dhcp4_srv.cc 87.6 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
45
#include <log/logger.h>
#include <cryptolink/cryptolink.h>
46

47
#include <asio.hpp>
48
#include <boost/bind.hpp>
49
#include <boost/foreach.hpp>
50
#include <boost/shared_ptr.hpp>
51
52
53

#include <iomanip>

54
55
using namespace isc;
using namespace isc::asiolink;
56
using namespace isc::cryptolink;
57
using namespace isc::dhcp;
58
using namespace isc::dhcp_ddns;
59
using namespace isc::hooks;
60
61
using namespace isc::log;
using namespace std;
62

63
/// Structure that holds registered hook indexes
64
65
struct Dhcp4Hooks {
    int hook_index_buffer4_receive_;///< index for "buffer4_receive" hook point
66
67
    int hook_index_pkt4_receive_;   ///< index for "pkt4_receive" hook point
    int hook_index_subnet4_select_; ///< index for "subnet4_select" hook point
68
    int hook_index_lease4_release_; ///< index for "lease4_release" hook point
69
    int hook_index_pkt4_send_;      ///< index for "pkt4_send" hook point
70
    int hook_index_buffer4_send_;   ///< index for "buffer4_send" hook point
71

72
73
74
    /// Constructor that registers hook points for DHCPv4 engine
    Dhcp4Hooks() {
        hook_index_buffer4_receive_= HooksManager::registerHook("buffer4_receive");
75
76
77
        hook_index_pkt4_receive_   = HooksManager::registerHook("pkt4_receive");
        hook_index_subnet4_select_ = HooksManager::registerHook("subnet4_select");
        hook_index_pkt4_send_      = HooksManager::registerHook("pkt4_send");
78
79
        hook_index_lease4_release_ = HooksManager::registerHook("lease4_release");
        hook_index_buffer4_send_   = HooksManager::registerHook("buffer4_send");
80
81
82
83
84
85
86
    }
};

// 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.
87
Dhcp4Hooks Hooks;
88

89
90
91
namespace isc {
namespace dhcp {

92
Dhcpv4Exchange::Dhcpv4Exchange(const AllocEnginePtr& alloc_engine,
93
94
                               const Pkt4Ptr& query,
                               const Subnet4Ptr& subnet)
95
96
    : alloc_engine_(alloc_engine), query_(query), resp_(),
      context_(new AllocEngine::ClientContext4()) {
97

98
99
100
101
102
103
104
105
    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");
106
107
    }

108
109
110
    // Create response message.
    initResponse();
    // Select subnet for the query message.
111
    context_->subnet_ = subnet;
112
    // Hardware address.
113
    context_->hwaddr_ = query->getHWAddr();
114
115
116
    // Client Identifier
    OptionPtr opt_clientid = query->getOption(DHO_DHCP_CLIENT_IDENTIFIER);
    if (opt_clientid) {
117
        context_->clientid_.reset(new ClientId(opt_clientid->getData()));
118
119
    }
    // Check for static reservations.
120
    alloc_engine->findReservation(*context_);
121
122
};

123
void
124
Dhcpv4Exchange::initResponse() {
125
126
127
128
129
130
131
132
133
134
135
136
    uint8_t resp_type = 0;
    switch (getQuery()->getType()) {
    case DHCPDISCOVER:
        resp_type = DHCPOFFER;
        break;
    case DHCPREQUEST:
    case DHCPINFORM:
        resp_type = DHCPACK;
        break;
    default:
        ;
    }
137
    // Only create a response if one is required.
138
139
    if (resp_type > 0) {
        resp_.reset(new Pkt4(resp_type, getQuery()->getTransid()));
140
141
142
143
144
145
146
147
148
        copyDefaultFields();
    }
}

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

149
150
    // explicitly set this to 0
    resp_->setSiaddr(IOAddress::IPV4_ZERO_ADDRESS());
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
    // 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);
190
191
192
    }
}

193
194
const std::string Dhcpv4Srv::VENDOR_CLASS_PREFIX("VENDOR_CLASS_");

195
Dhcpv4Srv::Dhcpv4Srv(uint16_t port, const bool use_bcast,
196
                     const bool direct_response_desired)
197
198
199
    : 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) {
200

201
    LOG_DEBUG(dhcp4_logger, DBG_DHCP4_START, DHCP4_OPEN_SOCKET).arg(port);
202
    try {
203
204
205
        // 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.
206
        if (port) {
207
208
209
210
211
212
213
214
            // 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);
215
        }
216

217
        // Instantiate allocation engine
218
219
        alloc_engine_.reset(new AllocEngine(AllocEngine::ALLOC_ITERATIVE, 100,
                                            false /* false = IPv4 */));
220

221
222
223
224
225
226
227
        // 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

228
    } catch (const std::exception &e) {
229
        LOG_ERROR(dhcp4_logger, DHCP4_SRV_CONSTRUCT_ERROR).arg(e.what());
230
231
232
        shutdown_ = true;
        return;
    }
233

Tomek Mrugalski's avatar
Tomek Mrugalski committed
234
    shutdown_ = false;
235
236
237
}

Dhcpv4Srv::~Dhcpv4Srv() {
Tomek Mrugalski's avatar
Tomek Mrugalski committed
238
    IfaceMgr::instance().closeSockets();
239
240
}

241
242
void
Dhcpv4Srv::shutdown() {
243
    LOG_DEBUG(dhcp4_logger, DBG_DHCP4_BASIC, DHCP4_SHUTDOWN_REQUEST);
244
245
246
    shutdown_ = true;
}

247
isc::dhcp::Subnet4Ptr
248
Dhcpv4Srv::selectSubnet(const Pkt4Ptr& query) const {
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263

    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
264
    if (HooksManager::calloutsPresent(hook_index_subnet4_select_)) {
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
        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()) {
285
            LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS,
286
287
                      DHCP4_HOOK_SUBNET4_SELECT_SKIP)
                .arg(query->getLabel());
288
289
290
291
292
293
294
            return (Subnet4Ptr());
        }

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

295
296
    if (subnet) {
        // Log at higher debug level that subnet has been found.
297
        LOG_DEBUG(packet_logger, DBG_DHCP4_BASIC_DATA, DHCP4_SUBNET_SELECTED)
298
299
300
301
302
303
304
305
306
307
308
309
310
311
            .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());
    }

312
    return (subnet);
313
314
}

Tomek Mrugalski's avatar
Tomek Mrugalski committed
315
316
Pkt4Ptr
Dhcpv4Srv::receivePacket(int timeout) {
317
318
319
    return (IfaceMgr::instance().receive4(timeout));
}

Tomek Mrugalski's avatar
Tomek Mrugalski committed
320
321
void
Dhcpv4Srv::sendPacket(const Pkt4Ptr& packet) {
322
323
324
    IfaceMgr::instance().send(packet);
}

325
326
bool
Dhcpv4Srv::run() {
Tomek Mrugalski's avatar
Tomek Mrugalski committed
327
    while (!shutdown_) {
Tomek Mrugalski's avatar
Tomek Mrugalski committed
328
        // client's message and server's response
329
        Pkt4Ptr query;
Tomek Mrugalski's avatar
Tomek Mrugalski committed
330
        Pkt4Ptr rsp;
331

332
        try {
333
334
335
336
337
338
339
340
341
342
            // 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;
            }
343
            LOG_DEBUG(packet_logger, DBG_DHCP4_DETAIL, DHCP4_BUFFER_WAIT).arg(timeout);
344
            query = receivePacket(timeout);
345

346
347
348
349
350
351
352
            // 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) {
353
                LOG_DEBUG(packet_logger, DBG_DHCP4_BASIC, DHCP4_BUFFER_RECEIVED)
354
355
356
357
358
359
360
361
362
363
364
                    .arg(query->getRemoteAddr().toText())
                    .arg(query->getRemotePort())
                    .arg(query->getLocalAddr().toText())
                    .arg(query->getLocalPort())
                    .arg(query->getIface());

            } else {
                LOG_DEBUG(packet_logger, DBG_DHCP4_DETAIL, DHCP4_BUFFER_WAIT_TIMEOUT)
                    .arg(timeout);
            }

365
366
367
368
369
370
        } 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
            // behavior of the system, but there is nothing we should log here.
371
372
            LOG_DEBUG(packet_logger, DBG_DHCP4_DETAIL, DHCP4_BUFFER_WAIT_SIGNAL)
                .arg(signal_set_->getNext());
373
        } catch (const std::exception& e) {
374
            // Log all other errors.
375
            LOG_ERROR(packet_logger, DHCP4_BUFFER_RECEIVE_FAIL).arg(e.what());
376
377
        }

378
379
380
        // 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
381
382
383
384
385
386
387
        // 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.
388
389
        handleSignal();

390
391
        // Execute ready timers for the lease database, e.g. Lease File Cleanup.
        try {
392
            LeaseMgrFactory::instance().getIOService()->poll();
393
394
395
396
397
398

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

399
        // Timeout may be reached or signal received, which breaks select()
400
401
        // with no reception occurred. No need to log anything here because
        // we have logged right after the call to receivePacket().
402
403
404
405
        if (!query) {
            continue;
        }

406
407
408
409
410
411
412
413
414
        // 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));

415
416
417
        bool skip_unpack = false;

        // The packet has just been received so contains the uninterpreted wire
418
        // data; execute callouts registered for buffer4_receive.
419
        if (HooksManager::calloutsPresent(Hooks.hook_index_buffer4_receive_)) {
420
421
422
423
424
425
426
427
428
            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
429
430
            HooksManager::callCallouts(Hooks.hook_index_buffer4_receive_,
                                       *callout_handle);
431
432
433
434
435
436

            // 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()) {
437
                LOG_DEBUG(hooks_logger, DBG_DHCP4_DETAIL, DHCP4_HOOK_BUFFER_RCVD_SKIP)
438
439
440
                    .arg(query->getRemoteAddr().toText())
                    .arg(query->getLocalAddr().toText())
                    .arg(query->getIface());
441
442
443
444
445
446
447
448
449
                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
450
            try {
451
452
453
454
                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
455
456
                query->unpack();
            } catch (const std::exception& e) {
457
                // Failed to parse the packet.
458
459
                LOG_DEBUG(bad_packet_logger, DBG_DHCP4_DETAIL,
                          DHCP4_PACKET_DROP_0001)
460
461
462
                    .arg(query->getRemoteAddr().toText())
                    .arg(query->getLocalAddr().toText())
                    .arg(query->getIface())
463
                    .arg(e.what());
464
465
                continue;
            }
466
        }
467

Tomek Mrugalski's avatar
Tomek Mrugalski committed
468
469
470
        // 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.
471
472
        classifyPacket(query);

473
474
475
        // 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)) {
476
            continue;
477
        }
478

479
        // We have sanity checked (in accept() that the Message Type option
480
481
        // exists, so we can safely get it here.
        int type = query->getType();
482
        LOG_DEBUG(packet_logger, DBG_DHCP4_BASIC_DATA, DHCP4_PACKET_RECEIVED)
483
            .arg(query->getLabel())
484
            .arg(query->getName())
485
            .arg(type)
486
487
            .arg(query->getRemoteAddr())
            .arg(query->getLocalAddr())
488
            .arg(query->getIface());
489
490
        LOG_DEBUG(packet_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_QUERY_DATA)
            .arg(query->getLabel())
491
492
            .arg(query->toText());

Tomek Mrugalski's avatar
Tomek Mrugalski committed
493
        // Let's execute all callouts registered for pkt4_receive
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
        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()) {
511
                LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS, DHCP4_HOOK_PACKET_RCVD_SKIP)
512
                    .arg(query->getLabel());
513
514
                continue;
            }
515

516
517
            callout_handle->getArgument("query4", query);
        }
518

519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
        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:
541
                rsp = processInform(query);
542
543
544
545
546
547
548
                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.
                ;
549
            }
550
551
        } catch (const isc::Exception& e) {

552
553
554
555
556
557
            // 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.)
558
559
560
561
            LOG_DEBUG(bad_packet_logger, DBG_DHCP4_BASIC,
                      DHCP4_PACKET_DROP_0007)
                .arg(query->getLabel())
                .arg(e.what());
562
        }
563

564
565
566
        if (!rsp) {
            continue;
        }
567

568

569
570
        // Specifies if server should do the packing
        bool skip_pack = false;
571

Tomek Mrugalski's avatar
Tomek Mrugalski committed
572
        // Execute all callouts registered for pkt4_send
573
574
        if (HooksManager::calloutsPresent(hook_index_pkt4_send_)) {
            CalloutHandlePtr callout_handle = getCalloutHandle(query);
575

576
577
            // Delete all previous arguments
            callout_handle->deleteAllArguments();
578

579
580
            // Clear skip flag if it was set in previous callouts
            callout_handle->setSkip(false);
581

582
583
            // Set our response
            callout_handle->setArgument("response4", rsp);
584

585
586
587
            // Call all installed callouts
            HooksManager::callCallouts(hook_index_pkt4_send_,
                                       *callout_handle);
588

589
590
591
592
            // 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()) {
593
                LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS, DHCP4_HOOK_PACKET_SEND_SKIP)
594
                    .arg(query->getLabel());
595
596
597
598
599
600
                skip_pack = true;
            }
        }

        if (!skip_pack) {
            try {
601
602
                LOG_DEBUG(options_logger, DBG_DHCP4_DETAIL, DHCP4_PACKET_PACK)
                    .arg(rsp->getLabel());
603
604
                rsp->pack();
            } catch (const std::exception& e) {
605
606
                LOG_ERROR(options_logger, DHCP4_PACKET_PACK_FAIL)
                    .arg(rsp->getLabel())
607
608
609
610
611
612
613
614
                    .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
615
            // Let's execute all callouts registered for buffer4_send
616
            if (HooksManager::calloutsPresent(Hooks.hook_index_buffer4_send_)) {
617
                CalloutHandlePtr callout_handle = getCalloutHandle(query);
618

619
620
                // Delete previously set arguments
                callout_handle->deleteAllArguments();
621

622
623
                // Pass incoming packet as argument
                callout_handle->setArgument("response4", rsp);
624

625
                // Call callouts
Tomek Mrugalski's avatar
Tomek Mrugalski committed
626
627
                HooksManager::callCallouts(Hooks.hook_index_buffer4_send_,
                                           *callout_handle);
628

629
630
631
632
                // 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()) {
633
                    LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS,
634
635
                              DHCP4_HOOK_BUFFER_SEND_SKIP)
                        .arg(rsp->getLabel());
636
                    continue;
637
                }
638
639

                callout_handle->getArgument("response4", rsp);
640
            }
641

642
            LOG_DEBUG(packet_logger, DBG_DHCP4_BASIC, DHCP4_PACKET_SEND)
643
                .arg(rsp->getLabel())
644
                .arg(rsp->getName())
645
646
647
648
649
650
                .arg(static_cast<int>(rsp->getType()))
                .arg(rsp->getLocalAddr())
                .arg(rsp->getLocalPort())
                .arg(rsp->getRemoteAddr())
                .arg(rsp->getRemotePort())
                .arg(rsp->getIface());
651
652

            LOG_DEBUG(packet_logger, DBG_DHCP4_DETAIL_DATA,
653
                      DHCP4_RESPONSE_DATA)
654
655
656
657
                .arg(rsp->getLabel())
                .arg(rsp->getName())
                .arg(static_cast<int>(rsp->getType()))
                .arg(rsp->toText());
658
659
            sendPacket(rsp);
        } catch (const std::exception& e) {
660
661
            LOG_ERROR(packet_logger, DHCP4_PACKET_SEND_FAIL)
                .arg(rsp->getLabel())
662
                .arg(e.what());
663
        }
664
665
666
667
668
    }

    return (true);
}

669
string
670
Dhcpv4Srv::srvidToString(const OptionPtr& srvid) {
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
    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());
687
688
}

689
isc::dhcp_ddns::D2Dhcid
690
691
692
693
694
695
696
697
698
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");

699
700
    }

701
702
703
704
705
706
707
708
709
    // 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);
710

711
712
713
    } catch (const Exception& ex) {
        isc_throw(DhcidComputeError, "unable to compute DHCID because the"
                  " hostname: " << lease->hostname_ << " is invalid");
714
715

    }
716
717
718

    // Prefer client id to HW address to compute DHCID. If Client Id is
    // NULL, use HW address.
719
    try {
720
721
722
723
        if (lease->client_id_) {
            return (D2Dhcid(lease->client_id_->getClientId(), fqdn_wire));

        } else {
724
            return (D2Dhcid(lease->hwaddr_, fqdn_wire));
725
        }
726
    } catch (const Exception& ex) {
727
728
        isc_throw(DhcidComputeError, "unable to compute DHCID: "
                  << ex.what());
729

730
    }
731
732
733

}

734
void
735
Dhcpv4Srv::appendServerID(Dhcpv4Exchange& ex) {
736
737
738
    // 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.
739
740
    /// @todo: perhaps we should consider some more sophisticated server id
    /// generation, but for the current use cases, it should be ok.
741
742
743
    OptionPtr opt_srvid(new Option4AddrLst(DHO_DHCP_SERVER_IDENTIFIER,
                                           ex.getResponse()->getLocalAddr()));
    ex.getResponse()->addOption(opt_srvid);
744
745
}

746
void
747
Dhcpv4Srv::appendRequestedOptions(Dhcpv4Exchange& ex) {
748
749
    // Get the subnet relevant for the client. We will need it
    // to get the options associated with it.
750
    Subnet4Ptr subnet = ex.getContext()->subnet_;
751
752
753
754
755
756
757
    // 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;
    }
758

759
760
    Pkt4Ptr query = ex.getQuery();

761
762
763
    // try to get the 'Parameter Request List' option which holds the
    // codes of requested options.
    OptionUint8ArrayPtr option_prl = boost::dynamic_pointer_cast<
764
        OptionUint8Array>(query->getOption(DHO_DHCP_PARAMETER_REQUEST_LIST));
765
766
767
768
769
    // If there is no PRL option in the message from the client then
    // there is nothing to do.
    if (!option_prl) {
        return;
    }
770

771
772
    Pkt4Ptr resp = ex.getResponse();

773
774
775
776
777
778
    // 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) {
779
        if (!resp->getOption(*opt)) {
780
            OptionDescriptor desc = subnet->getCfgOption()->get("dhcp4", *opt);
781
            if (desc.option_) {
782
                resp->addOption(desc.option_);
783
            }
784
785
        }
    }
Tomek Mrugalski's avatar
Tomek Mrugalski committed
786
}
787

788
void
789
Dhcpv4Srv::appendRequestedVendorOptions(Dhcpv4Exchange& ex) {
790
    // Get the configured subnet suitable for the incoming packet.
791
    Subnet4Ptr subnet = ex.getContext()->subnet_;
792
793
794
795
796
797
798
799
800
801
    // 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
802
803
    boost::shared_ptr<OptionVendor> vendor_req = boost::dynamic_pointer_cast<
        OptionVendor>(ex.getQuery()->getOption(DHO_VIVSO_SUBOPTIONS));
804
805
806
807
808
809
810
    if (!vendor_req) {
        return;
    }

    uint32_t vendor_id = vendor_req->getVendorId();

    // Let's try to get ORO within that vendor-option
811
812
    /// @todo This is very specific to vendor-id=4491 (Cable Labs). Other
    /// vendors may have different policies.
Tomek Mrugalski's avatar
Tomek Mrugalski committed
813
814
    OptionUint8ArrayPtr oro =
        boost::dynamic_pointer_cast<OptionUint8Array>(vendor_req->getOption(DOCSIS3_V4_ORO));
815
816
817
818
819
820
821
822
823
824

    // 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;
825
    const std::vector<uint8_t>& requested_opts = oro->getValues();
826

Tomek Mrugalski's avatar
Tomek Mrugalski committed
827
    for (std::vector<uint8_t>::const_iterator code = requested_opts.begin();
828
         code != requested_opts.end(); ++code) {
829
        if  (!vendor_rsp->getOption(*code)) {
830
831
            OptionDescriptor desc = subnet->getCfgOption()->get(vendor_id,
                                                                *code);
832
833
            if (desc.option_) {
                vendor_rsp->addOption(desc.option_);
834
835
                added = true;
            }
836
837
        }

838
        if (added) {
839
            ex.getResponse()->addOption(vendor_rsp);
840
841
        }
    }
Tomek Mrugalski's avatar
Tomek Mrugalski committed
842
}
843

844

845
void
846
Dhcpv4Srv::appendBasicOptions(Dhcpv4Exchange& ex) {
847
848
849
850
851
852
    // 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 };
853

854
855
856
857
    static size_t required_options_size =
        sizeof(required_options) / sizeof(required_options[0]);

    // Get the subnet.
858
    Subnet4Ptr subnet = ex.getContext()->subnet_;
859
860
861
862
    if (!subnet) {
        return;
    }

863
864
    Pkt4Ptr resp = ex.getResponse();

865
866
867
    // 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) {
868
        OptionPtr opt = resp->getOption(required_options[i]);
869
870
        if (!opt) {
            // Check whether option has been configured.
871
872
            OptionDescriptor desc = subnet->getCfgOption()->
                get("dhcp4", required_options[i]);
873
            if (desc.option_) {
874
                resp->addOption(desc.option_);
875
876
877
            }
        }
    }
Tomek Mrugalski's avatar
Tomek Mrugalski committed
878
}
879

880
void
881
Dhcpv4Srv::processClientName(Dhcpv4Exchange& ex) {
882
883
884
    // 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.
885
    try {
886
        Pkt4Ptr resp = ex.getResponse();
887
        Option4ClientFqdnPtr fqdn = boost::dynamic_pointer_cast<Option4ClientFqdn>
888
            (ex.getQuery()->getOption(DHO_FQDN));
889
        if (fqdn) {
890
            LOG_DEBUG(ddns_logger, DBG_DHCP4_DETAIL, DHCP4_CLIENT_FQDN_PROCESS)
891
                .arg(ex.getQuery()->getLabel());
892
            processClientFqdnOption(ex);
893
894

        } else {
895
            OptionStringPtr hostname = boost::dynamic_pointer_cast<OptionString>
896
                (ex.getQuery()->getOption(DHO_HOST_NAME));
897
            if (hostname) {
898
                LOG_DEBUG(ddns_logger, DBG_DHCP4_DETAIL, DHCP4_CLIENT_HOSTNAME_PROCESS)
899
                    .arg(ex.getQuery()->getLabel());
900
                processHostnameOption(ex);
901
902
            }
        }
903
    } catch (const Exception& e) {
904
905
906
907
908
909
910
911
        // 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.
912
        LOG_DEBUG(ddns_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_CLIENT_NAME_PROC_FAIL)
913
914
            .arg(ex.getQuery()->getLabel())
            .arg(e.what());
915
916
917
918
    }
}

void
919
Dhcpv4Srv::processClientFqdnOption(Dhcpv4Exchange& ex) {
920
921
922
923
    // Obtain the FQDN option from the client's message.
    Option4ClientFqdnPtr fqdn = boost::dynamic_pointer_cast<
        Option4ClientFqdn>(ex.getQuery()->getOption(DHO_FQDN));

924
    LOG_DEBUG(ddns_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_CLIENT_FQDN_DATA)
925
926
927
        .arg(ex.getQuery()->getLabel())
        .arg(fqdn->toText());

928
929
930
931
    // Create the DHCPv4 Client FQDN Option to be included in the server's
    // response to a client.
    Option4ClientFqdnPtr fqdn_resp(new Option4ClientFqdn(*fqdn));

932
933
934
935
    // 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);
936

937
938
939
    // Carry over the client's E flag.
    fqdn_resp->setFlag(Option4ClientFqdn::FLAG_E,
                       fqdn->getFlag(Option4ClientFqdn::FLAG_E));
940

941
    if (ex.getContext()->host_ && !ex.getContext()->host_->getHostname().empty()) {
942
943
944
        D2ClientMgr& d2_mgr = CfgMgr::instance().getD2ClientMgr();
        fqdn_resp->setDomainName(d2_mgr.qualifyName(ex.getContext()->host_->getHostname(),
                                                    true), Option4ClientFqdn::FULL);
945

946
947
948
949
950
    } 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);
    }
951
952
953
954
955
956
957
958
959
960

    // 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.
Francis Dupont's avatar
Francis Dupont committed
961
    // If we don't store the option in the response message, we will have to
962
963
    // propagate it in the different way to the functions which acquire the
    // lease. This would require modifications to the API of this class.
964
    LOG_DEBUG(ddns_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_RESPONSE_FQDN_DATA)
965
966
        .arg(ex.getQuery()->getLabel())
        .arg(fqdn_resp->toText());
967
    ex.getResponse()->addOption(fqdn_resp);
968
969
970
}

void
971
Dhcpv4Srv::processHostnameOption(Dhcpv4Exchange& ex) {
972
973
974
975
    // Obtain the Hostname option from the client's message.
    OptionStringPtr opt_hostname = boost::dynamic_pointer_cast<OptionString>
        (ex.getQuery()->getOption(DHO_HOST_NAME));

976
    LOG_DEBUG(ddns_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_CLIENT_HOSTNAME_DATA)
977
978
979
        .arg(ex.getQuery()->getLabel())
        .arg(opt_hostname->getValue());

980
981
982
    // Fetch D2 configuration.
    D2ClientMgr& d2_mgr = CfgMgr::instance().getD2ClientMgr();

983
    // Do nothing if the DNS updates are disabled.
984
    if (!d2_mgr.ddnsEnabled()) {
985
986
987
        return;
    }

988
    std::string hostname = isc::util::str::trim(opt_hostname->getValue());
989
    unsigned int label_count = OptionDataTypeUtil::getLabelCount(hostname);
990
    // The hostname option sent by the client should be at least 1 octet long.
991
992
993
    // 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.
994
    if (label_count == 0) {
995
        LOG_DEBUG(ddns_logger, DBG_DHCP4_DETAIL_DATA, DHCP4_EMPTY_HOSTNAME)
996
            .arg(ex.getQuery()->getLabel());
997
998
        return;
    }
999
1000
    // Copy construct the hostname provided by the client. It is entirely
    // possible that we will use the hostname option provided by the client
For faster browsing, not all history is shown. View entire blame