                                 "Warning: %d active (bootable) partitions present\n",
 641                                 has_activated);
 642                         fprintf(stderr,
 643                                 "Usually, a disk should have exactly one active partition\n");
 644                         break;
 645         }
 646
 647         if(inconsistency && !force) {
 648                 fprintf(stderr,
 649                         "inconsistency detected!\n" );
 650                 if(dirty) {
 651                         fprintf(stderr,
 652                                 "Retry with the -f switch to go ahead anyways\n");
 653                         exit(1);
 654                 }
 655         }
 656
 657         if(doprint && tpartition->sys_ind) {
 658                 printf("The following command will recreate the partition for drive %c:\n",
 659                        drive);
 660                 used_dev.tracks =
 661                         (_DWORD(tpartition->nr_sects) +
 662                          (BEGIN(tpartition) % sec_per_cyl)) /
 663                         sec_per_cyl;
 664                 printf("mpartition -c -b %d -l %d -t %d -h %d -s %d -b %u %c:\n",
 665                        BEGIN(tpartition), PART_SIZE(tpartition),
 666                        used_dev.tracks, used_dev.heads, used_dev.sectors,
 667                        BEGIN(tpartition), drive);
 668         }
 669
 670         if(dirty) {
 671                 /* write data back to the disk */
 672                 if(verbose>=2)
 673                         print_sector("Writing sector", buf, 512);
 674                 if (PWRITES(Stream, (char *) buf, 0, 512) != 512) {
 675                         fprintf(stderr,"Error writing partition table");
 676                         exit(1);
 677                 }
 678                 if(verbose>=3)
 679                         print_sector("Sector written", buf, 512);
 680         }
 681         FREE(&Stream);
 682         exit(0);
 683 }