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slcand: fix whitespace issues and unify coding style 

Fixed coding style inspired by Linux checkpatch.pl
Additionally removed a comment in the write() result check in the 'if (speed)'
statement to make sure the write() is not optimized away as the executed code
was empty.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
pull/1/head
Oliver Hartkopp 2013-09-15 21:54:37 +02:00
parent 94006e996d
commit 35d2bc1381
1 changed files with 106 additions and 117 deletions
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221
slcand.c
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@ -87,27 +87,28 @@ void print_usage(char *prg)
exit(EXIT_FAILURE); exit(EXIT_FAILURE);
} }
static int slcand_running = 0; static int slcand_running;
static int exit_code = 0; static int exit_code;
static char ttypath[TTYPATH_LENGTH]; static char ttypath[TTYPATH_LENGTH];
static char pidfile[PIDFILE_LENGTH]; static char pidfile[PIDFILE_LENGTH];
static void child_handler (int signum) static void child_handler(int signum)
{ {
switch (signum) { switch (signum) {
case SIGUSR1: case SIGUSR1:
/* exit parent */ /* exit parent */
exit(EXIT_SUCCESS); exit(EXIT_SUCCESS);
break; break;
case SIGALRM: case SIGALRM:
case SIGCHLD: case SIGCHLD:
syslog (LOG_NOTICE, "received signal %i on %s", signum, ttypath); syslog(LOG_NOTICE, "received signal %i on %s", signum, ttypath);
exit_code = EXIT_FAILURE; exit_code = EXIT_FAILURE;
slcand_running = 0; slcand_running = 0;
break; break;
case SIGINT: case SIGINT:
case SIGTERM: case SIGTERM:
syslog (LOG_NOTICE, "received signal %i on %s", signum, ttypath); syslog(LOG_NOTICE, "received signal %i on %s", signum, ttypath);
exit_code = EXIT_SUCCESS; exit_code = EXIT_SUCCESS;
slcand_running = 0; slcand_running = 0;
break; break;
@ -117,6 +118,7 @@ static void child_handler (int signum)
static int look_up_uart_speed(long int s) static int look_up_uart_speed(long int s)
{ {
switch (s) { switch (s) {
case 9600: case 9600:
return B9600; return B9600;
case 19200: case 19200:
@ -170,124 +172,119 @@ static int look_up_uart_speed(long int s)
} }
} }
static pid_t daemonize (const char *lockfile, char *tty, char *name) static pid_t daemonize(const char *lockfile, char *tty, char *name)
{ {
pid_t pid, sid, parent; pid_t pid, sid, parent;
int lfp = -1; int lfp = -1;
FILE * pFile; FILE *pFile;
FILE * dummyFile; FILE *dummyFile;
char const *pidprefix = "/var/run/"; char const *pidprefix = "/var/run/";
char const *pidsuffix = ".pid"; char const *pidsuffix = ".pid";
snprintf(pidfile, PIDFILE_LENGTH, "%s%s-%s%s", pidprefix, DAEMON_NAME, tty, pidsuffix); snprintf(pidfile, PIDFILE_LENGTH, "%s%s-%s%s", pidprefix, DAEMON_NAME, tty, pidsuffix);
/* already a daemon */ /* already a daemon */
if (getppid () == 1) if (getppid() == 1)
return 0; return 0;
/* Create the lock file as the current user */ /* Create the lock file as the current user */
if (lockfile && lockfile[0]) if (lockfile && lockfile[0]) {
{
lfp = open (lockfile, O_RDWR | O_CREAT, 0640); lfp = open(lockfile, O_RDWR | O_CREAT, 0640);
if (lfp < 0) if (lfp < 0)
{ {
syslog (LOG_ERR, "unable to create lock file %s, code=%d (%s)", syslog(LOG_ERR, "unable to create lock file %s, code=%d (%s)",
lockfile, errno, strerror (errno)); lockfile, errno, strerror(errno));
exit (EXIT_FAILURE); exit(EXIT_FAILURE);
} }
} }
/* Drop user if there is one, and we were run as root */ /* Drop user if there is one, and we were run as root */
if (getuid () == 0 || geteuid () == 0) if (getuid() == 0 || geteuid() == 0) {
{ struct passwd *pw = getpwnam(RUN_AS_USER);
struct passwd *pw = getpwnam (RUN_AS_USER);
if (pw) if (pw)
{ {
//syslog (LOG_NOTICE, "setting user to " RUN_AS_USER); /* syslog(LOG_NOTICE, "setting user to " RUN_AS_USER); */
setuid (pw->pw_uid); setuid(pw->pw_uid);
} }
} }
/* Trap signals that we expect to receive */ /* Trap signals that we expect to receive */
signal (SIGINT, child_handler); signal(SIGINT, child_handler);
signal (SIGTERM, child_handler); signal(SIGTERM, child_handler);
signal (SIGCHLD, child_handler); signal(SIGCHLD, child_handler);
signal (SIGUSR1, child_handler); signal(SIGUSR1, child_handler);
signal (SIGALRM, child_handler); signal(SIGALRM, child_handler);
/* Fork off the parent process */ /* Fork off the parent process */
pid = fork (); pid = fork();
if (pid < 0) if (pid < 0) {
{ syslog(LOG_ERR, "unable to fork daemon, code=%d (%s)",
syslog (LOG_ERR, "unable to fork daemon, code=%d (%s)", errno, strerror(errno));
errno, strerror (errno)); exit(EXIT_FAILURE);
exit (EXIT_FAILURE);
} }
/* If we got a good PID, then we can exit the parent process. */
if (pid > 0)
{
/* 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 /* Wait for confirmation from the child via SIGTERM or SIGCHLD, or
for five seconds to elapse (SIGALRM). pause() should not return. */ for five seconds to elapse (SIGALRM). pause() should not return. */
alarm (5); alarm(5);
pause (); pause();
exit (EXIT_FAILURE); exit(EXIT_FAILURE);
} }
/* At this point we are executing as the child process */ /* At this point we are executing as the child process */
parent = getppid (); parent = getppid();
/* Cancel certain signals */ /* Cancel certain signals */
signal (SIGCHLD, SIG_DFL); /* A child process dies */ signal(SIGCHLD, SIG_DFL); /* A child process dies */
signal (SIGTSTP, SIG_IGN); /* Various TTY signals */ signal(SIGTSTP, SIG_IGN); /* Various TTY signals */
signal (SIGTTOU, SIG_IGN); signal(SIGTTOU, SIG_IGN);
signal (SIGTTIN, SIG_IGN); signal(SIGTTIN, SIG_IGN);
signal (SIGHUP, SIG_IGN); /* Ignore hangup signal */ signal(SIGHUP, SIG_IGN); /* Ignore hangup signal */
signal (SIGINT, child_handler); signal(SIGINT, child_handler);
signal (SIGTERM, child_handler); signal(SIGTERM, child_handler);
/* Change the file mode mask */ /* Change the file mode mask */
umask (0); umask(0);
/* Create a new SID for the child process */ /* Create a new SID for the child process */
sid = setsid (); sid = setsid();
if (sid < 0) if (sid < 0) {
{ syslog(LOG_ERR, "unable to create a new session, code %d (%s)",
syslog (LOG_ERR, "unable to create a new session, code %d (%s)", errno, strerror(errno));
errno, strerror (errno)); exit(EXIT_FAILURE);
exit (EXIT_FAILURE);
} }
pFile = fopen (pidfile,"w"); pFile = fopen(pidfile, "w");
if (NULL == pFile) if (NULL == pFile) {
{ syslog(LOG_ERR, "unable to create pid file %s, code=%d (%s)",
syslog (LOG_ERR, "unable to create pid file %s, code=%d (%s)", pidfile, errno, strerror(errno));
pidfile, errno, strerror (errno)); exit(EXIT_FAILURE);
exit (EXIT_FAILURE);
} }
fprintf (pFile, "%d\n", sid); fprintf(pFile, "%d\n", sid);
fclose (pFile); fclose(pFile);
/* Change the current working directory. This prevents the current /* Change the current working directory. This prevents the current
directory from being locked; hence not being able to remove it. */ directory from being locked; hence not being able to remove it. */
if ((chdir ("/")) < 0) if (chdir("/") < 0) {
{ syslog(LOG_ERR, "unable to change directory to %s, code %d (%s)",
syslog (LOG_ERR, "unable to change directory to %s, code %d (%s)", "/", errno, strerror(errno));
"/", errno, strerror (errno)); exit(EXIT_FAILURE);
exit (EXIT_FAILURE);
} }
/* Redirect standard files to /dev/null */ /* Redirect standard files to /dev/null */
dummyFile = freopen ("/dev/null", "r", stdin); dummyFile = freopen("/dev/null", "r", stdin);
dummyFile = freopen ("/dev/null", "w", stdout); dummyFile = freopen("/dev/null", "w", stdout);
dummyFile = freopen ("/dev/null", "w", stderr); dummyFile = freopen("/dev/null", "w", stderr);
/* Tell the parent process that we are A-okay */ /* Tell the parent process that we are A-okay */
//kill (parent, SIGUSR1); /* kill(parent, SIGUSR1); */
return parent; return parent;
} }
int main (int argc, char *argv[]) int main(int argc, char *argv[])
{ {
char *tty = NULL; char *tty = NULL;
char const *devprefix = "/dev/"; char const *devprefix = "/dev/";
@ -307,6 +304,9 @@ int main (int argc, char *argv[])
char *btr = NULL; char *btr = NULL;
int run_as_daemon = 1; int run_as_daemon = 1;
pid_t parent_pid = 0; pid_t parent_pid = 0;
char *pch;
int ldisc = LDISC_N_SLCAN;
int fd;
ttypath[0] = '\0'; ttypath[0] = '\0';
@ -354,53 +354,48 @@ int main (int argc, char *argv[])
} }
/* Initialize the logging interface */ /* Initialize the logging interface */
openlog (DAEMON_NAME, LOG_PID, LOG_LOCAL5); openlog(DAEMON_NAME, LOG_PID, LOG_LOCAL5);
/* Parse serial device name and optional can interface name */ /* Parse serial device name and optional can interface name */
tty = argv[optind]; tty = argv[optind];
if(NULL == tty) { if (NULL == tty)
print_usage(argv[0]); print_usage(argv[0]);
}
name = argv[optind + 1]; name = argv[optind + 1];
/* Prepare the tty device name string */ /* Prepare the tty device name string */
char * pch; pch = strstr(tty, devprefix);
pch = strstr (tty, devprefix); if (pch == tty)
if (pch == tty) {
print_usage(argv[0]); print_usage(argv[0]);
}
snprintf (ttypath, TTYPATH_LENGTH, "%s%s", devprefix, tty); snprintf(ttypath, TTYPATH_LENGTH, "%s%s", devprefix, tty);
syslog (LOG_INFO, "starting on TTY device %s", ttypath); syslog(LOG_INFO, "starting on TTY device %s", ttypath);
/* Daemonize */ /* Daemonize */
if(run_as_daemon) { if (run_as_daemon)
parent_pid = daemonize ("/var/lock/" DAEMON_NAME, tty, name); parent_pid = daemonize("/var/lock/" DAEMON_NAME, tty, name);
}
else { else {
/* Trap signals that we expect to receive */ /* Trap signals that we expect to receive */
signal (SIGINT, child_handler); signal(SIGINT, child_handler);
signal (SIGTERM, child_handler); signal(SIGTERM, child_handler);
} }
/* */ /* */
slcand_running = 1; slcand_running = 1;
/* Now we are a daemon -- do the work for which we were paid */ /* Now we are a daemon -- do the work for which we were paid */
int fd; fd = open(ttypath, O_RDWR | O_NONBLOCK | O_NOCTTY);
int ldisc = LDISC_N_SLCAN; if (fd < 0) {
syslog(LOG_NOTICE, "failed to open TTY device %s\n", ttypath);
if ((fd = open (ttypath, O_RDWR | O_NONBLOCK | O_NOCTTY )) < 0) {
syslog (LOG_NOTICE, "failed to open TTY device %s\n", ttypath);
perror(ttypath); perror(ttypath);
exit(EXIT_FAILURE); exit(EXIT_FAILURE);
} }
/* Configure baud rate */ /* Configure baud rate */
memset(&tios, 0, sizeof(struct termios)); memset(&tios, 0, sizeof(struct termios));
if(tcgetattr(fd, &tios) < 0) { if (tcgetattr(fd, &tios) < 0) {
syslog (LOG_NOTICE, "failed to get attributes for TTY device %s: %s\n", ttypath, strerror(errno)); syslog(LOG_NOTICE, "failed to get attributes for TTY device %s: %s\n", ttypath, strerror(errno));
exit (EXIT_FAILURE); exit(EXIT_FAILURE);
} }
/* Get old values for later restore */ /* Get old values for later restore */
@ -412,15 +407,12 @@ int main (int argc, char *argv[])
cfsetospeed(&tios, look_up_uart_speed(uart_speed)); cfsetospeed(&tios, look_up_uart_speed(uart_speed));
/* apply changes */ /* apply changes */
if(tcsetattr(fd, TCSADRAIN, &tios) < 0) { if (tcsetattr(fd, TCSADRAIN, &tios) < 0)
syslog(LOG_NOTICE, "Cannot set attributes for device \"%s\": %s!\n", ttypath, strerror(errno)); syslog(LOG_NOTICE, "Cannot set attributes for device \"%s\": %s!\n", ttypath, strerror(errno));
}
if (speed) { if (speed) {
sprintf(buf, "C\rS%s\r", speed); sprintf(buf, "C\rS%s\r", speed);
if(write(fd, buf, strlen(buf)) < 0) { write(fd, buf, strlen(buf));
//syslog (LO, "failed to get attributes for TTY device %s: %s\n", ttypath, strerror(errno));
}
} }
if (btr) { if (btr) {
@ -439,52 +431,51 @@ int main (int argc, char *argv[])
} }
/* set slcan like discipline on given tty */ /* set slcan like discipline on given tty */
if (ioctl (fd, TIOCSETD, &ldisc) < 0) { if (ioctl(fd, TIOCSETD, &ldisc) < 0) {
perror("ioctl TIOCSETD"); perror("ioctl TIOCSETD");
exit(1); exit(1);
} }
/* retrieve the name of the created CAN netdevice */ /* retrieve the name of the created CAN netdevice */
if (ioctl (fd, SIOCGIFNAME, buf) < 0) { if (ioctl(fd, SIOCGIFNAME, buf) < 0) {
perror("ioctl SIOCGIFNAME"); perror("ioctl SIOCGIFNAME");
exit(1); exit(1);
} }
syslog (LOG_NOTICE, "attached TTY %s to netdevice %s\n", ttypath, buf); syslog(LOG_NOTICE, "attached TTY %s to netdevice %s\n", ttypath, buf);
/* try to rename the created netdevice */ /* try to rename the created netdevice */
if (name) { if (name) {
struct ifreq ifr; struct ifreq ifr;
int s = socket(PF_INET, SOCK_DGRAM, 0); int s = socket(PF_INET, SOCK_DGRAM, 0);
if (s < 0) if (s < 0)
perror("socket for interface rename"); perror("socket for interface rename");
else { else {
strncpy (ifr.ifr_name, buf, IFNAMSIZ); strncpy(ifr.ifr_name, buf, IFNAMSIZ);
strncpy (ifr.ifr_newname, name, IFNAMSIZ); strncpy(ifr.ifr_newname, name, IFNAMSIZ);
if (ioctl(s, SIOCSIFNAME, &ifr) < 0) { if (ioctl(s, SIOCSIFNAME, &ifr) < 0) {
syslog (LOG_NOTICE, "netdevice %s rename to %s failed\n", buf, name); syslog(LOG_NOTICE, "netdevice %s rename to %s failed\n", buf, name);
perror("ioctl SIOCSIFNAME rename"); perror("ioctl SIOCSIFNAME rename");
exit(1); exit(1);
} else } else
syslog (LOG_NOTICE, "netdevice %s renamed to %s\n", buf, name); syslog(LOG_NOTICE, "netdevice %s renamed to %s\n", buf, name);
close(s); close(s);
} }
} }
if(parent_pid > 0) { if (parent_pid > 0)
kill(parent_pid, SIGUSR1); kill(parent_pid, SIGUSR1);
}
/* The Big Loop */ /* The Big Loop */
while (slcand_running) { while (slcand_running)
sleep(1); /* wait 1 second */ sleep(1); /* wait 1 second */
}
/* Reset line discipline */ /* Reset line discipline */
syslog (LOG_INFO, "stopping on TTY device %s", ttypath); syslog(LOG_INFO, "stopping on TTY device %s", ttypath);
ldisc = N_TTY; ldisc = N_TTY;
if (ioctl (fd, TIOCSETD, &ldisc) < 0) { if (ioctl(fd, TIOCSETD, &ldisc) < 0) {
perror("ioctl TIOCSETD"); perror("ioctl TIOCSETD");
exit(EXIT_FAILURE); exit(EXIT_FAILURE);
} }
@ -499,17 +490,15 @@ int main (int argc, char *argv[])
cfsetospeed(&tios, old_ospeed); cfsetospeed(&tios, old_ospeed);
/* apply changes */ /* apply changes */
if(tcsetattr(fd, TCSADRAIN, &tios) < 0) { if (tcsetattr(fd, TCSADRAIN, &tios) < 0)
syslog(LOG_NOTICE, "Cannot set attributes for device \"%s\": %s!\n", ttypath, strerror(errno)); syslog(LOG_NOTICE, "Cannot set attributes for device \"%s\": %s!\n", ttypath, strerror(errno));
}
/* Remove pidfile */ /* Remove pidfile */
if(run_as_daemon) { if (run_as_daemon)
unlink(pidfile); unlink(pidfile);
}
/* Finish up */ /* Finish up */
syslog (LOG_NOTICE, "terminated on %s", ttypath); syslog(LOG_NOTICE, "terminated on %s", ttypath);
closelog (); closelog();
return exit_code; return exit_code;
} }