1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
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
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
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
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
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
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
// Copyright (C) 2013-2024 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include <config.h>
#include <asiolink/asio_wrapper.h>
#include <asiolink/io_service_mgr.h>
#include <cc/command_interpreter.h>
#include <config/command_mgr.h>
#include <config/http_command_mgr.h>
#include <d2/d2_controller.h>
#include <d2/d2_process.h>
#include <d2srv/d2_cfg_mgr.h>
#include <d2srv/d2_log.h>
#include <d2srv/d2_stats.h>
#include <d2srv/d2_tsig_key.h>
#include <hooks/hooks.h>
#include <hooks/hooks_manager.h>

using namespace isc::asiolink;
using namespace isc::config;
using namespace isc::hooks;
using namespace isc::process;

namespace {

/// Structure that holds registered hook indexes.
struct D2ProcessHooks {
    int hooks_index_d2_srv_configured_;

    /// Constructor that registers hook points for the D2 server.
    D2ProcessHooks() {
        hooks_index_d2_srv_configured_ = HooksManager::registerHook("d2_srv_configured");
    }

};

// 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.
D2ProcessHooks Hooks;

}

namespace isc {
namespace d2 {

// Setting to 80% for now. This is an arbitrary choice and should probably
// be configurable.
const unsigned int D2Process::QUEUE_RESTART_PERCENT = 80;

D2Process::D2Process(const char* name, const asiolink::IOServicePtr& io_service)
    : DProcessBase(name, io_service, DCfgMgrBasePtr(new D2CfgMgr())),
      reconf_queue_flag_(false), shutdown_type_(SD_NORMAL) {

    // Instantiate queue manager.  Note that queue manager does not start
    // listening at this point.  That can only occur after configuration has
    // been received.  This means that until we receive the configuration,
    // D2 will neither receive nor process NameChangeRequests.
    // Pass in IOService for NCR IO event processing.
    queue_mgr_.reset(new D2QueueMgr(getIOService()));

    // Instantiate update manager.
    // Pass in both queue manager and configuration manager.
    // Pass in IOService for DNS update transaction IO event processing.
    D2CfgMgrPtr tmp = getD2CfgMgr();
    update_mgr_.reset(new D2UpdateMgr(queue_mgr_, tmp, getIOService()));

    // Initialize stats manager.
    D2Stats::init();
};

void
D2Process::init() {
    using namespace isc::config;
    // Command managers use IO service to run asynchronous socket operations.
    CommandMgr::instance().setIOService(getIOService());
    HttpCommandMgr::instance().setIOService(getIOService());

    // Set the HTTP authentication default realm.
    HttpCommandConfig::DEFAULT_AUTHENTICATION_REALM = "kea-dhcp-ddns-server";

    // D2 server does not use the interface manager.
    HttpCommandMgr::instance().addExternalSockets(false);
};

void
D2Process::run() {
    LOG_INFO(d2_logger, DHCP_DDNS_STARTED).arg(VERSION);
    D2ControllerPtr controller =
        boost::dynamic_pointer_cast<D2Controller>(D2Controller::instance());
    try {
        // Now logging was initialized so commands can be registered.
        controller->registerCommands();

        // Loop forever until we are allowed to shutdown.
        while (!canShutdown()) {
            // Check on the state of the request queue. Take any
            // actions necessary regarding it.
            checkQueueStatus();

            // Give update manager a time slice to queue new jobs and
            // process finished ones.
            update_mgr_->sweep();

            // Wait on IO event(s) - block until one or more of the following
            // has occurred:
            //   a. NCR message has been received
            //   b. Transaction IO has completed
            //   c. Interval timer expired
            //   d. Control channel event
            //   e. Something stopped IO service (runIO returns 0)
            if (runIO() == 0) {
                // Pretty sure this amounts to an unexpected stop and we
                // should bail out now.  Normal shutdowns do not utilize
                // stopping the IOService.
                isc_throw(DProcessBaseError,
                          "Primary IO service stopped unexpectedly");
            }
        }
    } catch (const std::exception& ex) {
        LOG_FATAL(d2_logger, DHCP_DDNS_FAILED).arg(ex.what());
        controller->deregisterCommands();
        isc_throw (DProcessBaseError,
                   "Process run method failed: " << ex.what());
    }

    /// @todo - if queue isn't empty, we may need to persist its contents
    /// this might be the place to do it, once there is a persistence mgr.
    /// This may also be better in checkQueueStatus.

    controller->deregisterCommands();

    LOG_DEBUG(d2_logger, isc::log::DBGLVL_START_SHUT, DHCP_DDNS_RUN_EXIT);

};

size_t
D2Process::runIO() {
    // Handle events registered by hooks using external IOService objects.
    IOServiceMgr::instance().pollIOServices();
    // We want to block until at least one handler is called.  We'll use
    // boost::asio::io_service directly for two reasons. First off
    // asiolink::IOService::runOne is a void and boost::asio::io_service::stopped
    // is not present in older versions of boost.  We need to know if any
    // handlers ran or if the io_service was stopped.  That latter represents
    // some form of error and the application cannot proceed with a stopped
    // service.  Secondly, asiolink::IOService does not provide the poll
    // method.  This is a handy method which runs all ready handlers without
    // blocking.

    // Poll runs all that are ready. If none are ready it returns immediately
    // with a count of zero.
    size_t cnt = getIOService()->poll();
    if (!cnt) {
        // Poll ran no handlers either none are ready or the service has been
        // stopped.  Either way, call runOne to wait for a IO event. If the
        // service is stopped it will return immediately with a cnt of zero.
        cnt = getIOService()->runOne();
    }
    config::HttpCommandMgr::instance().garbageCollectListeners();
    return (cnt);
}

bool
D2Process::canShutdown() const {
    bool all_clear = false;

    // If we have been told to shutdown, find out if we are ready to do so.
    if (shouldShutdown()) {
        switch (shutdown_type_) {
        case SD_NORMAL:
            // For a normal shutdown we need to stop the queue manager but
            // wait until we have finished all the transactions in progress.
            all_clear = (((queue_mgr_->getMgrState() != D2QueueMgr::RUNNING) &&
                          (queue_mgr_->getMgrState() != D2QueueMgr::STOPPING))
                         && (update_mgr_->getTransactionCount() == 0));
            break;

        case SD_DRAIN_FIRST:
            // For a drain first shutdown we need to stop the queue manager but
            // process all of the requests in the receive queue first.
            all_clear = (((queue_mgr_->getMgrState() != D2QueueMgr::RUNNING) &&
                          (queue_mgr_->getMgrState() != D2QueueMgr::STOPPING))
                          && (queue_mgr_->getQueueSize() == 0)
                          && (update_mgr_->getTransactionCount() == 0));
            break;

        case SD_NOW:
            // Get out right now, no niceties.
            all_clear = true;
            break;

        default:
            // shutdown_type_ is an enum and should only be one of the above.
            // if its getting through to this, something is whacked.
            break;
        }

        if (all_clear) {
            LOG_DEBUG(d2_logger, isc::log::DBGLVL_START_SHUT,
                     DHCP_DDNS_CLEARED_FOR_SHUTDOWN)
                .arg(getShutdownTypeStr(shutdown_type_));
        }
    }

    return (all_clear);
}

isc::data::ConstElementPtr
D2Process::shutdown(isc::data::ConstElementPtr args) {
    LOG_DEBUG(d2_logger, isc::log::DBGLVL_START_SHUT,
              DHCP_DDNS_SHUTDOWN_COMMAND)
        .arg(args ? args->str() : "(no arguments)");

    // Default shutdown type is normal.
    std::string type_str(getShutdownTypeStr(SD_NORMAL));
    shutdown_type_ = SD_NORMAL;

    if (args) {
        if ((args->getType() == isc::data::Element::map) &&
            args->contains("type")) {
            type_str = args->get("type")->stringValue();

            if (type_str == getShutdownTypeStr(SD_NORMAL)) {
                shutdown_type_ = SD_NORMAL;
            } else if (type_str == getShutdownTypeStr(SD_DRAIN_FIRST)) {
                shutdown_type_ = SD_DRAIN_FIRST;
            } else if (type_str == getShutdownTypeStr(SD_NOW)) {
                shutdown_type_ = SD_NOW;
            } else {
                setShutdownFlag(false);
                return (isc::config::createAnswer(CONTROL_RESULT_ERROR,
                                                  "Invalid Shutdown type: " +
                                                  type_str));
            }
        }
    }

    // Set the base class's shutdown flag.
    setShutdownFlag(true);
    return (isc::config::createAnswer(CONTROL_RESULT_SUCCESS,
                                      "Shutdown initiated, type is: " +
                                      type_str));
}

isc::data::ConstElementPtr
D2Process::configure(isc::data::ConstElementPtr config_set, bool check_only) {
    LOG_DEBUG(d2_logger, isc::log::DBGLVL_TRACE_BASIC, DHCP_DDNS_CONFIGURE)
        .arg(check_only ? "check" : "update")
        .arg(getD2CfgMgr()->redactConfig(config_set)->str());

    isc::data::ConstElementPtr answer;
    answer = getCfgMgr()->simpleParseConfig(config_set, check_only,
                std::bind(&D2Process::reconfigureCommandChannel, this));
    if (check_only) {
        return (answer);
    }

    int rcode = 0;
    isc::data::ConstElementPtr comment;
    comment = isc::config::parseAnswer(rcode, answer);

    if (rcode) {
        // Non-zero means we got an invalid configuration, take no further
        // action. In integrated mode, this will send a failed response back
        // to the configuration backend.
        reconf_queue_flag_ = false;
        return (answer);
    }

    // Set the reconf_queue_flag to indicate that we need to reconfigure
    // the queue manager.  Reconfiguring the queue manager may be asynchronous
    // and require one or more events to occur, therefore we set a flag
    // indicating it needs to be done but we cannot do it here.  It must
    // be done over time, while events are being processed.  Remember that
    // the method we are in now is invoked as part of the configuration event
    // callback.  This means you can't wait for events here, you are already
    // in one.
    /// (@todo NOTE This could be turned into a bitmask of flags if we find other
    /// things that need reconfiguration.  It might also be useful if we
    /// did some analysis to decide what if anything we need to do.)
    reconf_queue_flag_ = true;

    // This hook point notifies hooks libraries that the configuration of the
    // D2 server has completed. It provides the hook library with the pointer
    // to the common IO service object, new server configuration in the JSON
    // format and with the pointer to the configuration storage where the
    // parsed configuration is stored.
    std::string error("");
    if (HooksManager::calloutsPresent(Hooks.hooks_index_d2_srv_configured_)) {
        CalloutHandlePtr callout_handle = HooksManager::createCalloutHandle();

        callout_handle->setArgument("io_context", getIOService());
        callout_handle->setArgument("json_config", config_set);
        callout_handle->setArgument("server_config",
                                    getD2CfgMgr()->getD2CfgContext());
        callout_handle->setArgument("error", error);

        HooksManager::callCallouts(Hooks.hooks_index_d2_srv_configured_,
                                   *callout_handle);

        // The config can be rejected by a hook.
        if (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_DROP) {
            callout_handle->getArgument("error", error);
            LOG_ERROR(d2_logger, DHCP_DDNS_CONFIGURED_CALLOUT_DROP)
                .arg(error);
            reconf_queue_flag_ = false;
            answer = isc::config::createAnswer(CONTROL_RESULT_ERROR, error);
            return (answer);
        }
    }

    /// Let postponed hook initializations run.
    try {
        // Handle events registered by hooks using external IOService objects.
        IOServiceMgr::instance().pollIOServices();
    } catch (const std::exception& ex) {
        std::ostringstream err;
        err << "Error initializing hooks: "
            << ex.what();
        return (isc::config::createAnswer(CONTROL_RESULT_ERROR, err.str()));
    }

    // If we are here, configuration was valid, at least it parsed correctly
    // and therefore contained no invalid values.
    // Return the success answer from above.
    return (answer);
}

void
D2Process::checkQueueStatus() {
    switch (queue_mgr_->getMgrState()){
    case D2QueueMgr::RUNNING:
        if (reconf_queue_flag_ || shouldShutdown()) {
            /// If we need to reconfigure the queue manager or we have been
            /// told to shutdown, then stop listening first.  Stopping entails
            /// canceling active listening which may generate an IO event, so
            /// instigate the stop and get out.
            try {
                LOG_DEBUG(d2_logger, isc::log::DBGLVL_START_SHUT,
                          DHCP_DDNS_QUEUE_MGR_STOPPING)
                    .arg(reconf_queue_flag_ ? "reconfiguration" : "shutdown");
                queue_mgr_->stopListening();
            } catch (const isc::Exception& ex) {
                // It is very unlikely that we would experience an error
                // here, but theoretically possible.
                LOG_ERROR(d2_logger, DHCP_DDNS_QUEUE_MGR_STOP_ERROR)
                          .arg(ex.what());
            }
        }
        break;

    case D2QueueMgr::STOPPED_QUEUE_FULL: {
            /// Resume receiving once the queue has decreased by twenty
            /// percent.  This is an arbitrary choice.
            /// @todo this value should probably be configurable.
            size_t threshold = (((queue_mgr_->getMaxQueueSize()
                                * QUEUE_RESTART_PERCENT)) / 100);
            if (queue_mgr_->getQueueSize() <= threshold) {
                LOG_INFO (d2_logger, DHCP_DDNS_QUEUE_MGR_RESUMING)
                          .arg(threshold).arg(queue_mgr_->getMaxQueueSize());
                try {
                    queue_mgr_->startListening();
                } catch (const isc::Exception& ex) {
                    LOG_ERROR(d2_logger, DHCP_DDNS_QUEUE_MGR_RESUME_ERROR)
                              .arg(ex.what());
                }
            }

        break;
        }

    case D2QueueMgr::STOPPED_RECV_ERROR:
        /// If the receive error is not due to some fallout from shutting
        /// down then we will attempt to recover by reconfiguring the listener.
        /// This will close and destruct the current listener and make a new
        /// one with new resources.
        /// @todo This may need a safety valve such as retry count or a timer
        /// to keep from endlessly retrying over and over, with little time
        /// in between.
        if (!shouldShutdown()) {
            LOG_INFO (d2_logger, DHCP_DDNS_QUEUE_MGR_RECOVERING);
            reconfigureQueueMgr();
        }
        break;

    case D2QueueMgr::STOPPING:
        /// We are waiting for IO to cancel, so this is a NOP.
        /// @todo Possible timer for self-defense?  We could conceivably
        /// get into a condition where we never get the event, which would
        /// leave us stuck in stopping.  This is hugely unlikely but possible?
        break;

    default:
        // If the reconfigure flag is set, then we are in a state now where
        // we can do the reconfigure. In other words, we aren't RUNNING or
        // STOPPING.
        if (reconf_queue_flag_) {
            LOG_DEBUG(d2_logger, isc::log::DBGLVL_TRACE_BASIC,
                      DHCP_DDNS_QUEUE_MGR_RECONFIGURING);
            reconfigureQueueMgr();
        }
        break;
    }
}

void
D2Process::reconfigureQueueMgr() {
    // Set reconfigure flag to false.  We are only here because we have
    // a valid configuration to work with so if we fail below, it will be
    // an operational issue, such as a busy IP address. That will leave
    // queue manager in INITTED state, which is fine.
    // What we don't want is to continually attempt to reconfigure so set
    // the flag false now.
    /// @todo This method assumes only 1 type of listener.  This will change
    /// to support at least a TCP version, possibly some form of RDBMS listener
    /// as well.
    reconf_queue_flag_ = false;
    try {
        // Wipe out the current listener.
        queue_mgr_->removeListener();

        // Get the configuration parameters that affect Queue Manager.
        const D2ParamsPtr& d2_params = getD2CfgMgr()->getD2Params();

        /// Warn the user if the server address is not the loopback.
        /// @todo Remove this once we provide a secure mechanism.
        std::string ip_address = d2_params->getIpAddress().toText();
        if (ip_address == "0.0.0.0" || ip_address == "::") {
            LOG_WARN(d2_logger, DHCP_DDNS_LISTENING_ON_ALL_INTERFACES).arg(ip_address);
        } else if (ip_address != "127.0.0.1" && ip_address != "::1") {
           LOG_WARN(d2_logger, DHCP_DDNS_NOT_ON_LOOPBACK).arg(ip_address);
        }

        // Instantiate the listener.
        if (d2_params->getNcrProtocol() == dhcp_ddns::NCR_UDP) {
            queue_mgr_->initUDPListener(d2_params->getIpAddress(),
                                        d2_params->getPort(),
                                        d2_params->getNcrFormat(), true);
        } else {
            /// @todo Add TCP/IP once it's supported
            // We should never get this far but if we do deal with it.
            isc_throw(DProcessBaseError, "Unsupported NCR listener protocol:"
                      << dhcp_ddns::ncrProtocolToString(d2_params->
                                                        getNcrProtocol()));
        }

        // Now start it. This assumes that starting is a synchronous,
        // blocking call that executes quickly.
        /// @todo Should that change then we will have to expand the state model
        /// to accommodate this.
        queue_mgr_->startListening();
    } catch (const isc::Exception& ex) {
        // Queue manager failed to initialize and therefore not listening.
        // This is most likely due to an unavailable IP address or port,
        // which is a configuration issue.
        LOG_ERROR(d2_logger, DHCP_DDNS_QUEUE_MGR_START_ERROR).arg(ex.what());
    }
}

D2Process::~D2Process() {
    queue_mgr_->stopListening();
    getIOService()->stopAndPoll();
    queue_mgr_->removeListener();
}

D2CfgMgrPtr
D2Process::getD2CfgMgr() {
    // The base class gives a base class pointer to our configuration manager.
    // Since we are D2, and we need D2 specific extensions, we need a pointer
    // to D2CfgMgr for some things.
    return (boost::dynamic_pointer_cast<D2CfgMgr>(getCfgMgr()));
}

const char* D2Process::getShutdownTypeStr(const ShutdownType& type) {
    const char* str;
    switch (type) {
    case SD_NORMAL:
        str = "normal";
        break;
    case SD_DRAIN_FIRST:
        str = "drain_first";
        break;
    case SD_NOW:
        str = "now";
        break;
    default:
        str = "invalid";
        break;
    }

    return (str);
}

void
D2Process::reconfigureCommandChannel() {
    // Get new socket configuration.
    isc::data::ConstElementPtr sock_cfg = getD2CfgMgr()->getControlSocketInfo();

    // Determine if the socket configuration has changed. It has if
    // both old and new configuration is specified but respective
    // data elements aren't equal.
    bool sock_changed = (sock_cfg && current_control_socket_ &&
                         !sock_cfg->equals(*current_control_socket_));

    // If the previous or new socket configuration doesn't exist or
    // the new configuration differs from the old configuration we
    // close the existing socket and open a new socket as appropriate.
    // Note that closing an existing socket means the client will not
    // receive the configuration result.
    if (!sock_cfg || !current_control_socket_ || sock_changed) {
        // Close the existing socket.
        if (current_control_socket_) {
            isc::config::CommandMgr::instance().closeCommandSocket();
            current_control_socket_.reset();
        }

        // Open the new socket.
        if (sock_cfg) {
            isc::config::CommandMgr::instance().openCommandSocket(sock_cfg);
        }
    }

    // Commit the new socket configuration.
    current_control_socket_ = sock_cfg;

    // HTTP control socket is simpler: just (re)configure it.

    // Get new config.
    HttpCommandConfigPtr http_config =
        getD2CfgMgr()->getHttpControlSocketInfo();
    HttpCommandMgr::instance().configure(http_config);
}

} // namespace isc::d2
} // namespace isc