pdns/dumresp.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 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25 #include "iputils.hh"
  26 #include "sstuff.hh"
  27 #include "statbag.hh"
  28 #include <atomic>
  29 #include <sys/mman.h>
  30 #include <thread>
  31 StatBag S;
  32
  33 std::atomic<uint64_t>* g_counter;
  34
  35 void printStatus()
  36 {
  37   auto prev= g_counter->load();
  38   for(;;) {
  39     sleep(1);
  40     cout<<g_counter->load()-prev<<"\t"<<g_counter->load()<<endl;
  41     prev=g_counter->load();
  42   }
  43 }
  44
  45 void usage() {
  46   cerr<<"Syntax: dumresp LOCAL-ADDRESS LOCAL-PORT NUMBER-OF-PROCESSES"<<endl;
  47 }
  48
  49 int main(int argc, char** argv)
  50 try
  51 {
  52   for(int i = 1; i < argc; i++) {
  53     if((string) argv[i] == "--help"){
  54       usage();
  55       return(EXIT_SUCCESS);
  56     }
  57
  58     if((string) argv[i] == "--version"){
  59       cerr<<"dumresp "<<VERSION<<endl;
  60       return(EXIT_SUCCESS);
  61     }
  62   }
  63
  64   if(argc != 4) {
  65     usage();
  66     exit(EXIT_FAILURE);
  67   }
  68
  69   auto ptr = mmap(NULL, sizeof(std::atomic<uint64_t>), PROT_READ | PROT_WRITE,
  70                   MAP_SHARED | MAP_ANONYMOUS, -1, 0);
  71
  72   g_counter = new(ptr) std::atomic<uint64_t>();
  73
  74   int i=1;
  75   for(; i < atoi(argv[3]); ++i) {
  76     if(!fork())
  77       break;
  78   }
  79   if(i==1) {
  80     std::thread t(printStatus);
  81     t.detach();
  82   }
  83
  84   ComboAddress local(argv[1], atoi(argv[2]));
  85   Socket s(local.sin4.sin_family, SOCK_DGRAM);
  86 #ifdef SO_REUSEPORT
  87   int one=1;
  88   if(setsockopt(s.getHandle(), SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one)) < 0)
  89     unixDie("setsockopt for REUSEPORT");
  90 #endif
  91
  92   s.bind(local);
  93   cout<<"Bound to "<<local.toStringWithPort()<<endl;
  94   char buffer[1500];
  95   struct dnsheader* dh = (struct dnsheader*)buffer;
  96   int len;
  97   ComboAddress rem=local;
  98   socklen_t socklen = rem.getSocklen();
  99   for(;;) {
 100     len=recvfrom(s.getHandle(), buffer, sizeof(buffer), 0, (struct sockaddr*)&rem, &socklen);
 101     (*g_counter)++;
 102     if(len < 0)
 103       unixDie("recvfrom");
 104
 105     if(dh->qr)
 106       continue;
 107     dh->qr=1;
 108     dh->ad=0;
 109     if(sendto(s.getHandle(), buffer, len, 0,  (struct sockaddr*)&rem, socklen) < 0)
 110       unixDie("sendto");
 111
 112   }
 113 }
 114 catch(std::exception& e)
 115 {
 116   cerr<<"Fatal error: "<<e.what()<<endl;
 117   exit(EXIT_FAILURE);
 118 }