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flightgear/src/Network/generic.cxx
2020-07-03 12:34:37 +01:00

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C++

// generic.cxx -- generic protocol class
//
// Written by Curtis Olson, started November 1999.
//
// Copyright (C) 1999 Curtis L. Olson - http://www.flightgear.org/~curt
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
// $Id$
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <string.h> // strstr()
#include <stdlib.h> // strtod(), atoi()
#include <cstdio>
#include <simgear/debug/logstream.hxx>
#include <simgear/io/iochannel.hxx>
#include <simgear/structure/exception.hxx>
#include <simgear/misc/sg_path.hxx>
#include <simgear/misc/stdint.hxx>
#include <simgear/misc/strutils.hxx>
#include <simgear/props/props.hxx>
#include <simgear/props/props_io.hxx>
#include <simgear/math/SGMath.hxx>
#include <Main/globals.hxx>
#include <Main/fg_props.hxx>
#include <Main/fg_os.hxx>
#include <Main/util.hxx>
#include "generic.hxx"
using simgear::strutils::unescape;
class FGProtocolWrapper {
public:
virtual ~FGProtocolWrapper() {}
virtual int wrap( size_t n, uint8_t * buf ) = 0;
virtual int unwrap( size_t n, uint8_t * buf ) = 0;
};
/**
* http://www.ka9q.net/papers/kiss.html
*/
class FGKissWrapper : public FGProtocolWrapper {
public:
virtual int wrap( size_t n, uint8_t * buf );
virtual int unwrap( size_t n, uint8_t * buf );
private:
static const uint8_t FEND;
static const uint8_t FESC;
static const uint8_t TFEND;
static const uint8_t TFESC;
};
const uint8_t FGKissWrapper::FEND = 0xC0;
const uint8_t FGKissWrapper::FESC = 0xDB;
const uint8_t FGKissWrapper::TFEND = 0xDC;
const uint8_t FGKissWrapper::TFESC = 0xDD;
int FGKissWrapper::wrap( size_t n, uint8_t * buf )
{
std::vector<uint8_t> dest;
uint8_t *sp = buf;
dest.push_back(FEND);
dest.push_back(0); // command/channel always zero
for( size_t i = 0; i < n; i++ ) {
uint8_t c = *sp++;
switch( c ) {
case FESC:
dest.push_back(FESC);
dest.push_back(TFESC);
break;
case FEND:
dest.push_back(FESC);
dest.push_back(TFEND);
break;
default:
dest.push_back(c);
break;
}
}
dest.push_back(FEND);
memcpy( buf, dest.data(), dest.size() );
return dest.size();
}
int FGKissWrapper::unwrap( size_t n, uint8_t * buf )
{
uint8_t * sp = buf;
// look for FEND
while( 0 < n && FEND != *sp ) {
sp++;
n--;
}
// ignore all leading FEND
while( 0 < n && FEND == *sp ) {
sp++;
n--;
}
if( 0 == n ) return 0;
std::vector<uint8_t> dest;
{
bool escaped = false;
while( 0 < n ) {
n--;
uint8_t c = *sp++;
if( escaped ) {
switch( c ) {
case TFESC:
dest.push_back( FESC );
break;
case TFEND:
dest.push_back( FEND );
break;
default: // this is an error - ignore and continue
break;
}
escaped = false;
} else {
switch( c ) {
case FESC:
escaped = true;
break;
case FEND:
if( 0 != n ) {
SG_LOG(SG_IO, SG_WARN,
"KISS frame detected FEND before end of frame. Trailing data dropped." );
}
n = 0;
break;
default:
dest.push_back( c );
break;
}
}
}
}
memcpy( buf, dest.data(), dest.size() );
return dest.size();
}
class FGSTXETXWrapper : public FGProtocolWrapper {
public:
virtual int wrap( size_t n, uint8_t * buf );
virtual int unwrap( size_t n, uint8_t * buf );
static const uint8_t STX;
static const uint8_t ETX;
static const uint8_t DLE;
};
const uint8_t FGSTXETXWrapper::STX = 0x02;
const uint8_t FGSTXETXWrapper::ETX = 0x03;
const uint8_t FGSTXETXWrapper::DLE = 0x00;
int FGSTXETXWrapper::wrap( size_t n, uint8_t * buf )
{
// stuff payload as
// <dle><stx>payload<dle><etx>
// if payload contains <dle>, stuff <dle> as <dle><dle>
std::vector<uint8_t> dest;
uint8_t *sp = buf;
dest.push_back(DLE);
dest.push_back(STX);
while( n > 0 ) {
n--;
if( DLE == *sp )
dest.push_back(DLE);
dest.push_back(*sp++);
}
dest.push_back(DLE);
dest.push_back(ETX);
memcpy( buf, dest.data(), dest.size() );
return dest.size();
}
int FGSTXETXWrapper::unwrap( size_t n, uint8_t * buf )
{
return n;
}
FGGeneric::FGGeneric(vector<string> tokens) : exitOnError(false), initOk(false), wrapper(NULL)
{
size_t configToken;
if (tokens[1] == "socket") {
configToken = 7;
} else if (tokens[1] == "file") {
configToken = 5;
} else {
configToken = 6;
}
if ((configToken >= tokens.size())||(tokens[ configToken ] == "")) {
SG_LOG(SG_NETWORK, SG_ALERT,
"Not enough tokens passed for generic '" << tokens[1] << "' protocol. ");
return;
}
string config = tokens[ configToken ];
file_name = config+".xml";
direction = tokens[2];
if (direction != "in" && direction != "out" && direction != "bi") {
SG_LOG(SG_NETWORK, SG_ALERT, "Unsuported protocol direction: "
<< direction);
return;
}
reinit();
}
FGGeneric::~FGGeneric() {
delete wrapper;
}
union u32 {
uint32_t intVal;
float floatVal;
};
union u64 {
uint64_t longVal;
double doubleVal;
};
// generate the message
bool FGGeneric::gen_message_binary() {
string generic_sentence;
length = 0;
double val;
for (unsigned int i = 0; i < _out_message.size(); i++) {
switch (_out_message[i].type) {
case FG_INT:
{
val = _out_message[i].offset +
_out_message[i].prop->getFloatValue() * _out_message[i].factor;
int32_t intVal = val;
if (binary_byte_order != BYTE_ORDER_MATCHES_NETWORK_ORDER) {
intVal = (int32_t) sg_bswap_32((uint32_t)intVal);
}
memcpy(&buf[length], &intVal, sizeof(int32_t));
length += sizeof(int32_t);
break;
}
case FG_BOOL:
buf[length] = (char) (_out_message[i].prop->getBoolValue() ? true : false);
length += 1;
break;
case FG_FIXED:
{
val = _out_message[i].offset +
_out_message[i].prop->getFloatValue() * _out_message[i].factor;
int32_t fixed = (int)(val * 65536.0f);
if (binary_byte_order != BYTE_ORDER_MATCHES_NETWORK_ORDER) {
fixed = (int32_t) sg_bswap_32((uint32_t)fixed);
}
memcpy(&buf[length], &fixed, sizeof(int32_t));
length += sizeof(int32_t);
break;
}
case FG_FLOAT:
{
val = _out_message[i].offset +
_out_message[i].prop->getFloatValue() * _out_message[i].factor;
u32 tmpun32;
tmpun32.floatVal = static_cast<float>(val);
if (binary_byte_order != BYTE_ORDER_MATCHES_NETWORK_ORDER) {
tmpun32.intVal = sg_bswap_32(tmpun32.intVal);
}
memcpy(&buf[length], &tmpun32.intVal, sizeof(uint32_t));
length += sizeof(uint32_t);
break;
}
case FG_DOUBLE:
{
val = _out_message[i].offset +
_out_message[i].prop->getDoubleValue() * _out_message[i].factor;
u64 tmpun64;
tmpun64.doubleVal = val;
if (binary_byte_order != BYTE_ORDER_MATCHES_NETWORK_ORDER) {
tmpun64.longVal = sg_bswap_64(tmpun64.longVal);
}
memcpy(&buf[length], &tmpun64.longVal, sizeof(uint64_t));
length += sizeof(uint64_t);
break;
}
case FG_BYTE:
{
val = _out_message[i].offset +
_out_message[i].prop->getFloatValue() * _out_message[i].factor;
int8_t byteVal = val;
memcpy(&buf[length], &byteVal, sizeof(int8_t));
length += sizeof(int8_t);
break;
}
case FG_WORD:
{
val = _out_message[i].offset +
_out_message[i].prop->getFloatValue() * _out_message[i].factor;
int16_t wordVal = val;
memcpy(&buf[length], &wordVal, sizeof(int16_t));
length += sizeof(int16_t);
break;
}
default: // SG_STRING
const char *strdata = _out_message[i].prop->getStringValue();
int32_t strlength = strlen(strdata);
if (binary_byte_order == BYTE_ORDER_NEEDS_CONVERSION) {
SG_LOG( SG_IO, SG_ALERT, "Generic protocol: "
"FG_STRING will be written in host byte order.");
}
/* Format for strings is
* [length as int, 4 bytes][ASCII data, length bytes]
*/
if (binary_byte_order != BYTE_ORDER_MATCHES_NETWORK_ORDER) {
strlength = sg_bswap_32(strlength);
}
memcpy(&buf[length], &strlength, sizeof(int32_t));
length += sizeof(int32_t);
strncpy(&buf[length], strdata, strlength);
length += strlength;
/* FIXME padding for alignment? Something like:
* length += (strlength % 4 > 0 ? sizeof(int32_t) - strlength % 4 : 0;
*/
break;
}
}
// add the footer to the packet ("line")
switch (binary_footer_type) {
case FOOTER_LENGTH:
binary_footer_value = length;
break;
case FOOTER_MAGIC:
case FOOTER_NONE:
break;
}
if (binary_footer_type != FOOTER_NONE) {
int32_t intValue = binary_footer_value;
if (binary_byte_order != BYTE_ORDER_MATCHES_NETWORK_ORDER) {
intValue = sg_bswap_32(binary_footer_value);
}
memcpy(&buf[length], &intValue, sizeof(int32_t));
length += sizeof(int32_t);
}
if( wrapper ) length = wrapper->wrap( length, reinterpret_cast<uint8_t*>(buf) );
return true;
}
bool FGGeneric::gen_message_ascii() {
string generic_sentence;
char tmp[255];
length = 0;
double val;
for (unsigned int i = 0; i < _out_message.size(); i++) {
if (i > 0) {
generic_sentence += var_separator;
}
string format = simgear::strutils::sanitizePrintfFormat(_out_message[i].format);
switch (_out_message[i].type) {
case FG_BYTE:
case FG_WORD:
case FG_INT:
val = _out_message[i].offset +
_out_message[i].prop->getFloatValue() * _out_message[i].factor;
snprintf(tmp, 255, format.c_str(), (int)val);
break;
case FG_BOOL:
snprintf(tmp, 255, format.c_str(),
_out_message[i].prop->getBoolValue());
break;
case FG_FIXED:
val = _out_message[i].offset +
_out_message[i].prop->getFloatValue() * _out_message[i].factor;
snprintf(tmp, 255, format.c_str(), (float)val);
break;
case FG_FLOAT:
val = _out_message[i].offset +
_out_message[i].prop->getFloatValue() * _out_message[i].factor;
snprintf(tmp, 255, format.c_str(), (float)val);
break;
case FG_DOUBLE:
val = _out_message[i].offset +
_out_message[i].prop->getDoubleValue() * _out_message[i].factor;
snprintf(tmp, 255, format.c_str(), (double)val);
break;
default: // SG_STRING
snprintf(tmp, 255, format.c_str(),
_out_message[i].prop->getStringValue());
}
generic_sentence += tmp;
}
/* After each lot of variables has been added, put the line separator
* char/string
*/
generic_sentence += line_separator;
length = generic_sentence.length();
strncpy( buf, generic_sentence.c_str(), length );
return true;
}
bool FGGeneric::gen_message() {
if (binary_mode) {
return gen_message_binary();
} else {
return gen_message_ascii();
}
}
bool FGGeneric::parse_message_binary(int length) {
char *p2, *p1 = buf;
int32_t tmp32;
int i = -1;
p2 = p1 + length;
while ((++i < (int)_in_message.size()) && (p1 < p2)) {
switch (_in_message[i].type) {
case FG_INT:
if (binary_byte_order == BYTE_ORDER_NEEDS_CONVERSION) {
tmp32 = sg_bswap_32(*(int32_t *)p1);
} else {
tmp32 = *(int32_t *)p1;
}
updateValue(_in_message[i], (int)tmp32);
p1 += sizeof(int32_t);
break;
case FG_BOOL:
updateValue(_in_message[i], p1[0] != 0);
p1 += 1;
break;
case FG_FIXED:
if (binary_byte_order == BYTE_ORDER_NEEDS_CONVERSION) {
tmp32 = sg_bswap_32(*(int32_t *)p1);
} else {
tmp32 = *(int32_t *)p1;
}
updateValue(_in_message[i], (float)tmp32 / 65536.0f);
p1 += sizeof(int32_t);
break;
case FG_FLOAT:
u32 tmpun32;
if (binary_byte_order == BYTE_ORDER_NEEDS_CONVERSION) {
tmpun32.intVal = sg_bswap_32(*(uint32_t *)p1);
} else {
tmpun32.floatVal = *(float *)p1;
}
updateValue(_in_message[i], tmpun32.floatVal);
p1 += sizeof(int32_t);
break;
case FG_DOUBLE:
u64 tmpun64;
if (binary_byte_order == BYTE_ORDER_NEEDS_CONVERSION) {
tmpun64.longVal = sg_bswap_64(*(uint64_t *)p1);
} else {
tmpun64.doubleVal = *(double *)p1;
}
updateValue(_in_message[i], tmpun64.doubleVal);
p1 += sizeof(int64_t);
break;
case FG_BYTE:
tmp32 = *(int8_t *)p1;
updateValue(_in_message[i], (int)tmp32);
p1 += sizeof(int8_t);
break;
case FG_WORD:
if (binary_byte_order == BYTE_ORDER_NEEDS_CONVERSION) {
tmp32 = sg_bswap_16(*(int16_t *)p1);
} else {
tmp32 = *(int16_t *)p1;
}
updateValue(_in_message[i], (int)tmp32);
p1 += sizeof(int16_t);
break;
default: // SG_STRING
SG_LOG( SG_IO, SG_ALERT, "Generic protocol: "
"Ignoring unsupported binary input chunk type.");
break;
}
}
return true;
}
bool FGGeneric::parse_message_ascii(int length) {
char *p1 = buf;
int i = -1;
int chunks = _in_message.size();
int line_separator_size = line_separator.size();
if (length < line_separator_size ||
line_separator.compare(buf + length - line_separator_size) != 0) {
SG_LOG(SG_IO, SG_WARN,
"Input line does not end with expected line separator." );
} else {
buf[length - line_separator_size] = 0;
}
size_t varsep_len = var_separator.length();
while ((++i < chunks) && p1) {
char* p2 = NULL;
if (varsep_len > 0)
{
p2 = strstr(p1, var_separator.c_str());
if (p2) {
*p2 = 0;
p2 += varsep_len;
}
}
switch (_in_message[i].type) {
case FG_BYTE:
case FG_WORD:
case FG_INT:
updateValue(_in_message[i], atoi(p1));
break;
case FG_BOOL:
updateValue(_in_message[i], atof(p1) != 0.0);
break;
case FG_FIXED:
case FG_FLOAT:
updateValue(_in_message[i], (float)strtod(p1, 0));
break;
case FG_DOUBLE:
updateValue(_in_message[i], (double)strtod(p1, 0));
break;
default: // SG_STRING
_in_message[i].prop->setStringValue(p1);
break;
}
p1 = p2;
}
return true;
}
bool FGGeneric::parse_message_len(int length) {
if (binary_mode) {
return parse_message_binary(length);
} else {
return parse_message_ascii(length);
}
}
// open hailing frequencies
bool FGGeneric::open() {
if ( is_enabled() ) {
SG_LOG( SG_IO, SG_ALERT, "This shouldn't happen, but the channel "
<< "is already in use, ignoring" );
return false;
}
SGIOChannel *io = get_io_channel();
if ( ! io->open( get_direction() ) ) {
SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
return false;
}
set_enabled( true );
if ( ((get_direction() == SG_IO_OUT )||
(get_direction() == SG_IO_BI))
&& ! preamble.empty() ) {
if ( ! io->write( preamble.c_str(), preamble.size() ) ) {
SG_LOG( SG_IO, SG_WARN, "Error writing preamble." );
return false;
}
}
return true;
}
// process work for this port
bool FGGeneric::process() {
SGIOChannel *io = get_io_channel();
if ( (get_direction() == SG_IO_OUT) ||
(get_direction() == SG_IO_BI) ) {
gen_message();
if ( ! io->write( buf, length ) ) {
SG_LOG( SG_IO, SG_WARN, "Error writing data." );
goto error_out;
}
}
if (( get_direction() == SG_IO_IN ) ||
(get_direction() == SG_IO_BI) ) {
if ( io->get_type() == sgFileType ) {
if (!binary_mode) {
length = io->readline( buf, FG_MAX_MSG_SIZE );
if ( length > 0 ) {
parse_message_len( length );
} else {
SG_LOG( SG_IO, SG_ALERT, "Error reading data." );
return false;
}
} else {
length = io->read( buf, binary_record_length );
if ( length == binary_record_length ) {
parse_message_len( length );
} else {
SG_LOG( SG_IO, SG_ALERT,
"Generic protocol: Received binary "
"record of unexpected size, expected: "
<< binary_record_length << " but received: "
<< length);
}
}
} else {
if (!binary_mode) {
while ((length = io->readline( buf, FG_MAX_MSG_SIZE )) > 0 ) {
parse_message_len( length );
}
} else {
while ((length = io->read( buf, binary_record_length ))
== binary_record_length ) {
parse_message_len( length );
}
if ( length > 0 ) {
SG_LOG( SG_IO, SG_ALERT,
"Generic protocol: Received binary "
"record of unexpected size, expected: "
<< binary_record_length << " but received: "
<< length);
}
}
}
}
return true;
error_out:
if (exitOnError) {
fgOSExit(1);
return true; // should not get there, but please the compiler
} else
return false;
}
// close the channel
bool FGGeneric::close() {
SGIOChannel *io = get_io_channel();
if ( ((get_direction() == SG_IO_OUT)||
(get_direction() == SG_IO_BI))
&& ! postamble.empty() ) {
if ( ! io->write( postamble.c_str(), postamble.size() ) ) {
SG_LOG( SG_IO, SG_ALERT, "Error writing postamble." );
return false;
}
}
set_enabled( false );
if ( ! io->close() ) {
return false;
}
return true;
}
void
FGGeneric::reinit()
{
SGPath path = globals->findDataPath("Protocol/" + file_name);
if (!path.exists()) {
SG_LOG(SG_NETWORK, SG_WARN, "Couldn't find protocol file for '" << file_name << "'");
return;
}
SG_LOG(SG_NETWORK, SG_INFO, "Reading communication protocol from " << path);
SGPropertyNode root;
try {
readProperties(path, &root);
} catch (const sg_exception & ex) {
SG_LOG(SG_NETWORK, SG_ALERT,
"Unable to load the protocol configuration file: " << ex.getFormattedMessage() );
return;
}
if (direction == "out") {
SGPropertyNode *output = root.getNode("generic/output");
if (output) {
_out_message.clear();
if (!read_config(output, _out_message))
{
// bad configuration
return;
}
}
} else if (direction == "in") {
SGPropertyNode *input = root.getNode("generic/input");
if (input) {
_in_message.clear();
if (!read_config(input, _in_message))
{
// bad configuration
return;
}
if (!binary_mode && (line_separator.empty() ||
*line_separator.rbegin() != '\n')) {
SG_LOG(SG_IO, SG_WARN,
"Warning: Appending newline to line separator in generic input.");
line_separator.push_back('\n');
}
}
}
initOk = true;
}
bool
FGGeneric::read_config(SGPropertyNode *root, vector<_serial_prot> &msg)
{
binary_mode = root->getBoolValue("binary_mode");
if (!binary_mode) {
/* These variables specified in the $FG_ROOT/data/Protocol/xxx.xml
* file for each format
*
* var_sep_string = the string/charachter to place between variables
* line_sep_string = the string/charachter to place at the end of each
* lot of variables
*/
preamble = unescape(root->getStringValue("preamble"));
postamble = unescape(root->getStringValue("postamble"));
var_sep_string = unescape(root->getStringValue("var_separator"));
line_sep_string = unescape(root->getStringValue("line_separator"));
if ( var_sep_string == "newline" ) {
var_separator = '\n';
} else if ( var_sep_string == "tab" ) {
var_separator = '\t';
} else if ( var_sep_string == "space" ) {
var_separator = ' ';
} else if ( var_sep_string == "formfeed" ) {
var_separator = '\f';
} else if ( var_sep_string == "carriagereturn" ) {
var_sep_string = '\r';
} else if ( var_sep_string == "verticaltab" ) {
var_separator = '\v';
} else {
var_separator = var_sep_string;
}
if ( line_sep_string == "newline" ) {
line_separator = '\n';
} else if ( line_sep_string == "tab" ) {
line_separator = '\t';
} else if ( line_sep_string == "space" ) {
line_separator = ' ';
} else if ( line_sep_string == "formfeed" ) {
line_separator = '\f';
} else if ( line_sep_string == "carriagereturn" ) {
line_separator = '\r';
} else if ( line_sep_string == "verticaltab" ) {
line_separator = '\v';
} else {
line_separator = line_sep_string;
}
} else {
// default values: no footer and record_length = sizeof(representation)
binary_footer_type = FOOTER_NONE;
binary_record_length = -1;
// default choice is network byte order (big endian)
if (sgIsLittleEndian()) {
binary_byte_order = BYTE_ORDER_NEEDS_CONVERSION;
} else {
binary_byte_order = BYTE_ORDER_MATCHES_NETWORK_ORDER;
}
if ( root->hasValue("binary_footer") ) {
string footer_type = root->getStringValue("binary_footer");
if ( footer_type == "length" ) {
binary_footer_type = FOOTER_LENGTH;
} else if ( footer_type.substr(0, 5) == "magic" ) {
binary_footer_type = FOOTER_MAGIC;
binary_footer_value = strtol(footer_type.substr(6,
footer_type.length() - 6).c_str(), (char**)0, 0);
} else if ( footer_type != "none" ) {
SG_LOG(SG_IO, SG_ALERT,
"generic protocol: Unknown generic binary protocol "
"footer '" << footer_type << "', using no footer.");
}
}
if ( root->hasValue("record_length") ) {
binary_record_length = root->getIntValue("record_length");
}
if ( root->hasValue("byte_order") ) {
string byte_order = root->getStringValue("byte_order");
if (byte_order == "network" ) {
if ( sgIsLittleEndian() ) {
binary_byte_order = BYTE_ORDER_NEEDS_CONVERSION;
} else {
binary_byte_order = BYTE_ORDER_MATCHES_NETWORK_ORDER;
}
} else if ( byte_order == "host" ) {
binary_byte_order = BYTE_ORDER_MATCHES_NETWORK_ORDER;
} else {
SG_LOG(SG_IO, SG_ALERT,
"generic protocol: Undefined generic binary protocol"
"byte order, using HOST byte order.");
}
}
if( root->hasValue( "wrapper" ) ) {
string w = root->getStringValue( "wrapper" );
if( w == "kiss" ) wrapper = new FGKissWrapper();
else if( w == "stxetx" ) wrapper = new FGSTXETXWrapper();
else SG_LOG(SG_IO, SG_ALERT,
"generic protocol: Undefined binary protocol wrapper '" + w + "' ignored" );
}
}
int record_length = 0; // Only used for binary protocols.
vector<SGPropertyNode_ptr> chunks = root->getChildren("chunk");
for (unsigned int i = 0; i < chunks.size(); i++) {
_serial_prot chunk;
// chunk.name = chunks[i]->getStringValue("name");
chunk.format = unescape(chunks[i]->getStringValue("format", "%d"));
chunk.offset = chunks[i]->getDoubleValue("offset");
chunk.factor = chunks[i]->getDoubleValue("factor", 1.0);
chunk.min = chunks[i]->getDoubleValue("min");
chunk.max = chunks[i]->getDoubleValue("max");
chunk.wrap = chunks[i]->getBoolValue("wrap");
chunk.rel = chunks[i]->getBoolValue("relative");
if( chunks[i]->hasChild("const") ) {
chunk.prop = new SGPropertyNode();
chunk.prop->setStringValue( chunks[i]->getStringValue("const", "" ) );
} else {
string node = chunks[i]->getStringValue("node", "/null");
chunk.prop = fgGetNode(node.c_str(), true);
}
string type = chunks[i]->getStringValue("type");
// Note: officially the type is called 'bool' but for backward
// compatibility 'boolean' will also be supported.
if (type == "bool" || type == "boolean") {
chunk.type = FG_BOOL;
record_length += 1;
} else if (type == "float") {
chunk.type = FG_FLOAT;
record_length += sizeof(int32_t);
} else if (type == "double") {
chunk.type = FG_DOUBLE;
record_length += sizeof(int64_t);
} else if (type == "fixed") {
chunk.type = FG_FIXED;
record_length += sizeof(int32_t);
} else if (type == "string") {
chunk.type = FG_STRING;
} else if (type == "byte") {
chunk.type = FG_BYTE;
record_length += sizeof(int8_t);
} else if (type == "word") {
chunk.type = FG_WORD;
record_length += sizeof(int16_t);
} else {
chunk.type = FG_INT;
record_length += sizeof(int32_t);
}
msg.push_back(chunk);
}
if( !binary_mode )
{
if ((chunks.size() > 1)&&(var_sep_string.length() == 0))
{
// ASCII protocols really need a separator when there is more than one chunk per line
SG_LOG(SG_IO, SG_ALERT,
"generic protocol: Invalid configuration. "
"'var_separator' must not be empty for protocols which have more than one chunk per line.");
return false;
}
}
else
{
if (binary_record_length == -1) {
binary_record_length = record_length;
} else if (binary_record_length < record_length) {
SG_LOG(SG_IO, SG_ALERT,
"generic protocol: Requested binary record length shorter than "
" requested record representation.");
binary_record_length = record_length;
}
}
return true;
}
void FGGeneric::updateValue(FGGeneric::_serial_prot& prot, bool val)
{
if( prot.rel )
{
// value inverted if received true, otherwise leave unchanged
if( val )
setValue(prot.prop, !getValue<bool>(prot.prop));
}
else
{
setValue(prot.prop, val);
}
}