xref: /optee_os/core/tee/fs_dirfile.c (revision ba6d8df98e3cf376aab45d0d958204c498a94123)
1 /*
2  * Copyright (c) 2017, Linaro Limited
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright notice,
9  * this list of conditions and the following disclaimer.
10  *
11  * 2. Redistributions in binary form must reproduce the above copyright notice,
12  * this list of conditions and the following disclaimer in the documentation
13  * and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
19  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25  * POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <assert.h>
29 #include <bitstring.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <tee/fs_dirfile.h>
34 #include <types_ext.h>
35 
36 struct tee_fs_dirfile_dirh {
37 	const struct tee_fs_dirfile_operations *fops;
38 	struct tee_file_handle *fh;
39 	int nbits;
40 	bitstr_t *files;
41 	size_t ndents;
42 };
43 
44 struct dirfile_entry {
45 	TEE_UUID uuid;
46 	uint8_t oid[TEE_OBJECT_ID_MAX_LEN];
47 	uint32_t oidlen;
48 	uint8_t hash[TEE_FS_HTREE_HASH_SIZE];
49 	uint32_t file_number;
50 };
51 
52 /*
53  * File layout
54  *
55  * dirfile_entry.0
56  * ...
57  * dirfile_entry.n
58  *
59  * where n the index is disconnected from file_number in struct dirfile_entry
60  */
61 
62 static TEE_Result maybe_grow_files(struct tee_fs_dirfile_dirh *dirh, int idx)
63 {
64 	void *p;
65 
66 	if (idx < dirh->nbits)
67 		return TEE_SUCCESS;
68 
69 	p = realloc(dirh->files, bitstr_size(idx + 1));
70 	if (!p)
71 		return TEE_ERROR_OUT_OF_MEMORY;
72 	dirh->files = p;
73 
74 	bit_nclear(dirh->files, dirh->nbits, idx);
75 	dirh->nbits = idx + 1;
76 
77 	return TEE_SUCCESS;
78 }
79 
80 static TEE_Result set_file(struct tee_fs_dirfile_dirh *dirh, int idx)
81 {
82 	TEE_Result res = maybe_grow_files(dirh, idx);
83 
84 	if (!res)
85 		bit_set(dirh->files, idx);
86 
87 	return res;
88 }
89 
90 static void clear_file(struct tee_fs_dirfile_dirh *dirh, int idx)
91 {
92 	if (idx < dirh->nbits)
93 		bit_clear(dirh->files, idx);
94 }
95 
96 static bool test_file(struct tee_fs_dirfile_dirh *dirh, int idx)
97 {
98 	if (idx < dirh->nbits)
99 		return bit_test(dirh->files, idx);
100 
101 	return false;
102 }
103 
104 static TEE_Result read_dent(struct tee_fs_dirfile_dirh *dirh, int idx,
105 			    struct dirfile_entry *dent)
106 {
107 	TEE_Result res;
108 	size_t l;
109 
110 	l = sizeof(*dent);
111 	res = dirh->fops->read(dirh->fh, sizeof(struct dirfile_entry) * idx,
112 			       dent, &l);
113 	if (!res && l != sizeof(*dent))
114 		res = TEE_ERROR_ITEM_NOT_FOUND;
115 
116 	return res;
117 }
118 
119 static TEE_Result write_dent(struct tee_fs_dirfile_dirh *dirh, size_t n,
120 			     struct dirfile_entry *dent)
121 {
122 	TEE_Result res;
123 
124 	res = dirh->fops->write(dirh->fh, sizeof(*dent) * n,
125 				dent, sizeof(*dent));
126 	if (!res && n >= dirh->ndents)
127 		dirh->ndents = n + 1;
128 
129 	return res;
130 }
131 
132 TEE_Result tee_fs_dirfile_open(const struct tee_fs_dirfile_operations *fops,
133 			       struct tee_fs_dirfile_dirh **dirh_ret)
134 {
135 	TEE_Result res;
136 	struct tee_fs_dirfile_dirh *dirh = calloc(1, sizeof(*dirh));
137 	size_t n;
138 
139 	if (!dirh)
140 		return TEE_ERROR_OUT_OF_MEMORY;
141 
142 	dirh->fops = fops;
143 	res = fops->open(false, NULL, NULL, &dirh->fh);
144 	if (res) {
145 		res = fops->open(true, NULL, NULL, &dirh->fh);
146 		if (res)
147 			goto out;
148 	}
149 
150 	for (n = 0;; n++) {
151 		struct dirfile_entry dent;
152 
153 		res = read_dent(dirh, n, &dent);
154 		if (res) {
155 			if (res == TEE_ERROR_ITEM_NOT_FOUND)
156 				res = TEE_SUCCESS;
157 			goto out;
158 		}
159 
160 		if (!dent.oidlen)
161 			continue;
162 
163 		if (test_file(dirh, dent.file_number)) {
164 			DMSG("clearing duplicate file number %" PRIu32,
165 			     dent.file_number);
166 			memset(&dent, 0, sizeof(dent));
167 			res = write_dent(dirh, n, &dent);
168 			if (res)
169 				goto out;
170 			continue;
171 		}
172 
173 		res = set_file(dirh, dent.file_number);
174 		if (res != TEE_SUCCESS)
175 			goto out;
176 	}
177 out:
178 	if (!res) {
179 		dirh->ndents = n;
180 		*dirh_ret = dirh;
181 	} else {
182 		tee_fs_dirfile_close(dirh);
183 	}
184 	return res;
185 }
186 
187 void tee_fs_dirfile_close(struct tee_fs_dirfile_dirh *dirh)
188 {
189 	if (dirh) {
190 		dirh->fops->close(dirh->fh);
191 		free(dirh->files);
192 		free(dirh);
193 	}
194 }
195 
196 TEE_Result tee_fs_dirfile_commit_writes(struct tee_fs_dirfile_dirh *dirh)
197 {
198 	return dirh->fops->commit_writes(dirh->fh, NULL);
199 }
200 
201 TEE_Result tee_fs_dirfile_get_tmp(struct tee_fs_dirfile_dirh *dirh,
202 				  struct tee_fs_dirfile_fileh *dfh)
203 {
204 	TEE_Result res;
205 	int i = 0;
206 
207 	if (dirh->files) {
208 		bit_ffc(dirh->files, dirh->nbits, &i);
209 		if (i == -1)
210 			i = dirh->nbits;
211 	}
212 
213 	res = set_file(dirh, i);
214 	if (!res)
215 		dfh->file_number = i;
216 
217 	return res;
218 }
219 
220 TEE_Result tee_fs_dirfile_find(struct tee_fs_dirfile_dirh *dirh,
221 			       const TEE_UUID *uuid, const void *oid,
222 			       size_t oidlen, struct tee_fs_dirfile_fileh *dfh)
223 {
224 	TEE_Result res;
225 	struct dirfile_entry dent;
226 	int n;
227 	int first_free = -1;
228 
229 	for (n = 0;; n++) {
230 		res = read_dent(dirh, n, &dent);
231 		if (res == TEE_ERROR_ITEM_NOT_FOUND && !oidlen) {
232 			memset(&dent, 0, sizeof(dent));
233 			if (first_free != -1)
234 				n = first_free;
235 			break;
236 		}
237 		if (res)
238 			return res;
239 
240 		/* TODO check this loop when oidlen == 0 */
241 
242 		if (!dent.oidlen && first_free == -1)
243 			first_free = n;
244 		if (dent.oidlen != oidlen)
245 			continue;
246 
247 		assert(!oidlen || !dent.oidlen ||
248 		       test_file(dirh, dent.file_number));
249 
250 		if (!memcmp(&dent.uuid, uuid, sizeof(dent.uuid)) &&
251 		    !memcmp(&dent.oid, oid, oidlen))
252 			break;
253 	}
254 
255 	if (dfh) {
256 		dfh->idx = n;
257 		dfh->file_number = dent.file_number;
258 		memcpy(dfh->hash, dent.hash, sizeof(dent.hash));
259 	}
260 
261 	return TEE_SUCCESS;
262 }
263 
264 TEE_Result tee_fs_dirfile_fileh_to_fname(const struct tee_fs_dirfile_fileh *dfh,
265 					 char *fname, size_t *fnlen)
266 {
267 	int r;
268 	size_t l = *fnlen;
269 
270 	if (dfh)
271 		r = snprintf(fname, l, "%" PRIx32, dfh->file_number);
272 	else
273 		r = snprintf(fname, l, "dirf.db");
274 
275 	if (r < 0)
276 		return TEE_ERROR_GENERIC;
277 
278 	*fnlen = r + 1;
279 	if ((size_t)r >= l)
280 		return TEE_ERROR_SHORT_BUFFER;
281 
282 	return TEE_SUCCESS;
283 }
284 
285 TEE_Result tee_fs_dirfile_rename(struct tee_fs_dirfile_dirh *dirh,
286 				 const TEE_UUID *uuid,
287 				 struct tee_fs_dirfile_fileh *dfh,
288 				 const void *oid, size_t oidlen)
289 {
290 	TEE_Result res;
291 	struct dirfile_entry dent;
292 
293 	if (!oidlen || oidlen > sizeof(dent.oid))
294 		return TEE_ERROR_BAD_PARAMETERS;
295 	memset(&dent, 0, sizeof(dent));
296 	dent.uuid = *uuid;
297 	memcpy(dent.oid, oid, oidlen);
298 	dent.oidlen = oidlen;
299 	memcpy(dent.hash, dfh->hash, sizeof(dent.hash));
300 	dent.file_number = dfh->file_number;
301 
302 	if (dfh->idx < 0) {
303 		struct tee_fs_dirfile_fileh dfh2;
304 
305 		res = tee_fs_dirfile_find(dirh, uuid, oid, oidlen, &dfh2);
306 		if (res) {
307 			if (res == TEE_ERROR_ITEM_NOT_FOUND)
308 				res = tee_fs_dirfile_find(dirh, uuid, NULL, 0,
309 							  &dfh2);
310 			if (res)
311 				return res;
312 		}
313 		dfh->idx = dfh2.idx;
314 	}
315 
316 	return write_dent(dirh, dfh->idx, &dent);
317 }
318 
319 TEE_Result tee_fs_dirfile_remove(struct tee_fs_dirfile_dirh *dirh,
320 				 const struct tee_fs_dirfile_fileh *dfh)
321 {
322 	TEE_Result res;
323 	struct dirfile_entry dent;
324 	uint32_t file_number;
325 
326 	res = read_dent(dirh, dfh->idx, &dent);
327 	if (res)
328 		return res;
329 
330 	if (!dent.oidlen)
331 		return TEE_SUCCESS;
332 
333 	file_number = dent.file_number;
334 	assert(dfh->file_number == file_number);
335 	assert(test_file(dirh, file_number));
336 
337 	memset(&dent, 0, sizeof(dent));
338 	res = write_dent(dirh, dfh->idx, &dent);
339 	if (!res)
340 		clear_file(dirh, file_number);
341 
342 	return res;
343 }
344 
345 TEE_Result tee_fs_dirfile_update_hash(struct tee_fs_dirfile_dirh *dirh,
346 				      const struct tee_fs_dirfile_fileh *dfh)
347 {
348 	TEE_Result res;
349 	struct dirfile_entry dent;
350 
351 	res = read_dent(dirh, dfh->idx, &dent);
352 	if (res)
353 		return res;
354 	assert(dent.file_number == dfh->file_number);
355 	assert(test_file(dirh, dent.file_number));
356 
357 	memcpy(&dent.hash, dfh->hash, sizeof(dent.hash));
358 
359 	return write_dent(dirh, dfh->idx, &dent);
360 }
361 
362 TEE_Result tee_fs_dirfile_get_next(struct tee_fs_dirfile_dirh *dirh,
363 				   const TEE_UUID *uuid, int *idx, void *oid,
364 				   size_t *oidlen)
365 {
366 	TEE_Result res;
367 	int i = *idx + 1;
368 	struct dirfile_entry dent;
369 
370 	if (i < 0)
371 		i = 0;
372 
373 	for (;; i++) {
374 		res = read_dent(dirh, i, &dent);
375 		if (res)
376 			return res;
377 		if (!memcmp(&dent.uuid, uuid, sizeof(dent.uuid)) &&
378 		    dent.oidlen)
379 			break;
380 	}
381 
382 	if (*oidlen < dent.oidlen)
383 		return TEE_ERROR_SHORT_BUFFER;
384 
385 	memcpy(oid, dent.oid, dent.oidlen);
386 	*oidlen = dent.oidlen;
387 	*idx = i;
388 
389 	return TEE_SUCCESS;
390 }
391