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// Copyright (C) 2012-2014 Internet Systems Consortium, Inc. ("ISC")
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.
#include <config.h>
#include <asiolink/asiolink.h>
#include <cc/data.h>
#include <cc/session.h>
#include <config/ccsession.h>
#include <dhcp/iface_mgr.h>
#include <dhcp4/json_config_parser.h>
#include <dhcp4/ctrl_dhcp4_srv.h>
#include <dhcp4/dhcp4_log.h>
#include <dhcp4/spec_config.h>
#include <dhcpsrv/cfgmgr.h>
#include <dhcpsrv/dhcp_config_parser.h>
#include <exceptions/exceptions.h>
#include <hooks/hooks_manager.h>
#include <util/buffer.h>
#include <cassert>
#include <iostream>
#include <sstream>
#include <string>
#include <vector>
using namespace isc::asiolink;
using namespace isc::cc;
using namespace isc::config;
using namespace isc::data;
using namespace isc::dhcp;
using namespace isc::hooks;
using namespace isc::log;
using namespace isc::util;
using namespace std;
namespace isc {
namespace dhcp {
/// @brief Helper session object that represents raw connection to msgq.
isc::cc::Session* cc_session_ = NULL;
/// @brief Session that receives configuration and commands
isc::config::ModuleCCSession* config_session_ = NULL;
/// @brief A dummy configuration handler that always returns success.
///
/// This configuration handler does not perform configuration
/// parsing and always returns success. A dummy handler should
/// be installed using \ref isc::config::ModuleCCSession ctor
/// to get the initial configuration. This initial configuration
/// comprises values for only those elements that were modified
/// the previous session. The \ref dhcp4ConfigHandler can't be
/// used to parse the initial configuration because it needs the
/// full configuration to satisfy dependencies between the
/// various configuration values. Installing the dummy handler
/// that guarantees to return success causes initial configuration
/// to be stored for the session being created and that it can
/// be later accessed with
/// \ref isc::config::ConfigData::getFullConfig().
///
/// @param new_config new configuration.
///
/// @return success configuration status.
ConstElementPtr
dhcp4StubConfigHandler(ConstElementPtr) {
// This configuration handler is intended to be used only
// when the initial configuration comes in. To receive this
// configuration a pointer to this handler must be passed
// using ModuleCCSession constructor. This constructor will
// invoke the handler and will store the configuration for
// the configuration session when the handler returns success.
// Since this configuration is partial we just pretend to
// parse it and always return success. The function that
// initiates the session must get the configuration on its
// own using getFullConfig.
return (isc::config::createAnswer(0, "Configuration accepted."));
}
ConstElementPtr
bundyConfigHandler(ConstElementPtr new_config) {
if (!ControlledDhcpv4Srv::getInstance() || !config_session_) {
// That should never happen as we install config_handler
// after we instantiate the server.
ConstElementPtr answer =
isc::config::createAnswer(1, "Configuration rejected,"
" server is during startup/shutdown phase.");
return (answer);
}
// The configuration passed to this handler function is partial.
// In other words, it just includes the values being modified.
// In the same time, there are dependencies between various
// DHCP configuration parsers. For example: the option value can
// be set if the definition of this option is set. If someone removes
// an existing option definition then the partial configuration that
// removes that definition is triggered while a relevant option value
// may remain configured. This eventually results in the DHCP server
// configuration being in the inconsistent state.
// In order to work around this problem we need to merge the new
// configuration with the existing (full) configuration.
// Let's create a new object that will hold the merged configuration.
boost::shared_ptr<MapElement> merged_config(new MapElement());
// Let's get the existing configuration.
ConstElementPtr full_config = config_session_->getFullConfig();
// The full_config and merged_config should be always non-NULL
// but to provide some level of exception safety we check that they
// really are (in case we go out of memory).
if (full_config && merged_config) {
merged_config->setValue(full_config->mapValue());
// Merge an existing and new configuration.
isc::data::merge(merged_config, new_config);
LOG_DEBUG(dhcp4_logger, DBG_DHCP4_COMMAND, DHCP4_CONFIG_UPDATE)
.arg(full_config->str());
}
// Configure the server.
return (ControlledDhcpv4Srv::processConfig(merged_config));
}
void ControlledDhcpv4Srv::init(const std::string& config_file) {
// Call base class's init.
Daemon::init(config_file);
string specfile;
if (getenv("B10_FROM_BUILD")) {
specfile = string(getenv("B10_FROM_BUILD")) +
"/src/bin/dhcp4/dhcp4.spec";
} else {
specfile = string(DHCP4_SPECFILE_LOCATION);
}
/// @todo: Check if session is not established already. Throw, if it is.
LOG_DEBUG(dhcp4_logger, DBG_DHCP4_START, DHCP4_CCSESSION_STARTING)
.arg(specfile);
cc_session_ = new Session(io_service_.get_io_service());
// Create a session with the dummy configuration handler.
// Dumy configuration handler is internally invoked by the
// constructor and on success the constructor updates
// the current session with the configuration that had been
// committed in the previous session. If we did not install
// the dummy handler, the previous configuration would have
// been lost.
config_session_ = new ModuleCCSession(specfile, *cc_session_,
dhcp4StubConfigHandler,
processCommand, false);
config_session_->start();
// We initially create ModuleCCSession() without configHandler, as
// the session module is too eager to send partial configuration.
// We want to get the full configuration, so we explicitly call
// getFullConfig() and then pass it to our configHandler.
config_session_->setConfigHandler(bundyConfigHandler);
try {
configureDhcp4Server(*this, config_session_->getFullConfig());
// Server will start DDNS communications if its enabled.
server_->startD2();
// Configuration may disable or enable interfaces so we have to
// reopen sockets according to new configuration.
openActiveSockets(getPort(), useBroadcast());
} catch (const std::exception& ex) {
LOG_ERROR(dhcp4_logger, DHCP4_CONFIG_LOAD_FAIL).arg(ex.what());
}
/// Integrate the asynchronous I/O model of BIND 10 configuration
/// control with the "select" model of the DHCP server. This is
/// fully explained in \ref dhcpv4Session.
int ctrl_socket = cc_session_->getSocketDesc();
LOG_DEBUG(dhcp4_logger, DBG_DHCP4_START, DHCP4_CCSESSION_STARTED)
.arg(ctrl_socket);
IfaceMgr::instance().addExternalSocket(ctrl_socket, sessionReader);
}
void ControlledDhcpv4Srv::cleanup() {
if (config_session_) {
delete config_session_;
config_session_ = NULL;
}
if (cc_session_) {
int ctrl_socket = cc_session_->getSocketDesc();
cc_session_->disconnect();
IfaceMgr::instance().deleteExternalSocket(ctrl_socket);
delete cc_session_;
cc_session_ = NULL;
}
}
void
Daemon::loggerInit(const char* log_name, bool verbose) {
isc::log::initLogger(log_name,
(verbose ? isc::log::DEBUG : isc::log::INFO),
isc::log::MAX_DEBUG_LEVEL, NULL, true);
}
};
};
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