xref: /netbsd-src/usr.sbin/installboot/ffs.c (revision 001c68bd94f75ce9270b69227c4199fbf34ee396)
1 /*	$NetBSD: ffs.c,v 1.12 2003/05/30 09:22:50 dsl Exp $	*/
2 
3 /*-
4  * Copyright (c) 2002 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Matt Fredette.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the NetBSD
21  *	Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 #if defined(__RCSID) && !defined(__lint)
41 __RCSID("$NetBSD: ffs.c,v 1.12 2003/05/30 09:22:50 dsl Exp $");
42 #endif	/* !__lint */
43 
44 #include <sys/param.h>
45 #include <sys/mount.h>
46 
47 #include <assert.h>
48 #include <err.h>
49 #include <errno.h>
50 #include <fcntl.h>
51 #include <stdarg.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <unistd.h>
56 
57 #include "installboot.h"
58 
59 #undef DIRBLKSIZ
60 
61 #include <ufs/ufs/dinode.h>
62 #include <ufs/ufs/dir.h>
63 #include <ufs/ffs/fs.h>
64 #include <ufs/ffs/ffs_extern.h>
65 #include <ufs/ufs/ufs_bswap.h>
66 
67 static int	ffs_read_disk_block(ib_params *, uint64_t, int, char *);
68 static int	ffs_find_disk_blocks_ufs1(ib_params *, ino_t,
69 		    int (*)(ib_params *, void *, uint64_t, uint32_t), void *);
70 static int	ffs_find_disk_blocks_ufs2(ib_params *, ino_t,
71 		    int (*)(ib_params *, void *, uint64_t, uint32_t), void *);
72 static int	ffs_findstage2_ino(ib_params *, void *, uint64_t, uint32_t);
73 static int	ffs_findstage2_blocks(ib_params *, void *, uint64_t, uint32_t);
74 
75 static int is_ufs2;
76 
77 
78 /* This reads a disk block from the filesystem. */
79 static int
80 ffs_read_disk_block(ib_params *params, uint64_t blkno, int size, char *blk)
81 {
82 	int	rv;
83 
84 	assert(params != NULL);
85 	assert(blk != NULL);
86 	assert(params->filesystem != NULL);
87 	assert(params->fsfd != -1);
88 	assert(blkno >= 0);
89 	assert(size > 0);
90 	assert(blk != NULL);
91 
92 	rv = pread(params->fsfd, blk, size, blkno * DEV_BSIZE);
93 	if (rv == -1) {
94 		warn("Reading block %llu in `%s'",
95 		    (unsigned long long)blkno, params->filesystem);
96 		return (0);
97 	} else if (rv != size) {
98 		warnx("Reading block %llu in `%s': short read",
99 		    (unsigned long long)blkno, params->filesystem);
100 		return (0);
101 	}
102 
103 	return (1);
104 }
105 
106 /*
107  * This iterates over the data blocks belonging to an inode,
108  * making a callback each iteration with the disk block number
109  * and the size.
110  */
111 static int
112 ffs_find_disk_blocks_ufs1(ib_params *params, ino_t ino,
113 	int (*callback)(ib_params *, void *, uint64_t, uint32_t),
114 	void *state)
115 {
116 	char		sbbuf[SBLOCKSIZE];
117 	struct fs	*fs;
118 	char		inodebuf[MAXBSIZE];
119 	struct ufs1_dinode	*inode;
120 	int		level_i;
121 	int32_t	blk, lblk, nblk;
122 	int		rv;
123 #define LEVELS 4
124 	struct {
125 		int32_t		*blknums;
126 		unsigned long	blkcount;
127 		char		diskbuf[MAXBSIZE];
128 	} level[LEVELS];
129 
130 	assert(params != NULL);
131 	assert(params->fstype != NULL);
132 	assert(callback != NULL);
133 	assert(state != NULL);
134 
135 	/* Read the superblock. */
136 	if (!ffs_read_disk_block(params, params->fstype->sblockloc, SBLOCKSIZE,
137 	    sbbuf))
138 		return (0);
139 	fs = (struct fs *)sbbuf;
140 	if (params->fstype->needswap)
141 		ffs_sb_swap(fs, fs);
142 
143 	if (fs->fs_inopb <= 0) {
144 		warnx("Bad inopb %d in superblock in `%s'",
145 		    fs->fs_inopb, params->filesystem);
146 		return (0);
147 	}
148 
149 	/* Read the inode. */
150 	if (! ffs_read_disk_block(params, fsbtodb(fs, ino_to_fsba(fs, ino)),
151 		fs->fs_bsize, inodebuf))
152 		return (0);
153 	inode = (struct ufs1_dinode *)inodebuf;
154 	inode += ino_to_fsbo(fs, ino);
155 	if (params->fstype->needswap)
156 		ffs_dinode1_swap(inode, inode);
157 
158 	/* Get the block count and initialize for our block walk. */
159 	nblk = howmany(inode->di_size, fs->fs_bsize);
160 	lblk = 0;
161 	level_i = 0;
162 	level[0].blknums = &inode->di_db[0];
163 	level[0].blkcount = NDADDR;
164 	level[1].blknums = &inode->di_ib[0];
165 	level[1].blkcount = 1;
166 	level[2].blknums = &inode->di_ib[1];
167 	level[2].blkcount = 1;
168 	level[3].blknums = &inode->di_ib[2];
169 	level[3].blkcount = 1;
170 
171 	/* Walk the data blocks. */
172 	while (nblk > 0) {
173 
174 		/*
175 		 * If there are no more blocks at this indirection
176 		 * level, move up one indirection level and loop.
177 		 */
178 		if (level[level_i].blkcount == 0) {
179 			if (++level_i == LEVELS)
180 				break;
181 			continue;
182 		}
183 
184 		/* Get the next block at this level. */
185 		blk = *(level[level_i].blknums++);
186 		level[level_i].blkcount--;
187 		if (params->fstype->needswap)
188 			blk = bswap32(blk);
189 
190 #if 0
191 		fprintf(stderr, "ino %lu blk %lu level %d\n", ino, blk,
192 		    level_i);
193 #endif
194 
195 		/*
196 		 * If we're not at the direct level, descend one
197 		 * level, read in that level's new block list,
198 		 * and loop.
199 		 */
200 		if (level_i > 0) {
201 			level_i--;
202 			if (blk == 0)
203 				memset(level[level_i].diskbuf, 0, MAXBSIZE);
204 			else if (! ffs_read_disk_block(params,
205 				fsbtodb(fs, blk),
206 				fs->fs_bsize, level[level_i].diskbuf))
207 				return (0);
208 			/* XXX ondisk32 */
209 			level[level_i].blknums =
210 				(int32_t *)level[level_i].diskbuf;
211 			level[level_i].blkcount = NINDIR(fs);
212 			continue;
213 		}
214 
215 		/* blk is the next direct level block. */
216 #if 0
217 		fprintf(stderr, "ino %lu db %lu blksize %lu\n", ino,
218 		    fsbtodb(fs, blk), sblksize(fs, inode->di_size, lblk));
219 #endif
220 		rv = (*callback)(params, state,
221 		    fsbtodb(fs, blk), sblksize(fs, inode->di_size, lblk));
222 		lblk++;
223 		nblk--;
224 		if (rv != 1)
225 			return (rv);
226 	}
227 
228 	if (nblk != 0) {
229 		warnx("Inode %d in `%s' ran out of blocks?", ino,
230 		    params->filesystem);
231 		return (0);
232 	}
233 
234 	return (1);
235 }
236 
237 /*
238  * This iterates over the data blocks belonging to an inode,
239  * making a callback each iteration with the disk block number
240  * and the size.
241  */
242 static int
243 ffs_find_disk_blocks_ufs2(ib_params *params, ino_t ino,
244 	int (*callback)(ib_params *, void *, uint64_t, uint32_t),
245 	void *state)
246 {
247 	char		sbbuf[SBLOCKSIZE];
248 	struct fs	*fs;
249 	char		inodebuf[MAXBSIZE];
250 	struct ufs2_dinode	*inode;
251 	int		level_i;
252 	int64_t	blk, lblk, nblk;
253 	int		rv;
254 #define LEVELS 4
255 	struct {
256 		int64_t		*blknums;
257 		unsigned long	blkcount;
258 		char		diskbuf[MAXBSIZE];
259 	} level[LEVELS];
260 
261 	assert(params != NULL);
262 	assert(params->fstype != NULL);
263 	assert(callback != NULL);
264 	assert(state != NULL);
265 
266 	/* Read the superblock. */
267 	if (!ffs_read_disk_block(params, params->fstype->sblockloc, SBLOCKSIZE,
268 	    sbbuf))
269 		return (0);
270 	fs = (struct fs *)sbbuf;
271 	if (params->fstype->needswap)
272 		ffs_sb_swap(fs, fs);
273 
274 	if (fs->fs_inopb <= 0) {
275 		warnx("Bad inopb %d in superblock in `%s'",
276 		    fs->fs_inopb, params->filesystem);
277 		return (0);
278 	}
279 
280 	/* Read the inode. */
281 	if (! ffs_read_disk_block(params, fsbtodb(fs, ino_to_fsba(fs, ino)),
282 		fs->fs_bsize, inodebuf))
283 		return (0);
284 	inode = (struct ufs2_dinode *)inodebuf;
285 	inode += ino_to_fsbo(fs, ino);
286 	if (params->fstype->needswap)
287 		ffs_dinode2_swap(inode, inode);
288 
289 	/* Get the block count and initialize for our block walk. */
290 	nblk = howmany(inode->di_size, fs->fs_bsize);
291 	lblk = 0;
292 	level_i = 0;
293 	level[0].blknums = &inode->di_db[0];
294 	level[0].blkcount = NDADDR;
295 	level[1].blknums = &inode->di_ib[0];
296 	level[1].blkcount = 1;
297 	level[2].blknums = &inode->di_ib[1];
298 	level[2].blkcount = 1;
299 	level[3].blknums = &inode->di_ib[2];
300 	level[3].blkcount = 1;
301 
302 	/* Walk the data blocks. */
303 	while (nblk > 0) {
304 
305 		/*
306 		 * If there are no more blocks at this indirection
307 		 * level, move up one indirection level and loop.
308 		 */
309 		if (level[level_i].blkcount == 0) {
310 			if (++level_i == LEVELS)
311 				break;
312 			continue;
313 		}
314 
315 		/* Get the next block at this level. */
316 		blk = *(level[level_i].blknums++);
317 		level[level_i].blkcount--;
318 		if (params->fstype->needswap)
319 			blk = bswap64(blk);
320 
321 #if 0
322 		fprintf(stderr, "ino %lu blk %llu level %d\n", ino,
323 		    (unsigned long long)blk, level_i);
324 #endif
325 
326 		/*
327 		 * If we're not at the direct level, descend one
328 		 * level, read in that level's new block list,
329 		 * and loop.
330 		 */
331 		if (level_i > 0) {
332 			level_i--;
333 			if (blk == 0)
334 				memset(level[level_i].diskbuf, 0, MAXBSIZE);
335 			else if (! ffs_read_disk_block(params,
336 				fsbtodb(fs, blk),
337 				fs->fs_bsize, level[level_i].diskbuf))
338 				return (0);
339 			level[level_i].blknums =
340 				(int64_t *)level[level_i].diskbuf;
341 			level[level_i].blkcount = NINDIR(fs);
342 			continue;
343 		}
344 
345 		/* blk is the next direct level block. */
346 #if 0
347 		fprintf(stderr, "ino %lu db %llu blksize %lu\n", ino,
348 		    fsbtodb(fs, blk), sblksize(fs, inode->di_size, lblk));
349 #endif
350 		rv = (*callback)(params, state,
351 		    fsbtodb(fs, blk), sblksize(fs, inode->di_size, lblk));
352 		lblk++;
353 		nblk--;
354 		if (rv != 1)
355 			return (rv);
356 	}
357 
358 	if (nblk != 0) {
359 		warnx("Inode %d in `%s' ran out of blocks?", ino,
360 		    params->filesystem);
361 		return (0);
362 	}
363 
364 	return (1);
365 }
366 
367 /*
368  * This callback reads a block of the root directory,
369  * searches for an entry for the secondary bootstrap,
370  * and saves the inode number if one is found.
371  */
372 static int
373 ffs_findstage2_ino(ib_params *params, void *_ino,
374 	uint64_t blk, uint32_t blksize)
375 {
376 	char		dirbuf[MAXBSIZE];
377 	struct direct	*de, *ede;
378 	uint32_t	ino;
379 
380 	assert(params != NULL);
381 	assert(params->fstype != NULL);
382 	assert(params->stage2 != NULL);
383 	assert(_ino != NULL);
384 
385 	/* Skip directory holes. */
386 	if (blk == 0)
387 		return (1);
388 
389 	/* Read the directory block. */
390 	if (! ffs_read_disk_block(params, blk, blksize, dirbuf))
391 		return (0);
392 
393 	/* Loop over the directory entries. */
394 	de = (struct direct *)&dirbuf[0];
395 	ede = (struct direct *)&dirbuf[blksize];
396 	while (de < ede) {
397 		ino = de->d_ino;
398 		if (params->fstype->needswap) {
399 			ino = bswap32(ino);
400 			de->d_reclen = bswap16(de->d_reclen);
401 		}
402 		if (ino != 0 && strcmp(de->d_name, params->stage2) == 0) {
403 			*((uint32_t *)_ino) = ino;
404 			return (2);
405 		}
406 		if (de->d_reclen == 0)
407 			break;
408 		de = (struct direct *)((char *)de + de->d_reclen);
409 	}
410 
411 	return (1);
412 }
413 
414 struct findblks_state {
415 	uint32_t	maxblk;
416 	uint32_t	nblk;
417 	ib_block	*blocks;
418 };
419 
420 /* This callback records the blocks of the secondary bootstrap. */
421 static int
422 ffs_findstage2_blocks(ib_params *params, void *_state,
423 	uint64_t blk, uint32_t blksize)
424 {
425 	struct findblks_state *state = _state;
426 
427 	assert(params != NULL);
428 	assert(params->stage2 != NULL);
429 	assert(_state != NULL);
430 
431 	if (state->nblk == state->maxblk) {
432 		warnx("Secondary bootstrap `%s' has too many blocks (max %d)",
433 		    params->stage2, state->maxblk);
434 		return (0);
435 	}
436 	state->blocks[state->nblk].block = blk;
437 	state->blocks[state->nblk].blocksize = blksize;
438 	state->nblk++;
439 	return (1);
440 }
441 
442 /*
443  *	publically visible functions
444  */
445 
446 static off_t sblock_try[] = SBLOCKSEARCH;
447 
448 int
449 ffs_match(ib_params *params)
450 {
451 	char		sbbuf[SBLOCKSIZE];
452 	struct fs	*fs;
453 	int i;
454 	off_t loc;
455 
456 	assert(params != NULL);
457 	assert(params->fstype != NULL);
458 
459 	fs = (struct fs *)sbbuf;
460 	for (i = 0; sblock_try[i] != -1; i++) {
461 		loc = sblock_try[i] / DEV_BSIZE;
462 		if (!ffs_read_disk_block(params, loc, SBLOCKSIZE, sbbuf))
463 			continue;
464 		switch (fs->fs_magic) {
465 		case FS_UFS2_MAGIC:
466 			is_ufs2 = 1;
467 			/* FALLTHROUGH */
468 		case FS_UFS1_MAGIC:
469 			params->fstype->needswap = 0;
470 			params->fstype->blocksize = fs->fs_bsize;
471 			params->fstype->sblockloc = loc;
472 			return (1);
473 		case FS_UFS2_MAGIC_SWAPPED:
474 			is_ufs2 = 1;
475 			/* FALLTHROUGH */
476 		case FS_UFS1_MAGIC_SWAPPED:
477 			params->fstype->needswap = 1;
478 			params->fstype->blocksize = bswap32(fs->fs_bsize);
479 			params->fstype->sblockloc = loc;
480 			return (1);
481 		default:
482 			continue;
483 		}
484 	}
485 
486 	return (0);
487 }
488 
489 int
490 ffs_findstage2(ib_params *params, uint32_t *maxblk, ib_block *blocks)
491 {
492 	int			rv;
493 	uint32_t		ino;
494 	struct findblks_state	state;
495 
496 	assert(params != NULL);
497 	assert(params->stage2 != NULL);
498 	assert(maxblk != NULL);
499 	assert(blocks != NULL);
500 
501 	if (params->flags & IB_STAGE2START)
502 		return (hardcode_stage2(params, maxblk, blocks));
503 
504 	/* The secondary bootstrap must be clearly in /. */
505 	if (params->stage2[0] == '/')
506 		params->stage2++;
507 	if (strchr(params->stage2, '/') != NULL) {
508 		warnx("The secondary bootstrap `%s' must be in /",
509 		    params->stage2);
510 		return (0);
511 	}
512 
513 	/* Get the inode number of the secondary bootstrap. */
514 	if (is_ufs2)
515 		rv = ffs_find_disk_blocks_ufs2(params, ROOTINO,
516 		    ffs_findstage2_ino, &ino);
517 	else
518 		rv = ffs_find_disk_blocks_ufs1(params, ROOTINO,
519 		    ffs_findstage2_ino, &ino);
520 	if (rv != 2) {
521 		warnx("Could not find secondary bootstrap `%s' in `%s'",
522 		    params->stage2, params->filesystem);
523 		return (0);
524 	}
525 
526 	/* Record the disk blocks of the secondary bootstrap. */
527 	state.maxblk = *maxblk;
528 	state.nblk = 0;
529 	state.blocks = blocks;
530 	if (is_ufs2)
531 		rv = ffs_find_disk_blocks_ufs2(params, ino,
532 		    ffs_findstage2_blocks, &state);
533 	else
534 		rv = ffs_find_disk_blocks_ufs1(params, ino,
535 		    ffs_findstage2_blocks, &state);
536 	if (! rv) {
537 		return (0);
538 	}
539 
540 	*maxblk = state.nblk;
541 	return (1);
542 }
543