510 lines
10 KiB
C
510 lines
10 KiB
C
/*
|
|
* Helpers for formatting and printing strings
|
|
*
|
|
* Copyright 31 August 2008 James Bottomley
|
|
* Copyright (C) 2013, Intel Corporation
|
|
*/
|
|
#include <linux/bug.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/math64.h>
|
|
#include <linux/export.h>
|
|
#include <linux/ctype.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/string.h>
|
|
#include <linux/string_helpers.h>
|
|
|
|
/**
|
|
* string_get_size - get the size in the specified units
|
|
* @size: The size to be converted in blocks
|
|
* @blk_size: Size of the block (use 1 for size in bytes)
|
|
* @units: units to use (powers of 1000 or 1024)
|
|
* @buf: buffer to format to
|
|
* @len: length of buffer
|
|
*
|
|
* This function returns a string formatted to 3 significant figures
|
|
* giving the size in the required units. @buf should have room for
|
|
* at least 9 bytes and will always be zero terminated.
|
|
*
|
|
*/
|
|
void string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
|
|
char *buf, int len)
|
|
{
|
|
static const char *const units_10[] = {
|
|
"B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"
|
|
};
|
|
static const char *const units_2[] = {
|
|
"B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"
|
|
};
|
|
static const char *const *const units_str[] = {
|
|
[STRING_UNITS_10] = units_10,
|
|
[STRING_UNITS_2] = units_2,
|
|
};
|
|
static const unsigned int divisor[] = {
|
|
[STRING_UNITS_10] = 1000,
|
|
[STRING_UNITS_2] = 1024,
|
|
};
|
|
int i, j;
|
|
u32 remainder = 0, sf_cap, exp;
|
|
char tmp[8];
|
|
const char *unit;
|
|
|
|
tmp[0] = '\0';
|
|
i = 0;
|
|
if (!size)
|
|
goto out;
|
|
|
|
while (blk_size >= divisor[units]) {
|
|
remainder = do_div(blk_size, divisor[units]);
|
|
i++;
|
|
}
|
|
|
|
exp = divisor[units] / (u32)blk_size;
|
|
if (size >= exp) {
|
|
remainder = do_div(size, divisor[units]);
|
|
remainder *= blk_size;
|
|
i++;
|
|
} else {
|
|
remainder *= size;
|
|
}
|
|
|
|
size *= blk_size;
|
|
size += remainder / divisor[units];
|
|
remainder %= divisor[units];
|
|
|
|
while (size >= divisor[units]) {
|
|
remainder = do_div(size, divisor[units]);
|
|
i++;
|
|
}
|
|
|
|
sf_cap = size;
|
|
for (j = 0; sf_cap*10 < 1000; j++)
|
|
sf_cap *= 10;
|
|
|
|
if (j) {
|
|
remainder *= 1000;
|
|
remainder /= divisor[units];
|
|
snprintf(tmp, sizeof(tmp), ".%03u", remainder);
|
|
tmp[j+1] = '\0';
|
|
}
|
|
|
|
out:
|
|
if (i >= ARRAY_SIZE(units_2))
|
|
unit = "UNK";
|
|
else
|
|
unit = units_str[units][i];
|
|
|
|
snprintf(buf, len, "%u%s %s", (u32)size,
|
|
tmp, unit);
|
|
}
|
|
EXPORT_SYMBOL(string_get_size);
|
|
|
|
static bool unescape_space(char **src, char **dst)
|
|
{
|
|
char *p = *dst, *q = *src;
|
|
|
|
switch (*q) {
|
|
case 'n':
|
|
*p = '\n';
|
|
break;
|
|
case 'r':
|
|
*p = '\r';
|
|
break;
|
|
case 't':
|
|
*p = '\t';
|
|
break;
|
|
case 'v':
|
|
*p = '\v';
|
|
break;
|
|
case 'f':
|
|
*p = '\f';
|
|
break;
|
|
default:
|
|
return false;
|
|
}
|
|
*dst += 1;
|
|
*src += 1;
|
|
return true;
|
|
}
|
|
|
|
static bool unescape_octal(char **src, char **dst)
|
|
{
|
|
char *p = *dst, *q = *src;
|
|
u8 num;
|
|
|
|
if (isodigit(*q) == 0)
|
|
return false;
|
|
|
|
num = (*q++) & 7;
|
|
while (num < 32 && isodigit(*q) && (q - *src < 3)) {
|
|
num <<= 3;
|
|
num += (*q++) & 7;
|
|
}
|
|
*p = num;
|
|
*dst += 1;
|
|
*src = q;
|
|
return true;
|
|
}
|
|
|
|
static bool unescape_hex(char **src, char **dst)
|
|
{
|
|
char *p = *dst, *q = *src;
|
|
int digit;
|
|
u8 num;
|
|
|
|
if (*q++ != 'x')
|
|
return false;
|
|
|
|
num = digit = hex_to_bin(*q++);
|
|
if (digit < 0)
|
|
return false;
|
|
|
|
digit = hex_to_bin(*q);
|
|
if (digit >= 0) {
|
|
q++;
|
|
num = (num << 4) | digit;
|
|
}
|
|
*p = num;
|
|
*dst += 1;
|
|
*src = q;
|
|
return true;
|
|
}
|
|
|
|
static bool unescape_special(char **src, char **dst)
|
|
{
|
|
char *p = *dst, *q = *src;
|
|
|
|
switch (*q) {
|
|
case '\"':
|
|
*p = '\"';
|
|
break;
|
|
case '\\':
|
|
*p = '\\';
|
|
break;
|
|
case 'a':
|
|
*p = '\a';
|
|
break;
|
|
case 'e':
|
|
*p = '\e';
|
|
break;
|
|
default:
|
|
return false;
|
|
}
|
|
*dst += 1;
|
|
*src += 1;
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* string_unescape - unquote characters in the given string
|
|
* @src: source buffer (escaped)
|
|
* @dst: destination buffer (unescaped)
|
|
* @size: size of the destination buffer (0 to unlimit)
|
|
* @flags: combination of the flags (bitwise OR):
|
|
* %UNESCAPE_SPACE:
|
|
* '\f' - form feed
|
|
* '\n' - new line
|
|
* '\r' - carriage return
|
|
* '\t' - horizontal tab
|
|
* '\v' - vertical tab
|
|
* %UNESCAPE_OCTAL:
|
|
* '\NNN' - byte with octal value NNN (1 to 3 digits)
|
|
* %UNESCAPE_HEX:
|
|
* '\xHH' - byte with hexadecimal value HH (1 to 2 digits)
|
|
* %UNESCAPE_SPECIAL:
|
|
* '\"' - double quote
|
|
* '\\' - backslash
|
|
* '\a' - alert (BEL)
|
|
* '\e' - escape
|
|
* %UNESCAPE_ANY:
|
|
* all previous together
|
|
*
|
|
* Description:
|
|
* The function unquotes characters in the given string.
|
|
*
|
|
* Because the size of the output will be the same as or less than the size of
|
|
* the input, the transformation may be performed in place.
|
|
*
|
|
* Caller must provide valid source and destination pointers. Be aware that
|
|
* destination buffer will always be NULL-terminated. Source string must be
|
|
* NULL-terminated as well.
|
|
*
|
|
* Return:
|
|
* The amount of the characters processed to the destination buffer excluding
|
|
* trailing '\0' is returned.
|
|
*/
|
|
int string_unescape(char *src, char *dst, size_t size, unsigned int flags)
|
|
{
|
|
char *out = dst;
|
|
|
|
while (*src && --size) {
|
|
if (src[0] == '\\' && src[1] != '\0' && size > 1) {
|
|
src++;
|
|
size--;
|
|
|
|
if (flags & UNESCAPE_SPACE &&
|
|
unescape_space(&src, &out))
|
|
continue;
|
|
|
|
if (flags & UNESCAPE_OCTAL &&
|
|
unescape_octal(&src, &out))
|
|
continue;
|
|
|
|
if (flags & UNESCAPE_HEX &&
|
|
unescape_hex(&src, &out))
|
|
continue;
|
|
|
|
if (flags & UNESCAPE_SPECIAL &&
|
|
unescape_special(&src, &out))
|
|
continue;
|
|
|
|
*out++ = '\\';
|
|
}
|
|
*out++ = *src++;
|
|
}
|
|
*out = '\0';
|
|
|
|
return out - dst;
|
|
}
|
|
EXPORT_SYMBOL(string_unescape);
|
|
|
|
static bool escape_passthrough(unsigned char c, char **dst, char *end)
|
|
{
|
|
char *out = *dst;
|
|
|
|
if (out < end)
|
|
*out = c;
|
|
*dst = out + 1;
|
|
return true;
|
|
}
|
|
|
|
static bool escape_space(unsigned char c, char **dst, char *end)
|
|
{
|
|
char *out = *dst;
|
|
unsigned char to;
|
|
|
|
switch (c) {
|
|
case '\n':
|
|
to = 'n';
|
|
break;
|
|
case '\r':
|
|
to = 'r';
|
|
break;
|
|
case '\t':
|
|
to = 't';
|
|
break;
|
|
case '\v':
|
|
to = 'v';
|
|
break;
|
|
case '\f':
|
|
to = 'f';
|
|
break;
|
|
default:
|
|
return false;
|
|
}
|
|
|
|
if (out < end)
|
|
*out = '\\';
|
|
++out;
|
|
if (out < end)
|
|
*out = to;
|
|
++out;
|
|
|
|
*dst = out;
|
|
return true;
|
|
}
|
|
|
|
static bool escape_special(unsigned char c, char **dst, char *end)
|
|
{
|
|
char *out = *dst;
|
|
unsigned char to;
|
|
|
|
switch (c) {
|
|
case '\\':
|
|
to = '\\';
|
|
break;
|
|
case '\a':
|
|
to = 'a';
|
|
break;
|
|
case '\e':
|
|
to = 'e';
|
|
break;
|
|
default:
|
|
return false;
|
|
}
|
|
|
|
if (out < end)
|
|
*out = '\\';
|
|
++out;
|
|
if (out < end)
|
|
*out = to;
|
|
++out;
|
|
|
|
*dst = out;
|
|
return true;
|
|
}
|
|
|
|
static bool escape_null(unsigned char c, char **dst, char *end)
|
|
{
|
|
char *out = *dst;
|
|
|
|
if (c)
|
|
return false;
|
|
|
|
if (out < end)
|
|
*out = '\\';
|
|
++out;
|
|
if (out < end)
|
|
*out = '0';
|
|
++out;
|
|
|
|
*dst = out;
|
|
return true;
|
|
}
|
|
|
|
static bool escape_octal(unsigned char c, char **dst, char *end)
|
|
{
|
|
char *out = *dst;
|
|
|
|
if (out < end)
|
|
*out = '\\';
|
|
++out;
|
|
if (out < end)
|
|
*out = ((c >> 6) & 0x07) + '0';
|
|
++out;
|
|
if (out < end)
|
|
*out = ((c >> 3) & 0x07) + '0';
|
|
++out;
|
|
if (out < end)
|
|
*out = ((c >> 0) & 0x07) + '0';
|
|
++out;
|
|
|
|
*dst = out;
|
|
return true;
|
|
}
|
|
|
|
static bool escape_hex(unsigned char c, char **dst, char *end)
|
|
{
|
|
char *out = *dst;
|
|
|
|
if (out < end)
|
|
*out = '\\';
|
|
++out;
|
|
if (out < end)
|
|
*out = 'x';
|
|
++out;
|
|
if (out < end)
|
|
*out = hex_asc_hi(c);
|
|
++out;
|
|
if (out < end)
|
|
*out = hex_asc_lo(c);
|
|
++out;
|
|
|
|
*dst = out;
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* string_escape_mem - quote characters in the given memory buffer
|
|
* @src: source buffer (unescaped)
|
|
* @isz: source buffer size
|
|
* @dst: destination buffer (escaped)
|
|
* @osz: destination buffer size
|
|
* @flags: combination of the flags (bitwise OR):
|
|
* %ESCAPE_SPACE: (special white space, not space itself)
|
|
* '\f' - form feed
|
|
* '\n' - new line
|
|
* '\r' - carriage return
|
|
* '\t' - horizontal tab
|
|
* '\v' - vertical tab
|
|
* %ESCAPE_SPECIAL:
|
|
* '\\' - backslash
|
|
* '\a' - alert (BEL)
|
|
* '\e' - escape
|
|
* %ESCAPE_NULL:
|
|
* '\0' - null
|
|
* %ESCAPE_OCTAL:
|
|
* '\NNN' - byte with octal value NNN (3 digits)
|
|
* %ESCAPE_ANY:
|
|
* all previous together
|
|
* %ESCAPE_NP:
|
|
* escape only non-printable characters (checked by isprint)
|
|
* %ESCAPE_ANY_NP:
|
|
* all previous together
|
|
* %ESCAPE_HEX:
|
|
* '\xHH' - byte with hexadecimal value HH (2 digits)
|
|
* @only: NULL-terminated string containing characters used to limit
|
|
* the selected escape class. If characters are included in @only
|
|
* that would not normally be escaped by the classes selected
|
|
* in @flags, they will be copied to @dst unescaped.
|
|
*
|
|
* Description:
|
|
* The process of escaping byte buffer includes several parts. They are applied
|
|
* in the following sequence.
|
|
* 1. The character is matched to the printable class, if asked, and in
|
|
* case of match it passes through to the output.
|
|
* 2. The character is not matched to the one from @only string and thus
|
|
* must go as-is to the output.
|
|
* 3. The character is checked if it falls into the class given by @flags.
|
|
* %ESCAPE_OCTAL and %ESCAPE_HEX are going last since they cover any
|
|
* character. Note that they actually can't go together, otherwise
|
|
* %ESCAPE_HEX will be ignored.
|
|
*
|
|
* Caller must provide valid source and destination pointers. Be aware that
|
|
* destination buffer will not be NULL-terminated, thus caller have to append
|
|
* it if needs.
|
|
*
|
|
* Return:
|
|
* The total size of the escaped output that would be generated for
|
|
* the given input and flags. To check whether the output was
|
|
* truncated, compare the return value to osz. There is room left in
|
|
* dst for a '\0' terminator if and only if ret < osz.
|
|
*/
|
|
int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz,
|
|
unsigned int flags, const char *only)
|
|
{
|
|
char *p = dst;
|
|
char *end = p + osz;
|
|
bool is_dict = only && *only;
|
|
|
|
while (isz--) {
|
|
unsigned char c = *src++;
|
|
|
|
/*
|
|
* Apply rules in the following sequence:
|
|
* - the character is printable, when @flags has
|
|
* %ESCAPE_NP bit set
|
|
* - the @only string is supplied and does not contain a
|
|
* character under question
|
|
* - the character doesn't fall into a class of symbols
|
|
* defined by given @flags
|
|
* In these cases we just pass through a character to the
|
|
* output buffer.
|
|
*/
|
|
if ((flags & ESCAPE_NP && isprint(c)) ||
|
|
(is_dict && !strchr(only, c))) {
|
|
/* do nothing */
|
|
} else {
|
|
if (flags & ESCAPE_SPACE && escape_space(c, &p, end))
|
|
continue;
|
|
|
|
if (flags & ESCAPE_SPECIAL && escape_special(c, &p, end))
|
|
continue;
|
|
|
|
if (flags & ESCAPE_NULL && escape_null(c, &p, end))
|
|
continue;
|
|
|
|
/* ESCAPE_OCTAL and ESCAPE_HEX always go last */
|
|
if (flags & ESCAPE_OCTAL && escape_octal(c, &p, end))
|
|
continue;
|
|
|
|
if (flags & ESCAPE_HEX && escape_hex(c, &p, end))
|
|
continue;
|
|
}
|
|
|
|
escape_passthrough(c, &p, end);
|
|
}
|
|
|
|
return p - dst;
|
|
}
|
|
EXPORT_SYMBOL(string_escape_mem);
|