// SPDX-License-Identifier: GPL-2.0-only/* * 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/fs.h>#include <linux/limits.h>#include <linux/mm.h>#include <linux/slab.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, }; static const unsigned int rounding[] = { 500, 50, 5 }; int i = 0, j; u32 remainder = 0, sf_cap; char tmp[8]; const char *unit; tmp[0] = '\0'; if (blk_size == 0) size = 0; if (size == 0) goto out; /* This is Napier's algorithm. Reduce the original block size to * * coefficient * divisor[units]^i * * we do the reduction so both coefficients are just under 32 bits so * that multiplying them together won't overflow 64 bits and we keep * as much precision as possible in the numbers. * * Note: it's safe to throw away the remainders here because all the * precision is in the coefficients. */ while (blk_size >> 32) { do_div(blk_size, divisor[units]); i++; } while (size >> 32) { do_div(size, divisor[units]); i++; } /* now perform the actual multiplication keeping i as the sum of the * two logarithms */ size *= blk_size; /* and logarithmically reduce it until it's just under the divisor */ while (size >= divisor[units]) { remainder = do_div(size, divisor[units]); i++; } /* work out in j how many digits of precision we need from the * remainder */ sf_cap = size; for (j = 0; sf_cap*10 < 1000; j++) sf_cap *= 10; if (units == STRING_UNITS_2) { /* express the remainder as a decimal. It's currently the * numerator of a fraction whose denominator is * divisor[units], which is 1 << 10 for STRING_UNITS_2 */ remainder *= 1000; remainder >>= 10; } /* add a 5 to the digit below what will be printed to ensure * an arithmetical round up and carry it through to size */ remainder += rounding[j]; if (remainder >= 1000) { remainder -= 1000; size += 1; } if (j) { 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; Lines 1–500 of 629. Load more
// SPDX-License-Identifier: GPL-2.0-only /* * 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/fs.h> #include <linux/limits.h> #include <linux/mm.h> #include <linux/slab.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, }; static const unsigned int rounding[] = { 500, 50, 5 }; int i = 0, j; u32 remainder = 0, sf_cap; char tmp[8]; const char *unit; tmp[0] = '\0'; if (blk_size == 0) size = 0; if (size == 0) goto out; /* This is Napier's algorithm. Reduce the original block size to * * coefficient * divisor[units]^i * * we do the reduction so both coefficients are just under 32 bits so * that multiplying them together won't overflow 64 bits and we keep * as much precision as possible in the numbers. * * Note: it's safe to throw away the remainders here because all the * precision is in the coefficients. */ while (blk_size >> 32) { do_div(blk_size, divisor[units]); i++; } while (size >> 32) { do_div(size, divisor[units]); i++; } /* now perform the actual multiplication keeping i as the sum of the * two logarithms */ size *= blk_size; /* and logarithmically reduce it until it's just under the divisor */ while (size >= divisor[units]) { remainder = do_div(size, divisor[units]); i++; } /* work out in j how many digits of precision we need from the * remainder */ sf_cap = size; for (j = 0; sf_cap*10 < 1000; j++) sf_cap *= 10; if (units == STRING_UNITS_2) { /* express the remainder as a decimal. It's currently the * numerator of a fraction whose denominator is * divisor[units], which is 1 << 10 for STRING_UNITS_2 */ remainder *= 1000; remainder >>= 10; } /* add a 5 to the digit below what will be printed to ensure * an arithmetical round up and carry it through to size */ remainder += rounding[j]; if (remainder >= 1000) { remainder -= 1000; size += 1; } if (j) { 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;