developer.intra2net.com Git - pingcheck/blob - src/host/pingscheduler.cpp

   1 /*
   2 The software in this package is distributed under the GNU General
   3 Public License version 2 (with a special exception described below).
   4
   5 A copy of GNU General Public License (GPL) is included in this distribution,
   6 in the file COPYING.GPL.
   7
   8 As a special exception, if other files instantiate templates or use macros
   9 or inline functions from this file, or you compile this file and link it
  10 with other works to produce a work based on this file, this file
  11 does not by itself cause the resulting work to be covered
  12 by the GNU General Public License.
  13
  14 However the source code for this file must still be made available
  15 in accordance with section (3) of the GNU General Public License.
  16
  17 This exception does not invalidate any other reasons why a work based
  18 on this file might be covered by the GNU General Public License.
  19 */
  20 #include "host/pingscheduler.h"
  21
  22 #include <iostream>
  23 #include <limits>
  24
  25 #include <boost/bind.hpp>
  26 #include <boost/foreach.hpp>
  27
  28 #include <logfunc.hpp>
  29
  30 #include "boost_assert_handler.h"
  31 #include "host/pingerfactory.h"
  32 #include "dns/dnsmaster.h"
  33 #include "icmp/icmppinger.h"
  34 #include "link/linkstatus.h"
  35
  36 using namespace std;
  37 using boost::asio::io_service;
  38 using boost::bind;
  39 using boost::date_time::time_resolution_traits_adapted64_impl;
  40 using boost::posix_time::microsec_clock;
  41 using boost::posix_time::ptime;
  42 using boost::posix_time::seconds;
  43 using boost::shared_ptr;
  44 using I2n::Logger::GlobalLogger;
  45
  46 //-----------------------------------------------------------------------------
  47 // PingScheduler
  48 //-----------------------------------------------------------------------------
  49
  50 /**
  51  * @brief Parameterized constructor.
  52  *
  53  * @param io_serv The one @c io_serv object that controls async processing
  54  * @param network_interface The name of the network interface sending the pings.
  55  * @param destination_address The remote address to ping.
  56  * @param destination_port The remote port to ping.
  57  * @param ping_protocol_list A list of protocols to use.
  58  * @param ping_interval_in_sec Amount of time between each ping.
  59  * @param ping_fail_percentage_limit Maximum amount of pings that can fail.
  60  * @param link_analyzer The object to monitor the link status.
  61  * @param first_delay Delay in seconds from start_pinging to first ping attempt
  62  */
  63 PingScheduler::PingScheduler(
  64         const IoServiceItem io_serv,
  65         const string &network_interface,
  66         const string &destination_address,
  67         const uint16_t destination_port,
  68         const PingProtocolList &ping_protocol_list,
  69         const long ping_interval_in_sec,
  70         const int ping_fail_percentage_limit,
  71         const int ping_reply_timeout,
  72         LinkStatusItem link_analyzer,
  73         const int first_delay
  74
  75 ) :
  76     IoService( io_serv ),
  77     NetworkInterfaceName( network_interface ),
  78     DestinationAddress( destination_address ),
  79     DestinationPort( destination_port ),
  80     Protocols( ping_protocol_list ),
  81     ProtocolIter(),
  82     PingIntervalInSec( ping_interval_in_sec ),
  83     FirstDelay( first_delay ),
  84     NextPingTimer( *io_serv ),
  85     TimeSentLastPing( microsec_clock::universal_time() ),
  86     PingReplyTimeout( ping_reply_timeout ),
  87     HostAnalyzer( destination_address, ping_fail_percentage_limit,
  88                   link_analyzer ),
  89     Resolver(),
  90     Ping(),
  91     WantToPing( false ),
  92     LogPrefix(),
  93     ContinueOnOutdatedIps( false )
  94 {
  95     BOOST_ASSERT( !network_interface.empty() );
  96     BOOST_ASSERT( !destination_address.empty() );
  97     BOOST_ASSERT( ( 0 < destination_port ) &&
  98                   ( destination_port < numeric_limits<uint16_t>::max() ) );
  99     BOOST_ASSERT( 0 < ping_interval_in_sec );
 100     BOOST_ASSERT( (0 <= ping_fail_percentage_limit) &&
 101                   ( ping_fail_percentage_limit <= 100) );
 102
 103     update_log_prefix();
 104
 105     init_ping_protocol();
 106 }
 107
 108 /**
 109  * @brief Destructor.
 110  */
 111 PingScheduler::~PingScheduler()
 112 {
 113 }
 114
 115 void PingScheduler::stop_pinging()
 116 {
 117     // stop pinger and resolver
 118     GlobalLogger.debug() << LogPrefix << "scheduler: stop pinging";
 119     Ping->stop_pinging();
 120     Resolver->cancel_resolve();
 121
 122     // now cancel the own timer in case that pinger cancelation called callback
 123     GlobalLogger.debug() << LogPrefix << "scheduler: cancel timer";
 124     NextPingTimer.cancel();
 125 }
 126
 127 /**
 128  * @brief Start into infinite loop of calls to ping
 129  *
 130  * Does not start yet but set NextPingTimer (possibly to 0), so action starts
 131  *   when io_service is started
 132  */
 133 void PingScheduler::start_pinging()
 134 {
 135     if ( FirstDelay > 0 )
 136         GlobalLogger.info() << LogPrefix << "Delaying first ping by "
 137                                          << FirstDelay << "s";
 138     else
 139         GlobalLogger.info() << LogPrefix << "Schedule ping as soon as possible";
 140
 141     (void) NextPingTimer.expires_from_now( seconds( FirstDelay ) );
 142     NextPingTimer.async_wait( bind( &PingScheduler::ping, this,
 143                                           boost::asio::placeholders::error ) );
 144 }
 145
 146
 147 /**
 148  * @brief call Ping::ping and schedule a call to ping_done_handler when finished
 149  */
 150 void PingScheduler::ping(const boost::system::error_code &error)
 151 {
 152     if ( error )
 153     {   // get here, e.g. by NextPingTimer.cancel in stop_pinging
 154         if ( error ==  boost::asio::error::operation_aborted )
 155             GlobalLogger.error() << LogPrefix << "Timer for ping was cancelled!"
 156                                  << " --> Stopping";
 157         else
 158             GlobalLogger.error() << LogPrefix << "Received error " << error
 159                                  << " waiting for ping! Stopping";
 160         return;
 161     }
 162
 163     // ping as soon as dns is ready
 164     WantToPing = true;
 165     ping_when_ready();
 166 }
 167
 168
 169 void PingScheduler::ping_when_ready()
 170 {
 171     if ( !WantToPing )
 172     {
 173         GlobalLogger.info() << LogPrefix << "not pinging (not requested to)";
 174         return;
 175     }
 176     else if ( Resolver && Resolver->is_resolving() )
 177     {
 178         GlobalLogger.info() << LogPrefix << "not pinging (DNS not finished)";
 179         return;
 180     }
 181     else if ( !Resolver )
 182         // should not happen, but check anyway
 183         GlobalLogger.warning() << LogPrefix << "Have no resolver!";
 184
 185     GlobalLogger.info() << LogPrefix << "start ping";
 186     WantToPing = false;
 187
 188     // try to get an up-to-date IP
 189     HostAddress ip = Resolver->get_next_ip();
 190
 191     if ( !ip.is_valid() && ContinueOnOutdatedIps)
 192     {   // we failed to resolve --> try to use outdated IP
 193         GlobalLogger.info() << LogPrefix << "Checking for outdated IPs";
 194         bool check_up_to_date = false;
 195         ip = Resolver->get_next_ip(check_up_to_date);
 196     }
 197     if ( ip.is_valid() )
 198         Ping->ping(
 199                 Resolver->get_next_ip().get_ip(),
 200                 DestinationPort,
 201                 boost::bind(&PingScheduler::ping_done_handler, this, _1)
 202         );
 203     else
 204     {   // should not happen
 205         GlobalLogger.error() << LogPrefix << "No IP to ping "
 206                              << "-- this should not have happened!!";
 207         WantToPing = true;
 208         if ( !Resolver->is_resolving() )
 209             start_resolving_ping_address();
 210     }
 211
 212     // next time try with up-to-date IP
 213     ContinueOnOutdatedIps = false;
 214 }
 215
 216
 217 //------------------------------------------------------------------------------
 218 // Post Processing of Ping result
 219 //------------------------------------------------------------------------------
 220
 221 /**
 222  * @brief called when Ping::ping is done; calls functions to update
 223  *   statistics, ping interval and elapsed time;
 224  *   schedules a call to ping, thereby closing the loop
 225  */
 226 void PingScheduler::ping_done_handler( const bool ping_success )
 227 {
 228     // post-processing
 229     // You must call these 3 methods exactly in this order
 230     // TODO Fix this method, once it has a semantic dependency with the
 231     // update_ping_statistics method, because it depends on the PingAnalyzer
 232     // statistics to update the exceeded_ping_failed_limit
 233     HostAnalyzer.update_ping_statistics( ping_success );
 234     update_ping_interval();
 235     update_ping_elapsed_time();
 236
 237     // get next protocol, possibly start resolving IPs
 238     update_ping_protocol();
 239
 240     // schedule next ping
 241     (void) NextPingTimer.expires_from_now( seconds( PingIntervalInSec ) );
 242     NextPingTimer.async_wait( bind( &PingScheduler::ping, this,
 243                                          boost::asio::placeholders::error ) );
 244 }
 245
 246 void PingScheduler::update_ping_interval()
 247 {
 248     // have to ping more often?
 249     if ( HostAnalyzer.exceeded_ping_failed_limit() )
 250     {
 251         PingIntervalInSec.speed_up();
 252
 253         GlobalLogger.debug() << LogPrefix << "- Speeding up ping interval to: "
 254                              << PingIntervalInSec << "s";
 255     }
 256     else
 257     {
 258         PingIntervalInSec.back_to_original();
 259
 260         GlobalLogger.debug() << LogPrefix << "- Stick to the original ping "
 261                              << "interval: " << PingIntervalInSec << "s";
 262     }
 263 }
 264
 265 void PingScheduler::update_ping_elapsed_time()
 266 {
 267     ptime now = microsec_clock::universal_time();
 268     time_resolution_traits_adapted64_impl::int_type elapsed_time_in_sec =
 269             (now - TimeSentLastPing).total_seconds();
 270     GlobalLogger.debug() << LogPrefix << "- Time elapsed since last ping: "
 271                                       << elapsed_time_in_sec << "s";
 272
 273     TimeSentLastPing = microsec_clock::universal_time();
 274 }
 275
 276
 277 //------------------------------------------------------------------------------
 278 // Ping Protocol Rotation
 279 //------------------------------------------------------------------------------
 280
 281 void PingScheduler::init_ping_protocol()
 282 {
 283     ProtocolIter = Protocols.end();
 284     get_next_ping_protocol();
 285 }
 286
 287 void PingScheduler::update_ping_protocol()
 288 {
 289     if ( can_change_ping_protocol() )
 290     {
 291         get_next_ping_protocol();
 292     }
 293 }
 294
 295 void PingScheduler::get_next_ping_protocol()
 296 {
 297     ++ProtocolIter;
 298     if (ProtocolIter == Protocols.end())
 299         ProtocolIter = Protocols.begin();
 300     PingProtocol ping_protocol = *ProtocolIter;
 301     // --> ProtocolIter still points to currently used protocol which is
 302     //     required in dns_resolve_callback
 303
 304     if (Ping)
 305         Ping->stop_pinging();
 306
 307     Ping = PingerFactory::createPinger(ping_protocol, IoService,
 308                                        NetworkInterfaceName, PingReplyTimeout);
 309
 310     update_dns_resolver( ping_protocol );
 311 }
 312
 313 bool PingScheduler::can_change_ping_protocol() const
 314 {
 315     // TODO can_change_ping_protocol() and get_next_ping_protocol() may be
 316     // implemented in a Algorithm class that can be exchanged in this class to
 317     // provide an algorithm neutral class
 318     return true;
 319 }
 320
 321 //------------------------------------------------------------------------------
 322 // DNS host name resolution
 323 //------------------------------------------------------------------------------
 324
 325 // show "!" after host name if running on outdated IPs
 326 void PingScheduler::update_log_prefix()
 327 {
 328     std::stringstream temp;
 329     temp << "PS(" << DestinationAddress;
 330     if (ContinueOnOutdatedIps)
 331         temp << "!";
 332     temp << "): ";
 333     LogPrefix = temp.str();
 334 }
 335
 336 void PingScheduler::update_dns_resolver( PingProtocol current_protocol )
 337 {
 338     if (Resolver && Resolver->is_resolving())
 339     {
 340         GlobalLogger.warning() << LogPrefix
 341                           << "Resolver still seems to be resolving --> cancel!";
 342         Resolver->cancel_resolve();
 343     }
 344
 345     // DNS master caches created resolvers and resolved IPs, so this will
 346     // probably just return an existing resolver with already resolved IPs for
 347     // requested protocol ( ICMP/TCP is ignored, only IPv4/v6 is important)
 348     Resolver = DnsMaster::get_instance()->get_resolver_for(DestinationAddress,
 349                                                            current_protocol);
 350     // start resolving if no ips available
 351     if ( Resolver->have_up_to_date_ip() )
 352     {
 353         if (!Resolver->is_resolving())
 354             GlobalLogger.warning() << LogPrefix << "have up to date IPs but "
 355                 << "resolver seems to be resolving all the same... "
 356                 << "Start pinging anyway!";
 357         ping_when_ready();
 358     }
 359     else
 360         start_resolving_ping_address();
 361 }
 362
 363 void PingScheduler::start_resolving_ping_address()
 364 {
 365     Resolver->async_resolve( boost::bind(&PingScheduler::dns_resolve_callback,
 366                                           this, _1, _2) );
 367 }
 368
 369 void PingScheduler::dns_resolve_callback(const bool was_success,
 370                                          const int cname_count)
 371 {
 372     GlobalLogger.info() << LogPrefix << "dns resolution finished "
 373                         << "with success = " << was_success << " "
 374                         << "and cname_count = " << cname_count;
 375
 376     // TODO this is too simple, but need to think more about how to update here!
 377     // (may have to switch back some time to resolver for original host or so
 378     ContinueOnOutdatedIps = !was_success;
 379     update_log_prefix();
 380
 381     if ( was_success )
 382     {
 383         HostAnalyzer.set_resolved_ip_count( Resolver->get_resolved_ip_count());
 384         ping_when_ready();
 385     }
 386     else
 387     {   // host name resolution failed; try again bypassing first outdated CNAME
 388         // or using cached IP
 389
 390         std::string skip_host = Resolver->get_skip_cname();
 391
 392         if (skip_host.empty())
 393         {   // continue with IP
 394             GlobalLogger.notice() << LogPrefix << "DNS failed, "
 395                 << "try anyway with cached data";
 396             HostAnalyzer.set_resolved_ip_count(0);
 397             ping_when_ready();
 398         }
 399         else
 400         {   // have CNAME to continue
 401             GlobalLogger.notice() << LogPrefix << "DNS failed, "
 402                 << "try again skipping a CNAME and resolving "
 403                 << skip_host << " directly";
 404             Resolver = DnsMaster::get_instance()
 405                                    ->get_resolver_for(skip_host, *ProtocolIter);
 406             start_resolving_ping_address();
 407
 408             // (the original resolver is still alive and cached by DnsMaster and
 409             //  counting down time to re-try on its own until cancel_resolve)
 410         }
 411     }
 412 }