netscanner.cpp

查看局域网的信息,类似网上邻居的功能,例如查看哪台计算机在线等

   {
      FD_ZERO(&fds);
      FD_SET(nmblookupFd,&fds);
      tv.tv_sec=10;
      tv.tv_usec=0;
      int result=select(nmblookupFd+1,&fds,0,0,&tv);
      //error
      if (result<0)
         done=1;
      //timeout
      else if (result==0)
      {
         timeOuts++;
         //3 time outs make 30 seconds, this should be *much* more than enough
         if (timeOuts>=3)
            done=1;
      }
      else if (result>0)
      {
         //read stuff
         int bytesRead=::read(nmblookupFd,tmpBuf,16*1024);
         //pipe closed
         if (bytesRead==0)
            done=1;
         else
         {
            char *newBuf=new char[bufferSize+bytesRead];
            if (receiveBuffer!=0)
            {
               memcpy(newBuf,receiveBuffer,bufferSize);
               delete [] receiveBuffer;
            };
            memcpy(newBuf+bufferSize,tmpBuf,bytesRead);
            receiveBuffer=newBuf;
            bufferSize+=bytesRead;
         };
      };
   } while (!done);
   pclose(nmblookupFile);

   delete [] tmpBuf;
   //we received nothing
   if (receiveBuffer==0)
      return;

   //check for a terrminating '\0'
   if (receiveBuffer[bufferSize-1]=='\0')
      receiveBuffer[bufferSize-1]='\0';

   //cerr<<receiveBuffer<<endl;

   tmpBuf=receiveBuffer;
   int bytesLeft=bufferSize;

   int bufferState=0;
   while (bytesLeft>0)
   {
      //getDebug()<<"bytesLeft: "<<bytesLeft<<" received: "<<bufferSize<<endl;
      //since we added a terminating \0 we can be sure here
      char *endOfLine=(char*)memchr(tmpBuf,'\n',bytesLeft);
      //point to the last character
      if (endOfLine==0)
         endOfLine=receiveBuffer+bufferSize-1;

      //0-terminate the string
      *endOfLine='\0';
      //now tmpBuf to endOfLine is a 0-terminated string
      int strLength=strlen(tmpBuf);
      //hmm, if this happens, there must be something really wrong
      if (strLength>1000)
         break;

      bytesLeft=bytesLeft-strLength-1;

      if (bufferState==0)
      {
         if (isdigit(tmpBuf[0]))
            bufferState=1;
      };
      //yes, no else !
      if (bufferState==1)
      {
         char tmpIP[1024];
         //cerr<<"tmpBuf: -"<<tmpBuf<<"-"<<endl;
         sscanf(tmpBuf,"%s *<00>\n",tmpIP);
         getDebug()<<"NetScanner::nmblookupScan: tmpIP: -"<<tmpIP<<"-"<<endl;
         struct sockaddr_in addr;
         if (inet_aton(tmpIP,&addr.sin_addr))
            if  (!hostAlreadyInList(addr.sin_addr.s_addr,newList))
            {
               if (validator.isValid(addr.sin_addr.s_addr))
               {
                  getDebug()<<"NetScanner::nmblookupScan: adding "<<inet_ntoa(addr.sin_addr)<<endl;
                  newList->append(Node(dummy,addr.sin_addr.s_addr));
               };
            };
      };
      tmpBuf=endOfLine+1;
   };
   getDebug()<<"NetScanner::nmblookupScan: finished"<<endl;
   delete [] receiveBuffer;
};

void NetScanner::pingScan(SimpleList<Node>* newList)   //the ping-version
{
   getDebug()<<"NetScanner::pingScan()"<<endl;
   //newList->clear();
   MyString dummy("");
   getDebug()<<"NetScanner::pingScan: m_maxPings: "<<m_maxPings<<endl;

/*   int bufferSize(60*1024);
   getDebug()<<"NetScanner::pingScan: regaining root privileges for setting up the icmp socket"<<endl;
   seteuid(0);
   int sockFD=socket(AF_INET,SOCK_RAW,IPPROTO_ICMP);
   getDebug()<<"NetScanner::pingScan: setsockopt returns "<<setsockopt(sockFD,SOL_SOCKET,SO_RCVBUF,&bufferSize,sizeof(bufferSize))<<endl;
   //make the socket non-blocking
   //long int options = O_NONBLOCK | ::fcntl(sockFD, F_GETFL);
   //getDebug()<<"NetScanner::pingScan:: made it non blocking: "<<::fcntl( sockFD, F_SETFL, options )<<endl;
   seteuid(getuid());
   getDebug()<<"NetScanner::pingScan: dropped root privileges again"<<endl;*/

   pid_t pid=getpid();
   ICMPEchoRequest echo;
   echo.type=ICMP_ECHO;
   echo.code=0;
   echo.id=pid;
   echo.seqNumber=0;
   echo.checkSum=0;
   echo.checkSum=in_cksum((unsigned short *)&echo,8);

   char receiveBuf[16*1024];
   //before we start first read everything what might be in the receive buffer
   //of the raw socket

   timeval tv1;
   //wait a moment for answers
   tv1.tv_sec = 0;
   tv1.tv_usec = 0;
   fd_set clearSet;
   FD_ZERO(&clearSet);
   FD_SET(m_rawSocketFD,&clearSet);
   while(select(m_rawSocketFD,&clearSet,0,0,&tv1)>0)
   {
      ::recvfrom(m_rawSocketFD,&receiveBuf,16*1024,0,0,0);
      tv1.tv_sec = 0;
      tv1.tv_usec = 0;
      FD_ZERO(&clearSet);
      FD_SET(m_rawSocketFD,&clearSet);
   };
   //now the buffer should be empty
   
   //wait a moment for answers
   tv1.tv_sec = 0;
   tv1.tv_usec = m_firstWait*10*1000;//0.5 sec

   int loopCount(2);
   if (m_secondWait<0) loopCount=1;
   for (int repeatOnce=0; repeatOnce<loopCount; repeatOnce++)
   {
      getDebug()<<"******************** starting loop *****************"<<endl;
      unsigned int current(0);
      int finished(0);
      while (!finished)
      {
         for (int con=0; con<m_maxPings; con++)
         {
            struct in_addr tmpIP;
            do
            {
               tmpIP=getIPfromArray(current);
               current++;
               getDebug()<<"NetScanner::pingScan(): trying "<<inet_ntoa(tmpIP)<<endl;
               if (hostAlreadyInList(tmpIP.s_addr,newList))
                  getDebug()<<"already in list :-)"<<endl;
               if (!validator.isValid(tmpIP.s_addr))
                  getDebug()<<"NetScanner::pingScan(): invalid IP :-("<<endl;
               //ping only hosts which are allowed to receive the results
               //and which are not in the list
            } while ( (tmpIP.s_addr!=0)
                      && ((!validator.isValid(tmpIP.s_addr))
                      || (hostAlreadyInList(tmpIP.s_addr,newList))));

            finished=(tmpIP.s_addr==0);
            if (!finished)
            {
               //send the icmp echo request
               struct sockaddr_in toAddr;
               toAddr.sin_family = AF_INET;
               toAddr.sin_addr = tmpIP;
               toAddr.sin_port = 0;
               int sb=sendto(m_rawSocketFD,(char*)&echo,sizeof(echo),0,(sockaddr*)&toAddr,sizeof(toAddr));
               //int sb=sendto(sockFD,(char*)&echo,sizeof(echo),0,(sockaddr*)&toAddr,sizeof(toAddr));
               getDebug()<<"NetScanner::pingScan: pinging "<<inet_ntoa(toAddr.sin_addr)<<endl;
            }
            else break;
         };
         select(0,0,0,0,&tv1);
         //now read the answers, hopefully
         struct sockaddr_in fromAddr;
         socklen_t length(sizeof(fromAddr));
         int received(0);

         fd_set sockFDset;
         FD_ZERO(&sockFDset);
         FD_SET(m_rawSocketFD,&sockFDset);
         //FD_SET(sockFD,&sockFDset);
         tv1.tv_sec=0;
         tv1.tv_usec=0;
         while(select(m_rawSocketFD+1,&sockFDset,0,0,&tv1)>0)
         //while(select(sockFD+1,&sockFDset,0,0,&tv1)>0)
            //do
         {
            //getDebug()<<"** recvfrom...";
            received=recvfrom(m_rawSocketFD,&receiveBuf,16*1024,0,(sockaddr*)&fromAddr,&length);
            //received=recvfrom(sockFD,&receiveBuf,1024,0,(sockaddr*)&fromAddr,&length);
            //getDebug()<<" done ****"<<endl;
            if (received!=-1)
            {
               getDebug()<<"NetScanner::pingScan: received from "<<inet_ntoa(fromAddr.sin_addr)<<" "<<received<<" b, ";
               struct ip *ipFrame=(ip*)&receiveBuf;
               int icmpOffset=(ipFrame->ip_hl)*4;
               icmp *recIcmpFrame=(icmp*)(receiveBuf+icmpOffset);
               int iType=recIcmpFrame->icmp_type;
               //getDebug()<<"icmp type: "<<iType;
               //getDebug()<<", icmp id: "<<recIcmpFrame->icmp_id<<endl;
               //if its a ICMP echo reply
               if ((iType==ICMP_ECHOREPLY)
                   //to an echo request we sent
                   && (recIcmpFrame->icmp_id==pid)
                   //and the host is not yet in the list
                   && (!hostAlreadyInList(fromAddr.sin_addr.s_addr,newList)))
               {
                  //this is an answer to our request :-)
                  getDebug()<<"NetScanner::pingScan: adding "<<inet_ntoa(fromAddr.sin_addr)<<endl;
                  newList->append(Node(dummy,fromAddr.sin_addr.s_addr));
               };
            };
            tv1.tv_sec=0;
            tv1.tv_usec=0;
            FD_ZERO(&sockFDset);
            FD_SET(m_rawSocketFD,&sockFDset);
            //FD_SET(sockFD,&sockFDset);
         };
      };
      tv1.tv_sec = 0;
      tv1.tv_usec = m_secondWait*10*1000;//0.5 sec
   };
   getDebug()<<"NetScanner::pingScan() ends"<<endl;
};

void NetScanner::doScan()
{
   getDebug()<<" NetScanner::doScan"<<endl;
   //child
   SimpleList<Node>* tmpPingList=new SimpleList<Node>;
   getDebug()<<" NetScanner::doScan: created list"<<endl;
   if (m_useNmblookup)
      nmblookupScan(tmpPingList);
   pingScan(tmpPingList);
   // get the names from cache or lookup
   completeNames(tmpPingList);
   getDebug()<<"NetScanner::doScan: completed names"<<endl;
   if (m_deliverUnnamedHosts==0)
      removeUnnamedHosts(tmpPingList);

   getDebug()<<"NetScanner::doScan: added hosts"<<endl;
   
   delete hostList;
   hostList=tmpPingList;
};

int NetScanner::hostAlreadyInList(int ip, SimpleList<Node>* nodes)
{
   for (Node* node=nodes->first(); node!=0; node=nodes->next())
   {
      if (node->ip==ip)
         return 1;
   };
   return 0;
};

void NetScanner::removeUnnamedHosts(SimpleList<Node>* nodes)
{
   struct in_addr tmpAddr;
   Node* pre(0);
   for (Node* node=nodes->first(); node!=0; node=nodes->next())
   {
      //in node this is already in NBO
      tmpAddr.s_addr=node->ip;
      const char* ip=inet_ntoa(tmpAddr);
      //this way we only compare the whole string via strcmp()
      //if at least the first char is already the same
      if (ip[0]==node->name[0])
      {
         //this host has no name
         if (strcmp(ip,node->name.data())==0)
         {
            nodes->remove(node);
            //set the pointer to the previous item
            if (pre==0) node=nodes->first();
            else node=pre;
         };
      };
      pre=node;
   };
};

void NetScanner::completeNames(SimpleList<Node>* nodes)
{
   struct sockaddr_in tmpAddr;
   //for every host
   for (Node* node=nodes->first(); node!=0; node=nodes->next())
   {
      tmpAddr.sin_addr.s_addr=node->ip;
      getDebug()<<"\n NetScanner::completeNames: looking up "<<inet_ntoa(tmpAddr.sin_addr)<<endl;
      int done(0);
      //first look wether we have the name already
      if (hostList!=0) for (Node* oldNode=hostList->first(); oldNode!=0; oldNode=hostList->next())
      {
         if (node->ip==oldNode->ip)
         {
            getDebug()<<"NetScanner::completeNames: cached: "<<oldNode->name<<" :-)"<<endl;
            node->name=oldNode->name;
            done=1;
            break;
         };
      };
      //otherwise do a name lookup
      if (!done)
      {
         //IPAddress tmpAddress(node->ip);
         //getDebug()<<"NetScanner::completeNames: doing actual lookup"<<endl;
         node->name=ip2Name(tmpAddr.sin_addr);
         getDebug()<<"NetScanner::completeNames: resolved: "<<node->name<<endl;
      };
   };
};

#undef getDebug