1 /* $NetBSD: ustarfs.c,v 1.27 2006/01/27 01:11:27 uwe 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 typedef struct ust_active_struct { 120 ustar_t uas_active; 121 char uas_1cyl[18 * 2 * 512]; 122 ustoffs uas_volsize; /* XXX this is hardwired now */ 123 ustoffs uas_windowbase; /* relative to volume 0 */ 124 ustoffs uas_filestart; /* relative to volume 0 */ 125 ustoffs uas_fseek; /* relative to file */ 126 ustoffs uas_filesize; /* relative to volume 0 */ 127 int uas_init_window; /* data present in window */ 128 int uas_init_fs; /* ust FS actually found */ 129 int uas_volzerosig; /* ID volume 0 by signature */ 130 int uas_sigdone; /* did sig already */ 131 int uas_offset; /* amount of cylinder below lba 0 */ 132 } ust_active_t; 133 134 static const char formatid[] = "USTARFS", 135 metaname[] = "USTAR.volsize."; 136 137 static const int ustarfs_mode_offset = BBSIZE; 138 139 static int checksig __P((ust_active_t *)); 140 static int convert __P((const char *, int, int)); 141 static int get_volume __P((struct open_file *, int)); 142 static void setwindow(ust_active_t *, ustoffs, ustoffs); 143 static int real_fs_cylinder_read __P((struct open_file *, ustoffs, int)); 144 static int ustarfs_cylinder_read __P((struct open_file *, ustoffs, int)); 145 static void ustarfs_sscanf __P((const char *, const char *, int *)); 146 static int read512block __P((struct open_file *, ustoffs, char block[512])); 147 static int init_volzero_sig __P((struct open_file *)); 148 149 #ifdef HAVE_CHANGEDISK_HOOK 150 /* 151 * Called when the next volume is prompted. 152 * Machine dependent code can eject the medium etc. 153 * The new medium must be ready when this hook returns. 154 */ 155 void changedisk_hook __P((struct open_file *)); 156 #endif 157 158 static int 159 convert(f, base, fw) 160 const char *f; 161 int base, fw; 162 { 163 int i, c, result = 0; 164 165 while(fw > 0 && *f == ' ') { 166 --fw; 167 ++f; 168 } 169 for(i = 0; i < fw; ++i) { 170 c = f[i]; 171 if ('0' <= c && c < '0' + base) { 172 c -= '0'; 173 result = result * base + c; 174 } else break; 175 } 176 return result; 177 } 178 179 static void 180 ustarfs_sscanf(s,f,xi) 181 const char *s,*f; 182 int *xi; 183 { 184 *xi = convert(s, 8, convert(f + 1, 10, 99)); 185 } 186 187 static int 188 ustarfs_cylinder_read(f, seek2, forcelabel) 189 struct open_file *f; 190 ustoffs seek2; 191 int forcelabel; 192 { 193 int i, e; 194 195 for (i = 0; i < 3; ++i) { 196 e = real_fs_cylinder_read(f, seek2, forcelabel); 197 if (e == 0) 198 return 0; 199 } 200 return e; 201 } 202 203 static int 204 real_fs_cylinder_read(f, seek2, forcelabel) 205 struct open_file *f; 206 ustoffs seek2; 207 int forcelabel; 208 { 209 int i; 210 int e = 0; /* XXX work around gcc warning */ 211 ustoffs lda; 212 char *xferbase; 213 ust_active_t *ustf; 214 size_t xferrqst, xfercount; 215 216 ustf = f->f_fsdata; 217 xferrqst = sizeof ustf->uas_1cyl; 218 xferbase = ustf->uas_1cyl; 219 lda = pda2lda(seek2); 220 if (lda < 0) { 221 lda = -lda; 222 ustf->uas_offset = lda; 223 /* 224 * don't read the label unless we have to. (Preserve 225 * sequential block access so tape boot works.) 226 */ 227 if (!forcelabel) { 228 memset(xferbase, 0, lda); 229 xferrqst -= lda; 230 xferbase += lda; 231 seek2 += lda; 232 } 233 } else 234 ustf->uas_offset = 0; 235 while(xferrqst > 0) { 236 #if !defined(LIBSA_NO_TWIDDLE) 237 twiddle(); 238 #endif 239 for (i = 0; i < 3; ++i) { 240 e = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ, 241 seek2 / 512, xferrqst, xferbase, &xfercount); 242 if (e == 0) 243 break; 244 printf("@"); 245 } 246 if (e) 247 break; 248 if (xfercount != xferrqst) 249 printf("Warning, unexpected short transfer %d/%d\n", 250 (int)xfercount, (int)xferrqst); 251 xferrqst -= xfercount; 252 xferbase += xfercount; 253 seek2 += xfercount; 254 } 255 return e; 256 } 257 258 static int 259 checksig(ustf) 260 ust_active_t *ustf; 261 { 262 int i, rcs; 263 264 for(i = rcs = 0; i < (int)(sizeof ustf->uas_1cyl); ++i) 265 rcs += ustf->uas_1cyl[i]; 266 return rcs; 267 } 268 269 static int 270 get_volume(f, vn) 271 struct open_file *f; 272 int vn; 273 { 274 int e, needvolume, havevolume; 275 ust_active_t *ustf; 276 277 ustf = f->f_fsdata; 278 havevolume = vda2vn(ustf->uas_windowbase, ustf->uas_volsize); 279 needvolume = vn; 280 while(havevolume != needvolume) { 281 printf("\nPlease "); 282 if (havevolume >= 0) 283 printf("remove disk %d, ", havevolume + 1); 284 printf("insert disk %d, and press return...", 285 needvolume + 1); 286 #ifdef HAVE_CHANGEDISK_HOOK 287 changedisk_hook(f); 288 #else 289 for (;;) { 290 int c = getchar(); 291 if ((c == '\n') || (c == '\r')) 292 break; 293 } 294 #endif 295 printf("\n"); 296 e = ustarfs_cylinder_read(f, 0, needvolume != 0); 297 if (e) 298 return e; 299 if(strncmp(formatid, ustf->uas_1cyl, strlen(formatid))) { 300 /* no magic, might be OK if we want volume 0 */ 301 if (ustf->uas_volzerosig == checksig(ustf)) { 302 havevolume = 0; 303 continue; 304 } 305 printf("Disk is not from the volume set?!\n"); 306 havevolume = -2; 307 continue; 308 } 309 ustarfs_sscanf(ustf->uas_1cyl + strlen(formatid), "%9o", 310 &havevolume); 311 --havevolume; 312 } 313 return 0; 314 } 315 316 static void 317 setwindow(ust_active_t *ustf, ustoffs pda, ustoffs vda) 318 { 319 ustf->uas_windowbase = lda2vda(pda2lda(pda), ustf->uas_volsize, 320 vda2vn(vda, ustf->uas_volsize)) 321 + ustf->uas_offset; 322 ustf->uas_init_window = 1; 323 } 324 325 static int 326 read512block(f, vda, block) 327 struct open_file *f; 328 ustoffs vda; 329 char block[512]; 330 { 331 ustoffs pda; 332 ssize_t e; 333 int dienow; 334 ust_active_t *ustf; 335 336 dienow = 0; 337 ustf = f->f_fsdata; 338 339 /* 340 * if (vda in window) 341 * copy out and return data 342 * if (vda is on some other disk) 343 * do disk swap 344 * get physical disk address 345 * round down to cylinder boundary 346 * read cylinder 347 * set window (in vda space) and try again 348 * [ there is an implicit assumption that windowbase always identifies 349 * the current volume, even if initwindow == 0. This way, a 350 * windowbase of 0 causes the initial volume to be disk 0 ] 351 */ 352 tryagain: 353 if(ustf->uas_init_window 354 && ustf->uas_windowbase <= vda && vda < 355 ustf->uas_windowbase + 356 (int)(sizeof ustf->uas_1cyl) - ustf->uas_offset) { 357 memcpy(block, ustf->uas_1cyl 358 + (vda - ustf->uas_windowbase) 359 + ustf->uas_offset, 512); 360 return 0; 361 } 362 if (dienow++) 363 panic("ustarfs read512block"); 364 ustf->uas_init_window = 0; 365 e = get_volume(f, vda2vn(vda, ustf->uas_volsize)); 366 if (e) 367 return e; 368 pda = lda2pda(vda2lda(vda, ustf->uas_volsize)); 369 pda-= pda % sizeof ustf->uas_1cyl; 370 e = ustarfs_cylinder_read(f, pda, 0); 371 if (e) 372 return e; 373 setwindow(ustf, pda, vda); 374 goto tryagain; 375 } 376 377 static int 378 init_volzero_sig(f) 379 struct open_file *f; 380 { 381 int e; 382 ust_active_t *ustf; 383 384 ustf = f->f_fsdata; 385 if (!ustf->uas_sigdone) { 386 e = ustarfs_cylinder_read(f, 0, 0); 387 if (e) 388 return e; 389 ustf->uas_volzerosig = checksig(ustf); 390 setwindow(ustf, 0, 0); 391 } 392 return 0; 393 } 394 395 int 396 ustarfs_open(path, f) 397 const char *path; 398 struct open_file *f; 399 400 { 401 ust_active_t *ustf; 402 ustoffs offset; 403 char block[512]; 404 int filesize; 405 int e, e2; 406 int newvolblocks; 407 408 if (*path == '/') 409 ++path; 410 f->f_fsdata = ustf = alloc(sizeof *ustf); 411 memset(ustf, 0, sizeof *ustf); 412 offset = 0; 413 /* default to 2880 sector floppy */ 414 ustf->uas_volsize = 80 * 2 * 18 * 512 - lda2pda(0); 415 ustf->uas_fseek = 0; 416 e = init_volzero_sig(f); 417 if (e) 418 return e; 419 e2 = EINVAL; 420 for(;;) { 421 ustf->uas_filestart = offset; 422 e = read512block(f, offset, block); 423 if (e) 424 break; 425 memcpy(&ustf->uas_active, block, sizeof ustf->uas_active); 426 if(strncmp(ustf->uas_active.ust_magic, "ustar", 5)) { 427 e = e2; 428 break; 429 } 430 e2 = ENOENT; /* it must be an actual ustarfs */ 431 ustf->uas_init_fs = 1; 432 /* if volume metadata is found, use it */ 433 if(strncmp(ustf->uas_active.ust_name, metaname, 434 strlen(metaname)) == 0) { 435 ustarfs_sscanf(ustf->uas_active.ust_name 436 + strlen(metaname), "%99o", &newvolblocks); 437 ustf->uas_volsize = newvolblocks * 512 438 - lda2pda(0); 439 } 440 ustarfs_sscanf(ustf->uas_active.ust_size,"%12o",&filesize); 441 if(strncmp(ustf->uas_active.ust_name, path, 442 sizeof ustf->uas_active.ust_name) == 0) { 443 ustf->uas_filesize = filesize; 444 break; 445 } 446 offset += USTAR_NAME_BLOCK + filesize; 447 filesize %= 512; 448 if (filesize) 449 offset += 512 - filesize; 450 } 451 if (e) { 452 dealloc(ustf, sizeof *ustf); 453 f->f_fsdata = 0; 454 } 455 return e; 456 } 457 458 #ifndef LIBSA_NO_FS_WRITE 459 int 460 ustarfs_write(f, start, size, resid) 461 struct open_file *f; 462 void *start; 463 size_t size; 464 size_t *resid; 465 { 466 return (EROFS); 467 } 468 #endif /* !LIBSA_NO_FS_WRITE */ 469 470 #ifndef LIBSA_NO_FS_SEEK 471 off_t 472 ustarfs_seek(f, offs, whence) 473 struct open_file *f; 474 off_t offs; 475 int whence; 476 { 477 ust_active_t *ustf; 478 479 ustf = f->f_fsdata; 480 switch (whence) { 481 case SEEK_SET: 482 ustf->uas_fseek = offs; 483 break; 484 case SEEK_CUR: 485 ustf->uas_fseek += offs; 486 break; 487 case SEEK_END: 488 ustf->uas_fseek = ustf->uas_filesize - offs; 489 break; 490 default: 491 return -1; 492 } 493 return ustf->uas_fseek; 494 } 495 #endif /* !LIBSA_NO_FS_SEEK */ 496 497 int 498 ustarfs_read(f, start, size, resid) 499 struct open_file *f; 500 void *start; 501 size_t size; 502 size_t *resid; 503 { 504 ust_active_t *ustf; 505 int e; 506 char *space512; 507 int blkoffs, 508 readoffs, 509 bufferoffset; 510 size_t seg; 511 size_t infile, 512 inbuffer; 513 514 e = 0; 515 space512 = alloc(512); 516 ustf = f->f_fsdata; 517 while(size != 0) { 518 if (ustf->uas_fseek >= ustf->uas_filesize) 519 break; 520 bufferoffset = ustf->uas_fseek % 512; 521 blkoffs = ustf->uas_fseek - bufferoffset; 522 readoffs = ustf->uas_filestart + 512 + blkoffs; 523 e = read512block(f, readoffs, space512); 524 if (e) 525 break; 526 seg = size; 527 inbuffer = 512 - bufferoffset; 528 if (inbuffer < seg) 529 seg = inbuffer; 530 infile = ustf->uas_filesize - ustf->uas_fseek; 531 if (infile < seg) 532 seg = infile; 533 memcpy(start, space512 + bufferoffset, seg); 534 ustf->uas_fseek += seg; 535 start = (caddr_t)start + seg; 536 size -= seg; 537 } 538 if (resid) 539 *resid = size; 540 dealloc(space512, 512); 541 return e; 542 } 543 544 int 545 ustarfs_stat(f, sb) 546 struct open_file *f; 547 struct stat *sb; 548 { 549 int mode, uid, gid; 550 ust_active_t *ustf; 551 552 if (f == NULL) 553 return EINVAL; 554 ustf = f->f_fsdata; 555 memset(sb, 0, sizeof *sb); 556 ustarfs_sscanf(ustf->uas_active.ust_mode, "%8o", &mode); 557 ustarfs_sscanf(ustf->uas_active.ust_uid, "%8o", &uid); 558 ustarfs_sscanf(ustf->uas_active.ust_gid, "%8o", &gid); 559 sb->st_mode = mode; 560 sb->st_uid = uid; 561 sb->st_gid = gid; 562 sb->st_size = ustf->uas_filesize; 563 return 0; 564 } 565 566 #ifndef LIBSA_NO_FS_CLOSE 567 int 568 ustarfs_close(f) 569 struct open_file *f; 570 { 571 if (f == NULL || f->f_fsdata == NULL) 572 return EINVAL; 573 dealloc(f->f_fsdata, sizeof(ust_active_t)); 574 f->f_fsdata = 0; 575 return 0; 576 } 577 #endif /* !LIBSA_NO_FS_CLOSE */ 578