Some clean-ups and documentation.

dreibh · Oct 13, 2024 · 5337383 · 5337383
1 parent 3c32206
commit 5337383
Showing 1 changed file with 23 additions and 6 deletions.
diff --git a/src/iomodule-udp.cc b/src/iomodule-udp.cc
@@ -233,6 +233,20 @@ unsigned int UDPModule::sendRequest(const DestinationInfo& destination,
    }
 
    // ====== Message scatter/gather array ===================================
+#if defined(IP_HDRINCL) && defined(IPV6_HDRINCL)
+   const std::array<boost::asio::const_buffer, 3> buffer {
+      SourceAddress.is_v6() ? boost::asio::buffer(ipv6Header.data(), ipv6Header.size()) :
+                              boost::asio::buffer(ipv4Header.data(), ipv4Header.size()),
+      boost::asio::buffer(udpHeader.data(), udpHeader.size()),
+      boost::asio::buffer(tsHeader.data(),  tsHeader.size())
+   };
+#else
+   // NOTE:
+   // IP_HDRINCL and/or IPV6_HDRINCL is not available: This means that it is
+   // not possible to explicitly set the source IP address in the header here.
+   // This includes the UDP Pseudo Header for the checksum computation!
+   // Therefore, the UDPSocketEndpoint must be bound to a fixed IP address.
+   // (by option: --source <address>)
    std::vector<boost::asio::const_buffer> buffer;
    if(SourceAddress.is_v6()) {
       buffer = {
@@ -244,9 +258,10 @@ unsigned int UDPModule::sendRequest(const DestinationInfo& destination,
       };
 #if !defined(IPV6_HDRINCL)
       if(localEndpoint.address() != UDPSocketEndpoint.address()) {
-         HPCT_LOG(warning) << "Cannot set source IPv6 address without IPV6_HDRINCL! Explicitly set source address!\n"
-                           << "localEndpoint="     << localEndpoint.address()     << "\n"
-                           << "UDPSocketEndpoint=" << UDPSocketEndpoint.address() << "\n";
+         HPCT_LOG(error) << "Cannot set source IPv6 address without IPV6_HDRINCL! Explicitly set source address!\n"
+                         << "localEndpoint="     << localEndpoint.address()     << "\n"
+                         << "UDPSocketEndpoint=" << UDPSocketEndpoint.address() << "\n";
+         return 0;
       }
 #endif
    }
@@ -260,12 +275,14 @@ unsigned int UDPModule::sendRequest(const DestinationInfo& destination,
       };
 #if !defined(IP_HDRINCL)
       if(localEndpoint.address() != UDPSocketEndpoint.address()) {
-         HPCT_LOG(warning) << "Cannot set source IPv4 address without IP_HDRINCL! Explicitly set source address!\n"
-                           << "localEndpoint="     << localEndpoint.address()     << "\n"
-                           << "UDPSocketEndpoint=" << UDPSocketEndpoint.address() << "\n";
+         HPCT_LOG(error) << "Cannot set source IPv4 address without IP_HDRINCL! Explicitly set source address!\n"
+                         << "localEndpoint="     << localEndpoint.address()     << "\n"
+                         << "UDPSocketEndpoint=" << UDPSocketEndpoint.address() << "\n";
+         return 0;
       }
 #endif
    }
+#endif
 
    // ====== Prepare ResultEntry array ======================================
    const unsigned int        entries      = (1 + (toRound -fromRound)) * (1 + (fromTTL -toTTL));