summaryrefslogtreecommitdiff
path: root/fsck.c
blob: dd77628958c0cfa66c59f4c7c66277da0dc22b05 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
#include "cache.h"
#include "object.h"
#include "blob.h"
#include "tree.h"
#include "tree-walk.h"
#include "commit.h"
#include "tag.h"
#include "fsck.h"
 
static int fsck_walk_tree(struct tree *tree, fsck_walk_func walk, void *data)
{
	struct tree_desc desc;
	struct name_entry entry;
	int res = 0;
 
	if (parse_tree(tree))
		return -1;
 
	init_tree_desc(&desc, tree->buffer, tree->size);
	while (tree_entry(&desc, &entry)) {
		int result;
 
		if (S_ISGITLINK(entry.mode))
			continue;
		if (S_ISDIR(entry.mode))
			result = walk(&lookup_tree(entry.sha1)->object, OBJ_TREE, data);
		else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode))
			result = walk(&lookup_blob(entry.sha1)->object, OBJ_BLOB, data);
		else {
			result = error("in tree %s: entry %s has bad mode %.6o",
					sha1_to_hex(tree->object.sha1), entry.path, entry.mode);
		}
		if (result < 0)
			return result;
		if (!res)
			res = result;
	}
	return res;
}
 
static int fsck_walk_commit(struct commit *commit, fsck_walk_func walk, void *data)
{
	struct commit_list *parents;
	int res;
	int result;
 
	if (parse_commit(commit))
		return -1;
 
	result = walk((struct object *)commit->tree, OBJ_TREE, data);
	if (result < 0)
		return result;
	res = result;
 
	parents = commit->parents;
	while (parents) {
		result = walk((struct object *)parents->item, OBJ_COMMIT, data);
		if (result < 0)
			return result;
		if (!res)
			res = result;
		parents = parents->next;
	}
	return res;
}
 
static int fsck_walk_tag(struct tag *tag, fsck_walk_func walk, void *data)
{
	if (parse_tag(tag))
		return -1;
	return walk(tag->tagged, OBJ_ANY, data);
}
 
int fsck_walk(struct object *obj, fsck_walk_func walk, void *data)
{
	if (!obj)
		return -1;
	switch (obj->type) {
	case OBJ_BLOB:
		return 0;
	case OBJ_TREE:
		return fsck_walk_tree((struct tree *)obj, walk, data);
	case OBJ_COMMIT:
		return fsck_walk_commit((struct commit *)obj, walk, data);
	case OBJ_TAG:
		return fsck_walk_tag((struct tag *)obj, walk, data);
	default:
		error("Unknown object type for %s", sha1_to_hex(obj->sha1));
		return -1;
	}
}
 
/*
 * The entries in a tree are ordered in the _path_ order,
 * which means that a directory entry is ordered by adding
 * a slash to the end of it.
 *
 * So a directory called "a" is ordered _after_ a file
 * called "a.c", because "a/" sorts after "a.c".
 */
#define TREE_UNORDERED (-1)
#define TREE_HAS_DUPS  (-2)
 
static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
{
	int len1 = strlen(name1);
	int len2 = strlen(name2);
	int len = len1 < len2 ? len1 : len2;
	unsigned char c1, c2;
	int cmp;
 
	cmp = memcmp(name1, name2, len);
	if (cmp < 0)
		return 0;
	if (cmp > 0)
		return TREE_UNORDERED;
 
	/*
	 * Ok, the first <len> characters are the same.
	 * Now we need to order the next one, but turn
	 * a '\0' into a '/' for a directory entry.
	 */
	c1 = name1[len];
	c2 = name2[len];
	if (!c1 && !c2)
		/*
		 * git-write-tree used to write out a nonsense tree that has
		 * entries with the same name, one blob and one tree.  Make
		 * sure we do not have duplicate entries.
		 */
		return TREE_HAS_DUPS;
	if (!c1 && S_ISDIR(mode1))
		c1 = '/';
	if (!c2 && S_ISDIR(mode2))
		c2 = '/';
	return c1 < c2 ? 0 : TREE_UNORDERED;
}
 
static int fsck_tree(struct tree *item, int strict, fsck_error error_func)
{
	int retval;
	int has_null_sha1 = 0;
	int has_full_path = 0;
	int has_empty_name = 0;
	int has_dot = 0;
	int has_dotdot = 0;
	int has_dotgit = 0;
	int has_zero_pad = 0;
	int has_bad_modes = 0;
	int has_dup_entries = 0;
	int not_properly_sorted = 0;
	struct tree_desc desc;
	unsigned o_mode;
	const char *o_name;
 
	init_tree_desc(&desc, item->buffer, item->size);
 
	o_mode = 0;
	o_name = NULL;
 
	while (desc.size) {
		unsigned mode;
		const char *name;
		const unsigned char *sha1;
 
		sha1 = tree_entry_extract(&desc, &name, &mode);
 
		has_null_sha1 |= is_null_sha1(sha1);
		has_full_path |= !!strchr(name, '/');
		has_empty_name |= !*name;
		has_dot |= !strcmp(name, ".");
		has_dotdot |= !strcmp(name, "..");
		has_dotgit |= !strcmp(name, ".git");
		has_zero_pad |= *(char *)desc.buffer == '0';
		update_tree_entry(&desc);
 
		switch (mode) {
		/*
		 * Standard modes..
		 */
		case S_IFREG | 0755:
		case S_IFREG | 0644:
		case S_IFLNK:
		case S_IFDIR:
		case S_IFGITLINK:
			break;
		/*
		 * This is nonstandard, but we had a few of these
		 * early on when we honored the full set of mode
		 * bits..
		 */
		case S_IFREG | 0664:
			if (!strict)
				break;
		default:
			has_bad_modes = 1;
		}
 
		if (o_name) {
			switch (verify_ordered(o_mode, o_name, mode, name)) {
			case TREE_UNORDERED:
				not_properly_sorted = 1;
				break;
			case TREE_HAS_DUPS:
				has_dup_entries = 1;
				break;
			default:
				break;
			}
		}
 
		o_mode = mode;
		o_name = name;
	}
 
	retval = 0;
	if (has_null_sha1)
		retval += error_func(&item->object, FSCK_WARN, "contains entries pointing to null sha1");
	if (has_full_path)
		retval += error_func(&item->object, FSCK_WARN, "contains full pathnames");
	if (has_empty_name)
		retval += error_func(&item->object, FSCK_WARN, "contains empty pathname");
	if (has_dot)
		retval += error_func(&item->object, FSCK_WARN, "contains '.'");
	if (has_dotdot)
		retval += error_func(&item->object, FSCK_WARN, "contains '..'");
	if (has_dotgit)
		retval += error_func(&item->object, FSCK_WARN, "contains '.git'");
	if (has_zero_pad)
		retval += error_func(&item->object, FSCK_WARN, "contains zero-padded file modes");
	if (has_bad_modes)
		retval += error_func(&item->object, FSCK_WARN, "contains bad file modes");
	if (has_dup_entries)
		retval += error_func(&item->object, FSCK_ERROR, "contains duplicate file entries");
	if (not_properly_sorted)
		retval += error_func(&item->object, FSCK_ERROR, "not properly sorted");
	return retval;
}
 
static int fsck_ident(const char **ident, struct object *obj, fsck_error error_func)
{
	char *end;
 
	if (**ident == '<')
		return error_func(obj, FSCK_ERROR, "invalid author/committer line - missing space before email");
	*ident += strcspn(*ident, "<>\n");
	if (**ident == '>')
		return error_func(obj, FSCK_ERROR, "invalid author/committer line - bad name");
	if (**ident != '<')
		return error_func(obj, FSCK_ERROR, "invalid author/committer line - missing email");
	if ((*ident)[-1] != ' ')
		return error_func(obj, FSCK_ERROR, "invalid author/committer line - missing space before email");
	(*ident)++;
	*ident += strcspn(*ident, "<>\n");
	if (**ident != '>')
		return error_func(obj, FSCK_ERROR, "invalid author/committer line - bad email");
	(*ident)++;
	if (**ident != ' ')
		return error_func(obj, FSCK_ERROR, "invalid author/committer line - missing space before date");
	(*ident)++;
	if (**ident == '0' && (*ident)[1] != ' ')
		return error_func(obj, FSCK_ERROR, "invalid author/committer line - zero-padded date");
	if (date_overflows(strtoul(*ident, &end, 10)))
		return error_func(obj, FSCK_ERROR, "invalid author/committer line - date causes integer overflow");
	if (end == *ident || *end != ' ')
		return error_func(obj, FSCK_ERROR, "invalid author/committer line - bad date");
	*ident = end + 1;
	if ((**ident != '+' && **ident != '-') ||
	    !isdigit((*ident)[1]) ||
	    !isdigit((*ident)[2]) ||
	    !isdigit((*ident)[3]) ||
	    !isdigit((*ident)[4]) ||
	    ((*ident)[5] != '\n'))
		return error_func(obj, FSCK_ERROR, "invalid author/committer line - bad time zone");
	(*ident) += 6;
	return 0;
}
 
static int fsck_commit_buffer(struct commit *commit, const char *buffer,
	unsigned long size, fsck_error error_func)
{
	unsigned char tree_sha1[20], sha1[20];
	struct commit_graft *graft;
	unsigned parent_count, parent_line_count = 0;
	int err;
 
	if (!skip_prefix(buffer, "tree ", &buffer))
		return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'tree' line");
	if (get_sha1_hex(buffer, tree_sha1) || buffer[40] != '\n')
		return error_func(&commit->object, FSCK_ERROR, "invalid 'tree' line format - bad sha1");
	buffer += 41;
	while (skip_prefix(buffer, "parent ", &buffer)) {
		if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n')
			return error_func(&commit->object, FSCK_ERROR, "invalid 'parent' line format - bad sha1");
		buffer += 41;
		parent_line_count++;
	}
	graft = lookup_commit_graft(commit->object.sha1);
	parent_count = commit_list_count(commit->parents);
	if (graft) {
		if (graft->nr_parent == -1 && !parent_count)
			; /* shallow commit */
		else if (graft->nr_parent != parent_count)
			return error_func(&commit->object, FSCK_ERROR, "graft objects missing");
	} else {
		if (parent_count != parent_line_count)
			return error_func(&commit->object, FSCK_ERROR, "parent objects missing");
	}
	if (!skip_prefix(buffer, "author ", &buffer))
		return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'author' line");
	err = fsck_ident(&buffer, &commit->object, error_func);
	if (err)
		return err;
	if (!skip_prefix(buffer, "committer ", &buffer))
		return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'committer' line");
	err = fsck_ident(&buffer, &commit->object, error_func);
	if (err)
		return err;
	if (!commit->tree)
		return error_func(&commit->object, FSCK_ERROR, "could not load commit's tree %s", sha1_to_hex(tree_sha1));
 
	return 0;
}
 
static int fsck_commit(struct commit *commit, const char *data,
	unsigned long size, fsck_error error_func)
{
	const char *buffer = data ?  data : get_commit_buffer(commit, &size);
	int ret = fsck_commit_buffer(commit, buffer, size, error_func);
	if (!data)
		unuse_commit_buffer(commit, buffer);
	return ret;
}
 
static int fsck_tag(struct tag *tag, const char *data,
	unsigned long size, fsck_error error_func)
{
	struct object *tagged = tag->tagged;
 
	if (!tagged)
		return error_func(&tag->object, FSCK_ERROR, "could not load tagged object");
	return 0;
}
 
int fsck_object(struct object *obj, void *data, unsigned long size,
	int strict, fsck_error error_func)
{
	if (!obj)
		return error_func(obj, FSCK_ERROR, "no valid object to fsck");
 
	if (obj->type == OBJ_BLOB)
		return 0;
	if (obj->type == OBJ_TREE)
		return fsck_tree((struct tree *) obj, strict, error_func);
	if (obj->type == OBJ_COMMIT)
		return fsck_commit((struct commit *) obj, (const char *) data,
			size, error_func);
	if (obj->type == OBJ_TAG)
		return fsck_tag((struct tag *) obj, (const char *) data,
			size, error_func);
 
	return error_func(obj, FSCK_ERROR, "unknown type '%d' (internal fsck error)",
			  obj->type);
}
 
int fsck_error_function(struct object *obj, int type, const char *fmt, ...)
{
	va_list ap;
	struct strbuf sb = STRBUF_INIT;
 
	strbuf_addf(&sb, "object %s:", sha1_to_hex(obj->sha1));
 
	va_start(ap, fmt);
	strbuf_vaddf(&sb, fmt, ap);
	va_end(ap);
 
	error("%s", sb.buf);
	strbuf_release(&sb);
	return 1;
}