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Specialized socket using the TCP protocol. More...

#include <D:/private/SFML/SFML/include/SFML/Network/TcpSocket.hpp>

Inheritance diagram for sf::TcpSocket:
sf::Socket

Public Types

enum class  TlsStatus { NotConnected , HandshakeStarted , HandshakeComplete , Error }
 TLS status codes that may be returned by TLS setup. More...
enum class  Status {
  Done , NotReady , Partial , Disconnected ,
  Error
}
 Status codes that may be returned by socket functions. More...

Public Member Functions

 TcpSocket ()
 Default constructor.
 ~TcpSocket () override
 Destructor.
 TcpSocket (const TcpSocket &)=delete
 Deleted copy constructor.
TcpSocketoperator= (const TcpSocket &)=delete
 Deleted copy assignment.
 TcpSocket (TcpSocket &&) noexcept
 Move constructor.
TcpSocketoperator= (TcpSocket &&) noexcept
 Move assignment.
unsigned short getLocalPort () const
 Get the port to which the socket is bound locally.
std::optional< IpAddressgetRemoteAddress () const
 Get the address of the connected peer.
unsigned short getRemotePort () const
 Get the port of the connected peer to which the socket is connected.
Status connect (IpAddress remoteAddress, unsigned short remotePort, Time timeout=Time::Zero)
 Connect the socket to a remote peer.
void disconnect ()
 Disconnect the socket from its remote peer.
TlsStatus setupTlsClient (const sf::String &hostname, bool verifyPeer=true)
 Set up transport layer security as a client.
TlsStatus setupTlsClient (const sf::String &hostname, const char *certificateChainData)
 Set up transport layer security as a client.
TlsStatus setupTlsClient (const sf::String &hostname, const std::byte *certificateChainData, std::size_t certificateChainSize)
 Set up transport layer security as a client.
TlsStatus setupTlsClient (const sf::String &hostname, std::string_view certificateChainData)
 Set up transport layer security as a client.
TlsStatus setupTlsServer (const std::byte *certificateChainData, std::size_t certificateChainSize, const std::byte *privateKeyData, std::size_t privateKeySize, const std::byte *privateKeyPasswordData, std::size_t privateKeyPasswordSize)
 Set up transport layer security as a server.
TlsStatus setupTlsServer (std::string_view certificateChainData, std::string_view privateKeyData, std::string_view privateKeyPasswordData={})
 Set up transport layer security as a server.
std::optional< std::string > getCurrentCiphersuiteName () const
 Get the name of the TLS ciphersuite currently in use.
Status send (const void *data, std::size_t size)
 Send raw data to the remote peer.
Status send (const void *data, std::size_t size, std::size_t &sent)
 Send raw data to the remote peer.
Status receive (void *data, std::size_t size, std::size_t &received)
 Receive raw data from the remote peer.
Status send (Packet &packet)
 Send a formatted packet of data to the remote peer.
Status receive (Packet &packet)
 Receive a formatted packet of data from the remote peer.
void setBlocking (bool blocking)
 Set the blocking state of the socket.
bool isBlocking () const
 Tell whether the socket is in blocking or non-blocking mode.

Static Public Attributes

static constexpr unsigned short AnyPort {0}
 Some special values used by sockets.

Protected Types

enum class  Type { Tcp , Udp }
 Types of protocols that the socket can use. More...

Protected Member Functions

SocketHandle getNativeHandle () const
 Return the internal handle of the socket.
void create (IpAddress::Type addressType=IpAddress::Type::IpV4)
 Create the internal representation of the socket.
void create (SocketHandle handle)
 Create the internal representation of the socket from a socket handle.
void close ()
 Close the socket gracefully.

Friends

class TcpListener

Detailed Description

Specialized socket using the TCP protocol.

TCP is a connected protocol, which means that a TCP socket can only communicate with the host it is connected to.

It can't send or receive anything if it is not connected.

The TCP protocol is reliable but adds a slight overhead. It ensures that your data will always be received in order and without errors (no data corrupted, lost or duplicated).

When a socket is connected to a remote host, you can retrieve information about this host with the getRemoteAddress and getRemotePort functions. You can also get the local port to which the socket is bound (which is automatically chosen when the socket is connected), with the getLocalPort function.

Sending and receiving data can use either the low-level or the high-level functions. The low-level functions process a raw sequence of bytes, and cannot ensure that one call to Send will exactly match one call to Receive at the other end of the socket.

The high-level interface uses packets (see sf::Packet), which are easier to use and provide more safety regarding the data that is exchanged. You can look at the sf::Packet class to get more details about how they work.

The socket is automatically disconnected when it is destroyed, but if you want to explicitly close the connection while the socket instance is still alive, you can call disconnect.

Usage example:

// ----- The client -----
// Create a socket and connect it to 192.168.1.50 on port 55001
socket.connect("192.168.1.50", 55001);
// Send a message to the connected host
std::string message = "Hi, I am a client";
socket.send(message.c_str(), message.size() + 1);
// Receive an answer from the server
std::array<char, 1024> buffer;
std::size_t received = 0;
socket.receive(buffer.data(), buffer.size(), received);
std::cout << "The server said: " << buffer.data() << std::endl;
// ----- The server -----
// Create a listener to wait for incoming connections on port 55001
sf::TcpListener listener;
listener.listen(55001);
// Wait for a connection
listener.accept(socket);
std::cout << "New client connected: " << socket.getRemoteAddress().value() << std::endl;
// Receive a message from the client
std::array<char, 1024> buffer;
std::size_t received = 0;
socket.receive(buffer.data(), buffer.size(), received);
std::cout << "The client said: " << buffer.data() << std::endl;
// Send an answer
std::string message = "Welcome, client";
socket.send(message.c_str(), message.size() + 1);
Socket that listens to new TCP connections.
Status listen(unsigned short port, IpAddress address=IpAddress::Any)
Start listening for incoming connection attempts.
Status accept(TcpSocket &socket)
Accept a new connection.
Specialized socket using the TCP protocol.
Definition TcpSocket.hpp:58
std::optional< IpAddress > getRemoteAddress() const
Get the address of the connected peer.
Status connect(IpAddress remoteAddress, unsigned short remotePort, Time timeout=Time::Zero)
Connect the socket to a remote peer.
Status receive(void *data, std::size_t size, std::size_t &received)
Receive raw data from the remote peer.
Status send(const void *data, std::size_t size)
Send raw data to the remote peer.
See also
sf::Socket, sf::UdpSocket, sf::Packet

Definition at line 57 of file TcpSocket.hpp.

Member Enumeration Documentation

◆ Status

enum class sf::Socket::Status
stronginherited

Status codes that may be returned by socket functions.

Enumerator
Done 

The socket has sent / received the data.

NotReady 

The socket is not ready to send / receive data yet.

Partial 

The socket sent a part of the data.

Disconnected 

The TCP socket has been disconnected.

Error 

An unexpected error happened.

Definition at line 49 of file Socket.hpp.

◆ TlsStatus

enum class sf::TcpSocket::TlsStatus
strong

TLS status codes that may be returned by TLS setup.

Enumerator
NotConnected 

TCP connection not yet connected.

HandshakeStarted 

TLS handshake has been started.

HandshakeComplete 

TLS handshake is complete, stream is encrypted.

Error 

An unexpected error happened.

Definition at line 64 of file TcpSocket.hpp.

◆ Type

enum class sf::Socket::Type
strongprotectedinherited

Types of protocols that the socket can use.

Enumerator
Tcp 

TCP protocol.

Udp 

UDP protocol.

Definition at line 129 of file Socket.hpp.

Constructor & Destructor Documentation

◆ TcpSocket() [1/3]

sf::TcpSocket::TcpSocket ( )

Default constructor.

◆ ~TcpSocket()

sf::TcpSocket::~TcpSocket ( )
override

Destructor.

◆ TcpSocket() [2/3]

sf::TcpSocket::TcpSocket ( const TcpSocket & )
delete

Deleted copy constructor.

◆ TcpSocket() [3/3]

sf::TcpSocket::TcpSocket ( TcpSocket && )
noexcept

Move constructor.

Member Function Documentation

◆ close()

void sf::Socket::close ( )
protectedinherited

Close the socket gracefully.

This function can only be accessed by derived classes.

◆ connect()

Status sf::TcpSocket::connect ( IpAddress remoteAddress,
unsigned short remotePort,
Time timeout = Time::Zero )
nodiscard

Connect the socket to a remote peer.

In blocking mode, this function may take a while, especially if the remote peer is not reachable. The last parameter allows you to stop trying to connect after a given timeout. If the socket is already connected, the connection is forcibly disconnected before attempting to connect again.

Parameters
remoteAddressAddress of the remote peer
remotePortPort of the remote peer
timeoutOptional maximum time to wait
Returns
Status code
See also
disconnect

◆ create() [1/2]

void sf::Socket::create ( IpAddress::Type addressType = IpAddress::Type::IpV4)
protectedinherited

Create the internal representation of the socket.

This function can only be accessed by derived classes.

Parameters
addressTypeThe address type of the socket

◆ create() [2/2]

void sf::Socket::create ( SocketHandle handle)
protectedinherited

Create the internal representation of the socket from a socket handle.

This function can only be accessed by derived classes.

Parameters
handleOS-specific handle of the socket to wrap

◆ disconnect()

void sf::TcpSocket::disconnect ( )

Disconnect the socket from its remote peer.

This function gracefully closes the connection. If the socket is not connected, this function has no effect.

See also
connect

◆ getCurrentCiphersuiteName()

std::optional< std::string > sf::TcpSocket::getCurrentCiphersuiteName ( ) const
nodiscard

Get the name of the TLS ciphersuite currently in use.

Returns
TLS ciphersuite currently in use or std::nullopt if TLS is not set up
See also
setupTlsClient, setupTlsServer

◆ getLocalPort()

unsigned short sf::TcpSocket::getLocalPort ( ) const
nodiscard

Get the port to which the socket is bound locally.

If the socket is not connected, this function returns 0.

Returns
Port to which the socket is bound
See also
connect, getRemotePort

◆ getNativeHandle()

SocketHandle sf::Socket::getNativeHandle ( ) const
nodiscardprotectedinherited

Return the internal handle of the socket.

The returned handle may be invalid if the socket was not created yet (or already destroyed). This function can only be accessed by derived classes.

Returns
The internal (OS-specific) handle of the socket

◆ getRemoteAddress()

std::optional< IpAddress > sf::TcpSocket::getRemoteAddress ( ) const
nodiscard

Get the address of the connected peer.

If the socket is not connected, this function returns an unset optional.

Returns
Address of the remote peer
See also
getRemotePort

◆ getRemotePort()

unsigned short sf::TcpSocket::getRemotePort ( ) const
nodiscard

Get the port of the connected peer to which the socket is connected.

If the socket is not connected, this function returns 0.

Returns
Remote port to which the socket is connected
See also
getRemoteAddress

◆ isBlocking()

bool sf::Socket::isBlocking ( ) const
nodiscardinherited

Tell whether the socket is in blocking or non-blocking mode.

Returns
true if the socket is blocking, false otherwise
See also
setBlocking

◆ operator=() [1/2]

TcpSocket & sf::TcpSocket::operator= ( const TcpSocket & )
delete

Deleted copy assignment.

◆ operator=() [2/2]

TcpSocket & sf::TcpSocket::operator= ( TcpSocket && )
noexcept

Move assignment.

◆ receive() [1/2]

Status sf::TcpSocket::receive ( Packet & packet)
nodiscard

Receive a formatted packet of data from the remote peer.

In blocking mode, this function will wait until the whole packet has been received. This function will fail if the socket is not connected.

Parameters
packetPacket to fill with the received data
Returns
Status code
See also
send

◆ receive() [2/2]

Status sf::TcpSocket::receive ( void * data,
std::size_t size,
std::size_t & received )
nodiscard

Receive raw data from the remote peer.

In blocking mode, this function will wait until some bytes are actually received. This function will fail if the socket is not connected.

Parameters
dataPointer to the array to fill with the received bytes
sizeMaximum number of bytes that can be received
receivedThis variable is filled with the actual number of bytes received
Returns
Status code
See also
send

◆ send() [1/3]

Status sf::TcpSocket::send ( const void * data,
std::size_t size )
nodiscard

Send raw data to the remote peer.

To be able to handle partial sends over non-blocking sockets, use the send(const void*, std::size_t, std::size_t&) overload instead. This function will fail if the socket is not connected.

Parameters
dataPointer to the sequence of bytes to send
sizeNumber of bytes to send
Returns
Status code
See also
receive

◆ send() [2/3]

Status sf::TcpSocket::send ( const void * data,
std::size_t size,
std::size_t & sent )
nodiscard

Send raw data to the remote peer.

This function will fail if the socket is not connected.

Parameters
dataPointer to the sequence of bytes to send
sizeNumber of bytes to send
sentThe number of bytes sent will be written here
Returns
Status code
See also
receive

◆ send() [3/3]

Status sf::TcpSocket::send ( Packet & packet)
nodiscard

Send a formatted packet of data to the remote peer.

In non-blocking mode, if this function returns sf::Socket::Status::Partial, you must retry sending the same unmodified packet before sending anything else in order to guarantee the packet arrives at the remote peer uncorrupted. This function will fail if the socket is not connected.

Parameters
packetPacket to send
Returns
Status code
See also
receive

◆ setBlocking()

void sf::Socket::setBlocking ( bool blocking)
inherited

Set the blocking state of the socket.

In blocking mode, calls will not return until they have completed their task. For example, a call to Receive in blocking mode won't return until some data was actually received. In non-blocking mode, calls will always return immediately, using the return code to signal whether there was data available or not. By default, all sockets are blocking.

Parameters
blockingtrue to set the socket as blocking, false for non-blocking
See also
isBlocking

◆ setupTlsClient() [1/4]

TlsStatus sf::TcpSocket::setupTlsClient ( const sf::String & hostname,
bool verifyPeer = true )

Set up transport layer security as a client.

Once the TCP connection is connected, transport layer security can be set up.

All the necessary cryptographic initialization will be performed when this function is called.

If this function is called before the TCP connection is connected, it will return TlsStatus::NotConnected and must be called again once the TCP connection is connected.

If this function started TLS setup but could not finish it within this call e.g. because this socket was set to non-blocking, it will return TlsStatus::HandshakeStarted and this function will have to be called repeatedly until TlsStatus::HandshakeComplete is returned. If this socket is blocking, TlsStatus::HandshakeComplete should be returned within the same function call if TLS setup was successful.

If TlsStatus::Error is returned, something went wrong with TLS setup and the connection must be reconnected and TLS setup reattempted after it is connected again.

If verification is enabled, this function verifies the peer using the system provided certificate store. If the peer does not have a certificate that was signed by a certificate authority i.e. a self-signed certificate, the entire certificate chain can be provided using the alternative overload.

Servers that host multiple services under different names need to know which of those services we want to connect to in order to reply with the correct certificate chain. Server name indication (SNI) is used for this purpose. The hostname provided to this function is sent to the server if it supports SNI in order for it to return the corresponding certificate chain. The hostname is then used to verify the certificate chain that was returned by the server. If the server does not support SNI or only serves a single certificate chain, the hostname will only be used for verification.

Parameters
hostnameHostname of the remote peer, used for verification
verifyPeertrue to enable peer verification, false to disable it
Returns
TLS status code
See also
setupTlsServer

◆ setupTlsClient() [2/4]

TlsStatus sf::TcpSocket::setupTlsClient ( const sf::String & hostname,
const char * certificateChainData )

Set up transport layer security as a client.

Once the TCP connection is connected, transport layer security can be set up.

All the necessary cryptographic initialization will be performed when this function is called.

If this function is called before the TCP connection is connected, it will return TlsStatus::NotConnected and must be called again once the TCP connection is connected.

If this function started TLS setup but could not finish it within this call e.g. because this socket was set to non-blocking, it will return TlsStatus::HandshakeStarted and this function will have to be called repeatedly until TlsStatus::HandshakeComplete is returned. If this socket is blocking, TlsStatus::HandshakeComplete should be returned within the same function call if TLS setup was successful.

If TlsStatus::Error is returned, something went wrong with TLS setup and the connection must be reconnected and TLS setup reattempted after it is connected again.

Servers that host multiple services under different names need to know which of those services we want to connect to in order to reply with the correct certificate chain. Server name indication (SNI) is used for this purpose. The hostname provided to this function is sent to the server if it supports SNI in order for it to return the corresponding certificate chain. The hostname is then used to verify the certificate chain that was returned by the server. If the server does not support SNI or only serves a single certificate chain, the hostname will only be used for verification.

When calling this overload, the certificate chain to verify the host with has to be provided. Verification is always enabled when calling this overload.

The certificate data should be provided in PEM format.

This overload is provided to prevent a const char* argument resulting in the bool verifyPeer overload being called instead of the std::string_view overload.

Parameters
hostnameHostname of the remote peer, used for verification
certificateChainDataNull terminated string containing certificate chain data in PEM encoding
Returns
TLS status code
See also
setupTlsServer

◆ setupTlsClient() [3/4]

TlsStatus sf::TcpSocket::setupTlsClient ( const sf::String & hostname,
const std::byte * certificateChainData,
std::size_t certificateChainSize )

Set up transport layer security as a client.

Once the TCP connection is connected, transport layer security can be set up.

All the necessary cryptographic initialization will be performed when this function is called.

If this function is called before the TCP connection is connected, it will return TlsStatus::NotConnected and must be called again once the TCP connection is connected.

If this function started TLS setup but could not finish it within this call e.g. because this socket was set to non-blocking, it will return TlsStatus::HandshakeStarted and this function will have to be called repeatedly until TlsStatus::HandshakeComplete is returned. If this socket is blocking, TlsStatus::HandshakeComplete should be returned within the same function call if TLS setup was successful.

If TlsStatus::Error is returned, something went wrong with TLS setup and the connection must be reconnected and TLS setup reattempted after it is connected again.

Servers that host multiple services under different names need to know which of those services we want to connect to in order to reply with the correct certificate chain. Server name indication (SNI) is used for this purpose. The hostname provided to this function is sent to the server if it supports SNI in order for it to return the corresponding certificate chain. The hostname is then used to verify the certificate chain that was returned by the server. If the server does not support SNI or only serves a single certificate chain, the hostname will only be used for verification.

When calling this overload, the certificate chain to verify the host with has to be provided. Verification is always enabled when calling this overload.

The certificate data can be provided in PEM or DER format.

Parameters
hostnameHostname of the remote peer, used for verification
certificateChainDataCertificate chain data in PEM or DER encoding
certificateChainSizeSize of the certificate chain data
Returns
TLS status code
See also
setupTlsServer

◆ setupTlsClient() [4/4]

TlsStatus sf::TcpSocket::setupTlsClient ( const sf::String & hostname,
std::string_view certificateChainData )

Set up transport layer security as a client.

Once the TCP connection is connected, transport layer security can be set up.

All the necessary cryptographic initialization will be performed when this function is called.

If this function is called before the TCP connection is connected, it will return TlsStatus::NotConnected and must be called again once the TCP connection is connected.

If this function started TLS setup but could not finish it within this call e.g. because this socket was set to non-blocking, it will return TlsStatus::HandshakeStarted and this function will have to be called repeatedly until TlsStatus::HandshakeComplete is returned. If this socket is blocking, TlsStatus::HandshakeComplete should be returned within the same function call if TLS setup was successful.

If TlsStatus::Error is returned, something went wrong with TLS setup and the connection must be reconnected and TLS setup reattempted after it is connected again.

Servers that host multiple services under different names need to know which of those services we want to connect to in order to reply with the correct certificate chain. Server name indication (SNI) is used for this purpose. The hostname provided to this function is sent to the server if it supports SNI in order for it to return the corresponding certificate chain. The hostname is then used to verify the certificate chain that was returned by the server. If the server does not support SNI or only serves a single certificate chain, the hostname will only be used for verification.

When calling this overload, the certificate chain to verify the host with has to be provided. Verification is always enabled when calling this overload.

The certificate data should be provided in PEM format.

Parameters
hostnameHostname of the remote peer, used for verification
certificateChainDataCertificate chain data in PEM encoding
Returns
TLS status code
See also
setupTlsServer

◆ setupTlsServer() [1/2]

TlsStatus sf::TcpSocket::setupTlsServer ( const std::byte * certificateChainData,
std::size_t certificateChainSize,
const std::byte * privateKeyData,
std::size_t privateKeySize,
const std::byte * privateKeyPasswordData,
std::size_t privateKeyPasswordSize )

Set up transport layer security as a server.

Once the TCP connection is connected, transport layer security can be set up.

All the necessary cryptographic initialization will be performed when this function is called.

If this function is called before the TCP connection is connected, it will return TlsStatus::NotConnected and must be called again once the TCP connection is connected.

If this function started TLS setup but could not finish it within this call e.g. because this socket was set to non-blocking, it will return TlsStatus::HandshakeStarted and this function will have to be called repeatedly until TlsStatus::HandshakeComplete is returned. If this socket is blocking, TlsStatus::HandshakeComplete should be returned within the same function call if TLS setup was successful.

If TlsStatus::Error is returned, something went wrong with TLS setup and the connection must be disconnected. The client must reconnect and reattempt TLS setup again.

As a server, a certificate chain as well as a private key must be provided.

The certificate and private key data can be provided in PEM or DER format.

If the private key is secured by a password, the password must be provided.

Parameters
certificateChainDataCertificate chain data in PEM or DER encoding
certificateChainSizeSize of the certificate chain data
privateKeyDataPrivate key data in PEM or DER encoding
privateKeySizeSize of the private key data
privateKeyPasswordDataPrivate key password data
privateKeyPasswordSizeSize of the private key password data
Returns
TLS status code
See also
setupTlsClient

◆ setupTlsServer() [2/2]

TlsStatus sf::TcpSocket::setupTlsServer ( std::string_view certificateChainData,
std::string_view privateKeyData,
std::string_view privateKeyPasswordData = {} )

Set up transport layer security as a server.

Once the TCP connection is connected, transport layer security can be set up.

All the necessary cryptographic initialization will be performed when this function is called.

If this function is called before the TCP connection is connected, it will return TlsStatus::NotConnected and must be called again once the TCP connection is connected.

If this function started TLS setup but could not finish it within this call e.g. because this socket was set to non-blocking, it will return TlsStatus::HandshakeStarted and this function will have to be called repeatedly until TlsStatus::HandshakeComplete is returned. If this socket is blocking, TlsStatus::HandshakeComplete should be returned within the same function call if TLS setup was successful.

If TlsStatus::Error is returned, something went wrong with TLS setup and the connection must be disconnected. The client must reconnect and reattempt TLS setup again.

As a server, a certificate chain as well as a private key must be provided.

The certificate and private key data should be provided in PEM format.

If the private key is secured by a password, the password must be provided.

Parameters
certificateChainDataCertificate chain data in PEM encoding
privateKeyDataPrivate key data in PEM encoding
privateKeyPasswordDataPrivate key password if required
Returns
TLS status code
See also
setupTlsClient

◆ TcpListener

friend class TcpListener
friend

Definition at line 597 of file TcpSocket.hpp.

Member Data Documentation

◆ AnyPort

unsigned short sf::Socket::AnyPort {0}
staticconstexprinherited

Some special values used by sockets.

Special value that tells the system to pick any available port

Definition at line 63 of file Socket.hpp.


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