src/shared: refactor shared code

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>

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;
+}