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Diffstat (limited to 'src/bin/dhcp4/dhcp4_srv.cc')
| -rw-r--r-- | src/bin/dhcp4/dhcp4_srv.cc | 4570 |
1 files changed, 4570 insertions, 0 deletions
diff --git a/src/bin/dhcp4/dhcp4_srv.cc b/src/bin/dhcp4/dhcp4_srv.cc new file mode 100644 index 0000000..ec1f56f --- /dev/null +++ b/src/bin/dhcp4/dhcp4_srv.cc @@ -0,0 +1,4570 @@ +// Copyright (C) 2011-2023 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 <kea_version.h> + +#include <dhcp/dhcp4.h> +#include <dhcp/duid.h> +#include <dhcp/hwaddr.h> +#include <dhcp/iface_mgr.h> +#include <dhcp/libdhcp++.h> +#include <dhcp/option4_addrlst.h> +#include <dhcp/option_custom.h> +#include <dhcp/option_int.h> +#include <dhcp/option_int_array.h> +#include <dhcp/option_vendor.h> +#include <dhcp/option_vendor_class.h> +#include <dhcp/option_string.h> +#include <dhcp/pkt4.h> +#include <dhcp/pkt4o6.h> +#include <dhcp/pkt6.h> +#include <dhcp/docsis3_option_defs.h> +#include <dhcp4/client_handler.h> +#include <dhcp4/dhcp4to6_ipc.h> +#include <dhcp4/dhcp4_log.h> +#include <dhcp4/dhcp4_srv.h> +#include <asiolink/addr_utilities.h> +#include <dhcpsrv/cfgmgr.h> +#include <dhcpsrv/cfg_host_operations.h> +#include <dhcpsrv/cfg_iface.h> +#include <dhcpsrv/cfg_shared_networks.h> +#include <dhcpsrv/cfg_subnets4.h> +#include <dhcpsrv/fuzz.h> +#include <dhcpsrv/lease_mgr.h> +#include <dhcpsrv/lease_mgr_factory.h> +#include <dhcpsrv/ncr_generator.h> +#include <dhcpsrv/shared_network.h> +#include <dhcpsrv/subnet.h> +#include <dhcpsrv/subnet_selector.h> +#include <dhcpsrv/utils.h> +#include <eval/evaluate.h> +#include <eval/eval_messages.h> +#include <hooks/callout_handle.h> +#include <hooks/hooks_log.h> +#include <hooks/hooks_manager.h> +#include <stats/stats_mgr.h> +#include <util/strutil.h> +#include <log/logger.h> +#include <cryptolink/cryptolink.h> +#include <process/cfgrpt/config_report.h> + +#ifdef HAVE_MYSQL +#include <dhcpsrv/mysql_lease_mgr.h> +#endif +#ifdef HAVE_PGSQL +#include <dhcpsrv/pgsql_lease_mgr.h> +#endif +#include <dhcpsrv/memfile_lease_mgr.h> + +#include <boost/algorithm/string.hpp> +#include <boost/foreach.hpp> +#include <boost/pointer_cast.hpp> +#include <boost/shared_ptr.hpp> + +#include <functional> +#include <iomanip> +#include <set> +#include <cstdlib> + +using namespace isc; +using namespace isc::asiolink; +using namespace isc::cryptolink; +using namespace isc::dhcp; +using namespace isc::dhcp_ddns; +using namespace isc::hooks; +using namespace isc::log; +using namespace isc::stats; +using namespace isc::util; +using namespace std; +namespace ph = std::placeholders; + +namespace { + +/// Structure that holds registered hook indexes +struct Dhcp4Hooks { + int hook_index_buffer4_receive_; ///< index for "buffer4_receive" hook point + int hook_index_pkt4_receive_; ///< index for "pkt4_receive" hook point + int hook_index_subnet4_select_; ///< index for "subnet4_select" hook point + int hook_index_leases4_committed_; ///< index for "leases4_committed" hook point + int hook_index_lease4_release_; ///< index for "lease4_release" hook point + int hook_index_pkt4_send_; ///< index for "pkt4_send" hook point + int hook_index_buffer4_send_; ///< index for "buffer4_send" hook point + int hook_index_lease4_decline_; ///< index for "lease4_decline" hook point + int hook_index_host4_identifier_; ///< index for "host4_identifier" hook point + int hook_index_ddns4_update_; ///< index for "ddns4_update" hook point + + /// Constructor that registers hook points for DHCPv4 engine + Dhcp4Hooks() { + hook_index_buffer4_receive_ = HooksManager::registerHook("buffer4_receive"); + hook_index_pkt4_receive_ = HooksManager::registerHook("pkt4_receive"); + hook_index_subnet4_select_ = HooksManager::registerHook("subnet4_select"); + hook_index_leases4_committed_ = HooksManager::registerHook("leases4_committed"); + hook_index_lease4_release_ = HooksManager::registerHook("lease4_release"); + hook_index_pkt4_send_ = HooksManager::registerHook("pkt4_send"); + hook_index_buffer4_send_ = HooksManager::registerHook("buffer4_send"); + hook_index_lease4_decline_ = HooksManager::registerHook("lease4_decline"); + hook_index_host4_identifier_ = HooksManager::registerHook("host4_identifier"); + hook_index_ddns4_update_ = HooksManager::registerHook("ddns4_update"); + } +}; + +/// List of statistics which is initialized to 0 during the DHCPv4 +/// server startup. +std::set<std::string> dhcp4_statistics = { + "pkt4-received", + "pkt4-discover-received", + "pkt4-offer-received", + "pkt4-request-received", + "pkt4-ack-received", + "pkt4-nak-received", + "pkt4-release-received", + "pkt4-decline-received", + "pkt4-inform-received", + "pkt4-unknown-received", + "pkt4-sent", + "pkt4-offer-sent", + "pkt4-ack-sent", + "pkt4-nak-sent", + "pkt4-parse-failed", + "pkt4-receive-drop", + "v4-allocation-fail", + "v4-allocation-fail-shared-network", + "v4-allocation-fail-subnet", + "v4-allocation-fail-no-pools", + "v4-allocation-fail-classes", + "v4-reservation-conflicts", + "v4-lease-reuses", +}; + +} // end of anonymous namespace + +// Declare a Hooks object. As this is outside any function or method, it +// will be instantiated (and the constructor run) when the module is loaded. +// As a result, the hook indexes will be defined before any method in this +// module is called. +Dhcp4Hooks Hooks; + +namespace isc { +namespace dhcp { + +Dhcpv4Exchange::Dhcpv4Exchange(const AllocEnginePtr& alloc_engine, + const Pkt4Ptr& query, + AllocEngine::ClientContext4Ptr& context, + const Subnet4Ptr& subnet, + bool& drop) + : alloc_engine_(alloc_engine), query_(query), resp_(), + context_(context) { + + if (!alloc_engine_) { + isc_throw(BadValue, "alloc_engine value must not be NULL" + " when creating an instance of the Dhcpv4Exchange"); + } + + if (!query_) { + isc_throw(BadValue, "query value must not be NULL when" + " creating an instance of the Dhcpv4Exchange"); + } + + // Reset the given context argument. + context.reset(); + + // Create response message. + initResponse(); + // Select subnet for the query message. + context_->subnet_ = subnet; + + // If subnet found, retrieve client identifier which will be needed + // for allocations and search for reservations associated with a + // subnet/shared network. + SharedNetwork4Ptr sn; + if (subnet && !context_->early_global_reservations_lookup_) { + OptionPtr opt_clientid = query->getOption(DHO_DHCP_CLIENT_IDENTIFIER); + if (opt_clientid) { + context_->clientid_.reset(new ClientId(opt_clientid->getData())); + } + } + + if (subnet) { + // Find static reservations if not disabled for our subnet. + if (subnet->getReservationsInSubnet() || + subnet->getReservationsGlobal()) { + // Before we can check for static reservations, we need to prepare a set + // of identifiers to be used for this. + if (!context_->early_global_reservations_lookup_) { + setHostIdentifiers(context_); + } + + // Check for static reservations. + alloc_engine->findReservation(*context_); + + // Get shared network to see if it is set for a subnet. + subnet->getSharedNetwork(sn); + } + } + + // Global host reservations are independent of a selected subnet. If the + // global reservations contain client classes we should use them in case + // they are meant to affect pool selection. Also, if the subnet does not + // belong to a shared network we can use the reserved client classes + // because there is no way our subnet could change. Such classes may + // affect selection of a pool within the selected subnet. + auto global_host = context_->globalHost(); + auto current_host = context_->currentHost(); + if ((!context_->early_global_reservations_lookup_ && + global_host && !global_host->getClientClasses4().empty()) || + (!sn && current_host && !current_host->getClientClasses4().empty())) { + // We have already evaluated client classes and some of them may + // be in conflict with the reserved classes. Suppose there are + // two classes defined in the server configuration: first_class + // and second_class and the test for the second_class it looks + // like this: "not member('first_class')". If the first_class + // initially evaluates to false, the second_class evaluates to + // true. If the first_class is now set within the hosts reservations + // and we don't remove the previously evaluated second_class we'd + // end up with both first_class and second_class evaluated to + // true. In order to avoid that, we have to remove the classes + // evaluated in the first pass and evaluate them again. As + // a result, the first_class set via the host reservation will + // replace the second_class because the second_class will this + // time evaluate to false as desired. + removeDependentEvaluatedClasses(query); + setReservedClientClasses(context_); + evaluateClasses(query, false); + } + + // Set KNOWN builtin class if something was found, UNKNOWN if not. + if (!context_->hosts_.empty()) { + query->addClass("KNOWN"); + LOG_DEBUG(dhcp4_logger, DBG_DHCP4_BASIC, DHCP4_CLASS_ASSIGNED) + .arg(query->getLabel()) + .arg("KNOWN"); + } else { + query->addClass("UNKNOWN"); + LOG_DEBUG(dhcp4_logger, DBG_DHCP4_BASIC, DHCP4_CLASS_ASSIGNED) + .arg(query->getLabel()) + .arg("UNKNOWN"); + } + + // Perform second pass of classification. + evaluateClasses(query, true); + + const ClientClasses& classes = query_->getClasses(); + if (!classes.empty()) { + LOG_DEBUG(dhcp4_logger, DBG_DHCP4_BASIC, DHCP4_CLASS_ASSIGNED) + .arg(query_->getLabel()) + .arg(classes.toText()); + } + + // Check the DROP special class. + if (query_->inClass("DROP")) { + LOG_DEBUG(packet4_logger, DBGLVL_PKT_HANDLING, DHCP4_PACKET_DROP_0013) + .arg(query_->getHWAddrLabel()) + .arg(query_->toText()); + isc::stats::StatsMgr::instance().addValue("pkt4-receive-drop", + static_cast<int64_t>(1)); + drop = true; + } +} + +void +Dhcpv4Exchange::initResponse() { + uint8_t resp_type = 0; + switch (getQuery()->getType()) { + case DHCPDISCOVER: + resp_type = DHCPOFFER; + break; + case DHCPREQUEST: + case DHCPINFORM: + resp_type = DHCPACK; + break; + default: + ; + } + // Only create a response if one is required. + if (resp_type > 0) { + resp_.reset(new Pkt4(resp_type, getQuery()->getTransid())); + copyDefaultFields(); + copyDefaultOptions(); + + if (getQuery()->isDhcp4o6()) { + initResponse4o6(); + } + } +} + +void +Dhcpv4Exchange::initResponse4o6() { + Pkt4o6Ptr query = boost::dynamic_pointer_cast<Pkt4o6>(getQuery()); + if (!query) { + return; + } + const Pkt6Ptr& query6 = query->getPkt6(); + Pkt6Ptr resp6(new Pkt6(DHCPV6_DHCPV4_RESPONSE, query6->getTransid())); + // Don't add client-id or server-id + // But copy relay info + if (!query6->relay_info_.empty()) { + resp6->copyRelayInfo(query6); + } + // Copy interface, and remote address and port + resp6->setIface(query6->getIface()); + resp6->setIndex(query6->getIndex()); + resp6->setRemoteAddr(query6->getRemoteAddr()); + resp6->setRemotePort(query6->getRemotePort()); + resp_.reset(new Pkt4o6(resp_, resp6)); +} + +void +Dhcpv4Exchange::copyDefaultFields() { + resp_->setIface(query_->getIface()); + resp_->setIndex(query_->getIndex()); + + // explicitly set this to 0 + resp_->setSiaddr(IOAddress::IPV4_ZERO_ADDRESS()); + // ciaddr is always 0, except for the Renew/Rebind state and for + // Inform when it may be set to the ciaddr sent by the client. + if (query_->getType() == DHCPINFORM) { + resp_->setCiaddr(query_->getCiaddr()); + } else { + resp_->setCiaddr(IOAddress::IPV4_ZERO_ADDRESS()); + } + resp_->setHops(query_->getHops()); + + // copy MAC address + resp_->setHWAddr(query_->getHWAddr()); + + // relay address + resp_->setGiaddr(query_->getGiaddr()); + + // If src/dest HW addresses are used by the packet filtering class + // we need to copy them as well. There is a need to check that the + // address being set is not-NULL because an attempt to set the NULL + // HW would result in exception. If these values are not set, the + // the default HW addresses (zeroed) should be generated by the + // packet filtering class when creating Ethernet header for + // outgoing packet. + HWAddrPtr src_hw_addr = query_->getLocalHWAddr(); + if (src_hw_addr) { + resp_->setLocalHWAddr(src_hw_addr); + } + HWAddrPtr dst_hw_addr = query_->getRemoteHWAddr(); + if (dst_hw_addr) { + resp_->setRemoteHWAddr(dst_hw_addr); + } + + // Copy flags from the request to the response per RFC 2131 + resp_->setFlags(query_->getFlags()); +} + +void +Dhcpv4Exchange::copyDefaultOptions() { + // Let's copy client-id to response. See RFC6842. + // It is possible to disable RFC6842 to keep backward compatibility + bool echo = CfgMgr::instance().getCurrentCfg()->getEchoClientId(); + OptionPtr client_id = query_->getOption(DHO_DHCP_CLIENT_IDENTIFIER); + if (client_id && echo) { + resp_->addOption(client_id); + } + + // If this packet is relayed, we want to copy Relay Agent Info option + // when it is not empty. + OptionPtr rai = query_->getOption(DHO_DHCP_AGENT_OPTIONS); + if (rai && (rai->len() > Option::OPTION4_HDR_LEN)) { + resp_->addOption(rai); + } + + // RFC 3011 states about the Subnet Selection Option + + // "Servers configured to support this option MUST return an + // identical copy of the option to any client that sends it, + // regardless of whether or not the client requests the option in + // a parameter request list. Clients using this option MUST + // discard DHCPOFFER or DHCPACK packets that do not contain this + // option." + OptionPtr subnet_sel = query_->getOption(DHO_SUBNET_SELECTION); + if (subnet_sel) { + resp_->addOption(subnet_sel); + } +} + +void +Dhcpv4Exchange::setHostIdentifiers(AllocEngine::ClientContext4Ptr context) { + const ConstCfgHostOperationsPtr cfg = + CfgMgr::instance().getCurrentCfg()->getCfgHostOperations4(); + + // Collect host identifiers. The identifiers are stored in order of preference. + // The server will use them in that order to search for host reservations. + BOOST_FOREACH(const Host::IdentifierType& id_type, + cfg->getIdentifierTypes()) { + switch (id_type) { + case Host::IDENT_HWADDR: + if (context->hwaddr_ && !context->hwaddr_->hwaddr_.empty()) { + context->addHostIdentifier(id_type, context->hwaddr_->hwaddr_); + } + break; + + case Host::IDENT_DUID: + if (context->clientid_) { + const std::vector<uint8_t>& vec = context->clientid_->getClientId(); + if (!vec.empty()) { + // Client identifier type = DUID? Client identifier holding a DUID + // comprises Type (1 byte), IAID (4 bytes), followed by the actual + // DUID. Thus, the minimal length is 6. + if ((vec[0] == CLIENT_ID_OPTION_TYPE_DUID) && (vec.size() > 5)) { + // Extract DUID, skip IAID. + context->addHostIdentifier(id_type, + std::vector<uint8_t>(vec.begin() + 5, + vec.end())); + } + } + } + break; + + case Host::IDENT_CIRCUIT_ID: + { + OptionPtr rai = context->query_->getOption(DHO_DHCP_AGENT_OPTIONS); + if (rai) { + OptionPtr circuit_id_opt = rai->getOption(RAI_OPTION_AGENT_CIRCUIT_ID); + if (circuit_id_opt) { + const OptionBuffer& circuit_id_vec = circuit_id_opt->getData(); + if (!circuit_id_vec.empty()) { + context->addHostIdentifier(id_type, circuit_id_vec); + } + } + } + } + break; + + case Host::IDENT_CLIENT_ID: + if (context->clientid_) { + const std::vector<uint8_t>& vec = context->clientid_->getClientId(); + if (!vec.empty()) { + context->addHostIdentifier(id_type, vec); + } + } + break; + case Host::IDENT_FLEX: + { + if (!HooksManager::calloutsPresent(Hooks.hook_index_host4_identifier_)) { + break; + } + + CalloutHandlePtr callout_handle = getCalloutHandle(context->query_); + + Host::IdentifierType type = Host::IDENT_FLEX; + std::vector<uint8_t> id; + + // Use the RAII wrapper to make sure that the callout handle state is + // reset when this object goes out of scope. All hook points must do + // it to prevent possible circular dependency between the callout + // handle and its arguments. + ScopedCalloutHandleState callout_handle_state(callout_handle); + + // Pass incoming packet as argument + callout_handle->setArgument("query4", context->query_); + callout_handle->setArgument("id_type", type); + callout_handle->setArgument("id_value", id); + + // Call callouts + HooksManager::callCallouts(Hooks.hook_index_host4_identifier_, + *callout_handle); + + callout_handle->getArgument("id_type", type); + callout_handle->getArgument("id_value", id); + + if ((callout_handle->getStatus() == CalloutHandle::NEXT_STEP_CONTINUE) && + !id.empty()) { + + LOG_DEBUG(packet4_logger, DBGLVL_TRACE_BASIC, DHCP4_FLEX_ID) + .arg(Host::getIdentifierAsText(type, &id[0], id.size())); + + context->addHostIdentifier(type, id); + } + break; + } + default: + ; + } + } +} + +void +Dhcpv4Exchange::removeDependentEvaluatedClasses(const Pkt4Ptr& query) { + const ClientClassDictionaryPtr& dict = + CfgMgr::instance().getCurrentCfg()->getClientClassDictionary(); + const ClientClassDefListPtr& defs_ptr = dict->getClasses(); + for (auto def : *defs_ptr) { + // Only remove evaluated classes. Other classes can be + // assigned via hooks libraries and we should not remove + // them because there is no way they can be added back. + if (def->getMatchExpr()) { + query->classes_.erase(def->getName()); + } + } +} + +void +Dhcpv4Exchange::setReservedClientClasses(AllocEngine::ClientContext4Ptr context) { + if (context->currentHost() && context->query_) { + const ClientClasses& classes = context->currentHost()->getClientClasses4(); + for (ClientClasses::const_iterator cclass = classes.cbegin(); + cclass != classes.cend(); ++cclass) { + context->query_->addClass(*cclass); + } + } +} + +void +Dhcpv4Exchange::conditionallySetReservedClientClasses() { + if (context_->subnet_) { + SharedNetwork4Ptr shared_network; + context_->subnet_->getSharedNetwork(shared_network); + if (shared_network) { + ConstHostPtr host = context_->currentHost(); + if (host && (host->getIPv4SubnetID() != SUBNET_ID_GLOBAL)) { + setReservedClientClasses(context_); + } + } + } +} + +void +Dhcpv4Exchange::setReservedMessageFields() { + ConstHostPtr host = context_->currentHost(); + // Nothing to do if host reservations not specified for this client. + if (host) { + if (!host->getNextServer().isV4Zero()) { + resp_->setSiaddr(host->getNextServer()); + } + + std::string sname = host->getServerHostname(); + if (!sname.empty()) { + resp_->setSname(reinterpret_cast<const uint8_t*>(sname.c_str()), + sname.size()); + } + + std::string bootfile = host->getBootFileName(); + if (!bootfile.empty()) { + resp_->setFile(reinterpret_cast<const uint8_t*>(bootfile.c_str()), + bootfile.size()); + } + } +} + +void Dhcpv4Exchange::classifyByVendor(const Pkt4Ptr& pkt) { + // Built-in vendor class processing + boost::shared_ptr<OptionString> vendor_class = + boost::dynamic_pointer_cast<OptionString>(pkt->getOption(DHO_VENDOR_CLASS_IDENTIFIER)); + + if (!vendor_class) { + return; + } + + pkt->addClass(Dhcpv4Srv::VENDOR_CLASS_PREFIX + vendor_class->getValue()); +} + +void Dhcpv4Exchange::classifyPacket(const Pkt4Ptr& pkt) { + // All packets belong to ALL. + pkt->addClass("ALL"); + + // First: built-in vendor class processing. + classifyByVendor(pkt); + + // Run match expressions on classes not depending on KNOWN/UNKNOWN. + evaluateClasses(pkt, false); +} + +void Dhcpv4Exchange::evaluateClasses(const Pkt4Ptr& pkt, bool depend_on_known) { + // Note getClientClassDictionary() cannot be null + const ClientClassDictionaryPtr& dict = + CfgMgr::instance().getCurrentCfg()->getClientClassDictionary(); + const ClientClassDefListPtr& defs_ptr = dict->getClasses(); + for (ClientClassDefList::const_iterator it = defs_ptr->cbegin(); + it != defs_ptr->cend(); ++it) { + // Note second cannot be null + const ExpressionPtr& expr_ptr = (*it)->getMatchExpr(); + // Nothing to do without an expression to evaluate + if (!expr_ptr) { + continue; + } + // Not the right time if only when required + if ((*it)->getRequired()) { + continue; + } + // Not the right pass. + if ((*it)->getDependOnKnown() != depend_on_known) { + continue; + } + (*it)->test(pkt, expr_ptr); + } +} + +const std::string Dhcpv4Srv::VENDOR_CLASS_PREFIX("VENDOR_CLASS_"); + +Dhcpv4Srv::Dhcpv4Srv(uint16_t server_port, uint16_t client_port, + const bool use_bcast, const bool direct_response_desired) + : io_service_(new IOService()), server_port_(server_port), + client_port_(client_port), shutdown_(true), + alloc_engine_(), use_bcast_(use_bcast), + network_state_(new NetworkState(NetworkState::DHCPv4)), + cb_control_(new CBControlDHCPv4()), + test_send_responses_to_source_(false) { + + const char* env = std::getenv("KEA_TEST_SEND_RESPONSES_TO_SOURCE"); + if (env) { + LOG_WARN(dhcp4_logger, DHCP4_TESTING_MODE_SEND_TO_SOURCE_ENABLED); + test_send_responses_to_source_ = true; + } + + LOG_DEBUG(dhcp4_logger, DBG_DHCP4_START, DHCP4_OPEN_SOCKET) + .arg(server_port); + + try { + // Port 0 is used for testing purposes where we don't open broadcast + // capable sockets. So, set the packet filter handling direct traffic + // only if we are in non-test mode. + if (server_port) { + // First call to instance() will create IfaceMgr (it's a singleton) + // it may throw something if things go wrong. + // The 'true' value of the call to setMatchingPacketFilter imposes + // that IfaceMgr will try to use the mechanism to respond directly + // to the client which doesn't have address assigned. This capability + // may be lacking on some OSes, so there is no guarantee that server + // will be able to respond directly. + IfaceMgr::instance().setMatchingPacketFilter(direct_response_desired); + } + + // Instantiate allocation engine. The number of allocation attempts equal + // to zero indicates that the allocation engine will use the number of + // attempts depending on the pool size. + alloc_engine_.reset(new AllocEngine(0)); + + /// @todo call loadLibraries() when handling configuration changes + + } catch (const std::exception &e) { + LOG_ERROR(dhcp4_logger, DHCP4_SRV_CONSTRUCT_ERROR).arg(e.what()); + shutdown_ = true; + return; + } + + // Initializing all observations with default value + setPacketStatisticsDefaults(); + shutdown_ = false; +} + +void Dhcpv4Srv::setPacketStatisticsDefaults() { + isc::stats::StatsMgr& stats_mgr = isc::stats::StatsMgr::instance(); + + // Iterate over set of observed statistics + for (auto it = dhcp4_statistics.begin(); it != dhcp4_statistics.end(); ++it) { + // Initialize them with default value 0 + stats_mgr.setValue((*it), static_cast<int64_t>(0)); + } +} + +Dhcpv4Srv::~Dhcpv4Srv() { + // Discard any parked packets + discardPackets(); + + try { + stopD2(); + } catch (const std::exception& ex) { + // Highly unlikely, but lets Report it but go on + LOG_ERROR(dhcp4_logger, DHCP4_SRV_D2STOP_ERROR).arg(ex.what()); + } + + try { + Dhcp4to6Ipc::instance().close(); + } catch (const std::exception& ex) { + // Highly unlikely, but lets Report it but go on + LOG_ERROR(dhcp4_logger, DHCP4_SRV_DHCP4O6_ERROR).arg(ex.what()); + } + + IfaceMgr::instance().closeSockets(); + + // The lease manager was instantiated during DHCPv4Srv configuration, + // so we should clean up after ourselves. + LeaseMgrFactory::destroy(); + + // Explicitly unload hooks + HooksManager::prepareUnloadLibraries(); + if (!HooksManager::unloadLibraries()) { + auto names = HooksManager::getLibraryNames(); + std::string msg; + if (!names.empty()) { + msg = names[0]; + for (size_t i = 1; i < names.size(); ++i) { + msg += std::string(", ") + names[i]; + } + } + LOG_ERROR(dhcp4_logger, DHCP4_SRV_UNLOAD_LIBRARIES_ERROR).arg(msg); + } +} + +void +Dhcpv4Srv::shutdown() { + LOG_DEBUG(dhcp4_logger, DBG_DHCP4_BASIC, DHCP4_SHUTDOWN_REQUEST); + shutdown_ = true; +} + +isc::dhcp::Subnet4Ptr +Dhcpv4Srv::selectSubnet(const Pkt4Ptr& query, bool& drop, + bool sanity_only) const { + + // DHCPv4-over-DHCPv6 is a special (and complex) case + if (query->isDhcp4o6()) { + return (selectSubnet4o6(query, drop, sanity_only)); + } + + Subnet4Ptr subnet; + + const SubnetSelector& selector = CfgSubnets4::initSelector(query); + + CfgMgr& cfgmgr = CfgMgr::instance(); + subnet = cfgmgr.getCurrentCfg()->getCfgSubnets4()->selectSubnet(selector); + + // Let's execute all callouts registered for subnet4_select + // (skip callouts if the selectSubnet was called to do sanity checks only) + if (!sanity_only && + HooksManager::calloutsPresent(Hooks.hook_index_subnet4_select_)) { + CalloutHandlePtr callout_handle = getCalloutHandle(query); + + // Use the RAII wrapper to make sure that the callout handle state is + // reset when this object goes out of scope. All hook points must do + // it to prevent possible circular dependency between the callout + // handle and its arguments. + ScopedCalloutHandleState callout_handle_state(callout_handle); + + // Enable copying options from the packet within hook library. + ScopedEnableOptionsCopy<Pkt4> query4_options_copy(query); + + // Set new arguments + callout_handle->setArgument("query4", query); + callout_handle->setArgument("subnet4", subnet); + callout_handle->setArgument("subnet4collection", + cfgmgr.getCurrentCfg()-> + getCfgSubnets4()->getAll()); + + // Call user (and server-side) callouts + HooksManager::callCallouts(Hooks.hook_index_subnet4_select_, + *callout_handle); + + // Callouts decided to skip this step. This means that no subnet + // will be selected. Packet processing will continue, but it will + // be severely limited (i.e. only global options will be assigned) + if (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_SKIP) { + LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS, + DHCP4_HOOK_SUBNET4_SELECT_SKIP) + .arg(query->getLabel()); + return (Subnet4Ptr()); + } + + // Callouts decided to drop the packet. It is a superset of the + // skip case so no subnet will be selected. + if (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_DROP) { + LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS, + DHCP4_HOOK_SUBNET4_SELECT_DROP) + .arg(query->getLabel()); + drop = true; + return (Subnet4Ptr()); + } + + // Use whatever subnet was specified by the callout + callout_handle->getArgument("subnet4", subnet); + } + + if (subnet) { + // Log at higher debug level that subnet has been found. + LOG_DEBUG(packet4_logger, DBG_DHCP4_BASIC_DATA, DHCP4_SUBNET_SELECTED) + .arg(query->getLabel()) + .arg(subnet->getID()); + // Log detailed information about the selected subnet at the + // lower debug level. + LOG_DEBUG(packet4_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_SUBNET_DATA) + .arg(query->getLabel()) + .arg(subnet->toText()); + + } else { + LOG_DEBUG(packet4_logger, DBG_DHCP4_DETAIL, + DHCP4_SUBNET_SELECTION_FAILED) + .arg(query->getLabel()); + } + + return (subnet); +} + +isc::dhcp::Subnet4Ptr +Dhcpv4Srv::selectSubnet4o6(const Pkt4Ptr& query, bool& drop, + bool sanity_only) const { + Subnet4Ptr subnet; + + SubnetSelector selector; + selector.ciaddr_ = query->getCiaddr(); + selector.giaddr_ = query->getGiaddr(); + selector.local_address_ = query->getLocalAddr(); + selector.client_classes_ = query->classes_; + selector.iface_name_ = query->getIface(); + // Mark it as DHCPv4-over-DHCPv6 + selector.dhcp4o6_ = true; + // Now the DHCPv6 part + selector.remote_address_ = query->getRemoteAddr(); + selector.first_relay_linkaddr_ = IOAddress("::"); + + // Handle a DHCPv6 relayed query + Pkt4o6Ptr query4o6 = boost::dynamic_pointer_cast<Pkt4o6>(query); + if (!query4o6) { + isc_throw(Unexpected, "Can't get DHCP4o6 message"); + } + const Pkt6Ptr& query6 = query4o6->getPkt6(); + + // Initialize fields specific to relayed messages. + if (query6 && !query6->relay_info_.empty()) { + BOOST_REVERSE_FOREACH(Pkt6::RelayInfo relay, query6->relay_info_) { + if (!relay.linkaddr_.isV6Zero() && + !relay.linkaddr_.isV6LinkLocal()) { + selector.first_relay_linkaddr_ = relay.linkaddr_; + break; + } + } + selector.interface_id_ = + query6->getAnyRelayOption(D6O_INTERFACE_ID, + Pkt6::RELAY_GET_FIRST); + } + + // If the Subnet Selection option is present, extract its value. + OptionPtr sbnsel = query->getOption(DHO_SUBNET_SELECTION); + if (sbnsel) { + OptionCustomPtr oc = boost::dynamic_pointer_cast<OptionCustom>(sbnsel); + if (oc) { + selector.option_select_ = oc->readAddress(); + } + } + + CfgMgr& cfgmgr = CfgMgr::instance(); + subnet = cfgmgr.getCurrentCfg()->getCfgSubnets4()->selectSubnet4o6(selector); + + // Let's execute all callouts registered for subnet4_select. + // (skip callouts if the selectSubnet was called to do sanity checks only) + if (!sanity_only && + HooksManager::calloutsPresent(Hooks.hook_index_subnet4_select_)) { + CalloutHandlePtr callout_handle = getCalloutHandle(query); + + // Use the RAII wrapper to make sure that the callout handle state is + // reset when this object goes out of scope. All hook points must do + // it to prevent possible circular dependency between the callout + // handle and its arguments. + ScopedCalloutHandleState callout_handle_state(callout_handle); + + // Set new arguments + callout_handle->setArgument("query4", query); + callout_handle->setArgument("subnet4", subnet); + callout_handle->setArgument("subnet4collection", + cfgmgr.getCurrentCfg()-> + getCfgSubnets4()->getAll()); + + // Call user (and server-side) callouts + HooksManager::callCallouts(Hooks.hook_index_subnet4_select_, + *callout_handle); + + // Callouts decided to skip this step. This means that no subnet + // will be selected. Packet processing will continue, but it will + // be severely limited (i.e. only global options will be assigned) + if (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_SKIP) { + LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS, + DHCP4_DHCP4O6_HOOK_SUBNET4_SELECT_SKIP) + .arg(query->getLabel()); + return (Subnet4Ptr()); + } + + // Callouts decided to drop the packet. It is a superset of the + // skip case so no subnet will be selected. + if (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_DROP) { + LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS, + DHCP4_DHCP4O6_HOOK_SUBNET4_SELECT_DROP) + .arg(query->getLabel()); + drop = true; + return (Subnet4Ptr()); + } + + // Use whatever subnet was specified by the callout + callout_handle->getArgument("subnet4", subnet); + } + + if (subnet) { + // Log at higher debug level that subnet has been found. + LOG_DEBUG(packet4_logger, DBG_DHCP4_BASIC_DATA, + DHCP4_DHCP4O6_SUBNET_SELECTED) + .arg(query->getLabel()) + .arg(subnet->getID()); + // Log detailed information about the selected subnet at the + // lower debug level. + LOG_DEBUG(packet4_logger, DBG_DHCP4_DETAIL_DATA, + DHCP4_DHCP4O6_SUBNET_DATA) + .arg(query->getLabel()) + .arg(subnet->toText()); + + } else { + LOG_DEBUG(packet4_logger, DBG_DHCP4_DETAIL, + DHCP4_DHCP4O6_SUBNET_SELECTION_FAILED) + .arg(query->getLabel()); + } + + return (subnet); +} + +Pkt4Ptr +Dhcpv4Srv::receivePacket(int timeout) { + return (IfaceMgr::instance().receive4(timeout)); +} + +void +Dhcpv4Srv::sendPacket(const Pkt4Ptr& packet) { + IfaceMgr::instance().send(packet); +} + +bool +Dhcpv4Srv::earlyGHRLookup(const Pkt4Ptr& query, + AllocEngine::ClientContext4Ptr ctx) { + // Pointer to client's query. + ctx->query_ = query; + + // Hardware address. + ctx->hwaddr_ = query->getHWAddr(); + + // Get the early-global-reservations-lookup flag value. + data::ConstElementPtr egrl = CfgMgr::instance().getCurrentCfg()-> + getConfiguredGlobal(CfgGlobals::EARLY_GLOBAL_RESERVATIONS_LOOKUP); + if (egrl) { + ctx->early_global_reservations_lookup_ = egrl->boolValue(); + } + + // Perform early global reservations lookup when wanted. + if (ctx->early_global_reservations_lookup_) { + // Retrieve retrieve client identifier. + OptionPtr opt_clientid = query->getOption(DHO_DHCP_CLIENT_IDENTIFIER); + if (opt_clientid) { + ctx->clientid_.reset(new ClientId(opt_clientid->getData())); + } + + // Get the host identifiers. + Dhcpv4Exchange::setHostIdentifiers(ctx); + + // Check for global host reservations. + ConstHostPtr global_host = alloc_engine_->findGlobalReservation(*ctx); + + if (global_host && !global_host->getClientClasses4().empty()) { + // Remove dependent evaluated classes. + Dhcpv4Exchange::removeDependentEvaluatedClasses(query); + + // Add classes from the global reservations. + const ClientClasses& classes = global_host->getClientClasses4(); + for (ClientClasses::const_iterator cclass = classes.cbegin(); + cclass != classes.cend(); ++cclass) { + query->addClass(*cclass); + } + + // Evaluate classes before KNOWN. + Dhcpv4Exchange::evaluateClasses(query, false); + } + + if (global_host) { + // Add the KNOWN class; + query->addClass("KNOWN"); + LOG_DEBUG(dhcp4_logger, DBG_DHCP4_BASIC, DHCP4_CLASS_ASSIGNED) + .arg(query->getLabel()) + .arg("KNOWN"); + + // Evaluate classes after KNOWN. + Dhcpv4Exchange::evaluateClasses(query, true); + + // Check the DROP special class. + if (query->inClass("DROP")) { + LOG_DEBUG(packet4_logger, DBGLVL_PKT_HANDLING, + DHCP4_PACKET_DROP_0014) + .arg(query->getHWAddrLabel()) + .arg(query->toText()); + isc::stats::StatsMgr::instance().addValue("pkt4-receive-drop", + static_cast<int64_t>(1)); + return (false); + } + + // Store the reservation. + ctx->hosts_[SUBNET_ID_GLOBAL] = global_host; + } + } + + return (true); +} + +int +Dhcpv4Srv::run() { +#ifdef ENABLE_AFL + // Set up structures needed for fuzzing. + Fuzz fuzzer(4, server_port_); + // + // The next line is needed as a signature for AFL to recognize that we are + // running persistent fuzzing. This has to be in the main image file. + while (__AFL_LOOP(fuzzer.maxLoopCount())) { + // Read from stdin and put the data read into an address/port on which + // Kea is listening, read for Kea to read it via asynchronous I/O. + fuzzer.transfer(); +#else + while (!shutdown_) { +#endif // ENABLE_AFL + try { + run_one(); + getIOService()->poll(); + } catch (const std::exception& e) { + // General catch-all exception that are not caught by more specific + // catches. This one is for exceptions derived from std::exception. + LOG_ERROR(packet4_logger, DHCP4_PACKET_PROCESS_STD_EXCEPTION) + .arg(e.what()); + } catch (...) { + // General catch-all exception that are not caught by more specific + // catches. This one is for other exceptions, not derived from + // std::exception. + LOG_ERROR(packet4_logger, DHCP4_PACKET_PROCESS_EXCEPTION); + } + } + + // Stop everything before we change into single-threaded mode. + MultiThreadingCriticalSection cs; + + // destroying the thread pool + MultiThreadingMgr::instance().apply(false, 0, 0); + + return (getExitValue()); +} + +void +Dhcpv4Srv::run_one() { + // client's message and server's response + Pkt4Ptr query; + + try { + // Set select() timeout to 1s. This value should not be modified + // because it is important that the select() returns control + // frequently so as the IOService can be polled for ready handlers. + uint32_t timeout = 1; + query = receivePacket(timeout); + + // Log if packet has arrived. We can't log the detailed information + // about the DHCP message because it hasn't been unpacked/parsed + // yet, and it can't be parsed at this point because hooks will + // have to process it first. The only information available at this + // point are: the interface, source address and destination addresses + // and ports. + if (query) { + LOG_DEBUG(packet4_logger, DBG_DHCP4_BASIC, DHCP4_BUFFER_RECEIVED) + .arg(query->getRemoteAddr().toText()) + .arg(query->getRemotePort()) + .arg(query->getLocalAddr().toText()) + .arg(query->getLocalPort()) + .arg(query->getIface()); + } + + // We used to log that the wait was interrupted, but this is no longer + // the case. Our wait time is 1s now, so the lack of query packet more + // likely means that nothing new appeared within a second, rather than + // we were interrupted. And we don't want to print a message every + // second. + + } catch (const SignalInterruptOnSelect&) { + // Packet reception interrupted because a signal has been received. + // This is not an error because we might have received a SIGTERM, + // SIGINT, SIGHUP or SIGCHLD which are handled by the server. For + // signals that are not handled by the server we rely on the default + // behavior of the system. + LOG_DEBUG(packet4_logger, DBG_DHCP4_DETAIL, DHCP4_BUFFER_WAIT_SIGNAL); + } catch (const std::exception& e) { + // Log all other errors. + LOG_ERROR(packet4_logger, DHCP4_BUFFER_RECEIVE_FAIL).arg(e.what()); + } + + // Timeout may be reached or signal received, which breaks select() + // with no reception occurred. No need to log anything here because + // we have logged right after the call to receivePacket(). + if (!query) { + return; + } + + // If the DHCP service has been globally disabled, drop the packet. + if (!network_state_->isServiceEnabled()) { + LOG_DEBUG(bad_packet4_logger, DBGLVL_PKT_HANDLING, DHCP4_PACKET_DROP_0008) + .arg(query->getLabel()); + return; + } else { + if (MultiThreadingMgr::instance().getMode()) { + typedef function<void()> CallBack; + boost::shared_ptr<CallBack> call_back = + boost::make_shared<CallBack>(std::bind(&Dhcpv4Srv::processPacketAndSendResponseNoThrow, + this, query)); + if (!MultiThreadingMgr::instance().getThreadPool().add(call_back)) { + LOG_DEBUG(dhcp4_logger, DBG_DHCP4_BASIC, DHCP4_PACKET_QUEUE_FULL); + } + } else { + processPacketAndSendResponse(query); + } + } +} + +void +Dhcpv4Srv::processPacketAndSendResponseNoThrow(Pkt4Ptr& query) { + try { + processPacketAndSendResponse(query); + } catch (const std::exception& e) { + LOG_ERROR(packet4_logger, DHCP4_PACKET_PROCESS_STD_EXCEPTION) + .arg(e.what()); + } catch (...) { + LOG_ERROR(packet4_logger, DHCP4_PACKET_PROCESS_EXCEPTION); + } +} + +void +Dhcpv4Srv::processPacketAndSendResponse(Pkt4Ptr& query) { + Pkt4Ptr rsp; + processPacket(query, rsp); + if (!rsp) { + return; + } + + CalloutHandlePtr callout_handle = getCalloutHandle(query); + processPacketBufferSend(callout_handle, rsp); +} + +void +Dhcpv4Srv::processPacket(Pkt4Ptr& query, Pkt4Ptr& rsp, bool allow_packet_park) { + // All packets belong to ALL. + query->addClass("ALL"); + + // Log reception of the packet. We need to increase it early, as any + // failures in unpacking will cause the packet to be dropped. We + // will increase type specific statistic further down the road. + // See processStatsReceived(). + isc::stats::StatsMgr::instance().addValue("pkt4-received", + static_cast<int64_t>(1)); + + bool skip_unpack = false; + + // The packet has just been received so contains the uninterpreted wire + // data; execute callouts registered for buffer4_receive. + if (HooksManager::calloutsPresent(Hooks.hook_index_buffer4_receive_)) { + CalloutHandlePtr callout_handle = getCalloutHandle(query); + + // Use the RAII wrapper to make sure that the callout handle state is + // reset when this object goes out of scope. All hook points must do + // it to prevent possible circular dependency between the callout + // handle and its arguments. + ScopedCalloutHandleState callout_handle_state(callout_handle); + + // Enable copying options from the packet within hook library. + ScopedEnableOptionsCopy<Pkt4> query4_options_copy(query); + + // Pass incoming packet as argument + callout_handle->setArgument("query4", query); + + // Call callouts + HooksManager::callCallouts(Hooks.hook_index_buffer4_receive_, + *callout_handle); + + // Callouts decided to drop the received packet. + // The response (rsp) is null so the caller (run_one) will + // immediately return too. + if (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_DROP) { + LOG_DEBUG(hooks_logger, DBGLVL_PKT_HANDLING, + DHCP4_HOOK_BUFFER_RCVD_DROP) + .arg(query->getRemoteAddr().toText()) + .arg(query->getLocalAddr().toText()) + .arg(query->getIface()); + return; + } + + // Callouts decided to skip the next processing step. The next + // processing step would be to parse the packet, so skip at this + // stage means that callouts did the parsing already, so server + // should skip parsing. + if (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_SKIP) { + LOG_DEBUG(hooks_logger, DBG_DHCP4_DETAIL, + DHCP4_HOOK_BUFFER_RCVD_SKIP) + .arg(query->getRemoteAddr().toText()) + .arg(query->getLocalAddr().toText()) + .arg(query->getIface()); + skip_unpack = true; + } + + callout_handle->getArgument("query4", query); + } + + // Unpack the packet information unless the buffer4_receive callouts + // indicated they did it + if (!skip_unpack) { + try { + LOG_DEBUG(options4_logger, DBG_DHCP4_DETAIL, DHCP4_BUFFER_UNPACK) + .arg(query->getRemoteAddr().toText()) + .arg(query->getLocalAddr().toText()) + .arg(query->getIface()); + query->unpack(); + } catch (const SkipRemainingOptionsError& e) { + // An option failed to unpack but we are to attempt to process it + // anyway. Log it and let's hope for the best. + LOG_DEBUG(options4_logger, DBG_DHCP4_DETAIL, + DHCP4_PACKET_OPTIONS_SKIPPED) + .arg(e.what()); + } catch (const std::exception& e) { + // Failed to parse the packet. + LOG_DEBUG(bad_packet4_logger, DBGLVL_PKT_HANDLING, DHCP4_PACKET_DROP_0001) + .arg(query->getRemoteAddr().toText()) + .arg(query->getLocalAddr().toText()) + .arg(query->getIface()) + .arg(e.what()) + .arg(query->getHWAddrLabel()); + + // Increase the statistics of parse failures and dropped packets. + isc::stats::StatsMgr::instance().addValue("pkt4-parse-failed", + static_cast<int64_t>(1)); + isc::stats::StatsMgr::instance().addValue("pkt4-receive-drop", + static_cast<int64_t>(1)); + return; + } + } + + // Update statistics accordingly for received packet. + processStatsReceived(query); + + // Assign this packet to one or more classes if needed. We need to do + // this before calling accept(), because getSubnet4() may need client + // class information. + classifyPacket(query); + + // Now it is classified the deferred unpacking can be done. + deferredUnpack(query); + + // Check whether the message should be further processed or discarded. + // There is no need to log anything here. This function logs by itself. + if (!accept(query)) { + // Increase the statistic of dropped packets. + isc::stats::StatsMgr::instance().addValue("pkt4-receive-drop", + static_cast<int64_t>(1)); + return; + } + + // We have sanity checked (in accept() that the Message Type option + // exists, so we can safely get it here. + int type = query->getType(); + LOG_DEBUG(packet4_logger, DBG_DHCP4_BASIC_DATA, DHCP4_PACKET_RECEIVED) + .arg(query->getLabel()) + .arg(query->getName()) + .arg(type) + .arg(query->getRemoteAddr()) + .arg(query->getLocalAddr()) + .arg(query->getIface()); + LOG_DEBUG(packet4_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_QUERY_DATA) + .arg(query->getLabel()) + .arg(query->toText()); + + // Let's execute all callouts registered for pkt4_receive + if (HooksManager::calloutsPresent(Hooks.hook_index_pkt4_receive_)) { + CalloutHandlePtr callout_handle = getCalloutHandle(query); + + // Use the RAII wrapper to make sure that the callout handle state is + // reset when this object goes out of scope. All hook points must do + // it to prevent possible circular dependency between the callout + // handle and its arguments. + ScopedCalloutHandleState callout_handle_state(callout_handle); + + // Enable copying options from the packet within hook library. + ScopedEnableOptionsCopy<Pkt4> query4_options_copy(query); + + // Pass incoming packet as argument + callout_handle->setArgument("query4", query); + + // Call callouts + HooksManager::callCallouts(Hooks.hook_index_pkt4_receive_, + *callout_handle); + + // Callouts decided to skip the next processing step. The next + // processing step would be to process the packet, so skip at this + // stage means drop. + if ((callout_handle->getStatus() == CalloutHandle::NEXT_STEP_SKIP) || + (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_DROP)) { + LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS, + DHCP4_HOOK_PACKET_RCVD_SKIP) + .arg(query->getLabel()); + return; + } + + callout_handle->getArgument("query4", query); + } + + // Check the DROP special class. + if (query->inClass("DROP")) { + LOG_DEBUG(packet4_logger, DBGLVL_PKT_HANDLING, DHCP4_PACKET_DROP_0010) + .arg(query->getHWAddrLabel()) + .arg(query->toText()); + isc::stats::StatsMgr::instance().addValue("pkt4-receive-drop", + static_cast<int64_t>(1)); + return; + } + + processDhcp4Query(query, rsp, allow_packet_park); +} + +void +Dhcpv4Srv::processDhcp4QueryAndSendResponse(Pkt4Ptr& query, Pkt4Ptr& rsp, + bool allow_packet_park) { + try { + processDhcp4Query(query, rsp, allow_packet_park); + if (!rsp) { + return; + } + + CalloutHandlePtr callout_handle = getCalloutHandle(query); + processPacketBufferSend(callout_handle, rsp); + } catch (const std::exception& e) { + LOG_ERROR(packet4_logger, DHCP4_PACKET_PROCESS_STD_EXCEPTION) + .arg(e.what()); + } catch (...) { + LOG_ERROR(packet4_logger, DHCP4_PACKET_PROCESS_EXCEPTION); + } +} + +void +Dhcpv4Srv::processDhcp4Query(Pkt4Ptr& query, Pkt4Ptr& rsp, + bool allow_packet_park) { + // Create a client race avoidance RAII handler. + ClientHandler client_handler; + + // Check for lease modifier queries from the same client being processed. + if (MultiThreadingMgr::instance().getMode() && + ((query->getType() == DHCPDISCOVER) || + (query->getType() == DHCPREQUEST) || + (query->getType() == DHCPRELEASE) || + (query->getType() == DHCPDECLINE))) { + ContinuationPtr cont = + makeContinuation(std::bind(&Dhcpv4Srv::processDhcp4QueryAndSendResponse, + this, query, rsp, allow_packet_park)); + if (!client_handler.tryLock(query, cont)) { + return; + } + } + + AllocEngine::ClientContext4Ptr ctx(new AllocEngine::ClientContext4()); + if (!earlyGHRLookup(query, ctx)) { + return; + } + + try { + switch (query->getType()) { + case DHCPDISCOVER: + rsp = processDiscover(query, ctx); + break; + + case DHCPREQUEST: + // Note that REQUEST is used for many things in DHCPv4: for + // requesting new leases, renewing existing ones and even + // for rebinding. + rsp = processRequest(query, ctx); + break; + + case DHCPRELEASE: + processRelease(query, ctx); + break; + + case DHCPDECLINE: + processDecline(query, ctx); + break; + + case DHCPINFORM: + rsp = processInform(query, ctx); + break; + + default: + // Only action is to output a message if debug is enabled, + // and that is covered by the debug statement before the + // "switch" statement. + ; + } + } catch (const std::exception& e) { + + // Catch-all exception (we used to call only isc::Exception, but + // std::exception could potentially be raised and if we don't catch + // it here, it would be caught in main() and the process would + // terminate). Just log the problem and ignore the packet. + // (The problem is logged as a debug message because debug is + // disabled by default - it prevents a DDOS attack based on the + // sending of problem packets.) + LOG_DEBUG(bad_packet4_logger, DBGLVL_PKT_HANDLING, DHCP4_PACKET_DROP_0007) + .arg(query->getLabel()) + .arg(e.what()); + + // Increase the statistic of dropped packets. + isc::stats::StatsMgr::instance().addValue("pkt4-receive-drop", + static_cast<int64_t>(1)); + } + + CalloutHandlePtr callout_handle = getCalloutHandle(query); + if (ctx && HooksManager::calloutsPresent(Hooks.hook_index_leases4_committed_)) { + // The ScopedCalloutHandleState class which guarantees that the task + // is added to the thread pool after the response is reset (if needed) + // and CalloutHandle state is reset. In ST it does nothing. + // A smart pointer is used to store the ScopedCalloutHandleState so that + // a copy of the pointer is created by the lambda and only on the + // destruction of the last reference the task is added. + // In MT there are 2 cases: + // 1. packet is unparked before current thread smart pointer to + // ScopedCalloutHandleState is destroyed: + // - the lambda uses the smart pointer to set the callout which adds the + // task, but the task is added after ScopedCalloutHandleState is + // destroyed, on the destruction of the last reference which is held + // by the current thread. + // 2. packet is unparked after the current thread smart pointer to + // ScopedCalloutHandleState is destroyed: + // - the current thread reference to ScopedCalloutHandleState is + // destroyed, but the reference in the lambda keeps it alive until + // the lambda is called and the last reference is released, at which + // time the task is actually added. + // Use the RAII wrapper to make sure that the callout handle state is + // reset when this object goes out of scope. All hook points must do + // it to prevent possible circular dependency between the callout + // handle and its arguments. + std::shared_ptr<ScopedCalloutHandleState> callout_handle_state = + std::make_shared<ScopedCalloutHandleState>(callout_handle); + + ScopedEnableOptionsCopy<Pkt4> query4_options_copy(query); + + // Also pass the corresponding query packet as argument + callout_handle->setArgument("query4", query); + + Lease4CollectionPtr new_leases(new Lease4Collection()); + // Filter out the new lease if it was reused so not committed. + if (ctx->new_lease_ && (ctx->new_lease_->reuseable_valid_lft_ == 0)) { + new_leases->push_back(ctx->new_lease_); + } + callout_handle->setArgument("leases4", new_leases); + + Lease4CollectionPtr deleted_leases(new Lease4Collection()); + if (ctx->old_lease_) { + if ((!ctx->new_lease_) || (ctx->new_lease_->addr_ != ctx->old_lease_->addr_)) { + deleted_leases->push_back(ctx->old_lease_); + } + } + callout_handle->setArgument("deleted_leases4", deleted_leases); + + if (allow_packet_park) { + // Get the parking limit. Parsing should ensure the value is present. + uint32_t parked_packet_limit = 0; + data::ConstElementPtr ppl = CfgMgr::instance().getCurrentCfg()-> + getConfiguredGlobal(CfgGlobals::PARKED_PACKET_LIMIT); + if (ppl) { + parked_packet_limit = ppl->intValue(); + } + + if (parked_packet_limit) { + const auto& parking_lot = ServerHooks::getServerHooks(). + getParkingLotPtr("leases4_committed"); + + if (parking_lot && (parking_lot->size() >= parked_packet_limit)) { + // We can't park it so we're going to throw it on the floor. + LOG_DEBUG(packet4_logger, DBGLVL_PKT_HANDLING, + DHCP4_HOOK_LEASES4_PARKING_LOT_FULL) + .arg(parked_packet_limit) + .arg(query->getLabel()); + isc::stats::StatsMgr::instance().addValue("pkt4-receive-drop", + static_cast<int64_t>(1)); + rsp.reset(); + return; + } + } + + // We proactively park the packet. We'll unpark it without invoking + // the callback (i.e. drop) unless the callout status is set to + // NEXT_STEP_PARK. Otherwise the callback we bind here will be + // executed when the hook library unparks the packet. + HooksManager::park("leases4_committed", query, + [this, callout_handle, query, rsp, callout_handle_state]() mutable { + if (MultiThreadingMgr::instance().getMode()) { + typedef function<void()> CallBack; + boost::shared_ptr<CallBack> call_back = + boost::make_shared<CallBack>(std::bind(&Dhcpv4Srv::sendResponseNoThrow, + this, callout_handle, query, rsp)); + callout_handle_state->on_completion_ = [call_back]() { + MultiThreadingMgr::instance().getThreadPool().add(call_back); + }; + } else { + processPacketPktSend(callout_handle, query, rsp); + processPacketBufferSend(callout_handle, rsp); + } + }); + } + + try { + // Call all installed callouts + HooksManager::callCallouts(Hooks.hook_index_leases4_committed_, + *callout_handle); + } catch (...) { + // Make sure we don't orphan a parked packet. + if (allow_packet_park) { + HooksManager::drop("leases4_committed", query); + } + + throw; + } + + if ((callout_handle->getStatus() == CalloutHandle::NEXT_STEP_PARK) + && allow_packet_park) { + LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS, DHCP4_HOOK_LEASES4_COMMITTED_PARK) + .arg(query->getLabel()); + // Since the hook library(ies) are going to do the unparking, then + // reset the pointer to the response to indicate to the caller that + // it should return, as the packet processing will continue via + // the callback. + rsp.reset(); + } else { + // Drop the park job on the packet, it isn't needed. + HooksManager::drop("leases4_committed", query); + if (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_DROP) { + LOG_DEBUG(hooks_logger, DBGLVL_PKT_HANDLING, DHCP4_HOOK_LEASES4_COMMITTED_DROP) + .arg(query->getLabel()); + rsp.reset(); + } + } + } + + // If we have a response prep it for shipment. + if (rsp) { + processPacketPktSend(callout_handle, query, rsp); + } +} + +void +Dhcpv4Srv::sendResponseNoThrow(hooks::CalloutHandlePtr& callout_handle, + Pkt4Ptr& query, Pkt4Ptr& rsp) { + try { + processPacketPktSend(callout_handle, query, rsp); + processPacketBufferSend(callout_handle, rsp); + } catch (const std::exception& e) { + LOG_ERROR(packet4_logger, DHCP4_PACKET_PROCESS_STD_EXCEPTION) + .arg(e.what()); + } catch (...) { + LOG_ERROR(packet4_logger, DHCP4_PACKET_PROCESS_EXCEPTION); + } +} + +void +Dhcpv4Srv::processPacketPktSend(hooks::CalloutHandlePtr& callout_handle, + Pkt4Ptr& query, Pkt4Ptr& rsp) { + if (!rsp) { + return; + } + + // Specifies if server should do the packing + bool skip_pack = false; + + // Execute all callouts registered for pkt4_send + if (HooksManager::calloutsPresent(Hooks.hook_index_pkt4_send_)) { + + // Use the RAII wrapper to make sure that the callout handle state is + // reset when this object goes out of scope. All hook points must do + // it to prevent possible circular dependency between the callout + // handle and its arguments. + ScopedCalloutHandleState callout_handle_state(callout_handle); + + // Enable copying options from the query and response packets within + // hook library. + ScopedEnableOptionsCopy<Pkt4> query_resp_options_copy(query, rsp); + + // Pass incoming packet as argument + callout_handle->setArgument("query4", query); + + // Set our response + callout_handle->setArgument("response4", rsp); + + // Call all installed callouts + HooksManager::callCallouts(Hooks.hook_index_pkt4_send_, + *callout_handle); + + // Callouts decided to skip the next processing step. The next + // processing step would be to pack the packet (create wire data). + // That step will be skipped if any callout sets skip flag. + // It essentially means that the callout already did packing, + // so the server does not have to do it again. + if (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_SKIP) { + LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS, DHCP4_HOOK_PACKET_SEND_SKIP) + .arg(query->getLabel()); + skip_pack = true; + } + + /// Callouts decided to drop the packet. + if (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_DROP) { + LOG_DEBUG(hooks_logger, DBGLVL_PKT_HANDLING, DHCP4_HOOK_PACKET_SEND_DROP) + .arg(rsp->getLabel()); + rsp.reset(); + return; + } + } + + if (!skip_pack) { + try { + LOG_DEBUG(options4_logger, DBG_DHCP4_DETAIL, DHCP4_PACKET_PACK) + .arg(rsp->getLabel()); + rsp->pack(); + } catch (const std::exception& e) { + LOG_ERROR(options4_logger, DHCP4_PACKET_PACK_FAIL) + .arg(rsp->getLabel()) + .arg(e.what()); + } + } +} + +void +Dhcpv4Srv::processPacketBufferSend(CalloutHandlePtr& callout_handle, + Pkt4Ptr& rsp) { + if (!rsp) { + return; + } + + try { + // Now all fields and options are constructed into output wire buffer. + // Option objects modification does not make sense anymore. Hooks + // can only manipulate wire buffer at this stage. + // Let's execute all callouts registered for buffer4_send + if (HooksManager::calloutsPresent(Hooks.hook_index_buffer4_send_)) { + + // Use the RAII wrapper to make sure that the callout handle state is + // reset when this object goes out of scope. All hook points must do + // it to prevent possible circular dependency between the callout + // handle and its arguments. + ScopedCalloutHandleState callout_handle_state(callout_handle); + + // Enable copying options from the packet within hook library. + ScopedEnableOptionsCopy<Pkt4> resp4_options_copy(rsp); + + // Pass incoming packet as argument + callout_handle->setArgument("response4", rsp); + + // Call callouts + HooksManager::callCallouts(Hooks.hook_index_buffer4_send_, + *callout_handle); + + // Callouts decided to skip the next processing step. The next + // processing step would be to parse the packet, so skip at this + // stage means drop. + if ((callout_handle->getStatus() == CalloutHandle::NEXT_STEP_SKIP) || + (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_DROP)) { + LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS, + DHCP4_HOOK_BUFFER_SEND_SKIP) + .arg(rsp->getLabel()); + return; + } + + callout_handle->getArgument("response4", rsp); + } + + LOG_DEBUG(packet4_logger, DBG_DHCP4_BASIC, DHCP4_PACKET_SEND) + .arg(rsp->getLabel()) + .arg(rsp->getName()) + .arg(static_cast<int>(rsp->getType())) + .arg(rsp->getLocalAddr().isV4Zero() ? "*" : rsp->getLocalAddr().toText()) + .arg(rsp->getLocalPort()) + .arg(rsp->getRemoteAddr()) + .arg(rsp->getRemotePort()) + .arg(rsp->getIface().empty() ? "to be determined from routing" : + rsp->getIface()); + + LOG_DEBUG(packet4_logger, DBG_DHCP4_DETAIL_DATA, + DHCP4_RESPONSE_DATA) + .arg(rsp->getLabel()) + .arg(rsp->getName()) + .arg(static_cast<int>(rsp->getType())) + .arg(rsp->toText()); + sendPacket(rsp); + + // Update statistics accordingly for sent packet. + processStatsSent(rsp); + + } catch (const std::exception& e) { + LOG_ERROR(packet4_logger, DHCP4_PACKET_SEND_FAIL) + .arg(rsp->getLabel()) + .arg(e.what()); + } +} + +string +Dhcpv4Srv::srvidToString(const OptionPtr& srvid) { + if (!srvid) { + isc_throw(BadValue, "NULL pointer passed to srvidToString()"); + } + boost::shared_ptr<Option4AddrLst> generated = + boost::dynamic_pointer_cast<Option4AddrLst>(srvid); + if (!srvid) { + isc_throw(BadValue, "Pointer to invalid option passed to srvidToString()"); + } + + Option4AddrLst::AddressContainer addrs = generated->getAddresses(); + if (addrs.size() != 1) { + isc_throw(BadValue, "Malformed option passed to srvidToString(). " + << "Expected to contain a single IPv4 address."); + } + + return (addrs[0].toText()); +} + +void +Dhcpv4Srv::appendServerID(Dhcpv4Exchange& ex) { + + // Do not append generated server identifier if there is one appended already. + // This is when explicitly configured server identifier option is present. + if (ex.getResponse()->getOption(DHO_DHCP_SERVER_IDENTIFIER)) { + return; + } + + // Use local address on which the packet has been received as a + // server identifier. In some cases it may be a different address, + // e.g. broadcast packet or DHCPv4o6 packet. + IOAddress local_addr = ex.getQuery()->getLocalAddr(); + Pkt4Ptr query = ex.getQuery(); + + if (local_addr.isV4Bcast() || query->isDhcp4o6()) { + local_addr = IfaceMgr::instance().getSocket(query).addr_; + } + + OptionPtr opt_srvid(new Option4AddrLst(DHO_DHCP_SERVER_IDENTIFIER, + local_addr)); + ex.getResponse()->addOption(opt_srvid); +} + +void +Dhcpv4Srv::buildCfgOptionList(Dhcpv4Exchange& ex) { + CfgOptionList& co_list = ex.getCfgOptionList(); + + // Retrieve subnet. + Subnet4Ptr subnet = ex.getContext()->subnet_; + if (!subnet) { + // All methods using the CfgOptionList object return soon when + // there is no subnet so do the same + return; + } + + // Firstly, host specific options. + const ConstHostPtr& host = ex.getContext()->currentHost(); + if (host && !host->getCfgOption4()->empty()) { + co_list.push_back(host->getCfgOption4()); + } + + // Secondly, pool specific options. + Pkt4Ptr resp = ex.getResponse(); + IOAddress addr = IOAddress::IPV4_ZERO_ADDRESS(); + if (resp) { + addr = resp->getYiaddr(); + } + if (!addr.isV4Zero()) { + PoolPtr pool = subnet->getPool(Lease::TYPE_V4, addr, false); + if (pool && !pool->getCfgOption()->empty()) { + co_list.push_back(pool->getCfgOption()); + } + } + + // Thirdly, subnet configured options. + if (!subnet->getCfgOption()->empty()) { + co_list.push_back(subnet->getCfgOption()); + } + + // Fourthly, shared network specific options. + SharedNetwork4Ptr network; + subnet->getSharedNetwork(network); + if (network && !network->getCfgOption()->empty()) { + co_list.push_back(network->getCfgOption()); + } + + // Each class in the incoming packet + const ClientClasses& classes = ex.getQuery()->getClasses(); + for (ClientClasses::const_iterator cclass = classes.cbegin(); + cclass != classes.cend(); ++cclass) { + // Find the client class definition for this class + const ClientClassDefPtr& ccdef = CfgMgr::instance().getCurrentCfg()-> + getClientClassDictionary()->findClass(*cclass); + if (!ccdef) { + // Not found: the class is built-in or not configured + if (!isClientClassBuiltIn(*cclass)) { + LOG_DEBUG(dhcp4_logger, DBG_DHCP4_BASIC, DHCP4_CLASS_UNCONFIGURED) + .arg(ex.getQuery()->getLabel()) + .arg(*cclass); + } + // Skip it + continue; + } + + if (ccdef->getCfgOption()->empty()) { + // Skip classes which don't configure options + continue; + } + + co_list.push_back(ccdef->getCfgOption()); + } + + // Last global options + if (!CfgMgr::instance().getCurrentCfg()->getCfgOption()->empty()) { + co_list.push_back(CfgMgr::instance().getCurrentCfg()->getCfgOption()); + } +} + +void +Dhcpv4Srv::appendRequestedOptions(Dhcpv4Exchange& ex) { + // Get the subnet relevant for the client. We will need it + // to get the options associated with it. + Subnet4Ptr subnet = ex.getContext()->subnet_; + // If we can't find the subnet for the client there is no way + // to get the options to be sent to a client. We don't log an + // error because it will be logged by the assignLease method + // anyway. + if (!subnet) { + return; + } + + // Unlikely short cut + const CfgOptionList& co_list = ex.getCfgOptionList(); + if (co_list.empty()) { + return; + } + + Pkt4Ptr query = ex.getQuery(); + Pkt4Ptr resp = ex.getResponse(); + set<uint8_t> requested_opts; + + // try to get the 'Parameter Request List' option which holds the + // codes of requested options. + OptionUint8ArrayPtr option_prl = boost::dynamic_pointer_cast< + OptionUint8Array>(query->getOption(DHO_DHCP_PARAMETER_REQUEST_LIST)); + + // Get the list of options that client requested. + if (option_prl) { + for (uint16_t code : option_prl->getValues()) { + static_cast<void>(requested_opts.insert(code)); + } + } + + std::set<uint8_t> cancelled_opts; + + // Iterate on the configured option list to add persistent and + // cancelled options. + for (auto const& copts : co_list) { + const OptionContainerPtr& opts = copts->getAll(DHCP4_OPTION_SPACE); + if (!opts) { + continue; + } + // Get persistent options. + const OptionContainerPersistIndex& pidx = opts->get<2>(); + const OptionContainerPersistRange& prange = pidx.equal_range(true); + for (OptionContainerPersistIndex::const_iterator desc = prange.first; + desc != prange.second; ++desc) { + // Add the persistent option code to requested options. + if (desc->option_) { + uint8_t code = static_cast<uint8_t>(desc->option_->getType()); + static_cast<void>(requested_opts.insert(code)); + } + } + // Get cancelled options. + const OptionContainerCancelIndex& cidx = opts->get<5>(); + const OptionContainerCancelRange& crange = cidx.equal_range(true); + for (OptionContainerCancelIndex::const_iterator desc = crange.first; + desc != crange.second; ++desc) { + // Add the cancelled option code to cancelled options. + if (desc->option_) { + uint8_t code = static_cast<uint8_t>(desc->option_->getType()); + static_cast<void>(cancelled_opts.insert(code)); + } + } + } + + // For each requested option code get the first instance of the option + // to be returned to the client. + for (uint8_t opt : requested_opts) { + if (cancelled_opts.count(opt) > 0) { + continue; + } + // Skip special cases: DHO_VIVSO_SUBOPTIONS. + if (opt == DHO_VIVSO_SUBOPTIONS) { + continue; + } + // Add nothing when it is already there. + if (!resp->getOption(opt)) { + // Iterate on the configured option list + for (auto const& copts : co_list) { + OptionDescriptor desc = copts->get(DHCP4_OPTION_SPACE, opt); + // Got it: add it and jump to the outer loop + if (desc.option_) { + resp->addOption(desc.option_); + break; + } + } + } + } + + // Special cases for vendor class and options which are identified + // by the code/type and the vendor/enterprise id vs. the code/type only. + if ((requested_opts.count(DHO_VIVCO_SUBOPTIONS) > 0) && + (cancelled_opts.count(DHO_VIVCO_SUBOPTIONS) == 0)) { + // Keep vendor ids which are already in the response to insert + // VIVCO options at most once per vendor. + set<uint32_t> vendor_ids; + // Get what already exists in the response. + for (auto opt : resp->getOptions(DHO_VIVCO_SUBOPTIONS)) { + OptionVendorClassPtr vendor_opts; + vendor_opts = boost::dynamic_pointer_cast<OptionVendorClass>(opt.second); + if (vendor_opts) { + uint32_t vendor_id = vendor_opts->getVendorId(); + static_cast<void>(vendor_ids.insert(vendor_id)); + } + } + // Iterate on the configured option list. + for (auto const& copts : co_list) { + for (OptionDescriptor desc : copts->getList(DHCP4_OPTION_SPACE, + DHO_VIVCO_SUBOPTIONS)) { + if (!desc.option_) { + continue; + } + OptionVendorClassPtr vendor_opts = + boost::dynamic_pointer_cast<OptionVendorClass>(desc.option_); + if (!vendor_opts) { + continue; + } + // Is the vendor id already in the response? + uint32_t vendor_id = vendor_opts->getVendorId(); + if (vendor_ids.count(vendor_id) > 0) { + continue; + } + // Got it: add it. + resp->Pkt::addOption(desc.option_); + static_cast<void>(vendor_ids.insert(vendor_id)); + } + } + } + + if ((requested_opts.count(DHO_VIVSO_SUBOPTIONS) > 0) && + (cancelled_opts.count(DHO_VIVSO_SUBOPTIONS) == 0)) { + // Keep vendor ids which are already in the response to insert + // VIVSO options at most once per vendor. + set<uint32_t> vendor_ids; + // Get what already exists in the response. + for (auto opt : resp->getOptions(DHO_VIVSO_SUBOPTIONS)) { + OptionVendorPtr vendor_opts; + vendor_opts = boost::dynamic_pointer_cast<OptionVendor>(opt.second); + if (vendor_opts) { + uint32_t vendor_id = vendor_opts->getVendorId(); + static_cast<void>(vendor_ids.insert(vendor_id)); + } + } + // Iterate on the configured option list + for (auto const& copts : co_list) { + for (OptionDescriptor desc : copts->getList(DHCP4_OPTION_SPACE, + DHO_VIVSO_SUBOPTIONS)) { + if (!desc.option_) { + continue; + } + OptionVendorPtr vendor_opts = + boost::dynamic_pointer_cast<OptionVendor>(desc.option_); + if (!vendor_opts) { + continue; + } + // Is the vendor id already in the response? + uint32_t vendor_id = vendor_opts->getVendorId(); + if (vendor_ids.count(vendor_id) > 0) { + continue; + } + // Append a fresh vendor option as the next method should + // add suboptions to it. + vendor_opts.reset(new OptionVendor(Option::V4, vendor_id)); + resp->Pkt::addOption(vendor_opts); + static_cast<void>(vendor_ids.insert(vendor_id)); + } + } + } +} + +void +Dhcpv4Srv::appendRequestedVendorOptions(Dhcpv4Exchange& ex) { + // Get the configured subnet suitable for the incoming packet. + Subnet4Ptr subnet = ex.getContext()->subnet_; + + const CfgOptionList& co_list = ex.getCfgOptionList(); + + // Leave if there is no subnet matching the incoming packet. + // There is no need to log the error message here because + // it will be logged in the assignLease() when it fails to + // pick the suitable subnet. We don't want to duplicate + // error messages in such case. + // + // Also, if there's no options to possibly assign, give up. + if (!subnet || co_list.empty()) { + return; + } + + Pkt4Ptr query = ex.getQuery(); + Pkt4Ptr resp = ex.getResponse(); + set<uint32_t> vendor_ids; + + // The server could have provided the option using client classification or + // hooks. If there're vendor info options in the response already, use them. + map<uint32_t, OptionVendorPtr> vendor_rsps; + for (auto opt : resp->getOptions(DHO_VIVSO_SUBOPTIONS)) { + OptionVendorPtr vendor_rsp; + vendor_rsp = boost::dynamic_pointer_cast<OptionVendor>(opt.second); + if (vendor_rsp) { + uint32_t vendor_id = vendor_rsp->getVendorId(); + vendor_rsps[vendor_id] = vendor_rsp; + static_cast<void>(vendor_ids.insert(vendor_id)); + } + } + + // Next, try to get the vendor-id from the client packet's + // vendor-specific information option (125). + map<uint32_t, OptionVendorPtr> vendor_reqs; + for (auto opt : query->getOptions(DHO_VIVSO_SUBOPTIONS)) { + OptionVendorPtr vendor_req; + vendor_req = boost::dynamic_pointer_cast<OptionVendor>(opt.second); + if (vendor_req) { + uint32_t vendor_id = vendor_req->getVendorId(); + vendor_reqs[vendor_id] = vendor_req; + static_cast<void>(vendor_ids.insert(vendor_id)); + } + } + + // Finally, try to get the vendor-id from the client packet's + // vendor-specific class option (124). + for (auto opt : query->getOptions(DHO_VIVCO_SUBOPTIONS)) { + OptionVendorClassPtr vendor_class; + vendor_class = boost::dynamic_pointer_cast<OptionVendorClass>(opt.second); + if (vendor_class) { + uint32_t vendor_id = vendor_class->getVendorId(); + static_cast<void>(vendor_ids.insert(vendor_id)); + } + } + + // If there's no vendor option in either request or response, then there's no way + // to figure out what the vendor-id values are and we give up. + if (vendor_ids.empty()) { + return; + } + + map<uint32_t, set<uint8_t> > requested_opts; + + // Let's try to get ORO within that vendor-option. + // This is specific to vendor-id=4491 (Cable Labs). Other vendors may have + // different policies. + OptionUint8ArrayPtr oro; + if (vendor_reqs.count(VENDOR_ID_CABLE_LABS) > 0) { + OptionVendorPtr vendor_req = vendor_reqs[VENDOR_ID_CABLE_LABS]; + OptionPtr oro_generic = vendor_req->getOption(DOCSIS3_V4_ORO); + if (oro_generic) { + // Vendor ID 4491 makes Kea look at DOCSIS3_V4_OPTION_DEFINITIONS + // when parsing options. Based on that, oro_generic will have been + // created as an OptionUint8Array, but might not be for other + // vendor IDs. + oro = boost::dynamic_pointer_cast<OptionUint8Array>(oro_generic); + } + if (oro) { + set<uint8_t> oro_req_opts; + for (uint8_t code : oro->getValues()) { + static_cast<void>(oro_req_opts.insert(code)); + } + requested_opts[VENDOR_ID_CABLE_LABS] = oro_req_opts; + } + } + + for (uint32_t vendor_id : vendor_ids) { + + std::set<uint8_t> cancelled_opts; + + // Iterate on the configured option list to add persistent and + // cancelled options, + for (auto const& copts : co_list) { + const OptionContainerPtr& opts = copts->getAll(vendor_id); + if (!opts) { + continue; + } + + // Get persistent options. + const OptionContainerPersistIndex& pidx = opts->get<2>(); + const OptionContainerPersistRange& prange = pidx.equal_range(true); + for (OptionContainerPersistIndex::const_iterator desc = prange.first; + desc != prange.second; ++desc) { + // Add the persistent option code to requested options. + if (desc->option_) { + uint8_t code = static_cast<uint8_t>(desc->option_->getType()); + static_cast<void>(requested_opts[vendor_id].insert(code)); + } + } + + // Get cancelled options. + const OptionContainerCancelIndex& cidx = opts->get<5>(); + const OptionContainerCancelRange& crange = cidx.equal_range(true); + for (OptionContainerCancelIndex::const_iterator desc = crange.first; + desc != crange.second; ++desc) { + // Add the cancelled option code to cancelled options. + if (desc->option_) { + uint8_t code = static_cast<uint8_t>(desc->option_->getType()); + static_cast<void>(cancelled_opts.insert(code)); + } + } + } + + // If there is nothing to add don't do anything with this vendor. + // This will explicitly not echo back vendor options from the request + // that either correspond to a vendor not known to Kea even if the + // option encapsulates data or there are no persistent options + // configured for this vendor so Kea does not send any option back. + if (requested_opts[vendor_id].empty()) { + continue; + } + + + // It's possible that vivso was inserted already by client class or + // a hook. If that is so, let's use it. + OptionVendorPtr vendor_rsp; + if (vendor_rsps.count(vendor_id) > 0) { + vendor_rsp = vendor_rsps[vendor_id]; + } else { + vendor_rsp.reset(new OptionVendor(Option::V4, vendor_id)); + } + + // Get the list of options that client requested. + bool added = false; + + for (uint8_t opt : requested_opts[vendor_id]) { + if (cancelled_opts.count(opt) > 0) { + continue; + } + if (!vendor_rsp->getOption(opt)) { + for (auto const& copts : co_list) { + OptionDescriptor desc = copts->get(vendor_id, opt); + if (desc.option_) { + vendor_rsp->addOption(desc.option_); + added = true; + break; + } + } + } + } + + // If we added some sub-options and the vendor opts option is not in + // the response already, then add it. + if (added && (vendor_rsps.count(vendor_id) == 0)) { + resp->Pkt::addOption(vendor_rsp); + } + } +} + +void +Dhcpv4Srv::appendBasicOptions(Dhcpv4Exchange& ex) { + // Identify options that we always want to send to the + // client (if they are configured). + static const std::vector<uint16_t> required_options = { + DHO_ROUTERS, + DHO_DOMAIN_NAME_SERVERS, + DHO_DOMAIN_NAME, + DHO_DHCP_SERVER_IDENTIFIER }; + + // Get the subnet. + Subnet4Ptr subnet = ex.getContext()->subnet_; + if (!subnet) { + return; + } + + // Unlikely short cut + const CfgOptionList& co_list = ex.getCfgOptionList(); + if (co_list.empty()) { + return; + } + + Pkt4Ptr resp = ex.getResponse(); + + // Try to find all 'required' options in the outgoing + // message. Those that are not present will be added. + for (auto const& required : required_options) { + OptionPtr opt = resp->getOption(required); + if (!opt) { + // Check whether option has been configured. + for (auto const& copts : co_list) { + OptionDescriptor desc = copts->get(DHCP4_OPTION_SPACE, required); + if (desc.option_) { + resp->addOption(desc.option_); + break; + } + } + } + } +} + +void +Dhcpv4Srv::processClientName(Dhcpv4Exchange& ex) { + // It is possible that client has sent both Client FQDN and Hostname + // option. In that the server should prefer Client FQDN option and + // ignore the Hostname option. + try { + Pkt4Ptr query = ex.getQuery(); + Pkt4Ptr resp = ex.getResponse(); + Option4ClientFqdnPtr fqdn = boost::dynamic_pointer_cast<Option4ClientFqdn> + (query->getOption(DHO_FQDN)); + if (fqdn) { + LOG_DEBUG(ddns4_logger, DBG_DHCP4_DETAIL, DHCP4_CLIENT_FQDN_PROCESS) + .arg(query->getLabel()); + processClientFqdnOption(ex); + + } else { + LOG_DEBUG(ddns4_logger, DBG_DHCP4_DETAIL, + DHCP4_CLIENT_HOSTNAME_PROCESS) + .arg(query->getLabel()); + processHostnameOption(ex); + } + + // Based on the output option added to the response above, we figure out + // the values for the hostname and dns flags to set in the context. These + // will be used to populate the lease. + std::string hostname; + bool fqdn_fwd = false; + bool fqdn_rev = false; + + + OptionStringPtr opt_hostname; + fqdn = boost::dynamic_pointer_cast<Option4ClientFqdn>(resp->getOption(DHO_FQDN)); + if (fqdn) { + hostname = fqdn->getDomainName(); + CfgMgr::instance().getD2ClientMgr().getUpdateDirections(*fqdn, fqdn_fwd, fqdn_rev); + } else { + opt_hostname = boost::dynamic_pointer_cast<OptionString> + (resp->getOption(DHO_HOST_NAME)); + + if (opt_hostname) { + hostname = opt_hostname->getValue(); + // DHO_HOST_NAME is string option which cannot be blank, + // we use "." to know we should replace it with a fully + // generated name. The local string variable needs to be + // blank in logic below. + if (hostname == ".") { + hostname = ""; + } + + /// @todo It could be configurable what sort of updates the + /// server is doing when Hostname option was sent. + if (ex.getContext()->getDdnsParams()->getEnableUpdates()) { + fqdn_fwd = true; + fqdn_rev = true; + } + } + } + + // Optionally, call a hook that may possibly override the decisions made + // earlier. + if (HooksManager::calloutsPresent(Hooks.hook_index_ddns4_update_)) { + CalloutHandlePtr callout_handle = getCalloutHandle(query); + + // Use the RAII wrapper to make sure that the callout handle state is + // reset when this object goes out of scope. All hook points must do + // it to prevent possible circular dependency between the callout + // handle and its arguments. + ScopedCalloutHandleState callout_handle_state(callout_handle); + + // Setup the callout arguments. + Subnet4Ptr subnet = ex.getContext()->subnet_; + callout_handle->setArgument("query4", query); + callout_handle->setArgument("response4", resp); + callout_handle->setArgument("subnet4", subnet); + callout_handle->setArgument("hostname", hostname); + callout_handle->setArgument("fwd-update", fqdn_fwd); + callout_handle->setArgument("rev-update", fqdn_rev); + callout_handle->setArgument("ddns-params", ex.getContext()->getDdnsParams()); + + // Call callouts + HooksManager::callCallouts(Hooks.hook_index_ddns4_update_, *callout_handle); + + // Let's get the parameters returned by hook. + string hook_hostname; + bool hook_fqdn_fwd = false; + bool hook_fqdn_rev = false; + callout_handle->getArgument("hostname", hook_hostname); + callout_handle->getArgument("fwd-update", hook_fqdn_fwd); + callout_handle->getArgument("rev-update", hook_fqdn_rev); + + // If there's anything changed by the hook, log it and then update + // the parameters. + if ((hostname != hook_hostname) || (fqdn_fwd != hook_fqdn_fwd) || + (fqdn_rev != hook_fqdn_rev)) { + LOG_DEBUG(hooks_logger, DBGLVL_PKT_HANDLING, DHCP4_HOOK_DDNS_UPDATE) + .arg(hostname).arg(hook_hostname).arg(fqdn_fwd).arg(hook_fqdn_fwd) + .arg(fqdn_rev).arg(hook_fqdn_rev); + hostname = hook_hostname; + fqdn_fwd = hook_fqdn_fwd; + fqdn_rev = hook_fqdn_rev; + + // If there's an outbound host-name option in the response we + // need to updated it with the new host name. + OptionStringPtr hostname_opt = boost::dynamic_pointer_cast<OptionString> + (resp->getOption(DHO_HOST_NAME)); + if (hostname_opt) { + hostname_opt->setValue(hook_hostname); + } + + // If there's an outbound FQDN option in the response we need + // to update it with the new host name. + Option4ClientFqdnPtr fqdn = boost::dynamic_pointer_cast<Option4ClientFqdn> + (resp->getOption(DHO_FQDN)); + if (fqdn) { + fqdn->setDomainName(hook_hostname, Option4ClientFqdn::FULL); + // Hook disabled updates, Set flags back to client accordingly. + fqdn->setFlag(Option4ClientFqdn::FLAG_S, 0); + fqdn->setFlag(Option4ClientFqdn::FLAG_N, 1); + } + } + } + + // Update the context + auto ctx = ex.getContext(); + ctx->fwd_dns_update_ = fqdn_fwd; + ctx->rev_dns_update_ = fqdn_rev; + ctx->hostname_ = hostname; + + } catch (const Exception& e) { + // In some rare cases it is possible that the client's name processing + // fails. For example, the Hostname option may be malformed, or there + // may be an error in the server's logic which would cause multiple + // attempts to add the same option to the response message. This + // error message aggregates all these errors so they can be diagnosed + // from the log. We don't want to throw an exception here because, + // it will impact the processing of the whole packet. We rather want + // the processing to continue, even if the client's name is wrong. + LOG_DEBUG(ddns4_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_CLIENT_NAME_PROC_FAIL) + .arg(ex.getQuery()->getLabel()) + .arg(e.what()); + } +} + +void +Dhcpv4Srv::processClientFqdnOption(Dhcpv4Exchange& ex) { + // Obtain the FQDN option from the client's message. + Option4ClientFqdnPtr fqdn = boost::dynamic_pointer_cast< + Option4ClientFqdn>(ex.getQuery()->getOption(DHO_FQDN)); + + LOG_DEBUG(ddns4_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_CLIENT_FQDN_DATA) + .arg(ex.getQuery()->getLabel()) + .arg(fqdn->toText()); + + // Create the DHCPv4 Client FQDN Option to be included in the server's + // response to a client. + Option4ClientFqdnPtr fqdn_resp(new Option4ClientFqdn(*fqdn)); + + // Set the server S, N, and O flags based on client's flags and + // current configuration. + D2ClientMgr& d2_mgr = CfgMgr::instance().getD2ClientMgr(); + d2_mgr.adjustFqdnFlags<Option4ClientFqdn>(*fqdn, *fqdn_resp, + *(ex.getContext()->getDdnsParams())); + // Carry over the client's E flag. + fqdn_resp->setFlag(Option4ClientFqdn::FLAG_E, + fqdn->getFlag(Option4ClientFqdn::FLAG_E)); + + if (ex.getContext()->currentHost() && + !ex.getContext()->currentHost()->getHostname().empty()) { + D2ClientMgr& d2_mgr = CfgMgr::instance().getD2ClientMgr(); + fqdn_resp->setDomainName(d2_mgr.qualifyName(ex.getContext()->currentHost()->getHostname(), + *(ex.getContext()->getDdnsParams()), true), + Option4ClientFqdn::FULL); + + } else { + // Adjust the domain name based on domain name value and type sent by the + // client and current configuration. + d2_mgr.adjustDomainName<Option4ClientFqdn>(*fqdn, *fqdn_resp, + *(ex.getContext()->getDdnsParams())); + } + + // Add FQDN option to the response message. Note that, there may be some + // cases when server may choose not to include the FQDN option in a + // response to a client. In such cases, the FQDN should be removed from the + // outgoing message. In theory we could cease to include the FQDN option + // in this function until it is confirmed that it should be included. + // However, we include it here for simplicity. Functions used to acquire + // lease for a client will scan the response message for FQDN and if it + // is found they will take necessary actions to store the FQDN information + // in the lease database as well as to generate NameChangeRequests to DNS. + // If we don't store the option in the response message, we will have to + // propagate it in the different way to the functions which acquire the + // lease. This would require modifications to the API of this class. + LOG_DEBUG(ddns4_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_RESPONSE_FQDN_DATA) + .arg(ex.getQuery()->getLabel()) + .arg(fqdn_resp->toText()); + ex.getResponse()->addOption(fqdn_resp); +} + +void +Dhcpv4Srv::processHostnameOption(Dhcpv4Exchange& ex) { + // Fetch D2 configuration. + D2ClientMgr& d2_mgr = CfgMgr::instance().getD2ClientMgr(); + + // Obtain the Hostname option from the client's message. + OptionStringPtr opt_hostname = boost::dynamic_pointer_cast<OptionString> + (ex.getQuery()->getOption(DHO_HOST_NAME)); + + if (opt_hostname) { + LOG_DEBUG(ddns4_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_CLIENT_HOSTNAME_DATA) + .arg(ex.getQuery()->getLabel()) + .arg(opt_hostname->getValue()); + } + + AllocEngine::ClientContext4Ptr ctx = ex.getContext(); + + // Hostname reservations take precedence over any other configuration, + // i.e. DDNS configuration. If we have a reserved hostname we should + // use it and send it back. + if (ctx->currentHost() && !ctx->currentHost()->getHostname().empty()) { + // Qualify if there is a suffix configured. + std::string hostname = d2_mgr.qualifyName(ctx->currentHost()->getHostname(), + *(ex.getContext()->getDdnsParams()), false); + // Convert it to lower case. + boost::algorithm::to_lower(hostname); + LOG_DEBUG(ddns4_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_RESERVED_HOSTNAME_ASSIGNED) + .arg(ex.getQuery()->getLabel()) + .arg(hostname); + + // Add it to the response + OptionStringPtr opt_hostname_resp(new OptionString(Option::V4, DHO_HOST_NAME, hostname)); + ex.getResponse()->addOption(opt_hostname_resp); + + // We're done here. + return; + } + + // There is no reservation for this client however there is still a + // possibility that we'll have to send hostname option to this client + // if the client has included hostname option or the configuration of + // the server requires that we send the option regardless. + D2ClientConfig::ReplaceClientNameMode replace_name_mode = + ex.getContext()->getDdnsParams()->getReplaceClientNameMode(); + + // If we don't have a hostname then either we'll supply it or do nothing. + if (!opt_hostname) { + // If we're configured to supply it then add it to the response. + // Use the root domain to signal later on that we should replace it. + if (replace_name_mode == D2ClientConfig::RCM_ALWAYS || + replace_name_mode == D2ClientConfig::RCM_WHEN_NOT_PRESENT) { + LOG_DEBUG(ddns4_logger, DBG_DHCP4_DETAIL_DATA, + DHCP4_GENERATE_FQDN) + .arg(ex.getQuery()->getLabel()); + OptionStringPtr opt_hostname_resp(new OptionString(Option::V4, + DHO_HOST_NAME, + ".")); + ex.getResponse()->addOption(opt_hostname_resp); + } + + return; + } + + // Client sent us a hostname option so figure out what to do with it. + LOG_DEBUG(ddns4_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_CLIENT_HOSTNAME_DATA) + .arg(ex.getQuery()->getLabel()) + .arg(opt_hostname->getValue()); + + std::string hostname = isc::util::str::trim(opt_hostname->getValue()); + unsigned int label_count; + + try { + // Parsing into labels can throw on malformed content so we're + // going to explicitly catch that here. + label_count = OptionDataTypeUtil::getLabelCount(hostname); + } catch (const std::exception& exc) { + LOG_DEBUG(ddns4_logger, DBG_DHCP4_DETAIL, DHCP4_CLIENT_HOSTNAME_MALFORMED) + .arg(ex.getQuery()->getLabel()) + .arg(exc.what()); + return; + } + + // The hostname option sent by the client should be at least 1 octet long. + // If it isn't we ignore this option. (Per RFC 2131, section 3.14) + /// @todo It would be more liberal to accept this and let it fall into + /// the case of replace or less than two below. + if (label_count == 0) { + LOG_DEBUG(ddns4_logger, DBG_DHCP4_DETAIL, DHCP4_EMPTY_HOSTNAME) + .arg(ex.getQuery()->getLabel()); + return; + } + + // Stores the value we eventually use, so we can send it back. + OptionStringPtr opt_hostname_resp; + + // The hostname option may be unqualified or fully qualified. The lab_count + // holds the number of labels for the name. The number of 1 means that + // there is only root label "." (even for unqualified names, as the + // getLabelCount function treats each name as a fully qualified one). + // By checking the number of labels present in the hostname we may infer + // whether client has sent the fully qualified or unqualified hostname. + + if ((replace_name_mode == D2ClientConfig::RCM_ALWAYS || + replace_name_mode == D2ClientConfig::RCM_WHEN_PRESENT) + || label_count < 2) { + // Set to root domain to signal later on that we should replace it. + // DHO_HOST_NAME is a string option which cannot be empty. + /// @todo We may want to reconsider whether it is appropriate for the + /// client to send a root domain name as a Hostname. There are + /// also extensions to the auto generation of the client's name, + /// e.g. conversion to the puny code which may be considered at some + /// point. + /// For now, we just remain liberal and expect that the DNS will handle + /// conversion if needed and possible. + opt_hostname_resp.reset(new OptionString(Option::V4, DHO_HOST_NAME, ".")); + } else { + // Sanitize the name the client sent us, if we're configured to do so. + isc::util::str::StringSanitizerPtr sanitizer = + ex.getContext()->getDdnsParams()->getHostnameSanitizer(); + + if (sanitizer) { + hostname = sanitizer->scrub(hostname); + } + + // Convert hostname to lower case. + boost::algorithm::to_lower(hostname); + + if (label_count == 2) { + // If there are two labels, it means that the client has specified + // the unqualified name. We have to concatenate the unqualified name + // with the domain name. The false value passed as a second argument + // indicates that the trailing dot should not be appended to the + // hostname. We don't want to append the trailing dot because + // we don't know whether the hostname is partial or not and some + // clients do not handle the hostnames with the trailing dot. + opt_hostname_resp.reset( + new OptionString(Option::V4, DHO_HOST_NAME, + d2_mgr.qualifyName(hostname, *(ex.getContext()->getDdnsParams()), + false))); + } else { + opt_hostname_resp.reset(new OptionString(Option::V4, DHO_HOST_NAME, hostname)); + } + } + + LOG_DEBUG(ddns4_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_RESPONSE_HOSTNAME_DATA) + .arg(ex.getQuery()->getLabel()) + .arg(opt_hostname_resp->getValue()); + ex.getResponse()->addOption(opt_hostname_resp); +} + +void +Dhcpv4Srv::createNameChangeRequests(const Lease4Ptr& lease, + const Lease4Ptr& old_lease, + const DdnsParams& ddns_params) { + if (!lease) { + isc_throw(isc::Unexpected, + "NULL lease specified when creating NameChangeRequest"); + } + + // Nothing to do if updates are not enabled. + if (!ddns_params.getEnableUpdates()) { + return; + } + + if (!old_lease || ddns_params.getUpdateOnRenew() || !lease->hasIdenticalFqdn(*old_lease)) { + if (old_lease) { + // Queue's up a remove of the old lease's DNS (if needed) + queueNCR(CHG_REMOVE, old_lease); + } + + // We may need to generate the NameChangeRequest for the new lease. It + // will be generated only if hostname is set and if forward or reverse + // update has been requested. + queueNCR(CHG_ADD, lease); + } +} + +void +Dhcpv4Srv::assignLease(Dhcpv4Exchange& ex) { + // Get the pointers to the query and the response messages. + Pkt4Ptr query = ex.getQuery(); + Pkt4Ptr resp = ex.getResponse(); + + // Get the context. + AllocEngine::ClientContext4Ptr ctx = ex.getContext(); + + // Get the server identifier. It will be used to determine the state + // of the client. + OptionCustomPtr opt_serverid = boost::dynamic_pointer_cast< + OptionCustom>(query->getOption(DHO_DHCP_SERVER_IDENTIFIER)); + + // Check if the client has sent a requested IP address option or + // ciaddr. + OptionCustomPtr opt_requested_address = boost::dynamic_pointer_cast< + OptionCustom>(query->getOption(DHO_DHCP_REQUESTED_ADDRESS)); + IOAddress hint(IOAddress::IPV4_ZERO_ADDRESS()); + if (opt_requested_address) { + hint = opt_requested_address->readAddress(); + + } else if (!query->getCiaddr().isV4Zero()) { + hint = query->getCiaddr(); + + } + + // "Fake" allocation is processing of DISCOVER message. We pretend to do an + // allocation, but we do not put the lease in the database. That is ok, + // because we do not guarantee that the user will get that exact lease. If + // the user selects this server to do actual allocation (i.e. sends REQUEST) + // it should include this hint. That will help us during the actual lease + // allocation. + bool fake_allocation = (query->getType() == DHCPDISCOVER); + + // Subnet should have been already selected when the context was created. + Subnet4Ptr subnet = ctx->subnet_; + + // This flag controls whether or not the server should respond to the clients + // in the INIT-REBOOT state. We will initialize it to a configured value only + // when the client is in that state. + auto authoritative = false; + + // If there is no server id and there is a Requested IP Address option + // the client is in the INIT-REBOOT state in which the server has to + // determine whether the client's notion of the address is correct + // and whether the client is known, i.e., has a lease. + auto init_reboot = (!fake_allocation && !opt_serverid && opt_requested_address); + if (init_reboot) { + LOG_INFO(lease4_logger, DHCP4_INIT_REBOOT) + .arg(query->getLabel()) + .arg(hint.toText()); + + // Find the authoritative flag configuration. + if (subnet) { + authoritative = subnet->getAuthoritative(); + } else { + // If there is no subnet, use the global value. + auto flag = CfgMgr::instance().getCurrentCfg()->getConfiguredGlobals()-> + get(CfgGlobals::AUTHORITATIVE); + if (flag && (flag->getType() == data::Element::boolean)) { + authoritative = flag->boolValue(); + } + } + } + + // If there is no subnet configuration for that client we ignore the + // request from the INIT-REBOOT client if we're not authoritative, because + // we don't know whether the network configuration is correct for this + // client. We return DHCPNAK if we're authoritative, though. + if (!subnet && (!init_reboot || authoritative)) { + // This particular client is out of luck today. We do not have + // information about the subnet he is connected to. This likely means + // misconfiguration of the server (or some relays). + + // Perhaps this should be logged on some higher level? + LOG_ERROR(bad_packet4_logger, DHCP4_PACKET_NAK_0001) + .arg(query->getLabel()) + .arg(query->getRemoteAddr().toText()) + .arg(query->getName()); + resp->setType(DHCPNAK); + resp->setYiaddr(IOAddress::IPV4_ZERO_ADDRESS()); + return; + } + + HWAddrPtr hwaddr = query->getHWAddr(); + + Subnet4Ptr original_subnet = subnet; + + // Get client-id. It is not mandatory in DHCPv4. + ClientIdPtr client_id = ex.getContext()->clientid_; + + // In the INIT-REBOOT state, a client remembering its previously assigned + // address is trying to confirm whether or not this address is still usable. + if (init_reboot) { + Lease4Ptr lease; + + auto const& classes = query->getClasses(); + + // We used to issue a separate query (two actually: one for client-id + // and another one for hw-addr for) each subnet in the shared network. + // That was horribly inefficient if the client didn't have any lease + // (or there were many subnets and the client happened to be in one + // of the last subnets). + // + // We now issue at most two queries: get all the leases for specific + // client-id and then get all leases for specific hw-address. + if (original_subnet && client_id) { + + // Get all the leases for this client-id + Lease4Collection leases_client_id = LeaseMgrFactory::instance().getLease4(*client_id); + if (!leases_client_id.empty()) { + Subnet4Ptr s = original_subnet; + + // Among those returned try to find a lease that belongs to + // current shared network. + while (s) { + for (auto l = leases_client_id.begin(); l != leases_client_id.end(); ++l) { + if ((*l)->subnet_id_ == s->getID()) { + lease = *l; + break; + } + } + + if (lease) { + break; + + } else { + s = s->getNextSubnet(original_subnet, classes); + } + } + } + } + + // If we haven't found a lease yet, try again by hardware-address. + // The logic is the same. + if (original_subnet && !lease && hwaddr) { + + // Get all leases for this particular hw-address. + Lease4Collection leases_hwaddr = LeaseMgrFactory::instance().getLease4(*hwaddr); + if (!leases_hwaddr.empty()) { + Subnet4Ptr s = original_subnet; + + // Pick one that belongs to a subnet in this shared network. + while (s) { + for (auto l = leases_hwaddr.begin(); l != leases_hwaddr.end(); ++l) { + if ((*l)->subnet_id_ == s->getID()) { + lease = *l; + break; + } + } + + if (lease) { + break; + + } else { + s = s->getNextSubnet(original_subnet, classes); + } + } + } + } + + // Check the first error case: unknown client. We check this before + // validating the address sent because we don't want to respond if + // we don't know this client, except if we're authoritative. + bool known_client = lease && lease->belongsToClient(hwaddr, client_id); + if (!authoritative && !known_client) { + LOG_DEBUG(bad_packet4_logger, DBG_DHCP4_DETAIL, + DHCP4_NO_LEASE_INIT_REBOOT) + .arg(query->getLabel()) + .arg(hint.toText()); + + ex.deleteResponse(); + return; + } + + // If we know this client, check if his notion of the IP address is + // correct, if we don't know him, check if we are authoritative. + if ((known_client && (lease->addr_ != hint)) || + (!known_client && authoritative) || + (!original_subnet)) { + LOG_DEBUG(bad_packet4_logger, DBG_DHCP4_DETAIL, + DHCP4_PACKET_NAK_0002) + .arg(query->getLabel()) + .arg(hint.toText()); + + resp->setType(DHCPNAK); + resp->setYiaddr(IOAddress::IPV4_ZERO_ADDRESS()); + return; + } + } + + CalloutHandlePtr callout_handle = getCalloutHandle(query); + + // We need to set these values in the context as they haven't been set yet. + ctx->requested_address_ = hint; + ctx->fake_allocation_ = fake_allocation; + ctx->callout_handle_ = callout_handle; + + // If client query contains an FQDN or Hostname option, server + // should respond to the client with the appropriate FQDN or Hostname + // option to indicate if it takes responsibility for the DNS updates. + // This is also the source for the hostname and dns flags that are + // initially added to the lease. In most cases, this information is + // good now. If we end up changing subnets in allocation we'll have to + // do it again and then update the lease. + processClientName(ex); + + // Get a lease. + Lease4Ptr lease = alloc_engine_->allocateLease4(*ctx); + + // Tracks whether or not the client name (FQDN or host) has changed since + // the lease was allocated. + bool client_name_changed = false; + + // Subnet may be modified by the allocation engine, if the initial subnet + // belongs to a shared network. + if (subnet && ctx->subnet_ && subnet->getID() != ctx->subnet_->getID()) { + SharedNetwork4Ptr network; + subnet->getSharedNetwork(network); + LOG_DEBUG(packet4_logger, DBG_DHCP4_BASIC_DATA, DHCP4_SUBNET_DYNAMICALLY_CHANGED) + .arg(query->getLabel()) + .arg(subnet->toText()) + .arg(ctx->subnet_->toText()) + .arg(network ? network->getName() : "<no network?>"); + + subnet = ctx->subnet_; + + if (lease) { + // We changed subnets and that means DDNS parameters might be different + // so we need to rerun client name processing logic. Arguably we could + // compare DDNS parameters for both subnets and then decide if we need + // to rerun the name logic, but that's not likely to be any faster than + // just re-running the name logic. @todo When inherited parameter + // performance is improved this argument could be revisited. + // Another case is the new subnet has a reserved hostname. + + // First, we need to remove the prior values from the response and reset + // those in context, to give processClientName a clean slate. + resp->delOption(DHO_FQDN); + resp->delOption(DHO_HOST_NAME); + ctx->hostname_ = ""; + ctx->fwd_dns_update_ = false; + ctx->rev_dns_update_ = false; + + // Regenerate the name and dns flags. + processClientName(ex); + + // If the results are different from the values already on the + // lease, flag it so the lease gets updated down below. + if ((lease->hostname_ != ctx->hostname_) || + (lease->fqdn_fwd_ != ctx->fwd_dns_update_) || + (lease->fqdn_rev_ != ctx->rev_dns_update_)) { + lease->hostname_ = ctx->hostname_; + lease->fqdn_fwd_ = ctx->fwd_dns_update_; + lease->fqdn_rev_ = ctx->rev_dns_update_; + client_name_changed = true; + } + } + } + + if (lease) { + // We have a lease! Let's set it in the packet and send it back to + // the client. + if (fake_allocation) { + LOG_INFO(lease4_logger, DHCP4_LEASE_ADVERT) + .arg(query->getLabel()) + .arg(lease->addr_.toText()); + } else { + LOG_INFO(lease4_logger, DHCP4_LEASE_ALLOC) + .arg(query->getLabel()) + .arg(lease->addr_.toText()) + .arg(Lease::lifetimeToText(lease->valid_lft_)); + } + + // We're logging this here, because this is the place where we know + // which subnet has been actually used for allocation. If the + // client identifier matching is disabled, we want to make sure that + // the user is notified. + if (!ctx->subnet_->getMatchClientId()) { + LOG_DEBUG(dhcp4_logger, DBG_DHCP4_DETAIL, DHCP4_CLIENTID_IGNORED_FOR_LEASES) + .arg(ctx->query_->getLabel()) + .arg(ctx->subnet_->getID()); + } + + resp->setYiaddr(lease->addr_); + + /// @todo The server should check what ciaddr the client has supplied + /// in ciaddr. Currently the ciaddr is ignored except for the subnet + /// selection. If the client supplied an invalid address, the server + /// will also return an invalid address here. + if (!fake_allocation) { + // If this is a renewing client it will set a ciaddr which the + // server may include in the response. If this is a new allocation + // the client will set ciaddr to 0 and this will also be propagated + // to the server's resp. + resp->setCiaddr(query->getCiaddr()); + } + + // We may need to update FQDN or hostname if the server is to generate + // a new name from the allocated IP address or if the allocation engine + // switched to a different subnet within a shared network. + postAllocateNameUpdate(ctx, lease, query, resp, client_name_changed); + + // Reuse the lease if possible. + if (lease->reuseable_valid_lft_ > 0) { + lease->valid_lft_ = lease->reuseable_valid_lft_; + LOG_INFO(lease4_logger, DHCP4_LEASE_REUSE) + .arg(query->getLabel()) + .arg(lease->addr_.toText()) + .arg(Lease::lifetimeToText(lease->valid_lft_)); + + // Increment the reuse statistics. + StatsMgr::instance().addValue("v4-lease-reuses", int64_t(1)); + StatsMgr::instance().addValue(StatsMgr::generateName("subnet", lease->subnet_id_, + "v4-lease-reuses"), + int64_t(1)); + } + + // IP Address Lease time (type 51) + // If we're not allocating on discover then we just sent the lifetime on the lease. + // Otherwise (i.e. offer_lft > 0), the lease's lifetime has been set to offer_lft but + // we want to send the client the proper valid lifetime so we have to fetch it. + auto send_lft = (ctx->offer_lft_ ? AllocEngine::getValidLft(*ctx) : lease->valid_lft_); + OptionPtr opt(new OptionUint32(Option::V4, DHO_DHCP_LEASE_TIME, send_lft)); + + resp->addOption(opt); + + // Subnet mask (type 1) + resp->addOption(getNetmaskOption(subnet)); + + // Set T1 and T2 per configuration. + setTeeTimes(lease, subnet, resp); + + // Create NameChangeRequests if this is a real allocation. + if (!fake_allocation) { + try { + createNameChangeRequests(lease, ctx->old_lease_, + *ex.getContext()->getDdnsParams()); + } catch (const Exception& ex) { + LOG_ERROR(ddns4_logger, DHCP4_NCR_CREATION_FAILED) + .arg(query->getLabel()) + .arg(ex.what()); + } + } + + } else { + // Allocation engine did not allocate a lease. The engine logged + // cause of that failure. + if (ctx->unknown_requested_addr_) { + Subnet4Ptr s = original_subnet; + // Address might have been rejected via class guard (i.e. not + // allowed for this client). We need to determine if we truly + // do not know about the address or whether this client just + // isn't allowed to have that address. We should only DHCPNAK + // For the latter. + while (s) { + if (s->inPool(Lease::TYPE_V4, hint)) { + break; + } + + s = s->getNextSubnet(original_subnet); + } + + // If we didn't find a subnet, it's not an address we know about + // so we drop the DHCPNAK. + if (!s) { + LOG_DEBUG(bad_packet4_logger, DBG_DHCP4_DETAIL, + DHCP4_UNKNOWN_ADDRESS_REQUESTED) + .arg(query->getLabel()) + .arg(query->getCiaddr().toText()) + .arg(opt_requested_address ? + opt_requested_address->readAddress().toText() : "(no address)"); + ex.deleteResponse(); + return; + } + } + + LOG_DEBUG(bad_packet4_logger, DBG_DHCP4_DETAIL, fake_allocation ? + DHCP4_PACKET_NAK_0003 : DHCP4_PACKET_NAK_0004) + .arg(query->getLabel()) + .arg(query->getCiaddr().toText()) + .arg(opt_requested_address ? + opt_requested_address->readAddress().toText() : "(no address)"); + + resp->setType(DHCPNAK); + resp->setYiaddr(IOAddress::IPV4_ZERO_ADDRESS()); + + resp->delOption(DHO_FQDN); + resp->delOption(DHO_HOST_NAME); + } +} + +void +Dhcpv4Srv::postAllocateNameUpdate(const AllocEngine::ClientContext4Ptr& ctx, const Lease4Ptr& lease, + const Pkt4Ptr& query, const Pkt4Ptr& resp, bool client_name_changed) { + // We may need to update FQDN or hostname if the server is to generate + // new name from the allocated IP address or if the allocation engine + // has switched to a different subnet within a shared network. Get + // FQDN and hostname options from the response. + OptionStringPtr opt_hostname; + Option4ClientFqdnPtr fqdn = boost::dynamic_pointer_cast< + Option4ClientFqdn>(resp->getOption(DHO_FQDN)); + if (!fqdn) { + opt_hostname = boost::dynamic_pointer_cast<OptionString>(resp->getOption(DHO_HOST_NAME)); + if (!opt_hostname) { + // We don't have either one, nothing to do. + return; + } + } + + // Empty hostname on the lease means we need to generate it. + if (lease->hostname_.empty()) { + // Note that if we have received the hostname option, rather than + // Client FQDN the trailing dot is not appended to the generated + // hostname because some clients don't handle the trailing dot in + // the hostname. Whether the trailing dot is appended or not is + // controlled by the second argument to the generateFqdn(). + lease->hostname_ = CfgMgr::instance().getD2ClientMgr() + .generateFqdn(lease->addr_, *(ctx->getDdnsParams()), static_cast<bool>(fqdn)); + + LOG_DEBUG(ddns4_logger, DBG_DHCP4_DETAIL, DHCP4_RESPONSE_HOSTNAME_GENERATE) + .arg(query->getLabel()) + .arg(lease->hostname_); + + client_name_changed = true; + } + + if (client_name_changed) { + // The operations below are rather safe, but we want to catch + // any potential exceptions (e.g. invalid lease database backend + // implementation) and log an error. + try { + /// TKM - do this on committed-discover + if (!ctx->fake_allocation_ || (ctx->offer_lft_ > 0)) { + // The lease can't be reused. + lease->reuseable_valid_lft_ = 0; + + // The lease update should be safe, because the lease should + // be already in the database. In most cases the exception + // would be thrown if the lease was missing. + LeaseMgrFactory::instance().updateLease4(lease); + } + + // The name update in the outbound option should be also safe, + // because the generated name is well formed. + if (fqdn) { + fqdn->setDomainName(lease->hostname_, Option4ClientFqdn::FULL); + } else { + opt_hostname->setValue(lease->hostname_); + } + } catch (const Exception& ex) { + LOG_ERROR(ddns4_logger, DHCP4_POST_ALLOCATION_NAME_UPDATE_FAIL) + .arg(query->getLabel()) + .arg(lease->hostname_) + .arg(ex.what()); + } + } +} + +/// @todo This logic to be modified if we decide to support infinite lease times. +void +Dhcpv4Srv::setTeeTimes(const Lease4Ptr& lease, const Subnet4Ptr& subnet, Pkt4Ptr resp) { + + uint32_t t2_time = 0; + // If T2 is explicitly configured we'll use try value. + if (!subnet->getT2().unspecified()) { + t2_time = subnet->getT2(); + } else if (subnet->getCalculateTeeTimes()) { + // Calculating tee times is enabled, so calculated it. + t2_time = static_cast<uint32_t>(round(subnet->getT2Percent() * (lease->valid_lft_))); + } + + // Send the T2 candidate value only if it's sane: to be sane it must be less than + // the valid life time. + uint32_t timer_ceiling = lease->valid_lft_; + if (t2_time > 0 && t2_time < timer_ceiling) { + OptionUint32Ptr t2(new OptionUint32(Option::V4, DHO_DHCP_REBINDING_TIME, t2_time)); + resp->addOption(t2); + // When we send T2, timer ceiling for T1 becomes T2. + timer_ceiling = t2_time; + } + + uint32_t t1_time = 0; + // If T1 is explicitly configured we'll use try value. + if (!subnet->getT1().unspecified()) { + t1_time = subnet->getT1(); + } else if (subnet->getCalculateTeeTimes()) { + // Calculating tee times is enabled, so calculate it. + t1_time = static_cast<uint32_t>(round(subnet->getT1Percent() * (lease->valid_lft_))); + } + + // Send T1 if it's sane: If we sent T2, T1 must be less than that. If not it must be + // less than the valid life time. + if (t1_time > 0 && t1_time < timer_ceiling) { + OptionUint32Ptr t1(new OptionUint32(Option::V4, DHO_DHCP_RENEWAL_TIME, t1_time)); + resp->addOption(t1); + } +} + +uint16_t +Dhcpv4Srv::checkRelayPort(const Dhcpv4Exchange& ex) { + + // Look for a relay-port RAI sub-option in the query. + const Pkt4Ptr& query = ex.getQuery(); + const OptionPtr& rai = query->getOption(DHO_DHCP_AGENT_OPTIONS); + if (rai && rai->getOption(RAI_OPTION_RELAY_PORT)) { + // Got the sub-option so use the remote port set by the relay. + return (query->getRemotePort()); + } + return (0); +} + +void +Dhcpv4Srv::adjustIfaceData(Dhcpv4Exchange& ex) { + adjustRemoteAddr(ex); + + // Initialize the pointers to the client's message and the server's + // response. + Pkt4Ptr query = ex.getQuery(); + Pkt4Ptr response = ex.getResponse(); + + // The DHCPINFORM is generally unicast to the client. The only situation + // when the server is unable to unicast to the client is when the client + // doesn't include ciaddr and the message is relayed. In this case the + // server has to reply via relay agent. For other messages we send back + // through relay if message is relayed, and unicast to the client if the + // message is not relayed. + // If client port was set from the command line enforce all responses + // to it. Of course it is only for testing purposes. + // Note that the call to this function may throw if invalid combination + // of hops and giaddr is found (hops = 0 if giaddr = 0 and hops != 0 if + // giaddr != 0). The exception will propagate down and eventually cause the + // packet to be discarded. + if (client_port_) { + response->setRemotePort(client_port_); + } else if (((query->getType() == DHCPINFORM) && + ((!query->getCiaddr().isV4Zero()) || + (!query->isRelayed() && !query->getRemoteAddr().isV4Zero()))) || + ((query->getType() != DHCPINFORM) && !query->isRelayed())) { + response->setRemotePort(DHCP4_CLIENT_PORT); + + } else { + // RFC 8357 section 5.1 + uint16_t relay_port = checkRelayPort(ex); + response->setRemotePort(relay_port ? relay_port : DHCP4_SERVER_PORT); + } + + CfgIfacePtr cfg_iface = CfgMgr::instance().getCurrentCfg()->getCfgIface(); + if (query->isRelayed() && + (cfg_iface->getSocketType() == CfgIface::SOCKET_UDP) && + (cfg_iface->getOutboundIface() == CfgIface::USE_ROUTING)) { + + // Mark the response to follow routing + response->setLocalAddr(IOAddress::IPV4_ZERO_ADDRESS()); + response->resetIndex(); + // But keep the interface name + response->setIface(query->getIface()); + + } else { + + IOAddress local_addr = query->getLocalAddr(); + + // In many cases the query is sent to a broadcast address. This address + // appears as a local address in the query message. We can't simply copy + // this address to a response message and use it as a source address. + // Instead we will need to use the address assigned to the interface + // on which the query has been received. In other cases, we will just + // use this address as a source address for the response. + // Do the same for DHCPv4-over-DHCPv6 exchanges. + if (local_addr.isV4Bcast() || query->isDhcp4o6()) { + local_addr = IfaceMgr::instance().getSocket(query).addr_; + } + + // We assume that there is an appropriate socket bound to this address + // and that the address is correct. This is safe assumption because + // the local address of the query is set when the query is received. + // The query sent to an incorrect address wouldn't have been received. + // However, if socket is closed for this address between the reception + // of the query and sending a response, the IfaceMgr should detect it + // and return an error. + response->setLocalAddr(local_addr); + // In many cases the query is sent to a broadcast address. This address + // appears as a local address in the query message. Therefore we can't + // simply copy local address from the query and use it as a source + // address for the response. Instead, we have to check what address our + // socket is bound to and use it as a source address. This operation + // may throw if for some reason the socket is closed. + /// @todo Consider an optimization that we use local address from + /// the query if this address is not broadcast. + response->setIndex(query->getIndex()); + response->setIface(query->getIface()); + } + + if (server_port_) { + response->setLocalPort(server_port_); + } else { + response->setLocalPort(DHCP4_SERVER_PORT); + } +} + +void +Dhcpv4Srv::adjustRemoteAddr(Dhcpv4Exchange& ex) { + // Initialize the pointers to the client's message and the server's + // response. + Pkt4Ptr query = ex.getQuery(); + Pkt4Ptr response = ex.getResponse(); + + // DHCPv4-over-DHCPv6 is simple + if (query->isDhcp4o6()) { + response->setRemoteAddr(query->getRemoteAddr()); + return; + } + + // The DHCPINFORM is slightly different than other messages in a sense + // that the server should always unicast the response to the ciaddr. + // It appears however that some clients don't set the ciaddr. We still + // want to provision these clients and we do what we can't to send the + // packet to the address where client can receive it. + if (query->getType() == DHCPINFORM) { + // If client adheres to RFC2131 it will set the ciaddr and in this + // case we always unicast our response to this address. + if (!query->getCiaddr().isV4Zero()) { + response->setRemoteAddr(query->getCiaddr()); + + // If we received DHCPINFORM via relay and the ciaddr is not set we + // will try to send the response via relay. The caveat is that the + // relay will not have any idea where to forward the packet because + // the yiaddr is likely not set. So, the broadcast flag is set so + // as the response may be broadcast. + } else if (query->isRelayed()) { + response->setRemoteAddr(query->getGiaddr()); + response->setFlags(response->getFlags() | BOOTP_BROADCAST); + + // If there is no ciaddr and no giaddr the only thing we can do is + // to use the source address of the packet. + } else { + response->setRemoteAddr(query->getRemoteAddr()); + } + // Remote address is now set so return. + return; + } + + // If received relayed message, server responds to the relay address. + if (query->isRelayed()) { + // The client should set the ciaddr when sending the DHCPINFORM + // but in case he didn't, the relay may not be able to determine the + // address of the client, because yiaddr is not set when responding + // to Confirm and the only address available was the source address + // of the client. The source address is however not used here because + // the message is relayed. Therefore, we set the BROADCAST flag so + // as the relay can broadcast the packet. + if ((query->getType() == DHCPINFORM) && + query->getCiaddr().isV4Zero()) { + response->setFlags(BOOTP_BROADCAST); + } + response->setRemoteAddr(query->getGiaddr()); + + // If giaddr is 0 but client set ciaddr, server should unicast the + // response to ciaddr. + } else if (!query->getCiaddr().isV4Zero()) { + response->setRemoteAddr(query->getCiaddr()); + + // We can't unicast the response to the client when sending DHCPNAK, + // because we haven't allocated address for him. Therefore, + // DHCPNAK is broadcast. + } else if (response->getType() == DHCPNAK) { + response->setRemoteAddr(IOAddress::IPV4_BCAST_ADDRESS()); + + // If yiaddr is set it means that we have created a lease for a client. + } else if (!response->getYiaddr().isV4Zero()) { + // If the broadcast bit is set in the flags field, we have to + // send the response to broadcast address. Client may have requested it + // because it doesn't support reception of messages on the interface + // which doesn't have an address assigned. The other case when response + // must be broadcasted is when our server does not support responding + // directly to a client without address assigned. + const bool bcast_flag = ((query->getFlags() & Pkt4::FLAG_BROADCAST_MASK) != 0); + if (!IfaceMgr::instance().isDirectResponseSupported() || bcast_flag) { + response->setRemoteAddr(IOAddress::IPV4_BCAST_ADDRESS()); + + // Client cleared the broadcast bit and we support direct responses + // so we should unicast the response to a newly allocated address - + // yiaddr. + } else { + response->setRemoteAddr(response ->getYiaddr()); + + } + + // In most cases, we should have the remote address found already. If we + // found ourselves at this point, the rational thing to do is to respond + // to the address we got the query from. + } else { + response->setRemoteAddr(query->getRemoteAddr()); + } + + // For testing *only*. + if (getSendResponsesToSource()) { + response->setRemoteAddr(query->getRemoteAddr()); + } +} + +void +Dhcpv4Srv::setFixedFields(Dhcpv4Exchange& ex) { + Pkt4Ptr query = ex.getQuery(); + Pkt4Ptr response = ex.getResponse(); + + // Step 1: Start with fixed fields defined on subnet level. + Subnet4Ptr subnet = ex.getContext()->subnet_; + if (subnet) { + IOAddress subnet_next_server = subnet->getSiaddr(); + if (!subnet_next_server.isV4Zero()) { + response->setSiaddr(subnet_next_server); + } + + const string& sname = subnet->getSname(); + if (!sname.empty()) { + // Converting string to (const uint8_t*, size_t len) format is + // tricky. reinterpret_cast is not the most elegant solution, + // but it does avoid us making unnecessary copy. We will convert + // sname and file fields in Pkt4 to string one day and life + // will be easier. + response->setSname(reinterpret_cast<const uint8_t*>(sname.c_str()), + sname.size()); + } + + const string& filename = subnet->getFilename(); + if (!filename.empty()) { + // Converting string to (const uint8_t*, size_t len) format is + // tricky. reinterpret_cast is not the most elegant solution, + // but it does avoid us making unnecessary copy. We will convert + // sname and file fields in Pkt4 to string one day and life + // will be easier. + response->setFile(reinterpret_cast<const uint8_t*>(filename.c_str()), + filename.size()); + } + } + + // Step 2: Try to set the values based on classes. + // Any values defined in classes will override those from subnet level. + const ClientClasses classes = query->getClasses(); + if (!classes.empty()) { + + // Let's get class definitions + const ClientClassDictionaryPtr& dict = + CfgMgr::instance().getCurrentCfg()->getClientClassDictionary(); + + // Now we need to iterate over the classes assigned to the + // query packet and find corresponding class definitions for it. + // We want the first value found for each field. We track how + // many we've found so we can stop if we have all three. + IOAddress next_server = IOAddress::IPV4_ZERO_ADDRESS(); + string sname; + string filename; + size_t found_cnt = 0; // How many fields we have found. + for (ClientClasses::const_iterator name = classes.cbegin(); + name != classes.cend() && found_cnt < 3; ++name) { + + ClientClassDefPtr cl = dict->findClass(*name); + if (!cl) { + // Let's skip classes that don't have definitions. Currently + // these are automatic classes VENDOR_CLASS_something, but there + // may be other classes assigned under other circumstances, e.g. + // by hooks. + continue; + } + + if (next_server == IOAddress::IPV4_ZERO_ADDRESS()) { + next_server = cl->getNextServer(); + if (!next_server.isV4Zero()) { + response->setSiaddr(next_server); + found_cnt++; + } + } + + if (sname.empty()) { + sname = cl->getSname(); + if (!sname.empty()) { + // Converting string to (const uint8_t*, size_t len) format is + // tricky. reinterpret_cast is not the most elegant solution, + // but it does avoid us making unnecessary copy. We will convert + // sname and file fields in Pkt4 to string one day and life + // will be easier. + response->setSname(reinterpret_cast<const uint8_t*>(sname.c_str()), + sname.size()); + found_cnt++; + } + } + + if (filename.empty()) { + filename = cl->getFilename(); + if (!filename.empty()) { + // Converting string to (const uint8_t*, size_t len) format is + // tricky. reinterpret_cast is not the most elegant solution, + // but it does avoid us making unnecessary copy. We will convert + // sname and file fields in Pkt4 to string one day and life + // will be easier. + response->setFile(reinterpret_cast<const uint8_t*>(filename.c_str()), + filename.size()); + found_cnt++; + } + } + } + } + + // Step 3: try to set values using HR. Any values coming from there will override + // the subnet or class values. + ex.setReservedMessageFields(); +} + +OptionPtr +Dhcpv4Srv::getNetmaskOption(const Subnet4Ptr& subnet) { + uint32_t netmask = getNetmask4(subnet->get().second).toUint32(); + + OptionPtr opt(new OptionInt<uint32_t>(Option::V4, + DHO_SUBNET_MASK, netmask)); + + return (opt); +} + +Pkt4Ptr +Dhcpv4Srv::processDiscover(Pkt4Ptr& discover, AllocEngine::ClientContext4Ptr& context) { + // server-id is forbidden. + sanityCheck(discover, FORBIDDEN); + + bool drop = false; + Subnet4Ptr subnet = selectSubnet(discover, drop); + + // Stop here if selectSubnet decided to drop the packet + if (drop) { + return (Pkt4Ptr()); + } + + Dhcpv4Exchange ex(alloc_engine_, discover, context, subnet, drop); + + // Stop here if Dhcpv4Exchange constructor decided to drop the packet + if (drop) { + return (Pkt4Ptr()); + } + + if (MultiThreadingMgr::instance().getMode()) { + // The lease reclamation cannot run at the same time. + ReadLockGuard share(alloc_engine_->getReadWriteMutex()); + + assignLease(ex); + } else { + assignLease(ex); + } + + if (!ex.getResponse()) { + // The offer is empty so return it *now*! + return (Pkt4Ptr()); + } + + // Adding any other options makes sense only when we got the lease. + if (!ex.getResponse()->getYiaddr().isV4Zero()) { + // If this is global reservation or the subnet doesn't belong to a shared + // network we have already fetched it and evaluated the classes. + ex.conditionallySetReservedClientClasses(); + + // Required classification + requiredClassify(ex); + + buildCfgOptionList(ex); + appendRequestedOptions(ex); + appendRequestedVendorOptions(ex); + // There are a few basic options that we always want to + // include in the response. If client did not request + // them we append them for him. + appendBasicOptions(ex); + + // Set fixed fields (siaddr, sname, filename) if defined in + // the reservation, class or subnet specific configuration. + setFixedFields(ex); + + } else { + // If the server can't offer an address, it drops the packet. + return (Pkt4Ptr()); + + } + + // Set the src/dest IP address, port and interface for the outgoing + // packet. + adjustIfaceData(ex); + + appendServerID(ex); + + return (ex.getResponse()); +} + +Pkt4Ptr +Dhcpv4Srv::processRequest(Pkt4Ptr& request, AllocEngine::ClientContext4Ptr& context) { + // Since we cannot distinguish between client states + // we'll make server-id is optional for REQUESTs. + sanityCheck(request, OPTIONAL); + + bool drop = false; + Subnet4Ptr subnet = selectSubnet(request, drop); + + // Stop here if selectSubnet decided to drop the packet + if (drop) { + return (Pkt4Ptr()); + } + + Dhcpv4Exchange ex(alloc_engine_, request, context, subnet, drop); + + // Stop here if Dhcpv4Exchange constructor decided to drop the packet + if (drop) { + return (Pkt4Ptr()); + } + + // Note that we treat REQUEST message uniformly, regardless if this is a + // first request (requesting for new address), renewing existing address + // or even rebinding. + if (MultiThreadingMgr::instance().getMode()) { + // The lease reclamation cannot run at the same time. + ReadLockGuard share(alloc_engine_->getReadWriteMutex()); + + assignLease(ex); + } else { + assignLease(ex); + } + + Pkt4Ptr response = ex.getResponse(); + if (!response) { + // The ack is empty so return it *now*! + return (Pkt4Ptr()); + } else if (request->inClass("BOOTP")) { + // Put BOOTP responses in the BOOTP class. + response->addClass("BOOTP"); + } + + // Adding any other options makes sense only when we got the lease. + if (!response->getYiaddr().isV4Zero()) { + // If this is global reservation or the subnet doesn't belong to a shared + // network we have already fetched it and evaluated the classes. + ex.conditionallySetReservedClientClasses(); + + // Required classification + requiredClassify(ex); + + buildCfgOptionList(ex); + appendRequestedOptions(ex); + appendRequestedVendorOptions(ex); + // There are a few basic options that we always want to + // include in the response. If client did not request + // them we append them for him. + appendBasicOptions(ex); + + // Set fixed fields (siaddr, sname, filename) if defined in + // the reservation, class or subnet specific configuration. + setFixedFields(ex); + } + + // Set the src/dest IP address, port and interface for the outgoing + // packet. + adjustIfaceData(ex); + + appendServerID(ex); + + // Return the pointer to the context, which will be required by the + // leases4_committed callouts. + context = ex.getContext(); + + return (ex.getResponse()); +} + +void +Dhcpv4Srv::processRelease(Pkt4Ptr& release, AllocEngine::ClientContext4Ptr& context) { + // Server-id is mandatory in DHCPRELEASE (see table 5, RFC2131) + // but ISC DHCP does not enforce this, so we'll follow suit. + sanityCheck(release, OPTIONAL); + + // Try to find client-id. Note that for the DHCPRELEASE we don't check if the + // match-client-id configuration parameter is disabled because this parameter + // is configured for subnets and we don't select subnet for the DHCPRELEASE. + // Bogus clients usually generate new client identifiers when they first + // connect to the network, so whatever client identifier has been used to + // acquire the lease, the client identifier carried in the DHCPRELEASE is + // likely to be the same and the lease will be correctly identified in the + // lease database. If supplied client identifier differs from the one used + // to acquire the lease then the lease will remain in the database and + // simply expire. + ClientIdPtr client_id; + OptionPtr opt = release->getOption(DHO_DHCP_CLIENT_IDENTIFIER); + if (opt) { + client_id = ClientIdPtr(new ClientId(opt->getData())); + } + + try { + // Do we have a lease for that particular address? + Lease4Ptr lease = LeaseMgrFactory::instance().getLease4(release->getCiaddr()); + + if (!lease) { + // No such lease - bogus release + LOG_DEBUG(lease4_logger, DBG_DHCP4_DETAIL, DHCP4_RELEASE_FAIL_NO_LEASE) + .arg(release->getLabel()) + .arg(release->getCiaddr().toText()); + return; + } + + if (!lease->belongsToClient(release->getHWAddr(), client_id)) { + LOG_DEBUG(lease4_logger, DBG_DHCP4_DETAIL, DHCP4_RELEASE_FAIL_WRONG_CLIENT) + .arg(release->getLabel()) + .arg(release->getCiaddr().toText()); + return; + } + + bool skip = false; + + // Execute all callouts registered for lease4_release + if (HooksManager::calloutsPresent(Hooks.hook_index_lease4_release_)) { + CalloutHandlePtr callout_handle = getCalloutHandle(release); + + // Use the RAII wrapper to make sure that the callout handle state is + // reset when this object goes out of scope. All hook points must do + // it to prevent possible circular dependency between the callout + // handle and its arguments. + ScopedCalloutHandleState callout_handle_state(callout_handle); + + // Enable copying options from the packet within hook library. + ScopedEnableOptionsCopy<Pkt4> query4_options_copy(release); + + // Pass the original packet + callout_handle->setArgument("query4", release); + + // Pass the lease to be updated + callout_handle->setArgument("lease4", lease); + + // Call all installed callouts + HooksManager::callCallouts(Hooks.hook_index_lease4_release_, + *callout_handle); + + // Callouts decided to skip the next processing step. The next + // processing step would be to send the packet, so skip at this + // stage means "drop response". + if ((callout_handle->getStatus() == CalloutHandle::NEXT_STEP_SKIP) || + (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_DROP)) { + skip = true; + LOG_DEBUG(hooks_logger, DBGLVL_PKT_HANDLING, + DHCP4_HOOK_LEASE4_RELEASE_SKIP) + .arg(release->getLabel()); + } + } + + // Callout didn't indicate to skip the release process. Let's release + // the lease. + if (!skip) { + // Ok, we've passed all checks. Let's release this address. + bool success = false; // was the removal operation successful? + bool expired = false; // explicitly expired instead of removed? + auto expiration_cfg = CfgMgr::instance().getCurrentCfg()->getCfgExpiration(); + + // Delete lease only if affinity is disabled. + if (expiration_cfg->getFlushReclaimedTimerWaitTime() && + expiration_cfg->getHoldReclaimedTime() && + lease->valid_lft_ != Lease::INFINITY_LFT) { + // Expire the lease. + lease->valid_lft_ = 0; + LeaseMgrFactory::instance().updateLease4(lease); + expired = true; + success = true; + } else { + success = LeaseMgrFactory::instance().deleteLease(lease); + } + + if (success) { + context.reset(new AllocEngine::ClientContext4()); + context->old_lease_ = lease; + + // Release successful + LOG_INFO(lease4_logger, DHCP4_RELEASE) + .arg(release->getLabel()) + .arg(lease->addr_.toText()); + + if (expired) { + LOG_INFO(lease4_logger, DHCP4_RELEASE_EXPIRED) + .arg(release->getLabel()) + .arg(lease->addr_.toText()); + } else { + LOG_INFO(lease4_logger, DHCP4_RELEASE_DELETED) + .arg(release->getLabel()) + .arg(lease->addr_.toText()); + + // Need to decrease statistic for assigned addresses. + StatsMgr::instance().addValue( + StatsMgr::generateName("subnet", lease->subnet_id_, "assigned-addresses"), + static_cast<int64_t>(-1)); + + const auto& subnet = CfgMgr::instance().getCurrentCfg()->getCfgSubnets4()->getBySubnetId(lease->subnet_id_); + if (subnet) { + const auto& pool = subnet->getPool(Lease::TYPE_V4, lease->addr_, false); + if (pool) { + StatsMgr::instance().addValue( + StatsMgr::generateName("subnet", subnet->getID(), + StatsMgr::generateName("pool", pool->getID(), "assigned-addresses")), + static_cast<int64_t>(-1)); + } + } + + // Remove existing DNS entries for the lease, if any. + queueNCR(CHG_REMOVE, lease); + } + } else { + // Release failed + LOG_ERROR(lease4_logger, DHCP4_RELEASE_FAIL) + .arg(release->getLabel()) + .arg(lease->addr_.toText()); + } + } + } catch (const isc::Exception& ex) { + LOG_ERROR(lease4_logger, DHCP4_RELEASE_EXCEPTION) + .arg(release->getLabel()) + .arg(release->getCiaddr()) + .arg(ex.what()); + } +} + +void +Dhcpv4Srv::processDecline(Pkt4Ptr& decline, AllocEngine::ClientContext4Ptr& context) { + // Server-id is mandatory in DHCPDECLINE (see table 5, RFC2131) + // but ISC DHCP does not enforce this, so we'll follow suit. + sanityCheck(decline, OPTIONAL); + + // Client is supposed to specify the address being declined in + // Requested IP address option, but must not set its ciaddr. + // (again, see table 5 in RFC2131). + + OptionCustomPtr opt_requested_address = boost::dynamic_pointer_cast< + OptionCustom>(decline->getOption(DHO_DHCP_REQUESTED_ADDRESS)); + if (!opt_requested_address) { + + isc_throw(RFCViolation, "Mandatory 'Requested IP address' option missing" + " in DHCPDECLINE sent from " << decline->getLabel()); + } + IOAddress addr(opt_requested_address->readAddress()); + + // We could also extract client's address from ciaddr, but that's clearly + // against RFC2131. + + // Now we need to check whether this address really belongs to the client + // that attempts to decline it. + const Lease4Ptr lease = LeaseMgrFactory::instance().getLease4(addr); + + if (!lease) { + // Client tried to decline an address, but we don't have a lease for + // that address. Let's ignore it. + // + // We could assume that we're recovering from a mishandled migration + // to a new server and mark the address as declined, but the window of + // opportunity for that to be useful is small and the attack vector + // would be pretty severe. + LOG_WARN(dhcp4_logger, DHCP4_DECLINE_LEASE_NOT_FOUND) + .arg(addr.toText()).arg(decline->getLabel()); + return; + } + + // Get client-id, if available. + OptionPtr opt_clientid = decline->getOption(DHO_DHCP_CLIENT_IDENTIFIER); + ClientIdPtr client_id; + if (opt_clientid) { + client_id.reset(new ClientId(opt_clientid->getData())); + } + + // Check if the client attempted to decline a lease it doesn't own. + if (!lease->belongsToClient(decline->getHWAddr(), client_id)) { + + // Get printable hardware addresses + string client_hw = decline->getHWAddr() ? + decline->getHWAddr()->toText(false) : "(none)"; + string lease_hw = lease->hwaddr_ ? + lease->hwaddr_->toText(false) : "(none)"; + + // Get printable client-ids + string client_id_txt = client_id ? client_id->toText() : "(none)"; + string lease_id_txt = lease->client_id_ ? + lease->client_id_->toText() : "(none)"; + + // Print the warning and we're done here. + LOG_WARN(dhcp4_logger, DHCP4_DECLINE_LEASE_MISMATCH) + .arg(addr.toText()).arg(decline->getLabel()) + .arg(client_hw).arg(lease_hw).arg(client_id_txt).arg(lease_id_txt); + + return; + } + + // Ok, all is good. The client is reporting its own address. Let's + // process it. + declineLease(lease, decline, context); +} + +void +Dhcpv4Srv::declineLease(const Lease4Ptr& lease, const Pkt4Ptr& decline, + AllocEngine::ClientContext4Ptr& context) { + + // Let's check if there are hooks installed for decline4 hook point. + // If they are, let's pass the lease and client's packet. If the hook + // sets status to drop, we reject this Decline. + if (HooksManager::calloutsPresent(Hooks.hook_index_lease4_decline_)) { + CalloutHandlePtr callout_handle = getCalloutHandle(decline); + + // Use the RAII wrapper to make sure that the callout handle state is + // reset when this object goes out of scope. All hook points must do + // it to prevent possible circular dependency between the callout + // handle and its arguments. + ScopedCalloutHandleState callout_handle_state(callout_handle); + + // Enable copying options from the packet within hook library. + ScopedEnableOptionsCopy<Pkt4> query4_options_copy(decline); + + // Pass the original packet + callout_handle->setArgument("query4", decline); + + // Pass the lease to be updated + callout_handle->setArgument("lease4", lease); + + // Call callouts + HooksManager::callCallouts(Hooks.hook_index_lease4_decline_, + *callout_handle); + + // Check if callouts decided to skip the next processing step. + // If any of them did, we will drop the packet. + if ((callout_handle->getStatus() == CalloutHandle::NEXT_STEP_SKIP) || + (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_DROP)) { + LOG_DEBUG(hooks_logger, DBGLVL_PKT_HANDLING, DHCP4_HOOK_DECLINE_SKIP) + .arg(decline->getLabel()).arg(lease->addr_.toText()); + return; + } + } + + Lease4Ptr old_values = boost::make_shared<Lease4>(*lease); + + // @todo: Call hooks. + + // We need to disassociate the lease from the client. Once we move a lease + // to declined state, it is no longer associated with the client in any + // way. + lease->decline(CfgMgr::instance().getCurrentCfg()->getDeclinePeriod()); + + try { + LeaseMgrFactory::instance().updateLease4(lease); + } catch (const Exception& ex) { + // Update failed. + LOG_ERROR(lease4_logger, DHCP4_DECLINE_FAIL) + .arg(decline->getLabel()) + .arg(lease->addr_.toText()) + .arg(ex.what()); + return; + } + + // Remove existing DNS entries for the lease, if any. + // queueNCR will do the necessary checks and will skip the update, if not needed. + queueNCR(CHG_REMOVE, old_values); + + // Bump up the statistics. + + // Per subnet declined addresses counter. + StatsMgr::instance().addValue( + StatsMgr::generateName("subnet", lease->subnet_id_, "declined-addresses"), + static_cast<int64_t>(1)); + + const auto& subnet = CfgMgr::instance().getCurrentCfg()->getCfgSubnets4()->getBySubnetId(lease->subnet_id_); + if (subnet) { + const auto& pool = subnet->getPool(Lease::TYPE_V4, lease->addr_, false); + if (pool) { + StatsMgr::instance().addValue( + StatsMgr::generateName("subnet", subnet->getID(), + StatsMgr::generateName("pool", pool->getID(), "declined-addresses")), + static_cast<int64_t>(1)); + } + } + + // Global declined addresses counter. + StatsMgr::instance().addValue("declined-addresses", static_cast<int64_t>(1)); + + // We do not want to decrease the assigned-addresses at this time. While + // technically a declined address is no longer allocated, the primary usage + // of the assigned-addresses statistic is to monitor pool utilization. Most + // people would forget to include declined-addresses in the calculation, + // and simply do assigned-addresses/total-addresses. This would have a bias + // towards under-representing pool utilization, if we decreased allocated + // immediately after receiving DHCPDECLINE, rather than later when we recover + // the address. + + context.reset(new AllocEngine::ClientContext4()); + context->new_lease_ = lease; + + LOG_INFO(lease4_logger, DHCP4_DECLINE_LEASE).arg(lease->addr_.toText()) + .arg(decline->getLabel()).arg(lease->valid_lft_); +} + +Pkt4Ptr +Dhcpv4Srv::processInform(Pkt4Ptr& inform, AllocEngine::ClientContext4Ptr& context) { + // server-id is supposed to be forbidden (as is requested address) + // but ISC DHCP does not enforce either. So neither will we. + sanityCheck(inform, OPTIONAL); + + bool drop = false; + Subnet4Ptr subnet = selectSubnet(inform, drop); + + // Stop here if selectSubnet decided to drop the packet + if (drop) { + return (Pkt4Ptr()); + } + + Dhcpv4Exchange ex(alloc_engine_, inform, context, subnet, drop); + + // Stop here if Dhcpv4Exchange constructor decided to drop the packet + if (drop) { + return (Pkt4Ptr()); + } + + Pkt4Ptr ack = ex.getResponse(); + + // If this is global reservation or the subnet doesn't belong to a shared + // network we have already fetched it and evaluated the classes. + ex.conditionallySetReservedClientClasses(); + + requiredClassify(ex); + + buildCfgOptionList(ex); + appendRequestedOptions(ex); + appendRequestedVendorOptions(ex); + appendBasicOptions(ex); + adjustIfaceData(ex); + + // Set fixed fields (siaddr, sname, filename) if defined in + // the reservation, class or subnet specific configuration. + setFixedFields(ex); + + // There are cases for the DHCPINFORM that the server receives it via + // relay but will send the response to the client's unicast address + // carried in the ciaddr. In this case, the giaddr and hops field should + // be cleared (these fields were copied by the copyDefaultFields function). + // Also Relay Agent Options should be removed if present. + if (ack->getRemoteAddr() != inform->getGiaddr()) { + LOG_DEBUG(packet4_logger, DBG_DHCP4_DETAIL, DHCP4_INFORM_DIRECT_REPLY) + .arg(inform->getLabel()) + .arg(ack->getRemoteAddr()) + .arg(ack->getIface()); + ack->setHops(0); + ack->setGiaddr(IOAddress::IPV4_ZERO_ADDRESS()); + ack->delOption(DHO_DHCP_AGENT_OPTIONS); + } + + // The DHCPACK must contain server id. + appendServerID(ex); + + return (ex.getResponse()); +} + +bool +Dhcpv4Srv::accept(const Pkt4Ptr& query) const { + // Check that the message type is accepted by the server. We rely on the + // function called to log a message if needed. + if (!acceptMessageType(query)) { + return (false); + } + // Check if the message from directly connected client (if directly + // connected) should be dropped or processed. + if (!acceptDirectRequest(query)) { + LOG_DEBUG(bad_packet4_logger, DBGLVL_PKT_HANDLING, DHCP4_PACKET_DROP_0002) + .arg(query->getLabel()) + .arg(query->getIface()); + return (false); + } + + // Check if the DHCPv4 packet has been sent to us or to someone else. + // If it hasn't been sent to us, drop it! + if (!acceptServerId(query)) { + LOG_DEBUG(bad_packet4_logger, DBGLVL_PKT_HANDLING, DHCP4_PACKET_DROP_0003) + .arg(query->getLabel()) + .arg(query->getIface()); + return (false); + } + + return (true); +} + +bool +Dhcpv4Srv::acceptDirectRequest(const Pkt4Ptr& pkt) const { + // Accept all relayed messages. + if (pkt->isRelayed()) { + return (true); + } + + // Accept all DHCPv4-over-DHCPv6 messages. + if (pkt->isDhcp4o6()) { + return (true); + } + + // The source address must not be zero for the DHCPINFORM message from + // the directly connected client because the server will not know where + // to respond if the ciaddr was not present. + try { + if (pkt->getType() == DHCPINFORM) { + if (pkt->getRemoteAddr().isV4Zero() && + pkt->getCiaddr().isV4Zero()) { + return (false); + } + } + } catch (...) { + // If we got here, it is probably because the message type hasn't + // been set. But, this should not really happen assuming that + // we validate the message type prior to calling this function. + return (false); + } + bool drop = false; + bool result = (!pkt->getLocalAddr().isV4Bcast() || + selectSubnet(pkt, drop, true)); + if (drop) { + // The packet must be dropped but as sanity_only is true it is dead code. + return (false); + } + return (result); +} + +bool +Dhcpv4Srv::acceptMessageType(const Pkt4Ptr& query) const { + // When receiving a packet without message type option, getType() will + // throw. + int type; + try { + type = query->getType(); + + } catch (...) { + LOG_DEBUG(bad_packet4_logger, DBGLVL_PKT_HANDLING, DHCP4_PACKET_DROP_0004) + .arg(query->getLabel()) + .arg(query->getIface()); + return (false); + } + + // Once we know that the message type is within a range of defined DHCPv4 + // messages, we do a detailed check to make sure that the received message + // is targeted at server. Note that we could have received some Offer + // message broadcasted by the other server to a relay. Even though, the + // server would rather unicast its response to a relay, let's be on the + // safe side. Also, we want to drop other messages which we don't support. + // All these valid messages that we are not going to process are dropped + // silently. + + switch(type) { + case DHCPDISCOVER: + case DHCPREQUEST: + case DHCPRELEASE: + case DHCPDECLINE: + case DHCPINFORM: + return (true); + break; + + case DHCP_NOTYPE: + LOG_DEBUG(bad_packet4_logger, DBGLVL_PKT_HANDLING, DHCP4_PACKET_DROP_0009) + .arg(query->getLabel()); + break; + + default: + // If we receive a message with a non-existing type, we are logging it. + if (type >= DHCP_TYPES_EOF) { + LOG_DEBUG(bad_packet4_logger, DBGLVL_PKT_HANDLING, DHCP4_PACKET_DROP_0005) + .arg(query->getLabel()) + .arg(type); + } else { + // Exists but we don't support it. + LOG_DEBUG(bad_packet4_logger, DBGLVL_PKT_HANDLING, DHCP4_PACKET_DROP_0006) + .arg(query->getLabel()) + .arg(type); + } + break; + } + + return (false); +} + +bool +Dhcpv4Srv::acceptServerId(const Pkt4Ptr& query) const { + // This function is meant to be called internally by the server class, so + // we rely on the caller to sanity check the pointer and we don't check + // it here. + + // Check if server identifier option is present. If it is not present + // we accept the message because it is targeted to all servers. + // Note that we don't check cases that server identifier is mandatory + // but not present. This is meant to be sanity checked in other + // functions. + OptionPtr option = query->getOption(DHO_DHCP_SERVER_IDENTIFIER); + if (!option) { + return (true); + } + // Server identifier is present. Let's convert it to 4-byte address + // and try to match with server identifiers used by the server. + OptionCustomPtr option_custom = + boost::dynamic_pointer_cast<OptionCustom>(option); + // Unable to convert the option to the option type which encapsulates it. + // We treat this as non-matching server id. + if (!option_custom) { + return (false); + } + // The server identifier option should carry exactly one IPv4 address. + // If the option definition for the server identifier doesn't change, + // the OptionCustom object should have exactly one IPv4 address and + // this check is somewhat redundant. On the other hand, if someone + // breaks option it may be better to check that here. + if (option_custom->getDataFieldsNum() != 1) { + return (false); + } + + // The server identifier MUST be an IPv4 address. If given address is + // v6, it is wrong. + IOAddress server_id = option_custom->readAddress(); + if (!server_id.isV4()) { + return (false); + } + + // According to RFC5107, the RAI_OPTION_SERVER_ID_OVERRIDE option if + // present, should match DHO_DHCP_SERVER_IDENTIFIER option. + OptionPtr rai_option = query->getOption(DHO_DHCP_AGENT_OPTIONS); + if (rai_option) { + OptionPtr rai_suboption = rai_option->getOption(RAI_OPTION_SERVER_ID_OVERRIDE); + if (rai_suboption && (server_id.toBytes() == rai_suboption->toBinary())) { + return (true); + } + } + + // Skip address check if configured to ignore the server id. + SrvConfigPtr cfg = CfgMgr::instance().getCurrentCfg(); + if (cfg->getIgnoreServerIdentifier()) { + return (true); + } + + // This function iterates over all interfaces on which the + // server is listening to find the one which has a socket bound + // to the address carried in the server identifier option. + // This has some performance implications. However, given that + // typically there will be just a few active interfaces the + // performance hit should be acceptable. If it turns out to + // be significant, we will have to cache server identifiers + // when sockets are opened. + if (IfaceMgr::instance().hasOpenSocket(server_id)) { + return (true); + } + + // There are some cases when an administrator explicitly sets server + // identifier (option 54) that should be used for a given, subnet, + // network etc. It doesn't have to be an address assigned to any of + // the server interfaces. Thus, we have to check if the server + // identifier received is the one that we explicitly set in the + // server configuration. At this point, we don't know which subnet + // the client belongs to so we can't match the server id with any + // subnet. We simply check if this server identifier is configured + // anywhere. This should be good enough to eliminate exchanges + // with other servers in the same network. + + /// @todo Currently we only check server identifiers configured at the + /// subnet, shared network, client class and global levels. + /// This should be sufficient for most of cases. At this point, trying to + /// support server identifiers on the host reservations level seems to be an + /// overkill and is probably not needed. In fact, at this point we don't + /// know the reservations for the client communicating with the server. + /// We may revise some of these choices in the future. + + // Check if there is at least one subnet configured with this server + // identifier. + ConstCfgSubnets4Ptr cfg_subnets = cfg->getCfgSubnets4(); + if (cfg_subnets->hasSubnetWithServerId(server_id)) { + return (true); + } + + // This server identifier is not configured for any of the subnets, so + // check on the shared network level. + CfgSharedNetworks4Ptr cfg_networks = cfg->getCfgSharedNetworks4(); + if (cfg_networks->hasNetworkWithServerId(server_id)) { + return (true); + } + + // Check if the server identifier is configured at client class level. + const ClientClasses& classes = query->getClasses(); + for (ClientClasses::const_iterator cclass = classes.cbegin(); + cclass != classes.cend(); ++cclass) { + // Find the client class definition for this class + const ClientClassDefPtr& ccdef = CfgMgr::instance().getCurrentCfg()-> + getClientClassDictionary()->findClass(*cclass); + if (!ccdef) { + continue; + } + + if (ccdef->getCfgOption()->empty()) { + // Skip classes which don't configure options + continue; + } + + OptionCustomPtr context_opt_server_id = boost::dynamic_pointer_cast<OptionCustom> + (ccdef->getCfgOption()->get(DHCP4_OPTION_SPACE, DHO_DHCP_SERVER_IDENTIFIER).option_); + if (context_opt_server_id && (context_opt_server_id->readAddress() == server_id)) { + return (true); + } + } + + // Finally, it is possible that the server identifier is specified + // on the global level. + ConstCfgOptionPtr cfg_global_options = cfg->getCfgOption(); + OptionCustomPtr opt_server_id = boost::dynamic_pointer_cast<OptionCustom> + (cfg_global_options->get(DHCP4_OPTION_SPACE, DHO_DHCP_SERVER_IDENTIFIER).option_); + + return (opt_server_id && (opt_server_id->readAddress() == server_id)); +} + +void +Dhcpv4Srv::sanityCheck(const Pkt4Ptr& query, RequirementLevel serverid) { + OptionPtr server_id = query->getOption(DHO_DHCP_SERVER_IDENTIFIER); + switch (serverid) { + case FORBIDDEN: + if (server_id) { + isc_throw(RFCViolation, "Server-id option was not expected, but" + << " received in message " + << query->getName()); + } + break; + + case MANDATORY: + if (!server_id) { + isc_throw(RFCViolation, "Server-id option was expected, but not" + " received in message " + << query->getName()); + } + break; + + case OPTIONAL: + // do nothing here + ; + } + + // If there is HWAddress set and it is non-empty, then we're good + if (query->getHWAddr() && !query->getHWAddr()->hwaddr_.empty()) { + return; + } + + // There has to be something to uniquely identify the client: + // either non-zero MAC address or client-id option present (or both) + OptionPtr client_id = query->getOption(DHO_DHCP_CLIENT_IDENTIFIER); + + // If there's no client-id (or a useless one is provided, i.e. 0 length) + if (!client_id || client_id->len() == client_id->getHeaderLen()) { + isc_throw(RFCViolation, "Missing or useless client-id and no HW address" + " provided in message " + << query->getName()); + } +} + +void Dhcpv4Srv::classifyPacket(const Pkt4Ptr& pkt) { + Dhcpv4Exchange::classifyPacket(pkt); +} + +void Dhcpv4Srv::requiredClassify(Dhcpv4Exchange& ex) { + // First collect required classes + Pkt4Ptr query = ex.getQuery(); + ClientClasses classes = query->getClasses(true); + Subnet4Ptr subnet = ex.getContext()->subnet_; + + if (subnet) { + // Begin by the shared-network + SharedNetwork4Ptr network; + subnet->getSharedNetwork(network); + if (network) { + const ClientClasses& to_add = network->getRequiredClasses(); + for (ClientClasses::const_iterator cclass = to_add.cbegin(); + cclass != to_add.cend(); ++cclass) { + classes.insert(*cclass); + } + } + + // Followed by the subnet + const ClientClasses& to_add = subnet->getRequiredClasses(); + for(ClientClasses::const_iterator cclass = to_add.cbegin(); + cclass != to_add.cend(); ++cclass) { + classes.insert(*cclass); + } + + // And finish by the pool + Pkt4Ptr resp = ex.getResponse(); + IOAddress addr = IOAddress::IPV4_ZERO_ADDRESS(); + if (resp) { + addr = resp->getYiaddr(); + } + if (!addr.isV4Zero()) { + PoolPtr pool = subnet->getPool(Lease::TYPE_V4, addr, false); + if (pool) { + const ClientClasses& to_add = pool->getRequiredClasses(); + for (ClientClasses::const_iterator cclass = to_add.cbegin(); + cclass != to_add.cend(); ++cclass) { + classes.insert(*cclass); + } + } + } + + // host reservation??? + } + + // Run match expressions + // Note getClientClassDictionary() cannot be null + const ClientClassDictionaryPtr& dict = + CfgMgr::instance().getCurrentCfg()->getClientClassDictionary(); + for (ClientClasses::const_iterator cclass = classes.cbegin(); + cclass != classes.cend(); ++cclass) { + const ClientClassDefPtr class_def = dict->findClass(*cclass); + if (!class_def) { + LOG_DEBUG(dhcp4_logger, DBG_DHCP4_BASIC, DHCP4_CLASS_UNDEFINED) + .arg(*cclass); + continue; + } + const ExpressionPtr& expr_ptr = class_def->getMatchExpr(); + // Nothing to do without an expression to evaluate + if (!expr_ptr) { + LOG_DEBUG(dhcp4_logger, DBG_DHCP4_BASIC, DHCP4_CLASS_UNTESTABLE) + .arg(*cclass); + continue; + } + // Evaluate the expression which can return false (no match), + // true (match) or raise an exception (error) + try { + bool status = evaluateBool(*expr_ptr, *query); + if (status) { + LOG_INFO(dhcp4_logger, EVAL_RESULT) + .arg(*cclass) + .arg(status); + // Matching: add the class + query->addClass(*cclass); + } else { + LOG_DEBUG(dhcp4_logger, DBG_DHCP4_DETAIL, EVAL_RESULT) + .arg(*cclass) + .arg(status); + } + } catch (const Exception& ex) { + LOG_ERROR(dhcp4_logger, EVAL_RESULT) + .arg(*cclass) + .arg(ex.what()); + } catch (...) { + LOG_ERROR(dhcp4_logger, EVAL_RESULT) + .arg(*cclass) + .arg("get exception?"); + } + } +} + +void +Dhcpv4Srv::deferredUnpack(Pkt4Ptr& query) { + // Iterate on the list of deferred option codes + BOOST_FOREACH(const uint16_t& code, query->getDeferredOptions()) { + OptionDefinitionPtr def; + // Iterate on client classes + const ClientClasses& classes = query->getClasses(); + for (ClientClasses::const_iterator cclass = classes.cbegin(); + cclass != classes.cend(); ++cclass) { + // Get the client class definition for this class + const ClientClassDefPtr& ccdef = + CfgMgr::instance().getCurrentCfg()-> + getClientClassDictionary()->findClass(*cclass); + // If not found skip it + if (!ccdef) { + continue; + } + // If there is no option definition skip it + if (!ccdef->getCfgOptionDef()) { + continue; + } + def = ccdef->getCfgOptionDef()->get(DHCP4_OPTION_SPACE, code); + // Stop at the first client class with a definition + if (def) { + break; + } + } + // If not found try the global definition + if (!def) { + def = LibDHCP::getOptionDef(DHCP4_OPTION_SPACE, code); + } + if (!def) { + def = LibDHCP::getRuntimeOptionDef(DHCP4_OPTION_SPACE, code); + } + // Finish by last resort definition + if (!def) { + def = LibDHCP::getLastResortOptionDef(DHCP4_OPTION_SPACE, code); + } + // If not defined go to the next option + if (!def) { + continue; + } + // Get the existing option for its content and remove all + OptionPtr opt = query->getOption(code); + if (!opt) { + // should not happen but do not crash anyway + LOG_DEBUG(bad_packet4_logger, DBG_DHCP4_DETAIL, + DHCP4_DEFERRED_OPTION_MISSING) + .arg(code); + continue; + } + // Because options have already been fused, the buffer contains entire + // data. + const OptionBuffer buf = opt->getData(); + try { + // Unpack the option + opt = def->optionFactory(Option::V4, code, buf); + } catch (const std::exception& e) { + // Failed to parse the option. + LOG_DEBUG(bad_packet4_logger, DBG_DHCP4_DETAIL, + DHCP4_DEFERRED_OPTION_UNPACK_FAIL) + .arg(code) + .arg(e.what()); + continue; + } + while (query->delOption(code)) { + // continue + } + // Add the unpacked option. + query->addOption(opt); + } +} + +void +Dhcpv4Srv::startD2() { + D2ClientMgr& d2_mgr = CfgMgr::instance().getD2ClientMgr(); + if (d2_mgr.ddnsEnabled()) { + // Updates are enabled, so lets start the sender, passing in + // our error handler. + // This may throw so wherever this is called needs to ready. + d2_mgr.startSender(std::bind(&Dhcpv4Srv::d2ClientErrorHandler, + this, ph::_1, ph::_2)); + } +} + +void +Dhcpv4Srv::stopD2() { + D2ClientMgr& d2_mgr = CfgMgr::instance().getD2ClientMgr(); + if (d2_mgr.ddnsEnabled()) { + // Updates are enabled, so lets stop the sender + d2_mgr.stopSender(); + } +} + +void +Dhcpv4Srv::d2ClientErrorHandler(const + dhcp_ddns::NameChangeSender::Result result, + dhcp_ddns::NameChangeRequestPtr& ncr) { + LOG_ERROR(ddns4_logger, DHCP4_DDNS_REQUEST_SEND_FAILED). + arg(result).arg((ncr ? ncr->toText() : " NULL ")); + // We cannot communicate with kea-dhcp-ddns, suspend further updates. + /// @todo We may wish to revisit this, but for now we will simply turn + /// them off. + CfgMgr::instance().getD2ClientMgr().suspendUpdates(); +} + +std::string +Dhcpv4Srv::getVersion(bool extended) { + std::stringstream tmp; + + tmp << VERSION; + if (extended) { + tmp << endl << EXTENDED_VERSION << endl; + tmp << "linked with:" << endl; + tmp << Logger::getVersion() << endl; + tmp << CryptoLink::getVersion() << endl; + tmp << "database:" << endl; +#ifdef HAVE_MYSQL + tmp << MySqlLeaseMgr::getDBVersion() << endl; +#endif +#ifdef HAVE_PGSQL + tmp << PgSqlLeaseMgr::getDBVersion() << endl; +#endif + tmp << Memfile_LeaseMgr::getDBVersion(Memfile_LeaseMgr::V4); + + // @todo: more details about database runtime + } + + return (tmp.str()); +} + +void Dhcpv4Srv::processStatsReceived(const Pkt4Ptr& query) { + // Note that we're not bumping pkt4-received statistic as it was + // increased early in the packet reception code. + + string stat_name = "pkt4-unknown-received"; + try { + switch (query->getType()) { + case DHCPDISCOVER: + stat_name = "pkt4-discover-received"; + break; + case DHCPOFFER: + // Should not happen, but let's keep a counter for it + stat_name = "pkt4-offer-received"; + break; + case DHCPREQUEST: + stat_name = "pkt4-request-received"; + break; + case DHCPACK: + // Should not happen, but let's keep a counter for it + stat_name = "pkt4-ack-received"; + break; + case DHCPNAK: + // Should not happen, but let's keep a counter for it + stat_name = "pkt4-nak-received"; + break; + case DHCPRELEASE: + stat_name = "pkt4-release-received"; + break; + case DHCPDECLINE: + stat_name = "pkt4-decline-received"; + break; + case DHCPINFORM: + stat_name = "pkt4-inform-received"; + break; + default: + ; // do nothing + } + } + catch (...) { + // If the incoming packet doesn't have option 53 (message type) + // or a hook set pkt4_receive_skip, then Pkt4::getType() may + // throw an exception. That's ok, we'll then use the default + // name of pkt4-unknown-received. + } + + isc::stats::StatsMgr::instance().addValue(stat_name, + static_cast<int64_t>(1)); +} + +void Dhcpv4Srv::processStatsSent(const Pkt4Ptr& response) { + // Increase generic counter for sent packets. + isc::stats::StatsMgr::instance().addValue("pkt4-sent", + static_cast<int64_t>(1)); + + // Increase packet type specific counter for packets sent. + string stat_name; + switch (response->getType()) { + case DHCPOFFER: + stat_name = "pkt4-offer-sent"; + break; + case DHCPACK: + stat_name = "pkt4-ack-sent"; + break; + case DHCPNAK: + stat_name = "pkt4-nak-sent"; + break; + default: + // That should never happen + return; + } + + isc::stats::StatsMgr::instance().addValue(stat_name, + static_cast<int64_t>(1)); +} + +int Dhcpv4Srv::getHookIndexBuffer4Receive() { + return (Hooks.hook_index_buffer4_receive_); +} + +int Dhcpv4Srv::getHookIndexPkt4Receive() { + return (Hooks.hook_index_pkt4_receive_); +} + +int Dhcpv4Srv::getHookIndexSubnet4Select() { + return (Hooks.hook_index_subnet4_select_); +} + +int Dhcpv4Srv::getHookIndexLease4Release() { + return (Hooks.hook_index_lease4_release_); +} + +int Dhcpv4Srv::getHookIndexPkt4Send() { + return (Hooks.hook_index_pkt4_send_); +} + +int Dhcpv4Srv::getHookIndexBuffer4Send() { + return (Hooks.hook_index_buffer4_send_); +} + +int Dhcpv4Srv::getHookIndexLease4Decline() { + return (Hooks.hook_index_lease4_decline_); +} + +void Dhcpv4Srv::discardPackets() { + // Dump all of our current packets, anything that is mid-stream + HooksManager::clearParkingLots(); +} + +std::list<std::list<std::string>> Dhcpv4Srv::jsonPathsToRedact() const { + static std::list<std::list<std::string>> const list({ + {"config-control", "config-databases", "[]"}, + {"hooks-libraries", "[]", "parameters", "*"}, + {"hosts-database"}, + {"hosts-databases", "[]"}, + {"lease-database"}, + }); + return list; +} + +} // namespace dhcp +} // namespace isc |