Merge changes Id53a8305,Ie74822a6

* changes:
  CEC : Add OSD String Validator for CEC Messages
  CEC : Add ASCII validator for CEC messages

services/core/java/com/android/server/hdmi/HdmiCecMessageValidator.java

@@ -128,7 +128,7 @@ public class HdmiCecMessageValidator {
         FixedLengthValidator oneByteValidator = new FixedLengthValidator(1);
         addValidationInfo(Constants.MESSAGE_CEC_VERSION, oneByteValidator, DEST_DIRECT);
         addValidationInfo(Constants.MESSAGE_SET_MENU_LANGUAGE,
-                new FixedLengthValidator(3), DEST_BROADCAST);
+                new AsciiValidator(3), DEST_BROADCAST);
 
         // TODO: Handle messages for the Deck Control.
 
@@ -148,8 +148,8 @@ public class HdmiCecMessageValidator {
                 maxLengthValidator, DEST_ALL | SRC_UNREGISTERED);
 
         // Messages for the OSD.
-        addValidationInfo(Constants.MESSAGE_SET_OSD_STRING, maxLengthValidator, DEST_DIRECT);
+        addValidationInfo(Constants.MESSAGE_SET_OSD_STRING, new OsdStringValidator(), DEST_DIRECT);
-        addValidationInfo(Constants.MESSAGE_SET_OSD_NAME, maxLengthValidator, DEST_DIRECT);
+        addValidationInfo(Constants.MESSAGE_SET_OSD_NAME, new AsciiValidator(1, 14), DEST_DIRECT);
 
         // Messages for the Device Menu Control.
         addValidationInfo(Constants.MESSAGE_MENU_REQUEST, oneByteValidator, DEST_DIRECT);
@@ -299,6 +299,37 @@ public class HdmiCecMessageValidator {
         return (value >= min && value <= max);
     }
 
+    /**
+     * Check if the given value is a valid Display Control. A valid value is one which falls within
+     * the range description defined in CEC 1.4 Specification : Operand Descriptions (Section 17)
+     *
+     * @param value Display Control
+     * @return true if the Display Control is valid
+     */
+    private boolean isValidDisplayControl(int value) {
+        value = value & 0xFF;
+        return (value == 0x00 || value == 0x40 || value == 0x80 || value == 0xC0);
+    }
+
+    /**
+     * Check if the given params has valid ASCII characters.
+     * A valid ASCII character is a printable character. It should fall within range description
+     * defined in CEC 1.4 Specification : Operand Descriptions (Section 17)
+     *
+     * @param params parameter consisting of string
+     * @param offset Start offset of string
+     * @param maxLength Maximum length of string to be evaluated
+     * @return true if the given type is valid
+     */
+    private boolean isValidAsciiString(byte[] params, int offset, int maxLength) {
+        for (int i = offset; i < params.length && i < maxLength; i++) {
+            if (!isWithinRange(params[i], 0x20, 0x7E)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
     private class PhysicalAddressValidator implements ParameterValidator {
         @Override
         public int isValid(byte[] params) {
@@ -359,4 +390,55 @@ public class HdmiCecMessageValidator {
                             || params[0] == 0x1F);
         }
     }
+
+    /**
+     * Check if the given parameters represents printable characters.
+     * A valid parameter should lie within the range description of ASCII defined in CEC 1.4
+     * Specification : Operand Descriptions (Section 17)
+     */
+    private class AsciiValidator implements ParameterValidator {
+        private final int mMinLength;
+        private final int mMaxLength;
+
+        AsciiValidator(int length) {
+            mMinLength = length;
+            mMaxLength = length;
+        }
+
+        AsciiValidator(int minLength, int maxLength) {
+            mMinLength = minLength;
+            mMaxLength = maxLength;
+        }
+
+        @Override
+        public int isValid(byte[] params) {
+            // If the length is longer than expected, we assume it's OK since the parameter can be
+            // extended in the future version.
+            if (params.length < mMinLength) {
+                return ERROR_PARAMETER_SHORT;
+            }
+            return toErrorCode(isValidAsciiString(params, 0, mMaxLength));
+        }
+    }
+
+    /**
+     * Check if the given parameters is valid OSD String.
+     * A valid parameter should lie within the range description of ASCII defined in CEC 1.4
+     * Specification : Operand Descriptions (Section 17)
+     */
+    private class OsdStringValidator implements ParameterValidator {
+        @Override
+        public int isValid(byte[] params) {
+            // If the length is longer than expected, we assume it's OK since the parameter can be
+            // extended in the future version.
+            if (params.length < 2) {
+                return ERROR_PARAMETER_SHORT;
+            }
+            return toErrorCode(
+                    // Display Control
+                    isValidDisplayControl(params[0])
+                    // OSD String
+                    && isValidAsciiString(params, 1, 14));
+        }
+    }
 }

services/tests/servicestests/src/com/android/server/hdmi/HdmiCecMessageValidatorTest.java

@@ -17,6 +17,7 @@
 package com.android.server.hdmi;
 
 import static com.android.server.hdmi.HdmiCecMessageValidator.ERROR_DESTINATION;
+import static com.android.server.hdmi.HdmiCecMessageValidator.ERROR_PARAMETER;
 import static com.android.server.hdmi.HdmiCecMessageValidator.ERROR_PARAMETER_SHORT;
 import static com.android.server.hdmi.HdmiCecMessageValidator.ERROR_SOURCE;
 import static com.android.server.hdmi.HdmiCecMessageValidator.OK;
@@ -71,6 +72,44 @@ public class HdmiCecMessageValidatorTest {
         assertMessageValidity("04:90").isEqualTo(ERROR_PARAMETER_SHORT);
     }
 
+    @Test
+    public void isValid_setMenuLanguage() {
+        assertMessageValidity("4F:32:53:50:41").isEqualTo(OK);
+        assertMessageValidity("0F:32:45:4E:47:8C:49:D3:48").isEqualTo(OK);
+
+        assertMessageValidity("40:32:53:50:41").isEqualTo(ERROR_DESTINATION);
+        assertMessageValidity("F0:32").isEqualTo(ERROR_SOURCE);
+        assertMessageValidity("4F:32:45:55").isEqualTo(ERROR_PARAMETER_SHORT);
+        assertMessageValidity("4F:32:19:7F:83").isEqualTo(ERROR_PARAMETER);
+    }
+
+    @Test
+    public void isValid_setOsdString() {
+        assertMessageValidity("40:64:80:41").isEqualTo(OK);
+        // Even though the parameter string in this message is longer than 14 bytes, it is accepted
+        // as this parameter might be extended in future versions.
+        assertMessageValidity("04:64:00:4C:69:76:69:6E:67:52:6F:6F:6D:20:54:56:C4").isEqualTo(OK);
+
+        assertMessageValidity("4F:64:40:41").isEqualTo(ERROR_DESTINATION);
+        assertMessageValidity("F0:64:C0:41").isEqualTo(ERROR_SOURCE);
+        assertMessageValidity("40:64:00").isEqualTo(ERROR_PARAMETER_SHORT);
+        // Invalid Display Control
+        assertMessageValidity("40:64:20:4C:69:76").isEqualTo(ERROR_PARAMETER);
+        // Invalid ASCII characters
+        assertMessageValidity("40:64:40:4C:69:7F").isEqualTo(ERROR_PARAMETER);
+    }
+
+    @Test
+    public void isValid_setOsdName() {
+        assertMessageValidity("40:47:4C:69:76:69:6E:67:52:6F:6F:6D:54:56").isEqualTo(OK);
+        assertMessageValidity("40:47:54:56").isEqualTo(OK);
+
+        assertMessageValidity("4F:47:54:56").isEqualTo(ERROR_DESTINATION);
+        assertMessageValidity("F0:47:54:56").isEqualTo(ERROR_SOURCE);
+        assertMessageValidity("40:47").isEqualTo(ERROR_PARAMETER_SHORT);
+        assertMessageValidity("40:47:4C:69:7F").isEqualTo(ERROR_PARAMETER);
+    }
+
     private IntegerSubject assertMessageValidity(String message) {
         return assertThat(mHdmiCecMessageValidator.isValid(buildMessage(message)));
     }