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