utf8.c revision 7b4d7cc08283e5485dcfa49ffdf1915de1d5e81b
/*-*- 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 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"
#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;
}
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;
}