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- // SPDX-License-Identifier: GPL-2.0+
- /*
- * Copyright 2008 Freescale Semiconductor, Inc.
- * Copyright 2013 Wolfgang Denk <wd@denx.de>
- */
- /*
- * 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 <malloc.h>
- #include <mapmem.h>
- #include <linux/sizes.h>
- /**
- * struct expr_arg: Holds an argument to an expression
- *
- * @ival: Integer value (if width is not CMD_DATA_SIZE_STR)
- * @sval: String value (if width is CMD_DATA_SIZE_STR)
- */
- struct expr_arg {
- union {
- ulong ival;
- char *sval;
- };
- };
- static int get_arg(char *s, int w, struct expr_arg *argp)
- {
- struct expr_arg arg;
- /*
- * 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;
- int len;
- char *str;
- addr = simple_strtoul(&s[1], NULL, 16);
- switch (w) {
- case 1:
- p = map_sysmem(addr, sizeof(uchar));
- val = (ulong)*(uchar *)p;
- unmap_sysmem(p);
- arg.ival = val;
- break;
- case 2:
- p = map_sysmem(addr, sizeof(ushort));
- val = (ulong)*(ushort *)p;
- unmap_sysmem(p);
- arg.ival = val;
- break;
- case CMD_DATA_SIZE_STR:
- p = map_sysmem(addr, SZ_64K);
- /* Maximum string length of 64KB plus terminator */
- len = strnlen((char *)p, SZ_64K) + 1;
- str = malloc(len);
- if (!str) {
- printf("Out of memory\n");
- return -ENOMEM;
- }
- memcpy(str, p, len);
- str[len - 1] = '\0';
- unmap_sysmem(p);
- arg.sval = str;
- break;
- case 4:
- p = map_sysmem(addr, sizeof(u32));
- val = *(u32 *)p;
- unmap_sysmem(p);
- arg.ival = val;
- break;
- default:
- p = map_sysmem(addr, sizeof(ulong));
- val = *p;
- unmap_sysmem(p);
- arg.ival = val;
- break;
- }
- } else {
- if (w == CMD_DATA_SIZE_STR)
- return -EINVAL;
- arg.ival = simple_strtoul(s, NULL, 16);
- }
- *argp = arg;
- return 0;
- }
- #ifdef CONFIG_REGEX
- #include <slre.h>
- /*
- * 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;
- }
- /**
- * substitute() - Substitute part of one string with another
- *
- * This updates @string so that the first occurrence of @old is replaced with
- * @new
- *
- * @string: String buffer containing string to update at the start
- * @slen: Pointer to current string length, updated on success
- * @ssize: Size of string buffer
- * @old: Old string to find in the buffer (no terminator needed)
- * @olen: Length of @old excluding terminator
- * @new: New string to replace @old with
- * @nlen: Length of @new excluding terminator
- * @return pointer to immediately after the copied @new in @string, or NULL if
- * no replacement took place
- */
- static char *substitute(char *string, int *slen, int ssize,
- const char *old, int olen, const char *new, int nlen)
- {
- 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 substitute */
- memcpy(p, new, nlen);
- *slen += nlen - olen;
- return p + nlen;
- }
- int setexpr_regex_sub(char *data, uint data_size, char *nbuf, uint nbuf_size,
- const char *r, const char *s, bool global)
- {
- struct slre slre;
- char *datap = data;
- int res, len, nlen, loop;
- if (slre_compile(&slre, r) == 0) {
- printf("Error compiling regex: %s\n", slre.err_str);
- return 1;
- }
- len = strlen(data);
- for (loop = 0;; loop++) {
- struct cap caps[slre.num_caps + 2];
- const char *old;
- char *np;
- int i, olen;
- (void) memset(caps, 0, sizeof(caps));
- res = slre_match(&slre, datap, len - (datap - data), 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", data);
- return 1;
- } else {
- break;
- }
- }
- debug("## MATCH ## %s\n", data);
- if (!s)
- return 1;
- old = caps[0].ptr;
- olen = caps[0].len;
- nlen = strlen(s);
- if (nlen + 1 >= nbuf_size) {
- printf("## error: pattern buffer overflow: have %d, need %d\n",
- nbuf_size, 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,
- nbuf_size - (np - nbuf),
- backref, 2,
- caps[i].ptr, caps[i].len);
- if (np == NULL)
- return 1;
- }
- }
- debug("## SUBST(2) ## %s\n", nbuf);
- datap = substitute(datap, &len, data_size - (datap - data),
- 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);
- return 0;
- }
- #define SLRE_BUFSZ 16384
- #define SLRE_PATSZ 4096
- /*
- * Perform regex operations on a environment variable
- *
- * Returns 0 if OK, 1 in case of errors.
- */
- static int regex_sub_var(const char *name, const char *r, const char *s,
- const char *t, int global)
- {
- struct slre slre;
- char data[SLRE_BUFSZ];
- char nbuf[SLRE_PATSZ];
- const char *value;
- int len;
- int ret;
- if (!name)
- return 1;
- if (slre_compile(&slre, r) == 0) {
- printf("Error compiling regex: %s\n", slre.err_str);
- return 1;
- }
- if (!t) {
- value = env_get(name);
- if (!value) {
- 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);
- ret = setexpr_regex_sub(data, SLRE_BUFSZ, nbuf, SLRE_PATSZ, r, s,
- global);
- if (ret)
- return 1;
- 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[])
- {
- struct expr_arg aval, bval;
- ulong value;
- int ret = 0;
- 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);
- if (get_arg(argv[2], w, &aval))
- return CMD_RET_FAILURE;
- /* plain assignment: "setexpr name value" */
- if (argc == 3) {
- if (w == CMD_DATA_SIZE_STR) {
- ret = env_set(argv[1], aval.sval);
- free(aval.sval);
- } else {
- ret = env_set_hex(argv[1], aval.ival);
- }
- return ret;
- }
- /* 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_var(argv[1], argv[3], argv[4], argv[5], 1);
- if (strcmp(argv[2], "sub") == 0)
- return regex_sub_var(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;
- if (get_arg(argv[4], w, &bval)) {
- if (w == CMD_DATA_SIZE_STR)
- free(aval.sval);
- return CMD_RET_FAILURE;
- }
- if (w == CMD_DATA_SIZE_STR) {
- int len;
- char *str;
- switch (argv[3][0]) {
- case '+':
- len = strlen(aval.sval) + strlen(bval.sval) + 1;
- str = malloc(len);
- if (!str) {
- printf("Out of memory\n");
- ret = CMD_RET_FAILURE;
- } else {
- /* These were copied out and checked earlier */
- strcpy(str, aval.sval);
- strcat(str, bval.sval);
- ret = env_set(argv[1], str);
- if (ret)
- printf("Could not set var\n");
- free(str);
- }
- break;
- default:
- printf("invalid op\n");
- ret = 1;
- }
- } else {
- ulong a = aval.ival;
- ulong b = bval.ival;
- 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);
- }
- if (w == CMD_DATA_SIZE_STR) {
- free(aval.sval);
- free(bval.sval);
- }
- return ret;
- }
- U_BOOT_CMD(
- setexpr, 6, 0, do_setexpr,
- "set environment variable as the result of eval expression",
- "[.b, .w, .l, .s] name [*]value1 <op> [*]value2\n"
- " - set environment variable 'name' to the result of the evaluated\n"
- " expression specified by <op>. <op> can be &, |, ^, +, -, *, /, %\n"
- " (for strings only + is supported)\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
- );
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