Raw CAN socket class. More...

#include <simple_socket/CANRawSocket.h>

Inheritance diagram for NET::CANRawSocket:

Collaboration diagram for NET::CANRawSocket:

Public Types
enum	ShutdownDirection { STOP_SEND = SHUT_WR , STOP_RECEIVE = SHUT_RD , STOP_BOTH = SHUT_RDWR }

Public Member Functions
	CANRawSocket ()
void	send (const ::can_frame &frame)
	(overload) send can_frame through a connected socket
int	receive (::can_frame &frame)
	(overload) receive can frame from a bound socket
int	timedReceive (::can_frame &frame, int timeout)
	(overload) receive can frame from a bound socket with timeout
void	sendTo (const ::can_frame &frame, std::string_view interface)
int	receiveFrom (::can_frame &frame, std::string &interface)
int	timedReceiveFrom (::can_frame &frame, std::string &interface, int timeout)
void	setReceiveFilter (const ::can_filter *filters, size_t len)
void	setErrorFilter (::can_err_mask_t filter)
void	setLocalLoopback (bool enable)
void	setReceiveOwnMessages (bool enable)
void	connect (std::string_view interface="")
void	bind (std::string_view interface="")
std::string	getLocalInterface () const
std::string	getForeignInterface () const
int	nativeHandle () noexcept
	return the native handle of the open socket
int	send (const void *buffer, size_t len)
	send data through a connected socket
int	receive (void *buffer, size_t len)
	receive data from a bound socket
int	timedReceive (void *buffer, size_t len, int timeout)
	receive data from a bound socket, return after the given timespan
void	disconnect ()
	Disconnect and unset any foreign addresses.
void	shutdown (ShutdownDirection type)
	shutdown the connection in the specified direction
bool	peerDisconnected () const noexcept
	returns whether a currently associated peer disconnected

Static Public Member Functions
static std::string	formatCANID (::canid_t can_id)
	format canid_t into string for logs

Protected Member Functions
std::string	getInterfaceName (const sockaddr_can &addr) const
	get CAN interface name from socket address structure
int	getInterfaceIndex (std::string_view interface) const
	get CAN interface index from interface name
void	listen (int backlog=5)
	listen for incoming connections
int	sendAll (const void *buffer, size_t len)
	send data through a connected socket
int	receiveAll (void *buffer, size_t len)
	receive exactly the requested amount unless the peer disconnects
int	accept () const
	allows stream sockets to accept connections into Handles
int	timedAccept (int timeout) const
	allows stream sockets timed accept

Protected Attributes
int	m_socket
bool	m_peerDisconnected
bool	m_connectionOriented

Detailed Description

Raw CAN socket class.

Definition at line 9 of file CANRawSocket.h.

Member Enumeration Documentation

◆ ShutdownDirection

enum NET::SimpleSocket::ShutdownDirection

inherited

Enumerator
STOP_SEND	disable all variants of send() on the socket, receive calls still work
STOP_RECEIVE	disable all variants of receive() on the socket, send calls still work
STOP_BOTH	disable all send() and receive() calls on the socket

Definition at line 57 of file SimpleSocket.h.

Constructor & Destructor Documentation

◆ CANRawSocket()

CANRawSocket::CANRawSocket ( )

Construct a raw CAN socket

Exceptions

SocketException thrown if unable to create the socket

Definition at line 11 of file CANRawSocket.cpp.

Member Function Documentation

◆ accept()

int SimpleSocket::accept ( ) const

protectedinherited

allows stream sockets to accept connections into Handles

Definition at line 144 of file SimpleSocket.cpp.

◆ bind()

void CANSocket::bind ( std::string_view interface = "" )

inherited

Set the local interface to the specified interface

Parameters

interface specifies the CAN interface to bind to

Exceptions

SocketException thrown if setting local path fails

Definition at line 28 of file CANSocket.cpp.

◆ connect()

void CANSocket::connect ( std::string_view interface = "" )

inherited

Establish a socket connection with the given socket

Parameters

interface specifies the CAN interface to connect to

Exceptions

SocketException thrown if unable to establish connection

Definition at line 18 of file CANSocket.cpp.

◆ disconnect()

void SimpleSocket::disconnect ( )

inherited

Disconnect and unset any foreign addresses.

This will ungracefully abort the connection by sending an RST frame. disconnect() should not be used under normal circumstances, as it will terminate the connection OOB, preventing the other end of the communication from retrieving data that would still be available in the OS buffer.

For normal termination of a connection use shutdown().

Exceptions

SocketException thrown if unable to disconnect

Definition at line 112 of file SimpleSocket.cpp.

◆ formatCANID()

std::string CANSocket::formatCANID ( ::canid_t can_id )

staticinherited

format canid_t into string for logs

Definition at line 91 of file CANSocket.cpp.

◆ getForeignInterface()

std::string CANSocket::getForeignInterface ( ) const

inherited

Get the foreign interface. Call connect() before using this function.

Returns: foreign interface

Exceptions

SocketException thrown if fetch fails

Definition at line 49 of file CANSocket.cpp.

◆ getInterfaceIndex()

int CANSocket::getInterfaceIndex ( std::string_view interface ) const

protectedinherited

get CAN interface index from interface name

Definition at line 71 of file CANSocket.cpp.

◆ getInterfaceName()

std::string CANSocket::getInterfaceName ( const sockaddr_can & addr ) const

protectedinherited

get CAN interface name from socket address structure

Definition at line 60 of file CANSocket.cpp.

◆ getLocalInterface()

std::string CANSocket::getLocalInterface ( ) const

inherited

Get the local interface (after binding the socket)

Returns: local interface of socket

Exceptions

SocketException thrown if fetch fails

Definition at line 38 of file CANSocket.cpp.

◆ listen()

void SimpleSocket::listen ( int backlog = 5 )

protectedinherited

listen for incoming connections

listen() can be called on a bound socket. The socket will then go into a passive state and accept incoming connections. To answer to an incoming connection call accept() or timedAccept() on the socket.

The backlog is a buffer for incoming connections. If backlog is set to 0, the number of incoming connections is only limited by the operating system. If backlog is set to a value > 0, only the upper limit of connections is set, the OS can limit the number further.

After starting to listen, use accept to accept incoming connections.

Parameters

backlog upper limit of pending incoming connections

Exceptions

SocketException

Definition at line 137 of file SimpleSocket.cpp.

◆ nativeHandle()

int NET::SimpleSocket::nativeHandle ( )

inlinenoexceptinherited

return the native handle of the open socket

Definition at line 68 of file SimpleSocket.h.

◆ peerDisconnected()

bool SimpleSocket::peerDisconnected ( ) const

noexceptinherited

returns whether a currently associated peer disconnected

For stream sockets this is set when the peer closes or resets the connection. Use this function after a call to receive, returned 0 received bytes.

For connected datagram sockets it may also be set when the network reports that the configured peer is unreachable.

The flag is cleared by a successful connect().

Returns: true if a peer disconnected

Examples: TCP_Client.cpp.

Definition at line 132 of file SimpleSocket.cpp.

◆ receive() [1/2]

int CANRawSocket::receive ( ::can_frame & frame )

(overload) receive can frame from a bound socket

Definition at line 20 of file CANRawSocket.cpp.

◆ receive() [2/2]

int SimpleSocket::receive	(	void *	buffer,
		size_t	len )

inherited

receive data from a bound socket

receive() can only be used on a socket that called bind() or connect() before. If you try to use receive() on a not bound socket, SocketException will be thrown.

If using a stream oriented Socket, receive can return a part of a received messge, e.g. if you send 100 bytes, it's possible you will receive 50 bytes two times in a row. However, the order of the sent data will be preserved.

If you are using a datagram oriented sockets, you will only receive whole datagrams. But beware of using a too small buffer. If the receive buffer is too small for the received datagram, the data you didn't read in the receive call will be discared.

If the remote host has closed the connection (on a connection based socket like TCP or SCTP) receive() will return 0. If you are using a connectionless protocol (like UDP) there is no way to determine wheter the connection has been closed by the remote host or not.

Parameters

buffer	the buffer the received data will be written to
len	length of the provided buffer, receive will not read more than that

Returns: number of bytes received

Exceptions

SocketException in case an error occured

Definition at line 70 of file SimpleSocket.cpp.

◆ receiveAll()

int SimpleSocket::receiveAll	(	void *	buffer,
		size_t	len )

protectedinherited

receive exactly the requested amount unless the peer disconnects

receiveAll() repeatedly calls receive() until len bytes have been received. This is useful for fixed-size data on TCP, where one receive() call is not guaranteed to return all bytes sent by the peer.

If the peer closes or resets the connection before len bytes arrive, the function returns the number of bytes received so far. In that case peerDisconnected() is set by the underlying receive() call.

Parameters

buffer	buffer the received data will be written to
len	number of bytes to receive

Returns: number of bytes received

Exceptions

SocketException on receive errors other than peer loss

Definition at line 188 of file SimpleSocket.cpp.

◆ receiveFrom()

int CANRawSocket::receiveFrom	(	::can_frame &	frame,
		std::string &	interface )

Read one CAN frame from this socket.

In order to receive data, the socket has to be bound at least to a specific interface. This is done by explicitly binding the socket, or sending data through the socket.

Parameters

frame	CAN frame structure to be send
interface	specifies the CAN interface used for reception

Returns: number of bytes received

Exceptions

SocketException thrown if unable to receive datagram

Definition at line 43 of file CANRawSocket.cpp.

◆ send() [1/2]

void CANRawSocket::send ( const ::can_frame & frame )

(overload) send can_frame through a connected socket

Definition at line 15 of file CANRawSocket.cpp.

◆ send() [2/2]

int SimpleSocket::send	(	const void *	buffer,
		size_t	len )

inherited

send data through a connected socket

send() can only be used on a socket that called connect() before. If you try to use send() on a not connected socket, SocketException will be thrown.

If you are using a stream oriented socket (like TCPSocket), the operating system is allowed to send only a part of the packet you told it to send, so send() will return the number of bytes actually sent. It is your responsibility to resend the data not sent by send()

If you are using a datagram oriented socket (like UDPSocket or SCTPSocket) the operating system will only send and receive complete datagrams, but send() will fail if you are trying to send too much data. In that case SocketException will be thrown.

Parameters

buffer	data to be send
len	length of the data to be sent

Returns: number of bytes sent

Exceptions

SocketException if sending went wrong

Definition at line 50 of file SimpleSocket.cpp.

◆ sendAll()

int SimpleSocket::sendAll	(	const void *	buffer,
		size_t	len )

protectedinherited

send data through a connected socket

sendAll() can only be used on a socket that called connect() before. If you try to use sendAll() on a unconnected socket, a SocketException will be thrown.

When using a stream oriented socket, the operating system is allowed to send only a bit of the data you requested it to send. Because of this, you would have to check the number of sent bytes when using send(), and resend unsent data manually. sendAll() takes that responsibility from you and resends as long as it needs, to completely send the data given to it.

Parameters

buffer	data to be send
len	length of the data to be sent

Returns: number of bytes sent

Exceptions

SocketException

Definition at line 175 of file SimpleSocket.cpp.

◆ sendTo()

void CANRawSocket::sendTo	(	const ::can_frame &	frame,
		std::string_view	interface )

Send the given CAN frame using the specified interface.

Can be substituted with send() if the socket is first connected to any interface. If sendTo() is used on a connected socket, the destination parameters will be ignored, and the datagram will be sent to the connected socket.

Like send(), sendTo() blocks until the message was sent.

Parameters

frame	CAN frame structure to be send
interface	specifies the CAN interface to send used for sending

Exceptions

SocketException thrown if unable to send frame

Definition at line 30 of file CANRawSocket.cpp.

◆ setErrorFilter()

void CANRawSocket::setErrorFilter ( ::can_err_mask_t filter )

Parameters

filter Linux SocketCAN error-class mask

Exceptions

SocketException

Definition at line 85 of file CANRawSocket.cpp.

◆ setLocalLoopback()

void CANRawSocket::setLocalLoopback ( bool enable )

Parameters

enable

Exceptions

SocketException

Definition at line 91 of file CANRawSocket.cpp.

◆ setReceiveFilter()

void CANRawSocket::setReceiveFilter	(	const ::can_filter *	filters,
		size_t	len )

Parameters

filters	Linux SocketCAN receive filters array
len	number of filters to set

Exceptions

SocketException

Definition at line 79 of file CANRawSocket.cpp.

◆ setReceiveOwnMessages()

void CANRawSocket::setReceiveOwnMessages ( bool enable )

Parameters

enable

Exceptions

SocketException

Definition at line 98 of file CANRawSocket.cpp.

◆ shutdown()

void SimpleSocket::shutdown ( ShutdownDirection type )

inherited

shutdown the connection in the specified direction

This will gracefully end a connection by sending a FIN frame. Use this to end a normal communication cycle. To abort a connection see disconnect().

Depending on the specified ShutdownDirection, calls for that direction will stop working. Use this function if you want to have more control than just destroing the socket. It allows you to cut the connection in one direction, or both.

If you use shutdown() on an unconnected socket, the corresponding calls will simply stop working.

Parameters

type	the ShutdownDirection that be used

Exceptions

SocketException in case an error occured

Examples: TCP_Server.cpp.

Definition at line 126 of file SimpleSocket.cpp.

◆ timedAccept()

int SimpleSocket::timedAccept ( int timeout ) const

protectedinherited

allows stream sockets timed accept

Definition at line 158 of file SimpleSocket.cpp.

◆ timedReceive() [1/2]

int CANRawSocket::timedReceive	(	::can_frame &	frame,
		int	timeout )

(overload) receive can frame from a bound socket with timeout

Definition at line 25 of file CANRawSocket.cpp.

◆ timedReceive() [2/2]

int SimpleSocket::timedReceive	(	void *	buffer,
		size_t	len,
		int	timeout )

inherited

receive data from a bound socket, return after the given timespan

timedReceive() can only be used on a socket that called bind() or connect before. If you try to use receive() on a not bound socket, SocketException will be thrown.

If using a stream oriented Socket, receive can return a part of a received messge, e.g. if you send 100 bytes, it's possible you will receive 50 bytes two times in a row. However, the order of the sent data will be preserved.

If you are using a datagram oriented sockets, you will only receive whole datagrams. But beware of using a too small buffer. If the receive buffer is too small for the received datagram, the data you didn't read in the receive call will be discared.

If the remote host has closed the connection (on a connection based socket like TCP or SCTP) receive() will return 0. If you are using a connectionless protocol (like UDP) there is no way to determine wheter the connection has been closed by the remote host or not.

Parameters

buffer	the buffer the received data will be written to
len	length of the provided buffer, receive will not read more than that
timeout	the timeout in ms after which receive will give up and return

Returns: number of bytes received, 0 on timeout

Exceptions

SocketException in case an error occured

Examples: TCP_Client.cpp.

Definition at line 89 of file SimpleSocket.cpp.

◆ timedReceiveFrom()

int CANRawSocket::timedReceiveFrom	(	::can_frame &	frame,
		std::string &	interface,
		int	timeout )

Read one CAN frame from this socket. If no interface has received a frame before the timeout runs out, the function will return without changing the buffer.

In order to receive data, the socket has to be bound at least to a specific interface. This is done by explicitly binding the socket, or sending data through the socket.

Parameters

frame	CAN frame structure to be send
interface	specifies the CAN interface used for reception
timeout	timeout in milliseconds

Returns: number of bytes received, 0 on timeout

Exceptions

SocketException thrown if unable to receive datagram

Definition at line 56 of file CANRawSocket.cpp.

Member Data Documentation

◆ m_connectionOriented

bool NET::SimpleSocket::m_connectionOriented

protectedinherited

Definition at line 268 of file SimpleSocket.h.

◆ m_peerDisconnected

bool NET::SimpleSocket::m_peerDisconnected

protectedinherited

Definition at line 267 of file SimpleSocket.h.

◆ m_socket

int NET::SimpleSocket::m_socket

protectedinherited

Definition at line 266 of file SimpleSocket.h.

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

include/simple_socket/CANRawSocket.h
src/CANRawSocket.cpp

simple-socket library 1.5.0

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Enumeration Documentation

◆ ShutdownDirection

Constructor & Destructor Documentation

◆ CANRawSocket()

Member Function Documentation

◆ accept()

◆ bind()

◆ connect()

◆ disconnect()

◆ formatCANID()

◆ getForeignInterface()

◆ getInterfaceIndex()

◆ getInterfaceName()

◆ getLocalInterface()

◆ listen()

◆ nativeHandle()

◆ peerDisconnected()

◆ receive() [1/2]

◆ receive() [2/2]

◆ receiveAll()

◆ receiveFrom()

◆ send() [1/2]

◆ send() [2/2]

◆ sendAll()

◆ sendTo()

◆ setErrorFilter()

◆ setLocalLoopback()

◆ setReceiveFilter()

◆ setReceiveOwnMessages()

◆ shutdown()

◆ timedAccept()

◆ timedReceive() [1/2]

◆ timedReceive() [2/2]

◆ timedReceiveFrom()

Member Data Documentation

◆ m_connectionOriented

◆ m_peerDisconnected

◆ m_socket