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canlogserver: fix infinite loops during signal handling 

Fix infinite loops that prevent graceful termination when the server
receives SIGINT or SIGTERM signals. Without this fix, Ctrl-C and kill
commands are ignored, making it impossible to stop the server cleanly.

Two scenarios cause the infinite loops:

1) The bind() retry loop: When the port is busy, the loop retries
   indefinitely without checking the running flag set by the signal
   handler.

2) The accept() loop: The loop is unconditional, so when accept() is
   interrupted by a signal and returns EINTR, the loop immediately
   restarts, ignoring the shutdown request.

Signed-off-by: Oleksij Rempel <linux@rempel-privat.de>
pull/628/head
Oleksij Rempel 2026-01-01 18:24:52 +01:00 committed by Oleksij Rempel
parent 99ab67143a
commit f6ccef1957
1 changed files with 17 additions and 3 deletions
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20
canlogserver.c
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@ -177,7 +177,8 @@ int main(int argc, char **argv)
sigset_t sigset; sigset_t sigset;
fd_set rdfs; fd_set rdfs;
int s[MAXDEV]; int s[MAXDEV];
int socki, accsocket; int socki;
int accsocket = -1;
canid_t mask[MAXDEV] = {0}; canid_t mask[MAXDEV] = {0};
canid_t value[MAXDEV] = {0}; canid_t value[MAXDEV] = {0};
int inv_filter[MAXDEV] = {0}; int inv_filter[MAXDEV] = {0};
@ -286,7 +287,7 @@ int main(int argc, char **argv)
inaddr.sin_addr.s_addr = htonl(INADDR_ANY); inaddr.sin_addr.s_addr = htonl(INADDR_ANY);
inaddr.sin_port = htons(port); inaddr.sin_port = htons(port);
while(bind(socki, (struct sockaddr*)&inaddr, sizeof(inaddr)) < 0) { while(running && bind(socki, (struct sockaddr*)&inaddr, sizeof(inaddr)) < 0) {
struct timespec f = { struct timespec f = {
.tv_nsec = 100 * 1000 * 1000, .tv_nsec = 100 * 1000 * 1000,
}; };
@ -295,18 +296,24 @@ int main(int argc, char **argv)
nanosleep(&f, NULL); nanosleep(&f, NULL);
} }
if (!running) {
close(socki);
return 128 + signal_num;
}
if (listen(socki, 3) != 0) { if (listen(socki, 3) != 0) {
perror("listen"); perror("listen");
exit(1); exit(1);
} }
while(1) { while(running) {
accsocket = accept(socki, (struct sockaddr*)&clientaddr, &sin_size); accsocket = accept(socki, (struct sockaddr*)&clientaddr, &sin_size);
if (accsocket > 0) { if (accsocket > 0) {
//printf("accepted\n"); //printf("accepted\n");
if (!fork()) if (!fork())
break; break;
close(accsocket); close(accsocket);
accsocket = -1;
} }
else if (errno != EINTR) { else if (errno != EINTR) {
perror("accept"); perror("accept");
@ -314,6 +321,13 @@ int main(int argc, char **argv)
} }
} }
if (!running) {
if (accsocket > 0)
close(accsocket);
close(socki);
return 128 + signal_num;
}
for (i=0; i<currmax; i++) { for (i=0; i<currmax; i++) {
pr_debug("open %d '%s' m%08X v%08X i%d e%d.\n", pr_debug("open %d '%s' m%08X v%08X i%d e%d.\n",