From: Theo Buehler <tb@theobuehler.org>
Subject: Re: bgpctl: fix mrt default file handling
To: tech@openbsd.org
Date: Thu, 7 May 2026 14:15:14 +0200

On Thu, May 07, 2026 at 01:40:49PM +0200, Claudio Jeker wrote:
> bgpctl(8) has this in show mrt:
>              file name  Read the MRT dump from file name instead of using
>                         stdin.
> 
> So if no file argument is passed to bgpctl then stdin should be used.
> I broke this when fixing a coverity report that something like
> 	bgpctl show mrt file a file b
> would leak a filedescriptor.
> 
> Adjust the code to use STDIN_FILENO instead of -1 as initial value of
> res.mrtfd.

looks good, ok

> 
> -- 
> :wq Claudio
> 
> Index: parser.c
> ===================================================================
> RCS file: /cvs/src/usr.sbin/bgpctl/parser.c,v
> diff -u -p -r1.139 parser.c
> --- parser.c	4 Nov 2025 15:30:50 -0000	1.139
> +++ parser.c	6 May 2026 18:37:29 -0000
> @@ -489,7 +489,7 @@ parse(int argc, char *argv[])
>  
>  	memset(&res, 0, sizeof(res));
>  	res.rtableid = getrtable();
> -	res.mrtfd = -1;
> +	res.mrtfd = STDIN_FILENO;
>  	TAILQ_INIT(&res.set);
>  
>  	while (argc >= 0) {
> @@ -802,7 +802,7 @@ match_token(int argc, char *argv[], cons
>  			break;
>  		case FILENAME:
>  			if (word != NULL && wordlen > 0) {
> -				if (res.mrtfd != -1)
> +				if (res.mrtfd != STDIN_FILENO)
>  					errx(1, "mrt file already set");
>  				if ((res.mrtfd = open(word, O_RDONLY)) == -1) {
>  					/*
>