X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/e5568f75972dfc723778653c11cb6b4dc825716a..13fec9890cf095cc781fdf7b8917cb03bf32dd4c:/bsd/vfs/vfs_utfconv.c

diff --git a/bsd/vfs/vfs_utfconv.c b/bsd/vfs/vfs_utfconv.c
index 7c2f193f4..11af9238a 100644
--- a/bsd/vfs/vfs_utfconv.c
+++ b/bsd/vfs/vfs_utfconv.c
@@ -117,10 +117,31 @@ unicode_decomposeable(u_int16_t character) {
     	return (0);
 }
 
+
+/*
+ * Get the combing class.
+ *
+ * Similar to CFUniCharGetCombiningPropertyForCharacter.
+ */
+static inline u_int8_t
+get_combining_class(u_int16_t character) {
+	const u_int8_t *bitmap = __CFUniCharCombiningPropertyBitmap;
+
+	u_int8_t value = bitmap[(character >> 8)];
+
+	if (value) {
+		bitmap = bitmap + (value * 256);
+		return bitmap[character % 256];
+	}
+	return (0);
+}
+
+
 static int unicode_decompose(u_int16_t character, u_int16_t *convertedChars);
 
 static u_int16_t unicode_combine(u_int16_t base, u_int16_t combining);
 
+static void priortysort(u_int16_t* characters, int count);
 
 char utf_extrabytes[32] = {
 	 0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
@@ -316,6 +337,7 @@ utf8_decodestr(const u_int8_t* utf8p, size_t utf8len, u_int16_t* ucsp,
 	u_int16_t* bufend;
 	unsigned int ucs_ch;
 	unsigned int byte;
+	int combcharcnt = 0;
 	int result = 0;
 	int decompose, precompose, swapbytes;
 
@@ -416,6 +438,7 @@ utf8_decodestr(const u_int8_t* utf8p, size_t utf8len, u_int16_t* ucsp,
 						if (ucsp >= bufend)
 							goto toolong;
 					}
+					combcharcnt += count - 1;
 					continue;			
 				}
 			} else if (precompose && (ucsp != bufstart)) {
@@ -436,8 +459,25 @@ utf8_decodestr(const u_int8_t* utf8p, size_t utf8len, u_int16_t* ucsp,
 		if (ucs_ch == altslash)
 			ucs_ch = '/';
 
+		/*
+		 * Make multiple combining character sequences canonical
+		 */
+		if (unicode_combinable(ucs_ch)) {
+			++combcharcnt;   /* start tracking a run */
+		} else if (combcharcnt) {
+			if (combcharcnt > 1) {
+				priortysort(ucsp - combcharcnt, combcharcnt);
+			}
+			combcharcnt = 0;  /* start over */
+		}
 		*ucsp++ = swapbytes ? NXSwapShort(ucs_ch) : ucs_ch;
 	}
+	/*
+	 * Make a previous combining sequence canonical
+	 */
+	if (combcharcnt > 1) {
+		priortysort(ucsp - combcharcnt, combcharcnt);
+	}
 
 exit:
 	*ucslen = (u_int8_t*)ucsp - (u_int8_t*)bufstart;
@@ -454,6 +494,91 @@ toolong:
 }
 
 
+/*
+ * utf8_validatestr - Check for a valid UTF-8 string.
+ */
+int
+utf8_validatestr(const u_int8_t* utf8p, size_t utf8len)
+{
+	unsigned int byte;
+	u_int32_t ch;
+	unsigned int ucs_ch;
+	size_t extrabytes;
+
+	while (utf8len-- > 0 && (byte = *utf8p++) != '\0') {
+		if (byte < 0x80)
+			continue;  /* plain ascii */
+
+		extrabytes = utf_extrabytes[byte >> 3];
+
+		if (utf8len < extrabytes)
+			goto invalid;
+		utf8len -= extrabytes;
+
+		switch (extrabytes) {
+		case 1:
+			ch = byte; ch <<= 6;   /* 1st byte */
+			byte = *utf8p++;       /* 2nd byte */
+			if ((byte >> 6) != 2)
+				goto invalid;
+			ch += byte;
+			ch -= 0x00003080UL;
+			if (ch < 0x0080)
+				goto invalid;
+			break;
+		case 2:
+			ch = byte; ch <<= 6;   /* 1st byte */
+			byte = *utf8p++;       /* 2nd byte */
+			if ((byte >> 6) != 2)
+				goto invalid;
+			ch += byte; ch <<= 6;
+			byte = *utf8p++;       /* 3rd byte */
+			if ((byte >> 6) != 2)
+				goto invalid;
+			ch += byte;
+			ch -= 0x000E2080UL;
+			if (ch < 0x0800)
+				goto invalid;
+			if (ch >= 0xD800) {
+				if (ch <= 0xDFFF)
+					goto invalid;
+				if (ch == 0xFFFE || ch == 0xFFFF)
+					goto invalid;
+			}
+			break;
+		case 3:
+			ch = byte; ch <<= 6;   /* 1st byte */
+			byte = *utf8p++;       /* 2nd byte */
+			if ((byte >> 6) != 2)
+				goto invalid;
+			ch += byte; ch <<= 6;
+			byte = *utf8p++;       /* 3rd byte */
+			if ((byte >> 6) != 2)
+				goto invalid;
+			ch += byte; ch <<= 6;
+			byte = *utf8p++;       /* 4th byte */
+			if ((byte >> 6) != 2)
+				goto invalid;
+			ch += byte;
+			ch -= 0x03C82080UL + SP_HALF_BASE;
+			ucs_ch = (ch >> SP_HALF_SHIFT) + SP_HIGH_FIRST;
+			if (ucs_ch < SP_HIGH_FIRST || ucs_ch > SP_HIGH_LAST)
+				goto invalid;
+			ucs_ch = (ch & SP_HALF_MASK) + SP_LOW_FIRST;
+			if (ucs_ch < SP_LOW_FIRST || ucs_ch > SP_LOW_LAST)
+				goto invalid;
+			break;
+		default:
+			goto invalid;
+		}
+		
+	}
+	return (0);
+invalid:
+	return (EINVAL);
+}
+
+
  /*
   * Unicode 3.2 decomposition code (derived from Core Foundation)
   */
@@ -644,3 +769,39 @@ unicode_combine(u_int16_t base, u_int16_t combining)
 	return (value);
 }
 
+
+/*
+ * priortysort - order combining chars into canonical order
+ *
+ * Similar to CFUniCharPrioritySort
+ */
+static void
+priortysort(u_int16_t* characters, int count)
+{
+	u_int32_t p1, p2;
+	u_int16_t *ch1, *ch2;
+	u_int16_t *end;
+	int changes = 1;
+
+	end = characters + count;
+	do {
+		changes = 0;
+		ch1 = characters;
+		ch2 = characters + 1;
+		p2 = get_combining_class(*ch1);
+		while (ch2 < end) {
+			p1 = p2;
+			p2 = get_combining_class(*ch2);
+			if (p1 > p2) {
+				u_int32_t tmp;
+
+				tmp = *ch1;
+				*ch1 = *ch2;
+				*ch2 = tmp;
+				changes = 1;
+			}
+			++ch1;
+			++ch2;
+		}
+	} while (changes);
+}