xref: /openbmc/u-boot/tools/env/fw_env.c (revision ec35e123)
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 struct common_args common_args;
39 struct printenv_args printenv_args;
40 struct setenv_args setenv_args;
41 
42 #define DIV_ROUND_UP(n, d)	(((n) + (d) - 1) / (d))
43 
44 #define min(x, y) ({				\
45 	typeof(x) _min1 = (x);			\
46 	typeof(y) _min2 = (y);			\
47 	(void) (&_min1 == &_min2);		\
48 	_min1 < _min2 ? _min1 : _min2; })
49 
50 struct envdev_s {
51 	const char *devname;		/* Device name */
52 	ulong devoff;			/* Device offset */
53 	ulong env_size;			/* environment size */
54 	ulong erase_size;		/* device erase size */
55 	ulong env_sectors;		/* number of environment sectors */
56 	uint8_t mtd_type;		/* type of the MTD device */
57 };
58 
59 static struct envdev_s envdevices[2] =
60 {
61 	{
62 		.mtd_type = MTD_ABSENT,
63 	}, {
64 		.mtd_type = MTD_ABSENT,
65 	},
66 };
67 static int dev_current;
68 
69 #define DEVNAME(i)    envdevices[(i)].devname
70 #define DEVOFFSET(i)  envdevices[(i)].devoff
71 #define ENVSIZE(i)    envdevices[(i)].env_size
72 #define DEVESIZE(i)   envdevices[(i)].erase_size
73 #define ENVSECTORS(i) envdevices[(i)].env_sectors
74 #define DEVTYPE(i)    envdevices[(i)].mtd_type
75 
76 #define CUR_ENVSIZE ENVSIZE(dev_current)
77 
78 #define ENV_SIZE      getenvsize()
79 
80 struct env_image_single {
81 	uint32_t	crc;	/* CRC32 over data bytes    */
82 	char		data[];
83 };
84 
85 struct env_image_redundant {
86 	uint32_t	crc;	/* CRC32 over data bytes    */
87 	unsigned char	flags;	/* active or obsolete */
88 	char		data[];
89 };
90 
91 enum flag_scheme {
92 	FLAG_NONE,
93 	FLAG_BOOLEAN,
94 	FLAG_INCREMENTAL,
95 };
96 
97 struct environment {
98 	void			*image;
99 	uint32_t		*crc;
100 	unsigned char		*flags;
101 	char			*data;
102 	enum flag_scheme	flag_scheme;
103 };
104 
105 static struct environment environment = {
106 	.flag_scheme = FLAG_NONE,
107 };
108 
109 static int env_aes_cbc_crypt(char *data, const int enc);
110 
111 static int HaveRedundEnv = 0;
112 
113 static unsigned char active_flag = 1;
114 /* obsolete_flag must be 0 to efficiently set it on NOR flash without erasing */
115 static unsigned char obsolete_flag = 0;
116 
117 #define DEFAULT_ENV_INSTANCE_STATIC
118 #include <env_default.h>
119 
120 static int flash_io (int mode);
121 static char *envmatch (char * s1, char * s2);
122 static int parse_config (void);
123 
124 #if defined(CONFIG_FILE)
125 static int get_config (char *);
126 #endif
127 static inline ulong getenvsize (void)
128 {
129 	ulong rc = CUR_ENVSIZE - sizeof(uint32_t);
130 
131 	if (HaveRedundEnv)
132 		rc -= sizeof (char);
133 
134 	if (common_args.aes_flag)
135 		rc &= ~(AES_KEY_LENGTH - 1);
136 
137 	return rc;
138 }
139 
140 static char *skip_chars(char *s)
141 {
142 	for (; *s != '\0'; s++) {
143 		if (isblank(*s))
144 			return s;
145 	}
146 	return NULL;
147 }
148 
149 static char *skip_blanks(char *s)
150 {
151 	for (; *s != '\0'; s++) {
152 		if (!isblank(*s))
153 			return s;
154 	}
155 	return NULL;
156 }
157 
158 /*
159  * Search the environment for a variable.
160  * Return the value, if found, or NULL, if not found.
161  */
162 char *fw_getenv (char *name)
163 {
164 	char *env, *nxt;
165 
166 	for (env = environment.data; *env; env = nxt + 1) {
167 		char *val;
168 
169 		for (nxt = env; *nxt; ++nxt) {
170 			if (nxt >= &environment.data[ENV_SIZE]) {
171 				fprintf (stderr, "## Error: "
172 					"environment not terminated\n");
173 				return NULL;
174 			}
175 		}
176 		val = envmatch (name, env);
177 		if (!val)
178 			continue;
179 		return val;
180 	}
181 	return NULL;
182 }
183 
184 /*
185  * Search the default environment for a variable.
186  * Return the value, if found, or NULL, if not found.
187  */
188 char *fw_getdefenv(char *name)
189 {
190 	char *env, *nxt;
191 
192 	for (env = default_environment; *env; env = nxt + 1) {
193 		char *val;
194 
195 		for (nxt = env; *nxt; ++nxt) {
196 			if (nxt >= &default_environment[ENV_SIZE]) {
197 				fprintf(stderr, "## Error: "
198 					"default environment not terminated\n");
199 				return NULL;
200 			}
201 		}
202 		val = envmatch(name, env);
203 		if (!val)
204 			continue;
205 		return val;
206 	}
207 	return NULL;
208 }
209 
210 int parse_aes_key(char *key, uint8_t *bin_key)
211 {
212 	char tmp[5] = { '0', 'x', 0, 0, 0 };
213 	unsigned long ul;
214 	int i;
215 
216 	if (strnlen(key, 64) != 32) {
217 		fprintf(stderr,
218 			"## Error: '-a' option requires 16-byte AES key\n");
219 		return -1;
220 	}
221 
222 	for (i = 0; i < 16; i++) {
223 		tmp[2] = key[0];
224 		tmp[3] = key[1];
225 		errno = 0;
226 		ul = strtoul(tmp, NULL, 16);
227 		if (errno) {
228 			fprintf(stderr,
229 				"## Error: '-a' option requires valid AES key\n");
230 			return -1;
231 		}
232 		bin_key[i] = ul & 0xff;
233 		key += 2;
234 	}
235 	return 0;
236 }
237 
238 /*
239  * Print the current definition of one, or more, or all
240  * environment variables
241  */
242 int fw_printenv (int argc, char *argv[])
243 {
244 	char *env, *nxt;
245 	int i, rc = 0;
246 
247 	if (fw_env_open())
248 		return -1;
249 
250 	if (argc == 0) {		/* Print all env variables  */
251 		for (env = environment.data; *env; env = nxt + 1) {
252 			for (nxt = env; *nxt; ++nxt) {
253 				if (nxt >= &environment.data[ENV_SIZE]) {
254 					fprintf (stderr, "## Error: "
255 						"environment not terminated\n");
256 					return -1;
257 				}
258 			}
259 
260 			printf ("%s\n", env);
261 		}
262 		return 0;
263 	}
264 
265 	if (printenv_args.name_suppress && argc != 1) {
266 		fprintf(stderr,
267 			"## Error: `-n' option requires exactly one argument\n");
268 		return -1;
269 	}
270 
271 	for (i = 0; i < argc; ++i) {	/* print single env variables   */
272 		char *name = argv[i];
273 		char *val = NULL;
274 
275 		for (env = environment.data; *env; env = nxt + 1) {
276 
277 			for (nxt = env; *nxt; ++nxt) {
278 				if (nxt >= &environment.data[ENV_SIZE]) {
279 					fprintf (stderr, "## Error: "
280 						"environment not terminated\n");
281 					return -1;
282 				}
283 			}
284 			val = envmatch (name, env);
285 			if (val) {
286 				if (!printenv_args.name_suppress) {
287 					fputs (name, stdout);
288 					putc ('=', stdout);
289 				}
290 				puts (val);
291 				break;
292 			}
293 		}
294 		if (!val) {
295 			fprintf (stderr, "## Error: \"%s\" not defined\n", name);
296 			rc = -1;
297 		}
298 	}
299 
300 	return rc;
301 }
302 
303 int fw_env_close(void)
304 {
305 	int ret;
306 	if (common_args.aes_flag) {
307 		ret = env_aes_cbc_crypt(environment.data, 1);
308 		if (ret) {
309 			fprintf(stderr,
310 				"Error: can't encrypt env for flash\n");
311 			return ret;
312 		}
313 	}
314 
315 	/*
316 	 * Update CRC
317 	 */
318 	*environment.crc = crc32(0, (uint8_t *) environment.data, ENV_SIZE);
319 
320 	/* write environment back to flash */
321 	if (flash_io(O_RDWR)) {
322 		fprintf(stderr,
323 			"Error: can't write fw_env to flash\n");
324 			return -1;
325 	}
326 
327 	return 0;
328 }
329 
330 
331 /*
332  * Set/Clear a single variable in the environment.
333  * This is called in sequence to update the environment
334  * in RAM without updating the copy in flash after each set
335  */
336 int fw_env_write(char *name, char *value)
337 {
338 	int len;
339 	char *env, *nxt;
340 	char *oldval = NULL;
341 	int deleting, creating, overwriting;
342 
343 	/*
344 	 * search if variable with this name already exists
345 	 */
346 	for (nxt = env = environment.data; *env; env = nxt + 1) {
347 		for (nxt = env; *nxt; ++nxt) {
348 			if (nxt >= &environment.data[ENV_SIZE]) {
349 				fprintf(stderr, "## Error: "
350 					"environment not terminated\n");
351 				errno = EINVAL;
352 				return -1;
353 			}
354 		}
355 		if ((oldval = envmatch (name, env)) != NULL)
356 			break;
357 	}
358 
359 	deleting = (oldval && !(value && strlen(value)));
360 	creating = (!oldval && (value && strlen(value)));
361 	overwriting = (oldval && (value && strlen(value)));
362 
363 	/* check for permission */
364 	if (deleting) {
365 		if (env_flags_validate_varaccess(name,
366 		    ENV_FLAGS_VARACCESS_PREVENT_DELETE)) {
367 			printf("Can't delete \"%s\"\n", name);
368 			errno = EROFS;
369 			return -1;
370 		}
371 	} else if (overwriting) {
372 		if (env_flags_validate_varaccess(name,
373 		    ENV_FLAGS_VARACCESS_PREVENT_OVERWR)) {
374 			printf("Can't overwrite \"%s\"\n", name);
375 			errno = EROFS;
376 			return -1;
377 		} else if (env_flags_validate_varaccess(name,
378 		    ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR)) {
379 			const char *defval = fw_getdefenv(name);
380 
381 			if (defval == NULL)
382 				defval = "";
383 			if (strcmp(oldval, defval)
384 			    != 0) {
385 				printf("Can't overwrite \"%s\"\n", name);
386 				errno = EROFS;
387 				return -1;
388 			}
389 		}
390 	} else if (creating) {
391 		if (env_flags_validate_varaccess(name,
392 		    ENV_FLAGS_VARACCESS_PREVENT_CREATE)) {
393 			printf("Can't create \"%s\"\n", name);
394 			errno = EROFS;
395 			return -1;
396 		}
397 	} else
398 		/* Nothing to do */
399 		return 0;
400 
401 	if (deleting || overwriting) {
402 		if (*++nxt == '\0') {
403 			*env = '\0';
404 		} else {
405 			for (;;) {
406 				*env = *nxt++;
407 				if ((*env == '\0') && (*nxt == '\0'))
408 					break;
409 				++env;
410 			}
411 		}
412 		*++env = '\0';
413 	}
414 
415 	/* Delete only ? */
416 	if (!value || !strlen(value))
417 		return 0;
418 
419 	/*
420 	 * Append new definition at the end
421 	 */
422 	for (env = environment.data; *env || *(env + 1); ++env);
423 	if (env > environment.data)
424 		++env;
425 	/*
426 	 * Overflow when:
427 	 * "name" + "=" + "val" +"\0\0"  > CUR_ENVSIZE - (env-environment)
428 	 */
429 	len = strlen (name) + 2;
430 	/* add '=' for first arg, ' ' for all others */
431 	len += strlen(value) + 1;
432 
433 	if (len > (&environment.data[ENV_SIZE] - env)) {
434 		fprintf (stderr,
435 			"Error: environment overflow, \"%s\" deleted\n",
436 			name);
437 		return -1;
438 	}
439 
440 	while ((*env = *name++) != '\0')
441 		env++;
442 	*env = '=';
443 	while ((*++env = *value++) != '\0')
444 		;
445 
446 	/* end is marked with double '\0' */
447 	*++env = '\0';
448 
449 	return 0;
450 }
451 
452 /*
453  * Deletes or sets environment variables. Returns -1 and sets errno error codes:
454  * 0	  - OK
455  * EINVAL - need at least 1 argument
456  * EROFS  - certain variables ("ethaddr", "serial#") cannot be
457  *	    modified or deleted
458  *
459  */
460 int fw_setenv(int argc, char *argv[])
461 {
462 	int i;
463 	size_t len;
464 	char *name, **valv;
465 	char *value = NULL;
466 	int valc;
467 
468 	if (argc < 1) {
469 		fprintf(stderr, "## Error: variable name missing\n");
470 		errno = EINVAL;
471 		return -1;
472 	}
473 
474 	if (fw_env_open()) {
475 		fprintf(stderr, "Error: environment not initialized\n");
476 		return -1;
477 	}
478 
479 	name = argv[0];
480 	valv = argv + 1;
481 	valc = argc - 1;
482 
483 	if (env_flags_validate_env_set_params(name, valv, valc) < 0)
484 		return 1;
485 
486 	len = 0;
487 	for (i = 0; i < valc; ++i) {
488 		char *val = valv[i];
489 		size_t val_len = strlen(val);
490 
491 		if (value)
492 			value[len - 1] = ' ';
493 		value = realloc(value, len + val_len + 1);
494 		if (!value) {
495 			fprintf(stderr,
496 				"Cannot malloc %zu bytes: %s\n",
497 				len, strerror(errno));
498 			return -1;
499 		}
500 
501 		memcpy(value + len, val, val_len);
502 		len += val_len;
503 		value[len++] = '\0';
504 	}
505 
506 	fw_env_write(name, value);
507 
508 	free(value);
509 
510 	return fw_env_close();
511 }
512 
513 /*
514  * Parse  a file  and configure the u-boot variables.
515  * The script file has a very simple format, as follows:
516  *
517  * Each line has a couple with name, value:
518  * <white spaces>variable_name<white spaces>variable_value
519  *
520  * Both variable_name and variable_value are interpreted as strings.
521  * Any character after <white spaces> and before ending \r\n is interpreted
522  * as variable's value (no comment allowed on these lines !)
523  *
524  * Comments are allowed if the first character in the line is #
525  *
526  * Returns -1 and sets errno error codes:
527  * 0	  - OK
528  * -1     - Error
529  */
530 int fw_parse_script(char *fname)
531 {
532 	FILE *fp;
533 	char dump[1024];	/* Maximum line length in the file */
534 	char *name;
535 	char *val;
536 	int lineno = 0;
537 	int len;
538 	int ret = 0;
539 
540 	if (fw_env_open()) {
541 		fprintf(stderr, "Error: environment not initialized\n");
542 		return -1;
543 	}
544 
545 	if (strcmp(fname, "-") == 0)
546 		fp = stdin;
547 	else {
548 		fp = fopen(fname, "r");
549 		if (fp == NULL) {
550 			fprintf(stderr, "I cannot open %s for reading\n",
551 				 fname);
552 			return -1;
553 		}
554 	}
555 
556 	while (fgets(dump, sizeof(dump), fp)) {
557 		lineno++;
558 		len = strlen(dump);
559 
560 		/*
561 		 * Read a whole line from the file. If the line is too long
562 		 * or is not terminated, reports an error and exit.
563 		 */
564 		if (dump[len - 1] != '\n') {
565 			fprintf(stderr,
566 			"Line %d not corrected terminated or too long\n",
567 				lineno);
568 			ret = -1;
569 			break;
570 		}
571 
572 		/* Drop ending line feed / carriage return */
573 		dump[--len] = '\0';
574 		if (len && dump[len - 1] == '\r')
575 			dump[--len] = '\0';
576 
577 		/* Skip comment or empty lines */
578 		if (len == 0 || dump[0] == '#')
579 			continue;
580 
581 		/*
582 		 * Search for variable's name,
583 		 * remove leading whitespaces
584 		 */
585 		name = skip_blanks(dump);
586 		if (!name)
587 			continue;
588 
589 		/* The first white space is the end of variable name */
590 		val = skip_chars(name);
591 		len = strlen(name);
592 		if (val) {
593 			*val++ = '\0';
594 			if ((val - name) < len)
595 				val = skip_blanks(val);
596 			else
597 				val = NULL;
598 		}
599 
600 #ifdef DEBUG
601 		fprintf(stderr, "Setting %s : %s\n",
602 			name, val ? val : " removed");
603 #endif
604 
605 		if (env_flags_validate_type(name, val) < 0) {
606 			ret = -1;
607 			break;
608 		}
609 
610 		/*
611 		 * If there is an error setting a variable,
612 		 * try to save the environment and returns an error
613 		 */
614 		if (fw_env_write(name, val)) {
615 			fprintf(stderr,
616 			"fw_env_write returns with error : %s\n",
617 				strerror(errno));
618 			ret = -1;
619 			break;
620 		}
621 
622 	}
623 
624 	/* Close file if not stdin */
625 	if (strcmp(fname, "-") != 0)
626 		fclose(fp);
627 
628 	ret |= fw_env_close();
629 
630 	return ret;
631 
632 }
633 
634 /*
635  * Test for bad block on NAND, just returns 0 on NOR, on NAND:
636  * 0	- block is good
637  * > 0	- block is bad
638  * < 0	- failed to test
639  */
640 static int flash_bad_block (int fd, uint8_t mtd_type, loff_t *blockstart)
641 {
642 	if (mtd_type == MTD_NANDFLASH) {
643 		int badblock = ioctl (fd, MEMGETBADBLOCK, blockstart);
644 
645 		if (badblock < 0) {
646 			perror ("Cannot read bad block mark");
647 			return badblock;
648 		}
649 
650 		if (badblock) {
651 #ifdef DEBUG
652 			fprintf (stderr, "Bad block at 0x%llx, "
653 				 "skipping\n", *blockstart);
654 #endif
655 			return badblock;
656 		}
657 	}
658 
659 	return 0;
660 }
661 
662 /*
663  * Read data from flash at an offset into a provided buffer. On NAND it skips
664  * bad blocks but makes sure it stays within ENVSECTORS (dev) starting from
665  * the DEVOFFSET (dev) block. On NOR the loop is only run once.
666  */
667 static int flash_read_buf (int dev, int fd, void *buf, size_t count,
668 			   off_t offset, uint8_t mtd_type)
669 {
670 	size_t blocklen;	/* erase / write length - one block on NAND,
671 				   0 on NOR */
672 	size_t processed = 0;	/* progress counter */
673 	size_t readlen = count;	/* current read length */
674 	off_t top_of_range;	/* end of the last block we may use */
675 	off_t block_seek;	/* offset inside the current block to the start
676 				   of the data */
677 	loff_t blockstart;	/* running start of the current block -
678 				   MEMGETBADBLOCK needs 64 bits */
679 	int rc;
680 
681 	blockstart = (offset / DEVESIZE (dev)) * DEVESIZE (dev);
682 
683 	/* Offset inside a block */
684 	block_seek = offset - blockstart;
685 
686 	if (mtd_type == MTD_NANDFLASH) {
687 		/*
688 		 * NAND: calculate which blocks we are reading. We have
689 		 * to read one block at a time to skip bad blocks.
690 		 */
691 		blocklen = DEVESIZE (dev);
692 
693 		/*
694 		 * To calculate the top of the range, we have to use the
695 		 * global DEVOFFSET (dev), which can be different from offset
696 		 */
697 		top_of_range = ((DEVOFFSET(dev) / blocklen) +
698 				ENVSECTORS (dev)) * blocklen;
699 
700 		/* Limit to one block for the first read */
701 		if (readlen > blocklen - block_seek)
702 			readlen = blocklen - block_seek;
703 	} else {
704 		blocklen = 0;
705 		top_of_range = offset + count;
706 	}
707 
708 	/* This only runs once on NOR flash */
709 	while (processed < count) {
710 		rc = flash_bad_block (fd, mtd_type, &blockstart);
711 		if (rc < 0)		/* block test failed */
712 			return -1;
713 
714 		if (blockstart + block_seek + readlen > top_of_range) {
715 			/* End of range is reached */
716 			fprintf (stderr,
717 				 "Too few good blocks within range\n");
718 			return -1;
719 		}
720 
721 		if (rc) {		/* block is bad */
722 			blockstart += blocklen;
723 			continue;
724 		}
725 
726 		/*
727 		 * If a block is bad, we retry in the next block at the same
728 		 * offset - see common/env_nand.c::writeenv()
729 		 */
730 		lseek (fd, blockstart + block_seek, SEEK_SET);
731 
732 		rc = read (fd, buf + processed, readlen);
733 		if (rc != readlen) {
734 			fprintf (stderr, "Read error on %s: %s\n",
735 				 DEVNAME (dev), strerror (errno));
736 			return -1;
737 		}
738 #ifdef DEBUG
739 		fprintf(stderr, "Read 0x%x bytes at 0x%llx on %s\n",
740 			 rc, blockstart + block_seek, DEVNAME(dev));
741 #endif
742 		processed += readlen;
743 		readlen = min (blocklen, count - processed);
744 		block_seek = 0;
745 		blockstart += blocklen;
746 	}
747 
748 	return processed;
749 }
750 
751 /*
752  * Write count bytes at offset, but stay within ENVSECTORS (dev) sectors of
753  * DEVOFFSET (dev). Similar to the read case above, on NOR and dataflash we
754  * erase and write the whole data at once.
755  */
756 static int flash_write_buf (int dev, int fd, void *buf, size_t count,
757 			    off_t offset, uint8_t mtd_type)
758 {
759 	void *data;
760 	struct erase_info_user erase;
761 	size_t blocklen;	/* length of NAND block / NOR erase sector */
762 	size_t erase_len;	/* whole area that can be erased - may include
763 				   bad blocks */
764 	size_t erasesize;	/* erase / write length - one block on NAND,
765 				   whole area on NOR */
766 	size_t processed = 0;	/* progress counter */
767 	size_t write_total;	/* total size to actually write - excluding
768 				   bad blocks */
769 	off_t erase_offset;	/* offset to the first erase block (aligned)
770 				   below offset */
771 	off_t block_seek;	/* offset inside the erase block to the start
772 				   of the data */
773 	off_t top_of_range;	/* end of the last block we may use */
774 	loff_t blockstart;	/* running start of the current block -
775 				   MEMGETBADBLOCK needs 64 bits */
776 	int rc;
777 
778 	/*
779 	 * For mtd devices only offset and size of the environment do matter
780 	 */
781 	if (mtd_type == MTD_ABSENT) {
782 		blocklen = count;
783 		top_of_range = offset + count;
784 		erase_len = blocklen;
785 		blockstart = offset;
786 		block_seek = 0;
787 		write_total = blocklen;
788 	} else {
789 		blocklen = DEVESIZE(dev);
790 
791 		top_of_range = ((DEVOFFSET(dev) / blocklen) +
792 					ENVSECTORS(dev)) * blocklen;
793 
794 		erase_offset = (offset / blocklen) * blocklen;
795 
796 		/* Maximum area we may use */
797 		erase_len = top_of_range - erase_offset;
798 
799 		blockstart = erase_offset;
800 		/* Offset inside a block */
801 		block_seek = offset - erase_offset;
802 
803 		/*
804 		 * Data size we actually write: from the start of the block
805 		 * to the start of the data, then count bytes of data, and
806 		 * to the end of the block
807 		 */
808 		write_total = ((block_seek + count + blocklen - 1) /
809 							blocklen) * blocklen;
810 	}
811 
812 	/*
813 	 * Support data anywhere within erase sectors: read out the complete
814 	 * area to be erased, replace the environment image, write the whole
815 	 * block back again.
816 	 */
817 	if (write_total > count) {
818 		data = malloc (erase_len);
819 		if (!data) {
820 			fprintf (stderr,
821 				 "Cannot malloc %zu bytes: %s\n",
822 				 erase_len, strerror (errno));
823 			return -1;
824 		}
825 
826 		rc = flash_read_buf (dev, fd, data, write_total, erase_offset,
827 				     mtd_type);
828 		if (write_total != rc)
829 			return -1;
830 
831 #ifdef DEBUG
832 		fprintf(stderr, "Preserving data ");
833 		if (block_seek != 0)
834 			fprintf(stderr, "0x%x - 0x%lx", 0, block_seek - 1);
835 		if (block_seek + count != write_total) {
836 			if (block_seek != 0)
837 				fprintf(stderr, " and ");
838 			fprintf(stderr, "0x%lx - 0x%x",
839 				block_seek + count, write_total - 1);
840 		}
841 		fprintf(stderr, "\n");
842 #endif
843 		/* Overwrite the old environment */
844 		memcpy (data + block_seek, buf, count);
845 	} else {
846 		/*
847 		 * We get here, iff offset is block-aligned and count is a
848 		 * multiple of blocklen - see write_total calculation above
849 		 */
850 		data = buf;
851 	}
852 
853 	if (mtd_type == MTD_NANDFLASH) {
854 		/*
855 		 * NAND: calculate which blocks we are writing. We have
856 		 * to write one block at a time to skip bad blocks.
857 		 */
858 		erasesize = blocklen;
859 	} else {
860 		erasesize = erase_len;
861 	}
862 
863 	erase.length = erasesize;
864 
865 	/* This only runs once on NOR flash and SPI-dataflash */
866 	while (processed < write_total) {
867 		rc = flash_bad_block (fd, mtd_type, &blockstart);
868 		if (rc < 0)		/* block test failed */
869 			return rc;
870 
871 		if (blockstart + erasesize > top_of_range) {
872 			fprintf (stderr, "End of range reached, aborting\n");
873 			return -1;
874 		}
875 
876 		if (rc) {		/* block is bad */
877 			blockstart += blocklen;
878 			continue;
879 		}
880 
881 		if (mtd_type != MTD_ABSENT) {
882 			erase.start = blockstart;
883 			ioctl(fd, MEMUNLOCK, &erase);
884 			/* These do not need an explicit erase cycle */
885 			if (mtd_type != MTD_DATAFLASH)
886 				if (ioctl(fd, MEMERASE, &erase) != 0) {
887 					fprintf(stderr,
888 						"MTD erase error on %s: %s\n",
889 						DEVNAME(dev), strerror(errno));
890 					return -1;
891 				}
892 		}
893 
894 		if (lseek (fd, blockstart, SEEK_SET) == -1) {
895 			fprintf (stderr,
896 				 "Seek error on %s: %s\n",
897 				 DEVNAME (dev), strerror (errno));
898 			return -1;
899 		}
900 
901 #ifdef DEBUG
902 		fprintf(stderr, "Write 0x%x bytes at 0x%llx\n", erasesize,
903 			blockstart);
904 #endif
905 		if (write (fd, data + processed, erasesize) != erasesize) {
906 			fprintf (stderr, "Write error on %s: %s\n",
907 				 DEVNAME (dev), strerror (errno));
908 			return -1;
909 		}
910 
911 		if (mtd_type != MTD_ABSENT)
912 			ioctl(fd, MEMLOCK, &erase);
913 
914 		processed  += erasesize;
915 		block_seek = 0;
916 		blockstart += erasesize;
917 	}
918 
919 	if (write_total > count)
920 		free (data);
921 
922 	return processed;
923 }
924 
925 /*
926  * Set obsolete flag at offset - NOR flash only
927  */
928 static int flash_flag_obsolete (int dev, int fd, off_t offset)
929 {
930 	int rc;
931 	struct erase_info_user erase;
932 
933 	erase.start  = DEVOFFSET (dev);
934 	erase.length = DEVESIZE (dev);
935 	/* This relies on the fact, that obsolete_flag == 0 */
936 	rc = lseek (fd, offset, SEEK_SET);
937 	if (rc < 0) {
938 		fprintf (stderr, "Cannot seek to set the flag on %s \n",
939 			 DEVNAME (dev));
940 		return rc;
941 	}
942 	ioctl (fd, MEMUNLOCK, &erase);
943 	rc = write (fd, &obsolete_flag, sizeof (obsolete_flag));
944 	ioctl (fd, MEMLOCK, &erase);
945 	if (rc < 0)
946 		perror ("Could not set obsolete flag");
947 
948 	return rc;
949 }
950 
951 /* Encrypt or decrypt the environment before writing or reading it. */
952 static int env_aes_cbc_crypt(char *payload, const int enc)
953 {
954 	uint8_t *data = (uint8_t *)payload;
955 	const int len = getenvsize();
956 	uint8_t key_exp[AES_EXPAND_KEY_LENGTH];
957 	uint32_t aes_blocks;
958 
959 	/* First we expand the key. */
960 	aes_expand_key(common_args.aes_key, key_exp);
961 
962 	/* Calculate the number of AES blocks to encrypt. */
963 	aes_blocks = DIV_ROUND_UP(len, AES_KEY_LENGTH);
964 
965 	if (enc)
966 		aes_cbc_encrypt_blocks(key_exp, data, data, aes_blocks);
967 	else
968 		aes_cbc_decrypt_blocks(key_exp, data, data, aes_blocks);
969 
970 	return 0;
971 }
972 
973 static int flash_write (int fd_current, int fd_target, int dev_target)
974 {
975 	int rc;
976 
977 	switch (environment.flag_scheme) {
978 	case FLAG_NONE:
979 		break;
980 	case FLAG_INCREMENTAL:
981 		(*environment.flags)++;
982 		break;
983 	case FLAG_BOOLEAN:
984 		*environment.flags = active_flag;
985 		break;
986 	default:
987 		fprintf (stderr, "Unimplemented flash scheme %u \n",
988 			 environment.flag_scheme);
989 		return -1;
990 	}
991 
992 #ifdef DEBUG
993 	fprintf(stderr, "Writing new environment at 0x%lx on %s\n",
994 		DEVOFFSET (dev_target), DEVNAME (dev_target));
995 #endif
996 
997 	rc = flash_write_buf(dev_target, fd_target, environment.image,
998 			      CUR_ENVSIZE, DEVOFFSET(dev_target),
999 			      DEVTYPE(dev_target));
1000 	if (rc < 0)
1001 		return rc;
1002 
1003 	if (environment.flag_scheme == FLAG_BOOLEAN) {
1004 		/* Have to set obsolete flag */
1005 		off_t offset = DEVOFFSET (dev_current) +
1006 			offsetof (struct env_image_redundant, flags);
1007 #ifdef DEBUG
1008 		fprintf(stderr,
1009 			"Setting obsolete flag in environment at 0x%lx on %s\n",
1010 			DEVOFFSET (dev_current), DEVNAME (dev_current));
1011 #endif
1012 		flash_flag_obsolete (dev_current, fd_current, offset);
1013 	}
1014 
1015 	return 0;
1016 }
1017 
1018 static int flash_read (int fd)
1019 {
1020 	struct mtd_info_user mtdinfo;
1021 	struct stat st;
1022 	int rc;
1023 
1024 	rc = fstat(fd, &st);
1025 	if (rc < 0) {
1026 		fprintf(stderr, "Cannot stat the file %s\n",
1027 			DEVNAME(dev_current));
1028 		return -1;
1029 	}
1030 
1031 	if (S_ISCHR(st.st_mode)) {
1032 		rc = ioctl(fd, MEMGETINFO, &mtdinfo);
1033 		if (rc < 0) {
1034 			fprintf(stderr, "Cannot get MTD information for %s\n",
1035 				DEVNAME(dev_current));
1036 			return -1;
1037 		}
1038 		if (mtdinfo.type != MTD_NORFLASH &&
1039 		    mtdinfo.type != MTD_NANDFLASH &&
1040 		    mtdinfo.type != MTD_DATAFLASH &&
1041 		    mtdinfo.type != MTD_UBIVOLUME) {
1042 			fprintf (stderr, "Unsupported flash type %u on %s\n",
1043 				 mtdinfo.type, DEVNAME(dev_current));
1044 			return -1;
1045 		}
1046 	} else {
1047 		memset(&mtdinfo, 0, sizeof(mtdinfo));
1048 		mtdinfo.type = MTD_ABSENT;
1049 	}
1050 
1051 	DEVTYPE(dev_current) = mtdinfo.type;
1052 
1053 	rc = flash_read_buf(dev_current, fd, environment.image, CUR_ENVSIZE,
1054 			     DEVOFFSET (dev_current), mtdinfo.type);
1055 	if (rc != CUR_ENVSIZE)
1056 		return -1;
1057 
1058 	return 0;
1059 }
1060 
1061 static int flash_io (int mode)
1062 {
1063 	int fd_current, fd_target, rc, dev_target;
1064 
1065 	/* dev_current: fd_current, erase_current */
1066 	fd_current = open (DEVNAME (dev_current), mode);
1067 	if (fd_current < 0) {
1068 		fprintf (stderr,
1069 			 "Can't open %s: %s\n",
1070 			 DEVNAME (dev_current), strerror (errno));
1071 		return -1;
1072 	}
1073 
1074 	if (mode == O_RDWR) {
1075 		if (HaveRedundEnv) {
1076 			/* switch to next partition for writing */
1077 			dev_target = !dev_current;
1078 			/* dev_target: fd_target, erase_target */
1079 			fd_target = open (DEVNAME (dev_target), mode);
1080 			if (fd_target < 0) {
1081 				fprintf (stderr,
1082 					 "Can't open %s: %s\n",
1083 					 DEVNAME (dev_target),
1084 					 strerror (errno));
1085 				rc = -1;
1086 				goto exit;
1087 			}
1088 		} else {
1089 			dev_target = dev_current;
1090 			fd_target = fd_current;
1091 		}
1092 
1093 		rc = flash_write (fd_current, fd_target, dev_target);
1094 
1095 		if (HaveRedundEnv) {
1096 			if (close (fd_target)) {
1097 				fprintf (stderr,
1098 					"I/O error on %s: %s\n",
1099 					DEVNAME (dev_target),
1100 					strerror (errno));
1101 				rc = -1;
1102 			}
1103 		}
1104 	} else {
1105 		rc = flash_read (fd_current);
1106 	}
1107 
1108 exit:
1109 	if (close (fd_current)) {
1110 		fprintf (stderr,
1111 			 "I/O error on %s: %s\n",
1112 			 DEVNAME (dev_current), strerror (errno));
1113 		return -1;
1114 	}
1115 
1116 	return rc;
1117 }
1118 
1119 /*
1120  * s1 is either a simple 'name', or a 'name=value' pair.
1121  * s2 is a 'name=value' pair.
1122  * If the names match, return the value of s2, else NULL.
1123  */
1124 
1125 static char *envmatch (char * s1, char * s2)
1126 {
1127 	if (s1 == NULL || s2 == NULL)
1128 		return NULL;
1129 
1130 	while (*s1 == *s2++)
1131 		if (*s1++ == '=')
1132 			return s2;
1133 	if (*s1 == '\0' && *(s2 - 1) == '=')
1134 		return s2;
1135 	return NULL;
1136 }
1137 
1138 /*
1139  * Prevent confusion if running from erased flash memory
1140  */
1141 int fw_env_open(void)
1142 {
1143 	int crc0, crc0_ok;
1144 	unsigned char flag0;
1145 	void *addr0;
1146 
1147 	int crc1, crc1_ok;
1148 	unsigned char flag1;
1149 	void *addr1;
1150 
1151 	int ret;
1152 
1153 	struct env_image_single *single;
1154 	struct env_image_redundant *redundant;
1155 
1156 	if (parse_config ())		/* should fill envdevices */
1157 		return -1;
1158 
1159 	addr0 = calloc(1, CUR_ENVSIZE);
1160 	if (addr0 == NULL) {
1161 		fprintf(stderr,
1162 			"Not enough memory for environment (%ld bytes)\n",
1163 			CUR_ENVSIZE);
1164 		return -1;
1165 	}
1166 
1167 	/* read environment from FLASH to local buffer */
1168 	environment.image = addr0;
1169 
1170 	if (HaveRedundEnv) {
1171 		redundant = addr0;
1172 		environment.crc		= &redundant->crc;
1173 		environment.flags	= &redundant->flags;
1174 		environment.data	= redundant->data;
1175 	} else {
1176 		single = addr0;
1177 		environment.crc		= &single->crc;
1178 		environment.flags	= NULL;
1179 		environment.data	= single->data;
1180 	}
1181 
1182 	dev_current = 0;
1183 	if (flash_io (O_RDONLY))
1184 		return -1;
1185 
1186 	crc0 = crc32 (0, (uint8_t *) environment.data, ENV_SIZE);
1187 
1188 	if (common_args.aes_flag) {
1189 		ret = env_aes_cbc_crypt(environment.data, 0);
1190 		if (ret)
1191 			return ret;
1192 	}
1193 
1194 	crc0_ok = (crc0 == *environment.crc);
1195 	if (!HaveRedundEnv) {
1196 		if (!crc0_ok) {
1197 			fprintf (stderr,
1198 				"Warning: Bad CRC, using default environment\n");
1199 			memcpy(environment.data, default_environment, sizeof default_environment);
1200 		}
1201 	} else {
1202 		flag0 = *environment.flags;
1203 
1204 		dev_current = 1;
1205 		addr1 = calloc(1, CUR_ENVSIZE);
1206 		if (addr1 == NULL) {
1207 			fprintf(stderr,
1208 				"Not enough memory for environment (%ld bytes)\n",
1209 				CUR_ENVSIZE);
1210 			return -1;
1211 		}
1212 		redundant = addr1;
1213 
1214 		/*
1215 		 * have to set environment.image for flash_read(), careful -
1216 		 * other pointers in environment still point inside addr0
1217 		 */
1218 		environment.image = addr1;
1219 		if (flash_io (O_RDONLY))
1220 			return -1;
1221 
1222 		/* Check flag scheme compatibility */
1223 		if (DEVTYPE(dev_current) == MTD_NORFLASH &&
1224 		    DEVTYPE(!dev_current) == MTD_NORFLASH) {
1225 			environment.flag_scheme = FLAG_BOOLEAN;
1226 		} else if (DEVTYPE(dev_current) == MTD_NANDFLASH &&
1227 			   DEVTYPE(!dev_current) == MTD_NANDFLASH) {
1228 			environment.flag_scheme = FLAG_INCREMENTAL;
1229 		} else if (DEVTYPE(dev_current) == MTD_DATAFLASH &&
1230 			   DEVTYPE(!dev_current) == MTD_DATAFLASH) {
1231 			environment.flag_scheme = FLAG_BOOLEAN;
1232 		} else if (DEVTYPE(dev_current) == MTD_UBIVOLUME &&
1233 			   DEVTYPE(!dev_current) == MTD_UBIVOLUME) {
1234 			environment.flag_scheme = FLAG_INCREMENTAL;
1235 		} else if (DEVTYPE(dev_current) == MTD_ABSENT &&
1236 			   DEVTYPE(!dev_current) == MTD_ABSENT) {
1237 			environment.flag_scheme = FLAG_INCREMENTAL;
1238 		} else {
1239 			fprintf (stderr, "Incompatible flash types!\n");
1240 			return -1;
1241 		}
1242 
1243 		crc1 = crc32 (0, (uint8_t *) redundant->data, ENV_SIZE);
1244 
1245 		if (common_args.aes_flag) {
1246 			ret = env_aes_cbc_crypt(redundant->data, 0);
1247 			if (ret)
1248 				return ret;
1249 		}
1250 
1251 		crc1_ok = (crc1 == redundant->crc);
1252 		flag1 = redundant->flags;
1253 
1254 		if (crc0_ok && !crc1_ok) {
1255 			dev_current = 0;
1256 		} else if (!crc0_ok && crc1_ok) {
1257 			dev_current = 1;
1258 		} else if (!crc0_ok && !crc1_ok) {
1259 			fprintf (stderr,
1260 				"Warning: Bad CRC, using default environment\n");
1261 			memcpy (environment.data, default_environment,
1262 				sizeof default_environment);
1263 			dev_current = 0;
1264 		} else {
1265 			switch (environment.flag_scheme) {
1266 			case FLAG_BOOLEAN:
1267 				if (flag0 == active_flag &&
1268 				    flag1 == obsolete_flag) {
1269 					dev_current = 0;
1270 				} else if (flag0 == obsolete_flag &&
1271 					   flag1 == active_flag) {
1272 					dev_current = 1;
1273 				} else if (flag0 == flag1) {
1274 					dev_current = 0;
1275 				} else if (flag0 == 0xFF) {
1276 					dev_current = 0;
1277 				} else if (flag1 == 0xFF) {
1278 					dev_current = 1;
1279 				} else {
1280 					dev_current = 0;
1281 				}
1282 				break;
1283 			case FLAG_INCREMENTAL:
1284 				if (flag0 == 255 && flag1 == 0)
1285 					dev_current = 1;
1286 				else if ((flag1 == 255 && flag0 == 0) ||
1287 					 flag0 >= flag1)
1288 					dev_current = 0;
1289 				else /* flag1 > flag0 */
1290 					dev_current = 1;
1291 				break;
1292 			default:
1293 				fprintf (stderr, "Unknown flag scheme %u \n",
1294 					 environment.flag_scheme);
1295 				return -1;
1296 			}
1297 		}
1298 
1299 		/*
1300 		 * If we are reading, we don't need the flag and the CRC any
1301 		 * more, if we are writing, we will re-calculate CRC and update
1302 		 * flags before writing out
1303 		 */
1304 		if (dev_current) {
1305 			environment.image	= addr1;
1306 			environment.crc		= &redundant->crc;
1307 			environment.flags	= &redundant->flags;
1308 			environment.data	= redundant->data;
1309 			free (addr0);
1310 		} else {
1311 			environment.image	= addr0;
1312 			/* Other pointers are already set */
1313 			free (addr1);
1314 		}
1315 #ifdef DEBUG
1316 		fprintf(stderr, "Selected env in %s\n", DEVNAME(dev_current));
1317 #endif
1318 	}
1319 	return 0;
1320 }
1321 
1322 
1323 static int parse_config ()
1324 {
1325 	struct stat st;
1326 
1327 #if defined(CONFIG_FILE)
1328 	if (!common_args.config_file)
1329 		common_args.config_file = CONFIG_FILE;
1330 
1331 	/* Fills in DEVNAME(), ENVSIZE(), DEVESIZE(). Or don't. */
1332 	if (get_config(common_args.config_file)) {
1333 		fprintf(stderr, "Cannot parse config file '%s': %m\n",
1334 			common_args.config_file);
1335 		return -1;
1336 	}
1337 #else
1338 	DEVNAME (0) = DEVICE1_NAME;
1339 	DEVOFFSET (0) = DEVICE1_OFFSET;
1340 	ENVSIZE (0) = ENV1_SIZE;
1341 	/* Default values are: erase-size=env-size */
1342 	DEVESIZE (0) = ENVSIZE (0);
1343 	/* #sectors=env-size/erase-size (rounded up) */
1344 	ENVSECTORS (0) = (ENVSIZE(0) + DEVESIZE(0) - 1) / DEVESIZE(0);
1345 #ifdef DEVICE1_ESIZE
1346 	DEVESIZE (0) = DEVICE1_ESIZE;
1347 #endif
1348 #ifdef DEVICE1_ENVSECTORS
1349 	ENVSECTORS (0) = DEVICE1_ENVSECTORS;
1350 #endif
1351 
1352 #ifdef HAVE_REDUND
1353 	DEVNAME (1) = DEVICE2_NAME;
1354 	DEVOFFSET (1) = DEVICE2_OFFSET;
1355 	ENVSIZE (1) = ENV2_SIZE;
1356 	/* Default values are: erase-size=env-size */
1357 	DEVESIZE (1) = ENVSIZE (1);
1358 	/* #sectors=env-size/erase-size (rounded up) */
1359 	ENVSECTORS (1) = (ENVSIZE(1) + DEVESIZE(1) - 1) / DEVESIZE(1);
1360 #ifdef DEVICE2_ESIZE
1361 	DEVESIZE (1) = DEVICE2_ESIZE;
1362 #endif
1363 #ifdef DEVICE2_ENVSECTORS
1364 	ENVSECTORS (1) = DEVICE2_ENVSECTORS;
1365 #endif
1366 	HaveRedundEnv = 1;
1367 #endif
1368 #endif
1369 	if (stat (DEVNAME (0), &st)) {
1370 		fprintf (stderr,
1371 			"Cannot access MTD device %s: %s\n",
1372 			DEVNAME (0), strerror (errno));
1373 		return -1;
1374 	}
1375 
1376 	if (HaveRedundEnv && stat (DEVNAME (1), &st)) {
1377 		fprintf (stderr,
1378 			"Cannot access MTD device %s: %s\n",
1379 			DEVNAME (1), strerror (errno));
1380 		return -1;
1381 	}
1382 	return 0;
1383 }
1384 
1385 #if defined(CONFIG_FILE)
1386 static int get_config (char *fname)
1387 {
1388 	FILE *fp;
1389 	int i = 0;
1390 	int rc;
1391 	char dump[128];
1392 	char *devname;
1393 
1394 	fp = fopen (fname, "r");
1395 	if (fp == NULL)
1396 		return -1;
1397 
1398 	while (i < 2 && fgets (dump, sizeof (dump), fp)) {
1399 		/* Skip incomplete conversions and comment strings */
1400 		if (dump[0] == '#')
1401 			continue;
1402 
1403 		rc = sscanf (dump, "%ms %lx %lx %lx %lx",
1404 			     &devname,
1405 			     &DEVOFFSET (i),
1406 			     &ENVSIZE (i),
1407 			     &DEVESIZE (i),
1408 			     &ENVSECTORS (i));
1409 
1410 		if (rc < 3)
1411 			continue;
1412 
1413 		DEVNAME(i) = devname;
1414 
1415 		if (rc < 4)
1416 			/* Assume the erase size is the same as the env-size */
1417 			DEVESIZE(i) = ENVSIZE(i);
1418 
1419 		if (rc < 5)
1420 			/* Assume enough env sectors to cover the environment */
1421 			ENVSECTORS (i) = (ENVSIZE(i) + DEVESIZE(i) - 1) / DEVESIZE(i);
1422 
1423 		i++;
1424 	}
1425 	fclose (fp);
1426 
1427 	HaveRedundEnv = i - 1;
1428 	if (!i) {			/* No valid entries found */
1429 		errno = EINVAL;
1430 		return -1;
1431 	} else
1432 		return 0;
1433 }
1434 #endif
1435