[people/ms/u-boot.git] / common / cmd_setexpr.c

/*
 * Copyright 2008 Freescale Semiconductor, Inc.
 * Copyright 2013 Wolfgang Denk <wd@denx.de>
 *
 * 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
 */

/*
 * This file provides a shell like 'expr' function to return.
 */

#include <common.h>
#include <config.h>
#include <command.h>

static ulong get_arg(char *s, int w)
{
	ulong *p;

	/*
	 * if the parameter starts with a '*' then assume
	 * it is a pointer to the value we want
	 */

	if (s[0] == '*') {
		p = (ulong *)simple_strtoul(&s[1], NULL, 16);
		switch (w) {
		case 1: return((ulong)(*(uchar *)p));
		case 2: return((ulong)(*(ushort *)p));
		case 4:
		default: return(*p);
		}
	} else {
		return simple_strtoul(s, NULL, 16);
	}
}

#ifdef CONFIG_REGEX

#include <slre.h>

#define SLRE_BUFSZ	16384
#define SLRE_PATSZ	4096

/*
 * memstr - Find the first substring in memory
 * @s1: The string to be searched
 * @s2: The string to search for
 *
 * Similar to and based on strstr(),
 * but strings do not need to be NUL terminated.
 */
static char *memstr(const char *s1, int l1, const char *s2, int l2)
{
	if (!l2)
		return (char *)s1;

	while (l1 >= l2) {
		l1--;
		if (!memcmp(s1, s2, l2))
			return (char *)s1;
		s1++;
	}
	return NULL;
}

static char *substitute(char *string,	/* string buffer */
			int *slen,	/* current string length */
			int ssize,	/* string bufer size */
			const char *old,/* old (replaced) string */
			int olen,	/* length of old string */
			const char *new,/* new (replacement) string */
			int nlen)	/* length of new string */
{
	char *p = memstr(string, *slen, old, olen);

	if (p == NULL)
		return NULL;

	debug("## Match at pos %ld: match len %d, subst len %d\n",
		(long)(p - string), olen, nlen);

	/* make sure replacement matches */
	if (*slen + nlen - olen > ssize) {
		printf("## error: substitution buffer overflow\n");
		return NULL;
	}

	/* move tail if needed */
	if (olen != nlen) {
		int tail, len;

		len = (olen > nlen) ? olen : nlen;

		tail = ssize - (p + len - string);

		debug("## tail len %d\n", tail);

		memmove(p + nlen, p + olen, tail);
	}

	/* insert substitue */
	memcpy(p, new, nlen);

	*slen += nlen - olen;

	return p + nlen;
}

/*
 * Perform regex operations on a environment variable
 *
 * Returns 0 if OK, 1 in case of errors.
 */
static int regex_sub(const char *name,
	const char *r, const char *s, const char *t,
	int global)
{
	struct slre slre;
	char data[SLRE_BUFSZ];
	char *datap = data;
	const char *value;
	int res, len, nlen, loop;

	if (name == NULL)
		return 1;

	if (slre_compile(&slre, r) == 0) {
		printf("Error compiling regex: %s\n", slre.err_str);
		return 1;
	}

	if (t == NULL) {
		value = getenv(name);

		if (value == NULL) {
			printf("## Error: variable \"%s\" not defined\n", name);
			return 1;
		}
		t = value;
	}

	debug("REGEX on %s=%s\n", name, t);
	debug("REGEX=\"%s\", SUBST=\"%s\", GLOBAL=%d\n",
		r, s ? s : "<NULL>", global);

	len = strlen(t);
	if (len + 1 > SLRE_BUFSZ) {
		printf("## error: subst buffer overflow: have %d, need %d\n",
			SLRE_BUFSZ, len + 1);
		return 1;
	}

	strcpy(data, t);

	if (s == NULL)
		nlen = 0;
	else
		nlen = strlen(s);

	for (loop = 0;; loop++) {
		struct cap caps[slre.num_caps + 2];
		char nbuf[SLRE_PATSZ];
		const char *old;
		char *np;
		int i, olen;

		(void) memset(caps, 0, sizeof(caps));

		res = slre_match(&slre, datap, len, caps);

		debug("Result: %d\n", res);

		for (i = 0; i < slre.num_caps; i++) {
			if (caps[i].len > 0) {
				debug("Substring %d: [%.*s]\n", i,
					caps[i].len, caps[i].ptr);
			}
		}

		if (res == 0) {
			if (loop == 0) {
				printf("%s: No match\n", t);
				return 1;
			} else {
				break;
			}
		}

		debug("## MATCH ## %s\n", data);

		if (s == NULL) {
			printf("%s=%s\n", name, t);
			return 1;
		}

		old = caps[0].ptr;
		olen = caps[0].len;

		if (nlen + 1 >= SLRE_PATSZ) {
			printf("## error: pattern buffer overflow: have %d, need %d\n",
				SLRE_BUFSZ, nlen + 1);
			return 1;
		}
		strcpy(nbuf, s);

		debug("## SUBST(1) ## %s\n", nbuf);

		/*
		 * Handle back references
		 *
		 * Support for \0 ... \9, where \0 is the
		 * whole matched pattern (similar to &).
		 *
		 * Implementation is a bit simpleminded as
		 * backrefs are substituted sequentially, one
		 * by one.  This will lead to somewhat
		 * unexpected results if the replacement
		 * strings contain any \N strings then then
		 * may get substitued, too.  We accept this
		 * restriction for the sake of simplicity.
		 */
		for (i = 0; i < 10; ++i) {
			char backref[2] = {
				'\\',
				'0',
			};

			if (caps[i].len == 0)
				break;

			backref[1] += i;

			debug("## BACKREF %d: replace \"%.*s\" by \"%.*s\" in \"%s\"\n",
				i,
				2, backref,
				caps[i].len, caps[i].ptr,
				nbuf);

			for (np = nbuf;;) {
				char *p = memstr(np, nlen, backref, 2);

				if (p == NULL)
					break;

				np = substitute(np, &nlen,
					SLRE_PATSZ,
					backref, 2,
					caps[i].ptr, caps[i].len);

				if (np == NULL)
					return 1;
			}
		}
		debug("## SUBST(2) ## %s\n", nbuf);

		datap = substitute(datap, &len, SLRE_BUFSZ,
				old, olen,
				nbuf, nlen);

		if (datap == NULL)
			return 1;

		debug("## REMAINDER: %s\n", datap);

		debug("## RESULT: %s\n", data);

		if (!global)
			break;
	}
	debug("## FINAL (now setenv()) :  %s\n", data);

	printf("%s=%s\n", name, data);

	return setenv(name, data);
}
#endif

static int do_setexpr(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
	ulong a, b;
	ulong value;
	int w;

	/*
	 * We take 3, 5, or 6 arguments:
	 * 3 : setexpr name value
	 * 5 : setexpr name val1 op val2
	 *     setexpr name [g]sub r s
	 * 6 : setexpr name [g]sub r s t
	 */

	/* > 6 already tested by max command args */
	if ((argc < 3) || (argc == 4))
		return CMD_RET_USAGE;

	w = cmd_get_data_size(argv[0], 4);

	a = get_arg(argv[2], w);

	/* plain assignment: "setexpr name value" */
	if (argc == 3) {
		setenv_hex(argv[1], a);
		return 0;
	}

	/* 5 or 6 args (6 args only with [g]sub) */
#ifdef CONFIG_REGEX
	/*
	 * rexep handling: "setexpr name [g]sub r s [t]"
	 * with 5 args, "t" will be NULL
	 */
	if (strcmp(argv[2], "gsub") == 0)
		return regex_sub(argv[1], argv[3], argv[4], argv[5], 1);

	if (strcmp(argv[2], "sub") == 0)
		return regex_sub(argv[1], argv[3], argv[4], argv[5], 0);
#endif

	/* standard operators: "setexpr name val1 op val2" */
	if (argc != 5)
		return CMD_RET_USAGE;

	if (strlen(argv[3]) != 1)
		return CMD_RET_USAGE;

	b = get_arg(argv[4], w);

	switch (argv[3][0]) {
	case '|':
		value = a | b;
		break;
	case '&':
		value = a & b;
		break;
	case '+':
		value = a + b;
		break;
	case '^':
		value = a ^ b;
		break;
	case '-':
		value = a - b;
		break;
	case '*':
		value = a * b;
		break;
	case '/':
		value = a / b;
		break;
	case '%':
		value = a % b;
		break;
	default:
		printf("invalid op\n");
		return 1;
	}

	setenv_hex(argv[1], value);

	return 0;
}

U_BOOT_CMD(
	setexpr, 6, 0, do_setexpr,
	"set environment variable as the result of eval expression",
	"[.b, .w, .l] name [*]value1 <op> [*]value2\n"
	"    - set environment variable 'name' to the result of the evaluated\n"
	"      expression specified by <op>.  <op> can be &, |, ^, +, -, *, /, %\n"
	"      size argument is only meaningful if value1 and/or value2 are\n"
	"      memory addresses (*)\n"
	"setexpr[.b, .w, .l] name [*]value\n"
	"    - load a value into a variable"
#ifdef CONFIG_REGEX
	"\n"
	"setexpr name gsub r s [t]\n"
	"    - For each substring matching the regular expression <r> in the\n"
	"      string <t>, substitute the string <s>.  The result is\n"
	"      assigned to <name>.  If <t> is not supplied, use the old\n"
	"      value of <name>\n"
	"setexpr name sub r s [t]\n"
	"    - Just like gsub(), but replace only the first matching substring"
#endif
);
Commit	Line	Data
d058698f KG	1	/*
d058698f KG	2	* Copyright 2008 Freescale Semiconductor, Inc.
855f18ea	3	* Copyright 2013 Wolfgang Denk <wd@denx.de>
d058698f KG	4	*
	5	* See file CREDITS for list of people who contributed to this
	6	* project.
	7	*
	8	* This program is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU General Public License as
	10	* published by the Free Software Foundation; either version 2 of
	11	* the License, or (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	21	* MA 02111-1307 USA
	22	*/
	23
	24	/*
	25	* This file provides a shell like 'expr' function to return.
	26	*/
	27
	28	#include <common.h>
	29	#include <config.h>
	30	#include <command.h>
	31
47ab5ad1 FM	32	static ulong get_arg(char *s, int w)
	33	{
	34	ulong *p;
	35
482126e2	36	/*
47ab5ad1 FM	37	* if the parameter starts with a '*' then assume
	38	* it is a pointer to the value we want
	39	*/
	40
	41	if (s[0] == '*') {
	42	p = (ulong *)simple_strtoul(&s[1], NULL, 16);
	43	switch (w) {
	44	case 1: return((ulong)((uchar )p));
	45	case 2: return((ulong)((ushort )p));
	46	case 4:
	47	default: return(*p);
	48	}
	49	} else {
	50	return simple_strtoul(s, NULL, 16);
	51	}
	52	}
	53
855f18ea WD	54	#ifdef CONFIG_REGEX
	55
	56	#include <slre.h>
	57
	58	#define SLRE_BUFSZ 16384
	59	#define SLRE_PATSZ 4096
	60
	61	/*
	62	* memstr - Find the first substring in memory
	63	* @s1: The string to be searched
	64	* @s2: The string to search for
	65	*
	66	* Similar to and based on strstr(),
	67	* but strings do not need to be NUL terminated.
	68	*/
	69	static char memstr(const char s1, int l1, const char *s2, int l2)
	70	{
	71	if (!l2)
	72	return (char *)s1;
	73
	74	while (l1 >= l2) {
	75	l1--;
	76	if (!memcmp(s1, s2, l2))
	77	return (char *)s1;
	78	s1++;
	79	}
	80	return NULL;
	81	}
	82
	83	static char substitute(char string, /* string buffer */
	84	int slen, / current string length */
	85	int ssize, /* string bufer size */
	86	const char old,/ old (replaced) string */
	87	int olen, /* length of old string */
	88	const char new,/ new (replacement) string */
	89	int nlen) /* length of new string */
	90	{
	91	char p = memstr(string, slen, old, olen);
	92
	93	if (p == NULL)
	94	return NULL;
	95
	96	debug("## Match at pos %ld: match len %d, subst len %d\n",
	97	(long)(p - string), olen, nlen);
	98
	99	/* make sure replacement matches */
	100	if (*slen + nlen - olen > ssize) {
	101	printf("## error: substitution buffer overflow\n");
	102	return NULL;
	103	}
	104
	105	/* move tail if needed */
	106	if (olen != nlen) {
	107	int tail, len;
	108
	109	len = (olen > nlen) ? olen : nlen;
	110
	111	tail = ssize - (p + len - string);
	112
	113	debug("## tail len %d\n", tail);
	114
	115	memmove(p + nlen, p + olen, tail);
	116	}
	117
118	/* insert substitue */
119	memcpy(p, new, nlen);
120
121	*slen += nlen - olen;
122
123	return p + nlen;
124	}
125
126	/*
127	* Perform regex operations on a environment variable
128	*
129	* Returns 0 if OK, 1 in case of errors.
130	*/
131	static int regex_sub(const char *name,
132	const char r, const char s, const char *t,
133	int global)
134	{
135	struct slre slre;
136	char data[SLRE_BUFSZ];
137	char *datap = data;
138	const char *value;
139	int res, len, nlen, loop;
140
141	if (name == NULL)
142	return 1;
143
144	if (slre_compile(&slre, r) == 0) {
145	printf("Error compiling regex: %s\n", slre.err_str);
146	return 1;
147	}
148
149	if (t == NULL) {
150	value = getenv(name);
151
152	if (value == NULL) {
153	printf("## Error: variable \"%s\" not defined\n", name);
154	return 1;
155	}
156	t = value;
157	}
158
159	debug("REGEX on %s=%s\n", name, t);
160	debug("REGEX=\"%s\", SUBST=\"%s\", GLOBAL=%d\n",
161	r, s ? s : "<NULL>", global);
162
163	len = strlen(t);
164	if (len + 1 > SLRE_BUFSZ) {
165	printf("## error: subst buffer overflow: have %d, need %d\n",
166	SLRE_BUFSZ, len + 1);
167	return 1;
168	}
169
170	strcpy(data, t);
171
172	if (s == NULL)
173	nlen = 0;
174	else
175	nlen = strlen(s);
176
177	for (loop = 0;; loop++) {
178	struct cap caps[slre.num_caps + 2];
179	char nbuf[SLRE_PATSZ];
180	const char *old;
181	char *np;
182	int i, olen;
183
184	(void) memset(caps, 0, sizeof(caps));
185
186	res = slre_match(&slre, datap, len, caps);
187
188	debug("Result: %d\n", res);
189
190	for (i = 0; i < slre.num_caps; i++) {
191	if (caps[i].len > 0) {
192	debug("Substring %d: [%.*s]\n", i,
193	caps[i].len, caps[i].ptr);
194	}
195	}
196
197	if (res == 0) {
198	if (loop == 0) {
199	printf("%s: No match\n", t);
200	return 1;
201	} else {
202	break;
203	}
204	}
205
206	debug("## MATCH ## %s\n", data);
207
208	if (s == NULL) {
209	printf("%s=%s\n", name, t);
210	return 1;
211	}
212
213	old = caps[0].ptr;
214	olen = caps[0].len;
215
216	if (nlen + 1 >= SLRE_PATSZ) {
217	printf("## error: pattern buffer overflow: have %d, need %d\n",
218	SLRE_BUFSZ, nlen + 1);
219	return 1;
220	}
221	strcpy(nbuf, s);
222
223	debug("## SUBST(1) ## %s\n", nbuf);
224
225	/*
226	* Handle back references
227	*
228	* Support for \0 ... \9, where \0 is the
229	* whole matched pattern (similar to &).
230	*
231	* Implementation is a bit simpleminded as
232	* backrefs are substituted sequentially, one
233	* by one. This will lead to somewhat
234	* unexpected results if the replacement
235	* strings contain any \N strings then then
236	* may get substitued, too. We accept this
237	* restriction for the sake of simplicity.
238	*/
239	for (i = 0; i < 10; ++i) {
240	char backref[2] = {
241	'\\',
242	'0',
243	};
244
245	if (caps[i].len == 0)
246	break;
247
248	backref[1] += i;
249
250	debug("## BACKREF %d: replace \"%.s\" by \"%.s\" in \"%s\"\n",
251	i,
252	2, backref,
253	caps[i].len, caps[i].ptr,
254	nbuf);
255
256	for (np = nbuf;;) {
257	char *p = memstr(np, nlen, backref, 2);
258
259	if (p == NULL)
260	break;
261
262	np = substitute(np, &nlen,
263	SLRE_PATSZ,
264	backref, 2,
265	caps[i].ptr, caps[i].len);
266
267	if (np == NULL)
268	return 1;
269	}
270	}
271	debug("## SUBST(2) ## %s\n", nbuf);
272
273	datap = substitute(datap, &len, SLRE_BUFSZ,
274	old, olen,
275	nbuf, nlen);
276
277	if (datap == NULL)
278	return 1;
279
280	debug("## REMAINDER: %s\n", datap);
281
282	debug("## RESULT: %s\n", data);
283
284	if (!global)
285	break;
286	}
287	debug("## FINAL (now setenv()) : %s\n", data);
288
289	printf("%s=%s\n", name, data);
290
291	return setenv(name, data);
292	}
293	#endif
294
088f1b19	295	static int do_setexpr(cmd_tbl_t cmdtp, int flag, int argc, char const argv[])
d058698f KG	296	{
d058698f KG	297	ulong a, b;
41ef372c	298	ulong value;
47ab5ad1	299	int w;
d058698f	300
855f18ea WD	301	/*
	302	* We take 3, 5, or 6 arguments:
	303	* 3 : setexpr name value
	304	* 5 : setexpr name val1 op val2
	305	* setexpr name [g]sub r s
	306	* 6 : setexpr name [g]sub r s t
	307	*/
	308
	309	/* > 6 already tested by max command args */
	310	if ((argc < 3) \|\| (argc == 4))
4c12eeb8	311	return CMD_RET_USAGE;
d058698f	312
47ab5ad1 FM	313	w = cmd_get_data_size(argv[0], 4);
	314
	315	a = get_arg(argv[2], w);
4823b45d	316
103c94b1	317	/* plain assignment: "setexpr name value" */
4823b45d	318	if (argc == 3) {
41ef372c	319	setenv_hex(argv[1], a);
4823b45d JH	320	return 0;
	321	}
	322
855f18ea WD	323	/* 5 or 6 args (6 args only with [g]sub) */
	324	#ifdef CONFIG_REGEX
	325	/*
	326	* rexep handling: "setexpr name [g]sub r s [t]"
	327	* with 5 args, "t" will be NULL
	328	*/
	329	if (strcmp(argv[2], "gsub") == 0)
	330	return regex_sub(argv[1], argv[3], argv[4], argv[5], 1);
	331
	332	if (strcmp(argv[2], "sub") == 0)
	333	return regex_sub(argv[1], argv[3], argv[4], argv[5], 0);
	334	#endif
	335
103c94b1 WD	336	/* standard operators: "setexpr name val1 op val2" */
	337	if (argc != 5)
	338	return CMD_RET_USAGE;
	339
	340	if (strlen(argv[3]) != 1)
	341	return CMD_RET_USAGE;
	342
47ab5ad1	343	b = get_arg(argv[4], w);
d058698f KG	344
d058698f KG	345	switch (argv[3][0]) {
41ef372c SG	346	case '\|':
	347	value = a \| b;
	348	break;
	349	case '&':
	350	value = a & b;
	351	break;
	352	case '+':
	353	value = a + b;
	354	break;
	355	case '^':
	356	value = a ^ b;
	357	break;
	358	case '-':
	359	value = a - b;
	360	break;
	361	case '*':
	362	value = a * b;
	363	break;
	364	case '/':
	365	value = a / b;
	366	break;
	367	case '%':
	368	value = a % b;
	369	break;
d058698f KG	370	default:
	371	printf("invalid op\n");
	372	return 1;
	373	}
	374
41ef372c	375	setenv_hex(argv[1], value);
d058698f KG	376
	377	return 0;
	378	}
	379
	380	U_BOOT_CMD(
855f18ea	381	setexpr, 6, 0, do_setexpr,
2fb2604d	382	"set environment variable as the result of eval expression",
4823b45d	383	"[.b, .w, .l] name []value1 <op> []value2\n"
d058698f	384	" - set environment variable 'name' to the result of the evaluated\n"
855f18ea	385	" expression specified by <op>. <op> can be &, \|, ^, +, -, *, /, %\n"
4823b45d JH	386	" size argument is only meaningful if value1 and/or value2 are\n"
4823b45d JH	387	" memory addresses (*)\n"
103c94b1 WD	388	"setexpr[.b, .w, .l] name [*]value\n"
103c94b1 WD	389	" - load a value into a variable"
855f18ea WD	390	#ifdef CONFIG_REGEX
	391	"\n"
	392	"setexpr name gsub r s [t]\n"
	393	" - For each substring matching the regular expression <r> in the\n"
	394	" string <t>, substitute the string <s>. The result is\n"
	395	" assigned to <name>. If <t> is not supplied, use the old\n"
	396	" value of <name>\n"
	397	"setexpr name sub r s [t]\n"
	398	" - Just like gsub(), but replace only the first matching substring"
	399	#endif
d058698f	400	);