[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 <log.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>
f7ae49fc	15	#include <log.h>
2068cea1	16	#include <mapmem.h>
d058698f	17
47ab5ad1 FM	18	static ulong get_arg(char *s, int w)
47ab5ad1 FM	19	{
482126e2	20	/*
2068cea1 JH	21	* If the parameter starts with a '*' then assume it is a pointer to
2068cea1 JH	22	* the value we want.
47ab5ad1	23	*/
47ab5ad1	24	if (s[0] == '*') {
2068cea1 JH	25	ulong *p;
	26	ulong addr;
	27	ulong val;
	28
	29	addr = simple_strtoul(&s[1], NULL, 16);
47ab5ad1	30	switch (w) {
2068cea1 JH	31	case 1:
	32	p = map_sysmem(addr, sizeof(uchar));
	33	val = (ulong)(uchar )p;
	34	unmap_sysmem(p);
	35	return val;
	36	case 2:
	37	p = map_sysmem(addr, sizeof(ushort));
	38	val = (ulong)(ushort )p;
	39	unmap_sysmem(p);
	40	return val;
47ab5ad1	41	case 4:
2068cea1 JH	42	default:
	43	p = map_sysmem(addr, sizeof(ulong));
	44	val = *p;
	45	unmap_sysmem(p);
	46	return val;
47ab5ad1 FM	47	}
	48	} else {
	49	return simple_strtoul(s, NULL, 16);
	50	}
	51	}
	52
855f18ea WD	53	#ifdef CONFIG_REGEX
	54
	55	#include <slre.h>
	56
	57	#define SLRE_BUFSZ 16384
	58	#define SLRE_PATSZ 4096
	59
	60	/*
	61	* memstr - Find the first substring in memory
	62	* @s1: The string to be searched
	63	* @s2: The string to search for
	64	*
	65	* Similar to and based on strstr(),
	66	* but strings do not need to be NUL terminated.
	67	*/
	68	static char memstr(const char s1, int l1, const char *s2, int l2)
	69	{
	70	if (!l2)
	71	return (char *)s1;
	72
	73	while (l1 >= l2) {
	74	l1--;
	75	if (!memcmp(s1, s2, l2))
	76	return (char *)s1;
	77	s1++;
	78	}
	79	return NULL;
	80	}
	81
	82	static char substitute(char string, /* string buffer */
	83	int slen, / current string length */
	84	int ssize, /* string bufer size */
	85	const char old,/ old (replaced) string */
	86	int olen, /* length of old string */
	87	const char new,/ new (replacement) string */
	88	int nlen) /* length of new string */
	89	{
	90	char p = memstr(string, slen, old, olen);
	91
	92	if (p == NULL)
	93	return NULL;
	94
	95	debug("## Match at pos %ld: match len %d, subst len %d\n",
	96	(long)(p - string), olen, nlen);
	97
	98	/* make sure replacement matches */
	99	if (*slen + nlen - olen > ssize) {
	100	printf("## error: substitution buffer overflow\n");
	101	return NULL;
	102	}
	103
	104	/* move tail if needed */
	105	if (olen != nlen) {
	106	int tail, len;
	107
	108	len = (olen > nlen) ? olen : nlen;
	109
	110	tail = ssize - (p + len - string);
	111
	112	debug("## tail len %d\n", tail);
	113
	114	memmove(p + nlen, p + olen, tail);
	115	}
	116
117	/* insert substitue */
118	memcpy(p, new, nlen);
119
120	*slen += nlen - olen;
121
122	return p + nlen;
123	}
124
125	/*
126	* Perform regex operations on a environment variable
127	*
128	* Returns 0 if OK, 1 in case of errors.
129	*/
130	static int regex_sub(const char *name,
131	const char r, const char s, const char *t,
132	int global)
133	{
134	struct slre slre;
135	char data[SLRE_BUFSZ];
136	char *datap = data;
137	const char *value;
138	int res, len, nlen, loop;
139
140	if (name == NULL)
141	return 1;
142
143	if (slre_compile(&slre, r) == 0) {
144	printf("Error compiling regex: %s\n", slre.err_str);
145	return 1;
146	}
147
148	if (t == NULL) {
00caae6d	149	value = env_get(name);
855f18ea WD	150
	151	if (value == NULL) {
	152	printf("## Error: variable \"%s\" not defined\n", name);
	153	return 1;
	154	}
	155	t = value;
	156	}
	157
	158	debug("REGEX on %s=%s\n", name, t);
	159	debug("REGEX=\"%s\", SUBST=\"%s\", GLOBAL=%d\n",
	160	r, s ? s : "<NULL>", global);
	161
	162	len = strlen(t);
	163	if (len + 1 > SLRE_BUFSZ) {
	164	printf("## error: subst buffer overflow: have %d, need %d\n",
	165	SLRE_BUFSZ, len + 1);
	166	return 1;
	167	}
	168
	169	strcpy(data, t);
	170
	171	if (s == NULL)
	172	nlen = 0;
	173	else
	174	nlen = strlen(s);
	175
	176	for (loop = 0;; loop++) {
	177	struct cap caps[slre.num_caps + 2];
	178	char nbuf[SLRE_PATSZ];
	179	const char *old;
	180	char *np;
	181	int i, olen;
	182
	183	(void) memset(caps, 0, sizeof(caps));
	184
	185	res = slre_match(&slre, datap, len, caps);
	186
	187	debug("Result: %d\n", res);
	188
	189	for (i = 0; i < slre.num_caps; i++) {
	190	if (caps[i].len > 0) {
	191	debug("Substring %d: [%.*s]\n", i,
	192	caps[i].len, caps[i].ptr);
	193	}
	194	}
	195
	196	if (res == 0) {
	197	if (loop == 0) {
	198	printf("%s: No match\n", t);
	199	return 1;
	200	} else {
	201	break;
	202	}
	203	}
	204
	205	debug("## MATCH ## %s\n", data);
	206
	207	if (s == NULL) {
	208	printf("%s=%s\n", name, t);
	209	return 1;
	210	}
	211
	212	old = caps[0].ptr;
	213	olen = caps[0].len;
214
215	if (nlen + 1 >= SLRE_PATSZ) {
216	printf("## error: pattern buffer overflow: have %d, need %d\n",
217	SLRE_BUFSZ, nlen + 1);
218	return 1;
219	}
220	strcpy(nbuf, s);
221
222	debug("## SUBST(1) ## %s\n", nbuf);
223
224	/*
225	* Handle back references
226	*
227	* Support for \0 ... \9, where \0 is the
228	* whole matched pattern (similar to &).
229	*
230	* Implementation is a bit simpleminded as
231	* backrefs are substituted sequentially, one
232	* by one. This will lead to somewhat
233	* unexpected results if the replacement
234	* strings contain any \N strings then then
235	* may get substitued, too. We accept this
236	* restriction for the sake of simplicity.
237	*/
238	for (i = 0; i < 10; ++i) {
239	char backref[2] = {
240	'\\',
241	'0',
242	};
243
244	if (caps[i].len == 0)
245	break;
246
247	backref[1] += i;
248
249	debug("## BACKREF %d: replace \"%.s\" by \"%.s\" in \"%s\"\n",
250	i,
251	2, backref,
252	caps[i].len, caps[i].ptr,
253	nbuf);
254
255	for (np = nbuf;;) {
256	char *p = memstr(np, nlen, backref, 2);
257
258	if (p == NULL)
259	break;
260
261	np = substitute(np, &nlen,
262	SLRE_PATSZ,
263	backref, 2,
264	caps[i].ptr, caps[i].len);
265
266	if (np == NULL)
267	return 1;
268	}
269	}
270	debug("## SUBST(2) ## %s\n", nbuf);
271
272	datap = substitute(datap, &len, SLRE_BUFSZ,
273	old, olen,
274	nbuf, nlen);
275
276	if (datap == NULL)
277	return 1;
278
279	debug("## REMAINDER: %s\n", datap);
280
281	debug("## RESULT: %s\n", data);
282
283	if (!global)
284	break;
285	}
382bee57	286	debug("## FINAL (now env_set()) : %s\n", data);
855f18ea WD	287
	288	printf("%s=%s\n", name, data);
	289
382bee57	290	return env_set(name, data);
855f18ea WD	291	}
	292	#endif
	293
09140113 SG	294	static int do_setexpr(struct cmd_tbl *cmdtp, int flag, int argc,
09140113 SG	295	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) {
018f5303	319	env_set_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
018f5303	375	env_set_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	);