- SECoP protocol for scriptcontext

binprot.c

@@ -72,9 +72,12 @@
  * chksum-crc: simple 8bit checksum
  */
 
+#define SIMULATE_ERROR 0
+static int simulate_error = 0;
+
 typedef enum {intType, hexType, floatType, strType,
   skipType, codeType, checkType, crcType,
-  dumpType, endType, errorType} BinDataType; // items on this line stay at end
+  dumpType, endType, errorType} BinDataType; /* items on this line stay at end */
 
 typedef enum {modbusCrc, kellerCrc, rsportCrc, syconCrc, chksumCrc} CrcAlgorithm;
 
@@ -83,7 +86,8 @@ typedef struct {
   CrcAlgorithm algo;
   int crcStart;
   pDynString inp;
-  char *nextFmt; // position of next format token
+  char *nextFmt; /* position of next format token */
+  char *readFmt; /* position of first read format */
   pDynString result;
   int expectedChars;
   BinDataType type;
@@ -94,6 +98,8 @@ typedef struct {
   int syconState;
   unsigned char chksum;
   pDynString data;
+  int try_again_count;
+  int try_again_max;
 } BinPrivate;
 
 #define MAXDUMP 999
@@ -383,6 +389,15 @@ void BinShuffle(char *input, int order) {
       break;
   }
 }
+
+/*----------------------------------------------------------------------------*/
+void BinResetWrite(Ascon *a) {
+  BinPrivate *p = a->private;
+  p->nextFmt = p->readFmt;
+  a->wrPos = 0;
+  a->lineCount = 0;
+  a->state = AsconWriting;
+}
 /*----------------------------------------------------------------------------*/
 int BinHandler(Ascon *a) {
   int res;
@@ -408,6 +423,7 @@ int BinHandler(Ascon *a) {
     /* exchange buffers */
     dyn = p->inp;
     p->inp = a->wrBuffer;
+    p->try_again_count = p->try_again_max;
     a->wrBuffer = dyn;
     DynStringClear(dyn);
     str = GetCharArray(p->inp);
@@ -507,10 +523,10 @@ int BinHandler(Ascon *a) {
           l += 4;
           break;
         case strType:
-	  ls = strlen(item);
-	  if (ls > size) {
-	    item[size] = '\0';
-	  }
+          ls = strlen(item);
+          if (ls > size) {
+            item[size] = '\0';
+          }
           DynStringConcat(dyn, item);
           if (size == NUL_TERMINATED) {
             DynStringConcatChar(dyn, 0);
@@ -520,7 +536,7 @@ int BinHandler(Ascon *a) {
               DynStringConcatChar(dyn, 0);
             }
             l += size;
-	  }
+          }
           break;
         }
       }
@@ -530,7 +546,8 @@ int BinHandler(Ascon *a) {
       BinToSycon(dyn);
     }
 
-    p->nextFmt = str + pos;
+    p->readFmt = str + pos;
+    p->nextFmt = p->readFmt;
     p->type = hexType; /* initialize to anything < dumpType */
     do {
       res = BinReadItem(a);
@@ -540,15 +557,11 @@ int BinHandler(Ascon *a) {
         return 1;
       }
     } while (res == 1);
-    p->nextFmt = str + pos;
-    a->wrPos = 0;
+    BinResetWrite(a);
     if (GetDynStringLength(a->wrBuffer) == 0) {
       /* prevent to swallow "garbage" */
       a->state = AsconWriteDone;
-    } else {
-      a->state = AsconWriting;
     }
-    a->lineCount = 0;
     return 1;
   case AsconReadStart:
     DynStringClear(p->result);
@@ -558,10 +571,16 @@ int BinHandler(Ascon *a) {
     break;
   case AsconReading:
     res = AsconBaseHandler(a);
+    if (a->state == AsconTimeout && p->try_again_count > 0) {
+      p->try_again_count--;
+      DynStringCopy(a->errmsg, "timeout");
+      BinResetWrite(a);
+      return 0;
+    }
     if (res == 0) {
       if (GetDynStringLength(a->rdBuffer) == 0) {
         /* wait for the first byte - or timeout */
-        return res;
+        return 0;
       }
       if (p->type >= dumpType) {
         l = GetDynStringLength(a->rdBuffer);
@@ -578,15 +597,23 @@ int BinHandler(Ascon *a) {
           DynStringConcat(a->errmsg, GetCharArray(p->result));
           a->state = AsconFailed;
         } else {
-          a->state = AsconReadDone;
+          if (p->try_again_count != p->try_again_max) {
+             Log(INFO, "com", "sock0:recovered from (%s) after: %s", GetCharArray(a->errmsg), GetCharArray(p->inp));
+           }
+           a->state = AsconReadDone;
         }
         /* exchange buffers */
         dyn = a->rdBuffer;
         a->rdBuffer = p->result;
         p->result = dyn;
+        if (a->state == AsconFailed && p->try_again_count > 0) {
+          p->try_again_count--;
+          BinResetWrite(a);
+          return 0;
+        }
         return 1;
       }
-      return res;
+      return 0;
     }
     if (p->crcAlgorithm == syconCrc) {
       switch (p->syconState) {
@@ -745,13 +772,23 @@ int BinHandler(Ascon *a) {
       p->expectedChars--;
       if ((unsigned char)a->lastChar != p->iValue) {
         i = GetDynStringLength(a->rdBuffer) - 1;
-        snprintf(item, sizeof item, "BINERR: response[%d]==%2.2x != %2.2x ", i, (unsigned char)a->lastChar, (unsigned char)p->iValue);
+        snprintf(item, sizeof item, "BINERR:  [%d]==%2.2x != %2.2x ", i, (unsigned char)a->lastChar, (unsigned char)p->iValue);
         DynStringCopy(a->errmsg, item);
         p->type = errorType;
         p->dumpFrom = 0;
         /* skip to end */
         p->nextFmt = "";
       }
+#if SIMULATE_ERROR > 0
+      if (p->try_again_max > 0 && simulate_error++ > SIMULATE_ERROR) {
+        DynStringCopy(a->errmsg, "simulate ");
+        p->type = errorType;
+        p->dumpFrom = 0;
+        /* skip to end */
+        p->nextFmt = "";
+        simulate_error = 0;
+      }
+#endif
     }
     if (p->expectedChars <= 0) {
       BinReadItem(a);
@@ -773,6 +810,7 @@ static int BinInit(Ascon * a, SConnection * con, int argc, char *argv[])
 {
   BinPrivate *p;
 
+/* args: 2 <protocol>, 3 <timeout>, 4 <try_again_max>
 /* argv[2] may be modbus-crc (default), keller-crc, rsport-crc or sycon-crc */
   
   if (argc < 2) {
@@ -807,6 +845,12 @@ static int BinInit(Ascon * a, SConnection * con, int argc, char *argv[])
   } else {
     a->timeout = 2.0; /* sec */
   }
+  if (argc > 4) {
+    p->try_again_max = atoi(argv[4]);
+  } else {
+    p->try_again_max = 0;
+  }
+  
   return 1;
 }