netstat output changes in 8.0?

[Nick Rogers]

Thanks a lot. Thats a bummer. What are the chances of getting something like
that worked into arp(8) permanently?

On Tue, Jan 26, 2010 at 4:41 AM, Ruslan Ermilov <ru at freebsd.org> wrote:

> On Mon, Jan 25, 2010 at 07:01:46PM -0800, Nick Rogers wrote:
> > Before 8.0-RELEASE, if I ran netstat -rn, it listed a separate route for
> > each host on the network, along with its MAC address. For example ...
> >
> > 172.20.172.17      00:02:b3:2f:64:6a  UHLW        1     105712   1500
> >  vlan172    595
> > 172.20.172.20      00:1e:c9:bb:7c:a9  UHLW        1       1002   1500
> >  vlan172    598
> > 172.20.172.22      00:14:5e:16:bb:b6  UHLW        1        107   1500
> >  vlan172    491
> >
> > This behavior seems to have changed in 8.0, where now only the
> > locally-assigned IP addresses and related CIDRs are displayed.
>
> From src/UPDATING:
>
> : 20081214:
> :         __FreeBSD_version 800059 incorporates the new arp-v2 rewrite.
> :         RTF_CLONING, RTF_LLINFO and RTF_WASCLONED flags are eliminated.
> :         The new code reduced struct rtentry{} by 16 bytes on 32-bit
> :         architecture and 40 bytes on 64-bit architecture. The userland
> :         applications "arp" and "ndp" have been updated accordingly.
> :         The output from "netstat -r" shows only routing entries and
> :         none of the L2 information.
>
> > Is there any way to get this behavior back, perhaps with a new flag that
> I
> > am not able to find? Or some sysctl? I have a script that was relying on
> > each host's "expire" flag in the routing table to determine when the MAC
> > address first appeared on the network according to ARP.
>
> If you need to know when a particular ARP entry expires, a variation
> of the following patch can be used, perhaps hiding this output by the
> -v (verbose) option.
>
> %%%
> Index: arp.c
> ===================================================================
> --- arp.c       (revision 203016)
> +++ arp.c       (working copy)
> @@ -101,7 +101,8 @@
>  static int nflag;      /* no reverse dns lookups */
>  static char *rifname;
>
> -static int     expire_time, flags, doing_proxy, proxy_only;
> +static time_t  expire_time;
> +static int     flags, doing_proxy, proxy_only;
>
>  /* which function we're supposed to do */
>  #define F_GET          1
> @@ -594,6 +595,15 @@
>                printf(" on %s", ifname);
>        if (rtm->rtm_rmx.rmx_expire == 0)
>                printf(" permanent");
> +       else {
> +               static struct timeval tv;
> +               if (tv.tv_sec == 0)
> +                       gettimeofday(&tv, 0);
> +               if ((expire_time = rtm->rtm_rmx.rmx_expire - tv.tv_sec) >
> 0)
> +                       printf(" expires %d", (int)expire_time);
> +               else
> +                       printf(" expired");
> +       }
>        if (addr->sin_other & SIN_PROXY)
>                printf(" published (proxy only)");
>        if (rtm->rtm_flags & RTF_ANNOUNCE)
> %%%
>
>
> Cheers,
> --
> Ruslan Ermilov
> ru at FreeBSD.org
> FreeBSD committer
>