sys/lib/libsa/ustarfs.c

   1 /*      $NetBSD: ustarfs.c,v 1.34 2011/12/25 06:09:08 tsutsui Exp $     */
   2
   3 /* [Notice revision 2.2]
   4  * Copyright (c) 1997, 1998 Avalon Computer Systems, Inc.
   5  * All rights reserved.
   6  *
   7  * Author: Ross Harvey
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright and
  13  *    author notice, this list of conditions, and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of Avalon Computer Systems, Inc. nor the names of
  18  *    its contributors may be used to endorse or promote products derived
  19  *    from this software without specific prior written permission.
  20  * 4. This copyright will be assigned to The NetBSD Foundation on
  21  *    1/1/2000 unless these terms (including possibly the assignment
  22  *    date) are updated in writing by Avalon prior to the latest specified
  23  *    assignment date.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY AVALON COMPUTER SYSTEMS, INC. AND CONTRIBUTORS
  26  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL AVALON OR THE CONTRIBUTORS
  29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  35  * POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38
  39 /*
  40  ******************************* USTAR FS *******************************
  41  */
  42
  43 /*
  44  * Implement an ROFS with an 8K boot area followed by ustar-format data.
  45  * The point: minimal FS overhead, and it's easy (well, `possible') to
  46  * split files over multiple volumes.
  47  *
  48  * XXX - TODO LIST
  49  * --- - ---- ----
  50  * XXX - tag volume numbers and verify that the correct volume is
  51  *       inserted after volume swaps.
  52  *
  53  * XXX - stop hardwiring FS metadata for floppies...embed it in a file,
  54  *       file name, or something. (Remember __SYMDEF? :-)
  55  *
  56  * XXX Does not currently implement:
  57  * XXX
  58  * XXX LIBSA_NO_FS_CLOSE
  59  * XXX LIBSA_NO_FS_SEEK
  60  * XXX LIBSA_NO_FS_WRITE
  61  * XXX LIBSA_NO_FS_SYMLINK (does this even make sense?)
  62  * XXX LIBSA_FS_SINGLECOMPONENT
  63  */
  64
  65 #ifdef _STANDALONE
  66 #include <lib/libkern/libkern.h>
  67 #else
  68 #include <string.h>
  69 #endif
  70 #include "stand.h"
  71 #include "ustarfs.h"
  72
  73 #define BBSIZE  8192
  74 #define USTAR_NAME_BLOCK 512
  75
  76 /*
  77  * Virtual offset: relative to start of ustar archive
  78  * Logical offset: volume-relative
  79  * Physical offset: the usual meaning
  80  */
  81
  82 /* virtual offset to volume number */
  83
  84 #define vda2vn(_v,_volsize) ((_v) / (_volsize))
  85
  86 /* conversions between the three different levels of disk addresses */
  87
  88 #define vda2lda(_v,_volsize) ((_v) % (_volsize))
  89 #define lda2vda(_v,_volsize,_volnumber) ((_v) + (_volsize) * (_volnumber))
  90
  91 #define lda2pda(_lda) ((_lda) + ustarfs_mode_offset)
  92 #define pda2lda(_pda) ((_pda) - ustarfs_mode_offset)
  93 /*
  94  * Change this to off_t if you want to support big volumes. If we only use
  95  * ustarfs on floppies it can stay int for libsa code density.
  96  *
  97  * It needs to be signed.
  98  */
  99 typedef int ustoffs;
 100
 101 typedef struct ustar_struct {
 102         char    ust_name[100],
 103                 ust_mode[8],
 104                 ust_uid[8],
 105                 ust_gid[8],
 106                 ust_size[12],
 107                 ust_misc[12 + 8 + 1 + 100],
 108                 ust_magic[6],
 109         /* there is more, but we don't care */
 110                 ust_pad[1];     /* make it aligned */
 111 } ustar_t;
 112
 113 /*
 114  * We buffer one even cylinder of data...it's actually only really one
 115  * cyl on a 1.44M floppy, but on other devices it's fast enough with any
 116  * kind of block buffering, so we optimize for the slowest device.
 117  */
 118
 119 #ifndef USTAR_SECT_PER_CYL
 120 #define USTAR_SECT_PER_CYL      (18 * 2)
 121 #endif
 122
 123 typedef struct ust_active_struct {
 124         ustar_t uas_active;
 125         char    uas_1cyl[USTAR_SECT_PER_CYL * 512];
 126         ustoffs uas_volsize;            /* XXX this is hardwired now */
 127         ustoffs uas_windowbase;         /* relative to volume 0 */
 128         ustoffs uas_filestart;          /* relative to volume 0 */
 129         ustoffs uas_fseek;              /* relative to file */
 130         ustoffs uas_filesize;           /* relative to volume 0 */
 131         int     uas_init_window;        /* data present in window */
 132         int     uas_init_fs;            /* ust FS actually found */
 133         int     uas_volzerosig;         /* ID volume 0 by signature */
 134         int     uas_sigdone;            /* did sig already */
 135         int     uas_offset;             /* amount of cylinder below lba 0 */
 136 } ust_active_t;
 137
 138 static const char formatid[] = "USTARFS",
 139                   metaname[] = "USTAR.volsize.";
 140
 141 static const int ustarfs_mode_offset = BBSIZE;
 142
 143 static int checksig(ust_active_t *);
 144 static int convert(const char *, int, int);
 145 static int get_volume(struct open_file *, int);
 146 static void setwindow(ust_active_t *, ustoffs, ustoffs);
 147 static int real_fs_cylinder_read(struct open_file *, ustoffs, int);
 148 static int ustarfs_cylinder_read(struct open_file *, ustoffs, int);
 149 static void ustarfs_sscanf(const char *, const char *, int *);
 150 static int read512block(struct open_file *, ustoffs, char block[512]);
 151 static int init_volzero_sig(struct open_file *);
 152
 153 #ifdef HAVE_CHANGEDISK_HOOK
 154 /*
 155  * Called when the next volume is prompted.
 156  * Machine dependent code can eject the medium etc.
 157  * The new medium must be ready when this hook returns.
 158  */
 159 void changedisk_hook(struct open_file *);
 160 #endif
 161
 162 static int
 163 convert(const char *f, int base, int fw)
 164 {
 165         int     i, c, result = 0;
 166
 167         while(fw > 0 && *f == ' ') {
 168                 --fw;
 169                 ++f;
 170         }
 171         for(i = 0; i < fw; ++i) {
 172                 c = f[i];
 173                 if ('0' <= c && c < '0' + base) {
 174                         c -= '0';
 175                         result = result * base + c;
 176                 } else  break;
 177         }
 178         return result;
 179 }
 180
 181 static void
 182 ustarfs_sscanf(const char *s, const char *f, int *xi)
 183 {
 184
 185         *xi = convert(s, 8, convert(f + 1, 10, 99));
 186 }
 187
 188 static int
 189 ustarfs_cylinder_read(struct open_file *f, ustoffs seek2, int forcelabel)
 190 {
 191         int i, e;
 192
 193         for (i = 0; i < 3; ++i) {
 194                 e = real_fs_cylinder_read(f, seek2, forcelabel);
 195                 if (e == 0)
 196                         return 0;
 197         }
 198         return e;
 199 }
 200
 201 static int
 202 real_fs_cylinder_read(struct open_file *f, ustoffs seek2, int forcelabel)
 203 {
 204         int i;
 205         int e = 0;      /* XXX work around gcc warning */
 206         ustoffs lda;
 207         char *xferbase;
 208         ust_active_t *ustf;
 209         size_t xferrqst, xfercount;
 210
 211         ustf = f->f_fsdata;
 212         xferrqst = sizeof ustf->uas_1cyl;
 213         xferbase = ustf->uas_1cyl;
 214         lda = pda2lda(seek2);
 215         if (lda < 0) {
 216                 lda = -lda;
 217                 ustf->uas_offset = lda;
 218                 /*
 219                  * don't read the label unless we have to. (Preserve
 220                  * sequential block access so tape boot works.)
 221                  */
 222                 if (!forcelabel) {
 223                         memset(xferbase, 0, lda);
 224                         xferrqst -= lda;
 225                         xferbase += lda;
 226                         seek2    += lda;
 227                 }
 228         } else {
 229                 ustf->uas_offset = 0;
 230         }
 231         while(xferrqst > 0) {
 232 #if !defined(LIBSA_NO_TWIDDLE)
 233                 twiddle();
 234 #endif
 235                 for (i = 0; i < 3; ++i) {
 236                         e = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
 237                             seek2 / 512, xferrqst, xferbase, &xfercount);
 238                         if (e == 0)
 239                                 break;
 240                         printf("@");
 241                 }
 242                 if (e)
 243                         break;
 244                 if (xfercount != xferrqst)
 245                         printf("Warning, unexpected short transfer %d/%d\n",
 246                                 (int)xfercount, (int)xferrqst);
 247                 xferrqst -= xfercount;
 248                 xferbase += xfercount;
 249                 seek2    += xfercount;
 250         }
 251         return e;
 252 }
 253
 254 static int
 255 checksig(ust_active_t *ustf)
 256 {
 257         int     i, rcs;
 258
 259         for(i = rcs = 0; i < (int)(sizeof ustf->uas_1cyl); ++i)
 260                 rcs += ustf->uas_1cyl[i];
 261         return rcs;
 262 }
 263
 264 static int
 265 get_volume(struct open_file *f, int vn)
 266 {
 267         int     e, needvolume, havevolume;
 268         ust_active_t *ustf;
 269
 270         ustf = f->f_fsdata;
 271         havevolume = vda2vn(ustf->uas_windowbase, ustf->uas_volsize);
 272         needvolume = vn;
 273         while(havevolume != needvolume) {
 274                 printf("\nPlease ");
 275                 if (havevolume >= 0)
 276                         printf("remove disk %d, ", havevolume + 1);
 277                 printf("insert disk %d, and press return...",
 278                         needvolume + 1);
 279 #ifdef HAVE_CHANGEDISK_HOOK
 280                 changedisk_hook(f);
 281 #else
 282                 for (;;) {
 283                         int c = getchar();
 284                         if ((c == '\n') || (c == '\r'))
 285                                 break;
 286                 }
 287 #endif
 288                 printf("\n");
 289                 e = ustarfs_cylinder_read(f, 0, needvolume != 0);
 290                 if (e)
 291                         return e;
 292                 if(strncmp(formatid, ustf->uas_1cyl, strlen(formatid))) {
 293                         /* no magic, might be OK if we want volume 0 */
 294                         if (ustf->uas_volzerosig == checksig(ustf)) {
 295                                 havevolume = 0;
 296                                 continue;
 297                         }
 298                         printf("Disk is not from the volume set?!\n");
 299                         havevolume = -2;
 300                         continue;
 301                 }
 302                 ustarfs_sscanf(ustf->uas_1cyl + strlen(formatid), "%9o",
 303                         &havevolume);
 304                 --havevolume;
 305         }
 306         return 0;
 307 }
 308
 309 static void
 310 setwindow(ust_active_t *ustf, ustoffs pda, ustoffs vda)
 311 {
 312         ustf->uas_windowbase = lda2vda(pda2lda(pda), ustf->uas_volsize,
 313                                         vda2vn(vda, ustf->uas_volsize))
 314                              + ustf->uas_offset;
 315         ustf->uas_init_window = 1;
 316 }
 317
 318 static int
 319 read512block(struct open_file *f, ustoffs vda, char block[512])
 320 {
 321         ustoffs pda;
 322         ssize_t e;
 323         int     dienow;
 324         ust_active_t *ustf;
 325
 326         dienow = 0;
 327         ustf = f->f_fsdata;
 328
 329         /*
 330          * if (vda in window)
 331          *      copy out and return data
 332          * if (vda is on some other disk)
 333          *      do disk swap
 334          * get physical disk address
 335          * round down to cylinder boundary
 336          * read cylinder
 337          * set window (in vda space) and try again
 338          * [ there is an implicit assumption that windowbase always identifies
 339          *    the current volume, even if initwindow == 0. This way, a
 340          *    windowbase of 0 causes the initial volume to be disk 0 ]
 341          */
 342 tryagain:
 343         if(ustf->uas_init_window
 344         && ustf->uas_windowbase <= vda && vda <
 345            ustf->uas_windowbase +
 346              (int)(sizeof ustf->uas_1cyl) - ustf->uas_offset) {
 347                 memcpy(block, ustf->uas_1cyl
 348                                 + (vda - ustf->uas_windowbase)
 349                                 + ustf->uas_offset, 512);
 350                 return 0;
 351         }
 352         if (dienow++)
 353                 panic("ustarfs read512block");
 354         ustf->uas_init_window = 0;
 355         e = get_volume(f, vda2vn(vda, ustf->uas_volsize));
 356         if (e)
 357                 return e;
 358         pda = lda2pda(vda2lda(vda, ustf->uas_volsize));
 359         pda-= pda % sizeof ustf->uas_1cyl;
 360         e = ustarfs_cylinder_read(f, pda, 0);
 361         if (e)
 362                 return e;
 363         setwindow(ustf, pda, vda);
 364         goto tryagain;
 365 }
 366
 367 static int
 368 init_volzero_sig(struct open_file *f)
 369 {
 370         int e;
 371         ust_active_t *ustf;
 372
 373         ustf = f->f_fsdata;
 374         if (!ustf->uas_sigdone) {
 375                 e = ustarfs_cylinder_read(f, 0, 0);
 376                 if (e)
 377                         return e;
 378                 ustf->uas_volzerosig = checksig(ustf);
 379                 setwindow(ustf, 0, 0);
 380         }
 381         return 0;
 382 }
 383
 384 __compactcall int
 385 ustarfs_open(const char *path, struct open_file *f)
 386 {
 387         ust_active_t *ustf;
 388         ustoffs offset;
 389         char    block[512];
 390         int     filesize;
 391         int     e, e2;
 392         int     newvolblocks;
 393
 394         if (*path == '/')
 395                 ++path;
 396         f->f_fsdata = ustf = alloc(sizeof *ustf);
 397         memset(ustf, 0, sizeof *ustf);
 398         offset = 0;
 399         /* default to 2880 sector floppy */
 400         ustf->uas_volsize = 80 * 2 * 18 * 512 - lda2pda(0);
 401         ustf->uas_fseek = 0;
 402         e = init_volzero_sig(f);
 403         if (e)
 404                 return e;
 405         e2 = EINVAL;
 406         for(;;) {
 407                 ustf->uas_filestart = offset;
 408                 e = read512block(f, offset, block);
 409                 if (e)
 410                         break;
 411                 memcpy(&ustf->uas_active, block, sizeof ustf->uas_active);
 412                 if(strncmp(ustf->uas_active.ust_magic, "ustar", 5)) {
 413                         e = e2;
 414                         break;
 415                 }
 416                 e2 = ENOENT;    /* it must be an actual ustarfs */
 417                 ustf->uas_init_fs = 1;
 418                 /* if volume metadata is found, use it */
 419                 if(strncmp(ustf->uas_active.ust_name, metaname,
 420                     strlen(metaname)) == 0) {
 421                         ustarfs_sscanf(ustf->uas_active.ust_name
 422                                 + strlen(metaname), "%99o", &newvolblocks);
 423                         ustf->uas_volsize = newvolblocks * 512
 424                                           - lda2pda(0);
 425                 }
 426                 ustarfs_sscanf(ustf->uas_active.ust_size,"%12o",&filesize);
 427                 if(strncmp(ustf->uas_active.ust_name, path,
 428                     sizeof ustf->uas_active.ust_name) == 0) {
 429                         ustf->uas_filesize = filesize;
 430                         break;
 431                 }
 432                 offset += USTAR_NAME_BLOCK + filesize;
 433                 filesize %= 512;
 434                 if (filesize)
 435                         offset += 512 - filesize;
 436         }
 437         if (e) {
 438                 dealloc(ustf, sizeof *ustf);
 439                 f->f_fsdata = 0;
 440         }
 441         return e;
 442 }
 443
 444 #ifndef LIBSA_NO_FS_WRITE
 445 __compactcall int
 446 ustarfs_write(struct open_file *f, void *start, size_t size, size_t *resid)
 447 {
 448
 449         return EROFS;
 450 }
 451 #endif /* !LIBSA_NO_FS_WRITE */
 452
 453 #ifndef LIBSA_NO_FS_SEEK
 454 __compactcall off_t
 455 ustarfs_seek(struct open_file *f, off_t offs, int whence)
 456 {
 457         ust_active_t *ustf;
 458
 459         ustf = f->f_fsdata;
 460         switch (whence) {
 461         case SEEK_SET:
 462                 ustf->uas_fseek = offs;
 463                 break;
 464         case SEEK_CUR:
 465                 ustf->uas_fseek += offs;
 466                 break;
 467         case SEEK_END:
 468                 ustf->uas_fseek = ustf->uas_filesize - offs;
 469                 break;
 470         default:
 471                 return -1;
 472         }
 473         return ustf->uas_fseek;
 474 }
 475 #endif /* !LIBSA_NO_FS_SEEK */
 476
 477 __compactcall int
 478 ustarfs_read(struct open_file *f, void *start, size_t size, size_t *resid)
 479 {
 480         ust_active_t *ustf;
 481         int     e;
 482         char    *space512;
 483         int     blkoffs;
 484         int     readoffs;
 485         int     bufferoffset;
 486         size_t  seg;
 487         size_t  infile;
 488         size_t  inbuffer;
 489
 490         e = 0;
 491         space512 = alloc(512);
 492         ustf = f->f_fsdata;
 493         while(size != 0) {
 494                 if (ustf->uas_fseek >= ustf->uas_filesize)
 495                         break;
 496                 bufferoffset = ustf->uas_fseek % 512;
 497                 blkoffs  = ustf->uas_fseek - bufferoffset;
 498                 readoffs = ustf->uas_filestart + 512 + blkoffs;
 499                 e = read512block(f, readoffs, space512);
 500                 if (e)
 501                         break;
 502                 seg = size;
 503                 inbuffer = 512 - bufferoffset;
 504                 if (inbuffer < seg)
 505                         seg = inbuffer;
 506                 infile = ustf->uas_filesize - ustf->uas_fseek;
 507                 if (infile < seg)
 508                         seg = infile;
 509                 memcpy(start, space512 + bufferoffset, seg);
 510                 ustf->uas_fseek += seg;
 511                 start = (char *)start + seg;
 512                 size -= seg;
 513         }
 514         if (resid)
 515                 *resid = size;
 516         dealloc(space512, 512);
 517         return e;
 518 }
 519
 520 __compactcall int
 521 ustarfs_stat(struct open_file *f, struct stat *sb)
 522 {
 523         int     mode, uid, gid;
 524         ust_active_t *ustf;
 525
 526         if (f == NULL)
 527                 return EINVAL;
 528         ustf = f->f_fsdata;
 529         memset(sb, 0, sizeof *sb);
 530         ustarfs_sscanf(ustf->uas_active.ust_mode, "%8o", &mode);
 531         ustarfs_sscanf(ustf->uas_active.ust_uid, "%8o", &uid);
 532         ustarfs_sscanf(ustf->uas_active.ust_gid, "%8o", &gid);
 533         sb->st_mode = mode;
 534         sb->st_uid  = uid;
 535         sb->st_gid  = gid;
 536         sb->st_size = ustf->uas_filesize;
 537         return 0;
 538 }
 539
 540
 541 #if defined(LIBSA_ENABLE_LS_OP)
 542 __compactcall void
 543 ustarfs_ls(struct open_file *f, const char *pattern,
 544                 void (*funcp)(char* arg), char* path)
 545 {
 546         printf("Currently ls command is unsupported by ustarfs\n");
 547         return;
 548 }
 549 #endif
 550
 551 #ifndef LIBSA_NO_FS_CLOSE
 552 __compactcall int
 553 ustarfs_close(struct open_file *f)
 554 {
 555         if (f == NULL || f->f_fsdata == NULL)
 556                 return EINVAL;
 557         dealloc(f->f_fsdata, sizeof(ust_active_t));
 558         f->f_fsdata = 0;
 559         return 0;
 560 }
 561 #endif /* !LIBSA_NO_FS_CLOSE */