[J-u-boot.git] / common / cmd_setexpr.c

/*
 * Copyright 2008 Freescale Semiconductor, Inc.
 * Copyright 2013 Wolfgang Denk <[email protected]>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

/*
 * 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 <[email protected]>
d058698f	4	*
3765b3e7	5	* SPDX-License-Identifier: GPL-2.0+
d058698f KG	6	*/
	7
	8	/*
	9	* This file provides a shell like 'expr' function to return.
	10	*/
	11
	12	#include <common.h>
	13	#include <config.h>
	14	#include <command.h>
	15
47ab5ad1 FM	16	static ulong get_arg(char *s, int w)
	17	{
	18	ulong *p;
	19
482126e2	20	/*
47ab5ad1 FM	21	* if the parameter starts with a '*' then assume
	22	* it is a pointer to the value we want
	23	*/
	24
	25	if (s[0] == '*') {
	26	p = (ulong *)simple_strtoul(&s[1], NULL, 16);
	27	switch (w) {
	28	case 1: return((ulong)((uchar )p));
	29	case 2: return((ulong)((ushort )p));
	30	case 4:
	31	default: return(*p);
	32	}
	33	} else {
	34	return simple_strtoul(s, NULL, 16);
	35	}
	36	}
	37
855f18ea WD	38	#ifdef CONFIG_REGEX
	39
	40	#include <slre.h>
	41
	42	#define SLRE_BUFSZ 16384
	43	#define SLRE_PATSZ 4096
	44
	45	/*
	46	* memstr - Find the first substring in memory
	47	* @s1: The string to be searched
	48	* @s2: The string to search for
	49	*
	50	* Similar to and based on strstr(),
	51	* but strings do not need to be NUL terminated.
	52	*/
	53	static char memstr(const char s1, int l1, const char *s2, int l2)
	54	{
	55	if (!l2)
	56	return (char *)s1;
	57
	58	while (l1 >= l2) {
	59	l1--;
	60	if (!memcmp(s1, s2, l2))
	61	return (char *)s1;
	62	s1++;
	63	}
	64	return NULL;
	65	}
	66
	67	static char substitute(char string, /* string buffer */
	68	int slen, / current string length */
	69	int ssize, /* string bufer size */
	70	const char old,/ old (replaced) string */
	71	int olen, /* length of old string */
	72	const char new,/ new (replacement) string */
	73	int nlen) /* length of new string */
	74	{
	75	char p = memstr(string, slen, old, olen);
	76
	77	if (p == NULL)
	78	return NULL;
	79
	80	debug("## Match at pos %ld: match len %d, subst len %d\n",
	81	(long)(p - string), olen, nlen);
	82
	83	/* make sure replacement matches */
	84	if (*slen + nlen - olen > ssize) {
	85	printf("## error: substitution buffer overflow\n");
	86	return NULL;
	87	}
	88
	89	/* move tail if needed */
	90	if (olen != nlen) {
	91	int tail, len;
	92
	93	len = (olen > nlen) ? olen : nlen;
	94
	95	tail = ssize - (p + len - string);
	96
	97	debug("## tail len %d\n", tail);
	98
	99	memmove(p + nlen, p + olen, tail);
	100	}
	101
102	/* insert substitue */
103	memcpy(p, new, nlen);
104
105	*slen += nlen - olen;
106
107	return p + nlen;
108	}
109
110	/*
111	* Perform regex operations on a environment variable
112	*
113	* Returns 0 if OK, 1 in case of errors.
114	*/
115	static int regex_sub(const char *name,
116	const char r, const char s, const char *t,
117	int global)
118	{
119	struct slre slre;
120	char data[SLRE_BUFSZ];
121	char *datap = data;
122	const char *value;
123	int res, len, nlen, loop;
124
125	if (name == NULL)
126	return 1;
127
128	if (slre_compile(&slre, r) == 0) {
129	printf("Error compiling regex: %s\n", slre.err_str);
130	return 1;
131	}
132
133	if (t == NULL) {
134	value = getenv(name);
135
136	if (value == NULL) {
137	printf("## Error: variable \"%s\" not defined\n", name);
138	return 1;
139	}
140	t = value;
141	}
142
143	debug("REGEX on %s=%s\n", name, t);
144	debug("REGEX=\"%s\", SUBST=\"%s\", GLOBAL=%d\n",
145	r, s ? s : "<NULL>", global);
146
147	len = strlen(t);
148	if (len + 1 > SLRE_BUFSZ) {
149	printf("## error: subst buffer overflow: have %d, need %d\n",
150	SLRE_BUFSZ, len + 1);
151	return 1;
152	}
153
154	strcpy(data, t);
155
156	if (s == NULL)
157	nlen = 0;
158	else
159	nlen = strlen(s);
160
161	for (loop = 0;; loop++) {
162	struct cap caps[slre.num_caps + 2];
163	char nbuf[SLRE_PATSZ];
164	const char *old;
165	char *np;
166	int i, olen;
167
168	(void) memset(caps, 0, sizeof(caps));
169
170	res = slre_match(&slre, datap, len, caps);
171
172	debug("Result: %d\n", res);
173
174	for (i = 0; i < slre.num_caps; i++) {
175	if (caps[i].len > 0) {
176	debug("Substring %d: [%.*s]\n", i,
177	caps[i].len, caps[i].ptr);
178	}
179	}
180
181	if (res == 0) {
182	if (loop == 0) {
183	printf("%s: No match\n", t);
184	return 1;
185	} else {
186	break;
187	}
188	}
189
190	debug("## MATCH ## %s\n", data);
191
192	if (s == NULL) {
193	printf("%s=%s\n", name, t);
194	return 1;
195	}
196
197	old = caps[0].ptr;
198	olen = caps[0].len;
199
200	if (nlen + 1 >= SLRE_PATSZ) {
201	printf("## error: pattern buffer overflow: have %d, need %d\n",
202	SLRE_BUFSZ, nlen + 1);
203	return 1;
204	}
205	strcpy(nbuf, s);
206
207	debug("## SUBST(1) ## %s\n", nbuf);
208
209	/*
210	* Handle back references
211	*
212	* Support for \0 ... \9, where \0 is the
213	* whole matched pattern (similar to &).
214	*
215	* Implementation is a bit simpleminded as
216	* backrefs are substituted sequentially, one
217	* by one. This will lead to somewhat
218	* unexpected results if the replacement
219	* strings contain any \N strings then then
220	* may get substitued, too. We accept this
221	* restriction for the sake of simplicity.
222	*/
223	for (i = 0; i < 10; ++i) {
224	char backref[2] = {
225	'\\',
226	'0',
227	};
228
229	if (caps[i].len == 0)
230	break;
231
232	backref[1] += i;
233
234	debug("## BACKREF %d: replace \"%.s\" by \"%.s\" in \"%s\"\n",
235	i,
236	2, backref,
237	caps[i].len, caps[i].ptr,
238	nbuf);
239
240	for (np = nbuf;;) {
241	char *p = memstr(np, nlen, backref, 2);
242
243	if (p == NULL)
244	break;
245
246	np = substitute(np, &nlen,
247	SLRE_PATSZ,
248	backref, 2,
249	caps[i].ptr, caps[i].len);
250
251	if (np == NULL)
252	return 1;
253	}
254	}
255	debug("## SUBST(2) ## %s\n", nbuf);
256
257	datap = substitute(datap, &len, SLRE_BUFSZ,
258	old, olen,
259	nbuf, nlen);
260
261	if (datap == NULL)
262	return 1;
263
264	debug("## REMAINDER: %s\n", datap);
265
266	debug("## RESULT: %s\n", data);
267
268	if (!global)
269	break;
270	}
271	debug("## FINAL (now setenv()) : %s\n", data);
272
273	printf("%s=%s\n", name, data);
274
275	return setenv(name, data);
276	}
277	#endif
278
088f1b19	279	static int do_setexpr(cmd_tbl_t cmdtp, int flag, int argc, char const argv[])
d058698f KG	280	{
d058698f KG	281	ulong a, b;
41ef372c	282	ulong value;
47ab5ad1	283	int w;
d058698f	284
855f18ea WD	285	/*
	286	* We take 3, 5, or 6 arguments:
	287	* 3 : setexpr name value
	288	* 5 : setexpr name val1 op val2
	289	* setexpr name [g]sub r s
	290	* 6 : setexpr name [g]sub r s t
	291	*/
	292
	293	/* > 6 already tested by max command args */
	294	if ((argc < 3) \|\| (argc == 4))
4c12eeb8	295	return CMD_RET_USAGE;
d058698f	296
47ab5ad1 FM	297	w = cmd_get_data_size(argv[0], 4);
	298
	299	a = get_arg(argv[2], w);
4823b45d	300
103c94b1	301	/* plain assignment: "setexpr name value" */
4823b45d	302	if (argc == 3) {
41ef372c	303	setenv_hex(argv[1], a);
4823b45d JH	304	return 0;
	305	}
	306
855f18ea WD	307	/* 5 or 6 args (6 args only with [g]sub) */
	308	#ifdef CONFIG_REGEX
	309	/*
	310	* rexep handling: "setexpr name [g]sub r s [t]"
	311	* with 5 args, "t" will be NULL
	312	*/
	313	if (strcmp(argv[2], "gsub") == 0)
	314	return regex_sub(argv[1], argv[3], argv[4], argv[5], 1);
	315
	316	if (strcmp(argv[2], "sub") == 0)
	317	return regex_sub(argv[1], argv[3], argv[4], argv[5], 0);
	318	#endif
	319
103c94b1 WD	320	/* standard operators: "setexpr name val1 op val2" */
	321	if (argc != 5)
	322	return CMD_RET_USAGE;
	323
	324	if (strlen(argv[3]) != 1)
	325	return CMD_RET_USAGE;
	326
47ab5ad1	327	b = get_arg(argv[4], w);
d058698f KG	328
d058698f KG	329	switch (argv[3][0]) {
41ef372c SG	330	case '\|':
	331	value = a \| b;
	332	break;
	333	case '&':
	334	value = a & b;
	335	break;
	336	case '+':
	337	value = a + b;
	338	break;
	339	case '^':
	340	value = a ^ b;
	341	break;
	342	case '-':
	343	value = a - b;
	344	break;
	345	case '*':
	346	value = a * b;
	347	break;
	348	case '/':
	349	value = a / b;
	350	break;
	351	case '%':
	352	value = a % b;
	353	break;
d058698f KG	354	default:
	355	printf("invalid op\n");
	356	return 1;
	357	}
	358
41ef372c	359	setenv_hex(argv[1], value);
d058698f KG	360
	361	return 0;
	362	}
	363
	364	U_BOOT_CMD(
855f18ea	365	setexpr, 6, 0, do_setexpr,
2fb2604d	366	"set environment variable as the result of eval expression",
4823b45d	367	"[.b, .w, .l] name []value1 <op> []value2\n"
d058698f	368	" - set environment variable 'name' to the result of the evaluated\n"
855f18ea	369	" expression specified by <op>. <op> can be &, \|, ^, +, -, *, /, %\n"
4823b45d JH	370	" size argument is only meaningful if value1 and/or value2 are\n"
4823b45d JH	371	" memory addresses (*)\n"
103c94b1 WD	372	"setexpr[.b, .w, .l] name [*]value\n"
103c94b1 WD	373	" - load a value into a variable"
855f18ea WD	374	#ifdef CONFIG_REGEX
	375	"\n"
	376	"setexpr name gsub r s [t]\n"
	377	" - For each substring matching the regular expression <r> in the\n"
	378	" string <t>, substitute the string <s>. The result is\n"
	379	" assigned to <name>. If <t> is not supplied, use the old\n"
	380	" value of <name>\n"
	381	"setexpr name sub r s [t]\n"
	382	" - Just like gsub(), but replace only the first matching substring"
	383	#endif
d058698f	384	);