Bug#35693207 TLS_BUSY_TRY_AGAIN handling need to update whatever was sent

In case Transporter::doSend() received a TLS_BUSY_TRY_AGAIN status
from writev() it returned immediately without updating the 'sum_sent'
of buffered data being sent before the failure.

This patch will 'break' out of the send-loop instead of just returning.
We will then fall through to the code where such status update is
supposed to take place.

The code for checking TLS_BUSY_TRY_AGAIN is also moved into the
code section where we handle errors (nBytesSent <= 0)

Change-Id: I1af2ba15626d9219716acc0a0d01eb4766f9eda9

Author: Ole John Aske

storage/ndb/src/common/transporter/TCP_Transporter.cpp

@@ -394,20 +394,14 @@ TCP_Transporter::doSend(bool need_wakeup)
       }
     }
 
-    if (Uint32(nBytesSent) == remain)  //Completed this send
+    if (likely(Uint32(nBytesSent) == remain))  //Completed this send
     {
       sum_sent += nBytesSent;
       assert(sum >= sum_sent);
       remain = sum - sum_sent;
       //g_eventLogger->info("Sent %d bytes on trp %u", nBytesSent, getTransporterIndex());
       break;
     }
-    else if (nBytesSent == TLS_BUSY_TRY_AGAIN)
-    {
-      // TLS is doing protocol layer stuff. We need to keep polling and
-      // trying to send until it is done.
-      return true;
-    }
     else if (nBytesSent > 0)           //Sent some, more pending
     {
       sum_sent += nBytesSent;
@@ -434,10 +428,16 @@ TCP_Transporter::doSend(bool need_wakeup)
         iov[pos].iov_base = ((char*)(iov[pos].iov_base))+nBytesSent;
       }
     }
-    else                               //Send failed, terminate
+    else                               //Send failed, handle or disconnect?
     {
       const int err = ndb_socket_errno();
 
+      if (nBytesSent == TLS_BUSY_TRY_AGAIN)
+      {
+        // In case TLS was 'BUSY' TransporterRegistry will send-retry later.
+        break;
+      }
+
 #if defined DEBUG_TRANSPORTER
       g_eventLogger->error("Send Failure(disconnect==%d) to node = %d "
                            "nBytesSent = %d "
@@ -559,7 +559,7 @@ TCP_Transporter::doReceive(TransporterReceiveHandle& recvdata)
 
       if(nBytesRead == TLS_BUSY_TRY_AGAIN) return TLS_BUSY_TRY_AGAIN;
 
-      if (nBytesRead > 0)
+      if (likely(nBytesRead > 0))
       {
         receiveBuffer.sizeOfData += nBytesRead;
         receiveBuffer.insertPtr  += nBytesRead;

storage/ndb/src/common/util/NdbSocket.cpp

@@ -189,7 +189,11 @@ static ssize_t handle_ssl_error(int err, const char * fn) {
       return 0;           // caller should close the socket
     case SSL_ERROR_WANT_READ:
     case SSL_ERROR_WANT_WRITE:
-      return TLS_BUSY_TRY_AGAIN;
+      // FIXME Bug#3569340:
+      //
+      // Note that for upper transporter layers we expect either 0 or -1
+      // to be returned in case of failures.
+      return TLS_BUSY_TRY_AGAIN;  // <- return -1;
     case SSL_ERROR_SYSCALL:
       return -1;          // caller should check errno and close the socket
     case SSL_ERROR_ZERO_RETURN: