QCanBusFrame: Extend valid check for frame id >= 2^29

All changes to canId have to go through setFrameId,
which marks frames with id >= 2^29 as invalid.

This can then be checked by isValid().

Change-Id: Ie9a80c35608cdb215d8d1ce3cb314bdc77924e05
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

2 files changed, 31 insertions, 10 deletions

diff --git a/src/serialbus/qcanbusframe.h b/src/serialbus/qcanbusframe.h
index f8b1b06..84c0060 100644
--- a/src/serialbus/qcanbusframe.h
+++ b/src/serialbus/qcanbusframe.h
@@ -73,10 +73,10 @@ public:
     };
 
     explicit QCanBusFrame(FrameType type = DataFrame) Q_DECL_NOTHROW :
-        canId(0x0),
         isExtendedFrame(0x0),
         version(0x0)
     {
+        setFrameId(0x0);
         setFrameType(type);
     }
 
@@ -99,14 +99,15 @@ public:
     Q_FLAGS(FrameErrors)
 
     explicit QCanBusFrame(quint32 identifier, const QByteArray &data) :
-        canId(identifier & 0x1FFFFFFFU),
         format(DataFrame),
-        isExtendedFrame((identifier & 0x1FFFF800U) ? 0x1 : 0x0),
+        isExtendedFrame(0x0),
         version(0x0),
         load(data)
     {
         Q_UNUSED(extra);
         Q_UNUSED(reserved);
+
+        setFrameId(identifier);
     }
 
     bool isValid() const Q_DECL_NOTHROW
@@ -118,6 +119,9 @@ public:
         if (!isExtendedFrame && (canId & 0x1FFFF800U))
             return false;
 
+        if (!isValidFrameId)
+            return false;
+
         // maximum permitted payload size in CAN FD
         if (load.length() > 64)
             return false;
@@ -168,8 +172,14 @@ public:
     }
     void setFrameId(quint32 newFrameId)
     {
-        canId = (newFrameId & 0x1FFFFFFFU);
-        setExtendedFrameFormat(isExtendedFrame || (newFrameId & 0x1FFFF800U));
+        if (newFrameId < 0x20000000U) {
+            isValidFrameId = true;
+            canId = newFrameId;
+            setExtendedFrameFormat(isExtendedFrame || (newFrameId & 0x1FFFF800U));
+        } else {
+            isValidFrameId = false;
+            canId = 0;
+        }
     }
 
     void setPayload(const QByteArray &data) { load = data; }
@@ -239,7 +249,8 @@ private:
 
     quint8 isExtendedFrame:1;
     quint8 version:5;
-    quint8 extra: 2; // unused
+    quint8 isValidFrameId:1;
+    quint8 extra: 1; // unused
 
     // reserved for future use
     quint8 reserved[3];
diff --git a/tests/auto/qcanbusframe/tst_qcanbusframe.cpp b/tests/auto/qcanbusframe/tst_qcanbusframe.cpp
index f8b3781..56fe064 100644
--- a/tests/auto/qcanbusframe/tst_qcanbusframe.cpp
+++ b/tests/auto/qcanbusframe/tst_qcanbusframe.cpp
@@ -104,22 +104,32 @@ void tst_QCanBusFrame::id()
     frame.setExtendedFrameFormat(false);
     frame.setFrameId(2047u);
     QCOMPARE(frame.frameId(), 2047u);
-    QVERIFY(frame.hasExtendedFrameFormat() == false);
+    QVERIFY(frame.isValid());
+    QVERIFY(!frame.hasExtendedFrameFormat());
     // id > 2^11 -> extended format
     frame.setExtendedFrameFormat(false);
     frame.setFrameId(2048u);
     QCOMPARE(frame.frameId(), 2048u);
-    QVERIFY(frame.hasExtendedFrameFormat() == true);
+    QVERIFY(frame.isValid());
+    QVERIFY(frame.hasExtendedFrameFormat());
     // id < 2^11 -> no extended format
     frame.setExtendedFrameFormat(false);
     frame.setFrameId(512u);
     QCOMPARE(frame.frameId(), 512u);
-    QVERIFY(frame.hasExtendedFrameFormat() == false);
+    QVERIFY(frame.isValid());
+    QVERIFY(!frame.hasExtendedFrameFormat());
     // id < 2^11 -> keep extended format
     frame.setExtendedFrameFormat(true);
     frame.setFrameId(512u);
     QCOMPARE(frame.frameId(), 512u);
-    QVERIFY(frame.hasExtendedFrameFormat() == true);
+    QVERIFY(frame.isValid());
+    QVERIFY(frame.hasExtendedFrameFormat());
+    // id >= 2^29 -> invalid
+    frame.setExtendedFrameFormat(false);
+    frame.setFrameId(536870912u);
+    QCOMPARE(frame.frameId(), 0u);
+    QVERIFY(!frame.isValid());
+    QVERIFY(!frame.hasExtendedFrameFormat());
 }
 
 void tst_QCanBusFrame::payload()