pdns/recursordist/rec-tcpout.cc

   1 /*
   2  * This file is part of PowerDNS or dnsdist.
   3  * Copyright -- PowerDNS.COM B.V. and its contributors
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of version 2 of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * In addition, for the avoidance of any doubt, permission is granted to
  10  * link this program with OpenSSL and to (re)distribute the binaries
  11  * produced as the result of such linking.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22
  23 #include "rec-tcpout.hh"
  24
  25 // This line from /usr/include/openssl/ssl2.h: # define CERT char
  26 // throws dnsrecords.hh off the rails.
  27 #undef CERT
  28
  29 #include "syncres.hh"
  30
  31 timeval TCPOutConnectionManager::s_maxIdleTime;
  32 size_t TCPOutConnectionManager::s_maxQueries;
  33 size_t TCPOutConnectionManager::s_maxIdlePerAuth;
  34 size_t TCPOutConnectionManager::s_maxIdlePerThread;
  35
  36 void TCPOutConnectionManager::cleanup(const struct timeval& now)
  37 {
  38   if (s_maxIdleTime.tv_sec == 0 && s_maxIdleTime.tv_usec == 0) {
  39     // no maximum idle time
  40     return;
  41   }
  42
  43   for (auto it = d_idle_connections.begin(); it != d_idle_connections.end();) {
  44     timeval idle = now - it->second.d_last_used;
  45     if (s_maxIdleTime < idle) {
  46       it = d_idle_connections.erase(it);
  47     }
  48     else {
  49       ++it;
  50     }
  51   }
  52 }
  53
  54 void TCPOutConnectionManager::store(const struct timeval& now, const ComboAddress& ip, Connection&& connection)
  55 {
  56   ++connection.d_numqueries;
  57   if (s_maxQueries > 0 && connection.d_numqueries >= s_maxQueries) {
  58     return;
  59   }
  60
  61   if (d_idle_connections.size() >= s_maxIdlePerThread || d_idle_connections.count(ip) >= s_maxIdlePerAuth) {
  62     cleanup(now);
  63   }
  64
  65   if (d_idle_connections.size() >= s_maxIdlePerThread) {
  66     return;
  67   }
  68   if (d_idle_connections.count(ip) >= s_maxIdlePerAuth) {
  69     return;
  70   }
  71
  72   gettimeofday(&connection.d_last_used, nullptr);
  73   d_idle_connections.emplace(ip, std::move(connection));
  74 }
  75
  76 TCPOutConnectionManager::Connection TCPOutConnectionManager::get(const ComboAddress& ip)
  77 {
  78   if (d_idle_connections.count(ip) > 0) {
  79     auto h = d_idle_connections.extract(ip);
  80     return h.mapped();
  81   }
  82   return Connection{};
  83 }
  84
  85 uint64_t getCurrentIdleTCPConnections()
  86 {
  87   return broadcastAccFunction<uint64_t>([] { return t_tcp_manager.getSize(); });
  88 }