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authorEvgeny S Maksimov <admin@vragam.net>2019-01-18 21:48:41 +0300
committerEvgeny S Maksimov <admin@vragam.net>2019-01-18 21:48:41 +0300
commitcbe838ad644ce5e787f080e292bc332e50efa4a0 (patch)
tree0c09249dc18b16fe2803b4d4a42670141f13e4ef /src/org/traccar/protocol/NavisFrameDecoder.java
parentfc707a69c3c95223ecb8e263d7de32a72ec84af3 (diff)
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Added strict implementation for frame decoder
Diffstat (limited to 'src/org/traccar/protocol/NavisFrameDecoder.java')
-rw-r--r--src/org/traccar/protocol/NavisFrameDecoder.java55
1 files changed, 44 insertions, 11 deletions
diff --git a/src/org/traccar/protocol/NavisFrameDecoder.java b/src/org/traccar/protocol/NavisFrameDecoder.java
index 2480629ac..aa057b51f 100644
--- a/src/org/traccar/protocol/NavisFrameDecoder.java
+++ b/src/org/traccar/protocol/NavisFrameDecoder.java
@@ -25,17 +25,13 @@ public class NavisFrameDecoder extends BaseFrameDecoder {
private static final int NTCB_HEADER_LENGHT = 16;
private static final int NTCB_LENGHT_OFFSET = 12;
+ private static final int FLEX_HEADER_LENGHT = 2;
private static final int MAX_FRAME_LENGHT = 65551;
- private static byte src8Checksum(ByteBuf buf, int length) {
- byte sum = (byte) 0xFF;
- for (int i = 0; i < length; i++) {
- sum ^= buf.getUnsignedByte(i);
- for (int j = 0; j < 8; j++) {
- sum = (sum & 0x80) != 0 ? (byte) ((sum << 1) ^ 0x31) : (byte) (sum << 1);
- }
- }
- return sum;
+ private final NavisProtocolDecoder protocolDecoder;
+
+ public NavisFrameDecoder(NavisProtocolDecoder protocolDecoder) {
+ this.protocolDecoder = protocolDecoder;
}
@Override
@@ -52,12 +48,49 @@ public class NavisFrameDecoder extends BaseFrameDecoder {
return buf.readRetainedSlice(1);
} else if (buf.getByte(buf.readerIndex()) == 0x7E /* "~" */) {
// FLEX frame
+ if (protocolDecoder.getFLEXDataSize() == 0) {
+ return null;
+ }
if (buf.readableBytes() > MAX_FRAME_LENGHT) {
throw new TooLongFrameException();
}
- if (src8Checksum(buf, buf.readableBytes() - 1) == buf.getByte(buf.readableBytes() - 1)) {
- return buf.readRetainedSlice(buf.readableBytes());
+ if (buf.readableBytes() > FLEX_HEADER_LENGHT) {
+ int length = 0;
+ switch (buf.getByte(buf.readerIndex() + 1)) {
+ // FLEX 1.0
+ case 0x41: // "A"
+ length = protocolDecoder.getFLEXDataSize()
+ * buf.getByte(buf.readerIndex() + FLEX_HEADER_LENGHT) + 2;
+ break;
+ case 0x54: // "T"
+ length = protocolDecoder.getFLEXDataSize() + 5;
+ break;
+ case 0x43: // "C"
+ length = protocolDecoder.getFLEXDataSize() + 1;
+ break;
+ // FLEX 2.0 (Extra packages)
+ case 0x45: // "E"
+ length++;
+ for (int i = 0; i < buf.getByte(buf.readerIndex() + FLEX_HEADER_LENGHT); i++) {
+ if (buf.readableBytes() > FLEX_HEADER_LENGHT + length + 1) {
+ length += buf.getUnsignedShort(length + FLEX_HEADER_LENGHT) + 2;
+ } else {
+ return null;
+ }
+ }
+ length++;
+ break;
+ case 0x58: // "X"
+ length = buf.getUnsignedShortLE(buf.readerIndex() + FLEX_HEADER_LENGHT) + 7;
+ break;
+ default:
+ break;
+ }
+
+ if (buf.readableBytes() >= FLEX_HEADER_LENGHT + length) {
+ return buf.readRetainedSlice(buf.readableBytes());
+ }
}
} else {
// NTCB frame