xref: /openbmc/u-boot/tools/env/fw_env.c (revision 71b75644)
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) || *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'/`--noheader' 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 	if (!opts)
509 		opts = &default_opts;
510 
511 	/*
512 	 * Update CRC
513 	 */
514 	*environment.crc = crc32(0, (uint8_t *) environment.data, ENV_SIZE);
515 
516 	/* write environment back to flash */
517 	if (flash_io(O_RDWR)) {
518 		fprintf(stderr,
519 			"Error: can't write fw_env to flash\n");
520 			return -1;
521 	}
522 
523 	return 0;
524 }
525 
526 
527 /*
528  * Set/Clear a single variable in the environment.
529  * This is called in sequence to update the environment
530  * in RAM without updating the copy in flash after each set
531  */
532 int fw_env_write(char *name, char *value)
533 {
534 	int len;
535 	char *env, *nxt;
536 	char *oldval = NULL;
537 	int deleting, creating, overwriting;
538 
539 	/*
540 	 * search if variable with this name already exists
541 	 */
542 	for (nxt = env = environment.data; *env; env = nxt + 1) {
543 		for (nxt = env; *nxt; ++nxt) {
544 			if (nxt >= &environment.data[ENV_SIZE]) {
545 				fprintf(stderr, "## Error: "
546 					"environment not terminated\n");
547 				errno = EINVAL;
548 				return -1;
549 			}
550 		}
551 		if ((oldval = envmatch (name, env)) != NULL)
552 			break;
553 	}
554 
555 	deleting = (oldval && !(value && strlen(value)));
556 	creating = (!oldval && (value && strlen(value)));
557 	overwriting = (oldval && (value && strlen(value)));
558 
559 	/* check for permission */
560 	if (deleting) {
561 		if (env_flags_validate_varaccess(name,
562 		    ENV_FLAGS_VARACCESS_PREVENT_DELETE)) {
563 			printf("Can't delete \"%s\"\n", name);
564 			errno = EROFS;
565 			return -1;
566 		}
567 	} else if (overwriting) {
568 		if (env_flags_validate_varaccess(name,
569 		    ENV_FLAGS_VARACCESS_PREVENT_OVERWR)) {
570 			printf("Can't overwrite \"%s\"\n", name);
571 			errno = EROFS;
572 			return -1;
573 		} else if (env_flags_validate_varaccess(name,
574 		    ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR)) {
575 			const char *defval = fw_getdefenv(name);
576 
577 			if (defval == NULL)
578 				defval = "";
579 			if (strcmp(oldval, defval)
580 			    != 0) {
581 				printf("Can't overwrite \"%s\"\n", name);
582 				errno = EROFS;
583 				return -1;
584 			}
585 		}
586 	} else if (creating) {
587 		if (env_flags_validate_varaccess(name,
588 		    ENV_FLAGS_VARACCESS_PREVENT_CREATE)) {
589 			printf("Can't create \"%s\"\n", name);
590 			errno = EROFS;
591 			return -1;
592 		}
593 	} else
594 		/* Nothing to do */
595 		return 0;
596 
597 	if (deleting || overwriting) {
598 		if (*++nxt == '\0') {
599 			*env = '\0';
600 		} else {
601 			for (;;) {
602 				*env = *nxt++;
603 				if ((*env == '\0') && (*nxt == '\0'))
604 					break;
605 				++env;
606 			}
607 		}
608 		*++env = '\0';
609 	}
610 
611 	/* Delete only ? */
612 	if (!value || !strlen(value))
613 		return 0;
614 
615 	/*
616 	 * Append new definition at the end
617 	 */
618 	for (env = environment.data; *env || *(env + 1); ++env);
619 	if (env > environment.data)
620 		++env;
621 	/*
622 	 * Overflow when:
623 	 * "name" + "=" + "val" +"\0\0"  > CUR_ENVSIZE - (env-environment)
624 	 */
625 	len = strlen (name) + 2;
626 	/* add '=' for first arg, ' ' for all others */
627 	len += strlen(value) + 1;
628 
629 	if (len > (&environment.data[ENV_SIZE] - env)) {
630 		fprintf (stderr,
631 			"Error: environment overflow, \"%s\" deleted\n",
632 			name);
633 		return -1;
634 	}
635 
636 	while ((*env = *name++) != '\0')
637 		env++;
638 	*env = '=';
639 	while ((*++env = *value++) != '\0')
640 		;
641 
642 	/* end is marked with double '\0' */
643 	*++env = '\0';
644 
645 	return 0;
646 }
647 
648 /*
649  * Deletes or sets environment variables. Returns -1 and sets errno error codes:
650  * 0	  - OK
651  * EINVAL - need at least 1 argument
652  * EROFS  - certain variables ("ethaddr", "serial#") cannot be
653  *	    modified or deleted
654  *
655  */
656 int fw_env_set(int argc, char *argv[], struct env_opts *opts)
657 {
658 	int i;
659 	size_t len;
660 	char *name, **valv;
661 	char *oldval;
662 	char *value = NULL;
663 	int valc;
664 	int ret;
665 
666 	if (!opts)
667 		opts = &default_opts;
668 
669 	if (argc < 1) {
670 		fprintf(stderr, "## Error: variable name missing\n");
671 		errno = EINVAL;
672 		return -1;
673 	}
674 
675 	if (fw_env_open(opts)) {
676 		fprintf(stderr, "Error: environment not initialized\n");
677 		return -1;
678 	}
679 
680 	name = argv[0];
681 	valv = argv + 1;
682 	valc = argc - 1;
683 
684 	if (env_flags_validate_env_set_params(name, valv, valc) < 0) {
685 		fw_env_close(opts);
686 		return -1;
687 	}
688 
689 	len = 0;
690 	for (i = 0; i < valc; ++i) {
691 		char *val = valv[i];
692 		size_t val_len = strlen(val);
693 
694 		if (value)
695 			value[len - 1] = ' ';
696 		oldval = value;
697 		value = realloc(value, len + val_len + 1);
698 		if (!value) {
699 			fprintf(stderr,
700 				"Cannot malloc %zu bytes: %s\n",
701 				len, strerror(errno));
702 			free(oldval);
703 			return -1;
704 		}
705 
706 		memcpy(value + len, val, val_len);
707 		len += val_len;
708 		value[len++] = '\0';
709 	}
710 
711 	fw_env_write(name, value);
712 
713 	free(value);
714 
715 	ret = fw_env_flush(opts);
716 	fw_env_close(opts);
717 
718 	return ret;
719 }
720 
721 /*
722  * Parse  a file  and configure the u-boot variables.
723  * The script file has a very simple format, as follows:
724  *
725  * Each line has a couple with name, value:
726  * <white spaces>variable_name<white spaces>variable_value
727  *
728  * Both variable_name and variable_value are interpreted as strings.
729  * Any character after <white spaces> and before ending \r\n is interpreted
730  * as variable's value (no comment allowed on these lines !)
731  *
732  * Comments are allowed if the first character in the line is #
733  *
734  * Returns -1 and sets errno error codes:
735  * 0	  - OK
736  * -1     - Error
737  */
738 int fw_parse_script(char *fname, struct env_opts *opts)
739 {
740 	FILE *fp;
741 	char dump[1024];	/* Maximum line length in the file */
742 	char *name;
743 	char *val;
744 	int lineno = 0;
745 	int len;
746 	int ret = 0;
747 
748 	if (!opts)
749 		opts = &default_opts;
750 
751 	if (fw_env_open(opts)) {
752 		fprintf(stderr, "Error: environment not initialized\n");
753 		return -1;
754 	}
755 
756 	if (strcmp(fname, "-") == 0)
757 		fp = stdin;
758 	else {
759 		fp = fopen(fname, "r");
760 		if (fp == NULL) {
761 			fprintf(stderr, "I cannot open %s for reading\n",
762 				 fname);
763 			return -1;
764 		}
765 	}
766 
767 	while (fgets(dump, sizeof(dump), fp)) {
768 		lineno++;
769 		len = strlen(dump);
770 
771 		/*
772 		 * Read a whole line from the file. If the line is too long
773 		 * or is not terminated, reports an error and exit.
774 		 */
775 		if (dump[len - 1] != '\n') {
776 			fprintf(stderr,
777 			"Line %d not corrected terminated or too long\n",
778 				lineno);
779 			ret = -1;
780 			break;
781 		}
782 
783 		/* Drop ending line feed / carriage return */
784 		dump[--len] = '\0';
785 		if (len && dump[len - 1] == '\r')
786 			dump[--len] = '\0';
787 
788 		/* Skip comment or empty lines */
789 		if (len == 0 || dump[0] == '#')
790 			continue;
791 
792 		/*
793 		 * Search for variable's name,
794 		 * remove leading whitespaces
795 		 */
796 		name = skip_blanks(dump);
797 		if (!name)
798 			continue;
799 
800 		/* The first white space is the end of variable name */
801 		val = skip_chars(name);
802 		len = strlen(name);
803 		if (val) {
804 			*val++ = '\0';
805 			if ((val - name) < len)
806 				val = skip_blanks(val);
807 			else
808 				val = NULL;
809 		}
810 
811 #ifdef DEBUG
812 		fprintf(stderr, "Setting %s : %s\n",
813 			name, val ? val : " removed");
814 #endif
815 
816 		if (env_flags_validate_type(name, val) < 0) {
817 			ret = -1;
818 			break;
819 		}
820 
821 		/*
822 		 * If there is an error setting a variable,
823 		 * try to save the environment and returns an error
824 		 */
825 		if (fw_env_write(name, val)) {
826 			fprintf(stderr,
827 			"fw_env_write returns with error : %s\n",
828 				strerror(errno));
829 			ret = -1;
830 			break;
831 		}
832 
833 	}
834 
835 	/* Close file if not stdin */
836 	if (strcmp(fname, "-") != 0)
837 		fclose(fp);
838 
839 	ret |= fw_env_flush(opts);
840 
841 	fw_env_close(opts);
842 
843 	return ret;
844 }
845 
846 /**
847  * environment_end() - compute offset of first byte right after environemnt
848  * @dev - index of enviroment buffer
849  * Return:
850  *  device offset of first byte right after environemnt
851  */
852 off_t environment_end(int dev)
853 {
854 	/* environment is block aligned */
855 	return DEVOFFSET(dev) + ENVSECTORS(dev) * DEVESIZE(dev);
856 }
857 
858 /*
859  * Test for bad block on NAND, just returns 0 on NOR, on NAND:
860  * 0	- block is good
861  * > 0	- block is bad
862  * < 0	- failed to test
863  */
864 static int flash_bad_block(int fd, uint8_t mtd_type, loff_t blockstart)
865 {
866 	if (mtd_type == MTD_NANDFLASH) {
867 		int badblock = ioctl(fd, MEMGETBADBLOCK, &blockstart);
868 
869 		if (badblock < 0) {
870 			perror ("Cannot read bad block mark");
871 			return badblock;
872 		}
873 
874 		if (badblock) {
875 #ifdef DEBUG
876 			fprintf (stderr, "Bad block at 0x%llx, skipping\n",
877 				(unsigned long long)blockstart);
878 #endif
879 			return badblock;
880 		}
881 	}
882 
883 	return 0;
884 }
885 
886 /*
887  * Read data from flash at an offset into a provided buffer. On NAND it skips
888  * bad blocks but makes sure it stays within ENVSECTORS (dev) starting from
889  * the DEVOFFSET (dev) block. On NOR the loop is only run once.
890  */
891 static int flash_read_buf (int dev, int fd, void *buf, size_t count,
892 			   off_t offset)
893 {
894 	size_t blocklen;	/* erase / write length - one block on NAND,
895 				   0 on NOR */
896 	size_t processed = 0;	/* progress counter */
897 	size_t readlen = count;	/* current read length */
898 	off_t block_seek;	/* offset inside the current block to the start
899 				   of the data */
900 	loff_t blockstart;	/* running start of the current block -
901 				   MEMGETBADBLOCK needs 64 bits */
902 	int rc;
903 
904 	blockstart = (offset / DEVESIZE (dev)) * DEVESIZE (dev);
905 
906 	/* Offset inside a block */
907 	block_seek = offset - blockstart;
908 
909 	if (DEVTYPE(dev) == MTD_NANDFLASH) {
910 		/*
911 		 * NAND: calculate which blocks we are reading. We have
912 		 * to read one block at a time to skip bad blocks.
913 		 */
914 		blocklen = DEVESIZE (dev);
915 
916 		/* Limit to one block for the first read */
917 		if (readlen > blocklen - block_seek)
918 			readlen = blocklen - block_seek;
919 	} else {
920 		blocklen = 0;
921 	}
922 
923 	/* This only runs once on NOR flash */
924 	while (processed < count) {
925 		rc = flash_bad_block(fd, DEVTYPE(dev), blockstart);
926 		if (rc < 0)		/* block test failed */
927 			return -1;
928 
929 		if (blockstart + block_seek + readlen > environment_end(dev)) {
930 			/* End of range is reached */
931 			fprintf (stderr,
932 				 "Too few good blocks within range\n");
933 			return -1;
934 		}
935 
936 		if (rc) {		/* block is bad */
937 			blockstart += blocklen;
938 			continue;
939 		}
940 
941 		/*
942 		 * If a block is bad, we retry in the next block at the same
943 		 * offset - see env/nand.c::writeenv()
944 		 */
945 		lseek (fd, blockstart + block_seek, SEEK_SET);
946 
947 		rc = read (fd, buf + processed, readlen);
948 		if (rc != readlen) {
949 			fprintf (stderr, "Read error on %s: %s\n",
950 				 DEVNAME (dev), strerror (errno));
951 			return -1;
952 		}
953 #ifdef DEBUG
954 		fprintf(stderr, "Read 0x%x bytes at 0x%llx on %s\n",
955 			rc, (unsigned long long) blockstart + block_seek,
956 			DEVNAME(dev));
957 #endif
958 		processed += readlen;
959 		readlen = min (blocklen, count - processed);
960 		block_seek = 0;
961 		blockstart += blocklen;
962 	}
963 
964 	return processed;
965 }
966 
967 /*
968  * Write count bytes from begin of environment, but stay within
969  * ENVSECTORS(dev) sectors of
970  * DEVOFFSET (dev). Similar to the read case above, on NOR and dataflash we
971  * erase and write the whole data at once.
972  */
973 static int flash_write_buf(int dev, int fd, void *buf, size_t count)
974 {
975 	void *data;
976 	struct erase_info_user erase;
977 	size_t blocklen;	/* length of NAND block / NOR erase sector */
978 	size_t erase_len;	/* whole area that can be erased - may include
979 				   bad blocks */
980 	size_t erasesize;	/* erase / write length - one block on NAND,
981 				   whole area on NOR */
982 	size_t processed = 0;	/* progress counter */
983 	size_t write_total;	/* total size to actually write - excluding
984 				   bad blocks */
985 	off_t erase_offset;	/* offset to the first erase block (aligned)
986 				   below offset */
987 	off_t block_seek;	/* offset inside the erase block to the start
988 				   of the data */
989 	loff_t blockstart;	/* running start of the current block -
990 				   MEMGETBADBLOCK needs 64 bits */
991 	int rc;
992 
993 	/*
994 	 * For mtd devices only offset and size of the environment do matter
995 	 */
996 	if (DEVTYPE(dev) == MTD_ABSENT) {
997 		blocklen = count;
998 		erase_len = blocklen;
999 		blockstart = DEVOFFSET(dev);
1000 		block_seek = 0;
1001 		write_total = blocklen;
1002 	} else {
1003 		blocklen = DEVESIZE(dev);
1004 
1005 		erase_offset = DEVOFFSET(dev);
1006 
1007 		/* Maximum area we may use */
1008 		erase_len = environment_end(dev) - erase_offset;
1009 
1010 		blockstart = erase_offset;
1011 
1012 		/* Offset inside a block */
1013 		block_seek = DEVOFFSET(dev) - erase_offset;
1014 
1015 		/*
1016 		 * Data size we actually write: from the start of the block
1017 		 * to the start of the data, then count bytes of data, and
1018 		 * to the end of the block
1019 		 */
1020 		write_total = ((block_seek + count + blocklen - 1) /
1021 							blocklen) * blocklen;
1022 	}
1023 
1024 	/*
1025 	 * Support data anywhere within erase sectors: read out the complete
1026 	 * area to be erased, replace the environment image, write the whole
1027 	 * block back again.
1028 	 */
1029 	if (write_total > count) {
1030 		data = malloc (erase_len);
1031 		if (!data) {
1032 			fprintf (stderr,
1033 				 "Cannot malloc %zu bytes: %s\n",
1034 				 erase_len, strerror (errno));
1035 			return -1;
1036 		}
1037 
1038 		rc = flash_read_buf(dev, fd, data, write_total, erase_offset);
1039 		if (write_total != rc)
1040 			return -1;
1041 
1042 #ifdef DEBUG
1043 		fprintf(stderr, "Preserving data ");
1044 		if (block_seek != 0)
1045 			fprintf(stderr, "0x%x - 0x%lx", 0, block_seek - 1);
1046 		if (block_seek + count != write_total) {
1047 			if (block_seek != 0)
1048 				fprintf(stderr, " and ");
1049 			fprintf(stderr, "0x%lx - 0x%lx",
1050 				(unsigned long) block_seek + count,
1051 				(unsigned long) write_total - 1);
1052 		}
1053 		fprintf(stderr, "\n");
1054 #endif
1055 		/* Overwrite the old environment */
1056 		memcpy (data + block_seek, buf, count);
1057 	} else {
1058 		/*
1059 		 * We get here, iff offset is block-aligned and count is a
1060 		 * multiple of blocklen - see write_total calculation above
1061 		 */
1062 		data = buf;
1063 	}
1064 
1065 	if (DEVTYPE(dev) == MTD_NANDFLASH) {
1066 		/*
1067 		 * NAND: calculate which blocks we are writing. We have
1068 		 * to write one block at a time to skip bad blocks.
1069 		 */
1070 		erasesize = blocklen;
1071 	} else {
1072 		erasesize = erase_len;
1073 	}
1074 
1075 	erase.length = erasesize;
1076 
1077 	/* This only runs once on NOR flash and SPI-dataflash */
1078 	while (processed < write_total) {
1079 		rc = flash_bad_block(fd, DEVTYPE(dev), blockstart);
1080 		if (rc < 0)		/* block test failed */
1081 			return rc;
1082 
1083 		if (blockstart + erasesize > environment_end(dev)) {
1084 			fprintf (stderr, "End of range reached, aborting\n");
1085 			return -1;
1086 		}
1087 
1088 		if (rc) {		/* block is bad */
1089 			blockstart += blocklen;
1090 			continue;
1091 		}
1092 
1093 		if (DEVTYPE(dev) != MTD_ABSENT) {
1094 			erase.start = blockstart;
1095 			ioctl(fd, MEMUNLOCK, &erase);
1096 			/* These do not need an explicit erase cycle */
1097 			if (DEVTYPE(dev) != MTD_DATAFLASH)
1098 				if (ioctl(fd, MEMERASE, &erase) != 0) {
1099 					fprintf(stderr,
1100 						"MTD erase error on %s: %s\n",
1101 						DEVNAME(dev), strerror(errno));
1102 					return -1;
1103 				}
1104 		}
1105 
1106 		if (lseek (fd, blockstart, SEEK_SET) == -1) {
1107 			fprintf (stderr,
1108 				 "Seek error on %s: %s\n",
1109 				 DEVNAME (dev), strerror (errno));
1110 			return -1;
1111 		}
1112 
1113 #ifdef DEBUG
1114 		fprintf(stderr, "Write 0x%llx bytes at 0x%llx\n",
1115 			(unsigned long long) erasesize,
1116 			(unsigned long long) blockstart);
1117 #endif
1118 		if (write (fd, data + processed, erasesize) != erasesize) {
1119 			fprintf (stderr, "Write error on %s: %s\n",
1120 				 DEVNAME (dev), strerror (errno));
1121 			return -1;
1122 		}
1123 
1124 		if (DEVTYPE(dev) != MTD_ABSENT)
1125 			ioctl(fd, MEMLOCK, &erase);
1126 
1127 		processed  += erasesize;
1128 		block_seek = 0;
1129 		blockstart += erasesize;
1130 	}
1131 
1132 	if (write_total > count)
1133 		free (data);
1134 
1135 	return processed;
1136 }
1137 
1138 /*
1139  * Set obsolete flag at offset - NOR flash only
1140  */
1141 static int flash_flag_obsolete (int dev, int fd, off_t offset)
1142 {
1143 	int rc;
1144 	struct erase_info_user erase;
1145 
1146 	erase.start  = DEVOFFSET (dev);
1147 	erase.length = DEVESIZE (dev);
1148 	/* This relies on the fact, that obsolete_flag == 0 */
1149 	rc = lseek (fd, offset, SEEK_SET);
1150 	if (rc < 0) {
1151 		fprintf (stderr, "Cannot seek to set the flag on %s \n",
1152 			 DEVNAME (dev));
1153 		return rc;
1154 	}
1155 	ioctl (fd, MEMUNLOCK, &erase);
1156 	rc = write (fd, &obsolete_flag, sizeof (obsolete_flag));
1157 	ioctl (fd, MEMLOCK, &erase);
1158 	if (rc < 0)
1159 		perror ("Could not set obsolete flag");
1160 
1161 	return rc;
1162 }
1163 
1164 static int flash_write (int fd_current, int fd_target, int dev_target)
1165 {
1166 	int rc;
1167 
1168 	switch (environment.flag_scheme) {
1169 	case FLAG_NONE:
1170 		break;
1171 	case FLAG_INCREMENTAL:
1172 		(*environment.flags)++;
1173 		break;
1174 	case FLAG_BOOLEAN:
1175 		*environment.flags = active_flag;
1176 		break;
1177 	default:
1178 		fprintf (stderr, "Unimplemented flash scheme %u \n",
1179 			 environment.flag_scheme);
1180 		return -1;
1181 	}
1182 
1183 #ifdef DEBUG
1184 	fprintf(stderr, "Writing new environment at 0x%llx on %s\n",
1185 		DEVOFFSET (dev_target), DEVNAME (dev_target));
1186 #endif
1187 
1188 	if (IS_UBI(dev_target)) {
1189 		if (ubi_update_start(fd_target, CUR_ENVSIZE) < 0)
1190 			return 0;
1191 		return ubi_write(fd_target, environment.image, CUR_ENVSIZE);
1192 	}
1193 
1194 	rc = flash_write_buf(dev_target, fd_target, environment.image,
1195 			     CUR_ENVSIZE);
1196 	if (rc < 0)
1197 		return rc;
1198 
1199 	if (environment.flag_scheme == FLAG_BOOLEAN) {
1200 		/* Have to set obsolete flag */
1201 		off_t offset = DEVOFFSET (dev_current) +
1202 			offsetof (struct env_image_redundant, flags);
1203 #ifdef DEBUG
1204 		fprintf(stderr,
1205 			"Setting obsolete flag in environment at 0x%llx on %s\n",
1206 			DEVOFFSET (dev_current), DEVNAME (dev_current));
1207 #endif
1208 		flash_flag_obsolete (dev_current, fd_current, offset);
1209 	}
1210 
1211 	return 0;
1212 }
1213 
1214 static int flash_read (int fd)
1215 {
1216 	int rc;
1217 
1218 	if (IS_UBI(dev_current)) {
1219 		DEVTYPE(dev_current) = MTD_ABSENT;
1220 
1221 		return ubi_read(fd, environment.image, CUR_ENVSIZE);
1222 	}
1223 
1224 	rc = flash_read_buf(dev_current, fd, environment.image, CUR_ENVSIZE,
1225 			    DEVOFFSET(dev_current));
1226 	if (rc != CUR_ENVSIZE)
1227 		return -1;
1228 
1229 	return 0;
1230 }
1231 
1232 static int flash_io (int mode)
1233 {
1234 	int fd_current, fd_target, rc, dev_target;
1235 
1236 	/* dev_current: fd_current, erase_current */
1237 	fd_current = open (DEVNAME (dev_current), mode);
1238 	if (fd_current < 0) {
1239 		fprintf (stderr,
1240 			 "Can't open %s: %s\n",
1241 			 DEVNAME (dev_current), strerror (errno));
1242 		return -1;
1243 	}
1244 
1245 	if (mode == O_RDWR) {
1246 		if (HaveRedundEnv) {
1247 			/* switch to next partition for writing */
1248 			dev_target = !dev_current;
1249 			/* dev_target: fd_target, erase_target */
1250 			fd_target = open (DEVNAME (dev_target), mode);
1251 			if (fd_target < 0) {
1252 				fprintf (stderr,
1253 					 "Can't open %s: %s\n",
1254 					 DEVNAME (dev_target),
1255 					 strerror (errno));
1256 				rc = -1;
1257 				goto exit;
1258 			}
1259 		} else {
1260 			dev_target = dev_current;
1261 			fd_target = fd_current;
1262 		}
1263 
1264 		rc = flash_write (fd_current, fd_target, dev_target);
1265 
1266 		if (fsync(fd_current) &&
1267 		    !(errno == EINVAL || errno == EROFS)) {
1268 			fprintf (stderr,
1269 				 "fsync failed on %s: %s\n",
1270 				 DEVNAME (dev_current), strerror (errno));
1271 		}
1272 
1273 		if (HaveRedundEnv) {
1274 			if (fsync(fd_target) &&
1275 			    !(errno == EINVAL || errno == EROFS)) {
1276 				fprintf (stderr,
1277 					 "fsync failed on %s: %s\n",
1278 					 DEVNAME (dev_current), strerror (errno));
1279 			}
1280 
1281 			if (close (fd_target)) {
1282 				fprintf (stderr,
1283 					"I/O error on %s: %s\n",
1284 					DEVNAME (dev_target),
1285 					strerror (errno));
1286 				rc = -1;
1287 			}
1288 		}
1289 	} else {
1290 		rc = flash_read (fd_current);
1291 	}
1292 
1293 exit:
1294 	if (close (fd_current)) {
1295 		fprintf (stderr,
1296 			 "I/O error on %s: %s\n",
1297 			 DEVNAME (dev_current), strerror (errno));
1298 		return -1;
1299 	}
1300 
1301 	return rc;
1302 }
1303 
1304 /*
1305  * Prevent confusion if running from erased flash memory
1306  */
1307 int fw_env_open(struct env_opts *opts)
1308 {
1309 	int crc0, crc0_ok;
1310 	unsigned char flag0;
1311 	void *addr0 = NULL;
1312 
1313 	int crc1, crc1_ok;
1314 	unsigned char flag1;
1315 	void *addr1 = NULL;
1316 
1317 	int ret;
1318 
1319 	struct env_image_single *single;
1320 	struct env_image_redundant *redundant;
1321 
1322 	if (!opts)
1323 		opts = &default_opts;
1324 
1325 	if (parse_config(opts))		/* should fill envdevices */
1326 		return -EINVAL;
1327 
1328 	addr0 = calloc(1, CUR_ENVSIZE);
1329 	if (addr0 == NULL) {
1330 		fprintf(stderr,
1331 			"Not enough memory for environment (%ld bytes)\n",
1332 			CUR_ENVSIZE);
1333 		ret = -ENOMEM;
1334 		goto open_cleanup;
1335 	}
1336 
1337 	/* read environment from FLASH to local buffer */
1338 	environment.image = addr0;
1339 
1340 	if (HaveRedundEnv) {
1341 		redundant = addr0;
1342 		environment.crc		= &redundant->crc;
1343 		environment.flags	= &redundant->flags;
1344 		environment.data	= redundant->data;
1345 	} else {
1346 		single = addr0;
1347 		environment.crc		= &single->crc;
1348 		environment.flags	= NULL;
1349 		environment.data	= single->data;
1350 	}
1351 
1352 	dev_current = 0;
1353 	if (flash_io(O_RDONLY)) {
1354 		ret = -EIO;
1355 		goto open_cleanup;
1356 	}
1357 
1358 	crc0 = crc32 (0, (uint8_t *) environment.data, ENV_SIZE);
1359 
1360 	crc0_ok = (crc0 == *environment.crc);
1361 	if (!HaveRedundEnv) {
1362 		if (!crc0_ok) {
1363 			fprintf (stderr,
1364 				"Warning: Bad CRC, using default environment\n");
1365 			memcpy(environment.data, default_environment, sizeof default_environment);
1366 		}
1367 	} else {
1368 		flag0 = *environment.flags;
1369 
1370 		dev_current = 1;
1371 		addr1 = calloc(1, CUR_ENVSIZE);
1372 		if (addr1 == NULL) {
1373 			fprintf(stderr,
1374 				"Not enough memory for environment (%ld bytes)\n",
1375 				CUR_ENVSIZE);
1376 			ret = -ENOMEM;
1377 			goto open_cleanup;
1378 		}
1379 		redundant = addr1;
1380 
1381 		/*
1382 		 * have to set environment.image for flash_read(), careful -
1383 		 * other pointers in environment still point inside addr0
1384 		 */
1385 		environment.image = addr1;
1386 		if (flash_io(O_RDONLY)) {
1387 			ret = -EIO;
1388 			goto open_cleanup;
1389 		}
1390 
1391 		/* Check flag scheme compatibility */
1392 		if (DEVTYPE(dev_current) == MTD_NORFLASH &&
1393 		    DEVTYPE(!dev_current) == MTD_NORFLASH) {
1394 			environment.flag_scheme = FLAG_BOOLEAN;
1395 		} else if (DEVTYPE(dev_current) == MTD_NANDFLASH &&
1396 			   DEVTYPE(!dev_current) == MTD_NANDFLASH) {
1397 			environment.flag_scheme = FLAG_INCREMENTAL;
1398 		} else if (DEVTYPE(dev_current) == MTD_DATAFLASH &&
1399 			   DEVTYPE(!dev_current) == MTD_DATAFLASH) {
1400 			environment.flag_scheme = FLAG_BOOLEAN;
1401 		} else if (DEVTYPE(dev_current) == MTD_UBIVOLUME &&
1402 			   DEVTYPE(!dev_current) == MTD_UBIVOLUME) {
1403 			environment.flag_scheme = FLAG_INCREMENTAL;
1404 		} else if (DEVTYPE(dev_current) == MTD_ABSENT &&
1405 			   DEVTYPE(!dev_current) == MTD_ABSENT &&
1406 			   IS_UBI(dev_current) == IS_UBI(!dev_current)) {
1407 			environment.flag_scheme = FLAG_INCREMENTAL;
1408 		} else {
1409 			fprintf (stderr, "Incompatible flash types!\n");
1410 			ret = -EINVAL;
1411 			goto open_cleanup;
1412 		}
1413 
1414 		crc1 = crc32 (0, (uint8_t *) redundant->data, ENV_SIZE);
1415 
1416 		crc1_ok = (crc1 == redundant->crc);
1417 		flag1 = redundant->flags;
1418 
1419 		if (crc0_ok && !crc1_ok) {
1420 			dev_current = 0;
1421 		} else if (!crc0_ok && crc1_ok) {
1422 			dev_current = 1;
1423 		} else if (!crc0_ok && !crc1_ok) {
1424 			fprintf (stderr,
1425 				"Warning: Bad CRC, using default environment\n");
1426 			memcpy (environment.data, default_environment,
1427 				sizeof default_environment);
1428 			dev_current = 0;
1429 		} else {
1430 			switch (environment.flag_scheme) {
1431 			case FLAG_BOOLEAN:
1432 				if (flag0 == active_flag &&
1433 				    flag1 == obsolete_flag) {
1434 					dev_current = 0;
1435 				} else if (flag0 == obsolete_flag &&
1436 					   flag1 == active_flag) {
1437 					dev_current = 1;
1438 				} else if (flag0 == flag1) {
1439 					dev_current = 0;
1440 				} else if (flag0 == 0xFF) {
1441 					dev_current = 0;
1442 				} else if (flag1 == 0xFF) {
1443 					dev_current = 1;
1444 				} else {
1445 					dev_current = 0;
1446 				}
1447 				break;
1448 			case FLAG_INCREMENTAL:
1449 				if (flag0 == 255 && flag1 == 0)
1450 					dev_current = 1;
1451 				else if ((flag1 == 255 && flag0 == 0) ||
1452 					 flag0 >= flag1)
1453 					dev_current = 0;
1454 				else /* flag1 > flag0 */
1455 					dev_current = 1;
1456 				break;
1457 			default:
1458 				fprintf (stderr, "Unknown flag scheme %u \n",
1459 					 environment.flag_scheme);
1460 				return -1;
1461 			}
1462 		}
1463 
1464 		/*
1465 		 * If we are reading, we don't need the flag and the CRC any
1466 		 * more, if we are writing, we will re-calculate CRC and update
1467 		 * flags before writing out
1468 		 */
1469 		if (dev_current) {
1470 			environment.image	= addr1;
1471 			environment.crc		= &redundant->crc;
1472 			environment.flags	= &redundant->flags;
1473 			environment.data	= redundant->data;
1474 			free (addr0);
1475 		} else {
1476 			environment.image	= addr0;
1477 			/* Other pointers are already set */
1478 			free (addr1);
1479 		}
1480 #ifdef DEBUG
1481 		fprintf(stderr, "Selected env in %s\n", DEVNAME(dev_current));
1482 #endif
1483 	}
1484 	return 0;
1485 
1486 open_cleanup:
1487 	if (addr0)
1488 		free(addr0);
1489 
1490 	if (addr1)
1491 		free(addr0);
1492 
1493 	return ret;
1494 }
1495 
1496 /*
1497  * Simply free allocated buffer with environment
1498  */
1499 int fw_env_close(struct env_opts *opts)
1500 {
1501 	if (environment.image)
1502 		free(environment.image);
1503 
1504 	environment.image = NULL;
1505 
1506 	return 0;
1507 }
1508 
1509 static int check_device_config(int dev)
1510 {
1511 	struct stat st;
1512 	int32_t lnum = 0;
1513 	int fd, rc = 0;
1514 
1515 	/* Fills in IS_UBI(), converts DEVNAME() with ubi volume name */
1516 	ubi_check_dev(dev);
1517 
1518 	fd = open(DEVNAME(dev), O_RDONLY);
1519 	if (fd < 0) {
1520 		fprintf(stderr,
1521 			"Cannot open %s: %s\n",
1522 			DEVNAME(dev), strerror(errno));
1523 		return -1;
1524 	}
1525 
1526 	rc = fstat(fd, &st);
1527 	if (rc < 0) {
1528 		fprintf(stderr, "Cannot stat the file %s\n",
1529 			DEVNAME(dev));
1530 		goto err;
1531 	}
1532 
1533 	if (IS_UBI(dev)) {
1534 		rc = ioctl(fd, UBI_IOCEBISMAP, &lnum);
1535 		if (rc < 0) {
1536 			fprintf(stderr, "Cannot get UBI information for %s\n",
1537 				DEVNAME(dev));
1538 			goto err;
1539 		}
1540 	} else if (S_ISCHR(st.st_mode)) {
1541 		struct mtd_info_user mtdinfo;
1542 		rc = ioctl(fd, MEMGETINFO, &mtdinfo);
1543 		if (rc < 0) {
1544 			fprintf(stderr, "Cannot get MTD information for %s\n",
1545 				DEVNAME(dev));
1546 			goto err;
1547 		}
1548 		if (mtdinfo.type != MTD_NORFLASH &&
1549 		    mtdinfo.type != MTD_NANDFLASH &&
1550 		    mtdinfo.type != MTD_DATAFLASH &&
1551 		    mtdinfo.type != MTD_UBIVOLUME) {
1552 			fprintf(stderr, "Unsupported flash type %u on %s\n",
1553 				mtdinfo.type, DEVNAME(dev));
1554 			goto err;
1555 		}
1556 		DEVTYPE(dev) = mtdinfo.type;
1557 		if (DEVESIZE(dev) == 0)
1558 			/* Assume the erase size is the same as the env-size */
1559 			DEVESIZE(dev) = ENVSIZE(dev);
1560 	} else {
1561 		uint64_t size;
1562 		DEVTYPE(dev) = MTD_ABSENT;
1563 		if (DEVESIZE(dev) == 0)
1564 			/* Assume the erase size to be 512 bytes */
1565 			DEVESIZE(dev) = 0x200;
1566 
1567 		/*
1568 		 * Check for negative offsets, treat it as backwards offset
1569 		 * from the end of the block device
1570 		 */
1571 		if (DEVOFFSET(dev) < 0) {
1572 			rc = ioctl(fd, BLKGETSIZE64, &size);
1573 			if (rc < 0) {
1574 				fprintf(stderr, "Could not get block device size on %s\n",
1575 					DEVNAME(dev));
1576 				goto err;
1577 			}
1578 
1579 			DEVOFFSET(dev) = DEVOFFSET(dev) + size;
1580 #ifdef DEBUG
1581 			fprintf(stderr, "Calculated device offset 0x%llx on %s\n",
1582 				DEVOFFSET(dev), DEVNAME(dev));
1583 #endif
1584 		}
1585 	}
1586 
1587 	if (ENVSECTORS(dev) == 0)
1588 		/* Assume enough sectors to cover the environment */
1589 		ENVSECTORS(dev) = DIV_ROUND_UP(ENVSIZE(dev), DEVESIZE(dev));
1590 
1591 	if (DEVOFFSET(dev) % DEVESIZE(dev) != 0) {
1592 		fprintf(stderr, "Environment does not start on (erase) block boundary\n");
1593 		errno = EINVAL;
1594 		return -1;
1595 	}
1596 
1597 	if (ENVSIZE(dev) > ENVSECTORS(dev) * DEVESIZE(dev)) {
1598 		fprintf(stderr, "Environment does not fit into available sectors\n");
1599 		errno = EINVAL;
1600 		return -1;
1601 	}
1602 
1603 err:
1604 	close(fd);
1605 	return rc;
1606 }
1607 
1608 static int parse_config(struct env_opts *opts)
1609 {
1610 	int rc;
1611 
1612 	if (!opts)
1613 		opts = &default_opts;
1614 
1615 #if defined(CONFIG_FILE)
1616 	/* Fills in DEVNAME(), ENVSIZE(), DEVESIZE(). Or don't. */
1617 	if (get_config(opts->config_file)) {
1618 		fprintf(stderr, "Cannot parse config file '%s': %m\n",
1619 			opts->config_file);
1620 		return -1;
1621 	}
1622 #else
1623 	DEVNAME (0) = DEVICE1_NAME;
1624 	DEVOFFSET (0) = DEVICE1_OFFSET;
1625 	ENVSIZE (0) = ENV1_SIZE;
1626 
1627 	/* Set defaults for DEVESIZE, ENVSECTORS later once we
1628 	 * know DEVTYPE
1629 	 */
1630 #ifdef DEVICE1_ESIZE
1631 	DEVESIZE (0) = DEVICE1_ESIZE;
1632 #endif
1633 #ifdef DEVICE1_ENVSECTORS
1634 	ENVSECTORS (0) = DEVICE1_ENVSECTORS;
1635 #endif
1636 
1637 #ifdef HAVE_REDUND
1638 	DEVNAME (1) = DEVICE2_NAME;
1639 	DEVOFFSET (1) = DEVICE2_OFFSET;
1640 	ENVSIZE (1) = ENV2_SIZE;
1641 
1642 	/* Set defaults for DEVESIZE, ENVSECTORS later once we
1643 	 * know DEVTYPE
1644 	 */
1645 #ifdef DEVICE2_ESIZE
1646 	DEVESIZE (1) = DEVICE2_ESIZE;
1647 #endif
1648 #ifdef DEVICE2_ENVSECTORS
1649 	ENVSECTORS (1) = DEVICE2_ENVSECTORS;
1650 #endif
1651 	HaveRedundEnv = 1;
1652 #endif
1653 #endif
1654 	rc = check_device_config(0);
1655 	if (rc < 0)
1656 		return rc;
1657 
1658 	if (HaveRedundEnv) {
1659 		rc = check_device_config(1);
1660 		if (rc < 0)
1661 			return rc;
1662 
1663 		if (ENVSIZE(0) != ENVSIZE(1)) {
1664 			fprintf(stderr,
1665 				"Redundant environments have unequal size");
1666 			return -1;
1667 		}
1668 	}
1669 
1670 	usable_envsize = CUR_ENVSIZE - sizeof(uint32_t);
1671 	if (HaveRedundEnv)
1672 		usable_envsize -= sizeof(char);
1673 
1674 	return 0;
1675 }
1676 
1677 #if defined(CONFIG_FILE)
1678 static int get_config (char *fname)
1679 {
1680 	FILE *fp;
1681 	int i = 0;
1682 	int rc;
1683 	char dump[128];
1684 	char *devname;
1685 
1686 	fp = fopen (fname, "r");
1687 	if (fp == NULL)
1688 		return -1;
1689 
1690 	while (i < 2 && fgets (dump, sizeof (dump), fp)) {
1691 		/* Skip incomplete conversions and comment strings */
1692 		if (dump[0] == '#')
1693 			continue;
1694 
1695 		rc = sscanf(dump, "%ms %lli %lx %lx %lx",
1696 			    &devname,
1697 			    &DEVOFFSET(i),
1698 			    &ENVSIZE(i),
1699 			    &DEVESIZE(i),
1700 			    &ENVSECTORS(i));
1701 
1702 		if (rc < 3)
1703 			continue;
1704 
1705 		DEVNAME(i) = devname;
1706 
1707 		/* Set defaults for DEVESIZE, ENVSECTORS later once we
1708 		 * know DEVTYPE
1709 		 */
1710 
1711 		i++;
1712 	}
1713 	fclose (fp);
1714 
1715 	HaveRedundEnv = i - 1;
1716 	if (!i) {			/* No valid entries found */
1717 		errno = EINVAL;
1718 		return -1;
1719 	} else
1720 		return 0;
1721 }
1722 #endif
1723