[J-u-boot.git] / cmd / setexpr.c

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

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

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

static ulong get_arg(char *s, int w)
{
	/*
	 * If the parameter starts with a '*' then assume it is a pointer to
	 * the value we want.
	 */
	if (s[0] == '*') {
		ulong *p;
		ulong addr;
		ulong val;

		addr = simple_strtoul(&s[1], NULL, 16);
		switch (w) {
		case 1:
			p = map_sysmem(addr, sizeof(uchar));
			val = (ulong)*(uchar *)p;
			unmap_sysmem(p);
			return val;
		case 2:
			p = map_sysmem(addr, sizeof(ushort));
			val = (ulong)*(ushort *)p;
			unmap_sysmem(p);
			return val;
		case 4:
		default:
			p = map_sysmem(addr, sizeof(ulong));
			val = *p;
			unmap_sysmem(p);
			return val;
		}
	} 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 = env_get(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 env_set()) :  %s\n", data);

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

	return env_set(name, data);
}
#endif

static int do_setexpr(struct cmd_tbl *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) {
		env_set_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;
	}

	env_set_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
83d290c5	1	// SPDX-License-Identifier: GPL-2.0+
d058698f KG	2	/*
d058698f KG	3	* Copyright 2008 Freescale Semiconductor, Inc.
855f18ea	4	* Copyright 2013 Wolfgang Denk <[email protected]>
d058698f KG	5	*/
	6
	7	/*
	8	* This file provides a shell like 'expr' function to return.
	9	*/
	10
	11	#include <common.h>
	12	#include <config.h>
	13	#include <command.h>
c7694dd4	14	#include <env.h>
2068cea1	15	#include <mapmem.h>
d058698f	16
47ab5ad1 FM	17	static ulong get_arg(char *s, int w)
47ab5ad1 FM	18	{
482126e2	19	/*
2068cea1 JH	20	* If the parameter starts with a '*' then assume it is a pointer to
2068cea1 JH	21	* the value we want.
47ab5ad1	22	*/
47ab5ad1	23	if (s[0] == '*') {
2068cea1 JH	24	ulong *p;
	25	ulong addr;
	26	ulong val;
	27
	28	addr = simple_strtoul(&s[1], NULL, 16);
47ab5ad1	29	switch (w) {
2068cea1 JH	30	case 1:
	31	p = map_sysmem(addr, sizeof(uchar));
	32	val = (ulong)(uchar )p;
	33	unmap_sysmem(p);
	34	return val;
	35	case 2:
	36	p = map_sysmem(addr, sizeof(ushort));
	37	val = (ulong)(ushort )p;
	38	unmap_sysmem(p);
	39	return val;
47ab5ad1	40	case 4:
2068cea1 JH	41	default:
	42	p = map_sysmem(addr, sizeof(ulong));
	43	val = *p;
	44	unmap_sysmem(p);
	45	return val;
47ab5ad1 FM	46	}
	47	} else {
	48	return simple_strtoul(s, NULL, 16);
	49	}
	50	}
	51
855f18ea WD	52	#ifdef CONFIG_REGEX
	53
	54	#include <slre.h>
	55
	56	#define SLRE_BUFSZ 16384
	57	#define SLRE_PATSZ 4096
	58
	59	/*
	60	* memstr - Find the first substring in memory
	61	* @s1: The string to be searched
	62	* @s2: The string to search for
	63	*
	64	* Similar to and based on strstr(),
	65	* but strings do not need to be NUL terminated.
	66	*/
	67	static char memstr(const char s1, int l1, const char *s2, int l2)
	68	{
	69	if (!l2)
	70	return (char *)s1;
	71
	72	while (l1 >= l2) {
	73	l1--;
	74	if (!memcmp(s1, s2, l2))
	75	return (char *)s1;
	76	s1++;
	77	}
	78	return NULL;
	79	}
	80
	81	static char substitute(char string, /* string buffer */
	82	int slen, / current string length */
	83	int ssize, /* string bufer size */
	84	const char old,/ old (replaced) string */
	85	int olen, /* length of old string */
	86	const char new,/ new (replacement) string */
	87	int nlen) /* length of new string */
	88	{
	89	char p = memstr(string, slen, old, olen);
	90
	91	if (p == NULL)
	92	return NULL;
	93
	94	debug("## Match at pos %ld: match len %d, subst len %d\n",
	95	(long)(p - string), olen, nlen);
	96
	97	/* make sure replacement matches */
	98	if (*slen + nlen - olen > ssize) {
	99	printf("## error: substitution buffer overflow\n");
	100	return NULL;
	101	}
	102
	103	/* move tail if needed */
	104	if (olen != nlen) {
	105	int tail, len;
	106
	107	len = (olen > nlen) ? olen : nlen;
	108
	109	tail = ssize - (p + len - string);
	110
	111	debug("## tail len %d\n", tail);
	112
	113	memmove(p + nlen, p + olen, tail);
	114	}
	115
116	/* insert substitue */
117	memcpy(p, new, nlen);
118
119	*slen += nlen - olen;
120
121	return p + nlen;
122	}
123
124	/*
125	* Perform regex operations on a environment variable
126	*
127	* Returns 0 if OK, 1 in case of errors.
128	*/
129	static int regex_sub(const char *name,
130	const char r, const char s, const char *t,
131	int global)
132	{
133	struct slre slre;
134	char data[SLRE_BUFSZ];
135	char *datap = data;
136	const char *value;
137	int res, len, nlen, loop;
138
139	if (name == NULL)
140	return 1;
141
142	if (slre_compile(&slre, r) == 0) {
143	printf("Error compiling regex: %s\n", slre.err_str);
144	return 1;
145	}
146
147	if (t == NULL) {
00caae6d	148	value = env_get(name);
855f18ea WD	149
	150	if (value == NULL) {
	151	printf("## Error: variable \"%s\" not defined\n", name);
	152	return 1;
	153	}
	154	t = value;
	155	}
	156
	157	debug("REGEX on %s=%s\n", name, t);
	158	debug("REGEX=\"%s\", SUBST=\"%s\", GLOBAL=%d\n",
	159	r, s ? s : "<NULL>", global);
	160
	161	len = strlen(t);
	162	if (len + 1 > SLRE_BUFSZ) {
	163	printf("## error: subst buffer overflow: have %d, need %d\n",
	164	SLRE_BUFSZ, len + 1);
	165	return 1;
	166	}
	167
	168	strcpy(data, t);
	169
	170	if (s == NULL)
	171	nlen = 0;
	172	else
	173	nlen = strlen(s);
	174
	175	for (loop = 0;; loop++) {
	176	struct cap caps[slre.num_caps + 2];
	177	char nbuf[SLRE_PATSZ];
	178	const char *old;
	179	char *np;
	180	int i, olen;
	181
	182	(void) memset(caps, 0, sizeof(caps));
	183
	184	res = slre_match(&slre, datap, len, caps);
	185
	186	debug("Result: %d\n", res);
	187
	188	for (i = 0; i < slre.num_caps; i++) {
	189	if (caps[i].len > 0) {
	190	debug("Substring %d: [%.*s]\n", i,
	191	caps[i].len, caps[i].ptr);
	192	}
	193	}
	194
	195	if (res == 0) {
	196	if (loop == 0) {
	197	printf("%s: No match\n", t);
	198	return 1;
	199	} else {
	200	break;
	201	}
	202	}
	203
	204	debug("## MATCH ## %s\n", data);
	205
	206	if (s == NULL) {
	207	printf("%s=%s\n", name, t);
	208	return 1;
	209	}
	210
	211	old = caps[0].ptr;
	212	olen = caps[0].len;
213
214	if (nlen + 1 >= SLRE_PATSZ) {
215	printf("## error: pattern buffer overflow: have %d, need %d\n",
216	SLRE_BUFSZ, nlen + 1);
217	return 1;
218	}
219	strcpy(nbuf, s);
220
221	debug("## SUBST(1) ## %s\n", nbuf);
222
223	/*
224	* Handle back references
225	*
226	* Support for \0 ... \9, where \0 is the
227	* whole matched pattern (similar to &).
228	*
229	* Implementation is a bit simpleminded as
230	* backrefs are substituted sequentially, one
231	* by one. This will lead to somewhat
232	* unexpected results if the replacement
233	* strings contain any \N strings then then
234	* may get substitued, too. We accept this
235	* restriction for the sake of simplicity.
236	*/
237	for (i = 0; i < 10; ++i) {
238	char backref[2] = {
239	'\\',
240	'0',
241	};
242
243	if (caps[i].len == 0)
244	break;
245
246	backref[1] += i;
247
248	debug("## BACKREF %d: replace \"%.s\" by \"%.s\" in \"%s\"\n",
249	i,
250	2, backref,
251	caps[i].len, caps[i].ptr,
252	nbuf);
253
254	for (np = nbuf;;) {
255	char *p = memstr(np, nlen, backref, 2);
256
257	if (p == NULL)
258	break;
259
260	np = substitute(np, &nlen,
261	SLRE_PATSZ,
262	backref, 2,
263	caps[i].ptr, caps[i].len);
264
265	if (np == NULL)
266	return 1;
267	}
268	}
269	debug("## SUBST(2) ## %s\n", nbuf);
270
271	datap = substitute(datap, &len, SLRE_BUFSZ,
272	old, olen,
273	nbuf, nlen);
274
275	if (datap == NULL)
276	return 1;
277
278	debug("## REMAINDER: %s\n", datap);
279
280	debug("## RESULT: %s\n", data);
281
282	if (!global)
283	break;
284	}
382bee57	285	debug("## FINAL (now env_set()) : %s\n", data);
855f18ea WD	286
	287	printf("%s=%s\n", name, data);
	288
382bee57	289	return env_set(name, data);
855f18ea WD	290	}
	291	#endif
	292
09140113 SG	293	static int do_setexpr(struct cmd_tbl *cmdtp, int flag, int argc,
09140113 SG	294	char *const argv[])
d058698f KG	295	{
d058698f KG	296	ulong a, b;
41ef372c	297	ulong value;
47ab5ad1	298	int w;
d058698f	299
855f18ea WD	300	/*
	301	* We take 3, 5, or 6 arguments:
	302	* 3 : setexpr name value
	303	* 5 : setexpr name val1 op val2
	304	* setexpr name [g]sub r s
	305	* 6 : setexpr name [g]sub r s t
	306	*/
	307
	308	/* > 6 already tested by max command args */
	309	if ((argc < 3) \|\| (argc == 4))
4c12eeb8	310	return CMD_RET_USAGE;
d058698f	311
47ab5ad1 FM	312	w = cmd_get_data_size(argv[0], 4);
	313
	314	a = get_arg(argv[2], w);
4823b45d	315
103c94b1	316	/* plain assignment: "setexpr name value" */
4823b45d	317	if (argc == 3) {
018f5303	318	env_set_hex(argv[1], a);
4823b45d JH	319	return 0;
	320	}
	321
855f18ea WD	322	/* 5 or 6 args (6 args only with [g]sub) */
	323	#ifdef CONFIG_REGEX
	324	/*
	325	* rexep handling: "setexpr name [g]sub r s [t]"
	326	* with 5 args, "t" will be NULL
	327	*/
	328	if (strcmp(argv[2], "gsub") == 0)
	329	return regex_sub(argv[1], argv[3], argv[4], argv[5], 1);
	330
	331	if (strcmp(argv[2], "sub") == 0)
	332	return regex_sub(argv[1], argv[3], argv[4], argv[5], 0);
	333	#endif
	334
103c94b1 WD	335	/* standard operators: "setexpr name val1 op val2" */
	336	if (argc != 5)
	337	return CMD_RET_USAGE;
	338
	339	if (strlen(argv[3]) != 1)
	340	return CMD_RET_USAGE;
	341
47ab5ad1	342	b = get_arg(argv[4], w);
d058698f KG	343
d058698f KG	344	switch (argv[3][0]) {
41ef372c SG	345	case '\|':
	346	value = a \| b;
	347	break;
	348	case '&':
	349	value = a & b;
	350	break;
	351	case '+':
	352	value = a + b;
	353	break;
	354	case '^':
	355	value = a ^ b;
	356	break;
	357	case '-':
	358	value = a - b;
	359	break;
	360	case '*':
	361	value = a * b;
	362	break;
	363	case '/':
	364	value = a / b;
	365	break;
	366	case '%':
	367	value = a % b;
	368	break;
d058698f KG	369	default:
	370	printf("invalid op\n");
	371	return 1;
	372	}
	373
018f5303	374	env_set_hex(argv[1], value);
d058698f KG	375
	376	return 0;
	377	}
	378
	379	U_BOOT_CMD(
855f18ea	380	setexpr, 6, 0, do_setexpr,
2fb2604d	381	"set environment variable as the result of eval expression",
4823b45d	382	"[.b, .w, .l] name []value1 <op> []value2\n"
d058698f	383	" - set environment variable 'name' to the result of the evaluated\n"
855f18ea	384	" expression specified by <op>. <op> can be &, \|, ^, +, -, *, /, %\n"
4823b45d JH	385	" size argument is only meaningful if value1 and/or value2 are\n"
4823b45d JH	386	" memory addresses (*)\n"
103c94b1 WD	387	"setexpr[.b, .w, .l] name [*]value\n"
103c94b1 WD	388	" - load a value into a variable"
855f18ea WD	389	#ifdef CONFIG_REGEX
	390	"\n"
	391	"setexpr name gsub r s [t]\n"
	392	" - For each substring matching the regular expression <r> in the\n"
	393	" string <t>, substitute the string <s>. The result is\n"
	394	" assigned to <name>. If <t> is not supplied, use the old\n"
	395	" value of <name>\n"
	396	"setexpr name sub r s [t]\n"
	397	" - Just like gsub(), but replace only the first matching substring"
	398	#endif
d058698f	399	);