n-api: throw RangeError napi_create_typedarray()

According to the ECMA spec, we should throw a RangeError in the
following cases:
  - `(length * elementSize) + offset` > the size of the array passed in
  - `offset % elementSize` != `0`

In the current implementation, this check was omitted. So, the following
code will cause a crash.
  ```
  napi_create_typedarray(env, napi_uint16_array, 2 /* length */,
                         buffer, 1 /* byte_offset */, &output_array);
  ```

This change fixes the problem and write some related tests.

Refs:
https://tc39.github.io/ecma262/#sec-typedarray-buffer-byteoffset-length

PR-URL: nodejs#18037
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>

doc/api/errors.md

@@ -997,6 +997,18 @@ While using `N-API`, `Constructor.prototype` was not an object.
 While calling `napi_create_dataview()`, a given `offset` was outside the bounds
 of the dataview or `offset + length` was larger than a length of given `buffer`.
 
+<a id="ERR_NAPI_INVALID_TYPEDARRAY_ALIGNMENT"></a>
+### ERR_NAPI_INVALID_TYPEDARRAY_ALIGNMENT
+
+While calling `napi_create_typedarray()`, the provided `offset` was not a
+multiple of the element size.
+
+<a id="ERR_NAPI_INVALID_TYPEDARRAY_LENGTH"></a>
+### ERR_NAPI_INVALID_TYPEDARRAY_LENGTH
+
+While calling `napi_create_typedarray()`, `(length * size_of_element) +
+byte_offset` was larger than the length of given `buffer`.
+
 <a id="ERR_NO_ICU"></a>
 ### ERR_NO_ICU
 

lib/internal/errors.js

@@ -265,6 +265,9 @@ E('ERR_NAPI_CONS_PROTOTYPE_OBJECT', 'Constructor.prototype must be an object');
 E('ERR_NAPI_INVALID_DATAVIEW_ARGS',
   'byte_offset + byte_length should be less than or eqaul to the size in ' +
   'bytes of the array passed in');
+E('ERR_NAPI_INVALID_TYPEDARRAY_ALIGNMENT', 'start offset of %s should be a ' +
+  'multiple of %s');
+E('ERR_NAPI_INVALID_TYPEDARRAY_LENGTH', 'Invalid typed array length');
 E('ERR_NO_CRYPTO', 'Node.js is not compiled with OpenSSL crypto support');
 E('ERR_NO_ICU', '%s is not supported on Node.js compiled without ICU');
 E('ERR_PARSE_HISTORY_DATA', 'Could not parse history data in %s');

src/node_api.cc

@@ -142,6 +142,30 @@ struct napi_env__ {
   (!try_catch.HasCaught() ? napi_ok \
                          : napi_set_last_error((env), napi_pending_exception))
 
+#define THROW_RANGE_ERROR_IF_FALSE(env, condition, error, message) \
+  do {                                                             \
+    if (!(condition)) {                                            \
+      napi_throw_range_error((env), (error), (message));           \
+      return napi_set_last_error((env), napi_generic_failure);     \
+    }                                                              \
+  } while (0)
+
+#define CREATE_TYPED_ARRAY(                                                    \
+    env, type, size_of_element, buffer, byte_offset, length, out)              \
+  do {                                                                         \
+    if ((size_of_element) > 1) {                                               \
+      THROW_RANGE_ERROR_IF_FALSE(                                              \
+          (env), (byte_offset) % (size_of_element) == 0,                       \
+          "ERR_NAPI_INVALID_TYPEDARRAY_ALIGNMENT",                             \
+          "start offset of "#type" should be a multiple of "#size_of_element); \
+    }                                                                          \
+    THROW_RANGE_ERROR_IF_FALSE((env), (length) * (size_of_element) +           \
+        (byte_offset) <= buffer->ByteLength(),                                 \
+        "ERR_NAPI_INVALID_TYPEDARRAY_LENGTH",                                  \
+        "Invalid typed array length");                                         \
+    (out) = v8::type::New((buffer), (byte_offset), (length));                  \
+  } while (0)
+
 namespace {
 namespace v8impl {
 
@@ -3063,31 +3087,40 @@ napi_status napi_create_typedarray(napi_env env,
 
   switch (type) {
     case napi_int8_array:
-      typedArray = v8::Int8Array::New(buffer, byte_offset, length);
+      CREATE_TYPED_ARRAY(
+          env, Int8Array, 1, buffer, byte_offset, length, typedArray);
       break;
     case napi_uint8_array:
-      typedArray = v8::Uint8Array::New(buffer, byte_offset, length);
+      CREATE_TYPED_ARRAY(
+          env, Uint8Array, 1, buffer, byte_offset, length, typedArray);
       break;
     case napi_uint8_clamped_array:
-      typedArray = v8::Uint8ClampedArray::New(buffer, byte_offset, length);
+      CREATE_TYPED_ARRAY(
+          env, Uint8ClampedArray, 1, buffer, byte_offset, length, typedArray);
       break;
     case napi_int16_array:
-      typedArray = v8::Int16Array::New(buffer, byte_offset, length);
+      CREATE_TYPED_ARRAY(
+          env, Int16Array, 2, buffer, byte_offset, length, typedArray);
       break;
     case napi_uint16_array:
-      typedArray = v8::Uint16Array::New(buffer, byte_offset, length);
+      CREATE_TYPED_ARRAY(
+          env, Uint16Array, 2, buffer, byte_offset, length, typedArray);
       break;
     case napi_int32_array:
-      typedArray = v8::Int32Array::New(buffer, byte_offset, length);
+      CREATE_TYPED_ARRAY(
+          env, Int32Array, 4, buffer, byte_offset, length, typedArray);
       break;
     case napi_uint32_array:
-      typedArray = v8::Uint32Array::New(buffer, byte_offset, length);
+      CREATE_TYPED_ARRAY(
+          env, Uint32Array, 4, buffer, byte_offset, length, typedArray);
       break;
     case napi_float32_array:
-      typedArray = v8::Float32Array::New(buffer, byte_offset, length);
+      CREATE_TYPED_ARRAY(
+          env, Float32Array, 4, buffer, byte_offset, length, typedArray);
       break;
     case napi_float64_array:
-      typedArray = v8::Float64Array::New(buffer, byte_offset, length);
+      CREATE_TYPED_ARRAY(
+          env, Float64Array, 8, buffer, byte_offset, length, typedArray);
       break;
     default:
       return napi_set_last_error(env, napi_invalid_arg);

test/addons-napi/test_typedarray/test.js

@@ -55,3 +55,21 @@ arrayTypes.forEach((currentType) => {
   assert.notStrictEqual(theArray, template);
   assert.strictEqual(theArray.buffer, buffer);
 });
+
+arrayTypes.forEach((currentType) => {
+  const template = Reflect.construct(currentType, buffer);
+  assert.throws(() => {
+    test_typedarray.CreateTypedArray(template, buffer, 0, 136);
+  }, /Invalid typed array length/);
+});
+
+const nonByteArrayTypes = [ Int16Array, Uint16Array, Int32Array, Uint32Array,
+                            Float32Array, Float64Array ];
+nonByteArrayTypes.forEach((currentType) => {
+  const template = Reflect.construct(currentType, buffer);
+  assert.throws(() => {
+    test_typedarray.CreateTypedArray(template, buffer,
+                                     currentType.BYTES_PER_ELEMENT + 1, 1);
+    console.log(`start of offset ${currentType}`);
+  }, /start offset of/);
+});

test/addons-napi/test_typedarray/test_typedarray.c

@@ -97,11 +97,11 @@ napi_value External(napi_env env, napi_callback_info info) {
 }
 
 napi_value CreateTypedArray(napi_env env, napi_callback_info info) {
-  size_t argc = 2;
-  napi_value args[2];
+  size_t argc = 4;
+  napi_value args[4];
   NAPI_CALL(env, napi_get_cb_info(env, info, &argc, args, NULL, NULL));
 
-  NAPI_ASSERT(env, argc == 2, "Wrong number of arguments");
+  NAPI_ASSERT(env, argc == 2 || argc == 4, "Wrong number of arguments");
 
   napi_value input_array = args[0];
   napi_valuetype valuetype0;
@@ -136,6 +136,28 @@ napi_value CreateTypedArray(napi_env env, napi_callback_info info) {
   NAPI_CALL(env, napi_get_typedarray_info(
       env, input_array, &type, &length, NULL, &in_array_buffer, &byte_offset));
 
+  if (argc == 4) {
+    napi_valuetype valuetype2;
+    NAPI_CALL(env, napi_typeof(env, args[2], &valuetype2));
+
+    NAPI_ASSERT(env, valuetype2 == napi_number,
+        "Wrong type of arguments. Expects a number as third argument.");
+
+    uint32_t uint32_length;
+    NAPI_CALL(env, napi_get_value_uint32(env, args[2], &uint32_length));
+    length = uint32_length;
+
+    napi_valuetype valuetype3;
+    NAPI_CALL(env, napi_typeof(env, args[3], &valuetype3));
+
+    NAPI_ASSERT(env, valuetype3 == napi_number,
+        "Wrong type of arguments. Expects a number as third argument.");
+
+    uint32_t uint32_byte_offset;
+    NAPI_CALL(env, napi_get_value_uint32(env, args[3], &uint32_byte_offset));
+    byte_offset = uint32_byte_offset;
+  }
+
   napi_value output_array;
   NAPI_CALL(env, napi_create_typedarray(
       env, type, length, input_buffer, byte_offset, &output_array));