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openblt/Host/Source/LibOpenBLT/port/linux/canif/socketcan/socketcan.c

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/************************************************************************************//**
* \file socketcan.c
* \brief Linux SocketCAN interface source file.
* \ingroup SocketCan
* \internal
*----------------------------------------------------------------------------------------
* C O P Y R I G H T
*----------------------------------------------------------------------------------------
* Copyright (c) 2017 by Feaser http://www.feaser.com All rights reserved
*
*----------------------------------------------------------------------------------------
* L I C E N S E
*----------------------------------------------------------------------------------------
* This file is part of OpenBLT. OpenBLT is free software: you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published by the Free
* Software Foundation, either version 3 of the License, or (at your option) any later
* version.
*
* OpenBLT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU General Public License for more details.
*
* You have received a copy of the GNU General Public License along with OpenBLT. It
* should be located in ".\Doc\license.html". If not, contact Feaser to obtain a copy.
*
* \endinternal
****************************************************************************************/
/****************************************************************************************
* Include files
****************************************************************************************/
#include <assert.h> /* for assertions */
#include <stdint.h> /* for standard integer types */
#include <stddef.h> /* for NULL declaration */
#include <stdbool.h> /* for boolean type */
#include <stdlib.h> /* for standard library */
#include <string.h> /* for string library */
#include <pthread.h> /* for posix threads */
#include <unistd.h> /* UNIX standard functions */
#include <fcntl.h> /* file control operations */
#include <sys/time.h> /* time definitions */
#include <sys/ioctl.h> /* I/O control operations */
#include <net/if.h> /* network interfaces */
#include <linux/can.h> /* CAN kernel definitions */
#include <linux/can/raw.h> /* CAN raw sockets */
#include "util.h" /* Utility module */
#include "candriver.h" /* Generic CAN driver module */
#include "socketcan.h" /* SocketCAN interface */
/****************************************************************************************
* Type definitions
****************************************************************************************/
/** \brief Groups data for thread control. */
typedef struct t_socket_can_thread_ctrl
{
bool terminate; /**< flag to request thread termination. */
bool terminated; /**< handshake flag. */
} tSocketCanThreadCtrl;
/***************************************************************************************
* Function prototypes
****************************************************************************************/
/* CAN interface functions. */
static void SocketCanInit(tCanSettings const * settings);
static void SocketCanTerminate(void);
static bool SocketCanConnect(void);
static void SocketCanDisconnect(void);
static bool SocketCanTransmit(tCanMsg const * msg);
static bool SocketCanIsBusError(void);
static void SocketCanRegisterEvents(tCanEvents const * events);
/* Event thread functions. */
static bool SocketCanStartEventThread(void);
static void SocketCanStopEventThread(void);
static void *SocketCanEventThread(void *param);
/****************************************************************************************
* Local constant declarations
****************************************************************************************/
/** \brief CAN interface structure filled with SocketCAN specifics. */
static const tCanInterface socketCanInterface =
{
SocketCanInit,
SocketCanTerminate,
SocketCanConnect,
SocketCanDisconnect,
SocketCanTransmit,
SocketCanIsBusError,
SocketCanRegisterEvents
};
/****************************************************************************************
* Local data declarations
****************************************************************************************/
/** \brief The settings to use in this CAN interface. */
static tCanSettings socketCanSettings;
/** \brief List with callback functions that this driver should use. */
static volatile tCanEvents * socketCanEventsList;
/** \brief Total number of event entries into the \ref socketCanEventsList list. */
static volatile uint32_t socketCanEventsEntries;
/** \brief Event thread control. */
static volatile tSocketCanThreadCtrl eventThreadCtrl;
/** \brief The ID of the event thread. */
static pthread_t eventThreadId;
/** \brief CAN raw socket. */
static volatile int32_t canSocket;
/***********************************************************************************//**
** \brief Obtains a pointer to the CAN interface structure, so that it can be linked
** to the generic CAN driver module.
** \return Pointer to CAN interface structure.
**
****************************************************************************************/
tCanInterface const * SocketCanGetInterface(void)
{
return &socketCanInterface;
} /*** end of SocketCanGetInterface ***/
/************************************************************************************//**
** \brief Initializes the CAN interface. Note that this module assumes that the CAN
** device was already properly configured and brought online on the Linux
** system. Terminal command "ip addr" can be used to verify this.
** \param settings Pointer to the CAN interface settings.
**
****************************************************************************************/
static void SocketCanInit(tCanSettings const * settings)
{
char * canDeviceName;
/* Initialize locals. */
socketCanEventsList = NULL;
socketCanEventsEntries = 0;
/* Reset CAN interface settings. */
socketCanSettings.devicename = "";
socketCanSettings.channel = 0;
socketCanSettings.baudrate = CAN_BR500K;
socketCanSettings.code = 0x00000000u;
socketCanSettings.mask = 0x00000000u;
/* Initialize the critical section module. */
UtilCriticalSectionInit();
/* Check parameters. */
assert(settings != NULL);
/* Only continue with valid parameters. */
if (settings != NULL) /*lint !e774 */
{
/* Shallow copy the CAN interface settings for later usage. */
socketCanSettings = *settings;
/* The devicename is a pointer and it is not gauranteed that it stays valid so we
* need to deep copy this one. note the +1 for '\0' in malloc.
*/
assert(settings->devicename != NULL);
if (settings->devicename != NULL) /*lint !e774 */
{
canDeviceName = malloc(strlen(settings->devicename) + 1);
assert(canDeviceName != NULL);
if (canDeviceName != NULL) /*lint !e774 */
{
strcpy(canDeviceName, settings->devicename);
socketCanSettings.devicename = canDeviceName;
}
}
}
} /*** end of SocketCanInit ***/
/************************************************************************************//**
** \brief Terminates the CAN interface.
**
****************************************************************************************/
static void SocketCanTerminate(void)
{
/* Release memory that was allocated for storing the device name. */
if (socketCanSettings.devicename != NULL)
{
free((char *)socketCanSettings.devicename);
}
/* Reset CAN interface settings. */
socketCanSettings.devicename = "";
socketCanSettings.channel = 0;
socketCanSettings.baudrate = CAN_BR500K;
socketCanSettings.code = 0x00000000u;
socketCanSettings.mask = 0x00000000u;
/* Release memory that was allocated for CAN events and reset the entry count. */
if ( (socketCanEventsList != NULL) && (socketCanEventsEntries != 0) )
{
free((void *)socketCanEventsList);
socketCanEventsEntries = 0;
}
/* Terminate the critical section module. */
UtilCriticalSectionTerminate();
} /*** end of SocketCanTerminate ***/
/************************************************************************************//**
** \brief Connects the CAN interface. Note that the channel and baudrate settings
** are ignored for the SocketCAN, because these are expected to be configured
** when the CAN device was brought online on the Linux system.
** \return True if connected, false otherwise.
**
****************************************************************************************/
static bool SocketCanConnect(void)
{
bool result = false;
struct sockaddr_can addr;
struct ifreq ifr;
int32_t flags;
struct can_filter rxFilter;
/* Check settings. */
assert(socketCanSettings.devicename != NULL);
/* Only continue with valid settings. */
if (socketCanSettings.devicename != NULL) /*lint !e774 */
{
/* Set positive result at this point and negate upon error detected. */
result = true;
/* Create an ifreq structure for passing data in and out of ioctl. */
strncpy(ifr.ifr_name, socketCanSettings.devicename, IFNAMSIZ - 1);
ifr.ifr_name[IFNAMSIZ - 1] = '\0';
/* Get open socket descriptor */
if ((canSocket = socket(PF_CAN, (int)SOCK_RAW, CAN_RAW)) < 0)
{
result = false;
}
if (result)
{
/* Obtain interface index. */
if (ioctl(canSocket, SIOCGIFINDEX, &ifr) < 0)
{
close(canSocket);
result = false;
}
}
if (result)
{
/* Configure socket to work in non-blocking mode. */
flags = fcntl(canSocket, F_GETFL, 0);
if (flags == -1)
{
flags = 0;
}
if (fcntl(canSocket, F_SETFL, flags | O_NONBLOCK) == -1)
{
close(canSocket);
result = false;
}
}
if (result)
{
/* Set the address info. */
addr.can_family = AF_CAN;
addr.can_ifindex = ifr.ifr_ifindex;
/* Bind the socket. */
if (bind(canSocket, (struct sockaddr *)&addr, sizeof(addr)) < 0) /*lint !e740 */
{
close(canSocket);
result = false;
}
}
/* Configure reception acceptance filter, if it is not supposed to be fully open. */
if ( (result) && (socketCanSettings.mask != 0x00000000u) )
{
/* Configure reception acceptance filter. The CAN_MSG_EXT_ID_MASK-bit from
* the CAN driver is currently the same as the CAN_EFF_FLAG-bit from SocketCAN.
* However, we don't know if this gets changed in the future in SocketCAN so
* process this bit manually.
*/
rxFilter.can_id = socketCanSettings.code;
if ((rxFilter.can_id & CAN_MSG_EXT_ID_MASK) != 0)
{
rxFilter.can_id &= ~CAN_MSG_EXT_ID_MASK;
rxFilter.can_id |= CAN_EFF_FLAG;
}
rxFilter.can_mask = socketCanSettings.mask;
if ((rxFilter.can_mask & CAN_MSG_EXT_ID_MASK) != 0)
{
rxFilter.can_mask &= ~CAN_MSG_EXT_ID_MASK;
rxFilter.can_mask |= CAN_EFF_FLAG;
}
if (setsockopt(canSocket, SOL_CAN_RAW, CAN_RAW_FILTER, &rxFilter, sizeof(rxFilter)) != 0)
{
close(canSocket);
result = false;
}
}
if (result)
{
/* Start the event thread. */
if (!SocketCanStartEventThread())
{
close(canSocket);
result = false;
}
}
}
/* Give the result back to the caller. */
return result;
} /*** end of SocketCanConnect ***/
/************************************************************************************//**
** \brief Disconnects the CAN interface.
**
****************************************************************************************/
static void SocketCanDisconnect(void)
{
/* Stop the event thread. */
SocketCanStopEventThread();
/* Close the socket. */
close(canSocket);
} /*** end of SocketCanDisconnect ***/
/************************************************************************************//**
** \brief Submits a message for transmission on the CAN bus.
** \param msg Pointer to CAN message structure.
** \return True if successful, false otherwise.
**
****************************************************************************************/
static bool SocketCanTransmit(tCanMsg const * msg)
{
bool result = false;
struct can_frame canTxFrame;
tCanEvents volatile const * pEvents;
/* Check parameters. */
assert(msg != NULL);
/* Only continue with valid parameters. */
if (msg != NULL) /*lint !e774 */
{
/* Construct the message frame. */
canTxFrame.can_id = msg->id;
if ((msg->id & CAN_MSG_EXT_ID_MASK) != 0)
{
canTxFrame.can_id &= ~CAN_MSG_EXT_ID_MASK;
canTxFrame.can_id |= CAN_EFF_FLAG;
}
canTxFrame.can_dlc = ((msg->dlc <= CAN_MSG_MAX_LEN) ? msg->dlc : CAN_MSG_MAX_LEN);
for (uint8_t idx = 0; idx < canTxFrame.can_dlc; idx++)
{
canTxFrame.data[idx] = msg->data[idx];
}
/* Submit the frame for transmission. */
if (write(canSocket, &canTxFrame, sizeof(struct can_frame)) == (ssize_t)sizeof(struct can_frame))
{
/* Update result value to success. */
result = true;
/* Trigger transmit complete event(s). */
pEvents = socketCanEventsList;
for (uint32_t idx = 0; idx < socketCanEventsEntries; idx++)
{
if (pEvents != NULL)
{
if (pEvents->MsgTxed != NULL)
{
pEvents->MsgTxed(msg);
}
/* Move on to the next entry in the list. */
pEvents++;
}
}
}
}
/* Give the result back to the caller. */
return result;
} /*** end of SocketCanTransmit ***/
/************************************************************************************//**
** \brief Checks if a bus off or bus heavy situation occurred.
** \return True if a bus error situation was detected, false otherwise.
**
****************************************************************************************/
static bool SocketCanIsBusError(void)
{
bool result= false;
/* The purpose of this function is that when an error is detected, SocketCanConnect()
* can be called to reset the error. With SocketCAN a bus off error is reset on
* network link level and not by this interface module. It is therefore not needed to
* check for the errors here. It is better to configure the automatic bus off recovery
* on network link level. For example:
* ip link set can0 type can bitrate 500000 restart-ms 100
* where "restart-ms <value>" specifies the number of milliseconds after which that
* automatic recovery is started.
*/
/* Give the result back to the caller. */
return result;
} /*** end of SocketCanIsBusError ***/
/************************************************************************************//**
** \brief Registers the event callback functions that should be called by the CAN
** interface.
** \param events Pointer to structure with event callback function pointers.
**
****************************************************************************************/
static void SocketCanRegisterEvents(tCanEvents const * events)
{
/* Check parameters. */
assert(events != NULL);
/* Only continue with valid parameters. */
if (events != NULL) /*lint !e774 */
{
/* Increase length of the list to make space for one more event entry. Note that
* it is okay to call realloc with a NULL pointer. In this case it simply behaves
* as malloc.
*/
socketCanEventsList = realloc((void *)socketCanEventsList,
(sizeof(tCanEvents) * (socketCanEventsEntries + 1)));
/* Assert reallocation. */
assert(socketCanEventsList != NULL);
/* Only continue if reallocation was successful. */
if (socketCanEventsList != NULL)
{
/* Increment events entry count. */
socketCanEventsEntries++;
/* Store the events in the new entry. */
socketCanEventsList[socketCanEventsEntries - 1] = *events;
}
/* Reallocation failed. */
else
{
/* Reset events entry count. */
socketCanEventsEntries = 0;
}
}
} /*** end of SocketCanRegisterEvents ***/
/************************************************************************************//**
** \brief Starts the event thread.
** \return True if the thread was successfully started, false otherwise.
**
****************************************************************************************/
static bool SocketCanStartEventThread(void)
{
bool result = false;
/* Prepare thread parameters. */
UtilCriticalSectionEnter();
eventThreadCtrl.terminate = false;
eventThreadCtrl.terminated = false;
UtilCriticalSectionExit();
/* Create and start the event thread */
if (pthread_create(&eventThreadId, NULL, &SocketCanEventThread, NULL) == 0) /*lint !e546 */
{
result = true;
}
/* Give the result back to the caller. */
return result;
} /*** end of SocketCanStartEventThread ***/
/************************************************************************************//**
** \brief Stops the event thread. It sets the termination request and then waits for
** the termination handshake.
** \return None.
**
****************************************************************************************/
static void SocketCanStopEventThread(void)
{
bool terminatedCpy = false;
/* Set the terminate request. */
UtilCriticalSectionEnter();
eventThreadCtrl.terminate = true;
UtilCriticalSectionExit();
/* Wait for thread to terminate. */
while (!terminatedCpy)
{
UtilCriticalSectionEnter();
terminatedCpy = eventThreadCtrl.terminated;
UtilCriticalSectionExit();
/* Wait a little without starving the CPU. */
UtilTimeDelayMs(10);
}
} /*** end of SocketCanStopEventThread ***/
/************************************************************************************//**
** \brief Event thread that handles the asynchronous reception of data from the CAN
** interface.
** \param arg Pointer to thread parameters.
** \return Thread return value. Not used in this case, so always set to NULL.
**
****************************************************************************************/
static void *SocketCanEventThread(void *param)
{
bool terminateRequest = false;
struct can_frame canRxFrame;
tCanMsg rxMsg;
tCanEvents volatile const * pEvents;
/* Unused parameter. */
(void)param;
/* Run thread as long as it is not requested to terminate. */
while (!terminateRequest)
{
/* Update termination request. */
UtilCriticalSectionEnter();
terminateRequest = eventThreadCtrl.terminate;
UtilCriticalSectionExit();
/* Check if CAN frames were received. */
while (read(canSocket, &canRxFrame, sizeof(struct can_frame)) == (ssize_t)sizeof(struct can_frame))
{
/* Ignore remote frames and error information. */
if ( (canRxFrame.can_id & CAN_RTR_FLAG) || (canRxFrame.can_id & CAN_ERR_FLAG) )
{
continue;
}
/* It was a regular CAN message with either 11- or 29-bit identifier. */
else
{
/* Copy it to the CAN message object */
rxMsg.id = canRxFrame.can_id;
if (rxMsg.id & CAN_EFF_FLAG)
{
rxMsg.id &= ~CAN_EFF_FLAG;
rxMsg.id |= CAN_MSG_EXT_ID_MASK;
}
rxMsg.dlc = canRxFrame.can_dlc;
for (uint8_t idx = 0; idx < rxMsg.dlc; idx++)
{
rxMsg.data[idx] = canRxFrame.data[idx];
}
/* Trigger message reception event(s). */
pEvents = socketCanEventsList;
for (uint32_t idx = 0; idx < socketCanEventsEntries; idx++)
{
if (pEvents != NULL)
{
if (pEvents->MsgRxed != NULL)
{
pEvents->MsgRxed(&rxMsg);
}
/* Move on to the next entry in the list. */
pEvents++;
}
}
}
}
/* Wait a little to not starve the CPU, but not too long to prevent interference with
* data throughput.
*/
(void)usleep(10u);
}
/* handshake */
UtilCriticalSectionEnter();
eventThreadCtrl.terminated = true;
UtilCriticalSectionExit();
/* exit the thread */
return NULL;
} /*** end of SocketCanEventThread ***/
/*********************************** end of socketcan.c ********************************/
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