xref: /openbmc/u-boot/tools/env/fw_env.c (revision ed4708aa)
1 /*
2  * (C) Copyright 2000-2010
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * (C) Copyright 2008
6  * Guennadi Liakhovetski, DENX Software Engineering, lg@denx.de.
7  *
8  * SPDX-License-Identifier:	GPL-2.0+
9  */
10 
11 #define _GNU_SOURCE
12 
13 #include <compiler.h>
14 #include <errno.h>
15 #include <env_flags.h>
16 #include <fcntl.h>
17 #include <linux/stringify.h>
18 #include <ctype.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <stddef.h>
22 #include <string.h>
23 #include <sys/types.h>
24 #include <sys/ioctl.h>
25 #include <sys/stat.h>
26 #include <unistd.h>
27 
28 #ifdef MTD_OLD
29 # include <stdint.h>
30 # include <linux/mtd/mtd.h>
31 #else
32 # define  __user	/* nothing */
33 # include <mtd/mtd-user.h>
34 #endif
35 
36 #include "fw_env.h"
37 
38 struct env_opts default_opts = {
39 #ifdef CONFIG_FILE
40 	.config_file = CONFIG_FILE
41 #endif
42 };
43 
44 #define DIV_ROUND_UP(n, d)	(((n) + (d) - 1) / (d))
45 
46 #define min(x, y) ({				\
47 	typeof(x) _min1 = (x);			\
48 	typeof(y) _min2 = (y);			\
49 	(void) (&_min1 == &_min2);		\
50 	_min1 < _min2 ? _min1 : _min2; })
51 
52 struct envdev_s {
53 	const char *devname;		/* Device name */
54 	ulong devoff;			/* Device offset */
55 	ulong env_size;			/* environment size */
56 	ulong erase_size;		/* device erase size */
57 	ulong env_sectors;		/* number of environment sectors */
58 	uint8_t mtd_type;		/* type of the MTD device */
59 };
60 
61 static struct envdev_s envdevices[2] =
62 {
63 	{
64 		.mtd_type = MTD_ABSENT,
65 	}, {
66 		.mtd_type = MTD_ABSENT,
67 	},
68 };
69 static int dev_current;
70 
71 #define DEVNAME(i)    envdevices[(i)].devname
72 #define DEVOFFSET(i)  envdevices[(i)].devoff
73 #define ENVSIZE(i)    envdevices[(i)].env_size
74 #define DEVESIZE(i)   envdevices[(i)].erase_size
75 #define ENVSECTORS(i) envdevices[(i)].env_sectors
76 #define DEVTYPE(i)    envdevices[(i)].mtd_type
77 
78 #define CUR_ENVSIZE ENVSIZE(dev_current)
79 
80 static unsigned long usable_envsize;
81 #define ENV_SIZE      usable_envsize
82 
83 struct env_image_single {
84 	uint32_t	crc;	/* CRC32 over data bytes    */
85 	char		data[];
86 };
87 
88 struct env_image_redundant {
89 	uint32_t	crc;	/* CRC32 over data bytes    */
90 	unsigned char	flags;	/* active or obsolete */
91 	char		data[];
92 };
93 
94 enum flag_scheme {
95 	FLAG_NONE,
96 	FLAG_BOOLEAN,
97 	FLAG_INCREMENTAL,
98 };
99 
100 struct environment {
101 	void			*image;
102 	uint32_t		*crc;
103 	unsigned char		*flags;
104 	char			*data;
105 	enum flag_scheme	flag_scheme;
106 };
107 
108 static struct environment environment = {
109 	.flag_scheme = FLAG_NONE,
110 };
111 
112 static int env_aes_cbc_crypt(char *data, const int enc, uint8_t *key);
113 
114 static int HaveRedundEnv = 0;
115 
116 static unsigned char active_flag = 1;
117 /* obsolete_flag must be 0 to efficiently set it on NOR flash without erasing */
118 static unsigned char obsolete_flag = 0;
119 
120 #define DEFAULT_ENV_INSTANCE_STATIC
121 #include <env_default.h>
122 
123 static int flash_io (int mode);
124 static char *envmatch (char * s1, char * s2);
125 static int parse_config(struct env_opts *opts);
126 
127 #if defined(CONFIG_FILE)
128 static int get_config (char *);
129 #endif
130 
131 static char *skip_chars(char *s)
132 {
133 	for (; *s != '\0'; s++) {
134 		if (isblank(*s))
135 			return s;
136 	}
137 	return NULL;
138 }
139 
140 static char *skip_blanks(char *s)
141 {
142 	for (; *s != '\0'; s++) {
143 		if (!isblank(*s))
144 			return s;
145 	}
146 	return NULL;
147 }
148 
149 /*
150  * Search the environment for a variable.
151  * Return the value, if found, or NULL, if not found.
152  */
153 char *fw_getenv (char *name)
154 {
155 	char *env, *nxt;
156 
157 	for (env = environment.data; *env; env = nxt + 1) {
158 		char *val;
159 
160 		for (nxt = env; *nxt; ++nxt) {
161 			if (nxt >= &environment.data[ENV_SIZE]) {
162 				fprintf (stderr, "## Error: "
163 					"environment not terminated\n");
164 				return NULL;
165 			}
166 		}
167 		val = envmatch (name, env);
168 		if (!val)
169 			continue;
170 		return val;
171 	}
172 	return NULL;
173 }
174 
175 /*
176  * Search the default environment for a variable.
177  * Return the value, if found, or NULL, if not found.
178  */
179 char *fw_getdefenv(char *name)
180 {
181 	char *env, *nxt;
182 
183 	for (env = default_environment; *env; env = nxt + 1) {
184 		char *val;
185 
186 		for (nxt = env; *nxt; ++nxt) {
187 			if (nxt >= &default_environment[ENV_SIZE]) {
188 				fprintf(stderr, "## Error: "
189 					"default environment not terminated\n");
190 				return NULL;
191 			}
192 		}
193 		val = envmatch(name, env);
194 		if (!val)
195 			continue;
196 		return val;
197 	}
198 	return NULL;
199 }
200 
201 int parse_aes_key(char *key, uint8_t *bin_key)
202 {
203 	char tmp[5] = { '0', 'x', 0, 0, 0 };
204 	unsigned long ul;
205 	int i;
206 
207 	if (strnlen(key, 64) != 32) {
208 		fprintf(stderr,
209 			"## Error: '-a' option requires 16-byte AES key\n");
210 		return -1;
211 	}
212 
213 	for (i = 0; i < 16; i++) {
214 		tmp[2] = key[0];
215 		tmp[3] = key[1];
216 		errno = 0;
217 		ul = strtoul(tmp, NULL, 16);
218 		if (errno) {
219 			fprintf(stderr,
220 				"## Error: '-a' option requires valid AES key\n");
221 			return -1;
222 		}
223 		bin_key[i] = ul & 0xff;
224 		key += 2;
225 	}
226 	return 0;
227 }
228 
229 /*
230  * Print the current definition of one, or more, or all
231  * environment variables
232  */
233 int fw_printenv(int argc, char *argv[], int value_only, struct env_opts *opts)
234 {
235 	char *env, *nxt;
236 	int i, rc = 0;
237 
238 	if (!opts)
239 		opts = &default_opts;
240 
241 	if (fw_env_open(opts))
242 		return -1;
243 
244 	if (argc == 0) {		/* Print all env variables  */
245 		for (env = environment.data; *env; env = nxt + 1) {
246 			for (nxt = env; *nxt; ++nxt) {
247 				if (nxt >= &environment.data[ENV_SIZE]) {
248 					fprintf (stderr, "## Error: "
249 						"environment not terminated\n");
250 					return -1;
251 				}
252 			}
253 
254 			printf ("%s\n", env);
255 		}
256 		return 0;
257 	}
258 
259 	if (value_only && argc != 1) {
260 		fprintf(stderr,
261 			"## Error: `-n' option requires exactly one argument\n");
262 		return -1;
263 	}
264 
265 	for (i = 0; i < argc; ++i) {	/* print single env variables   */
266 		char *name = argv[i];
267 		char *val = NULL;
268 
269 		for (env = environment.data; *env; env = nxt + 1) {
270 
271 			for (nxt = env; *nxt; ++nxt) {
272 				if (nxt >= &environment.data[ENV_SIZE]) {
273 					fprintf (stderr, "## Error: "
274 						"environment not terminated\n");
275 					return -1;
276 				}
277 			}
278 			val = envmatch (name, env);
279 			if (val) {
280 				if (!value_only) {
281 					fputs (name, stdout);
282 					putc ('=', stdout);
283 				}
284 				puts (val);
285 				break;
286 			}
287 		}
288 		if (!val) {
289 			fprintf (stderr, "## Error: \"%s\" not defined\n", name);
290 			rc = -1;
291 		}
292 	}
293 
294 	return rc;
295 }
296 
297 int fw_env_close(struct env_opts *opts)
298 {
299 	int ret;
300 
301 	if (!opts)
302 		opts = &default_opts;
303 
304 	if (opts->aes_flag) {
305 		ret = env_aes_cbc_crypt(environment.data, 1,
306 					opts->aes_key);
307 		if (ret) {
308 			fprintf(stderr,
309 				"Error: can't encrypt env for flash\n");
310 			return ret;
311 		}
312 	}
313 
314 	/*
315 	 * Update CRC
316 	 */
317 	*environment.crc = crc32(0, (uint8_t *) environment.data, ENV_SIZE);
318 
319 	/* write environment back to flash */
320 	if (flash_io(O_RDWR)) {
321 		fprintf(stderr,
322 			"Error: can't write fw_env to flash\n");
323 			return -1;
324 	}
325 
326 	return 0;
327 }
328 
329 
330 /*
331  * Set/Clear a single variable in the environment.
332  * This is called in sequence to update the environment
333  * in RAM without updating the copy in flash after each set
334  */
335 int fw_env_write(char *name, char *value)
336 {
337 	int len;
338 	char *env, *nxt;
339 	char *oldval = NULL;
340 	int deleting, creating, overwriting;
341 
342 	/*
343 	 * search if variable with this name already exists
344 	 */
345 	for (nxt = env = environment.data; *env; env = nxt + 1) {
346 		for (nxt = env; *nxt; ++nxt) {
347 			if (nxt >= &environment.data[ENV_SIZE]) {
348 				fprintf(stderr, "## Error: "
349 					"environment not terminated\n");
350 				errno = EINVAL;
351 				return -1;
352 			}
353 		}
354 		if ((oldval = envmatch (name, env)) != NULL)
355 			break;
356 	}
357 
358 	deleting = (oldval && !(value && strlen(value)));
359 	creating = (!oldval && (value && strlen(value)));
360 	overwriting = (oldval && (value && strlen(value)));
361 
362 	/* check for permission */
363 	if (deleting) {
364 		if (env_flags_validate_varaccess(name,
365 		    ENV_FLAGS_VARACCESS_PREVENT_DELETE)) {
366 			printf("Can't delete \"%s\"\n", name);
367 			errno = EROFS;
368 			return -1;
369 		}
370 	} else if (overwriting) {
371 		if (env_flags_validate_varaccess(name,
372 		    ENV_FLAGS_VARACCESS_PREVENT_OVERWR)) {
373 			printf("Can't overwrite \"%s\"\n", name);
374 			errno = EROFS;
375 			return -1;
376 		} else if (env_flags_validate_varaccess(name,
377 		    ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR)) {
378 			const char *defval = fw_getdefenv(name);
379 
380 			if (defval == NULL)
381 				defval = "";
382 			if (strcmp(oldval, defval)
383 			    != 0) {
384 				printf("Can't overwrite \"%s\"\n", name);
385 				errno = EROFS;
386 				return -1;
387 			}
388 		}
389 	} else if (creating) {
390 		if (env_flags_validate_varaccess(name,
391 		    ENV_FLAGS_VARACCESS_PREVENT_CREATE)) {
392 			printf("Can't create \"%s\"\n", name);
393 			errno = EROFS;
394 			return -1;
395 		}
396 	} else
397 		/* Nothing to do */
398 		return 0;
399 
400 	if (deleting || overwriting) {
401 		if (*++nxt == '\0') {
402 			*env = '\0';
403 		} else {
404 			for (;;) {
405 				*env = *nxt++;
406 				if ((*env == '\0') && (*nxt == '\0'))
407 					break;
408 				++env;
409 			}
410 		}
411 		*++env = '\0';
412 	}
413 
414 	/* Delete only ? */
415 	if (!value || !strlen(value))
416 		return 0;
417 
418 	/*
419 	 * Append new definition at the end
420 	 */
421 	for (env = environment.data; *env || *(env + 1); ++env);
422 	if (env > environment.data)
423 		++env;
424 	/*
425 	 * Overflow when:
426 	 * "name" + "=" + "val" +"\0\0"  > CUR_ENVSIZE - (env-environment)
427 	 */
428 	len = strlen (name) + 2;
429 	/* add '=' for first arg, ' ' for all others */
430 	len += strlen(value) + 1;
431 
432 	if (len > (&environment.data[ENV_SIZE] - env)) {
433 		fprintf (stderr,
434 			"Error: environment overflow, \"%s\" deleted\n",
435 			name);
436 		return -1;
437 	}
438 
439 	while ((*env = *name++) != '\0')
440 		env++;
441 	*env = '=';
442 	while ((*++env = *value++) != '\0')
443 		;
444 
445 	/* end is marked with double '\0' */
446 	*++env = '\0';
447 
448 	return 0;
449 }
450 
451 /*
452  * Deletes or sets environment variables. Returns -1 and sets errno error codes:
453  * 0	  - OK
454  * EINVAL - need at least 1 argument
455  * EROFS  - certain variables ("ethaddr", "serial#") cannot be
456  *	    modified or deleted
457  *
458  */
459 int fw_setenv(int argc, char *argv[], struct env_opts *opts)
460 {
461 	int i;
462 	size_t len;
463 	char *name, **valv;
464 	char *value = NULL;
465 	int valc;
466 
467 	if (!opts)
468 		opts = &default_opts;
469 
470 	if (argc < 1) {
471 		fprintf(stderr, "## Error: variable name missing\n");
472 		errno = EINVAL;
473 		return -1;
474 	}
475 
476 	if (fw_env_open(opts)) {
477 		fprintf(stderr, "Error: environment not initialized\n");
478 		return -1;
479 	}
480 
481 	name = argv[0];
482 	valv = argv + 1;
483 	valc = argc - 1;
484 
485 	if (env_flags_validate_env_set_params(name, valv, valc) < 0)
486 		return 1;
487 
488 	len = 0;
489 	for (i = 0; i < valc; ++i) {
490 		char *val = valv[i];
491 		size_t val_len = strlen(val);
492 
493 		if (value)
494 			value[len - 1] = ' ';
495 		value = realloc(value, len + val_len + 1);
496 		if (!value) {
497 			fprintf(stderr,
498 				"Cannot malloc %zu bytes: %s\n",
499 				len, strerror(errno));
500 			return -1;
501 		}
502 
503 		memcpy(value + len, val, val_len);
504 		len += val_len;
505 		value[len++] = '\0';
506 	}
507 
508 	fw_env_write(name, value);
509 
510 	free(value);
511 
512 	return fw_env_close(opts);
513 }
514 
515 /*
516  * Parse  a file  and configure the u-boot variables.
517  * The script file has a very simple format, as follows:
518  *
519  * Each line has a couple with name, value:
520  * <white spaces>variable_name<white spaces>variable_value
521  *
522  * Both variable_name and variable_value are interpreted as strings.
523  * Any character after <white spaces> and before ending \r\n is interpreted
524  * as variable's value (no comment allowed on these lines !)
525  *
526  * Comments are allowed if the first character in the line is #
527  *
528  * Returns -1 and sets errno error codes:
529  * 0	  - OK
530  * -1     - Error
531  */
532 int fw_parse_script(char *fname, struct env_opts *opts)
533 {
534 	FILE *fp;
535 	char dump[1024];	/* Maximum line length in the file */
536 	char *name;
537 	char *val;
538 	int lineno = 0;
539 	int len;
540 	int ret = 0;
541 
542 	if (!opts)
543 		opts = &default_opts;
544 
545 	if (fw_env_open(opts)) {
546 		fprintf(stderr, "Error: environment not initialized\n");
547 		return -1;
548 	}
549 
550 	if (strcmp(fname, "-") == 0)
551 		fp = stdin;
552 	else {
553 		fp = fopen(fname, "r");
554 		if (fp == NULL) {
555 			fprintf(stderr, "I cannot open %s for reading\n",
556 				 fname);
557 			return -1;
558 		}
559 	}
560 
561 	while (fgets(dump, sizeof(dump), fp)) {
562 		lineno++;
563 		len = strlen(dump);
564 
565 		/*
566 		 * Read a whole line from the file. If the line is too long
567 		 * or is not terminated, reports an error and exit.
568 		 */
569 		if (dump[len - 1] != '\n') {
570 			fprintf(stderr,
571 			"Line %d not corrected terminated or too long\n",
572 				lineno);
573 			ret = -1;
574 			break;
575 		}
576 
577 		/* Drop ending line feed / carriage return */
578 		dump[--len] = '\0';
579 		if (len && dump[len - 1] == '\r')
580 			dump[--len] = '\0';
581 
582 		/* Skip comment or empty lines */
583 		if (len == 0 || dump[0] == '#')
584 			continue;
585 
586 		/*
587 		 * Search for variable's name,
588 		 * remove leading whitespaces
589 		 */
590 		name = skip_blanks(dump);
591 		if (!name)
592 			continue;
593 
594 		/* The first white space is the end of variable name */
595 		val = skip_chars(name);
596 		len = strlen(name);
597 		if (val) {
598 			*val++ = '\0';
599 			if ((val - name) < len)
600 				val = skip_blanks(val);
601 			else
602 				val = NULL;
603 		}
604 
605 #ifdef DEBUG
606 		fprintf(stderr, "Setting %s : %s\n",
607 			name, val ? val : " removed");
608 #endif
609 
610 		if (env_flags_validate_type(name, val) < 0) {
611 			ret = -1;
612 			break;
613 		}
614 
615 		/*
616 		 * If there is an error setting a variable,
617 		 * try to save the environment and returns an error
618 		 */
619 		if (fw_env_write(name, val)) {
620 			fprintf(stderr,
621 			"fw_env_write returns with error : %s\n",
622 				strerror(errno));
623 			ret = -1;
624 			break;
625 		}
626 
627 	}
628 
629 	/* Close file if not stdin */
630 	if (strcmp(fname, "-") != 0)
631 		fclose(fp);
632 
633 	ret |= fw_env_close(opts);
634 
635 	return ret;
636 }
637 
638 /*
639  * Test for bad block on NAND, just returns 0 on NOR, on NAND:
640  * 0	- block is good
641  * > 0	- block is bad
642  * < 0	- failed to test
643  */
644 static int flash_bad_block (int fd, uint8_t mtd_type, loff_t *blockstart)
645 {
646 	if (mtd_type == MTD_NANDFLASH) {
647 		int badblock = ioctl (fd, MEMGETBADBLOCK, blockstart);
648 
649 		if (badblock < 0) {
650 			perror ("Cannot read bad block mark");
651 			return badblock;
652 		}
653 
654 		if (badblock) {
655 #ifdef DEBUG
656 			fprintf (stderr, "Bad block at 0x%llx, "
657 				 "skipping\n", *blockstart);
658 #endif
659 			return badblock;
660 		}
661 	}
662 
663 	return 0;
664 }
665 
666 /*
667  * Read data from flash at an offset into a provided buffer. On NAND it skips
668  * bad blocks but makes sure it stays within ENVSECTORS (dev) starting from
669  * the DEVOFFSET (dev) block. On NOR the loop is only run once.
670  */
671 static int flash_read_buf (int dev, int fd, void *buf, size_t count,
672 			   off_t offset, uint8_t mtd_type)
673 {
674 	size_t blocklen;	/* erase / write length - one block on NAND,
675 				   0 on NOR */
676 	size_t processed = 0;	/* progress counter */
677 	size_t readlen = count;	/* current read length */
678 	off_t top_of_range;	/* end of the last block we may use */
679 	off_t block_seek;	/* offset inside the current block to the start
680 				   of the data */
681 	loff_t blockstart;	/* running start of the current block -
682 				   MEMGETBADBLOCK needs 64 bits */
683 	int rc;
684 
685 	blockstart = (offset / DEVESIZE (dev)) * DEVESIZE (dev);
686 
687 	/* Offset inside a block */
688 	block_seek = offset - blockstart;
689 
690 	if (mtd_type == MTD_NANDFLASH) {
691 		/*
692 		 * NAND: calculate which blocks we are reading. We have
693 		 * to read one block at a time to skip bad blocks.
694 		 */
695 		blocklen = DEVESIZE (dev);
696 
697 		/*
698 		 * To calculate the top of the range, we have to use the
699 		 * global DEVOFFSET (dev), which can be different from offset
700 		 */
701 		top_of_range = ((DEVOFFSET(dev) / blocklen) +
702 				ENVSECTORS (dev)) * blocklen;
703 
704 		/* Limit to one block for the first read */
705 		if (readlen > blocklen - block_seek)
706 			readlen = blocklen - block_seek;
707 	} else {
708 		blocklen = 0;
709 		top_of_range = offset + count;
710 	}
711 
712 	/* This only runs once on NOR flash */
713 	while (processed < count) {
714 		rc = flash_bad_block (fd, mtd_type, &blockstart);
715 		if (rc < 0)		/* block test failed */
716 			return -1;
717 
718 		if (blockstart + block_seek + readlen > top_of_range) {
719 			/* End of range is reached */
720 			fprintf (stderr,
721 				 "Too few good blocks within range\n");
722 			return -1;
723 		}
724 
725 		if (rc) {		/* block is bad */
726 			blockstart += blocklen;
727 			continue;
728 		}
729 
730 		/*
731 		 * If a block is bad, we retry in the next block at the same
732 		 * offset - see common/env_nand.c::writeenv()
733 		 */
734 		lseek (fd, blockstart + block_seek, SEEK_SET);
735 
736 		rc = read (fd, buf + processed, readlen);
737 		if (rc != readlen) {
738 			fprintf (stderr, "Read error on %s: %s\n",
739 				 DEVNAME (dev), strerror (errno));
740 			return -1;
741 		}
742 #ifdef DEBUG
743 		fprintf(stderr, "Read 0x%x bytes at 0x%llx on %s\n",
744 			 rc, blockstart + block_seek, DEVNAME(dev));
745 #endif
746 		processed += readlen;
747 		readlen = min (blocklen, count - processed);
748 		block_seek = 0;
749 		blockstart += blocklen;
750 	}
751 
752 	return processed;
753 }
754 
755 /*
756  * Write count bytes at offset, but stay within ENVSECTORS (dev) sectors of
757  * DEVOFFSET (dev). Similar to the read case above, on NOR and dataflash we
758  * erase and write the whole data at once.
759  */
760 static int flash_write_buf (int dev, int fd, void *buf, size_t count,
761 			    off_t offset, uint8_t mtd_type)
762 {
763 	void *data;
764 	struct erase_info_user erase;
765 	size_t blocklen;	/* length of NAND block / NOR erase sector */
766 	size_t erase_len;	/* whole area that can be erased - may include
767 				   bad blocks */
768 	size_t erasesize;	/* erase / write length - one block on NAND,
769 				   whole area on NOR */
770 	size_t processed = 0;	/* progress counter */
771 	size_t write_total;	/* total size to actually write - excluding
772 				   bad blocks */
773 	off_t erase_offset;	/* offset to the first erase block (aligned)
774 				   below offset */
775 	off_t block_seek;	/* offset inside the erase block to the start
776 				   of the data */
777 	off_t top_of_range;	/* end of the last block we may use */
778 	loff_t blockstart;	/* running start of the current block -
779 				   MEMGETBADBLOCK needs 64 bits */
780 	int rc;
781 
782 	/*
783 	 * For mtd devices only offset and size of the environment do matter
784 	 */
785 	if (mtd_type == MTD_ABSENT) {
786 		blocklen = count;
787 		top_of_range = offset + count;
788 		erase_len = blocklen;
789 		blockstart = offset;
790 		block_seek = 0;
791 		write_total = blocklen;
792 	} else {
793 		blocklen = DEVESIZE(dev);
794 
795 		top_of_range = ((DEVOFFSET(dev) / blocklen) +
796 					ENVSECTORS(dev)) * blocklen;
797 
798 		erase_offset = (offset / blocklen) * blocklen;
799 
800 		/* Maximum area we may use */
801 		erase_len = top_of_range - erase_offset;
802 
803 		blockstart = erase_offset;
804 		/* Offset inside a block */
805 		block_seek = offset - erase_offset;
806 
807 		/*
808 		 * Data size we actually write: from the start of the block
809 		 * to the start of the data, then count bytes of data, and
810 		 * to the end of the block
811 		 */
812 		write_total = ((block_seek + count + blocklen - 1) /
813 							blocklen) * blocklen;
814 	}
815 
816 	/*
817 	 * Support data anywhere within erase sectors: read out the complete
818 	 * area to be erased, replace the environment image, write the whole
819 	 * block back again.
820 	 */
821 	if (write_total > count) {
822 		data = malloc (erase_len);
823 		if (!data) {
824 			fprintf (stderr,
825 				 "Cannot malloc %zu bytes: %s\n",
826 				 erase_len, strerror (errno));
827 			return -1;
828 		}
829 
830 		rc = flash_read_buf (dev, fd, data, write_total, erase_offset,
831 				     mtd_type);
832 		if (write_total != rc)
833 			return -1;
834 
835 #ifdef DEBUG
836 		fprintf(stderr, "Preserving data ");
837 		if (block_seek != 0)
838 			fprintf(stderr, "0x%x - 0x%lx", 0, block_seek - 1);
839 		if (block_seek + count != write_total) {
840 			if (block_seek != 0)
841 				fprintf(stderr, " and ");
842 			fprintf(stderr, "0x%lx - 0x%x",
843 				block_seek + count, write_total - 1);
844 		}
845 		fprintf(stderr, "\n");
846 #endif
847 		/* Overwrite the old environment */
848 		memcpy (data + block_seek, buf, count);
849 	} else {
850 		/*
851 		 * We get here, iff offset is block-aligned and count is a
852 		 * multiple of blocklen - see write_total calculation above
853 		 */
854 		data = buf;
855 	}
856 
857 	if (mtd_type == MTD_NANDFLASH) {
858 		/*
859 		 * NAND: calculate which blocks we are writing. We have
860 		 * to write one block at a time to skip bad blocks.
861 		 */
862 		erasesize = blocklen;
863 	} else {
864 		erasesize = erase_len;
865 	}
866 
867 	erase.length = erasesize;
868 
869 	/* This only runs once on NOR flash and SPI-dataflash */
870 	while (processed < write_total) {
871 		rc = flash_bad_block (fd, mtd_type, &blockstart);
872 		if (rc < 0)		/* block test failed */
873 			return rc;
874 
875 		if (blockstart + erasesize > top_of_range) {
876 			fprintf (stderr, "End of range reached, aborting\n");
877 			return -1;
878 		}
879 
880 		if (rc) {		/* block is bad */
881 			blockstart += blocklen;
882 			continue;
883 		}
884 
885 		if (mtd_type != MTD_ABSENT) {
886 			erase.start = blockstart;
887 			ioctl(fd, MEMUNLOCK, &erase);
888 			/* These do not need an explicit erase cycle */
889 			if (mtd_type != MTD_DATAFLASH)
890 				if (ioctl(fd, MEMERASE, &erase) != 0) {
891 					fprintf(stderr,
892 						"MTD erase error on %s: %s\n",
893 						DEVNAME(dev), strerror(errno));
894 					return -1;
895 				}
896 		}
897 
898 		if (lseek (fd, blockstart, SEEK_SET) == -1) {
899 			fprintf (stderr,
900 				 "Seek error on %s: %s\n",
901 				 DEVNAME (dev), strerror (errno));
902 			return -1;
903 		}
904 
905 #ifdef DEBUG
906 		fprintf(stderr, "Write 0x%x bytes at 0x%llx\n", erasesize,
907 			blockstart);
908 #endif
909 		if (write (fd, data + processed, erasesize) != erasesize) {
910 			fprintf (stderr, "Write error on %s: %s\n",
911 				 DEVNAME (dev), strerror (errno));
912 			return -1;
913 		}
914 
915 		if (mtd_type != MTD_ABSENT)
916 			ioctl(fd, MEMLOCK, &erase);
917 
918 		processed  += erasesize;
919 		block_seek = 0;
920 		blockstart += erasesize;
921 	}
922 
923 	if (write_total > count)
924 		free (data);
925 
926 	return processed;
927 }
928 
929 /*
930  * Set obsolete flag at offset - NOR flash only
931  */
932 static int flash_flag_obsolete (int dev, int fd, off_t offset)
933 {
934 	int rc;
935 	struct erase_info_user erase;
936 
937 	erase.start  = DEVOFFSET (dev);
938 	erase.length = DEVESIZE (dev);
939 	/* This relies on the fact, that obsolete_flag == 0 */
940 	rc = lseek (fd, offset, SEEK_SET);
941 	if (rc < 0) {
942 		fprintf (stderr, "Cannot seek to set the flag on %s \n",
943 			 DEVNAME (dev));
944 		return rc;
945 	}
946 	ioctl (fd, MEMUNLOCK, &erase);
947 	rc = write (fd, &obsolete_flag, sizeof (obsolete_flag));
948 	ioctl (fd, MEMLOCK, &erase);
949 	if (rc < 0)
950 		perror ("Could not set obsolete flag");
951 
952 	return rc;
953 }
954 
955 /* Encrypt or decrypt the environment before writing or reading it. */
956 static int env_aes_cbc_crypt(char *payload, const int enc, uint8_t *key)
957 {
958 	uint8_t *data = (uint8_t *)payload;
959 	const int len = usable_envsize;
960 	uint8_t key_exp[AES_EXPAND_KEY_LENGTH];
961 	uint32_t aes_blocks;
962 
963 	/* First we expand the key. */
964 	aes_expand_key(key, key_exp);
965 
966 	/* Calculate the number of AES blocks to encrypt. */
967 	aes_blocks = DIV_ROUND_UP(len, AES_KEY_LENGTH);
968 
969 	if (enc)
970 		aes_cbc_encrypt_blocks(key_exp, data, data, aes_blocks);
971 	else
972 		aes_cbc_decrypt_blocks(key_exp, data, data, aes_blocks);
973 
974 	return 0;
975 }
976 
977 static int flash_write (int fd_current, int fd_target, int dev_target)
978 {
979 	int rc;
980 
981 	switch (environment.flag_scheme) {
982 	case FLAG_NONE:
983 		break;
984 	case FLAG_INCREMENTAL:
985 		(*environment.flags)++;
986 		break;
987 	case FLAG_BOOLEAN:
988 		*environment.flags = active_flag;
989 		break;
990 	default:
991 		fprintf (stderr, "Unimplemented flash scheme %u \n",
992 			 environment.flag_scheme);
993 		return -1;
994 	}
995 
996 #ifdef DEBUG
997 	fprintf(stderr, "Writing new environment at 0x%lx on %s\n",
998 		DEVOFFSET (dev_target), DEVNAME (dev_target));
999 #endif
1000 
1001 	rc = flash_write_buf(dev_target, fd_target, environment.image,
1002 			      CUR_ENVSIZE, DEVOFFSET(dev_target),
1003 			      DEVTYPE(dev_target));
1004 	if (rc < 0)
1005 		return rc;
1006 
1007 	if (environment.flag_scheme == FLAG_BOOLEAN) {
1008 		/* Have to set obsolete flag */
1009 		off_t offset = DEVOFFSET (dev_current) +
1010 			offsetof (struct env_image_redundant, flags);
1011 #ifdef DEBUG
1012 		fprintf(stderr,
1013 			"Setting obsolete flag in environment at 0x%lx on %s\n",
1014 			DEVOFFSET (dev_current), DEVNAME (dev_current));
1015 #endif
1016 		flash_flag_obsolete (dev_current, fd_current, offset);
1017 	}
1018 
1019 	return 0;
1020 }
1021 
1022 static int flash_read (int fd)
1023 {
1024 	struct mtd_info_user mtdinfo;
1025 	struct stat st;
1026 	int rc;
1027 
1028 	rc = fstat(fd, &st);
1029 	if (rc < 0) {
1030 		fprintf(stderr, "Cannot stat the file %s\n",
1031 			DEVNAME(dev_current));
1032 		return -1;
1033 	}
1034 
1035 	if (S_ISCHR(st.st_mode)) {
1036 		rc = ioctl(fd, MEMGETINFO, &mtdinfo);
1037 		if (rc < 0) {
1038 			fprintf(stderr, "Cannot get MTD information for %s\n",
1039 				DEVNAME(dev_current));
1040 			return -1;
1041 		}
1042 		if (mtdinfo.type != MTD_NORFLASH &&
1043 		    mtdinfo.type != MTD_NANDFLASH &&
1044 		    mtdinfo.type != MTD_DATAFLASH &&
1045 		    mtdinfo.type != MTD_UBIVOLUME) {
1046 			fprintf (stderr, "Unsupported flash type %u on %s\n",
1047 				 mtdinfo.type, DEVNAME(dev_current));
1048 			return -1;
1049 		}
1050 	} else {
1051 		memset(&mtdinfo, 0, sizeof(mtdinfo));
1052 		mtdinfo.type = MTD_ABSENT;
1053 	}
1054 
1055 	DEVTYPE(dev_current) = mtdinfo.type;
1056 
1057 	rc = flash_read_buf(dev_current, fd, environment.image, CUR_ENVSIZE,
1058 			     DEVOFFSET (dev_current), mtdinfo.type);
1059 	if (rc != CUR_ENVSIZE)
1060 		return -1;
1061 
1062 	return 0;
1063 }
1064 
1065 static int flash_io (int mode)
1066 {
1067 	int fd_current, fd_target, rc, dev_target;
1068 
1069 	/* dev_current: fd_current, erase_current */
1070 	fd_current = open (DEVNAME (dev_current), mode);
1071 	if (fd_current < 0) {
1072 		fprintf (stderr,
1073 			 "Can't open %s: %s\n",
1074 			 DEVNAME (dev_current), strerror (errno));
1075 		return -1;
1076 	}
1077 
1078 	if (mode == O_RDWR) {
1079 		if (HaveRedundEnv) {
1080 			/* switch to next partition for writing */
1081 			dev_target = !dev_current;
1082 			/* dev_target: fd_target, erase_target */
1083 			fd_target = open (DEVNAME (dev_target), mode);
1084 			if (fd_target < 0) {
1085 				fprintf (stderr,
1086 					 "Can't open %s: %s\n",
1087 					 DEVNAME (dev_target),
1088 					 strerror (errno));
1089 				rc = -1;
1090 				goto exit;
1091 			}
1092 		} else {
1093 			dev_target = dev_current;
1094 			fd_target = fd_current;
1095 		}
1096 
1097 		rc = flash_write (fd_current, fd_target, dev_target);
1098 
1099 		if (HaveRedundEnv) {
1100 			if (close (fd_target)) {
1101 				fprintf (stderr,
1102 					"I/O error on %s: %s\n",
1103 					DEVNAME (dev_target),
1104 					strerror (errno));
1105 				rc = -1;
1106 			}
1107 		}
1108 	} else {
1109 		rc = flash_read (fd_current);
1110 	}
1111 
1112 exit:
1113 	if (close (fd_current)) {
1114 		fprintf (stderr,
1115 			 "I/O error on %s: %s\n",
1116 			 DEVNAME (dev_current), strerror (errno));
1117 		return -1;
1118 	}
1119 
1120 	return rc;
1121 }
1122 
1123 /*
1124  * s1 is either a simple 'name', or a 'name=value' pair.
1125  * s2 is a 'name=value' pair.
1126  * If the names match, return the value of s2, else NULL.
1127  */
1128 
1129 static char *envmatch (char * s1, char * s2)
1130 {
1131 	if (s1 == NULL || s2 == NULL)
1132 		return NULL;
1133 
1134 	while (*s1 == *s2++)
1135 		if (*s1++ == '=')
1136 			return s2;
1137 	if (*s1 == '\0' && *(s2 - 1) == '=')
1138 		return s2;
1139 	return NULL;
1140 }
1141 
1142 /*
1143  * Prevent confusion if running from erased flash memory
1144  */
1145 int fw_env_open(struct env_opts *opts)
1146 {
1147 	int crc0, crc0_ok;
1148 	unsigned char flag0;
1149 	void *addr0;
1150 
1151 	int crc1, crc1_ok;
1152 	unsigned char flag1;
1153 	void *addr1;
1154 
1155 	int ret;
1156 
1157 	struct env_image_single *single;
1158 	struct env_image_redundant *redundant;
1159 
1160 	if (!opts)
1161 		opts = &default_opts;
1162 
1163 	if (parse_config(opts))		/* should fill envdevices */
1164 		return -1;
1165 
1166 	addr0 = calloc(1, CUR_ENVSIZE);
1167 	if (addr0 == NULL) {
1168 		fprintf(stderr,
1169 			"Not enough memory for environment (%ld bytes)\n",
1170 			CUR_ENVSIZE);
1171 		return -1;
1172 	}
1173 
1174 	/* read environment from FLASH to local buffer */
1175 	environment.image = addr0;
1176 
1177 	if (HaveRedundEnv) {
1178 		redundant = addr0;
1179 		environment.crc		= &redundant->crc;
1180 		environment.flags	= &redundant->flags;
1181 		environment.data	= redundant->data;
1182 	} else {
1183 		single = addr0;
1184 		environment.crc		= &single->crc;
1185 		environment.flags	= NULL;
1186 		environment.data	= single->data;
1187 	}
1188 
1189 	dev_current = 0;
1190 	if (flash_io (O_RDONLY))
1191 		return -1;
1192 
1193 	crc0 = crc32 (0, (uint8_t *) environment.data, ENV_SIZE);
1194 
1195 	if (opts->aes_flag) {
1196 		ret = env_aes_cbc_crypt(environment.data, 0,
1197 					opts->aes_key);
1198 		if (ret)
1199 			return ret;
1200 	}
1201 
1202 	crc0_ok = (crc0 == *environment.crc);
1203 	if (!HaveRedundEnv) {
1204 		if (!crc0_ok) {
1205 			fprintf (stderr,
1206 				"Warning: Bad CRC, using default environment\n");
1207 			memcpy(environment.data, default_environment, sizeof default_environment);
1208 		}
1209 	} else {
1210 		flag0 = *environment.flags;
1211 
1212 		dev_current = 1;
1213 		addr1 = calloc(1, CUR_ENVSIZE);
1214 		if (addr1 == NULL) {
1215 			fprintf(stderr,
1216 				"Not enough memory for environment (%ld bytes)\n",
1217 				CUR_ENVSIZE);
1218 			return -1;
1219 		}
1220 		redundant = addr1;
1221 
1222 		/*
1223 		 * have to set environment.image for flash_read(), careful -
1224 		 * other pointers in environment still point inside addr0
1225 		 */
1226 		environment.image = addr1;
1227 		if (flash_io (O_RDONLY))
1228 			return -1;
1229 
1230 		/* Check flag scheme compatibility */
1231 		if (DEVTYPE(dev_current) == MTD_NORFLASH &&
1232 		    DEVTYPE(!dev_current) == MTD_NORFLASH) {
1233 			environment.flag_scheme = FLAG_BOOLEAN;
1234 		} else if (DEVTYPE(dev_current) == MTD_NANDFLASH &&
1235 			   DEVTYPE(!dev_current) == MTD_NANDFLASH) {
1236 			environment.flag_scheme = FLAG_INCREMENTAL;
1237 		} else if (DEVTYPE(dev_current) == MTD_DATAFLASH &&
1238 			   DEVTYPE(!dev_current) == MTD_DATAFLASH) {
1239 			environment.flag_scheme = FLAG_BOOLEAN;
1240 		} else if (DEVTYPE(dev_current) == MTD_UBIVOLUME &&
1241 			   DEVTYPE(!dev_current) == MTD_UBIVOLUME) {
1242 			environment.flag_scheme = FLAG_INCREMENTAL;
1243 		} else if (DEVTYPE(dev_current) == MTD_ABSENT &&
1244 			   DEVTYPE(!dev_current) == MTD_ABSENT) {
1245 			environment.flag_scheme = FLAG_INCREMENTAL;
1246 		} else {
1247 			fprintf (stderr, "Incompatible flash types!\n");
1248 			return -1;
1249 		}
1250 
1251 		crc1 = crc32 (0, (uint8_t *) redundant->data, ENV_SIZE);
1252 
1253 		if (opts->aes_flag) {
1254 			ret = env_aes_cbc_crypt(redundant->data, 0,
1255 						opts->aes_key);
1256 			if (ret)
1257 				return ret;
1258 		}
1259 
1260 		crc1_ok = (crc1 == redundant->crc);
1261 		flag1 = redundant->flags;
1262 
1263 		if (crc0_ok && !crc1_ok) {
1264 			dev_current = 0;
1265 		} else if (!crc0_ok && crc1_ok) {
1266 			dev_current = 1;
1267 		} else if (!crc0_ok && !crc1_ok) {
1268 			fprintf (stderr,
1269 				"Warning: Bad CRC, using default environment\n");
1270 			memcpy (environment.data, default_environment,
1271 				sizeof default_environment);
1272 			dev_current = 0;
1273 		} else {
1274 			switch (environment.flag_scheme) {
1275 			case FLAG_BOOLEAN:
1276 				if (flag0 == active_flag &&
1277 				    flag1 == obsolete_flag) {
1278 					dev_current = 0;
1279 				} else if (flag0 == obsolete_flag &&
1280 					   flag1 == active_flag) {
1281 					dev_current = 1;
1282 				} else if (flag0 == flag1) {
1283 					dev_current = 0;
1284 				} else if (flag0 == 0xFF) {
1285 					dev_current = 0;
1286 				} else if (flag1 == 0xFF) {
1287 					dev_current = 1;
1288 				} else {
1289 					dev_current = 0;
1290 				}
1291 				break;
1292 			case FLAG_INCREMENTAL:
1293 				if (flag0 == 255 && flag1 == 0)
1294 					dev_current = 1;
1295 				else if ((flag1 == 255 && flag0 == 0) ||
1296 					 flag0 >= flag1)
1297 					dev_current = 0;
1298 				else /* flag1 > flag0 */
1299 					dev_current = 1;
1300 				break;
1301 			default:
1302 				fprintf (stderr, "Unknown flag scheme %u \n",
1303 					 environment.flag_scheme);
1304 				return -1;
1305 			}
1306 		}
1307 
1308 		/*
1309 		 * If we are reading, we don't need the flag and the CRC any
1310 		 * more, if we are writing, we will re-calculate CRC and update
1311 		 * flags before writing out
1312 		 */
1313 		if (dev_current) {
1314 			environment.image	= addr1;
1315 			environment.crc		= &redundant->crc;
1316 			environment.flags	= &redundant->flags;
1317 			environment.data	= redundant->data;
1318 			free (addr0);
1319 		} else {
1320 			environment.image	= addr0;
1321 			/* Other pointers are already set */
1322 			free (addr1);
1323 		}
1324 #ifdef DEBUG
1325 		fprintf(stderr, "Selected env in %s\n", DEVNAME(dev_current));
1326 #endif
1327 	}
1328 	return 0;
1329 }
1330 
1331 
1332 static int parse_config(struct env_opts *opts)
1333 {
1334 	struct stat st;
1335 
1336 	if (!opts)
1337 		opts = &default_opts;
1338 
1339 #if defined(CONFIG_FILE)
1340 	/* Fills in DEVNAME(), ENVSIZE(), DEVESIZE(). Or don't. */
1341 	if (get_config(opts->config_file)) {
1342 		fprintf(stderr, "Cannot parse config file '%s': %m\n",
1343 			opts->config_file);
1344 		return -1;
1345 	}
1346 #else
1347 	DEVNAME (0) = DEVICE1_NAME;
1348 	DEVOFFSET (0) = DEVICE1_OFFSET;
1349 	ENVSIZE (0) = ENV1_SIZE;
1350 	/* Default values are: erase-size=env-size */
1351 	DEVESIZE (0) = ENVSIZE (0);
1352 	/* #sectors=env-size/erase-size (rounded up) */
1353 	ENVSECTORS (0) = (ENVSIZE(0) + DEVESIZE(0) - 1) / DEVESIZE(0);
1354 #ifdef DEVICE1_ESIZE
1355 	DEVESIZE (0) = DEVICE1_ESIZE;
1356 #endif
1357 #ifdef DEVICE1_ENVSECTORS
1358 	ENVSECTORS (0) = DEVICE1_ENVSECTORS;
1359 #endif
1360 
1361 #ifdef HAVE_REDUND
1362 	DEVNAME (1) = DEVICE2_NAME;
1363 	DEVOFFSET (1) = DEVICE2_OFFSET;
1364 	ENVSIZE (1) = ENV2_SIZE;
1365 	/* Default values are: erase-size=env-size */
1366 	DEVESIZE (1) = ENVSIZE (1);
1367 	/* #sectors=env-size/erase-size (rounded up) */
1368 	ENVSECTORS (1) = (ENVSIZE(1) + DEVESIZE(1) - 1) / DEVESIZE(1);
1369 #ifdef DEVICE2_ESIZE
1370 	DEVESIZE (1) = DEVICE2_ESIZE;
1371 #endif
1372 #ifdef DEVICE2_ENVSECTORS
1373 	ENVSECTORS (1) = DEVICE2_ENVSECTORS;
1374 #endif
1375 	HaveRedundEnv = 1;
1376 #endif
1377 #endif
1378 	if (stat (DEVNAME (0), &st)) {
1379 		fprintf (stderr,
1380 			"Cannot access MTD device %s: %s\n",
1381 			DEVNAME (0), strerror (errno));
1382 		return -1;
1383 	}
1384 
1385 	if (HaveRedundEnv && stat (DEVNAME (1), &st)) {
1386 		fprintf (stderr,
1387 			"Cannot access MTD device %s: %s\n",
1388 			DEVNAME (1), strerror (errno));
1389 		return -1;
1390 	}
1391 
1392 	if (HaveRedundEnv && ENVSIZE(0) != ENVSIZE(1)) {
1393 		ENVSIZE(0) = ENVSIZE(1) = min(ENVSIZE(0), ENVSIZE(1));
1394 		fprintf(stderr,
1395 			"Redundant environments have inequal size, set to 0x%08lx\n",
1396 			ENVSIZE(1));
1397 	}
1398 
1399 	usable_envsize = CUR_ENVSIZE - sizeof(uint32_t);
1400 	if (HaveRedundEnv)
1401 		usable_envsize -= sizeof(char);
1402 
1403 	if (opts->aes_flag)
1404 		usable_envsize &= ~(AES_KEY_LENGTH - 1);
1405 
1406 	return 0;
1407 }
1408 
1409 #if defined(CONFIG_FILE)
1410 static int get_config (char *fname)
1411 {
1412 	FILE *fp;
1413 	int i = 0;
1414 	int rc;
1415 	char dump[128];
1416 	char *devname;
1417 
1418 	fp = fopen (fname, "r");
1419 	if (fp == NULL)
1420 		return -1;
1421 
1422 	while (i < 2 && fgets (dump, sizeof (dump), fp)) {
1423 		/* Skip incomplete conversions and comment strings */
1424 		if (dump[0] == '#')
1425 			continue;
1426 
1427 		rc = sscanf (dump, "%ms %lx %lx %lx %lx",
1428 			     &devname,
1429 			     &DEVOFFSET (i),
1430 			     &ENVSIZE (i),
1431 			     &DEVESIZE (i),
1432 			     &ENVSECTORS (i));
1433 
1434 		if (rc < 3)
1435 			continue;
1436 
1437 		DEVNAME(i) = devname;
1438 
1439 		if (rc < 4)
1440 			/* Assume the erase size is the same as the env-size */
1441 			DEVESIZE(i) = ENVSIZE(i);
1442 
1443 		if (rc < 5)
1444 			/* Assume enough env sectors to cover the environment */
1445 			ENVSECTORS (i) = (ENVSIZE(i) + DEVESIZE(i) - 1) / DEVESIZE(i);
1446 
1447 		i++;
1448 	}
1449 	fclose (fp);
1450 
1451 	HaveRedundEnv = i - 1;
1452 	if (!i) {			/* No valid entries found */
1453 		errno = EINVAL;
1454 		return -1;
1455 	} else
1456 		return 0;
1457 }
1458 #endif
1459