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- /**
- * @page dhcpv4 DHCPv4 Server Component
- *
- * BIND10 offers DHCPv4 server implementation. It is implemented as
- * b10-dhcp4 component. Its primary code is located in
- * isc::dhcp::Dhcpv4Srv class. It uses \ref libdhcp extensively,
- * especially isc::dhcp::Pkt4, isc::dhcp::Option and
- * isc::dhcp::IfaceMgr classes. Currently this code offers skeleton
- * functionality, i.e. it is able to receive and process incoming
- * requests and trasmit responses. However, it does not have database
- * management, so it returns only one, hardcoded lease to whoever asks
- * for it.
- *
- * DHCPv4 server component does not support direct traffic (relayed
- * only), as support for transmission to hosts without IPv4 address
- * assigned is not implemented in IfaceMgr yet.
- *
- * DHCPv4 server component does not use BIND10 logging yet.
- *
- * @section dhcpv4Session BIND10 message queue integration
- *
- * DHCPv4 server component is now integrated with the BIND10 message queue.
- * The integration is performed by establishSession() and disconnectSession()
- * functions in isc::dhcp::ControlledDhcpv4Srv class. main() method deifined
- * in the src/bin/dhcp4/main.cc file instantiates isc::dhcp::ControlledDhcpv4Srv
- * class that establishes connection with msgq and install necessary handlers
- * for receiving commands and configuration updates. It is derived from
- * a base isc::dhcp::Dhcpv4Srv class that implements DHCPv4 server functionality,
- * without any controlling mechanisms.
- *
- * ControlledDhcpv4Srv instantiates several components to make management
- * session possible. In particular, isc::cc::Session cc_session
- * object uses ASIO for establishing connection. It registers its socket
- * in isc::asiolink::IOService io_service object. Typically, other components
- * (e.g. auth or resolver) that use ASIO for their communication, register their
- * other sockets in the
- * same io_service and then just call io_service.run() method that does
- * not return, until one of the callback decides that it is time to shut down
- * the whole component cal calls io_service.stop(). DHCPv4 works in a
- * different way. It does receive messages using select()
- * (see isc::dhcp::IfaceMgr::receive4()), which is incompatible with ASIO.
- * To solve this problem, socket descriptor is extracted from cc_session
- * object and is passed to IfaceMgr by using isc::dhcp::IfaceMgr::set_session_socket().
- * IfaceMgr then uses this socket in its select() call. If there is some
- * data to be read, it calls registered callback that is supposed to
- * read and process incoming data.
- *
- * This somewhat complicated approach is needed for a simple reason. In
- * embedded deployments there will be no message queue. Not referring directly
- * to anything related to message queue in isc::dhcp::Dhcpv4Srv and
- * isc::dhcp::IfaceMgr classes brings in two benefits. First, the can
- * be used with and without message queue. Second benefit is related to the
- * first one: \ref libdhcp is supposed to be simple and robust and not require
- * many dependencies. One notable example of a use case that benefits from
- * this approach is a perfdhcp tool. Finally, the idea is that it should be
- * possible to instantiate Dhcpv4Srv object directly, thus getting a server
- * that does not support msgq. That is useful for embedded environments.
- * It may also be useful in validation.
- *
- */
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