1 /* $NetBSD: ext2fs.c,v 1.20 2014/03/20 03:13:18 christos Exp $ */
2
3 /*
4 * Copyright (c) 1997 Manuel Bouyer.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 /*-
28 * Copyright (c) 1993
29 * The Regents of the University of California. All rights reserved.
30 *
31 * This code is derived from software contributed to Berkeley by
32 * The Mach Operating System project at Carnegie-Mellon University.
33 *
34 * Redistribution and use in source and binary forms, with or without
35 * modification, are permitted provided that the following conditions
36 * are met:
37 * 1. Redistributions of source code must retain the above copyright
38 * notice, this list of conditions and the following disclaimer.
39 * 2. Redistributions in binary form must reproduce the above copyright
40 * notice, this list of conditions and the following disclaimer in the
41 * documentation and/or other materials provided with the distribution.
42 * 3. Neither the name of the University nor the names of its contributors
43 * may be used to endorse or promote products derived from this software
44 * without specific prior written permission.
45 *
46 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
47 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
48 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
49 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
50 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
51 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
52 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
53 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
54 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
55 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
56 * SUCH DAMAGE.
57 *
58 *
59 * Copyright (c) 1990, 1991 Carnegie Mellon University
60 * All Rights Reserved.
61 *
62 * Author: David Golub
63 *
64 * Permission to use, copy, modify and distribute this software and its
65 * documentation is hereby granted, provided that both the copyright
66 * notice and this permission notice appear in all copies of the
67 * software, derivative works or modified versions, and any portions
68 * thereof, and that both notices appear in supporting documentation.
69 *
70 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
71 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
72 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
73 *
74 * Carnegie Mellon requests users of this software to return to
75 *
76 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
77 * School of Computer Science
78 * Carnegie Mellon University
79 * Pittsburgh PA 15213-3890
80 *
81 * any improvements or extensions that they make and grant Carnegie the
82 * rights to redistribute these changes.
83 */
84
85 /*
86 * Stand-alone file reading package for Ext2 file system.
87 */
88
89 /* #define EXT2FS_DEBUG */
90
91 #include <sys/param.h>
92 #include <sys/time.h>
93 #include <ufs/ext2fs/ext2fs_dinode.h>
94 #include <ufs/ext2fs/ext2fs_dir.h>
95 #include <ufs/ext2fs/ext2fs.h>
96 #ifdef _STANDALONE
97 #include <lib/libkern/libkern.h>
98 #else
99 #include <string.h>
100 #endif
101
102 #include "stand.h"
103 #include "ext2fs.h"
104
105 #if defined(LIBSA_FS_SINGLECOMPONENT) && !defined(LIBSA_NO_FS_SYMLINK)
106 #define LIBSA_NO_FS_SYMLINK
107 #endif
108
109 #if defined(LIBSA_NO_TWIDDLE)
110 #define twiddle()
111 #endif
112
113 #ifndef indp_t
114 #define indp_t int32_t
115 #endif
116 typedef uint32_t ino32_t;
117 #ifndef FSBTODB
118 #define FSBTODB(fs, indp) EXT2_FSBTODB(fs, indp)
119 #endif
120
121 /*
122 * To avoid having a lot of filesystem-block sized buffers lurking (which
123 * could be 32k) we only keep a few entries of the indirect block map.
124 * With 8k blocks, 2^8 blocks is ~500k so we reread the indirect block
125 * ~13 times pulling in a 6M kernel.
126 * The cache size must be smaller than the smallest filesystem block,
127 * so LN2_IND_CACHE_SZ <= 9 (UFS2 and 4k blocks).
128 */
129 #define LN2_IND_CACHE_SZ 6
130 #define IND_CACHE_SZ (1 << LN2_IND_CACHE_SZ)
131 #define IND_CACHE_MASK (IND_CACHE_SZ - 1)
132
133 /*
134 * In-core open file.
135 */
136 struct file {
137 off_t f_seekp; /* seek pointer */
138 struct m_ext2fs *f_fs; /* pointer to super-block */
139 struct ext2fs_dinode f_di; /* copy of on-disk inode */
140 uint f_nishift; /* for blocks in indirect block */
141 indp_t f_ind_cache_block;
142 indp_t f_ind_cache[IND_CACHE_SZ];
143
144 char *f_buf; /* buffer for data block */
145 size_t f_buf_size; /* size of data block */
146 daddr_t f_buf_blkno; /* block number of data block */
147 };
148
149
150 static int read_inode(ino32_t, struct open_file *);
151 static int block_map(struct open_file *, indp_t, indp_t *);
152 static int buf_read_file(struct open_file *, char **, size_t *);
153 static int search_directory(const char *, int, struct open_file *, ino32_t *);
154 static int read_sblock(struct open_file *, struct m_ext2fs *);
155 static int read_gdblock(struct open_file *, struct m_ext2fs *);
156 #ifdef EXT2FS_DEBUG
157 static void dump_sblock(struct m_ext2fs *);
158 #endif
159
160 /*
161 * Read a new inode into a file structure.
162 */
163 static int
read_inode(ino32_t inumber,struct open_file * f)164 read_inode(ino32_t inumber, struct open_file *f)
165 {
166 struct file *fp = (struct file *)f->f_fsdata;
167 struct m_ext2fs *fs = fp->f_fs;
168 char *buf;
169 size_t rsize;
170 int rc;
171 daddr_t inode_sector;
172 struct ext2fs_dinode *dip;
173
174 inode_sector = FSBTODB(fs, ino_to_fsba(fs, inumber));
175
176 /*
177 * Read inode and save it.
178 */
179 buf = fp->f_buf;
180 twiddle();
181 rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
182 inode_sector, fs->e2fs_bsize, buf, &rsize);
183 if (rc)
184 return rc;
185 if (rsize != fs->e2fs_bsize)
186 return EIO;
187
188 dip = (struct ext2fs_dinode *)(buf +
189 EXT2_DINODE_SIZE(fs) * ino_to_fsbo(fs, inumber));
190 e2fs_iload(dip, &fp->f_di);
191
192 /*
193 * Clear out the old buffers
194 */
195 fp->f_ind_cache_block = ~0;
196 fp->f_buf_blkno = -1;
197 return rc;
198 }
199
200 /*
201 * Given an offset in a file, find the disk block number that
202 * contains that block.
203 */
204 static int
block_map(struct open_file * f,indp_t file_block,indp_t * disk_block_p)205 block_map(struct open_file *f, indp_t file_block, indp_t *disk_block_p)
206 {
207 struct file *fp = (struct file *)f->f_fsdata;
208 struct m_ext2fs *fs = fp->f_fs;
209 uint level;
210 indp_t ind_cache;
211 indp_t ind_block_num;
212 size_t rsize;
213 int rc;
214 indp_t *buf = (void *)fp->f_buf;
215
216 /*
217 * Index structure of an inode:
218 *
219 * e2di_blocks[0..EXT2FS_NDADDR-1]
220 * hold block numbers for blocks
221 * 0..EXT2FS_NDADDR-1
222 *
223 * e2di_blocks[EXT2FS_NDADDR+0]
224 * block EXT2FS_NDADDR+0 is the single indirect block
225 * holds block numbers for blocks
226 * EXT2FS_NDADDR .. EXT2FS_NDADDR + EXT2_NINDIR(fs)-1
227 *
228 * e2di_blocks[EXT2FS_NDADDR+1]
229 * block EXT2FS_NDADDR+1 is the double indirect block
230 * holds block numbers for INDEX blocks for blocks
231 * EXT2FS_NDADDR + EXT2_NINDIR(fs) ..
232 * EXT2FS_NDADDR + EXT2_NINDIR(fs) + EXT2_NINDIR(fs)**2 - 1
233 *
234 * e2di_blocks[EXT2FS_NDADDR+2]
235 * block EXT2FS_NDADDR+2 is the triple indirect block
236 * holds block numbers for double-indirect
237 * blocks for blocks
238 * EXT2FS_NDADDR + EXT2_NINDIR(fs) + EXT2_NINDIR(fs)**2 ..
239 * EXT2FS_NDADDR + EXT2_NINDIR(fs) + EXT2_NINDIR(fs)**2
240 * + EXT2_NINDIR(fs)**3 - 1
241 */
242
243 if (file_block < EXT2FS_NDADDR) {
244 /* Direct block. */
245 *disk_block_p = fs2h32(fp->f_di.e2di_blocks[file_block]);
246 return 0;
247 }
248
249 file_block -= EXT2FS_NDADDR;
250
251 ind_cache = file_block >> LN2_IND_CACHE_SZ;
252 if (ind_cache == fp->f_ind_cache_block) {
253 *disk_block_p =
254 fs2h32(fp->f_ind_cache[file_block & IND_CACHE_MASK]);
255 return 0;
256 }
257
258 for (level = 0;;) {
259 level += fp->f_nishift;
260 if (file_block < (indp_t)1 << level)
261 break;
262 if (level > EXT2FS_NIADDR * fp->f_nishift)
263 /* Block number too high */
264 return EFBIG;
265 file_block -= (indp_t)1 << level;
266 }
267
268 ind_block_num =
269 fs2h32(fp->f_di.e2di_blocks[EXT2FS_NDADDR +
270 (level / fp->f_nishift - 1)]);
271
272 for (;;) {
273 level -= fp->f_nishift;
274 if (ind_block_num == 0) {
275 *disk_block_p = 0; /* missing */
276 return 0;
277 }
278
279 twiddle();
280 /*
281 * If we were feeling brave, we could work out the number
282 * of the disk sector and read a single disk sector instead
283 * of a filesystem block.
284 * However we don't do this very often anyway...
285 */
286 rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
287 FSBTODB(fp->f_fs, ind_block_num), fs->e2fs_bsize,
288 buf, &rsize);
289 if (rc)
290 return rc;
291 if (rsize != fs->e2fs_bsize)
292 return EIO;
293 ind_block_num = fs2h32(buf[file_block >> level]);
294 if (level == 0)
295 break;
296 file_block &= (1 << level) - 1;
297 }
298
299 /* Save the part of the block that contains this sector */
300 memcpy(fp->f_ind_cache, &buf[file_block & ~IND_CACHE_MASK],
301 IND_CACHE_SZ * sizeof fp->f_ind_cache[0]);
302 fp->f_ind_cache_block = ind_cache;
303
304 *disk_block_p = ind_block_num;
305
306 return 0;
307 }
308
309 /*
310 * Read a portion of a file into an internal buffer.
311 * Return the location in the buffer and the amount in the buffer.
312 */
313 static int
buf_read_file(struct open_file * f,char ** buf_p,size_t * size_p)314 buf_read_file(struct open_file *f, char **buf_p, size_t *size_p)
315 {
316 struct file *fp = (struct file *)f->f_fsdata;
317 struct m_ext2fs *fs = fp->f_fs;
318 long off;
319 indp_t file_block;
320 indp_t disk_block = 0; /* XXX: gcc */
321 size_t block_size;
322 int rc;
323
324 off = ext2_blkoff(fs, fp->f_seekp);
325 file_block = ext2_lblkno(fs, fp->f_seekp);
326 block_size = fs->e2fs_bsize; /* no fragment */
327
328 if (file_block != fp->f_buf_blkno) {
329 rc = block_map(f, file_block, &disk_block);
330 if (rc)
331 return rc;
332
333 if (disk_block == 0) {
334 memset(fp->f_buf, 0, block_size);
335 fp->f_buf_size = block_size;
336 } else {
337 twiddle();
338 rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
339 FSBTODB(fs, disk_block),
340 block_size, fp->f_buf, &fp->f_buf_size);
341 if (rc)
342 return rc;
343 }
344
345 fp->f_buf_blkno = file_block;
346 }
347
348 /*
349 * Return address of byte in buffer corresponding to
350 * offset, and size of remainder of buffer after that
351 * byte.
352 */
353 *buf_p = fp->f_buf + off;
354 *size_p = block_size - off;
355
356 /*
357 * But truncate buffer at end of file.
358 */
359 /* XXX should handle LARGEFILE */
360 if (*size_p > fp->f_di.e2di_size - fp->f_seekp)
361 *size_p = fp->f_di.e2di_size - fp->f_seekp;
362
363 return 0;
364 }
365
366 /*
367 * Search a directory for a name and return its
368 * inode number.
369 */
370 static int
search_directory(const char * name,int length,struct open_file * f,ino32_t * inumber_p)371 search_directory(const char *name, int length, struct open_file *f,
372 ino32_t *inumber_p)
373 {
374 struct file *fp = (struct file *)f->f_fsdata;
375 struct ext2fs_direct *dp;
376 struct ext2fs_direct *edp;
377 char *buf;
378 size_t buf_size;
379 int namlen;
380 int rc;
381
382 fp->f_seekp = 0;
383 /* XXX should handle LARGEFILE */
384 while (fp->f_seekp < (off_t)fp->f_di.e2di_size) {
385 rc = buf_read_file(f, &buf, &buf_size);
386 if (rc)
387 return rc;
388
389 dp = (struct ext2fs_direct *)buf;
390 edp = (struct ext2fs_direct *)(buf + buf_size);
391 for (; dp < edp;
392 dp = (void *)((char *)dp + fs2h16(dp->e2d_reclen))) {
393 if (fs2h16(dp->e2d_reclen) <= 0)
394 break;
395 if (fs2h32(dp->e2d_ino) == (ino32_t)0)
396 continue;
397 namlen = dp->e2d_namlen;
398 if (namlen == length &&
399 !memcmp(name, dp->e2d_name, length)) {
400 /* found entry */
401 *inumber_p = fs2h32(dp->e2d_ino);
402 return 0;
403 }
404 }
405 fp->f_seekp += buf_size;
406 }
407 return ENOENT;
408 }
409
410 int
read_sblock(struct open_file * f,struct m_ext2fs * fs)411 read_sblock(struct open_file *f, struct m_ext2fs *fs)
412 {
413 static uint8_t sbbuf[SBSIZE];
414 struct ext2fs ext2fs;
415 size_t buf_size;
416 int rc;
417
418 rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
419 SBOFF / DEV_BSIZE, SBSIZE, sbbuf, &buf_size);
420 if (rc)
421 return rc;
422
423 if (buf_size != SBSIZE)
424 return EIO;
425
426 e2fs_sbload((void *)sbbuf, &ext2fs);
427 if (ext2fs.e2fs_magic != E2FS_MAGIC)
428 return EINVAL;
429 if (ext2fs.e2fs_rev > E2FS_REV1 ||
430 (ext2fs.e2fs_rev == E2FS_REV1 &&
431 (ext2fs.e2fs_first_ino != EXT2_FIRSTINO ||
432 (ext2fs.e2fs_inode_size != 128 && ext2fs.e2fs_inode_size != 256) ||
433 ext2fs.e2fs_features_incompat & ~EXT2F_INCOMPAT_SUPP))) {
434 return ENODEV;
435 }
436
437 e2fs_sbload((void *)sbbuf, &fs->e2fs);
438 /* compute in-memory m_ext2fs values */
439 fs->e2fs_ncg =
440 howmany(fs->e2fs.e2fs_bcount - fs->e2fs.e2fs_first_dblock,
441 fs->e2fs.e2fs_bpg);
442 /* XXX assume hw bsize = 512 */
443 fs->e2fs_fsbtodb = fs->e2fs.e2fs_log_bsize + 1;
444 fs->e2fs_bsize = MINBSIZE << fs->e2fs.e2fs_log_bsize;
445 fs->e2fs_bshift = LOG_MINBSIZE + fs->e2fs.e2fs_log_bsize;
446 fs->e2fs_qbmask = fs->e2fs_bsize - 1;
447 fs->e2fs_bmask = ~fs->e2fs_qbmask;
448 fs->e2fs_ngdb =
449 howmany(fs->e2fs_ncg, fs->e2fs_bsize / sizeof(struct ext2_gd));
450 fs->e2fs_ipb = fs->e2fs_bsize / ext2fs.e2fs_inode_size;
451 fs->e2fs_itpg = fs->e2fs.e2fs_ipg / fs->e2fs_ipb;
452
453 return 0;
454 }
455
456 int
read_gdblock(struct open_file * f,struct m_ext2fs * fs)457 read_gdblock(struct open_file *f, struct m_ext2fs *fs)
458 {
459 struct file *fp = (struct file *)f->f_fsdata;
460 size_t rsize;
461 uint gdpb;
462 int i, rc;
463
464 gdpb = fs->e2fs_bsize / sizeof(struct ext2_gd);
465
466 for (i = 0; i < fs->e2fs_ngdb; i++) {
467 rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
468 FSBTODB(fs, fs->e2fs.e2fs_first_dblock +
469 1 /* superblock */ + i),
470 fs->e2fs_bsize, fp->f_buf, &rsize);
471 if (rc)
472 return rc;
473 if (rsize != fs->e2fs_bsize)
474 return EIO;
475
476 e2fs_cgload((struct ext2_gd *)fp->f_buf,
477 &fs->e2fs_gd[i * gdpb],
478 (i == (fs->e2fs_ngdb - 1)) ?
479 (fs->e2fs_ncg - gdpb * i) * sizeof(struct ext2_gd):
480 fs->e2fs_bsize);
481 }
482
483 return 0;
484 }
485
486
487 /*
488 * Open a file.
489 */
490 __compactcall int
ext2fs_open(const char * path,struct open_file * f)491 ext2fs_open(const char *path, struct open_file *f)
492 {
493 #ifndef LIBSA_FS_SINGLECOMPONENT
494 const char *cp, *ncp;
495 int c;
496 #endif
497 ino32_t inumber;
498 struct file *fp;
499 struct m_ext2fs *fs;
500 int rc;
501 #ifndef LIBSA_NO_FS_SYMLINK
502 ino32_t parent_inumber;
503 int nlinks = 0;
504 char namebuf[MAXPATHLEN+1];
505 char *buf;
506 #endif
507
508 /* allocate file system specific data structure */
509 fp = alloc(sizeof(struct file));
510 memset(fp, 0, sizeof(struct file));
511 f->f_fsdata = (void *)fp;
512
513 /* allocate space and read super block */
514 fs = alloc(sizeof(*fs));
515 memset(fs, 0, sizeof(*fs));
516 fp->f_fs = fs;
517 twiddle();
518
519 rc = read_sblock(f, fs);
520 if (rc)
521 goto out;
522
523 #ifdef EXT2FS_DEBUG
524 dump_sblock(fs);
525 #endif
526
527 /* alloc a block sized buffer used for all fs transfers */
528 fp->f_buf = alloc(fs->e2fs_bsize);
529
530 /* read group descriptor blocks */
531 fs->e2fs_gd = alloc(sizeof(struct ext2_gd) * fs->e2fs_ncg);
532 rc = read_gdblock(f, fs);
533 if (rc)
534 goto out;
535
536 /*
537 * Calculate indirect block levels.
538 */
539 {
540 indp_t mult;
541 int ln2;
542
543 /*
544 * We note that the number of indirect blocks is always
545 * a power of 2. This lets us use shifts and masks instead
546 * of divide and remainder and avoinds pulling in the
547 * 64bit division routine into the boot code.
548 */
549 mult = EXT2_NINDIR(fs);
550 #ifdef DEBUG
551 if (!powerof2(mult)) {
552 /* Hummm was't a power of 2 */
553 rc = EINVAL;
554 goto out;
555 }
556 #endif
557 for (ln2 = 0; mult != 1; ln2++)
558 mult >>= 1;
559
560 fp->f_nishift = ln2;
561 }
562
563 inumber = EXT2_ROOTINO;
564 if ((rc = read_inode(inumber, f)) != 0)
565 goto out;
566
567 #ifndef LIBSA_FS_SINGLECOMPONENT
568 cp = path;
569 while (*cp) {
570
571 /*
572 * Remove extra separators
573 */
574 while (*cp == '/')
575 cp++;
576 if (*cp == '\0')
577 break;
578
579 /*
580 * Check that current node is a directory.
581 */
582 if ((fp->f_di.e2di_mode & EXT2_IFMT) != EXT2_IFDIR) {
583 rc = ENOTDIR;
584 goto out;
585 }
586
587 /*
588 * Get next component of path name.
589 */
590 ncp = cp;
591 while ((c = *cp) != '\0' && c != '/')
592 cp++;
593
594 /*
595 * Look up component in current directory.
596 * Save directory inumber in case we find a
597 * symbolic link.
598 */
599 #ifndef LIBSA_NO_FS_SYMLINK
600 parent_inumber = inumber;
601 #endif
602 rc = search_directory(ncp, cp - ncp, f, &inumber);
603 if (rc)
604 goto out;
605
606 /*
607 * Open next component.
608 */
609 if ((rc = read_inode(inumber, f)) != 0)
610 goto out;
611
612 #ifndef LIBSA_NO_FS_SYMLINK
613 /*
614 * Check for symbolic link.
615 */
616 if ((fp->f_di.e2di_mode & EXT2_IFMT) == EXT2_IFLNK) {
617 /* XXX should handle LARGEFILE */
618 int link_len = fp->f_di.e2di_size;
619 int len;
620
621 len = strlen(cp);
622
623 if (link_len + len > MAXPATHLEN ||
624 ++nlinks > MAXSYMLINKS) {
625 rc = ENOENT;
626 goto out;
627 }
628
629 memmove(&namebuf[link_len], cp, len + 1);
630
631 if (link_len < EXT2_MAXSYMLINKLEN) {
632 memcpy(namebuf, fp->f_di.e2di_blocks, link_len);
633 } else {
634 /*
635 * Read file for symbolic link
636 */
637 size_t buf_size;
638 indp_t disk_block;
639
640 buf = fp->f_buf;
641 rc = block_map(f, (indp_t)0, &disk_block);
642 if (rc)
643 goto out;
644
645 twiddle();
646 rc = DEV_STRATEGY(f->f_dev)(f->f_devdata,
647 F_READ, FSBTODB(fs, disk_block),
648 fs->e2fs_bsize, buf, &buf_size);
649 if (rc)
650 goto out;
651
652 memcpy(namebuf, buf, link_len);
653 }
654
655 /*
656 * If relative pathname, restart at parent directory.
657 * If absolute pathname, restart at root.
658 */
659 cp = namebuf;
660 if (*cp != '/')
661 inumber = parent_inumber;
662 else
663 inumber = (ino32_t)EXT2_ROOTINO;
664
665 if ((rc = read_inode(inumber, f)) != 0)
666 goto out;
667 }
668 #endif /* !LIBSA_NO_FS_SYMLINK */
669 }
670
671 /*
672 * Found terminal component.
673 */
674 rc = 0;
675
676 #else /* !LIBSA_FS_SINGLECOMPONENT */
677
678 /* look up component in the current (root) directory */
679 rc = search_directory(path, strlen(path), f, &inumber);
680 if (rc)
681 goto out;
682
683 /* open it */
684 rc = read_inode(inumber, f);
685
686 #endif /* !LIBSA_FS_SINGLECOMPONENT */
687
688 fp->f_seekp = 0; /* reset seek pointer */
689
690 out:
691 if (rc)
692 ext2fs_close(f);
693 else
694 fsmod = "ext2fs";
695 return rc;
696 }
697
698 __compactcall int
ext2fs_close(struct open_file * f)699 ext2fs_close(struct open_file *f)
700 {
701 struct file *fp = (struct file *)f->f_fsdata;
702
703 f->f_fsdata = NULL;
704 if (fp == NULL)
705 return 0;
706
707 if (fp->f_fs->e2fs_gd)
708 dealloc(fp->f_fs->e2fs_gd,
709 sizeof(struct ext2_gd) * fp->f_fs->e2fs_ncg);
710 if (fp->f_buf)
711 dealloc(fp->f_buf, fp->f_fs->e2fs_bsize);
712 dealloc(fp->f_fs, sizeof(*fp->f_fs));
713 dealloc(fp, sizeof(struct file));
714 return 0;
715 }
716
717 /*
718 * Copy a portion of a file into kernel memory.
719 * Cross block boundaries when necessary.
720 */
721 __compactcall int
ext2fs_read(struct open_file * f,void * start,size_t size,size_t * resid)722 ext2fs_read(struct open_file *f, void *start, size_t size, size_t *resid)
723 {
724 struct file *fp = (struct file *)f->f_fsdata;
725 size_t csize;
726 char *buf;
727 size_t buf_size;
728 int rc = 0;
729 char *addr = start;
730
731 while (size != 0) {
732 /* XXX should handle LARGEFILE */
733 if (fp->f_seekp >= (off_t)fp->f_di.e2di_size)
734 break;
735
736 rc = buf_read_file(f, &buf, &buf_size);
737 if (rc)
738 break;
739
740 csize = size;
741 if (csize > buf_size)
742 csize = buf_size;
743
744 memcpy(addr, buf, csize);
745
746 fp->f_seekp += csize;
747 addr += csize;
748 size -= csize;
749 }
750 if (resid)
751 *resid = size;
752 return rc;
753 }
754
755 /*
756 * Not implemented.
757 */
758 #ifndef LIBSA_NO_FS_WRITE
759 __compactcall int
ext2fs_write(struct open_file * f,void * start,size_t size,size_t * resid)760 ext2fs_write(struct open_file *f, void *start, size_t size, size_t *resid)
761 {
762
763 return EROFS;
764 }
765 #endif /* !LIBSA_NO_FS_WRITE */
766
767 #ifndef LIBSA_NO_FS_SEEK
768 __compactcall off_t
ext2fs_seek(struct open_file * f,off_t offset,int where)769 ext2fs_seek(struct open_file *f, off_t offset, int where)
770 {
771 struct file *fp = (struct file *)f->f_fsdata;
772
773 switch (where) {
774 case SEEK_SET:
775 fp->f_seekp = offset;
776 break;
777 case SEEK_CUR:
778 fp->f_seekp += offset;
779 break;
780 case SEEK_END:
781 /* XXX should handle LARGEFILE */
782 fp->f_seekp = fp->f_di.e2di_size - offset;
783 break;
784 default:
785 return -1;
786 }
787 return fp->f_seekp;
788 }
789 #endif /* !LIBSA_NO_FS_SEEK */
790
791 __compactcall int
ext2fs_stat(struct open_file * f,struct stat * sb)792 ext2fs_stat(struct open_file *f, struct stat *sb)
793 {
794 struct file *fp = (struct file *)f->f_fsdata;
795
796 /* only important stuff */
797 memset(sb, 0, sizeof *sb);
798 sb->st_mode = fp->f_di.e2di_mode;
799 sb->st_uid = fp->f_di.e2di_uid;
800 sb->st_gid = fp->f_di.e2di_gid;
801 /* XXX should handle LARGEFILE */
802 sb->st_size = fp->f_di.e2di_size;
803 return 0;
804 }
805
806 #if defined(LIBSA_ENABLE_LS_OP)
807
808 #include "ls.h"
809
810 static const char *const typestr[] = {
811 "unknown",
812 "REG",
813 "DIR",
814 "CHR",
815 "BLK",
816 "FIFO",
817 "SOCK",
818 "LNK"
819 };
820
821 __compactcall void
ext2fs_ls(struct open_file * f,const char * pattern)822 ext2fs_ls(struct open_file *f, const char *pattern)
823 {
824 struct file *fp = (struct file *)f->f_fsdata;
825 size_t block_size = fp->f_fs->e2fs_bsize;
826 char *buf;
827 size_t buf_size;
828 lsentry_t *names = NULL;
829
830 fp->f_seekp = 0;
831 while (fp->f_seekp < (off_t)fp->f_di.e2di_size) {
832 struct ext2fs_direct *dp, *edp;
833 int rc = buf_read_file(f, &buf, &buf_size);
834 if (rc)
835 goto out;
836 if (buf_size != block_size || buf_size == 0)
837 goto out;
838
839 dp = (struct ext2fs_direct *)buf;
840 edp = (struct ext2fs_direct *)(buf + buf_size);
841
842 for (; dp < edp;
843 dp = (void *)((char *)dp + fs2h16(dp->e2d_reclen))) {
844 const char *t;
845
846 if (fs2h16(dp->e2d_reclen) <= 0)
847 goto out;
848
849 if (fs2h32(dp->e2d_ino) == 0)
850 continue;
851
852 if (dp->e2d_type >= NELEM(typestr) ||
853 !(t = typestr[dp->e2d_type])) {
854 /*
855 * This does not handle "old"
856 * filesystems properly. On little
857 * endian machines, we get a bogus
858 * type name if the namlen matches a
859 * valid type identifier. We could
860 * check if we read namlen "0" and
861 * handle this case specially, if
862 * there were a pressing need...
863 */
864 printf("bad dir entry\n");
865 goto out;
866 }
867 lsadd(&names, pattern, dp->e2d_name,
868 strlen(dp->e2d_name), fs2h32(dp->e2d_ino), t);
869 }
870 fp->f_seekp += buf_size;
871 }
872
873 lsprint(names);
874 out: lsfree(names);
875 }
876 #endif
877
878 /*
879 * byte swap functions for big endian machines
880 * (ext2fs is always little endian)
881 *
882 * XXX: We should use src/sys/ufs/ext2fs/ext2fs_bswap.c
883 */
884
885 /* These functions are only needed if native byte order is not big endian */
886 #if BYTE_ORDER == BIG_ENDIAN
887 void
e2fs_sb_bswap(struct ext2fs * old,struct ext2fs * new)888 e2fs_sb_bswap(struct ext2fs *old, struct ext2fs *new)
889 {
890
891 /* preserve unused fields */
892 memcpy(new, old, sizeof(struct ext2fs));
893 new->e2fs_icount = bswap32(old->e2fs_icount);
894 new->e2fs_bcount = bswap32(old->e2fs_bcount);
895 new->e2fs_rbcount = bswap32(old->e2fs_rbcount);
896 new->e2fs_fbcount = bswap32(old->e2fs_fbcount);
897 new->e2fs_ficount = bswap32(old->e2fs_ficount);
898 new->e2fs_first_dblock = bswap32(old->e2fs_first_dblock);
899 new->e2fs_log_bsize = bswap32(old->e2fs_log_bsize);
900 new->e2fs_fsize = bswap32(old->e2fs_fsize);
901 new->e2fs_bpg = bswap32(old->e2fs_bpg);
902 new->e2fs_fpg = bswap32(old->e2fs_fpg);
903 new->e2fs_ipg = bswap32(old->e2fs_ipg);
904 new->e2fs_mtime = bswap32(old->e2fs_mtime);
905 new->e2fs_wtime = bswap32(old->e2fs_wtime);
906 new->e2fs_mnt_count = bswap16(old->e2fs_mnt_count);
907 new->e2fs_max_mnt_count = bswap16(old->e2fs_max_mnt_count);
908 new->e2fs_magic = bswap16(old->e2fs_magic);
909 new->e2fs_state = bswap16(old->e2fs_state);
910 new->e2fs_beh = bswap16(old->e2fs_beh);
911 new->e2fs_minrev = bswap16(old->e2fs_minrev);
912 new->e2fs_lastfsck = bswap32(old->e2fs_lastfsck);
913 new->e2fs_fsckintv = bswap32(old->e2fs_fsckintv);
914 new->e2fs_creator = bswap32(old->e2fs_creator);
915 new->e2fs_rev = bswap32(old->e2fs_rev);
916 new->e2fs_ruid = bswap16(old->e2fs_ruid);
917 new->e2fs_rgid = bswap16(old->e2fs_rgid);
918 new->e2fs_first_ino = bswap32(old->e2fs_first_ino);
919 new->e2fs_inode_size = bswap16(old->e2fs_inode_size);
920 new->e2fs_block_group_nr = bswap16(old->e2fs_block_group_nr);
921 new->e2fs_features_compat = bswap32(old->e2fs_features_compat);
922 new->e2fs_features_incompat = bswap32(old->e2fs_features_incompat);
923 new->e2fs_features_rocompat = bswap32(old->e2fs_features_rocompat);
924 new->e2fs_algo = bswap32(old->e2fs_algo);
925 new->e2fs_reserved_ngdb = bswap16(old->e2fs_reserved_ngdb);
926 }
927
e2fs_cg_bswap(struct ext2_gd * old,struct ext2_gd * new,int size)928 void e2fs_cg_bswap(struct ext2_gd *old, struct ext2_gd *new, int size)
929 {
930 int i;
931
932 for (i = 0; i < (size / sizeof(struct ext2_gd)); i++) {
933 new[i].ext2bgd_b_bitmap = bswap32(old[i].ext2bgd_b_bitmap);
934 new[i].ext2bgd_i_bitmap = bswap32(old[i].ext2bgd_i_bitmap);
935 new[i].ext2bgd_i_tables = bswap32(old[i].ext2bgd_i_tables);
936 new[i].ext2bgd_nbfree = bswap16(old[i].ext2bgd_nbfree);
937 new[i].ext2bgd_nifree = bswap16(old[i].ext2bgd_nifree);
938 new[i].ext2bgd_ndirs = bswap16(old[i].ext2bgd_ndirs);
939 }
940 }
941
e2fs_i_bswap(struct ext2fs_dinode * old,struct ext2fs_dinode * new)942 void e2fs_i_bswap(struct ext2fs_dinode *old, struct ext2fs_dinode *new)
943 {
944
945 new->e2di_mode = bswap16(old->e2di_mode);
946 new->e2di_uid = bswap16(old->e2di_uid);
947 new->e2di_gid = bswap16(old->e2di_gid);
948 new->e2di_nlink = bswap16(old->e2di_nlink);
949 new->e2di_size = bswap32(old->e2di_size);
950 new->e2di_atime = bswap32(old->e2di_atime);
951 new->e2di_ctime = bswap32(old->e2di_ctime);
952 new->e2di_mtime = bswap32(old->e2di_mtime);
953 new->e2di_dtime = bswap32(old->e2di_dtime);
954 new->e2di_nblock = bswap32(old->e2di_nblock);
955 new->e2di_flags = bswap32(old->e2di_flags);
956 new->e2di_gen = bswap32(old->e2di_gen);
957 new->e2di_facl = bswap32(old->e2di_facl);
958 new->e2di_dacl = bswap32(old->e2di_dacl);
959 new->e2di_faddr = bswap32(old->e2di_faddr);
960 memcpy(&new->e2di_blocks[0], &old->e2di_blocks[0],
961 (EXT2FS_NDADDR + EXT2FS_NIADDR) * sizeof(uint32_t));
962 }
963 #endif
964
965 #ifdef EXT2FS_DEBUG
966 void
dump_sblock(struct m_ext2fs * fs)967 dump_sblock(struct m_ext2fs *fs)
968 {
969
970 printf("fs->e2fs.e2fs_bcount = %u\n", fs->e2fs.e2fs_bcount);
971 printf("fs->e2fs.e2fs_first_dblock = %u\n", fs->e2fs.e2fs_first_dblock);
972 printf("fs->e2fs.e2fs_log_bsize = %u\n", fs->e2fs.e2fs_log_bsize);
973 printf("fs->e2fs.e2fs_bpg = %u\n", fs->e2fs.e2fs_bpg);
974 printf("fs->e2fs.e2fs_ipg = %u\n", fs->e2fs.e2fs_ipg);
975 printf("fs->e2fs.e2fs_magic = 0x%x\n", fs->e2fs.e2fs_magic);
976 printf("fs->e2fs.e2fs_rev = %u\n", fs->e2fs.e2fs_rev);
977
978 if (fs->e2fs.e2fs_rev == E2FS_REV1) {
979 printf("fs->e2fs.e2fs_first_ino = %u\n",
980 fs->e2fs.e2fs_first_ino);
981 printf("fs->e2fs.e2fs_inode_size = %u\n",
982 fs->e2fs.e2fs_inode_size);
983 printf("fs->e2fs.e2fs_features_compat = %u\n",
984 fs->e2fs.e2fs_features_compat);
985 printf("fs->e2fs.e2fs_features_incompat = %u\n",
986 fs->e2fs.e2fs_features_incompat);
987 printf("fs->e2fs.e2fs_features_rocompat = %u\n",
988 fs->e2fs.e2fs_features_rocompat);
989 printf("fs->e2fs.e2fs_reserved_ngdb = %u\n",
990 fs->e2fs.e2fs_reserved_ngdb);
991 }
992
993 printf("fs->e2fs_bsize = %u\n", fs->e2fs_bsize);
994 printf("fs->e2fs_fsbtodb = %u\n", fs->e2fs_fsbtodb);
995 printf("fs->e2fs_ncg = %u\n", fs->e2fs_ncg);
996 printf("fs->e2fs_ngdb = %u\n", fs->e2fs_ngdb);
997 printf("fs->e2fs_ipb = %u\n", fs->e2fs_ipb);
998 printf("fs->e2fs_itpg = %u\n", fs->e2fs_itpg);
999 }
1000 #endif
1001