/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. 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/>. ***/ /* This file is 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 Lesser 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ #include <errno.h> #include <stdlib.h> #include <inttypes.h> #include <string.h> #include <stdbool.h> #include "utf8.h" #define FILTER_CHAR '_' 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 inline bool is_continuation_char(uint8_t ch) { if ((ch & 0xc0) != 0x80) /* 10xxxxxx */ return false; return true; } static inline void merge_continuation_char(uint32_t *u_ch, uint8_t ch) { *u_ch <<= 6; *u_ch |= ch & 0x3f; } 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') || (0x7F <= ch && ch <= 0x9F); } char* utf8_is_printable_n(const char* str, size_t length) { uint32_t val = 0; uint32_t min = 0; const uint8_t *p; assert(str); for (p = (const uint8_t*) str; length; p++, length--) { if (*p < 128) { val = *p; } else { if ((*p & 0xe0) == 0xc0) { /* 110xxxxx two-char seq. */ min = 128; val = (uint32_t) (*p & 0x1e); goto ONE_REMAINING; } else if ((*p & 0xf0) == 0xe0) { /* 1110xxxx three-char seq.*/ min = (1 << 11); val = (uint32_t) (*p & 0x0f); goto TWO_REMAINING; } else if ((*p & 0xf8) == 0xf0) { /* 11110xxx four-char seq */ min = (1 << 16); val = (uint32_t) (*p & 0x07); } else goto error; p++; length--; if (!length || !is_continuation_char(*p)) goto error; merge_continuation_char(&val, *p); TWO_REMAINING: p++; length--; if (!is_continuation_char(*p)) goto error; merge_continuation_char(&val, *p); ONE_REMAINING: p++; length--; if (!is_continuation_char(*p)) goto error; merge_continuation_char(&val, *p); if (val < min) goto error; } if (is_unicode_control(val)) goto error; } return (char*) str; error: return NULL; } static char* utf8_validate(const char *str, char *output) { uint32_t val = 0; uint32_t min = 0; const uint8_t *p, *last; int size; uint8_t *o; assert(str); o = (uint8_t*) output; for (p = (const uint8_t*) str; *p; p++) { if (*p < 128) { if (o) *o = *p; } else { last = p; if ((*p & 0xe0) == 0xc0) { /* 110xxxxx two-char seq. */ size = 2; min = 128; val = (uint32_t) (*p & 0x1e); goto ONE_REMAINING; } else if ((*p & 0xf0) == 0xe0) { /* 1110xxxx three-char seq.*/ size = 3; min = (1 << 11); val = (uint32_t) (*p & 0x0f); goto TWO_REMAINING; } else if ((*p & 0xf8) == 0xf0) { /* 11110xxx four-char seq */ size = 4; min = (1 << 16); val = (uint32_t) (*p & 0x07); } else goto error; p++; if (!is_continuation_char(*p)) goto error; merge_continuation_char(&val, *p); TWO_REMAINING: p++; if (!is_continuation_char(*p)) goto error; merge_continuation_char(&val, *p); ONE_REMAINING: p++; if (!is_continuation_char(*p)) goto error; merge_continuation_char(&val, *p); if (val < min) goto error; if (!is_unicode_valid(val)) goto error; if (o) { memcpy(o, last, (size_t) size); o += size; } continue; error: if (o) { *o = FILTER_CHAR; p = last; /* We retry at the next character */ } else goto failure; } if (o) o++; } if (o) { *o = '\0'; return output; } return (char*) str; failure: return NULL; } char* utf8_is_valid (const char *str) { return utf8_validate(str, NULL); } char* utf8_filter (const char *str) { char *new_str; assert(str); new_str = malloc(strlen(str) + 1); if (!new_str) return NULL; return utf8_validate(str, new_str); } 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 *ascii_filter(const char *str) { const char *s; char *r, *d; size_t l; assert(str); l = strlen(str); r = malloc(l + 1); if (!r) return NULL; for (s = str, d = r; *s; s++) if ((unsigned char) *s < 128) *(d++) = *s; *d = 0; return r; }