pdns/dnsdist-dynbpf.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 #include "dnsdist-dynbpf.hh"
  23
  24 #ifdef HAVE_EBPF
  25
  26 bool DynBPFFilter::block(const ComboAddress& addr, const struct timespec& until)
  27 {
  28   bool inserted = false;
  29   std::unique_lock<std::mutex> lock(d_mutex);
  30
  31   if (d_excludedSubnets.match(addr)) {
  32     /* do not add a block for excluded subnets */
  33     return inserted;
  34   }
  35
  36   const container_t::iterator it = d_entries.find(addr);
  37   if (it != d_entries.end()) {
  38     if (it->d_until < until) {
  39       d_entries.replace(it, BlockEntry(addr, until));
  40     }
  41   }
  42   else {
  43     d_bpf->block(addr);
  44     d_entries.insert(BlockEntry(addr, until));
  45     inserted = true;
  46   }
  47   return inserted;
  48 }
  49
  50 void DynBPFFilter::purgeExpired(const struct timespec& now)
  51 {
  52   std::unique_lock<std::mutex> lock(d_mutex);
  53
  54   typedef nth_index<container_t,1>::type ordered_until;
  55   ordered_until& ou = get<1>(d_entries);
  56
  57   for (ordered_until::iterator it=ou.begin(); it != ou.end(); ) {
  58     if (it->d_until < now) {
  59       ComboAddress addr = it->d_addr;
  60       it = ou.erase(it);
  61       d_bpf->unblock(addr);
  62     }
  63     else {
  64       break;
  65     }
  66   }
  67 }
  68
  69 std::vector<std::tuple<ComboAddress, uint64_t, struct timespec> > DynBPFFilter::getAddrStats()
  70 {
  71   std::vector<std::tuple<ComboAddress, uint64_t, struct timespec> > result;
  72   if (!d_bpf) {
  73     return result;
  74   }
  75
  76   const auto& stats = d_bpf->getAddrStats();
  77   for (const auto& stat : stats) {
  78     const container_t::iterator it = d_entries.find(stat.first);
  79     if (it != d_entries.end()) {
  80       result.push_back(std::make_tuple(stat.first, stat.second, it->d_until));
  81     }
  82   }
  83   return result;
  84 }
  85
  86 #endif /* HAVE_EBPF */