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Merge pull request #37 from kohtala/master 

isotptun: add option to daemonize (-D)
pull/39/merge
Marc Kleine-Budde 2017-02-16 14:26:13 +01:00 committed by GitHub
parent 99f1664e0c 35f3dc375b
commit cb33a55720
1 changed files with 78 additions and 32 deletions
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110
isotptun.c
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@ -55,6 +55,8 @@
#include <libgen.h>
#include <errno.h>
#include <signal.h>
#include <stdarg.h>
#include <syslog.h>
#include <net/if.h>
#include <sys/types.h>
@ -65,6 +67,9 @@
#include <linux/can/isotp.h>
#include <linux/if_tun.h>
/* Change this to whatever your daemon is called */
#define DAEMON_NAME "isotptun"
#define NO_CAN_ID 0xFFFFFFFFU
#define DEFAULT_NAME "ctun%d"
@ -74,6 +79,26 @@
static volatile int running = 1;
static void fake_syslog(int priority, const char *format, ...)
{
va_list ap;
fprintf(stderr, "[%d] ", priority);
va_start(ap, format);
vfprintf(stderr, format, ap);
va_end(ap);
fprintf(stderr, "\n");
}
typedef void (*syslog_t)(int priority, const char *format, ...);
static syslog_t syslogger = syslog;
void perror_syslog(const char *s)
{
const char *colon = s ? ": " : "";
syslogger(LOG_ERR, "%s%s%s", s, colon, strerror(errno));
}
void print_usage(char *prg)
{
fprintf(stderr, "\nUsage: %s [options] <CAN interface>\n\n", prg);
@ -90,6 +115,7 @@ void print_usage(char *prg)
fprintf(stderr, " -b <bs> (blocksize. 0 = off)\n");
fprintf(stderr, " -m <val> (STmin in ms/ns. See spec.)\n");
fprintf(stderr, " -w <num> (max. wait frame transmissions.)\n");
fprintf(stderr, " -D (daemonize to background when tun device created)\n");
fprintf(stderr, " -h (half duplex mode.)\n");
fprintf(stderr, " -v (verbose mode. Print symbols for tunneled msgs.)\n");
fprintf(stderr, "\nCAN IDs and addresses are given and expected in hexadecimal values.\n");
@ -118,14 +144,11 @@ int main(int argc, char **argv)
unsigned char buffer[BUF_LEN];
static char name[IFNAMSIZ] = DEFAULT_NAME;
int nbytes;
signal(SIGTERM, sigterm);
signal(SIGHUP, sigterm);
signal(SIGINT, sigterm);
int run_as_daemon = 0;
addr.can_addr.tp.tx_id = addr.can_addr.tp.rx_id = NO_CAN_ID;
while ((opt = getopt(argc, argv, "s:d:n:x:p:P:t:b:m:whL:v?")) != -1) {
while ((opt = getopt(argc, argv, "s:d:n:x:p:P:t:b:m:whL:vD?")) != -1) {
switch (opt) {
case 's':
addr.can_addr.tp.tx_id = strtoul(optarg, (char **)NULL, 16);
@ -154,9 +177,9 @@ int main(int argc, char **argv)
else if (elements == 2)
opts.flags |= (CAN_ISOTP_EXTEND_ADDR | CAN_ISOTP_RX_EXT_ADDR);
else {
printf("incorrect extended addr values '%s'.\n", optarg);
fprintf(stderr, "incorrect extended addr values '%s'.\n", optarg);
print_usage(basename(argv[0]));
exit(0);
exit(EXIT_FAILURE);
}
break;
}
@ -174,9 +197,9 @@ int main(int argc, char **argv)
else if (sscanf(optarg, ":%hhx", &opts.rxpad_content) == 1)
opts.flags |= CAN_ISOTP_RX_PADDING;
else {
printf("incorrect padding values '%s'.\n", optarg);
fprintf(stderr, "incorrect padding values '%s'.\n", optarg);
print_usage(basename(argv[0]));
exit(0);
exit(EXIT_FAILURE);
}
break;
}
@ -189,9 +212,9 @@ int main(int argc, char **argv)
else if (optarg[0] == 'a')
opts.flags |= (CAN_ISOTP_CHK_PAD_LEN | CAN_ISOTP_CHK_PAD_DATA);
else {
printf("unknown padding check option '%c'.\n", optarg[0]);
fprintf(stderr, "unknown padding check option '%c'.\n", optarg[0]);
print_usage(basename(argv[0]));
exit(0);
exit(EXIT_FAILURE);
}
break;
@ -220,9 +243,9 @@ int main(int argc, char **argv)
&llopts.mtu,
&llopts.tx_dl,
&llopts.tx_flags) != 3) {
printf("unknown link layer options '%s'.\n", optarg);
fprintf(stderr, "unknown link layer options '%s'.\n", optarg);
print_usage(basename(argv[0]));
exit(0);
exit(EXIT_FAILURE);
}
break;
@ -230,15 +253,19 @@ int main(int argc, char **argv)
verbose = 1;
break;
case 'D':
run_as_daemon = 1;
break;
case '?':
print_usage(basename(argv[0]));
exit(0);
exit(EXIT_SUCCESS);
break;
default:
fprintf(stderr, "Unknown option %c\n", opt);
print_usage(basename(argv[0]));
exit(1);
exit(EXIT_FAILURE);
break;
}
}
@ -247,12 +274,18 @@ int main(int argc, char **argv)
(addr.can_addr.tp.tx_id == NO_CAN_ID) ||
(addr.can_addr.tp.rx_id == NO_CAN_ID)) {
print_usage(basename(argv[0]));
exit(1);
exit(EXIT_FAILURE);
}
if (!run_as_daemon)
syslogger = fake_syslog;
/* Initialize the logging interface */
openlog(DAEMON_NAME, LOG_PID, LOG_LOCAL5);
if ((s = socket(PF_CAN, SOCK_DGRAM, CAN_ISOTP)) < 0) {
perror("socket");
exit(1);
perror_syslog("socket");
exit(EXIT_FAILURE);
}
setsockopt(s, SOL_CAN_ISOTP, CAN_ISOTP_OPTS, &opts, sizeof(opts));
@ -260,33 +293,33 @@ int main(int argc, char **argv)
if (llopts.tx_dl) {
if (setsockopt(s, SOL_CAN_ISOTP, CAN_ISOTP_LL_OPTS, &llopts, sizeof(llopts)) < 0) {
perror("link layer sockopt");
exit(1);
perror_syslog("link layer sockopt");
exit(EXIT_FAILURE);
}
}
strncpy(ifr.ifr_name, argv[optind], IFNAMSIZ);
ifr.ifr_ifindex = if_nametoindex(ifr.ifr_name);
if (!ifr.ifr_ifindex) {
perror("if_nametoindex");
perror_syslog("if_nametoindex");
close(s);
exit(1);
exit(EXIT_FAILURE);
}
addr.can_family = AF_CAN;
addr.can_ifindex = ifr.ifr_ifindex;
if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
perror("bind");
perror_syslog("bind");
close(s);
exit(1);
exit(EXIT_FAILURE);
}
if ((t = open("/dev/net/tun", O_RDWR)) < 0) {
perror("open tunfd");
perror_syslog("open tunfd");
close(s);
close(t);
exit(1);
exit(EXIT_FAILURE);
}
memset(&ifr, 0, sizeof(ifr));
@ -295,12 +328,25 @@ int main(int argc, char **argv)
ifr.ifr_name[IFNAMSIZ - 1] = '\0';
if (ioctl(t, TUNSETIFF, (void *) &ifr) < 0) {
perror("ioctl tunfd");
perror_syslog("ioctl tunfd");
close(s);
close(t);
exit(1);
exit(EXIT_FAILURE);
}
/* Now the tun device exists. We can daemonize to let the
* parent continue and use the network interface. */
if (run_as_daemon) {
if (daemon(0, 0)) {
syslogger(LOG_ERR, "failed to daemonize");
exit(EXIT_FAILURE);
}
}
signal(SIGTERM, sigterm);
signal(SIGHUP, sigterm);
signal(SIGINT, sigterm);
while (running) {
FD_ZERO(&rdfs);
@ -308,14 +354,14 @@ int main(int argc, char **argv)
FD_SET(t, &rdfs);
if ((ret = select(t+1, &rdfs, NULL, NULL, NULL)) < 0) {
perror("select");
perror_syslog("select");
continue;
}
if (FD_ISSET(s, &rdfs)) {
nbytes = read(s, buffer, BUF_LEN);
if (nbytes < 0) {
perror("read isotp socket");
perror_syslog("read isotp socket");
return -1;
}
if (nbytes > MAX_PDU_LENGTH)
@ -333,7 +379,7 @@ int main(int argc, char **argv)
if (FD_ISSET(t, &rdfs)) {
nbytes = read(t, buffer, BUF_LEN);
if (nbytes < 0) {
perror("read tunfd");
perror_syslog("read tunfd");
return -1;
}
if (nbytes > MAX_PDU_LENGTH)
@ -351,5 +397,5 @@ int main(int argc, char **argv)
close(s);
close(t);
return 0;
return EXIT_SUCCESS;
}