xref: /openbmc/u-boot/tools/env/fw_env.c (revision dffceb4b)
1 /*
2  * (C) Copyright 2000-2010
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * (C) Copyright 2008
6  * Guennadi Liakhovetski, DENX Software Engineering, lg@denx.de.
7  *
8  * SPDX-License-Identifier:	GPL-2.0+
9  */
10 
11 #define _GNU_SOURCE
12 
13 #include <compiler.h>
14 #include <errno.h>
15 #include <env_flags.h>
16 #include <fcntl.h>
17 #include <linux/stringify.h>
18 #include <stdio.h>
19 #include <stdlib.h>
20 #include <stddef.h>
21 #include <string.h>
22 #include <sys/types.h>
23 #include <sys/ioctl.h>
24 #include <sys/stat.h>
25 #include <unistd.h>
26 
27 #ifdef MTD_OLD
28 # include <stdint.h>
29 # include <linux/mtd/mtd.h>
30 #else
31 # define  __user	/* nothing */
32 # include <mtd/mtd-user.h>
33 #endif
34 
35 #include "fw_env.h"
36 
37 #define DIV_ROUND_UP(n, d)	(((n) + (d) - 1) / (d))
38 
39 #define WHITESPACE(c) ((c == '\t') || (c == ' '))
40 
41 #define min(x, y) ({				\
42 	typeof(x) _min1 = (x);			\
43 	typeof(y) _min2 = (y);			\
44 	(void) (&_min1 == &_min2);		\
45 	_min1 < _min2 ? _min1 : _min2; })
46 
47 struct envdev_s {
48 	const char *devname;		/* Device name */
49 	ulong devoff;			/* Device offset */
50 	ulong env_size;			/* environment size */
51 	ulong erase_size;		/* device erase size */
52 	ulong env_sectors;		/* number of environment sectors */
53 	uint8_t mtd_type;		/* type of the MTD device */
54 };
55 
56 static struct envdev_s envdevices[2] =
57 {
58 	{
59 		.mtd_type = MTD_ABSENT,
60 	}, {
61 		.mtd_type = MTD_ABSENT,
62 	},
63 };
64 static int dev_current;
65 
66 #define DEVNAME(i)    envdevices[(i)].devname
67 #define DEVOFFSET(i)  envdevices[(i)].devoff
68 #define ENVSIZE(i)    envdevices[(i)].env_size
69 #define DEVESIZE(i)   envdevices[(i)].erase_size
70 #define ENVSECTORS(i) envdevices[(i)].env_sectors
71 #define DEVTYPE(i)    envdevices[(i)].mtd_type
72 
73 #define CUR_ENVSIZE ENVSIZE(dev_current)
74 
75 #define ENV_SIZE      getenvsize()
76 
77 struct env_image_single {
78 	uint32_t	crc;	/* CRC32 over data bytes    */
79 	char		data[];
80 };
81 
82 struct env_image_redundant {
83 	uint32_t	crc;	/* CRC32 over data bytes    */
84 	unsigned char	flags;	/* active or obsolete */
85 	char		data[];
86 };
87 
88 enum flag_scheme {
89 	FLAG_NONE,
90 	FLAG_BOOLEAN,
91 	FLAG_INCREMENTAL,
92 };
93 
94 struct environment {
95 	void			*image;
96 	uint32_t		*crc;
97 	unsigned char		*flags;
98 	char			*data;
99 	enum flag_scheme	flag_scheme;
100 };
101 
102 static struct environment environment = {
103 	.flag_scheme = FLAG_NONE,
104 };
105 
106 static int env_aes_cbc_crypt(char *data, const int enc);
107 
108 static int HaveRedundEnv = 0;
109 
110 static unsigned char active_flag = 1;
111 /* obsolete_flag must be 0 to efficiently set it on NOR flash without erasing */
112 static unsigned char obsolete_flag = 0;
113 
114 #define DEFAULT_ENV_INSTANCE_STATIC
115 #include <env_default.h>
116 
117 static int flash_io (int mode);
118 static char *envmatch (char * s1, char * s2);
119 static int parse_config (void);
120 
121 #if defined(CONFIG_FILE)
122 static int get_config (char *);
123 #endif
124 static inline ulong getenvsize (void)
125 {
126 	ulong rc = CUR_ENVSIZE - sizeof(uint32_t);
127 
128 	if (HaveRedundEnv)
129 		rc -= sizeof (char);
130 
131 	if (common_args.aes_flag)
132 		rc &= ~(AES_KEY_LENGTH - 1);
133 
134 	return rc;
135 }
136 
137 static char *fw_string_blank(char *s, int noblank)
138 {
139 	int i;
140 	int len = strlen(s);
141 
142 	for (i = 0; i < len; i++, s++) {
143 		if ((noblank && !WHITESPACE(*s)) ||
144 			(!noblank && WHITESPACE(*s)))
145 			break;
146 	}
147 	if (i == len)
148 		return NULL;
149 
150 	return s;
151 }
152 
153 /*
154  * Search the environment for a variable.
155  * Return the value, if found, or NULL, if not found.
156  */
157 char *fw_getenv (char *name)
158 {
159 	char *env, *nxt;
160 
161 	for (env = environment.data; *env; env = nxt + 1) {
162 		char *val;
163 
164 		for (nxt = env; *nxt; ++nxt) {
165 			if (nxt >= &environment.data[ENV_SIZE]) {
166 				fprintf (stderr, "## Error: "
167 					"environment not terminated\n");
168 				return NULL;
169 			}
170 		}
171 		val = envmatch (name, env);
172 		if (!val)
173 			continue;
174 		return val;
175 	}
176 	return NULL;
177 }
178 
179 /*
180  * Search the default environment for a variable.
181  * Return the value, if found, or NULL, if not found.
182  */
183 char *fw_getdefenv(char *name)
184 {
185 	char *env, *nxt;
186 
187 	for (env = default_environment; *env; env = nxt + 1) {
188 		char *val;
189 
190 		for (nxt = env; *nxt; ++nxt) {
191 			if (nxt >= &default_environment[ENV_SIZE]) {
192 				fprintf(stderr, "## Error: "
193 					"default environment not terminated\n");
194 				return NULL;
195 			}
196 		}
197 		val = envmatch(name, env);
198 		if (!val)
199 			continue;
200 		return val;
201 	}
202 	return NULL;
203 }
204 
205 int parse_aes_key(char *key, uint8_t *bin_key)
206 {
207 	char tmp[5] = { '0', 'x', 0, 0, 0 };
208 	unsigned long ul;
209 	int i;
210 
211 	if (strnlen(key, 64) != 32) {
212 		fprintf(stderr,
213 			"## Error: '-a' option requires 16-byte AES key\n");
214 		return -1;
215 	}
216 
217 	for (i = 0; i < 16; i++) {
218 		tmp[2] = key[0];
219 		tmp[3] = key[1];
220 		errno = 0;
221 		ul = strtoul(tmp, NULL, 16);
222 		if (errno) {
223 			fprintf(stderr,
224 				"## Error: '-a' option requires valid AES key\n");
225 			return -1;
226 		}
227 		bin_key[i] = ul & 0xff;
228 		key += 2;
229 	}
230 	return 0;
231 }
232 
233 /*
234  * Print the current definition of one, or more, or all
235  * environment variables
236  */
237 int fw_printenv (int argc, char *argv[])
238 {
239 	char *env, *nxt;
240 	int i, rc = 0;
241 
242 	if (fw_env_open())
243 		return -1;
244 
245 	if (argc == 0) {		/* Print all env variables  */
246 		for (env = environment.data; *env; env = nxt + 1) {
247 			for (nxt = env; *nxt; ++nxt) {
248 				if (nxt >= &environment.data[ENV_SIZE]) {
249 					fprintf (stderr, "## Error: "
250 						"environment not terminated\n");
251 					return -1;
252 				}
253 			}
254 
255 			printf ("%s\n", env);
256 		}
257 		return 0;
258 	}
259 
260 	if (printenv_args.name_suppress && argc != 1) {
261 		fprintf(stderr,
262 			"## Error: `-n' option requires exactly one argument\n");
263 		return -1;
264 	}
265 
266 	for (i = 0; i < argc; ++i) {	/* print single env variables   */
267 		char *name = argv[i];
268 		char *val = NULL;
269 
270 		for (env = environment.data; *env; env = nxt + 1) {
271 
272 			for (nxt = env; *nxt; ++nxt) {
273 				if (nxt >= &environment.data[ENV_SIZE]) {
274 					fprintf (stderr, "## Error: "
275 						"environment not terminated\n");
276 					return -1;
277 				}
278 			}
279 			val = envmatch (name, env);
280 			if (val) {
281 				if (!printenv_args.name_suppress) {
282 					fputs (name, stdout);
283 					putc ('=', stdout);
284 				}
285 				puts (val);
286 				break;
287 			}
288 		}
289 		if (!val) {
290 			fprintf (stderr, "## Error: \"%s\" not defined\n", name);
291 			rc = -1;
292 		}
293 	}
294 
295 	return rc;
296 }
297 
298 int fw_env_close(void)
299 {
300 	int ret;
301 	if (common_args.aes_flag) {
302 		ret = env_aes_cbc_crypt(environment.data, 1);
303 		if (ret) {
304 			fprintf(stderr,
305 				"Error: can't encrypt env for flash\n");
306 			return ret;
307 		}
308 	}
309 
310 	/*
311 	 * Update CRC
312 	 */
313 	*environment.crc = crc32(0, (uint8_t *) environment.data, ENV_SIZE);
314 
315 	/* write environment back to flash */
316 	if (flash_io(O_RDWR)) {
317 		fprintf(stderr,
318 			"Error: can't write fw_env to flash\n");
319 			return -1;
320 	}
321 
322 	return 0;
323 }
324 
325 
326 /*
327  * Set/Clear a single variable in the environment.
328  * This is called in sequence to update the environment
329  * in RAM without updating the copy in flash after each set
330  */
331 int fw_env_write(char *name, char *value)
332 {
333 	int len;
334 	char *env, *nxt;
335 	char *oldval = NULL;
336 	int deleting, creating, overwriting;
337 
338 	/*
339 	 * search if variable with this name already exists
340 	 */
341 	for (nxt = env = environment.data; *env; env = nxt + 1) {
342 		for (nxt = env; *nxt; ++nxt) {
343 			if (nxt >= &environment.data[ENV_SIZE]) {
344 				fprintf(stderr, "## Error: "
345 					"environment not terminated\n");
346 				errno = EINVAL;
347 				return -1;
348 			}
349 		}
350 		if ((oldval = envmatch (name, env)) != NULL)
351 			break;
352 	}
353 
354 	deleting = (oldval && !(value && strlen(value)));
355 	creating = (!oldval && (value && strlen(value)));
356 	overwriting = (oldval && (value && strlen(value)));
357 
358 	/* check for permission */
359 	if (deleting) {
360 		if (env_flags_validate_varaccess(name,
361 		    ENV_FLAGS_VARACCESS_PREVENT_DELETE)) {
362 			printf("Can't delete \"%s\"\n", name);
363 			errno = EROFS;
364 			return -1;
365 		}
366 	} else if (overwriting) {
367 		if (env_flags_validate_varaccess(name,
368 		    ENV_FLAGS_VARACCESS_PREVENT_OVERWR)) {
369 			printf("Can't overwrite \"%s\"\n", name);
370 			errno = EROFS;
371 			return -1;
372 		} else if (env_flags_validate_varaccess(name,
373 		    ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR)) {
374 			const char *defval = fw_getdefenv(name);
375 
376 			if (defval == NULL)
377 				defval = "";
378 			if (strcmp(oldval, defval)
379 			    != 0) {
380 				printf("Can't overwrite \"%s\"\n", name);
381 				errno = EROFS;
382 				return -1;
383 			}
384 		}
385 	} else if (creating) {
386 		if (env_flags_validate_varaccess(name,
387 		    ENV_FLAGS_VARACCESS_PREVENT_CREATE)) {
388 			printf("Can't create \"%s\"\n", name);
389 			errno = EROFS;
390 			return -1;
391 		}
392 	} else
393 		/* Nothing to do */
394 		return 0;
395 
396 	if (deleting || overwriting) {
397 		if (*++nxt == '\0') {
398 			*env = '\0';
399 		} else {
400 			for (;;) {
401 				*env = *nxt++;
402 				if ((*env == '\0') && (*nxt == '\0'))
403 					break;
404 				++env;
405 			}
406 		}
407 		*++env = '\0';
408 	}
409 
410 	/* Delete only ? */
411 	if (!value || !strlen(value))
412 		return 0;
413 
414 	/*
415 	 * Append new definition at the end
416 	 */
417 	for (env = environment.data; *env || *(env + 1); ++env);
418 	if (env > environment.data)
419 		++env;
420 	/*
421 	 * Overflow when:
422 	 * "name" + "=" + "val" +"\0\0"  > CUR_ENVSIZE - (env-environment)
423 	 */
424 	len = strlen (name) + 2;
425 	/* add '=' for first arg, ' ' for all others */
426 	len += strlen(value) + 1;
427 
428 	if (len > (&environment.data[ENV_SIZE] - env)) {
429 		fprintf (stderr,
430 			"Error: environment overflow, \"%s\" deleted\n",
431 			name);
432 		return -1;
433 	}
434 
435 	while ((*env = *name++) != '\0')
436 		env++;
437 	*env = '=';
438 	while ((*++env = *value++) != '\0')
439 		;
440 
441 	/* end is marked with double '\0' */
442 	*++env = '\0';
443 
444 	return 0;
445 }
446 
447 /*
448  * Deletes or sets environment variables. Returns -1 and sets errno error codes:
449  * 0	  - OK
450  * EINVAL - need at least 1 argument
451  * EROFS  - certain variables ("ethaddr", "serial#") cannot be
452  *	    modified or deleted
453  *
454  */
455 int fw_setenv(int argc, char *argv[])
456 {
457 	int i;
458 	size_t len;
459 	char *name, **valv;
460 	char *value = NULL;
461 	int valc;
462 
463 	if (argc < 1) {
464 		fprintf(stderr, "## Error: variable name missing\n");
465 		errno = EINVAL;
466 		return -1;
467 	}
468 
469 	if (fw_env_open()) {
470 		fprintf(stderr, "Error: environment not initialized\n");
471 		return -1;
472 	}
473 
474 	name = argv[0];
475 	valv = argv + 1;
476 	valc = argc - 1;
477 
478 	if (env_flags_validate_env_set_params(name, valv, valc) < 0)
479 		return 1;
480 
481 	len = 0;
482 	for (i = 0; i < valc; ++i) {
483 		char *val = valv[i];
484 		size_t val_len = strlen(val);
485 
486 		if (value)
487 			value[len - 1] = ' ';
488 		value = realloc(value, len + val_len + 1);
489 		if (!value) {
490 			fprintf(stderr,
491 				"Cannot malloc %zu bytes: %s\n",
492 				len, strerror(errno));
493 			return -1;
494 		}
495 
496 		memcpy(value + len, val, val_len);
497 		len += val_len;
498 		value[len++] = '\0';
499 	}
500 
501 	fw_env_write(name, value);
502 
503 	free(value);
504 
505 	return fw_env_close();
506 }
507 
508 /*
509  * Parse  a file  and configure the u-boot variables.
510  * The script file has a very simple format, as follows:
511  *
512  * Each line has a couple with name, value:
513  * <white spaces>variable_name<white spaces>variable_value
514  *
515  * Both variable_name and variable_value are interpreted as strings.
516  * Any character after <white spaces> and before ending \r\n is interpreted
517  * as variable's value (no comment allowed on these lines !)
518  *
519  * Comments are allowed if the first character in the line is #
520  *
521  * Returns -1 and sets errno error codes:
522  * 0	  - OK
523  * -1     - Error
524  */
525 int fw_parse_script(char *fname)
526 {
527 	FILE *fp;
528 	char dump[1024];	/* Maximum line length in the file */
529 	char *name;
530 	char *val;
531 	int lineno = 0;
532 	int len;
533 	int ret = 0;
534 
535 	if (fw_env_open()) {
536 		fprintf(stderr, "Error: environment not initialized\n");
537 		return -1;
538 	}
539 
540 	if (strcmp(fname, "-") == 0)
541 		fp = stdin;
542 	else {
543 		fp = fopen(fname, "r");
544 		if (fp == NULL) {
545 			fprintf(stderr, "I cannot open %s for reading\n",
546 				 fname);
547 			return -1;
548 		}
549 	}
550 
551 	while (fgets(dump, sizeof(dump), fp)) {
552 		lineno++;
553 		len = strlen(dump);
554 
555 		/*
556 		 * Read a whole line from the file. If the line is too long
557 		 * or is not terminated, reports an error and exit.
558 		 */
559 		if (dump[len - 1] != '\n') {
560 			fprintf(stderr,
561 			"Line %d not corrected terminated or too long\n",
562 				lineno);
563 			ret = -1;
564 			break;
565 		}
566 
567 		/* Drop ending line feed / carriage return */
568 		while (len > 0 && (dump[len - 1] == '\n' ||
569 				dump[len - 1] == '\r')) {
570 			dump[len - 1] = '\0';
571 			len--;
572 		}
573 
574 		/* Skip comment or empty lines */
575 		if ((len == 0) || dump[0] == '#')
576 			continue;
577 
578 		/*
579 		 * Search for variable's name,
580 		 * remove leading whitespaces
581 		 */
582 		name = fw_string_blank(dump, 1);
583 		if (!name)
584 			continue;
585 
586 		/* The first white space is the end of variable name */
587 		val = fw_string_blank(name, 0);
588 		len = strlen(name);
589 		if (val) {
590 			*val++ = '\0';
591 			if ((val - name) < len)
592 				val = fw_string_blank(val, 1);
593 			else
594 				val = NULL;
595 		}
596 
597 #ifdef DEBUG
598 		fprintf(stderr, "Setting %s : %s\n",
599 			name, val ? val : " removed");
600 #endif
601 
602 		if (env_flags_validate_type(name, val) < 0) {
603 			ret = -1;
604 			break;
605 		}
606 
607 		/*
608 		 * If there is an error setting a variable,
609 		 * try to save the environment and returns an error
610 		 */
611 		if (fw_env_write(name, val)) {
612 			fprintf(stderr,
613 			"fw_env_write returns with error : %s\n",
614 				strerror(errno));
615 			ret = -1;
616 			break;
617 		}
618 
619 	}
620 
621 	/* Close file if not stdin */
622 	if (strcmp(fname, "-") != 0)
623 		fclose(fp);
624 
625 	ret |= fw_env_close();
626 
627 	return ret;
628 
629 }
630 
631 /*
632  * Test for bad block on NAND, just returns 0 on NOR, on NAND:
633  * 0	- block is good
634  * > 0	- block is bad
635  * < 0	- failed to test
636  */
637 static int flash_bad_block (int fd, uint8_t mtd_type, loff_t *blockstart)
638 {
639 	if (mtd_type == MTD_NANDFLASH) {
640 		int badblock = ioctl (fd, MEMGETBADBLOCK, blockstart);
641 
642 		if (badblock < 0) {
643 			perror ("Cannot read bad block mark");
644 			return badblock;
645 		}
646 
647 		if (badblock) {
648 #ifdef DEBUG
649 			fprintf (stderr, "Bad block at 0x%llx, "
650 				 "skipping\n", *blockstart);
651 #endif
652 			return badblock;
653 		}
654 	}
655 
656 	return 0;
657 }
658 
659 /*
660  * Read data from flash at an offset into a provided buffer. On NAND it skips
661  * bad blocks but makes sure it stays within ENVSECTORS (dev) starting from
662  * the DEVOFFSET (dev) block. On NOR the loop is only run once.
663  */
664 static int flash_read_buf (int dev, int fd, void *buf, size_t count,
665 			   off_t offset, uint8_t mtd_type)
666 {
667 	size_t blocklen;	/* erase / write length - one block on NAND,
668 				   0 on NOR */
669 	size_t processed = 0;	/* progress counter */
670 	size_t readlen = count;	/* current read length */
671 	off_t top_of_range;	/* end of the last block we may use */
672 	off_t block_seek;	/* offset inside the current block to the start
673 				   of the data */
674 	loff_t blockstart;	/* running start of the current block -
675 				   MEMGETBADBLOCK needs 64 bits */
676 	int rc;
677 
678 	blockstart = (offset / DEVESIZE (dev)) * DEVESIZE (dev);
679 
680 	/* Offset inside a block */
681 	block_seek = offset - blockstart;
682 
683 	if (mtd_type == MTD_NANDFLASH) {
684 		/*
685 		 * NAND: calculate which blocks we are reading. We have
686 		 * to read one block at a time to skip bad blocks.
687 		 */
688 		blocklen = DEVESIZE (dev);
689 
690 		/*
691 		 * To calculate the top of the range, we have to use the
692 		 * global DEVOFFSET (dev), which can be different from offset
693 		 */
694 		top_of_range = ((DEVOFFSET(dev) / blocklen) +
695 				ENVSECTORS (dev)) * blocklen;
696 
697 		/* Limit to one block for the first read */
698 		if (readlen > blocklen - block_seek)
699 			readlen = blocklen - block_seek;
700 	} else {
701 		blocklen = 0;
702 		top_of_range = offset + count;
703 	}
704 
705 	/* This only runs once on NOR flash */
706 	while (processed < count) {
707 		rc = flash_bad_block (fd, mtd_type, &blockstart);
708 		if (rc < 0)		/* block test failed */
709 			return -1;
710 
711 		if (blockstart + block_seek + readlen > top_of_range) {
712 			/* End of range is reached */
713 			fprintf (stderr,
714 				 "Too few good blocks within range\n");
715 			return -1;
716 		}
717 
718 		if (rc) {		/* block is bad */
719 			blockstart += blocklen;
720 			continue;
721 		}
722 
723 		/*
724 		 * If a block is bad, we retry in the next block at the same
725 		 * offset - see common/env_nand.c::writeenv()
726 		 */
727 		lseek (fd, blockstart + block_seek, SEEK_SET);
728 
729 		rc = read (fd, buf + processed, readlen);
730 		if (rc != readlen) {
731 			fprintf (stderr, "Read error on %s: %s\n",
732 				 DEVNAME (dev), strerror (errno));
733 			return -1;
734 		}
735 #ifdef DEBUG
736 		fprintf(stderr, "Read 0x%x bytes at 0x%llx on %s\n",
737 			 rc, blockstart + block_seek, DEVNAME(dev));
738 #endif
739 		processed += readlen;
740 		readlen = min (blocklen, count - processed);
741 		block_seek = 0;
742 		blockstart += blocklen;
743 	}
744 
745 	return processed;
746 }
747 
748 /*
749  * Write count bytes at offset, but stay within ENVSECTORS (dev) sectors of
750  * DEVOFFSET (dev). Similar to the read case above, on NOR and dataflash we
751  * erase and write the whole data at once.
752  */
753 static int flash_write_buf (int dev, int fd, void *buf, size_t count,
754 			    off_t offset, uint8_t mtd_type)
755 {
756 	void *data;
757 	struct erase_info_user erase;
758 	size_t blocklen;	/* length of NAND block / NOR erase sector */
759 	size_t erase_len;	/* whole area that can be erased - may include
760 				   bad blocks */
761 	size_t erasesize;	/* erase / write length - one block on NAND,
762 				   whole area on NOR */
763 	size_t processed = 0;	/* progress counter */
764 	size_t write_total;	/* total size to actually write - excluding
765 				   bad blocks */
766 	off_t erase_offset;	/* offset to the first erase block (aligned)
767 				   below offset */
768 	off_t block_seek;	/* offset inside the erase block to the start
769 				   of the data */
770 	off_t top_of_range;	/* end of the last block we may use */
771 	loff_t blockstart;	/* running start of the current block -
772 				   MEMGETBADBLOCK needs 64 bits */
773 	int rc;
774 
775 	/*
776 	 * For mtd devices only offset and size of the environment do matter
777 	 */
778 	if (mtd_type == MTD_ABSENT) {
779 		blocklen = count;
780 		top_of_range = offset + count;
781 		erase_len = blocklen;
782 		blockstart = offset;
783 		block_seek = 0;
784 		write_total = blocklen;
785 	} else {
786 		blocklen = DEVESIZE(dev);
787 
788 		top_of_range = ((DEVOFFSET(dev) / blocklen) +
789 					ENVSECTORS(dev)) * blocklen;
790 
791 		erase_offset = (offset / blocklen) * blocklen;
792 
793 		/* Maximum area we may use */
794 		erase_len = top_of_range - erase_offset;
795 
796 		blockstart = erase_offset;
797 		/* Offset inside a block */
798 		block_seek = offset - erase_offset;
799 
800 		/*
801 		 * Data size we actually write: from the start of the block
802 		 * to the start of the data, then count bytes of data, and
803 		 * to the end of the block
804 		 */
805 		write_total = ((block_seek + count + blocklen - 1) /
806 							blocklen) * blocklen;
807 	}
808 
809 	/*
810 	 * Support data anywhere within erase sectors: read out the complete
811 	 * area to be erased, replace the environment image, write the whole
812 	 * block back again.
813 	 */
814 	if (write_total > count) {
815 		data = malloc (erase_len);
816 		if (!data) {
817 			fprintf (stderr,
818 				 "Cannot malloc %zu bytes: %s\n",
819 				 erase_len, strerror (errno));
820 			return -1;
821 		}
822 
823 		rc = flash_read_buf (dev, fd, data, write_total, erase_offset,
824 				     mtd_type);
825 		if (write_total != rc)
826 			return -1;
827 
828 #ifdef DEBUG
829 		fprintf(stderr, "Preserving data ");
830 		if (block_seek != 0)
831 			fprintf(stderr, "0x%x - 0x%lx", 0, block_seek - 1);
832 		if (block_seek + count != write_total) {
833 			if (block_seek != 0)
834 				fprintf(stderr, " and ");
835 			fprintf(stderr, "0x%lx - 0x%x",
836 				block_seek + count, write_total - 1);
837 		}
838 		fprintf(stderr, "\n");
839 #endif
840 		/* Overwrite the old environment */
841 		memcpy (data + block_seek, buf, count);
842 	} else {
843 		/*
844 		 * We get here, iff offset is block-aligned and count is a
845 		 * multiple of blocklen - see write_total calculation above
846 		 */
847 		data = buf;
848 	}
849 
850 	if (mtd_type == MTD_NANDFLASH) {
851 		/*
852 		 * NAND: calculate which blocks we are writing. We have
853 		 * to write one block at a time to skip bad blocks.
854 		 */
855 		erasesize = blocklen;
856 	} else {
857 		erasesize = erase_len;
858 	}
859 
860 	erase.length = erasesize;
861 
862 	/* This only runs once on NOR flash and SPI-dataflash */
863 	while (processed < write_total) {
864 		rc = flash_bad_block (fd, mtd_type, &blockstart);
865 		if (rc < 0)		/* block test failed */
866 			return rc;
867 
868 		if (blockstart + erasesize > top_of_range) {
869 			fprintf (stderr, "End of range reached, aborting\n");
870 			return -1;
871 		}
872 
873 		if (rc) {		/* block is bad */
874 			blockstart += blocklen;
875 			continue;
876 		}
877 
878 		if (mtd_type != MTD_ABSENT) {
879 			erase.start = blockstart;
880 			ioctl(fd, MEMUNLOCK, &erase);
881 			/* These do not need an explicit erase cycle */
882 			if (mtd_type != MTD_DATAFLASH)
883 				if (ioctl(fd, MEMERASE, &erase) != 0) {
884 					fprintf(stderr,
885 						"MTD erase error on %s: %s\n",
886 						DEVNAME(dev), strerror(errno));
887 					return -1;
888 				}
889 		}
890 
891 		if (lseek (fd, blockstart, SEEK_SET) == -1) {
892 			fprintf (stderr,
893 				 "Seek error on %s: %s\n",
894 				 DEVNAME (dev), strerror (errno));
895 			return -1;
896 		}
897 
898 #ifdef DEBUG
899 		fprintf(stderr, "Write 0x%x bytes at 0x%llx\n", erasesize,
900 			blockstart);
901 #endif
902 		if (write (fd, data + processed, erasesize) != erasesize) {
903 			fprintf (stderr, "Write error on %s: %s\n",
904 				 DEVNAME (dev), strerror (errno));
905 			return -1;
906 		}
907 
908 		if (mtd_type != MTD_ABSENT)
909 			ioctl(fd, MEMLOCK, &erase);
910 
911 		processed  += erasesize;
912 		block_seek = 0;
913 		blockstart += erasesize;
914 	}
915 
916 	if (write_total > count)
917 		free (data);
918 
919 	return processed;
920 }
921 
922 /*
923  * Set obsolete flag at offset - NOR flash only
924  */
925 static int flash_flag_obsolete (int dev, int fd, off_t offset)
926 {
927 	int rc;
928 	struct erase_info_user erase;
929 
930 	erase.start  = DEVOFFSET (dev);
931 	erase.length = DEVESIZE (dev);
932 	/* This relies on the fact, that obsolete_flag == 0 */
933 	rc = lseek (fd, offset, SEEK_SET);
934 	if (rc < 0) {
935 		fprintf (stderr, "Cannot seek to set the flag on %s \n",
936 			 DEVNAME (dev));
937 		return rc;
938 	}
939 	ioctl (fd, MEMUNLOCK, &erase);
940 	rc = write (fd, &obsolete_flag, sizeof (obsolete_flag));
941 	ioctl (fd, MEMLOCK, &erase);
942 	if (rc < 0)
943 		perror ("Could not set obsolete flag");
944 
945 	return rc;
946 }
947 
948 /* Encrypt or decrypt the environment before writing or reading it. */
949 static int env_aes_cbc_crypt(char *payload, const int enc)
950 {
951 	uint8_t *data = (uint8_t *)payload;
952 	const int len = getenvsize();
953 	uint8_t key_exp[AES_EXPAND_KEY_LENGTH];
954 	uint32_t aes_blocks;
955 
956 	/* First we expand the key. */
957 	aes_expand_key(common_args.aes_key, key_exp);
958 
959 	/* Calculate the number of AES blocks to encrypt. */
960 	aes_blocks = DIV_ROUND_UP(len, AES_KEY_LENGTH);
961 
962 	if (enc)
963 		aes_cbc_encrypt_blocks(key_exp, data, data, aes_blocks);
964 	else
965 		aes_cbc_decrypt_blocks(key_exp, data, data, aes_blocks);
966 
967 	return 0;
968 }
969 
970 static int flash_write (int fd_current, int fd_target, int dev_target)
971 {
972 	int rc;
973 
974 	switch (environment.flag_scheme) {
975 	case FLAG_NONE:
976 		break;
977 	case FLAG_INCREMENTAL:
978 		(*environment.flags)++;
979 		break;
980 	case FLAG_BOOLEAN:
981 		*environment.flags = active_flag;
982 		break;
983 	default:
984 		fprintf (stderr, "Unimplemented flash scheme %u \n",
985 			 environment.flag_scheme);
986 		return -1;
987 	}
988 
989 #ifdef DEBUG
990 	fprintf(stderr, "Writing new environment at 0x%lx on %s\n",
991 		DEVOFFSET (dev_target), DEVNAME (dev_target));
992 #endif
993 
994 	rc = flash_write_buf(dev_target, fd_target, environment.image,
995 			      CUR_ENVSIZE, DEVOFFSET(dev_target),
996 			      DEVTYPE(dev_target));
997 	if (rc < 0)
998 		return rc;
999 
1000 	if (environment.flag_scheme == FLAG_BOOLEAN) {
1001 		/* Have to set obsolete flag */
1002 		off_t offset = DEVOFFSET (dev_current) +
1003 			offsetof (struct env_image_redundant, flags);
1004 #ifdef DEBUG
1005 		fprintf(stderr,
1006 			"Setting obsolete flag in environment at 0x%lx on %s\n",
1007 			DEVOFFSET (dev_current), DEVNAME (dev_current));
1008 #endif
1009 		flash_flag_obsolete (dev_current, fd_current, offset);
1010 	}
1011 
1012 	return 0;
1013 }
1014 
1015 static int flash_read (int fd)
1016 {
1017 	struct mtd_info_user mtdinfo;
1018 	struct stat st;
1019 	int rc;
1020 
1021 	rc = fstat(fd, &st);
1022 	if (rc < 0) {
1023 		fprintf(stderr, "Cannot stat the file %s\n",
1024 			DEVNAME(dev_current));
1025 		return -1;
1026 	}
1027 
1028 	if (S_ISCHR(st.st_mode)) {
1029 		rc = ioctl(fd, MEMGETINFO, &mtdinfo);
1030 		if (rc < 0) {
1031 			fprintf(stderr, "Cannot get MTD information for %s\n",
1032 				DEVNAME(dev_current));
1033 			return -1;
1034 		}
1035 		if (mtdinfo.type != MTD_NORFLASH &&
1036 		    mtdinfo.type != MTD_NANDFLASH &&
1037 		    mtdinfo.type != MTD_DATAFLASH &&
1038 		    mtdinfo.type != MTD_UBIVOLUME) {
1039 			fprintf (stderr, "Unsupported flash type %u on %s\n",
1040 				 mtdinfo.type, DEVNAME(dev_current));
1041 			return -1;
1042 		}
1043 	} else {
1044 		memset(&mtdinfo, 0, sizeof(mtdinfo));
1045 		mtdinfo.type = MTD_ABSENT;
1046 	}
1047 
1048 	DEVTYPE(dev_current) = mtdinfo.type;
1049 
1050 	rc = flash_read_buf(dev_current, fd, environment.image, CUR_ENVSIZE,
1051 			     DEVOFFSET (dev_current), mtdinfo.type);
1052 	if (rc != CUR_ENVSIZE)
1053 		return -1;
1054 
1055 	return 0;
1056 }
1057 
1058 static int flash_io (int mode)
1059 {
1060 	int fd_current, fd_target, rc, dev_target;
1061 
1062 	/* dev_current: fd_current, erase_current */
1063 	fd_current = open (DEVNAME (dev_current), mode);
1064 	if (fd_current < 0) {
1065 		fprintf (stderr,
1066 			 "Can't open %s: %s\n",
1067 			 DEVNAME (dev_current), strerror (errno));
1068 		return -1;
1069 	}
1070 
1071 	if (mode == O_RDWR) {
1072 		if (HaveRedundEnv) {
1073 			/* switch to next partition for writing */
1074 			dev_target = !dev_current;
1075 			/* dev_target: fd_target, erase_target */
1076 			fd_target = open (DEVNAME (dev_target), mode);
1077 			if (fd_target < 0) {
1078 				fprintf (stderr,
1079 					 "Can't open %s: %s\n",
1080 					 DEVNAME (dev_target),
1081 					 strerror (errno));
1082 				rc = -1;
1083 				goto exit;
1084 			}
1085 		} else {
1086 			dev_target = dev_current;
1087 			fd_target = fd_current;
1088 		}
1089 
1090 		rc = flash_write (fd_current, fd_target, dev_target);
1091 
1092 		if (HaveRedundEnv) {
1093 			if (close (fd_target)) {
1094 				fprintf (stderr,
1095 					"I/O error on %s: %s\n",
1096 					DEVNAME (dev_target),
1097 					strerror (errno));
1098 				rc = -1;
1099 			}
1100 		}
1101 	} else {
1102 		rc = flash_read (fd_current);
1103 	}
1104 
1105 exit:
1106 	if (close (fd_current)) {
1107 		fprintf (stderr,
1108 			 "I/O error on %s: %s\n",
1109 			 DEVNAME (dev_current), strerror (errno));
1110 		return -1;
1111 	}
1112 
1113 	return rc;
1114 }
1115 
1116 /*
1117  * s1 is either a simple 'name', or a 'name=value' pair.
1118  * s2 is a 'name=value' pair.
1119  * If the names match, return the value of s2, else NULL.
1120  */
1121 
1122 static char *envmatch (char * s1, char * s2)
1123 {
1124 	if (s1 == NULL || s2 == NULL)
1125 		return NULL;
1126 
1127 	while (*s1 == *s2++)
1128 		if (*s1++ == '=')
1129 			return s2;
1130 	if (*s1 == '\0' && *(s2 - 1) == '=')
1131 		return s2;
1132 	return NULL;
1133 }
1134 
1135 /*
1136  * Prevent confusion if running from erased flash memory
1137  */
1138 int fw_env_open(void)
1139 {
1140 	int crc0, crc0_ok;
1141 	unsigned char flag0;
1142 	void *addr0;
1143 
1144 	int crc1, crc1_ok;
1145 	unsigned char flag1;
1146 	void *addr1;
1147 
1148 	int ret;
1149 
1150 	struct env_image_single *single;
1151 	struct env_image_redundant *redundant;
1152 
1153 	if (parse_config ())		/* should fill envdevices */
1154 		return -1;
1155 
1156 	addr0 = calloc(1, CUR_ENVSIZE);
1157 	if (addr0 == NULL) {
1158 		fprintf(stderr,
1159 			"Not enough memory for environment (%ld bytes)\n",
1160 			CUR_ENVSIZE);
1161 		return -1;
1162 	}
1163 
1164 	/* read environment from FLASH to local buffer */
1165 	environment.image = addr0;
1166 
1167 	if (HaveRedundEnv) {
1168 		redundant = addr0;
1169 		environment.crc		= &redundant->crc;
1170 		environment.flags	= &redundant->flags;
1171 		environment.data	= redundant->data;
1172 	} else {
1173 		single = addr0;
1174 		environment.crc		= &single->crc;
1175 		environment.flags	= NULL;
1176 		environment.data	= single->data;
1177 	}
1178 
1179 	dev_current = 0;
1180 	if (flash_io (O_RDONLY))
1181 		return -1;
1182 
1183 	crc0 = crc32 (0, (uint8_t *) environment.data, ENV_SIZE);
1184 
1185 	if (common_args.aes_flag) {
1186 		ret = env_aes_cbc_crypt(environment.data, 0);
1187 		if (ret)
1188 			return ret;
1189 	}
1190 
1191 	crc0_ok = (crc0 == *environment.crc);
1192 	if (!HaveRedundEnv) {
1193 		if (!crc0_ok) {
1194 			fprintf (stderr,
1195 				"Warning: Bad CRC, using default environment\n");
1196 			memcpy(environment.data, default_environment, sizeof default_environment);
1197 		}
1198 	} else {
1199 		flag0 = *environment.flags;
1200 
1201 		dev_current = 1;
1202 		addr1 = calloc(1, CUR_ENVSIZE);
1203 		if (addr1 == NULL) {
1204 			fprintf(stderr,
1205 				"Not enough memory for environment (%ld bytes)\n",
1206 				CUR_ENVSIZE);
1207 			return -1;
1208 		}
1209 		redundant = addr1;
1210 
1211 		/*
1212 		 * have to set environment.image for flash_read(), careful -
1213 		 * other pointers in environment still point inside addr0
1214 		 */
1215 		environment.image = addr1;
1216 		if (flash_io (O_RDONLY))
1217 			return -1;
1218 
1219 		/* Check flag scheme compatibility */
1220 		if (DEVTYPE(dev_current) == MTD_NORFLASH &&
1221 		    DEVTYPE(!dev_current) == MTD_NORFLASH) {
1222 			environment.flag_scheme = FLAG_BOOLEAN;
1223 		} else if (DEVTYPE(dev_current) == MTD_NANDFLASH &&
1224 			   DEVTYPE(!dev_current) == MTD_NANDFLASH) {
1225 			environment.flag_scheme = FLAG_INCREMENTAL;
1226 		} else if (DEVTYPE(dev_current) == MTD_DATAFLASH &&
1227 			   DEVTYPE(!dev_current) == MTD_DATAFLASH) {
1228 			environment.flag_scheme = FLAG_BOOLEAN;
1229 		} else if (DEVTYPE(dev_current) == MTD_UBIVOLUME &&
1230 			   DEVTYPE(!dev_current) == MTD_UBIVOLUME) {
1231 			environment.flag_scheme = FLAG_INCREMENTAL;
1232 		} else if (DEVTYPE(dev_current) == MTD_ABSENT &&
1233 			   DEVTYPE(!dev_current) == MTD_ABSENT) {
1234 			environment.flag_scheme = FLAG_INCREMENTAL;
1235 		} else {
1236 			fprintf (stderr, "Incompatible flash types!\n");
1237 			return -1;
1238 		}
1239 
1240 		crc1 = crc32 (0, (uint8_t *) redundant->data, ENV_SIZE);
1241 
1242 		if (common_args.aes_flag) {
1243 			ret = env_aes_cbc_crypt(redundant->data, 0);
1244 			if (ret)
1245 				return ret;
1246 		}
1247 
1248 		crc1_ok = (crc1 == redundant->crc);
1249 		flag1 = redundant->flags;
1250 
1251 		if (crc0_ok && !crc1_ok) {
1252 			dev_current = 0;
1253 		} else if (!crc0_ok && crc1_ok) {
1254 			dev_current = 1;
1255 		} else if (!crc0_ok && !crc1_ok) {
1256 			fprintf (stderr,
1257 				"Warning: Bad CRC, using default environment\n");
1258 			memcpy (environment.data, default_environment,
1259 				sizeof default_environment);
1260 			dev_current = 0;
1261 		} else {
1262 			switch (environment.flag_scheme) {
1263 			case FLAG_BOOLEAN:
1264 				if (flag0 == active_flag &&
1265 				    flag1 == obsolete_flag) {
1266 					dev_current = 0;
1267 				} else if (flag0 == obsolete_flag &&
1268 					   flag1 == active_flag) {
1269 					dev_current = 1;
1270 				} else if (flag0 == flag1) {
1271 					dev_current = 0;
1272 				} else if (flag0 == 0xFF) {
1273 					dev_current = 0;
1274 				} else if (flag1 == 0xFF) {
1275 					dev_current = 1;
1276 				} else {
1277 					dev_current = 0;
1278 				}
1279 				break;
1280 			case FLAG_INCREMENTAL:
1281 				if (flag0 == 255 && flag1 == 0)
1282 					dev_current = 1;
1283 				else if ((flag1 == 255 && flag0 == 0) ||
1284 					 flag0 >= flag1)
1285 					dev_current = 0;
1286 				else /* flag1 > flag0 */
1287 					dev_current = 1;
1288 				break;
1289 			default:
1290 				fprintf (stderr, "Unknown flag scheme %u \n",
1291 					 environment.flag_scheme);
1292 				return -1;
1293 			}
1294 		}
1295 
1296 		/*
1297 		 * If we are reading, we don't need the flag and the CRC any
1298 		 * more, if we are writing, we will re-calculate CRC and update
1299 		 * flags before writing out
1300 		 */
1301 		if (dev_current) {
1302 			environment.image	= addr1;
1303 			environment.crc		= &redundant->crc;
1304 			environment.flags	= &redundant->flags;
1305 			environment.data	= redundant->data;
1306 			free (addr0);
1307 		} else {
1308 			environment.image	= addr0;
1309 			/* Other pointers are already set */
1310 			free (addr1);
1311 		}
1312 #ifdef DEBUG
1313 		fprintf(stderr, "Selected env in %s\n", DEVNAME(dev_current));
1314 #endif
1315 	}
1316 	return 0;
1317 }
1318 
1319 
1320 static int parse_config ()
1321 {
1322 	struct stat st;
1323 
1324 #if defined(CONFIG_FILE)
1325 	/* Fills in DEVNAME(), ENVSIZE(), DEVESIZE(). Or don't. */
1326 	if (get_config(common_args.config_file)) {
1327 		fprintf(stderr, "Cannot parse config file '%s': %m\n",
1328 			common_args.config_file);
1329 		return -1;
1330 	}
1331 #else
1332 	DEVNAME (0) = DEVICE1_NAME;
1333 	DEVOFFSET (0) = DEVICE1_OFFSET;
1334 	ENVSIZE (0) = ENV1_SIZE;
1335 	/* Default values are: erase-size=env-size */
1336 	DEVESIZE (0) = ENVSIZE (0);
1337 	/* #sectors=env-size/erase-size (rounded up) */
1338 	ENVSECTORS (0) = (ENVSIZE(0) + DEVESIZE(0) - 1) / DEVESIZE(0);
1339 #ifdef DEVICE1_ESIZE
1340 	DEVESIZE (0) = DEVICE1_ESIZE;
1341 #endif
1342 #ifdef DEVICE1_ENVSECTORS
1343 	ENVSECTORS (0) = DEVICE1_ENVSECTORS;
1344 #endif
1345 
1346 #ifdef HAVE_REDUND
1347 	DEVNAME (1) = DEVICE2_NAME;
1348 	DEVOFFSET (1) = DEVICE2_OFFSET;
1349 	ENVSIZE (1) = ENV2_SIZE;
1350 	/* Default values are: erase-size=env-size */
1351 	DEVESIZE (1) = ENVSIZE (1);
1352 	/* #sectors=env-size/erase-size (rounded up) */
1353 	ENVSECTORS (1) = (ENVSIZE(1) + DEVESIZE(1) - 1) / DEVESIZE(1);
1354 #ifdef DEVICE2_ESIZE
1355 	DEVESIZE (1) = DEVICE2_ESIZE;
1356 #endif
1357 #ifdef DEVICE2_ENVSECTORS
1358 	ENVSECTORS (1) = DEVICE2_ENVSECTORS;
1359 #endif
1360 	HaveRedundEnv = 1;
1361 #endif
1362 #endif
1363 	if (stat (DEVNAME (0), &st)) {
1364 		fprintf (stderr,
1365 			"Cannot access MTD device %s: %s\n",
1366 			DEVNAME (0), strerror (errno));
1367 		return -1;
1368 	}
1369 
1370 	if (HaveRedundEnv && stat (DEVNAME (1), &st)) {
1371 		fprintf (stderr,
1372 			"Cannot access MTD device %s: %s\n",
1373 			DEVNAME (1), strerror (errno));
1374 		return -1;
1375 	}
1376 	return 0;
1377 }
1378 
1379 #if defined(CONFIG_FILE)
1380 static int get_config (char *fname)
1381 {
1382 	FILE *fp;
1383 	int i = 0;
1384 	int rc;
1385 	char dump[128];
1386 	char *devname;
1387 
1388 	fp = fopen (fname, "r");
1389 	if (fp == NULL)
1390 		return -1;
1391 
1392 	while (i < 2 && fgets (dump, sizeof (dump), fp)) {
1393 		/* Skip incomplete conversions and comment strings */
1394 		if (dump[0] == '#')
1395 			continue;
1396 
1397 		rc = sscanf (dump, "%ms %lx %lx %lx %lx",
1398 			     &devname,
1399 			     &DEVOFFSET (i),
1400 			     &ENVSIZE (i),
1401 			     &DEVESIZE (i),
1402 			     &ENVSECTORS (i));
1403 
1404 		if (rc < 3)
1405 			continue;
1406 
1407 		DEVNAME(i) = devname;
1408 
1409 		if (rc < 4)
1410 			/* Assume the erase size is the same as the env-size */
1411 			DEVESIZE(i) = ENVSIZE(i);
1412 
1413 		if (rc < 5)
1414 			/* Assume enough env sectors to cover the environment */
1415 			ENVSECTORS (i) = (ENVSIZE(i) + DEVESIZE(i) - 1) / DEVESIZE(i);
1416 
1417 		i++;
1418 	}
1419 	fclose (fp);
1420 
1421 	HaveRedundEnv = i - 1;
1422 	if (!i) {			/* No valid entries found */
1423 		errno = EINVAL;
1424 		return -1;
1425 	} else
1426 		return 0;
1427 }
1428 #endif
1429