Date: Sun, 12 Dec 2004 22:28:50 +0100 From: Wilko Bulte <wb@freebie.xs4all.nl> To: Brooks Davis <brooks@one-eyed-alien.net> Cc: cvs-src@FreeBSD.ORG Subject: Re: cvs commit: src/sbin/ifconfig ifconfig.c src/sys/net if.c if.h Message-ID: <20041212212850.GA1493@freebie.xs4all.nl> In-Reply-To: <20041212205321.GA28802@odin.ac.hmc.edu> References: <200412122012.iBCKCou6068020@repoman.freebsd.org> <20041212204111.GB5503@electra.cse.Buffalo.EDU> <20041212205321.GA28802@odin.ac.hmc.edu>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sun, Dec 12, 2004 at 12:53:21PM -0800, Brooks Davis wrote..
> On Sun, Dec 12, 2004 at 03:41:11PM -0500, Ken Smith wrote:
> > On Sun, Dec 12, 2004 at 08:12:50PM +0000, Brooks Davis wrote:
> > > brooks 2004-12-12 20:12:50 UTC
> > >=20
> > > FreeBSD src repository
> > >=20
> > > Modified files: (Branch: RELENG_4)
> > > sbin/ifconfig ifconfig.c=20
> > > sys/net if.c if.h=20
> > > Log:
> > > MFC the addition of ifi_datalen to struct if_data and ifconfig supp=
ort
> > > for it. The change to struct if_data differs slightly from the one=
in
> > > 5.3 in that a pad is added after ifi_xmitquota rather then adding
> > > ifi_link_state before ifi_recvquota. This is necessicary to mainta=
in
> > > the 4.x ABI.
> > > =20
> > > Revision Changes Path
> > > 1.51.2.23 +4 -1 src/sbin/ifconfig/ifconfig.c
> > > 1.85.2.28 +2 -0 src/sys/net/if.c
> > > 1.58.2.12 +2 -0 src/sys/net/if.h
> >=20
> > In if.h you are adding new fields that didn't exist before:
> >=20
> > #ifndef _NET_IF_H_
> > @@ -97,6 +97,8 @@ struct if_data {
> > u_char ifi_hdrlen; /* media header length */
> > u_char ifi_recvquota; /* polling quota for receive intrs */
> > u_char ifi_xmitquota; /* polling quota for xmit intrs */
> > + u_char ifi_do_no_use; /* pad for ifi_datalen's position */
> > + u_char ifi_datalen; /* length of this data struct */
> > u_long ifi_mtu; /* maximum transmission unit */
> > u_long ifi_metric; /* routing metric (external only) */
> > u_long ifi_baudrate; /* linespeed */
> >=20
> > So any already compiled executables that use the if_data structure would
> > be looking for ifi_mtu/ifi_metric/ifi_baudrate in the wrong place after
> > this change. Are you absolutely sure this is not breaking ABI?
>=20
> ifi_mtu, etc remain in the same location because the two new variables
> fill in the hidden padding required to align ifi_mtu. I've verified
> that old and new ifconfigs work with old and new kernels. The change
Als on 64 bit machines? Just wondering..
> will allow 4.11 ifconfigs to work with 6.x if we add fields to struct
> if_data (fairly probable).
--=20
Wilko Bulte wilko@FreeBSD.org
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20041212212850.GA1493>