398 lines
9.1 KiB
C
Executable File
398 lines
9.1 KiB
C
Executable File
/*
|
|
* slcand.c - userspace daemon for serial line CAN interface driver SLCAN
|
|
*
|
|
* Copyright (c) 2009 Robert Haddon <robert.haddon@verari.com>
|
|
* Copyright (c) 2009 Verari Systems Inc.
|
|
*
|
|
* This program 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 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program 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 should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*
|
|
* Send feedback to <linux-can@vger.kernel.org>
|
|
*
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/socket.h>
|
|
#include <fcntl.h>
|
|
#include <syslog.h>
|
|
#include <errno.h>
|
|
#include <pwd.h>
|
|
#include <signal.h>
|
|
#include <sys/ioctl.h>
|
|
#include <net/if.h>
|
|
#include <termios.h>
|
|
#include <linux/tty.h>
|
|
|
|
/* Change this to whatever your daemon is called */
|
|
#define DAEMON_NAME "slcand"
|
|
|
|
/* Change this to the user under which to run */
|
|
#define RUN_AS_USER "root"
|
|
|
|
/* The length of ttypath buffer */
|
|
#define TTYPATH_LENGTH 64
|
|
|
|
/* UART flow control types */
|
|
#define FLOW_NONE 0
|
|
#define FLOW_HW 1
|
|
#define FLOW_SW 2
|
|
|
|
void print_usage(char *prg)
|
|
{
|
|
fprintf(stderr, "\nUsage: %s [options] <tty> [canif-name]\n\n", prg);
|
|
fprintf(stderr, "Options: -o (send open command 'O\\r')\n");
|
|
fprintf(stderr, " -c (send close command 'C\\r')\n");
|
|
fprintf(stderr, " -f (read status flags with 'F\\r' to reset error states)\n");
|
|
fprintf(stderr, " -s <speed> (set CAN speed 0..8)\n");
|
|
fprintf(stderr, " -S <speed> (set UART speed in baud)\n");
|
|
fprintf(stderr, " -t <type> (set UART flow control type 'hw' or 'sw')\n");
|
|
fprintf(stderr, " -b <btr> (set bit time register value)\n");
|
|
fprintf(stderr, " -F (stay in foreground; no daemonize)\n");
|
|
fprintf(stderr, " -h (show this help page)\n");
|
|
fprintf(stderr, "\nExamples:\n");
|
|
fprintf(stderr, "slcand -o -c -f -s6 ttyUSB0\n");
|
|
fprintf(stderr, "slcand -o -c -f -s6 ttyUSB0 can0\n");
|
|
fprintf(stderr, "slcand -o -c -f -s6 /dev/ttyUSB0\n");
|
|
fprintf(stderr, "\n");
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
static int slcand_running;
|
|
static int exit_code;
|
|
static char ttypath[TTYPATH_LENGTH];
|
|
|
|
static void child_handler(int signum)
|
|
{
|
|
switch (signum) {
|
|
|
|
case SIGUSR1:
|
|
/* exit parent */
|
|
exit(EXIT_SUCCESS);
|
|
break;
|
|
case SIGALRM:
|
|
case SIGCHLD:
|
|
syslog(LOG_NOTICE, "received signal %i on %s", signum, ttypath);
|
|
exit_code = EXIT_FAILURE;
|
|
slcand_running = 0;
|
|
break;
|
|
case SIGINT:
|
|
case SIGTERM:
|
|
syslog(LOG_NOTICE, "received signal %i on %s", signum, ttypath);
|
|
exit_code = EXIT_SUCCESS;
|
|
slcand_running = 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int look_up_uart_speed(long int s)
|
|
{
|
|
switch (s) {
|
|
|
|
case 9600:
|
|
return B9600;
|
|
case 19200:
|
|
return B19200;
|
|
case 38400:
|
|
return B38400;
|
|
case 57600:
|
|
return B57600;
|
|
case 115200:
|
|
return B115200;
|
|
case 230400:
|
|
return B230400;
|
|
case 460800:
|
|
return B460800;
|
|
case 500000:
|
|
return B500000;
|
|
case 576000:
|
|
return B576000;
|
|
case 921600:
|
|
return B921600;
|
|
case 1000000:
|
|
return B1000000;
|
|
case 1152000:
|
|
return B1152000;
|
|
case 1500000:
|
|
return B1500000;
|
|
case 2000000:
|
|
return B2000000;
|
|
#ifdef B2500000
|
|
case 2500000:
|
|
return B2500000;
|
|
#endif
|
|
#ifdef B3000000
|
|
case 3000000:
|
|
return B3000000;
|
|
#endif
|
|
#ifdef B3500000
|
|
case 3500000:
|
|
return B3500000;
|
|
#endif
|
|
#ifdef B3710000
|
|
case 3710000
|
|
return B3710000;
|
|
#endif
|
|
#ifdef B4000000
|
|
case 4000000:
|
|
return B4000000;
|
|
#endif
|
|
default:
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
int main(int argc, char *argv[])
|
|
{
|
|
char *tty = NULL;
|
|
char const *devprefix = "/dev/";
|
|
char *name = NULL;
|
|
char buf[IFNAMSIZ+1];
|
|
struct termios tios;
|
|
speed_t old_ispeed;
|
|
speed_t old_ospeed;
|
|
|
|
int opt;
|
|
int send_open = 0;
|
|
int send_close = 0;
|
|
int send_read_status_flags = 0;
|
|
char *speed = NULL;
|
|
char *uart_speed_str = NULL;
|
|
long int uart_speed = 0;
|
|
int flow_type = FLOW_NONE;
|
|
char *btr = NULL;
|
|
int run_as_daemon = 1;
|
|
char *pch;
|
|
int ldisc = N_SLCAN;
|
|
int fd;
|
|
|
|
ttypath[0] = '\0';
|
|
|
|
while ((opt = getopt(argc, argv, "ocfs:S:t:b:?hF")) != -1) {
|
|
switch (opt) {
|
|
case 'o':
|
|
send_open = 1;
|
|
break;
|
|
case 'c':
|
|
send_close = 1;
|
|
break;
|
|
case 'f':
|
|
send_read_status_flags = 1;
|
|
break;
|
|
case 's':
|
|
speed = optarg;
|
|
if (strlen(speed) > 1)
|
|
print_usage(argv[0]);
|
|
break;
|
|
case 'S':
|
|
uart_speed_str = optarg;
|
|
errno = 0;
|
|
uart_speed = strtol(uart_speed_str, NULL, 10);
|
|
if (errno)
|
|
print_usage(argv[0]);
|
|
if (look_up_uart_speed(uart_speed) == -1) {
|
|
fprintf(stderr, "Unsupported UART speed (%lu)\n", uart_speed);
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
break;
|
|
case 't':
|
|
if (!strcmp(optarg, "hw")) {
|
|
flow_type = FLOW_HW;
|
|
} else if (!strcmp(optarg, "sw")) {
|
|
flow_type = FLOW_SW;
|
|
} else {
|
|
fprintf(stderr, "Unsupported flow type (%s)\n", optarg);
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
break;
|
|
case 'b':
|
|
btr = optarg;
|
|
if (strlen(btr) > 6)
|
|
print_usage(argv[0]);
|
|
break;
|
|
case 'F':
|
|
run_as_daemon = 0;
|
|
break;
|
|
case 'h':
|
|
case '?':
|
|
default:
|
|
print_usage(argv[0]);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Initialize the logging interface */
|
|
openlog(DAEMON_NAME, LOG_PID, LOG_LOCAL5);
|
|
|
|
/* Parse serial device name and optional can interface name */
|
|
tty = argv[optind];
|
|
if (NULL == tty)
|
|
print_usage(argv[0]);
|
|
|
|
name = argv[optind + 1];
|
|
|
|
/* Prepare the tty device name string */
|
|
pch = strstr(tty, devprefix);
|
|
if (pch != tty)
|
|
snprintf(ttypath, TTYPATH_LENGTH, "%s%s", devprefix, tty);
|
|
else
|
|
snprintf(ttypath, TTYPATH_LENGTH, "%s", tty);
|
|
|
|
syslog(LOG_INFO, "starting on TTY device %s", ttypath);
|
|
|
|
/* Daemonize */
|
|
if (run_as_daemon) {
|
|
if (daemon(0, 0)) {
|
|
syslog(LOG_ERR, "failed to daemonize");
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
}
|
|
else {
|
|
/* Trap signals that we expect to receive */
|
|
signal(SIGINT, child_handler);
|
|
signal(SIGTERM, child_handler);
|
|
}
|
|
|
|
/* */
|
|
slcand_running = 1;
|
|
|
|
/* Now we are a daemon -- do the work for which we were paid */
|
|
fd = open(ttypath, O_RDWR | O_NONBLOCK | O_NOCTTY);
|
|
if (fd < 0) {
|
|
syslog(LOG_NOTICE, "failed to open TTY device %s\n", ttypath);
|
|
perror(ttypath);
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
/* Configure baud rate */
|
|
memset(&tios, 0, sizeof(struct termios));
|
|
if (tcgetattr(fd, &tios) < 0) {
|
|
syslog(LOG_NOTICE, "failed to get attributes for TTY device %s: %s\n", ttypath, strerror(errno));
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
/* Get old values for later restore */
|
|
old_ispeed = cfgetispeed(&tios);
|
|
old_ospeed = cfgetospeed(&tios);
|
|
|
|
/* Reset UART settings */
|
|
cfmakeraw(&tios);
|
|
tios.c_iflag &= ~IXOFF;
|
|
tios.c_cflag &= ~CRTSCTS;
|
|
|
|
/* Baud Rate */
|
|
cfsetispeed(&tios, look_up_uart_speed(uart_speed));
|
|
cfsetospeed(&tios, look_up_uart_speed(uart_speed));
|
|
|
|
/* Flow control */
|
|
if (flow_type == FLOW_HW)
|
|
tios.c_cflag |= CRTSCTS;
|
|
else if (flow_type == FLOW_SW)
|
|
tios.c_iflag |= (IXON | IXOFF);
|
|
|
|
/* apply changes */
|
|
if (tcsetattr(fd, TCSADRAIN, &tios) < 0)
|
|
syslog(LOG_NOTICE, "Cannot set attributes for device \"%s\": %s!\n", ttypath, strerror(errno));
|
|
|
|
if (speed) {
|
|
sprintf(buf, "C\rS%s\r", speed);
|
|
write(fd, buf, strlen(buf));
|
|
}
|
|
|
|
if (btr) {
|
|
sprintf(buf, "C\rs%s\r", btr);
|
|
write(fd, buf, strlen(buf));
|
|
}
|
|
|
|
if (send_read_status_flags) {
|
|
sprintf(buf, "F\r");
|
|
write(fd, buf, strlen(buf));
|
|
}
|
|
|
|
if (send_open) {
|
|
sprintf(buf, "O\r");
|
|
write(fd, buf, strlen(buf));
|
|
}
|
|
|
|
/* set slcan like discipline on given tty */
|
|
if (ioctl(fd, TIOCSETD, &ldisc) < 0) {
|
|
perror("ioctl TIOCSETD");
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
/* retrieve the name of the created CAN netdevice */
|
|
if (ioctl(fd, SIOCGIFNAME, buf) < 0) {
|
|
perror("ioctl SIOCGIFNAME");
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
syslog(LOG_NOTICE, "attached TTY %s to netdevice %s\n", ttypath, buf);
|
|
|
|
/* try to rename the created netdevice */
|
|
if (name) {
|
|
struct ifreq ifr;
|
|
int s = socket(PF_INET, SOCK_DGRAM, 0);
|
|
|
|
if (s < 0)
|
|
perror("socket for interface rename");
|
|
else {
|
|
strncpy(ifr.ifr_name, buf, IFNAMSIZ);
|
|
strncpy(ifr.ifr_newname, name, IFNAMSIZ);
|
|
|
|
if (ioctl(s, SIOCSIFNAME, &ifr) < 0) {
|
|
syslog(LOG_NOTICE, "netdevice %s rename to %s failed\n", buf, name);
|
|
perror("ioctl SIOCSIFNAME rename");
|
|
exit(EXIT_FAILURE);
|
|
} else
|
|
syslog(LOG_NOTICE, "netdevice %s renamed to %s\n", buf, name);
|
|
|
|
close(s);
|
|
}
|
|
}
|
|
|
|
/* The Big Loop */
|
|
while (slcand_running)
|
|
sleep(1); /* wait 1 second */
|
|
|
|
/* Reset line discipline */
|
|
syslog(LOG_INFO, "stopping on TTY device %s", ttypath);
|
|
ldisc = N_TTY;
|
|
if (ioctl(fd, TIOCSETD, &ldisc) < 0) {
|
|
perror("ioctl TIOCSETD");
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
if (send_close) {
|
|
sprintf(buf, "C\r");
|
|
write(fd, buf, strlen(buf));
|
|
}
|
|
|
|
/* Reset old rates */
|
|
cfsetispeed(&tios, old_ispeed);
|
|
cfsetospeed(&tios, old_ospeed);
|
|
|
|
/* apply changes */
|
|
if (tcsetattr(fd, TCSADRAIN, &tios) < 0)
|
|
syslog(LOG_NOTICE, "Cannot set attributes for device \"%s\": %s!\n", ttypath, strerror(errno));
|
|
|
|
/* Finish up */
|
|
syslog(LOG_NOTICE, "terminated on %s", ttypath);
|
|
closelog();
|
|
return exit_code;
|
|
}
|