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Diffstat (limited to 'src/shared/utf8.c')
| -rw-r--r-- | src/shared/utf8.c | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/src/shared/utf8.c b/src/shared/utf8.c new file mode 100644 index 0000000000..1044fb6489 --- /dev/null +++ b/src/shared/utf8.c @@ -0,0 +1,249 @@ +/*** + This file is part of udev, forked from systemd. + + Copyright 2008-2011 Kay Sievers + Copyright 2012 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +/* 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 <errno.h> +#include <stdlib.h> +#include <inttypes.h> +#include <string.h> +#include <stdbool.h> + +#include "utf8.h" +#include "util.h" + +static inline bool is_unicode_valid(uint32_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 is_unicode_control(uint32_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 < ' ' && ch != '\t' && ch != '\n') || + (0x7F <= ch && ch <= 0x9F); +} + +/* count of characters used to encode one unicode char */ +static int utf8_encoded_expected_len(const char *str) { + unsigned char c = (unsigned char)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) { + int unichar; + int len; + int i; + + len = utf8_encoded_expected_len(str); + switch (len) { + case 1: + return (int)str[0]; + case 2: + unichar = str[0] & 0x1f; + break; + case 3: + unichar = (int)str[0] & 0x0f; + break; + case 4: + unichar = (int)str[0] & 0x07; + break; + case 5: + unichar = (int)str[0] & 0x03; + break; + case 6: + unichar = (int)str[0] & 0x01; + break; + default: + return -1; + } + + for (i = 1; i < len; i++) { + if (((int)str[i] & 0xc0) != 0x80) + return -1; + unichar <<= 6; + unichar |= (int)str[i] & 0x3f; + } + + return unichar; +} + +bool utf8_is_printable(const char* str, size_t length) { + const uint8_t *p; + + assert(str); + + for (p = (const uint8_t*) str; length;) { + int encoded_len = utf8_encoded_valid_unichar((const char *)p); + int val = utf8_encoded_to_unichar((const char*)p); + + if (encoded_len < 0 || val < 0 || is_unicode_control(val)) + return false; + + length -= encoded_len; + p += encoded_len; + } + + return true; +} + +char *ascii_is_valid(const char *str) { + const char *p; + + assert(str); + + for (p = str; *p; p++) + if ((unsigned char) *p >= 128) + return NULL; + + return (char*) str; +} + +char *utf16_to_utf8(const void *s, size_t length) { + char *r; + const uint8_t *f; + uint8_t *t; + + r = new(char, (length*3+1)/2 + 1); + if (!r) + return NULL; + + t = (uint8_t*) r; + + for (f = s; f < (const uint8_t*) s + length; f += 2) { + uint16_t c; + + c = (f[1] << 8) | f[0]; + + if (c == 0) { + *t = 0; + return r; + } else if (c < 0x80) { + *(t++) = (uint8_t) c; + } else if (c < 0x800) { + *(t++) = (uint8_t) (0xc0 | (c >> 6)); + *(t++) = (uint8_t) (0x80 | (c & 0x3f)); + } else { + *(t++) = (uint8_t) (0xe0 | (c >> 12)); + *(t++) = (uint8_t) (0x80 | ((c >> 6) & 0x3f)); + *(t++) = (uint8_t) (0x80 | (c & 0x3f)); + } + } + + *t = 0; + + return r; +} + +/* expected size used to encode one unicode char */ +static int utf8_unichar_to_encoded_len(int 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) { + int len; + int unichar; + int i; + + len = utf8_encoded_expected_len(str); + if (len == 0) + return -1; + + /* 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 -1; + + unichar = utf8_encoded_to_unichar(str); + + /* check if encoded length matches encoded value */ + if (utf8_unichar_to_encoded_len(unichar) != len) + return -1; + + /* check if value has valid range */ + if (!is_unicode_valid(unichar)) + return -1; + + return len; +} |