socket.cpp

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/************************************************************************
 ** This file is part of the network simulator Shawn.                  **
 ** Copyright (C) 2004-2007 by the SwarmNet (www.swarmnet.de) project  **
 ** Shawn is free software; you can redistribute it and/or modify it   **
 ** under the terms of the BSD License. Refer to the shawn-licence.txt **
 ** file in the root of the Shawn source tree for further details.     **
 ************************************************************************/

#ifdef SHAWN
    #include <apps/tcpip/socket.h>
    #include <sys/simulation/simulation_controller.h>
#else
    #include "socket.h"
#endif

#ifdef BUILD_TCPIP


#ifndef WIN32
    #include <sys/types.h>
    #include <sys/socket.h>
    #include <netinet/in.h>
    #include <netinet/tcp.h>
    #include <arpa/inet.h>
    #include <netdb.h>
    #include <errno.h>
    #include <fcntl.h>
#else
    #ifdef ERROR
        #undef ERROR
    #endif

    #include <winsock2.h>

    #ifndef vsnprintf
        #define vsnprintf _vsnprintf
    #endif

#endif

#include <cstdio>
#include <cstring>
#include <cstdarg>
#include <cassert>
#include <string>
#include <vector>
#include <string>
#include <algorithm>
#include <string.h>

using namespace std;


#ifdef SHAWN
    extern "C" void init_tcpip( shawn::SimulationController& sc )
    {
            // std::cout << "tcpip init" << std::endl;
    }
#endif

namespace tcpip
{
    const int Socket::lengthLen = 4;

#ifdef WIN32
    bool Socket::init_windows_sockets_ = true;
    bool Socket::windows_sockets_initialized_ = false;
    int Socket::instance_count_ = 0;
#endif

    // ----------------------------------------------------------------------
    Socket::
        Socket(std::string host, int port) 
        : host_( host ),
        port_( port ),
        socket_(-1),
        server_socket_(-1),
        blocking_(true),
        verbose_(false)
    {
        init();
    }

    // ----------------------------------------------------------------------
    Socket::
		Socket(int port) 
        : host_(""),
        port_( port ),
        socket_(-1),
        server_socket_(-1),
        blocking_(true),
        verbose_(false)
    {
        init();
    }

    // ----------------------------------------------------------------------
    void
        Socket::
		init()
    {
#ifdef WIN32
        instance_count_++;

        if( init_windows_sockets_ && !windows_sockets_initialized_ )
        {
            WSAData wsaData;
            if( WSAStartup(MAKEWORD(1, 1), &wsaData) != 0 )
                BailOnSocketError("Unable to init WSA Sockets");
            windows_sockets_initialized_ = true;
        }
#endif
    }

    // ----------------------------------------------------------------------
    Socket::
		~Socket()
    {
        // Close first an existing client connection ...
        close();
#ifdef WIN32
        instance_count_--;
#endif

        // ... then the server socket
        if( server_socket_ >= 0 )
        {
#ifdef WIN32
            ::closesocket( server_socket_ );
#else
			::close( server_socket_ );
#endif
            server_socket_ = -1;
        }

#ifdef WIN32
        if( server_socket_ == -1 && socket_ == -1 
            && init_windows_sockets_ && instance_count_ == 0 )
                WSACleanup();
                windows_sockets_initialized_ = false;
#endif
    }

    // ----------------------------------------------------------------------
    void 
        Socket::
		BailOnSocketError( std::string context) 
        const throw( SocketException )
    {
#ifdef WIN32
        int e = WSAGetLastError();
        std::string msg = GetWinsockErrorString( e );
#else
        std::string msg = strerror( errno );
#endif
        throw SocketException( context + ": " + msg );
    }

    // ----------------------------------------------------------------------
    int  
        Socket::
		port()
    {
        return port_;
    }


    // ----------------------------------------------------------------------
    bool 
        Socket::
		datawaiting(int sock) 
        const throw()
    {
        fd_set fds;
        FD_ZERO( &fds );
        FD_SET( sock, &fds );

        struct timeval tv;
        tv.tv_sec = 0;
        tv.tv_usec = 0;

        int r = select( sock+1, &fds, NULL, NULL, &tv);

        if (r < 0)
            BailOnSocketError("tcpip::Socket::datawaiting @ select");

        if( FD_ISSET( sock, &fds ) )
            return true;
        else
            return false;
    }

    // ----------------------------------------------------------------------
    bool
        Socket::
		atoaddr( std::string address, struct in_addr& addr)
    {
        struct hostent* host;
        struct in_addr saddr;

        // First try nnn.nnn.nnn.nnn form
        saddr.s_addr = inet_addr(address.c_str());
        if (saddr.s_addr != static_cast<unsigned int>(-1)) 
        {
            addr = saddr;
            return true;
        }

        host = gethostbyname(address.c_str());
        if( host ) {
            addr = *((struct in_addr*)host->h_addr_list[0]);
            return true;
        }

        return false;
    }


    // ----------------------------------------------------------------------
    void 
        Socket::
		accept()
        throw( SocketException )
    {
        if( socket_ >= 0 )
            return;

        struct sockaddr_in client_addr;
#ifdef WIN32
        int addrlen = sizeof(client_addr);
#else
        socklen_t addrlen = sizeof(client_addr);
#endif

        if( server_socket_ < 0 )
        {
            struct sockaddr_in self;

            //Create the server socket
            server_socket_ = static_cast<int>(socket( AF_INET, SOCK_STREAM, 0 ));
            if( server_socket_ < 0 )
                BailOnSocketError("tcpip::Socket::accept() @ socket");
            
            //"Address already in use" error protection
            {
                int reuseaddr = 1;

                #ifdef WIN32
                    //setsockopt(server_socket_, SOL_SOCKET, SO_REUSEADDR, (const char*)&reuseaddr, sizeof(reuseaddr));
                    // No address reuse in Windows!!!
                #else
                    setsockopt(server_socket_, SOL_SOCKET, SO_REUSEADDR, &reuseaddr, sizeof(reuseaddr));
                #endif
            }

            // Initialize address/port structure
            memset(&self, 0, sizeof(self));
            self.sin_family = AF_INET;
            self.sin_port = htons(port_);
            self.sin_addr.s_addr = htonl(INADDR_ANY);

            // Assign a port number to the socket
            if ( bind(server_socket_, (struct sockaddr*)&self, sizeof(self)) != 0 )
                BailOnSocketError("tcpip::Socket::accept() Unable to create listening socket");


            // Make it a "listening socket"
            if ( listen(server_socket_, 10) == -1 )
                BailOnSocketError("tcpip::Socket::accept() Unable to listen on server socket");

            // Make the newly created socket blocking or not
            set_blocking(blocking_);
        }

        socket_ = static_cast<int>(::accept(server_socket_, (struct sockaddr*)&client_addr, &addrlen));

        if( socket_ >= 0 )
        {
            int x = 1;
            setsockopt(socket_, IPPROTO_TCP, TCP_NODELAY, (const char*)&x, sizeof(x));
        }
    }

    // ----------------------------------------------------------------------
    void 
        Socket::
		set_blocking(bool blocking) 
        throw(SocketException )
    {
        blocking_ = blocking;

        if( server_socket_ > 0 )
        {
#ifdef WIN32
            ULONG NonBlock = blocking_ ? 0 : 1;
            if (ioctlsocket(server_socket_, FIONBIO, &NonBlock) == SOCKET_ERROR)
                BailOnSocketError("tcpip::Socket::set_blocking() Unable to initialize non blocking I/O");
#else
            long arg = fcntl(server_socket_, F_GETFL, NULL);
            if (blocking_)
            {
                arg &= ~O_NONBLOCK;
            } else {
                arg |= O_NONBLOCK;
            }
            fcntl(server_socket_, F_SETFL, arg);
#endif
        }
    
    }

    // ----------------------------------------------------------------------
    void 
        Socket::
		connect()
        throw( SocketException )
    {
        in_addr addr;
        if( !atoaddr( host_.c_str(), addr) )
            BailOnSocketError("tcpip::Socket::connect() @ Invalid network address");

        sockaddr_in address;
        memset( (char*)&address, 0, sizeof(address) );
        address.sin_family = AF_INET;
        address.sin_port = htons( port_ );
        address.sin_addr.s_addr = addr.s_addr;

        socket_ = static_cast<int>(socket( PF_INET, SOCK_STREAM, 0 ));
        if( socket_ < 0 )
            BailOnSocketError("tcpip::Socket::connect() @ socket");

        if( ::connect( socket_, (sockaddr const*)&address, sizeof(address) ) < 0 )
            BailOnSocketError("tcpip::Socket::connect() @ connect");

        if( socket_ >= 0 )
        {
            int x = 1;
            setsockopt(socket_, IPPROTO_TCP, TCP_NODELAY, (const char*)&x, sizeof(x));
        }

    }

    // ----------------------------------------------------------------------
    void 
        Socket::
		close()
    {
        // Close client-connection 
        if( socket_ >= 0 )
        {
#ifdef WIN32
            ::closesocket( socket_ );
#else
			::close( socket_ );
#endif

            socket_ = -1;
        }
    }

    // ----------------------------------------------------------------------
    void 
        Socket::
		send( const std::vector<unsigned char> &buffer)
        throw( SocketException )
    {
        if( socket_ < 0 )
            return;

        printBufferOnVerbose(buffer, "Send");

        size_t numbytes = buffer.size();
        unsigned char const *bufPtr = &buffer[0];
        while( numbytes > 0 )
        {
#ifdef WIN32
            int bytesSent = ::send( socket_, (const char*)bufPtr, static_cast<int>(numbytes), 0 );
#else
            int bytesSent = ::send( socket_, bufPtr, numbytes, 0 );
#endif
            if( bytesSent < 0 )
                BailOnSocketError( "send failed" );

            numbytes -= bytesSent;
            bufPtr += bytesSent;
        }
    }



    // ----------------------------------------------------------------------

    void
        Socket::
		sendExact( const Storage &b)
        throw( SocketException )
    {
        int length = static_cast<int>(b.size());
        Storage length_storage;
        length_storage.writeInt(lengthLen + length);

        // Sending length_storage and b independently would probably be possible and
        // avoid some copying here, but both parts would have to go through the
        // TCP/IP stack on their own which probably would cost more performance.
        vector<unsigned char> msg;
        msg.insert(msg.end(), length_storage.begin(), length_storage.end());
        msg.insert(msg.end(), b.begin(), b.end());
        send(msg);
    }


    // ----------------------------------------------------------------------
    size_t
        Socket::
		recvAndCheck(unsigned char * const buffer, std::size_t len)
        const
    {
#ifdef WIN32
        const int bytesReceived = recv( socket_, (char*)buffer, static_cast<int>(len), 0 );
#else
        const int bytesReceived = static_cast<int>(recv( socket_, buffer, len, 0 ));
#endif
        if( bytesReceived == 0 )
            throw SocketException( "tcpip::Socket::recvAndCheck @ recv: peer shutdown" );
        if( bytesReceived < 0 )
            BailOnSocketError( "tcpip::Socket::recvAndCheck @ recv" );

        return static_cast<size_t>(bytesReceived);
    }


    // ----------------------------------------------------------------------
    void
        Socket::
		receiveComplete(unsigned char * buffer, size_t len)
        const
    {
        while (len > 0)
        {
            const size_t bytesReceived = recvAndCheck(buffer, len);
            len -= bytesReceived;
            buffer += bytesReceived;
        }
    }


    // ----------------------------------------------------------------------
    void
        Socket::
		printBufferOnVerbose(const std::vector<unsigned char> buffer, const std::string &label)
        const
    {
        if (verbose_)
        {
            cerr << label << " " << buffer.size() <<  " bytes via tcpip::Socket: [";
            // cache end iterator for performance
            const vector<unsigned char>::const_iterator end = buffer.end();
            for (vector<unsigned char>::const_iterator it = buffer.begin(); end != it; ++it)
                cerr << " " << static_cast<int>(*it) << " ";
            cerr << "]" << endl;
        }
    }


    // ----------------------------------------------------------------------
    vector<unsigned char> 
        Socket::
		receive(int bufSize)
        throw( SocketException )
    {
        vector<unsigned char> buffer;

        if( socket_ < 0 )
            connect();

        if( !datawaiting( socket_) )
            return buffer;

        buffer.resize(bufSize);
        const size_t bytesReceived = recvAndCheck(&buffer[0], bufSize);

        buffer.resize(bytesReceived);

        printBufferOnVerbose(buffer, "Rcvd");

        return buffer;
    }

    // ----------------------------------------------------------------------
    

    bool
        Socket::
		receiveExact( Storage &msg )
        throw( SocketException )
    {
        // buffer for received bytes
        // According to the C++ standard elements of a std::vector are stored
        // contiguously. Explicitly &buffer[n] == &buffer[0] + n for 0 <= n < buffer.size().
        vector<unsigned char> buffer(lengthLen);

        // receive length of TraCI message
        receiveComplete(&buffer[0], lengthLen);
        Storage length_storage(&buffer[0], lengthLen);
        const int totalLen = length_storage.readInt();
        assert(totalLen > lengthLen);

        // extent buffer
        buffer.resize(totalLen);

        // receive remaining TraCI message
        receiveComplete(&buffer[lengthLen], totalLen - lengthLen);

        // copy message content into passed Storage
        msg.reset();
        msg.writePacket(&buffer[lengthLen], totalLen - lengthLen);
        
        printBufferOnVerbose(buffer, "Rcvd Storage with");

        return true;
    }
    
    
    // ----------------------------------------------------------------------
    bool 
        Socket::
		has_client_connection() 
        const
    {
        return socket_ >= 0;
    }

    // ----------------------------------------------------------------------
    bool 
        Socket::
		is_blocking() 
        throw()
    {
        return blocking_;
    }


#ifdef WIN32
    // ----------------------------------------------------------------------
    std::string 
        Socket::
        GetWinsockErrorString(int err) 
        const
    {

        switch( err)
        {
        case 0:                 return "No error";
        case WSAEINTR:          return "Interrupted system call";
        case WSAEBADF:          return "Bad file number";
        case WSAEACCES:         return "Permission denied";
        case WSAEFAULT:         return "Bad address";
        case WSAEINVAL:         return "Invalid argument";
        case WSAEMFILE:         return "Too many open sockets";
        case WSAEWOULDBLOCK:    return "Operation would block";
        case WSAEINPROGRESS:    return "Operation now in progress";
        case WSAEALREADY:       return "Operation already in progress";
        case WSAENOTSOCK:       return "Socket operation on non-socket";
        case WSAEDESTADDRREQ:   return "Destination address required";
        case WSAEMSGSIZE:       return "Message too long";
        case WSAEPROTOTYPE:     return "Protocol wrong type for socket";
        case WSAENOPROTOOPT:    return "Bad protocol option";
        case WSAEPROTONOSUPPORT:    return "Protocol not supported";
        case WSAESOCKTNOSUPPORT:    return "Socket type not supported";
        case WSAEOPNOTSUPP:     return "Operation not supported on socket";
        case WSAEPFNOSUPPORT:   return "Protocol family not supported";
        case WSAEAFNOSUPPORT:   return "Address family not supported";
        case WSAEADDRINUSE:     return "Address already in use";
        case WSAEADDRNOTAVAIL:  return "Can't assign requested address";
        case WSAENETDOWN:       return "Network is down";
        case WSAENETUNREACH:    return "Network is unreachable";
        case WSAENETRESET:      return "Net Socket reset";
        case WSAECONNABORTED:   return "Software caused tcpip::Socket abort";
        case WSAECONNRESET:     return "Socket reset by peer";
        case WSAENOBUFS:        return "No buffer space available";
        case WSAEISCONN:        return "Socket is already connected";
        case WSAENOTCONN:       return "Socket is not connected";
        case WSAESHUTDOWN:      return "Can't send after socket shutdown";
        case WSAETOOMANYREFS:   return "Too many references, can't splice";
        case WSAETIMEDOUT:      return "Socket timed out";
        case WSAECONNREFUSED:   return "Socket refused";
        case WSAELOOP:          return "Too many levels of symbolic links";
        case WSAENAMETOOLONG:   return "File name too long";
        case WSAEHOSTDOWN:      return "Host is down";
        case WSAEHOSTUNREACH:   return "No route to host";
        case WSAENOTEMPTY:      return "Directory not empty";
        case WSAEPROCLIM:       return "Too many processes";
        case WSAEUSERS:         return "Too many users";
        case WSAEDQUOT:         return "Disc quota exceeded";
        case WSAESTALE:         return "Stale NFS file handle";
        case WSAEREMOTE:        return "Too many levels of remote in path";
        case WSASYSNOTREADY:    return "Network system is unavailable";
        case WSAVERNOTSUPPORTED:    return "Winsock version out of range";
        case WSANOTINITIALISED: return "WSAStartup not yet called";
        case WSAEDISCON:        return "Graceful shutdown in progress";
        case WSAHOST_NOT_FOUND: return "Host not found";
        case WSANO_DATA:        return "No host data of that type was found";
        }

        return "unknown";
    }

#endif // WIN32

} // namespace tcpip

#endif // BUILD_TCPIP

/*-----------------------------------------------------------------------
* Source  $Source: $
* Version $Revision: 612 $
* Date    $Date: 2011-06-14 15:16:52 +0200 (Di, 14. Jun 2011) $
*-----------------------------------------------------------------------
* $Log: $
*-----------------------------------------------------------------------*/