nicdrv.c File Reference

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 <arpa/inet.h>
#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include <netpacket/packet.h>
#include <pthread.h>
#include <stdlib.h>
#include "ethercattype.h"
#include "nicdrv.h"

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Data Structures
struct	ec_stackT
	pointer structure to Tx and Rx stacks More...
Defines
#define	RX_PRIM priMAC[1]
	second MAC word is used for identification
#define	RX_SEC secMAC[1]
	second MAC word is used for identification
Enumerations
enum	{ ECT_RED_NONE, ECT_RED_DOUBLE }
	Redundancy modes. More...
Functions
int	ec_setupnic (const char *ifname, int secondary)
	Basic setup to connect NIC to socket.
int	ec_closenic (void)
	Close sockets used.
void	ec_setupheader (void *p)
	Fill buffer with ethernet header structure.
uint8	ec_getindex (void)
	Get new frame identifier index and allocate corresponding rx buffer.
void	ec_setbufstat (uint8 idx, int bufstat)
	Set rx buffer status.
int	ec_outframe (uint8 idx, int stacknumber)
	Transmit buffer over socket (non blocking).
int	ec_outframe_red (uint8 idx)
	Transmit buffer over socket (non blocking).
int	ec_inframe (uint8 idx, int stacknumber)
	Non blocking receive frame function.
int	ec_waitinframe (uint8 idx, int timeout)
	Blocking receive frame function.
int	ec_srconfirm (uint8 idx, int timeout)
	Blocking send and recieve frame function.
Variables
ec_bufT	ec_rxbuf [EC_MAXBUF]
	primary rx buffers
int	ec_rxbufstat [EC_MAXBUF]
	primary rx buffer status
ec_bufT	ec_txbuf [EC_MAXBUF]
	transmit buffers
int	ec_txbuflength [EC_MAXBUF]
	transmit buffer lenghts
ec_bufT	ec_txbuf2
	temporary tx buffer
int	ec_txbuflength2
	temporary tx buffer length
int	sockhandle = -1
	primary socket handle
int	sockhandle2 = -1
	secondary socket handle
int	ec_incnt
	global rx packet counter, counts only EtherCAT packets
int	ec_errcnt
	global error packet counter, ie non EtherCAT packets
int	ec_redstate
	current redundancy state
int	hlp_txtime
	global helper var to count time used in tx socket
int	hlp_rxtime
	global helper var ri count time used in rx socket
const uint16	priMAC [3] = { 0x0101, 0x0101, 0x0101 }
	Primary source MAC address used for EtherCAT.
const uint16	secMAC [3] = { 0x0404, 0x0404, 0x0404 }
	Secondary source MAC address used for EtherCAT.
pthread_mutex_t	ec_getindex_mutex = PTHREAD_MUTEX_INITIALIZER
pthread_mutex_t	ec_tx_mutex = PTHREAD_MUTEX_INITIALIZER
pthread_mutex_t	ec_rx_mutex = PTHREAD_MUTEX_INITIALIZER

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 allways 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 recieved. 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 resend through interface B. This layer if fully transparent for the higher layers.

Definition in file nicdrv.c.

Define Documentation

#define RX_PRIM priMAC[1]

second MAC word is used for identification

Definition at line 176 of file nicdrv.c.

#define RX_SEC secMAC[1]

second MAC word is used for identification

Definition at line 178 of file nicdrv.c.

Enumeration Type Documentation

anonymous enum

Redundancy modes.

Enumerator:

ECT_RED_NONE	No redundancy, single NIC mode.
ECT_RED_DOUBLE	Double redundant NIC connecetion.

Definition at line 86 of file nicdrv.c.

Function Documentation

int ec_closenic ( void )

Close sockets used.

Returns:: 0

Definition at line 255 of file nicdrv.c.

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uint8 ec_getindex ( void )

Get new frame identifier index and allocate corresponding rx buffer.

Returns:: new index.

Definition at line 284 of file nicdrv.c.

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int ec_inframe	(	uint8	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 retreives 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]`	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 411 of file nicdrv.c.

int ec_outframe	(	uint8	idx,
		int	stacknumber
	)

Transmit buffer over socket (non blocking).

Parameters:

`[in]`	idx	= index in tx buffer array
`[in]`	stacknumber	= 0=Primary 1=Secondary stack

Returns:: socket send result

Definition at line 332 of file nicdrv.c.

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int ec_outframe_red ( uint8 idx )

Transmit buffer over socket (non blocking).

Parameters:

[in] idx = index in tx buffer array

Returns:: socket send result

Definition at line 349 of file nicdrv.c.

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void ec_setbufstat	(	uint8	idx,
		int	bufstat
	)

Set rx buffer status.

Parameters:

`[in]`	idx	= index in buffer array
`[in]`	bufstat	= status to set

Definition at line 321 of file nicdrv.c.

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void ec_setupheader ( void * p )

Fill buffer with ethernet header structure.

Destination MAC is allways broadcast. Ethertype is allways ETH_P_ECAT.

Parameters:

[out] p = buffer

Definition at line 268 of file nicdrv.c.

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int ec_setupnic	(	const char *	ifname,
		int	secondary
	)

Basic setup to connect NIC to socket.

Parameters:

`[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 189 of file nicdrv.c.

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int ec_srconfirm	(	uint8	idx,
		int	timeout
	)

Blocking send and recieve 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]`	idx	= index of frame
`[in]`	timeout	= timeout in us

Returns:: Workcounter or EC_NOFRAME

Definition at line 619 of file nicdrv.c.

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int ec_waitinframe	(	uint8	idx,
		int	timeout
	)

Blocking receive frame function.

Calls ec_waitinframe_red().

Parameters:

`[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 589 of file nicdrv.c.

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Variable Documentation

int ec_errcnt

global error packet counter, ie non EtherCAT packets

Definition at line 157 of file nicdrv.c.

pthread_mutex_t ec_getindex_mutex = PTHREAD_MUTEX_INITIALIZER

Definition at line 180 of file nicdrv.c.

int ec_incnt

global rx packet counter, counts only EtherCAT packets

Definition at line 155 of file nicdrv.c.

int ec_redstate

current redundancy state

Definition at line 159 of file nicdrv.c.

pthread_mutex_t ec_rx_mutex = PTHREAD_MUTEX_INITIALIZER

Definition at line 182 of file nicdrv.c.

ec_bufT ec_rxbuf[EC_MAXBUF]

primary rx buffers

Definition at line 114 of file nicdrv.c.

int ec_rxbufstat[EC_MAXBUF]

primary rx buffer status

Definition at line 116 of file nicdrv.c.

pthread_mutex_t ec_tx_mutex = PTHREAD_MUTEX_INITIALIZER

Definition at line 181 of file nicdrv.c.

ec_bufT ec_txbuf[EC_MAXBUF]

transmit buffers

Definition at line 134 of file nicdrv.c.

ec_bufT ec_txbuf2

temporary tx buffer

Definition at line 138 of file nicdrv.c.

int ec_txbuflength[EC_MAXBUF]

transmit buffer lenghts

Definition at line 136 of file nicdrv.c.

int ec_txbuflength2

temporary tx buffer length

Definition at line 140 of file nicdrv.c.

int hlp_rxtime

global helper var ri count time used in rx socket

Definition at line 164 of file nicdrv.c.

int hlp_txtime

global helper var to count time used in tx socket

Definition at line 162 of file nicdrv.c.

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 171 of file nicdrv.c.

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

Secondary source MAC address used for EtherCAT.

Definition at line 173 of file nicdrv.c.

int sockhandle = -1

primary socket handle

Definition at line 143 of file nicdrv.c.

int sockhandle2 = -1

secondary socket handle

Definition at line 145 of file nicdrv.c.

nicdrv.c File Reference

Data Structures

Defines

Enumerations

Functions

Variables

Detailed Description

Define Documentation

Enumeration Type Documentation

Function Documentation

Variable Documentation