Re: [PATCH 1/3] slcand: daemonize _after_ interface is created, renamed and up.

[Marc Kleine-Budde <mkl@pengutronix.de>]

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On 06/08/2015 01:55 PM, Armin Burchardt wrote:
> Create interface, then daemonize to avoid race-conditions,
> ie. in init.d-scripts.
> 
> Signed-off-by: Armin Burchardt <armin@uni-bremen.de>
> ---
>  slcand.c | 35 ++++++++++++++++++-----------------
>  1 file changed, 18 insertions(+), 17 deletions(-)
> 
> diff --git a/slcand.c b/slcand.c
> index e5e4752..af7ca98 100644
> --- a/slcand.c
> +++ b/slcand.c
> @@ -255,23 +255,7 @@ int main(int argc, char *argv[])
>  
>  	syslog(LOG_INFO, "starting on TTY device %s", ttypath);
>  
> -	/* 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;
> -
> -	/* Now we are a daemon -- do the work for which we were paid */
> +	/* Create file handle for tty device. */
>  	fd = open(ttypath, O_RDWR | O_NONBLOCK | O_NOCTTY);
>  	if (fd < 0) {
>  		syslog(LOG_NOTICE, "failed to open TTY device %s\n", ttypath);
> @@ -365,6 +349,23 @@ int main(int argc, char *argv[])
>  		}	
>  	}
>  
> +	/* Daemonize (_after_ interface is up to avoid race-conditions,
> +	 * ie. between init.d-scripts). */
> +	if (run_as_daemon) {
> +		if (daemon(0, 0)) {
> +			syslog(LOG_ERR, "failed to daemonize");
> +			exit(EXIT_FAILURE);
> +		}
> +	}
> +	else {

Please change to

} else {

> +		/* Trap signals that we expect to receive */
> +		signal(SIGINT, child_handler);
> +		signal(SIGTERM, child_handler);
> +	}
> +
> +	/* */

Empty comment? I know you just moved the code around :)

> +	slcand_running = 1;
> +
>  	/* The Big Loop */
>  	while (slcand_running)
>  		sleep(1); /* wait 1 second */
> 

Marc

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