cvs commit: src/sys/netinet/libalias alias_util.c

[M. Warner Losh]

In message: <200712041928.36391.max at love2party.net>
            Max Laier <max at love2party.net> writes:
: On Tuesday 04 December 2007, Alexey Dokuchaev wrote:
: > On Mon, Dec 03, 2007 at 04:57:33PM -0500, John Baldwin wrote:
: > > On Monday 03 December 2007 10:24:52 am Dag-Erling Sm??rgrav wrote:
: > > > John Birrell <jb at FreeBSD.org> writes:
: > > > >   Log:
: > > > >   Fix strict alias warnings.
: > > >
: > > > A much simpler solution (relative to the previous revision):
: > > >
: > > > @@ -131,10 +131,10 @@
: > > >                 sum += oddbyte;
: > > >         }
: > > >  /* "Pseudo-header" data */
: > > > -       ptr = (u_short *) & (pip->ip_dst);
: > > > +       ptr = (void *)&pip->ip_dst;
: > > >         sum += *ptr++;
: > > >         sum += *ptr;
: > > > -       ptr = (u_short *) & (pip->ip_src);
: > > > +       ptr = (void *)&pip->ip_src;
: > > >         sum += *ptr++;
: > > >         sum += *ptr;
: > > >         sum += htons((u_short) ntcp);
: > >
: > > *ptr++ would choke since pointer arith on (void *) is undefined
: > > AFAIK.
: >
: > I've been under impression that ++ on void * whould simply increase it
: > by one.
: 
: wasn't that the reason why caddr_t exists?  i.e. pointer arithmetic on 
: void * is bad, but on caddr_t it's kinda okay.

Let's go look at the original code:

        u_short *ptr;

and restate your objections...

Warner