OW_SocketUtils.cpp

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#include "OW_config.h"
#include "OW_SocketException.hpp"
#include "OW_SocketUtils.hpp"
#include "OW_PosixUnnamedPipe.hpp"
#include "OW_Assertion.hpp"
#include "OW_Socket.hpp"
#include "OW_Format.hpp"
#include "OW_Thread.hpp"
#include "OW_System.hpp"
#include "OW_Select.hpp"

#ifndef OW_HAVE_GETHOSTBYNAME_R
#include "OW_Mutex.hpp"
#include "OW_MutexLock.hpp"
#endif

extern "C"
{
#if !defined(OW_WIN32)
#include <ctype.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <sys/socket.h>
#ifdef OW_HAVE_SYS_RESOURCE_H
#include <sys/resource.h>
#endif
#include <netdb.h>
#include <arpa/inet.h>
#include <unistd.h>
#endif
}

#include <cstring>
#include <cstdio>
#include <cerrno>

namespace OW_NAMESPACE
{

namespace SocketUtils 
{

String
inetAddrToString(UInt64 addr)
{
   struct in_addr iaddr;
   iaddr.s_addr = addr;
   String s(inet_ntoa(iaddr));
   return s;
}
#ifndef MAX
   #define MAX(A,B) (((A) > (B))? (A): (B))
#endif

#if defined(OW_WIN32)
int
waitForIO(SocketHandle_t fd, HANDLE eventArg, int timeOutSecs,
   long networkEvents)
{
   DWORD timeout = (timeOutSecs != -1)
      ? static_cast<DWORD>(timeOutSecs * 1000)
      : INFINITE;

   if (networkEvents != -1L)
   {
      if(::WSAEventSelect(fd, eventArg, networkEvents) != 0)
      {
         OW_THROW(SocketException, 
            Format("WSAEventSelect failed in waitForIO: %1",
            System::lastErrorMsg(true)).c_str());
      }
   }

   int cc;
   if(Socket::getShutDownMechanism() != NULL)
   {
      HANDLE events[2];
      events[0] = Socket::getShutDownMechanism();
      events[1] = eventArg;

      DWORD index = ::WaitForMultipleObjects(
         2,
         events,
         FALSE,
         timeout);

      switch (index)
      {
         case WAIT_FAILED:
            cc = -1;
            break;
         case WAIT_TIMEOUT:
            cc = ETIMEDOUT;
            break;
         default:
            index -= WAIT_OBJECT_0;
            // If not shutdown event, then reset
            if (index != 0)
            {
               ::ResetEvent(eventArg);
               cc = 0;
            }
            else
            {
               // Shutdown handle was signaled
               cc = -2;
            }
            break;
      }
   }
   else
   {
      switch(::WaitForSingleObject(eventArg, timeout))
      {
         case WAIT_OBJECT_0:
            ::ResetEvent(eventArg);
            cc = 0;
            break;
         case WAIT_TIMEOUT:
            cc = ETIMEDOUT;
            break;
         default:
            cc = -1;
            break;
      }
   }

   // Set socket back to blocking
   if(::WSAEventSelect(fd, eventArg, 0) != 0)
   {
      OW_THROW(SocketException, 
         Format("Resetting socket with WSAEventSelect failed: %1",
         System::lastErrorMsg(true)).c_str());
   }
   u_long ioctlarg = 0;
   ::ioctlsocket(fd, FIONBIO, &ioctlarg);
   return cc;
}

#else

int
waitForIO(SocketHandle_t fd, int timeOutSecs, SocketFlags::EWaitDirectionFlag waitFlag)
{
   if (fd == -1)
   {
      errno = EBADF;
      return -1;
   }

   Select::SelectObject so(fd); 
   if (waitFlag == SocketFlags::E_WAIT_FOR_INPUT)
   {
      so.waitForRead = true; 
   }
   else if (waitFlag == SocketFlags::E_WAIT_FOR_OUTPUT)
   {
      so.waitForWrite = true; 
   }
   else
   {
      so.waitForRead = true; 
      so.waitForWrite = true; 
   }
   Select::SelectObjectArray selarray; 
   selarray.push_back(so); 

   PosixUnnamedPipeRef lUPipe;
   int pipefd = -1;
   if (Socket::getShutDownMechanism())
   {
      UnnamedPipeRef foo = Socket::getShutDownMechanism();
      lUPipe = foo.cast_to<PosixUnnamedPipe>();
      OW_ASSERT(lUPipe);
      pipefd = lUPipe->getInputHandle();
   }
   if (pipefd != -1)
   {
      so = Select::SelectObject(pipefd); 
      so.waitForRead = true; 
      selarray.push_back(so); 
   }

   int rc = Select::selectRW(selarray, timeOutSecs*1000); 
   switch (rc)
   {
   case Select::SELECT_TIMEOUT:
      rc = ETIMEDOUT; 
      break; 
   case 2:
      rc = -1; // pipe was signalled
      break; 
   case 1: 
      if (pipefd != -1)
      {
         if (selarray[1].readAvailable)
         {
            rc = -1; 
         }
      }
      if (selarray[0].writeAvailable || selarray[0].readAvailable)
      {
         rc = 0; 
      }
      break; 
   default: 
      rc = -1; 
   }
   return rc; 

}
#endif   // 

#ifndef OW_HAVE_GETHOSTBYNAME_R
} // end namespace SocketUtils
extern Mutex gethostbynameMutex;  // defined in SocketAddress.cpp
namespace SocketUtils {
#endif

#ifndef OW_WIN32
String getFullyQualifiedHostName()
{
   char hostName [2048];
   if (gethostname (hostName, sizeof(hostName)) == 0)
   {
#ifndef OW_HAVE_GETHOSTBYNAME_R
      MutexLock lock(gethostbynameMutex);
      struct hostent *he;
      if ((he = gethostbyname (hostName)) != 0)
      {
         return he->h_name;
      }
      else
      {
         OW_THROW(SocketException, Format("SocketUtils::getFullyQualifiedHostName: gethostbyname failed: %1", h_errno).c_str());
      }
#else
      hostent hostbuf;
      hostent* host = &hostbuf;
#if (OW_GETHOSTBYNAME_R_ARGUMENTS == 6 || OW_GETHOSTBYNAME_R_ARGUMENTS == 5)
      char buf[2048];
      int h_err = 0;
#elif (OW_GETHOSTBYNAME_R_ARGUMENTS == 3)
      hostent_data hostdata;
      int h_err = 0;    
#else
#error Not yet supported: gethostbyname_r() with other argument counts.
#endif /* OW_GETHOSTBYNAME_R_ARGUMENTS */
      // gethostbyname_r will randomly fail on some platforms/networks
      // maybe the DNS server is overloaded or something.  So we'll
      // give it a few tries to see if it can get it right.
      bool worked = false;
      for (int i = 0; i < 10 && (!worked || host == 0); ++i)
      {
#if (OW_GETHOSTBYNAME_R_ARGUMENTS == 6)        
         if (gethostbyname_r(hostName, &hostbuf, buf, sizeof(buf),
                  &host, &h_err) != -1)
         {
            worked = true;
            break;
         }
#elif (OW_GETHOSTBYNAME_R_ARGUMENTS == 5)
         // returns NULL if not successful
         if ((host = gethostbyname_r(hostName, &hostbuf, buf, sizeof(buf), &h_err))) {
            worked = true;
            break;
         }
#elif (OW_GETHOSTBYNAME_R_ARGUMENTS == 3)
         if (gethostbyname_r(hostName, &hostbuf, &hostdata) == 0)
         {
            worked = true;
            break;
         }
         else
         {
           h_err = h_errno;
         }
#else
#error Not yet supported: gethostbyname_r() with other argument counts.
#endif /* OW_GETHOSTBYNAME_R_ARGUMENTS */
      }
      if (worked && host != 0)
      {
         return host->h_name;
      }
      else
      {
         OW_THROW(SocketException, Format("SocketUtils::getFullyQualifiedHostName: gethostbyname_r(%1) failed: %2", hostName, h_err).c_str());
      }
#endif
   }
   else
   {
      OW_THROW(SocketException, Format("SocketUtils::getFullyQualifiedHostName: gethostname failed: %1(%2)", errno, strerror(errno)).c_str());
   }
   return "";
}
#else
// WIN32 defined
String getFullyQualifiedHostName()
{
   String rv;
   struct hostent *hostentp;
   char bfr[1024], ipaddrstr[128];
   struct in_addr iaHost;

   if(gethostname(bfr, sizeof(bfr)-1) == SOCKET_ERROR)
   {
      OW_THROW(SocketException, 
         Format("SocketUtils::getFullyQualifiedHostName: gethostname failed: %1(%2)", 
            WSAGetLastError(), System::lastErrorMsg(true)).c_str());
   }

   if(strchr(bfr, '.'))
   {
      // Guess we already have the DNS name
      return String(bfr);
   }

   if((hostentp = gethostbyname(bfr)) == NULL)
   {
      OW_THROW(SocketException, 
         Format("SocketUtils::getFullyQualifiedHostName: gethostbyname"
            " failed: %1(%2)", WSAGetLastError(),
            System::lastErrorMsg(true)).c_str());
   }

   if(strchr(hostentp->h_name, '.'))
   {
      rv = hostentp->h_name;
   }
   else
   {
      rv = inet_ntoa(*(struct in_addr*) (hostentp->h_addr_list[0]));
      iaHost.s_addr = inet_addr(rv.c_str());
      if(iaHost.s_addr != INADDR_NONE)
      {
         hostentp = gethostbyaddr((const char*)&iaHost,
            sizeof(struct in_addr), AF_INET);
         if(hostentp)
         {
            if(strchr(hostentp->h_name, '.'))
            {
               // GOT IT
               rv = hostentp->h_name;
            }
         }
      }
   }

   return rv;
}
#endif


} // end namespace SocketUtils

} // end namespace OW_NAMESPACE

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