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