mojo: Validate fixed size array for the mojo java bindings.

R=ppi@chromium.org

Review URL: https://codereview.chromium.org/522653004

Cr-Commit-Position: refs/heads/master@{#292862}

mojo/public/java/BUILD.gn

@@ -44,6 +44,7 @@ android_library("bindings") {
     "bindings/src/org/chromium/mojo/bindings/MessageWithHeader.java",
     "bindings/src/org/chromium/mojo/bindings/RouterImpl.java",
     "bindings/src/org/chromium/mojo/bindings/Router.java",
+    "bindings/src/org/chromium/mojo/bindings/SerializationException.java",
     "bindings/src/org/chromium/mojo/bindings/SideEffectFreeCloseable.java",
     "bindings/src/org/chromium/mojo/bindings/Struct.java",
   ]

mojo/public/java/bindings/src/org/chromium/mojo/bindings/BindingsHelper.java

@@ -28,6 +28,11 @@ public class BindingsHelper {
      */
     public static final int POINTER_SIZE = 8;
 
+    /**
+     * The value used for the expected length of a non-fixed size array.
+     */
+    public static final int UNSPECIFIED_ARRAY_LENGTH = -1;
+
     /**
      * Align |size| on {@link BindingsHelper#ALIGNMENT}.
      */

mojo/public/java/bindings/src/org/chromium/mojo/bindings/Encoder.java

@@ -226,7 +226,8 @@ public class Encoder {
             encodeNullPointer(offset);
             return;
         }
-        encode(v.getBytes(Charset.forName("utf8")), offset);
+        encode(v.getBytes(
+                Charset.forName("utf8")), offset, BindingsHelper.UNSPECIFIED_ARRAY_LENGTH);
     }
 
     /**
@@ -286,18 +287,22 @@ public class Encoder {
     /**
      * Returns an {@link Encoder} suitable for encoding an array of pointer of the given length.
      */
-    public Encoder encodePointerArray(int length, int offset) {
-        return encoderForArray(BindingsHelper.POINTER_SIZE, length, offset);
+    public Encoder encodePointerArray(int length, int offset, int expectedLength) {
+        return encoderForArray(BindingsHelper.POINTER_SIZE, length, offset, expectedLength);
     }
 
     /**
      * Encodes an array of booleans.
      */
-    public void encode(boolean[] v, int offset) {
+    public void encode(boolean[] v, int offset, int expectedLength) {
         if (v == null) {
             encodeNullPointer(offset);
             return;
         }
+        if (expectedLength != BindingsHelper.UNSPECIFIED_ARRAY_LENGTH &&
+                expectedLength != v.length) {
+            throw new SerializationException("Trying to encode a fixed array of incorrect length.");
+        }
         byte[] bytes = new byte[(v.length + 7) / BindingsHelper.ALIGNMENT];
         for (int i = 0; i < bytes.length; ++i) {
             for (int j = 0; j < BindingsHelper.ALIGNMENT; ++j) {
@@ -313,78 +318,83 @@ public class Encoder {
     /**
      * Encodes an array of bytes.
      */
-    public void encode(byte[] v, int offset) {
+    public void encode(byte[] v, int offset, int expectedLength) {
         if (v == null) {
             encodeNullPointer(offset);
             return;
         }
+        if (expectedLength != BindingsHelper.UNSPECIFIED_ARRAY_LENGTH &&
+                expectedLength != v.length) {
+            throw new SerializationException("Trying to encode a fixed array of incorrect length.");
+        }
         encodeByteArray(v, v.length, offset);
     }
 
     /**
      * Encodes an array of shorts.
      */
-    public void encode(short[] v, int offset) {
+    public void encode(short[] v, int offset, int expectedLength) {
         if (v == null) {
             encodeNullPointer(offset);
             return;
         }
-        encoderForArray(2, v.length, offset).append(v);
+        encoderForArray(2, v.length, offset, expectedLength).append(v);
     }
 
     /**
      * Encodes an array of ints.
      */
-    public void encode(int[] v, int offset) {
+    public void encode(int[] v, int offset, int expectedLength) {
         if (v == null) {
             encodeNullPointer(offset);
             return;
         }
-        encoderForArray(4, v.length, offset).append(v);
+        encoderForArray(4, v.length, offset, expectedLength).append(v);
     }
 
     /**
      * Encodes an array of floats.
      */
-    public void encode(float[] v, int offset) {
+    public void encode(float[] v, int offset, int expectedLength) {
         if (v == null) {
             encodeNullPointer(offset);
             return;
         }
-        encoderForArray(4, v.length, offset).append(v);
+        encoderForArray(4, v.length, offset, expectedLength).append(v);
     }
 
     /**
      * Encodes an array of longs.
      */
-    public void encode(long[] v, int offset) {
+    public void encode(long[] v, int offset, int expectedLength) {
         if (v == null) {
             encodeNullPointer(offset);
             return;
         }
-        encoderForArray(8, v.length, offset).append(v);
+        encoderForArray(8, v.length, offset, expectedLength).append(v);
     }
 
     /**
      * Encodes an array of doubles.
      */
-    public void encode(double[] v, int offset) {
+    public void encode(double[] v, int offset, int expectedLength) {
         if (v == null) {
             encodeNullPointer(offset);
             return;
         }
-        encoderForArray(8, v.length, offset).append(v);
+        encoderForArray(8, v.length, offset, expectedLength).append(v);
     }
 
     /**
      * Encodes an array of {@link Handle}.
      */
-    public void encode(Handle[] v, int offset) {
+    public void encode(Handle[] v, int offset, int expectedLength) {
         if (v == null) {
             encodeNullPointer(offset);
             return;
         }
-        Encoder e = encoderForArray(BindingsHelper.SERIALIZED_HANDLE_SIZE, v.length, offset);
+        Encoder e = encoderForArray(
+                BindingsHelper.SERIALIZED_HANDLE_SIZE, v.length, offset, expectedLength);
         for (int i = 0; i < v.length; ++i) {
             e.encode(v[i], DataHeader.HEADER_SIZE + BindingsHelper.SERIALIZED_HANDLE_SIZE * i);
         }
@@ -393,13 +403,14 @@ public class Encoder {
     /**
      * Encodes an array of {@link Interface}.
      */
-    public <T extends Interface> void encode(T[] v, int offset,
+    public <T extends Interface> void encode(T[] v, int offset, int expectedLength,
             Interface.Manager<T, ?> manager) {
         if (v == null) {
             encodeNullPointer(offset);
             return;
         }
-        Encoder e = encoderForArray(BindingsHelper.SERIALIZED_HANDLE_SIZE, v.length, offset);
+        Encoder e = encoderForArray(
+                BindingsHelper.SERIALIZED_HANDLE_SIZE, v.length, offset, expectedLength);
         for (int i = 0; i < v.length; ++i) {
             e.encode(v[i], DataHeader.HEADER_SIZE + BindingsHelper.SERIALIZED_HANDLE_SIZE * i,
                     manager);
@@ -409,12 +420,14 @@ public class Encoder {
     /**
      * Encodes an array of {@link InterfaceRequest}.
      */
-    public <I extends Interface> void encode(InterfaceRequest<I>[] v, int offset) {
+    public <I extends Interface> void encode(InterfaceRequest<I>[] v, int offset,
+            int expectedLength) {
         if (v == null) {
             encodeNullPointer(offset);
             return;
         }
-        Encoder e = encoderForArray(BindingsHelper.SERIALIZED_HANDLE_SIZE, v.length, offset);
+        Encoder e = encoderForArray(
+                BindingsHelper.SERIALIZED_HANDLE_SIZE, v.length, offset, expectedLength);
         for (int i = 0; i < v.length; ++i) {
             e.encode(v[i], DataHeader.HEADER_SIZE + BindingsHelper.SERIALIZED_HANDLE_SIZE * i);
         }
@@ -431,7 +444,12 @@ public class Encoder {
         encode((long) mEncoderState.dataEnd - (mBaseOffset + offset), offset);
     }
 
-    private Encoder encoderForArray(int elementSizeInByte, int length, int offset) {
+    private Encoder encoderForArray(
+            int elementSizeInByte, int length, int offset, int expectedLength) {
+        if (expectedLength != BindingsHelper.UNSPECIFIED_ARRAY_LENGTH &&
+                expectedLength != length) {
+            throw new SerializationException("Trying to encode a fixed array of incorrect length.");
+        }
         return encoderForArrayByTotalSize(length * elementSizeInByte, length, offset);
     }
 

mojo/public/java/bindings/src/org/chromium/mojo/bindings/SerializationException.java

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.mojo.bindings;
+
+/**
+ * Error that can be thrown when serializing a mojo message.
+ */
+public class SerializationException extends RuntimeException {
+
+    /**
+     * Constructs a new serialization exception with the specified detail message.
+     */
+    public SerializationException(String message) {
+        super(message);
+    }
+
+    /**
+     * Constructs a new serialization exception with the specified cause.
+     */
+    public SerializationException(Exception cause) {
+        super(cause);
+    }
+
+}

mojo/public/tools/bindings/generators/java_templates/struct_definition.tmpl

 {% from "constant_definition.tmpl" import constant_def %}
 {% from "enum_definition.tmpl" import enum_def %}
 
+{%- macro array_expected_length(kind) -%}
+{%- if kind|is_fixed_array_kind -%}
+{{kind.length}}
+{%- else -%}
+org.chromium.mojo.bindings.BindingsHelper.UNSPECIFIED_ARRAY_LENGTH
+{%- endif -%}
+{%- endmacro -%}
+
 {% macro encode(variable, kind, offset, bit, level=0) %}
 {% if kind|is_pointer_array_kind %}
 {% set sub_kind = kind.kind %}
 if ({{variable}} == null) {
     encoder{{level}}.encodeNullPointer({{offset}});
 } else {
-    org.chromium.mojo.bindings.Encoder encoder{{level + 1}} = encoder{{level}}.encodePointerArray({{variable}}.length, {{offset}});
+    org.chromium.mojo.bindings.Encoder encoder{{level + 1}} = encoder{{level}}.encodePointerArray({{variable}}.length, {{offset}}, {{array_expected_length(kind)}});
     for (int i{{level}} = 0; i{{level}} < {{variable}}.length; ++i{{level}}) {
         {{encode(variable~'[i'~level~']', sub_kind, 'DataHeader.HEADER_SIZE + org.chromium.mojo.bindings.BindingsHelper.POINTER_SIZE * i'~level, 0, level+1)|indent(8)}}
     }
@@ -26,7 +34,7 @@ org.chromium.mojo.bindings.Decoder decoder{{level+1}} = decoder{{level}}.readPoi
 if (decoder{{level+1}} == null) {
     {{variable}} = null;
 } else {
-    DataHeader si{{level+1}} = decoder{{level+1}}.readDataHeader();
+    DataHeader si{{level+1}} = decoder{{level+1}}.readArrayDataHeader({{array_expected_length(kind)}});
     {{variable}} = {{kind|new_array('si'~(level+1)~'.numFields')}};
     for (int i{{level+1}} = 0; i{{level+1}} < si{{level+1}}.numFields; ++i{{level+1}}) {
         {{decode(variable~'[i'~(level+1)~']', kind.kind, 'DataHeader.HEADER_SIZE + org.chromium.mojo.bindings.BindingsHelper.POINTER_SIZE * i'~(level+1), 0, level+1)|indent(8)}}

mojo/public/tools/bindings/generators/mojom_java_generator.py

@@ -186,6 +186,12 @@ def DecodeMethod(context, kind, offset, bit):
       params.append(GetArrayNullabilityFlags(kind))
     else:
       params.append(GetJavaTrueFalse(mojom.IsNullableKind(kind)))
+  if mojom.IsAnyArrayKind(kind):
+    if mojom.IsFixedArrayKind(kind):
+      params.append(str(kind.length))
+    else:
+      params.append(
+        "org.chromium.mojo.bindings.BindingsHelper.UNSPECIFIED_ARRAY_LENGTH");
   if mojom.IsInterfaceKind(kind):
     params.append('%s.MANAGER' % GetJavaType(context, kind))
   if mojom.IsAnyArrayKind(kind) and mojom.IsInterfaceKind(kind.kind):
@@ -197,6 +203,12 @@ def EncodeMethod(context, kind, variable, offset, bit):
   params = [ variable, str(offset) ]
   if (kind == mojom.BOOL):
     params.append(str(bit))
+  if mojom.IsAnyArrayKind(kind):
+    if mojom.IsFixedArrayKind(kind):
+      params.append(str(kind.length))
+    else:
+      params.append(
+        "org.chromium.mojo.bindings.BindingsHelper.UNSPECIFIED_ARRAY_LENGTH");
   if mojom.IsInterfaceKind(kind):
     params.append('%s.MANAGER' % GetJavaType(context, kind))
   if mojom.IsAnyArrayKind(kind) and mojom.IsInterfaceKind(kind.kind):
@@ -357,6 +369,7 @@ class Generator(generator.Generator):
     "encode_method": EncodeMethod,
     "has_method_with_response": HasMethodWithResponse,
     "has_method_without_response": HasMethodWithoutResponse,
+    "is_fixed_array_kind": mojom.IsFixedArrayKind,
     "is_handle": mojom.IsNonInterfaceHandleKind,
     "is_nullable_kind": mojom.IsNullableKind,
     "is_pointer_array_kind": IsPointerArrayKind,