pdns/dynmessenger.cc

   1 /*
   2     PowerDNS Versatile Database Driven Nameserver
   3     Copyright (C) 2002 - 2008  PowerDNS.COM BV
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License version 2
   7     as published by the Free Software Foundation
   8
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18 */
  19 #include "dynmessenger.hh"
  20 #include <cstdio>
  21 #include <cstdlib>
  22 #include <cstring>
  23 #include <cerrno>
  24 #include <iostream>
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27
  28 DynMessenger::DynMessenger(const string &localdir, const string &fname)
  29 {
  30   d_s=socket(AF_UNIX,SOCK_STREAM,0);
  31   Utility::setCloseOnExec(d_s);
  32
  33   if(d_s<0) {
  34     throw PDNSException(string("socket")+strerror(errno));
  35   }
  36
  37   memset(&d_local,0,sizeof(d_local));
  38
  39   string localname=localdir;
  40
  41   localname+="/lsockXXXXXX";
  42   d_local.sun_family=AF_UNIX;
  43   strcpy(d_local.sun_path,localname.c_str());
  44
  45   if(mkstemp(d_local.sun_path)<0)
  46     throw PDNSException("Unable to generate local temporary file: "+string(strerror(errno)));
  47
  48   unlink(d_local.sun_path);
  49
  50   if(bind(d_s, (sockaddr*)&d_local,sizeof(d_local))<0) {
  51     unlink(d_local.sun_path);
  52     throw PDNSException("Unable to bind to local temporary file: "+string(strerror(errno)));
  53   }
  54
  55   if(chmod(d_local.sun_path,0666)<0) { // make sure that pdns can reply!
  56     unlink(d_local.sun_path);
  57     perror("fchmod");
  58     exit(1);
  59   }
  60
  61   memset(&d_remote,0,sizeof(d_remote));
  62
  63   d_remote.sun_family=AF_UNIX;
  64   strcpy(d_remote.sun_path,fname.c_str());
  65   if(connect(d_s,(sockaddr*)&d_remote,sizeof(d_remote))<0) {
  66     unlink(d_local.sun_path);
  67     throw PDNSException("Unable to connect to remote '"+fname+"': "+string(strerror(errno)));
  68   }
  69
  70 }
  71
  72 DynMessenger::DynMessenger(const ComboAddress& remote, const string &secret)
  73 {
  74   *d_local.sun_path=0;
  75   d_s=socket(AF_INET, SOCK_STREAM,0);
  76   Utility::setCloseOnExec(d_s);
  77
  78   if(d_s<0) {
  79     throw PDNSException(string("socket")+strerror(errno));
  80   }
  81
  82   if(connect(d_s, (sockaddr*)&remote, remote.getSocklen())<0) {
  83     close(d_s);
  84     throw PDNSException("Unable to connect to remote '"+remote.toStringWithPort()+"': "+string(strerror(errno)));
  85   }
  86
  87   string login=secret+"\n";
  88   writen2(d_s, login);
  89 }
  90
  91 DynMessenger::~DynMessenger()
  92 {
  93   if(*d_local.sun_path && unlink(d_local.sun_path)<0)
  94     cerr<<"Warning: unable to unlink local unix domain endpoint: "<<strerror(errno)<<endl;
  95   close(d_s);
  96 }
  97
  98 int DynMessenger::send(const string &msg) const
  99 {
 100   if(writen2(d_s, msg+"\n") < 0) { // sue me
 101     perror("sendto");
 102     return -1;
 103   }
 104   return 0;
 105 }
 106
 107 string DynMessenger::receive() const
 108 {
 109   char buffer[1500];
 110
 111   int retlen;
 112   string answer;
 113   for(;;) {
 114     retlen=recv(d_s,buffer,sizeof(buffer),0);
 115     if(retlen<0)
 116       throw PDNSException("Error from remote: "+string(strerror(errno)));
 117
 118     answer.append(buffer,retlen);
 119     if(retlen!=sizeof(buffer))
 120       break;
 121   }
 122
 123   return answer;
 124 }
 125