blob: e111b8ba98ad7c276621aca949ccd31ba5dc12ed [file] [log] [blame]
// 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 <config.h>
#include <command.h>
#include <ctype.h>
#include <env.h>
#include <log.h>
#include <malloc.h>
#include <mapmem.h>
#include <vsprintf.h>
#include <linux/errno.h>
#include <linux/sizes.h>
#include "printf.h"
#define MAX_STR_LEN 128
/**
* 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 = hextoul(&s[1], NULL);
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 = hextoul(s, NULL);
}
*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) {
debug("%s: No match\n", data);
} else {
debug("## MATCH ## %s\n", data);
}
break;
}
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;
debug("%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, except fmt operation, which
* takes 4 to 8 arguments (limited by _maxargs):
* 3 : setexpr name value
* 5 : setexpr name val1 op val2
* setexpr name [g]sub r s
* 6 : setexpr name [g]sub r s t
* setexpr name fmt format [val1] [val2] [val3] [val4]
*/
if (argc < 3)
return CMD_RET_USAGE;
w = cmd_get_data_size(argv[0], 4);
if (get_arg(argv[2], w, &aval))
return CMD_RET_FAILURE;
/* format string assignment: "setexpr name fmt %d value" */
if (strcmp(argv[2], "fmt") == 0 && IS_ENABLED(CONFIG_CMD_SETEXPR_FMT)) {
char str[MAX_STR_LEN];
int result;
if (argc == 3)
return CMD_RET_USAGE;
result = printf_setexpr(str, sizeof(str), argc - 3, &argv[3]);
if (result)
return result;
return env_set(argv[1], str);
}
if (argc == 4 || argc > 6)
return CMD_RET_USAGE;
/* 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, 8, 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_CMD_SETEXPR_FMT
"\n"
"setexpr name fmt <format> [value1] [value2] [value3] [value4]\n"
" - set environment variable 'name' to the result of the bash like\n"
" format string evaluation of value."
#endif
#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>. If no substring matching <r> is found in <t>,\n"
" assign <t> to <name>.\n"
"setexpr name sub r s [t]\n"
" - Just like gsub(), but replace only the first matching substring"
#endif
);