/*
- * Copyright (c) 2009 Nicira Networks.
+ * Copyright (c) 2009, 2010 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include "unicode.h"
+#include <inttypes.h>
+
+#include "dynamic-string.h"
+#include "util.h"
+
/* Returns the unicode code point corresponding to leading surrogate 'leading'
* and trailing surrogate 'trailing'. The return value will not make any
* sense if 'leading' or 'trailing' are not in the correct ranges for leading
int x1 = trailing & 0x3ff;
return (u << 16) | (x0 << 10) | x1;
}
+
+/* Returns the number of Unicode characters in UTF-8 string 's'. */
+size_t
+utf8_length(const char *s_)
+{
+ const uint8_t *s;
+ size_t length;
+
+ length = 0;
+ for (s = (const uint8_t *) s_; *s != '\0'; s++) {
+ /* The most-significant bits of the first byte in a character are one
+ * of 2#01, 2#00, or 2#11. 2#10 is a continuation byte. */
+ length += (*s & 0xc0) != 0x80;
+ }
+ return length;
+}
+
+static char *
+invalid_utf8_sequence(const uint8_t *s, int n, size_t *lengthp)
+{
+ struct ds msg;
+ int i;
+
+ if (lengthp) {
+ *lengthp = 0;
+ }
+
+ ds_init(&msg);
+ ds_put_cstr(&msg, "invalid UTF-8 sequence");
+ for (i = 0; i < n; i++) {
+ ds_put_format(&msg, " 0x%02"PRIx8, s[i]);
+ }
+ return ds_steal_cstr(&msg);
+}
+
+struct utf8_sequence {
+ uint8_t octets[5][2];
+};
+
+static const struct utf8_sequence *
+lookup_utf8_sequence(uint8_t c)
+{
+ static const struct utf8_sequence seqs[] = {
+ { { { 0x01, 0x7f },
+ { 0, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0 } } },
+
+ { { { 0xc2, 0xdf }, { 0x80, 0xbf },
+ { 0, 0 }, { 0, 0 }, { 0, 0 } } },
+
+ { { { 0xe0, 0xe0 }, { 0xa0, 0xbf }, { 0x80, 0xbf },
+ {0,0}, {0, 0 } } },
+
+ { { { 0xe1, 0xec }, { 0x80, 0xbf }, { 0x80, 0xbf },
+ { 0, 0 }, { 0, 0 } } },
+
+ { { { 0xed, 0xed }, { 0x80, 0x9f }, { 0x80, 0xbf },
+ { 0, 0 }, { 0, 0 } } },
+
+ { { { 0xee, 0xef }, { 0x80, 0xbf }, { 0x80, 0xbf },
+ { 0, 0 }, { 0, 0 } } },
+
+ { { { 0xf0, 0xf0 }, { 0x90, 0xbf }, { 0x80, 0xbf }, { 0x80, 0xbf },
+ { 0, 0 } } },
+
+ { { { 0xf1, 0xf3 }, { 0x80, 0xbf }, { 0x80, 0xbf }, { 0x80, 0xbf },
+ { 0, 0 } } },
+
+ { { { 0xf4, 0xf4 }, { 0x80, 0x8f }, { 0x80, 0xbf }, { 0x80, 0xbf },
+ { 0, 0 } } },
+ };
+
+ size_t i;
+
+ for (i = 0; i < ARRAY_SIZE(seqs); i++) {
+ const uint8_t *o = seqs[i].octets[0];
+ if (c >= o[0] && c <= o[1]) {
+ return &seqs[i];
+ }
+ }
+ return NULL;
+}
+
+/* Checks that 's' is a valid, null-terminated UTF-8 string. If so, returns a
+ * null pointer and sets '*lengthp' to the number of Unicode characters in
+ * 's'. If not, returns an error message that the caller must free and sets
+ * '*lengthp' to 0.
+ *
+ * 'lengthp' may be NULL if the length is not needed. */
+char *
+utf8_validate(const char *s_, size_t *lengthp)
+{
+ size_t length = 0;
+ const uint8_t *s;
+
+ for (s = (const uint8_t *) s_; *s != '\0'; ) {
+ length++;
+ if (s[0] < 0x80) {
+ s++;
+ } else {
+ const struct utf8_sequence *seq;
+ int i;
+
+ seq = lookup_utf8_sequence(s[0]);
+ if (!seq) {
+ return invalid_utf8_sequence(s, 1, lengthp);
+ }
+
+ for (i = 1; seq->octets[i][0]; i++) {
+ const uint8_t *o = seq->octets[i];
+ if (s[i] < o[0] || s[i] > o[1]) {
+ return invalid_utf8_sequence(s, i + 1, lengthp);
+ }
+ }
+ s += i;
+ }
+ }
+ if (lengthp) {
+ *lengthp = length;
+ }
+ return NULL;
+}