Messages in this thread | | | Subject | Re: Network Security hole (was -> Re: arp bug ) | Date | Sat, 02 Mar 2002 16:43:23 -0800 | From | erich@uruk ... |
| |
Russell King <rmk@arm.linux.org.uk> wrote:
> On Sat, Mar 02, 2002 at 04:21:24PM -0800, erich@uruk.org wrote: > > The fact that the routing layer and application layers of Linux's > > TCP/IP stack are one and the same is a difficulty here which the > > IP firewalling code in Linux does not fix. I.e. if I wanted to > > have routing as well, but not accept any packets internally *not* > > destined for my interface, I'm not sure how to specify it without > > something like TCP wrappers, as sleazy as they can be, and they > > don't offer this kind of capability in general as is. > > Linux 2.4 netfilter: > > Incoming Outgoing > interface interface > ----+------------------- FORWARD -----------------+-------> > | ^ > v | > INPUT -------------> Application -----------> OUTPUT > > The names in capitals are the names of the tables. You can control > packets that the local machine sees completely independently of what > gets routed through the machine with a kernel supporting iptables > by adding the appropriate rules to the input and forward tables.
Hmm. This would seem to be false in the RH 7.2 kernel 2.4.9-21 kernel I'm working with.
My IP masquerading rule (which claims to be in the "forward" chain, with target "MASQ"), was blocked when I did input address masking.
I.e. Yes, I actually tested this before posting.
If you're calling it a bug, then so be it. But the result would be a bit better than how my Linux system works now.
-- Erich Stefan Boleyn <erich@uruk.org> http://www.uruk.org/ "Reality is truly stranger than fiction; Probably why fiction is so popular" - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |