#include <socketcan.hpp>

Inheritance diagram for uavcan_linux::SocketCanIface:

Classes
struct	RxItem

struct	TxItem

Public Member Functions
std::int16_t	configureFilters (const uavcan::CanFilterConfig *const filter_configs, const std::uint16_t num_configs) override

std::uint64_t	getErrorCount () const override

const decltype(errors_) &	getErrors () const

int	getFileDescriptor () const

std::uint16_t	getNumFilters () const override

bool	hasReadyRx () const

bool	hasReadyTx () const

void	poll (bool read, bool write)

std::int16_t	receive (uavcan::CanFrame &out_frame, uavcan::MonotonicTime &out_ts_monotonic, uavcan::UtcTime &out_ts_utc, uavcan::CanIOFlags &out_flags) override

std::int16_t	send (const uavcan::CanFrame &frame, const uavcan::MonotonicTime tx_deadline, const uavcan::CanIOFlags flags) override

	SocketCanIface (const SystemClock &clock, int socket_fd, int max_frames_in_socket_tx_queue=2)

virtual	~SocketCanIface ()

Public Member Functions inherited from uavcan::ICanIface
virtual int16_t	receive (CanFrame &out_frame, MonotonicTime &out_ts_monotonic, UtcTime &out_ts_utc, CanIOFlags &out_flags)=0

virtual int16_t	send (const CanFrame &frame, MonotonicTime tx_deadline, CanIOFlags flags)=0

virtual	~ICanIface ()

Static Public Member Functions
static int	openSocket (const std::string &iface_name)

Static Public Attributes
static constexpr unsigned	NumFilters = 8

Private Member Functions
bool	checkHWFilters (const ::can_frame &frame) const

void	confirmSentFrame ()

void	incrementNumFramesInSocketTxQueue ()

void	pollRead ()

void	pollWrite ()

int	read (uavcan::CanFrame &frame, uavcan::UtcTime &ts_utc, bool &loopback) const

void	registerError (SocketCanError e)

bool	wasInPendingLoopbackSet (const uavcan::CanFrame &frame)

int	write (const uavcan::CanFrame &frame) const

Static Private Member Functions
static inline ::can_frame	makeSocketCanFrame (const uavcan::CanFrame &uavcan_frame)

static uavcan::CanFrame	makeUavcanFrame (const ::can_frame &sockcan_frame)

Private Attributes
const SystemClock &	clock_

std::map< SocketCanError, std::uint64_t >	errors_

const int	fd_

unsigned	frames_in_socket_tx_queue_ = 0

std::vector<::can_filter >	hw_filters_container_

const unsigned	max_frames_in_socket_tx_queue_

std::unordered_multiset< std::uint32_t >	pending_loopback_ids_

std::queue< RxItem >	rx_queue_

std::uint64_t	tx_frame_counter_ = 0
	Increments with every frame pushed into the TX queue. More...

std::priority_queue< TxItem >	tx_queue_

Detailed Description

Single SocketCAN socket interface.

SocketCAN socket adapter maintains TX and RX queues in user space. At any moment socket's buffer contains no more than 'max_frames_in_socket_tx_queue_' TX frames, rest is waiting in the user space TX queue; when the socket produces loopback for the previously sent TX frame the next frame from the user space TX queue will be sent into the socket.

This approach allows to properly maintain TX timeouts (http://stackoverflow.com/questions/19633015/). TX timestamping is implemented by means of reading RX timestamps of loopback frames (see "TX timestamping" on linux-can mailing list, http://permalink.gmane.org/gmane.linux.can/5322).

Note that if max_frames_in_socket_tx_queue_ is greater than one, frame reordering may occur (depending on the unrderlying logic).

This class is too complex and needs to be refactored later. At least, basic socket IO and configuration should be extracted into a different class.

Definition at line 60 of file socketcan.hpp.

Constructor & Destructor Documentation

◆ SocketCanIface()

uavcan_linux::SocketCanIface::SocketCanIface	(	const SystemClock &	clock,
		int	socket_fd,
		int	max_frames_in_socket_tx_queue = `2`
	)

inline

Takes ownership of socket's file descriptor.

max_frames_in_socket_tx_queue See a note in the class comment.

Definition at line 372 of file socketcan.hpp.

◆ ~SocketCanIface()

virtual uavcan_linux::SocketCanIface::~SocketCanIface ( )

inlinevirtual

Socket file descriptor will be closed.

Definition at line 383 of file socketcan.hpp.

Member Function Documentation

◆ checkHWFilters()

bool uavcan_linux::SocketCanIface::checkHWFilters ( const ::can_frame & frame ) const

inlineprivate

Returns true if a frame accepted by HW filters

Definition at line 347 of file socketcan.hpp.

◆ configureFilters()

std::int16_t uavcan_linux::SocketCanIface::configureFilters	(	const uavcan::CanFilterConfig *const	filter_configs,
		const std::uint16_t	num_configs
	)

inlineoverridevirtual

Configure the hardware CAN filters. CanFilterConfig.

Returns: 0 = success, negative for error.

Implements uavcan::ICanIface.

Definition at line 451 of file socketcan.hpp.

◆ confirmSentFrame()

void uavcan_linux::SocketCanIface::confirmSentFrame ( )

inlineprivate

Definition at line 166 of file socketcan.hpp.

◆ getErrorCount()

std::uint64_t uavcan_linux::SocketCanIface::getErrorCount ( ) const

inlineoverridevirtual

Returns total number of errors of each kind detected since the object was created.

Implements uavcan::ICanIface.

Definition at line 499 of file socketcan.hpp.

◆ getErrors()

const decltype(errors_) & uavcan_linux::SocketCanIface::getErrors ( ) const

inline

Returns number of errors of each kind in a map.

Definition at line 509 of file socketcan.hpp.

◆ getFileDescriptor()

int uavcan_linux::SocketCanIface::getFileDescriptor ( ) const

inline

Definition at line 511 of file socketcan.hpp.

◆ getNumFilters()

std::uint16_t uavcan_linux::SocketCanIface::getNumFilters ( ) const

inlineoverridevirtual

Number of available hardware filters.

Implements uavcan::ICanIface.

Definition at line 493 of file socketcan.hpp.

◆ hasReadyRx()

bool uavcan_linux::SocketCanIface::hasReadyRx ( ) const

inline

Definition at line 445 of file socketcan.hpp.

◆ hasReadyTx()

bool uavcan_linux::SocketCanIface::hasReadyTx ( ) const

inline

Definition at line 446 of file socketcan.hpp.

◆ incrementNumFramesInSocketTxQueue()

void uavcan_linux::SocketCanIface::incrementNumFramesInSocketTxQueue ( )

inlineprivate

Definition at line 160 of file socketcan.hpp.

◆ makeSocketCanFrame()

static inline ::can_frame uavcan_linux::SocketCanIface::makeSocketCanFrame ( const uavcan::CanFrame & uavcan_frame )

inlinestaticprivate

Definition at line 62 of file socketcan.hpp.

◆ makeUavcanFrame()

static uavcan::CanFrame uavcan_linux::SocketCanIface::makeUavcanFrame ( const ::can_frame & sockcan_frame )

inlinestaticprivate

Definition at line 83 of file socketcan.hpp.

◆ openSocket()

static int uavcan_linux::SocketCanIface::openSocket ( const std::string & iface_name )

inlinestatic

Open and configure a CAN socket on iface specified by name.

Parameters

iface_name String containing iface name, e.g. "can0", "vcan1", "slcan0"

Returns: Socket descriptor or negative number on error.

Definition at line 518 of file socketcan.hpp.

◆ poll()

void uavcan_linux::SocketCanIface::poll	(	bool	read,
		bool	write
	)

inline

Performs socket read/write.

Parameters

read	Socket is readable
write	Socket is writeable

Definition at line 433 of file socketcan.hpp.

◆ pollRead()

void uavcan_linux::SocketCanIface::pollRead ( )

inlineprivate

Definition at line 308 of file socketcan.hpp.

◆ pollWrite()

void uavcan_linux::SocketCanIface::pollWrite ( )

inlineprivate

Definition at line 272 of file socketcan.hpp.

◆ read()

int uavcan_linux::SocketCanIface::read	(	uavcan::CanFrame &	frame,
		uavcan::UtcTime &	ts_utc,
		bool &	loopback
	)		const

inlineprivate

SocketCAN git show 1e55659ce6ddb5247cee0b1f720d77a799902b85 MSG_DONTROUTE is set for any packet from localhost, MSG_CONFIRM is set for any pakcet of your socket. Diff: https://git.ucsd.edu/abuss/linux/commit/1e55659ce6ddb5247cee0b1f720d77a799902b85 Man: https://www.kernel.org/doc/Documentation/networking/can.txt (chapter 4.1.6).

Definition at line 217 of file socketcan.hpp.

◆ receive()

std::int16_t uavcan_linux::SocketCanIface::receive	(	uavcan::CanFrame &	out_frame,
		uavcan::MonotonicTime &	out_ts_monotonic,
		uavcan::UtcTime &	out_ts_utc,
		uavcan::CanIOFlags &	out_flags
	)

inlineoverride

Will read the socket only if RX queue is empty. Normally, poll() needs to be executed first.

Definition at line 406 of file socketcan.hpp.

◆ registerError()

void uavcan_linux::SocketCanIface::registerError ( SocketCanError e )

inlineprivate

Definition at line 158 of file socketcan.hpp.

◆ send()

std::int16_t uavcan_linux::SocketCanIface::send	(	const uavcan::CanFrame &	frame,
		const uavcan::MonotonicTime	tx_deadline,
		const uavcan::CanIOFlags	flags
	)

inlineoverride

Assumes that the socket is writeable

Definition at line 392 of file socketcan.hpp.

◆ wasInPendingLoopbackSet()

bool uavcan_linux::SocketCanIface::wasInPendingLoopbackSet ( const uavcan::CanFrame & frame )

inlineprivate

Definition at line 178 of file socketcan.hpp.

◆ write()

int uavcan_linux::SocketCanIface::write ( const uavcan::CanFrame & frame ) const

inlineprivate

Definition at line 188 of file socketcan.hpp.

Member Data Documentation

◆ clock_

const SystemClock& uavcan_linux::SocketCanIface::clock_

private

Definition at line 142 of file socketcan.hpp.

◆ errors_

std::map<SocketCanError, std::uint64_t> uavcan_linux::SocketCanIface::errors_

private

Definition at line 150 of file socketcan.hpp.

◆ fd_

const int uavcan_linux::SocketCanIface::fd_

private

Definition at line 143 of file socketcan.hpp.

◆ frames_in_socket_tx_queue_

unsigned uavcan_linux::SocketCanIface::frames_in_socket_tx_queue_ = 0

private

Definition at line 146 of file socketcan.hpp.

◆ hw_filters_container_

std::vector<::can_filter> uavcan_linux::SocketCanIface::hw_filters_container_

private

Definition at line 156 of file socketcan.hpp.

◆ max_frames_in_socket_tx_queue_

const unsigned uavcan_linux::SocketCanIface::max_frames_in_socket_tx_queue_

private

Definition at line 145 of file socketcan.hpp.

◆ NumFilters

constexpr unsigned uavcan_linux::SocketCanIface::NumFilters = 8

staticconstexpr

SocketCAN emulates the CAN filters in software, so the number of filters is virtually unlimited. This method returns a constant value.

Definition at line 492 of file socketcan.hpp.

◆ pending_loopback_ids_

std::unordered_multiset<std::uint32_t> uavcan_linux::SocketCanIface::pending_loopback_ids_

private

Definition at line 154 of file socketcan.hpp.

◆ rx_queue_

std::queue<RxItem> uavcan_linux::SocketCanIface::rx_queue_

private

Definition at line 153 of file socketcan.hpp.

◆ tx_frame_counter_

std::uint64_t uavcan_linux::SocketCanIface::tx_frame_counter_ = 0

private

Increments with every frame pushed into the TX queue.

Definition at line 148 of file socketcan.hpp.

◆ tx_queue_

std::priority_queue<TxItem> uavcan_linux::SocketCanIface::tx_queue_

private

Definition at line 152 of file socketcan.hpp.

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

socketcan.hpp

Classes

Public Member Functions

Static Public Member Functions

Static Public Attributes

Private Member Functions

Static Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ SocketCanIface()

◆ ~SocketCanIface()

Member Function Documentation

◆ checkHWFilters()

◆ configureFilters()

◆ confirmSentFrame()

◆ getErrorCount()

◆ getErrors()

◆ getFileDescriptor()

◆ getNumFilters()

◆ hasReadyRx()

◆ hasReadyTx()

◆ incrementNumFramesInSocketTxQueue()

◆ makeSocketCanFrame()

◆ makeUavcanFrame()

◆ openSocket()

◆ poll()

◆ pollRead()

◆ pollWrite()

◆ read()

◆ receive()

◆ registerError()

◆ send()

◆ wasInPendingLoopbackSet()

◆ write()

Member Data Documentation

◆ clock_

◆ errors_

◆ fd_

◆ frames_in_socket_tx_queue_

◆ hw_filters_container_

◆ max_frames_in_socket_tx_queue_

◆ NumFilters

◆ pending_loopback_ids_

◆ rx_queue_

◆ tx_frame_counter_

◆ tx_queue_