xref: /openbmc/u-boot/tools/env/fw_env.c (revision 7dd12830)
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 <ctype.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <stddef.h>
22 #include <string.h>
23 #include <sys/types.h>
24 #include <sys/ioctl.h>
25 #include <sys/stat.h>
26 #include <unistd.h>
27 
28 #ifdef MTD_OLD
29 # include <stdint.h>
30 # include <linux/mtd/mtd.h>
31 #else
32 # define  __user	/* nothing */
33 # include <mtd/mtd-user.h>
34 #endif
35 
36 #include "fw_env.h"
37 
38 #define DIV_ROUND_UP(n, d)	(((n) + (d) - 1) / (d))
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 static unsigned long usable_envsize;
75 #define ENV_SIZE      usable_envsize
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, uint8_t *key);
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(struct env_opts *opts);
120 
121 #if defined(CONFIG_FILE)
122 static int get_config (char *);
123 #endif
124 
125 static char *skip_chars(char *s)
126 {
127 	for (; *s != '\0'; s++) {
128 		if (isblank(*s))
129 			return s;
130 	}
131 	return NULL;
132 }
133 
134 static char *skip_blanks(char *s)
135 {
136 	for (; *s != '\0'; s++) {
137 		if (!isblank(*s))
138 			return s;
139 	}
140 	return NULL;
141 }
142 
143 /*
144  * Search the environment for a variable.
145  * Return the value, if found, or NULL, if not found.
146  */
147 char *fw_getenv (char *name)
148 {
149 	char *env, *nxt;
150 
151 	for (env = environment.data; *env; env = nxt + 1) {
152 		char *val;
153 
154 		for (nxt = env; *nxt; ++nxt) {
155 			if (nxt >= &environment.data[ENV_SIZE]) {
156 				fprintf (stderr, "## Error: "
157 					"environment not terminated\n");
158 				return NULL;
159 			}
160 		}
161 		val = envmatch (name, env);
162 		if (!val)
163 			continue;
164 		return val;
165 	}
166 	return NULL;
167 }
168 
169 /*
170  * Search the default environment for a variable.
171  * Return the value, if found, or NULL, if not found.
172  */
173 char *fw_getdefenv(char *name)
174 {
175 	char *env, *nxt;
176 
177 	for (env = default_environment; *env; env = nxt + 1) {
178 		char *val;
179 
180 		for (nxt = env; *nxt; ++nxt) {
181 			if (nxt >= &default_environment[ENV_SIZE]) {
182 				fprintf(stderr, "## Error: "
183 					"default environment not terminated\n");
184 				return NULL;
185 			}
186 		}
187 		val = envmatch(name, env);
188 		if (!val)
189 			continue;
190 		return val;
191 	}
192 	return NULL;
193 }
194 
195 int parse_aes_key(char *key, uint8_t *bin_key)
196 {
197 	char tmp[5] = { '0', 'x', 0, 0, 0 };
198 	unsigned long ul;
199 	int i;
200 
201 	if (strnlen(key, 64) != 32) {
202 		fprintf(stderr,
203 			"## Error: '-a' option requires 16-byte AES key\n");
204 		return -1;
205 	}
206 
207 	for (i = 0; i < 16; i++) {
208 		tmp[2] = key[0];
209 		tmp[3] = key[1];
210 		errno = 0;
211 		ul = strtoul(tmp, NULL, 16);
212 		if (errno) {
213 			fprintf(stderr,
214 				"## Error: '-a' option requires valid AES key\n");
215 			return -1;
216 		}
217 		bin_key[i] = ul & 0xff;
218 		key += 2;
219 	}
220 	return 0;
221 }
222 
223 /*
224  * Print the current definition of one, or more, or all
225  * environment variables
226  */
227 int fw_printenv(int argc, char *argv[], int value_only, struct env_opts *opts)
228 {
229 	char *env, *nxt;
230 	int i, rc = 0;
231 
232 	if (fw_env_open(opts))
233 		return -1;
234 
235 	if (argc == 0) {		/* Print all env variables  */
236 		for (env = environment.data; *env; env = nxt + 1) {
237 			for (nxt = env; *nxt; ++nxt) {
238 				if (nxt >= &environment.data[ENV_SIZE]) {
239 					fprintf (stderr, "## Error: "
240 						"environment not terminated\n");
241 					return -1;
242 				}
243 			}
244 
245 			printf ("%s\n", env);
246 		}
247 		return 0;
248 	}
249 
250 	if (value_only && argc != 1) {
251 		fprintf(stderr,
252 			"## Error: `-n' option requires exactly one argument\n");
253 		return -1;
254 	}
255 
256 	for (i = 0; i < argc; ++i) {	/* print single env variables   */
257 		char *name = argv[i];
258 		char *val = NULL;
259 
260 		for (env = environment.data; *env; env = nxt + 1) {
261 
262 			for (nxt = env; *nxt; ++nxt) {
263 				if (nxt >= &environment.data[ENV_SIZE]) {
264 					fprintf (stderr, "## Error: "
265 						"environment not terminated\n");
266 					return -1;
267 				}
268 			}
269 			val = envmatch (name, env);
270 			if (val) {
271 				if (!value_only) {
272 					fputs (name, stdout);
273 					putc ('=', stdout);
274 				}
275 				puts (val);
276 				break;
277 			}
278 		}
279 		if (!val) {
280 			fprintf (stderr, "## Error: \"%s\" not defined\n", name);
281 			rc = -1;
282 		}
283 	}
284 
285 	return rc;
286 }
287 
288 int fw_env_close(struct env_opts *opts)
289 {
290 	int ret;
291 
292 	if (opts->aes_flag) {
293 		ret = env_aes_cbc_crypt(environment.data, 1,
294 					opts->aes_key);
295 		if (ret) {
296 			fprintf(stderr,
297 				"Error: can't encrypt env for flash\n");
298 			return ret;
299 		}
300 	}
301 
302 	/*
303 	 * Update CRC
304 	 */
305 	*environment.crc = crc32(0, (uint8_t *) environment.data, ENV_SIZE);
306 
307 	/* write environment back to flash */
308 	if (flash_io(O_RDWR)) {
309 		fprintf(stderr,
310 			"Error: can't write fw_env to flash\n");
311 			return -1;
312 	}
313 
314 	return 0;
315 }
316 
317 
318 /*
319  * Set/Clear a single variable in the environment.
320  * This is called in sequence to update the environment
321  * in RAM without updating the copy in flash after each set
322  */
323 int fw_env_write(char *name, char *value)
324 {
325 	int len;
326 	char *env, *nxt;
327 	char *oldval = NULL;
328 	int deleting, creating, overwriting;
329 
330 	/*
331 	 * search if variable with this name already exists
332 	 */
333 	for (nxt = env = environment.data; *env; env = nxt + 1) {
334 		for (nxt = env; *nxt; ++nxt) {
335 			if (nxt >= &environment.data[ENV_SIZE]) {
336 				fprintf(stderr, "## Error: "
337 					"environment not terminated\n");
338 				errno = EINVAL;
339 				return -1;
340 			}
341 		}
342 		if ((oldval = envmatch (name, env)) != NULL)
343 			break;
344 	}
345 
346 	deleting = (oldval && !(value && strlen(value)));
347 	creating = (!oldval && (value && strlen(value)));
348 	overwriting = (oldval && (value && strlen(value)));
349 
350 	/* check for permission */
351 	if (deleting) {
352 		if (env_flags_validate_varaccess(name,
353 		    ENV_FLAGS_VARACCESS_PREVENT_DELETE)) {
354 			printf("Can't delete \"%s\"\n", name);
355 			errno = EROFS;
356 			return -1;
357 		}
358 	} else if (overwriting) {
359 		if (env_flags_validate_varaccess(name,
360 		    ENV_FLAGS_VARACCESS_PREVENT_OVERWR)) {
361 			printf("Can't overwrite \"%s\"\n", name);
362 			errno = EROFS;
363 			return -1;
364 		} else if (env_flags_validate_varaccess(name,
365 		    ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR)) {
366 			const char *defval = fw_getdefenv(name);
367 
368 			if (defval == NULL)
369 				defval = "";
370 			if (strcmp(oldval, defval)
371 			    != 0) {
372 				printf("Can't overwrite \"%s\"\n", name);
373 				errno = EROFS;
374 				return -1;
375 			}
376 		}
377 	} else if (creating) {
378 		if (env_flags_validate_varaccess(name,
379 		    ENV_FLAGS_VARACCESS_PREVENT_CREATE)) {
380 			printf("Can't create \"%s\"\n", name);
381 			errno = EROFS;
382 			return -1;
383 		}
384 	} else
385 		/* Nothing to do */
386 		return 0;
387 
388 	if (deleting || overwriting) {
389 		if (*++nxt == '\0') {
390 			*env = '\0';
391 		} else {
392 			for (;;) {
393 				*env = *nxt++;
394 				if ((*env == '\0') && (*nxt == '\0'))
395 					break;
396 				++env;
397 			}
398 		}
399 		*++env = '\0';
400 	}
401 
402 	/* Delete only ? */
403 	if (!value || !strlen(value))
404 		return 0;
405 
406 	/*
407 	 * Append new definition at the end
408 	 */
409 	for (env = environment.data; *env || *(env + 1); ++env);
410 	if (env > environment.data)
411 		++env;
412 	/*
413 	 * Overflow when:
414 	 * "name" + "=" + "val" +"\0\0"  > CUR_ENVSIZE - (env-environment)
415 	 */
416 	len = strlen (name) + 2;
417 	/* add '=' for first arg, ' ' for all others */
418 	len += strlen(value) + 1;
419 
420 	if (len > (&environment.data[ENV_SIZE] - env)) {
421 		fprintf (stderr,
422 			"Error: environment overflow, \"%s\" deleted\n",
423 			name);
424 		return -1;
425 	}
426 
427 	while ((*env = *name++) != '\0')
428 		env++;
429 	*env = '=';
430 	while ((*++env = *value++) != '\0')
431 		;
432 
433 	/* end is marked with double '\0' */
434 	*++env = '\0';
435 
436 	return 0;
437 }
438 
439 /*
440  * Deletes or sets environment variables. Returns -1 and sets errno error codes:
441  * 0	  - OK
442  * EINVAL - need at least 1 argument
443  * EROFS  - certain variables ("ethaddr", "serial#") cannot be
444  *	    modified or deleted
445  *
446  */
447 int fw_setenv(int argc, char *argv[], struct env_opts *opts)
448 {
449 	int i;
450 	size_t len;
451 	char *name, **valv;
452 	char *value = NULL;
453 	int valc;
454 
455 	if (argc < 1) {
456 		fprintf(stderr, "## Error: variable name missing\n");
457 		errno = EINVAL;
458 		return -1;
459 	}
460 
461 	if (fw_env_open(opts)) {
462 		fprintf(stderr, "Error: environment not initialized\n");
463 		return -1;
464 	}
465 
466 	name = argv[0];
467 	valv = argv + 1;
468 	valc = argc - 1;
469 
470 	if (env_flags_validate_env_set_params(name, valv, valc) < 0)
471 		return 1;
472 
473 	len = 0;
474 	for (i = 0; i < valc; ++i) {
475 		char *val = valv[i];
476 		size_t val_len = strlen(val);
477 
478 		if (value)
479 			value[len - 1] = ' ';
480 		value = realloc(value, len + val_len + 1);
481 		if (!value) {
482 			fprintf(stderr,
483 				"Cannot malloc %zu bytes: %s\n",
484 				len, strerror(errno));
485 			return -1;
486 		}
487 
488 		memcpy(value + len, val, val_len);
489 		len += val_len;
490 		value[len++] = '\0';
491 	}
492 
493 	fw_env_write(name, value);
494 
495 	free(value);
496 
497 	return fw_env_close(opts);
498 }
499 
500 /*
501  * Parse  a file  and configure the u-boot variables.
502  * The script file has a very simple format, as follows:
503  *
504  * Each line has a couple with name, value:
505  * <white spaces>variable_name<white spaces>variable_value
506  *
507  * Both variable_name and variable_value are interpreted as strings.
508  * Any character after <white spaces> and before ending \r\n is interpreted
509  * as variable's value (no comment allowed on these lines !)
510  *
511  * Comments are allowed if the first character in the line is #
512  *
513  * Returns -1 and sets errno error codes:
514  * 0	  - OK
515  * -1     - Error
516  */
517 int fw_parse_script(char *fname, struct env_opts *opts)
518 {
519 	FILE *fp;
520 	char dump[1024];	/* Maximum line length in the file */
521 	char *name;
522 	char *val;
523 	int lineno = 0;
524 	int len;
525 	int ret = 0;
526 
527 	if (fw_env_open(opts)) {
528 		fprintf(stderr, "Error: environment not initialized\n");
529 		return -1;
530 	}
531 
532 	if (strcmp(fname, "-") == 0)
533 		fp = stdin;
534 	else {
535 		fp = fopen(fname, "r");
536 		if (fp == NULL) {
537 			fprintf(stderr, "I cannot open %s for reading\n",
538 				 fname);
539 			return -1;
540 		}
541 	}
542 
543 	while (fgets(dump, sizeof(dump), fp)) {
544 		lineno++;
545 		len = strlen(dump);
546 
547 		/*
548 		 * Read a whole line from the file. If the line is too long
549 		 * or is not terminated, reports an error and exit.
550 		 */
551 		if (dump[len - 1] != '\n') {
552 			fprintf(stderr,
553 			"Line %d not corrected terminated or too long\n",
554 				lineno);
555 			ret = -1;
556 			break;
557 		}
558 
559 		/* Drop ending line feed / carriage return */
560 		dump[--len] = '\0';
561 		if (len && dump[len - 1] == '\r')
562 			dump[--len] = '\0';
563 
564 		/* Skip comment or empty lines */
565 		if (len == 0 || dump[0] == '#')
566 			continue;
567 
568 		/*
569 		 * Search for variable's name,
570 		 * remove leading whitespaces
571 		 */
572 		name = skip_blanks(dump);
573 		if (!name)
574 			continue;
575 
576 		/* The first white space is the end of variable name */
577 		val = skip_chars(name);
578 		len = strlen(name);
579 		if (val) {
580 			*val++ = '\0';
581 			if ((val - name) < len)
582 				val = skip_blanks(val);
583 			else
584 				val = NULL;
585 		}
586 
587 #ifdef DEBUG
588 		fprintf(stderr, "Setting %s : %s\n",
589 			name, val ? val : " removed");
590 #endif
591 
592 		if (env_flags_validate_type(name, val) < 0) {
593 			ret = -1;
594 			break;
595 		}
596 
597 		/*
598 		 * If there is an error setting a variable,
599 		 * try to save the environment and returns an error
600 		 */
601 		if (fw_env_write(name, val)) {
602 			fprintf(stderr,
603 			"fw_env_write returns with error : %s\n",
604 				strerror(errno));
605 			ret = -1;
606 			break;
607 		}
608 
609 	}
610 
611 	/* Close file if not stdin */
612 	if (strcmp(fname, "-") != 0)
613 		fclose(fp);
614 
615 	ret |= fw_env_close(opts);
616 
617 	return ret;
618 }
619 
620 /*
621  * Test for bad block on NAND, just returns 0 on NOR, on NAND:
622  * 0	- block is good
623  * > 0	- block is bad
624  * < 0	- failed to test
625  */
626 static int flash_bad_block (int fd, uint8_t mtd_type, loff_t *blockstart)
627 {
628 	if (mtd_type == MTD_NANDFLASH) {
629 		int badblock = ioctl (fd, MEMGETBADBLOCK, blockstart);
630 
631 		if (badblock < 0) {
632 			perror ("Cannot read bad block mark");
633 			return badblock;
634 		}
635 
636 		if (badblock) {
637 #ifdef DEBUG
638 			fprintf (stderr, "Bad block at 0x%llx, "
639 				 "skipping\n", *blockstart);
640 #endif
641 			return badblock;
642 		}
643 	}
644 
645 	return 0;
646 }
647 
648 /*
649  * Read data from flash at an offset into a provided buffer. On NAND it skips
650  * bad blocks but makes sure it stays within ENVSECTORS (dev) starting from
651  * the DEVOFFSET (dev) block. On NOR the loop is only run once.
652  */
653 static int flash_read_buf (int dev, int fd, void *buf, size_t count,
654 			   off_t offset, uint8_t mtd_type)
655 {
656 	size_t blocklen;	/* erase / write length - one block on NAND,
657 				   0 on NOR */
658 	size_t processed = 0;	/* progress counter */
659 	size_t readlen = count;	/* current read length */
660 	off_t top_of_range;	/* end of the last block we may use */
661 	off_t block_seek;	/* offset inside the current block to the start
662 				   of the data */
663 	loff_t blockstart;	/* running start of the current block -
664 				   MEMGETBADBLOCK needs 64 bits */
665 	int rc;
666 
667 	blockstart = (offset / DEVESIZE (dev)) * DEVESIZE (dev);
668 
669 	/* Offset inside a block */
670 	block_seek = offset - blockstart;
671 
672 	if (mtd_type == MTD_NANDFLASH) {
673 		/*
674 		 * NAND: calculate which blocks we are reading. We have
675 		 * to read one block at a time to skip bad blocks.
676 		 */
677 		blocklen = DEVESIZE (dev);
678 
679 		/*
680 		 * To calculate the top of the range, we have to use the
681 		 * global DEVOFFSET (dev), which can be different from offset
682 		 */
683 		top_of_range = ((DEVOFFSET(dev) / blocklen) +
684 				ENVSECTORS (dev)) * blocklen;
685 
686 		/* Limit to one block for the first read */
687 		if (readlen > blocklen - block_seek)
688 			readlen = blocklen - block_seek;
689 	} else {
690 		blocklen = 0;
691 		top_of_range = offset + count;
692 	}
693 
694 	/* This only runs once on NOR flash */
695 	while (processed < count) {
696 		rc = flash_bad_block (fd, mtd_type, &blockstart);
697 		if (rc < 0)		/* block test failed */
698 			return -1;
699 
700 		if (blockstart + block_seek + readlen > top_of_range) {
701 			/* End of range is reached */
702 			fprintf (stderr,
703 				 "Too few good blocks within range\n");
704 			return -1;
705 		}
706 
707 		if (rc) {		/* block is bad */
708 			blockstart += blocklen;
709 			continue;
710 		}
711 
712 		/*
713 		 * If a block is bad, we retry in the next block at the same
714 		 * offset - see common/env_nand.c::writeenv()
715 		 */
716 		lseek (fd, blockstart + block_seek, SEEK_SET);
717 
718 		rc = read (fd, buf + processed, readlen);
719 		if (rc != readlen) {
720 			fprintf (stderr, "Read error on %s: %s\n",
721 				 DEVNAME (dev), strerror (errno));
722 			return -1;
723 		}
724 #ifdef DEBUG
725 		fprintf(stderr, "Read 0x%x bytes at 0x%llx on %s\n",
726 			 rc, blockstart + block_seek, DEVNAME(dev));
727 #endif
728 		processed += readlen;
729 		readlen = min (blocklen, count - processed);
730 		block_seek = 0;
731 		blockstart += blocklen;
732 	}
733 
734 	return processed;
735 }
736 
737 /*
738  * Write count bytes at offset, but stay within ENVSECTORS (dev) sectors of
739  * DEVOFFSET (dev). Similar to the read case above, on NOR and dataflash we
740  * erase and write the whole data at once.
741  */
742 static int flash_write_buf (int dev, int fd, void *buf, size_t count,
743 			    off_t offset, uint8_t mtd_type)
744 {
745 	void *data;
746 	struct erase_info_user erase;
747 	size_t blocklen;	/* length of NAND block / NOR erase sector */
748 	size_t erase_len;	/* whole area that can be erased - may include
749 				   bad blocks */
750 	size_t erasesize;	/* erase / write length - one block on NAND,
751 				   whole area on NOR */
752 	size_t processed = 0;	/* progress counter */
753 	size_t write_total;	/* total size to actually write - excluding
754 				   bad blocks */
755 	off_t erase_offset;	/* offset to the first erase block (aligned)
756 				   below offset */
757 	off_t block_seek;	/* offset inside the erase block to the start
758 				   of the data */
759 	off_t top_of_range;	/* end of the last block we may use */
760 	loff_t blockstart;	/* running start of the current block -
761 				   MEMGETBADBLOCK needs 64 bits */
762 	int rc;
763 
764 	/*
765 	 * For mtd devices only offset and size of the environment do matter
766 	 */
767 	if (mtd_type == MTD_ABSENT) {
768 		blocklen = count;
769 		top_of_range = offset + count;
770 		erase_len = blocklen;
771 		blockstart = offset;
772 		block_seek = 0;
773 		write_total = blocklen;
774 	} else {
775 		blocklen = DEVESIZE(dev);
776 
777 		top_of_range = ((DEVOFFSET(dev) / blocklen) +
778 					ENVSECTORS(dev)) * blocklen;
779 
780 		erase_offset = (offset / blocklen) * blocklen;
781 
782 		/* Maximum area we may use */
783 		erase_len = top_of_range - erase_offset;
784 
785 		blockstart = erase_offset;
786 		/* Offset inside a block */
787 		block_seek = offset - erase_offset;
788 
789 		/*
790 		 * Data size we actually write: from the start of the block
791 		 * to the start of the data, then count bytes of data, and
792 		 * to the end of the block
793 		 */
794 		write_total = ((block_seek + count + blocklen - 1) /
795 							blocklen) * blocklen;
796 	}
797 
798 	/*
799 	 * Support data anywhere within erase sectors: read out the complete
800 	 * area to be erased, replace the environment image, write the whole
801 	 * block back again.
802 	 */
803 	if (write_total > count) {
804 		data = malloc (erase_len);
805 		if (!data) {
806 			fprintf (stderr,
807 				 "Cannot malloc %zu bytes: %s\n",
808 				 erase_len, strerror (errno));
809 			return -1;
810 		}
811 
812 		rc = flash_read_buf (dev, fd, data, write_total, erase_offset,
813 				     mtd_type);
814 		if (write_total != rc)
815 			return -1;
816 
817 #ifdef DEBUG
818 		fprintf(stderr, "Preserving data ");
819 		if (block_seek != 0)
820 			fprintf(stderr, "0x%x - 0x%lx", 0, block_seek - 1);
821 		if (block_seek + count != write_total) {
822 			if (block_seek != 0)
823 				fprintf(stderr, " and ");
824 			fprintf(stderr, "0x%lx - 0x%x",
825 				block_seek + count, write_total - 1);
826 		}
827 		fprintf(stderr, "\n");
828 #endif
829 		/* Overwrite the old environment */
830 		memcpy (data + block_seek, buf, count);
831 	} else {
832 		/*
833 		 * We get here, iff offset is block-aligned and count is a
834 		 * multiple of blocklen - see write_total calculation above
835 		 */
836 		data = buf;
837 	}
838 
839 	if (mtd_type == MTD_NANDFLASH) {
840 		/*
841 		 * NAND: calculate which blocks we are writing. We have
842 		 * to write one block at a time to skip bad blocks.
843 		 */
844 		erasesize = blocklen;
845 	} else {
846 		erasesize = erase_len;
847 	}
848 
849 	erase.length = erasesize;
850 
851 	/* This only runs once on NOR flash and SPI-dataflash */
852 	while (processed < write_total) {
853 		rc = flash_bad_block (fd, mtd_type, &blockstart);
854 		if (rc < 0)		/* block test failed */
855 			return rc;
856 
857 		if (blockstart + erasesize > top_of_range) {
858 			fprintf (stderr, "End of range reached, aborting\n");
859 			return -1;
860 		}
861 
862 		if (rc) {		/* block is bad */
863 			blockstart += blocklen;
864 			continue;
865 		}
866 
867 		if (mtd_type != MTD_ABSENT) {
868 			erase.start = blockstart;
869 			ioctl(fd, MEMUNLOCK, &erase);
870 			/* These do not need an explicit erase cycle */
871 			if (mtd_type != MTD_DATAFLASH)
872 				if (ioctl(fd, MEMERASE, &erase) != 0) {
873 					fprintf(stderr,
874 						"MTD erase error on %s: %s\n",
875 						DEVNAME(dev), strerror(errno));
876 					return -1;
877 				}
878 		}
879 
880 		if (lseek (fd, blockstart, SEEK_SET) == -1) {
881 			fprintf (stderr,
882 				 "Seek error on %s: %s\n",
883 				 DEVNAME (dev), strerror (errno));
884 			return -1;
885 		}
886 
887 #ifdef DEBUG
888 		fprintf(stderr, "Write 0x%x bytes at 0x%llx\n", erasesize,
889 			blockstart);
890 #endif
891 		if (write (fd, data + processed, erasesize) != erasesize) {
892 			fprintf (stderr, "Write error on %s: %s\n",
893 				 DEVNAME (dev), strerror (errno));
894 			return -1;
895 		}
896 
897 		if (mtd_type != MTD_ABSENT)
898 			ioctl(fd, MEMLOCK, &erase);
899 
900 		processed  += erasesize;
901 		block_seek = 0;
902 		blockstart += erasesize;
903 	}
904 
905 	if (write_total > count)
906 		free (data);
907 
908 	return processed;
909 }
910 
911 /*
912  * Set obsolete flag at offset - NOR flash only
913  */
914 static int flash_flag_obsolete (int dev, int fd, off_t offset)
915 {
916 	int rc;
917 	struct erase_info_user erase;
918 
919 	erase.start  = DEVOFFSET (dev);
920 	erase.length = DEVESIZE (dev);
921 	/* This relies on the fact, that obsolete_flag == 0 */
922 	rc = lseek (fd, offset, SEEK_SET);
923 	if (rc < 0) {
924 		fprintf (stderr, "Cannot seek to set the flag on %s \n",
925 			 DEVNAME (dev));
926 		return rc;
927 	}
928 	ioctl (fd, MEMUNLOCK, &erase);
929 	rc = write (fd, &obsolete_flag, sizeof (obsolete_flag));
930 	ioctl (fd, MEMLOCK, &erase);
931 	if (rc < 0)
932 		perror ("Could not set obsolete flag");
933 
934 	return rc;
935 }
936 
937 /* Encrypt or decrypt the environment before writing or reading it. */
938 static int env_aes_cbc_crypt(char *payload, const int enc, uint8_t *key)
939 {
940 	uint8_t *data = (uint8_t *)payload;
941 	const int len = usable_envsize;
942 	uint8_t key_exp[AES_EXPAND_KEY_LENGTH];
943 	uint32_t aes_blocks;
944 
945 	/* First we expand the key. */
946 	aes_expand_key(key, key_exp);
947 
948 	/* Calculate the number of AES blocks to encrypt. */
949 	aes_blocks = DIV_ROUND_UP(len, AES_KEY_LENGTH);
950 
951 	if (enc)
952 		aes_cbc_encrypt_blocks(key_exp, data, data, aes_blocks);
953 	else
954 		aes_cbc_decrypt_blocks(key_exp, data, data, aes_blocks);
955 
956 	return 0;
957 }
958 
959 static int flash_write (int fd_current, int fd_target, int dev_target)
960 {
961 	int rc;
962 
963 	switch (environment.flag_scheme) {
964 	case FLAG_NONE:
965 		break;
966 	case FLAG_INCREMENTAL:
967 		(*environment.flags)++;
968 		break;
969 	case FLAG_BOOLEAN:
970 		*environment.flags = active_flag;
971 		break;
972 	default:
973 		fprintf (stderr, "Unimplemented flash scheme %u \n",
974 			 environment.flag_scheme);
975 		return -1;
976 	}
977 
978 #ifdef DEBUG
979 	fprintf(stderr, "Writing new environment at 0x%lx on %s\n",
980 		DEVOFFSET (dev_target), DEVNAME (dev_target));
981 #endif
982 
983 	rc = flash_write_buf(dev_target, fd_target, environment.image,
984 			      CUR_ENVSIZE, DEVOFFSET(dev_target),
985 			      DEVTYPE(dev_target));
986 	if (rc < 0)
987 		return rc;
988 
989 	if (environment.flag_scheme == FLAG_BOOLEAN) {
990 		/* Have to set obsolete flag */
991 		off_t offset = DEVOFFSET (dev_current) +
992 			offsetof (struct env_image_redundant, flags);
993 #ifdef DEBUG
994 		fprintf(stderr,
995 			"Setting obsolete flag in environment at 0x%lx on %s\n",
996 			DEVOFFSET (dev_current), DEVNAME (dev_current));
997 #endif
998 		flash_flag_obsolete (dev_current, fd_current, offset);
999 	}
1000 
1001 	return 0;
1002 }
1003 
1004 static int flash_read (int fd)
1005 {
1006 	struct mtd_info_user mtdinfo;
1007 	struct stat st;
1008 	int rc;
1009 
1010 	rc = fstat(fd, &st);
1011 	if (rc < 0) {
1012 		fprintf(stderr, "Cannot stat the file %s\n",
1013 			DEVNAME(dev_current));
1014 		return -1;
1015 	}
1016 
1017 	if (S_ISCHR(st.st_mode)) {
1018 		rc = ioctl(fd, MEMGETINFO, &mtdinfo);
1019 		if (rc < 0) {
1020 			fprintf(stderr, "Cannot get MTD information for %s\n",
1021 				DEVNAME(dev_current));
1022 			return -1;
1023 		}
1024 		if (mtdinfo.type != MTD_NORFLASH &&
1025 		    mtdinfo.type != MTD_NANDFLASH &&
1026 		    mtdinfo.type != MTD_DATAFLASH &&
1027 		    mtdinfo.type != MTD_UBIVOLUME) {
1028 			fprintf (stderr, "Unsupported flash type %u on %s\n",
1029 				 mtdinfo.type, DEVNAME(dev_current));
1030 			return -1;
1031 		}
1032 	} else {
1033 		memset(&mtdinfo, 0, sizeof(mtdinfo));
1034 		mtdinfo.type = MTD_ABSENT;
1035 	}
1036 
1037 	DEVTYPE(dev_current) = mtdinfo.type;
1038 
1039 	rc = flash_read_buf(dev_current, fd, environment.image, CUR_ENVSIZE,
1040 			     DEVOFFSET (dev_current), mtdinfo.type);
1041 	if (rc != CUR_ENVSIZE)
1042 		return -1;
1043 
1044 	return 0;
1045 }
1046 
1047 static int flash_io (int mode)
1048 {
1049 	int fd_current, fd_target, rc, dev_target;
1050 
1051 	/* dev_current: fd_current, erase_current */
1052 	fd_current = open (DEVNAME (dev_current), mode);
1053 	if (fd_current < 0) {
1054 		fprintf (stderr,
1055 			 "Can't open %s: %s\n",
1056 			 DEVNAME (dev_current), strerror (errno));
1057 		return -1;
1058 	}
1059 
1060 	if (mode == O_RDWR) {
1061 		if (HaveRedundEnv) {
1062 			/* switch to next partition for writing */
1063 			dev_target = !dev_current;
1064 			/* dev_target: fd_target, erase_target */
1065 			fd_target = open (DEVNAME (dev_target), mode);
1066 			if (fd_target < 0) {
1067 				fprintf (stderr,
1068 					 "Can't open %s: %s\n",
1069 					 DEVNAME (dev_target),
1070 					 strerror (errno));
1071 				rc = -1;
1072 				goto exit;
1073 			}
1074 		} else {
1075 			dev_target = dev_current;
1076 			fd_target = fd_current;
1077 		}
1078 
1079 		rc = flash_write (fd_current, fd_target, dev_target);
1080 
1081 		if (HaveRedundEnv) {
1082 			if (close (fd_target)) {
1083 				fprintf (stderr,
1084 					"I/O error on %s: %s\n",
1085 					DEVNAME (dev_target),
1086 					strerror (errno));
1087 				rc = -1;
1088 			}
1089 		}
1090 	} else {
1091 		rc = flash_read (fd_current);
1092 	}
1093 
1094 exit:
1095 	if (close (fd_current)) {
1096 		fprintf (stderr,
1097 			 "I/O error on %s: %s\n",
1098 			 DEVNAME (dev_current), strerror (errno));
1099 		return -1;
1100 	}
1101 
1102 	return rc;
1103 }
1104 
1105 /*
1106  * s1 is either a simple 'name', or a 'name=value' pair.
1107  * s2 is a 'name=value' pair.
1108  * If the names match, return the value of s2, else NULL.
1109  */
1110 
1111 static char *envmatch (char * s1, char * s2)
1112 {
1113 	if (s1 == NULL || s2 == NULL)
1114 		return NULL;
1115 
1116 	while (*s1 == *s2++)
1117 		if (*s1++ == '=')
1118 			return s2;
1119 	if (*s1 == '\0' && *(s2 - 1) == '=')
1120 		return s2;
1121 	return NULL;
1122 }
1123 
1124 /*
1125  * Prevent confusion if running from erased flash memory
1126  */
1127 int fw_env_open(struct env_opts *opts)
1128 {
1129 	int crc0, crc0_ok;
1130 	unsigned char flag0;
1131 	void *addr0;
1132 
1133 	int crc1, crc1_ok;
1134 	unsigned char flag1;
1135 	void *addr1;
1136 
1137 	int ret;
1138 
1139 	struct env_image_single *single;
1140 	struct env_image_redundant *redundant;
1141 
1142 	if (parse_config(opts))		/* should fill envdevices */
1143 		return -1;
1144 
1145 	addr0 = calloc(1, CUR_ENVSIZE);
1146 	if (addr0 == NULL) {
1147 		fprintf(stderr,
1148 			"Not enough memory for environment (%ld bytes)\n",
1149 			CUR_ENVSIZE);
1150 		return -1;
1151 	}
1152 
1153 	/* read environment from FLASH to local buffer */
1154 	environment.image = addr0;
1155 
1156 	if (HaveRedundEnv) {
1157 		redundant = addr0;
1158 		environment.crc		= &redundant->crc;
1159 		environment.flags	= &redundant->flags;
1160 		environment.data	= redundant->data;
1161 	} else {
1162 		single = addr0;
1163 		environment.crc		= &single->crc;
1164 		environment.flags	= NULL;
1165 		environment.data	= single->data;
1166 	}
1167 
1168 	dev_current = 0;
1169 	if (flash_io (O_RDONLY))
1170 		return -1;
1171 
1172 	crc0 = crc32 (0, (uint8_t *) environment.data, ENV_SIZE);
1173 
1174 	if (opts->aes_flag) {
1175 		ret = env_aes_cbc_crypt(environment.data, 0,
1176 					opts->aes_key);
1177 		if (ret)
1178 			return ret;
1179 	}
1180 
1181 	crc0_ok = (crc0 == *environment.crc);
1182 	if (!HaveRedundEnv) {
1183 		if (!crc0_ok) {
1184 			fprintf (stderr,
1185 				"Warning: Bad CRC, using default environment\n");
1186 			memcpy(environment.data, default_environment, sizeof default_environment);
1187 		}
1188 	} else {
1189 		flag0 = *environment.flags;
1190 
1191 		dev_current = 1;
1192 		addr1 = calloc(1, CUR_ENVSIZE);
1193 		if (addr1 == NULL) {
1194 			fprintf(stderr,
1195 				"Not enough memory for environment (%ld bytes)\n",
1196 				CUR_ENVSIZE);
1197 			return -1;
1198 		}
1199 		redundant = addr1;
1200 
1201 		/*
1202 		 * have to set environment.image for flash_read(), careful -
1203 		 * other pointers in environment still point inside addr0
1204 		 */
1205 		environment.image = addr1;
1206 		if (flash_io (O_RDONLY))
1207 			return -1;
1208 
1209 		/* Check flag scheme compatibility */
1210 		if (DEVTYPE(dev_current) == MTD_NORFLASH &&
1211 		    DEVTYPE(!dev_current) == MTD_NORFLASH) {
1212 			environment.flag_scheme = FLAG_BOOLEAN;
1213 		} else if (DEVTYPE(dev_current) == MTD_NANDFLASH &&
1214 			   DEVTYPE(!dev_current) == MTD_NANDFLASH) {
1215 			environment.flag_scheme = FLAG_INCREMENTAL;
1216 		} else if (DEVTYPE(dev_current) == MTD_DATAFLASH &&
1217 			   DEVTYPE(!dev_current) == MTD_DATAFLASH) {
1218 			environment.flag_scheme = FLAG_BOOLEAN;
1219 		} else if (DEVTYPE(dev_current) == MTD_UBIVOLUME &&
1220 			   DEVTYPE(!dev_current) == MTD_UBIVOLUME) {
1221 			environment.flag_scheme = FLAG_INCREMENTAL;
1222 		} else if (DEVTYPE(dev_current) == MTD_ABSENT &&
1223 			   DEVTYPE(!dev_current) == MTD_ABSENT) {
1224 			environment.flag_scheme = FLAG_INCREMENTAL;
1225 		} else {
1226 			fprintf (stderr, "Incompatible flash types!\n");
1227 			return -1;
1228 		}
1229 
1230 		crc1 = crc32 (0, (uint8_t *) redundant->data, ENV_SIZE);
1231 
1232 		if (opts->aes_flag) {
1233 			ret = env_aes_cbc_crypt(redundant->data, 0,
1234 						opts->aes_key);
1235 			if (ret)
1236 				return ret;
1237 		}
1238 
1239 		crc1_ok = (crc1 == redundant->crc);
1240 		flag1 = redundant->flags;
1241 
1242 		if (crc0_ok && !crc1_ok) {
1243 			dev_current = 0;
1244 		} else if (!crc0_ok && crc1_ok) {
1245 			dev_current = 1;
1246 		} else if (!crc0_ok && !crc1_ok) {
1247 			fprintf (stderr,
1248 				"Warning: Bad CRC, using default environment\n");
1249 			memcpy (environment.data, default_environment,
1250 				sizeof default_environment);
1251 			dev_current = 0;
1252 		} else {
1253 			switch (environment.flag_scheme) {
1254 			case FLAG_BOOLEAN:
1255 				if (flag0 == active_flag &&
1256 				    flag1 == obsolete_flag) {
1257 					dev_current = 0;
1258 				} else if (flag0 == obsolete_flag &&
1259 					   flag1 == active_flag) {
1260 					dev_current = 1;
1261 				} else if (flag0 == flag1) {
1262 					dev_current = 0;
1263 				} else if (flag0 == 0xFF) {
1264 					dev_current = 0;
1265 				} else if (flag1 == 0xFF) {
1266 					dev_current = 1;
1267 				} else {
1268 					dev_current = 0;
1269 				}
1270 				break;
1271 			case FLAG_INCREMENTAL:
1272 				if (flag0 == 255 && flag1 == 0)
1273 					dev_current = 1;
1274 				else if ((flag1 == 255 && flag0 == 0) ||
1275 					 flag0 >= flag1)
1276 					dev_current = 0;
1277 				else /* flag1 > flag0 */
1278 					dev_current = 1;
1279 				break;
1280 			default:
1281 				fprintf (stderr, "Unknown flag scheme %u \n",
1282 					 environment.flag_scheme);
1283 				return -1;
1284 			}
1285 		}
1286 
1287 		/*
1288 		 * If we are reading, we don't need the flag and the CRC any
1289 		 * more, if we are writing, we will re-calculate CRC and update
1290 		 * flags before writing out
1291 		 */
1292 		if (dev_current) {
1293 			environment.image	= addr1;
1294 			environment.crc		= &redundant->crc;
1295 			environment.flags	= &redundant->flags;
1296 			environment.data	= redundant->data;
1297 			free (addr0);
1298 		} else {
1299 			environment.image	= addr0;
1300 			/* Other pointers are already set */
1301 			free (addr1);
1302 		}
1303 #ifdef DEBUG
1304 		fprintf(stderr, "Selected env in %s\n", DEVNAME(dev_current));
1305 #endif
1306 	}
1307 	return 0;
1308 }
1309 
1310 
1311 static int parse_config(struct env_opts *opts)
1312 {
1313 	struct stat st;
1314 
1315 #if defined(CONFIG_FILE)
1316 	if (!common_args.config_file)
1317 		common_args.config_file = CONFIG_FILE;
1318 
1319 	/* Fills in DEVNAME(), ENVSIZE(), DEVESIZE(). Or don't. */
1320 	if (get_config(opts->config_file)) {
1321 		fprintf(stderr, "Cannot parse config file '%s': %m\n",
1322 			opts->config_file);
1323 		return -1;
1324 	}
1325 #else
1326 	DEVNAME (0) = DEVICE1_NAME;
1327 	DEVOFFSET (0) = DEVICE1_OFFSET;
1328 	ENVSIZE (0) = ENV1_SIZE;
1329 	/* Default values are: erase-size=env-size */
1330 	DEVESIZE (0) = ENVSIZE (0);
1331 	/* #sectors=env-size/erase-size (rounded up) */
1332 	ENVSECTORS (0) = (ENVSIZE(0) + DEVESIZE(0) - 1) / DEVESIZE(0);
1333 #ifdef DEVICE1_ESIZE
1334 	DEVESIZE (0) = DEVICE1_ESIZE;
1335 #endif
1336 #ifdef DEVICE1_ENVSECTORS
1337 	ENVSECTORS (0) = DEVICE1_ENVSECTORS;
1338 #endif
1339 
1340 #ifdef HAVE_REDUND
1341 	DEVNAME (1) = DEVICE2_NAME;
1342 	DEVOFFSET (1) = DEVICE2_OFFSET;
1343 	ENVSIZE (1) = ENV2_SIZE;
1344 	/* Default values are: erase-size=env-size */
1345 	DEVESIZE (1) = ENVSIZE (1);
1346 	/* #sectors=env-size/erase-size (rounded up) */
1347 	ENVSECTORS (1) = (ENVSIZE(1) + DEVESIZE(1) - 1) / DEVESIZE(1);
1348 #ifdef DEVICE2_ESIZE
1349 	DEVESIZE (1) = DEVICE2_ESIZE;
1350 #endif
1351 #ifdef DEVICE2_ENVSECTORS
1352 	ENVSECTORS (1) = DEVICE2_ENVSECTORS;
1353 #endif
1354 	HaveRedundEnv = 1;
1355 #endif
1356 #endif
1357 	if (stat (DEVNAME (0), &st)) {
1358 		fprintf (stderr,
1359 			"Cannot access MTD device %s: %s\n",
1360 			DEVNAME (0), strerror (errno));
1361 		return -1;
1362 	}
1363 
1364 	if (HaveRedundEnv && stat (DEVNAME (1), &st)) {
1365 		fprintf (stderr,
1366 			"Cannot access MTD device %s: %s\n",
1367 			DEVNAME (1), strerror (errno));
1368 		return -1;
1369 	}
1370 
1371 	if (HaveRedundEnv && ENVSIZE(0) != ENVSIZE(1)) {
1372 		ENVSIZE(0) = ENVSIZE(1) = min(ENVSIZE(0), ENVSIZE(1));
1373 		fprintf(stderr,
1374 			"Redundant environments have inequal size, set to 0x%08lx\n",
1375 			ENVSIZE(1));
1376 	}
1377 
1378 	usable_envsize = CUR_ENVSIZE - sizeof(uint32_t);
1379 	if (HaveRedundEnv)
1380 		usable_envsize -= sizeof(char);
1381 
1382 	if (opts->aes_flag)
1383 		usable_envsize &= ~(AES_KEY_LENGTH - 1);
1384 
1385 	return 0;
1386 }
1387 
1388 #if defined(CONFIG_FILE)
1389 static int get_config (char *fname)
1390 {
1391 	FILE *fp;
1392 	int i = 0;
1393 	int rc;
1394 	char dump[128];
1395 	char *devname;
1396 
1397 	fp = fopen (fname, "r");
1398 	if (fp == NULL)
1399 		return -1;
1400 
1401 	while (i < 2 && fgets (dump, sizeof (dump), fp)) {
1402 		/* Skip incomplete conversions and comment strings */
1403 		if (dump[0] == '#')
1404 			continue;
1405 
1406 		rc = sscanf (dump, "%ms %lx %lx %lx %lx",
1407 			     &devname,
1408 			     &DEVOFFSET (i),
1409 			     &ENVSIZE (i),
1410 			     &DEVESIZE (i),
1411 			     &ENVSECTORS (i));
1412 
1413 		if (rc < 3)
1414 			continue;
1415 
1416 		DEVNAME(i) = devname;
1417 
1418 		if (rc < 4)
1419 			/* Assume the erase size is the same as the env-size */
1420 			DEVESIZE(i) = ENVSIZE(i);
1421 
1422 		if (rc < 5)
1423 			/* Assume enough env sectors to cover the environment */
1424 			ENVSECTORS (i) = (ENVSIZE(i) + DEVESIZE(i) - 1) / DEVESIZE(i);
1425 
1426 		i++;
1427 	}
1428 	fclose (fp);
1429 
1430 	HaveRedundEnv = i - 1;
1431 	if (!i) {			/* No valid entries found */
1432 		errno = EINVAL;
1433 		return -1;
1434 	} else
1435 		return 0;
1436 }
1437 #endif
1438