Support for getMaxTransceiveLength() API.

Maximum transceive length is enforced in calls to transceive.
Change-Id: I94a4f16283e5fd5df9143b02e52c16f868b1c3ab

4 files changed, 70 insertions, 6 deletions

diff --git a/src/com/android/nfc/DeviceHost.java b/src/com/android/nfc/DeviceHost.java
index d8192b7..70a6011 100644
--- a/src/com/android/nfc/DeviceHost.java
+++ b/src/com/android/nfc/DeviceHost.java
@@ -80,6 +80,8 @@ public interface DeviceHost {
         boolean formatNdef(byte[] key);
         boolean isNdefFormatable();
         boolean makeReadOnly();
+
+        int getConnectedTechnology();
     }
 
     public interface NfceeEndpoint {
@@ -179,4 +181,9 @@ public interface DeviceHost {
     public int getTimeout(int technology);
 
     public void doAbort();
+
+    boolean canMakeReadOnly(int technology);
+
+    int getMaxTransceiveLength(int technology);
+
 }
diff --git a/src/com/android/nfc/NfcService.java b/src/com/android/nfc/NfcService.java
index 705a82a..1568b27 100755
--- a/src/com/android/nfc/NfcService.java
+++ b/src/com/android/nfc/NfcService.java
@@ -890,13 +890,21 @@ public class NfcService extends Application implements DeviceHostListener {
             /* find the tag in the hmap */
             tag = (TagEndpoint) findObject(nativeHandle);
             if (tag != null) {
+                // Check if length is within limits
+                if (data.length > getMaxTransceiveLength(tag.getConnectedTechnology())) {
+                    return new TransceiveResult(TransceiveResult.RESULT_EXCEEDED_LENGTH, null);
+                }
                 int[] targetLost = new int[1];
                 response = tag.transceive(data, raw, targetLost);
-                TransceiveResult transResult = new TransceiveResult(
-                        (response != null) ? true : false,
-                        (targetLost[0] == 1) ? true : false,
-                        response);
-                return transResult;
+                int result;
+                if (response != null) {
+                    result = TransceiveResult.RESULT_SUCCESS;
+                } else if (targetLost[0] == 1) {
+                    result = TransceiveResult.RESULT_TAGLOST;
+                } else {
+                    result = TransceiveResult.RESULT_FAILURE;
+                }
+                return new TransceiveResult(result, response);
             }
             return null;
         }
@@ -1070,6 +1078,20 @@ public class NfcService extends Application implements DeviceHostListener {
 
             mDeviceHost.resetTimeouts();
         }
+
+        @Override
+        public boolean canMakeReadOnly(int ndefType) throws RemoteException {
+            mContext.enforceCallingOrSelfPermission(NFC_PERM, NFC_PERM_ERROR);
+
+            return mDeviceHost.canMakeReadOnly(ndefType);
+        }
+
+        @Override
+        public int getMaxTransceiveLength(int tech) throws RemoteException {
+            mContext.enforceCallingOrSelfPermission(NFC_PERM, NFC_PERM_ERROR);
+
+            return mDeviceHost.getMaxTransceiveLength(tech);
+        }
     };
 
     private void _nfcEeClose(boolean checkPid, int callingPid) throws IOException {
diff --git a/src/com/android/nfc/nxp/NativeNfcManager.java b/src/com/android/nfc/nxp/NativeNfcManager.java
index bce9fa9..90236ad 100755
--- a/src/com/android/nfc/nxp/NativeNfcManager.java
+++ b/src/com/android/nfc/nxp/NativeNfcManager.java
@@ -23,6 +23,8 @@ import android.annotation.SdkConstant;
 import android.annotation.SdkConstant.SdkConstantType;
 import android.content.Context;
 import android.nfc.ErrorCodes;
+import android.nfc.tech.Ndef;
+import android.nfc.tech.TagTechnology;
 import android.util.Log;
 
 /**
@@ -151,6 +153,38 @@ public class NativeNfcManager implements DeviceHost {
         return doGetTimeout(tech);
     }
 
+
+    @Override
+    public boolean canMakeReadOnly(int ndefType) {
+        return (ndefType == Ndef.TYPE_1 || ndefType == Ndef.TYPE_2);
+    }
+
+    @Override
+    public int getMaxTransceiveLength(int technology) {
+        switch (technology) {
+            case (TagTechnology.NFC_A):
+            case (TagTechnology.MIFARE_CLASSIC):
+            case (TagTechnology.MIFARE_ULTRALIGHT):
+                return 253; // PN544 RF buffer = 255 bytes, subtract two for CRC
+            case (TagTechnology.NFC_B):
+                return 0; // PN544 does not support transceive of raw NfcB
+            case (TagTechnology.NFC_V):
+                return 253; // PN544 RF buffer = 255 bytes, subtract two for CRC
+            case (TagTechnology.ISO_DEP):
+                /* The maximum length of a normal IsoDep frame consists of:
+                 * CLA, INS, P1, P2, LC, LE + 255 payload bytes = 261 bytes
+                 * such a frame is supported. Extended length frames however
+                 * are not supported.
+                 */
+                return 261; // Will be automatically split in two frames on the RF layer
+            case (TagTechnology.NFC_F):
+                return 252; // PN544 RF buffer = 255 bytes, subtract one for SoD, two for CRC
+            default:
+                return 0;
+        }
+
+    }
+
     /**
      * Notifies Ndef Message (TODO: rename into notifyTargetDiscovered)
      */
diff --git a/src/com/android/nfc/nxp/NativeNfcTag.java b/src/com/android/nfc/nxp/NativeNfcTag.java
index f0e123e..dcbbf14 100755
--- a/src/com/android/nfc/nxp/NativeNfcTag.java
+++ b/src/com/android/nfc/nxp/NativeNfcTag.java
@@ -415,7 +415,8 @@ public class NativeNfcTag implements TagEndpoint {
         }
     }
 
-    private int getConnectedTechnology() {
+    @Override
+    public int getConnectedTechnology() {
         if (mConnectedTechIndex != -1 && mConnectedTechIndex < mTechList.length) {
             return mTechList[mConnectedTechIndex];
         } else {