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1 /*
2  * htree.c --- hash tree routines
3  *
4  * Copyright (C) 2002 Theodore Ts'o.  This file may be redistributed
5  * under the terms of the GNU Public License.
6  */
7 
8 #include "config.h"
9 #include <stdio.h>
10 #include <unistd.h>
11 #include <stdlib.h>
12 #include <ctype.h>
13 #include <string.h>
14 #include <time.h>
15 #ifdef HAVE_ERRNO_H
16 #include <errno.h>
17 #endif
18 #include <sys/types.h>
19 #ifdef HAVE_GETOPT_H
20 #include <getopt.h>
21 #else
22 extern int optind;
23 extern char *optarg;
24 #endif
25 
26 #include "debugfs.h"
27 #include "uuid/uuid.h"
28 #include "e2p/e2p.h"
29 
30 static FILE *pager;
31 
htree_dump_leaf_node(ext2_filsys fs,ext2_ino_t ino,struct ext2_inode * inode,struct ext2_dx_root_info * rootnode,blk64_t blk,char * buf)32 static void htree_dump_leaf_node(ext2_filsys fs, ext2_ino_t ino,
33 				 struct ext2_inode *inode,
34 				 struct ext2_dx_root_info * rootnode,
35 				 blk64_t blk, char *buf)
36 {
37 	errcode_t	errcode;
38 	struct ext2_dir_entry *dirent;
39 	int		thislen, col = 0;
40 	unsigned int	offset = 0;
41 	char		name[EXT2_NAME_LEN + 1];
42 	char		tmp[EXT2_NAME_LEN + 64];
43 	blk64_t		pblk;
44 	ext2_dirhash_t 	hash, minor_hash;
45 	unsigned int	rec_len;
46 	int		hash_alg;
47 	int		hash_flags = inode->i_flags & EXT4_CASEFOLD_FL;
48 	int		csum_size = 0;
49 
50 	if (ext2fs_has_feature_metadata_csum(fs->super))
51 		csum_size = sizeof(struct ext2_dir_entry_tail);
52 
53 	errcode = ext2fs_bmap2(fs, ino, inode, buf, 0, blk, 0, &pblk);
54 	if (errcode) {
55 		com_err("htree_dump_leaf_node", errcode,
56 			"while mapping logical block %llu\n",
57 			(unsigned long long) blk);
58 		return;
59 	}
60 
61 	fprintf(pager, "Reading directory block %llu, phys %llu\n",
62 		(unsigned long long) blk, (unsigned long long) pblk);
63 	errcode = ext2fs_read_dir_block4(current_fs, pblk, buf, 0, ino);
64 	if (errcode) {
65 		com_err("htree_dump_leaf_node", errcode,
66 			"while reading block %llu (%llu)\n",
67 			(unsigned long long) blk, (unsigned long long) pblk);
68 		return;
69 	}
70 	hash_alg = rootnode->hash_version;
71 	if ((hash_alg <= EXT2_HASH_TEA) &&
72 	    (fs->super->s_flags & EXT2_FLAGS_UNSIGNED_HASH))
73 		hash_alg += 3;
74 
75 	while (offset < fs->blocksize) {
76 		dirent = (struct ext2_dir_entry *) (buf + offset);
77 		errcode = ext2fs_get_rec_len(fs, dirent, &rec_len);
78 		if (errcode) {
79 			com_err("htree_dump_leaf_inode", errcode,
80 				"while getting rec_len for block %lu",
81 				(unsigned long) blk);
82 			return;
83 		}
84 		thislen = ext2fs_dirent_name_len(dirent);
85 		if (((offset + rec_len) > fs->blocksize) ||
86 		    (rec_len < 8) ||
87 		    ((rec_len % 4) != 0) ||
88 		    ((unsigned) thislen + 8 > rec_len)) {
89 			fprintf(pager, "Corrupted directory block (%llu)!\n",
90 				(unsigned long long) blk);
91 			break;
92 		}
93 		strncpy(name, dirent->name, thislen);
94 		name[thislen] = '\0';
95 		errcode = ext2fs_dirhash2(hash_alg, name, thislen,
96 					  fs->encoding, hash_flags,
97 					  fs->super->s_hash_seed,
98 					  &hash, &minor_hash);
99 		if (errcode)
100 			com_err("htree_dump_leaf_node", errcode,
101 				"while calculating hash");
102 		if ((offset == fs->blocksize - csum_size) &&
103 		    (dirent->inode == 0) &&
104 		    (dirent->rec_len == csum_size) &&
105 		    (dirent->name_len == EXT2_DIR_NAME_LEN_CSUM)) {
106 			struct ext2_dir_entry_tail *t;
107 
108 			t = (struct ext2_dir_entry_tail *) dirent;
109 
110 			snprintf(tmp, EXT2_NAME_LEN + 64,
111 				 "leaf block checksum: 0x%08x  ",
112 				 t->det_checksum);
113 		} else {
114 			snprintf(tmp, EXT2_NAME_LEN + 64,
115 				 "%u 0x%08x-%08x (%d) %s   ",
116 				 dirent->inode, hash, minor_hash,
117 				 rec_len, name);
118 		}
119 		thislen = strlen(tmp);
120 		if (col + thislen > 80) {
121 			fprintf(pager, "\n");
122 			col = 0;
123 		}
124 		fprintf(pager, "%s", tmp);
125 		col += thislen;
126 		offset += rec_len;
127 	}
128 	fprintf(pager, "\n");
129 }
130 
131 
132 static void htree_dump_int_block(ext2_filsys fs, ext2_ino_t ino,
133 				 struct ext2_inode *inode,
134 				 struct ext2_dx_root_info * rootnode,
135 				 blk64_t blk, char *buf, int level);
136 
137 
htree_dump_int_node(ext2_filsys fs,ext2_ino_t ino,struct ext2_inode * inode,struct ext2_dx_root_info * rootnode,struct ext2_dx_entry * ent,__u32 crc,char * buf,int level)138 static void htree_dump_int_node(ext2_filsys fs, ext2_ino_t ino,
139 				struct ext2_inode *inode,
140 				struct ext2_dx_root_info * rootnode,
141 				struct ext2_dx_entry *ent, __u32 crc,
142 				char *buf, int level)
143 {
144 	struct ext2_dx_countlimit	dx_countlimit;
145 	struct ext2_dx_tail		*tail;
146 	int				hash, i;
147 	int				limit, count;
148 	int				remainder;
149 
150 	dx_countlimit = *((struct ext2_dx_countlimit *) ent);
151 	count = ext2fs_le16_to_cpu(dx_countlimit.count);
152 	limit = ext2fs_le16_to_cpu(dx_countlimit.limit);
153 
154 	fprintf(pager, "Number of entries (count): %d\n", count);
155 	fprintf(pager, "Number of entries (limit): %d\n", limit);
156 
157 	remainder = fs->blocksize - (limit * sizeof(struct ext2_dx_entry));
158 	if (ent == (struct ext2_dx_entry *)(rootnode + 1))
159 		remainder -= sizeof(struct ext2_dx_root_info) + 24;
160 	else
161 		remainder -= 8;
162 	if (ext2fs_has_feature_metadata_csum(fs->super) &&
163 	    remainder == sizeof(struct ext2_dx_tail)) {
164 		tail = (struct ext2_dx_tail *)(ent + limit);
165 		fprintf(pager, "Checksum: 0x%08x",
166 			ext2fs_le32_to_cpu(tail->dt_checksum));
167 		if (tail->dt_checksum != crc)
168 			fprintf(pager, " --- EXPECTED: 0x%08x", crc);
169 		fputc('\n', pager);
170 	}
171 
172 	for (i=0; i < count; i++) {
173 		hash = i ? ext2fs_le32_to_cpu(ent[i].hash) : 0;
174 		fprintf(pager, "Entry #%d: Hash 0x%08x%s, block %u\n", i,
175 			hash, (hash & 1) ? " (**)" : "",
176 			ext2fs_le32_to_cpu(ent[i].block));
177 		}
178 
179 	fprintf(pager, "\n");
180 
181 	for (i=0; i < count; i++) {
182 		unsigned int hashval, block;
183 
184 		hashval = ext2fs_le32_to_cpu(ent[i].hash);
185 		block = ext2fs_le32_to_cpu(ent[i].block);
186 		fprintf(pager, "Entry #%d: Hash 0x%08x, block %u\n", i,
187 		       i ? hashval : 0, block);
188 		if (level)
189 			htree_dump_int_block(fs, ino, inode, rootnode,
190 					     block, buf, level-1);
191 		else
192 			htree_dump_leaf_node(fs, ino, inode, rootnode,
193 					     block, buf);
194 	}
195 
196 	fprintf(pager, "---------------------\n");
197 }
198 
htree_dump_int_block(ext2_filsys fs,ext2_ino_t ino,struct ext2_inode * inode,struct ext2_dx_root_info * rootnode,blk64_t blk,char * buf,int level)199 static void htree_dump_int_block(ext2_filsys fs, ext2_ino_t ino,
200 				 struct ext2_inode *inode,
201 				 struct ext2_dx_root_info * rootnode,
202 				 blk64_t blk, char *buf, int level)
203 {
204 	char		*cbuf;
205 	errcode_t	errcode;
206 	blk64_t		pblk;
207 	__u32		crc;
208 
209 	cbuf = malloc(fs->blocksize);
210 	if (!cbuf) {
211 		fprintf(pager, "Couldn't allocate child block.\n");
212 		return;
213 	}
214 
215 	errcode = ext2fs_bmap2(fs, ino, inode, buf, 0, blk, 0, &pblk);
216 	if (errcode) {
217 		com_err("htree_dump_int_block", errcode,
218 			"while mapping logical block %llu\n",
219 			(unsigned long long) blk);
220 		goto errout;
221 	}
222 
223 	errcode = io_channel_read_blk64(current_fs->io, pblk, 1, buf);
224 	if (errcode) {
225 		com_err("htree_dump_int_block", errcode,
226 			"while reading block %llu\n",
227 			(unsigned long long) blk);
228 		goto errout;
229 	}
230 
231 	errcode = ext2fs_dx_csum(current_fs, ino,
232 				 (struct ext2_dir_entry *) buf, &crc, NULL);
233 	if (errcode) {
234 		com_err("htree_dump_int_block", errcode,
235 			"while calculating checksum for logical block %llu\n",
236 			(unsigned long long) blk);
237 		crc = (unsigned int) -1;
238 	}
239 	htree_dump_int_node(fs, ino, inode, rootnode,
240 			    (struct ext2_dx_entry *) (buf+8),
241 			    crc, cbuf, level);
242 errout:
243 	free(cbuf);
244 }
245 
246 
247 
do_htree_dump(int argc,char * argv[],int sci_idx EXT2FS_ATTR ((unused)),void * infop EXT2FS_ATTR ((unused)))248 void do_htree_dump(int argc, char *argv[], int sci_idx EXT2FS_ATTR((unused)),
249 		   void *infop EXT2FS_ATTR((unused)))
250 {
251 	ext2_ino_t	ino;
252 	struct ext2_inode inode;
253 	blk64_t		blk;
254 	char		*buf = NULL;
255 	struct 		ext2_dx_root_info  *rootnode;
256 	struct 		ext2_dx_entry *ent;
257 	errcode_t	errcode;
258 	__u32		crc;
259 
260 	if (check_fs_open(argv[0]))
261 		return;
262 
263 	pager = open_pager();
264 
265 	if (common_inode_args_process(argc, argv, &ino, 0))
266 		goto errout;
267 
268 	if (debugfs_read_inode(ino, &inode, argv[1]))
269 		goto errout;
270 
271 	if (!LINUX_S_ISDIR(inode.i_mode)) {
272 		com_err(argv[0], 0, "Not a directory");
273 		goto errout;
274 	}
275 
276 	if ((inode.i_flags & EXT2_BTREE_FL) == 0) {
277 		com_err(argv[0], 0, "Not a hash-indexed directory");
278 		goto errout;
279 	}
280 
281 	buf = malloc(2*current_fs->blocksize);
282 	if (!buf) {
283 		com_err(argv[0], 0, "Couldn't allocate htree buffer");
284 		goto errout;
285 	}
286 
287 	errcode = ext2fs_bmap2(current_fs, ino, &inode, buf, 0, 0, 0, &blk);
288 	if (errcode) {
289 		com_err("do_htree_block", errcode,
290 			"while mapping logical block 0\n");
291 		goto errout;
292 	}
293 
294 	errcode = io_channel_read_blk64(current_fs->io, blk,
295 					1, buf);
296 	if (errcode) {
297 		com_err(argv[0], errcode, "Error reading root node");
298 		goto errout;
299 	}
300 
301 	rootnode = (struct ext2_dx_root_info *) (buf + 24);
302 
303 	fprintf(pager, "Root node dump:\n");
304 	fprintf(pager, "\t Reserved zero: %u\n", rootnode->reserved_zero);
305 	fprintf(pager, "\t Hash Version: %d\n", rootnode->hash_version);
306 	fprintf(pager, "\t Info length: %d\n", rootnode->info_length);
307 	fprintf(pager, "\t Indirect levels: %d\n", rootnode->indirect_levels);
308 	fprintf(pager, "\t Flags: %#x\n", rootnode->unused_flags);
309 
310 	ent = (struct ext2_dx_entry *)
311 		((char *)rootnode + rootnode->info_length);
312 
313 	errcode = ext2fs_dx_csum(current_fs, ino,
314 				 (struct ext2_dir_entry *) buf, &crc, NULL);
315 	if (errcode) {
316 		com_err("htree_dump_int_block", errcode,
317 			"while calculating checksum for htree root\n");
318 		crc = (unsigned int) -1;
319 	}
320 	htree_dump_int_node(current_fs, ino, &inode, rootnode, ent, crc,
321 			    buf + current_fs->blocksize,
322 			    rootnode->indirect_levels);
323 
324 errout:
325 	free(buf);
326 	close_pager(pager);
327 }
328 
329 /*
330  * This function prints the hash of a given file.
331  */
do_dx_hash(int argc,char * argv[],int sci_idx EXT2FS_ATTR ((unused)),void * infop EXT2FS_ATTR ((unused)))332 void do_dx_hash(int argc, char *argv[], int sci_idx EXT2FS_ATTR((unused)),
333 		void *infop EXT2FS_ATTR((unused)))
334 {
335 	ext2_dirhash_t hash, minor_hash;
336 	errcode_t	err;
337 	int		c;
338 	int		hash_version = 0;
339 	__u32		hash_seed[4];
340 	int		hash_flags = 0;
341 	const struct ext2fs_nls_table *encoding = NULL;
342 
343 	hash_seed[0] = hash_seed[1] = hash_seed[2] = hash_seed[3] = 0;
344 
345 	reset_getopt();
346 	while ((c = getopt(argc, argv, "h:s:ce:")) != EOF) {
347 		switch (c) {
348 		case 'h':
349 			hash_version = e2p_string2hash(optarg);
350 			if (hash_version < 0)
351 				hash_version = atoi(optarg);
352 			break;
353 		case 's':
354 			if (uuid_parse(optarg, (unsigned char *) hash_seed)) {
355 				fprintf(stderr, "Invalid UUID format: %s\n",
356 					optarg);
357 				return;
358 			}
359 			break;
360 		case 'c':
361 			hash_flags |= EXT4_CASEFOLD_FL;
362 			break;
363 		case 'e':
364 			encoding = ext2fs_load_nls_table(e2p_str2encoding(optarg));
365 			if (!encoding) {
366 				fprintf(stderr, "Invalid encoding: %s\n",
367 					optarg);
368 				return;
369 			}
370 			break;
371 		default:
372 			goto print_usage;
373 		}
374 	}
375 	if (optind != argc-1) {
376 	print_usage:
377 		com_err(argv[0], 0, "usage: dx_hash [-h hash_alg] "
378 			"[-s hash_seed] [-c] [-e encoding] filename");
379 		return;
380 	}
381 	err = ext2fs_dirhash2(hash_version, argv[optind],
382 			      strlen(argv[optind]), encoding, hash_flags,
383 			      hash_seed, &hash, &minor_hash);
384 
385 	if (err) {
386 		com_err(argv[0], err, "while calculating hash");
387 		return;
388 	}
389 	printf("Hash of %s is 0x%0x (minor 0x%0x)\n", argv[optind],
390 	       hash, minor_hash);
391 }
392 
393 /*
394  * Search for particular directory entry (useful for debugging very
395  * large hash tree directories that have lost some blocks from the
396  * btree index).
397  */
398 struct process_block_struct {
399 	char	*search_name;
400 	char	*buf;
401 	int	len;
402 };
403 
404 static int search_dir_block(ext2_filsys fs, blk64_t *blocknr,
405 			    e2_blkcnt_t blockcnt, blk64_t ref_blk,
406 			    int ref_offset, void *priv_data);
407 
do_dirsearch(int argc,char * argv[],int sci_idx EXT2FS_ATTR ((unused)),void * infop EXT2FS_ATTR ((unused)))408 void do_dirsearch(int argc, char *argv[], int sci_idx EXT2FS_ATTR((unused)),
409 		  void *infop EXT2FS_ATTR((unused)))
410 {
411 	ext2_ino_t	inode;
412 	struct process_block_struct pb;
413 
414 	if (check_fs_open(argv[0]))
415 		return;
416 
417 	if (argc != 3) {
418 		com_err(0, 0, "Usage: dirsearch dir filename");
419 		return;
420 	}
421 
422 	inode = string_to_inode(argv[1]);
423 	if (!inode)
424 		return;
425 
426 	pb.buf = malloc(current_fs->blocksize);
427 	if (!pb.buf) {
428 		com_err("dirsearch", 0, "Couldn't allocate buffer");
429 		return;
430 	}
431 	pb.search_name = argv[2];
432 	pb.len = strlen(pb.search_name);
433 
434 	ext2fs_block_iterate3(current_fs, inode, BLOCK_FLAG_READ_ONLY, 0,
435 			      search_dir_block, &pb);
436 
437 	free(pb.buf);
438 }
439 
440 
search_dir_block(ext2_filsys fs,blk64_t * blocknr,e2_blkcnt_t blockcnt,blk64_t ref_blk EXT2FS_ATTR ((unused)),int ref_offset EXT2FS_ATTR ((unused)),void * priv_data)441 static int search_dir_block(ext2_filsys fs, blk64_t *blocknr,
442 			    e2_blkcnt_t blockcnt,
443 			    blk64_t ref_blk EXT2FS_ATTR((unused)),
444 			    int ref_offset EXT2FS_ATTR((unused)),
445 			    void *priv_data)
446 {
447 	struct process_block_struct *p;
448 	struct ext2_dir_entry *dirent;
449 	errcode_t	       	errcode;
450 	unsigned int		offset = 0;
451 	unsigned int		rec_len;
452 
453 	if (blockcnt < 0)
454 		return 0;
455 
456 	p = (struct process_block_struct *) priv_data;
457 
458 	errcode = io_channel_read_blk64(current_fs->io, *blocknr, 1, p->buf);
459 	if (errcode) {
460 		com_err("search_dir_block", errcode,
461 			"while reading block %lu", (unsigned long) *blocknr);
462 		return BLOCK_ABORT;
463 	}
464 
465 	while (offset < fs->blocksize) {
466 		dirent = (struct ext2_dir_entry *) (p->buf + offset);
467 		errcode = ext2fs_get_rec_len(fs, dirent, &rec_len);
468 		if (errcode) {
469 			com_err("htree_dump_leaf_inode", errcode,
470 				"while getting rec_len for block %lu",
471 				(unsigned long) *blocknr);
472 			return BLOCK_ABORT;
473 		}
474 		if (dirent->inode &&
475 		    p->len == ext2fs_dirent_name_len(dirent) &&
476 		    strncmp(p->search_name, dirent->name,
477 			    p->len) == 0) {
478 			printf("Entry found at logical block %lld, "
479 			       "phys %llu, offset %u\n", (long long)blockcnt,
480 			       (unsigned long long) *blocknr, offset);
481 			printf("offset %u\n", offset);
482 			return BLOCK_ABORT;
483 		}
484 		offset += rec_len;
485 	}
486 	return 0;
487 }
488 
489