EtherCAT RAW socket driver. More...

#include <sys/types.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <sys/socket.h>
#include <unistd.h>
#include <sys/time.h>
#include <time.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include <netpacket/packet.h>
#include <pthread.h>
#include "oshw.h"
#include "osal.h"

Include dependency graph for linux/nicdrv.c:

Go to the source code of this file.

Macros
#define	RX_PRIM priMAC[1]

#define	RX_SEC secMAC[1]

Enumerations
enum	{ ECT_RED_NONE, ECT_RED_DOUBLE }

Functions
void	ec_setupheader (void *p)

static void	ecx_clear_rxbufstat (int *rxbufstat)

int	ecx_closenic (ecx_portt *port)

int	ecx_getindex (ecx_portt *port)

int	ecx_inframe (ecx_portt *port, int idx, int stacknumber)

int	ecx_outframe (ecx_portt *port, int idx, int stacknumber)

int	ecx_outframe_red (ecx_portt *port, int idx)

static int	ecx_recvpkt (ecx_portt *port, int stacknumber)

void	ecx_setbufstat (ecx_portt *port, int idx, int bufstat)

int	ecx_setupnic (ecx_portt port, const char ifname, int secondary)

int	ecx_srconfirm (ecx_portt *port, int idx, int timeout)

int	ecx_waitinframe (ecx_portt *port, int idx, int timeout)

static int	ecx_waitinframe_red (ecx_portt port, int idx, osal_timert timer)

Variables
const uint16	priMAC [3] = { 0x0101, 0x0101, 0x0101 }

const uint16	secMAC [3] = { 0x0404, 0x0404, 0x0404 }

Detailed Description

EtherCAT RAW socket driver.

Low level interface functions to send and receive EtherCAT packets. EtherCAT has the property that packets are only send by the master, and the send packets always return in the receive buffer. There can be multiple packets "on the wire" before they return. To combine the received packets with the original send packets a buffer system is installed. The identifier is put in the index item of the EtherCAT header. The index is stored and compared when a frame is received. If there is a match the packet can be combined with the transmit packet and returned to the higher level function.

The socket layer can exhibit a reversal in the packet order (rare). If the Tx order is A-B-C the return order could be A-C-B. The indexed buffer will reorder the packets automatically.

The "redundant" option will configure two sockets and two NIC interfaces. Slaves are connected to both interfaces, one on the IN port and one on the OUT port. Packets are send via both interfaces. Any one of the connections (also an interconnect) can be removed and the slaves are still serviced with packets. The software layer will detect the possible failure modes and compensate. If needed the packets from interface A are resent through interface B. This layer if fully transparent for the higher layers.

Definition in file linux/nicdrv.c.

Macro Definition Documentation

◆ RX_PRIM

#define RX_PRIM priMAC[1]

second MAC word is used for identification

Definition at line 71 of file linux/nicdrv.c.

◆ RX_SEC

#define RX_SEC secMAC[1]

second MAC word is used for identification

Definition at line 73 of file linux/nicdrv.c.

Enumeration Type Documentation

◆ anonymous enum

anonymous enum

Redundancy modes

Enumerator
ECT_RED_NONE	No redundancy, single NIC mode
ECT_RED_DOUBLE	Double redundant NIC connection

Definition at line 51 of file linux/nicdrv.c.

Function Documentation

◆ ec_setupheader()

void ec_setupheader ( void * p )

Fill buffer with ethernet header structure. Destination MAC is always broadcast. Ethertype is always ETH_P_ECAT.

Parameters

[out] p = buffer

Definition at line 201 of file linux/nicdrv.c.

◆ ecx_clear_rxbufstat()

static void ecx_clear_rxbufstat ( int * rxbufstat )

static

Definition at line 75 of file linux/nicdrv.c.

◆ ecx_closenic()

int ecx_closenic ( ecx_portt * port )

inline

Close sockets used

Parameters

[in] port = port context struct

Returns: 0

Definition at line 186 of file linux/nicdrv.c.

◆ ecx_getindex()

int ecx_getindex ( ecx_portt * port )

Get new frame identifier index and allocate corresponding rx buffer.

Parameters

[in] port = port context struct

Returns: new index.

Definition at line 218 of file linux/nicdrv.c.

◆ ecx_inframe()

int ecx_inframe	(	ecx_portt *	port,
		int	idx,
		int	stacknumber
	)

Non blocking receive frame function. Uses RX buffer and index to combine read frame with transmitted frame. To compensate for received frames that are out-of-order all frames are stored in their respective indexed buffer. If a frame was placed in the buffer previously, the function retrieves it from that buffer index without calling ec_recvpkt. If the requested index is not already in the buffer it calls ec_recvpkt to fetch it. There are three options now, 1 no frame read, so exit. 2 frame read but other than requested index, store in buffer and exit. 3 frame read with matching index, store in buffer, set completed flag in buffer status and exit.

Parameters

[in]	port	= port context struct
[in]	idx	= requested index of frame
[in]	stacknumber	= 0=primary 1=secondary stack

Returns: Workcounter if a frame is found with corresponding index, otherwise EC_NOFRAME or EC_OTHERFRAME.

Definition at line 373 of file linux/nicdrv.c.

◆ ecx_outframe()

int ecx_outframe	(	ecx_portt *	port,
		int	idx,
		int	stacknumber
	)

Transmit buffer over socket (non blocking).

Parameters

[in]	port	= port context struct
[in]	idx	= index in tx buffer array
[in]	stacknumber	= 0=Primary 1=Secondary stack

Returns: socket send result

Definition at line 270 of file linux/nicdrv.c.

◆ ecx_outframe_red()

int ecx_outframe_red	(	ecx_portt *	port,
		int	idx
	)

Transmit buffer over socket (non blocking).

Parameters

[in]	port	= port context struct
[in]	idx	= index in tx buffer array

Returns: socket send result

Definition at line 299 of file linux/nicdrv.c.

◆ ecx_recvpkt()

static int ecx_recvpkt	(	ecx_portt *	port,
		int	stacknumber
	)

static

Non blocking read of socket. Put frame in temporary buffer.

Parameters

[in]	port	= port context struct
[in]	stacknumber	= 0=primary 1=secondary stack

Returns: >0 if frame is available and read

Definition at line 337 of file linux/nicdrv.c.

◆ ecx_setbufstat()

void ecx_setbufstat	(	ecx_portt *	port,
		int	idx,
		int	bufstat
	)

Set rx buffer status.

Parameters

[in]	port	= port context struct
[in]	idx	= index in buffer array
[in]	bufstat	= status to set

Definition at line 257 of file linux/nicdrv.c.

◆ ecx_setupnic()

int ecx_setupnic	(	ecx_portt *	port,
		const char *	ifname,
		int	secondary
	)

Basic setup to connect NIC to socket.

Parameters

[in]	port	= port context struct
[in]	ifname	= Name of NIC device, f.e. "eth0"
[in]	secondary	= if >0 then use secondary stack instead of primary

Returns: >0 if succeeded

Definition at line 90 of file linux/nicdrv.c.

◆ ecx_srconfirm()

int ecx_srconfirm	(	ecx_portt *	port,
		int	idx,
		int	timeout
	)

Blocking send and receive frame function. Used for non processdata frames. A datagram is build into a frame and transmitted via this function. It waits for an answer and returns the workcounter. The function retries if time is left and the result is WKC=0 or no frame received.

The function calls ec_outframe_red() and ec_waitinframe_red().

Parameters

[in]	port	= port context struct
[in]	idx	= index of frame
[in]	timeout	= timeout in us

Returns: Workcounter or EC_NOFRAME

Definition at line 573 of file linux/nicdrv.c.

◆ ecx_waitinframe()

int ecx_waitinframe	(	ecx_portt *	port,
		int	idx,
		int	timeout
	)

Blocking receive frame function. Calls ec_waitinframe_red().

Parameters

[in]	port	= port context struct
[in]	idx	= requested index of frame
[in]	timeout	= timeout in us

Returns: Workcounter if a frame is found with corresponding index, otherwise EC_NOFRAME.

Definition at line 550 of file linux/nicdrv.c.

◆ ecx_waitinframe_red()

static int ecx_waitinframe_red	(	ecx_portt *	port,
		int	idx,
		osal_timert *	timer
	)

static

Blocking redundant receive frame function. If redundant mode is not active then it skips the secondary stack and redundancy functions. In redundant mode it waits for both (primary and secondary) frames to come in. The result goes in an decision tree that decides, depending on the route of the packet and its possible missing arrival, how to reroute the original packet to get the data in an other try.

Parameters

[in]	port	= port context struct
[in]	idx	= requested index of frame
[in]	timer	= absolute timeout time

Returns: Workcounter if a frame is found with corresponding index, otherwise EC_NOFRAME.

Definition at line 467 of file linux/nicdrv.c.

Variable Documentation

◆ priMAC

const uint16 priMAC[3] = { 0x0101, 0x0101, 0x0101 }

Primary source MAC address used for EtherCAT. This address is not the MAC address used from the NIC. EtherCAT does not care about MAC addressing, but it is used here to differentiate the route the packet traverses through the EtherCAT segment. This is needed to find out the packet flow in redundant configurations.

Definition at line 66 of file linux/nicdrv.c.

◆ secMAC

const uint16 secMAC[3] = { 0x0404, 0x0404, 0x0404 }

Secondary source MAC address used for EtherCAT.

Definition at line 68 of file linux/nicdrv.c.

Macros

Enumerations

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ RX_PRIM

◆ RX_SEC

Enumeration Type Documentation

◆ anonymous enum

Function Documentation

◆ ec_setupheader()

◆ ecx_clear_rxbufstat()

◆ ecx_closenic()

◆ ecx_getindex()

◆ ecx_inframe()

◆ ecx_outframe()

◆ ecx_outframe_red()

◆ ecx_recvpkt()

◆ ecx_setbufstat()

◆ ecx_setupnic()

◆ ecx_srconfirm()

◆ ecx_waitinframe()

◆ ecx_waitinframe_red()

Variable Documentation

◆ priMAC

◆ secMAC