Date: Wed, 8 Jan 2003 23:22:22 +0100 From: Vincent Jardin <vjardin@wanadoo.fr> To: Jeffrey Hsu <hsu@FreeBSD.org> Cc: net@freebsd.org Subject: Re: rt_refcnt and rtentry protection ?? Message-ID: <3E075B1B006D4334@mel-rta7.wanadoo.fr> (added by postmaster@wanadoo.fr) In-Reply-To: <0H8E00ASUXB1HW@mta5.snfc21.pbi.net> References: <0H8E00ASUXB1HW@mta5.snfc21.pbi.net>
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>
> The roadmap for locking up the IP stack looks like roughly like ifaddr
> ref counts, ifnet list, routing radix tree, ARP, ifaddr uses, and rtentry.
However, it seems that the rtentries' rt_refcnt are not used like ifaddr,
ifnet, ... It looks like something dirty has been done a long time ago.
For example, the following lines:
rt = rtalloc1((struct sockaddr *)&sin, create, 0UL);
if (rt == 0)
return (0);
rt->rt_refcnt--;
if (rt->rt_flags & RTF_GATEWAY)
why = "host is not on local network";
else if ((rt->rt_flags & RTF_LLINFO) == 0)
why = "could not allocate llinfo";
else if (rt->rt_gateway->sa_family != AF_LINK)
why = "gateway route is not ours";
[...]
return ((struct llinfo_arp *)rt->rt_llinfo);
Why is rt_refnt decreased so early and not later ?
I would think that it would be more correct to have:
rt = rtalloc1((struct sockaddr *)&sin, create, 0UL);
if (rt == 0)
return (0);
if (rt->rt_flags & RTF_GATEWAY)
why = "host is not on local network";
else if ((rt->rt_flags & RTF_LLINFO) == 0)
why = "could not allocate llinfo";
else if (rt->rt_gateway->sa_family != AF_LINK)
why = "gateway route is not ours";
[...]
rt->rt_refcnt--;
return ((struct llinfo_arp *)rt->rt_llinfo);
It looks like rt_refcnt is decreased just after many rtalloc() in order just
to be sure that it won't be forgotten later, doesn'it ?
> I'm a little over 3/5 of the way done along this path.
Good luck,
Vincent
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