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// Copyright (C) 2014-2017 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
#include <config.h>
#include <cc/data.h>
#include <dhcp4/ctrl_dhcp4_srv.h>
#include <dhcp4/dhcp4_log.h>
#include <dhcp4/dhcp4to6_ipc.h>
#include <hooks/hooks_manager.h>
#include <dhcp4/json_config_parser.h>
#include <dhcpsrv/cfgmgr.h>
#include <dhcpsrv/cfg_db_access.h>
#include <config/command_mgr.h>
#include <stats/stats_mgr.h>
#include <cfgrpt/config_report.h>
using namespace isc::data;
using namespace isc::hooks;
using namespace isc::config;
using namespace isc::stats;
using namespace std;
namespace isc {
namespace dhcp {
ControlledDhcpv4Srv* ControlledDhcpv4Srv::server_ = NULL;
ConstElementPtr
ControlledDhcpv4Srv::commandShutdownHandler(const string&, ConstElementPtr) {
if (ControlledDhcpv4Srv::getInstance()) {
ControlledDhcpv4Srv::getInstance()->shutdown();
} else {
LOG_WARN(dhcp4_logger, DHCP4_NOT_RUNNING);
ConstElementPtr answer = isc::config::createAnswer(1,
"Shutdown failure.");
return (answer);
}
ConstElementPtr answer = isc::config::createAnswer(0, "Shutting down.");
return (answer);
}
ConstElementPtr
ControlledDhcpv4Srv::commandLibReloadHandler(const string&, ConstElementPtr) {
/// @todo delete any stored CalloutHandles referring to the old libraries
/// Get list of currently loaded libraries and reload them.
HookLibsCollection loaded = HooksManager::getLibraryInfo();
bool status = HooksManager::loadLibraries(loaded);
if (!status) {
LOG_ERROR(dhcp4_logger, DHCP4_HOOKS_LIBS_RELOAD_FAIL);
ConstElementPtr answer = isc::config::createAnswer(1,
"Failed to reload hooks libraries.");
return (answer);
}
ConstElementPtr answer = isc::config::createAnswer(0,
"Hooks libraries successfully reloaded.");
return (answer);
}
ConstElementPtr
ControlledDhcpv4Srv::commandConfigReloadHandler(const string&,
ConstElementPtr args) {
// Use set-config as it handles logging and server config
return (commandSetConfigHandler("set-config", args));
}
ConstElementPtr
ControlledDhcpv4Srv::commandConfigGetHandler(const string&,
ConstElementPtr /*args*/) {
ConstElementPtr config = CfgMgr::instance().getCurrentCfg()->toElement();
return (createAnswer(0, config));
}
ConstElementPtr
ControlledDhcpv4Srv::commandConfigWriteHandler(const string&,
ConstElementPtr args) {
string filename;
if (args) {
if (args->getType() != Element::map) {
return (createAnswer(CONTROL_RESULT_ERROR, "Argument must be a map"));
}
ConstElementPtr filename_param = args->get("filename");
if (filename_param) {
if (filename_param->getType() != Element::string) {
return (createAnswer(CONTROL_RESULT_ERROR,
"passed parameter 'filename' is not a string"));
}
filename = filename_param->stringValue();
}
}
if (filename.empty()) {
// filename parameter was not specified, so let's use whatever we remember
filename = getConfigFile();
if (filename.empty()) {
return (createAnswer(CONTROL_RESULT_ERROR, "Unable to determine filename."
"Please specify filename explicitly."));
}
}
// Now do the sanity checks on the filename
if (filename.find("..") != string::npos) {
// Trying to escape the directory.. nope.
return (createAnswer(CONTROL_RESULT_ERROR,
"Using '..' in filename is not allowed."));
}
if (filename.find("\\") != string::npos) {
// Trying to inject escapes (possibly to inject quotes and something
// nasty afterward)
return (createAnswer(CONTROL_RESULT_ERROR,
"Using \\ in filename is not allowed."));
}
if (filename[0] == '/') {
// Absolute paths are not allowed.
return (createAnswer(CONTROL_RESULT_ERROR,
"Absolute path in filename is not allowed."));
}
// Ok, it's time to write the file.
size_t size = 0;
try {
size = writeConfigFile(filename);
} catch (const isc::Exception& ex) {
return (createAnswer(CONTROL_RESULT_ERROR, string("Error during write-config:")
+ ex.what()));
}
if (size == 0) {
return (createAnswer(CONTROL_RESULT_ERROR, "Error writing configuration to "
+ filename));
}
// Ok, it's time to return the successful response.
ElementPtr params = Element::createMap();
params->set("size", Element::create(static_cast<long long>(size)));
params->set("filename", Element::create(filename));
return (createAnswer(CONTROL_RESULT_SUCCESS, "Configuration written to "
+ filename + " successful", params));
}
ConstElementPtr
ControlledDhcpv4Srv::commandSetConfigHandler(const string&,
ConstElementPtr args) {
const int status_code = 1; // 1 indicates an error
ConstElementPtr dhcp4;
string message;
// Command arguments are expected to be:
// { "Dhcp4": { ... }, "Logging": { ... } }
// The Logging component is technically optional. If it's not supplied
// logging will revert to default logging.
if (!args) {
message = "Missing mandatory 'arguments' parameter.";
} else {
dhcp4 = args->get("Dhcp4");
if (!dhcp4) {
message = "Missing mandatory 'Dhcp4' parameter.";
} else if (dhcp4->getType() != Element::map) {
message = "'Dhcp4' parameter expected to be a map.";
}
}
if (!message.empty()) {
// Something is amiss with arguments, return a failure response.
ConstElementPtr result = isc::config::createAnswer(status_code,
message);
return (result);
}
// We are starting the configuration process so we should remove any
// staging configuration that has been created during previous
// configuration attempts.
CfgMgr::instance().rollback();
// Logging is a sibling element and must be parsed explicitly.
// The call to configureLogger parses the given Logging element if
// not null, into the staging config. Note this does not alter the
// current loggers, they remain in effect until we apply the
// logging config below. If no logging is supplied logging will
// revert to default logging.
Daemon::configureLogger(args->get("Logging"),
CfgMgr::instance().getStagingCfg());
// Now we configure the server proper.
ConstElementPtr result = processConfig(dhcp4);
// If the configuration parsed successfully, apply the new logger
// configuration and the commit the new configuration. We apply
// the logging first in case there's a configuration failure.
int rcode = 0;
isc::config::parseAnswer(rcode, result);
if (rcode == 0) {
CfgMgr::instance().getStagingCfg()->applyLoggingCfg();
// Use new configuration.
CfgMgr::instance().commit();
}
return (result);
}
ConstElementPtr
ControlledDhcpv4Srv::commandVersionGetHandler(const string&, ConstElementPtr) {
ElementPtr extended = Element::create(Dhcpv4Srv::getVersion(true));
ElementPtr arguments = Element::createMap();
arguments->set("extended", extended);
ConstElementPtr answer = isc::config::createAnswer(0,
Dhcpv4Srv::getVersion(false),
arguments);
return (answer);
}
ConstElementPtr
ControlledDhcpv4Srv::commandBuildReportHandler(const string&,
ConstElementPtr) {
ConstElementPtr answer =
isc::config::createAnswer(0, isc::detail::getConfigReport());
return (answer);
}
ConstElementPtr
ControlledDhcpv4Srv::commandLeasesReclaimHandler(const string&,
ConstElementPtr args) {
int status_code = 1;
string message;
// args must be { "remove": <bool> }
if (!args) {
message = "Missing mandatory 'remove' parameter.";
} else {
ConstElementPtr remove_name = args->get("remove");
if (!remove_name) {
message = "Missing mandatory 'remove' parameter.";
} else if (remove_name->getType() != Element::boolean) {
message = "'remove' parameter expected to be a boolean.";
} else {
bool remove_lease = remove_name->boolValue();
server_->alloc_engine_->reclaimExpiredLeases4(0, 0, remove_lease);
status_code = 0;
message = "Reclamation of expired leases is complete.";
}
}
ConstElementPtr answer = isc::config::createAnswer(status_code, message);
return (answer);
}
ConstElementPtr
ControlledDhcpv4Srv::processCommand(const string& command,
ConstElementPtr args) {
LOG_DEBUG(dhcp4_logger, DBG_DHCP4_COMMAND, DHCP4_COMMAND_RECEIVED)
.arg(command).arg(args->str());
ControlledDhcpv4Srv* srv = ControlledDhcpv4Srv::getInstance();
if (!srv) {
ConstElementPtr no_srv = isc::config::createAnswer(1,
"Server object not initialized, so can't process command '" +
command + "', arguments: '" + args->str() + "'.");
return (no_srv);
}
try {
if (command == "shutdown") {
return (srv->commandShutdownHandler(command, args));
} else if (command == "libreload") {
return (srv->commandLibReloadHandler(command, args));
} else if (command == "config-reload") {
return (srv->commandConfigReloadHandler(command, args));
} else if (command == "set-config") {
return (srv->commandSetConfigHandler(command, args));
} else if (command == "config-get") {
return (srv->commandConfigGetHandler(command, args));
} else if (command == "version-get") {
return (srv->commandVersionGetHandler(command, args));
} else if (command == "build-report") {
return (srv->commandBuildReportHandler(command, args));
} else if (command == "leases-reclaim") {
return (srv->commandLeasesReclaimHandler(command, args));
} else if (command == "config-write") {
return (srv->commandConfigWriteHandler(command, args));
}
ConstElementPtr answer = isc::config::createAnswer(1,
"Unrecognized command:" + command);
return (answer);
} catch (const Exception& ex) {
return (isc::config::createAnswer(1, "Error while processing command '"
+ command + "':" + ex.what() +
", params: '" + args->str() + "'"));
}
}
isc::data::ConstElementPtr
ControlledDhcpv4Srv::processConfig(isc::data::ConstElementPtr config) {
LOG_DEBUG(dhcp4_logger, DBG_DHCP4_COMMAND, DHCP4_CONFIG_RECEIVED)
.arg(config->str());
ControlledDhcpv4Srv* srv = ControlledDhcpv4Srv::getInstance();
// Single stream instance used in all error clauses
std::ostringstream err;
if (!srv) {
err << "Server object not initialized, can't process config.";
return (isc::config::createAnswer(1, err.str()));
}
// We're going to modify the timers configuration. This is not allowed
// when the thread is running.
try {
TimerMgr::instance()->stopThread();
} catch (const std::exception& ex) {
err << "Unable to stop worker thread running timers: "
<< ex.what() << ".";
return (isc::config::createAnswer(1, err.str()));
}
ConstElementPtr answer = configureDhcp4Server(*srv, config);
// Check that configuration was successful. If not, do not reopen sockets
// and don't bother with DDNS stuff.
try {
int rcode = 0;
isc::config::parseAnswer(rcode, answer);
if (rcode != 0) {
return (answer);
}
} catch (const std::exception& ex) {
err << "Failed to process configuration:" << ex.what();
return (isc::config::createAnswer(1, err.str()));
}
// Re-open lease and host database with new parameters.
try {
CfgDbAccessPtr cfg_db = CfgMgr::instance().getStagingCfg()->getCfgDbAccess();
cfg_db->setAppendedParameters("universe=4");
cfg_db->createManagers();
} catch (const std::exception& ex) {
err << "Unable to open database: " << ex.what();
return (isc::config::createAnswer(1, err.str()));
}
// Server will start DDNS communications if its enabled.
try {
srv->startD2();
} catch (const std::exception& ex) {
err << "Error starting DHCP_DDNS client after server reconfiguration: "
<< ex.what();
return (isc::config::createAnswer(1, err.str()));
}
// Setup DHCPv4-over-DHCPv6 IPC
try {
Dhcp4to6Ipc::instance().open();
} catch (const std::exception& ex) {
std::ostringstream err;
err << "error starting DHCPv4-over-DHCPv6 IPC "
" after server reconfiguration: " << ex.what();
return (isc::config::createAnswer(1, err.str()));
}
// Configuration may change active interfaces. Therefore, we have to reopen
// sockets according to new configuration. It is possible that this
// operation will fail for some interfaces but the openSockets function
// guards against exceptions and invokes a callback function to
// log warnings. Since we allow that this fails for some interfaces there
// is no need to rollback configuration if socket fails to open on any
// of the interfaces.
CfgMgr::instance().getStagingCfg()->getCfgIface()->
openSockets(AF_INET, srv->getPort(), getInstance()->useBroadcast());
// Install the timers for handling leases reclamation.
try {
CfgMgr::instance().getStagingCfg()->getCfgExpiration()->
setupTimers(&ControlledDhcpv4Srv::reclaimExpiredLeases,
&ControlledDhcpv4Srv::deleteExpiredReclaimedLeases,
server_);
} catch (const std::exception& ex) {
err << "unable to setup timers for periodically running the"
" reclamation of the expired leases: "
<< ex.what() << ".";
return (isc::config::createAnswer(1, err.str()));
}
// Start worker thread if there are any timers installed.
if (TimerMgr::instance()->timersCount() > 0) {
try {
TimerMgr::instance()->startThread();
} catch (const std::exception& ex) {
err << "Unable to start worker thread running timers: "
<< ex.what() << ".";
return (isc::config::createAnswer(1, err.str()));
}
}
return (answer);
}
ControlledDhcpv4Srv::ControlledDhcpv4Srv(uint16_t port /*= DHCP4_SERVER_PORT*/)
: Dhcpv4Srv(port), io_service_(), timer_mgr_(TimerMgr::instance()) {
if (getInstance()) {
isc_throw(InvalidOperation,
"There is another Dhcpv4Srv instance already.");
}
server_ = this; // remember this instance for later use in handlers
// These are the commands always supported by the DHCPv4 server.
// Please keep the list in alphabetic order.
CommandMgr::instance().registerCommand("build-report",
boost::bind(&ControlledDhcpv4Srv::commandBuildReportHandler, this, _1, _2));
CommandMgr::instance().registerCommand("config-get",
boost::bind(&ControlledDhcpv4Srv::commandConfigGetHandler, this, _1, _2));
/// @todo: register config-reload (see CtrlDhcpv4Srv::commandConfigReloadHandler)
CommandMgr::instance().registerCommand("config-write",
boost::bind(&ControlledDhcpv4Srv::commandConfigWriteHandler, this, _1, _2));
CommandMgr::instance().registerCommand("libreload",
boost::bind(&ControlledDhcpv4Srv::commandLibReloadHandler, this, _1, _2));
CommandMgr::instance().registerCommand("leases-reclaim",
boost::bind(&ControlledDhcpv4Srv::commandLeasesReclaimHandler, this, _1, _2));
CommandMgr::instance().registerCommand("set-config",
boost::bind(&ControlledDhcpv4Srv::commandSetConfigHandler, this, _1, _2));
CommandMgr::instance().registerCommand("shutdown",
boost::bind(&ControlledDhcpv4Srv::commandShutdownHandler, this, _1, _2));
CommandMgr::instance().registerCommand("version-get",
boost::bind(&ControlledDhcpv4Srv::commandVersionGetHandler, this, _1, _2));
// Register statistic related commands
CommandMgr::instance().registerCommand("statistic-get",
boost::bind(&StatsMgr::statisticGetHandler, _1, _2));
CommandMgr::instance().registerCommand("statistic-reset",
boost::bind(&StatsMgr::statisticResetHandler, _1, _2));
CommandMgr::instance().registerCommand("statistic-remove",
boost::bind(&StatsMgr::statisticRemoveHandler, _1, _2));
CommandMgr::instance().registerCommand("statistic-get-all",
boost::bind(&StatsMgr::statisticGetAllHandler, _1, _2));
CommandMgr::instance().registerCommand("statistic-reset-all",
boost::bind(&StatsMgr::statisticResetAllHandler, _1, _2));
CommandMgr::instance().registerCommand("statistic-remove-all",
boost::bind(&StatsMgr::statisticRemoveAllHandler, _1, _2));
}
void ControlledDhcpv4Srv::shutdown() {
io_service_.stop(); // Stop ASIO transmissions
Dhcpv4Srv::shutdown(); // Initiate DHCPv4 shutdown procedure.
}
ControlledDhcpv4Srv::~ControlledDhcpv4Srv() {
try {
cleanup();
// Stop worker thread running timers, if it is running. Then
// unregister any timers.
timer_mgr_->stopThread();
timer_mgr_->unregisterTimers();
// Close the command socket (if it exists).
CommandMgr::instance().closeCommandSocket();
// Deregister any registered commands (please keep in alphabetic order)
CommandMgr::instance().deregisterCommand("build-report");
CommandMgr::instance().deregisterCommand("config-get");
CommandMgr::instance().deregisterCommand("config-write");
CommandMgr::instance().deregisterCommand("leases-reclaim");
CommandMgr::instance().deregisterCommand("libreload");
CommandMgr::instance().deregisterCommand("set-config");
CommandMgr::instance().deregisterCommand("shutdown");
CommandMgr::instance().deregisterCommand("statistic-get");
CommandMgr::instance().deregisterCommand("statistic-get-all");
CommandMgr::instance().deregisterCommand("statistic-remove");
CommandMgr::instance().deregisterCommand("statistic-remove-all");
CommandMgr::instance().deregisterCommand("statistic-reset");
CommandMgr::instance().deregisterCommand("statistic-reset-all");
CommandMgr::instance().deregisterCommand("version-get");
} catch (...) {
// Don't want to throw exceptions from the destructor. The server
// is shutting down anyway.
;
}
server_ = NULL; // forget this instance. Noone should call any handlers at
// this stage.
}
void ControlledDhcpv4Srv::sessionReader(void) {
// Process one asio event. If there are more events, iface_mgr will call
// this callback more than once.
if (getInstance()) {
getInstance()->io_service_.run_one();
}
}
void
ControlledDhcpv4Srv::reclaimExpiredLeases(const size_t max_leases,
const uint16_t timeout,
const bool remove_lease,
const uint16_t max_unwarned_cycles) {
server_->alloc_engine_->reclaimExpiredLeases4(max_leases, timeout,
remove_lease,
max_unwarned_cycles);
// We're using the ONE_SHOT timer so there is a need to re-schedule it.
TimerMgr::instance()->setup(CfgExpiration::RECLAIM_EXPIRED_TIMER_NAME);
}
void
ControlledDhcpv4Srv::deleteExpiredReclaimedLeases(const uint32_t secs) {
server_->alloc_engine_->deleteExpiredReclaimedLeases4(secs);
// We're using the ONE_SHOT timer so there is a need to re-schedule it.
TimerMgr::instance()->setup(CfgExpiration::FLUSH_RECLAIMED_TIMER_NAME);
}
}; // end of isc::dhcp namespace
}; // end of isc namespace
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