rtalloc()/rtfree() problems on CURRENT

[Gleb Smirnoff]

  Dear Andre,

  first, thanks for your feedback.

On Tue, Feb 24, 2004 at 11:14:59AM +0100, Andre Oppermann wrote:
A> Most of the time, if you don't need a cloned route allocated, you can
A> just use rtalloc_ign(&ro, RTF_CLONING) to just get a reference to the
A> existing rtentry.  Not allocating a new cloned route saves work and
A> time for the rtalloc code.

Thanks for this hint. So if using rtalloc_ign() I do not need to call rtfree()?
Why does this situation is not clear in manpage? :)

A> >         if (ro.ro_rt != NULL) {
A> >                 struct rtentry *rt = ro.ro_rt;
A> > 
A> >                 /* here some read-only things are done with rt */
A> 
A> Maybe you do some nasty things to rt here?

Really, I don't :) Exact code is given at end of the mail.

A> >                 rtfree(ro.ro_rt);
A> >         }
A> > 
A> > But on CURRENT rtfree() causes panic. Here is backtrace:
A> ...
A> > Does this mean that something is broken in CURRENT or I am doing something wrong?
A> 
A> rtalloc() and rtfree() are used quite often in the network code and
A> otherwise work fine.  The odds are high that you are doing something
A> wrong.

Here is exact code:

        bzero((caddr_t)&ro, sizeof(ro));
        sin = (struct sockaddr_in *)&ro.ro_dst;
        sin->sin_len = sizeof(*sin);
        sin->sin_family = AF_INET;
        sin->sin_addr = fle->r.r_dst;
        rtalloc(&ro);
        if (ro.ro_rt != NULL) {
                struct rtentry *rt = ro.ro_rt;
 
                /* This is cloned route, use its parent */
                if (ro.ro_rt->rt_flags & RTF_WASCLONED &&
                    ro.ro_rt->rt_parent)
                        rt = ro.ro_rt->rt_parent;
 
                fle->o_ifx = rt->rt_ifp->if_index;
 
                if (rt->rt_flags & RTF_GATEWAY &&
                    rt->rt_gateway->sa_family == AF_INET)
                        fle->next_hop =
                            ((struct sockaddr_in *)(rt->rt_gateway))->sin_addr;
 
                if (rt_mask(rt))
                        fle->dst_mask =
                            bit_count(((struct sockaddr_in *)rt_mask(rt))->sin_addr.s_a
ddr);
                else if (rt->rt_flags & RTF_HOST)
                        /* Give up. We can't determine mask :( */
                        fle->dst_mask = 32;
 
                rtfree(ro.ro_rt);
        }

-- 
Totus tuus, Glebius.
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