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refactor to reduce complexity and fix endless loops
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@justinmclean
justinmclean committed Jan 6, 2018
1 parent ff882df commit 04245aa
Showing 1 changed file with 60 additions and 50 deletions.
110 changes: 60 additions & 50 deletions plc4j/protocols/s7/src/main/java/org/apache/plc4x/java/s7/netty/S7Protocol.java
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Original file line number Diff line number Diff line change
Expand Up @@ -104,71 +104,77 @@ protected void encode(ChannelHandlerContext ctx, S7Message in, List<Object> out)
switch (s7Parameter.getType()) {
case READ_VAR:
case WRITE_VAR:
VarParameter varParameter = (VarParameter) s7Parameter;
List<VarParameterItem> items = varParameter.getItems();
// ReadRequestItem count (Read one variable at a time)
buf.writeByte((byte) items.size());
for (VarParameterItem item : items) {
VariableAddressingMode addressMode = item.getAddressingMode();
if (addressMode == VariableAddressingMode.S7ANY) {
S7AnyVarParameterItem s7AnyRequestItem = (S7AnyVarParameterItem) item;
buf.writeByte(s7AnyRequestItem.getSpecificationType().getCode());
// Length of this item (excluding spec type and length)
buf.writeByte((byte) 0x0a);
buf.writeByte(s7AnyRequestItem.getAddressingMode().getCode());
buf.writeByte(s7AnyRequestItem.getTransportSize().getCode());
buf.writeShort(s7AnyRequestItem.getNumElements());
buf.writeShort(s7AnyRequestItem.getDataBlockNumber());
buf.writeByte(s7AnyRequestItem.getMemoryArea().getCode());
// A S7 address is 3 bytes long. Unfortunately the byte-offset is NOT located in
// byte 1 and byte 2 and the bit offset in byte 3. Siemens used the last 3 bits of
// byte 3 for the bit-offset and the remaining 5 bits of byte 3 to contain the lowest
// 5 bits of the byte-offset. The highest 5 bits of byte 1 are probably left unused
// for future extensions.
buf.writeShort((short) (s7AnyRequestItem.getByteOffset() >> 5));
buf.writeByte((byte) ((
(s7AnyRequestItem.getByteOffset() & 0x1F) << 3)
| (s7AnyRequestItem.getBitOffset() & 0x07)));
} else {
logger.error("writing this item type not implemented");
return;
}
}
encodeReadWriteVar(buf, (VarParameter) s7Parameter);
break;
case SETUP_COMMUNICATION:
SetupCommunicationParameter setupCommunication = (SetupCommunicationParameter) s7Parameter;
// Reserved (is always constant 0x00)
buf.writeByte((byte) 0x00);
buf.writeShort(setupCommunication.getMaxAmqCaller());
buf.writeShort(setupCommunication.getMaxAmqCallee());
buf.writeShort(setupCommunication.getPduLength());
encodeSetupCommunication(buf, (SetupCommunicationParameter) s7Parameter);
break;
default:
logger.error("writing this parameter type not implemented");
return;
}
}

if(!in.getPayloads().isEmpty()) {
if (!in.getPayloads().isEmpty()) {
for (S7Payload payload : in.getPayloads()) {
switch (payload.getType()) {
case READ_VAR:
case WRITE_VAR:
VarPayload varPayload = (VarPayload) payload;
for (VarPayloadItem payloadItem : varPayload.getPayloadItems()) {
buf.writeByte(payloadItem.getReturnCode().getCode());
buf.writeByte(payloadItem.getDataTransportSize().getCode());
buf.writeShort(payloadItem.getData().length);
buf.writeBytes(payloadItem.getData());
}
break;
ParameterType parameterType = payload.getType();
if (parameterType == ParameterType.READ_VAR || parameterType == ParameterType.WRITE_VAR) {
VarPayload varPayload = (VarPayload) payload;
for (VarPayloadItem payloadItem : varPayload.getPayloadItems()) {
buf.writeByte(payloadItem.getReturnCode().getCode());
buf.writeByte(payloadItem.getDataTransportSize().getCode());
buf.writeShort(payloadItem.getData().length);
buf.writeBytes(payloadItem.getData());
}
}
}
}

out.add(new DataTpdu(true, (byte) 1, Collections.emptyList(), buf));
}

private void encodeSetupCommunication(ByteBuf buf, SetupCommunicationParameter s7Parameter) {
// Reserved (is always constant 0x00)
buf.writeByte((byte) 0x00);
buf.writeShort(s7Parameter.getMaxAmqCaller());
buf.writeShort(s7Parameter.getMaxAmqCallee());
buf.writeShort(s7Parameter.getPduLength());
}

private void encodeReadWriteVar(ByteBuf buf, VarParameter s7Parameter) {
List<VarParameterItem> items = s7Parameter.getItems();
// ReadRequestItem count (Read one variable at a time)
buf.writeByte((byte) items.size());
for (VarParameterItem item : items) {
VariableAddressingMode addressMode = item.getAddressingMode();
if (addressMode == VariableAddressingMode.S7ANY) {
encodeS7AnyParameterItem(buf, (S7AnyVarParameterItem) item);
} else {
logger.error("writing this item type not implemented");
}
}
}

private void encodeS7AnyParameterItem(ByteBuf buf, S7AnyVarParameterItem s7AnyRequestItem) {
buf.writeByte(s7AnyRequestItem.getSpecificationType().getCode());
// Length of this item (excluding spec type and length)
buf.writeByte((byte) 0x0a);
buf.writeByte(s7AnyRequestItem.getAddressingMode().getCode());
buf.writeByte(s7AnyRequestItem.getTransportSize().getCode());
buf.writeShort(s7AnyRequestItem.getNumElements());
buf.writeShort(s7AnyRequestItem.getDataBlockNumber());
buf.writeByte(s7AnyRequestItem.getMemoryArea().getCode());
// A S7 address is 3 bytes long. Unfortunately the byte-offset is NOT located in
// byte 1 and byte 2 and the bit offset in byte 3. Siemens used the last 3 bits of
// byte 3 for the bit-offset and the remaining 5 bits of byte 3 to contain the lowest
// 5 bits of the byte-offset. The highest 5 bits of byte 1 are probably left unused
// for future extensions.
buf.writeShort((short) (s7AnyRequestItem.getByteOffset() >> 5));
buf.writeByte((byte) ((
(s7AnyRequestItem.getByteOffset() & 0x1F) << 3)
| (s7AnyRequestItem.getBitOffset() & 0x07)));
}

@Override
protected void decode(ChannelHandlerContext ctx, IsoTPMessage in, List<Object> out) throws Exception {
if (logger.isTraceEnabled()) {
Expand Down Expand Up @@ -200,7 +206,9 @@ protected void decode(ChannelHandlerContext ctx, IsoTPMessage in, List<Object> o
List<S7Parameter> s7Parameters = new LinkedList<>();
SetupCommunicationParameter setupCommunicationParameter = null;
VarParameter readWriteVarParameter = null;
for (int i = 0; i < headerParametersLength; ) {
int i = 0;

while (i < headerParametersLength) {
S7Parameter parameter = parseParameter(userData, isResponse, headerParametersLength - i);
s7Parameters.add(parameter);
if (parameter instanceof SetupCommunicationParameter) {
Expand All @@ -217,7 +225,9 @@ protected void decode(ChannelHandlerContext ctx, IsoTPMessage in, List<Object> o
List<S7Payload> s7Payloads = new LinkedList<>();
if(readWriteVarParameter != null) {
List<VarPayloadItem> payloadItems = new LinkedList<>();
for (int i = 0; i < userDataLength; ) {
i = 0;

while (i < userDataLength) {
DataTransportErrorCode dataTransportErrorCode = DataTransportErrorCode.valueOf(userData.readByte());
// This is a response to a WRITE_VAR request (It only contains the return code for every sent item.
if ((readWriteVarParameter.getType() == ParameterType.WRITE_VAR) &&
Expand Down

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