xref: /openbmc/u-boot/tools/env/fw_env.c (revision 95de1e2f)
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 #endif
128 static inline ulong getenvsize (void)
129 {
130 	ulong rc = CUR_ENVSIZE - sizeof(uint32_t);
131 
132 	if (HaveRedundEnv)
133 		rc -= sizeof (char);
134 
135 	if (aes_flag)
136 		rc &= ~(AES_KEY_LENGTH - 1);
137 
138 	return rc;
139 }
140 
141 static char *fw_string_blank(char *s, int noblank)
142 {
143 	int i;
144 	int len = strlen(s);
145 
146 	for (i = 0; i < len; i++, s++) {
147 		if ((noblank && !WHITESPACE(*s)) ||
148 			(!noblank && WHITESPACE(*s)))
149 			break;
150 	}
151 	if (i == len)
152 		return NULL;
153 
154 	return s;
155 }
156 
157 /*
158  * Search the environment for a variable.
159  * Return the value, if found, or NULL, if not found.
160  */
161 char *fw_getenv (char *name)
162 {
163 	char *env, *nxt;
164 
165 	for (env = environment.data; *env; env = nxt + 1) {
166 		char *val;
167 
168 		for (nxt = env; *nxt; ++nxt) {
169 			if (nxt >= &environment.data[ENV_SIZE]) {
170 				fprintf (stderr, "## Error: "
171 					"environment not terminated\n");
172 				return NULL;
173 			}
174 		}
175 		val = envmatch (name, env);
176 		if (!val)
177 			continue;
178 		return val;
179 	}
180 	return NULL;
181 }
182 
183 /*
184  * Search the default environment for a variable.
185  * Return the value, if found, or NULL, if not found.
186  */
187 char *fw_getdefenv(char *name)
188 {
189 	char *env, *nxt;
190 
191 	for (env = default_environment; *env; env = nxt + 1) {
192 		char *val;
193 
194 		for (nxt = env; *nxt; ++nxt) {
195 			if (nxt >= &default_environment[ENV_SIZE]) {
196 				fprintf(stderr, "## Error: "
197 					"default environment not terminated\n");
198 				return NULL;
199 			}
200 		}
201 		val = envmatch(name, env);
202 		if (!val)
203 			continue;
204 		return val;
205 	}
206 	return NULL;
207 }
208 
209 static int parse_aes_key(char *key)
210 {
211 	char tmp[5] = { '0', 'x', 0, 0, 0 };
212 	unsigned long ul;
213 	int i;
214 
215 	if (strnlen(key, 64) != 32) {
216 		fprintf(stderr,
217 			"## Error: '-a' option requires 16-byte AES key\n");
218 		return -1;
219 	}
220 
221 	for (i = 0; i < 16; i++) {
222 		tmp[2] = key[0];
223 		tmp[3] = key[1];
224 		errno = 0;
225 		ul = strtoul(tmp, NULL, 16);
226 		if (errno) {
227 			fprintf(stderr,
228 				"## Error: '-a' option requires valid AES key\n");
229 			return -1;
230 		}
231 		aes_key[i] = ul & 0xff;
232 		key += 2;
233 	}
234 	aes_flag = 1;
235 
236 	return 0;
237 }
238 
239 /*
240  * Print the current definition of one, or more, or all
241  * environment variables
242  */
243 int fw_printenv (int argc, char *argv[])
244 {
245 	char *env, *nxt;
246 	int i, n_flag;
247 	int rc = 0;
248 
249 	if (argc >= 2 && strcmp(argv[1], "-a") == 0) {
250 		if (argc < 3) {
251 			fprintf(stderr,
252 				"## Error: '-a' option requires AES key\n");
253 			return -1;
254 		}
255 		rc = parse_aes_key(argv[2]);
256 		if (rc)
257 			return rc;
258 		argv += 2;
259 		argc -= 2;
260 	}
261 
262 	if (fw_env_open())
263 		return -1;
264 
265 	if (argc == 1) {		/* Print all env variables  */
266 		for (env = environment.data; *env; env = nxt + 1) {
267 			for (nxt = env; *nxt; ++nxt) {
268 				if (nxt >= &environment.data[ENV_SIZE]) {
269 					fprintf (stderr, "## Error: "
270 						"environment not terminated\n");
271 					return -1;
272 				}
273 			}
274 
275 			printf ("%s\n", env);
276 		}
277 		return 0;
278 	}
279 
280 	if (strcmp (argv[1], "-n") == 0) {
281 		n_flag = 1;
282 		++argv;
283 		--argc;
284 		if (argc != 2) {
285 			fprintf (stderr, "## Error: "
286 				"`-n' option requires exactly one argument\n");
287 			return -1;
288 		}
289 	} else {
290 		n_flag = 0;
291 	}
292 
293 	for (i = 1; i < argc; ++i) {	/* print single env variables   */
294 		char *name = argv[i];
295 		char *val = NULL;
296 
297 		for (env = environment.data; *env; env = nxt + 1) {
298 
299 			for (nxt = env; *nxt; ++nxt) {
300 				if (nxt >= &environment.data[ENV_SIZE]) {
301 					fprintf (stderr, "## Error: "
302 						"environment not terminated\n");
303 					return -1;
304 				}
305 			}
306 			val = envmatch (name, env);
307 			if (val) {
308 				if (!n_flag) {
309 					fputs (name, stdout);
310 					putc ('=', stdout);
311 				}
312 				puts (val);
313 				break;
314 			}
315 		}
316 		if (!val) {
317 			fprintf (stderr, "## Error: \"%s\" not defined\n", name);
318 			rc = -1;
319 		}
320 	}
321 
322 	return rc;
323 }
324 
325 int fw_env_close(void)
326 {
327 	int ret;
328 	if (aes_flag) {
329 		ret = env_aes_cbc_crypt(environment.data, 1);
330 		if (ret) {
331 			fprintf(stderr,
332 				"Error: can't encrypt env for flash\n");
333 			return ret;
334 		}
335 	}
336 
337 	/*
338 	 * Update CRC
339 	 */
340 	*environment.crc = crc32(0, (uint8_t *) environment.data, ENV_SIZE);
341 
342 	/* write environment back to flash */
343 	if (flash_io(O_RDWR)) {
344 		fprintf(stderr,
345 			"Error: can't write fw_env to flash\n");
346 			return -1;
347 	}
348 
349 	return 0;
350 }
351 
352 
353 /*
354  * Set/Clear a single variable in the environment.
355  * This is called in sequence to update the environment
356  * in RAM without updating the copy in flash after each set
357  */
358 int fw_env_write(char *name, char *value)
359 {
360 	int len;
361 	char *env, *nxt;
362 	char *oldval = NULL;
363 	int deleting, creating, overwriting;
364 
365 	/*
366 	 * search if variable with this name already exists
367 	 */
368 	for (nxt = env = environment.data; *env; env = nxt + 1) {
369 		for (nxt = env; *nxt; ++nxt) {
370 			if (nxt >= &environment.data[ENV_SIZE]) {
371 				fprintf(stderr, "## Error: "
372 					"environment not terminated\n");
373 				errno = EINVAL;
374 				return -1;
375 			}
376 		}
377 		if ((oldval = envmatch (name, env)) != NULL)
378 			break;
379 	}
380 
381 	deleting = (oldval && !(value && strlen(value)));
382 	creating = (!oldval && (value && strlen(value)));
383 	overwriting = (oldval && (value && strlen(value)));
384 
385 	/* check for permission */
386 	if (deleting) {
387 		if (env_flags_validate_varaccess(name,
388 		    ENV_FLAGS_VARACCESS_PREVENT_DELETE)) {
389 			printf("Can't delete \"%s\"\n", name);
390 			errno = EROFS;
391 			return -1;
392 		}
393 	} else if (overwriting) {
394 		if (env_flags_validate_varaccess(name,
395 		    ENV_FLAGS_VARACCESS_PREVENT_OVERWR)) {
396 			printf("Can't overwrite \"%s\"\n", name);
397 			errno = EROFS;
398 			return -1;
399 		} else if (env_flags_validate_varaccess(name,
400 		    ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR)) {
401 			const char *defval = fw_getdefenv(name);
402 
403 			if (defval == NULL)
404 				defval = "";
405 			if (strcmp(oldval, defval)
406 			    != 0) {
407 				printf("Can't overwrite \"%s\"\n", name);
408 				errno = EROFS;
409 				return -1;
410 			}
411 		}
412 	} else if (creating) {
413 		if (env_flags_validate_varaccess(name,
414 		    ENV_FLAGS_VARACCESS_PREVENT_CREATE)) {
415 			printf("Can't create \"%s\"\n", name);
416 			errno = EROFS;
417 			return -1;
418 		}
419 	} else
420 		/* Nothing to do */
421 		return 0;
422 
423 	if (deleting || overwriting) {
424 		if (*++nxt == '\0') {
425 			*env = '\0';
426 		} else {
427 			for (;;) {
428 				*env = *nxt++;
429 				if ((*env == '\0') && (*nxt == '\0'))
430 					break;
431 				++env;
432 			}
433 		}
434 		*++env = '\0';
435 	}
436 
437 	/* Delete only ? */
438 	if (!value || !strlen(value))
439 		return 0;
440 
441 	/*
442 	 * Append new definition at the end
443 	 */
444 	for (env = environment.data; *env || *(env + 1); ++env);
445 	if (env > environment.data)
446 		++env;
447 	/*
448 	 * Overflow when:
449 	 * "name" + "=" + "val" +"\0\0"  > CUR_ENVSIZE - (env-environment)
450 	 */
451 	len = strlen (name) + 2;
452 	/* add '=' for first arg, ' ' for all others */
453 	len += strlen(value) + 1;
454 
455 	if (len > (&environment.data[ENV_SIZE] - env)) {
456 		fprintf (stderr,
457 			"Error: environment overflow, \"%s\" deleted\n",
458 			name);
459 		return -1;
460 	}
461 
462 	while ((*env = *name++) != '\0')
463 		env++;
464 	*env = '=';
465 	while ((*++env = *value++) != '\0')
466 		;
467 
468 	/* end is marked with double '\0' */
469 	*++env = '\0';
470 
471 	return 0;
472 }
473 
474 /*
475  * Deletes or sets environment variables. Returns -1 and sets errno error codes:
476  * 0	  - OK
477  * EINVAL - need at least 1 argument
478  * EROFS  - certain variables ("ethaddr", "serial#") cannot be
479  *	    modified or deleted
480  *
481  */
482 int fw_setenv(int argc, char *argv[])
483 {
484 	int i, rc;
485 	size_t len;
486 	char *name;
487 	char *value = NULL;
488 
489 	if (argc < 2) {
490 		errno = EINVAL;
491 		return -1;
492 	}
493 
494 	if (strcmp(argv[1], "-a") == 0) {
495 		if (argc < 3) {
496 			fprintf(stderr,
497 				"## Error: '-a' option requires AES key\n");
498 			return -1;
499 		}
500 		rc = parse_aes_key(argv[2]);
501 		if (rc)
502 			return rc;
503 		argv += 2;
504 		argc -= 2;
505 	}
506 
507 	if (argc < 2) {
508 		errno = EINVAL;
509 		return -1;
510 	}
511 
512 	if (fw_env_open()) {
513 		fprintf(stderr, "Error: environment not initialized\n");
514 		return -1;
515 	}
516 
517 	name = argv[1];
518 
519 	if (env_flags_validate_env_set_params(argc, argv) < 0)
520 		return 1;
521 
522 	len = 0;
523 	for (i = 2; i < argc; ++i) {
524 		char *val = argv[i];
525 		size_t val_len = strlen(val);
526 
527 		if (value)
528 			value[len - 1] = ' ';
529 		value = realloc(value, len + val_len + 1);
530 		if (!value) {
531 			fprintf(stderr,
532 				"Cannot malloc %zu bytes: %s\n",
533 				len, strerror(errno));
534 			return -1;
535 		}
536 
537 		memcpy(value + len, val, val_len);
538 		len += val_len;
539 		value[len++] = '\0';
540 	}
541 
542 	fw_env_write(name, value);
543 
544 	free(value);
545 
546 	return fw_env_close();
547 }
548 
549 /*
550  * Parse  a file  and configure the u-boot variables.
551  * The script file has a very simple format, as follows:
552  *
553  * Each line has a couple with name, value:
554  * <white spaces>variable_name<white spaces>variable_value
555  *
556  * Both variable_name and variable_value are interpreted as strings.
557  * Any character after <white spaces> and before ending \r\n is interpreted
558  * as variable's value (no comment allowed on these lines !)
559  *
560  * Comments are allowed if the first character in the line is #
561  *
562  * Returns -1 and sets errno error codes:
563  * 0	  - OK
564  * -1     - Error
565  */
566 int fw_parse_script(char *fname)
567 {
568 	FILE *fp;
569 	char dump[1024];	/* Maximum line length in the file */
570 	char *name;
571 	char *val;
572 	int lineno = 0;
573 	int len;
574 	int ret = 0;
575 
576 	if (fw_env_open()) {
577 		fprintf(stderr, "Error: environment not initialized\n");
578 		return -1;
579 	}
580 
581 	if (strcmp(fname, "-") == 0)
582 		fp = stdin;
583 	else {
584 		fp = fopen(fname, "r");
585 		if (fp == NULL) {
586 			fprintf(stderr, "I cannot open %s for reading\n",
587 				 fname);
588 			return -1;
589 		}
590 	}
591 
592 	while (fgets(dump, sizeof(dump), fp)) {
593 		lineno++;
594 		len = strlen(dump);
595 
596 		/*
597 		 * Read a whole line from the file. If the line is too long
598 		 * or is not terminated, reports an error and exit.
599 		 */
600 		if (dump[len - 1] != '\n') {
601 			fprintf(stderr,
602 			"Line %d not corrected terminated or too long\n",
603 				lineno);
604 			ret = -1;
605 			break;
606 		}
607 
608 		/* Drop ending line feed / carriage return */
609 		while (len > 0 && (dump[len - 1] == '\n' ||
610 				dump[len - 1] == '\r')) {
611 			dump[len - 1] = '\0';
612 			len--;
613 		}
614 
615 		/* Skip comment or empty lines */
616 		if ((len == 0) || dump[0] == '#')
617 			continue;
618 
619 		/*
620 		 * Search for variable's name,
621 		 * remove leading whitespaces
622 		 */
623 		name = fw_string_blank(dump, 1);
624 		if (!name)
625 			continue;
626 
627 		/* The first white space is the end of variable name */
628 		val = fw_string_blank(name, 0);
629 		len = strlen(name);
630 		if (val) {
631 			*val++ = '\0';
632 			if ((val - name) < len)
633 				val = fw_string_blank(val, 1);
634 			else
635 				val = NULL;
636 		}
637 
638 #ifdef DEBUG
639 		fprintf(stderr, "Setting %s : %s\n",
640 			name, val ? val : " removed");
641 #endif
642 
643 		if (env_flags_validate_type(name, val) < 0) {
644 			ret = -1;
645 			break;
646 		}
647 
648 		/*
649 		 * If there is an error setting a variable,
650 		 * try to save the environment and returns an error
651 		 */
652 		if (fw_env_write(name, val)) {
653 			fprintf(stderr,
654 			"fw_env_write returns with error : %s\n",
655 				strerror(errno));
656 			ret = -1;
657 			break;
658 		}
659 
660 	}
661 
662 	/* Close file if not stdin */
663 	if (strcmp(fname, "-") != 0)
664 		fclose(fp);
665 
666 	ret |= fw_env_close();
667 
668 	return ret;
669 
670 }
671 
672 /*
673  * Test for bad block on NAND, just returns 0 on NOR, on NAND:
674  * 0	- block is good
675  * > 0	- block is bad
676  * < 0	- failed to test
677  */
678 static int flash_bad_block (int fd, uint8_t mtd_type, loff_t *blockstart)
679 {
680 	if (mtd_type == MTD_NANDFLASH) {
681 		int badblock = ioctl (fd, MEMGETBADBLOCK, blockstart);
682 
683 		if (badblock < 0) {
684 			perror ("Cannot read bad block mark");
685 			return badblock;
686 		}
687 
688 		if (badblock) {
689 #ifdef DEBUG
690 			fprintf (stderr, "Bad block at 0x%llx, "
691 				 "skipping\n", *blockstart);
692 #endif
693 			return badblock;
694 		}
695 	}
696 
697 	return 0;
698 }
699 
700 /*
701  * Read data from flash at an offset into a provided buffer. On NAND it skips
702  * bad blocks but makes sure it stays within ENVSECTORS (dev) starting from
703  * the DEVOFFSET (dev) block. On NOR the loop is only run once.
704  */
705 static int flash_read_buf (int dev, int fd, void *buf, size_t count,
706 			   off_t offset, uint8_t mtd_type)
707 {
708 	size_t blocklen;	/* erase / write length - one block on NAND,
709 				   0 on NOR */
710 	size_t processed = 0;	/* progress counter */
711 	size_t readlen = count;	/* current read length */
712 	off_t top_of_range;	/* end of the last block we may use */
713 	off_t block_seek;	/* offset inside the current block to the start
714 				   of the data */
715 	loff_t blockstart;	/* running start of the current block -
716 				   MEMGETBADBLOCK needs 64 bits */
717 	int rc;
718 
719 	blockstart = (offset / DEVESIZE (dev)) * DEVESIZE (dev);
720 
721 	/* Offset inside a block */
722 	block_seek = offset - blockstart;
723 
724 	if (mtd_type == MTD_NANDFLASH) {
725 		/*
726 		 * NAND: calculate which blocks we are reading. We have
727 		 * to read one block at a time to skip bad blocks.
728 		 */
729 		blocklen = DEVESIZE (dev);
730 
731 		/*
732 		 * To calculate the top of the range, we have to use the
733 		 * global DEVOFFSET (dev), which can be different from offset
734 		 */
735 		top_of_range = ((DEVOFFSET(dev) / blocklen) +
736 				ENVSECTORS (dev)) * blocklen;
737 
738 		/* Limit to one block for the first read */
739 		if (readlen > blocklen - block_seek)
740 			readlen = blocklen - block_seek;
741 	} else {
742 		blocklen = 0;
743 		top_of_range = offset + count;
744 	}
745 
746 	/* This only runs once on NOR flash */
747 	while (processed < count) {
748 		rc = flash_bad_block (fd, mtd_type, &blockstart);
749 		if (rc < 0)		/* block test failed */
750 			return -1;
751 
752 		if (blockstart + block_seek + readlen > top_of_range) {
753 			/* End of range is reached */
754 			fprintf (stderr,
755 				 "Too few good blocks within range\n");
756 			return -1;
757 		}
758 
759 		if (rc) {		/* block is bad */
760 			blockstart += blocklen;
761 			continue;
762 		}
763 
764 		/*
765 		 * If a block is bad, we retry in the next block at the same
766 		 * offset - see common/env_nand.c::writeenv()
767 		 */
768 		lseek (fd, blockstart + block_seek, SEEK_SET);
769 
770 		rc = read (fd, buf + processed, readlen);
771 		if (rc != readlen) {
772 			fprintf (stderr, "Read error on %s: %s\n",
773 				 DEVNAME (dev), strerror (errno));
774 			return -1;
775 		}
776 #ifdef DEBUG
777 		fprintf(stderr, "Read 0x%x bytes at 0x%llx on %s\n",
778 			 rc, blockstart + block_seek, DEVNAME(dev));
779 #endif
780 		processed += readlen;
781 		readlen = min (blocklen, count - processed);
782 		block_seek = 0;
783 		blockstart += blocklen;
784 	}
785 
786 	return processed;
787 }
788 
789 /*
790  * Write count bytes at offset, but stay within ENVSECTORS (dev) sectors of
791  * DEVOFFSET (dev). Similar to the read case above, on NOR and dataflash we
792  * erase and write the whole data at once.
793  */
794 static int flash_write_buf (int dev, int fd, void *buf, size_t count,
795 			    off_t offset, uint8_t mtd_type)
796 {
797 	void *data;
798 	struct erase_info_user erase;
799 	size_t blocklen;	/* length of NAND block / NOR erase sector */
800 	size_t erase_len;	/* whole area that can be erased - may include
801 				   bad blocks */
802 	size_t erasesize;	/* erase / write length - one block on NAND,
803 				   whole area on NOR */
804 	size_t processed = 0;	/* progress counter */
805 	size_t write_total;	/* total size to actually write - excluding
806 				   bad blocks */
807 	off_t erase_offset;	/* offset to the first erase block (aligned)
808 				   below offset */
809 	off_t block_seek;	/* offset inside the erase block to the start
810 				   of the data */
811 	off_t top_of_range;	/* end of the last block we may use */
812 	loff_t blockstart;	/* running start of the current block -
813 				   MEMGETBADBLOCK needs 64 bits */
814 	int rc;
815 
816 	/*
817 	 * For mtd devices only offset and size of the environment do matter
818 	 */
819 	if (mtd_type == MTD_ABSENT) {
820 		blocklen = count;
821 		top_of_range = offset + count;
822 		erase_len = blocklen;
823 		blockstart = offset;
824 		block_seek = 0;
825 		write_total = blocklen;
826 	} else {
827 		blocklen = DEVESIZE(dev);
828 
829 		top_of_range = ((DEVOFFSET(dev) / blocklen) +
830 					ENVSECTORS(dev)) * blocklen;
831 
832 		erase_offset = (offset / blocklen) * blocklen;
833 
834 		/* Maximum area we may use */
835 		erase_len = top_of_range - erase_offset;
836 
837 		blockstart = erase_offset;
838 		/* Offset inside a block */
839 		block_seek = offset - erase_offset;
840 
841 		/*
842 		 * Data size we actually write: from the start of the block
843 		 * to the start of the data, then count bytes of data, and
844 		 * to the end of the block
845 		 */
846 		write_total = ((block_seek + count + blocklen - 1) /
847 							blocklen) * blocklen;
848 	}
849 
850 	/*
851 	 * Support data anywhere within erase sectors: read out the complete
852 	 * area to be erased, replace the environment image, write the whole
853 	 * block back again.
854 	 */
855 	if (write_total > count) {
856 		data = malloc (erase_len);
857 		if (!data) {
858 			fprintf (stderr,
859 				 "Cannot malloc %zu bytes: %s\n",
860 				 erase_len, strerror (errno));
861 			return -1;
862 		}
863 
864 		rc = flash_read_buf (dev, fd, data, write_total, erase_offset,
865 				     mtd_type);
866 		if (write_total != rc)
867 			return -1;
868 
869 #ifdef DEBUG
870 		fprintf(stderr, "Preserving data ");
871 		if (block_seek != 0)
872 			fprintf(stderr, "0x%x - 0x%lx", 0, block_seek - 1);
873 		if (block_seek + count != write_total) {
874 			if (block_seek != 0)
875 				fprintf(stderr, " and ");
876 			fprintf(stderr, "0x%lx - 0x%x",
877 				block_seek + count, write_total - 1);
878 		}
879 		fprintf(stderr, "\n");
880 #endif
881 		/* Overwrite the old environment */
882 		memcpy (data + block_seek, buf, count);
883 	} else {
884 		/*
885 		 * We get here, iff offset is block-aligned and count is a
886 		 * multiple of blocklen - see write_total calculation above
887 		 */
888 		data = buf;
889 	}
890 
891 	if (mtd_type == MTD_NANDFLASH) {
892 		/*
893 		 * NAND: calculate which blocks we are writing. We have
894 		 * to write one block at a time to skip bad blocks.
895 		 */
896 		erasesize = blocklen;
897 	} else {
898 		erasesize = erase_len;
899 	}
900 
901 	erase.length = erasesize;
902 
903 	/* This only runs once on NOR flash and SPI-dataflash */
904 	while (processed < write_total) {
905 		rc = flash_bad_block (fd, mtd_type, &blockstart);
906 		if (rc < 0)		/* block test failed */
907 			return rc;
908 
909 		if (blockstart + erasesize > top_of_range) {
910 			fprintf (stderr, "End of range reached, aborting\n");
911 			return -1;
912 		}
913 
914 		if (rc) {		/* block is bad */
915 			blockstart += blocklen;
916 			continue;
917 		}
918 
919 		if (mtd_type != MTD_ABSENT) {
920 			erase.start = blockstart;
921 			ioctl(fd, MEMUNLOCK, &erase);
922 			/* These do not need an explicit erase cycle */
923 			if (mtd_type != MTD_DATAFLASH)
924 				if (ioctl(fd, MEMERASE, &erase) != 0) {
925 					fprintf(stderr,
926 						"MTD erase error on %s: %s\n",
927 						DEVNAME(dev), strerror(errno));
928 					return -1;
929 				}
930 		}
931 
932 		if (lseek (fd, blockstart, SEEK_SET) == -1) {
933 			fprintf (stderr,
934 				 "Seek error on %s: %s\n",
935 				 DEVNAME (dev), strerror (errno));
936 			return -1;
937 		}
938 
939 #ifdef DEBUG
940 		fprintf(stderr, "Write 0x%x bytes at 0x%llx\n", erasesize,
941 			blockstart);
942 #endif
943 		if (write (fd, data + processed, erasesize) != erasesize) {
944 			fprintf (stderr, "Write error on %s: %s\n",
945 				 DEVNAME (dev), strerror (errno));
946 			return -1;
947 		}
948 
949 		if (mtd_type != MTD_ABSENT)
950 			ioctl(fd, MEMLOCK, &erase);
951 
952 		processed  += erasesize;
953 		block_seek = 0;
954 		blockstart += erasesize;
955 	}
956 
957 	if (write_total > count)
958 		free (data);
959 
960 	return processed;
961 }
962 
963 /*
964  * Set obsolete flag at offset - NOR flash only
965  */
966 static int flash_flag_obsolete (int dev, int fd, off_t offset)
967 {
968 	int rc;
969 	struct erase_info_user erase;
970 
971 	erase.start  = DEVOFFSET (dev);
972 	erase.length = DEVESIZE (dev);
973 	/* This relies on the fact, that obsolete_flag == 0 */
974 	rc = lseek (fd, offset, SEEK_SET);
975 	if (rc < 0) {
976 		fprintf (stderr, "Cannot seek to set the flag on %s \n",
977 			 DEVNAME (dev));
978 		return rc;
979 	}
980 	ioctl (fd, MEMUNLOCK, &erase);
981 	rc = write (fd, &obsolete_flag, sizeof (obsolete_flag));
982 	ioctl (fd, MEMLOCK, &erase);
983 	if (rc < 0)
984 		perror ("Could not set obsolete flag");
985 
986 	return rc;
987 }
988 
989 /* Encrypt or decrypt the environment before writing or reading it. */
990 static int env_aes_cbc_crypt(char *payload, const int enc)
991 {
992 	uint8_t *data = (uint8_t *)payload;
993 	const int len = getenvsize();
994 	uint8_t key_exp[AES_EXPAND_KEY_LENGTH];
995 	uint32_t aes_blocks;
996 
997 	/* First we expand the key. */
998 	aes_expand_key(aes_key, key_exp);
999 
1000 	/* Calculate the number of AES blocks to encrypt. */
1001 	aes_blocks = DIV_ROUND_UP(len, AES_KEY_LENGTH);
1002 
1003 	if (enc)
1004 		aes_cbc_encrypt_blocks(key_exp, data, data, aes_blocks);
1005 	else
1006 		aes_cbc_decrypt_blocks(key_exp, data, data, aes_blocks);
1007 
1008 	return 0;
1009 }
1010 
1011 static int flash_write (int fd_current, int fd_target, int dev_target)
1012 {
1013 	int rc;
1014 
1015 	switch (environment.flag_scheme) {
1016 	case FLAG_NONE:
1017 		break;
1018 	case FLAG_INCREMENTAL:
1019 		(*environment.flags)++;
1020 		break;
1021 	case FLAG_BOOLEAN:
1022 		*environment.flags = active_flag;
1023 		break;
1024 	default:
1025 		fprintf (stderr, "Unimplemented flash scheme %u \n",
1026 			 environment.flag_scheme);
1027 		return -1;
1028 	}
1029 
1030 #ifdef DEBUG
1031 	fprintf(stderr, "Writing new environment at 0x%lx on %s\n",
1032 		DEVOFFSET (dev_target), DEVNAME (dev_target));
1033 #endif
1034 
1035 	rc = flash_write_buf(dev_target, fd_target, environment.image,
1036 			      CUR_ENVSIZE, DEVOFFSET(dev_target),
1037 			      DEVTYPE(dev_target));
1038 	if (rc < 0)
1039 		return rc;
1040 
1041 	if (environment.flag_scheme == FLAG_BOOLEAN) {
1042 		/* Have to set obsolete flag */
1043 		off_t offset = DEVOFFSET (dev_current) +
1044 			offsetof (struct env_image_redundant, flags);
1045 #ifdef DEBUG
1046 		fprintf(stderr,
1047 			"Setting obsolete flag in environment at 0x%lx on %s\n",
1048 			DEVOFFSET (dev_current), DEVNAME (dev_current));
1049 #endif
1050 		flash_flag_obsolete (dev_current, fd_current, offset);
1051 	}
1052 
1053 	return 0;
1054 }
1055 
1056 static int flash_read (int fd)
1057 {
1058 	struct mtd_info_user mtdinfo;
1059 	struct stat st;
1060 	int rc;
1061 
1062 	rc = fstat(fd, &st);
1063 	if (rc < 0) {
1064 		fprintf(stderr, "Cannot stat the file %s\n",
1065 			DEVNAME(dev_current));
1066 		return -1;
1067 	}
1068 
1069 	if (S_ISCHR(st.st_mode)) {
1070 		rc = ioctl(fd, MEMGETINFO, &mtdinfo);
1071 		if (rc < 0) {
1072 			fprintf(stderr, "Cannot get MTD information for %s\n",
1073 				DEVNAME(dev_current));
1074 			return -1;
1075 		}
1076 		if (mtdinfo.type != MTD_NORFLASH &&
1077 		    mtdinfo.type != MTD_NANDFLASH &&
1078 		    mtdinfo.type != MTD_DATAFLASH &&
1079 		    mtdinfo.type != MTD_UBIVOLUME) {
1080 			fprintf (stderr, "Unsupported flash type %u on %s\n",
1081 				 mtdinfo.type, DEVNAME(dev_current));
1082 			return -1;
1083 		}
1084 	} else {
1085 		memset(&mtdinfo, 0, sizeof(mtdinfo));
1086 		mtdinfo.type = MTD_ABSENT;
1087 	}
1088 
1089 	DEVTYPE(dev_current) = mtdinfo.type;
1090 
1091 	rc = flash_read_buf(dev_current, fd, environment.image, CUR_ENVSIZE,
1092 			     DEVOFFSET (dev_current), mtdinfo.type);
1093 	if (rc != CUR_ENVSIZE)
1094 		return -1;
1095 
1096 	return 0;
1097 }
1098 
1099 static int flash_io (int mode)
1100 {
1101 	int fd_current, fd_target, rc, dev_target;
1102 
1103 	/* dev_current: fd_current, erase_current */
1104 	fd_current = open (DEVNAME (dev_current), mode);
1105 	if (fd_current < 0) {
1106 		fprintf (stderr,
1107 			 "Can't open %s: %s\n",
1108 			 DEVNAME (dev_current), strerror (errno));
1109 		return -1;
1110 	}
1111 
1112 	if (mode == O_RDWR) {
1113 		if (HaveRedundEnv) {
1114 			/* switch to next partition for writing */
1115 			dev_target = !dev_current;
1116 			/* dev_target: fd_target, erase_target */
1117 			fd_target = open (DEVNAME (dev_target), mode);
1118 			if (fd_target < 0) {
1119 				fprintf (stderr,
1120 					 "Can't open %s: %s\n",
1121 					 DEVNAME (dev_target),
1122 					 strerror (errno));
1123 				rc = -1;
1124 				goto exit;
1125 			}
1126 		} else {
1127 			dev_target = dev_current;
1128 			fd_target = fd_current;
1129 		}
1130 
1131 		rc = flash_write (fd_current, fd_target, dev_target);
1132 
1133 		if (HaveRedundEnv) {
1134 			if (close (fd_target)) {
1135 				fprintf (stderr,
1136 					"I/O error on %s: %s\n",
1137 					DEVNAME (dev_target),
1138 					strerror (errno));
1139 				rc = -1;
1140 			}
1141 		}
1142 	} else {
1143 		rc = flash_read (fd_current);
1144 	}
1145 
1146 exit:
1147 	if (close (fd_current)) {
1148 		fprintf (stderr,
1149 			 "I/O error on %s: %s\n",
1150 			 DEVNAME (dev_current), strerror (errno));
1151 		return -1;
1152 	}
1153 
1154 	return rc;
1155 }
1156 
1157 /*
1158  * s1 is either a simple 'name', or a 'name=value' pair.
1159  * s2 is a 'name=value' pair.
1160  * If the names match, return the value of s2, else NULL.
1161  */
1162 
1163 static char *envmatch (char * s1, char * s2)
1164 {
1165 	if (s1 == NULL || s2 == NULL)
1166 		return NULL;
1167 
1168 	while (*s1 == *s2++)
1169 		if (*s1++ == '=')
1170 			return s2;
1171 	if (*s1 == '\0' && *(s2 - 1) == '=')
1172 		return s2;
1173 	return NULL;
1174 }
1175 
1176 /*
1177  * Prevent confusion if running from erased flash memory
1178  */
1179 int fw_env_open(void)
1180 {
1181 	int crc0, crc0_ok;
1182 	unsigned char flag0;
1183 	void *addr0;
1184 
1185 	int crc1, crc1_ok;
1186 	unsigned char flag1;
1187 	void *addr1;
1188 
1189 	int ret;
1190 
1191 	struct env_image_single *single;
1192 	struct env_image_redundant *redundant;
1193 
1194 	if (parse_config ())		/* should fill envdevices */
1195 		return -1;
1196 
1197 	addr0 = calloc(1, CUR_ENVSIZE);
1198 	if (addr0 == NULL) {
1199 		fprintf(stderr,
1200 			"Not enough memory for environment (%ld bytes)\n",
1201 			CUR_ENVSIZE);
1202 		return -1;
1203 	}
1204 
1205 	/* read environment from FLASH to local buffer */
1206 	environment.image = addr0;
1207 
1208 	if (HaveRedundEnv) {
1209 		redundant = addr0;
1210 		environment.crc		= &redundant->crc;
1211 		environment.flags	= &redundant->flags;
1212 		environment.data	= redundant->data;
1213 	} else {
1214 		single = addr0;
1215 		environment.crc		= &single->crc;
1216 		environment.flags	= NULL;
1217 		environment.data	= single->data;
1218 	}
1219 
1220 	dev_current = 0;
1221 	if (flash_io (O_RDONLY))
1222 		return -1;
1223 
1224 	crc0 = crc32 (0, (uint8_t *) environment.data, ENV_SIZE);
1225 
1226 	if (aes_flag) {
1227 		ret = env_aes_cbc_crypt(environment.data, 0);
1228 		if (ret)
1229 			return ret;
1230 	}
1231 
1232 	crc0_ok = (crc0 == *environment.crc);
1233 	if (!HaveRedundEnv) {
1234 		if (!crc0_ok) {
1235 			fprintf (stderr,
1236 				"Warning: Bad CRC, using default environment\n");
1237 			memcpy(environment.data, default_environment, sizeof default_environment);
1238 		}
1239 	} else {
1240 		flag0 = *environment.flags;
1241 
1242 		dev_current = 1;
1243 		addr1 = calloc(1, CUR_ENVSIZE);
1244 		if (addr1 == NULL) {
1245 			fprintf(stderr,
1246 				"Not enough memory for environment (%ld bytes)\n",
1247 				CUR_ENVSIZE);
1248 			return -1;
1249 		}
1250 		redundant = addr1;
1251 
1252 		/*
1253 		 * have to set environment.image for flash_read(), careful -
1254 		 * other pointers in environment still point inside addr0
1255 		 */
1256 		environment.image = addr1;
1257 		if (flash_io (O_RDONLY))
1258 			return -1;
1259 
1260 		/* Check flag scheme compatibility */
1261 		if (DEVTYPE(dev_current) == MTD_NORFLASH &&
1262 		    DEVTYPE(!dev_current) == MTD_NORFLASH) {
1263 			environment.flag_scheme = FLAG_BOOLEAN;
1264 		} else if (DEVTYPE(dev_current) == MTD_NANDFLASH &&
1265 			   DEVTYPE(!dev_current) == MTD_NANDFLASH) {
1266 			environment.flag_scheme = FLAG_INCREMENTAL;
1267 		} else if (DEVTYPE(dev_current) == MTD_DATAFLASH &&
1268 			   DEVTYPE(!dev_current) == MTD_DATAFLASH) {
1269 			environment.flag_scheme = FLAG_BOOLEAN;
1270 		} else if (DEVTYPE(dev_current) == MTD_UBIVOLUME &&
1271 			   DEVTYPE(!dev_current) == MTD_UBIVOLUME) {
1272 			environment.flag_scheme = FLAG_INCREMENTAL;
1273 		} else if (DEVTYPE(dev_current) == MTD_ABSENT &&
1274 			   DEVTYPE(!dev_current) == MTD_ABSENT) {
1275 			environment.flag_scheme = FLAG_INCREMENTAL;
1276 		} else {
1277 			fprintf (stderr, "Incompatible flash types!\n");
1278 			return -1;
1279 		}
1280 
1281 		crc1 = crc32 (0, (uint8_t *) redundant->data, ENV_SIZE);
1282 
1283 		if (aes_flag) {
1284 			ret = env_aes_cbc_crypt(redundant->data, 0);
1285 			if (ret)
1286 				return ret;
1287 		}
1288 
1289 		crc1_ok = (crc1 == redundant->crc);
1290 		flag1 = redundant->flags;
1291 
1292 		if (crc0_ok && !crc1_ok) {
1293 			dev_current = 0;
1294 		} else if (!crc0_ok && crc1_ok) {
1295 			dev_current = 1;
1296 		} else if (!crc0_ok && !crc1_ok) {
1297 			fprintf (stderr,
1298 				"Warning: Bad CRC, using default environment\n");
1299 			memcpy (environment.data, default_environment,
1300 				sizeof default_environment);
1301 			dev_current = 0;
1302 		} else {
1303 			switch (environment.flag_scheme) {
1304 			case FLAG_BOOLEAN:
1305 				if (flag0 == active_flag &&
1306 				    flag1 == obsolete_flag) {
1307 					dev_current = 0;
1308 				} else if (flag0 == obsolete_flag &&
1309 					   flag1 == active_flag) {
1310 					dev_current = 1;
1311 				} else if (flag0 == flag1) {
1312 					dev_current = 0;
1313 				} else if (flag0 == 0xFF) {
1314 					dev_current = 0;
1315 				} else if (flag1 == 0xFF) {
1316 					dev_current = 1;
1317 				} else {
1318 					dev_current = 0;
1319 				}
1320 				break;
1321 			case FLAG_INCREMENTAL:
1322 				if (flag0 == 255 && flag1 == 0)
1323 					dev_current = 1;
1324 				else if ((flag1 == 255 && flag0 == 0) ||
1325 					 flag0 >= flag1)
1326 					dev_current = 0;
1327 				else /* flag1 > flag0 */
1328 					dev_current = 1;
1329 				break;
1330 			default:
1331 				fprintf (stderr, "Unknown flag scheme %u \n",
1332 					 environment.flag_scheme);
1333 				return -1;
1334 			}
1335 		}
1336 
1337 		/*
1338 		 * If we are reading, we don't need the flag and the CRC any
1339 		 * more, if we are writing, we will re-calculate CRC and update
1340 		 * flags before writing out
1341 		 */
1342 		if (dev_current) {
1343 			environment.image	= addr1;
1344 			environment.crc		= &redundant->crc;
1345 			environment.flags	= &redundant->flags;
1346 			environment.data	= redundant->data;
1347 			free (addr0);
1348 		} else {
1349 			environment.image	= addr0;
1350 			/* Other pointers are already set */
1351 			free (addr1);
1352 		}
1353 #ifdef DEBUG
1354 		fprintf(stderr, "Selected env in %s\n", DEVNAME(dev_current));
1355 #endif
1356 	}
1357 	return 0;
1358 }
1359 
1360 
1361 static int parse_config ()
1362 {
1363 	struct stat st;
1364 
1365 #if defined(CONFIG_FILE)
1366 	/* Fills in DEVNAME(), ENVSIZE(), DEVESIZE(). Or don't. */
1367 	if (get_config (CONFIG_FILE)) {
1368 		fprintf (stderr,
1369 			"Cannot parse config file: %s\n", strerror (errno));
1370 		return -1;
1371 	}
1372 #else
1373 	DEVNAME (0) = DEVICE1_NAME;
1374 	DEVOFFSET (0) = DEVICE1_OFFSET;
1375 	ENVSIZE (0) = ENV1_SIZE;
1376 	/* Default values are: erase-size=env-size */
1377 	DEVESIZE (0) = ENVSIZE (0);
1378 	/* #sectors=env-size/erase-size (rounded up) */
1379 	ENVSECTORS (0) = (ENVSIZE(0) + DEVESIZE(0) - 1) / DEVESIZE(0);
1380 #ifdef DEVICE1_ESIZE
1381 	DEVESIZE (0) = DEVICE1_ESIZE;
1382 #endif
1383 #ifdef DEVICE1_ENVSECTORS
1384 	ENVSECTORS (0) = DEVICE1_ENVSECTORS;
1385 #endif
1386 
1387 #ifdef HAVE_REDUND
1388 	DEVNAME (1) = DEVICE2_NAME;
1389 	DEVOFFSET (1) = DEVICE2_OFFSET;
1390 	ENVSIZE (1) = ENV2_SIZE;
1391 	/* Default values are: erase-size=env-size */
1392 	DEVESIZE (1) = ENVSIZE (1);
1393 	/* #sectors=env-size/erase-size (rounded up) */
1394 	ENVSECTORS (1) = (ENVSIZE(1) + DEVESIZE(1) - 1) / DEVESIZE(1);
1395 #ifdef DEVICE2_ESIZE
1396 	DEVESIZE (1) = DEVICE2_ESIZE;
1397 #endif
1398 #ifdef DEVICE2_ENVSECTORS
1399 	ENVSECTORS (1) = DEVICE2_ENVSECTORS;
1400 #endif
1401 	HaveRedundEnv = 1;
1402 #endif
1403 #endif
1404 	if (stat (DEVNAME (0), &st)) {
1405 		fprintf (stderr,
1406 			"Cannot access MTD device %s: %s\n",
1407 			DEVNAME (0), strerror (errno));
1408 		return -1;
1409 	}
1410 
1411 	if (HaveRedundEnv && stat (DEVNAME (1), &st)) {
1412 		fprintf (stderr,
1413 			"Cannot access MTD device %s: %s\n",
1414 			DEVNAME (1), strerror (errno));
1415 		return -1;
1416 	}
1417 	return 0;
1418 }
1419 
1420 #if defined(CONFIG_FILE)
1421 static int get_config (char *fname)
1422 {
1423 	FILE *fp;
1424 	int i = 0;
1425 	int rc;
1426 	char dump[128];
1427 	char *devname;
1428 
1429 	fp = fopen (fname, "r");
1430 	if (fp == NULL)
1431 		return -1;
1432 
1433 	while (i < 2 && fgets (dump, sizeof (dump), fp)) {
1434 		/* Skip incomplete conversions and comment strings */
1435 		if (dump[0] == '#')
1436 			continue;
1437 
1438 		rc = sscanf (dump, "%ms %lx %lx %lx %lx",
1439 			     &devname,
1440 			     &DEVOFFSET (i),
1441 			     &ENVSIZE (i),
1442 			     &DEVESIZE (i),
1443 			     &ENVSECTORS (i));
1444 
1445 		if (rc < 3)
1446 			continue;
1447 
1448 		DEVNAME(i) = devname;
1449 
1450 		if (rc < 4)
1451 			/* Assume the erase size is the same as the env-size */
1452 			DEVESIZE(i) = ENVSIZE(i);
1453 
1454 		if (rc < 5)
1455 			/* Assume enough env sectors to cover the environment */
1456 			ENVSECTORS (i) = (ENVSIZE(i) + DEVESIZE(i) - 1) / DEVESIZE(i);
1457 
1458 		i++;
1459 	}
1460 	fclose (fp);
1461 
1462 	HaveRedundEnv = i - 1;
1463 	if (!i) {			/* No valid entries found */
1464 		errno = EINVAL;
1465 		return -1;
1466 	} else
1467 		return 0;
1468 }
1469 #endif
1470