1 /* $NetBSD: ustarfs.c,v 1.16 2001/09/28 15:15:24 minoura 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 } ustar_t; 111 112 /* 113 * We buffer one even cylindar of data...it's actually only really one 114 * cyl on a 1.44M floppy, but on other devices it's fast enough with any 115 * kind of block buffering, so we optimize for the slowest device. 116 */ 117 118 typedef struct ust_active_struct { 119 ustar_t uas_active; 120 char uas_1cyl[18 * 2 * 512]; 121 ustoffs uas_volsize; /* XXX this is hardwired now */ 122 ustoffs uas_windowbase; /* relative to volume 0 */ 123 ustoffs uas_filestart; /* relative to volume 0 */ 124 ustoffs uas_fseek; /* relative to file */ 125 ustoffs uas_filesize; /* relative to volume 0 */ 126 int uas_init_window; /* data present in window */ 127 int uas_init_fs; /* ust FS actually found */ 128 int uas_volzerosig; /* ID volume 0 by signature */ 129 int uas_sigdone; /* did sig already */ 130 int uas_offset; /* amount of cylinder below lba 0 */ 131 } ust_active_t; 132 133 static const char formatid[] = "USTARFS", 134 metaname[] = "USTAR.volsize."; 135 136 static int ustarfs_mode_offset = BBSIZE; 137 138 static int checksig __P((ust_active_t *)); 139 static int convert __P((const char *, int, int)); 140 static int get_volume __P((struct open_file *, int)); 141 static void setwindow(ust_active_t *, ustoffs, ustoffs); 142 static int real_fs_cylinder_read __P((struct open_file *, ustoffs, int)); 143 static int ustarfs_cylinder_read __P((struct open_file *, ustoffs, int)); 144 static void ustarfs_sscanf __P((const char *, const char *, int *)); 145 static int read512block __P((struct open_file *, ustoffs, char block[512])); 146 static int init_volzero_sig __P((struct open_file *)); 147 148 #ifdef HAVE_CHANGEDISK_HOOK 149 /* 150 * Called when the next volume is prompted. 151 * Machine dependent code can eject the medium etc. 152 * The new medium must be ready when this hook returns. 153 */ 154 void changedisk_hook __P((struct open_file *)); 155 #endif 156 157 static int 158 convert(f, base, fw) 159 const char *f; 160 int base, fw; 161 { 162 int i, c, result = 0; 163 164 while(fw > 0 && *f == ' ') { 165 --fw; 166 ++f; 167 } 168 for(i = 0; i < fw; ++i) { 169 c = f[i]; 170 if ('0' <= c && c < '0' + base) { 171 c -= '0'; 172 result = result * base + c; 173 } else break; 174 } 175 return result; 176 } 177 178 static void 179 ustarfs_sscanf(s,f,xi) 180 const char *s,*f; 181 int *xi; 182 { 183 *xi = convert(s, 8, convert(f + 1, 10, 99)); 184 } 185 186 static int 187 ustarfs_cylinder_read(f, seek2, forcelabel) 188 struct open_file *f; 189 ustoffs seek2; 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(f, seek2, forcelabel) 203 struct open_file *f; 204 ustoffs seek2; 205 { 206 int i; 207 int e = 0; /* XXX work around gcc warning */ 208 ustoffs lda; 209 char *xferbase; 210 ust_active_t *ustf; 211 size_t xferrqst, xfercount; 212 213 ustf = f->f_fsdata; 214 xferrqst = sizeof ustf->uas_1cyl; 215 xferbase = ustf->uas_1cyl; 216 lda = pda2lda(seek2); 217 if (lda < 0) { 218 lda = -lda; 219 ustf->uas_offset = lda; 220 /* 221 * don't read the label unless we have to. (Preserve 222 * sequential block access so tape boot works.) 223 */ 224 if (!forcelabel) { 225 memset(xferbase, 0, lda); 226 xferrqst -= lda; 227 xferbase += lda; 228 seek2 += lda; 229 } 230 } else 231 ustf->uas_offset = 0; 232 while(xferrqst > 0) { 233 #if !defined(LIBSA_NO_TWIDDLE) 234 twiddle(); 235 #endif 236 for (i = 0; i < 3; ++i) { 237 e = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ, 238 seek2 / 512, xferrqst, xferbase, &xfercount); 239 if (e == 0) 240 break; 241 printf("@"); 242 } 243 if (e) 244 break; 245 if (xfercount != xferrqst) 246 printf("Warning, unexpected short transfer %d/%d\n", 247 (int)xfercount, (int)xferrqst); 248 xferrqst -= xfercount; 249 xferbase += xfercount; 250 seek2 += xfercount; 251 } 252 return e; 253 } 254 255 static int 256 checksig(ustf) 257 ust_active_t *ustf; 258 { 259 int i, rcs; 260 261 for(i = rcs = 0; i < sizeof ustf->uas_1cyl; ++i) 262 rcs += ustf->uas_1cyl[i]; 263 return rcs; 264 } 265 266 static int 267 get_volume(f, vn) 268 struct open_file *f; 269 int vn; 270 { 271 int e, needvolume, havevolume; 272 ust_active_t *ustf; 273 274 ustf = f->f_fsdata; 275 havevolume = vda2vn(ustf->uas_windowbase, ustf->uas_volsize); 276 needvolume = vn; 277 while(havevolume != needvolume) { 278 printf("\nPlease "); 279 if (havevolume >= 0) 280 printf("remove disk %d, ", havevolume + 1); 281 printf("insert disk %d, and press return...", 282 needvolume + 1); 283 #ifdef HAVE_CHANGEDISK_HOOK 284 changedisk_hook(f); 285 #else 286 getchar(); 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(f, vda, block) 320 struct open_file *f; 321 ustoffs vda; 322 char block[512]; 323 { 324 ustoffs pda; 325 ssize_t e; 326 int dienow; 327 ust_active_t *ustf; 328 329 dienow = 0; 330 ustf = f->f_fsdata; 331 332 /* 333 * if (vda in window) 334 * copy out and return data 335 * if (vda is on some other disk) 336 * do disk swap 337 * get physical disk address 338 * round down to cylinder boundary 339 * read cylindar 340 * set window (in vda space) and try again 341 * [ there is an implicit assumption that windowbase always identifies 342 * the current volume, even if initwindow == 0. This way, a 343 * windowbase of 0 causes the initial volume to be disk 0 ] 344 */ 345 tryagain: 346 if(ustf->uas_init_window 347 && ustf->uas_windowbase <= vda && vda < 348 ustf->uas_windowbase + sizeof ustf->uas_1cyl - ustf->uas_offset) { 349 memcpy(block, ustf->uas_1cyl 350 + (vda - ustf->uas_windowbase) 351 + ustf->uas_offset, 512); 352 return 0; 353 } 354 if (dienow++) 355 panic("ustarfs read512block"); 356 ustf->uas_init_window = 0; 357 e = get_volume(f, vda2vn(vda, ustf->uas_volsize)); 358 if (e) 359 return e; 360 pda = lda2pda(vda2lda(vda, ustf->uas_volsize)); 361 pda-= pda % sizeof ustf->uas_1cyl; 362 e = ustarfs_cylinder_read(f, pda, 0); 363 if (e) 364 return e; 365 setwindow(ustf, pda, vda); 366 goto tryagain; 367 } 368 369 static int 370 init_volzero_sig(f) 371 struct open_file *f; 372 { 373 int e; 374 ust_active_t *ustf; 375 376 ustf = f->f_fsdata; 377 if (!ustf->uas_sigdone) { 378 e = ustarfs_cylinder_read(f, 0, 0); 379 if (e) 380 return e; 381 ustf->uas_volzerosig = checksig(ustf); 382 setwindow(ustf, 0, 0); 383 } 384 return 0; 385 } 386 387 int 388 ustarfs_open(path, f) 389 char *path; 390 struct open_file *f; 391 392 { 393 ust_active_t *ustf; 394 ustoffs offset; 395 char block[512]; 396 int filesize; 397 int e, e2; 398 int newvolblocks; 399 400 if (*path == '/') 401 ++path; 402 f->f_fsdata = ustf = alloc(sizeof *ustf); 403 memset(ustf, 0, sizeof *ustf); 404 offset = 0; 405 /* default to 2880 sector floppy */ 406 ustf->uas_volsize = 80 * 2 * 18 * 512 - lda2pda(0); 407 ustf->uas_fseek = 0; 408 e = init_volzero_sig(f); 409 if (e) 410 return e; 411 e2 = EINVAL; 412 for(;;) { 413 ustf->uas_filestart = offset; 414 e = read512block(f, offset, block); 415 if (e) 416 break; 417 memcpy(&ustf->uas_active, block, sizeof ustf->uas_active); 418 if(strncmp(ustf->uas_active.ust_magic, "ustar", 5)) { 419 e = e2; 420 break; 421 } 422 e2 = ENOENT; /* it must be an actual ustarfs */ 423 ustf->uas_init_fs = 1; 424 /* if volume metadata is found, use it */ 425 if(strncmp(ustf->uas_active.ust_name, metaname, 426 strlen(metaname)) == 0) { 427 ustarfs_sscanf(ustf->uas_active.ust_name 428 + strlen(metaname), "%99o", &newvolblocks); 429 ustf->uas_volsize = newvolblocks * 512 430 - lda2pda(0); 431 } 432 ustarfs_sscanf(ustf->uas_active.ust_size,"%12o",&filesize); 433 if(strncmp(ustf->uas_active.ust_name, path, 434 sizeof ustf->uas_active.ust_name) == 0) { 435 ustf->uas_filesize = filesize; 436 break; 437 } 438 offset += USTAR_NAME_BLOCK + filesize; 439 filesize %= 512; 440 if (filesize) 441 offset += 512 - filesize; 442 } 443 if (e) { 444 free(ustf, sizeof *ustf); 445 f->f_fsdata = 0; 446 } 447 return e; 448 } 449 450 #ifndef LIBSA_NO_FS_WRITE 451 int 452 ustarfs_write(f, start, size, resid) 453 struct open_file *f; 454 void *start; 455 size_t size; 456 size_t *resid; 457 { 458 return (EROFS); 459 } 460 #endif /* !LIBSA_NO_FS_WRITE */ 461 462 #ifndef LIBSA_NO_FS_SEEK 463 off_t 464 ustarfs_seek(f, offs, whence) 465 struct open_file *f; 466 off_t offs; 467 int whence; 468 { 469 ust_active_t *ustf; 470 471 ustf = f->f_fsdata; 472 switch (whence) { 473 case SEEK_SET: 474 ustf->uas_fseek = offs; 475 break; 476 case SEEK_CUR: 477 ustf->uas_fseek += offs; 478 break; 479 case SEEK_END: 480 ustf->uas_fseek = ustf->uas_filesize - offs; 481 break; 482 default: 483 return -1; 484 } 485 return ustf->uas_fseek; 486 } 487 #endif /* !LIBSA_NO_FS_CLOSE */ 488 489 int 490 ustarfs_read(f, start, size, resid) 491 struct open_file *f; 492 void *start; 493 size_t size; 494 size_t *resid; 495 { 496 ust_active_t *ustf; 497 int e; 498 char *space512; 499 int blkoffs, 500 readoffs, 501 bufferoffset; 502 size_t seg; 503 int infile, 504 inbuffer; 505 506 e = 0; 507 space512 = alloc(512); 508 ustf = f->f_fsdata; 509 while(size != 0) { 510 if (ustf->uas_fseek >= ustf->uas_filesize) 511 break; 512 bufferoffset = ustf->uas_fseek % 512; 513 blkoffs = ustf->uas_fseek - bufferoffset; 514 readoffs = ustf->uas_filestart + 512 + blkoffs; 515 e = read512block(f, readoffs, space512); 516 if (e) 517 break; 518 seg = size; 519 inbuffer = 512 - bufferoffset; 520 if (inbuffer < seg) 521 seg = inbuffer; 522 infile = ustf->uas_filesize - ustf->uas_fseek; 523 if (infile < seg) 524 seg = infile; 525 memcpy(start, space512 + bufferoffset, seg); 526 ustf->uas_fseek += seg; 527 start = (caddr_t)start + seg; 528 size -= seg; 529 } 530 if (resid) 531 *resid = size; 532 free(space512, 512); 533 return e; 534 } 535 536 int 537 ustarfs_stat(f, sb) 538 struct open_file *f; 539 struct stat *sb; 540 { 541 int mode, uid, gid; 542 ust_active_t *ustf; 543 544 if (f == NULL) 545 return EINVAL; 546 ustf = f->f_fsdata; 547 memset(sb, 0, sizeof *sb); 548 ustarfs_sscanf(ustf->uas_active.ust_mode, "%8o", &mode); 549 ustarfs_sscanf(ustf->uas_active.ust_uid, "%8o", &uid); 550 ustarfs_sscanf(ustf->uas_active.ust_gid, "%8o", &gid); 551 sb->st_mode = mode; 552 sb->st_uid = uid; 553 sb->st_gid = gid; 554 sb->st_size = ustf->uas_filesize; 555 return 0; 556 } 557 558 #ifndef LIBSA_NO_FS_CLOSE 559 int 560 ustarfs_close(f) 561 struct open_file *f; 562 { 563 if (f == NULL || f->f_fsdata == NULL) 564 return EINVAL; 565 free(f->f_fsdata, sizeof(ust_active_t)); 566 f->f_fsdata = 0; 567 return 0; 568 } 569 #endif /* !LIBSA_NO_FS_CLOSE */ 570