nSocket Class Reference

wrapper for low level sockets. More...

#include <nSocket.h>

Collaboration diagram for nSocket:

[legend]

List of all members.

Public Member Functions
	nSocket ()
	constructor
	~nSocket ()
	destructor
int	Open ()
	open socket for sending data ( not bound to a specific IP or port )
int	Open (nAddress const &address)
	open socket for listening on the specified address info
int	Open (int port)
	open socket for listening bound to the specified port
int	Open (const nHostInfo &addr)
	open socket for listening on the specified host info
int	Close ()
	close the socket
bool	IsOpen () const
	returns whether the socket is open
void	Reset () const
	resets ( closes and reopens ) the socket
int	Connect (const nAddress &addr)
	connects the socket to the specified address
const nSocket *	CheckNewConnection () const
	listens for new data
int	Read (int8 *buf, int len, nAddress &addr) const
	reads data from the socket
int	Write (const int8 *buf, int len, const nAddress &addr) const
	writes data to the socket
int	Broadcast (const char *buf, int len, unsigned int port) const
	broadcasts data over the socket to the LAN
nAddress const &	GetAddress (void) const
	Gets the address the socket is bound to.
nSocket const &	GetAddress (nAddress &address) const
	Gets the address the socket is bound to.
int	GetSocket (void) const
	Gets the raw socket.
nSocket const &	GetSocket (int &socket) const
	Gets the raw socket.
void	MoveFrom (const nSocket &other)
	move data from other to this
	nSocket (const nSocket &other)
	copy constructor. Warning: uses data move semantics
nSocket &	operator= (const nSocket &other)
	copy operator. Warning: uses data move semantics
Private Member Functions
int	Create ()
	creates the socket without binding it
int	Bind (nAddress const &address)
	binds the socket to a specific address
int	Write (const int8 *buf, int len, const sockaddr *addr, int addrlen) const
	writes data to the socket
nSocket &	SetAddress (nAddress const &address)
	Sets the address the socket is bound to.
nSocket &	SetSocket (int socket)
	Sets the raw socket.
Private Attributes
int	socket_
	the raw socket
nAddress	address_
	the address the socket is bound to
nAddress	trueAddress_
	the address the socket is really bound to
int	family_
int	socktype_
int	protocol_
	more low level data determining the socket type
bool	broadcast_
	flag indicating whether this socket has been prepared for broadcasts
Classes
class	PermanentError
	exception thrown on probably unrecoverable error More...

---

Detailed Description

wrapper for low level sockets.

Definition at line 121 of file nSocket.h.

---

Constructor & Destructor Documentation

nSocket::nSocket

(

void

)

constructor

Definition at line 1486 of file nSocket.cpp.

        :socket_( -1 ), family_( PF_INET ), socktype_( SOCK_DGRAM ), protocol_( IPPROTO_UDP ), broadcast_( false )

nSocket::~nSocket

(

void

)

destructor

Definition at line 1500 of file nSocket.cpp.

References Close(), and IsOpen().

{
    if ( IsOpen() )

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nSocket::nSocket

(

const nSocket &

other

)

copy constructor. Warning: uses data move semantics

Parameters:

other

socket to move data from

Definition at line 2292 of file nSocket.cpp.

References MoveFrom(), and socket_.

{
    socket_ = -1;

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---

Member Function Documentation

int nSocket::Open

(

void

)

open socket for sending data ( not bound to a specific IP or port )

Returns:

0 on success

Definition at line 1698 of file nSocket.cpp.

Referenced by ANET_ListenOn(), nBasicNetworkSystem::Init(), Open(), and Reset().

{
    // bind to unspecific IP
    nAddress addr;

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int nSocket::Open

(

nAddress const &

addr

)

open socket for listening on the specified address info

Parameters:

addr

address to bind to

Returns:

0 on success

Definition at line 1674 of file nSocket.cpp.

References Bind(), Create(), IsOpen(), and tASSERT.

{
    tASSERT( !IsOpen() );

    // create
    if ( Create() != 0 )
    {
        return -2;
    }

    // bind

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int nSocket::Open

(

int

port

)

open socket for listening bound to the specified port

Parameters:

port

port to bind to

Returns:

0 on success

Definition at line 1716 of file nSocket.cpp.

References Open(), and nAddress::SetPort().

{
    // bind to unspecific IP, but specific port
    nAddress addr;
    addr.SetPort( port );

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int nSocket::Open

(

const nHostInfo &

addr

)

open socket for listening on the specified host info

Parameters:

addr

address to bind to

Returns:

0 on success

Parameters:

addr

host info to take opening information from

Returns:

0 on success

Definition at line 1766 of file nSocket.cpp.

References nHostInfo::address, nSocketType::family, family_, IsOpen(), Open(), nSocketType::protocol, protocol_, socktype_, tASSERT, nSocketType::type, and nHostInfo::type.

{
    tASSERT( !IsOpen() );

    family_ = addr.type.family;
    socktype_ = addr.type.type;
    protocol_ = addr.type.protocol;

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int nSocket::Close

(

void

)

close the socket

Returns:

0 on success

Definition at line 1787 of file nSocket.cpp.

References ANET_CloseSocket(), broadcast_, con, socket_, nAddress::ToString(), and trueAddress_.

Referenced by MoveFrom(), Reset(), nBasicNetworkSystem::Shutdown(), and ~nSocket().

{
#ifdef DEDICATED
    if ( socket_ != -1 )
        con << "Closing socket bound to " << trueAddress_.ToString() << "\n";
#endif

    ANET_CloseSocket( socket_ );
    socket_ = -1;
    broadcast_ = false;

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bool nSocket::IsOpen

(

void

)

const

returns whether the socket is open

Returns:

true if the socket is open, false otherwise

Definition at line 1849 of file nSocket.cpp.

References socket_.

Referenced by Bind(), Broadcast(), CheckNewConnection(), Create(), nBasicNetworkSystem::Init(), MoveFrom(), Open(), Read(), Write(), and ~nSocket().

{

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void nSocket::Reset

(

void

)

const

resets ( closes and reopens ) the socket

Returns:

Definition at line 1811 of file nSocket.cpp.

References address_, Close(), nAddress::GetPort(), Open(), nAddress::SetPort(), and trueAddress_.

Referenced by CheckNewConnection(), Read(), and Write().

{
    // logically, resetting is const. Physically not. const_cast is required.
    nSocket * reset = const_cast< nSocket * >( this );

    // remember the true address bound to
    nAddress trueAddress = trueAddress_;

    // try to reset a socket without disturbing the rest of the system
    reset->Close();

    // store old address
    nAddress oldAddress = address_;

    // first try: reopen with the same port as last time
    nAddress wishAddress = address_;
    wishAddress.SetPort( trueAddress.GetPort() );
    if ( 0 == reset->Open( wishAddress ) )
        return;

    // second try: reopen with the same premises
    if ( 0 == reset->Open( oldAddress ) )
        return;

    // last try: reopen with the last true address ( this is most probably wrong )

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int nSocket::Connect

(

const nAddress &

addr

)

connects the socket to the specified address

Parameters:

addr

Returns:

Definition at line 1865 of file nSocket.cpp.

{
    // not implemented, does not make sense here

const nSocket * nSocket::CheckNewConnection

(

void

)

const

listens for new data

Returns:

the new socket if a connection is there or NULL

Definition at line 1895 of file nSocket.cpp.

References ANET_Error(), IsOpen(), tRecorderBase::IsRunning(), nSocketError_Ignore, nSocketError_Reset, NULL, Reset(), socket_, Sys_Error(), and tASSERT.

{
    tASSERT( IsOpen() );

    int available=-1;

    // see if the playback has anything to say
    //if ( tRecorder::Playback( recordingSectionConnect, available ) )
    //    return this;

    // always return this when recoring or playback are running
    if ( tRecorder::IsRunning() )
        return this;


#ifdef DEBUG
    if ( sn_ResetSocket )
    {
        sn_ResetSocket = false;
        Reset();
    }
#endif

    //    for ( SocketArray::iterator iter = sockets.begin(); iter != sockets.end(); ++iter )
    int ret = ioctl (socket_, FIONREAD, &available);
    if ( ret == -1)
    {
        switch ( ANET_Error() )
        {
        case nSocketError_Reset:
            Reset();
            break;
        case nSocketError_Ignore:
            break;
        default:
            Sys_Error ("UDP: ioctlsocket (FIONREAD) failed\n");
            break;
        }
    }

    if ( ret >= 0 )
    {
        // record result
        // tRecorder::Record( recordingSectionConnect, available );
        return this;
    }

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int nSocket::Read	(	int8 *	buf,
		int	len,
		nAddress &	addr
	)			const

reads data from the socket

Parameters:

	buf	buffer to read to
	len	maximum number of bytes to read
	addr	the address where the data came from is stored here

Returns:

number of bytes truly read or something negative on failure

Definition at line 1998 of file nSocket.cpp.

References ANET_Error(), ReadArchiver< Archiver >::Archive(), con, tRandomizer::Get(), nAddress::GetAddressLength(), IsOpen(), nSocketError_Ignore, nSocketError_Reset, Reset(), socket_, tASSERT, nAddress::ToString(), and trueAddress_.

Referenced by rec_peer(), and sn_DiscardFromControlSocket().

{
    tASSERT( IsOpen() );

    // return value: real number of bytes read
    int ret = 0;

    static tReproducibleRandomizer randomizer;
#ifdef DEBUG
    // pretend nothing was received
    if ( sn_simulateReceivePacketLoss > randomizer.Get() )
        return -1;
#endif

    // check playback
    if ( !ReadArchiver< tPlaybackBlock >::Archive( buf, ret, addr ) )
    {

#ifdef DEBUG
        if ( sn_ResetSocket )
        {
            sn_ResetSocket = false;
            Reset();
        }
#endif

        // really receive
        NET_SIZE addrlen = addr.GetAddressLength();
        ret = recvfrom (socket_, buf, len, 0, addr, &addrlen );
        tASSERT( addrlen <= static_cast< NET_SIZE >( addr.GetAddressLength() ) );
    }

    // write recording
    ReadArchiver< tRecordingBlock >::Archive( buf, ret, addr );

    if ( ret <= 0 )
    {
        switch ( ANET_Error() )
        {
        case nSocketError_Reset:
            {
                Reset();
                return -1;
            }
            break;
        case nSocketError_Ignore:
            return -1;
            break;
        }
    }

    if ( ret >= 0 )
    {
        // con << "Read " << ret << " bytes from socket " << GetSocket() << ".\n";
    }

#ifdef PRINTPACKETS
    con << trueAddress_.ToString() << " << " << addr.ToString() << "\n";
#endif

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int nSocket::Write	(	const int8 *	buf,
		int	len,
		const nAddress &	addr
	)			const

writes data to the socket

Parameters:

	buf	pointer to data to send
	len	length of data to send
	addr	address to send data to

Returns:

the number of bytes sent or something negative on error

Definition at line 2148 of file nSocket.cpp.

References con, nAddress::GetAddressLength(), nAddress::ToString(), and trueAddress_.

Referenced by Broadcast(), and nSendBuffer::Send().

{
#ifdef PRINTPACKETS
    con << trueAddress_.ToString() << " >> " << addr.ToString() << "\n";
#endif

    // delegate to low level write

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int nSocket::Broadcast	(	const char *	buf,
		int	len,
		unsigned int	port
	)			const

broadcasts data over the socket to the LAN

Parameters:

	buf	pointer to data to send
	len	length of data to send
	port	port to broadcast on

Returns:

number of bytes truly send or something negative on error

Definition at line 2171 of file nSocket.cpp.

References broadcast_, Con_Printf(), IsOpen(), socket_, tASSERT, and Write().

Referenced by nSendBuffer::Broadcast().

{
    tASSERT( IsOpen() );

    if ( !broadcast_ )
    {
        int                             i = 1;

        // make this socket broadcast capable
        if (setsockopt(socket_, SOL_SOCKET, SO_BROADCAST, (char *)&i, sizeof(i)) < 0)
        {
            Con_Printf("Unable to make socket broadcast capable\n");
            return -1;
        }

        broadcast_ = true;
    }

    // prepare broadcasting address
    sockaddr_in broadcastaddr;
    broadcastaddr.sin_family = AF_INET;
    broadcastaddr.sin_addr.s_addr = INADDR_BROADCAST;
    broadcastaddr.sin_port = htons(port);

    // delegate to usual write function

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const nAddress & nSocket::GetAddress

(

void

)

const

Gets the address the socket is bound to.

Returns:

the address the socket is bound to

Definition at line 2209 of file nSocket.cpp.

References trueAddress_.

Referenced by nServerInfoBase::DoGetFrom(), and nServerInfo::GetBigServerInfoCommon().

{

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const nSocket & nSocket::GetAddress

(

nAddress &

address

)

const

Gets the address the socket is bound to.

Parameters:

address

the address that the socket is bound to to fill

Returns:

reference to this for chaining

Definition at line 2225 of file nSocket.cpp.

References trueAddress_.

{
    address = trueAddress_;

int nSocket::GetSocket

(

void

)

const [inline]

Gets the raw socket.

Returns:

the raw socket

Definition at line 311 of file nSocket.h.

References socket_.

Referenced by nBasicNetworkSystem::Select().

{
    return this->socket_;
}

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nSocket const & nSocket::GetSocket

(

int &

socket

)

const [inline]

Gets the raw socket.

Parameters:

socket

the raw socket to fill

Returns:

A reference to this to allow chaining

Definition at line 327 of file nSocket.h.

References socket_.

{
    socket = this->socket_;
    return *this;
}

void nSocket::MoveFrom

(

const nSocket &

other

)

move data from other to this

Parameters:

other

socket to move data from

Definition at line 2262 of file nSocket.cpp.

References address_, broadcast_, Close(), family_, IsOpen(), protocol_, socket_, socktype_, and trueAddress_.

Referenced by nSocket(), and operator=().

{
    // close this socket
    if ( IsOpen() )
        Close();


    // copy uncritical data
    address_ = other.address_;
    trueAddress_ = other.trueAddress_;
    family_ = other.family_;
    socktype_ = other.socktype_;
    protocol_ = other.protocol_;
    broadcast_ = other.broadcast_;

    // move socket
    socket_ = other.socket_;

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nSocket & nSocket::operator=

(

const nSocket &

other

)

copy operator. Warning: uses data move semantics

Parameters:

other

socket to move data from

Returns:

reference to this

Definition at line 2309 of file nSocket.cpp.

References MoveFrom().

{
    MoveFrom( other );

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int nSocket::Create

(

void

)

[private]

creates the socket without binding it

Returns:

0 on success

Definition at line 1516 of file nSocket.cpp.

References _true, con, family_, IsOpen(), protocol_, sn_InitOSNetworking(), socket_, socktype_, and tASSERT.

Referenced by Open().

{
    tASSERT( !IsOpen() );

    // initialize networking at OS level
    sn_InitOSNetworking();

    // open new socket
    socket_ = socket( family_, socktype_, protocol_ );
    if ( socket_ < 0 )
        return -1;

    // TODO: IP_TOS only Supported under Windows 2000
    // See: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winsock/winsock/socket_options.asp

    // Tutorial on using Windows 98+ RSVP (QoS / Resource reSerVation Protocol)
    // http://msdn.microsoft.com/msdnmag/issues/01/04/qos/default.aspx

    // set TOS to low latency ( see manpages getsockopt(2), ip(7) and socket(7) )
    // maybe this works for Windows, too?
#ifndef WIN32
    char tos = IPTOS_LOWDELAY;

    int ret = setsockopt( socket_, IPPROTO_IP, IP_TOS, &tos, sizeof(char) );

    // remove this error reporting some time later, the success is not critical
    if ( ret != 0 )
    {
        static bool warn=true;
        if ( warn )
            con << "Setting TOS to LOWDELAY failed.\n";
        warn=false;
    }
#endif    

    // unblock it
    bool _true = true;

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int nSocket::Bind

(

nAddress const &

addr

)

[private]

binds the socket to a specific address

Parameters:

addr

address to bind to

Returns:

0 on success

Definition at line 1601 of file nSocket.cpp.

References address_, ANET_CloseSocket(), ANET_Error(), ANET_GetSocketAddr(), BindArchiver< Archiver >::Archive(), nAddress::Compare(), con, nAddress::GetAddressLength(), IsOpen(), nSocketError_Reset, socket_, tASSERT, nAddress::ToString(), and trueAddress_.

Referenced by Open().

{
    tASSERT( IsOpen() );

    // copy address
    address_ = addr;

    int ret = 0;

    // see if the process was archived; if yes, return without action
    if ( !BindArchiver< tPlaybackBlock >::Archive( ret, trueAddress_ ) )
    {
        // just delegate
        ret = bind( socket_, addr, addr.GetAddressLength() );

        // read true address
        if ( 0 == ret )
            ANET_GetSocketAddr( socket_, trueAddress_ );
    }

    // record the bind
    BindArchiver< tRecordingBlock >::Archive( ret, trueAddress_ );

    if ( 0 == ret )
    {
        // report success
#ifdef DEDICATED
        static nAddress nullAddress;
        if ( 0 == nAddress::Compare( trueAddress_, addr ) || 0 == nAddress::Compare( nullAddress, addr ) )
            con << "Bound socket to " << trueAddress_.ToString() << ".\n";
        else
            con << "Bound socket to " << trueAddress_.ToString() << " ( " << address_.ToString() << " was requested ).\n";
#endif

        return 0;
    }
    else
    {
        // con << "nSocket::Open: Failed to bind socket to " << addr.ToString() << ".\n";

        // close the socket and report an error
        ANET_CloseSocket( socket_ );
        socket_ = -1;

        // throw exception on fatal error
#ifndef NOEXCEPT
        // name lookup failures won't be tolerated here
        if ( ANET_Error() == nSocketError_Reset )
        {
            tString details( "Unable to bind to " );
            details += address_.ToString();
            details += " because that is not an address of the local machine.";
            throw nSocket::PermanentError( details );
        }
#endif

        return -1;
    }

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int nSocket::Write	(	const int8 *	buf,
		int	len,
		const sockaddr *	addr,
		int	addrlen
	)			const [private]

writes data to the socket

Parameters:

	buf	pointer to data to send
	len	length of data to send
	addr	address to send data to
	addrlen	length of address data structure

Returns:

the number of bytes sent or something negative on error

Definition at line 2080 of file nSocket.cpp.

References ANET_Error(), tRandomizer::Get(), IsOpen(), tRecorderBase::IsPlayingBack(), nSocketError_Ignore, nSocketError_Reset, tRecorder::Playback(), tRecorder::Record(), Reset(), section, socket_, and tASSERT.

{
    tASSERT( IsOpen() );

#ifdef DEBUG
    if ( sn_ResetSocket )
    {
        sn_ResetSocket = false;
        Reset();
    }
#endif

    int ret = 0;

    // check if return value was archived
    static char const * section = "SEND";
    if ( !tRecorder::Playback( section, ret ) )
    {
        static tReproducibleRandomizer randomizer;
#ifdef DEBUG
        // pretend send was successful in packet loss simulation
        if ( sn_simulateSendPacketLoss > randomizer.Get() )
            ret = len;
        else
#endif
        {
            // don't send if a playback is running
            if ( !tRecorder::IsPlayingBack() )
                ret = sendto (socket_, buf, len, 0, addr, addrlen );
        }
    }

    if ( ret < 0 )
    {
        // log error
        tRecorder::Record( section, ret );

        // handle error
        switch ( ANET_Error() )
        {
        case nSocketError_Reset:
            {
                Reset();
                return -1;
            }
            break;
        case nSocketError_Ignore:
            return -1;
            break;
        }
    }

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nSocket & nSocket::SetAddress

(

nAddress const &

address

)

[private]

Sets the address the socket is bound to.

Parameters:

address

address the address that the socket should be bound to

Returns:

Definition at line 2243 of file nSocket.cpp.

References address_, and trueAddress_.

{
    address_ = address;
    trueAddress_ = address;

nSocket & nSocket::SetSocket

(

int

socket

)

[inline, private]

Sets the raw socket.

Parameters:

socket

the raw socket to set

Returns:

A reference to this to allow chaining

Definition at line 344 of file nSocket.h.

References socket_.

{
    this->socket_ = socket;
    return *this;
}

---

Member Data Documentation

int nSocket::socket_ [private]

the raw socket

Definition at line 176 of file nSocket.h.

Referenced by Bind(), Broadcast(), CheckNewConnection(), Close(), Create(), GetSocket(), IsOpen(), MoveFrom(), nSocket(), Read(), SetSocket(), and Write().

nAddress nSocket::address_ [private]

the address the socket is bound to

Definition at line 177 of file nSocket.h.

Referenced by Bind(), MoveFrom(), Reset(), and SetAddress().

nAddress nSocket::trueAddress_ [private]

the address the socket is really bound to

Definition at line 178 of file nSocket.h.

Referenced by Bind(), Close(), GetAddress(), MoveFrom(), Read(), Reset(), SetAddress(), and Write().

int nSocket::family_ [private]

Definition at line 179 of file nSocket.h.

Referenced by Create(), MoveFrom(), and Open().

int nSocket::socktype_ [private]

Definition at line 179 of file nSocket.h.

Referenced by Create(), MoveFrom(), and Open().

int nSocket::protocol_ [private]

more low level data determining the socket type

Definition at line 179 of file nSocket.h.

Referenced by Create(), MoveFrom(), and Open().

bool nSocket::broadcast_ [mutable, private]

flag indicating whether this socket has been prepared for broadcasts

Definition at line 180 of file nSocket.h.

Referenced by Broadcast(), Close(), and MoveFrom().

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The documentation for this class was generated from the following files:

• src/network/nSocket.h
• src/network/nSocket.cpp

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