summaryrefslogtreecommitdiff
path: root/common/env_flags.c
blob: 09f93d59d63367580f436dd82c16167ed6f86e92 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
/*
 * (C) Copyright 2012
 * Joe Hershberger, National Instruments, joe.hershberger@ni.com
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <linux/string.h>
#include <linux/ctype.h>

#ifdef USE_HOSTCC /* Eliminate "ANSI does not permit..." warnings */
#include <stdint.h>
#include <stdio.h>
#include "fw_env.h"
#include <env_attr.h>
#include <env_flags.h>
#define getenv fw_getenv
#else
#include <common.h>
#include <environment.h>
#endif

#ifdef CONFIG_CMD_NET
#define ENV_FLAGS_NET_VARTYPE_REPS "im"
#else
#define ENV_FLAGS_NET_VARTYPE_REPS ""
#endif

static const char env_flags_vartype_rep[] = "sdxb" ENV_FLAGS_NET_VARTYPE_REPS;
#ifdef CONFIG_CMD_ENV_FLAGS
static const char * const env_flags_vartype_names[] = {
	"string",
	"decimal",
	"hexadecimal",
	"boolean",
#ifdef CONFIG_CMD_NET
	"IP address",
	"MAC address",
#endif
};

/*
 * Print the whole list of available type flags.
 */
void env_flags_print_vartypes(void)
{
	enum env_flags_vartype curtype = (enum env_flags_vartype)0;

	while (curtype != env_flags_vartype_end) {
		printf("\t%c   -\t%s\n", env_flags_vartype_rep[curtype],
			env_flags_vartype_names[curtype]);
		curtype++;
	}
}

/*
 * Return the name of the type.
 */
const char *env_flags_get_vartype_name(enum env_flags_vartype type)
{
	return env_flags_vartype_names[type];
}
#endif /* CONFIG_CMD_ENV_FLAGS */

/*
 * Parse the flags string from a .flags attribute list into the vartype enum.
 */
enum env_flags_vartype env_flags_parse_vartype(const char *flags)
{
	char *type;

	if (strlen(flags) <= ENV_FLAGS_VARTYPE_LOC)
		return env_flags_vartype_string;

	type = strchr(env_flags_vartype_rep,
		flags[ENV_FLAGS_VARTYPE_LOC]);

	if (type != NULL)
		return (enum env_flags_vartype)
			(type - &env_flags_vartype_rep[0]);

	printf("## Warning: Unknown environment variable type '%c'\n",
		flags[ENV_FLAGS_VARTYPE_LOC]);
	return env_flags_vartype_string;
}

static inline int is_hex_prefix(const char *value)
{
	return value[0] == '0' && (value[1] == 'x' || value[1] == 'X');
}

static void skip_num(int hex, const char *value, const char **end,
	int max_digits)
{
	int i;

	if (hex && is_hex_prefix(value))
		value += 2;

	for (i = max_digits; i != 0; i--) {
		if (hex && !isxdigit(*value))
			break;
		if (!hex && !isdigit(*value))
			break;
		value++;
	}
	if (end != NULL)
		*end = value;
}

/*
 * Based on the declared type enum, validate that the value string complies
 * with that format
 */
static int _env_flags_validate_type(const char *value,
	enum env_flags_vartype type)
{
	const char *end;
#ifdef CONFIG_CMD_NET
	const char *cur;
	int i;
#endif

	switch (type) {
	case env_flags_vartype_string:
		break;
	case env_flags_vartype_decimal:
		skip_num(0, value, &end, -1);
		if (*end != '\0')
			return -1;
		break;
	case env_flags_vartype_hex:
		skip_num(1, value, &end, -1);
		if (*end != '\0')
			return -1;
		if (value + 2 == end && is_hex_prefix(value))
			return -1;
		break;
	case env_flags_vartype_bool:
		if (value[0] != '1' && value[0] != 'y' && value[0] != 't' &&
		    value[0] != 'Y' && value[0] != 'T' &&
		    value[0] != '0' && value[0] != 'n' && value[0] != 'f' &&
		    value[0] != 'N' && value[0] != 'F')
			return -1;
		if (value[1] != '\0')
			return -1;
		break;
#ifdef CONFIG_CMD_NET
	case env_flags_vartype_ipaddr:
		cur = value;
		for (i = 0; i < 4; i++) {
			skip_num(0, cur, &end, 3);
			if (cur == end)
				return -1;
			if (i != 3 && *end != '.')
				return -1;
			if (i == 3 && *end != '\0')
				return -1;
			cur = end + 1;
		}
		break;
	case env_flags_vartype_macaddr:
		cur = value;
		for (i = 0; i < 6; i++) {
			skip_num(1, cur, &end, 2);
			if (cur == end)
				return -1;
			if (cur + 2 == end && is_hex_prefix(cur))
				return -1;
			if (i != 5 && *end != ':')
				return -1;
			if (i == 5 && *end != '\0')
				return -1;
			cur = end + 1;
		}
		break;
#endif
	case env_flags_vartype_end:
		return -1;
	}

	/* OK */
	return 0;
}

/*
 * Look for flags in a provided list and failing that the static list
 */
static inline int env_flags_lookup(const char *flags_list, const char *name,
	char *flags)
{
	int ret = 1;

	if (!flags)
		/* bad parameter */
		return -1;

	/* try the env first */
	if (flags_list)
		ret = env_attr_lookup(flags_list, name, flags);

	if (ret != 0)
		/* if not found in the env, look in the static list */
		ret = env_attr_lookup(ENV_FLAGS_LIST_STATIC, name, flags);

	return ret;
}

#ifdef USE_HOSTCC /* Functions only used from tools/env */
/*
 * Look up any flags directly from the .flags variable and the static list
 * and convert them to the vartype enum.
 */
enum env_flags_vartype env_flags_get_type(const char *name)
{
	const char *flags_list = getenv(ENV_FLAGS_VAR);
	char flags[ENV_FLAGS_ATTR_MAX_LEN + 1];

	if (env_flags_lookup(flags_list, name, flags))
		return env_flags_vartype_string;

	if (strlen(flags) <= ENV_FLAGS_VARTYPE_LOC)
		return env_flags_vartype_string;

	return env_flags_parse_vartype(flags);
}

/*
 * Validate that the proposed new value for "name" is valid according to the
 * defined flags for that variable, if any.
 */
int env_flags_validate_type(const char *name, const char *value)
{
	enum env_flags_vartype type;

	if (value == NULL)
		return 0;
	type = env_flags_get_type(name);
	if (_env_flags_validate_type(value, type) < 0) {
		printf("## Error: flags type check failure for "
			"\"%s\" <= \"%s\" (type: %c)\n",
			name, value, env_flags_vartype_rep[type]);
		return -1;
	}
	return 0;
}

/*
 * Validate the parameters to "env set" directly
 */
int env_flags_validate_env_set_params(int argc, char * const argv[])
{
	if ((argc >= 3) && argv[2] != NULL) {
		enum env_flags_vartype type = env_flags_get_type(argv[1]);

		/*
		 * we don't currently check types that need more than
		 * one argument
		 */
		if (type != env_flags_vartype_string && argc > 3) {
			printf("## Error: too many parameters for setting "
				"\"%s\"\n", argv[1]);
			return -1;
		}
		return env_flags_validate_type(argv[1], argv[2]);
	}
	/* ok */
	return 0;
}

#else /* !USE_HOSTCC - Functions only used from lib/hashtable.c */

/*
 * Parse the flag charachters from the .flags attribute list into the binary
 * form to be stored in the environment entry->flags field.
 */
static int env_parse_flags_to_bin(const char *flags)
{
	return env_flags_parse_vartype(flags) & ENV_FLAGS_VARTYPE_BIN_MASK;
}

/*
 * Look for possible flags for a newly added variable
 * This is called specifically when the variable did not exist in the hash
 * previously, so the blanket update did not find this variable.
 */
void env_flags_init(ENTRY *var_entry)
{
	const char *var_name = var_entry->key;
	const char *flags_list = getenv(ENV_FLAGS_VAR);
	char flags[ENV_FLAGS_ATTR_MAX_LEN + 1] = "";
	int ret = 1;

	/* look in the ".flags" and static for a reference to this variable */
	ret = env_flags_lookup(flags_list, var_name, flags);

	/* if any flags were found, set the binary form to the entry */
	if (!ret && strlen(flags))
		var_entry->flags = env_parse_flags_to_bin(flags);
}

/*
 * Called on each existing env var prior to the blanket update since removing
 * a flag in the flag list should remove its flags.
 */
static int clear_flags(ENTRY *entry)
{
	entry->flags = 0;

	return 0;
}

/*
 * Call for each element in the list that defines flags for a variable
 */
static int set_flags(const char *name, const char *value)
{
	ENTRY e, *ep;

	e.key	= name;
	e.data	= NULL;
	hsearch_r(e, FIND, &ep, &env_htab, 0);

	/* does the env variable actually exist? */
	if (ep != NULL) {
		/* the flag list is empty, so clear the flags */
		if (value == NULL || strlen(value) == 0)
			ep->flags = 0;
		else
			/* assign the requested flags */
			ep->flags = env_parse_flags_to_bin(value);
	}

	return 0;
}

static int on_flags(const char *name, const char *value, enum env_op op,
	int flags)
{
	/* remove all flags */
	hwalk_r(&env_htab, clear_flags);

	/* configure any static flags */
	env_attr_walk(ENV_FLAGS_LIST_STATIC, set_flags);
	/* configure any dynamic flags */
	env_attr_walk(value, set_flags);

	return 0;
}
U_BOOT_ENV_CALLBACK(flags, on_flags);

/*
 * Perform consistency checking before creating, overwriting, or deleting an
 * environment variable. Called as a callback function by hsearch_r() and
 * hdelete_r(). Returns 0 in case of success, 1 in case of failure.
 * When (flag & H_FORCE) is set, do not print out any error message and force
 * overwriting of write-once variables.
 */

int env_flags_validate(const ENTRY *item, const char *newval, enum env_op op,
	int flag)
{
	const char *name;
#if !defined(CONFIG_ENV_OVERWRITE) && defined(CONFIG_OVERWRITE_ETHADDR_ONCE) \
&& defined(CONFIG_ETHADDR)
	const char *oldval = NULL;

	if (op != env_op_create)
		oldval = item->data;
#endif

	name = item->key;

	/* Default value for NULL to protect string-manipulating functions */
	newval = newval ? : "";

#ifndef CONFIG_ENV_OVERWRITE
	/*
	 * Some variables like "ethaddr" and "serial#" can be set only once and
	 * cannot be deleted, unless CONFIG_ENV_OVERWRITE is defined.
	 */
	if (op != env_op_create &&		/* variable exists */
		(flag & H_FORCE) == 0) {	/* and we are not forced */
		if (strcmp(name, "serial#") == 0 ||
		    (strcmp(name, "ethaddr") == 0
#if defined(CONFIG_OVERWRITE_ETHADDR_ONCE) && defined(CONFIG_ETHADDR)
		     && strcmp(oldval, __stringify(CONFIG_ETHADDR)) != 0
#endif	/* CONFIG_OVERWRITE_ETHADDR_ONCE && CONFIG_ETHADDR */
			)) {
			printf("Can't overwrite \"%s\"\n", name);
			return 1;
		}
	}
#endif

	/* validate the value to match the variable type */
	if (op != env_op_delete) {
		enum env_flags_vartype type = (enum env_flags_vartype)
			(ENV_FLAGS_VARTYPE_BIN_MASK & item->flags);

		if (_env_flags_validate_type(newval, type) < 0) {
			printf("## Error: flags type check failure for "
				"\"%s\" <= \"%s\" (type: %c)\n",
				name, newval, env_flags_vartype_rep[type]);
			return -1;
		}
	}

	return 0;
}

#endif