xref: /openbmc/libpldm/src/dsp/bios_table.c (revision d8bb75cb)
1 /* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
2 #include "array.h"
3 
4 #include <libpldm/base.h>
5 #include <libpldm/bios.h>
6 #include <libpldm/bios_table.h>
7 #include <libpldm/utils.h>
8 
9 #include <assert.h>
10 #include <endian.h>
11 #include <limits.h>
12 #include <stdbool.h>
13 #include <stdint.h>
14 #include <stdlib.h>
15 #include <string.h>
16 
17 #define POINTER_CHECK(pointer)                                                 \
18 	do {                                                                   \
19 		if ((pointer) == NULL)                                         \
20 			return PLDM_ERROR_INVALID_DATA;                        \
21 	} while (0)
22 
23 #define ATTR_TYPE_EXPECT(type, expected)                                       \
24 	do {                                                                   \
25 		if ((type) != (expected) && (type) != ((expected) | 0x80))     \
26 			return PLDM_ERROR_INVALID_DATA;                        \
27 	} while (0)
28 
29 #define BUFFER_SIZE_EXPECT(current_size, expected_size)                        \
30 	do {                                                                   \
31 		if ((current_size) < (expected_size))                          \
32 			return PLDM_ERROR_INVALID_LENGTH;                      \
33 	} while (0)
34 
35 #define MEMBER_SIZE(type, member) sizeof(((struct type *)0)->member)
36 
37 static void set_errmsg(const char **errmsg, const char *msg)
38 {
39 	if (errmsg != NULL) {
40 		*errmsg = msg;
41 	}
42 }
43 
44 static int get_bios_string_handle(uint16_t *val)
45 {
46 	static uint16_t handle = 0;
47 	assert(handle != UINT16_MAX);
48 	if (handle == UINT16_MAX) {
49 		return PLDM_ERROR_INVALID_DATA;
50 	}
51 
52 	*val = handle++;
53 	return PLDM_SUCCESS;
54 }
55 
56 LIBPLDM_ABI_STABLE
57 size_t pldm_bios_table_string_entry_encode_length(uint16_t string_length)
58 {
59 	return sizeof(struct pldm_bios_string_table_entry) -
60 	       MEMBER_SIZE(pldm_bios_string_table_entry, name) + string_length;
61 }
62 
63 LIBPLDM_ABI_STABLE
64 int pldm_bios_table_string_entry_encode(void *entry, size_t entry_length,
65 					const char *str, uint16_t str_length)
66 {
67 	if (str_length == 0) {
68 		return PLDM_ERROR_INVALID_DATA;
69 	}
70 	POINTER_CHECK(entry);
71 	POINTER_CHECK(str);
72 	size_t length = pldm_bios_table_string_entry_encode_length(str_length);
73 	BUFFER_SIZE_EXPECT(entry_length, length);
74 	struct pldm_bios_string_table_entry *string_entry = entry;
75 	uint16_t handle;
76 	int rc = get_bios_string_handle(&handle);
77 	if (rc != PLDM_SUCCESS) {
78 		return rc;
79 	}
80 	string_entry->string_handle = htole16(handle);
81 	string_entry->string_length = htole16(str_length);
82 	memcpy(string_entry->name, str, str_length);
83 	return PLDM_SUCCESS;
84 }
85 
86 LIBPLDM_ABI_STABLE
87 uint16_t pldm_bios_table_string_entry_decode_handle(
88 	const struct pldm_bios_string_table_entry *entry)
89 {
90 	return le16toh(entry->string_handle);
91 }
92 
93 LIBPLDM_ABI_STABLE
94 uint16_t pldm_bios_table_string_entry_decode_string_length(
95 	const struct pldm_bios_string_table_entry *entry)
96 {
97 	return le16toh(entry->string_length);
98 }
99 
100 LIBPLDM_ABI_STABLE
101 int pldm_bios_table_string_entry_decode_string(
102 	const struct pldm_bios_string_table_entry *entry, char *buffer,
103 	size_t size)
104 {
105 	POINTER_CHECK(entry);
106 	POINTER_CHECK(buffer);
107 	if (size == 0) {
108 		return PLDM_ERROR_INVALID_LENGTH;
109 	}
110 	size_t length =
111 		pldm_bios_table_string_entry_decode_string_length(entry);
112 	length = length < (size - 1) ? length : (size - 1);
113 	memcpy(buffer, entry->name, length);
114 	buffer[length] = 0;
115 	return PLDM_SUCCESS;
116 }
117 
118 static ssize_t string_table_entry_length(const void *table_entry)
119 {
120 	const struct pldm_bios_string_table_entry *entry = table_entry;
121 	size_t len = sizeof(*entry) - sizeof(entry->name) +
122 		     pldm_bios_table_string_entry_decode_string_length(entry);
123 	if (len > SSIZE_MAX) {
124 		return -1;
125 	}
126 	return (ssize_t)len;
127 }
128 
129 static int get_bios_attr_handle(uint16_t *val)
130 {
131 	static uint16_t handle = 0;
132 	assert(handle != UINT16_MAX);
133 	if (handle == UINT16_MAX) {
134 		return PLDM_ERROR_INVALID_DATA;
135 	}
136 
137 	*val = handle++;
138 	return PLDM_SUCCESS;
139 }
140 
141 static int attr_table_entry_encode_header(void *entry, size_t length,
142 					  uint8_t attr_type,
143 					  uint16_t string_handle)
144 {
145 	struct pldm_bios_attr_table_entry *attr_entry = entry;
146 
147 	assert(sizeof(*attr_entry) <= length);
148 	if (sizeof(*attr_entry) > length) {
149 		return PLDM_ERROR_INVALID_LENGTH;
150 	}
151 
152 	uint16_t handle;
153 	int rc = get_bios_attr_handle(&handle);
154 	if (rc != PLDM_SUCCESS) {
155 		return rc;
156 	}
157 
158 	attr_entry->attr_handle = htole16(handle);
159 	attr_entry->attr_type = attr_type;
160 	attr_entry->string_handle = htole16(string_handle);
161 
162 	return PLDM_SUCCESS;
163 }
164 
165 LIBPLDM_ABI_STABLE
166 uint16_t pldm_bios_table_attr_entry_decode_attribute_handle(
167 	const struct pldm_bios_attr_table_entry *entry)
168 {
169 	return le16toh(entry->attr_handle);
170 }
171 
172 LIBPLDM_ABI_STABLE
173 uint8_t pldm_bios_table_attr_entry_decode_attribute_type(
174 	const struct pldm_bios_attr_table_entry *entry)
175 {
176 	return entry->attr_type;
177 }
178 
179 LIBPLDM_ABI_STABLE
180 uint16_t pldm_bios_table_attr_entry_decode_string_handle(
181 	const struct pldm_bios_attr_table_entry *entry)
182 {
183 	return le16toh(entry->string_handle);
184 }
185 
186 LIBPLDM_ABI_STABLE
187 size_t pldm_bios_table_attr_entry_enum_encode_length(uint8_t pv_num,
188 						     uint8_t def_num)
189 {
190 	return sizeof(struct pldm_bios_attr_table_entry) -
191 	       MEMBER_SIZE(pldm_bios_attr_table_entry, metadata) +
192 	       sizeof(pv_num) + pv_num * sizeof(uint16_t) + sizeof(def_num) +
193 	       def_num;
194 }
195 
196 LIBPLDM_ABI_STABLE
197 int pldm_bios_table_attr_entry_enum_encode(
198 	void *entry, size_t entry_length,
199 	const struct pldm_bios_table_attr_entry_enum_info *info)
200 {
201 	POINTER_CHECK(entry);
202 	POINTER_CHECK(info);
203 	size_t length = pldm_bios_table_attr_entry_enum_encode_length(
204 		info->pv_num, info->def_num);
205 	BUFFER_SIZE_EXPECT(entry_length, length);
206 	uint8_t attr_type = info->read_only ? PLDM_BIOS_ENUMERATION_READ_ONLY :
207 					      PLDM_BIOS_ENUMERATION;
208 	int rc = attr_table_entry_encode_header(entry, entry_length, attr_type,
209 						info->name_handle);
210 	if (rc != PLDM_SUCCESS) {
211 		return rc;
212 	}
213 	struct pldm_bios_attr_table_entry *attr_entry = entry;
214 	attr_entry->metadata[0] = info->pv_num;
215 	uint16_t *pv_hdls =
216 		(uint16_t *)(attr_entry->metadata + 1 /* sizeof(pv num) */);
217 	size_t i;
218 	for (i = 0; i < info->pv_num; i++) {
219 		pv_hdls[i] = htole16(info->pv_handle[i]);
220 	}
221 	attr_entry->metadata[1 + info->pv_num * sizeof(uint16_t)] =
222 		info->def_num;
223 	memcpy(attr_entry->metadata + 1 /* sizeof(pv num) */ +
224 		       info->pv_num * sizeof(uint16_t) + 1 /* sizeof(def num)*/,
225 	       info->def_index, info->def_num);
226 	return PLDM_SUCCESS;
227 }
228 
229 #define ATTR_TYPE_EXPECT(type, expected)                                       \
230 	do {                                                                   \
231 		if ((type) != (expected) && (type) != ((expected) | 0x80))     \
232 			return PLDM_ERROR_INVALID_DATA;                        \
233 	} while (0)
234 
235 LIBPLDM_ABI_STABLE
236 int pldm_bios_table_attr_entry_enum_decode_pv_num(
237 	const struct pldm_bios_attr_table_entry *entry, uint8_t *pv_num)
238 {
239 	POINTER_CHECK(entry);
240 	POINTER_CHECK(pv_num);
241 	ATTR_TYPE_EXPECT(entry->attr_type, PLDM_BIOS_ENUMERATION);
242 	*pv_num = entry->metadata[0];
243 	return PLDM_SUCCESS;
244 }
245 
246 LIBPLDM_ABI_STABLE
247 int pldm_bios_table_attr_entry_enum_decode_def_num(
248 	const struct pldm_bios_attr_table_entry *entry, uint8_t *def_num)
249 {
250 	uint8_t pv_num;
251 
252 	POINTER_CHECK(entry);
253 	POINTER_CHECK(def_num);
254 	ATTR_TYPE_EXPECT(entry->attr_type, PLDM_BIOS_ENUMERATION);
255 	pv_num = entry->metadata[0];
256 	*def_num = entry->metadata[sizeof(uint8_t) + sizeof(uint16_t) * pv_num];
257 	return PLDM_SUCCESS;
258 }
259 
260 LIBPLDM_ABI_STABLE
261 int pldm_bios_table_attr_entry_enum_decode_pv_hdls(
262 	const struct pldm_bios_attr_table_entry *entry, uint16_t *pv_hdls,
263 	uint8_t pv_num)
264 {
265 	POINTER_CHECK(entry);
266 	POINTER_CHECK(pv_hdls);
267 	ATTR_TYPE_EXPECT(entry->attr_type, PLDM_BIOS_ENUMERATION);
268 	uint8_t num = entry->metadata[0];
269 	num = num < pv_num ? num : pv_num;
270 	size_t i;
271 	for (i = 0; i < num; i++) {
272 		uint16_t *hdl = (uint16_t *)(entry->metadata + sizeof(uint8_t) +
273 					     i * sizeof(uint16_t));
274 		pv_hdls[i] = le16toh(*hdl);
275 	}
276 	return PLDM_SUCCESS;
277 }
278 
279 LIBPLDM_ABI_STABLE
280 uint8_t pldm_bios_table_attr_entry_enum_decode_def_indices(
281 	const struct pldm_bios_attr_table_entry *entry, uint8_t *def_indices,
282 	uint8_t def_num)
283 {
284 	uint8_t num = 0;
285 
286 	/* TODO: Fix the API to propagate errors */
287 	pldm_bios_table_attr_entry_enum_decode_def_num(entry, &num);
288 	num = num < def_num ? num : def_num;
289 	uint8_t pv_num = entry->metadata[0];
290 	const uint8_t *p = entry->metadata +
291 			   sizeof(uint8_t) /* number of possible values*/
292 			   + pv_num * sizeof(uint16_t) /* possible values */
293 			   + sizeof(uint8_t); /* number of default values */
294 	memcpy(def_indices, p, num);
295 	return num;
296 }
297 
298 /** @brief Get length of an enum attribute entry
299  */
300 static ssize_t attr_table_entry_length_enum(const void *arg)
301 {
302 	const struct pldm_bios_attr_table_entry *entry = arg;
303 	uint8_t pv_num = entry->metadata[0];
304 	uint8_t def_num = 0;
305 
306 	/* TODO: Fix the API to propagate errors */
307 	pldm_bios_table_attr_entry_enum_decode_def_num(entry, &def_num);
308 	size_t len =
309 		pldm_bios_table_attr_entry_enum_encode_length(pv_num, def_num);
310 	if (len > SSIZE_MAX) {
311 		return -1;
312 	}
313 	return (ssize_t)len;
314 }
315 
316 struct attr_table_string_entry_fields {
317 	uint8_t string_type;
318 	uint16_t min_length;
319 	uint16_t max_length;
320 	uint16_t def_length;
321 	uint8_t def_string[1];
322 } __attribute__((packed));
323 
324 LIBPLDM_ABI_STABLE
325 size_t pldm_bios_table_attr_entry_string_encode_length(uint16_t def_str_len)
326 {
327 	return sizeof(struct pldm_bios_attr_table_entry) -
328 	       MEMBER_SIZE(pldm_bios_attr_table_entry, metadata) +
329 	       sizeof(struct attr_table_string_entry_fields) -
330 	       MEMBER_SIZE(attr_table_string_entry_fields, def_string) +
331 	       def_str_len;
332 }
333 
334 #define PLDM_STRING_TYPE_MAX	5
335 #define PLDM_STRING_TYPE_VENDOR 0xff
336 
337 LIBPLDM_ABI_STABLE
338 int pldm_bios_table_attr_entry_string_info_check(
339 	const struct pldm_bios_table_attr_entry_string_info *info,
340 	const char **errmsg)
341 {
342 	if (info->min_length > info->max_length) {
343 		set_errmsg(errmsg, "MinimumStingLength should not be greater "
344 				   "than MaximumStringLength");
345 		return PLDM_ERROR_INVALID_DATA;
346 	}
347 	if (info->min_length == info->max_length &&
348 	    info->def_length != info->min_length) {
349 		set_errmsg(errmsg, "Wrong DefaultStringLength");
350 		return PLDM_ERROR_INVALID_DATA;
351 	}
352 	if (info->def_length > info->max_length ||
353 	    info->def_length < info->min_length) {
354 		set_errmsg(errmsg, "Wrong DefaultStringLength");
355 		return PLDM_ERROR_INVALID_DATA;
356 	}
357 	if (info->string_type > PLDM_STRING_TYPE_MAX &&
358 	    info->string_type != PLDM_STRING_TYPE_VENDOR) {
359 		set_errmsg(errmsg, "Wrong StringType");
360 		return PLDM_ERROR_INVALID_DATA;
361 	}
362 	if (info->def_string && info->def_length != strlen(info->def_string)) {
363 		set_errmsg(errmsg, "Length of DefaultString should be equal to "
364 				   "DefaultStringLength");
365 		return PLDM_ERROR_INVALID_DATA;
366 	}
367 
368 	return PLDM_SUCCESS;
369 }
370 
371 LIBPLDM_ABI_STABLE
372 int pldm_bios_table_attr_entry_string_encode(
373 	void *entry, size_t entry_length,
374 	const struct pldm_bios_table_attr_entry_string_info *info)
375 {
376 	POINTER_CHECK(entry);
377 	POINTER_CHECK(info);
378 	size_t length = pldm_bios_table_attr_entry_string_encode_length(
379 		info->def_length);
380 	BUFFER_SIZE_EXPECT(entry_length, length);
381 	if (pldm_bios_table_attr_entry_string_info_check(info, NULL) !=
382 	    PLDM_SUCCESS) {
383 		return PLDM_ERROR_INVALID_DATA;
384 	}
385 	uint8_t attr_type = info->read_only ? PLDM_BIOS_STRING_READ_ONLY :
386 					      PLDM_BIOS_STRING;
387 	int rc = attr_table_entry_encode_header(entry, entry_length, attr_type,
388 						info->name_handle);
389 	if (rc != PLDM_SUCCESS) {
390 		return rc;
391 	}
392 	struct pldm_bios_attr_table_entry *attr_entry = entry;
393 	struct attr_table_string_entry_fields *attr_fields =
394 		(struct attr_table_string_entry_fields *)attr_entry->metadata;
395 	attr_fields->string_type = info->string_type;
396 	attr_fields->min_length = htole16(info->min_length);
397 	attr_fields->max_length = htole16(info->max_length);
398 	attr_fields->def_length = htole16(info->def_length);
399 	if (info->def_length != 0 && info->def_string != NULL) {
400 		memcpy(attr_fields->def_string, info->def_string,
401 		       info->def_length);
402 	}
403 	return PLDM_SUCCESS;
404 }
405 
406 LIBPLDM_ABI_STABLE
407 int pldm_bios_table_attr_entry_string_decode_def_string_length(
408 	const struct pldm_bios_attr_table_entry *entry,
409 	uint16_t *def_string_length)
410 {
411 	POINTER_CHECK(entry);
412 	POINTER_CHECK(def_string_length);
413 	ATTR_TYPE_EXPECT(entry->attr_type, PLDM_BIOS_STRING);
414 	struct attr_table_string_entry_fields *fields =
415 		(struct attr_table_string_entry_fields *)entry->metadata;
416 	*def_string_length = le16toh(fields->def_length);
417 	return PLDM_SUCCESS;
418 }
419 
420 LIBPLDM_ABI_STABLE
421 uint8_t pldm_bios_table_attr_entry_string_decode_string_type(
422 	const struct pldm_bios_attr_table_entry *entry)
423 {
424 	struct attr_table_string_entry_fields *fields =
425 		(struct attr_table_string_entry_fields *)entry->metadata;
426 	return fields->string_type;
427 }
428 
429 LIBPLDM_ABI_STABLE
430 uint16_t pldm_bios_table_attr_entry_string_decode_max_length(
431 	const struct pldm_bios_attr_table_entry *entry)
432 {
433 	struct attr_table_string_entry_fields *fields =
434 		(struct attr_table_string_entry_fields *)entry->metadata;
435 	return le16toh(fields->max_length);
436 }
437 
438 LIBPLDM_ABI_STABLE
439 uint16_t pldm_bios_table_attr_entry_string_decode_min_length(
440 	const struct pldm_bios_attr_table_entry *entry)
441 {
442 	struct attr_table_string_entry_fields *fields =
443 		(struct attr_table_string_entry_fields *)entry->metadata;
444 	return le16toh(fields->min_length);
445 }
446 
447 LIBPLDM_ABI_STABLE
448 uint16_t pldm_bios_table_attr_entry_string_decode_def_string(
449 	const struct pldm_bios_attr_table_entry *entry, char *buffer,
450 	size_t size)
451 {
452 	uint16_t length = 0;
453 	int rc;
454 
455 	if (!entry || !buffer || size == 0) {
456 		return 0;
457 	}
458 
459 	/* TODO: Rework the API to propagate the error */
460 	rc = pldm_bios_table_attr_entry_string_decode_def_string_length(
461 		entry, &length);
462 	if (rc != PLDM_SUCCESS) {
463 		return 0;
464 	}
465 
466 	length = length < (size - 1) ? length : (size - 1);
467 	struct attr_table_string_entry_fields *fields =
468 		(struct attr_table_string_entry_fields *)entry->metadata;
469 	memcpy(buffer, fields->def_string, length);
470 	buffer[length] = 0;
471 	return length;
472 }
473 
474 /** @brief Get length of a string attribute entry
475  */
476 static ssize_t attr_table_entry_length_string(const void *entry)
477 {
478 	uint16_t def_str_len = 0;
479 
480 	/* TODO: Rework the API to propagate the error */
481 	pldm_bios_table_attr_entry_string_decode_def_string_length(
482 		entry, &def_str_len);
483 	size_t len =
484 		pldm_bios_table_attr_entry_string_encode_length(def_str_len);
485 	if (len > SSIZE_MAX) {
486 		return -1;
487 	}
488 	return (ssize_t)len;
489 }
490 
491 struct attr_table_integer_entry_fields {
492 	uint64_t lower_bound;
493 	uint64_t upper_bound;
494 	uint32_t scalar_increment;
495 	uint64_t default_value;
496 } __attribute__((packed));
497 
498 LIBPLDM_ABI_STABLE
499 size_t pldm_bios_table_attr_entry_integer_encode_length(void)
500 {
501 	return sizeof(struct pldm_bios_attr_table_entry) - 1 +
502 	       sizeof(struct attr_table_integer_entry_fields);
503 }
504 
505 LIBPLDM_ABI_STABLE
506 int pldm_bios_table_attr_entry_integer_info_check(
507 	const struct pldm_bios_table_attr_entry_integer_info *info,
508 	const char **errmsg)
509 {
510 	if (info->lower_bound == info->upper_bound) {
511 		if (info->default_value != info->lower_bound) {
512 			set_errmsg(errmsg, "Wrong DefaultValue");
513 			return PLDM_ERROR_INVALID_DATA;
514 		}
515 		if (info->scalar_increment != 0) {
516 			set_errmsg(errmsg, "Wrong ScalarIncrement");
517 			return PLDM_ERROR_INVALID_DATA;
518 		}
519 		return PLDM_SUCCESS;
520 	}
521 	if (info->lower_bound > info->upper_bound) {
522 		set_errmsg(errmsg,
523 			   "LowerBound should not be greater than UpperBound");
524 		return PLDM_ERROR_INVALID_DATA;
525 	}
526 	if (info->default_value > info->upper_bound ||
527 	    info->default_value < info->lower_bound) {
528 		set_errmsg(errmsg, "Wrong DefaultValue");
529 		return PLDM_ERROR_INVALID_DATA;
530 	}
531 	if (info->scalar_increment == 0) {
532 		set_errmsg(errmsg, "ScalarIncrement should not be zero when "
533 				   "lower_bound != upper_bound");
534 		return PLDM_ERROR_INVALID_DATA;
535 	}
536 	if ((info->default_value - info->lower_bound) %
537 		    info->scalar_increment !=
538 	    0) {
539 		set_errmsg(errmsg, "Wrong DefaultValue or ScalarIncrement");
540 		return PLDM_ERROR_INVALID_DATA;
541 	}
542 	return PLDM_SUCCESS;
543 }
544 
545 LIBPLDM_ABI_STABLE
546 int pldm_bios_table_attr_entry_integer_encode(
547 	void *entry, size_t entry_length,
548 	const struct pldm_bios_table_attr_entry_integer_info *info)
549 {
550 	POINTER_CHECK(entry);
551 	POINTER_CHECK(info);
552 	size_t length = pldm_bios_table_attr_entry_integer_encode_length();
553 	BUFFER_SIZE_EXPECT(entry_length, length);
554 	if (pldm_bios_table_attr_entry_integer_info_check(info, NULL) !=
555 	    PLDM_SUCCESS) {
556 		return PLDM_ERROR_INVALID_DATA;
557 	}
558 	uint8_t attr_type = info->read_only ? PLDM_BIOS_INTEGER_READ_ONLY :
559 					      PLDM_BIOS_INTEGER;
560 	int rc = attr_table_entry_encode_header(entry, entry_length, attr_type,
561 						info->name_handle);
562 	if (rc != PLDM_SUCCESS) {
563 		return rc;
564 	}
565 	struct pldm_bios_attr_table_entry *attr_entry = entry;
566 	struct attr_table_integer_entry_fields *attr_fields =
567 		(struct attr_table_integer_entry_fields *)attr_entry->metadata;
568 	attr_fields->lower_bound = htole64(info->lower_bound);
569 	attr_fields->upper_bound = htole64(info->upper_bound);
570 	attr_fields->scalar_increment = htole32(info->scalar_increment);
571 	attr_fields->default_value = htole64(info->default_value);
572 	return PLDM_SUCCESS;
573 }
574 
575 LIBPLDM_ABI_STABLE
576 void pldm_bios_table_attr_entry_integer_decode(
577 	const struct pldm_bios_attr_table_entry *entry, uint64_t *lower,
578 	uint64_t *upper, uint32_t *scalar, uint64_t *def)
579 {
580 	struct attr_table_integer_entry_fields *fields =
581 		(struct attr_table_integer_entry_fields *)entry->metadata;
582 	*lower = le64toh(fields->lower_bound);
583 	*upper = le64toh(fields->upper_bound);
584 	*scalar = le32toh(fields->scalar_increment);
585 	*def = le64toh(fields->default_value);
586 }
587 
588 static ssize_t attr_table_entry_length_integer(const void *entry)
589 {
590 	(void)entry;
591 	size_t len = pldm_bios_table_attr_entry_integer_encode_length();
592 	if (len > SSIZE_MAX) {
593 		return -1;
594 	}
595 	return (ssize_t)len;
596 }
597 
598 struct table_entry_length {
599 	uint8_t attr_type;
600 	ssize_t (*entry_length_handler)(const void *);
601 };
602 
603 static const struct table_entry_length *
604 find_table_entry_length_by_type(uint8_t attr_type,
605 				const struct table_entry_length *handlers,
606 				size_t count)
607 {
608 	size_t i;
609 	for (i = 0; i < count; i++) {
610 		if (attr_type == handlers[i].attr_type) {
611 			return &handlers[i];
612 		}
613 	}
614 	return NULL;
615 }
616 
617 static const struct table_entry_length attr_table_entries[] = {
618 	{ .attr_type = PLDM_BIOS_ENUMERATION,
619 	  .entry_length_handler = attr_table_entry_length_enum },
620 	{ .attr_type = PLDM_BIOS_ENUMERATION_READ_ONLY,
621 	  .entry_length_handler = attr_table_entry_length_enum },
622 	{ .attr_type = PLDM_BIOS_STRING,
623 	  .entry_length_handler = attr_table_entry_length_string },
624 	{ .attr_type = PLDM_BIOS_STRING_READ_ONLY,
625 	  .entry_length_handler = attr_table_entry_length_string },
626 	{ .attr_type = PLDM_BIOS_INTEGER,
627 	  .entry_length_handler = attr_table_entry_length_integer },
628 	{ .attr_type = PLDM_BIOS_INTEGER_READ_ONLY,
629 	  .entry_length_handler = attr_table_entry_length_integer },
630 };
631 
632 static ssize_t attr_table_entry_length(const void *table_entry)
633 {
634 	const struct pldm_bios_attr_table_entry *entry = table_entry;
635 	const struct table_entry_length *attr_table_entry =
636 		find_table_entry_length_by_type(entry->attr_type,
637 						attr_table_entries,
638 						ARRAY_SIZE(attr_table_entries));
639 	assert(attr_table_entry != NULL);
640 	if (!attr_table_entry) {
641 		return -1;
642 	}
643 	assert(attr_table_entry->entry_length_handler != NULL);
644 	if (!attr_table_entry->entry_length_handler) {
645 		return -1;
646 	}
647 
648 	return attr_table_entry->entry_length_handler(entry);
649 }
650 
651 LIBPLDM_ABI_STABLE
652 uint16_t pldm_bios_table_attr_value_entry_decode_attribute_handle(
653 	const struct pldm_bios_attr_val_table_entry *entry)
654 {
655 	return le16toh(entry->attr_handle);
656 }
657 
658 LIBPLDM_ABI_STABLE
659 uint8_t pldm_bios_table_attr_value_entry_decode_attribute_type(
660 	const struct pldm_bios_attr_val_table_entry *entry)
661 {
662 	return entry->attr_type;
663 }
664 
665 LIBPLDM_ABI_STABLE
666 size_t pldm_bios_table_attr_value_entry_encode_enum_length(uint8_t count)
667 {
668 	return sizeof(struct pldm_bios_attr_val_table_entry) - 1 +
669 	       sizeof(count) + count;
670 }
671 
672 LIBPLDM_ABI_STABLE
673 uint8_t pldm_bios_table_attr_value_entry_enum_decode_number(
674 	const struct pldm_bios_attr_val_table_entry *entry)
675 {
676 	return entry->value[0];
677 }
678 
679 LIBPLDM_ABI_STABLE
680 uint8_t pldm_bios_table_attr_value_entry_enum_decode_handles(
681 	const struct pldm_bios_attr_val_table_entry *entry, uint8_t *handles,
682 	uint8_t number)
683 {
684 	uint8_t curr_num =
685 		pldm_bios_table_attr_value_entry_enum_decode_number(entry);
686 	curr_num = number < curr_num ? number : curr_num;
687 	memcpy(handles, &entry->value[1], curr_num);
688 
689 	return curr_num;
690 }
691 
692 LIBPLDM_ABI_STABLE
693 int pldm_bios_table_attr_value_entry_encode_enum(
694 	void *entry, size_t entry_length, uint16_t attr_handle,
695 	uint8_t attr_type, uint8_t count, const uint8_t *handles)
696 {
697 	POINTER_CHECK(entry);
698 	POINTER_CHECK(handles);
699 	if (count != 0 && handles == NULL) {
700 		return PLDM_ERROR_INVALID_DATA;
701 	}
702 	ATTR_TYPE_EXPECT(attr_type, PLDM_BIOS_ENUMERATION);
703 	size_t length =
704 		pldm_bios_table_attr_value_entry_encode_enum_length(count);
705 	BUFFER_SIZE_EXPECT(entry_length, length);
706 	struct pldm_bios_attr_val_table_entry *table_entry = entry;
707 	table_entry->attr_handle = htole16(attr_handle);
708 	table_entry->attr_type = attr_type;
709 	table_entry->value[0] = count;
710 	if (count != 0) {
711 		memcpy(&table_entry->value[1], handles, count);
712 	}
713 	return PLDM_SUCCESS;
714 }
715 
716 static ssize_t attr_value_table_entry_length_enum(const void *entry)
717 {
718 	uint8_t number =
719 		pldm_bios_table_attr_value_entry_enum_decode_number(entry);
720 	size_t len =
721 		pldm_bios_table_attr_value_entry_encode_enum_length(number);
722 	if (len > SSIZE_MAX) {
723 		return -1;
724 	}
725 	return (ssize_t)len;
726 }
727 
728 LIBPLDM_ABI_STABLE
729 size_t
730 pldm_bios_table_attr_value_entry_encode_string_length(uint16_t string_length)
731 {
732 	return sizeof(struct pldm_bios_attr_val_table_entry) - 1 +
733 	       sizeof(string_length) + string_length;
734 }
735 
736 LIBPLDM_ABI_STABLE
737 uint16_t pldm_bios_table_attr_value_entry_string_decode_length(
738 	const struct pldm_bios_attr_val_table_entry *entry)
739 {
740 	uint16_t str_length = 0;
741 	memcpy(&str_length, entry->value, sizeof(str_length));
742 	return le16toh(str_length);
743 }
744 
745 LIBPLDM_ABI_STABLE
746 void pldm_bios_table_attr_value_entry_string_decode_string(
747 	const struct pldm_bios_attr_val_table_entry *entry,
748 	struct variable_field *current_string)
749 {
750 	current_string->length =
751 		pldm_bios_table_attr_value_entry_string_decode_length(entry);
752 	current_string->ptr =
753 		entry->value + sizeof(uint16_t); // sizeof(CurrentStringLength)
754 }
755 
756 LIBPLDM_ABI_STABLE
757 int pldm_bios_table_attr_value_entry_encode_string(
758 	void *entry, size_t entry_length, uint16_t attr_handle,
759 	uint8_t attr_type, uint16_t str_length, const char *str)
760 {
761 	POINTER_CHECK(entry);
762 	if (str_length != 0 && str == NULL) {
763 		return PLDM_ERROR_INVALID_DATA;
764 	}
765 	ATTR_TYPE_EXPECT(attr_type, PLDM_BIOS_STRING);
766 	size_t length = pldm_bios_table_attr_value_entry_encode_string_length(
767 		str_length);
768 	BUFFER_SIZE_EXPECT(entry_length, length);
769 	struct pldm_bios_attr_val_table_entry *table_entry = entry;
770 	table_entry->attr_handle = htole16(attr_handle);
771 	table_entry->attr_type = attr_type;
772 	if (str_length != 0) {
773 		memcpy(table_entry->value + sizeof(str_length), str,
774 		       str_length);
775 	}
776 	str_length = htole16(str_length);
777 	memcpy(table_entry->value, &str_length, sizeof(str_length));
778 	return PLDM_SUCCESS;
779 }
780 
781 static ssize_t attr_value_table_entry_length_string(const void *entry)
782 {
783 	uint16_t str_length =
784 		pldm_bios_table_attr_value_entry_string_decode_length(entry);
785 	size_t len = pldm_bios_table_attr_value_entry_encode_string_length(
786 		str_length);
787 	if (len > SSIZE_MAX) {
788 		return -1;
789 	}
790 	return (ssize_t)len;
791 }
792 
793 LIBPLDM_ABI_STABLE
794 size_t pldm_bios_table_attr_value_entry_encode_integer_length(void)
795 {
796 	return sizeof(struct pldm_bios_attr_val_table_entry) - 1 +
797 	       sizeof(uint64_t);
798 }
799 
800 LIBPLDM_ABI_STABLE
801 int pldm_bios_table_attr_value_entry_encode_integer(void *entry,
802 						    size_t entry_length,
803 						    uint16_t attr_handle,
804 						    uint8_t attr_type,
805 						    uint64_t cv)
806 {
807 	POINTER_CHECK(entry);
808 	size_t length =
809 		pldm_bios_table_attr_value_entry_encode_integer_length();
810 	ATTR_TYPE_EXPECT(attr_type, PLDM_BIOS_INTEGER);
811 	BUFFER_SIZE_EXPECT(entry_length, length);
812 	struct pldm_bios_attr_val_table_entry *table_entry = entry;
813 	table_entry->attr_handle = htole16(attr_handle);
814 	table_entry->attr_type = attr_type;
815 	cv = htole64(cv);
816 	memcpy(table_entry->value, &cv, sizeof(uint64_t));
817 	return PLDM_SUCCESS;
818 }
819 
820 LIBPLDM_ABI_STABLE
821 uint64_t pldm_bios_table_attr_value_entry_integer_decode_cv(
822 	const struct pldm_bios_attr_val_table_entry *entry)
823 {
824 	uint64_t cv = 0;
825 	memcpy(&cv, entry->value, sizeof(cv));
826 	cv = le64toh(cv);
827 	return cv;
828 }
829 
830 static ssize_t attr_value_table_entry_length_integer(const void *entry)
831 {
832 	(void)entry;
833 	size_t len = pldm_bios_table_attr_value_entry_encode_integer_length();
834 	if (len > SSIZE_MAX) {
835 		return -1;
836 	}
837 	return (ssize_t)len;
838 }
839 
840 static const struct table_entry_length attr_value_table_entries[] = {
841 	{ .attr_type = PLDM_BIOS_ENUMERATION,
842 	  .entry_length_handler = attr_value_table_entry_length_enum },
843 	{ .attr_type = PLDM_BIOS_ENUMERATION_READ_ONLY,
844 	  .entry_length_handler = attr_value_table_entry_length_enum },
845 	{ .attr_type = PLDM_BIOS_STRING,
846 	  .entry_length_handler = attr_value_table_entry_length_string },
847 	{ .attr_type = PLDM_BIOS_STRING_READ_ONLY,
848 	  .entry_length_handler = attr_value_table_entry_length_string },
849 	{ .attr_type = PLDM_BIOS_INTEGER,
850 	  .entry_length_handler = attr_value_table_entry_length_integer },
851 	{ .attr_type = PLDM_BIOS_INTEGER_READ_ONLY,
852 	  .entry_length_handler = attr_value_table_entry_length_integer },
853 };
854 
855 static ssize_t attr_value_table_entry_length(const void *table_entry)
856 {
857 	const struct pldm_bios_attr_val_table_entry *entry = table_entry;
858 	const struct table_entry_length *entry_length =
859 		find_table_entry_length_by_type(
860 			entry->attr_type, attr_value_table_entries,
861 			ARRAY_SIZE(attr_value_table_entries));
862 	assert(entry_length != NULL);
863 	if (!entry_length) {
864 		return -1;
865 	}
866 	assert(entry_length->entry_length_handler != NULL);
867 	if (!entry_length->entry_length_handler) {
868 		return -1;
869 	}
870 
871 	return entry_length->entry_length_handler(entry);
872 }
873 
874 LIBPLDM_ABI_STABLE
875 size_t pldm_bios_table_attr_value_entry_length(
876 	const struct pldm_bios_attr_val_table_entry *entry)
877 {
878 	return attr_value_table_entry_length(entry);
879 }
880 
881 LIBPLDM_ABI_STABLE
882 uint16_t pldm_bios_table_attr_value_entry_decode_handle(
883 	const struct pldm_bios_attr_val_table_entry *entry)
884 {
885 	return le16toh(entry->attr_handle);
886 }
887 
888 static size_t pad_size_get(size_t size_without_pad)
889 {
890 	return ((size_without_pad % 4) ? (4 - size_without_pad % 4) : 0);
891 }
892 
893 static uint8_t *pad_append(uint8_t *table_end, size_t pad_size)
894 {
895 	while (pad_size--) {
896 		*table_end++ = 0;
897 	}
898 
899 	return table_end;
900 }
901 
902 static uint8_t *checksum_append(uint8_t *table_end, uint32_t checksum)
903 {
904 	checksum = htole32(checksum);
905 	memcpy(table_end, &checksum, sizeof(checksum));
906 
907 	return table_end + sizeof(checksum);
908 }
909 
910 LIBPLDM_ABI_STABLE
911 size_t pldm_bios_table_pad_checksum_size(size_t size_without_pad)
912 {
913 	size_t size = pad_size_get(size_without_pad) +
914 		      sizeof(uint32_t) /*sizeof(checksum)*/;
915 	return size;
916 }
917 
918 LIBPLDM_ABI_STABLE
919 int pldm_bios_table_append_pad_checksum(void *table, size_t capacity,
920 					size_t *size)
921 {
922 	if (!table || !size) {
923 		return PLDM_ERROR_INVALID_DATA;
924 	}
925 
926 	size_t pad_checksum_size = pldm_bios_table_pad_checksum_size(*size);
927 	size_t total_length = *size + pad_checksum_size;
928 	if (capacity < total_length) {
929 		return PLDM_ERROR_INVALID_LENGTH;
930 	}
931 
932 	uint8_t *table_end = (uint8_t *)table + *size;
933 	size_t pad_size = pad_size_get(*size);
934 	table_end = pad_append(table_end, pad_size);
935 
936 	uint32_t checksum = crc32(table, *size + pad_size);
937 	checksum_append(table_end, checksum);
938 	*size = total_length;
939 
940 	return PLDM_SUCCESS;
941 }
942 
943 struct pldm_bios_table_iter {
944 	const uint8_t *table_data;
945 	size_t table_len;
946 	size_t current_pos;
947 	ssize_t (*entry_length_handler)(const void *table_entry);
948 };
949 
950 LIBPLDM_ABI_STABLE
951 struct pldm_bios_table_iter *
952 pldm_bios_table_iter_create(const void *table, size_t length,
953 			    enum pldm_bios_table_types type)
954 {
955 	struct pldm_bios_table_iter *iter = malloc(sizeof(*iter));
956 	assert(iter != NULL);
957 	if (!iter) {
958 		return NULL;
959 	}
960 	iter->table_data = table;
961 	iter->table_len = length;
962 	iter->current_pos = 0;
963 	iter->entry_length_handler = NULL;
964 	switch (type) {
965 	case PLDM_BIOS_STRING_TABLE:
966 		iter->entry_length_handler = string_table_entry_length;
967 		break;
968 	case PLDM_BIOS_ATTR_TABLE:
969 		iter->entry_length_handler = attr_table_entry_length;
970 		break;
971 	case PLDM_BIOS_ATTR_VAL_TABLE:
972 		iter->entry_length_handler = attr_value_table_entry_length;
973 		break;
974 	}
975 
976 	return iter;
977 }
978 
979 LIBPLDM_ABI_STABLE
980 void pldm_bios_table_iter_free(struct pldm_bios_table_iter *iter)
981 {
982 	free(iter);
983 }
984 
985 #define pad_and_check_max 7
986 LIBPLDM_ABI_STABLE
987 bool pldm_bios_table_iter_is_end(const struct pldm_bios_table_iter *iter)
988 {
989 	ssize_t len;
990 
991 	if (iter->table_len - iter->current_pos <= pad_and_check_max) {
992 		return true;
993 	}
994 
995 	len = iter->entry_length_handler(iter->table_data + iter->current_pos);
996 
997 	return len < 0;
998 }
999 
1000 LIBPLDM_ABI_STABLE
1001 void pldm_bios_table_iter_next(struct pldm_bios_table_iter *iter)
1002 {
1003 	if (pldm_bios_table_iter_is_end(iter)) {
1004 		return;
1005 	}
1006 	const void *entry = iter->table_data + iter->current_pos;
1007 	ssize_t rc = iter->entry_length_handler(entry);
1008 	/* Prevent bad behaviour by acting as if we've hit the end of the iterator */
1009 	if (rc < 0) {
1010 		return;
1011 	}
1012 	iter->current_pos += rc;
1013 }
1014 
1015 LIBPLDM_ABI_STABLE
1016 const void *pldm_bios_table_iter_value(struct pldm_bios_table_iter *iter)
1017 {
1018 	return iter->table_data + iter->current_pos;
1019 }
1020 
1021 typedef bool (*equal_handler)(const void *entry, const void *key);
1022 
1023 static const void *
1024 pldm_bios_table_entry_find_by_iter(struct pldm_bios_table_iter *iter,
1025 				   const void *key, equal_handler equal)
1026 {
1027 	const void *entry;
1028 	while (!pldm_bios_table_iter_is_end(iter)) {
1029 		entry = pldm_bios_table_iter_value(iter);
1030 		if (equal(entry, key)) {
1031 			return entry;
1032 		}
1033 		pldm_bios_table_iter_next(iter);
1034 	}
1035 	return NULL;
1036 }
1037 
1038 static const void *
1039 pldm_bios_table_entry_find_from_table(const void *table, size_t length,
1040 				      enum pldm_bios_table_types type,
1041 				      equal_handler equal, const void *key)
1042 {
1043 	struct pldm_bios_table_iter *iter =
1044 		pldm_bios_table_iter_create(table, length, type);
1045 	const void *entry =
1046 		pldm_bios_table_entry_find_by_iter(iter, key, equal);
1047 	pldm_bios_table_iter_free(iter);
1048 	return entry;
1049 }
1050 
1051 static bool string_table_handle_equal(const void *entry, const void *key)
1052 {
1053 	const struct pldm_bios_string_table_entry *string_entry = entry;
1054 	uint16_t handle = *(uint16_t *)key;
1055 	if (pldm_bios_table_string_entry_decode_handle(string_entry) ==
1056 	    handle) {
1057 		return true;
1058 	}
1059 	return false;
1060 }
1061 
1062 LIBPLDM_ABI_STABLE
1063 const struct pldm_bios_string_table_entry *
1064 pldm_bios_table_string_find_by_handle(const void *table, size_t length,
1065 				      uint16_t handle)
1066 {
1067 	return pldm_bios_table_entry_find_from_table(table, length,
1068 						     PLDM_BIOS_STRING_TABLE,
1069 						     string_table_handle_equal,
1070 						     &handle);
1071 }
1072 
1073 struct string_equal_arg {
1074 	uint16_t str_length;
1075 	const char *str;
1076 };
1077 
1078 static bool string_table_string_equal(const void *entry, const void *key)
1079 {
1080 	const struct pldm_bios_string_table_entry *string_entry = entry;
1081 	const struct string_equal_arg *arg = key;
1082 	if (arg->str_length !=
1083 	    pldm_bios_table_string_entry_decode_string_length(string_entry)) {
1084 		return false;
1085 	}
1086 	if (memcmp(string_entry->name, arg->str, arg->str_length) != 0) {
1087 		return false;
1088 	}
1089 	return true;
1090 }
1091 
1092 LIBPLDM_ABI_STABLE
1093 const struct pldm_bios_string_table_entry *
1094 pldm_bios_table_string_find_by_string(const void *table, size_t length,
1095 				      const char *str)
1096 {
1097 	uint16_t str_length = strlen(str);
1098 	struct string_equal_arg arg = { str_length, str };
1099 	return pldm_bios_table_entry_find_from_table(table, length,
1100 						     PLDM_BIOS_STRING_TABLE,
1101 						     string_table_string_equal,
1102 						     &arg);
1103 }
1104 
1105 static bool attr_table_handle_equal(const void *entry, const void *key)
1106 {
1107 	uint16_t handle = *(uint16_t *)key;
1108 	return pldm_bios_table_attr_entry_decode_attribute_handle(entry) ==
1109 	       handle;
1110 }
1111 
1112 LIBPLDM_ABI_STABLE
1113 const struct pldm_bios_attr_table_entry *
1114 pldm_bios_table_attr_find_by_handle(const void *table, size_t length,
1115 				    uint16_t handle)
1116 {
1117 	return pldm_bios_table_entry_find_from_table(table, length,
1118 						     PLDM_BIOS_ATTR_TABLE,
1119 						     attr_table_handle_equal,
1120 						     &handle);
1121 }
1122 
1123 static bool attr_table_string_handle_equal(const void *entry, const void *key)
1124 {
1125 	uint16_t handle = *(uint16_t *)key;
1126 	return pldm_bios_table_attr_entry_decode_string_handle(entry) == handle;
1127 }
1128 
1129 LIBPLDM_ABI_STABLE
1130 const struct pldm_bios_attr_table_entry *
1131 pldm_bios_table_attr_find_by_string_handle(const void *table, size_t length,
1132 					   uint16_t handle)
1133 {
1134 	return pldm_bios_table_entry_find_from_table(
1135 		table, length, PLDM_BIOS_ATTR_TABLE,
1136 		attr_table_string_handle_equal, &handle);
1137 }
1138 
1139 static bool attr_value_table_handle_equal(const void *entry, const void *key)
1140 {
1141 	uint16_t handle = *(uint16_t *)key;
1142 	return pldm_bios_table_attr_value_entry_decode_handle(entry) == handle;
1143 }
1144 
1145 LIBPLDM_ABI_STABLE
1146 const struct pldm_bios_attr_val_table_entry *
1147 pldm_bios_table_attr_value_find_by_handle(const void *table, size_t length,
1148 					  uint16_t handle)
1149 {
1150 	return pldm_bios_table_entry_find_from_table(
1151 		table, length, PLDM_BIOS_ATTR_VAL_TABLE,
1152 		attr_value_table_handle_equal, &handle);
1153 }
1154 
1155 LIBPLDM_ABI_STABLE
1156 int pldm_bios_table_attr_value_copy_and_update(
1157 	const void *src_table, size_t src_length, void *dest_table,
1158 	size_t *dest_length, const void *entry, size_t entry_length)
1159 {
1160 	struct pldm_bios_table_iter *iter = pldm_bios_table_iter_create(
1161 		src_table, src_length, PLDM_BIOS_ATTR_VAL_TABLE);
1162 
1163 	int rc = PLDM_SUCCESS;
1164 	const struct pldm_bios_attr_val_table_entry *tmp;
1165 	const struct pldm_bios_attr_val_table_entry *to_update = entry;
1166 	size_t buffer_length = *dest_length;
1167 	size_t copied_length = 0;
1168 	size_t length = 0;
1169 	while (!pldm_bios_table_iter_is_end(iter)) {
1170 		tmp = pldm_bios_table_iter_attr_value_entry_value(iter);
1171 		length = attr_value_table_entry_length(tmp);
1172 
1173 		/* we need the tmp's entry_length here, iter_next will calculate
1174 		 * it too, use current_pos directly to avoid calculating it
1175 		 * twice */
1176 		iter->current_pos += length;
1177 		if (tmp->attr_handle == to_update->attr_handle) {
1178 			if (tmp->attr_type != to_update->attr_type) {
1179 				rc = PLDM_ERROR_INVALID_DATA;
1180 				goto out;
1181 			}
1182 			length = entry_length;
1183 			tmp = entry;
1184 		}
1185 		if (copied_length + length > buffer_length) {
1186 			rc = PLDM_ERROR_INVALID_LENGTH;
1187 			goto out;
1188 		}
1189 		memcpy((uint8_t *)dest_table + copied_length, tmp, length);
1190 		copied_length += length;
1191 	}
1192 
1193 	size_t pad_checksum_size =
1194 		pldm_bios_table_pad_checksum_size(copied_length);
1195 	if ((pad_checksum_size + copied_length) > buffer_length) {
1196 		rc = PLDM_ERROR_INVALID_LENGTH;
1197 		goto out;
1198 	}
1199 
1200 	rc = pldm_bios_table_append_pad_checksum(dest_table, buffer_length,
1201 						 &copied_length);
1202 	if (rc == PLDM_SUCCESS) {
1203 		*dest_length = copied_length;
1204 	}
1205 out:
1206 	pldm_bios_table_iter_free(iter);
1207 	return rc;
1208 }
1209 
1210 LIBPLDM_ABI_STABLE
1211 bool pldm_bios_table_checksum(const uint8_t *table, size_t size)
1212 {
1213 	if (table == NULL) {
1214 		return false;
1215 	}
1216 
1217 	// 12: BIOSStringHandle(uint16) + BIOSStringLength(uint16) +
1218 	//     Variable(4) + checksum(uint32)
1219 	if (size < 12) {
1220 		return false;
1221 	}
1222 
1223 	uint32_t src_crc = le32toh(*(uint32_t *)(table + size - 4));
1224 	uint32_t dst_crc = crc32(table, size - 4);
1225 
1226 	return src_crc == dst_crc;
1227 }
1228