#903: generic protocol: fix a rare corner case

ASCII protocols consisting of a single chunk only (one variable per line)
would not work when no "separator" was defined.
Also add error message for protocols with more than one var per line which
are missing a separator...

diff --git a/src/Network/generic.cxx b/src/Network/generic.cxx
index 94a00a0ebc39bcdcaa5453303822e2d8376a029a..dca36308739490aa765cb33c9a828e73fd7fb840 100644 (file)
--- a/src/Network/generic.cxx
+++ b/src/Network/generic.cxx
@@ -340,7 +340,7 @@ bool FGGeneric::parse_message_binary(int length) {
 }
 
 bool FGGeneric::parse_message_ascii(int length) {
-    char *p2, *p1 = buf;
+    char *p1 = buf;
     int i = -1;
     int chunks = _in_message.size();
     int line_separator_size = line_separator.size();
@@ -354,11 +354,17 @@ bool FGGeneric::parse_message_ascii(int length) {
         buf[length - line_separator_size] = 0;
     }
 
+    size_t varsep_len = var_separator.length();
     while ((++i < chunks) && p1) {
-        p2 = strstr(p1, var_separator.c_str());
-        if (p2) {
-            *p2 = 0;
-            p2 += var_separator.length();
+        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) {
@@ -542,13 +548,21 @@ FGGeneric::reinit()
         SGPropertyNode *output = root.getNode("generic/output");
         if (output) {
             _out_message.clear();
-            read_config(output, _out_message);
+            if (!read_config(output, _out_message))
+            {
+                // bad configuration
+                return;
+            }
         }
     } else if (direction == "in") {
         SGPropertyNode *input = root.getNode("generic/input");
         if (input) {
             _in_message.clear();
-            read_config(input, _in_message);
+            if (!read_config(input, _in_message))
+            {
+                // bad configuration
+                return;
+            }
             if (!binary_mode && (line_separator.size() == 0 ||
                 *line_separator.rbegin() != '\n')) {
 
@@ -563,7 +577,7 @@ FGGeneric::reinit()
 }
 
 
-void
+bool
 FGGeneric::read_config(SGPropertyNode *root, vector<_serial_prot> &msg)
 {
     binary_mode = root->getBoolValue("binary_mode");
@@ -663,6 +677,7 @@ FGGeneric::read_config(SGPropertyNode *root, vector<_serial_prot> &msg)
 
     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;
@@ -705,7 +720,19 @@ FGGeneric::read_config(SGPropertyNode *root, vector<_serial_prot> &msg)
 
     }
 
-    if( binary_mode ) {
+    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) {
@@ -715,6 +742,8 @@ FGGeneric::read_config(SGPropertyNode *root, vector<_serial_prot> &msg)
             binary_record_length = record_length;
         }
     }
+
+    return true;
 }
 
 void FGGeneric::updateValue(FGGeneric::_serial_prot& prot, bool val)

diff --git a/src/Network/generic.hxx b/src/Network/generic.hxx
index b3020a390273322af90da472026536ec476f0dd9..18493651cb1d3fb64badf305f7ad7d5a666eaab0 100644 (file)
--- a/src/Network/generic.hxx
+++ b/src/Network/generic.hxx
@@ -101,7 +101,7 @@ private:
     bool gen_message_binary();
     bool parse_message_ascii(int length);
     bool parse_message_binary(int length);
-    void read_config(SGPropertyNode *root, vector<_serial_prot> &msg);
+    bool read_config(SGPropertyNode *root, vector<_serial_prot> &msg);
     bool exitOnError;
     bool initOk;