-/*
- * $Id$
- */
-
/*
* slcand.c - userspace daemon for serial line CAN interface driver SLCAN
*
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
- * This code is derived from an example daemon code from
- *
- * http://en.wikipedia.org/wiki/Daemon_(computer_software)#Sample_Program_in_C_on_Linux
- * (accessed 2009-05-05)
- *
- * So it is additionally licensed under the GNU Free Documentation License:
- *
- * Permission is granted to copy, distribute and/or modify this document
- * under the terms of the GNU Free Documentation License, Version 1.2
- * or any later version published by the Free Software Foundation;
- * with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
- * A copy of the license is included in the section entitled "GNU
- * Free Documentation License".
- *
- * Send feedback to <socketcan-users@lists.berlios.de>
+ * Send feedback to <linux-can@vger.kernel.org>
*
*/
#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>
-
-/* default slcan line discipline since Kernel 2.6.25 */
-#define LDISC_N_SLCAN 17
+#include <net/if.h>
+#include <termios.h>
+#include <linux/tty.h>
+#include <linux/sockios.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"
-#define EXIT_SUCCESS 0
-#define EXIT_FAILURE 1
+/* 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 tty\n\n", prg);
- fprintf(stderr, "Example:\n");
- fprintf(stderr, "%s ttyUSB1\n", prg);
- fprintf(stderr, "%s ttyS0\n", 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, " -l (send listen only command 'L\\r', overrides -o)\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 void child_handler (int signum)
+static int slcand_running;
+static int exit_code;
+static char ttypath[TTYPATH_LENGTH];
+
+static void child_handler(int signum)
{
- switch (signum)
- {
- case SIGALRM:
- exit (EXIT_FAILURE);
- break;
+ switch (signum) {
+
case SIGUSR1:
- exit (EXIT_SUCCESS);
+ /* exit parent */
+ exit(EXIT_SUCCESS);
break;
+ case SIGALRM:
case SIGCHLD:
- exit (EXIT_FAILURE);
+ 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 void daemonize (const char *lockfile, char *tty)
+static int look_up_uart_speed(long int s)
{
- pid_t pid, sid, parent;
- int lfp = -1;
- FILE * pFile;
- char const *pidprefix = "/var/run/";
- char const *pidsuffix = ".pid";
- char *pidfile;
- pidfile = malloc((strlen(pidprefix) +strlen(DAEMON_NAME) + strlen(tty) + strlen(pidsuffix) + 1) * sizeof(char));
- sprintf(pidfile, "%s%s-%s%s", pidprefix, DAEMON_NAME, tty, pidsuffix);
-
- /* already a daemon */
- if (getppid () == 1)
- return;
-
- /* Create the lock file as the current user */
- if (lockfile && lockfile[0])
- {
- lfp = open (lockfile, O_RDWR | O_CREAT, 0640);
- if (lfp < 0)
- {
- syslog (LOG_ERR, "unable to create lock file %s, code=%d (%s)",
- lockfile, errno, strerror (errno));
- exit (EXIT_FAILURE);
- }
+ 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_listen = 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;
- /* Drop user if there is one, and we were run as root */
- if (getuid () == 0 || geteuid () == 0)
- {
- struct passwd *pw = getpwnam (RUN_AS_USER);
- if (pw)
- {
- syslog (LOG_NOTICE, "setting user to " RUN_AS_USER);
- setuid (pw->pw_uid);
+ ttypath[0] = '\0';
+
+ while ((opt = getopt(argc, argv, "ocfls: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 'l':
+ send_listen = 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;
}
}
- /* Trap signals that we expect to receive */
- signal (SIGCHLD, child_handler);
- signal (SIGUSR1, child_handler);
- signal (SIGALRM, child_handler);
-
- /* Fork off the parent process */
- pid = fork ();
- if (pid < 0)
- {
- syslog (LOG_ERR, "unable to fork daemon, code=%d (%s)",
- errno, strerror (errno));
- exit (EXIT_FAILURE);
- }
- /* If we got a good PID, then we can exit the parent process. */
- if (pid > 0)
- {
+ /* Initialize the logging interface */
+ openlog(DAEMON_NAME, LOG_PID, LOG_LOCAL5);
- /* Wait for confirmation from the child via SIGTERM or SIGCHLD, or
- for two seconds to elapse (SIGALRM). pause() should not return. */
- alarm (2);
- pause ();
+ /* Parse serial device name and optional can interface name */
+ tty = argv[optind];
+ if (NULL == tty)
+ print_usage(argv[0]);
- exit (EXIT_FAILURE);
- }
+ 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);
- /* At this point we are executing as the child process */
- parent = getppid ();
-
- /* Cancel certain signals */
- signal (SIGCHLD, SIG_DFL); /* A child process dies */
- signal (SIGTSTP, SIG_IGN); /* Various TTY signals */
- signal (SIGTTOU, SIG_IGN);
- signal (SIGTTIN, SIG_IGN);
- signal (SIGHUP, SIG_IGN); /* Ignore hangup signal */
- signal (SIGTERM, SIG_DFL); /* Die on SIGTERM */
-
- /* Change the file mode mask */
- umask (0);
-
- /* Create a new SID for the child process */
- sid = setsid ();
- if (sid < 0)
- {
- syslog (LOG_ERR, "unable to create a new session, code %d (%s)",
- errno, strerror (errno));
- exit (EXIT_FAILURE);
+ /* 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;
- pFile = fopen (pidfile,"w");
- if (pFile < 0)
- {
- syslog (LOG_ERR, "unable to create pid file %s, code=%d (%s)",
- pidfile, errno, strerror (errno));
- exit (EXIT_FAILURE);
+ /* 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);
}
- fprintf (pFile, "%d\n", sid);
- fclose (pFile);
-
- /* Change the current working directory. This prevents the current
- directory from being locked; hence not being able to remove it. */
- if ((chdir ("/")) < 0)
- {
- syslog (LOG_ERR, "unable to change directory to %s, code %d (%s)",
- "/", errno, strerror (errno));
- 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);
}
- /* Redirect standard files to /dev/null */
- freopen ("/dev/null", "r", stdin);
- freopen ("/dev/null", "w", stdout);
- freopen ("/dev/null", "w", stderr);
+ /* Get old values for later restore */
+ old_ispeed = cfgetispeed(&tios);
+ old_ospeed = cfgetospeed(&tios);
- /* Tell the parent process that we are A-okay */
- kill (parent, SIGUSR1);
-}
+ /* Reset UART settings */
+ cfmakeraw(&tios);
+ tios.c_iflag &= ~IXOFF;
+ tios.c_cflag &= ~CRTSCTS;
-int main (int argc, char *argv[])
-{
- char *tty;
- char *ttypath;
- char const *devprefix = "/dev/";
+ /* Baud Rate */
+ cfsetispeed(&tios, look_up_uart_speed(uart_speed));
+ cfsetospeed(&tios, look_up_uart_speed(uart_speed));
- /* Initialize the logging interface */
- openlog (DAEMON_NAME, LOG_PID, LOG_LOCAL5);
+ /* Flow control */
+ if (flow_type == FLOW_HW)
+ tios.c_cflag |= CRTSCTS;
+ else if (flow_type == FLOW_SW)
+ tios.c_iflag |= (IXON | IXOFF);
- /* See how we're called */
- if (argc != 2)
- print_usage(argv[0]);
- tty = argv[1];
+ /* apply changes */
+ if (tcsetattr(fd, TCSADRAIN, &tios) < 0)
+ syslog(LOG_NOTICE, "Cannot set attributes for device \"%s\": %s!\n", ttypath, strerror(errno));
- /* Prepare the tty device name string */
- char * pch;
- pch = strstr (tty, devprefix);
- if (pch == tty) {
- print_usage(argv[0]);
+ if (speed) {
+ sprintf(buf, "C\rS%s\r", speed);
+ write(fd, buf, strlen(buf));
}
- ttypath = malloc((strlen(devprefix) + strlen(tty)) * sizeof(char));
- sprintf (ttypath, "%s%s", devprefix, tty);
- syslog (LOG_INFO, "starting on TTY device %s", ttypath);
- /* Daemonize */
- daemonize ("/var/lock/" DAEMON_NAME, tty);
+ if (btr) {
+ sprintf(buf, "C\rs%s\r", btr);
+ write(fd, buf, strlen(buf));
+ }
- /* Now we are a daemon -- do the work for which we were paid */
- int fd;
- int ldisc = LDISC_N_SLCAN;
+ if (send_read_status_flags) {
+ sprintf(buf, "F\r");
+ write(fd, buf, strlen(buf));
+ }
- if ((fd = open (ttypath, O_WRONLY | O_NOCTTY )) < 0) {
- perror(ttypath);
- exit(1);
+ if (send_listen) {
+ sprintf(buf, "L\r");
+ write(fd, buf, strlen(buf));
+ } else if (send_open) {
+ sprintf(buf, "O\r");
+ write(fd, buf, strlen(buf));
}
- if (ioctl (fd, TIOCSETD, &ldisc) < 0) {
- perror("ioctl");
- exit(1);
+ /* 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 (1) {
- sleep(60); /* wait 60 seconds */
+ 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 0;
+ syslog(LOG_NOTICE, "terminated on %s", ttypath);
+ closelog();
+ return exit_code;
}
projects / can-utils.git / blobdiff