xref: /openbmc/u-boot/tools/env/fw_env.c (revision 0c331ebc)
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 #include <errno.h>
12 #include <env_flags.h>
13 #include <fcntl.h>
14 #include <linux/stringify.h>
15 #include <stdio.h>
16 #include <stdlib.h>
17 #include <stddef.h>
18 #include <string.h>
19 #include <sys/types.h>
20 #include <sys/ioctl.h>
21 #include <sys/stat.h>
22 #include <unistd.h>
23 
24 #ifdef MTD_OLD
25 # include <stdint.h>
26 # include <linux/mtd/mtd.h>
27 #else
28 # define  __user	/* nothing */
29 # include <mtd/mtd-user.h>
30 #endif
31 
32 #include "fw_env.h"
33 
34 #include <aes.h>
35 
36 #define DIV_ROUND_UP(n, d)	(((n) + (d) - 1) / (d))
37 
38 #define WHITESPACE(c) ((c == '\t') || (c == ' '))
39 
40 #define min(x, y) ({				\
41 	typeof(x) _min1 = (x);			\
42 	typeof(y) _min2 = (y);			\
43 	(void) (&_min1 == &_min2);		\
44 	_min1 < _min2 ? _min1 : _min2; })
45 
46 struct envdev_s {
47 	const char *devname;		/* Device name */
48 	ulong devoff;			/* Device offset */
49 	ulong env_size;			/* environment size */
50 	ulong erase_size;		/* device erase size */
51 	ulong env_sectors;		/* number of environment sectors */
52 	uint8_t mtd_type;		/* type of the MTD device */
53 };
54 
55 static struct envdev_s envdevices[2] =
56 {
57 	{
58 		.mtd_type = MTD_ABSENT,
59 	}, {
60 		.mtd_type = MTD_ABSENT,
61 	},
62 };
63 static int dev_current;
64 
65 #define DEVNAME(i)    envdevices[(i)].devname
66 #define DEVOFFSET(i)  envdevices[(i)].devoff
67 #define ENVSIZE(i)    envdevices[(i)].env_size
68 #define DEVESIZE(i)   envdevices[(i)].erase_size
69 #define ENVSECTORS(i) envdevices[(i)].env_sectors
70 #define DEVTYPE(i)    envdevices[(i)].mtd_type
71 
72 #define CUR_ENVSIZE ENVSIZE(dev_current)
73 
74 #define ENV_SIZE      getenvsize()
75 
76 struct env_image_single {
77 	uint32_t	crc;	/* CRC32 over data bytes    */
78 	char		data[];
79 };
80 
81 struct env_image_redundant {
82 	uint32_t	crc;	/* CRC32 over data bytes    */
83 	unsigned char	flags;	/* active or obsolete */
84 	char		data[];
85 };
86 
87 enum flag_scheme {
88 	FLAG_NONE,
89 	FLAG_BOOLEAN,
90 	FLAG_INCREMENTAL,
91 };
92 
93 struct environment {
94 	void			*image;
95 	uint32_t		*crc;
96 	unsigned char		*flags;
97 	char			*data;
98 	enum flag_scheme	flag_scheme;
99 };
100 
101 static struct environment environment = {
102 	.flag_scheme = FLAG_NONE,
103 };
104 
105 /* Is AES encryption used? */
106 static int aes_flag;
107 static uint8_t aes_key[AES_KEY_LENGTH] = { 0 };
108 static int env_aes_cbc_crypt(char *data, const int enc);
109 
110 static int HaveRedundEnv = 0;
111 
112 static unsigned char active_flag = 1;
113 /* obsolete_flag must be 0 to efficiently set it on NOR flash without erasing */
114 static unsigned char obsolete_flag = 0;
115 
116 #define DEFAULT_ENV_INSTANCE_STATIC
117 #include <env_default.h>
118 
119 static int flash_io (int mode);
120 static char *envmatch (char * s1, char * s2);
121 static int parse_config (void);
122 
123 #if defined(CONFIG_FILE)
124 static int get_config (char *);
125 #endif
126 static inline ulong getenvsize (void)
127 {
128 	ulong rc = CUR_ENVSIZE - sizeof(uint32_t);
129 
130 	if (HaveRedundEnv)
131 		rc -= sizeof (char);
132 
133 	if (aes_flag)
134 		rc &= ~(AES_KEY_LENGTH - 1);
135 
136 	return rc;
137 }
138 
139 static char *fw_string_blank(char *s, int noblank)
140 {
141 	int i;
142 	int len = strlen(s);
143 
144 	for (i = 0; i < len; i++, s++) {
145 		if ((noblank && !WHITESPACE(*s)) ||
146 			(!noblank && WHITESPACE(*s)))
147 			break;
148 	}
149 	if (i == len)
150 		return NULL;
151 
152 	return s;
153 }
154 
155 /*
156  * Search the environment for a variable.
157  * Return the value, if found, or NULL, if not found.
158  */
159 char *fw_getenv (char *name)
160 {
161 	char *env, *nxt;
162 
163 	for (env = environment.data; *env; env = nxt + 1) {
164 		char *val;
165 
166 		for (nxt = env; *nxt; ++nxt) {
167 			if (nxt >= &environment.data[ENV_SIZE]) {
168 				fprintf (stderr, "## Error: "
169 					"environment not terminated\n");
170 				return NULL;
171 			}
172 		}
173 		val = envmatch (name, env);
174 		if (!val)
175 			continue;
176 		return val;
177 	}
178 	return NULL;
179 }
180 
181 /*
182  * Search the default environment for a variable.
183  * Return the value, if found, or NULL, if not found.
184  */
185 char *fw_getdefenv(char *name)
186 {
187 	char *env, *nxt;
188 
189 	for (env = default_environment; *env; env = nxt + 1) {
190 		char *val;
191 
192 		for (nxt = env; *nxt; ++nxt) {
193 			if (nxt >= &default_environment[ENV_SIZE]) {
194 				fprintf(stderr, "## Error: "
195 					"default environment not terminated\n");
196 				return NULL;
197 			}
198 		}
199 		val = envmatch(name, env);
200 		if (!val)
201 			continue;
202 		return val;
203 	}
204 	return NULL;
205 }
206 
207 static int parse_aes_key(char *key)
208 {
209 	char tmp[5] = { '0', 'x', 0, 0, 0 };
210 	unsigned long ul;
211 	int i;
212 
213 	if (strnlen(key, 64) != 32) {
214 		fprintf(stderr,
215 			"## Error: '-a' option requires 16-byte AES key\n");
216 		return -1;
217 	}
218 
219 	for (i = 0; i < 16; i++) {
220 		tmp[2] = key[0];
221 		tmp[3] = key[1];
222 		errno = 0;
223 		ul = strtoul(tmp, NULL, 16);
224 		if (errno) {
225 			fprintf(stderr,
226 				"## Error: '-a' option requires valid AES key\n");
227 			return -1;
228 		}
229 		aes_key[i] = ul & 0xff;
230 		key += 2;
231 	}
232 	aes_flag = 1;
233 
234 	return 0;
235 }
236 
237 /*
238  * Print the current definition of one, or more, or all
239  * environment variables
240  */
241 int fw_printenv (int argc, char *argv[])
242 {
243 	char *env, *nxt;
244 	int i, n_flag;
245 	int rc = 0;
246 
247 	if (argc >= 2 && strcmp(argv[1], "-a") == 0) {
248 		if (argc < 3) {
249 			fprintf(stderr,
250 				"## Error: '-a' option requires AES key\n");
251 			return -1;
252 		}
253 		rc = parse_aes_key(argv[2]);
254 		if (rc)
255 			return rc;
256 		argv += 2;
257 		argc -= 2;
258 	}
259 
260 	if (fw_env_open())
261 		return -1;
262 
263 	if (argc == 1) {		/* Print all env variables  */
264 		for (env = environment.data; *env; env = nxt + 1) {
265 			for (nxt = env; *nxt; ++nxt) {
266 				if (nxt >= &environment.data[ENV_SIZE]) {
267 					fprintf (stderr, "## Error: "
268 						"environment not terminated\n");
269 					return -1;
270 				}
271 			}
272 
273 			printf ("%s\n", env);
274 		}
275 		return 0;
276 	}
277 
278 	if (strcmp (argv[1], "-n") == 0) {
279 		n_flag = 1;
280 		++argv;
281 		--argc;
282 		if (argc != 2) {
283 			fprintf (stderr, "## Error: "
284 				"`-n' option requires exactly one argument\n");
285 			return -1;
286 		}
287 	} else {
288 		n_flag = 0;
289 	}
290 
291 	for (i = 1; i < argc; ++i) {	/* print single env variables   */
292 		char *name = argv[i];
293 		char *val = NULL;
294 
295 		for (env = environment.data; *env; env = nxt + 1) {
296 
297 			for (nxt = env; *nxt; ++nxt) {
298 				if (nxt >= &environment.data[ENV_SIZE]) {
299 					fprintf (stderr, "## Error: "
300 						"environment not terminated\n");
301 					return -1;
302 				}
303 			}
304 			val = envmatch (name, env);
305 			if (val) {
306 				if (!n_flag) {
307 					fputs (name, stdout);
308 					putc ('=', stdout);
309 				}
310 				puts (val);
311 				break;
312 			}
313 		}
314 		if (!val) {
315 			fprintf (stderr, "## Error: \"%s\" not defined\n", name);
316 			rc = -1;
317 		}
318 	}
319 
320 	return rc;
321 }
322 
323 int fw_env_close(void)
324 {
325 	int ret;
326 	if (aes_flag) {
327 		ret = env_aes_cbc_crypt(environment.data, 1);
328 		if (ret) {
329 			fprintf(stderr,
330 				"Error: can't encrypt env for flash\n");
331 			return ret;
332 		}
333 	}
334 
335 	/*
336 	 * Update CRC
337 	 */
338 	*environment.crc = crc32(0, (uint8_t *) environment.data, ENV_SIZE);
339 
340 	/* write environment back to flash */
341 	if (flash_io(O_RDWR)) {
342 		fprintf(stderr,
343 			"Error: can't write fw_env to flash\n");
344 			return -1;
345 	}
346 
347 	return 0;
348 }
349 
350 
351 /*
352  * Set/Clear a single variable in the environment.
353  * This is called in sequence to update the environment
354  * in RAM without updating the copy in flash after each set
355  */
356 int fw_env_write(char *name, char *value)
357 {
358 	int len;
359 	char *env, *nxt;
360 	char *oldval = NULL;
361 	int deleting, creating, overwriting;
362 
363 	/*
364 	 * search if variable with this name already exists
365 	 */
366 	for (nxt = env = environment.data; *env; env = nxt + 1) {
367 		for (nxt = env; *nxt; ++nxt) {
368 			if (nxt >= &environment.data[ENV_SIZE]) {
369 				fprintf(stderr, "## Error: "
370 					"environment not terminated\n");
371 				errno = EINVAL;
372 				return -1;
373 			}
374 		}
375 		if ((oldval = envmatch (name, env)) != NULL)
376 			break;
377 	}
378 
379 	deleting = (oldval && !(value && strlen(value)));
380 	creating = (!oldval && (value && strlen(value)));
381 	overwriting = (oldval && (value && strlen(value)));
382 
383 	/* check for permission */
384 	if (deleting) {
385 		if (env_flags_validate_varaccess(name,
386 		    ENV_FLAGS_VARACCESS_PREVENT_DELETE)) {
387 			printf("Can't delete \"%s\"\n", name);
388 			errno = EROFS;
389 			return -1;
390 		}
391 	} else if (overwriting) {
392 		if (env_flags_validate_varaccess(name,
393 		    ENV_FLAGS_VARACCESS_PREVENT_OVERWR)) {
394 			printf("Can't overwrite \"%s\"\n", name);
395 			errno = EROFS;
396 			return -1;
397 		} else if (env_flags_validate_varaccess(name,
398 		    ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR)) {
399 			const char *defval = fw_getdefenv(name);
400 
401 			if (defval == NULL)
402 				defval = "";
403 			if (strcmp(oldval, defval)
404 			    != 0) {
405 				printf("Can't overwrite \"%s\"\n", name);
406 				errno = EROFS;
407 				return -1;
408 			}
409 		}
410 	} else if (creating) {
411 		if (env_flags_validate_varaccess(name,
412 		    ENV_FLAGS_VARACCESS_PREVENT_CREATE)) {
413 			printf("Can't create \"%s\"\n", name);
414 			errno = EROFS;
415 			return -1;
416 		}
417 	} else
418 		/* Nothing to do */
419 		return 0;
420 
421 	if (deleting || overwriting) {
422 		if (*++nxt == '\0') {
423 			*env = '\0';
424 		} else {
425 			for (;;) {
426 				*env = *nxt++;
427 				if ((*env == '\0') && (*nxt == '\0'))
428 					break;
429 				++env;
430 			}
431 		}
432 		*++env = '\0';
433 	}
434 
435 	/* Delete only ? */
436 	if (!value || !strlen(value))
437 		return 0;
438 
439 	/*
440 	 * Append new definition at the end
441 	 */
442 	for (env = environment.data; *env || *(env + 1); ++env);
443 	if (env > environment.data)
444 		++env;
445 	/*
446 	 * Overflow when:
447 	 * "name" + "=" + "val" +"\0\0"  > CUR_ENVSIZE - (env-environment)
448 	 */
449 	len = strlen (name) + 2;
450 	/* add '=' for first arg, ' ' for all others */
451 	len += strlen(value) + 1;
452 
453 	if (len > (&environment.data[ENV_SIZE] - env)) {
454 		fprintf (stderr,
455 			"Error: environment overflow, \"%s\" deleted\n",
456 			name);
457 		return -1;
458 	}
459 
460 	while ((*env = *name++) != '\0')
461 		env++;
462 	*env = '=';
463 	while ((*++env = *value++) != '\0')
464 		;
465 
466 	/* end is marked with double '\0' */
467 	*++env = '\0';
468 
469 	return 0;
470 }
471 
472 /*
473  * Deletes or sets environment variables. Returns -1 and sets errno error codes:
474  * 0	  - OK
475  * EINVAL - need at least 1 argument
476  * EROFS  - certain variables ("ethaddr", "serial#") cannot be
477  *	    modified or deleted
478  *
479  */
480 int fw_setenv(int argc, char *argv[])
481 {
482 	int i, rc;
483 	size_t len;
484 	char *name;
485 	char *value = NULL;
486 
487 	if (argc < 2) {
488 		errno = EINVAL;
489 		return -1;
490 	}
491 
492 	if (strcmp(argv[1], "-a") == 0) {
493 		if (argc < 3) {
494 			fprintf(stderr,
495 				"## Error: '-a' option requires AES key\n");
496 			return -1;
497 		}
498 		rc = parse_aes_key(argv[2]);
499 		if (rc)
500 			return rc;
501 		argv += 2;
502 		argc -= 2;
503 	}
504 
505 	if (argc < 2) {
506 		errno = EINVAL;
507 		return -1;
508 	}
509 
510 	if (fw_env_open()) {
511 		fprintf(stderr, "Error: environment not initialized\n");
512 		return -1;
513 	}
514 
515 	name = argv[1];
516 
517 	if (env_flags_validate_env_set_params(argc, argv) < 0)
518 		return 1;
519 
520 	len = 0;
521 	for (i = 2; i < argc; ++i) {
522 		char *val = argv[i];
523 		size_t val_len = strlen(val);
524 
525 		if (value)
526 			value[len - 1] = ' ';
527 		value = realloc(value, len + val_len + 1);
528 		if (!value) {
529 			fprintf(stderr,
530 				"Cannot malloc %zu bytes: %s\n",
531 				len, strerror(errno));
532 			return -1;
533 		}
534 
535 		memcpy(value + len, val, val_len);
536 		len += val_len;
537 		value[len++] = '\0';
538 	}
539 
540 	fw_env_write(name, value);
541 
542 	free(value);
543 
544 	return fw_env_close();
545 }
546 
547 /*
548  * Parse  a file  and configure the u-boot variables.
549  * The script file has a very simple format, as follows:
550  *
551  * Each line has a couple with name, value:
552  * <white spaces>variable_name<white spaces>variable_value
553  *
554  * Both variable_name and variable_value are interpreted as strings.
555  * Any character after <white spaces> and before ending \r\n is interpreted
556  * as variable's value (no comment allowed on these lines !)
557  *
558  * Comments are allowed if the first character in the line is #
559  *
560  * Returns -1 and sets errno error codes:
561  * 0	  - OK
562  * -1     - Error
563  */
564 int fw_parse_script(char *fname)
565 {
566 	FILE *fp;
567 	char dump[1024];	/* Maximum line length in the file */
568 	char *name;
569 	char *val;
570 	int lineno = 0;
571 	int len;
572 	int ret = 0;
573 
574 	if (fw_env_open()) {
575 		fprintf(stderr, "Error: environment not initialized\n");
576 		return -1;
577 	}
578 
579 	if (strcmp(fname, "-") == 0)
580 		fp = stdin;
581 	else {
582 		fp = fopen(fname, "r");
583 		if (fp == NULL) {
584 			fprintf(stderr, "I cannot open %s for reading\n",
585 				 fname);
586 			return -1;
587 		}
588 	}
589 
590 	while (fgets(dump, sizeof(dump), fp)) {
591 		lineno++;
592 		len = strlen(dump);
593 
594 		/*
595 		 * Read a whole line from the file. If the line is too long
596 		 * or is not terminated, reports an error and exit.
597 		 */
598 		if (dump[len - 1] != '\n') {
599 			fprintf(stderr,
600 			"Line %d not corrected terminated or too long\n",
601 				lineno);
602 			ret = -1;
603 			break;
604 		}
605 
606 		/* Drop ending line feed / carriage return */
607 		while (len > 0 && (dump[len - 1] == '\n' ||
608 				dump[len - 1] == '\r')) {
609 			dump[len - 1] = '\0';
610 			len--;
611 		}
612 
613 		/* Skip comment or empty lines */
614 		if ((len == 0) || dump[0] == '#')
615 			continue;
616 
617 		/*
618 		 * Search for variable's name,
619 		 * remove leading whitespaces
620 		 */
621 		name = fw_string_blank(dump, 1);
622 		if (!name)
623 			continue;
624 
625 		/* The first white space is the end of variable name */
626 		val = fw_string_blank(name, 0);
627 		len = strlen(name);
628 		if (val) {
629 			*val++ = '\0';
630 			if ((val - name) < len)
631 				val = fw_string_blank(val, 1);
632 			else
633 				val = NULL;
634 		}
635 
636 #ifdef DEBUG
637 		fprintf(stderr, "Setting %s : %s\n",
638 			name, val ? val : " removed");
639 #endif
640 
641 		if (env_flags_validate_type(name, val) < 0) {
642 			ret = -1;
643 			break;
644 		}
645 
646 		/*
647 		 * If there is an error setting a variable,
648 		 * try to save the environment and returns an error
649 		 */
650 		if (fw_env_write(name, val)) {
651 			fprintf(stderr,
652 			"fw_env_write returns with error : %s\n",
653 				strerror(errno));
654 			ret = -1;
655 			break;
656 		}
657 
658 	}
659 
660 	/* Close file if not stdin */
661 	if (strcmp(fname, "-") != 0)
662 		fclose(fp);
663 
664 	ret |= fw_env_close();
665 
666 	return ret;
667 
668 }
669 
670 /*
671  * Test for bad block on NAND, just returns 0 on NOR, on NAND:
672  * 0	- block is good
673  * > 0	- block is bad
674  * < 0	- failed to test
675  */
676 static int flash_bad_block (int fd, uint8_t mtd_type, loff_t *blockstart)
677 {
678 	if (mtd_type == MTD_NANDFLASH) {
679 		int badblock = ioctl (fd, MEMGETBADBLOCK, blockstart);
680 
681 		if (badblock < 0) {
682 			perror ("Cannot read bad block mark");
683 			return badblock;
684 		}
685 
686 		if (badblock) {
687 #ifdef DEBUG
688 			fprintf (stderr, "Bad block at 0x%llx, "
689 				 "skipping\n", *blockstart);
690 #endif
691 			return badblock;
692 		}
693 	}
694 
695 	return 0;
696 }
697 
698 /*
699  * Read data from flash at an offset into a provided buffer. On NAND it skips
700  * bad blocks but makes sure it stays within ENVSECTORS (dev) starting from
701  * the DEVOFFSET (dev) block. On NOR the loop is only run once.
702  */
703 static int flash_read_buf (int dev, int fd, void *buf, size_t count,
704 			   off_t offset, uint8_t mtd_type)
705 {
706 	size_t blocklen;	/* erase / write length - one block on NAND,
707 				   0 on NOR */
708 	size_t processed = 0;	/* progress counter */
709 	size_t readlen = count;	/* current read length */
710 	off_t top_of_range;	/* end of the last block we may use */
711 	off_t block_seek;	/* offset inside the current block to the start
712 				   of the data */
713 	loff_t blockstart;	/* running start of the current block -
714 				   MEMGETBADBLOCK needs 64 bits */
715 	int rc;
716 
717 	blockstart = (offset / DEVESIZE (dev)) * DEVESIZE (dev);
718 
719 	/* Offset inside a block */
720 	block_seek = offset - blockstart;
721 
722 	if (mtd_type == MTD_NANDFLASH) {
723 		/*
724 		 * NAND: calculate which blocks we are reading. We have
725 		 * to read one block at a time to skip bad blocks.
726 		 */
727 		blocklen = DEVESIZE (dev);
728 
729 		/*
730 		 * To calculate the top of the range, we have to use the
731 		 * global DEVOFFSET (dev), which can be different from offset
732 		 */
733 		top_of_range = ((DEVOFFSET(dev) / blocklen) +
734 				ENVSECTORS (dev)) * blocklen;
735 
736 		/* Limit to one block for the first read */
737 		if (readlen > blocklen - block_seek)
738 			readlen = blocklen - block_seek;
739 	} else {
740 		blocklen = 0;
741 		top_of_range = offset + count;
742 	}
743 
744 	/* This only runs once on NOR flash */
745 	while (processed < count) {
746 		rc = flash_bad_block (fd, mtd_type, &blockstart);
747 		if (rc < 0)		/* block test failed */
748 			return -1;
749 
750 		if (blockstart + block_seek + readlen > top_of_range) {
751 			/* End of range is reached */
752 			fprintf (stderr,
753 				 "Too few good blocks within range\n");
754 			return -1;
755 		}
756 
757 		if (rc) {		/* block is bad */
758 			blockstart += blocklen;
759 			continue;
760 		}
761 
762 		/*
763 		 * If a block is bad, we retry in the next block at the same
764 		 * offset - see common/env_nand.c::writeenv()
765 		 */
766 		lseek (fd, blockstart + block_seek, SEEK_SET);
767 
768 		rc = read (fd, buf + processed, readlen);
769 		if (rc != readlen) {
770 			fprintf (stderr, "Read error on %s: %s\n",
771 				 DEVNAME (dev), strerror (errno));
772 			return -1;
773 		}
774 #ifdef DEBUG
775 		fprintf(stderr, "Read 0x%x bytes at 0x%llx on %s\n",
776 			 rc, blockstart + block_seek, DEVNAME(dev));
777 #endif
778 		processed += readlen;
779 		readlen = min (blocklen, count - processed);
780 		block_seek = 0;
781 		blockstart += blocklen;
782 	}
783 
784 	return processed;
785 }
786 
787 /*
788  * Write count bytes at offset, but stay within ENVSECTORS (dev) sectors of
789  * DEVOFFSET (dev). Similar to the read case above, on NOR and dataflash we
790  * erase and write the whole data at once.
791  */
792 static int flash_write_buf (int dev, int fd, void *buf, size_t count,
793 			    off_t offset, uint8_t mtd_type)
794 {
795 	void *data;
796 	struct erase_info_user erase;
797 	size_t blocklen;	/* length of NAND block / NOR erase sector */
798 	size_t erase_len;	/* whole area that can be erased - may include
799 				   bad blocks */
800 	size_t erasesize;	/* erase / write length - one block on NAND,
801 				   whole area on NOR */
802 	size_t processed = 0;	/* progress counter */
803 	size_t write_total;	/* total size to actually write - excluding
804 				   bad blocks */
805 	off_t erase_offset;	/* offset to the first erase block (aligned)
806 				   below offset */
807 	off_t block_seek;	/* offset inside the erase block to the start
808 				   of the data */
809 	off_t top_of_range;	/* end of the last block we may use */
810 	loff_t blockstart;	/* running start of the current block -
811 				   MEMGETBADBLOCK needs 64 bits */
812 	int rc;
813 
814 	/*
815 	 * For mtd devices only offset and size of the environment do matter
816 	 */
817 	if (mtd_type == MTD_ABSENT) {
818 		blocklen = count;
819 		top_of_range = offset + count;
820 		erase_len = blocklen;
821 		blockstart = offset;
822 		block_seek = 0;
823 		write_total = blocklen;
824 	} else {
825 		blocklen = DEVESIZE(dev);
826 
827 		top_of_range = ((DEVOFFSET(dev) / blocklen) +
828 					ENVSECTORS(dev)) * blocklen;
829 
830 		erase_offset = (offset / blocklen) * blocklen;
831 
832 		/* Maximum area we may use */
833 		erase_len = top_of_range - erase_offset;
834 
835 		blockstart = erase_offset;
836 		/* Offset inside a block */
837 		block_seek = offset - erase_offset;
838 
839 		/*
840 		 * Data size we actually write: from the start of the block
841 		 * to the start of the data, then count bytes of data, and
842 		 * to the end of the block
843 		 */
844 		write_total = ((block_seek + count + blocklen - 1) /
845 							blocklen) * blocklen;
846 	}
847 
848 	/*
849 	 * Support data anywhere within erase sectors: read out the complete
850 	 * area to be erased, replace the environment image, write the whole
851 	 * block back again.
852 	 */
853 	if (write_total > count) {
854 		data = malloc (erase_len);
855 		if (!data) {
856 			fprintf (stderr,
857 				 "Cannot malloc %zu bytes: %s\n",
858 				 erase_len, strerror (errno));
859 			return -1;
860 		}
861 
862 		rc = flash_read_buf (dev, fd, data, write_total, erase_offset,
863 				     mtd_type);
864 		if (write_total != rc)
865 			return -1;
866 
867 #ifdef DEBUG
868 		fprintf(stderr, "Preserving data ");
869 		if (block_seek != 0)
870 			fprintf(stderr, "0x%x - 0x%lx", 0, block_seek - 1);
871 		if (block_seek + count != write_total) {
872 			if (block_seek != 0)
873 				fprintf(stderr, " and ");
874 			fprintf(stderr, "0x%lx - 0x%x",
875 				block_seek + count, write_total - 1);
876 		}
877 		fprintf(stderr, "\n");
878 #endif
879 		/* Overwrite the old environment */
880 		memcpy (data + block_seek, buf, count);
881 	} else {
882 		/*
883 		 * We get here, iff offset is block-aligned and count is a
884 		 * multiple of blocklen - see write_total calculation above
885 		 */
886 		data = buf;
887 	}
888 
889 	if (mtd_type == MTD_NANDFLASH) {
890 		/*
891 		 * NAND: calculate which blocks we are writing. We have
892 		 * to write one block at a time to skip bad blocks.
893 		 */
894 		erasesize = blocklen;
895 	} else {
896 		erasesize = erase_len;
897 	}
898 
899 	erase.length = erasesize;
900 
901 	/* This only runs once on NOR flash and SPI-dataflash */
902 	while (processed < write_total) {
903 		rc = flash_bad_block (fd, mtd_type, &blockstart);
904 		if (rc < 0)		/* block test failed */
905 			return rc;
906 
907 		if (blockstart + erasesize > top_of_range) {
908 			fprintf (stderr, "End of range reached, aborting\n");
909 			return -1;
910 		}
911 
912 		if (rc) {		/* block is bad */
913 			blockstart += blocklen;
914 			continue;
915 		}
916 
917 		if (mtd_type != MTD_ABSENT) {
918 			erase.start = blockstart;
919 			ioctl(fd, MEMUNLOCK, &erase);
920 			/* These do not need an explicit erase cycle */
921 			if (mtd_type != MTD_DATAFLASH)
922 				if (ioctl(fd, MEMERASE, &erase) != 0) {
923 					fprintf(stderr,
924 						"MTD erase error on %s: %s\n",
925 						DEVNAME(dev), strerror(errno));
926 					return -1;
927 				}
928 		}
929 
930 		if (lseek (fd, blockstart, SEEK_SET) == -1) {
931 			fprintf (stderr,
932 				 "Seek error on %s: %s\n",
933 				 DEVNAME (dev), strerror (errno));
934 			return -1;
935 		}
936 
937 #ifdef DEBUG
938 		fprintf(stderr, "Write 0x%x bytes at 0x%llx\n", erasesize,
939 			blockstart);
940 #endif
941 		if (write (fd, data + processed, erasesize) != erasesize) {
942 			fprintf (stderr, "Write error on %s: %s\n",
943 				 DEVNAME (dev), strerror (errno));
944 			return -1;
945 		}
946 
947 		if (mtd_type != MTD_ABSENT)
948 			ioctl(fd, MEMLOCK, &erase);
949 
950 		processed  += erasesize;
951 		block_seek = 0;
952 		blockstart += erasesize;
953 	}
954 
955 	if (write_total > count)
956 		free (data);
957 
958 	return processed;
959 }
960 
961 /*
962  * Set obsolete flag at offset - NOR flash only
963  */
964 static int flash_flag_obsolete (int dev, int fd, off_t offset)
965 {
966 	int rc;
967 	struct erase_info_user erase;
968 
969 	erase.start  = DEVOFFSET (dev);
970 	erase.length = DEVESIZE (dev);
971 	/* This relies on the fact, that obsolete_flag == 0 */
972 	rc = lseek (fd, offset, SEEK_SET);
973 	if (rc < 0) {
974 		fprintf (stderr, "Cannot seek to set the flag on %s \n",
975 			 DEVNAME (dev));
976 		return rc;
977 	}
978 	ioctl (fd, MEMUNLOCK, &erase);
979 	rc = write (fd, &obsolete_flag, sizeof (obsolete_flag));
980 	ioctl (fd, MEMLOCK, &erase);
981 	if (rc < 0)
982 		perror ("Could not set obsolete flag");
983 
984 	return rc;
985 }
986 
987 /* Encrypt or decrypt the environment before writing or reading it. */
988 static int env_aes_cbc_crypt(char *payload, const int enc)
989 {
990 	uint8_t *data = (uint8_t *)payload;
991 	const int len = getenvsize();
992 	uint8_t key_exp[AES_EXPAND_KEY_LENGTH];
993 	uint32_t aes_blocks;
994 
995 	/* First we expand the key. */
996 	aes_expand_key(aes_key, key_exp);
997 
998 	/* Calculate the number of AES blocks to encrypt. */
999 	aes_blocks = DIV_ROUND_UP(len, AES_KEY_LENGTH);
1000 
1001 	if (enc)
1002 		aes_cbc_encrypt_blocks(key_exp, data, data, aes_blocks);
1003 	else
1004 		aes_cbc_decrypt_blocks(key_exp, data, data, aes_blocks);
1005 
1006 	return 0;
1007 }
1008 
1009 static int flash_write (int fd_current, int fd_target, int dev_target)
1010 {
1011 	int rc;
1012 
1013 	switch (environment.flag_scheme) {
1014 	case FLAG_NONE:
1015 		break;
1016 	case FLAG_INCREMENTAL:
1017 		(*environment.flags)++;
1018 		break;
1019 	case FLAG_BOOLEAN:
1020 		*environment.flags = active_flag;
1021 		break;
1022 	default:
1023 		fprintf (stderr, "Unimplemented flash scheme %u \n",
1024 			 environment.flag_scheme);
1025 		return -1;
1026 	}
1027 
1028 #ifdef DEBUG
1029 	fprintf(stderr, "Writing new environment at 0x%lx on %s\n",
1030 		DEVOFFSET (dev_target), DEVNAME (dev_target));
1031 #endif
1032 
1033 	rc = flash_write_buf(dev_target, fd_target, environment.image,
1034 			      CUR_ENVSIZE, DEVOFFSET(dev_target),
1035 			      DEVTYPE(dev_target));
1036 	if (rc < 0)
1037 		return rc;
1038 
1039 	if (environment.flag_scheme == FLAG_BOOLEAN) {
1040 		/* Have to set obsolete flag */
1041 		off_t offset = DEVOFFSET (dev_current) +
1042 			offsetof (struct env_image_redundant, flags);
1043 #ifdef DEBUG
1044 		fprintf(stderr,
1045 			"Setting obsolete flag in environment at 0x%lx on %s\n",
1046 			DEVOFFSET (dev_current), DEVNAME (dev_current));
1047 #endif
1048 		flash_flag_obsolete (dev_current, fd_current, offset);
1049 	}
1050 
1051 	return 0;
1052 }
1053 
1054 static int flash_read (int fd)
1055 {
1056 	struct mtd_info_user mtdinfo;
1057 	struct stat st;
1058 	int rc;
1059 
1060 	rc = fstat(fd, &st);
1061 	if (rc < 0) {
1062 		fprintf(stderr, "Cannot stat the file %s\n",
1063 			DEVNAME(dev_current));
1064 		return -1;
1065 	}
1066 
1067 	if (S_ISCHR(st.st_mode)) {
1068 		rc = ioctl(fd, MEMGETINFO, &mtdinfo);
1069 		if (rc < 0) {
1070 			fprintf(stderr, "Cannot get MTD information for %s\n",
1071 				DEVNAME(dev_current));
1072 			return -1;
1073 		}
1074 		if (mtdinfo.type != MTD_NORFLASH &&
1075 		    mtdinfo.type != MTD_NANDFLASH &&
1076 		    mtdinfo.type != MTD_DATAFLASH &&
1077 		    mtdinfo.type != MTD_UBIVOLUME) {
1078 			fprintf (stderr, "Unsupported flash type %u on %s\n",
1079 				 mtdinfo.type, DEVNAME(dev_current));
1080 			return -1;
1081 		}
1082 	} else {
1083 		memset(&mtdinfo, 0, sizeof(mtdinfo));
1084 		mtdinfo.type = MTD_ABSENT;
1085 	}
1086 
1087 	DEVTYPE(dev_current) = mtdinfo.type;
1088 
1089 	rc = flash_read_buf(dev_current, fd, environment.image, CUR_ENVSIZE,
1090 			     DEVOFFSET (dev_current), mtdinfo.type);
1091 	if (rc != CUR_ENVSIZE)
1092 		return -1;
1093 
1094 	return 0;
1095 }
1096 
1097 static int flash_io (int mode)
1098 {
1099 	int fd_current, fd_target, rc, dev_target;
1100 
1101 	/* dev_current: fd_current, erase_current */
1102 	fd_current = open (DEVNAME (dev_current), mode);
1103 	if (fd_current < 0) {
1104 		fprintf (stderr,
1105 			 "Can't open %s: %s\n",
1106 			 DEVNAME (dev_current), strerror (errno));
1107 		return -1;
1108 	}
1109 
1110 	if (mode == O_RDWR) {
1111 		if (HaveRedundEnv) {
1112 			/* switch to next partition for writing */
1113 			dev_target = !dev_current;
1114 			/* dev_target: fd_target, erase_target */
1115 			fd_target = open (DEVNAME (dev_target), mode);
1116 			if (fd_target < 0) {
1117 				fprintf (stderr,
1118 					 "Can't open %s: %s\n",
1119 					 DEVNAME (dev_target),
1120 					 strerror (errno));
1121 				rc = -1;
1122 				goto exit;
1123 			}
1124 		} else {
1125 			dev_target = dev_current;
1126 			fd_target = fd_current;
1127 		}
1128 
1129 		rc = flash_write (fd_current, fd_target, dev_target);
1130 
1131 		if (HaveRedundEnv) {
1132 			if (close (fd_target)) {
1133 				fprintf (stderr,
1134 					"I/O error on %s: %s\n",
1135 					DEVNAME (dev_target),
1136 					strerror (errno));
1137 				rc = -1;
1138 			}
1139 		}
1140 	} else {
1141 		rc = flash_read (fd_current);
1142 	}
1143 
1144 exit:
1145 	if (close (fd_current)) {
1146 		fprintf (stderr,
1147 			 "I/O error on %s: %s\n",
1148 			 DEVNAME (dev_current), strerror (errno));
1149 		return -1;
1150 	}
1151 
1152 	return rc;
1153 }
1154 
1155 /*
1156  * s1 is either a simple 'name', or a 'name=value' pair.
1157  * s2 is a 'name=value' pair.
1158  * If the names match, return the value of s2, else NULL.
1159  */
1160 
1161 static char *envmatch (char * s1, char * s2)
1162 {
1163 	if (s1 == NULL || s2 == NULL)
1164 		return NULL;
1165 
1166 	while (*s1 == *s2++)
1167 		if (*s1++ == '=')
1168 			return s2;
1169 	if (*s1 == '\0' && *(s2 - 1) == '=')
1170 		return s2;
1171 	return NULL;
1172 }
1173 
1174 /*
1175  * Prevent confusion if running from erased flash memory
1176  */
1177 int fw_env_open(void)
1178 {
1179 	int crc0, crc0_ok;
1180 	unsigned char flag0;
1181 	void *addr0;
1182 
1183 	int crc1, crc1_ok;
1184 	unsigned char flag1;
1185 	void *addr1;
1186 
1187 	int ret;
1188 
1189 	struct env_image_single *single;
1190 	struct env_image_redundant *redundant;
1191 
1192 	if (parse_config ())		/* should fill envdevices */
1193 		return -1;
1194 
1195 	addr0 = calloc(1, CUR_ENVSIZE);
1196 	if (addr0 == NULL) {
1197 		fprintf(stderr,
1198 			"Not enough memory for environment (%ld bytes)\n",
1199 			CUR_ENVSIZE);
1200 		return -1;
1201 	}
1202 
1203 	/* read environment from FLASH to local buffer */
1204 	environment.image = addr0;
1205 
1206 	if (HaveRedundEnv) {
1207 		redundant = addr0;
1208 		environment.crc		= &redundant->crc;
1209 		environment.flags	= &redundant->flags;
1210 		environment.data	= redundant->data;
1211 	} else {
1212 		single = addr0;
1213 		environment.crc		= &single->crc;
1214 		environment.flags	= NULL;
1215 		environment.data	= single->data;
1216 	}
1217 
1218 	dev_current = 0;
1219 	if (flash_io (O_RDONLY))
1220 		return -1;
1221 
1222 	crc0 = crc32 (0, (uint8_t *) environment.data, ENV_SIZE);
1223 
1224 	if (aes_flag) {
1225 		ret = env_aes_cbc_crypt(environment.data, 0);
1226 		if (ret)
1227 			return ret;
1228 	}
1229 
1230 	crc0_ok = (crc0 == *environment.crc);
1231 	if (!HaveRedundEnv) {
1232 		if (!crc0_ok) {
1233 			fprintf (stderr,
1234 				"Warning: Bad CRC, using default environment\n");
1235 			memcpy(environment.data, default_environment, sizeof default_environment);
1236 		}
1237 	} else {
1238 		flag0 = *environment.flags;
1239 
1240 		dev_current = 1;
1241 		addr1 = calloc(1, CUR_ENVSIZE);
1242 		if (addr1 == NULL) {
1243 			fprintf(stderr,
1244 				"Not enough memory for environment (%ld bytes)\n",
1245 				CUR_ENVSIZE);
1246 			return -1;
1247 		}
1248 		redundant = addr1;
1249 
1250 		/*
1251 		 * have to set environment.image for flash_read(), careful -
1252 		 * other pointers in environment still point inside addr0
1253 		 */
1254 		environment.image = addr1;
1255 		if (flash_io (O_RDONLY))
1256 			return -1;
1257 
1258 		/* Check flag scheme compatibility */
1259 		if (DEVTYPE(dev_current) == MTD_NORFLASH &&
1260 		    DEVTYPE(!dev_current) == MTD_NORFLASH) {
1261 			environment.flag_scheme = FLAG_BOOLEAN;
1262 		} else if (DEVTYPE(dev_current) == MTD_NANDFLASH &&
1263 			   DEVTYPE(!dev_current) == MTD_NANDFLASH) {
1264 			environment.flag_scheme = FLAG_INCREMENTAL;
1265 		} else if (DEVTYPE(dev_current) == MTD_DATAFLASH &&
1266 			   DEVTYPE(!dev_current) == MTD_DATAFLASH) {
1267 			environment.flag_scheme = FLAG_BOOLEAN;
1268 		} else if (DEVTYPE(dev_current) == MTD_UBIVOLUME &&
1269 			   DEVTYPE(!dev_current) == MTD_UBIVOLUME) {
1270 			environment.flag_scheme = FLAG_INCREMENTAL;
1271 		} else if (DEVTYPE(dev_current) == MTD_ABSENT &&
1272 			   DEVTYPE(!dev_current) == MTD_ABSENT) {
1273 			environment.flag_scheme = FLAG_INCREMENTAL;
1274 		} else {
1275 			fprintf (stderr, "Incompatible flash types!\n");
1276 			return -1;
1277 		}
1278 
1279 		crc1 = crc32 (0, (uint8_t *) redundant->data, ENV_SIZE);
1280 
1281 		if (aes_flag) {
1282 			ret = env_aes_cbc_crypt(redundant->data, 0);
1283 			if (ret)
1284 				return ret;
1285 		}
1286 
1287 		crc1_ok = (crc1 == redundant->crc);
1288 		flag1 = redundant->flags;
1289 
1290 		if (crc0_ok && !crc1_ok) {
1291 			dev_current = 0;
1292 		} else if (!crc0_ok && crc1_ok) {
1293 			dev_current = 1;
1294 		} else if (!crc0_ok && !crc1_ok) {
1295 			fprintf (stderr,
1296 				"Warning: Bad CRC, using default environment\n");
1297 			memcpy (environment.data, default_environment,
1298 				sizeof default_environment);
1299 			dev_current = 0;
1300 		} else {
1301 			switch (environment.flag_scheme) {
1302 			case FLAG_BOOLEAN:
1303 				if (flag0 == active_flag &&
1304 				    flag1 == obsolete_flag) {
1305 					dev_current = 0;
1306 				} else if (flag0 == obsolete_flag &&
1307 					   flag1 == active_flag) {
1308 					dev_current = 1;
1309 				} else if (flag0 == flag1) {
1310 					dev_current = 0;
1311 				} else if (flag0 == 0xFF) {
1312 					dev_current = 0;
1313 				} else if (flag1 == 0xFF) {
1314 					dev_current = 1;
1315 				} else {
1316 					dev_current = 0;
1317 				}
1318 				break;
1319 			case FLAG_INCREMENTAL:
1320 				if (flag0 == 255 && flag1 == 0)
1321 					dev_current = 1;
1322 				else if ((flag1 == 255 && flag0 == 0) ||
1323 					 flag0 >= flag1)
1324 					dev_current = 0;
1325 				else /* flag1 > flag0 */
1326 					dev_current = 1;
1327 				break;
1328 			default:
1329 				fprintf (stderr, "Unknown flag scheme %u \n",
1330 					 environment.flag_scheme);
1331 				return -1;
1332 			}
1333 		}
1334 
1335 		/*
1336 		 * If we are reading, we don't need the flag and the CRC any
1337 		 * more, if we are writing, we will re-calculate CRC and update
1338 		 * flags before writing out
1339 		 */
1340 		if (dev_current) {
1341 			environment.image	= addr1;
1342 			environment.crc		= &redundant->crc;
1343 			environment.flags	= &redundant->flags;
1344 			environment.data	= redundant->data;
1345 			free (addr0);
1346 		} else {
1347 			environment.image	= addr0;
1348 			/* Other pointers are already set */
1349 			free (addr1);
1350 		}
1351 #ifdef DEBUG
1352 		fprintf(stderr, "Selected env in %s\n", DEVNAME(dev_current));
1353 #endif
1354 	}
1355 	return 0;
1356 }
1357 
1358 
1359 static int parse_config ()
1360 {
1361 	struct stat st;
1362 
1363 #if defined(CONFIG_FILE)
1364 	/* Fills in DEVNAME(), ENVSIZE(), DEVESIZE(). Or don't. */
1365 	if (get_config (CONFIG_FILE)) {
1366 		fprintf (stderr,
1367 			"Cannot parse config file: %s\n", strerror (errno));
1368 		return -1;
1369 	}
1370 #else
1371 	DEVNAME (0) = DEVICE1_NAME;
1372 	DEVOFFSET (0) = DEVICE1_OFFSET;
1373 	ENVSIZE (0) = ENV1_SIZE;
1374 	/* Default values are: erase-size=env-size */
1375 	DEVESIZE (0) = ENVSIZE (0);
1376 	/* #sectors=env-size/erase-size (rounded up) */
1377 	ENVSECTORS (0) = (ENVSIZE(0) + DEVESIZE(0) - 1) / DEVESIZE(0);
1378 #ifdef DEVICE1_ESIZE
1379 	DEVESIZE (0) = DEVICE1_ESIZE;
1380 #endif
1381 #ifdef DEVICE1_ENVSECTORS
1382 	ENVSECTORS (0) = DEVICE1_ENVSECTORS;
1383 #endif
1384 
1385 #ifdef HAVE_REDUND
1386 	DEVNAME (1) = DEVICE2_NAME;
1387 	DEVOFFSET (1) = DEVICE2_OFFSET;
1388 	ENVSIZE (1) = ENV2_SIZE;
1389 	/* Default values are: erase-size=env-size */
1390 	DEVESIZE (1) = ENVSIZE (1);
1391 	/* #sectors=env-size/erase-size (rounded up) */
1392 	ENVSECTORS (1) = (ENVSIZE(1) + DEVESIZE(1) - 1) / DEVESIZE(1);
1393 #ifdef DEVICE2_ESIZE
1394 	DEVESIZE (1) = DEVICE2_ESIZE;
1395 #endif
1396 #ifdef DEVICE2_ENVSECTORS
1397 	ENVSECTORS (1) = DEVICE2_ENVSECTORS;
1398 #endif
1399 	HaveRedundEnv = 1;
1400 #endif
1401 #endif
1402 	if (stat (DEVNAME (0), &st)) {
1403 		fprintf (stderr,
1404 			"Cannot access MTD device %s: %s\n",
1405 			DEVNAME (0), strerror (errno));
1406 		return -1;
1407 	}
1408 
1409 	if (HaveRedundEnv && stat (DEVNAME (1), &st)) {
1410 		fprintf (stderr,
1411 			"Cannot access MTD device %s: %s\n",
1412 			DEVNAME (1), strerror (errno));
1413 		return -1;
1414 	}
1415 	return 0;
1416 }
1417 
1418 #if defined(CONFIG_FILE)
1419 static int get_config (char *fname)
1420 {
1421 	FILE *fp;
1422 	int i = 0;
1423 	int rc;
1424 	char dump[128];
1425 	char *devname;
1426 
1427 	fp = fopen (fname, "r");
1428 	if (fp == NULL)
1429 		return -1;
1430 
1431 	while (i < 2 && fgets (dump, sizeof (dump), fp)) {
1432 		/* Skip incomplete conversions and comment strings */
1433 		if (dump[0] == '#')
1434 			continue;
1435 
1436 		rc = sscanf (dump, "%ms %lx %lx %lx %lx",
1437 			     &devname,
1438 			     &DEVOFFSET (i),
1439 			     &ENVSIZE (i),
1440 			     &DEVESIZE (i),
1441 			     &ENVSECTORS (i));
1442 
1443 		if (rc < 3)
1444 			continue;
1445 
1446 		DEVNAME(i) = devname;
1447 
1448 		if (rc < 4)
1449 			/* Assume the erase size is the same as the env-size */
1450 			DEVESIZE(i) = ENVSIZE(i);
1451 
1452 		if (rc < 5)
1453 			/* Assume enough env sectors to cover the environment */
1454 			ENVSECTORS (i) = (ENVSIZE(i) + DEVESIZE(i) - 1) / DEVESIZE(i);
1455 
1456 		i++;
1457 	}
1458 	fclose (fp);
1459 
1460 	HaveRedundEnv = i - 1;
1461 	if (!i) {			/* No valid entries found */
1462 		errno = EINVAL;
1463 		return -1;
1464 	} else
1465 		return 0;
1466 }
1467 #endif
1468