* 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 <linux-can@vger.kernel.org>
*
*/
/* The length of ttypath buffer */
#define TTYPATH_LENGTH 64
-/* The length of pidfile name buffer */
-#define PIDFILE_LENGTH 64
-
#define EXIT_SUCCESS 0
#define EXIT_FAILURE 1
+/* 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, " -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");
static int slcand_running;
static int exit_code;
static char ttypath[TTYPATH_LENGTH];
-static char pidfile[PIDFILE_LENGTH];
static void child_handler(int signum)
{
}
}
-static pid_t daemonize(const char *lockfile, char *tty, char *name)
-{
- pid_t pid, sid, parent;
- int lfp = -1;
- FILE *pFile;
- char const *pidprefix = "/var/run/";
- char const *pidsuffix = ".pid";
-
- snprintf(pidfile, PIDFILE_LENGTH, "%s%s-%s%s", pidprefix, DAEMON_NAME, tty, pidsuffix);
-
- /* already a daemon */
- if (getppid() == 1)
- return 0;
-
- /* 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);
- }
- }
-
- /* 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);
- }
- }
-
- /* Trap signals that we expect to receive */
- signal(SIGINT, child_handler);
- signal(SIGTERM, child_handler);
- 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) {
- /* Wait for confirmation from the child via SIGTERM or SIGCHLD, or
- for five seconds to elapse (SIGALRM). pause() should not return. */
- alarm(5);
- pause();
- exit(EXIT_FAILURE);
- }
-
- /* 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(SIGINT, child_handler);
- signal(SIGTERM, child_handler);
-
- /* 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);
- }
-
- pFile = fopen(pidfile, "w");
- if (NULL == pFile) {
- syslog(LOG_ERR, "unable to create pid file %s, code=%d (%s)",
- pidfile, errno, strerror(errno));
- 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);
- }
-
- /* Redirect standard files to /dev/null */
- pFile = freopen("/dev/null", "r", stdin);
- pFile = freopen("/dev/null", "w", stdout);
- pFile = freopen("/dev/null", "w", stderr);
-
- /* Tell the parent process that we are A-okay */
- /* kill(parent, SIGUSR1); */
- return parent;
-}
-
int main(int argc, char *argv[])
{
char *tty = NULL;
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;
- pid_t parent_pid = 0;
char *pch;
int ldisc = LDISC_N_SLCAN;
int fd;
ttypath[0] = '\0';
- while ((opt = getopt(argc, argv, "ocfs:S:b:?hF")) != -1) {
+ while ((opt = getopt(argc, argv, "ocfs:S:t:b:?hF")) != -1) {
switch (opt) {
case 'o':
send_open = 1;
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)
/* Prepare the tty device name string */
pch = strstr(tty, devprefix);
- if (pch == tty)
- print_usage(argv[0]);
+ if (pch != tty)
+ snprintf(ttypath, TTYPATH_LENGTH, "%s%s", devprefix, tty);
+ else
+ snprintf(ttypath, TTYPATH_LENGTH, "%s", tty);
- snprintf(ttypath, TTYPATH_LENGTH, "%s%s", devprefix, tty);
syslog(LOG_INFO, "starting on TTY device %s", ttypath);
/* Daemonize */
- if (run_as_daemon)
- parent_pid = daemonize("/var/lock/" DAEMON_NAME, tty, name);
+ 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);
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));
close(s);
}
}
- if (parent_pid > 0)
- kill(parent_pid, SIGUSR1);
/* The Big Loop */
while (slcand_running)
if (tcsetattr(fd, TCSADRAIN, &tios) < 0)
syslog(LOG_NOTICE, "Cannot set attributes for device \"%s\": %s!\n", ttypath, strerror(errno));
- /* Remove pidfile */
- if (run_as_daemon)
- unlink(pidfile);
-
/* Finish up */
syslog(LOG_NOTICE, "terminated on %s", ttypath);
closelog();
projects / can-utils.git / blobdiff