fpga: fix configCrossBar crashing if src or dest are nullptr

Signed-off-by: Niklas Eiling <niklas.eiling@eonerc.rwth-aachen.de>

fpga/include/villas/fpga/utils.hpp

@@ -42,7 +42,7 @@ public:
   ConnectString(std::string &connectString, int maxPortNum = 7);
   void parseString(std::string &connectString);
   int portStringToInt(std::string &str) const;
-  void configCrossBar(std::shared_ptr<villas::fpga::Card> card) const;
+  bool configCrossBar(std::shared_ptr<villas::fpga::Card> card) const;
   bool isBidirectional() const { return bidirectional; };
   bool isDmaLoopback() const { return srcType == ConnectType::LOOPBACK; };
   bool isSrcStdin() const { return srcType == ConnectType::DMA; };

fpga/lib/dma.cpp

@@ -65,7 +65,10 @@ villasfpga_handle villasfpga_init(const char *configFile) {
 
     // Configure Crossbar switch
     const fpga::ConnectString parsedConnectString(connectStr);
-    parsedConnectString.configCrossBar(handle->card);
+    if (!parsedConnectString.configCrossBar(handle->card)) {
+      logger->error("Failed to configure crossbar");
+      return nullptr;
+    }
 
     return handle;
   } catch (const RuntimeError &e) {

fpga/lib/utils.cpp

@@ -130,20 +130,20 @@ int fpga::ConnectString::portStringToInt(std::string &str) const {
 }
 
 // parses a string like "1->2" or "1<->stdout" and configures the crossbar accordingly
-void fpga::ConnectString::configCrossBar(
+bool fpga::ConnectString::configCrossBar(
     std::shared_ptr<villas::fpga::Card> card) const {
 
   auto dma = std::dynamic_pointer_cast<fpga::ip::Dma>(
       card->lookupIp(fpga::Vlnv("xilinx.com:ip:axi_dma:")));
   if (dma == nullptr) {
     logger->error("No DMA found on FPGA ");
-    throw std::runtime_error("No DMA found on FPGA");
+    return false;
   }
 
   if (isDmaLoopback()) {
     log->info("Configuring DMA loopback");
     dma->connectLoopback();
-    return;
+    return true;
   }
 
   auto aurora_channels = getAuroraChannels(card);
@@ -176,7 +176,12 @@ void fpga::ConnectString::configCrossBar(
   } else if (aurora_channels->size() > 0) {
     src = (*aurora_channels)[srcAsInt];
   } else {
-    throw std::runtime_error("No Aurora channels found on FPGA");
+    logger->error("No Aurora channels found on FPGA");
+    return false;
+  }
+  if (!src) {
+    logger->error("Source does not exist");
+    return false;
   }
 
   if (dinoDac && dstType == ConnectType::DINO) {
@@ -185,6 +190,13 @@ void fpga::ConnectString::configCrossBar(
     dest = dma;
   } else if (aurora_channels->size() > 0) {
     dest = (*aurora_channels)[dstAsInt];
+  } else {
+    logger->error("No Aurora channels found on FPGA");
+    return false;
+  }
+  if (!dest) {
+    logger->error("Destination does not exist");
+    return false;
   }
 
   src->connect(src->getDefaultMasterPort(), dest->getDefaultSlavePort());

fpga/src/villas-fpga-ctrl.cpp

@@ -186,7 +186,10 @@ int main(int argc, char *argv[]) {
     // Configure Crossbar switch
     for (std::string str : connectStr) {
       const fpga::ConnectString parsedConnectString(str);
-      parsedConnectString.configCrossBar(card);
+      if (!parsedConnectString.configCrossBar(card)) {
+        logger->error("Failed to configure crossbar");
+        return -1;
+      }
       if (parsedConnectString.isSrcStdin()) {
         readFromStdin = true;
         if (parsedConnectString.isBidirectional()) {

lib/nodes/fpga.cpp

@@ -69,7 +69,10 @@ int FpgaNode::prepare() {
   // Configure Crossbar switch
   for (std::string str : connectStrings) {
     const fpga::ConnectString parsedConnectString(str);
-    parsedConnectString.configCrossBar(card);
+    if (!parsedConnectString.configCrossBar(card)) {
+      logger->error("Failed to configure crossbar");
+      return -1;
+    }
   }
 
   auto reg = std::dynamic_pointer_cast<fpga::ip::Register>(