xref: /openbmc/u-boot/tools/env/fw_env.c (revision 48263504)
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 #include <dirent.h>
29 
30 #ifdef MTD_OLD
31 # include <stdint.h>
32 # include <linux/mtd/mtd.h>
33 #else
34 # define  __user	/* nothing */
35 # include <mtd/mtd-user.h>
36 #endif
37 
38 #include <mtd/ubi-user.h>
39 
40 #include "fw_env_private.h"
41 #include "fw_env.h"
42 
43 struct env_opts default_opts = {
44 #ifdef CONFIG_FILE
45 	.config_file = CONFIG_FILE
46 #endif
47 };
48 
49 #define DIV_ROUND_UP(n, d)	(((n) + (d) - 1) / (d))
50 
51 #define min(x, y) ({				\
52 	typeof(x) _min1 = (x);			\
53 	typeof(y) _min2 = (y);			\
54 	(void) (&_min1 == &_min2);		\
55 	_min1 < _min2 ? _min1 : _min2; })
56 
57 struct envdev_s {
58 	const char *devname;		/* Device name */
59 	long long devoff;		/* Device offset */
60 	ulong env_size;			/* environment size */
61 	ulong erase_size;		/* device erase size */
62 	ulong env_sectors;		/* number of environment sectors */
63 	uint8_t mtd_type;		/* type of the MTD device */
64 	int is_ubi;			/* set if we use UBI volume */
65 };
66 
67 static struct envdev_s envdevices[2] =
68 {
69 	{
70 		.mtd_type = MTD_ABSENT,
71 	}, {
72 		.mtd_type = MTD_ABSENT,
73 	},
74 };
75 static int dev_current;
76 
77 #define DEVNAME(i)    envdevices[(i)].devname
78 #define DEVOFFSET(i)  envdevices[(i)].devoff
79 #define ENVSIZE(i)    envdevices[(i)].env_size
80 #define DEVESIZE(i)   envdevices[(i)].erase_size
81 #define ENVSECTORS(i) envdevices[(i)].env_sectors
82 #define DEVTYPE(i)    envdevices[(i)].mtd_type
83 #define IS_UBI(i)     envdevices[(i)].is_ubi
84 
85 #define CUR_ENVSIZE ENVSIZE(dev_current)
86 
87 static unsigned long usable_envsize;
88 #define ENV_SIZE      usable_envsize
89 
90 struct env_image_single {
91 	uint32_t	crc;	/* CRC32 over data bytes    */
92 	char		data[];
93 };
94 
95 struct env_image_redundant {
96 	uint32_t	crc;	/* CRC32 over data bytes    */
97 	unsigned char	flags;	/* active or obsolete */
98 	char		data[];
99 };
100 
101 enum flag_scheme {
102 	FLAG_NONE,
103 	FLAG_BOOLEAN,
104 	FLAG_INCREMENTAL,
105 };
106 
107 struct environment {
108 	void			*image;
109 	uint32_t		*crc;
110 	unsigned char		*flags;
111 	char			*data;
112 	enum flag_scheme	flag_scheme;
113 };
114 
115 static struct environment environment = {
116 	.flag_scheme = FLAG_NONE,
117 };
118 
119 static int HaveRedundEnv = 0;
120 
121 static unsigned char active_flag = 1;
122 /* obsolete_flag must be 0 to efficiently set it on NOR flash without erasing */
123 static unsigned char obsolete_flag = 0;
124 
125 #define DEFAULT_ENV_INSTANCE_STATIC
126 #include <env_default.h>
127 
128 #define UBI_DEV_START "/dev/ubi"
129 #define UBI_SYSFS "/sys/class/ubi"
130 #define UBI_VOL_NAME_PATT "ubi%d_%d"
131 
132 static int is_ubi_devname(const char *devname)
133 {
134 	return !strncmp(devname, UBI_DEV_START, sizeof(UBI_DEV_START) - 1);
135 }
136 
137 static int ubi_check_volume_sysfs_name(const char *volume_sysfs_name,
138 				       const char *volname)
139 {
140 	char path[256];
141 	FILE *file;
142 	char *name;
143 	int ret;
144 
145 	strcpy(path, UBI_SYSFS "/");
146 	strcat(path, volume_sysfs_name);
147 	strcat(path, "/name");
148 
149 	file = fopen(path, "r");
150 	if (!file)
151 		return -1;
152 
153 	ret = fscanf(file, "%ms", &name);
154 	fclose(file);
155 	if (ret <= 0 || !name) {
156 		fprintf(stderr,
157 			"Failed to read from file %s, ret = %d, name = %s\n",
158 			path, ret, name);
159 		return -1;
160 	}
161 
162 	if (!strcmp(name, volname)) {
163 		free(name);
164 		return 0;
165 	}
166 	free(name);
167 
168 	return -1;
169 }
170 
171 static int ubi_get_volnum_by_name(int devnum, const char *volname)
172 {
173 	DIR *sysfs_ubi;
174 	struct dirent *dirent;
175 	int ret;
176 	int tmp_devnum;
177 	int volnum;
178 
179 	sysfs_ubi = opendir(UBI_SYSFS);
180 	if (!sysfs_ubi)
181 		return -1;
182 
183 #ifdef DEBUG
184 	fprintf(stderr, "Looking for volume name \"%s\"\n", volname);
185 #endif
186 
187 	while (1) {
188 		dirent = readdir(sysfs_ubi);
189 		if (!dirent)
190 			return -1;
191 
192 		ret = sscanf(dirent->d_name, UBI_VOL_NAME_PATT,
193 			     &tmp_devnum, &volnum);
194 		if (ret == 2 && devnum == tmp_devnum) {
195 			if (ubi_check_volume_sysfs_name(dirent->d_name,
196 							volname) == 0)
197 				return volnum;
198 		}
199 	}
200 
201 	return -1;
202 }
203 
204 static int ubi_get_devnum_by_devname(const char *devname)
205 {
206 	int devnum;
207 	int ret;
208 
209 	ret = sscanf(devname + sizeof(UBI_DEV_START) - 1, "%d", &devnum);
210 	if (ret != 1)
211 		return -1;
212 
213 	return devnum;
214 }
215 
216 static const char *ubi_get_volume_devname(const char *devname,
217 					  const char *volname)
218 {
219 	char *volume_devname;
220 	int volnum;
221 	int devnum;
222 	int ret;
223 
224 	devnum = ubi_get_devnum_by_devname(devname);
225 	if (devnum < 0)
226 		return NULL;
227 
228 	volnum = ubi_get_volnum_by_name(devnum, volname);
229 	if (volnum < 0)
230 		return NULL;
231 
232 	ret = asprintf(&volume_devname, "%s_%d", devname, volnum);
233 	if (ret < 0)
234 		return NULL;
235 
236 #ifdef DEBUG
237 	fprintf(stderr, "Found ubi volume \"%s:%s\" -> %s\n",
238 		devname, volname, volume_devname);
239 #endif
240 
241 	return volume_devname;
242 }
243 
244 static void ubi_check_dev(unsigned int dev_id)
245 {
246 	char *devname = (char *)DEVNAME(dev_id);
247 	char *pname;
248 	const char *volname = NULL;
249 	const char *volume_devname;
250 
251 	if (!is_ubi_devname(DEVNAME(dev_id)))
252 		return;
253 
254 	IS_UBI(dev_id) = 1;
255 
256 	for (pname = devname; *pname != '\0'; pname++) {
257 		if (*pname == ':') {
258 			*pname = '\0';
259 			volname = pname + 1;
260 			break;
261 		}
262 	}
263 
264 	if (volname) {
265 		/* Let's find real volume device name */
266 		volume_devname = ubi_get_volume_devname(devname, volname);
267 		if (!volume_devname) {
268 			fprintf(stderr, "Didn't found ubi volume \"%s\"\n",
269 				volname);
270 			return;
271 		}
272 
273 		free(devname);
274 		DEVNAME(dev_id) = volume_devname;
275 	}
276 }
277 
278 static int ubi_update_start(int fd, int64_t bytes)
279 {
280 	if (ioctl(fd, UBI_IOCVOLUP, &bytes))
281 		return -1;
282 	return 0;
283 }
284 
285 static int ubi_read(int fd, void *buf, size_t count)
286 {
287 	ssize_t ret;
288 
289 	while (count > 0) {
290 		ret = read(fd, buf, count);
291 		if (ret > 0) {
292 			count -= ret;
293 			buf += ret;
294 
295 			continue;
296 		}
297 
298 		if (ret == 0) {
299 			/*
300 			 * Happens in case of too short volume data size. If we
301 			 * return error status we will fail it will be treated
302 			 * as UBI device error.
303 			 *
304 			 * Leave catching this error to CRC check.
305 			 */
306 			fprintf(stderr, "Warning: end of data on ubi volume\n");
307 			return 0;
308 		} else if (errno == EBADF) {
309 			/*
310 			 * Happens in case of corrupted volume. The same as
311 			 * above, we cannot return error now, as we will still
312 			 * be able to successfully write environment later.
313 			 */
314 			fprintf(stderr, "Warning: corrupted volume?\n");
315 			return 0;
316 		} else if (errno == EINTR) {
317 			continue;
318 		}
319 
320 		fprintf(stderr, "Cannot read %u bytes from ubi volume, %s\n",
321 			(unsigned int)count, strerror(errno));
322 		return -1;
323 	}
324 
325 	return 0;
326 }
327 
328 static int ubi_write(int fd, const void *buf, size_t count)
329 {
330 	ssize_t ret;
331 
332 	while (count > 0) {
333 		ret = write(fd, buf, count);
334 		if (ret <= 0) {
335 			if (ret < 0 && errno == EINTR)
336 				continue;
337 
338 			fprintf(stderr, "Cannot write %u bytes to ubi volume\n",
339 				(unsigned int)count);
340 			return -1;
341 		}
342 
343 		count -= ret;
344 		buf += ret;
345 	}
346 
347 	return 0;
348 }
349 
350 static int flash_io (int mode);
351 static int parse_config(struct env_opts *opts);
352 
353 #if defined(CONFIG_FILE)
354 static int get_config (char *);
355 #endif
356 
357 static char *skip_chars(char *s)
358 {
359 	for (; *s != '\0'; s++) {
360 		if (isblank(*s))
361 			return s;
362 	}
363 	return NULL;
364 }
365 
366 static char *skip_blanks(char *s)
367 {
368 	for (; *s != '\0'; s++) {
369 		if (!isblank(*s))
370 			return s;
371 	}
372 	return NULL;
373 }
374 
375 /*
376  * s1 is either a simple 'name', or a 'name=value' pair.
377  * s2 is a 'name=value' pair.
378  * If the names match, return the value of s2, else NULL.
379  */
380 static char *envmatch(char *s1, char *s2)
381 {
382 	if (s1 == NULL || s2 == NULL)
383 		return NULL;
384 
385 	while (*s1 == *s2++)
386 		if (*s1++ == '=')
387 			return s2;
388 	if (*s1 == '\0' && *(s2 - 1) == '=')
389 		return s2;
390 	return NULL;
391 }
392 
393 /**
394  * Search the environment for a variable.
395  * Return the value, if found, or NULL, if not found.
396  */
397 char *fw_getenv (char *name)
398 {
399 	char *env, *nxt;
400 
401 	for (env = environment.data; *env; env = nxt + 1) {
402 		char *val;
403 
404 		for (nxt = env; *nxt; ++nxt) {
405 			if (nxt >= &environment.data[ENV_SIZE]) {
406 				fprintf (stderr, "## Error: "
407 					"environment not terminated\n");
408 				return NULL;
409 			}
410 		}
411 		val = envmatch (name, env);
412 		if (!val)
413 			continue;
414 		return val;
415 	}
416 	return NULL;
417 }
418 
419 /*
420  * Search the default environment for a variable.
421  * Return the value, if found, or NULL, if not found.
422  */
423 char *fw_getdefenv(char *name)
424 {
425 	char *env, *nxt;
426 
427 	for (env = default_environment; *env; env = nxt + 1) {
428 		char *val;
429 
430 		for (nxt = env; *nxt; ++nxt) {
431 			if (nxt >= &default_environment[ENV_SIZE]) {
432 				fprintf(stderr, "## Error: "
433 					"default environment not terminated\n");
434 				return NULL;
435 			}
436 		}
437 		val = envmatch(name, env);
438 		if (!val)
439 			continue;
440 		return val;
441 	}
442 	return NULL;
443 }
444 
445 /*
446  * Print the current definition of one, or more, or all
447  * environment variables
448  */
449 int fw_printenv(int argc, char *argv[], int value_only, struct env_opts *opts)
450 {
451 	int i, rc = 0;
452 
453 	if (value_only && argc != 1) {
454 		fprintf(stderr,
455 			"## Error: `-n' option requires exactly one argument\n");
456 		return -1;
457 	}
458 
459 	if (!opts)
460 		opts = &default_opts;
461 
462 	if (fw_env_open(opts))
463 		return -1;
464 
465 	if (argc == 0) {		/* Print all env variables  */
466 		char *env, *nxt;
467 		for (env = environment.data; *env; env = nxt + 1) {
468 			for (nxt = env; *nxt; ++nxt) {
469 				if (nxt >= &environment.data[ENV_SIZE]) {
470 					fprintf (stderr, "## Error: "
471 						"environment not terminated\n");
472 					return -1;
473 				}
474 			}
475 
476 			printf ("%s\n", env);
477 		}
478 		fw_env_close(opts);
479 		return 0;
480 	}
481 
482 	for (i = 0; i < argc; ++i) {	/* print a subset of env variables */
483 		char *name = argv[i];
484 		char *val = NULL;
485 
486 		val = fw_getenv(name);
487 		if (!val) {
488 			fprintf (stderr, "## Error: \"%s\" not defined\n", name);
489 			rc = -1;
490 			continue;
491 		}
492 
493 		if (value_only) {
494 			puts(val);
495 			break;
496 		}
497 
498 		printf("%s=%s\n", name, val);
499 	}
500 
501 	fw_env_close(opts);
502 
503 	return rc;
504 }
505 
506 int fw_env_flush(struct env_opts *opts)
507 {
508 	int ret;
509 
510 	if (!opts)
511 		opts = &default_opts;
512 
513 	/*
514 	 * Update CRC
515 	 */
516 	*environment.crc = crc32(0, (uint8_t *) environment.data, ENV_SIZE);
517 
518 	/* write environment back to flash */
519 	if (flash_io(O_RDWR)) {
520 		fprintf(stderr,
521 			"Error: can't write fw_env to flash\n");
522 			return -1;
523 	}
524 
525 	return 0;
526 }
527 
528 
529 /*
530  * Set/Clear a single variable in the environment.
531  * This is called in sequence to update the environment
532  * in RAM without updating the copy in flash after each set
533  */
534 int fw_env_write(char *name, char *value)
535 {
536 	int len;
537 	char *env, *nxt;
538 	char *oldval = NULL;
539 	int deleting, creating, overwriting;
540 
541 	/*
542 	 * search if variable with this name already exists
543 	 */
544 	for (nxt = env = environment.data; *env; env = nxt + 1) {
545 		for (nxt = env; *nxt; ++nxt) {
546 			if (nxt >= &environment.data[ENV_SIZE]) {
547 				fprintf(stderr, "## Error: "
548 					"environment not terminated\n");
549 				errno = EINVAL;
550 				return -1;
551 			}
552 		}
553 		if ((oldval = envmatch (name, env)) != NULL)
554 			break;
555 	}
556 
557 	deleting = (oldval && !(value && strlen(value)));
558 	creating = (!oldval && (value && strlen(value)));
559 	overwriting = (oldval && (value && strlen(value)));
560 
561 	/* check for permission */
562 	if (deleting) {
563 		if (env_flags_validate_varaccess(name,
564 		    ENV_FLAGS_VARACCESS_PREVENT_DELETE)) {
565 			printf("Can't delete \"%s\"\n", name);
566 			errno = EROFS;
567 			return -1;
568 		}
569 	} else if (overwriting) {
570 		if (env_flags_validate_varaccess(name,
571 		    ENV_FLAGS_VARACCESS_PREVENT_OVERWR)) {
572 			printf("Can't overwrite \"%s\"\n", name);
573 			errno = EROFS;
574 			return -1;
575 		} else if (env_flags_validate_varaccess(name,
576 		    ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR)) {
577 			const char *defval = fw_getdefenv(name);
578 
579 			if (defval == NULL)
580 				defval = "";
581 			if (strcmp(oldval, defval)
582 			    != 0) {
583 				printf("Can't overwrite \"%s\"\n", name);
584 				errno = EROFS;
585 				return -1;
586 			}
587 		}
588 	} else if (creating) {
589 		if (env_flags_validate_varaccess(name,
590 		    ENV_FLAGS_VARACCESS_PREVENT_CREATE)) {
591 			printf("Can't create \"%s\"\n", name);
592 			errno = EROFS;
593 			return -1;
594 		}
595 	} else
596 		/* Nothing to do */
597 		return 0;
598 
599 	if (deleting || overwriting) {
600 		if (*++nxt == '\0') {
601 			*env = '\0';
602 		} else {
603 			for (;;) {
604 				*env = *nxt++;
605 				if ((*env == '\0') && (*nxt == '\0'))
606 					break;
607 				++env;
608 			}
609 		}
610 		*++env = '\0';
611 	}
612 
613 	/* Delete only ? */
614 	if (!value || !strlen(value))
615 		return 0;
616 
617 	/*
618 	 * Append new definition at the end
619 	 */
620 	for (env = environment.data; *env || *(env + 1); ++env);
621 	if (env > environment.data)
622 		++env;
623 	/*
624 	 * Overflow when:
625 	 * "name" + "=" + "val" +"\0\0"  > CUR_ENVSIZE - (env-environment)
626 	 */
627 	len = strlen (name) + 2;
628 	/* add '=' for first arg, ' ' for all others */
629 	len += strlen(value) + 1;
630 
631 	if (len > (&environment.data[ENV_SIZE] - env)) {
632 		fprintf (stderr,
633 			"Error: environment overflow, \"%s\" deleted\n",
634 			name);
635 		return -1;
636 	}
637 
638 	while ((*env = *name++) != '\0')
639 		env++;
640 	*env = '=';
641 	while ((*++env = *value++) != '\0')
642 		;
643 
644 	/* end is marked with double '\0' */
645 	*++env = '\0';
646 
647 	return 0;
648 }
649 
650 /*
651  * Deletes or sets environment variables. Returns -1 and sets errno error codes:
652  * 0	  - OK
653  * EINVAL - need at least 1 argument
654  * EROFS  - certain variables ("ethaddr", "serial#") cannot be
655  *	    modified or deleted
656  *
657  */
658 int fw_env_set(int argc, char *argv[], struct env_opts *opts)
659 {
660 	int i;
661 	size_t len;
662 	char *name, **valv;
663 	char *oldval;
664 	char *value = NULL;
665 	int valc;
666 	int ret;
667 
668 	if (!opts)
669 		opts = &default_opts;
670 
671 	if (argc < 1) {
672 		fprintf(stderr, "## Error: variable name missing\n");
673 		errno = EINVAL;
674 		return -1;
675 	}
676 
677 	if (fw_env_open(opts)) {
678 		fprintf(stderr, "Error: environment not initialized\n");
679 		return -1;
680 	}
681 
682 	name = argv[0];
683 	valv = argv + 1;
684 	valc = argc - 1;
685 
686 	if (env_flags_validate_env_set_params(name, valv, valc) < 0) {
687 		fw_env_close(opts);
688 		return -1;
689 	}
690 
691 	len = 0;
692 	for (i = 0; i < valc; ++i) {
693 		char *val = valv[i];
694 		size_t val_len = strlen(val);
695 
696 		if (value)
697 			value[len - 1] = ' ';
698 		oldval = value;
699 		value = realloc(value, len + val_len + 1);
700 		if (!value) {
701 			fprintf(stderr,
702 				"Cannot malloc %zu bytes: %s\n",
703 				len, strerror(errno));
704 			free(oldval);
705 			return -1;
706 		}
707 
708 		memcpy(value + len, val, val_len);
709 		len += val_len;
710 		value[len++] = '\0';
711 	}
712 
713 	fw_env_write(name, value);
714 
715 	free(value);
716 
717 	ret = fw_env_flush(opts);
718 	fw_env_close(opts);
719 
720 	return ret;
721 }
722 
723 /*
724  * Parse  a file  and configure the u-boot variables.
725  * The script file has a very simple format, as follows:
726  *
727  * Each line has a couple with name, value:
728  * <white spaces>variable_name<white spaces>variable_value
729  *
730  * Both variable_name and variable_value are interpreted as strings.
731  * Any character after <white spaces> and before ending \r\n is interpreted
732  * as variable's value (no comment allowed on these lines !)
733  *
734  * Comments are allowed if the first character in the line is #
735  *
736  * Returns -1 and sets errno error codes:
737  * 0	  - OK
738  * -1     - Error
739  */
740 int fw_parse_script(char *fname, struct env_opts *opts)
741 {
742 	FILE *fp;
743 	char dump[1024];	/* Maximum line length in the file */
744 	char *name;
745 	char *val;
746 	int lineno = 0;
747 	int len;
748 	int ret = 0;
749 
750 	if (!opts)
751 		opts = &default_opts;
752 
753 	if (fw_env_open(opts)) {
754 		fprintf(stderr, "Error: environment not initialized\n");
755 		return -1;
756 	}
757 
758 	if (strcmp(fname, "-") == 0)
759 		fp = stdin;
760 	else {
761 		fp = fopen(fname, "r");
762 		if (fp == NULL) {
763 			fprintf(stderr, "I cannot open %s for reading\n",
764 				 fname);
765 			return -1;
766 		}
767 	}
768 
769 	while (fgets(dump, sizeof(dump), fp)) {
770 		lineno++;
771 		len = strlen(dump);
772 
773 		/*
774 		 * Read a whole line from the file. If the line is too long
775 		 * or is not terminated, reports an error and exit.
776 		 */
777 		if (dump[len - 1] != '\n') {
778 			fprintf(stderr,
779 			"Line %d not corrected terminated or too long\n",
780 				lineno);
781 			ret = -1;
782 			break;
783 		}
784 
785 		/* Drop ending line feed / carriage return */
786 		dump[--len] = '\0';
787 		if (len && dump[len - 1] == '\r')
788 			dump[--len] = '\0';
789 
790 		/* Skip comment or empty lines */
791 		if (len == 0 || dump[0] == '#')
792 			continue;
793 
794 		/*
795 		 * Search for variable's name,
796 		 * remove leading whitespaces
797 		 */
798 		name = skip_blanks(dump);
799 		if (!name)
800 			continue;
801 
802 		/* The first white space is the end of variable name */
803 		val = skip_chars(name);
804 		len = strlen(name);
805 		if (val) {
806 			*val++ = '\0';
807 			if ((val - name) < len)
808 				val = skip_blanks(val);
809 			else
810 				val = NULL;
811 		}
812 
813 #ifdef DEBUG
814 		fprintf(stderr, "Setting %s : %s\n",
815 			name, val ? val : " removed");
816 #endif
817 
818 		if (env_flags_validate_type(name, val) < 0) {
819 			ret = -1;
820 			break;
821 		}
822 
823 		/*
824 		 * If there is an error setting a variable,
825 		 * try to save the environment and returns an error
826 		 */
827 		if (fw_env_write(name, val)) {
828 			fprintf(stderr,
829 			"fw_env_write returns with error : %s\n",
830 				strerror(errno));
831 			ret = -1;
832 			break;
833 		}
834 
835 	}
836 
837 	/* Close file if not stdin */
838 	if (strcmp(fname, "-") != 0)
839 		fclose(fp);
840 
841 	ret |= fw_env_flush(opts);
842 
843 	fw_env_close(opts);
844 
845 	return ret;
846 }
847 
848 /**
849  * environment_end() - compute offset of first byte right after environemnt
850  * @dev - index of enviroment buffer
851  * Return:
852  *  device offset of first byte right after environemnt
853  */
854 off_t environment_end(int dev)
855 {
856 	/* environment is block aligned */
857 	return DEVOFFSET(dev) + ENVSECTORS(dev) * DEVESIZE(dev);
858 }
859 
860 /*
861  * Test for bad block on NAND, just returns 0 on NOR, on NAND:
862  * 0	- block is good
863  * > 0	- block is bad
864  * < 0	- failed to test
865  */
866 static int flash_bad_block(int fd, uint8_t mtd_type, loff_t blockstart)
867 {
868 	if (mtd_type == MTD_NANDFLASH) {
869 		int badblock = ioctl(fd, MEMGETBADBLOCK, &blockstart);
870 
871 		if (badblock < 0) {
872 			perror ("Cannot read bad block mark");
873 			return badblock;
874 		}
875 
876 		if (badblock) {
877 #ifdef DEBUG
878 			fprintf (stderr, "Bad block at 0x%llx, skipping\n",
879 				(unsigned long long)blockstart);
880 #endif
881 			return badblock;
882 		}
883 	}
884 
885 	return 0;
886 }
887 
888 /*
889  * Read data from flash at an offset into a provided buffer. On NAND it skips
890  * bad blocks but makes sure it stays within ENVSECTORS (dev) starting from
891  * the DEVOFFSET (dev) block. On NOR the loop is only run once.
892  */
893 static int flash_read_buf (int dev, int fd, void *buf, size_t count,
894 			   off_t offset)
895 {
896 	size_t blocklen;	/* erase / write length - one block on NAND,
897 				   0 on NOR */
898 	size_t processed = 0;	/* progress counter */
899 	size_t readlen = count;	/* current read length */
900 	off_t block_seek;	/* offset inside the current block to the start
901 				   of the data */
902 	loff_t blockstart;	/* running start of the current block -
903 				   MEMGETBADBLOCK needs 64 bits */
904 	int rc;
905 
906 	blockstart = (offset / DEVESIZE (dev)) * DEVESIZE (dev);
907 
908 	/* Offset inside a block */
909 	block_seek = offset - blockstart;
910 
911 	if (DEVTYPE(dev) == MTD_NANDFLASH) {
912 		/*
913 		 * NAND: calculate which blocks we are reading. We have
914 		 * to read one block at a time to skip bad blocks.
915 		 */
916 		blocklen = DEVESIZE (dev);
917 
918 		/* Limit to one block for the first read */
919 		if (readlen > blocklen - block_seek)
920 			readlen = blocklen - block_seek;
921 	} else {
922 		blocklen = 0;
923 	}
924 
925 	/* This only runs once on NOR flash */
926 	while (processed < count) {
927 		rc = flash_bad_block(fd, DEVTYPE(dev), blockstart);
928 		if (rc < 0)		/* block test failed */
929 			return -1;
930 
931 		if (blockstart + block_seek + readlen > environment_end(dev)) {
932 			/* End of range is reached */
933 			fprintf (stderr,
934 				 "Too few good blocks within range\n");
935 			return -1;
936 		}
937 
938 		if (rc) {		/* block is bad */
939 			blockstart += blocklen;
940 			continue;
941 		}
942 
943 		/*
944 		 * If a block is bad, we retry in the next block at the same
945 		 * offset - see env/nand.c::writeenv()
946 		 */
947 		lseek (fd, blockstart + block_seek, SEEK_SET);
948 
949 		rc = read (fd, buf + processed, readlen);
950 		if (rc != readlen) {
951 			fprintf (stderr, "Read error on %s: %s\n",
952 				 DEVNAME (dev), strerror (errno));
953 			return -1;
954 		}
955 #ifdef DEBUG
956 		fprintf(stderr, "Read 0x%x bytes at 0x%llx on %s\n",
957 			rc, (unsigned long long) blockstart + block_seek,
958 			DEVNAME(dev));
959 #endif
960 		processed += readlen;
961 		readlen = min (blocklen, count - processed);
962 		block_seek = 0;
963 		blockstart += blocklen;
964 	}
965 
966 	return processed;
967 }
968 
969 /*
970  * Write count bytes from begin of environment, but stay within
971  * ENVSECTORS(dev) sectors of
972  * DEVOFFSET (dev). Similar to the read case above, on NOR and dataflash we
973  * erase and write the whole data at once.
974  */
975 static int flash_write_buf(int dev, int fd, void *buf, size_t count)
976 {
977 	void *data;
978 	struct erase_info_user erase;
979 	size_t blocklen;	/* length of NAND block / NOR erase sector */
980 	size_t erase_len;	/* whole area that can be erased - may include
981 				   bad blocks */
982 	size_t erasesize;	/* erase / write length - one block on NAND,
983 				   whole area on NOR */
984 	size_t processed = 0;	/* progress counter */
985 	size_t write_total;	/* total size to actually write - excluding
986 				   bad blocks */
987 	off_t erase_offset;	/* offset to the first erase block (aligned)
988 				   below offset */
989 	off_t block_seek;	/* offset inside the erase block to the start
990 				   of the data */
991 	loff_t blockstart;	/* running start of the current block -
992 				   MEMGETBADBLOCK needs 64 bits */
993 	int rc;
994 
995 	/*
996 	 * For mtd devices only offset and size of the environment do matter
997 	 */
998 	if (DEVTYPE(dev) == MTD_ABSENT) {
999 		blocklen = count;
1000 		erase_len = blocklen;
1001 		blockstart = DEVOFFSET(dev);
1002 		block_seek = 0;
1003 		write_total = blocklen;
1004 	} else {
1005 		blocklen = DEVESIZE(dev);
1006 
1007 		erase_offset = DEVOFFSET(dev);
1008 
1009 		/* Maximum area we may use */
1010 		erase_len = environment_end(dev) - erase_offset;
1011 
1012 		blockstart = erase_offset;
1013 
1014 		/* Offset inside a block */
1015 		block_seek = DEVOFFSET(dev) - erase_offset;
1016 
1017 		/*
1018 		 * Data size we actually write: from the start of the block
1019 		 * to the start of the data, then count bytes of data, and
1020 		 * to the end of the block
1021 		 */
1022 		write_total = ((block_seek + count + blocklen - 1) /
1023 							blocklen) * blocklen;
1024 	}
1025 
1026 	/*
1027 	 * Support data anywhere within erase sectors: read out the complete
1028 	 * area to be erased, replace the environment image, write the whole
1029 	 * block back again.
1030 	 */
1031 	if (write_total > count) {
1032 		data = malloc (erase_len);
1033 		if (!data) {
1034 			fprintf (stderr,
1035 				 "Cannot malloc %zu bytes: %s\n",
1036 				 erase_len, strerror (errno));
1037 			return -1;
1038 		}
1039 
1040 		rc = flash_read_buf(dev, fd, data, write_total, erase_offset);
1041 		if (write_total != rc)
1042 			return -1;
1043 
1044 #ifdef DEBUG
1045 		fprintf(stderr, "Preserving data ");
1046 		if (block_seek != 0)
1047 			fprintf(stderr, "0x%x - 0x%lx", 0, block_seek - 1);
1048 		if (block_seek + count != write_total) {
1049 			if (block_seek != 0)
1050 				fprintf(stderr, " and ");
1051 			fprintf(stderr, "0x%lx - 0x%lx",
1052 				(unsigned long) block_seek + count,
1053 				(unsigned long) write_total - 1);
1054 		}
1055 		fprintf(stderr, "\n");
1056 #endif
1057 		/* Overwrite the old environment */
1058 		memcpy (data + block_seek, buf, count);
1059 	} else {
1060 		/*
1061 		 * We get here, iff offset is block-aligned and count is a
1062 		 * multiple of blocklen - see write_total calculation above
1063 		 */
1064 		data = buf;
1065 	}
1066 
1067 	if (DEVTYPE(dev) == MTD_NANDFLASH) {
1068 		/*
1069 		 * NAND: calculate which blocks we are writing. We have
1070 		 * to write one block at a time to skip bad blocks.
1071 		 */
1072 		erasesize = blocklen;
1073 	} else {
1074 		erasesize = erase_len;
1075 	}
1076 
1077 	erase.length = erasesize;
1078 
1079 	/* This only runs once on NOR flash and SPI-dataflash */
1080 	while (processed < write_total) {
1081 		rc = flash_bad_block(fd, DEVTYPE(dev), blockstart);
1082 		if (rc < 0)		/* block test failed */
1083 			return rc;
1084 
1085 		if (blockstart + erasesize > environment_end(dev)) {
1086 			fprintf (stderr, "End of range reached, aborting\n");
1087 			return -1;
1088 		}
1089 
1090 		if (rc) {		/* block is bad */
1091 			blockstart += blocklen;
1092 			continue;
1093 		}
1094 
1095 		if (DEVTYPE(dev) != MTD_ABSENT) {
1096 			erase.start = blockstart;
1097 			ioctl(fd, MEMUNLOCK, &erase);
1098 			/* These do not need an explicit erase cycle */
1099 			if (DEVTYPE(dev) != MTD_DATAFLASH)
1100 				if (ioctl(fd, MEMERASE, &erase) != 0) {
1101 					fprintf(stderr,
1102 						"MTD erase error on %s: %s\n",
1103 						DEVNAME(dev), strerror(errno));
1104 					return -1;
1105 				}
1106 		}
1107 
1108 		if (lseek (fd, blockstart, SEEK_SET) == -1) {
1109 			fprintf (stderr,
1110 				 "Seek error on %s: %s\n",
1111 				 DEVNAME (dev), strerror (errno));
1112 			return -1;
1113 		}
1114 
1115 #ifdef DEBUG
1116 		fprintf(stderr, "Write 0x%llx bytes at 0x%llx\n",
1117 			(unsigned long long) erasesize,
1118 			(unsigned long long) blockstart);
1119 #endif
1120 		if (write (fd, data + processed, erasesize) != erasesize) {
1121 			fprintf (stderr, "Write error on %s: %s\n",
1122 				 DEVNAME (dev), strerror (errno));
1123 			return -1;
1124 		}
1125 
1126 		if (DEVTYPE(dev) != MTD_ABSENT)
1127 			ioctl(fd, MEMLOCK, &erase);
1128 
1129 		processed  += erasesize;
1130 		block_seek = 0;
1131 		blockstart += erasesize;
1132 	}
1133 
1134 	if (write_total > count)
1135 		free (data);
1136 
1137 	return processed;
1138 }
1139 
1140 /*
1141  * Set obsolete flag at offset - NOR flash only
1142  */
1143 static int flash_flag_obsolete (int dev, int fd, off_t offset)
1144 {
1145 	int rc;
1146 	struct erase_info_user erase;
1147 
1148 	erase.start  = DEVOFFSET (dev);
1149 	erase.length = DEVESIZE (dev);
1150 	/* This relies on the fact, that obsolete_flag == 0 */
1151 	rc = lseek (fd, offset, SEEK_SET);
1152 	if (rc < 0) {
1153 		fprintf (stderr, "Cannot seek to set the flag on %s \n",
1154 			 DEVNAME (dev));
1155 		return rc;
1156 	}
1157 	ioctl (fd, MEMUNLOCK, &erase);
1158 	rc = write (fd, &obsolete_flag, sizeof (obsolete_flag));
1159 	ioctl (fd, MEMLOCK, &erase);
1160 	if (rc < 0)
1161 		perror ("Could not set obsolete flag");
1162 
1163 	return rc;
1164 }
1165 
1166 static int flash_write (int fd_current, int fd_target, int dev_target)
1167 {
1168 	int rc;
1169 
1170 	switch (environment.flag_scheme) {
1171 	case FLAG_NONE:
1172 		break;
1173 	case FLAG_INCREMENTAL:
1174 		(*environment.flags)++;
1175 		break;
1176 	case FLAG_BOOLEAN:
1177 		*environment.flags = active_flag;
1178 		break;
1179 	default:
1180 		fprintf (stderr, "Unimplemented flash scheme %u \n",
1181 			 environment.flag_scheme);
1182 		return -1;
1183 	}
1184 
1185 #ifdef DEBUG
1186 	fprintf(stderr, "Writing new environment at 0x%llx on %s\n",
1187 		DEVOFFSET (dev_target), DEVNAME (dev_target));
1188 #endif
1189 
1190 	if (IS_UBI(dev_target)) {
1191 		if (ubi_update_start(fd_target, CUR_ENVSIZE) < 0)
1192 			return 0;
1193 		return ubi_write(fd_target, environment.image, CUR_ENVSIZE);
1194 	}
1195 
1196 	rc = flash_write_buf(dev_target, fd_target, environment.image,
1197 			     CUR_ENVSIZE);
1198 	if (rc < 0)
1199 		return rc;
1200 
1201 	if (environment.flag_scheme == FLAG_BOOLEAN) {
1202 		/* Have to set obsolete flag */
1203 		off_t offset = DEVOFFSET (dev_current) +
1204 			offsetof (struct env_image_redundant, flags);
1205 #ifdef DEBUG
1206 		fprintf(stderr,
1207 			"Setting obsolete flag in environment at 0x%llx on %s\n",
1208 			DEVOFFSET (dev_current), DEVNAME (dev_current));
1209 #endif
1210 		flash_flag_obsolete (dev_current, fd_current, offset);
1211 	}
1212 
1213 	return 0;
1214 }
1215 
1216 static int flash_read (int fd)
1217 {
1218 	int rc;
1219 
1220 	if (IS_UBI(dev_current)) {
1221 		DEVTYPE(dev_current) = MTD_ABSENT;
1222 
1223 		return ubi_read(fd, environment.image, CUR_ENVSIZE);
1224 	}
1225 
1226 	rc = flash_read_buf(dev_current, fd, environment.image, CUR_ENVSIZE,
1227 			    DEVOFFSET(dev_current));
1228 	if (rc != CUR_ENVSIZE)
1229 		return -1;
1230 
1231 	return 0;
1232 }
1233 
1234 static int flash_io (int mode)
1235 {
1236 	int fd_current, fd_target, rc, dev_target;
1237 
1238 	/* dev_current: fd_current, erase_current */
1239 	fd_current = open (DEVNAME (dev_current), mode);
1240 	if (fd_current < 0) {
1241 		fprintf (stderr,
1242 			 "Can't open %s: %s\n",
1243 			 DEVNAME (dev_current), strerror (errno));
1244 		return -1;
1245 	}
1246 
1247 	if (mode == O_RDWR) {
1248 		if (HaveRedundEnv) {
1249 			/* switch to next partition for writing */
1250 			dev_target = !dev_current;
1251 			/* dev_target: fd_target, erase_target */
1252 			fd_target = open (DEVNAME (dev_target), mode);
1253 			if (fd_target < 0) {
1254 				fprintf (stderr,
1255 					 "Can't open %s: %s\n",
1256 					 DEVNAME (dev_target),
1257 					 strerror (errno));
1258 				rc = -1;
1259 				goto exit;
1260 			}
1261 		} else {
1262 			dev_target = dev_current;
1263 			fd_target = fd_current;
1264 		}
1265 
1266 		rc = flash_write (fd_current, fd_target, dev_target);
1267 
1268 		if (fsync(fd_current) &&
1269 		    !(errno == EINVAL || errno == EROFS)) {
1270 			fprintf (stderr,
1271 				 "fsync failed on %s: %s\n",
1272 				 DEVNAME (dev_current), strerror (errno));
1273 		}
1274 
1275 		if (HaveRedundEnv) {
1276 			if (fsync(fd_target) &&
1277 			    !(errno == EINVAL || errno == EROFS)) {
1278 				fprintf (stderr,
1279 					 "fsync failed on %s: %s\n",
1280 					 DEVNAME (dev_current), strerror (errno));
1281 			}
1282 
1283 			if (close (fd_target)) {
1284 				fprintf (stderr,
1285 					"I/O error on %s: %s\n",
1286 					DEVNAME (dev_target),
1287 					strerror (errno));
1288 				rc = -1;
1289 			}
1290 		}
1291 	} else {
1292 		rc = flash_read (fd_current);
1293 	}
1294 
1295 exit:
1296 	if (close (fd_current)) {
1297 		fprintf (stderr,
1298 			 "I/O error on %s: %s\n",
1299 			 DEVNAME (dev_current), strerror (errno));
1300 		return -1;
1301 	}
1302 
1303 	return rc;
1304 }
1305 
1306 /*
1307  * Prevent confusion if running from erased flash memory
1308  */
1309 int fw_env_open(struct env_opts *opts)
1310 {
1311 	int crc0, crc0_ok;
1312 	unsigned char flag0;
1313 	void *addr0 = NULL;
1314 
1315 	int crc1, crc1_ok;
1316 	unsigned char flag1;
1317 	void *addr1 = NULL;
1318 
1319 	int ret;
1320 
1321 	struct env_image_single *single;
1322 	struct env_image_redundant *redundant;
1323 
1324 	if (!opts)
1325 		opts = &default_opts;
1326 
1327 	if (parse_config(opts))		/* should fill envdevices */
1328 		return -EINVAL;
1329 
1330 	addr0 = calloc(1, CUR_ENVSIZE);
1331 	if (addr0 == NULL) {
1332 		fprintf(stderr,
1333 			"Not enough memory for environment (%ld bytes)\n",
1334 			CUR_ENVSIZE);
1335 		ret = -ENOMEM;
1336 		goto open_cleanup;
1337 	}
1338 
1339 	/* read environment from FLASH to local buffer */
1340 	environment.image = addr0;
1341 
1342 	if (HaveRedundEnv) {
1343 		redundant = addr0;
1344 		environment.crc		= &redundant->crc;
1345 		environment.flags	= &redundant->flags;
1346 		environment.data	= redundant->data;
1347 	} else {
1348 		single = addr0;
1349 		environment.crc		= &single->crc;
1350 		environment.flags	= NULL;
1351 		environment.data	= single->data;
1352 	}
1353 
1354 	dev_current = 0;
1355 	if (flash_io(O_RDONLY)) {
1356 		ret = -EIO;
1357 		goto open_cleanup;
1358 	}
1359 
1360 	crc0 = crc32 (0, (uint8_t *) environment.data, ENV_SIZE);
1361 
1362 	crc0_ok = (crc0 == *environment.crc);
1363 	if (!HaveRedundEnv) {
1364 		if (!crc0_ok) {
1365 			fprintf (stderr,
1366 				"Warning: Bad CRC, using default environment\n");
1367 			memcpy(environment.data, default_environment, sizeof default_environment);
1368 		}
1369 	} else {
1370 		flag0 = *environment.flags;
1371 
1372 		dev_current = 1;
1373 		addr1 = calloc(1, CUR_ENVSIZE);
1374 		if (addr1 == NULL) {
1375 			fprintf(stderr,
1376 				"Not enough memory for environment (%ld bytes)\n",
1377 				CUR_ENVSIZE);
1378 			ret = -ENOMEM;
1379 			goto open_cleanup;
1380 		}
1381 		redundant = addr1;
1382 
1383 		/*
1384 		 * have to set environment.image for flash_read(), careful -
1385 		 * other pointers in environment still point inside addr0
1386 		 */
1387 		environment.image = addr1;
1388 		if (flash_io(O_RDONLY)) {
1389 			ret = -EIO;
1390 			goto open_cleanup;
1391 		}
1392 
1393 		/* Check flag scheme compatibility */
1394 		if (DEVTYPE(dev_current) == MTD_NORFLASH &&
1395 		    DEVTYPE(!dev_current) == MTD_NORFLASH) {
1396 			environment.flag_scheme = FLAG_BOOLEAN;
1397 		} else if (DEVTYPE(dev_current) == MTD_NANDFLASH &&
1398 			   DEVTYPE(!dev_current) == MTD_NANDFLASH) {
1399 			environment.flag_scheme = FLAG_INCREMENTAL;
1400 		} else if (DEVTYPE(dev_current) == MTD_DATAFLASH &&
1401 			   DEVTYPE(!dev_current) == MTD_DATAFLASH) {
1402 			environment.flag_scheme = FLAG_BOOLEAN;
1403 		} else if (DEVTYPE(dev_current) == MTD_UBIVOLUME &&
1404 			   DEVTYPE(!dev_current) == MTD_UBIVOLUME) {
1405 			environment.flag_scheme = FLAG_INCREMENTAL;
1406 		} else if (DEVTYPE(dev_current) == MTD_ABSENT &&
1407 			   DEVTYPE(!dev_current) == MTD_ABSENT &&
1408 			   IS_UBI(dev_current) == IS_UBI(!dev_current)) {
1409 			environment.flag_scheme = FLAG_INCREMENTAL;
1410 		} else {
1411 			fprintf (stderr, "Incompatible flash types!\n");
1412 			ret = -EINVAL;
1413 			goto open_cleanup;
1414 		}
1415 
1416 		crc1 = crc32 (0, (uint8_t *) redundant->data, ENV_SIZE);
1417 
1418 		crc1_ok = (crc1 == redundant->crc);
1419 		flag1 = redundant->flags;
1420 
1421 		if (crc0_ok && !crc1_ok) {
1422 			dev_current = 0;
1423 		} else if (!crc0_ok && crc1_ok) {
1424 			dev_current = 1;
1425 		} else if (!crc0_ok && !crc1_ok) {
1426 			fprintf (stderr,
1427 				"Warning: Bad CRC, using default environment\n");
1428 			memcpy (environment.data, default_environment,
1429 				sizeof default_environment);
1430 			dev_current = 0;
1431 		} else {
1432 			switch (environment.flag_scheme) {
1433 			case FLAG_BOOLEAN:
1434 				if (flag0 == active_flag &&
1435 				    flag1 == obsolete_flag) {
1436 					dev_current = 0;
1437 				} else if (flag0 == obsolete_flag &&
1438 					   flag1 == active_flag) {
1439 					dev_current = 1;
1440 				} else if (flag0 == flag1) {
1441 					dev_current = 0;
1442 				} else if (flag0 == 0xFF) {
1443 					dev_current = 0;
1444 				} else if (flag1 == 0xFF) {
1445 					dev_current = 1;
1446 				} else {
1447 					dev_current = 0;
1448 				}
1449 				break;
1450 			case FLAG_INCREMENTAL:
1451 				if (flag0 == 255 && flag1 == 0)
1452 					dev_current = 1;
1453 				else if ((flag1 == 255 && flag0 == 0) ||
1454 					 flag0 >= flag1)
1455 					dev_current = 0;
1456 				else /* flag1 > flag0 */
1457 					dev_current = 1;
1458 				break;
1459 			default:
1460 				fprintf (stderr, "Unknown flag scheme %u \n",
1461 					 environment.flag_scheme);
1462 				return -1;
1463 			}
1464 		}
1465 
1466 		/*
1467 		 * If we are reading, we don't need the flag and the CRC any
1468 		 * more, if we are writing, we will re-calculate CRC and update
1469 		 * flags before writing out
1470 		 */
1471 		if (dev_current) {
1472 			environment.image	= addr1;
1473 			environment.crc		= &redundant->crc;
1474 			environment.flags	= &redundant->flags;
1475 			environment.data	= redundant->data;
1476 			free (addr0);
1477 		} else {
1478 			environment.image	= addr0;
1479 			/* Other pointers are already set */
1480 			free (addr1);
1481 		}
1482 #ifdef DEBUG
1483 		fprintf(stderr, "Selected env in %s\n", DEVNAME(dev_current));
1484 #endif
1485 	}
1486 	return 0;
1487 
1488 open_cleanup:
1489 	if (addr0)
1490 		free(addr0);
1491 
1492 	if (addr1)
1493 		free(addr0);
1494 
1495 	return ret;
1496 }
1497 
1498 /*
1499  * Simply free allocated buffer with environment
1500  */
1501 int fw_env_close(struct env_opts *opts)
1502 {
1503 	if (environment.image)
1504 		free(environment.image);
1505 
1506 	environment.image = NULL;
1507 
1508 	return 0;
1509 }
1510 
1511 static int check_device_config(int dev)
1512 {
1513 	struct stat st;
1514 	int32_t lnum = 0;
1515 	int fd, rc = 0;
1516 
1517 	/* Fills in IS_UBI(), converts DEVNAME() with ubi volume name */
1518 	ubi_check_dev(dev);
1519 
1520 	fd = open(DEVNAME(dev), O_RDONLY);
1521 	if (fd < 0) {
1522 		fprintf(stderr,
1523 			"Cannot open %s: %s\n",
1524 			DEVNAME(dev), strerror(errno));
1525 		return -1;
1526 	}
1527 
1528 	rc = fstat(fd, &st);
1529 	if (rc < 0) {
1530 		fprintf(stderr, "Cannot stat the file %s\n",
1531 			DEVNAME(dev));
1532 		goto err;
1533 	}
1534 
1535 	if (IS_UBI(dev)) {
1536 		rc = ioctl(fd, UBI_IOCEBISMAP, &lnum);
1537 		if (rc < 0) {
1538 			fprintf(stderr, "Cannot get UBI information for %s\n",
1539 				DEVNAME(dev));
1540 			goto err;
1541 		}
1542 	} else if (S_ISCHR(st.st_mode)) {
1543 		struct mtd_info_user mtdinfo;
1544 		rc = ioctl(fd, MEMGETINFO, &mtdinfo);
1545 		if (rc < 0) {
1546 			fprintf(stderr, "Cannot get MTD information for %s\n",
1547 				DEVNAME(dev));
1548 			goto err;
1549 		}
1550 		if (mtdinfo.type != MTD_NORFLASH &&
1551 		    mtdinfo.type != MTD_NANDFLASH &&
1552 		    mtdinfo.type != MTD_DATAFLASH &&
1553 		    mtdinfo.type != MTD_UBIVOLUME) {
1554 			fprintf(stderr, "Unsupported flash type %u on %s\n",
1555 				mtdinfo.type, DEVNAME(dev));
1556 			goto err;
1557 		}
1558 		DEVTYPE(dev) = mtdinfo.type;
1559 		if (DEVESIZE(dev) == 0)
1560 			/* Assume the erase size is the same as the env-size */
1561 			DEVESIZE(dev) = ENVSIZE(dev);
1562 	} else {
1563 		uint64_t size;
1564 		DEVTYPE(dev) = MTD_ABSENT;
1565 		if (DEVESIZE(dev) == 0)
1566 			/* Assume the erase size to be 512 bytes */
1567 			DEVESIZE(dev) = 0x200;
1568 
1569 		/*
1570 		 * Check for negative offsets, treat it as backwards offset
1571 		 * from the end of the block device
1572 		 */
1573 		if (DEVOFFSET(dev) < 0) {
1574 			rc = ioctl(fd, BLKGETSIZE64, &size);
1575 			if (rc < 0) {
1576 				fprintf(stderr, "Could not get block device size on %s\n",
1577 					DEVNAME(dev));
1578 				goto err;
1579 			}
1580 
1581 			DEVOFFSET(dev) = DEVOFFSET(dev) + size;
1582 #ifdef DEBUG
1583 			fprintf(stderr, "Calculated device offset 0x%llx on %s\n",
1584 				DEVOFFSET(dev), DEVNAME(dev));
1585 #endif
1586 		}
1587 	}
1588 
1589 	if (ENVSECTORS(dev) == 0)
1590 		/* Assume enough sectors to cover the environment */
1591 		ENVSECTORS(dev) = DIV_ROUND_UP(ENVSIZE(dev), DEVESIZE(dev));
1592 
1593 	if (DEVOFFSET(dev) % DEVESIZE(dev) != 0) {
1594 		fprintf(stderr, "Environment does not start on (erase) block boundary\n");
1595 		errno = EINVAL;
1596 		return -1;
1597 	}
1598 
1599 	if (ENVSIZE(dev) > ENVSECTORS(dev) * DEVESIZE(dev)) {
1600 		fprintf(stderr, "Environment does not fit into available sectors\n");
1601 		errno = EINVAL;
1602 		return -1;
1603 	}
1604 
1605 err:
1606 	close(fd);
1607 	return rc;
1608 }
1609 
1610 static int parse_config(struct env_opts *opts)
1611 {
1612 	int rc;
1613 
1614 	if (!opts)
1615 		opts = &default_opts;
1616 
1617 #if defined(CONFIG_FILE)
1618 	/* Fills in DEVNAME(), ENVSIZE(), DEVESIZE(). Or don't. */
1619 	if (get_config(opts->config_file)) {
1620 		fprintf(stderr, "Cannot parse config file '%s': %m\n",
1621 			opts->config_file);
1622 		return -1;
1623 	}
1624 #else
1625 	DEVNAME (0) = DEVICE1_NAME;
1626 	DEVOFFSET (0) = DEVICE1_OFFSET;
1627 	ENVSIZE (0) = ENV1_SIZE;
1628 
1629 	/* Set defaults for DEVESIZE, ENVSECTORS later once we
1630 	 * know DEVTYPE
1631 	 */
1632 #ifdef DEVICE1_ESIZE
1633 	DEVESIZE (0) = DEVICE1_ESIZE;
1634 #endif
1635 #ifdef DEVICE1_ENVSECTORS
1636 	ENVSECTORS (0) = DEVICE1_ENVSECTORS;
1637 #endif
1638 
1639 #ifdef HAVE_REDUND
1640 	DEVNAME (1) = DEVICE2_NAME;
1641 	DEVOFFSET (1) = DEVICE2_OFFSET;
1642 	ENVSIZE (1) = ENV2_SIZE;
1643 
1644 	/* Set defaults for DEVESIZE, ENVSECTORS later once we
1645 	 * know DEVTYPE
1646 	 */
1647 #ifdef DEVICE2_ESIZE
1648 	DEVESIZE (1) = DEVICE2_ESIZE;
1649 #endif
1650 #ifdef DEVICE2_ENVSECTORS
1651 	ENVSECTORS (1) = DEVICE2_ENVSECTORS;
1652 #endif
1653 	HaveRedundEnv = 1;
1654 #endif
1655 #endif
1656 	rc = check_device_config(0);
1657 	if (rc < 0)
1658 		return rc;
1659 
1660 	if (HaveRedundEnv) {
1661 		rc = check_device_config(1);
1662 		if (rc < 0)
1663 			return rc;
1664 
1665 		if (ENVSIZE(0) != ENVSIZE(1)) {
1666 			fprintf(stderr,
1667 				"Redundant environments have unequal size");
1668 			return -1;
1669 		}
1670 	}
1671 
1672 	usable_envsize = CUR_ENVSIZE - sizeof(uint32_t);
1673 	if (HaveRedundEnv)
1674 		usable_envsize -= sizeof(char);
1675 
1676 	return 0;
1677 }
1678 
1679 #if defined(CONFIG_FILE)
1680 static int get_config (char *fname)
1681 {
1682 	FILE *fp;
1683 	int i = 0;
1684 	int rc;
1685 	char dump[128];
1686 	char *devname;
1687 
1688 	fp = fopen (fname, "r");
1689 	if (fp == NULL)
1690 		return -1;
1691 
1692 	while (i < 2 && fgets (dump, sizeof (dump), fp)) {
1693 		/* Skip incomplete conversions and comment strings */
1694 		if (dump[0] == '#')
1695 			continue;
1696 
1697 		rc = sscanf(dump, "%ms %lli %lx %lx %lx",
1698 			    &devname,
1699 			    &DEVOFFSET(i),
1700 			    &ENVSIZE(i),
1701 			    &DEVESIZE(i),
1702 			    &ENVSECTORS(i));
1703 
1704 		if (rc < 3)
1705 			continue;
1706 
1707 		DEVNAME(i) = devname;
1708 
1709 		/* Set defaults for DEVESIZE, ENVSECTORS later once we
1710 		 * know DEVTYPE
1711 		 */
1712 
1713 		i++;
1714 	}
1715 	fclose (fp);
1716 
1717 	HaveRedundEnv = i - 1;
1718 	if (!i) {			/* No valid entries found */
1719 		errno = EINVAL;
1720 		return -1;
1721 	} else
1722 		return 0;
1723 }
1724 #endif
1725