xref: /openbmc/u-boot/tools/env/fw_env.c (revision 568b471e)
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/fs.h>
18 #include <linux/stringify.h>
19 #include <ctype.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <stddef.h>
23 #include <string.h>
24 #include <sys/types.h>
25 #include <sys/ioctl.h>
26 #include <sys/stat.h>
27 #include <unistd.h>
28 
29 #ifdef MTD_OLD
30 # include <stdint.h>
31 # include <linux/mtd/mtd.h>
32 #else
33 # define  __user	/* nothing */
34 # include <mtd/mtd-user.h>
35 #endif
36 
37 #include "fw_env.h"
38 
39 struct env_opts default_opts = {
40 #ifdef CONFIG_FILE
41 	.config_file = CONFIG_FILE
42 #endif
43 };
44 
45 #define DIV_ROUND_UP(n, d)	(((n) + (d) - 1) / (d))
46 
47 #define min(x, y) ({				\
48 	typeof(x) _min1 = (x);			\
49 	typeof(y) _min2 = (y);			\
50 	(void) (&_min1 == &_min2);		\
51 	_min1 < _min2 ? _min1 : _min2; })
52 
53 struct envdev_s {
54 	const char *devname;		/* Device name */
55 	long long devoff;		/* Device offset */
56 	ulong env_size;			/* environment size */
57 	ulong erase_size;		/* device erase size */
58 	ulong env_sectors;		/* number of environment sectors */
59 	uint8_t mtd_type;		/* type of the MTD device */
60 };
61 
62 static struct envdev_s envdevices[2] =
63 {
64 	{
65 		.mtd_type = MTD_ABSENT,
66 	}, {
67 		.mtd_type = MTD_ABSENT,
68 	},
69 };
70 static int dev_current;
71 
72 #define DEVNAME(i)    envdevices[(i)].devname
73 #define DEVOFFSET(i)  envdevices[(i)].devoff
74 #define ENVSIZE(i)    envdevices[(i)].env_size
75 #define DEVESIZE(i)   envdevices[(i)].erase_size
76 #define ENVSECTORS(i) envdevices[(i)].env_sectors
77 #define DEVTYPE(i)    envdevices[(i)].mtd_type
78 
79 #define CUR_ENVSIZE ENVSIZE(dev_current)
80 
81 static unsigned long usable_envsize;
82 #define ENV_SIZE      usable_envsize
83 
84 struct env_image_single {
85 	uint32_t	crc;	/* CRC32 over data bytes    */
86 	char		data[];
87 };
88 
89 struct env_image_redundant {
90 	uint32_t	crc;	/* CRC32 over data bytes    */
91 	unsigned char	flags;	/* active or obsolete */
92 	char		data[];
93 };
94 
95 enum flag_scheme {
96 	FLAG_NONE,
97 	FLAG_BOOLEAN,
98 	FLAG_INCREMENTAL,
99 };
100 
101 struct environment {
102 	void			*image;
103 	uint32_t		*crc;
104 	unsigned char		*flags;
105 	char			*data;
106 	enum flag_scheme	flag_scheme;
107 };
108 
109 static struct environment environment = {
110 	.flag_scheme = FLAG_NONE,
111 };
112 
113 static int env_aes_cbc_crypt(char *data, const int enc, uint8_t *key);
114 
115 static int HaveRedundEnv = 0;
116 
117 static unsigned char active_flag = 1;
118 /* obsolete_flag must be 0 to efficiently set it on NOR flash without erasing */
119 static unsigned char obsolete_flag = 0;
120 
121 #define DEFAULT_ENV_INSTANCE_STATIC
122 #include <env_default.h>
123 
124 static int flash_io (int mode);
125 static int parse_config(struct env_opts *opts);
126 
127 #if defined(CONFIG_FILE)
128 static int get_config (char *);
129 #endif
130 
131 static char *skip_chars(char *s)
132 {
133 	for (; *s != '\0'; s++) {
134 		if (isblank(*s))
135 			return s;
136 	}
137 	return NULL;
138 }
139 
140 static char *skip_blanks(char *s)
141 {
142 	for (; *s != '\0'; s++) {
143 		if (!isblank(*s))
144 			return s;
145 	}
146 	return NULL;
147 }
148 
149 /*
150  * s1 is either a simple 'name', or a 'name=value' pair.
151  * s2 is a 'name=value' pair.
152  * If the names match, return the value of s2, else NULL.
153  */
154 static char *envmatch(char *s1, char *s2)
155 {
156 	if (s1 == NULL || s2 == NULL)
157 		return NULL;
158 
159 	while (*s1 == *s2++)
160 		if (*s1++ == '=')
161 			return s2;
162 	if (*s1 == '\0' && *(s2 - 1) == '=')
163 		return s2;
164 	return NULL;
165 }
166 
167 /**
168  * Search the environment for a variable.
169  * Return the value, if found, or NULL, if not found.
170  */
171 char *fw_getenv (char *name)
172 {
173 	char *env, *nxt;
174 
175 	for (env = environment.data; *env; env = nxt + 1) {
176 		char *val;
177 
178 		for (nxt = env; *nxt; ++nxt) {
179 			if (nxt >= &environment.data[ENV_SIZE]) {
180 				fprintf (stderr, "## Error: "
181 					"environment not terminated\n");
182 				return NULL;
183 			}
184 		}
185 		val = envmatch (name, env);
186 		if (!val)
187 			continue;
188 		return val;
189 	}
190 	return NULL;
191 }
192 
193 /*
194  * Search the default environment for a variable.
195  * Return the value, if found, or NULL, if not found.
196  */
197 char *fw_getdefenv(char *name)
198 {
199 	char *env, *nxt;
200 
201 	for (env = default_environment; *env; env = nxt + 1) {
202 		char *val;
203 
204 		for (nxt = env; *nxt; ++nxt) {
205 			if (nxt >= &default_environment[ENV_SIZE]) {
206 				fprintf(stderr, "## Error: "
207 					"default environment not terminated\n");
208 				return NULL;
209 			}
210 		}
211 		val = envmatch(name, env);
212 		if (!val)
213 			continue;
214 		return val;
215 	}
216 	return NULL;
217 }
218 
219 int parse_aes_key(char *key, uint8_t *bin_key)
220 {
221 	char tmp[5] = { '0', 'x', 0, 0, 0 };
222 	unsigned long ul;
223 	int i;
224 
225 	if (strnlen(key, 64) != 32) {
226 		fprintf(stderr,
227 			"## Error: '-a' option requires 16-byte AES key\n");
228 		return -1;
229 	}
230 
231 	for (i = 0; i < 16; i++) {
232 		tmp[2] = key[0];
233 		tmp[3] = key[1];
234 		errno = 0;
235 		ul = strtoul(tmp, NULL, 16);
236 		if (errno) {
237 			fprintf(stderr,
238 				"## Error: '-a' option requires valid AES key\n");
239 			return -1;
240 		}
241 		bin_key[i] = ul & 0xff;
242 		key += 2;
243 	}
244 	return 0;
245 }
246 
247 /*
248  * Print the current definition of one, or more, or all
249  * environment variables
250  */
251 int fw_printenv(int argc, char *argv[], int value_only, struct env_opts *opts)
252 {
253 	int i, rc = 0;
254 
255 	if (value_only && argc != 1) {
256 		fprintf(stderr,
257 			"## Error: `-n' option requires exactly one argument\n");
258 		return -1;
259 	}
260 
261 	if (!opts)
262 		opts = &default_opts;
263 
264 	if (fw_env_open(opts))
265 		return -1;
266 
267 	if (argc == 0) {		/* Print all env variables  */
268 		char *env, *nxt;
269 		for (env = environment.data; *env; env = nxt + 1) {
270 			for (nxt = env; *nxt; ++nxt) {
271 				if (nxt >= &environment.data[ENV_SIZE]) {
272 					fprintf (stderr, "## Error: "
273 						"environment not terminated\n");
274 					return -1;
275 				}
276 			}
277 
278 			printf ("%s\n", env);
279 		}
280 		return 0;
281 	}
282 
283 	for (i = 0; i < argc; ++i) {	/* print a subset of env variables */
284 		char *name = argv[i];
285 		char *val = NULL;
286 
287 		val = fw_getenv(name);
288 		if (!val) {
289 			fprintf (stderr, "## Error: \"%s\" not defined\n", name);
290 			rc = -1;
291 			continue;
292 		}
293 
294 		if (value_only) {
295 			puts(val);
296 			break;
297 		}
298 
299 		printf("%s=%s\n", name, val);
300 	}
301 
302 	return rc;
303 }
304 
305 int fw_env_close(struct env_opts *opts)
306 {
307 	int ret;
308 
309 	if (!opts)
310 		opts = &default_opts;
311 
312 	if (opts->aes_flag) {
313 		ret = env_aes_cbc_crypt(environment.data, 1,
314 					opts->aes_key);
315 		if (ret) {
316 			fprintf(stderr,
317 				"Error: can't encrypt env for flash\n");
318 			return ret;
319 		}
320 	}
321 
322 	/*
323 	 * Update CRC
324 	 */
325 	*environment.crc = crc32(0, (uint8_t *) environment.data, ENV_SIZE);
326 
327 	/* write environment back to flash */
328 	if (flash_io(O_RDWR)) {
329 		fprintf(stderr,
330 			"Error: can't write fw_env to flash\n");
331 			return -1;
332 	}
333 
334 	return 0;
335 }
336 
337 
338 /*
339  * Set/Clear a single variable in the environment.
340  * This is called in sequence to update the environment
341  * in RAM without updating the copy in flash after each set
342  */
343 int fw_env_write(char *name, char *value)
344 {
345 	int len;
346 	char *env, *nxt;
347 	char *oldval = NULL;
348 	int deleting, creating, overwriting;
349 
350 	/*
351 	 * search if variable with this name already exists
352 	 */
353 	for (nxt = env = environment.data; *env; env = nxt + 1) {
354 		for (nxt = env; *nxt; ++nxt) {
355 			if (nxt >= &environment.data[ENV_SIZE]) {
356 				fprintf(stderr, "## Error: "
357 					"environment not terminated\n");
358 				errno = EINVAL;
359 				return -1;
360 			}
361 		}
362 		if ((oldval = envmatch (name, env)) != NULL)
363 			break;
364 	}
365 
366 	deleting = (oldval && !(value && strlen(value)));
367 	creating = (!oldval && (value && strlen(value)));
368 	overwriting = (oldval && (value && strlen(value)));
369 
370 	/* check for permission */
371 	if (deleting) {
372 		if (env_flags_validate_varaccess(name,
373 		    ENV_FLAGS_VARACCESS_PREVENT_DELETE)) {
374 			printf("Can't delete \"%s\"\n", name);
375 			errno = EROFS;
376 			return -1;
377 		}
378 	} else if (overwriting) {
379 		if (env_flags_validate_varaccess(name,
380 		    ENV_FLAGS_VARACCESS_PREVENT_OVERWR)) {
381 			printf("Can't overwrite \"%s\"\n", name);
382 			errno = EROFS;
383 			return -1;
384 		} else if (env_flags_validate_varaccess(name,
385 		    ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR)) {
386 			const char *defval = fw_getdefenv(name);
387 
388 			if (defval == NULL)
389 				defval = "";
390 			if (strcmp(oldval, defval)
391 			    != 0) {
392 				printf("Can't overwrite \"%s\"\n", name);
393 				errno = EROFS;
394 				return -1;
395 			}
396 		}
397 	} else if (creating) {
398 		if (env_flags_validate_varaccess(name,
399 		    ENV_FLAGS_VARACCESS_PREVENT_CREATE)) {
400 			printf("Can't create \"%s\"\n", name);
401 			errno = EROFS;
402 			return -1;
403 		}
404 	} else
405 		/* Nothing to do */
406 		return 0;
407 
408 	if (deleting || overwriting) {
409 		if (*++nxt == '\0') {
410 			*env = '\0';
411 		} else {
412 			for (;;) {
413 				*env = *nxt++;
414 				if ((*env == '\0') && (*nxt == '\0'))
415 					break;
416 				++env;
417 			}
418 		}
419 		*++env = '\0';
420 	}
421 
422 	/* Delete only ? */
423 	if (!value || !strlen(value))
424 		return 0;
425 
426 	/*
427 	 * Append new definition at the end
428 	 */
429 	for (env = environment.data; *env || *(env + 1); ++env);
430 	if (env > environment.data)
431 		++env;
432 	/*
433 	 * Overflow when:
434 	 * "name" + "=" + "val" +"\0\0"  > CUR_ENVSIZE - (env-environment)
435 	 */
436 	len = strlen (name) + 2;
437 	/* add '=' for first arg, ' ' for all others */
438 	len += strlen(value) + 1;
439 
440 	if (len > (&environment.data[ENV_SIZE] - env)) {
441 		fprintf (stderr,
442 			"Error: environment overflow, \"%s\" deleted\n",
443 			name);
444 		return -1;
445 	}
446 
447 	while ((*env = *name++) != '\0')
448 		env++;
449 	*env = '=';
450 	while ((*++env = *value++) != '\0')
451 		;
452 
453 	/* end is marked with double '\0' */
454 	*++env = '\0';
455 
456 	return 0;
457 }
458 
459 /*
460  * Deletes or sets environment variables. Returns -1 and sets errno error codes:
461  * 0	  - OK
462  * EINVAL - need at least 1 argument
463  * EROFS  - certain variables ("ethaddr", "serial#") cannot be
464  *	    modified or deleted
465  *
466  */
467 int fw_setenv(int argc, char *argv[], struct env_opts *opts)
468 {
469 	int i;
470 	size_t len;
471 	char *name, **valv;
472 	char *value = NULL;
473 	int valc;
474 
475 	if (!opts)
476 		opts = &default_opts;
477 
478 	if (argc < 1) {
479 		fprintf(stderr, "## Error: variable name missing\n");
480 		errno = EINVAL;
481 		return -1;
482 	}
483 
484 	if (fw_env_open(opts)) {
485 		fprintf(stderr, "Error: environment not initialized\n");
486 		return -1;
487 	}
488 
489 	name = argv[0];
490 	valv = argv + 1;
491 	valc = argc - 1;
492 
493 	if (env_flags_validate_env_set_params(name, valv, valc) < 0)
494 		return -1;
495 
496 	len = 0;
497 	for (i = 0; i < valc; ++i) {
498 		char *val = valv[i];
499 		size_t val_len = strlen(val);
500 
501 		if (value)
502 			value[len - 1] = ' ';
503 		value = realloc(value, len + val_len + 1);
504 		if (!value) {
505 			fprintf(stderr,
506 				"Cannot malloc %zu bytes: %s\n",
507 				len, strerror(errno));
508 			return -1;
509 		}
510 
511 		memcpy(value + len, val, val_len);
512 		len += val_len;
513 		value[len++] = '\0';
514 	}
515 
516 	fw_env_write(name, value);
517 
518 	free(value);
519 
520 	return fw_env_close(opts);
521 }
522 
523 /*
524  * Parse  a file  and configure the u-boot variables.
525  * The script file has a very simple format, as follows:
526  *
527  * Each line has a couple with name, value:
528  * <white spaces>variable_name<white spaces>variable_value
529  *
530  * Both variable_name and variable_value are interpreted as strings.
531  * Any character after <white spaces> and before ending \r\n is interpreted
532  * as variable's value (no comment allowed on these lines !)
533  *
534  * Comments are allowed if the first character in the line is #
535  *
536  * Returns -1 and sets errno error codes:
537  * 0	  - OK
538  * -1     - Error
539  */
540 int fw_parse_script(char *fname, struct env_opts *opts)
541 {
542 	FILE *fp;
543 	char dump[1024];	/* Maximum line length in the file */
544 	char *name;
545 	char *val;
546 	int lineno = 0;
547 	int len;
548 	int ret = 0;
549 
550 	if (!opts)
551 		opts = &default_opts;
552 
553 	if (fw_env_open(opts)) {
554 		fprintf(stderr, "Error: environment not initialized\n");
555 		return -1;
556 	}
557 
558 	if (strcmp(fname, "-") == 0)
559 		fp = stdin;
560 	else {
561 		fp = fopen(fname, "r");
562 		if (fp == NULL) {
563 			fprintf(stderr, "I cannot open %s for reading\n",
564 				 fname);
565 			return -1;
566 		}
567 	}
568 
569 	while (fgets(dump, sizeof(dump), fp)) {
570 		lineno++;
571 		len = strlen(dump);
572 
573 		/*
574 		 * Read a whole line from the file. If the line is too long
575 		 * or is not terminated, reports an error and exit.
576 		 */
577 		if (dump[len - 1] != '\n') {
578 			fprintf(stderr,
579 			"Line %d not corrected terminated or too long\n",
580 				lineno);
581 			ret = -1;
582 			break;
583 		}
584 
585 		/* Drop ending line feed / carriage return */
586 		dump[--len] = '\0';
587 		if (len && dump[len - 1] == '\r')
588 			dump[--len] = '\0';
589 
590 		/* Skip comment or empty lines */
591 		if (len == 0 || dump[0] == '#')
592 			continue;
593 
594 		/*
595 		 * Search for variable's name,
596 		 * remove leading whitespaces
597 		 */
598 		name = skip_blanks(dump);
599 		if (!name)
600 			continue;
601 
602 		/* The first white space is the end of variable name */
603 		val = skip_chars(name);
604 		len = strlen(name);
605 		if (val) {
606 			*val++ = '\0';
607 			if ((val - name) < len)
608 				val = skip_blanks(val);
609 			else
610 				val = NULL;
611 		}
612 
613 #ifdef DEBUG
614 		fprintf(stderr, "Setting %s : %s\n",
615 			name, val ? val : " removed");
616 #endif
617 
618 		if (env_flags_validate_type(name, val) < 0) {
619 			ret = -1;
620 			break;
621 		}
622 
623 		/*
624 		 * If there is an error setting a variable,
625 		 * try to save the environment and returns an error
626 		 */
627 		if (fw_env_write(name, val)) {
628 			fprintf(stderr,
629 			"fw_env_write returns with error : %s\n",
630 				strerror(errno));
631 			ret = -1;
632 			break;
633 		}
634 
635 	}
636 
637 	/* Close file if not stdin */
638 	if (strcmp(fname, "-") != 0)
639 		fclose(fp);
640 
641 	ret |= fw_env_close(opts);
642 
643 	return ret;
644 }
645 
646 /**
647  * environment_end() - compute offset of first byte right after environemnt
648  * @dev - index of enviroment buffer
649  * Return:
650  *  device offset of first byte right after environemnt
651  */
652 off_t environment_end(int dev)
653 {
654 	/* environment is block aligned */
655 	return DEVOFFSET(dev) + ENVSECTORS(dev) * DEVESIZE(dev);
656 }
657 
658 /*
659  * Test for bad block on NAND, just returns 0 on NOR, on NAND:
660  * 0	- block is good
661  * > 0	- block is bad
662  * < 0	- failed to test
663  */
664 static int flash_bad_block(int fd, uint8_t mtd_type, loff_t blockstart)
665 {
666 	if (mtd_type == MTD_NANDFLASH) {
667 		int badblock = ioctl(fd, MEMGETBADBLOCK, &blockstart);
668 
669 		if (badblock < 0) {
670 			perror ("Cannot read bad block mark");
671 			return badblock;
672 		}
673 
674 		if (badblock) {
675 #ifdef DEBUG
676 			fprintf (stderr, "Bad block at 0x%llx, skipping\n",
677 				(unsigned long long)blockstart);
678 #endif
679 			return badblock;
680 		}
681 	}
682 
683 	return 0;
684 }
685 
686 /*
687  * Read data from flash at an offset into a provided buffer. On NAND it skips
688  * bad blocks but makes sure it stays within ENVSECTORS (dev) starting from
689  * the DEVOFFSET (dev) block. On NOR the loop is only run once.
690  */
691 static int flash_read_buf (int dev, int fd, void *buf, size_t count,
692 			   off_t offset)
693 {
694 	size_t blocklen;	/* erase / write length - one block on NAND,
695 				   0 on NOR */
696 	size_t processed = 0;	/* progress counter */
697 	size_t readlen = count;	/* current read length */
698 	off_t block_seek;	/* offset inside the current block to the start
699 				   of the data */
700 	loff_t blockstart;	/* running start of the current block -
701 				   MEMGETBADBLOCK needs 64 bits */
702 	int rc;
703 
704 	blockstart = (offset / DEVESIZE (dev)) * DEVESIZE (dev);
705 
706 	/* Offset inside a block */
707 	block_seek = offset - blockstart;
708 
709 	if (DEVTYPE(dev) == MTD_NANDFLASH) {
710 		/*
711 		 * NAND: calculate which blocks we are reading. We have
712 		 * to read one block at a time to skip bad blocks.
713 		 */
714 		blocklen = DEVESIZE (dev);
715 
716 		/* Limit to one block for the first read */
717 		if (readlen > blocklen - block_seek)
718 			readlen = blocklen - block_seek;
719 	} else {
720 		blocklen = 0;
721 	}
722 
723 	/* This only runs once on NOR flash */
724 	while (processed < count) {
725 		rc = flash_bad_block(fd, DEVTYPE(dev), blockstart);
726 		if (rc < 0)		/* block test failed */
727 			return -1;
728 
729 		if (blockstart + block_seek + readlen > environment_end(dev)) {
730 			/* End of range is reached */
731 			fprintf (stderr,
732 				 "Too few good blocks within range\n");
733 			return -1;
734 		}
735 
736 		if (rc) {		/* block is bad */
737 			blockstart += blocklen;
738 			continue;
739 		}
740 
741 		/*
742 		 * If a block is bad, we retry in the next block at the same
743 		 * offset - see common/env_nand.c::writeenv()
744 		 */
745 		lseek (fd, blockstart + block_seek, SEEK_SET);
746 
747 		rc = read (fd, buf + processed, readlen);
748 		if (rc != readlen) {
749 			fprintf (stderr, "Read error on %s: %s\n",
750 				 DEVNAME (dev), strerror (errno));
751 			return -1;
752 		}
753 #ifdef DEBUG
754 		fprintf(stderr, "Read 0x%x bytes at 0x%llx on %s\n",
755 			rc, (unsigned long long) blockstart + block_seek,
756 			DEVNAME(dev));
757 #endif
758 		processed += readlen;
759 		readlen = min (blocklen, count - processed);
760 		block_seek = 0;
761 		blockstart += blocklen;
762 	}
763 
764 	return processed;
765 }
766 
767 /*
768  * Write count bytes from begin of environment, but stay within
769  * ENVSECTORS(dev) sectors of
770  * DEVOFFSET (dev). Similar to the read case above, on NOR and dataflash we
771  * erase and write the whole data at once.
772  */
773 static int flash_write_buf(int dev, int fd, void *buf, size_t count)
774 {
775 	void *data;
776 	struct erase_info_user erase;
777 	size_t blocklen;	/* length of NAND block / NOR erase sector */
778 	size_t erase_len;	/* whole area that can be erased - may include
779 				   bad blocks */
780 	size_t erasesize;	/* erase / write length - one block on NAND,
781 				   whole area on NOR */
782 	size_t processed = 0;	/* progress counter */
783 	size_t write_total;	/* total size to actually write - excluding
784 				   bad blocks */
785 	off_t erase_offset;	/* offset to the first erase block (aligned)
786 				   below offset */
787 	off_t block_seek;	/* offset inside the erase block to the start
788 				   of the data */
789 	loff_t blockstart;	/* running start of the current block -
790 				   MEMGETBADBLOCK needs 64 bits */
791 	int rc;
792 
793 	/*
794 	 * For mtd devices only offset and size of the environment do matter
795 	 */
796 	if (DEVTYPE(dev) == MTD_ABSENT) {
797 		blocklen = count;
798 		erase_len = blocklen;
799 		blockstart = DEVOFFSET(dev);
800 		block_seek = 0;
801 		write_total = blocklen;
802 	} else {
803 		blocklen = DEVESIZE(dev);
804 
805 		erase_offset = DEVOFFSET(dev);
806 
807 		/* Maximum area we may use */
808 		erase_len = environment_end(dev) - erase_offset;
809 
810 		blockstart = erase_offset;
811 
812 		/* Offset inside a block */
813 		block_seek = DEVOFFSET(dev) - erase_offset;
814 
815 		/*
816 		 * Data size we actually write: from the start of the block
817 		 * to the start of the data, then count bytes of data, and
818 		 * to the end of the block
819 		 */
820 		write_total = ((block_seek + count + blocklen - 1) /
821 							blocklen) * blocklen;
822 	}
823 
824 	/*
825 	 * Support data anywhere within erase sectors: read out the complete
826 	 * area to be erased, replace the environment image, write the whole
827 	 * block back again.
828 	 */
829 	if (write_total > count) {
830 		data = malloc (erase_len);
831 		if (!data) {
832 			fprintf (stderr,
833 				 "Cannot malloc %zu bytes: %s\n",
834 				 erase_len, strerror (errno));
835 			return -1;
836 		}
837 
838 		rc = flash_read_buf(dev, fd, data, write_total, erase_offset);
839 		if (write_total != rc)
840 			return -1;
841 
842 #ifdef DEBUG
843 		fprintf(stderr, "Preserving data ");
844 		if (block_seek != 0)
845 			fprintf(stderr, "0x%x - 0x%lx", 0, block_seek - 1);
846 		if (block_seek + count != write_total) {
847 			if (block_seek != 0)
848 				fprintf(stderr, " and ");
849 			fprintf(stderr, "0x%lx - 0x%lx",
850 				(unsigned long) block_seek + count,
851 				(unsigned long) write_total - 1);
852 		}
853 		fprintf(stderr, "\n");
854 #endif
855 		/* Overwrite the old environment */
856 		memcpy (data + block_seek, buf, count);
857 	} else {
858 		/*
859 		 * We get here, iff offset is block-aligned and count is a
860 		 * multiple of blocklen - see write_total calculation above
861 		 */
862 		data = buf;
863 	}
864 
865 	if (DEVTYPE(dev) == MTD_NANDFLASH) {
866 		/*
867 		 * NAND: calculate which blocks we are writing. We have
868 		 * to write one block at a time to skip bad blocks.
869 		 */
870 		erasesize = blocklen;
871 	} else {
872 		erasesize = erase_len;
873 	}
874 
875 	erase.length = erasesize;
876 
877 	/* This only runs once on NOR flash and SPI-dataflash */
878 	while (processed < write_total) {
879 		rc = flash_bad_block(fd, DEVTYPE(dev), blockstart);
880 		if (rc < 0)		/* block test failed */
881 			return rc;
882 
883 		if (blockstart + erasesize > environment_end(dev)) {
884 			fprintf (stderr, "End of range reached, aborting\n");
885 			return -1;
886 		}
887 
888 		if (rc) {		/* block is bad */
889 			blockstart += blocklen;
890 			continue;
891 		}
892 
893 		if (DEVTYPE(dev) != MTD_ABSENT) {
894 			erase.start = blockstart;
895 			ioctl(fd, MEMUNLOCK, &erase);
896 			/* These do not need an explicit erase cycle */
897 			if (DEVTYPE(dev) != MTD_DATAFLASH)
898 				if (ioctl(fd, MEMERASE, &erase) != 0) {
899 					fprintf(stderr,
900 						"MTD erase error on %s: %s\n",
901 						DEVNAME(dev), strerror(errno));
902 					return -1;
903 				}
904 		}
905 
906 		if (lseek (fd, blockstart, SEEK_SET) == -1) {
907 			fprintf (stderr,
908 				 "Seek error on %s: %s\n",
909 				 DEVNAME (dev), strerror (errno));
910 			return -1;
911 		}
912 
913 #ifdef DEBUG
914 		fprintf(stderr, "Write 0x%llx bytes at 0x%llx\n",
915 			(unsigned long long) erasesize,
916 			(unsigned long long) blockstart);
917 #endif
918 		if (write (fd, data + processed, erasesize) != erasesize) {
919 			fprintf (stderr, "Write error on %s: %s\n",
920 				 DEVNAME (dev), strerror (errno));
921 			return -1;
922 		}
923 
924 		if (DEVTYPE(dev) != MTD_ABSENT)
925 			ioctl(fd, MEMLOCK, &erase);
926 
927 		processed  += erasesize;
928 		block_seek = 0;
929 		blockstart += erasesize;
930 	}
931 
932 	if (write_total > count)
933 		free (data);
934 
935 	return processed;
936 }
937 
938 /*
939  * Set obsolete flag at offset - NOR flash only
940  */
941 static int flash_flag_obsolete (int dev, int fd, off_t offset)
942 {
943 	int rc;
944 	struct erase_info_user erase;
945 
946 	erase.start  = DEVOFFSET (dev);
947 	erase.length = DEVESIZE (dev);
948 	/* This relies on the fact, that obsolete_flag == 0 */
949 	rc = lseek (fd, offset, SEEK_SET);
950 	if (rc < 0) {
951 		fprintf (stderr, "Cannot seek to set the flag on %s \n",
952 			 DEVNAME (dev));
953 		return rc;
954 	}
955 	ioctl (fd, MEMUNLOCK, &erase);
956 	rc = write (fd, &obsolete_flag, sizeof (obsolete_flag));
957 	ioctl (fd, MEMLOCK, &erase);
958 	if (rc < 0)
959 		perror ("Could not set obsolete flag");
960 
961 	return rc;
962 }
963 
964 /* Encrypt or decrypt the environment before writing or reading it. */
965 static int env_aes_cbc_crypt(char *payload, const int enc, uint8_t *key)
966 {
967 	uint8_t *data = (uint8_t *)payload;
968 	const int len = usable_envsize;
969 	uint8_t key_exp[AES_EXPAND_KEY_LENGTH];
970 	uint32_t aes_blocks;
971 
972 	/* First we expand the key. */
973 	aes_expand_key(key, key_exp);
974 
975 	/* Calculate the number of AES blocks to encrypt. */
976 	aes_blocks = DIV_ROUND_UP(len, AES_KEY_LENGTH);
977 
978 	if (enc)
979 		aes_cbc_encrypt_blocks(key_exp, data, data, aes_blocks);
980 	else
981 		aes_cbc_decrypt_blocks(key_exp, data, data, aes_blocks);
982 
983 	return 0;
984 }
985 
986 static int flash_write (int fd_current, int fd_target, int dev_target)
987 {
988 	int rc;
989 
990 	switch (environment.flag_scheme) {
991 	case FLAG_NONE:
992 		break;
993 	case FLAG_INCREMENTAL:
994 		(*environment.flags)++;
995 		break;
996 	case FLAG_BOOLEAN:
997 		*environment.flags = active_flag;
998 		break;
999 	default:
1000 		fprintf (stderr, "Unimplemented flash scheme %u \n",
1001 			 environment.flag_scheme);
1002 		return -1;
1003 	}
1004 
1005 #ifdef DEBUG
1006 	fprintf(stderr, "Writing new environment at 0x%llx on %s\n",
1007 		DEVOFFSET (dev_target), DEVNAME (dev_target));
1008 #endif
1009 
1010 	rc = flash_write_buf(dev_target, fd_target, environment.image,
1011 			     CUR_ENVSIZE);
1012 	if (rc < 0)
1013 		return rc;
1014 
1015 	if (environment.flag_scheme == FLAG_BOOLEAN) {
1016 		/* Have to set obsolete flag */
1017 		off_t offset = DEVOFFSET (dev_current) +
1018 			offsetof (struct env_image_redundant, flags);
1019 #ifdef DEBUG
1020 		fprintf(stderr,
1021 			"Setting obsolete flag in environment at 0x%llx on %s\n",
1022 			DEVOFFSET (dev_current), DEVNAME (dev_current));
1023 #endif
1024 		flash_flag_obsolete (dev_current, fd_current, offset);
1025 	}
1026 
1027 	return 0;
1028 }
1029 
1030 static int flash_read (int fd)
1031 {
1032 	int rc;
1033 
1034 	rc = flash_read_buf(dev_current, fd, environment.image, CUR_ENVSIZE,
1035 			    DEVOFFSET(dev_current));
1036 	if (rc != CUR_ENVSIZE)
1037 		return -1;
1038 
1039 	return 0;
1040 }
1041 
1042 static int flash_io (int mode)
1043 {
1044 	int fd_current, fd_target, rc, dev_target;
1045 
1046 	/* dev_current: fd_current, erase_current */
1047 	fd_current = open (DEVNAME (dev_current), mode);
1048 	if (fd_current < 0) {
1049 		fprintf (stderr,
1050 			 "Can't open %s: %s\n",
1051 			 DEVNAME (dev_current), strerror (errno));
1052 		return -1;
1053 	}
1054 
1055 	if (mode == O_RDWR) {
1056 		if (HaveRedundEnv) {
1057 			/* switch to next partition for writing */
1058 			dev_target = !dev_current;
1059 			/* dev_target: fd_target, erase_target */
1060 			fd_target = open (DEVNAME (dev_target), mode);
1061 			if (fd_target < 0) {
1062 				fprintf (stderr,
1063 					 "Can't open %s: %s\n",
1064 					 DEVNAME (dev_target),
1065 					 strerror (errno));
1066 				rc = -1;
1067 				goto exit;
1068 			}
1069 		} else {
1070 			dev_target = dev_current;
1071 			fd_target = fd_current;
1072 		}
1073 
1074 		rc = flash_write (fd_current, fd_target, dev_target);
1075 
1076 		if (HaveRedundEnv) {
1077 			if (close (fd_target)) {
1078 				fprintf (stderr,
1079 					"I/O error on %s: %s\n",
1080 					DEVNAME (dev_target),
1081 					strerror (errno));
1082 				rc = -1;
1083 			}
1084 		}
1085 	} else {
1086 		rc = flash_read (fd_current);
1087 	}
1088 
1089 exit:
1090 	if (close (fd_current)) {
1091 		fprintf (stderr,
1092 			 "I/O error on %s: %s\n",
1093 			 DEVNAME (dev_current), strerror (errno));
1094 		return -1;
1095 	}
1096 
1097 	return rc;
1098 }
1099 
1100 /*
1101  * Prevent confusion if running from erased flash memory
1102  */
1103 int fw_env_open(struct env_opts *opts)
1104 {
1105 	int crc0, crc0_ok;
1106 	unsigned char flag0;
1107 	void *addr0;
1108 
1109 	int crc1, crc1_ok;
1110 	unsigned char flag1;
1111 	void *addr1;
1112 
1113 	int ret;
1114 
1115 	struct env_image_single *single;
1116 	struct env_image_redundant *redundant;
1117 
1118 	if (!opts)
1119 		opts = &default_opts;
1120 
1121 	if (parse_config(opts))		/* should fill envdevices */
1122 		return -1;
1123 
1124 	addr0 = calloc(1, CUR_ENVSIZE);
1125 	if (addr0 == NULL) {
1126 		fprintf(stderr,
1127 			"Not enough memory for environment (%ld bytes)\n",
1128 			CUR_ENVSIZE);
1129 		return -1;
1130 	}
1131 
1132 	/* read environment from FLASH to local buffer */
1133 	environment.image = addr0;
1134 
1135 	if (HaveRedundEnv) {
1136 		redundant = addr0;
1137 		environment.crc		= &redundant->crc;
1138 		environment.flags	= &redundant->flags;
1139 		environment.data	= redundant->data;
1140 	} else {
1141 		single = addr0;
1142 		environment.crc		= &single->crc;
1143 		environment.flags	= NULL;
1144 		environment.data	= single->data;
1145 	}
1146 
1147 	dev_current = 0;
1148 	if (flash_io (O_RDONLY))
1149 		return -1;
1150 
1151 	crc0 = crc32 (0, (uint8_t *) environment.data, ENV_SIZE);
1152 
1153 	if (opts->aes_flag) {
1154 		ret = env_aes_cbc_crypt(environment.data, 0,
1155 					opts->aes_key);
1156 		if (ret)
1157 			return ret;
1158 	}
1159 
1160 	crc0_ok = (crc0 == *environment.crc);
1161 	if (!HaveRedundEnv) {
1162 		if (!crc0_ok) {
1163 			fprintf (stderr,
1164 				"Warning: Bad CRC, using default environment\n");
1165 			memcpy(environment.data, default_environment, sizeof default_environment);
1166 		}
1167 	} else {
1168 		flag0 = *environment.flags;
1169 
1170 		dev_current = 1;
1171 		addr1 = calloc(1, CUR_ENVSIZE);
1172 		if (addr1 == NULL) {
1173 			fprintf(stderr,
1174 				"Not enough memory for environment (%ld bytes)\n",
1175 				CUR_ENVSIZE);
1176 			return -1;
1177 		}
1178 		redundant = addr1;
1179 
1180 		/*
1181 		 * have to set environment.image for flash_read(), careful -
1182 		 * other pointers in environment still point inside addr0
1183 		 */
1184 		environment.image = addr1;
1185 		if (flash_io (O_RDONLY))
1186 			return -1;
1187 
1188 		/* Check flag scheme compatibility */
1189 		if (DEVTYPE(dev_current) == MTD_NORFLASH &&
1190 		    DEVTYPE(!dev_current) == MTD_NORFLASH) {
1191 			environment.flag_scheme = FLAG_BOOLEAN;
1192 		} else if (DEVTYPE(dev_current) == MTD_NANDFLASH &&
1193 			   DEVTYPE(!dev_current) == MTD_NANDFLASH) {
1194 			environment.flag_scheme = FLAG_INCREMENTAL;
1195 		} else if (DEVTYPE(dev_current) == MTD_DATAFLASH &&
1196 			   DEVTYPE(!dev_current) == MTD_DATAFLASH) {
1197 			environment.flag_scheme = FLAG_BOOLEAN;
1198 		} else if (DEVTYPE(dev_current) == MTD_UBIVOLUME &&
1199 			   DEVTYPE(!dev_current) == MTD_UBIVOLUME) {
1200 			environment.flag_scheme = FLAG_INCREMENTAL;
1201 		} else if (DEVTYPE(dev_current) == MTD_ABSENT &&
1202 			   DEVTYPE(!dev_current) == MTD_ABSENT) {
1203 			environment.flag_scheme = FLAG_INCREMENTAL;
1204 		} else {
1205 			fprintf (stderr, "Incompatible flash types!\n");
1206 			return -1;
1207 		}
1208 
1209 		crc1 = crc32 (0, (uint8_t *) redundant->data, ENV_SIZE);
1210 
1211 		if (opts->aes_flag) {
1212 			ret = env_aes_cbc_crypt(redundant->data, 0,
1213 						opts->aes_key);
1214 			if (ret)
1215 				return ret;
1216 		}
1217 
1218 		crc1_ok = (crc1 == redundant->crc);
1219 		flag1 = redundant->flags;
1220 
1221 		if (crc0_ok && !crc1_ok) {
1222 			dev_current = 0;
1223 		} else if (!crc0_ok && crc1_ok) {
1224 			dev_current = 1;
1225 		} else if (!crc0_ok && !crc1_ok) {
1226 			fprintf (stderr,
1227 				"Warning: Bad CRC, using default environment\n");
1228 			memcpy (environment.data, default_environment,
1229 				sizeof default_environment);
1230 			dev_current = 0;
1231 		} else {
1232 			switch (environment.flag_scheme) {
1233 			case FLAG_BOOLEAN:
1234 				if (flag0 == active_flag &&
1235 				    flag1 == obsolete_flag) {
1236 					dev_current = 0;
1237 				} else if (flag0 == obsolete_flag &&
1238 					   flag1 == active_flag) {
1239 					dev_current = 1;
1240 				} else if (flag0 == flag1) {
1241 					dev_current = 0;
1242 				} else if (flag0 == 0xFF) {
1243 					dev_current = 0;
1244 				} else if (flag1 == 0xFF) {
1245 					dev_current = 1;
1246 				} else {
1247 					dev_current = 0;
1248 				}
1249 				break;
1250 			case FLAG_INCREMENTAL:
1251 				if (flag0 == 255 && flag1 == 0)
1252 					dev_current = 1;
1253 				else if ((flag1 == 255 && flag0 == 0) ||
1254 					 flag0 >= flag1)
1255 					dev_current = 0;
1256 				else /* flag1 > flag0 */
1257 					dev_current = 1;
1258 				break;
1259 			default:
1260 				fprintf (stderr, "Unknown flag scheme %u \n",
1261 					 environment.flag_scheme);
1262 				return -1;
1263 			}
1264 		}
1265 
1266 		/*
1267 		 * If we are reading, we don't need the flag and the CRC any
1268 		 * more, if we are writing, we will re-calculate CRC and update
1269 		 * flags before writing out
1270 		 */
1271 		if (dev_current) {
1272 			environment.image	= addr1;
1273 			environment.crc		= &redundant->crc;
1274 			environment.flags	= &redundant->flags;
1275 			environment.data	= redundant->data;
1276 			free (addr0);
1277 		} else {
1278 			environment.image	= addr0;
1279 			/* Other pointers are already set */
1280 			free (addr1);
1281 		}
1282 #ifdef DEBUG
1283 		fprintf(stderr, "Selected env in %s\n", DEVNAME(dev_current));
1284 #endif
1285 	}
1286 	return 0;
1287 }
1288 
1289 static int check_device_config(int dev)
1290 {
1291 	struct stat st;
1292 	int fd, rc = 0;
1293 
1294 	fd = open(DEVNAME(dev), O_RDONLY);
1295 	if (fd < 0) {
1296 		fprintf(stderr,
1297 			"Cannot open %s: %s\n",
1298 			DEVNAME(dev), strerror(errno));
1299 		return -1;
1300 	}
1301 
1302 	rc = fstat(fd, &st);
1303 	if (rc < 0) {
1304 		fprintf(stderr, "Cannot stat the file %s\n",
1305 			DEVNAME(dev));
1306 		goto err;
1307 	}
1308 
1309 	if (S_ISCHR(st.st_mode)) {
1310 		struct mtd_info_user mtdinfo;
1311 		rc = ioctl(fd, MEMGETINFO, &mtdinfo);
1312 		if (rc < 0) {
1313 			fprintf(stderr, "Cannot get MTD information for %s\n",
1314 				DEVNAME(dev));
1315 			goto err;
1316 		}
1317 		if (mtdinfo.type != MTD_NORFLASH &&
1318 		    mtdinfo.type != MTD_NANDFLASH &&
1319 		    mtdinfo.type != MTD_DATAFLASH &&
1320 		    mtdinfo.type != MTD_UBIVOLUME) {
1321 			fprintf(stderr, "Unsupported flash type %u on %s\n",
1322 				mtdinfo.type, DEVNAME(dev));
1323 			goto err;
1324 		}
1325 		DEVTYPE(dev) = mtdinfo.type;
1326 		if (DEVESIZE(dev) == 0)
1327 			/* Assume the erase size is the same as the env-size */
1328 			DEVESIZE(dev) = ENVSIZE(dev);
1329 	} else {
1330 		uint64_t size;
1331 		DEVTYPE(dev) = MTD_ABSENT;
1332 		if (DEVESIZE(dev) == 0)
1333 			/* Assume the erase size to be 512 bytes */
1334 			DEVESIZE(dev) = 0x200;
1335 
1336 		/*
1337 		 * Check for negative offsets, treat it as backwards offset
1338 		 * from the end of the block device
1339 		 */
1340 		if (DEVOFFSET(dev) < 0) {
1341 			rc = ioctl(fd, BLKGETSIZE64, &size);
1342 			if (rc < 0) {
1343 				fprintf(stderr, "Could not get block device size on %s\n",
1344 					DEVNAME(dev));
1345 				goto err;
1346 			}
1347 
1348 			DEVOFFSET(dev) = DEVOFFSET(dev) + size;
1349 #ifdef DEBUG
1350 			fprintf(stderr, "Calculated device offset 0x%llx on %s\n",
1351 				DEVOFFSET(dev), DEVNAME(dev));
1352 #endif
1353 		}
1354 	}
1355 
1356 	if (ENVSECTORS(dev) == 0)
1357 		/* Assume enough sectors to cover the environment */
1358 		ENVSECTORS(dev) = DIV_ROUND_UP(ENVSIZE(dev), DEVESIZE(dev));
1359 
1360 	if (DEVOFFSET(dev) % DEVESIZE(dev) != 0) {
1361 		fprintf(stderr, "Environment does not start on (erase) block boundary\n");
1362 		errno = EINVAL;
1363 		return -1;
1364 	}
1365 
1366 	if (ENVSIZE(dev) > ENVSECTORS(dev) * DEVESIZE(dev)) {
1367 		fprintf(stderr, "Environment does not fit into available sectors\n");
1368 		errno = EINVAL;
1369 		return -1;
1370 	}
1371 
1372 err:
1373 	close(fd);
1374 	return rc;
1375 }
1376 
1377 static int parse_config(struct env_opts *opts)
1378 {
1379 	int rc;
1380 
1381 	if (!opts)
1382 		opts = &default_opts;
1383 
1384 #if defined(CONFIG_FILE)
1385 	/* Fills in DEVNAME(), ENVSIZE(), DEVESIZE(). Or don't. */
1386 	if (get_config(opts->config_file)) {
1387 		fprintf(stderr, "Cannot parse config file '%s': %m\n",
1388 			opts->config_file);
1389 		return -1;
1390 	}
1391 #else
1392 	DEVNAME (0) = DEVICE1_NAME;
1393 	DEVOFFSET (0) = DEVICE1_OFFSET;
1394 	ENVSIZE (0) = ENV1_SIZE;
1395 
1396 	/* Set defaults for DEVESIZE, ENVSECTORS later once we
1397 	 * know DEVTYPE
1398 	 */
1399 #ifdef DEVICE1_ESIZE
1400 	DEVESIZE (0) = DEVICE1_ESIZE;
1401 #endif
1402 #ifdef DEVICE1_ENVSECTORS
1403 	ENVSECTORS (0) = DEVICE1_ENVSECTORS;
1404 #endif
1405 
1406 #ifdef HAVE_REDUND
1407 	DEVNAME (1) = DEVICE2_NAME;
1408 	DEVOFFSET (1) = DEVICE2_OFFSET;
1409 	ENVSIZE (1) = ENV2_SIZE;
1410 
1411 	/* Set defaults for DEVESIZE, ENVSECTORS later once we
1412 	 * know DEVTYPE
1413 	 */
1414 #ifdef DEVICE2_ESIZE
1415 	DEVESIZE (1) = DEVICE2_ESIZE;
1416 #endif
1417 #ifdef DEVICE2_ENVSECTORS
1418 	ENVSECTORS (1) = DEVICE2_ENVSECTORS;
1419 #endif
1420 	HaveRedundEnv = 1;
1421 #endif
1422 #endif
1423 	rc = check_device_config(0);
1424 	if (rc < 0)
1425 		return rc;
1426 
1427 	if (HaveRedundEnv) {
1428 		rc = check_device_config(1);
1429 		if (rc < 0)
1430 			return rc;
1431 
1432 		if (ENVSIZE(0) != ENVSIZE(1)) {
1433 			fprintf(stderr,
1434 				"Redundant environments have unequal size");
1435 			return -1;
1436 		}
1437 	}
1438 
1439 	usable_envsize = CUR_ENVSIZE - sizeof(uint32_t);
1440 	if (HaveRedundEnv)
1441 		usable_envsize -= sizeof(char);
1442 
1443 	if (opts->aes_flag)
1444 		usable_envsize &= ~(AES_KEY_LENGTH - 1);
1445 
1446 	return 0;
1447 }
1448 
1449 #if defined(CONFIG_FILE)
1450 static int get_config (char *fname)
1451 {
1452 	FILE *fp;
1453 	int i = 0;
1454 	int rc;
1455 	char dump[128];
1456 	char *devname;
1457 
1458 	fp = fopen (fname, "r");
1459 	if (fp == NULL)
1460 		return -1;
1461 
1462 	while (i < 2 && fgets (dump, sizeof (dump), fp)) {
1463 		/* Skip incomplete conversions and comment strings */
1464 		if (dump[0] == '#')
1465 			continue;
1466 
1467 		rc = sscanf(dump, "%ms %lli %lx %lx %lx",
1468 			    &devname,
1469 			    &DEVOFFSET(i),
1470 			    &ENVSIZE(i),
1471 			    &DEVESIZE(i),
1472 			    &ENVSECTORS(i));
1473 
1474 		if (rc < 3)
1475 			continue;
1476 
1477 		DEVNAME(i) = devname;
1478 
1479 		/* Set defaults for DEVESIZE, ENVSECTORS later once we
1480 		 * know DEVTYPE
1481 		 */
1482 
1483 		i++;
1484 	}
1485 	fclose (fp);
1486 
1487 	HaveRedundEnv = i - 1;
1488 	if (!i) {			/* No valid entries found */
1489 		errno = EINVAL;
1490 		return -1;
1491 	} else
1492 		return 0;
1493 }
1494 #endif
1495