CSocket.cpp

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/*
                    GNU GENERAL PUBLIC LICENSE
                       Version 2, June 1991

 Copyright (C) 1989, 1991 Free Software Foundation, Inc.
                       59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.

                            Preamble

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*/
static const char* Copyright= "(C) Copyright Michigan State University 2002, All rights reserved";
// Synchronization assumptions:
//    the (2) socket calls are recursive (threadsafe).
//    the (3) network database calls are not recursive (notthreadsafe).
//  as such, any calls to (3) network database calls are bracketed with
//  calls to globally synchronize the thread.

#include <config.h>
#include "CSocket.h"    
#include <CApplicationSerializer.h>

// Exception classes required:

#include <CTCPNoSuchHost.h>
#include <CTCPNoSuchService.h>
#include <CTCPBadSocketState.h>
#include <CTCPConnectionFailed.h>
#include <ErrnoException.h>
#include <CTCPConnectionLost.h>

// Standard and netork library headers.

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <arpa/inet.h>

// STL includes.

#include <vector>       

#ifdef HAVE_STD_NAMESPACE
using namespace std;
#endif
                        

// Manifest constannts:

#ifndef TRUE
#define TRUE 1
#endif
#ifndef FALSE
#define FALSE 0
#endif

// Static members:

map<CSocket::State, string> CSocket::m_StateNames;

CSocket::CSocket ()
   : m_Fd(-1),
     m_State(Disconnected)
 
{
  OpenSocket();
} 

CSocket::~CSocket ( )  //Destructor - Delete dynamic objects
{
  if(m_State == Connected) {
    Shutdown();
  }
  if(m_Fd > 0) {
    close(m_Fd);
  }
}

CSocket::CSocket (    int am_Fd,  CSocket::State am_State  ) :
  m_Fd(am_Fd),
  m_State(am_State)

{  
  StockStateMap();              // Ensure the statename map is stocked.
} 

// Functions for class CSocket

void 
CSocket::Connect(const string& host, const string& service)  
{ 
  // We must be disconnected to do any of this...
  
  vector<CSocket::State> allowedStates;
  allowedStates.push_back(Disconnected);

  if(m_State != Disconnected) throw CTCPBadSocketState(m_State, allowedStates,
                                                    "CSocket::Connect");

  // If the host is a dotted ip number just translate it.. otherwise
  // try to resolve the name:

  unsigned long int ipaddr;
  struct hostent* pEntry;

    CApplicationSerializer::getInstance()->Lock(); // <-- Critical region
    {                                              // (3) calls not threadsafe.
      ipaddr = inet_addr(host.c_str());
      if(ipaddr == INADDR_NONE) {       // Need to translate the name...
        pEntry = gethostbyname(host.c_str());
        if(pEntry) memcpy(&ipaddr, pEntry->h_addr, 4);
      }                                              // <-- End Critical region
      CApplicationSerializer::getInstance()->UnLock();
      if(!pEntry) throw CTCPNoSuchHost(host, 
                                       "Null return from gethostbyname(3)");
    }
  // Next resolve the service name... this can be either a number or a 
  // service name.  Note that the port number is in the service database
  // in network byte order.

  unsigned short port = Service(service);


  // Now we have everything we need to do call 'the other' Connect.

  Connect(ntohl(ipaddr), ntohs(port));
}  

void 
CSocket::Connect(unsigned long int IpAddress, unsigned short service)

{
  // Must be disconnected:

  vector<CSocket::State> allowedStates;
  allowedStates.push_back(Disconnected);

  if(m_State != Disconnected) throw CTCPBadSocketState(m_State, allowedStates,
                                                    "CSocket::Connect");

  // Both the ip address and service must be in network byte order to be 
  // acceptable to connect(2).

  IpAddress = htonl(IpAddress);
  service   = htons(service);

  // Build the socket peer address structure.

  sockaddr_in Peer;
  Peer.sin_port = service;
  memcpy(&(Peer.sin_addr), &IpAddress, sizeof(unsigned long int));
  Peer.sin_family = AF_INET;

  // Try the connect.

  if(connect(m_Fd, (const sockaddr*)&Peer, sizeof(sockaddr_in)) < 0) {
    int sErrno = errno;
    string Ip, Svc;
    CApplicationSerializer::getInstance()->Lock(); //<-- Critical section start
    {
      char port[50];
      Ip = inet_ntoa(Peer.sin_addr);
      sprintf(port,"%d", ntohs(service));
      Svc  = port;

    }
    CApplicationSerializer::getInstance()->UnLock(); //<-- End Crit. Section.
    errno = sErrno;             // sprintf e.g. destroys errno.
    throw CTCPConnectionFailed(Ip, Svc,
                               "CSocket::Connect client connect(2) failed");
  }

  m_State = Connected;
  

}

void 
CSocket::Bind(const string& service)  
{ 
  vector<CSocket::State> allowedStates;
  allowedStates.push_back(Disconnected);
  if(m_State != Disconnected) throw CTCPBadSocketState(m_State, allowedStates,
                                                       "CSocket::Bind");
  // Allow bind to re-use an existing address.. otherwise there are
  // terrible problems with servers that exit and then restart.

  int reuse=TRUE;
  if(setsockopt(m_Fd, SOL_SOCKET,
                SO_REUSEADDR,  &reuse, sizeof(int)) < 0) {
    throw CErrnoException("CSocket::Bind - setsockopt92) for re-use failed");
  }

  // Determine the service in network byte order.

  unsigned short port = Service(service);


  // Now bind the socket.

  sockaddr_in Peer;
  Peer.sin_port   = port;
  Peer.sin_family = AF_INET;
  Peer.sin_addr.s_addr = htonl(INADDR_ANY);

  if(bind(m_Fd, (sockaddr*)&Peer, sizeof(sockaddr_in)) < 0) {
    throw CErrnoException("Error from bind(2) in CSocket::Bind()");
  }
  m_State = Bound;

}  

void 
CSocket::Listen(unsigned int nBacklog)  
{ 
  // Throw CTCPBadSocketState if not bound:

  if(m_State != Bound) {
    vector<CSocket::State> allowedStates;
    allowedStates.push_back(Bound);
    throw CTCPBadSocketState(m_State, allowedStates, 
                             "CSocket::Listen");
  }
  if(listen(m_Fd, nBacklog) < 0) 
    throw CErrnoException("CSocket::Listen listen(2) failed");

  m_State = Listening;
}  

CSocket*  
CSocket::Accept(string& client)  
{ 
  // Throw CTCPBadSocket if not listening.

  if(m_State != Listening) {
    vector<CSocket::State> allowedStates;
    allowedStates.push_back(Listening);
    throw CTCPBadSocketState(m_State, allowedStates,
                             "CSocket::Accept");
  }
  
  // Attempt the accept.  If successfule, the return
  // value will be a socket fd.

  struct sockaddr_in peerInfo;
  socklen_t          addrlen(sizeof(sockaddr_in));
  int peerFd = accept(m_Fd, (sockaddr*)&peerInfo, &addrlen);
  if(peerFd < 0) {
    throw CErrnoException("CSocket::Accept accept(2) failed");
  }

  // At this time we have received a good connection. There are two things
  // we need to do:
  //   1. Construct a new CSocket in the connected state.
  //   2. Figure out and fill in the client:

  CSocket* pConnection = new CSocket(peerFd, Connected);
  client = AddressToHostString(peerInfo.sin_addr);

  return pConnection;
}  

void 
CSocket::Shutdown()  
{ 
  // Require that the socket be connected.

  if(m_State != Connected) {
    vector<CSocket::State> allowedStates;
    allowedStates.push_back(Connected);
    throw CTCPBadSocketState(m_State, allowedStates,
                             "CSocket::Shutdown");
  }

 
  if(shutdown(m_Fd, SHUT_RDWR) < 0) {
    throw CErrnoException("CSocket::Shutdown failed in call to shutdown(2)");
  }

  m_State = Disconnected;
  close(m_Fd);
  m_Fd = -1;                    // Mark the socket closed.
OpenSocket();
}  

int 
CSocket::Read(void* pBuffer, size_t nBytes)  
{ 
  // Require the socket be connected:

  if(m_State != Connected) {
    vector<CSocket::State> allowedStates;
    allowedStates.push_back(Connected);
    throw CTCPBadSocketState(m_State, allowedStates,
                             "CSocket::Read()");
  }
  // Attempt the read:

  int nB = read(m_Fd, pBuffer, nBytes);
  
  // Check for EOF:

  if(nB == 0) {
    m_State = Disconnected;
    throw CTCPConnectionLost(this, "CSocket::Read: from read(2)");
  }
  // Check for error:

  if(nB < 0) {
    m_State = Disconnected;
    throw CErrnoException("CSocket::Read failed read(2)");
  }
  // There's data to transfer.

  return nB;
}  


int 
CSocket::Write(void* pBuffer, size_t nBytes)  
{
  // Require that the socket is connected:

  

  // write(2) as many times as are needed to get the data out.


  char* p((char* )pBuffer);     // Pointer to current write.
  int   resid(nBytes);          // Number of remaining bytes to write.
  int   nWritten(0);            // Number  of bytes already written.

  while(resid) {
    int n = write(m_Fd, p, resid);
    if(n > 0) {                 // Do the book-keeping for a successful write.
      resid    -= n;
      nWritten += n;
      p        += n;
    } 
    else {                      // Write failed:
      if(nWritten > 0) {        // Assume if not first write, additional
        break;                  // Writes will give the same error.
      }
      if(errno == EPIPE) {      // Disconnected.
        m_State = Disconnected;
        throw CTCPConnectionLost(this,"CSocket::Write - first write of loop");
      }
      else {                    // Some other error:
        m_State = Disconnected;
        throw CErrnoException("CSocket::Write failed write(2)");
      }
    }
  }
  return nWritten;              // Indicate how many bytes were actually
                                // written. If < nBytes something unusual
                                // occured in the loop above.
}  

void 
CSocket::getPeer(unsigned short&  port, string& peer)  
{
  // Enforce connection requirement:

  if(m_State != Connected) {
    vector<CSocket::State> allowedStates;
    allowedStates.push_back(Connected);
    throw CTCPBadSocketState(m_State, allowedStates,
                             "CSocket::GetPeer");
  }
  // Try the call to getpeername(2):

  sockaddr_in PeerInfo;
  socklen_t   addrsize(sizeof(sockaddr_in));
  if(getpeername(m_Fd, (sockaddr*)&PeerInfo, &addrsize) < 0) {
    throw CErrnoException("CSocket::getPeer failed call to getpeername(2)");
  }
  // Pull out the port in local host byte order, and translate the
  // ip address:

  port = ntohs(PeerInfo.sin_port);
  peer = AddressToHostString(PeerInfo.sin_addr);

}  

void 
CSocket::OOBInline(bool State)  
{ 
  int state((int)State);
  if(setsockopt(m_Fd, SOL_SOCKET, 
                SO_OOBINLINE, (void*)&state, sizeof(int)) < 0) {
    throw CErrnoException("CSocket::OOBInline setsockopt(2) failed");
  }
}  

bool 
CSocket::isOOBInline()  
{ 
  unsigned int state;
  socklen_t    size(sizeof(int));
  if(getsockopt(m_Fd, SOL_SOCKET, 
                SO_OOBINLINE, (void*)&state, &size) < 0) {
    throw CErrnoException("CSocket::OOBInline getsockopt(2) failed");
  }
  return state ? TRUE : FALSE;
}  

void 
CSocket::setRcvLowWaterMark(size_t nBytes)  
{ 
  if(setsockopt(m_Fd, SOL_SOCKET, SO_RCVLOWAT, (void*)&nBytes, sizeof(size_t)) < 0) {
    if (errno == ENOPROTOOPT) {
      return; // Just not suppported is ok..
    }
    throw 
      CErrnoException("CSocket::setRcvLowWaterMark() setsockopt(2) failed");
  }
}


size_t 
CSocket::getRcvLowWaterMark()  
{ 
  int nBytes;
  socklen_t addrlen(sizeof(int));
  if(getsockopt(m_Fd, SOL_SOCKET, SO_RCVLOWAT, &nBytes, &addrlen) < 0) {
    throw 
      CErrnoException("CSocket::getRcvLowWaterMark() getsockopt(2) failed");
  }
  return (size_t)nBytes;
}  

void 
CSocket::setSndLowWaterMark(size_t nBytes)  
{ 
  if(setsockopt(m_Fd, SOL_SOCKET, SO_SNDLOWAT, &nBytes, sizeof(size_t)) < 0) {
    if (errno != ENOPROTOOPT) {
      CErrnoException("CSocket::setSndLowWaterMark() setsockopt(2) failed");
    }
  }  
}
size_t 
CSocket::getSndLowWaterMark()  
{
  int nBytes;
  socklen_t adrlen(sizeof(int));
  if(getsockopt(m_Fd, SOL_SOCKET, SO_SNDLOWAT, &nBytes, &adrlen) < 0) {
    throw 
      CErrnoException("CSocket::getRcvLowWaterMark() getsockopt(2) failed");
  }
  return (size_t)nBytes; 
}  

void 
CSocket::setRcvTimeout(unsigned int nMs)  
{ 
  //
  // First convert the nMs parameter into a timeval.
  //
  timeval timeout;
  timeout.tv_sec  = nMs / 1000;          // Number of seconds...
  timeout.tv_usec = (nMs % 1000) * 1000; // Left over milliseconds in uSec.

  // Now make the request:

  if(setsockopt(m_Fd, SOL_SOCKET, SO_RCVTIMEO, 
                &timeout, sizeof(timeval)) < 0) {
    if(errno != ENOPROTOOPT) {
      throw CErrnoException("CSocket::setRcvTimeout setsockopt(2) failed");
    }
  }
}  

unsigned int 
CSocket::getRcvTimeout()  
{ 
  timeval timeout;
  socklen_t adrlen(sizeof(timeval));
  
  // Get the timeout if possible: 

  if(getsockopt(m_Fd, SOL_SOCKET, SO_RCVTIMEO, 
                &timeout, &adrlen) < 0) {
    throw CErrnoException("CSocket::getRcvTimeout getsockopt(2) failed");
  }
  // Convert to ms and return.

  int nMs = timeout.tv_sec*1000; + timeout.tv_usec/1000000;
  return nMs;
}  

void 
CSocket::setSndTimeout(unsigned int nMs)  
{ 
  // Convert timeout to a timeval structure:

  timeval timeout;
  timeout.tv_sec  = nMs / 1000;          // Number of seconds...
  timeout.tv_usec = (nMs % 1000) * 1000; // Left over milliseconds in uSec.

  // Now make the request:

  if(setsockopt(m_Fd, SOL_SOCKET, SO_SNDTIMEO, 
                &timeout, sizeof(timeval)) < 0) {
    if(errno != ENOPROTOOPT) {
      throw CErrnoException("CSocket::setRcvTimeout setsockopt(2) failed");
    }
  }
}  

unsigned int 
CSocket::getSndTimeout()  
{ 
  timeval timeout;
  socklen_t adrlen(sizeof(timeval));
  
  // Get the timeout if possible: 

  if(getsockopt(m_Fd, SOL_SOCKET, SO_SNDTIMEO, 
                &timeout, &adrlen) < 0) {
    throw CErrnoException("CSocket::getRcvTimeout getsockopt(2) failed");
  }
  // Convert to ms and return.

  int nMs = timeout.tv_sec*1000; + timeout.tv_usec/1000000;
  return nMs;
}  

void 
CSocket::Debug(bool fState)  
{
  int state((int)fState);
  if(setsockopt(m_Fd, SOL_SOCKET, SO_DEBUG, &state, sizeof(int)) < 0) {
    throw CErrnoException("CSocket::Debug setsockopt(2) failed");
  }

}  

bool 
CSocket::isDebug()  
{ 
  int fstate;
  socklen_t adrlen(sizeof(int));
  if(getsockopt(m_Fd, SOL_SOCKET, SO_DEBUG, &fstate, &adrlen) < 0) {
    throw CErrnoException("CSocket:Debug getsockopt(2) failed");
  }
  return fstate ? TRUE : FALSE;
}  

void 
CSocket::SetNotRoutable(bool fRoutable)  
{ 
  int state((int)fRoutable);
  if(setsockopt(m_Fd, SOL_SOCKET, SO_DONTROUTE, &state, sizeof(int)) < 0) {
    throw CErrnoException("CSocket::SetNotRoutable setsockopt(2) failed");
  }

}  

bool 
CSocket::isNotRoutable()  
{ 
  int fState;
  socklen_t adrlen(sizeof(int));
  if(getsockopt(m_Fd, SOL_SOCKET, SO_DONTROUTE, &fState, &adrlen) < 0) {
    throw CErrnoException("CSocket::isNotRoutable getsockopt(2) failed");
  }
  return fState ? TRUE : FALSE;
}  

void 
CSocket::setSndBufSize(size_t nBufferSize)  
{ 
  unsigned int size((unsigned int)nBufferSize);
  if(setsockopt(m_Fd, SOL_SOCKET, SO_SNDBUF, &size, sizeof(int)) < 0) {
    throw CErrnoException("CSocket::setSndBufSize setsockopt(2) failed");
  }
}  

size_t 
CSocket::getSndBufSize()  
{ 
  unsigned int size;
  socklen_t    adrlen(sizeof(int));
  if(getsockopt(m_Fd, SOL_SOCKET, SO_SNDBUF, &size, &adrlen) < 0) {
    throw CErrnoException("CSocket::getSndBufSize getsockopt(2) failed");
  }
  return (size_t)size;
}  

void 
CSocket::setRcvBufSize(size_t nBytes)  
{
  unsigned int size = (unsigned int)nBytes;
 
  if(setsockopt(m_Fd, SOL_SOCKET, SO_RCVBUF, &size, sizeof(int)) < 0) {
    throw CErrnoException("CSocket::setRcvBufSize setsockopt(2) failed");
  }
}  

size_t 
CSocket::getRcvBufSize()  
{ 
  unsigned int size;
  socklen_t    adrlen(sizeof(int));
  if(getsockopt(m_Fd, SOL_SOCKET, SO_RCVBUF, &size, &adrlen) < 0) {
    throw CErrnoException("CSocket::getSndBufSize getsockopt(2) failed");
  }
  return (size_t)size;
}  

void 
CSocket::setLinger(bool lOn, int nLingerSeconds)  
{ 
  // The linger structure is filled in the way it is so that the user could
  // conceivably omit a timeout interval if lOn == FALSE since in that case,
  // nLingerSeconds won't be referenced.

  linger lInfo;
  lInfo.l_onoff = lOn;
  if(lOn) lInfo.l_linger = nLingerSeconds;

  // Set the linger parameters:

  if(setsockopt(m_Fd, SOL_SOCKET, SO_LINGER, &lInfo, sizeof(linger)) < 0) {
    throw CErrnoException("CSocket::setLinger setsockopt(2) failed");
  }
}  

void 
CSocket::getLinger(bool& isLingering, int& nLingerSeconds)  
{ 
  linger linfo;
  socklen_t addrlen(sizeof(linger));
    if(getsockopt(m_Fd, SOL_SOCKET, SO_LINGER, &linfo, &addrlen) < 0) {
      throw CErrnoException("CSocket::getLinger getsockopt(2) failed");
    }

  // Fill in the parameters from the linger structure:

  isLingering    = linfo.l_onoff;
  nLingerSeconds = linfo.l_linger; 
}
unsigned short
CSocket::Service(const string& rService)
{
  unsigned short port;
  int           nport;

  if(sscanf(rService.c_str(), "%d", &nport) != 1) { // Non numeric service number.
    struct servent* pEntry;
    CApplicationSerializer::getInstance()->Lock(); // <-- Critical region
    {                                              //  getservbyname not recursive
      pEntry = getservbyname(rService.c_str(), "tcp");
      if(pEntry) port = pEntry->s_port;
    }
    CApplicationSerializer::getInstance()->UnLock(); // <-- End critical rgn.
    if(!pEntry) throw CTCPNoSuchService(rService, 
                                     "Null return from getservbyname(3)");
  }
  else {
    port = nport;
    port = htons(port);
  }
  return port;
}

string
CSocket:: AddressToHostString(in_addr peer)
{
  string result;
  CApplicationSerializer::getInstance()->Lock(); // <-- Critical Region.
  {
    struct hostent* pEntry = gethostbyaddr((const char*)&peer, 
                                           sizeof(in_addr), AF_INET);
    if(pEntry) {                // Reverse DNS worked...
      result = pEntry->h_name;
      
    }
    else {                      // Need to return dotted address.
      result = inet_ntoa(peer);
    }
  }
  CApplicationSerializer::getInstance()->UnLock(); // <-- End Critical Region.

  return result;
}
string
CSocket::StateName(CSocket::State state)
{
  StockStateMap();
  return m_StateNames[state];
}
void 
CSocket::StockStateMap()
{
  if(!m_StateNames.empty()) {
    m_StateNames[Disconnected] = "Disconnected";
    m_StateNames[Bound]        = "Bound";
    m_StateNames[Listening]    = "Listening";
    m_StateNames[Connected]    = "Connected";
  }
}
void
CSocket::OpenSocket()
{
  int             protocol;
  struct protoent* pEntry;
  StockStateMap();              // Ensure the state name map is stocked.

  CApplicationSerializer::getInstance()->Lock(); //--> Critical region since
  {                                            // getprotoent not recursive.
    struct protoent* pEntry = getprotobyname("TCP");
    if(pEntry) protocol = pEntry->p_proto;
  }                                            // <-- End Critical Region.
  CApplicationSerializer::getInstance()->UnLock();

  if(!pEntry) throw 
              CErrnoException("Getting TCP protocol num from getprotoent(3)");

  m_Fd = socket(PF_INET, SOCK_STREAM, protocol);
  if(m_Fd == -1) throw
                   CErrnoException("Creating socket with socket(2)");

}

---