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Diffstat (limited to 'shared/systemd/src/basic/utf8.c')
| -rw-r--r-- | shared/systemd/src/basic/utf8.c | 546 |
1 files changed, 546 insertions, 0 deletions
diff --git a/shared/systemd/src/basic/utf8.c b/shared/systemd/src/basic/utf8.c new file mode 100644 index 00000000..e9958c91 --- /dev/null +++ b/shared/systemd/src/basic/utf8.c @@ -0,0 +1,546 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ + +/* 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 <string.h> + +#include "alloc-util.h" +#include "gunicode.h" +#include "hexdecoct.h" +#include "macro.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; +} + +#if 0 /* NM_IGNORED */ +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); +} +#endif /* NM_IGNORED */ + +/* count of characters used to encode one unicode char */ +static size_t utf8_encoded_expected_len(const char *str) { + uint8_t c; + + assert(str); + + c = (uint8_t) str[0]; + 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); + + 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; +} + +#if 0 /* NM_IGNORED */ +bool utf8_is_printable_newline(const char* str, size_t length, bool newline) { + const char *p; + + assert(str); + + for (p = str; length;) { + int encoded_len, r; + char32_t val; + + encoded_len = utf8_encoded_valid_unichar(p); + if (encoded_len < 0 || + (size_t) encoded_len > length) + return false; + + r = utf8_encoded_to_unichar(p, &val); + if (r < 0 || + unichar_is_control(val) || + (!newline && val == '\n')) + return false; + + length -= encoded_len; + p += encoded_len; + } + + return true; +} +#endif /* NM_IGNORED */ + +char *utf8_is_valid(const char *str) { + const char *p; + + assert(str); + + p = str; + while (*p) { + int len; + + len = utf8_encoded_valid_unichar(p); + if (len < 0) + return NULL; + + 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); + if (len > 0) { + s = mempcpy(s, str, len); + str += len; + } else { + s = stpcpy(s, UTF8_REPLACEMENT_CHARACTER); + str += 1; + } + } + + *s = '\0'; + + return p; +} + +#if 0 /* NM_IGNORED */ +char *utf8_escape_non_printable(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); + if (len > 0) { + if (utf8_is_printable(str, len)) { + s = mempcpy(s, str, len); + str += len; + } else { + while (len > 0) { + *(s++) = '\\'; + *(s++) = 'x'; + *(s++) = hexchar((int) *str >> 4); + *(s++) = hexchar((int) *str); + + str += 1; + len--; + } + } + } else { + s = stpcpy(s, UTF8_REPLACEMENT_CHARACTER); + str += 1; + } + } + + *s = '\0'; + + 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) { + char32_t unichar; + size_t len, i; + int r; + + assert(str); + + len = utf8_encoded_expected_len(str); + if (len == 0) + 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); + 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 != 0) { + char32_t c; + + if (utf8_encoded_to_unichar(str, &c) < 0) + return (size_t) -1; + + str = utf8_next_char(str); + + n += unichar_iswide(c) ? 2 : 1; + } + + return n; +} +#endif /* NM_IGNORED */ |