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* Re: MASQUERADE: Route sent us somewhere else (was Re: Fw: Rusty's brain broke!)
@ 2004-01-15  0:29 Henrik Nordstrom
  2004-01-15  2:15 ` Patrick McHardy
  0 siblings, 1 reply; 51+ messages in thread
From: Henrik Nordstrom @ 2004-01-15  0:29 UTC (permalink / raw)
  To: Netfilter Development Mailinglist



---------- Forwarded message ----------
Date: Wed, 14 Jan 2004 23:50:44 +0100 (CET)
From: Henrik Nordstrom <hno@marasystems.com>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: Harald Welte <laforge@netfilter.org>
Subject: Re: MASQUERADE: Route sent us somewhere else (was Re: Fw: Rusty's
    brain broke!) 

On Wed, 14 Jan 2004, Rusty Russell wrote:

> > And there are lots of users that have multiple DSL-dynip links these
> > days, trying to statically or dynamically balance web requests between
> > them, etc.
> 
> In that case, the interfaces are different, (ppp0 vs ppp1) so no
> problem.  You need something more complex to trigger the problem
> AFAICT.

Consider a firewall connected with ethernet to multiple DSL links not
using PPP-over-ethernet.

But i can not say I consider such setup sane in the DSL-dynip case, nor
how to overcome such trivial issues such as address assignment as such
setups generally use DHCP over the modem to assign the address and it is a
little hard to direct the DHCP request to the correct modem over a
broadcast ethernet.

A better case is the case of having multiple links from the same ethernet 
and wanting to SNAT based on the route taken. Masquerade with route lookup 
does this kind of magically by the route local source address field.

Hmm.. doesn't the SKB already have the route information by the time of
POSTROUTING? If so, why not simply use the route information already
there? MASQUERADE should never change the route taken, only the source
address of the packet so there should not be a need for an additional 
route lookup, and as the packet is already routed there should be no need 
to dig into the interface to find addressing informations..

I.e. why not use something like the following to find the source address 
in MASQUERADE:

    ((struct rtable*)skb->dst)->rt_src

Only worry is if there is POSTROUTING cases where skb->dst is not an
rtable (superset of dst_entry).

Regards
Henrik

^ permalink raw reply	[flat|nested] 51+ messages in thread

end of thread, other threads:[~2004-02-03  9:50 UTC | newest]

Thread overview: 51+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
     [not found] <20030725173900.E6E952C2AE@lists.samba.org>
     [not found] ` <200307251756.VAA12609@dub.inr.ac.ru>
2004-01-11 13:01   ` MASQUERADE: Route sent us somewhere else (was Re: Fw: Rusty's brain broke!) Harald Welte
2004-01-11 13:55     ` Julian Anastasov
2004-01-11 21:11       ` Henrik Nordstrom
2004-01-17 11:09         ` Future of CONNMARK (was " Harald Welte
2004-01-17 17:50           ` Henrik Nordstrom
2004-01-17 12:54             ` IP Options with libipq XiChimos
2004-01-21 13:44               ` Harald Welte
2004-01-18 13:20             ` Future of CONNMARK (was Re: MASQUERADE: Route sent us somewhere else (was Re: Fw: Rusty's brain broke!) Harald Welte
2004-01-18 17:16               ` Henrik Nordstrom
2004-01-19 23:15                 ` Herve Eychenne
2004-01-19 23:48                   ` Henrik Nordstrom
2004-01-20  1:13                     ` Herve Eychenne
2004-01-20  7:05                       ` Henrik Nordstrom
2004-01-20  7:12                         ` Henrik Nordstrom
2004-01-20 23:21                         ` Herve Eychenne
2004-01-20 18:34                           ` Buffer size XiChimos
2004-01-21  0:45                             ` Henrik Nordstrom
2004-01-20 19:58                               ` XiChimos
2004-01-21  2:25                                 ` Henrik Nordstrom
2004-01-21  2:47                                   ` XiChimos
2004-01-21  8:45                                     ` Henrik Nordstrom
2004-01-20 23:55                           ` Future of CONNMARK (was Re: MASQUERADE: Route sent us somewhere else (was Re: Fw: Rusty's brain broke!) Henrik Nordstrom
2004-01-21 23:49                           ` Harald Welte
2004-01-20 13:01                       ` Harald Welte
2004-01-21  0:17                         ` extensions manpage, howto etc Henrik Nordstrom
2004-01-21 22:02                           ` Harald Welte
2004-01-21  0:44                         ` iptables error reporting Henrik Nordstrom
2004-01-21  2:16                         ` iptables extensions manpage Henrik Nordstrom
2004-01-21 22:00                           ` Harald Welte
2004-02-02 23:40                 ` [patch, resent] Updated CONNMARK Henrik Nordstrom
2004-02-03  8:20                   ` Harald Welte
2004-02-03  9:03                     ` Henrik Nordstrom
2004-02-03  9:50                       ` Harald Welte
2004-01-18 19:14               ` iptables extension manpages Henrik Nordstrom
2004-01-17 18:46           ` Future of CONNMARK (was Re: MASQUERADE: Route sent us somewhere else (was Re: Fw: Rusty's brain broke!) Tom Eastep
2004-01-17 23:40             ` Henrik Nordstrom
2004-01-18  0:20               ` Tom Eastep
2004-01-12  1:07       ` Patrick McHardy
2004-01-12  4:30         ` Rusty Russell
2004-01-13  4:30           ` Patrick McHardy
2004-01-13  8:21           ` Julian Anastasov
2004-01-13 11:54           ` Harald Welte
2004-01-14  5:20             ` Rusty Russell
2004-01-12 11:08         ` Julian Anastasov
2004-01-14 16:11     ` kuznet
2004-01-14 23:42       ` Julian Anastasov
2004-01-15  0:29 Henrik Nordstrom
2004-01-15  2:15 ` Patrick McHardy
2004-01-15  7:00   ` Henrik Nordstrom
2004-01-15 11:58     ` Patrick McHardy
2004-01-15 13:07       ` Henrik Nordstrom

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