dhcp4_srv.cc 92.3 KB
Newer Older
1
// Copyright (C) 2011-2015 Internet Systems Consortium, Inc. ("ISC")
2
3
4
5
6
7
8
9
10
11
12
13
14
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.

15
#include <config.h>
16
#include <asiolink/io_address.h>
17
#include <dhcp/dhcp4.h>
18
19
#include <dhcp/duid.h>
#include <dhcp/hwaddr.h>
20
#include <dhcp/iface_mgr.h>
21
#include <dhcp/option4_addrlst.h>
22
#include <dhcp/option_int.h>
23
#include <dhcp/option_int_array.h>
24
#include <dhcp/option_vendor.h>
25
#include <dhcp/option_string.h>
26
#include <dhcp/pkt4.h>
27
#include <dhcp/docsis3_option_defs.h>
28
29
#include <dhcp4/dhcp4_log.h>
#include <dhcp4/dhcp4_srv.h>
30
31
#include <dhcpsrv/addr_utilities.h>
#include <dhcpsrv/callout_handle_store.h>
32
#include <dhcpsrv/cfgmgr.h>
33
#include <dhcpsrv/cfg_subnets4.h>
34
35
36
#include <dhcpsrv/lease_mgr.h>
#include <dhcpsrv/lease_mgr_factory.h>
#include <dhcpsrv/subnet.h>
37
#include <dhcpsrv/subnet_selector.h>
38
#include <dhcpsrv/utils.h>
39
#include <dhcpsrv/utils.h>
40
#include <hooks/callout_handle.h>
41
#include <hooks/hooks_log.h>
42
#include <hooks/hooks_manager.h>
43
#include <util/strutil.h>
44
#include <stats/stats_mgr.h>
45
46
#include <log/logger.h>
#include <cryptolink/cryptolink.h>
47
#include <cfgrpt/config_report.h>
48

49
50
51
52
53
54
55
56
#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>

57
#include <asio.hpp>
58
#include <boost/bind.hpp>
59
#include <boost/foreach.hpp>
60
#include <boost/shared_ptr.hpp>
61
62
63

#include <iomanip>

64
65
using namespace isc;
using namespace isc::asiolink;
66
using namespace isc::cryptolink;
67
using namespace isc::dhcp;
68
using namespace isc::dhcp_ddns;
69
using namespace isc::hooks;
70
71
using namespace isc::log;
using namespace std;
72

73
/// Structure that holds registered hook indexes
74
75
struct Dhcp4Hooks {
    int hook_index_buffer4_receive_;///< index for "buffer4_receive" hook point
76
77
    int hook_index_pkt4_receive_;   ///< index for "pkt4_receive" hook point
    int hook_index_subnet4_select_; ///< index for "subnet4_select" hook point
78
    int hook_index_lease4_release_; ///< index for "lease4_release" hook point
79
    int hook_index_pkt4_send_;      ///< index for "pkt4_send" hook point
80
    int hook_index_buffer4_send_;   ///< index for "buffer4_send" hook point
81

82
83
84
    /// Constructor that registers hook points for DHCPv4 engine
    Dhcp4Hooks() {
        hook_index_buffer4_receive_= HooksManager::registerHook("buffer4_receive");
85
86
87
        hook_index_pkt4_receive_   = HooksManager::registerHook("pkt4_receive");
        hook_index_subnet4_select_ = HooksManager::registerHook("subnet4_select");
        hook_index_pkt4_send_      = HooksManager::registerHook("pkt4_send");
88
89
        hook_index_lease4_release_ = HooksManager::registerHook("lease4_release");
        hook_index_buffer4_send_   = HooksManager::registerHook("buffer4_send");
90
91
92
93
94
95
96
    }
};

// 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.
97
Dhcp4Hooks Hooks;
98

99
100
101
namespace isc {
namespace dhcp {

102
Dhcpv4Exchange::Dhcpv4Exchange(const AllocEnginePtr& alloc_engine,
103
104
                               const Pkt4Ptr& query,
                               const Subnet4Ptr& subnet)
105
106
    : alloc_engine_(alloc_engine), query_(query), resp_(),
      context_(new AllocEngine::ClientContext4()) {
107

108
109
110
111
112
113
114
115
    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");
116
117
    }

118
119
120
    // Create response message.
    initResponse();
    // Select subnet for the query message.
121
    context_->subnet_ = subnet;
122
    // Hardware address.
123
    context_->hwaddr_ = query->getHWAddr();
124

125
    // Set client identifier if the match-client-id flag is enabled (default).
126
127
128
    // If the subnet wasn't found it doesn't matter because we will not be
    // able to allocate a lease anyway so this context will not be used.
    if (subnet) {
129
        if (subnet->getMatchClientId()) {
130
131
132
133
134
135
136
137
138
139
            OptionPtr opt_clientid = query->getOption(DHO_DHCP_CLIENT_IDENTIFIER);
            if (opt_clientid) {
                context_->clientid_.reset(new ClientId(opt_clientid->getData()));
            }
        } else {
            /// @todo When merging with #3806 use different logger.
            LOG_DEBUG(dhcp4_logger, DBG_DHCP4_DETAIL, DHCP4_CLIENTID_IGNORED_FOR_LEASES)
                .arg(query->getLabel())
                .arg(subnet->getID());
        }
140
141
    }
    // Check for static reservations.
142
    alloc_engine->findReservation(*context_);
143
144
};

145
void
146
Dhcpv4Exchange::initResponse() {
147
148
149
150
151
152
153
154
155
156
157
158
    uint8_t resp_type = 0;
    switch (getQuery()->getType()) {
    case DHCPDISCOVER:
        resp_type = DHCPOFFER;
        break;
    case DHCPREQUEST:
    case DHCPINFORM:
        resp_type = DHCPACK;
        break;
    default:
        ;
    }
159
    // Only create a response if one is required.
160
161
    if (resp_type > 0) {
        resp_.reset(new Pkt4(resp_type, getQuery()->getTransid()));
162
163
164
165
166
167
168
169
170
        copyDefaultFields();
    }
}

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

171
172
    // explicitly set this to 0
    resp_->setSiaddr(IOAddress::IPV4_ZERO_ADDRESS());
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
    // 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());

    // Let's copy client-id to response. See RFC6842.
    // It is possible to disable RFC6842 to keep backward compatibility
    bool echo = CfgMgr::instance().echoClientId();
    OptionPtr client_id = query_->getOption(DHO_DHCP_CLIENT_IDENTIFIER);
    if (client_id && echo) {
        resp_->addOption(client_id);
    }

    // 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);
    }

    // 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);
212
213
214
    }
}

215
216
const std::string Dhcpv4Srv::VENDOR_CLASS_PREFIX("VENDOR_CLASS_");

217
Dhcpv4Srv::Dhcpv4Srv(uint16_t port, const bool use_bcast,
218
                     const bool direct_response_desired)
219
220
221
    : shutdown_(true), alloc_engine_(), port_(port),
      use_bcast_(use_bcast), hook_index_pkt4_receive_(-1),
      hook_index_subnet4_select_(-1), hook_index_pkt4_send_(-1) {
222

223
    LOG_DEBUG(dhcp4_logger, DBG_DHCP4_START, DHCP4_OPEN_SOCKET).arg(port);
224
    try {
225
226
227
        // 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.
228
        if (port) {
229
230
231
232
233
234
235
236
            // 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);
237
        }
238

239
        // Instantiate allocation engine
240
241
        alloc_engine_.reset(new AllocEngine(AllocEngine::ALLOC_ITERATIVE, 100,
                                            false /* false = IPv4 */));
242

243
244
245
246
247
248
249
        // Register hook points
        hook_index_pkt4_receive_   = Hooks.hook_index_pkt4_receive_;
        hook_index_subnet4_select_ = Hooks.hook_index_subnet4_select_;
        hook_index_pkt4_send_      = Hooks.hook_index_pkt4_send_;

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

250
    } catch (const std::exception &e) {
251
        LOG_ERROR(dhcp4_logger, DHCP4_SRV_CONSTRUCT_ERROR).arg(e.what());
252
253
254
        shutdown_ = true;
        return;
    }
255

Tomek Mrugalski's avatar
Tomek Mrugalski committed
256
    shutdown_ = false;
257
258
259
}

Dhcpv4Srv::~Dhcpv4Srv() {
Tomek Mrugalski's avatar
Tomek Mrugalski committed
260
    IfaceMgr::instance().closeSockets();
261
262
}

263
264
void
Dhcpv4Srv::shutdown() {
265
    LOG_DEBUG(dhcp4_logger, DBG_DHCP4_BASIC, DHCP4_SHUTDOWN_REQUEST);
266
267
268
    shutdown_ = true;
}

269
isc::dhcp::Subnet4Ptr
270
Dhcpv4Srv::selectSubnet(const Pkt4Ptr& query) const {
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285

    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();

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

    // Let's execute all callouts registered for subnet4_select
286
    if (HooksManager::calloutsPresent(hook_index_subnet4_select_)) {
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
        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
        HooksManager::callCallouts(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->getSkip()) {
307
            LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS,
308
309
                      DHCP4_HOOK_SUBNET4_SELECT_SKIP)
                .arg(query->getLabel());
310
311
312
313
314
315
316
            return (Subnet4Ptr());
        }

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

317
318
    if (subnet) {
        // Log at higher debug level that subnet has been found.
319
        LOG_DEBUG(packet_logger, DBG_DHCP4_BASIC_DATA, DHCP4_SUBNET_SELECTED)
320
321
322
323
324
325
326
327
328
329
330
331
332
333
            .arg(query->getLabel())
            .arg(subnet->getID());
        // Log detailed information about the selected subnet at the
        // lower debug level.
        LOG_DEBUG(packet_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_SUBNET_DATA)
            .arg(query->getLabel())
            .arg(subnet->toText());

    } else {
        LOG_DEBUG(packet_logger, DBG_DHCP4_DETAIL,
                  DHCP4_SUBNET_SELECTION_FAILED)
            .arg(query->getLabel());
    }

334
    return (subnet);
335
336
}

Tomek Mrugalski's avatar
Tomek Mrugalski committed
337
338
Pkt4Ptr
Dhcpv4Srv::receivePacket(int timeout) {
339
340
341
    return (IfaceMgr::instance().receive4(timeout));
}

Tomek Mrugalski's avatar
Tomek Mrugalski committed
342
343
void
Dhcpv4Srv::sendPacket(const Pkt4Ptr& packet) {
344
345
346
    IfaceMgr::instance().send(packet);
}

347
348
bool
Dhcpv4Srv::run() {
Tomek Mrugalski's avatar
Tomek Mrugalski committed
349
    while (!shutdown_) {
Tomek Mrugalski's avatar
Tomek Mrugalski committed
350
        // client's message and server's response
351
        Pkt4Ptr query;
Tomek Mrugalski's avatar
Tomek Mrugalski committed
352
        Pkt4Ptr rsp;
353

354
        try {
355
356
357
358
359
360
361
362
363
364
            // The lease database backend may install some timers for which
            // the handlers need to be executed periodically. Retrieve the
            // maximum interval at which the handlers must be executed from
            // the lease manager.
            uint32_t timeout = LeaseMgrFactory::instance().getIOServiceExecInterval();
            // If the returned value is zero it means that there are no
            // timers installed, so use a default value.
            if (timeout == 0) {
                timeout = 1000;
            }
365
            LOG_DEBUG(packet_logger, DBG_DHCP4_DETAIL, DHCP4_BUFFER_WAIT).arg(timeout);
366
            query = receivePacket(timeout);
367

368
369
370
371
372
373
374
            // 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) {
375
                LOG_DEBUG(packet_logger, DBG_DHCP4_BASIC, DHCP4_BUFFER_RECEIVED)
376
377
378
379
380
381
382
                    .arg(query->getRemoteAddr().toText())
                    .arg(query->getRemotePort())
                    .arg(query->getLocalAddr().toText())
                    .arg(query->getLocalPort())
                    .arg(query->getIface());

            } else {
383
                LOG_DEBUG(packet_logger, DBG_DHCP4_DETAIL, DHCP4_BUFFER_WAIT_INTERRUPTED)
384
385
386
                    .arg(timeout);
            }

387
388
389
390
391
        } 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 or SIGHUP which are handled by the server. For signals
            // that are not handled by the server we rely on the default
392
            // behavior of the system.
393
394
            LOG_DEBUG(packet_logger, DBG_DHCP4_DETAIL, DHCP4_BUFFER_WAIT_SIGNAL)
                .arg(signal_set_->getNext());
395
        } catch (const std::exception& e) {
396
            // Log all other errors.
397
            LOG_ERROR(packet_logger, DHCP4_BUFFER_RECEIVE_FAIL).arg(e.what());
398
399
        }

400
401
402
        // 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
Francis Dupont's avatar
Francis Dupont committed
403
404
405
406
407
408
409
        // 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.
410
411
        handleSignal();

412
413
        // Execute ready timers for the lease database, e.g. Lease File Cleanup.
        try {
414
            LeaseMgrFactory::instance().getIOService()->poll();
415
416
417
418
419
420

        } catch (const std::exception& ex) {
            LOG_WARN(dhcp4_logger, DHCP4_LEASE_DATABASE_TIMERS_EXEC_FAIL)
                .arg(ex.what());
        }

421
        // Timeout may be reached or signal received, which breaks select()
422
423
        // with no reception occurred. No need to log anything here because
        // we have logged right after the call to receivePacket().
424
425
426
427
        if (!query) {
            continue;
        }

428
429
430
431
        // 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 packets further down the road.
        // See processStatsReceived().
Tomek Mrugalski's avatar
Tomek Mrugalski committed
432
433
        isc::stats::StatsMgr::instance().addValue("pkt4-received",
                                                  static_cast<uint64_t>(1));
434

435
436
437
438
439
440
441
442
443
        // In order to parse the DHCP options, the server needs to use some
        // configuration information such as: existing option spaces, option
        // definitions etc. This is the kind of information which is not
        // available in the libdhcp, so we need to supply our own implementation
        // of the option parsing function here, which would rely on the
        // configuration data.
        query->setCallback(boost::bind(&Dhcpv4Srv::unpackOptions, this,
                                       _1, _2, _3));

444
445
446
        bool skip_unpack = false;

        // The packet has just been received so contains the uninterpreted wire
447
        // data; execute callouts registered for buffer4_receive.
448
        if (HooksManager::calloutsPresent(Hooks.hook_index_buffer4_receive_)) {
449
450
451
452
453
454
455
456
457
            CalloutHandlePtr callout_handle = getCalloutHandle(query);

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

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

            // Call callouts
Tomek Mrugalski's avatar
Tomek Mrugalski committed
458
459
            HooksManager::callCallouts(Hooks.hook_index_buffer4_receive_,
                                       *callout_handle);
460
461
462
463
464
465

            // 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->getSkip()) {
466
                LOG_DEBUG(hooks_logger, DBG_DHCP4_DETAIL, DHCP4_HOOK_BUFFER_RCVD_SKIP)
467
468
469
                    .arg(query->getRemoteAddr().toText())
                    .arg(query->getLocalAddr().toText())
                    .arg(query->getIface());
470
471
472
473
474
475
476
477
478
                skip_unpack = true;
            }

            callout_handle->getArgument("query4", query);
        }

        // Unpack the packet information unless the buffer4_receive callouts
        // indicated they did it
        if (!skip_unpack) {
Tomek Mrugalski's avatar
Tomek Mrugalski committed
479
            try {
480
481
482
483
                LOG_DEBUG(options_logger, DBG_DHCP4_DETAIL, DHCP4_BUFFER_UNPACK)
                    .arg(query->getRemoteAddr().toText())
                    .arg(query->getLocalAddr().toText())
                    .arg(query->getIface());
Tomek Mrugalski's avatar
Tomek Mrugalski committed
484
485
                query->unpack();
            } catch (const std::exception& e) {
486
                // Failed to parse the packet.
487
488
                LOG_DEBUG(bad_packet_logger, DBG_DHCP4_DETAIL,
                          DHCP4_PACKET_DROP_0001)
489
490
491
                    .arg(query->getRemoteAddr().toText())
                    .arg(query->getLocalAddr().toText())
                    .arg(query->getIface())
492
                    .arg(e.what());
493
494

                // Increase the statistics of parse failues and dropped packets.
Tomek Mrugalski's avatar
Tomek Mrugalski committed
495
496
497
498
                isc::stats::StatsMgr::instance().addValue("pkt4-parse-failed",
                                                          static_cast<uint64_t>(1));
                isc::stats::StatsMgr::instance().addValue("pkt4-receive-drop",
                                                          static_cast<uint64_t>(1));
499
500
                continue;
            }
501
        }
502

503
504
505
        // Update statistics accordingly for received packet.
        processStatsReceived(query);

Tomek Mrugalski's avatar
Tomek Mrugalski committed
506
507
508
        // 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.
509
510
        classifyPacket(query);

511
512
513
        // 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)) {
514
            // Increase the statistic of dropped packets.
Tomek Mrugalski's avatar
Tomek Mrugalski committed
515
516
            isc::stats::StatsMgr::instance().addValue("pkt4-receive-drop",
                                                      static_cast<uint64_t>(1));
517
            continue;
518
        }
519

520
        // We have sanity checked (in accept() that the Message Type option
521
522
        // exists, so we can safely get it here.
        int type = query->getType();
523
        LOG_DEBUG(packet_logger, DBG_DHCP4_BASIC_DATA, DHCP4_PACKET_RECEIVED)
524
            .arg(query->getLabel())
525
            .arg(query->getName())
526
            .arg(type)
527
528
            .arg(query->getRemoteAddr())
            .arg(query->getLocalAddr())
529
            .arg(query->getIface());
530
531
        LOG_DEBUG(packet_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_QUERY_DATA)
            .arg(query->getLabel())
532
533
            .arg(query->toText());

Tomek Mrugalski's avatar
Tomek Mrugalski committed
534
        // Let's execute all callouts registered for pkt4_receive
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
        if (HooksManager::calloutsPresent(hook_index_pkt4_receive_)) {
            CalloutHandlePtr callout_handle = getCalloutHandle(query);

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

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

            // Call callouts
            HooksManager::callCallouts(hook_index_pkt4_receive_,
                                       *callout_handle);

            // Callouts decided to skip the next processing step. The next
            // processing step would to process the packet, so skip at this
            // stage means drop.
            if (callout_handle->getSkip()) {
552
                LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS, DHCP4_HOOK_PACKET_RCVD_SKIP)
553
                    .arg(query->getLabel());
554
555
                continue;
            }
556

557
558
            callout_handle->getArgument("query4", query);
        }
559

560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
        try {
            switch (query->getType()) {
            case DHCPDISCOVER:
                rsp = processDiscover(query);
                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);
                break;

            case DHCPRELEASE:
                processRelease(query);
                break;

            case DHCPDECLINE:
                processDecline(query);
                break;

            case DHCPINFORM:
582
                rsp = processInform(query);
583
584
585
586
587
588
589
                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.
                ;
590
            }
591
592
        } catch (const isc::Exception& e) {

593
594
595
596
597
598
            // Catch-all exception (at least for ones based on the isc Exception
            // class, which covers more or less all that are explicitly raised
            // in the Kea code).  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.)
599
600
601
602
            LOG_DEBUG(bad_packet_logger, DBG_DHCP4_BASIC,
                      DHCP4_PACKET_DROP_0007)
                .arg(query->getLabel())
                .arg(e.what());
603
604

            // Increase the statistic of dropped packets.
Tomek Mrugalski's avatar
Tomek Mrugalski committed
605
606
            isc::stats::StatsMgr::instance().addValue("pkt4-receive-drop",
                                                      static_cast<uint64_t>(1));
607
        }
608

609
610
611
        if (!rsp) {
            continue;
        }
612

613

614
615
        // Specifies if server should do the packing
        bool skip_pack = false;
616

Tomek Mrugalski's avatar
Tomek Mrugalski committed
617
        // Execute all callouts registered for pkt4_send
618
619
        if (HooksManager::calloutsPresent(hook_index_pkt4_send_)) {
            CalloutHandlePtr callout_handle = getCalloutHandle(query);
620

621
622
            // Delete all previous arguments
            callout_handle->deleteAllArguments();
623

624
625
            // Clear skip flag if it was set in previous callouts
            callout_handle->setSkip(false);
626

627
628
            // Set our response
            callout_handle->setArgument("response4", rsp);
629

630
631
632
            // Call all installed callouts
            HooksManager::callCallouts(hook_index_pkt4_send_,
                                       *callout_handle);
633

634
635
636
637
            // Callouts decided to skip the next processing step. The next
            // processing step would to send the packet, so skip at this
            // stage means "drop response".
            if (callout_handle->getSkip()) {
638
                LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS, DHCP4_HOOK_PACKET_SEND_SKIP)
639
                    .arg(query->getLabel());
640
641
642
643
644
645
                skip_pack = true;
            }
        }

        if (!skip_pack) {
            try {
646
647
                LOG_DEBUG(options_logger, DBG_DHCP4_DETAIL, DHCP4_PACKET_PACK)
                    .arg(rsp->getLabel());
648
649
                rsp->pack();
            } catch (const std::exception& e) {
650
651
                LOG_ERROR(options_logger, DHCP4_PACKET_PACK_FAIL)
                    .arg(rsp->getLabel())
652
653
654
655
656
657
658
659
                    .arg(e.what());
            }
        }

        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.
Tomek Mrugalski's avatar
Tomek Mrugalski committed
660
            // Let's execute all callouts registered for buffer4_send
661
            if (HooksManager::calloutsPresent(Hooks.hook_index_buffer4_send_)) {
662
                CalloutHandlePtr callout_handle = getCalloutHandle(query);
663

664
665
                // Delete previously set arguments
                callout_handle->deleteAllArguments();
666

667
668
                // Pass incoming packet as argument
                callout_handle->setArgument("response4", rsp);
669

670
                // Call callouts
Tomek Mrugalski's avatar
Tomek Mrugalski committed
671
672
                HooksManager::callCallouts(Hooks.hook_index_buffer4_send_,
                                           *callout_handle);
673

674
675
676
677
                // Callouts decided to skip the next processing step. The next
                // processing step would to parse the packet, so skip at this
                // stage means drop.
                if (callout_handle->getSkip()) {
678
                    LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS,
679
680
                              DHCP4_HOOK_BUFFER_SEND_SKIP)
                        .arg(rsp->getLabel());
681
                    continue;
682
                }
683
684

                callout_handle->getArgument("response4", rsp);
685
            }
686

687
            LOG_DEBUG(packet_logger, DBG_DHCP4_BASIC, DHCP4_PACKET_SEND)
688
                .arg(rsp->getLabel())
689
                .arg(rsp->getName())
690
691
692
693
694
695
                .arg(static_cast<int>(rsp->getType()))
                .arg(rsp->getLocalAddr())
                .arg(rsp->getLocalPort())
                .arg(rsp->getRemoteAddr())
                .arg(rsp->getRemotePort())
                .arg(rsp->getIface());
696
697

            LOG_DEBUG(packet_logger, DBG_DHCP4_DETAIL_DATA,
698
                      DHCP4_RESPONSE_DATA)
699
700
701
702
                .arg(rsp->getLabel())
                .arg(rsp->getName())
                .arg(static_cast<int>(rsp->getType()))
                .arg(rsp->toText());
703
            sendPacket(rsp);
704
705
706
707

            // Update statistics accordingly for sent packet.
            processStatsSent(rsp);

708
        } catch (const std::exception& e) {
709
710
            LOG_ERROR(packet_logger, DHCP4_PACKET_SEND_FAIL)
                .arg(rsp->getLabel())
711
                .arg(e.what());
712
        }
713
714
715
716
717
    }

    return (true);
}

718
string
719
Dhcpv4Srv::srvidToString(const OptionPtr& srvid) {
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
    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());
736
737
}

738
isc::dhcp_ddns::D2Dhcid
739
740
741
742
743
744
745
746
747
Dhcpv4Srv::computeDhcid(const Lease4Ptr& lease) {
    if (!lease) {
        isc_throw(DhcidComputeError, "a pointer to the lease must be not"
                  " NULL to compute DHCID");

    } else if (lease->hostname_.empty()) {
        isc_throw(DhcidComputeError, "unable to compute the DHCID for the"
                  " lease which has empty hostname set");

748
749
    }

750
751
752
753
754
755
756
757
758
    // In order to compute DHCID the client's hostname must be encoded in
    // canonical wire format. It is unlikely that the FQDN is malformed
    // because it is validated by the classes which encapsulate options
    // carrying client FQDN. However, if the client name was carried in the
    // Hostname option it is more likely as it carries the hostname as a
    // regular string.
    std::vector<uint8_t> fqdn_wire;
    try {
        OptionDataTypeUtil::writeFqdn(lease->hostname_, fqdn_wire, true);
759

760
761
762
    } catch (const Exception& ex) {
        isc_throw(DhcidComputeError, "unable to compute DHCID because the"
                  " hostname: " << lease->hostname_ << " is invalid");
763
764

    }
765
766
767

    // Prefer client id to HW address to compute DHCID. If Client Id is
    // NULL, use HW address.
768
    try {
769
770
771
772
        if (lease->client_id_) {
            return (D2Dhcid(lease->client_id_->getClientId(), fqdn_wire));

        } else {
773
            return (D2Dhcid(lease->hwaddr_, fqdn_wire));
774
        }
775
    } catch (const Exception& ex) {
776
777
        isc_throw(DhcidComputeError, "unable to compute DHCID: "
                  << ex.what());
778

779
    }
780
781
782

}

783
void
784
Dhcpv4Srv::appendServerID(Dhcpv4Exchange& ex) {
785
786
787
    // The source address for the outbound message should have been set already.
    // This is the address that to the best of the server's knowledge will be
    // available from the client.
788
789
    /// @todo: perhaps we should consider some more sophisticated server id
    /// generation, but for the current use cases, it should be ok.
790
791
792
    OptionPtr opt_srvid(new Option4AddrLst(DHO_DHCP_SERVER_IDENTIFIER,
                                           ex.getResponse()->getLocalAddr()));
    ex.getResponse()->addOption(opt_srvid);
793
794
}

795
void
796
Dhcpv4Srv::appendRequestedOptions(Dhcpv4Exchange& ex) {
797
798
    // Get the subnet relevant for the client. We will need it
    // to get the options associated with it.
799
    Subnet4Ptr subnet = ex.getContext()->subnet_;
800
801
802
803
804
805
806
    // 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;
    }
807

808
809
    Pkt4Ptr query = ex.getQuery();

810
811
812
    // try to get the 'Parameter Request List' option which holds the
    // codes of requested options.
    OptionUint8ArrayPtr option_prl = boost::dynamic_pointer_cast<
813
        OptionUint8Array>(query->getOption(DHO_DHCP_PARAMETER_REQUEST_LIST));
814
815
816
817
818
    // If there is no PRL option in the message from the client then
    // there is nothing to do.
    if (!option_prl) {
        return;
    }
819

820
821
    Pkt4Ptr resp = ex.getResponse();

822
823
824
825
826
827
    // Get the codes of requested options.
    const std::vector<uint8_t>& requested_opts = option_prl->getValues();
    // For each requested option code get the instance of the option
    // to be returned to the client.
    for (std::vector<uint8_t>::const_iterator opt = requested_opts.begin();
         opt != requested_opts.end(); ++opt) {
828
        if (!resp->getOption(*opt)) {
829
            OptionDescriptor desc = subnet->getCfgOption()->get("dhcp4", *opt);
830
            if (desc.option_) {
831
                resp->addOption(desc.option_);
832
            }
833
834
        }
    }
Tomek Mrugalski's avatar
Tomek Mrugalski committed
835
}
836

837
void
838
Dhcpv4Srv::appendRequestedVendorOptions(Dhcpv4Exchange& ex) {
839
    // Get the configured subnet suitable for the incoming packet.
840
    Subnet4Ptr subnet = ex.getContext()->subnet_;
841
842
843
844
845
846
847
848
849
850
    // 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.
    if (!subnet) {
        return;
    }

    // Try to get the vendor option
851
852
    boost::shared_ptr<OptionVendor> vendor_req = boost::dynamic_pointer_cast<
        OptionVendor>(ex.getQuery()->getOption(DHO_VIVSO_SUBOPTIONS));
853
854
855
856
857
858
859
    if (!vendor_req) {
        return;
    }

    uint32_t vendor_id = vendor_req->getVendorId();

    // Let's try to get ORO within that vendor-option
860
861
    /// @todo This is very specific to vendor-id=4491 (Cable Labs). Other
    /// vendors may have different policies.
Tomek Mrugalski's avatar
Tomek Mrugalski committed
862
863
    OptionUint8ArrayPtr oro =
        boost::dynamic_pointer_cast<OptionUint8Array>(vendor_req->getOption(DOCSIS3_V4_ORO));
864
865
866
867
868
869
870
871
872
873

    // Option ORO not found. Don't do anything then.
    if (!oro) {
        return;
    }

    boost::shared_ptr<OptionVendor> vendor_rsp(new OptionVendor(Option::V4, vendor_id));

    // Get the list of options that client requested.
    bool added = false;
874
    const std::vector<uint8_t>& requested_opts = oro->getValues();
875

Tomek Mrugalski's avatar
Tomek Mrugalski committed
876
    for (std::vector<uint8_t>::const_iterator code = requested_opts.begin();
877
         code != requested_opts.end(); ++code) {
878
        if  (!vendor_rsp->getOption(*code)) {
879
880
            OptionDescriptor desc = subnet->getCfgOption()->get(vendor_id,
                                                                *code);
881
882
            if (desc.option_) {
                vendor_rsp->addOption(desc.option_);
883
884
                added = true;
            }
885
886
        }

887
        if (added) {
888
            ex.getResponse()->addOption(vendor_rsp);
889
890
        }
    }
Tomek Mrugalski's avatar
Tomek Mrugalski committed
891
}
892

893

894
void
895
Dhcpv4Srv::appendBasicOptions(Dhcpv4Exchange& ex) {
896
897
898
899
900
901
    // Identify options that we always want to send to the
    // client (if they are configured).
    static const uint16_t required_options[] = {
        DHO_ROUTERS,
        DHO_DOMAIN_NAME_SERVERS,
        DHO_DOMAIN_NAME };
902

903
904
905
906
    static size_t required_options_size =
        sizeof(required_options) / sizeof(required_options[0]);

    // Get the subnet.
907
    Subnet4Ptr subnet = ex.getContext()->subnet_;
908
909
910
911
    if (!subnet) {
        return;
    }

912
913
    Pkt4Ptr resp = ex.getResponse();

914
915
916
    // Try to find all 'required' options in the outgoing
    // message. Those that are not present will be added.
    for (int i = 0; i < required_options_size; ++i) {
917
        OptionPtr opt = resp->getOption(required_options[i]);
918
919
        if (!opt) {
            // Check whether option has been configured.
920
921
            OptionDescriptor desc = subnet->getCfgOption()->
                get("dhcp4", required_options[i]);
922
            if (desc.option_) {
923
                resp->addOption(desc.option_);
924
925
926
            }
        }
    }
Tomek Mrugalski's avatar
Tomek Mrugalski committed
927
}
928

929
void
930
Dhcpv4Srv::processClientName(Dhcpv4Exchange& ex) {
931
932
933
    // It is possible that client has sent both Client FQDN and Hostname
    // option. In such case, server should prefer Client FQDN option and
    // ignore the Hostname option.
934
    try {
935
        Pkt4Ptr resp = ex.getResponse();
936
        Option4ClientFqdnPtr fqdn = boost::dynamic_pointer_cast<Option4ClientFqdn>
937
            (ex.getQuery()->getOption(DHO_FQDN));
938
        if (fqdn) {
939
            LOG_DEBUG(ddns_logger, DBG_DHCP4_DETAIL, DHCP4_CLIENT_FQDN_PROCESS)
940
                .arg(ex.getQuery()->getLabel());
941
            processClientFqdnOption(ex);
942
943

        } else {
944
            OptionStringPtr hostname = boost::dynamic_pointer_cast<OptionString>
945
                (ex.getQuery()->getOption(DHO_HOST_NAME));
946
            if (hostname) {
947
                LOG_DEBUG(ddns_logger, DBG_DHCP4_DETAIL, DHCP4_CLIENT_HOSTNAME_PROCESS)
948
                    .arg(ex.getQuery()->getLabel());
949
                processHostnameOption(ex);
950
951
            }
        }
952
    } catch (const Exception& e) {
953
954
955
956
957
958
959
960
        // 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.
961
        LOG_DEBUG(ddns_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_CLIENT_NAME_PROC_FAIL)
962
963
            .arg(ex.getQuery()->getLabel())
            .arg(e.what());
964
965
966
967
    }
}

void
968
Dhcpv4Srv::processClientFqdnOption(Dhcpv4Exchange& ex) {
969
970
971
972
    // Obtain the FQDN option from the client's message.
    Option4ClientFqdnPtr fqdn = boost::dynamic_pointer_cast<
        Option4ClientFqdn>(ex.getQuery()->getOption(DHO_FQDN));

973
    LOG_DEBUG(ddns_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_CLIENT_FQDN_DATA)
974
975
976
        .arg(ex.getQuery()->getLabel())
        .arg(fqdn->toText());

977
978
979
980
    // Create the DHCPv4 Client FQDN Option to be included in the server's
    // response to a client.
    Option4ClientFqdnPtr fqdn_resp(new Option4ClientFqdn(*fqdn));

981
982
983
984
    // 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);
985

986
987
988
    // Carry over the client's E flag.
    fqdn_resp->setFlag(Option4ClientFqdn::FLAG_E,
                       fqdn->getFlag(Option4ClientFqdn::FLAG_E));
989

990
    if (ex.getContext()->host_ && !ex.getContext()->host_->getHostname().empty()) {
991
992
993
        D2ClientMgr& d2_mgr = CfgMgr::instance().getD2ClientMgr();
        fqdn_resp->setDomainName(d2_mgr.qualifyName(ex.getContext()->host_->getHostname(),
                                                    true), Option4ClientFqdn::FULL);
994

995
996
997
998
999
    } 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);
    }
1000

For faster browsing, not all history is shown. View entire blame