xref: /openbmc/u-boot/tools/env/fw_env.c (revision 6b44ae6b)
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 <errno.h>
14 #include <env_flags.h>
15 #include <fcntl.h>
16 #include <linux/stringify.h>
17 #include <stdio.h>
18 #include <stdlib.h>
19 #include <stddef.h>
20 #include <string.h>
21 #include <sys/types.h>
22 #include <sys/ioctl.h>
23 #include <sys/stat.h>
24 #include <unistd.h>
25 
26 #ifdef MTD_OLD
27 # include <stdint.h>
28 # include <linux/mtd/mtd.h>
29 #else
30 # define  __user	/* nothing */
31 # include <mtd/mtd-user.h>
32 #endif
33 
34 #include "fw_env.h"
35 
36 #include <aes.h>
37 
38 #define DIV_ROUND_UP(n, d)	(((n) + (d) - 1) / (d))
39 
40 #define WHITESPACE(c) ((c == '\t') || (c == ' '))
41 
42 #define min(x, y) ({				\
43 	typeof(x) _min1 = (x);			\
44 	typeof(y) _min2 = (y);			\
45 	(void) (&_min1 == &_min2);		\
46 	_min1 < _min2 ? _min1 : _min2; })
47 
48 struct envdev_s {
49 	const char *devname;		/* Device name */
50 	ulong devoff;			/* Device offset */
51 	ulong env_size;			/* environment size */
52 	ulong erase_size;		/* device erase size */
53 	ulong env_sectors;		/* number of environment sectors */
54 	uint8_t mtd_type;		/* type of the MTD device */
55 };
56 
57 static struct envdev_s envdevices[2] =
58 {
59 	{
60 		.mtd_type = MTD_ABSENT,
61 	}, {
62 		.mtd_type = MTD_ABSENT,
63 	},
64 };
65 static int dev_current;
66 
67 #define DEVNAME(i)    envdevices[(i)].devname
68 #define DEVOFFSET(i)  envdevices[(i)].devoff
69 #define ENVSIZE(i)    envdevices[(i)].env_size
70 #define DEVESIZE(i)   envdevices[(i)].erase_size
71 #define ENVSECTORS(i) envdevices[(i)].env_sectors
72 #define DEVTYPE(i)    envdevices[(i)].mtd_type
73 
74 #define CUR_ENVSIZE ENVSIZE(dev_current)
75 
76 #define ENV_SIZE      getenvsize()
77 
78 struct env_image_single {
79 	uint32_t	crc;	/* CRC32 over data bytes    */
80 	char		data[];
81 };
82 
83 struct env_image_redundant {
84 	uint32_t	crc;	/* CRC32 over data bytes    */
85 	unsigned char	flags;	/* active or obsolete */
86 	char		data[];
87 };
88 
89 enum flag_scheme {
90 	FLAG_NONE,
91 	FLAG_BOOLEAN,
92 	FLAG_INCREMENTAL,
93 };
94 
95 struct environment {
96 	void			*image;
97 	uint32_t		*crc;
98 	unsigned char		*flags;
99 	char			*data;
100 	enum flag_scheme	flag_scheme;
101 };
102 
103 static struct environment environment = {
104 	.flag_scheme = FLAG_NONE,
105 };
106 
107 /* Is AES encryption used? */
108 static int aes_flag;
109 static uint8_t aes_key[AES_KEY_LENGTH] = { 0 };
110 static int env_aes_cbc_crypt(char *data, const int enc);
111 
112 static int HaveRedundEnv = 0;
113 
114 static unsigned char active_flag = 1;
115 /* obsolete_flag must be 0 to efficiently set it on NOR flash without erasing */
116 static unsigned char obsolete_flag = 0;
117 
118 #define DEFAULT_ENV_INSTANCE_STATIC
119 #include <env_default.h>
120 
121 static int flash_io (int mode);
122 static char *envmatch (char * s1, char * s2);
123 static int parse_config (void);
124 
125 #if defined(CONFIG_FILE)
126 static int get_config (char *);
127 static char *config_file = CONFIG_FILE;
128 #endif
129 static inline ulong getenvsize (void)
130 {
131 	ulong rc = CUR_ENVSIZE - sizeof(uint32_t);
132 
133 	if (HaveRedundEnv)
134 		rc -= sizeof (char);
135 
136 	if (aes_flag)
137 		rc &= ~(AES_KEY_LENGTH - 1);
138 
139 	return rc;
140 }
141 
142 static char *fw_string_blank(char *s, int noblank)
143 {
144 	int i;
145 	int len = strlen(s);
146 
147 	for (i = 0; i < len; i++, s++) {
148 		if ((noblank && !WHITESPACE(*s)) ||
149 			(!noblank && WHITESPACE(*s)))
150 			break;
151 	}
152 	if (i == len)
153 		return NULL;
154 
155 	return s;
156 }
157 
158 /*
159  * Search the environment for a variable.
160  * Return the value, if found, or NULL, if not found.
161  */
162 char *fw_getenv (char *name)
163 {
164 	char *env, *nxt;
165 
166 	for (env = environment.data; *env; env = nxt + 1) {
167 		char *val;
168 
169 		for (nxt = env; *nxt; ++nxt) {
170 			if (nxt >= &environment.data[ENV_SIZE]) {
171 				fprintf (stderr, "## Error: "
172 					"environment not terminated\n");
173 				return NULL;
174 			}
175 		}
176 		val = envmatch (name, env);
177 		if (!val)
178 			continue;
179 		return val;
180 	}
181 	return NULL;
182 }
183 
184 /*
185  * Search the default environment for a variable.
186  * Return the value, if found, or NULL, if not found.
187  */
188 char *fw_getdefenv(char *name)
189 {
190 	char *env, *nxt;
191 
192 	for (env = default_environment; *env; env = nxt + 1) {
193 		char *val;
194 
195 		for (nxt = env; *nxt; ++nxt) {
196 			if (nxt >= &default_environment[ENV_SIZE]) {
197 				fprintf(stderr, "## Error: "
198 					"default environment not terminated\n");
199 				return NULL;
200 			}
201 		}
202 		val = envmatch(name, env);
203 		if (!val)
204 			continue;
205 		return val;
206 	}
207 	return NULL;
208 }
209 
210 static int parse_aes_key(char *key)
211 {
212 	char tmp[5] = { '0', 'x', 0, 0, 0 };
213 	unsigned long ul;
214 	int i;
215 
216 	if (strnlen(key, 64) != 32) {
217 		fprintf(stderr,
218 			"## Error: '-a' option requires 16-byte AES key\n");
219 		return -1;
220 	}
221 
222 	for (i = 0; i < 16; i++) {
223 		tmp[2] = key[0];
224 		tmp[3] = key[1];
225 		errno = 0;
226 		ul = strtoul(tmp, NULL, 16);
227 		if (errno) {
228 			fprintf(stderr,
229 				"## Error: '-a' option requires valid AES key\n");
230 			return -1;
231 		}
232 		aes_key[i] = ul & 0xff;
233 		key += 2;
234 	}
235 	aes_flag = 1;
236 
237 	return 0;
238 }
239 
240 /*
241  * Print the current definition of one, or more, or all
242  * environment variables
243  */
244 int fw_printenv (int argc, char *argv[])
245 {
246 	char *env, *nxt;
247 	int i, n_flag;
248 	int rc = 0;
249 
250 #ifdef CONFIG_FILE
251 	if (argc >= 2 && strcmp(argv[1], "-c") == 0) {
252 		if (argc < 3) {
253 			fprintf(stderr,
254 				"## Error: '-c' option requires the config file to use\n");
255 			return -1;
256 		}
257 		config_file = argv[2];
258 		argv += 2;
259 		argc -= 2;
260 	}
261 #endif
262 
263 	if (argc >= 2 && strcmp(argv[1], "-a") == 0) {
264 		if (argc < 3) {
265 			fprintf(stderr,
266 				"## Error: '-a' option requires AES key\n");
267 			return -1;
268 		}
269 		rc = parse_aes_key(argv[2]);
270 		if (rc)
271 			return rc;
272 		argv += 2;
273 		argc -= 2;
274 	}
275 
276 	if (fw_env_open())
277 		return -1;
278 
279 	if (argc == 1) {		/* Print all env variables  */
280 		for (env = environment.data; *env; env = nxt + 1) {
281 			for (nxt = env; *nxt; ++nxt) {
282 				if (nxt >= &environment.data[ENV_SIZE]) {
283 					fprintf (stderr, "## Error: "
284 						"environment not terminated\n");
285 					return -1;
286 				}
287 			}
288 
289 			printf ("%s\n", env);
290 		}
291 		return 0;
292 	}
293 
294 	if (strcmp (argv[1], "-n") == 0) {
295 		n_flag = 1;
296 		++argv;
297 		--argc;
298 		if (argc != 2) {
299 			fprintf (stderr, "## Error: "
300 				"`-n' option requires exactly one argument\n");
301 			return -1;
302 		}
303 	} else {
304 		n_flag = 0;
305 	}
306 
307 	for (i = 1; i < argc; ++i) {	/* print single env variables   */
308 		char *name = argv[i];
309 		char *val = NULL;
310 
311 		for (env = environment.data; *env; env = nxt + 1) {
312 
313 			for (nxt = env; *nxt; ++nxt) {
314 				if (nxt >= &environment.data[ENV_SIZE]) {
315 					fprintf (stderr, "## Error: "
316 						"environment not terminated\n");
317 					return -1;
318 				}
319 			}
320 			val = envmatch (name, env);
321 			if (val) {
322 				if (!n_flag) {
323 					fputs (name, stdout);
324 					putc ('=', stdout);
325 				}
326 				puts (val);
327 				break;
328 			}
329 		}
330 		if (!val) {
331 			fprintf (stderr, "## Error: \"%s\" not defined\n", name);
332 			rc = -1;
333 		}
334 	}
335 
336 	return rc;
337 }
338 
339 int fw_env_close(void)
340 {
341 	int ret;
342 	if (aes_flag) {
343 		ret = env_aes_cbc_crypt(environment.data, 1);
344 		if (ret) {
345 			fprintf(stderr,
346 				"Error: can't encrypt env for flash\n");
347 			return ret;
348 		}
349 	}
350 
351 	/*
352 	 * Update CRC
353 	 */
354 	*environment.crc = crc32(0, (uint8_t *) environment.data, ENV_SIZE);
355 
356 	/* write environment back to flash */
357 	if (flash_io(O_RDWR)) {
358 		fprintf(stderr,
359 			"Error: can't write fw_env to flash\n");
360 			return -1;
361 	}
362 
363 	return 0;
364 }
365 
366 
367 /*
368  * Set/Clear a single variable in the environment.
369  * This is called in sequence to update the environment
370  * in RAM without updating the copy in flash after each set
371  */
372 int fw_env_write(char *name, char *value)
373 {
374 	int len;
375 	char *env, *nxt;
376 	char *oldval = NULL;
377 	int deleting, creating, overwriting;
378 
379 	/*
380 	 * search if variable with this name already exists
381 	 */
382 	for (nxt = env = environment.data; *env; env = nxt + 1) {
383 		for (nxt = env; *nxt; ++nxt) {
384 			if (nxt >= &environment.data[ENV_SIZE]) {
385 				fprintf(stderr, "## Error: "
386 					"environment not terminated\n");
387 				errno = EINVAL;
388 				return -1;
389 			}
390 		}
391 		if ((oldval = envmatch (name, env)) != NULL)
392 			break;
393 	}
394 
395 	deleting = (oldval && !(value && strlen(value)));
396 	creating = (!oldval && (value && strlen(value)));
397 	overwriting = (oldval && (value && strlen(value)));
398 
399 	/* check for permission */
400 	if (deleting) {
401 		if (env_flags_validate_varaccess(name,
402 		    ENV_FLAGS_VARACCESS_PREVENT_DELETE)) {
403 			printf("Can't delete \"%s\"\n", name);
404 			errno = EROFS;
405 			return -1;
406 		}
407 	} else if (overwriting) {
408 		if (env_flags_validate_varaccess(name,
409 		    ENV_FLAGS_VARACCESS_PREVENT_OVERWR)) {
410 			printf("Can't overwrite \"%s\"\n", name);
411 			errno = EROFS;
412 			return -1;
413 		} else if (env_flags_validate_varaccess(name,
414 		    ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR)) {
415 			const char *defval = fw_getdefenv(name);
416 
417 			if (defval == NULL)
418 				defval = "";
419 			if (strcmp(oldval, defval)
420 			    != 0) {
421 				printf("Can't overwrite \"%s\"\n", name);
422 				errno = EROFS;
423 				return -1;
424 			}
425 		}
426 	} else if (creating) {
427 		if (env_flags_validate_varaccess(name,
428 		    ENV_FLAGS_VARACCESS_PREVENT_CREATE)) {
429 			printf("Can't create \"%s\"\n", name);
430 			errno = EROFS;
431 			return -1;
432 		}
433 	} else
434 		/* Nothing to do */
435 		return 0;
436 
437 	if (deleting || overwriting) {
438 		if (*++nxt == '\0') {
439 			*env = '\0';
440 		} else {
441 			for (;;) {
442 				*env = *nxt++;
443 				if ((*env == '\0') && (*nxt == '\0'))
444 					break;
445 				++env;
446 			}
447 		}
448 		*++env = '\0';
449 	}
450 
451 	/* Delete only ? */
452 	if (!value || !strlen(value))
453 		return 0;
454 
455 	/*
456 	 * Append new definition at the end
457 	 */
458 	for (env = environment.data; *env || *(env + 1); ++env);
459 	if (env > environment.data)
460 		++env;
461 	/*
462 	 * Overflow when:
463 	 * "name" + "=" + "val" +"\0\0"  > CUR_ENVSIZE - (env-environment)
464 	 */
465 	len = strlen (name) + 2;
466 	/* add '=' for first arg, ' ' for all others */
467 	len += strlen(value) + 1;
468 
469 	if (len > (&environment.data[ENV_SIZE] - env)) {
470 		fprintf (stderr,
471 			"Error: environment overflow, \"%s\" deleted\n",
472 			name);
473 		return -1;
474 	}
475 
476 	while ((*env = *name++) != '\0')
477 		env++;
478 	*env = '=';
479 	while ((*++env = *value++) != '\0')
480 		;
481 
482 	/* end is marked with double '\0' */
483 	*++env = '\0';
484 
485 	return 0;
486 }
487 
488 /*
489  * Deletes or sets environment variables. Returns -1 and sets errno error codes:
490  * 0	  - OK
491  * EINVAL - need at least 1 argument
492  * EROFS  - certain variables ("ethaddr", "serial#") cannot be
493  *	    modified or deleted
494  *
495  */
496 int fw_setenv(int argc, char *argv[])
497 {
498 	int i, rc;
499 	size_t len;
500 	char *name;
501 	char *value = NULL;
502 
503 #ifdef CONFIG_FILE
504 	if (argc >= 2 && strcmp(argv[1], "-c") == 0) {
505 		if (argc < 3) {
506 			fprintf(stderr,
507 				"## Error: '-c' option requires the config file to use\n");
508 			return -1;
509 		}
510 		config_file = argv[2];
511 		argv += 2;
512 		argc -= 2;
513 	}
514 #endif
515 
516 	if (argc < 2) {
517 		errno = EINVAL;
518 		return -1;
519 	}
520 
521 	if (strcmp(argv[1], "-a") == 0) {
522 		if (argc < 3) {
523 			fprintf(stderr,
524 				"## Error: '-a' option requires AES key\n");
525 			return -1;
526 		}
527 		rc = parse_aes_key(argv[2]);
528 		if (rc)
529 			return rc;
530 		argv += 2;
531 		argc -= 2;
532 	}
533 
534 	if (argc < 2) {
535 		errno = EINVAL;
536 		return -1;
537 	}
538 
539 	if (fw_env_open()) {
540 		fprintf(stderr, "Error: environment not initialized\n");
541 		return -1;
542 	}
543 
544 	name = argv[1];
545 
546 	if (env_flags_validate_env_set_params(argc, argv) < 0)
547 		return 1;
548 
549 	len = 0;
550 	for (i = 2; i < argc; ++i) {
551 		char *val = argv[i];
552 		size_t val_len = strlen(val);
553 
554 		if (value)
555 			value[len - 1] = ' ';
556 		value = realloc(value, len + val_len + 1);
557 		if (!value) {
558 			fprintf(stderr,
559 				"Cannot malloc %zu bytes: %s\n",
560 				len, strerror(errno));
561 			return -1;
562 		}
563 
564 		memcpy(value + len, val, val_len);
565 		len += val_len;
566 		value[len++] = '\0';
567 	}
568 
569 	fw_env_write(name, value);
570 
571 	free(value);
572 
573 	return fw_env_close();
574 }
575 
576 /*
577  * Parse  a file  and configure the u-boot variables.
578  * The script file has a very simple format, as follows:
579  *
580  * Each line has a couple with name, value:
581  * <white spaces>variable_name<white spaces>variable_value
582  *
583  * Both variable_name and variable_value are interpreted as strings.
584  * Any character after <white spaces> and before ending \r\n is interpreted
585  * as variable's value (no comment allowed on these lines !)
586  *
587  * Comments are allowed if the first character in the line is #
588  *
589  * Returns -1 and sets errno error codes:
590  * 0	  - OK
591  * -1     - Error
592  */
593 int fw_parse_script(char *fname)
594 {
595 	FILE *fp;
596 	char dump[1024];	/* Maximum line length in the file */
597 	char *name;
598 	char *val;
599 	int lineno = 0;
600 	int len;
601 	int ret = 0;
602 
603 	if (fw_env_open()) {
604 		fprintf(stderr, "Error: environment not initialized\n");
605 		return -1;
606 	}
607 
608 	if (strcmp(fname, "-") == 0)
609 		fp = stdin;
610 	else {
611 		fp = fopen(fname, "r");
612 		if (fp == NULL) {
613 			fprintf(stderr, "I cannot open %s for reading\n",
614 				 fname);
615 			return -1;
616 		}
617 	}
618 
619 	while (fgets(dump, sizeof(dump), fp)) {
620 		lineno++;
621 		len = strlen(dump);
622 
623 		/*
624 		 * Read a whole line from the file. If the line is too long
625 		 * or is not terminated, reports an error and exit.
626 		 */
627 		if (dump[len - 1] != '\n') {
628 			fprintf(stderr,
629 			"Line %d not corrected terminated or too long\n",
630 				lineno);
631 			ret = -1;
632 			break;
633 		}
634 
635 		/* Drop ending line feed / carriage return */
636 		while (len > 0 && (dump[len - 1] == '\n' ||
637 				dump[len - 1] == '\r')) {
638 			dump[len - 1] = '\0';
639 			len--;
640 		}
641 
642 		/* Skip comment or empty lines */
643 		if ((len == 0) || dump[0] == '#')
644 			continue;
645 
646 		/*
647 		 * Search for variable's name,
648 		 * remove leading whitespaces
649 		 */
650 		name = fw_string_blank(dump, 1);
651 		if (!name)
652 			continue;
653 
654 		/* The first white space is the end of variable name */
655 		val = fw_string_blank(name, 0);
656 		len = strlen(name);
657 		if (val) {
658 			*val++ = '\0';
659 			if ((val - name) < len)
660 				val = fw_string_blank(val, 1);
661 			else
662 				val = NULL;
663 		}
664 
665 #ifdef DEBUG
666 		fprintf(stderr, "Setting %s : %s\n",
667 			name, val ? val : " removed");
668 #endif
669 
670 		if (env_flags_validate_type(name, val) < 0) {
671 			ret = -1;
672 			break;
673 		}
674 
675 		/*
676 		 * If there is an error setting a variable,
677 		 * try to save the environment and returns an error
678 		 */
679 		if (fw_env_write(name, val)) {
680 			fprintf(stderr,
681 			"fw_env_write returns with error : %s\n",
682 				strerror(errno));
683 			ret = -1;
684 			break;
685 		}
686 
687 	}
688 
689 	/* Close file if not stdin */
690 	if (strcmp(fname, "-") != 0)
691 		fclose(fp);
692 
693 	ret |= fw_env_close();
694 
695 	return ret;
696 
697 }
698 
699 /*
700  * Test for bad block on NAND, just returns 0 on NOR, on NAND:
701  * 0	- block is good
702  * > 0	- block is bad
703  * < 0	- failed to test
704  */
705 static int flash_bad_block (int fd, uint8_t mtd_type, loff_t *blockstart)
706 {
707 	if (mtd_type == MTD_NANDFLASH) {
708 		int badblock = ioctl (fd, MEMGETBADBLOCK, blockstart);
709 
710 		if (badblock < 0) {
711 			perror ("Cannot read bad block mark");
712 			return badblock;
713 		}
714 
715 		if (badblock) {
716 #ifdef DEBUG
717 			fprintf (stderr, "Bad block at 0x%llx, "
718 				 "skipping\n", *blockstart);
719 #endif
720 			return badblock;
721 		}
722 	}
723 
724 	return 0;
725 }
726 
727 /*
728  * Read data from flash at an offset into a provided buffer. On NAND it skips
729  * bad blocks but makes sure it stays within ENVSECTORS (dev) starting from
730  * the DEVOFFSET (dev) block. On NOR the loop is only run once.
731  */
732 static int flash_read_buf (int dev, int fd, void *buf, size_t count,
733 			   off_t offset, uint8_t mtd_type)
734 {
735 	size_t blocklen;	/* erase / write length - one block on NAND,
736 				   0 on NOR */
737 	size_t processed = 0;	/* progress counter */
738 	size_t readlen = count;	/* current read length */
739 	off_t top_of_range;	/* end of the last block we may use */
740 	off_t block_seek;	/* offset inside the current block to the start
741 				   of the data */
742 	loff_t blockstart;	/* running start of the current block -
743 				   MEMGETBADBLOCK needs 64 bits */
744 	int rc;
745 
746 	blockstart = (offset / DEVESIZE (dev)) * DEVESIZE (dev);
747 
748 	/* Offset inside a block */
749 	block_seek = offset - blockstart;
750 
751 	if (mtd_type == MTD_NANDFLASH) {
752 		/*
753 		 * NAND: calculate which blocks we are reading. We have
754 		 * to read one block at a time to skip bad blocks.
755 		 */
756 		blocklen = DEVESIZE (dev);
757 
758 		/*
759 		 * To calculate the top of the range, we have to use the
760 		 * global DEVOFFSET (dev), which can be different from offset
761 		 */
762 		top_of_range = ((DEVOFFSET(dev) / blocklen) +
763 				ENVSECTORS (dev)) * blocklen;
764 
765 		/* Limit to one block for the first read */
766 		if (readlen > blocklen - block_seek)
767 			readlen = blocklen - block_seek;
768 	} else {
769 		blocklen = 0;
770 		top_of_range = offset + count;
771 	}
772 
773 	/* This only runs once on NOR flash */
774 	while (processed < count) {
775 		rc = flash_bad_block (fd, mtd_type, &blockstart);
776 		if (rc < 0)		/* block test failed */
777 			return -1;
778 
779 		if (blockstart + block_seek + readlen > top_of_range) {
780 			/* End of range is reached */
781 			fprintf (stderr,
782 				 "Too few good blocks within range\n");
783 			return -1;
784 		}
785 
786 		if (rc) {		/* block is bad */
787 			blockstart += blocklen;
788 			continue;
789 		}
790 
791 		/*
792 		 * If a block is bad, we retry in the next block at the same
793 		 * offset - see common/env_nand.c::writeenv()
794 		 */
795 		lseek (fd, blockstart + block_seek, SEEK_SET);
796 
797 		rc = read (fd, buf + processed, readlen);
798 		if (rc != readlen) {
799 			fprintf (stderr, "Read error on %s: %s\n",
800 				 DEVNAME (dev), strerror (errno));
801 			return -1;
802 		}
803 #ifdef DEBUG
804 		fprintf(stderr, "Read 0x%x bytes at 0x%llx on %s\n",
805 			 rc, blockstart + block_seek, DEVNAME(dev));
806 #endif
807 		processed += readlen;
808 		readlen = min (blocklen, count - processed);
809 		block_seek = 0;
810 		blockstart += blocklen;
811 	}
812 
813 	return processed;
814 }
815 
816 /*
817  * Write count bytes at offset, but stay within ENVSECTORS (dev) sectors of
818  * DEVOFFSET (dev). Similar to the read case above, on NOR and dataflash we
819  * erase and write the whole data at once.
820  */
821 static int flash_write_buf (int dev, int fd, void *buf, size_t count,
822 			    off_t offset, uint8_t mtd_type)
823 {
824 	void *data;
825 	struct erase_info_user erase;
826 	size_t blocklen;	/* length of NAND block / NOR erase sector */
827 	size_t erase_len;	/* whole area that can be erased - may include
828 				   bad blocks */
829 	size_t erasesize;	/* erase / write length - one block on NAND,
830 				   whole area on NOR */
831 	size_t processed = 0;	/* progress counter */
832 	size_t write_total;	/* total size to actually write - excluding
833 				   bad blocks */
834 	off_t erase_offset;	/* offset to the first erase block (aligned)
835 				   below offset */
836 	off_t block_seek;	/* offset inside the erase block to the start
837 				   of the data */
838 	off_t top_of_range;	/* end of the last block we may use */
839 	loff_t blockstart;	/* running start of the current block -
840 				   MEMGETBADBLOCK needs 64 bits */
841 	int rc;
842 
843 	/*
844 	 * For mtd devices only offset and size of the environment do matter
845 	 */
846 	if (mtd_type == MTD_ABSENT) {
847 		blocklen = count;
848 		top_of_range = offset + count;
849 		erase_len = blocklen;
850 		blockstart = offset;
851 		block_seek = 0;
852 		write_total = blocklen;
853 	} else {
854 		blocklen = DEVESIZE(dev);
855 
856 		top_of_range = ((DEVOFFSET(dev) / blocklen) +
857 					ENVSECTORS(dev)) * blocklen;
858 
859 		erase_offset = (offset / blocklen) * blocklen;
860 
861 		/* Maximum area we may use */
862 		erase_len = top_of_range - erase_offset;
863 
864 		blockstart = erase_offset;
865 		/* Offset inside a block */
866 		block_seek = offset - erase_offset;
867 
868 		/*
869 		 * Data size we actually write: from the start of the block
870 		 * to the start of the data, then count bytes of data, and
871 		 * to the end of the block
872 		 */
873 		write_total = ((block_seek + count + blocklen - 1) /
874 							blocklen) * blocklen;
875 	}
876 
877 	/*
878 	 * Support data anywhere within erase sectors: read out the complete
879 	 * area to be erased, replace the environment image, write the whole
880 	 * block back again.
881 	 */
882 	if (write_total > count) {
883 		data = malloc (erase_len);
884 		if (!data) {
885 			fprintf (stderr,
886 				 "Cannot malloc %zu bytes: %s\n",
887 				 erase_len, strerror (errno));
888 			return -1;
889 		}
890 
891 		rc = flash_read_buf (dev, fd, data, write_total, erase_offset,
892 				     mtd_type);
893 		if (write_total != rc)
894 			return -1;
895 
896 #ifdef DEBUG
897 		fprintf(stderr, "Preserving data ");
898 		if (block_seek != 0)
899 			fprintf(stderr, "0x%x - 0x%lx", 0, block_seek - 1);
900 		if (block_seek + count != write_total) {
901 			if (block_seek != 0)
902 				fprintf(stderr, " and ");
903 			fprintf(stderr, "0x%lx - 0x%x",
904 				block_seek + count, write_total - 1);
905 		}
906 		fprintf(stderr, "\n");
907 #endif
908 		/* Overwrite the old environment */
909 		memcpy (data + block_seek, buf, count);
910 	} else {
911 		/*
912 		 * We get here, iff offset is block-aligned and count is a
913 		 * multiple of blocklen - see write_total calculation above
914 		 */
915 		data = buf;
916 	}
917 
918 	if (mtd_type == MTD_NANDFLASH) {
919 		/*
920 		 * NAND: calculate which blocks we are writing. We have
921 		 * to write one block at a time to skip bad blocks.
922 		 */
923 		erasesize = blocklen;
924 	} else {
925 		erasesize = erase_len;
926 	}
927 
928 	erase.length = erasesize;
929 
930 	/* This only runs once on NOR flash and SPI-dataflash */
931 	while (processed < write_total) {
932 		rc = flash_bad_block (fd, mtd_type, &blockstart);
933 		if (rc < 0)		/* block test failed */
934 			return rc;
935 
936 		if (blockstart + erasesize > top_of_range) {
937 			fprintf (stderr, "End of range reached, aborting\n");
938 			return -1;
939 		}
940 
941 		if (rc) {		/* block is bad */
942 			blockstart += blocklen;
943 			continue;
944 		}
945 
946 		if (mtd_type != MTD_ABSENT) {
947 			erase.start = blockstart;
948 			ioctl(fd, MEMUNLOCK, &erase);
949 			/* These do not need an explicit erase cycle */
950 			if (mtd_type != MTD_DATAFLASH)
951 				if (ioctl(fd, MEMERASE, &erase) != 0) {
952 					fprintf(stderr,
953 						"MTD erase error on %s: %s\n",
954 						DEVNAME(dev), strerror(errno));
955 					return -1;
956 				}
957 		}
958 
959 		if (lseek (fd, blockstart, SEEK_SET) == -1) {
960 			fprintf (stderr,
961 				 "Seek error on %s: %s\n",
962 				 DEVNAME (dev), strerror (errno));
963 			return -1;
964 		}
965 
966 #ifdef DEBUG
967 		fprintf(stderr, "Write 0x%x bytes at 0x%llx\n", erasesize,
968 			blockstart);
969 #endif
970 		if (write (fd, data + processed, erasesize) != erasesize) {
971 			fprintf (stderr, "Write error on %s: %s\n",
972 				 DEVNAME (dev), strerror (errno));
973 			return -1;
974 		}
975 
976 		if (mtd_type != MTD_ABSENT)
977 			ioctl(fd, MEMLOCK, &erase);
978 
979 		processed  += erasesize;
980 		block_seek = 0;
981 		blockstart += erasesize;
982 	}
983 
984 	if (write_total > count)
985 		free (data);
986 
987 	return processed;
988 }
989 
990 /*
991  * Set obsolete flag at offset - NOR flash only
992  */
993 static int flash_flag_obsolete (int dev, int fd, off_t offset)
994 {
995 	int rc;
996 	struct erase_info_user erase;
997 
998 	erase.start  = DEVOFFSET (dev);
999 	erase.length = DEVESIZE (dev);
1000 	/* This relies on the fact, that obsolete_flag == 0 */
1001 	rc = lseek (fd, offset, SEEK_SET);
1002 	if (rc < 0) {
1003 		fprintf (stderr, "Cannot seek to set the flag on %s \n",
1004 			 DEVNAME (dev));
1005 		return rc;
1006 	}
1007 	ioctl (fd, MEMUNLOCK, &erase);
1008 	rc = write (fd, &obsolete_flag, sizeof (obsolete_flag));
1009 	ioctl (fd, MEMLOCK, &erase);
1010 	if (rc < 0)
1011 		perror ("Could not set obsolete flag");
1012 
1013 	return rc;
1014 }
1015 
1016 /* Encrypt or decrypt the environment before writing or reading it. */
1017 static int env_aes_cbc_crypt(char *payload, const int enc)
1018 {
1019 	uint8_t *data = (uint8_t *)payload;
1020 	const int len = getenvsize();
1021 	uint8_t key_exp[AES_EXPAND_KEY_LENGTH];
1022 	uint32_t aes_blocks;
1023 
1024 	/* First we expand the key. */
1025 	aes_expand_key(aes_key, key_exp);
1026 
1027 	/* Calculate the number of AES blocks to encrypt. */
1028 	aes_blocks = DIV_ROUND_UP(len, AES_KEY_LENGTH);
1029 
1030 	if (enc)
1031 		aes_cbc_encrypt_blocks(key_exp, data, data, aes_blocks);
1032 	else
1033 		aes_cbc_decrypt_blocks(key_exp, data, data, aes_blocks);
1034 
1035 	return 0;
1036 }
1037 
1038 static int flash_write (int fd_current, int fd_target, int dev_target)
1039 {
1040 	int rc;
1041 
1042 	switch (environment.flag_scheme) {
1043 	case FLAG_NONE:
1044 		break;
1045 	case FLAG_INCREMENTAL:
1046 		(*environment.flags)++;
1047 		break;
1048 	case FLAG_BOOLEAN:
1049 		*environment.flags = active_flag;
1050 		break;
1051 	default:
1052 		fprintf (stderr, "Unimplemented flash scheme %u \n",
1053 			 environment.flag_scheme);
1054 		return -1;
1055 	}
1056 
1057 #ifdef DEBUG
1058 	fprintf(stderr, "Writing new environment at 0x%lx on %s\n",
1059 		DEVOFFSET (dev_target), DEVNAME (dev_target));
1060 #endif
1061 
1062 	rc = flash_write_buf(dev_target, fd_target, environment.image,
1063 			      CUR_ENVSIZE, DEVOFFSET(dev_target),
1064 			      DEVTYPE(dev_target));
1065 	if (rc < 0)
1066 		return rc;
1067 
1068 	if (environment.flag_scheme == FLAG_BOOLEAN) {
1069 		/* Have to set obsolete flag */
1070 		off_t offset = DEVOFFSET (dev_current) +
1071 			offsetof (struct env_image_redundant, flags);
1072 #ifdef DEBUG
1073 		fprintf(stderr,
1074 			"Setting obsolete flag in environment at 0x%lx on %s\n",
1075 			DEVOFFSET (dev_current), DEVNAME (dev_current));
1076 #endif
1077 		flash_flag_obsolete (dev_current, fd_current, offset);
1078 	}
1079 
1080 	return 0;
1081 }
1082 
1083 static int flash_read (int fd)
1084 {
1085 	struct mtd_info_user mtdinfo;
1086 	struct stat st;
1087 	int rc;
1088 
1089 	rc = fstat(fd, &st);
1090 	if (rc < 0) {
1091 		fprintf(stderr, "Cannot stat the file %s\n",
1092 			DEVNAME(dev_current));
1093 		return -1;
1094 	}
1095 
1096 	if (S_ISCHR(st.st_mode)) {
1097 		rc = ioctl(fd, MEMGETINFO, &mtdinfo);
1098 		if (rc < 0) {
1099 			fprintf(stderr, "Cannot get MTD information for %s\n",
1100 				DEVNAME(dev_current));
1101 			return -1;
1102 		}
1103 		if (mtdinfo.type != MTD_NORFLASH &&
1104 		    mtdinfo.type != MTD_NANDFLASH &&
1105 		    mtdinfo.type != MTD_DATAFLASH &&
1106 		    mtdinfo.type != MTD_UBIVOLUME) {
1107 			fprintf (stderr, "Unsupported flash type %u on %s\n",
1108 				 mtdinfo.type, DEVNAME(dev_current));
1109 			return -1;
1110 		}
1111 	} else {
1112 		memset(&mtdinfo, 0, sizeof(mtdinfo));
1113 		mtdinfo.type = MTD_ABSENT;
1114 	}
1115 
1116 	DEVTYPE(dev_current) = mtdinfo.type;
1117 
1118 	rc = flash_read_buf(dev_current, fd, environment.image, CUR_ENVSIZE,
1119 			     DEVOFFSET (dev_current), mtdinfo.type);
1120 	if (rc != CUR_ENVSIZE)
1121 		return -1;
1122 
1123 	return 0;
1124 }
1125 
1126 static int flash_io (int mode)
1127 {
1128 	int fd_current, fd_target, rc, dev_target;
1129 
1130 	/* dev_current: fd_current, erase_current */
1131 	fd_current = open (DEVNAME (dev_current), mode);
1132 	if (fd_current < 0) {
1133 		fprintf (stderr,
1134 			 "Can't open %s: %s\n",
1135 			 DEVNAME (dev_current), strerror (errno));
1136 		return -1;
1137 	}
1138 
1139 	if (mode == O_RDWR) {
1140 		if (HaveRedundEnv) {
1141 			/* switch to next partition for writing */
1142 			dev_target = !dev_current;
1143 			/* dev_target: fd_target, erase_target */
1144 			fd_target = open (DEVNAME (dev_target), mode);
1145 			if (fd_target < 0) {
1146 				fprintf (stderr,
1147 					 "Can't open %s: %s\n",
1148 					 DEVNAME (dev_target),
1149 					 strerror (errno));
1150 				rc = -1;
1151 				goto exit;
1152 			}
1153 		} else {
1154 			dev_target = dev_current;
1155 			fd_target = fd_current;
1156 		}
1157 
1158 		rc = flash_write (fd_current, fd_target, dev_target);
1159 
1160 		if (HaveRedundEnv) {
1161 			if (close (fd_target)) {
1162 				fprintf (stderr,
1163 					"I/O error on %s: %s\n",
1164 					DEVNAME (dev_target),
1165 					strerror (errno));
1166 				rc = -1;
1167 			}
1168 		}
1169 	} else {
1170 		rc = flash_read (fd_current);
1171 	}
1172 
1173 exit:
1174 	if (close (fd_current)) {
1175 		fprintf (stderr,
1176 			 "I/O error on %s: %s\n",
1177 			 DEVNAME (dev_current), strerror (errno));
1178 		return -1;
1179 	}
1180 
1181 	return rc;
1182 }
1183 
1184 /*
1185  * s1 is either a simple 'name', or a 'name=value' pair.
1186  * s2 is a 'name=value' pair.
1187  * If the names match, return the value of s2, else NULL.
1188  */
1189 
1190 static char *envmatch (char * s1, char * s2)
1191 {
1192 	if (s1 == NULL || s2 == NULL)
1193 		return NULL;
1194 
1195 	while (*s1 == *s2++)
1196 		if (*s1++ == '=')
1197 			return s2;
1198 	if (*s1 == '\0' && *(s2 - 1) == '=')
1199 		return s2;
1200 	return NULL;
1201 }
1202 
1203 /*
1204  * Prevent confusion if running from erased flash memory
1205  */
1206 int fw_env_open(void)
1207 {
1208 	int crc0, crc0_ok;
1209 	unsigned char flag0;
1210 	void *addr0;
1211 
1212 	int crc1, crc1_ok;
1213 	unsigned char flag1;
1214 	void *addr1;
1215 
1216 	int ret;
1217 
1218 	struct env_image_single *single;
1219 	struct env_image_redundant *redundant;
1220 
1221 	if (parse_config ())		/* should fill envdevices */
1222 		return -1;
1223 
1224 	addr0 = calloc(1, CUR_ENVSIZE);
1225 	if (addr0 == NULL) {
1226 		fprintf(stderr,
1227 			"Not enough memory for environment (%ld bytes)\n",
1228 			CUR_ENVSIZE);
1229 		return -1;
1230 	}
1231 
1232 	/* read environment from FLASH to local buffer */
1233 	environment.image = addr0;
1234 
1235 	if (HaveRedundEnv) {
1236 		redundant = addr0;
1237 		environment.crc		= &redundant->crc;
1238 		environment.flags	= &redundant->flags;
1239 		environment.data	= redundant->data;
1240 	} else {
1241 		single = addr0;
1242 		environment.crc		= &single->crc;
1243 		environment.flags	= NULL;
1244 		environment.data	= single->data;
1245 	}
1246 
1247 	dev_current = 0;
1248 	if (flash_io (O_RDONLY))
1249 		return -1;
1250 
1251 	crc0 = crc32 (0, (uint8_t *) environment.data, ENV_SIZE);
1252 
1253 	if (aes_flag) {
1254 		ret = env_aes_cbc_crypt(environment.data, 0);
1255 		if (ret)
1256 			return ret;
1257 	}
1258 
1259 	crc0_ok = (crc0 == *environment.crc);
1260 	if (!HaveRedundEnv) {
1261 		if (!crc0_ok) {
1262 			fprintf (stderr,
1263 				"Warning: Bad CRC, using default environment\n");
1264 			memcpy(environment.data, default_environment, sizeof default_environment);
1265 		}
1266 	} else {
1267 		flag0 = *environment.flags;
1268 
1269 		dev_current = 1;
1270 		addr1 = calloc(1, CUR_ENVSIZE);
1271 		if (addr1 == NULL) {
1272 			fprintf(stderr,
1273 				"Not enough memory for environment (%ld bytes)\n",
1274 				CUR_ENVSIZE);
1275 			return -1;
1276 		}
1277 		redundant = addr1;
1278 
1279 		/*
1280 		 * have to set environment.image for flash_read(), careful -
1281 		 * other pointers in environment still point inside addr0
1282 		 */
1283 		environment.image = addr1;
1284 		if (flash_io (O_RDONLY))
1285 			return -1;
1286 
1287 		/* Check flag scheme compatibility */
1288 		if (DEVTYPE(dev_current) == MTD_NORFLASH &&
1289 		    DEVTYPE(!dev_current) == MTD_NORFLASH) {
1290 			environment.flag_scheme = FLAG_BOOLEAN;
1291 		} else if (DEVTYPE(dev_current) == MTD_NANDFLASH &&
1292 			   DEVTYPE(!dev_current) == MTD_NANDFLASH) {
1293 			environment.flag_scheme = FLAG_INCREMENTAL;
1294 		} else if (DEVTYPE(dev_current) == MTD_DATAFLASH &&
1295 			   DEVTYPE(!dev_current) == MTD_DATAFLASH) {
1296 			environment.flag_scheme = FLAG_BOOLEAN;
1297 		} else if (DEVTYPE(dev_current) == MTD_UBIVOLUME &&
1298 			   DEVTYPE(!dev_current) == MTD_UBIVOLUME) {
1299 			environment.flag_scheme = FLAG_INCREMENTAL;
1300 		} else if (DEVTYPE(dev_current) == MTD_ABSENT &&
1301 			   DEVTYPE(!dev_current) == MTD_ABSENT) {
1302 			environment.flag_scheme = FLAG_INCREMENTAL;
1303 		} else {
1304 			fprintf (stderr, "Incompatible flash types!\n");
1305 			return -1;
1306 		}
1307 
1308 		crc1 = crc32 (0, (uint8_t *) redundant->data, ENV_SIZE);
1309 
1310 		if (aes_flag) {
1311 			ret = env_aes_cbc_crypt(redundant->data, 0);
1312 			if (ret)
1313 				return ret;
1314 		}
1315 
1316 		crc1_ok = (crc1 == redundant->crc);
1317 		flag1 = redundant->flags;
1318 
1319 		if (crc0_ok && !crc1_ok) {
1320 			dev_current = 0;
1321 		} else if (!crc0_ok && crc1_ok) {
1322 			dev_current = 1;
1323 		} else if (!crc0_ok && !crc1_ok) {
1324 			fprintf (stderr,
1325 				"Warning: Bad CRC, using default environment\n");
1326 			memcpy (environment.data, default_environment,
1327 				sizeof default_environment);
1328 			dev_current = 0;
1329 		} else {
1330 			switch (environment.flag_scheme) {
1331 			case FLAG_BOOLEAN:
1332 				if (flag0 == active_flag &&
1333 				    flag1 == obsolete_flag) {
1334 					dev_current = 0;
1335 				} else if (flag0 == obsolete_flag &&
1336 					   flag1 == active_flag) {
1337 					dev_current = 1;
1338 				} else if (flag0 == flag1) {
1339 					dev_current = 0;
1340 				} else if (flag0 == 0xFF) {
1341 					dev_current = 0;
1342 				} else if (flag1 == 0xFF) {
1343 					dev_current = 1;
1344 				} else {
1345 					dev_current = 0;
1346 				}
1347 				break;
1348 			case FLAG_INCREMENTAL:
1349 				if (flag0 == 255 && flag1 == 0)
1350 					dev_current = 1;
1351 				else if ((flag1 == 255 && flag0 == 0) ||
1352 					 flag0 >= flag1)
1353 					dev_current = 0;
1354 				else /* flag1 > flag0 */
1355 					dev_current = 1;
1356 				break;
1357 			default:
1358 				fprintf (stderr, "Unknown flag scheme %u \n",
1359 					 environment.flag_scheme);
1360 				return -1;
1361 			}
1362 		}
1363 
1364 		/*
1365 		 * If we are reading, we don't need the flag and the CRC any
1366 		 * more, if we are writing, we will re-calculate CRC and update
1367 		 * flags before writing out
1368 		 */
1369 		if (dev_current) {
1370 			environment.image	= addr1;
1371 			environment.crc		= &redundant->crc;
1372 			environment.flags	= &redundant->flags;
1373 			environment.data	= redundant->data;
1374 			free (addr0);
1375 		} else {
1376 			environment.image	= addr0;
1377 			/* Other pointers are already set */
1378 			free (addr1);
1379 		}
1380 #ifdef DEBUG
1381 		fprintf(stderr, "Selected env in %s\n", DEVNAME(dev_current));
1382 #endif
1383 	}
1384 	return 0;
1385 }
1386 
1387 
1388 static int parse_config ()
1389 {
1390 	struct stat st;
1391 
1392 #if defined(CONFIG_FILE)
1393 	/* Fills in DEVNAME(), ENVSIZE(), DEVESIZE(). Or don't. */
1394 	if (get_config (config_file)) {
1395 		fprintf (stderr,
1396 			"Cannot parse config file '%s': %s\n", config_file, strerror (errno));
1397 		return -1;
1398 	}
1399 #else
1400 	DEVNAME (0) = DEVICE1_NAME;
1401 	DEVOFFSET (0) = DEVICE1_OFFSET;
1402 	ENVSIZE (0) = ENV1_SIZE;
1403 	/* Default values are: erase-size=env-size */
1404 	DEVESIZE (0) = ENVSIZE (0);
1405 	/* #sectors=env-size/erase-size (rounded up) */
1406 	ENVSECTORS (0) = (ENVSIZE(0) + DEVESIZE(0) - 1) / DEVESIZE(0);
1407 #ifdef DEVICE1_ESIZE
1408 	DEVESIZE (0) = DEVICE1_ESIZE;
1409 #endif
1410 #ifdef DEVICE1_ENVSECTORS
1411 	ENVSECTORS (0) = DEVICE1_ENVSECTORS;
1412 #endif
1413 
1414 #ifdef HAVE_REDUND
1415 	DEVNAME (1) = DEVICE2_NAME;
1416 	DEVOFFSET (1) = DEVICE2_OFFSET;
1417 	ENVSIZE (1) = ENV2_SIZE;
1418 	/* Default values are: erase-size=env-size */
1419 	DEVESIZE (1) = ENVSIZE (1);
1420 	/* #sectors=env-size/erase-size (rounded up) */
1421 	ENVSECTORS (1) = (ENVSIZE(1) + DEVESIZE(1) - 1) / DEVESIZE(1);
1422 #ifdef DEVICE2_ESIZE
1423 	DEVESIZE (1) = DEVICE2_ESIZE;
1424 #endif
1425 #ifdef DEVICE2_ENVSECTORS
1426 	ENVSECTORS (1) = DEVICE2_ENVSECTORS;
1427 #endif
1428 	HaveRedundEnv = 1;
1429 #endif
1430 #endif
1431 	if (stat (DEVNAME (0), &st)) {
1432 		fprintf (stderr,
1433 			"Cannot access MTD device %s: %s\n",
1434 			DEVNAME (0), strerror (errno));
1435 		return -1;
1436 	}
1437 
1438 	if (HaveRedundEnv && stat (DEVNAME (1), &st)) {
1439 		fprintf (stderr,
1440 			"Cannot access MTD device %s: %s\n",
1441 			DEVNAME (1), strerror (errno));
1442 		return -1;
1443 	}
1444 	return 0;
1445 }
1446 
1447 #if defined(CONFIG_FILE)
1448 static int get_config (char *fname)
1449 {
1450 	FILE *fp;
1451 	int i = 0;
1452 	int rc;
1453 	char dump[128];
1454 	char *devname;
1455 
1456 	fp = fopen (fname, "r");
1457 	if (fp == NULL)
1458 		return -1;
1459 
1460 	while (i < 2 && fgets (dump, sizeof (dump), fp)) {
1461 		/* Skip incomplete conversions and comment strings */
1462 		if (dump[0] == '#')
1463 			continue;
1464 
1465 		rc = sscanf (dump, "%ms %lx %lx %lx %lx",
1466 			     &devname,
1467 			     &DEVOFFSET (i),
1468 			     &ENVSIZE (i),
1469 			     &DEVESIZE (i),
1470 			     &ENVSECTORS (i));
1471 
1472 		if (rc < 3)
1473 			continue;
1474 
1475 		DEVNAME(i) = devname;
1476 
1477 		if (rc < 4)
1478 			/* Assume the erase size is the same as the env-size */
1479 			DEVESIZE(i) = ENVSIZE(i);
1480 
1481 		if (rc < 5)
1482 			/* Assume enough env sectors to cover the environment */
1483 			ENVSECTORS (i) = (ENVSIZE(i) + DEVESIZE(i) - 1) / DEVESIZE(i);
1484 
1485 		i++;
1486 	}
1487 	fclose (fp);
1488 
1489 	HaveRedundEnv = i - 1;
1490 	if (!i) {			/* No valid entries found */
1491 		errno = EINVAL;
1492 		return -1;
1493 	} else
1494 		return 0;
1495 }
1496 #endif
1497