[Click] Using userlevel-click to forward packet

Cliff Frey cliff at meraki.com
Thu Nov 19 13:34:10 EST 2009


Luca,

You need to add a FromHost element to your config which will receive packets
from Linux, and a ToHost element that will deliver packets to Linux.

Cliff

On Thu, Nov 19, 2009 at 10:10 AM, Luca Belforte <
luca.belforte at student.uclouvain.be> wrote:

> I put here my click configuration
>
> I'm using click 1.7 because the 1.6 doesn't work with xorp
>
> //
> // Generated by XORP FEA
> //
>
>
> // Shared IPv4 input path and routing table
>
>    _xorp_ip4 :: Strip(14)
>   -> CheckIPHeader(INTERFACES 10.10.10.11/24 10.30.30.10/24)
>   -> _xorp_rt4 :: LinearIPLookup(10.10.10.11/32 2, 10.30.30.10/32 2);
>
>
> // ARP responses are copied to each ARPQuerier and the host.
>
>    _xorp_arpt :: Tee(3);
>
>
> // Input and output paths for eth1
>
>    FromDevice(eth1, SNIFFER false) -> _xorp_c0 :: Classifier(
>    12/0800,        // [0] IPv4 packet
>    12/0806 20/0001,    // [1] ARP request
>    12/0806 20/0002,    // [2] ARP reply
>    12/86dd 20/3aff 54/87,    // [3] IPv6 ICMP ND solicitation
>    12/86dd 20/3aff 54/88,    // [4] IPv6 ICMP ND advertisment
>    12/86dd,        // [5] IPv6 packet
>    -)            // [6] Unsupported protocol;
>    _xorp_out0 :: Queue(200) -> _xorp_to_device0 :: ToDevice(eth1);
>
>    // IPv4
>    _xorp_c0[0] -> Paint(1) -> _xorp_ip4;
>    _xorp_c0[1] -> ARPResponder(10.10.10.11 8:0:27:23:1a:29) -> _xorp_out0;
>    _xorp_arpq0 :: ARPQuerier(10.10.10.11, 8:0:27:23:1a:29) -> _xorp_out0;
>    _xorp_c0[2] -> _xorp_arpt;
>    _xorp_arpt[0] -> [1]_xorp_arpq0;
>
>    // Discard IPv6
>    _xorp_c0[5] -> Discard;
>    _xorp_c0[3] -> Discard;
>    _xorp_c0[4] -> Discard;
>
>    // Unknown protocol
>    _xorp_c0[6] -> Print("eth1 unknown protocol") -> Discard;
>
>
> // Input and output paths for eth2
>
>    FromDevice(eth2, SNIFFER false) -> _xorp_c1 :: Classifier(
>    12/0800,        // [0] IPv4 packet
>    12/0806 20/0001,    // [1] ARP request
>    12/0806 20/0002,    // [2] ARP reply
>    12/86dd 20/3aff 54/87,    // [3] IPv6 ICMP ND solicitation
>    12/86dd 20/3aff 54/88,    // [4] IPv6 ICMP ND advertisment
>    12/86dd,        // [5] IPv6 packet
>    -)            // [6] Unsupported protocol;
>    _xorp_out1 :: Queue(200) -> _xorp_to_device1 :: ToDevice(eth2);
>
>    // IPv4
>    _xorp_c1[0] -> Paint(2) -> _xorp_ip4;
>    _xorp_c1[1] -> ARPResponder(10.30.30.10 8:0:27:2b:ed:3f) -> _xorp_out1;
>    _xorp_arpq1 :: ARPQuerier(10.30.30.10, 8:0:27:2b:ed:3f) -> _xorp_out1;
>    _xorp_c1[2] -> _xorp_arpt;
>    _xorp_arpt[1] -> [1]_xorp_arpq1;
>
>    // Discard IPv6
>    _xorp_c1[5] -> Discard;
>    _xorp_c1[3] -> Discard;
>    _xorp_c1[4] -> Discard;
>
>    // Unknown protocol
>    _xorp_c1[6] -> Print("eth2 unknown protocol") -> Discard;
>
>
> // Local delivery
>
>    _xorp_toh :: Discard;
>
>    // IPv4
>    _xorp_rt4[2] -> EtherEncap(0x0800, 1:1:1:1:1:1, 2:2:2:2:2:2) ->
> _xorp_toh;
>    _xorp_arpt[2] -> _xorp_toh;
>
>
> // Forwarding path for eth1
>
>    // IPv4
>    _xorp_rt4[0] -> DropBroadcasts
>    -> _xorp_cp0 :: PaintTee(1)
>    -> _xorp_gio0 :: IPGWOptions(10.10.10.11)
>    -> FixIPSrc(10.10.10.11)
>    -> _xorp_dt0 :: DecIPTTL
>    -> _xorp_fr0 :: IPFragmenter(1500)
>    -> [0]_xorp_arpq0;
>    _xorp_dt0[1] -> ICMPError(10.10.10.11, timeexceeded) -> _xorp_rt4;
>    _xorp_fr0[1] -> ICMPError(10.10.10.11, unreachable, needfrag) ->
> _xorp_rt4;
>    _xorp_gio0[1] -> ICMPError(10.10.10.11, parameterproblem) -> _xorp_rt4;
>    _xorp_cp0[1] -> ICMPError(10.10.10.11, redirect, host) -> _xorp_rt4;
>
>
> // Forwarding path for eth2
>
>    // IPv4
>    _xorp_rt4[1] -> DropBroadcasts
>    -> _xorp_cp1 :: PaintTee(2)
>    -> _xorp_gio1 :: IPGWOptions(10.30.30.10)
>    -> FixIPSrc(10.30.30.10)
>    -> _xorp_dt1 :: DecIPTTL
>    -> _xorp_fr1 :: IPFragmenter(1500)
>    -> [0]_xorp_arpq1;
>    _xorp_dt1[1] -> ICMPError(10.30.30.10, timeexceeded) -> _xorp_rt4;
>    _xorp_fr1[1] -> ICMPError(10.30.30.10, unreachable, needfrag) ->
> _xorp_rt4;
>    _xorp_gio1[1] -> ICMPError(10.30.30.10, parameterproblem) -> _xorp_rt4;
>    _xorp_cp1[1] -> ICMPError(10.30.30.10, redirect, host) -> _xorp_rt4;
>
>
> And here we can see the correct routing table:
> 10.10.10.11/32        -        2
> 10.30.30.10/32        -        2
> 10.10.10.0/24        -        0
> 10.30.30.0/24        -        1
> 10.20.20.0/24        10.10.10.10    0
>
> (the subnet 10.20.20.0/24 come from the other router connected)
>
> So click know it.
>
> But if i do a :
>
> ping 10.20.20.10 (who exist) i have the following message:
> connect: Network is unreachable
>
> The connect command doesn't know the click route :(
>
> I really don't know what do
>
> Thanks
>
> Luca
>
> Luca Belforte wrote:
> > Hi Beyers,
> >
> > yes theoretically, but my problem is different. If y delete all the ip
> > route in the kernel (ip route flush all) so I'm sure the kernel can't
> > help. Then ping command doesn't work.
> >
> > My question is more how force click to process the who coming from the
> > system itself? (like a ping or traceroute command)
> >
> > Or opposite how to be sure that click process it?
> >
> > thanks
> >
> > Luca
> >
> > Beyers Cronje wrote:
> >
> >> Hi Luca,
> >>
> >> Theoretically using FromDevice with "SNIFFER false" then the kernel
> >> should not process the packets.
> >>
> >> Beyers
> >>
> >> On Wed, Nov 18, 2009 at 10:08 PM, Luca Belforte
> >> <luca.belforte at student.uclouvain.be
> >> <mailto:luca.belforte at student.uclouvain.be>> wrote:
> >>
> >>     Hello,
> >>
> >>     i have a xorp+click installation, who works, click receive the
> correct
> >>     routes.
> >>     But if i want to do a ping, or traceroute it still use the kernel
> >>     route
> >>     informations.
> >>     I tried to disable the SNIFFING mode, but without success.
> >>
> >>     How can i use click to route packet coming from the system?
> >>
> >>     Thanks in advance
> >>
> >>     Luca
> >>     _______________________________________________
> >>     click mailing list
> >>     click at amsterdam.lcs.mit.edu <mailto:click at amsterdam.lcs.mit.edu>
> >>     https://amsterdam.lcs.mit.edu/mailman/listinfo/click
> >>
> >>
> >>
> > _______________________________________________
> > click mailing list
> > click at amsterdam.lcs.mit.edu
> > https://amsterdam.lcs.mit.edu/mailman/listinfo/click
> >
> >
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