Care null character

Author: moznion

src/lua-urlencode.c

@@ -1,6 +1,11 @@
 #include "lua-urlencode.h"
 
-static const char xdigit[16] = "0123456789ABCDEF";
+#define UTF8_LEAD(c) ((uint8_t)(c) < 0x80 || ((uint8_t)(c) > 0xC1 && (uint8_t)(c) < 0xF5))
+#define UTF8_TRAIL(c) (((uint8_t)(c) & 0xC0) == 0x80)
+
+uint8_t utf8_len(const uint8_t* str);
+
+static const uint8_t xdigit[16] = "0123456789ABCDEF";
 static const int url_unreserved[256] = {
     0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x00-0x0F */
     0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x10-0x1F */
@@ -20,42 +25,27 @@ static const int url_unreserved[256] = {
     0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0xF0-0xFF */
 };
 
-typedef struct {
-    char* got;
-    char* err;
-} urlencode_result_t;
-
-static urlencode_result_t _encode_url(const unsigned char* input, const char* encoding) {
-    if (setlocale(LC_CTYPE, encoding) == NULL) {
-        const char* errmsg = "failed to configure the locale";
-        printf("%s\n", errmsg);
-        const urlencode_result_t result = {"", errmsg};
-        return result;
+static uint8_t* _encode_url(const uint8_t* input) {
+    if (input[0] == '\0') {
+        return "";
     }
 
     const long len = strlen(input);
-    const char* endmarker = input + len;
-    char* encoded;
-    encoded = (char*)malloc(sizeof(char) * len * 3 + 1);
+    const uint8_t* endmarker = input + len;
+    uint8_t* encoded;
+    encoded = (uint8_t*)malloc(sizeof(uint8_t) * len * 3 + 1);
 
     int in_cursor = 0;
     int out_cursor = 0;
-    int char_count = 0;
     while (input[in_cursor] != '\0') {
-        int charlen = mblen(&input[in_cursor], MB_CUR_MAX);
-        if (charlen < 0) {
-            const char* errmsg = "invalid character has come";
-            printf("%s\n", errmsg);
-            const urlencode_result_t result = {"", errmsg};
-            return result;
-        }
+        const uint8_t charlen = utf8_len(&input[in_cursor]);
 
         if (charlen == 0) {
             continue;
         }
 
         if (charlen <= 1) {
-            const unsigned char c = input[in_cursor];
+            const uint8_t c = input[in_cursor];
             in_cursor += charlen;
             if (url_unreserved[c]) {
                 encoded[out_cursor++] = c;
@@ -70,33 +60,22 @@ static urlencode_result_t _encode_url(const unsigned char* input, const char* en
         }
 
         for (int i = 0; i < charlen; i++, in_cursor++) {
-            const unsigned char c = input[in_cursor];
+            const uint8_t c = input[in_cursor];
             encoded[out_cursor++] = '%';
             encoded[out_cursor++] = xdigit[c >> 4];
             encoded[out_cursor++] = xdigit[c & 15];
         }
     }
     encoded[out_cursor] = '\0';
 
-    const urlencode_result_t result = {encoded, ""};
-    return result;
+    return encoded;
 }
 
 static int encode_url (lua_State* L) {
-    const unsigned char* input = luaL_checkstring(L, 1);
-    const unsigned char* encoding = luaL_checkstring(L, 2);
-    const urlencode_result_t result = _encode_url(input, encoding);
-
-    lua_pushstring(L, result.got);
-
-    const char* err = result.err;
-    if (strlen(err) <= 0) {
-        lua_pushnil(L);
-    } else {
-        lua_pushstring(L, err);
-    }
-
-    return 2;
+    const uint8_t* input = luaL_checkstring(L, 1);
+    const uint8_t* encoded = _encode_url(input);
+    lua_pushstring(L, encoded);
+    return 1;
 }
 
 #define __ 256
@@ -120,37 +99,23 @@ static const int hexval[256] = {
 };
 #undef __
 
-static urlencode_result_t _decode_url(const unsigned char* input, const char* encoding) {
-    if (setlocale(LC_CTYPE, encoding) == NULL) {
-        const char* errmsg = "failed to configure the locale";
-        printf("%s\n", errmsg);
-        const urlencode_result_t result = {"", errmsg};
-        return result;
-    }
-
+static uint8_t* _decode_url(const uint8_t* input) {
     const long len = strlen(input);
-    const char* endmarker = input + len;
-    char* decoded;
-    decoded = (char*)malloc(sizeof(char) * len + 1);
+    const uint8_t* endmarker = input + len;
+    uint8_t* decoded;
+    decoded = (uint8_t*)malloc(sizeof(uint8_t) * len + 1);
 
     int in_cursor = 0;
     int out_cursor = 0;
-    int char_count = 0;
     while (input[in_cursor] != '\0') {
-        int charlen = mblen(&input[in_cursor], MB_CUR_MAX);
-        if (charlen < 0) {
-            const char* errmsg = "invalid character has come";
-            printf("%s\n", errmsg);
-            const urlencode_result_t result = {"", errmsg};
-            return result;
-        }
+        const uint8_t charlen = utf8_len(&input[in_cursor]);
 
         if (charlen == 0) {
             continue;
         }
 
         if (charlen <= 1) {
-            const unsigned char c = input[in_cursor++];
+            const uint8_t c = input[in_cursor++];
 
             if (c == '+') {
                 decoded[out_cursor++] = ' ';
@@ -162,8 +127,15 @@ static urlencode_result_t _decode_url(const unsigned char* input, const char* en
                 continue;
             }
 
-            const unsigned int v1 = hexval[(unsigned int)input[in_cursor++]];
-            const unsigned int v2 = hexval[(unsigned int)input[in_cursor++]];
+            const unsigned int v1raw = input[in_cursor++];
+            const unsigned int v2raw = input[in_cursor++];
+            if (v1raw == 0x30 && v2raw == 0x30) {
+                // null char termination (%00)
+                return decoded;
+            }
+
+            const unsigned int v1 = hexval[v1raw];
+            const unsigned int v2 = hexval[v2raw];
             if ((v1 | v2) != 0xFF) {
                 decoded[out_cursor++] = (v1 << 4) | v2;
                 continue;
@@ -175,31 +147,103 @@ static urlencode_result_t _decode_url(const unsigned char* input, const char* en
         }
 
         for (int i = 0; i < charlen; i++, in_cursor++) {
-            const unsigned char c = input[in_cursor];
+            const uint8_t c = input[in_cursor];
             decoded[out_cursor++] = c;
         }
     }
     decoded[out_cursor] = '\0';
 
-    const urlencode_result_t result = {decoded, ""};
-    return result;
+    return decoded;
 }
 
 static int decode_url (lua_State* L) {
-    const unsigned char* input = luaL_checkstring(L, 1);
-    const unsigned char* encoding = luaL_checkstring(L, 2);
-    const urlencode_result_t result = _decode_url(input, encoding);
+    const uint8_t* input = luaL_checkstring(L, 1);
+    const uint8_t* decoded = _decode_url(input);
+
+    lua_pushstring(L, decoded);
+
+    return 1;
+}
+
+#define __ 0xFF
+/*
+ * 0x00: 0
+ * 0x01-0xC1: 1
+ * 0xF5-: 1
+ */
+static const uint8_t utf8_immediate_len[256] = {
+     0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x00-0x0F */
+     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x10-0x1F */
+     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x20-0x2F */
+     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x30-0x3F */
+     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x40-0x4F */
+     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x50-0x5F */
+     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x60-0x6F */
+     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x70-0x7F */
+     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x80-0x8F */
+     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x90-0x9F */
+     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0xA0-0xAF */
+     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0xB0-0xBF */
+     1, 1,__,__,__,__,__,__,__,__,__,__,__,__,__,__, /* 0xC0-0xCF */
+    __,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__, /* 0xD0-0xDF */
+    __,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__, /* 0xE0-0xEF */
+    __,__,__,__,__, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0xF0-0xFF */
+};
+#undef __
+
+/*
+ * 0xC2-0xDF: 2
+ * 0xE0-0xEF: 3
+ * 0xF0-0xF4: 4
+ */
+static const uint8_t utf8_count_len[256] = {
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x00-0x0F */
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x10-0x1F */
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x20-0x2F */
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x30-0x3F */
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x40-0x4F */
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x50-0x5F */
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x60-0x6F */
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x70-0x7F */
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x80-0x8F */
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x90-0x9F */
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0xA0-0xAF */
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0xB0-0xBF */
+    0,0,2,2,2,2,2,2,2,2,2,2,2,2,2,2, /* 0xC0-0xCF */
+    2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, /* 0xD0-0xDF */
+    3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3, /* 0xE0-0xEF */
+    4,4,4,4,4,0,0,0,0,0,0,0,0,0,0,0, /* 0xF0-0xFF */
+};
 
-    lua_pushstring(L, result.got);
+uint8_t utf8_len(const uint8_t* str) {
+    const uint8_t lead = *str;
 
-    const char* err = result.err;
-    if (strlen(err) <= 0) {
-        lua_pushnil(L);
-    } else {
-        lua_pushstring(L, err);
+    const uint8_t immediate_len = utf8_immediate_len[lead];
+    if (immediate_len != 0xFF) {
+        return immediate_len;
     }
 
-    return 2;
+    const uint8_t count = utf8_count_len[lead];
+    uint8_t trail = *(++str);
+
+    if (count == 3) {
+        if ((lead == 0xE0 && 0xA0 > trail) || (lead == 0xED && trail > 0x9F)) {
+            return 1;
+        }
+    } else if (count == 4) {
+        if ((lead == 0xF0 && 0x90 > trail) || (lead == 0xF4 && trail > 0x8F)) {
+            return 1;
+        }
+    }
+
+    uint8_t size = 1;
+    for (; size < count; ++size) {
+        if (!UTF8_TRAIL(trail)) {
+            return size;
+        }
+        trail = *(++str);
+    }
+    return size;
 }
 
 static const struct luaL_Reg R[] = {
@@ -241,3 +285,4 @@ LUALIB_API int luaopen_urlencode(lua_State * L) {
 #ifdef __cplusplus
 }
 #endif
+

src/lua-urlencode.h

@@ -16,6 +16,7 @@ extern "C" {
 #include <stdlib.h>
 #include <string.h>
 #include <locale.h>
+#include <stdint.h>
 
 #define URL_ENCODE_VERSION "0.0.1-0"
 #define URL_ENCODE_LIBNAME "urlencode"