netmanager.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

/*    netmanager.cpp
 *
 *    Copyright (c) 2000, Alexander Neundorf
 *    [e-mail]
 *
 *    You may distribute under the terms of the GNU General Public
 *    License as specified in the COPYING file.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 */

#include "config.h"
#include "netmanager.h"
#include "lisadefines.h"

#include <iostream.h>
#include <unistd.h>

#include <sys/un.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <strings.h>
#include <errno.h>

#ifndef AF_LOCAL
#define AF_LOCAL AF_UNIX
#endif

#include "getdebug.h"

#define getDebug() getDebug()<<procId
//#define getDebug() cerr<<procId

NetManager::NetManager(int& rawSocketFD, int portToUse, MyString configFile, int configStyle, int strictMode)
:NetScanner(rawSocketFD,strictMode)
//,validator()
,m_listenFD(-1)
,m_bcFD(-1)
,m_basePort(portToUse)
,m_pipeFD(-1)
,m_receiveBuffer(0)
,m_receivedBytes(0)
,m_childPid(0)
,m_lastUpdate(0)

,m_isInformed(0)
,m_isBeingScanned(0)
,m_firstRun(1)
,m_serverServer(0)
,m_servedThisPeriod(0)

,m_serveCount(0)
,m_refreshTime(60)
,m_initialRefreshTime(60)
,m_increasedRefreshTime(0)
,m_broadcastAddress(0)
,m_extraConfigFile(configFile)
,m_configStyle(configStyle)
,m_usedConfigFileName("")
{
   getDebug()<<"NetManager::NetManager"<<endl;
   m_startedAt=time(0);
};

NetManager::~NetManager()
{
   getDebug()<<"netknife destructor ..."<<endl;
   if (m_receiveBuffer!=0) delete [] m_receiveBuffer;
   ::close(m_listenFD);
   ::close(m_bcFD);
};

void NetManager::readConfig()
{
   m_usedConfigFileName=getConfigFileName();
   if (m_usedConfigFileName.isEmpty())
   {
      cout<<"configfile not found"<<endl;
      cout<<"use the command line option --help and \ntake a look at the README for more information"<<endl;
      exit(1);
   };

   Config config(m_usedConfigFileName);
   NetManager::configure(config);
   NetScanner::configure(config);
   validator.configure(config);
   //after reading the new configuration we should really update
   m_lastUpdate=0;
};

void NetManager::configure(Config& config)
{
   m_refreshTime=config.getEntry("UpdatePeriod",300);
   MyString tmp=stripWhiteSpace(config.getEntry("BroadcastNetwork","0.0.0.0/255.255.255.255;"));
   tmp=tmp+",";
   getDebug()<<"NetManager::readConfig: "<<tmp<<endl;
   MyString netAddressStr=tmp.left(tmp.find('/'));
   tmp=tmp.mid(tmp.find('/')+1);
   tmp=tmp.left(tmp.find(','));
   getDebug()<<"NetManager::readConfig: broadcastNet "<<netAddressStr<<" with mask "<<tmp<<endl;
   int netMask=inet_addr(tmp.c_str());
   int netAddress=inet_addr(netAddressStr.c_str());
   m_broadcastAddress= netAddress | (~netMask);
   getDebug()<<"NetManager::readConfig: net "<<ios::hex<<netAddress<<" with mask "<<netMask<<" gives "<<m_broadcastAddress<<endl;
   
   //maybe this way we can avoid that all servers on the net send
   //their requests synchronously, since now the refreshtime isn't
   //always the eact value of m_refreshTime, but differs always slightly
   if ((m_refreshTime%SELECT_TIMEOUT)==0) m_refreshTime+=2;
   //some limits from half a minute to half an hour
   if (m_refreshTime<30) m_refreshTime=30;
   if (m_refreshTime>1800) m_refreshTime=1800;
   m_initialRefreshTime=m_refreshTime;
};

int NetManager::prepare()
{
   getDebug()<<"NetManager::prepare"<<endl;

   ::close(m_listenFD);
   ::close(m_bcFD);
   int result(0);
   if (m_strictMode)
   {
      m_listenFD=::socket(AF_LOCAL, SOCK_STREAM, 0);
      //m_listenFD=::socket(AF_LOCAL, SOCK_STREAM, IPPROTO_TCP);
      MyString socketName("/tmp/resLisa-");
      socketName+=getenv("LOGNAME");
      ::unlink(socketName.data());
      sockaddr_un serverAddr;
      bzero((char*)&serverAddr, sizeof(serverAddr));
      serverAddr.sun_family      = AF_LOCAL;
      strcpy(serverAddr.sun_path,socketName.data());
      ::bind(m_listenFD,(sockaddr*) &serverAddr,sizeof(serverAddr));
   }
   else
   {
      //create a listening port and listen
      m_listenFD = ::socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

      sockaddr_in serverAddress;
      bzero((char*)&serverAddress, sizeof(serverAddress));
      serverAddress.sin_family      = AF_INET;
      serverAddress.sin_addr.s_addr = htonl(INADDR_ANY);
      serverAddress.sin_port        = htons(m_basePort);

      int on(1);
      result=setsockopt(m_listenFD, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
      if (result!=0)
      {
         cout<<"NetManager::prepare: setsockopt(SO_REUSEADDR) failed"<<endl;
         return 0;
      };
      result=::bind(m_listenFD, (struct sockaddr *) &serverAddress, sizeof(serverAddress));
      if (result!=0)
      {
         cout<<"NetManager::prepare: bind (TCP) failed"<<endl;
         return 0;
      };
   };
   result=::listen(m_listenFD, 32);
   if (result!=0)
   {
      cout<<"NetManager::prepare: listen failed"<<endl;
      return 0;
   };
   getDebug()<<"NetManager::prepare: listening on port "<<m_basePort<<"..."<<endl;

   return 1;
};

void NetManager::generateFDset(fd_set *tmpFDs)
{
   getDebug()<<"NetManager::generateFDset"<<endl;
   
   FD_ZERO(tmpFDs);
   FD_SET(m_listenFD,tmpFDs);
   getDebug()<<"NetManager::generateFDset: adding listen FD="<<m_listenFD<<endl;
   for (Client* tmpClient=clients.first(); tmpClient!=0; tmpClient=clients.next())
      if (tmpClient->fd()!=-1)
      {
         getDebug()<<"NetManager::generateFDset: adding client FD="<<tmpClient->fd()<<endl;
         FD_SET(tmpClient->fd(),tmpFDs);
      };

   if (m_pipeFD!=-1)
   {
      getDebug()<<"NetManager::generateFDset: adding pipeFD="<<m_pipeFD<<endl;
      FD_SET(m_pipeFD,tmpFDs);
   };

   if ((m_bcFD!=-1) && (!m_strictMode))
   {
      getDebug()<<"NetManager::generateFDset: adding m_bcFD="<<m_bcFD<<endl;
      FD_SET(m_bcFD,tmpFDs);
   };
};

int NetManager::waitForSomethingToHappen(fd_set *tmpFDs)
{
   getDebug()<<"NetManager::waitForSomethingToHappen for 10 seconds"<<endl;
   if (m_firstRun)
   {
      tv.tv_sec = 1;
      m_firstRun=0;
   }
   else
      tv.tv_sec = SELECT_TIMEOUT;

   tv.tv_usec = 0;
   //generateFDset(tmpFDs);
   int result=select(getMaxFD(),tmpFDs,0,0,&tv);
   if (result>0) return 1;
   else return 0;
};

int NetManager::getMaxFD()
{
   int maxFD(m_listenFD);
   for (Client* tmpClient=clients.first(); tmpClient!=0; tmpClient=clients.next())
      if (tmpClient->fd()>maxFD) maxFD=tmpClient->fd();

   if (m_pipeFD>maxFD) maxFD=m_pipeFD;
   if (m_bcFD>maxFD) maxFD=m_bcFD;

   getDebug()<<"NetManager::getMaxFD()="<<maxFD+1<<endl;
   return maxFD+1;
};

int fileReadable(const MyString& filename)
{
   FILE *file=::fopen(filename.data(), "r");
   if (file==0)
      return 0;
   fclose(file);
   return 1;
};

MyString NetManager::getConfigFileName()
{
   MyString tmpBase(CONFIGFILEBASENAME);

   if (m_strictMode)
      tmpBase=STRICTCONFIGFILEBASENAME;

   if (!m_extraConfigFile.isEmpty())
      m_configStyle=EXTRACONFIGSTYLE;

   MyString tmpFilename;
   if (m_configStyle==EXTRACONFIGSTYLE)
   {
      tmpFilename=m_extraConfigFile;
      if (fileReadable(tmpFilename))
         return tmpFilename;
      return "";
   }
   else if (m_configStyle==UNIXCONFIGSTYLE)
   {
      tmpFilename=getenv("HOME");
      tmpFilename+=MyString("/.")+tmpBase;
      if (fileReadable(tmpFilename))
         return tmpFilename;
      tmpFilename="/etc/";
      tmpFilename+=tmpBase;
      if (fileReadable(tmpFilename))
         return tmpFilename;
      return "";
   }
   else if (m_configStyle==KDE1CONFIGSTYLE)
   {
      tmpFilename=getenv("HOME");
      tmpFilename+=MyString("/.kde/share/config/")+tmpBase;
      if (fileReadable(tmpFilename))
         return tmpFilename;
      tmpFilename=getenv("KDEDIR");
      tmpFilename+=MyString("/share/config/")+tmpBase;
      if (fileReadable(tmpFilename))
         return tmpFilename;
      return "";
   }
   else if (m_configStyle==KDE2CONFIGSTYLE)
   {
      FILE *kdeConfig=popen("kde-config --path config","r");
      if (kdeConfig==0)
      {
         cout<<"could not execute kde-config, check your KDE 2 installation\n"<<endl;
         return "";
      };
      //this should be large enough
      char buf[4*1024];
      memset(buf,0,4*1024);
      fgets(buf,4*1024-1,kdeConfig);
      pclose(kdeConfig);
      int length=strlen(buf);
      if (buf[length-1]=='\n') buf[length-1]='\0';
      MyString kdeDirs(buf);
      while (kdeDirs.contains(':'))
      {
         MyString nextDir=kdeDirs.left(kdeDirs.find(':'));
         kdeDirs=kdeDirs.mid(kdeDirs.find(':')+1);
         nextDir=nextDir+tmpBase;
         getDebug()<<"trying to open "<<nextDir<<endl;
         if (fileReadable(nextDir))
            return nextDir;
      };
      kdeDirs=kdeDirs+tmpBase;
      getDebug()<<"trying to open "<<kdeDirs<<endl;
      if (fileReadable(kdeDirs))
         return kdeDirs;
      return "";
   }
   return "";
};

int NetManager::run()
{
   int continueMainLoop(1);
   //not forever
	while(continueMainLoop)
   {
      getDebug()<<"\nTCPServer::run: next loop: "<<clients.size()<<" clients"<<endl;
      fd_set tmpFDs;
      generateFDset(&tmpFDs);

      int result=waitForSomethingToHappen(&tmpFDs);
      getDebug()<<"NetManager::run: something happened..."<<endl;
      //timeout
      if (result==0)
      {
         getDebug()<<"NetManager::run: serverServer=="<<m_serverServer<<endl;
         getDebug()<<"NetManager::run: scanning after timeout"<<endl;
         scan();
      }
      else
      {
         //a new connection ?
         if (FD_ISSET(m_listenFD,&tmpFDs))
         {
            getDebug()<<"NetManager::run: on m_listenFD"<<endl;
            struct sockaddr_in clientAddress;
            ksize_t clilen(sizeof(clientAddress));
            bzero((char*)&clientAddress, clilen);
            int connectionFD=::accept(m_listenFD,(struct sockaddr *) &clientAddress, &clilen);
            if ((validator.isValid(clientAddress.sin_addr.s_addr)) || (m_strictMode))
            {
               getDebug()<<"NetManager::run: adding client"<<endl;
               addClient(connectionFD);
               m_servedThisPeriod=1;
               m_refreshTime=m_initialRefreshTime;
               m_increasedRefreshTime=0;
            }
            else
            {
               getDebug()<<"NetManager::run: kicking client"<<endl;
               ::close(connectionFD);
            };
         };
         checkClientsAndPipes(&tmpFDs);
      };
      serveAndClean();
   };   
   return 1;
};

void NetManager::addClient(int socketFD)
{
   getDebug()<<"NetManager::addClient on FD="<<socketFD<<endl;
   if (socketFD==-1) return;
   Client c(this,socketFD,0);
   clients.append(c);
};

void NetManager::checkClientsAndPipes(fd_set *tmpFDs)
{
   getDebug()<<"NetManager::checkClientsAndPipes()"<<endl;
   //actually the clients should not send anything
   for (Client *tmpClient=clients.first(); tmpClient!=0; tmpClient=clients.next())
   {
      getDebug()<<"NetManager::checkClientsAndPipes: checking client"<<endl;
      if (FD_ISSET(tmpClient->fd(),tmpFDs))
      {
         getDebug()<<"NetManager::checkClientsAndPipes: client sent something"<<endl;
         tmpClient->read();
      };
   };

   //now check wether we received a broadcast
   //m_bcFD should always be -1 in strictMode
   if ((m_bcFD!=-1) && (!m_strictMode))
   {
      getDebug()<<"NetManager::checkClientsAndPipe: checking bcFD"<<endl;
      //yes !
      if (FD_ISSET(m_bcFD,tmpFDs))
         answerBroadcast();
   };

   //read the stuff from the forked pipe
   if (m_pipeFD!=-1)
   {
      getDebug()<<"NetManager::checkClientsAndPipe: checking pipe"<<endl;
      if (FD_ISSET(m_pipeFD,tmpFDs))
      {
         getDebug()<<"NetManager::checkClientsAndPipes: pipe sent something"<<endl;
         int result=readDataFromFD(m_pipeFD);
         if (result!=1)
         {
            ::close(m_pipeFD);
            
            //can I really be 100% sure that the child will quit very soon ?
            //::waitpid(m_childPid,0,0);

            //I better wait for a short moment and then continue
            //it's better to have possibly a zombie than a blocking server IMO
            timeval tv;
            tv.tv_sec=0;
            tv.tv_usec=5*10*1000;//0.05 sec
            ::select(0,0,0,0,&tv);
            ::waitpid(m_childPid,0,WNOHANG);
            m_pipeFD=-1;
            getDebug()<<"NetManager::checkClientsAndPipes: everything read from pipe from proc "<<m_childPid<<endl;
            processScanResults();
         };
      };
   };
};

void NetManager::answerBroadcast()
{
   //actually we should never get here in strictMode
   if (m_strictMode) return;
   
   //this one is called only in checkClientsAndPipes()
   //if we are sure that we received something on m_bcFD
   //so we don't need to check here again
   
   getDebug()<<"NetManager::answerBroadcast: received BC"<<endl;
   struct sockaddr_in sAddr;
   socklen_t length(sizeof(sockaddr_in));
   char buf[1024];
   int result=recvfrom(m_bcFD, (void*)buf, 1024, 0, (sockaddr*)&sAddr,&length);
   getDebug()<<"NetManager::answerBroadcast: received succesfully"<<endl;
   //did recvfrom() succeed ?
   //our frame is exactly MYFRAMELENGTH bytes big, if the received one has a different size,
   //it must be something different
   if (result!=MYFRAMELENGTH) return;
   //if it has the correct size, it also must have the correct identifier
   MyFrameType *frame=(MyFrameType*)(void*)buf;
   if ((ntohl(frame->id)!=MY_ID) ||
       ((ntohl(frame->unused1)==getpid()) && (ntohl(frame->unused2)==m_startedAt)))
   {
      getDebug()<<"NetManager::answerBroadcast: must be the same machine"<<endl;
      return;
   };

   //getDebug()<<"received "<<ntohl(buf[0])<<" from "<<inet_ntoa(sAddr.sin_addr)<<hex<<" ";
   //getDebug()<<sAddr.sin_addr.s_addr<<" "<<ntohl(sAddr.sin_addr.s_addr)<<dec<<endl;
   //will we answer this request ?
   if (!validator.isValid(sAddr.sin_addr.s_addr))
   {
      getDebug()<<"NetManager::answerBroadcast: invalid sender"<<endl;
      return;
   };

   //create the answering socket

   int answerFD=::socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
   if (answerFD==-1)
   {
      getDebug()<<"NetManager::answerBroadcast: could not create answering socket"<<endl;
      return;
   };
   
   sAddr.sin_family=AF_INET;
   sAddr.sin_port=htons(m_basePort+1);
   MyFrameType answerFrame;
   answerFrame.id=htonl(MY_ID);
   answerFrame.unused1=0;
   answerFrame.unused2=0;
   //don't care about the result
   getDebug()<<"NetManager::answerBroadcast: sending answer"<<endl;

   result=::sendto(answerFD,(void*)&answerFrame,sizeof(answerFrame),0,(sockaddr*)&sAddr,length);
   getDebug()<<"sent "<<result<<" byte using sendto"<<endl;
   ::close(answerFD);
   //sent answer
};

void NetManager::serveAndClean()
{