svn commit: r199201 - in head: contrib/libpcap sbin/ifconfig share/man/man4 sys/kern sys/net sys/sys

[Dag-Erling Smørgrav]

Ed Schouten <ed at 80386.nl> writes:
> Xin LI <delphij at FreeBSD.org> writes:
> > @@ -198,6 +198,7 @@ struct ifnet {
> >  	void	*if_pf_kif;
> >  	void	*if_lagg;		/* lagg glue */
> >  	u_char	 if_alloctype;		/* if_type at time of allocation */
> > +	struct sbuf *if_description;	/* interface description */
> >  
> >  	/*
> >  	 * Spare fields are added so that we can modify sensitive data
> > @@ -205,7 +206,7 @@ struct ifnet {
> >  	 * be used with care where binary compatibility is required.
> >  	 */
> >  	char	 if_cspare[3];
> > -	void	*if_pspare[8];
> > +	void	*if_pspare[7];
> >  	int	if_ispare[4];
> So there used to be four chars in a row here (between if_description and
> if_cspare). Are you sure moving the pointer in between doesn't increase
> the structure size?

I can guarantee you that it does.  On i386, for instance, there are now
three bytes of implicit padding between if_alloctype and if_description,
and one more between if_cspare and if_pspare, so struct ifnet has grown
by four bytes.

We should have CASSERTs for sizeof(struct ifnet) and other structs we
really care about.

DES
-- 
Dag-Erling Smørgrav - des at des.no