pdns/dynmessenger.cc

   1 /*
   2     PowerDNS Versatile Database Driven Nameserver
   3     Copyright (C) 2002  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 as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18 */
  19 #include "dynmessenger.hh"
  20 #include <cstdio>
  21 #include <cstring>
  22 #include <cerrno>
  23 #include <iostream>
  24 #include <sys/types.h>
  25 #include <sys/stat.h>
  26
  27 DynMessenger::DynMessenger(const string &localdir, const string &fname)
  28 {
  29   d_s=socket(AF_UNIX,SOCK_STREAM,0);
  30
  31   if(d_s<0) {
  32     throw AhuException(string("socket")+strerror(errno));
  33   }
  34
  35   memset(&d_local,0,sizeof(d_local));
  36
  37   string localname=localdir;
  38
  39   localname+="/lsockXXXXXX";
  40   d_local.sun_family=AF_UNIX;
  41   strcpy(d_local.sun_path,localname.c_str());
  42
  43   if(mkstemp(d_local.sun_path)<0)
  44     throw AhuException("Unable to generate local temporary file: "+string(strerror(errno)));
  45
  46   unlink(d_local.sun_path);
  47
  48   if(bind(d_s, (sockaddr*)&d_local,sizeof(d_local))<0) {
  49     unlink(d_local.sun_path);
  50     throw AhuException("Unable to bind to local temporary file: "+string(strerror(errno)));
  51   }
  52
  53   if(chmod(d_local.sun_path,0666)<0) { // make sure that pdns can reply!
  54     unlink(d_local.sun_path);
  55     perror("fchmod");
  56     exit(1);
  57   }
  58
  59   memset(&d_remote,0,sizeof(d_remote));
  60
  61   d_remote.sun_family=AF_UNIX;
  62   strcpy(d_remote.sun_path,fname.c_str());
  63   if(connect(d_s,(sockaddr*)&d_remote,sizeof(d_remote))<0) {
  64     unlink(d_local.sun_path);
  65     throw AhuException("Unable to connect to remote '"+fname+"': "+string(strerror(errno)));
  66   }
  67
  68 }
  69
  70 DynMessenger::~DynMessenger()
  71 {
  72   if(unlink(d_local.sun_path)<0)
  73     cerr<<"Warning: unable to unlink local unix domain endpoint: "<<strerror(errno)<<endl;
  74   close(d_s);
  75 }
  76
  77 int DynMessenger::send(const string &msg) const
  78 {
  79   if(::send(d_s,msg.c_str(),msg.size()+1,0)<0) {
  80     perror("sendto");
  81     return -1;
  82   }
  83   return 0;
  84 }
  85
  86 /*
  87        int  recvfrom(int  s,  void  *buf,  size_t len, int flags,
  88        struct sockaddr *from, socklen_t *fromlen);
  89 */
  90
  91 string DynMessenger::receive() const
  92 {
  93   char buffer[1500];
  94   struct sockaddr_un dontcare;
  95
  96   int retlen;
  97   string answer;
  98   for(;;) {
  99     retlen=recv(d_s,buffer,sizeof(buffer),0);
 100     if(retlen<0)
 101       throw AhuException("Error from remote: "+string(strerror(errno)));
 102
 103     answer.append(buffer,retlen);
 104     if(retlen!=sizeof(buffer))
 105       break;
 106   }
 107
 108   return answer;
 109 }
 110