From: "Theo de Raadt" <deraadt@openbsd.org>
Subject: Re: ifconfig wg: "humanify" last handshake
To: "Omar Polo" <op@omarpolo.com>
Cc: tech@openbsd.org
Date: Wed, 06 Aug 2025 08:40:19 -0600

I disagree.

The problem with creating timestamps which are easier for humans to read,
is that they become more difficult for scripts to handle.

> tiny usability diff.  the rationale for it is that as time passes, the
> hander is (to me) to make sense out of the number of seconds since the
> last handshake, so optionally using a bigger time unit seems nice to me.
> 
> example:
> 
> # ifconfig wg0
> wg0: flags=80c3<UP,BROADCAST,RUNNING,NOARP,MULTICAST> mtu 1420
>         index 4 priority 0 llprio 3
>         [...]
>                 tx: 150444, rx: 356648
>                 last handshake: 5626 seconds ago
>                 [...]
> 
> with diff below it becomes
> 
> # ./obj/ifconfig wg0
> [...]
>                 last handshake: 93 minutes ago
> 
> (i think/hope noone parses ifconfig output to extract the raw number
> of seconds in wg interfaces)
> 
> 
> diff /usr/src
> path + /usr/src
> commit - 519f96cc72e084b9b4bd8458c870af05786040f2
> blob - a97d833f7cb4a299daf3cbe3ac8836933deae4fb
> file + sbin/ifconfig/ifconfig.c
> --- sbin/ifconfig/ifconfig.c
> +++ sbin/ifconfig/ifconfig.c
> @@ -5941,6 +5941,31 @@ process_wg_commands(void)
>  	}
>  }
>  
> +static char *
> +wg_humanify(time_t delta)
> +{
> +	static char		 buf[64];
> +	int			 r;
> +
> +	if (delta > 60 * 60 * 24 * 2)
> +		r = snprintf(buf, sizeof(buf), "%lld days ago",
> +		    delta / (60 * 60 * 24));
> +	else if (delta > 60 * 60 * 2)
> +		r = snprintf(buf, sizeof(buf), "%lld hours ago",
> +		    delta / (60 * 60));
> +	else if (delta > 60 * 2)
> +		r = snprintf(buf, sizeof(buf), "%lld minutes ago",
> +		    delta / 60);
> +	else
> +		r = snprintf(buf, sizeof(buf), "%lld seconds ago",
> +		    delta);
> +
> +	if (r == -1 || (size_t)r >= sizeof(buf))
> +		strlcpy(buf, "some time ago", sizeof(buf));
> +
> +	return buf;
> +}
> +
>  void
>  wg_status(int ifaliases)
>  {
> @@ -6007,9 +6032,12 @@ wg_status(int ifaliases)
>  			    wg_peer->p_txbytes, wg_peer->p_rxbytes);
>  
>  			if (wg_peer->p_last_handshake.tv_sec != 0) {
> +				time_t d;
> +
>  				clock_gettime(CLOCK_REALTIME, &now);
> -				printf("\t\tlast handshake: %lld seconds ago\n",
> -				    now.tv_sec - wg_peer->p_last_handshake.tv_sec);
> +				d = now.tv_sec - wg_peer->p_last_handshake.tv_sec;
> +				printf("\t\tlast handshake: %s\n",
> +				    wg_humanify(d));
>  			}
>  
>  
>