/* SPDX-License-Identifier: LGPL-2.1-or-later */
/* Parts of this file are based on the GLIB utf8 validation functions. The
* original license text follows. */
/* gutf8.c - Operations on UTF-8 strings.
*
* Copyright (C) 1999 Tom Tromey
* Copyright (C) 2000 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "nm-sd-adapt-shared.h"
#include <errno.h>
#include <stdbool.h>
#include <stdlib.h>
#include "alloc-util.h"
#include "gunicode.h"
#include "hexdecoct.h"
#include "macro.h"
#include "string-util.h"
#include "utf8.h"
bool unichar_is_valid(char32_t ch) {
if (ch >= 0x110000) /* End of unicode space */
return false;
if ((ch & 0xFFFFF800) == 0xD800) /* Reserved area for UTF-16 */
return false;
if ((ch >= 0xFDD0) && (ch <= 0xFDEF)) /* Reserved */
return false;
if ((ch & 0xFFFE) == 0xFFFE) /* BOM (Byte Order Mark) */
return false;
return true;
}
static bool unichar_is_control(char32_t ch) {
/*
0 to ' '-1 is the C0 range.
DEL=0x7F, and DEL+1 to 0x9F is C1 range.
'\t' is in C0 range, but more or less harmless and commonly used.
*/
return (ch < ' ' && !IN_SET(ch, '\t', '\n')) ||
(0x7F <= ch && ch <= 0x9F);
}
/* count of characters used to encode one unicode char */
static size_t utf8_encoded_expected_len(uint8_t c) {
if (c < 0x80)
return 1;
if ((c & 0xe0) == 0xc0)
return 2;
if ((c & 0xf0) == 0xe0)
return 3;
if ((c & 0xf8) == 0xf0)
return 4;
if ((c & 0xfc) == 0xf8)
return 5;
if ((c & 0xfe) == 0xfc)
return 6;
return 0;
}
/* decode one unicode char */
int utf8_encoded_to_unichar(const char *str, char32_t *ret_unichar) {
char32_t unichar;
size_t len, i;
assert(str);
len = utf8_encoded_expected_len(str[0]);
switch (len) {
case 1:
*ret_unichar = (char32_t)str[0];
return 0;
case 2:
unichar = str[0] & 0x1f;
break;
case 3:
unichar = (char32_t)str[0] & 0x0f;
break;
case 4:
unichar = (char32_t)str[0] & 0x07;
break;
case 5:
unichar = (char32_t)str[0] & 0x03;
break;
case 6:
unichar = (char32_t)str[0] & 0x01;
break;
default:
return -EINVAL;
}
for (i = 1; i < len; i++) {
if (((char32_t)str[i] & 0xc0) != 0x80)
return -EINVAL;
unichar <<= 6;
unichar |= (char32_t)str[i] & 0x3f;
}
*ret_unichar = unichar;
return 0;
}
bool utf8_is_printable_newline(const char* str, size_t length, bool allow_newline) {
const char *p;
assert(str);
for (p = str; length > 0;) {
int encoded_len, r;
char32_t val;
encoded_len = utf8_encoded_valid_unichar(p, length);
if (encoded_len < 0)
return false;
assert(encoded_len > 0 && (size_t) encoded_len <= length);
r = utf8_encoded_to_unichar(p, &val);
if (r < 0 ||
unichar_is_control(val) ||
(!allow_newline && val == '\n'))
return false;
length -= encoded_len;
p += encoded_len;
}
return true;
}
char *utf8_is_valid_n(const char *str, size_t len_bytes) {
/* Check if the string is composed of valid utf8 characters. If length len_bytes is given, stop after
* len_bytes. Otherwise, stop at NUL. */
assert(str);
for (const char *p = str; len_bytes != (size_t) -1 ? (size_t) (p - str) < len_bytes : *p != '\0'; ) {
int len;
if (_unlikely_(*p == '\0') && len_bytes != (size_t) -1)
return NULL; /* embedded NUL */
len = utf8_encoded_valid_unichar(p,
len_bytes != (size_t) -1 ? len_bytes - (p - str) : (size_t) -1);
if (_unlikely_(len < 0))
return NULL; /* invalid character */
p += len;
}
return (char*) str;
}
char *utf8_escape_invalid(const char *str) {
char *p, *s;
assert(str);
p = s = malloc(strlen(str) * 4 + 1);
if (!p)
return NULL;
while (*str) {
int len;
len = utf8_encoded_valid_unichar(str, (size_t) -1);
if (len > 0) {
s = mempcpy(s, str, len);
str += len;
} else {
s = stpcpy(s, UTF8_REPLACEMENT_CHARACTER);
str += 1;
}
}
*s = '\0';
(void) str_realloc(&p);
return p;
}
#if 0 /* NM_IGNORED */
static int utf8_char_console_width(const char *str) {
char32_t c;
int r;
r = utf8_encoded_to_unichar(str, &c);
if (r < 0)
return r;
/* TODO: we should detect combining characters */
return unichar_iswide(c) ? 2 : 1;
}
char *utf8_escape_non_printable_full(const char *str, size_t console_width) {
char *p, *s, *prev_s;
size_t n = 0; /* estimated print width */
assert(str);
if (console_width == 0)
return strdup("");
p = s = prev_s = malloc(strlen(str) * 4 + 1);
if (!p)
return NULL;
for (;;) {
int len;
char *saved_s = s;
if (!*str) /* done! */
goto finish;
len = utf8_encoded_valid_unichar(str, (size_t) -1);
if (len > 0) {
if (utf8_is_printable(str, len)) {
int w;
w = utf8_char_console_width(str);
assert(w >= 0);
if (n + w > console_width)
goto truncation;
s = mempcpy(s, str, len);
str += len;
n += w;
} else {
for (; len > 0; len--) {
if (n + 4 > console_width)
goto truncation;
*(s++) = '\\';
*(s++) = 'x';
*(s++) = hexchar((int) *str >> 4);
*(s++) = hexchar((int) *str);
str += 1;
n += 4;
}
}
} else {
if (n + 1 > console_width)
goto truncation;
s = mempcpy(s, UTF8_REPLACEMENT_CHARACTER, strlen(UTF8_REPLACEMENT_CHARACTER));
str += 1;
n += 1;
}
prev_s = saved_s;
}
truncation:
/* Try to go back one if we don't have enough space for the ellipsis */
if (n + 1 >= console_width)
s = prev_s;
s = mempcpy(s, "…", strlen("…"));
finish:
*s = '\0';
(void) str_realloc(&p);
return p;
}
#endif /* NM_IGNORED */
char *ascii_is_valid(const char *str) {
const char *p;
/* Check whether the string consists of valid ASCII bytes,
* i.e values between 0 and 127, inclusive. */
assert(str);
for (p = str; *p; p++)
if ((unsigned char) *p >= 128)
return NULL;
return (char*) str;
}
#if 0 /* NM_IGNORED */
char *ascii_is_valid_n(const char *str, size_t len) {
size_t i;
/* Very similar to ascii_is_valid(), but checks exactly len
* bytes and rejects any NULs in that range. */
assert(str);
for (i = 0; i < len; i++)
if ((unsigned char) str[i] >= 128 || str[i] == 0)
return NULL;
return (char*) str;
}
#endif /* NM_IGNORED */
/**
* utf8_encode_unichar() - Encode single UCS-4 character as UTF-8
* @out_utf8: output buffer of at least 4 bytes or NULL
* @g: UCS-4 character to encode
*
* This encodes a single UCS-4 character as UTF-8 and writes it into @out_utf8.
* The length of the character is returned. It is not zero-terminated! If the
* output buffer is NULL, only the length is returned.
*
* Returns: The length in bytes that the UTF-8 representation does or would
* occupy.
*/
size_t utf8_encode_unichar(char *out_utf8, char32_t g) {
if (g < (1 << 7)) {
if (out_utf8)
out_utf8[0] = g & 0x7f;
return 1;
} else if (g < (1 << 11)) {
if (out_utf8) {
out_utf8[0] = 0xc0 | ((g >> 6) & 0x1f);
out_utf8[1] = 0x80 | (g & 0x3f);
}
return 2;
} else if (g < (1 << 16)) {
if (out_utf8) {
out_utf8[0] = 0xe0 | ((g >> 12) & 0x0f);
out_utf8[1] = 0x80 | ((g >> 6) & 0x3f);
out_utf8[2] = 0x80 | (g & 0x3f);
}
return 3;
} else if (g < (1 << 21)) {
if (out_utf8) {
out_utf8[0] = 0xf0 | ((g >> 18) & 0x07);
out_utf8[1] = 0x80 | ((g >> 12) & 0x3f);
out_utf8[2] = 0x80 | ((g >> 6) & 0x3f);
out_utf8[3] = 0x80 | (g & 0x3f);
}
return 4;
}
return 0;
}
#if 0 /* NM_IGNORED */
char *utf16_to_utf8(const char16_t *s, size_t length /* bytes! */) {
const uint8_t *f;
char *r, *t;
assert(s);
/* Input length is in bytes, i.e. the shortest possible character takes 2 bytes. Each unicode character may
* take up to 4 bytes in UTF-8. Let's also account for a trailing NUL byte. */
if (length * 2 < length)
return NULL; /* overflow */
r = new(char, length * 2 + 1);
if (!r)
return NULL;
f = (const uint8_t*) s;
t = r;
while (f + 1 < (const uint8_t*) s + length) {
char16_t w1, w2;
/* see RFC 2781 section 2.2 */
w1 = f[1] << 8 | f[0];
f += 2;
if (!utf16_is_surrogate(w1)) {
t += utf8_encode_unichar(t, w1);
continue;
}
if (utf16_is_trailing_surrogate(w1))
continue; /* spurious trailing surrogate, ignore */
if (f + 1 >= (const uint8_t*) s + length)
break;
w2 = f[1] << 8 | f[0];
f += 2;
if (!utf16_is_trailing_surrogate(w2)) {
f -= 2;
continue; /* surrogate missing its trailing surrogate, ignore */
}
t += utf8_encode_unichar(t, utf16_surrogate_pair_to_unichar(w1, w2));
}
*t = 0;
return r;
}
size_t utf16_encode_unichar(char16_t *out, char32_t c) {
/* Note that this encodes as little-endian. */
switch (c) {
case 0 ... 0xd7ffU:
case 0xe000U ... 0xffffU:
out[0] = htole16(c);
return 1;
case 0x10000U ... 0x10ffffU:
c -= 0x10000U;
out[0] = htole16((c >> 10) + 0xd800U);
out[1] = htole16((c & 0x3ffU) + 0xdc00U);
return 2;
default: /* A surrogate (invalid) */
return 0;
}
}
char16_t *utf8_to_utf16(const char *s, size_t length) {
char16_t *n, *p;
size_t i;
int r;
assert(s);
n = new(char16_t, length + 1);
if (!n)
return NULL;
p = n;
for (i = 0; i < length;) {
char32_t unichar;
size_t e;
e = utf8_encoded_expected_len(s[i]);
if (e <= 1) /* Invalid and single byte characters are copied as they are */
goto copy;
if (i + e > length) /* sequence longer than input buffer, then copy as-is */
goto copy;
r = utf8_encoded_to_unichar(s + i, &unichar);
if (r < 0) /* sequence invalid, then copy as-is */
goto copy;
p += utf16_encode_unichar(p, unichar);
i += e;
continue;
copy:
*(p++) = htole16(s[i++]);
}
*p = 0;
return n;
}
size_t char16_strlen(const char16_t *s) {
size_t n = 0;
assert(s);
while (*s != 0)
n++, s++;
return n;
}
#endif /* NM_IGNORED */
/* expected size used to encode one unicode char */
static int utf8_unichar_to_encoded_len(char32_t unichar) {
if (unichar < 0x80)
return 1;
if (unichar < 0x800)
return 2;
if (unichar < 0x10000)
return 3;
if (unichar < 0x200000)
return 4;
if (unichar < 0x4000000)
return 5;
return 6;
}
/* validate one encoded unicode char and return its length */
int utf8_encoded_valid_unichar(const char *str, size_t length /* bytes */) {
char32_t unichar;
size_t len, i;
int r;
assert(str);
assert(length > 0);
/* We read until NUL, at most length bytes. (size_t) -1 may be used to disable the length check. */
len = utf8_encoded_expected_len(str[0]);
if (len == 0)
return -EINVAL;
/* Do we have a truncated multi-byte character? */
if (len > length)
return -EINVAL;
/* ascii is valid */
if (len == 1)
return 1;
/* check if expected encoded chars are available */
for (i = 0; i < len; i++)
if ((str[i] & 0x80) != 0x80)
return -EINVAL;
r = utf8_encoded_to_unichar(str, &unichar);
if (r < 0)
return r;
/* check if encoded length matches encoded value */
if (utf8_unichar_to_encoded_len(unichar) != (int) len)
return -EINVAL;
/* check if value has valid range */
if (!unichar_is_valid(unichar))
return -EINVAL;
return (int) len;
}
#if 0 /* NM_IGNORED */
size_t utf8_n_codepoints(const char *str) {
size_t n = 0;
/* Returns the number of UTF-8 codepoints in this string, or (size_t) -1 if the string is not valid UTF-8. */
while (*str != 0) {
int k;
k = utf8_encoded_valid_unichar(str, (size_t) -1);
if (k < 0)
return (size_t) -1;
str += k;
n++;
}
return n;
}
size_t utf8_console_width(const char *str) {
size_t n = 0;
/* Returns the approximate width a string will take on screen when printed on a character cell
* terminal/console. */
while (*str) {
int w;
w = utf8_char_console_width(str);
if (w < 0)
return (size_t) -1;
n += w;
str = utf8_next_char(str);
}
return n;
}
#endif /* NM_IGNORED */