xref: /openbmc/u-boot/tools/env/fw_env.c (revision 8ee59472)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2000-2010
4  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5  *
6  * (C) Copyright 2008
7  * Guennadi Liakhovetski, DENX Software Engineering, lg@denx.de.
8  */
9 
10 #define _GNU_SOURCE
11 
12 #include <compiler.h>
13 #include <errno.h>
14 #include <env_flags.h>
15 #include <fcntl.h>
16 #include <libgen.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 		.mtd_type = MTD_ABSENT,
70 	}, {
71 		.mtd_type = MTD_ABSENT,
72 	},
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 have_redund_env;
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, "Error: can't write fw_env to flash\n");
519 		return -1;
520 	}
521 
522 	return 0;
523 }
524 
525 /*
526  * Set/Clear a single variable in the environment.
527  * This is called in sequence to update the environment
528  * in RAM without updating the copy in flash after each set
529  */
530 int fw_env_write(char *name, char *value)
531 {
532 	int len;
533 	char *env, *nxt;
534 	char *oldval = NULL;
535 	int deleting, creating, overwriting;
536 
537 	/*
538 	 * search if variable with this name already exists
539 	 */
540 	for (nxt = env = environment.data; *env; env = nxt + 1) {
541 		for (nxt = env; *nxt; ++nxt) {
542 			if (nxt >= &environment.data[ENV_SIZE]) {
543 				fprintf(stderr, "## Error: "
544 					"environment not terminated\n");
545 				errno = EINVAL;
546 				return -1;
547 			}
548 		}
549 		oldval = envmatch(name, env);
550 		if (oldval)
551 			break;
552 	}
553 
554 	deleting = (oldval && !(value && strlen(value)));
555 	creating = (!oldval && (value && strlen(value)));
556 	overwriting = (oldval && (value && strlen(value)));
557 
558 	/* check for permission */
559 	if (deleting) {
560 		if (env_flags_validate_varaccess(name,
561 		    ENV_FLAGS_VARACCESS_PREVENT_DELETE)) {
562 			printf("Can't delete \"%s\"\n", name);
563 			errno = EROFS;
564 			return -1;
565 		}
566 	} else if (overwriting) {
567 		if (env_flags_validate_varaccess(name,
568 		    ENV_FLAGS_VARACCESS_PREVENT_OVERWR)) {
569 			printf("Can't overwrite \"%s\"\n", name);
570 			errno = EROFS;
571 			return -1;
572 		} else if (env_flags_validate_varaccess(name,
573 			   ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR)) {
574 			const char *defval = fw_getdefenv(name);
575 
576 			if (defval == NULL)
577 				defval = "";
578 			if (strcmp(oldval, defval)
579 			    != 0) {
580 				printf("Can't overwrite \"%s\"\n", name);
581 				errno = EROFS;
582 				return -1;
583 			}
584 		}
585 	} else if (creating) {
586 		if (env_flags_validate_varaccess(name,
587 		    ENV_FLAGS_VARACCESS_PREVENT_CREATE)) {
588 			printf("Can't create \"%s\"\n", name);
589 			errno = EROFS;
590 			return -1;
591 		}
592 	} else
593 		/* Nothing to do */
594 		return 0;
595 
596 	if (deleting || overwriting) {
597 		if (*++nxt == '\0') {
598 			*env = '\0';
599 		} else {
600 			for (;;) {
601 				*env = *nxt++;
602 				if ((*env == '\0') && (*nxt == '\0'))
603 					break;
604 				++env;
605 			}
606 		}
607 		*++env = '\0';
608 	}
609 
610 	/* Delete only ? */
611 	if (!value || !strlen(value))
612 		return 0;
613 
614 	/*
615 	 * Append new definition at the end
616 	 */
617 	for (env = environment.data; *env || *(env + 1); ++env)
618 		;
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", name);
632 		return -1;
633 	}
634 
635 	while ((*env = *name++) != '\0')
636 		env++;
637 	*env = '=';
638 	while ((*++env = *value++) != '\0')
639 		;
640 
641 	/* end is marked with double '\0' */
642 	*++env = '\0';
643 
644 	return 0;
645 }
646 
647 /*
648  * Deletes or sets environment variables. Returns -1 and sets errno error codes:
649  * 0	  - OK
650  * EINVAL - need at least 1 argument
651  * EROFS  - certain variables ("ethaddr", "serial#") cannot be
652  *	    modified or deleted
653  *
654  */
655 int fw_env_set(int argc, char *argv[], struct env_opts *opts)
656 {
657 	int i;
658 	size_t len;
659 	char *name, **valv;
660 	char *oldval;
661 	char *value = NULL;
662 	int valc;
663 	int ret;
664 
665 	if (!opts)
666 		opts = &default_opts;
667 
668 	if (argc < 1) {
669 		fprintf(stderr, "## Error: variable name missing\n");
670 		errno = EINVAL;
671 		return -1;
672 	}
673 
674 	if (fw_env_open(opts)) {
675 		fprintf(stderr, "Error: environment not initialized\n");
676 		return -1;
677 	}
678 
679 	name = argv[0];
680 	valv = argv + 1;
681 	valc = argc - 1;
682 
683 	if (env_flags_validate_env_set_params(name, valv, valc) < 0) {
684 		fw_env_close(opts);
685 		return -1;
686 	}
687 
688 	len = 0;
689 	for (i = 0; i < valc; ++i) {
690 		char *val = valv[i];
691 		size_t val_len = strlen(val);
692 
693 		if (value)
694 			value[len - 1] = ' ';
695 		oldval = value;
696 		value = realloc(value, len + val_len + 1);
697 		if (!value) {
698 			fprintf(stderr,
699 				"Cannot malloc %zu bytes: %s\n",
700 				len, strerror(errno));
701 			free(oldval);
702 			return -1;
703 		}
704 
705 		memcpy(value + len, val, val_len);
706 		len += val_len;
707 		value[len++] = '\0';
708 	}
709 
710 	fw_env_write(name, value);
711 
712 	free(value);
713 
714 	ret = fw_env_flush(opts);
715 	fw_env_close(opts);
716 
717 	return ret;
718 }
719 
720 /*
721  * Parse  a file  and configure the u-boot variables.
722  * The script file has a very simple format, as follows:
723  *
724  * Each line has a couple with name, value:
725  * <white spaces>variable_name<white spaces>variable_value
726  *
727  * Both variable_name and variable_value are interpreted as strings.
728  * Any character after <white spaces> and before ending \r\n is interpreted
729  * as variable's value (no comment allowed on these lines !)
730  *
731  * Comments are allowed if the first character in the line is #
732  *
733  * Returns -1 and sets errno error codes:
734  * 0	  - OK
735  * -1     - Error
736  */
737 int fw_parse_script(char *fname, struct env_opts *opts)
738 {
739 	FILE *fp;
740 	char dump[1024];	/* Maximum line length in the file */
741 	char *name;
742 	char *val;
743 	int lineno = 0;
744 	int len;
745 	int ret = 0;
746 
747 	if (!opts)
748 		opts = &default_opts;
749 
750 	if (fw_env_open(opts)) {
751 		fprintf(stderr, "Error: environment not initialized\n");
752 		return -1;
753 	}
754 
755 	if (strcmp(fname, "-") == 0)
756 		fp = stdin;
757 	else {
758 		fp = fopen(fname, "r");
759 		if (fp == NULL) {
760 			fprintf(stderr, "I cannot open %s for reading\n",
761 				fname);
762 			return -1;
763 		}
764 	}
765 
766 	while (fgets(dump, sizeof(dump), fp)) {
767 		lineno++;
768 		len = strlen(dump);
769 
770 		/*
771 		 * Read a whole line from the file. If the line is too long
772 		 * or is not terminated, reports an error and exit.
773 		 */
774 		if (dump[len - 1] != '\n') {
775 			fprintf(stderr,
776 				"Line %d not corrected terminated or too long\n",
777 				lineno);
778 			ret = -1;
779 			break;
780 		}
781 
782 		/* Drop ending line feed / carriage return */
783 		dump[--len] = '\0';
784 		if (len && dump[len - 1] == '\r')
785 			dump[--len] = '\0';
786 
787 		/* Skip comment or empty lines */
788 		if (len == 0 || dump[0] == '#')
789 			continue;
790 
791 		/*
792 		 * Search for variable's name,
793 		 * remove leading whitespaces
794 		 */
795 		name = skip_blanks(dump);
796 		if (!name)
797 			continue;
798 
799 		/* The first white space is the end of variable name */
800 		val = skip_chars(name);
801 		len = strlen(name);
802 		if (val) {
803 			*val++ = '\0';
804 			if ((val - name) < len)
805 				val = skip_blanks(val);
806 			else
807 				val = NULL;
808 		}
809 #ifdef DEBUG
810 		fprintf(stderr, "Setting %s : %s\n",
811 			name, val ? val : " removed");
812 #endif
813 
814 		if (env_flags_validate_type(name, val) < 0) {
815 			ret = -1;
816 			break;
817 		}
818 
819 		/*
820 		 * If there is an error setting a variable,
821 		 * try to save the environment and returns an error
822 		 */
823 		if (fw_env_write(name, val)) {
824 			fprintf(stderr,
825 				"fw_env_write returns with error : %s\n",
826 				strerror(errno));
827 			ret = -1;
828 			break;
829 		}
830 
831 	}
832 
833 	/* Close file if not stdin */
834 	if (strcmp(fname, "-") != 0)
835 		fclose(fp);
836 
837 	ret |= fw_env_flush(opts);
838 
839 	fw_env_close(opts);
840 
841 	return ret;
842 }
843 
844 /**
845  * environment_end() - compute offset of first byte right after environemnt
846  * @dev - index of enviroment buffer
847  * Return:
848  *  device offset of first byte right after environemnt
849  */
850 off_t environment_end(int dev)
851 {
852 	/* environment is block aligned */
853 	return DEVOFFSET(dev) + ENVSECTORS(dev) * DEVESIZE(dev);
854 }
855 
856 /*
857  * Test for bad block on NAND, just returns 0 on NOR, on NAND:
858  * 0	- block is good
859  * > 0	- block is bad
860  * < 0	- failed to test
861  */
862 static int flash_bad_block(int fd, uint8_t mtd_type, loff_t blockstart)
863 {
864 	if (mtd_type == MTD_NANDFLASH) {
865 		int badblock = ioctl(fd, MEMGETBADBLOCK, &blockstart);
866 
867 		if (badblock < 0) {
868 			perror("Cannot read bad block mark");
869 			return badblock;
870 		}
871 
872 		if (badblock) {
873 #ifdef DEBUG
874 			fprintf(stderr, "Bad block at 0x%llx, skipping\n",
875 				(unsigned long long)blockstart);
876 #endif
877 			return badblock;
878 		}
879 	}
880 
881 	return 0;
882 }
883 
884 /*
885  * Read data from flash at an offset into a provided buffer. On NAND it skips
886  * bad blocks but makes sure it stays within ENVSECTORS (dev) starting from
887  * the DEVOFFSET (dev) block. On NOR the loop is only run once.
888  */
889 static int flash_read_buf(int dev, int fd, void *buf, size_t count,
890 			  off_t offset)
891 {
892 	size_t blocklen;	/* erase / write length - one block on NAND,
893 				   0 on NOR */
894 	size_t processed = 0;	/* progress counter */
895 	size_t readlen = count;	/* current read length */
896 	off_t block_seek;	/* offset inside the current block to the start
897 				   of the data */
898 	loff_t blockstart;	/* running start of the current block -
899 				   MEMGETBADBLOCK needs 64 bits */
900 	int rc;
901 
902 	blockstart = (offset / DEVESIZE(dev)) * DEVESIZE(dev);
903 
904 	/* Offset inside a block */
905 	block_seek = offset - blockstart;
906 
907 	if (DEVTYPE(dev) == MTD_NANDFLASH) {
908 		/*
909 		 * NAND: calculate which blocks we are reading. We have
910 		 * to read one block at a time to skip bad blocks.
911 		 */
912 		blocklen = DEVESIZE(dev);
913 
914 		/* Limit to one block for the first read */
915 		if (readlen > blocklen - block_seek)
916 			readlen = blocklen - block_seek;
917 	} else {
918 		blocklen = 0;
919 	}
920 
921 	/* This only runs once on NOR flash */
922 	while (processed < count) {
923 		rc = flash_bad_block(fd, DEVTYPE(dev), blockstart);
924 		if (rc < 0)	/* block test failed */
925 			return -1;
926 
927 		if (blockstart + block_seek + readlen > environment_end(dev)) {
928 			/* End of range is reached */
929 			fprintf(stderr, "Too few good blocks within range\n");
930 			return -1;
931 		}
932 
933 		if (rc) {	/* block is bad */
934 			blockstart += blocklen;
935 			continue;
936 		}
937 
938 		/*
939 		 * If a block is bad, we retry in the next block at the same
940 		 * offset - see env/nand.c::writeenv()
941 		 */
942 		lseek(fd, blockstart + block_seek, SEEK_SET);
943 
944 		rc = read(fd, buf + processed, readlen);
945 		if (rc != readlen) {
946 			fprintf(stderr, "Read error on %s: %s\n",
947 				DEVNAME(dev), strerror(errno));
948 			return -1;
949 		}
950 #ifdef DEBUG
951 		fprintf(stderr, "Read 0x%x bytes at 0x%llx on %s\n",
952 			rc, (unsigned long long)blockstart + block_seek,
953 			DEVNAME(dev));
954 #endif
955 		processed += readlen;
956 		readlen = min(blocklen, count - processed);
957 		block_seek = 0;
958 		blockstart += blocklen;
959 	}
960 
961 	return processed;
962 }
963 
964 /*
965  * Write count bytes from begin of environment, but stay within
966  * ENVSECTORS(dev) sectors of
967  * DEVOFFSET (dev). Similar to the read case above, on NOR and dataflash we
968  * erase and write the whole data at once.
969  */
970 static int flash_write_buf(int dev, int fd, void *buf, size_t count)
971 {
972 	void *data;
973 	struct erase_info_user erase;
974 	size_t blocklen;	/* length of NAND block / NOR erase sector */
975 	size_t erase_len;	/* whole area that can be erased - may include
976 				   bad blocks */
977 	size_t erasesize;	/* erase / write length - one block on NAND,
978 				   whole area on NOR */
979 	size_t processed = 0;	/* progress counter */
980 	size_t write_total;	/* total size to actually write - excluding
981 				   bad blocks */
982 	off_t erase_offset;	/* offset to the first erase block (aligned)
983 				   below offset */
984 	off_t block_seek;	/* offset inside the erase block to the start
985 				   of the data */
986 	loff_t blockstart;	/* running start of the current block -
987 				   MEMGETBADBLOCK needs 64 bits */
988 	int rc;
989 
990 	/*
991 	 * For mtd devices only offset and size of the environment do matter
992 	 */
993 	if (DEVTYPE(dev) == MTD_ABSENT) {
994 		blocklen = count;
995 		erase_len = blocklen;
996 		blockstart = DEVOFFSET(dev);
997 		block_seek = 0;
998 		write_total = blocklen;
999 	} else {
1000 		blocklen = DEVESIZE(dev);
1001 
1002 		erase_offset = DEVOFFSET(dev);
1003 
1004 		/* Maximum area we may use */
1005 		erase_len = environment_end(dev) - erase_offset;
1006 
1007 		blockstart = erase_offset;
1008 
1009 		/* Offset inside a block */
1010 		block_seek = DEVOFFSET(dev) - erase_offset;
1011 
1012 		/*
1013 		 * Data size we actually write: from the start of the block
1014 		 * to the start of the data, then count bytes of data, and
1015 		 * to the end of the block
1016 		 */
1017 		write_total = ((block_seek + count + blocklen - 1) /
1018 			       blocklen) * blocklen;
1019 	}
1020 
1021 	/*
1022 	 * Support data anywhere within erase sectors: read out the complete
1023 	 * area to be erased, replace the environment image, write the whole
1024 	 * block back again.
1025 	 */
1026 	if (write_total > count) {
1027 		data = malloc(erase_len);
1028 		if (!data) {
1029 			fprintf(stderr,
1030 				"Cannot malloc %zu bytes: %s\n",
1031 				erase_len, strerror(errno));
1032 			return -1;
1033 		}
1034 
1035 		rc = flash_read_buf(dev, fd, data, write_total, erase_offset);
1036 		if (write_total != rc)
1037 			return -1;
1038 
1039 #ifdef DEBUG
1040 		fprintf(stderr, "Preserving data ");
1041 		if (block_seek != 0)
1042 			fprintf(stderr, "0x%x - 0x%lx", 0, block_seek - 1);
1043 		if (block_seek + count != write_total) {
1044 			if (block_seek != 0)
1045 				fprintf(stderr, " and ");
1046 			fprintf(stderr, "0x%lx - 0x%lx",
1047 				(unsigned long)block_seek + count,
1048 				(unsigned long)write_total - 1);
1049 		}
1050 		fprintf(stderr, "\n");
1051 #endif
1052 		/* Overwrite the old environment */
1053 		memcpy(data + block_seek, buf, count);
1054 	} else {
1055 		/*
1056 		 * We get here, iff offset is block-aligned and count is a
1057 		 * multiple of blocklen - see write_total calculation above
1058 		 */
1059 		data = buf;
1060 	}
1061 
1062 	if (DEVTYPE(dev) == MTD_NANDFLASH) {
1063 		/*
1064 		 * NAND: calculate which blocks we are writing. We have
1065 		 * to write one block at a time to skip bad blocks.
1066 		 */
1067 		erasesize = blocklen;
1068 	} else {
1069 		erasesize = erase_len;
1070 	}
1071 
1072 	erase.length = erasesize;
1073 
1074 	/* This only runs once on NOR flash and SPI-dataflash */
1075 	while (processed < write_total) {
1076 		rc = flash_bad_block(fd, DEVTYPE(dev), blockstart);
1077 		if (rc < 0)	/* block test failed */
1078 			return rc;
1079 
1080 		if (blockstart + erasesize > environment_end(dev)) {
1081 			fprintf(stderr, "End of range reached, aborting\n");
1082 			return -1;
1083 		}
1084 
1085 		if (rc) {	/* block is bad */
1086 			blockstart += blocklen;
1087 			continue;
1088 		}
1089 
1090 		if (DEVTYPE(dev) != MTD_ABSENT) {
1091 			erase.start = blockstart;
1092 			ioctl(fd, MEMUNLOCK, &erase);
1093 			/* These do not need an explicit erase cycle */
1094 			if (DEVTYPE(dev) != MTD_DATAFLASH)
1095 				if (ioctl(fd, MEMERASE, &erase) != 0) {
1096 					fprintf(stderr,
1097 						"MTD erase error on %s: %s\n",
1098 						DEVNAME(dev), strerror(errno));
1099 					return -1;
1100 				}
1101 		}
1102 
1103 		if (lseek(fd, blockstart, SEEK_SET) == -1) {
1104 			fprintf(stderr,
1105 				"Seek error on %s: %s\n",
1106 				DEVNAME(dev), strerror(errno));
1107 			return -1;
1108 		}
1109 #ifdef DEBUG
1110 		fprintf(stderr, "Write 0x%llx bytes at 0x%llx\n",
1111 			(unsigned long long)erasesize,
1112 			(unsigned long long)blockstart);
1113 #endif
1114 		if (write(fd, data + processed, erasesize) != erasesize) {
1115 			fprintf(stderr, "Write error on %s: %s\n",
1116 				DEVNAME(dev), strerror(errno));
1117 			return -1;
1118 		}
1119 
1120 		if (DEVTYPE(dev) != MTD_ABSENT)
1121 			ioctl(fd, MEMLOCK, &erase);
1122 
1123 		processed += erasesize;
1124 		block_seek = 0;
1125 		blockstart += erasesize;
1126 	}
1127 
1128 	if (write_total > count)
1129 		free(data);
1130 
1131 	return processed;
1132 }
1133 
1134 /*
1135  * Set obsolete flag at offset - NOR flash only
1136  */
1137 static int flash_flag_obsolete(int dev, int fd, off_t offset)
1138 {
1139 	int rc;
1140 	struct erase_info_user erase;
1141 
1142 	erase.start = DEVOFFSET(dev);
1143 	erase.length = DEVESIZE(dev);
1144 	/* This relies on the fact, that obsolete_flag == 0 */
1145 	rc = lseek(fd, offset, SEEK_SET);
1146 	if (rc < 0) {
1147 		fprintf(stderr, "Cannot seek to set the flag on %s\n",
1148 			DEVNAME(dev));
1149 		return rc;
1150 	}
1151 	ioctl(fd, MEMUNLOCK, &erase);
1152 	rc = write(fd, &obsolete_flag, sizeof(obsolete_flag));
1153 	ioctl(fd, MEMLOCK, &erase);
1154 	if (rc < 0)
1155 		perror("Could not set obsolete flag");
1156 
1157 	return rc;
1158 }
1159 
1160 static int flash_write(int fd_current, int fd_target, int dev_target)
1161 {
1162 	int rc;
1163 
1164 	switch (environment.flag_scheme) {
1165 	case FLAG_NONE:
1166 		break;
1167 	case FLAG_INCREMENTAL:
1168 		(*environment.flags)++;
1169 		break;
1170 	case FLAG_BOOLEAN:
1171 		*environment.flags = active_flag;
1172 		break;
1173 	default:
1174 		fprintf(stderr, "Unimplemented flash scheme %u\n",
1175 			environment.flag_scheme);
1176 		return -1;
1177 	}
1178 
1179 #ifdef DEBUG
1180 	fprintf(stderr, "Writing new environment at 0x%llx on %s\n",
1181 		DEVOFFSET(dev_target), DEVNAME(dev_target));
1182 #endif
1183 
1184 	if (IS_UBI(dev_target)) {
1185 		if (ubi_update_start(fd_target, CUR_ENVSIZE) < 0)
1186 			return 0;
1187 		return ubi_write(fd_target, environment.image, CUR_ENVSIZE);
1188 	}
1189 
1190 	rc = flash_write_buf(dev_target, fd_target, environment.image,
1191 			     CUR_ENVSIZE);
1192 	if (rc < 0)
1193 		return rc;
1194 
1195 	if (environment.flag_scheme == FLAG_BOOLEAN) {
1196 		/* Have to set obsolete flag */
1197 		off_t offset = DEVOFFSET(dev_current) +
1198 		    offsetof(struct env_image_redundant, flags);
1199 #ifdef DEBUG
1200 		fprintf(stderr,
1201 			"Setting obsolete flag in environment at 0x%llx on %s\n",
1202 			DEVOFFSET(dev_current), DEVNAME(dev_current));
1203 #endif
1204 		flash_flag_obsolete(dev_current, fd_current, offset);
1205 	}
1206 
1207 	return 0;
1208 }
1209 
1210 static int flash_read(int fd)
1211 {
1212 	int rc;
1213 
1214 	if (IS_UBI(dev_current)) {
1215 		DEVTYPE(dev_current) = MTD_ABSENT;
1216 
1217 		return ubi_read(fd, environment.image, CUR_ENVSIZE);
1218 	}
1219 
1220 	rc = flash_read_buf(dev_current, fd, environment.image, CUR_ENVSIZE,
1221 			    DEVOFFSET(dev_current));
1222 	if (rc != CUR_ENVSIZE)
1223 		return -1;
1224 
1225 	return 0;
1226 }
1227 
1228 static int flash_open_tempfile(const char **dname, const char **target_temp)
1229 {
1230 	char *dup_name = strdup(DEVNAME(dev_current));
1231 	char *temp_name = NULL;
1232 	int rc = -1;
1233 
1234 	if (!dup_name)
1235 		return -1;
1236 
1237 	*dname = dirname(dup_name);
1238 	if (!*dname)
1239 		goto err;
1240 
1241 	rc = asprintf(&temp_name, "%s/XXXXXX", *dname);
1242 	if (rc == -1)
1243 		goto err;
1244 
1245 	rc = mkstemp(temp_name);
1246 	if (rc == -1) {
1247 		/* fall back to in place write */
1248 		fprintf(stderr,
1249 			"Can't create %s: %s\n", temp_name, strerror(errno));
1250 		free(temp_name);
1251 	} else {
1252 		*target_temp = temp_name;
1253 		/* deliberately leak dup_name as dname /might/ point into
1254 		 * it and we need it for our caller
1255 		 */
1256 		dup_name = NULL;
1257 	}
1258 
1259 err:
1260 	if (dup_name)
1261 		free(dup_name);
1262 
1263 	return rc;
1264 }
1265 
1266 static int flash_io_write(int fd_current)
1267 {
1268 	int fd_target = -1, rc, dev_target;
1269 	const char *dname, *target_temp = NULL;
1270 
1271 	if (have_redund_env) {
1272 		/* switch to next partition for writing */
1273 		dev_target = !dev_current;
1274 		/* dev_target: fd_target, erase_target */
1275 		fd_target = open(DEVNAME(dev_target), O_RDWR);
1276 		if (fd_target < 0) {
1277 			fprintf(stderr,
1278 				"Can't open %s: %s\n",
1279 				DEVNAME(dev_target), strerror(errno));
1280 			rc = -1;
1281 			goto exit;
1282 		}
1283 	} else {
1284 		struct stat sb;
1285 
1286 		if (fstat(fd_current, &sb) == 0 && S_ISREG(sb.st_mode)) {
1287 			/* if any part of flash_open_tempfile() fails we fall
1288 			 * back to in-place writes
1289 			 */
1290 			fd_target = flash_open_tempfile(&dname, &target_temp);
1291 		}
1292 		dev_target = dev_current;
1293 		if (fd_target == -1)
1294 			fd_target = fd_current;
1295 	}
1296 
1297 	rc = flash_write(fd_current, fd_target, dev_target);
1298 
1299 	if (fsync(fd_current) && !(errno == EINVAL || errno == EROFS)) {
1300 		fprintf(stderr,
1301 			"fsync failed on %s: %s\n",
1302 			DEVNAME(dev_current), strerror(errno));
1303 	}
1304 
1305 	if (fd_current != fd_target) {
1306 		if (fsync(fd_target) &&
1307 		    !(errno == EINVAL || errno == EROFS)) {
1308 			fprintf(stderr,
1309 				"fsync failed on %s: %s\n",
1310 				DEVNAME(dev_current), strerror(errno));
1311 		}
1312 
1313 		if (close(fd_target)) {
1314 			fprintf(stderr,
1315 				"I/O error on %s: %s\n",
1316 				DEVNAME(dev_target), strerror(errno));
1317 			rc = -1;
1318 		}
1319 
1320 		if (target_temp) {
1321 			int dir_fd;
1322 
1323 			dir_fd = open(dname, O_DIRECTORY | O_RDONLY);
1324 			if (dir_fd == -1)
1325 				fprintf(stderr,
1326 					"Can't open %s: %s\n",
1327 					dname, strerror(errno));
1328 
1329 			if (rename(target_temp, DEVNAME(dev_target))) {
1330 				fprintf(stderr,
1331 					"rename failed %s => %s: %s\n",
1332 					target_temp, DEVNAME(dev_target),
1333 					strerror(errno));
1334 				rc = -1;
1335 			}
1336 
1337 			if (dir_fd != -1 && fsync(dir_fd))
1338 				fprintf(stderr,
1339 					"fsync failed on %s: %s\n",
1340 					dname, strerror(errno));
1341 
1342 			if (dir_fd != -1 && close(dir_fd))
1343 				fprintf(stderr,
1344 					"I/O error on %s: %s\n",
1345 					dname, strerror(errno));
1346 		}
1347 	}
1348  exit:
1349 	return rc;
1350 }
1351 
1352 static int flash_io(int mode)
1353 {
1354 	int fd_current, rc;
1355 
1356 	/* dev_current: fd_current, erase_current */
1357 	fd_current = open(DEVNAME(dev_current), mode);
1358 	if (fd_current < 0) {
1359 		fprintf(stderr,
1360 			"Can't open %s: %s\n",
1361 			DEVNAME(dev_current), strerror(errno));
1362 		return -1;
1363 	}
1364 
1365 	if (mode == O_RDWR) {
1366 		rc = flash_io_write(fd_current);
1367 	} else {
1368 		rc = flash_read(fd_current);
1369 	}
1370 
1371 	if (close(fd_current)) {
1372 		fprintf(stderr,
1373 			"I/O error on %s: %s\n",
1374 			DEVNAME(dev_current), strerror(errno));
1375 		return -1;
1376 	}
1377 
1378 	return rc;
1379 }
1380 
1381 /*
1382  * Prevent confusion if running from erased flash memory
1383  */
1384 int fw_env_open(struct env_opts *opts)
1385 {
1386 	int crc0, crc0_ok;
1387 	unsigned char flag0;
1388 	void *addr0 = NULL;
1389 
1390 	int crc1, crc1_ok;
1391 	unsigned char flag1;
1392 	void *addr1 = NULL;
1393 
1394 	int ret;
1395 
1396 	struct env_image_single *single;
1397 	struct env_image_redundant *redundant;
1398 
1399 	if (!opts)
1400 		opts = &default_opts;
1401 
1402 	if (parse_config(opts))	/* should fill envdevices */
1403 		return -EINVAL;
1404 
1405 	addr0 = calloc(1, CUR_ENVSIZE);
1406 	if (addr0 == NULL) {
1407 		fprintf(stderr,
1408 			"Not enough memory for environment (%ld bytes)\n",
1409 			CUR_ENVSIZE);
1410 		ret = -ENOMEM;
1411 		goto open_cleanup;
1412 	}
1413 
1414 	/* read environment from FLASH to local buffer */
1415 	environment.image = addr0;
1416 
1417 	if (have_redund_env) {
1418 		redundant = addr0;
1419 		environment.crc = &redundant->crc;
1420 		environment.flags = &redundant->flags;
1421 		environment.data = redundant->data;
1422 	} else {
1423 		single = addr0;
1424 		environment.crc = &single->crc;
1425 		environment.flags = NULL;
1426 		environment.data = single->data;
1427 	}
1428 
1429 	dev_current = 0;
1430 	if (flash_io(O_RDONLY)) {
1431 		ret = -EIO;
1432 		goto open_cleanup;
1433 	}
1434 
1435 	crc0 = crc32(0, (uint8_t *)environment.data, ENV_SIZE);
1436 
1437 	crc0_ok = (crc0 == *environment.crc);
1438 	if (!have_redund_env) {
1439 		if (!crc0_ok) {
1440 			fprintf(stderr,
1441 				"Warning: Bad CRC, using default environment\n");
1442 			memcpy(environment.data, default_environment,
1443 			       sizeof(default_environment));
1444 		}
1445 	} else {
1446 		flag0 = *environment.flags;
1447 
1448 		dev_current = 1;
1449 		addr1 = calloc(1, CUR_ENVSIZE);
1450 		if (addr1 == NULL) {
1451 			fprintf(stderr,
1452 				"Not enough memory for environment (%ld bytes)\n",
1453 				CUR_ENVSIZE);
1454 			ret = -ENOMEM;
1455 			goto open_cleanup;
1456 		}
1457 		redundant = addr1;
1458 
1459 		/*
1460 		 * have to set environment.image for flash_read(), careful -
1461 		 * other pointers in environment still point inside addr0
1462 		 */
1463 		environment.image = addr1;
1464 		if (flash_io(O_RDONLY)) {
1465 			ret = -EIO;
1466 			goto open_cleanup;
1467 		}
1468 
1469 		/* Check flag scheme compatibility */
1470 		if (DEVTYPE(dev_current) == MTD_NORFLASH &&
1471 		    DEVTYPE(!dev_current) == MTD_NORFLASH) {
1472 			environment.flag_scheme = FLAG_BOOLEAN;
1473 		} else if (DEVTYPE(dev_current) == MTD_NANDFLASH &&
1474 			   DEVTYPE(!dev_current) == MTD_NANDFLASH) {
1475 			environment.flag_scheme = FLAG_INCREMENTAL;
1476 		} else if (DEVTYPE(dev_current) == MTD_DATAFLASH &&
1477 			   DEVTYPE(!dev_current) == MTD_DATAFLASH) {
1478 			environment.flag_scheme = FLAG_BOOLEAN;
1479 		} else if (DEVTYPE(dev_current) == MTD_UBIVOLUME &&
1480 			   DEVTYPE(!dev_current) == MTD_UBIVOLUME) {
1481 			environment.flag_scheme = FLAG_INCREMENTAL;
1482 		} else if (DEVTYPE(dev_current) == MTD_ABSENT &&
1483 			   DEVTYPE(!dev_current) == MTD_ABSENT &&
1484 			   IS_UBI(dev_current) == IS_UBI(!dev_current)) {
1485 			environment.flag_scheme = FLAG_INCREMENTAL;
1486 		} else {
1487 			fprintf(stderr, "Incompatible flash types!\n");
1488 			ret = -EINVAL;
1489 			goto open_cleanup;
1490 		}
1491 
1492 		crc1 = crc32(0, (uint8_t *)redundant->data, ENV_SIZE);
1493 
1494 		crc1_ok = (crc1 == redundant->crc);
1495 		flag1 = redundant->flags;
1496 
1497 		if (crc0_ok && !crc1_ok) {
1498 			dev_current = 0;
1499 		} else if (!crc0_ok && crc1_ok) {
1500 			dev_current = 1;
1501 		} else if (!crc0_ok && !crc1_ok) {
1502 			fprintf(stderr,
1503 				"Warning: Bad CRC, using default environment\n");
1504 			memcpy(environment.data, default_environment,
1505 			       sizeof(default_environment));
1506 			dev_current = 0;
1507 		} else {
1508 			switch (environment.flag_scheme) {
1509 			case FLAG_BOOLEAN:
1510 				if (flag0 == active_flag &&
1511 				    flag1 == obsolete_flag) {
1512 					dev_current = 0;
1513 				} else if (flag0 == obsolete_flag &&
1514 					   flag1 == active_flag) {
1515 					dev_current = 1;
1516 				} else if (flag0 == flag1) {
1517 					dev_current = 0;
1518 				} else if (flag0 == 0xFF) {
1519 					dev_current = 0;
1520 				} else if (flag1 == 0xFF) {
1521 					dev_current = 1;
1522 				} else {
1523 					dev_current = 0;
1524 				}
1525 				break;
1526 			case FLAG_INCREMENTAL:
1527 				if (flag0 == 255 && flag1 == 0)
1528 					dev_current = 1;
1529 				else if ((flag1 == 255 && flag0 == 0) ||
1530 					 flag0 >= flag1)
1531 					dev_current = 0;
1532 				else	/* flag1 > flag0 */
1533 					dev_current = 1;
1534 				break;
1535 			default:
1536 				fprintf(stderr, "Unknown flag scheme %u\n",
1537 					environment.flag_scheme);
1538 				return -1;
1539 			}
1540 		}
1541 
1542 		/*
1543 		 * If we are reading, we don't need the flag and the CRC any
1544 		 * more, if we are writing, we will re-calculate CRC and update
1545 		 * flags before writing out
1546 		 */
1547 		if (dev_current) {
1548 			environment.image = addr1;
1549 			environment.crc = &redundant->crc;
1550 			environment.flags = &redundant->flags;
1551 			environment.data = redundant->data;
1552 			free(addr0);
1553 		} else {
1554 			environment.image = addr0;
1555 			/* Other pointers are already set */
1556 			free(addr1);
1557 		}
1558 #ifdef DEBUG
1559 		fprintf(stderr, "Selected env in %s\n", DEVNAME(dev_current));
1560 #endif
1561 	}
1562 	return 0;
1563 
1564  open_cleanup:
1565 	if (addr0)
1566 		free(addr0);
1567 
1568 	if (addr1)
1569 		free(addr0);
1570 
1571 	return ret;
1572 }
1573 
1574 /*
1575  * Simply free allocated buffer with environment
1576  */
1577 int fw_env_close(struct env_opts *opts)
1578 {
1579 	if (environment.image)
1580 		free(environment.image);
1581 
1582 	environment.image = NULL;
1583 
1584 	return 0;
1585 }
1586 
1587 static int check_device_config(int dev)
1588 {
1589 	struct stat st;
1590 	int32_t lnum = 0;
1591 	int fd, rc = 0;
1592 
1593 	/* Fills in IS_UBI(), converts DEVNAME() with ubi volume name */
1594 	ubi_check_dev(dev);
1595 
1596 	fd = open(DEVNAME(dev), O_RDONLY);
1597 	if (fd < 0) {
1598 		fprintf(stderr,
1599 			"Cannot open %s: %s\n", DEVNAME(dev), strerror(errno));
1600 		return -1;
1601 	}
1602 
1603 	rc = fstat(fd, &st);
1604 	if (rc < 0) {
1605 		fprintf(stderr, "Cannot stat the file %s\n", DEVNAME(dev));
1606 		goto err;
1607 	}
1608 
1609 	if (IS_UBI(dev)) {
1610 		rc = ioctl(fd, UBI_IOCEBISMAP, &lnum);
1611 		if (rc < 0) {
1612 			fprintf(stderr, "Cannot get UBI information for %s\n",
1613 				DEVNAME(dev));
1614 			goto err;
1615 		}
1616 	} else if (S_ISCHR(st.st_mode)) {
1617 		struct mtd_info_user mtdinfo;
1618 		rc = ioctl(fd, MEMGETINFO, &mtdinfo);
1619 		if (rc < 0) {
1620 			fprintf(stderr, "Cannot get MTD information for %s\n",
1621 				DEVNAME(dev));
1622 			goto err;
1623 		}
1624 		if (mtdinfo.type != MTD_NORFLASH &&
1625 		    mtdinfo.type != MTD_NANDFLASH &&
1626 		    mtdinfo.type != MTD_DATAFLASH &&
1627 		    mtdinfo.type != MTD_UBIVOLUME) {
1628 			fprintf(stderr, "Unsupported flash type %u on %s\n",
1629 				mtdinfo.type, DEVNAME(dev));
1630 			goto err;
1631 		}
1632 		DEVTYPE(dev) = mtdinfo.type;
1633 		if (DEVESIZE(dev) == 0)
1634 			/* Assume the erase size is the same as the env-size */
1635 			DEVESIZE(dev) = ENVSIZE(dev);
1636 	} else {
1637 		uint64_t size;
1638 		DEVTYPE(dev) = MTD_ABSENT;
1639 		if (DEVESIZE(dev) == 0)
1640 			/* Assume the erase size to be 512 bytes */
1641 			DEVESIZE(dev) = 0x200;
1642 
1643 		/*
1644 		 * Check for negative offsets, treat it as backwards offset
1645 		 * from the end of the block device
1646 		 */
1647 		if (DEVOFFSET(dev) < 0) {
1648 			rc = ioctl(fd, BLKGETSIZE64, &size);
1649 			if (rc < 0) {
1650 				fprintf(stderr,
1651 					"Could not get block device size on %s\n",
1652 					DEVNAME(dev));
1653 				goto err;
1654 			}
1655 
1656 			DEVOFFSET(dev) = DEVOFFSET(dev) + size;
1657 #ifdef DEBUG
1658 			fprintf(stderr,
1659 				"Calculated device offset 0x%llx on %s\n",
1660 				DEVOFFSET(dev), DEVNAME(dev));
1661 #endif
1662 		}
1663 	}
1664 
1665 	if (ENVSECTORS(dev) == 0)
1666 		/* Assume enough sectors to cover the environment */
1667 		ENVSECTORS(dev) = DIV_ROUND_UP(ENVSIZE(dev), DEVESIZE(dev));
1668 
1669 	if (DEVOFFSET(dev) % DEVESIZE(dev) != 0) {
1670 		fprintf(stderr,
1671 			"Environment does not start on (erase) block boundary\n");
1672 		errno = EINVAL;
1673 		return -1;
1674 	}
1675 
1676 	if (ENVSIZE(dev) > ENVSECTORS(dev) * DEVESIZE(dev)) {
1677 		fprintf(stderr,
1678 			"Environment does not fit into available sectors\n");
1679 		errno = EINVAL;
1680 		return -1;
1681 	}
1682 
1683  err:
1684 	close(fd);
1685 	return rc;
1686 }
1687 
1688 static int parse_config(struct env_opts *opts)
1689 {
1690 	int rc;
1691 
1692 	if (!opts)
1693 		opts = &default_opts;
1694 
1695 #if defined(CONFIG_FILE)
1696 	/* Fills in DEVNAME(), ENVSIZE(), DEVESIZE(). Or don't. */
1697 	if (get_config(opts->config_file)) {
1698 		fprintf(stderr, "Cannot parse config file '%s': %m\n",
1699 			opts->config_file);
1700 		return -1;
1701 	}
1702 #else
1703 	DEVNAME(0) = DEVICE1_NAME;
1704 	DEVOFFSET(0) = DEVICE1_OFFSET;
1705 	ENVSIZE(0) = ENV1_SIZE;
1706 
1707 	/* Set defaults for DEVESIZE, ENVSECTORS later once we
1708 	 * know DEVTYPE
1709 	 */
1710 #ifdef DEVICE1_ESIZE
1711 	DEVESIZE(0) = DEVICE1_ESIZE;
1712 #endif
1713 #ifdef DEVICE1_ENVSECTORS
1714 	ENVSECTORS(0) = DEVICE1_ENVSECTORS;
1715 #endif
1716 
1717 #ifdef HAVE_REDUND
1718 	DEVNAME(1) = DEVICE2_NAME;
1719 	DEVOFFSET(1) = DEVICE2_OFFSET;
1720 	ENVSIZE(1) = ENV2_SIZE;
1721 
1722 	/* Set defaults for DEVESIZE, ENVSECTORS later once we
1723 	 * know DEVTYPE
1724 	 */
1725 #ifdef DEVICE2_ESIZE
1726 	DEVESIZE(1) = DEVICE2_ESIZE;
1727 #endif
1728 #ifdef DEVICE2_ENVSECTORS
1729 	ENVSECTORS(1) = DEVICE2_ENVSECTORS;
1730 #endif
1731 	have_redund_env = 1;
1732 #endif
1733 #endif
1734 	rc = check_device_config(0);
1735 	if (rc < 0)
1736 		return rc;
1737 
1738 	if (have_redund_env) {
1739 		rc = check_device_config(1);
1740 		if (rc < 0)
1741 			return rc;
1742 
1743 		if (ENVSIZE(0) != ENVSIZE(1)) {
1744 			fprintf(stderr,
1745 				"Redundant environments have unequal size");
1746 			return -1;
1747 		}
1748 	}
1749 
1750 	usable_envsize = CUR_ENVSIZE - sizeof(uint32_t);
1751 	if (have_redund_env)
1752 		usable_envsize -= sizeof(char);
1753 
1754 	return 0;
1755 }
1756 
1757 #if defined(CONFIG_FILE)
1758 static int get_config(char *fname)
1759 {
1760 	FILE *fp;
1761 	int i = 0;
1762 	int rc;
1763 	char dump[128];
1764 	char *devname;
1765 
1766 	fp = fopen(fname, "r");
1767 	if (fp == NULL)
1768 		return -1;
1769 
1770 	while (i < 2 && fgets(dump, sizeof(dump), fp)) {
1771 		/* Skip incomplete conversions and comment strings */
1772 		if (dump[0] == '#')
1773 			continue;
1774 
1775 		rc = sscanf(dump, "%ms %lli %lx %lx %lx",
1776 			    &devname,
1777 			    &DEVOFFSET(i),
1778 			    &ENVSIZE(i), &DEVESIZE(i), &ENVSECTORS(i));
1779 
1780 		if (rc < 3)
1781 			continue;
1782 
1783 		DEVNAME(i) = devname;
1784 
1785 		/* Set defaults for DEVESIZE, ENVSECTORS later once we
1786 		 * know DEVTYPE
1787 		 */
1788 
1789 		i++;
1790 	}
1791 	fclose(fp);
1792 
1793 	have_redund_env = i - 1;
1794 	if (!i) {		/* No valid entries found */
1795 		errno = EINVAL;
1796 		return -1;
1797 	} else
1798 		return 0;
1799 }
1800 #endif
1801