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     Additionally, the license of this program contains a special
  10     exception which allows to distribute the program in binary form when
  11     it is linked against OpenSSL.
  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 St, Fifth Floor, Boston, MA  02110-1301  USA
  21 */
  22 #include "dynmessenger.hh"
  23 #include <cstdio>
  24 #include <cstdlib>
  25 #include <cstring>
  26 #include <cerrno>
  27 #include <iostream>
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30
  31 DynMessenger::DynMessenger(const string &localdir, const string &fname)
  32 {
  33   d_s=socket(AF_UNIX,SOCK_STREAM,0);
  34   Utility::setCloseOnExec(d_s);
  35
  36   if(d_s<0) {
  37     throw PDNSException(string("socket")+strerror(errno));
  38   }
  39
  40   string localname=localdir;
  41
  42   localname+="/lsockXXXXXX";
  43   if (makeUNsockaddr(localname, &d_local))
  44     throw PDNSException("Unable to bind to local temporary file, path '"+localname+"' is not a valid UNIX socket path.");
  45
  46   if(mkstemp(d_local.sun_path)<0)
  47     throw PDNSException("Unable to generate local temporary file: "+stringerror());
  48
  49   unlink(d_local.sun_path);
  50
  51   try {
  52     if(bind(d_s, (sockaddr*)&d_local,sizeof(d_local))<0)
  53       throw PDNSException("Unable to bind to local temporary file: "+stringerror());
  54
  55     // make sure that pdns can reply!
  56     if(chmod(d_local.sun_path,0666)<0)
  57       throw PDNSException("Unable to chmod local temporary file: "+stringerror());
  58
  59     if(makeUNsockaddr(fname, &d_remote))
  60       throw PDNSException("Unable to connect to remote '"+fname+"': Path is not a valid UNIX socket path.");
  61
  62     if(connect(d_s,(sockaddr*)&d_remote,sizeof(d_remote))<0)
  63       throw PDNSException("Unable to connect to remote '"+fname+"': "+stringerror());
  64
  65   } catch(...) {
  66     close(d_s);
  67     d_s=-1;
  68     unlink(d_local.sun_path);
  69     throw;
  70   }
  71 }
  72
  73 DynMessenger::DynMessenger(const ComboAddress& remote, const string &secret)
  74 {
  75   *d_local.sun_path=0;
  76   d_s=socket(AF_INET, SOCK_STREAM,0);
  77   Utility::setCloseOnExec(d_s);
  78
  79   if(d_s<0) {
  80     throw PDNSException(string("socket")+strerror(errno));
  81   }
  82
  83   if(connect(d_s, (sockaddr*)&remote, remote.getSocklen())<0) {
  84     close(d_s);
  85     d_s=-1;
  86     throw PDNSException("Unable to connect to remote '"+remote.toStringWithPort()+"': "+string(strerror(errno)));
  87   }
  88
  89   string login=secret+"\n";
  90   writen2(d_s, login);
  91 }
  92
  93 DynMessenger::~DynMessenger()
  94 {
  95   if (d_s > 0)
  96     close(d_s);
  97   if(*d_local.sun_path && unlink(d_local.sun_path)<0)
  98     cerr<<"Warning: unable to unlink local unix domain endpoint: "<<strerror(errno)<<endl;
  99 }
 100
 101 int DynMessenger::send(const string &msg) const
 102 {
 103   if(writen2(d_s, msg+"\n") < 0) { // sue me
 104     perror("sendto");
 105     return -1;
 106   }
 107   return 0;
 108 }
 109
 110 string DynMessenger::receive() const
 111 {
 112   char buffer[1500];
 113
 114   int retlen;
 115   string answer;
 116   for(;;) {
 117     retlen=recv(d_s,buffer,sizeof(buffer),0);
 118     if(retlen<0)
 119       throw PDNSException("Error from remote: "+string(strerror(errno)));
 120
 121     answer.append(buffer,retlen);
 122     if (retlen == 0)
 123       break;
 124   }
 125
 126   return answer;
 127 }
 128