dhcp4_srv.cc 118 KB
Newer Older
Francis Dupont's avatar
Francis Dupont committed
1
// Copyright (C) 2011-2017 Internet Systems Consortium, Inc. ("ISC")
2
//
3 4 5
// 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/.
6

7
#include <config.h>
8
#include <dhcp/dhcp4.h>
9 10
#include <dhcp/duid.h>
#include <dhcp/hwaddr.h>
11
#include <dhcp/iface_mgr.h>
12
#include <dhcp/libdhcp++.h>
13
#include <dhcp/option4_addrlst.h>
14
#include <dhcp/option_int.h>
15
#include <dhcp/option_int_array.h>
16
#include <dhcp/option_vendor.h>
17
#include <dhcp/option_string.h>
18
#include <dhcp/pkt4.h>
19 20
#include <dhcp/pkt4o6.h>
#include <dhcp/pkt6.h>
21
#include <dhcp/docsis3_option_defs.h>
22
#include <dhcp4/dhcp4to6_ipc.h>
23 24
#include <dhcp4/dhcp4_log.h>
#include <dhcp4/dhcp4_srv.h>
25 26
#include <dhcpsrv/addr_utilities.h>
#include <dhcpsrv/callout_handle_store.h>
27
#include <dhcpsrv/cfgmgr.h>
28
#include <dhcpsrv/cfg_host_operations.h>
29
#include <dhcpsrv/cfg_subnets4.h>
30 31
#include <dhcpsrv/lease_mgr.h>
#include <dhcpsrv/lease_mgr_factory.h>
32
#include <dhcpsrv/ncr_generator.h>
33
#include <dhcpsrv/shared_network.h>
34
#include <dhcpsrv/subnet.h>
35
#include <dhcpsrv/subnet_selector.h>
36
#include <dhcpsrv/utils.h>
37
#include <dhcpsrv/utils.h>
38 39
#include <eval/evaluate.h>
#include <eval/eval_messages.h>
40
#include <hooks/callout_handle.h>
41
#include <hooks/hooks_log.h>
42
#include <hooks/hooks_manager.h>
43
#include <stats/stats_mgr.h>
44
#include <util/strutil.h>
45
#include <stats/stats_mgr.h>
46 47
#include <log/logger.h>
#include <cryptolink/cryptolink.h>
48
#include <cfgrpt/config_report.h>
49

50 51 52 53 54 55
#ifdef HAVE_MYSQL
#include <dhcpsrv/mysql_lease_mgr.h>
#endif
#ifdef HAVE_PGSQL
#include <dhcpsrv/pgsql_lease_mgr.h>
#endif
Tomek Mrugalski's avatar
Tomek Mrugalski committed
56 57
#ifdef HAVE_CQL
#include <dhcpsrv/cql_lease_mgr.h>
58
#endif
59 60
#include <dhcpsrv/memfile_lease_mgr.h>

61
#include <boost/algorithm/string/join.hpp>
62
#include <boost/bind.hpp>
63
#include <boost/foreach.hpp>
64
#include <boost/shared_ptr.hpp>
65 66 67

#include <iomanip>

68 69
using namespace isc;
using namespace isc::asiolink;
70
using namespace isc::cryptolink;
71
using namespace isc::dhcp;
72
using namespace isc::dhcp_ddns;
73
using namespace isc::hooks;
74
using namespace isc::log;
Tomek Mrugalski's avatar
Tomek Mrugalski committed
75
using namespace isc::stats;
76
using namespace std;
77

78
/// Structure that holds registered hook indexes
79
struct Dhcp4Hooks {
80 81 82 83 84 85 86 87
    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_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
88

89 90
    /// Constructor that registers hook points for DHCPv4 engine
    Dhcp4Hooks() {
91 92 93 94 95 96 97 98
        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_pkt4_send_        = HooksManager::registerHook("pkt4_send");
        hook_index_lease4_release_   = HooksManager::registerHook("lease4_release");
        hook_index_buffer4_send_     = HooksManager::registerHook("buffer4_send");
        hook_index_lease4_decline_   = HooksManager::registerHook("lease4_decline");
        hook_index_host4_identifier_ = HooksManager::registerHook("host4_identifier");
99 100 101 102 103 104 105
    }
};

// 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.
106
Dhcp4Hooks Hooks;
107

108 109 110
namespace isc {
namespace dhcp {

111
Dhcpv4Exchange::Dhcpv4Exchange(const AllocEnginePtr& alloc_engine,
112 113
                               const Pkt4Ptr& query,
                               const Subnet4Ptr& subnet)
114 115
    : alloc_engine_(alloc_engine), query_(query), resp_(),
      context_(new AllocEngine::ClientContext4()) {
116

117 118 119 120 121 122 123 124
    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");
125 126
    }

127 128 129
    // Create response message.
    initResponse();
    // Select subnet for the query message.
130
    context_->subnet_ = subnet;
131
    // Hardware address.
132
    context_->hwaddr_ = query->getHWAddr();
133 134
    // Pointer to client's query.
    context_->query_ = query;
135

136 137 138
    // If subnet found, retrieve client identifier which will be needed
    // for allocations and search for reservations associated with a
    // subnet/shared network.
139
    if (subnet) {
140 141 142
        OptionPtr opt_clientid = query->getOption(DHO_DHCP_CLIENT_IDENTIFIER);
        if (opt_clientid) {
            context_->clientid_.reset(new ClientId(opt_clientid->getData()));
143
        }
144

145
        // Find static reservations if not disabled for our subnet.
146
        if (subnet->getHostReservationMode() != Network::HR_DISABLED) {
147 148 149
            // Before we can check for static reservations, we need to prepare a set
            // of identifiers to be used for this.
            setHostIdentifiers();
150

151 152
            // Check for static reservations.
            alloc_engine->findReservation(*context_);
153 154
        }
    }
155 156 157 158 159 160 161 162

    const ClientClasses& classes = query_->getClasses();
    if (!classes.empty()) {
        std::string joined_classes = boost::algorithm::join(classes, ", ");
        LOG_DEBUG(dhcp4_logger, DBG_DHCP4_BASIC, DHCP4_CLASS_ASSIGNED)
            .arg(query_->getLabel())
            .arg(joined_classes);
    }
163 164
};

165
void
166
Dhcpv4Exchange::initResponse() {
167 168 169 170 171 172 173 174 175 176 177 178
    uint8_t resp_type = 0;
    switch (getQuery()->getType()) {
    case DHCPDISCOVER:
        resp_type = DHCPOFFER;
        break;
    case DHCPREQUEST:
    case DHCPINFORM:
        resp_type = DHCPACK;
        break;
    default:
        ;
    }
179
    // Only create a response if one is required.
180 181
    if (resp_type > 0) {
        resp_.reset(new Pkt4(resp_type, getQuery()->getTransid()));
182
        copyDefaultFields();
Francis Dupont's avatar
Francis Dupont committed
183
        copyDefaultOptions();
184 185 186 187

        if (getQuery()->isDhcp4o6()) {
            initResponse4o6();
        }
188 189 190
    }
}

191 192 193 194 195
void
Dhcpv4Exchange::initResponse4o6() {
    Pkt4o6Ptr query = boost::dynamic_pointer_cast<Pkt4o6>(getQuery());
    if (!query) {
        return;
196
    }
197 198 199 200 201 202 203 204 205 206 207 208
    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
    resp6->setIface(query6->getIface());
    resp6->setIndex(query6->getIndex());
    resp6->setRemoteAddr(query6->getRemoteAddr());
    resp_.reset(new Pkt4o6(resp_, resp6));
209 210 211 212 213 214 215
}

void
Dhcpv4Exchange::copyDefaultFields() {
    resp_->setIface(query_->getIface());
    resp_->setIndex(query_->getIndex());

216 217
    // explicitly set this to 0
    resp_->setSiaddr(IOAddress::IPV4_ZERO_ADDRESS());
218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243
    // ciaddr is always 0, except for the Renew/Rebind state when it may
    // be set to the ciaddr sent by the client.
    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);
    }
244

245
    // Copy flags from the request to the response per RFC 2131
246
    resp_->setFlags(query_->getFlags());
247
}
248

249 250
void
Dhcpv4Exchange::copyDefaultOptions() {
251 252
    // Let's copy client-id to response. See RFC6842.
    // It is possible to disable RFC6842 to keep backward compatibility
253
    bool echo = CfgMgr::instance().getCurrentCfg()->getEchoClientId();
254 255 256 257
    OptionPtr client_id = query_->getOption(DHO_DHCP_CLIENT_IDENTIFIER);
    if (client_id && echo) {
        resp_->addOption(client_id);
    }
258 259 260 261 262

    // If this packet is relayed, we want to copy Relay Agent Info option
    OptionPtr rai = query_->getOption(DHO_DHCP_AGENT_OPTIONS);
    if (rai) {
        resp_->addOption(rai);
263
    }
264 265 266 267 268 269 270 271 272 273 274 275 276

    // 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);
    }
277 278
}

279 280 281 282
void
Dhcpv4Exchange::setHostIdentifiers() {
    const ConstCfgHostOperationsPtr cfg =
        CfgMgr::instance().getCurrentCfg()->getCfgHostOperations4();
283

284 285
    // Collect host identifiers. The identifiers are stored in order of preference.
    // The server will use them in that order to search for host reservations.
286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326
    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_->getDuid();
                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 = 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;

327 328 329 330 331 332 333 334
        case Host::IDENT_CLIENT_ID:
            if (context_->clientid_) {
                const std::vector<uint8_t>& vec = context_->clientid_->getDuid();
                if (!vec.empty()) {
                    context_->addHostIdentifier(id_type, vec);
                }
            }
            break;
335
        case Host::IDENT_FLEX:
336 337 338 339 340
            {
                if (!HooksManager::calloutsPresent(Hooks.hook_index_host4_identifier_)) {
                    break;
                }

341
                CalloutHandlePtr callout_handle = getCalloutHandle(context_->query_);
342

343 344 345 346 347 348 349 350 351 352 353
                Host::IdentifierType type = Host::IDENT_FLEX;
                std::vector<uint8_t> id;

                // Delete previously set arguments
                callout_handle->deleteAllArguments();

                // Pass incoming packet as argument
                callout_handle->setArgument("query4", context_->query_);
                callout_handle->setArgument("id_type", type);
                callout_handle->setArgument("id_value", id);

354 355 356
                // Call callouts
                HooksManager::callCallouts(Hooks.hook_index_host4_identifier_,
                                           *callout_handle);
357

358 359
                callout_handle->getArgument("id_type", type);
                callout_handle->getArgument("id_value", id);
360

361 362
                if ((callout_handle->getStatus() == CalloutHandle::NEXT_STEP_CONTINUE) &&
                    !id.empty()) {
363

364 365
                    LOG_DEBUG(packet4_logger, DBGLVL_TRACE_BASIC, DHCP4_FLEX_ID)
                        .arg(Host::getIdentifierAsText(type, &id[0], id.size()));
366

367
                    context_->addHostIdentifier(type, id);
368 369
                }
                break;
370
            }
371 372 373 374 375 376
        default:
            ;
        }
    }
}

377 378
void
Dhcpv4Exchange::setReservedClientClasses() {
379
    if (context_->currentHost() && query_) {
380
        BOOST_FOREACH(const std::string& client_class,
381
                      context_->currentHost()->getClientClasses4()) {
382 383 384 385 386
            query_->addClass(client_class);
        }
    }
}

387 388
void
Dhcpv4Exchange::setReservedMessageFields() {
389
    ConstHostPtr host = context_->currentHost();
390 391 392 393 394 395
    // Nothing to do if host reservations not specified for this client.
    if (host) {
        if (!host->getNextServer().isV4Zero()) {
            resp_->setSiaddr(host->getNextServer());
        }

396 397 398 399
        std::string sname = host->getServerHostname();
        if (!sname.empty()) {
            resp_->setSname(reinterpret_cast<const uint8_t*>(sname.c_str()),
                            sname.size());
400 401
        }

402 403 404 405
        std::string bootfile = host->getBootFileName();
        if (!bootfile.empty()) {
            resp_->setFile(reinterpret_cast<const uint8_t*>(bootfile.c_str()),
                           bootfile.size());
406 407 408 409
        }
    }
}

410 411
const std::string Dhcpv4Srv::VENDOR_CLASS_PREFIX("VENDOR_CLASS_");

412
Dhcpv4Srv::Dhcpv4Srv(uint16_t port, const bool use_bcast,
413
                     const bool direct_response_desired)
414
    : io_service_(new IOService()), shutdown_(true), alloc_engine_(), port_(port),
415
      use_bcast_(use_bcast) {
416

417
    LOG_DEBUG(dhcp4_logger, DBG_DHCP4_START, DHCP4_OPEN_SOCKET).arg(port);
418
    try {
419 420 421
        // 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.
422
        if (port) {
423 424 425 426 427 428 429 430
            // 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);
431
        }
432

433 434 435 436
        // 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(AllocEngine::ALLOC_ITERATIVE, 0,
437
                                            false /* false = IPv4 */));
438

439 440
        /// @todo call loadLibraries() when handling configuration changes

441
    } catch (const std::exception &e) {
442
        LOG_ERROR(dhcp4_logger, DHCP4_SRV_CONSTRUCT_ERROR).arg(e.what());
443 444 445
        shutdown_ = true;
        return;
    }
446

Tomek Mrugalski's avatar
Tomek Mrugalski committed
447
    shutdown_ = false;
448 449 450
}

Dhcpv4Srv::~Dhcpv4Srv() {
451 452 453 454 455 456
    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());
    }
457

458 459 460 461 462 463 464
    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());
    }

Tomek Mrugalski's avatar
Tomek Mrugalski committed
465
    IfaceMgr::instance().closeSockets();
Tomek Mrugalski's avatar
Tomek Mrugalski committed
466

467 468
    // The lease manager was instantiated during DHCPv4Srv configuration,
    // so we should clean up after ourselves.
Tomek Mrugalski's avatar
Tomek Mrugalski committed
469
    LeaseMgrFactory::destroy();
470 471 472

    // Explicitly unload hooks
    HooksManager::getHooksManager().unloadLibraries();
473 474
}

475 476
void
Dhcpv4Srv::shutdown() {
477
    LOG_DEBUG(dhcp4_logger, DBG_DHCP4_BASIC, DHCP4_SHUTDOWN_REQUEST);
478 479 480
    shutdown_ = true;
}

481
isc::dhcp::Subnet4Ptr
482
Dhcpv4Srv::selectSubnet(const Pkt4Ptr& query) const {
483

484 485 486 487 488
    // DHCPv4-over-DHCPv6 is a special (and complex) case
    if (query->isDhcp4o6()) {
        return (selectSubnet4o6(query));
    }

489 490 491 492 493 494 495 496 497 498
    Subnet4Ptr subnet;

    SubnetSelector selector;
    selector.ciaddr_ = query->getCiaddr();
    selector.giaddr_ = query->getGiaddr();
    selector.local_address_ = query->getLocalAddr();
    selector.remote_address_ = query->getRemoteAddr();
    selector.client_classes_ = query->classes_;
    selector.iface_name_ = query->getIface();

499 500 501 502 503
    // If the link-selection sub-option is present, extract its value.
    // "The link-selection sub-option is used by any DHCP relay agent
    // that desires to specify a subnet/link for a DHCP client request
    // that it is relaying but needs the subnet/link specification to
    // be different from the IP address the DHCP server should use
504
    // when communicating with the relay agent." (RFC 3527)
505
    //
506
    // Try first Relay Agent Link Selection sub-option
507 508
    OptionPtr rai = query->getOption(DHO_DHCP_AGENT_OPTIONS);
    if (rai) {
509 510 511 512 513 514 515 516
        OptionCustomPtr rai_custom =
            boost::dynamic_pointer_cast<OptionCustom>(rai);
        if (rai_custom) {
            OptionPtr link_select =
                rai_custom->getOption(RAI_OPTION_LINK_SELECTION);
            if (link_select) {
                OptionBuffer link_select_buf = link_select->getData();
                if (link_select_buf.size() == sizeof(uint32_t)) {
517
                    selector.option_select_ =
518
                        IOAddress::fromBytes(AF_INET, &link_select_buf[0]);
519 520 521
                }
            }
        }
522 523 524 525 526 527 528 529 530 531
    } else {
        // Or Subnet Selection option
        OptionPtr sbnsel = query->getOption(DHO_SUBNET_SELECTION);
        if (sbnsel) {
            OptionCustomPtr oc =
                boost::dynamic_pointer_cast<OptionCustom>(sbnsel);
            if (oc) {
                selector.option_select_ = oc->readAddress();
            }
        }
532 533
    }

534 535 536 537
    CfgMgr& cfgmgr = CfgMgr::instance();
    subnet = cfgmgr.getCurrentCfg()->getCfgSubnets4()->selectSubnet(selector);

    // Let's execute all callouts registered for subnet4_select
538
    if (HooksManager::calloutsPresent(Hooks.hook_index_subnet4_select_)) {
539 540 541 542 543
        CalloutHandlePtr callout_handle = getCalloutHandle(query);

        // We're reusing callout_handle from previous calls
        callout_handle->deleteAllArguments();

544 545 546
        // Enable copying options from the packet within hook library.
        ScopedEnableOptionsCopy<Pkt4> query4_options_copy(query);

547 548 549 550 551 552 553 554
        // 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
555
        HooksManager::callCallouts(Hooks.hook_index_subnet4_select_,
556 557 558 559 560
                                   *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)
561
        if (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_SKIP) {
562
            LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS,
563 564
                      DHCP4_HOOK_SUBNET4_SELECT_SKIP)
                .arg(query->getLabel());
565 566 567
            return (Subnet4Ptr());
        }

568 569
        /// @todo: Add support for DROP status

570 571 572 573
        // Use whatever subnet was specified by the callout
        callout_handle->getArgument("subnet4", subnet);
    }

574 575
    if (subnet) {
        // Log at higher debug level that subnet has been found.
576
        LOG_DEBUG(packet4_logger, DBG_DHCP4_BASIC_DATA, DHCP4_SUBNET_SELECTED)
577 578 579 580
            .arg(query->getLabel())
            .arg(subnet->getID());
        // Log detailed information about the selected subnet at the
        // lower debug level.
581
        LOG_DEBUG(packet4_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_SUBNET_DATA)
582 583 584 585
            .arg(query->getLabel())
            .arg(subnet->toText());

    } else {
586
        LOG_DEBUG(packet4_logger, DBG_DHCP4_DETAIL,
587 588 589 590
                  DHCP4_SUBNET_SELECTION_FAILED)
            .arg(query->getLabel());
    }

591
    return (subnet);
592 593
}

594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613
isc::dhcp::Subnet4Ptr
Dhcpv4Srv::selectSubnet4o6(const Pkt4Ptr& query) 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) {
614
        isc_throw(Unexpected, "Can't get DHCP4o6 message");
615 616 617 618 619 620 621 622 623 624 625 626 627 628
    }
    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,
629
                                      Pkt6::RELAY_GET_FIRST);
630 631
    }

Francis Dupont's avatar
Francis Dupont committed
632 633 634 635 636 637 638 639 640
    // 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();
        }
    }

641
    CfgMgr& cfgmgr = CfgMgr::instance();
Francis Dupont's avatar
Francis Dupont committed
642
    subnet = cfgmgr.getCurrentCfg()->getCfgSubnets4()->selectSubnet4o6(selector);
643 644

    // Let's execute all callouts registered for subnet4_select
645
    if (HooksManager::calloutsPresent(Hooks.hook_index_subnet4_select_)) {
646 647 648 649 650 651 652 653 654 655 656 657 658
        CalloutHandlePtr callout_handle = getCalloutHandle(query);

        // We're reusing callout_handle from previous calls
        callout_handle->deleteAllArguments();

        // 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
659
        HooksManager::callCallouts(Hooks.hook_index_subnet4_select_,
660 661 662 663 664
                                   *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)
665
        if (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_SKIP) {
666
            LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS,
667 668
                      DHCP4_HOOK_SUBNET4_SELECT_SKIP)
                .arg(query->getLabel());
669 670 671
            return (Subnet4Ptr());
        }

672 673
        /// @todo: Add support for DROP status

674 675 676 677
        // Use whatever subnet was specified by the callout
        callout_handle->getArgument("subnet4", subnet);
    }

678 679
    if (subnet) {
        // Log at higher debug level that subnet has been found.
680
        LOG_DEBUG(packet4_logger, DBG_DHCP4_BASIC_DATA, DHCP4_SUBNET_SELECTED)
681 682 683 684
            .arg(query->getLabel())
            .arg(subnet->getID());
        // Log detailed information about the selected subnet at the
        // lower debug level.
685
        LOG_DEBUG(packet4_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_SUBNET_DATA)
686 687 688 689
            .arg(query->getLabel())
            .arg(subnet->toText());

    } else {
690
        LOG_DEBUG(packet4_logger, DBG_DHCP4_DETAIL,
691 692 693 694
                  DHCP4_SUBNET_SELECTION_FAILED)
            .arg(query->getLabel());
    }

695
    return (subnet);
696 697
}

Tomek Mrugalski's avatar
Tomek Mrugalski committed
698 699
Pkt4Ptr
Dhcpv4Srv::receivePacket(int timeout) {
700 701 702
    return (IfaceMgr::instance().receive4(timeout));
}

Tomek Mrugalski's avatar
Tomek Mrugalski committed
703 704
void
Dhcpv4Srv::sendPacket(const Pkt4Ptr& packet) {
705 706 707
    IfaceMgr::instance().send(packet);
}

708 709
bool
Dhcpv4Srv::run() {
Tomek Mrugalski's avatar
Tomek Mrugalski committed
710
    while (!shutdown_) {
711
        try {
Francis Dupont's avatar
Francis Dupont committed
712
            run_one();
713
            getIOService()->poll();
714
        } catch (const std::exception& e) {
715 716
            // General catch-all exception that are not caught by more specific
            // catches. This one is for exceptions derived from std::exception.
717
            LOG_ERROR(packet4_logger, DHCP4_PACKET_PROCESS_STD_EXCEPTION)
718
                .arg(e.what());
719 720 721 722
        } catch (...) {
            // General catch-all exception that are not caught by more specific
            // catches. This one is for other exceptions, not derived from
            // std::exception.
723
            LOG_ERROR(packet4_logger, DHCP4_PACKET_PROCESS_EXCEPTION);
724
        }
725 726 727 728
    }

    return (true);
}
729

Francis Dupont's avatar
Francis Dupont committed
730 731 732 733 734
void
Dhcpv4Srv::run_one() {
    // client's message and server's response
    Pkt4Ptr query;
    Pkt4Ptr rsp;
735

Francis Dupont's avatar
Francis Dupont committed
736
    try {
737 738 739 740
        // 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;
Francis Dupont's avatar
Francis Dupont committed
741 742 743 744 745 746 747 748 749 750 751 752 753 754 755
        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());
756

757
        }
758 759 760 761 762
        // 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.
763

Francis Dupont's avatar
Francis Dupont committed
764 765 766
    } catch (const SignalInterruptOnSelect) {
        // Packet reception interrupted because a signal has been received.
        // This is not an error because we might have received a SIGTERM,
Josh Soref's avatar
Josh Soref committed
767
        // SIGINT, SIGHUP or SIGCHLD which are handled by the server. For
Francis Dupont's avatar
Francis Dupont committed
768 769 770 771 772 773 774 775
        // 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)
            .arg(signal_set_->getNext());
    } catch (const std::exception& e) {
        // Log all other errors.
        LOG_ERROR(packet4_logger, DHCP4_BUFFER_RECEIVE_FAIL).arg(e.what());
    }
776

Francis Dupont's avatar
Francis Dupont committed
777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794
    // Handle next signal received by the process. It must be called after
    // an attempt to receive a packet to properly handle server shut down.
    // The SIGTERM or SIGINT will be received prior to, or during execution
    // of select() (select is invoked by receivePacket()). When that
    // happens, select will be interrupted. The signal handler will be
    // invoked immediately after select(). The handler will set the
    // shutdown flag and cause the process to terminate before the next
    // select() function is called. If the function was called before
    // receivePacket the process could wait up to the duration of timeout
    // of select() to terminate.
    try {
        handleSignal();
    } catch (const std::exception& e) {
        // Standard exception occurred. Let's be on the safe side to
        // catch std::exception.
        LOG_ERROR(dhcp4_logger, DHCP4_HANDLE_SIGNAL_EXCEPTION)
            .arg(e.what());
    }
795

Francis Dupont's avatar
Francis Dupont committed
796 797 798 799 800 801
    // 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;
    }
802

803
    processPacket(query, rsp);
804

805 806 807
    if (!rsp) {
        return;
    }
808

809 810 811 812 813 814
    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_)) {
815 816 817 818 819
            CalloutHandlePtr callout_handle = getCalloutHandle(query);

            // Delete previously set arguments
            callout_handle->deleteAllArguments();

820 821 822
            // Enable copying options from the packet within hook library.
            ScopedEnableOptionsCopy<Pkt4> resp4_options_copy(rsp);

823
            // Pass incoming packet as argument
824
            callout_handle->setArgument("response4", rsp);
825 826

            // Call callouts
827
            HooksManager::callCallouts(Hooks.hook_index_buffer4_send_,
Tomek Mrugalski's avatar
Tomek Mrugalski committed
828
                                       *callout_handle);
829 830 831

            // Callouts decided to skip the next processing step. The next
            // processing step would to parse the packet, so skip at this
832
            // stage means drop.
833
            if (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_SKIP) {
834 835 836 837
                LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS,
                          DHCP4_HOOK_BUFFER_SEND_SKIP)
                    .arg(rsp->getLabel());
                return;
838 839
            }

840
            /// @todo: Add support for DROP status.
841

842
            callout_handle->getArgument("response4", rsp);
843 844
        }

845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870
        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())
            .arg(rsp->getLocalPort())
            .arg(rsp->getRemoteAddr())
            .arg(rsp->getRemotePort())
            .arg(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());
    }
871
}
872

873
void
874
Dhcpv4Srv::processPacket(Pkt4Ptr& query, Pkt4Ptr& rsp) {
875 876
    // Log reception of the packet. We need to increase it early, as any
    // failures in unpacking will cause the packet to be dropped. We
877
    // will increase type specific statistic further down the road.
878 879 880 881 882 883 884 885 886 887
    // 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);
888

889 890
        // Delete previously set arguments
        callout_handle->deleteAllArguments();
891

892 893 894
        // Enable copying options from the packet within hook library.
        ScopedEnableOptionsCopy<Pkt4> query4_options_copy(query);

895 896
        // Pass incoming packet as argument
        callout_handle->setArgument("query4", query);
897

898 899 900
        // Call callouts
        HooksManager::callCallouts(Hooks.hook_index_buffer4_receive_,
                                   *callout_handle);
901

902 903 904 905 906 907 908 909 910 911 912 913
        // Callouts decided to skip the next processing step. The next
        // processing step would 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;
        }
914

915
        callout_handle->getArgument("query4", query);
916

917 918
        /// @todo: add support for DROP status
    }
919

920 921 922
    // Unpack the packet information unless the buffer4_receive callouts
    // indicated they did it
    if (!skip_unpack) {
923
        try {
924 925 926 927 928
            LOG_DEBUG(options4_logger, DBG_DHCP4_DETAIL, DHCP4_BUFFER_UNPACK)
                .arg(query->getRemoteAddr().toText())
                .arg(query->getLocalAddr().toText())
                .arg(query->getIface());
            query->unpack();
929
        } catch (const std::exception& e) {
930 931 932 933 934 935
            // Failed to parse the packet.
            LOG_DEBUG(bad_packet4_logger, DBG_DHCP4_DETAIL,
                      DHCP4_PACKET_DROP_0001)
                .arg(query->getRemoteAddr().toText())
                .arg(query->getLocalAddr().toText())
                .arg(query->getIface())
936
                .arg(e.what());
937

Francis Dupont's avatar
Francis Dupont committed
938
            // Increase the statistics of parse failures and dropped packets.
939 940
            isc::stats::StatsMgr::instance().addValue("pkt4-parse-failed",
                                                      static_cast<int64_t>(1));
Tomek Mrugalski's avatar
Tomek Mrugalski committed
941
            isc::stats::StatsMgr::instance().addValue("pkt4-receive-drop",
942
                                                      static_cast<int64_t>(1));
943
            return;
944
        }
945
    }
946

947 948
    // Update statistics accordingly for received packet.
    processStatsReceived(query);
949

950 951 952 953
    // 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);
954

955 956 957
    // Now it is classified the deferred unpacking can be done.
    deferredUnpack(query);

958 959 960 961 962 963 964 965
    // 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;
    }
966

967 968 969 970 971 972 973 974 975 976 977 978 979 980 981
    // 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
Francis Dupont's avatar
Francis Dupont committed
982
    if (HooksManager::calloutsPresent(Hooks.hook_index_pkt4_receive_)) {