[3203] Minor tweaks in v4 client classification

src/bin/dhcp4/dhcp4_srv.cc

@@ -1808,16 +1808,16 @@ void Dhcpv4Srv::classifyPacket(const Pkt4Ptr& pkt) {
     if (vendor_class->getValue().find("docsis3.0") != std::string::npos) {
         pkt->addClass("docsis3.0");
         classes += "docsis3.0 ";
-    }
-
+    } else
     if (vendor_class->getValue().find("eRouter1.0") != std::string::npos) {
         pkt->addClass("eRouter1.0");
         classes += "eRouter1.0 ";
+    }else
+    {
+        classes += vendor_class->getValue();
+        pkt->addClass(vendor_class->getValue());
     }
 
-    classes += vendor_class->getValue();
-    pkt->addClass(vendor_class->getValue());
-
     if (!classes.empty()) {
         LOG_DEBUG(dhcp4_logger, DBG_DHCP4_BASIC, DHCP4_CLASS_ASSIGNED)
             .arg(classes);
@@ -1833,10 +1833,12 @@ bool Dhcpv4Srv::classSpecificProcessing(const Pkt4Ptr& query, const Pkt4Ptr& rsp
 
     if (query->inClass("docsis3.0")) {
 
-        // set next-server
-        // @todo uncomment this once 3191 is merged
-        // rsp->setSiaddr(subnet->getSiaddr());
+        // Set next-server. This is TFTP server address. Cable modems will
+        // download their configuration from that server.
+        rsp->setSiaddr(subnet->getSiaddr());
 
+        // Now try to set up file field in DHCPv4 packet. We will just copy
+        // content of the boot-file option, which contains the same information.
         Subnet::OptionDescriptor desc =
             subnet->getOptionDescriptor("dhcp4", DHO_BOOT_FILE_NAME);
 
@@ -1852,7 +1854,8 @@ bool Dhcpv4Srv::classSpecificProcessing(const Pkt4Ptr& query, const Pkt4Ptr& rsp
 
     if (query->inClass("eRouter1.0")) {
 
-
+        // Do not set TFTP server address for eRouter devices.
+        rsp->setSiaddr(IOAddress("0.0.0.0"));
     }
 
     return (true);

src/bin/dhcp4/dhcp4_srv.h

@@ -517,7 +517,13 @@ protected:
                          const std::string& option_space,
                          isc::dhcp::OptionCollection& options);
 
-    /// @brief Assigns incoming packet to a given class
+    /// @brief Assigns incoming packet to zero or more classes.
+    ///
+    /// @note For now, the client classification is very simple. It just uses
+    /// content of the vendor-class-identifier option as a class. The resulting
+    /// class will be stored in packet (see @ref isc::dhcp::Pkt4::classes_ and
+    /// @ref isc::dhcp::Pkt4::inClass).
+    ///
     /// @param pkt packet to be classified
     void classifyPacket(const Pkt4Ptr& pkt);