Date: Sat, 6 Jan 2018 15:02:08 -0500 From: John Lyon <johnllyon@gmail.com> To: Julian Elischer <julian@freebsd.org> Cc: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org>, Eugene Grosbein <eugen@grosbein.net> Subject: Re: Need Netgraph Help [fixed] Message-ID: <CAKfTJoWFrwOciBuddHm=i9DkiXTn4-QSqzn1Qai3zr6XMn85sA@mail.gmail.com> In-Reply-To: <c96502df-1ea3-555a-f773-1f402e753844@freebsd.org> References: <CAKfTJoUMxo7gsio7JJD8Vj_xPgFx5YEBH3_XViFhR0dt59==Dw@mail.gmail.com> <5A3225BF.6020205@omnilan.de> <CAKfTJoX78JhqsvB669Gxsr5UtZkbwuZrnVhOdU2UMacF7FmP1g@mail.gmail.com> <5A32F63E.8010205@grosbein.net> <5A338C5A.20300@omnilan.de> <CAKfTJoW5H82VLyBZ_5_sa9HU7Xbot7imeiP-ogVCNkHGe0_30Q@mail.gmail.com> <2e0525c8-2251-a5f5-45d1-fe44ebe318f7@freebsd.org> <CAKfTJoXe%2BZjDEMbF12-JcwBAs0uQoAFYAC3g1A_d0yM8by-z6g@mail.gmail.com> <ac0e236e-f27c-d4ed-8527-010dd025efff@freebsd.org> <4fee4ea6-9b35-afba-6d5d-24ecca3e28c6@freebsd.org> <CAKfTJoUuxKKkZEo5%2Bnv98jqk3T2D77-CS-rdqvVUQE%2BczHpzrw@mail.gmail.com> <3b8d46da-75e3-79f2-379c-b27a88e80733@freebsd.org> <CAKfTJoXdqm0Bj%2B85omHg6oiKhqDNkxfW5rs9nxsqH79qdCd9Gw@mail.gmail.com> <47C0E33A-E815-4860-A25C-F29BBB8D6787@gmail.com> <c96502df-1ea3-555a-f773-1f402e753844@freebsd.org>
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Thanks for the clarification and all the help.
After Marko clarified that that edges/hooks are bidirectional, I was able
to get it working WAN to LAN and LAN to WAN by using a pair of one2many and
ETF nodes.
The commands were (from memory):
#Create Unfiltered WAN Path
ngctl mkpeer igb0: one2many lower one
ngctl name igb0:lower wanmux
ngctl mkpeer wanmux: etf many0 downstream
ngctl name wanmux:many0 wanfilter
ngctl connect wanfilter: igb0: nomatch upper
#Create Unfilter LAN Path
ngctl mkpeer igb1: one2many lower one
ngctl name igb1:lower lanmux
ngctl mkpeer lanmux: etf many0 downstream
ngctl name lanmux:many0 lanfilter
ngctl connect lanfilter: igb1 nomatch upper
#Cross Connect Two Paths
ngctl connect wanfilter wanmux waneapout many1
ngctl connect lanfilter lanmux laneapout many1
#Filter Cross Connections
ngctl msg wanfilter: 'setfilter { matchhook=3D"waneapout" ethertype=3D0x888=
e }'
ngctl msg lanfilter: 'setfilter { matchhook=3D"laneapout" ethertype=3D0x888=
e }'
The graph looks like this:
igb0] <----> [mux0] <---> [etf0] <----> [igb0
\ /
X
/ \
igb1] <----> [mux1] <---> [etf1] <----> [igb1
It was conceptually easier for me to wrap my head around and it appears to
work (somewhat). But if I can get it to work, I like Julian's approach
better as it is simpler and uses fewer nodes.
Thanks again for all the help!
--------------------------------
John L. Lyon
PGP Key Available At:
https://www.dropbox.com/s/skmedtscs0tgex7/02150BFE.asc
On Sat, Jan 6, 2018 at 2:39 PM, Julian Elischer <julian@freebsd.org> wrote:
> On 6/1/18 9:22 pm, John Lyon wrote:
>
> I just woke up with a follow-up question that may be my aha moment. Are
> Netgraph edges between nodes always bidirectional? I have been treating a=
ll
> of the edges as unidirectional, requiring me to create two separate
> Netgraphs. But if they are bidirectional, that would explain some things=
.
>
>
> yes edges are bidirectional
>
> see the following paragraph from the ng_etf man page:
> -----
> Packets traveling in the other direction (towards the downstream hoo=
k)
> are also examined and filtered. If a packet has an ethertype that
> matches one of the values configured into the node, it must have
> arrived
> in on the hook for which that value was configured, otherwise it wil=
l
> be
> discarded. Ethertypes of values other than those configured by the
> con-
> trol messages must have arrived via the nomatch hook.
> -----
>
> here is the picture of what you need,
> You will see this below in the old emails:
>
> so you need this:
>
> em0]lower---downstream[ETF0]nomatch---upper[em0...
> eapout
> |
> |
> eapout
> em1]lower---downstream[ETF1]nomatch---upper[em1...
>
> ie. use an etf node on each interface.
>
> ngctl mkpeer igb0: etf lower downstream
> ngctl name igb0:lower waneapfilter
> ngctl connect waneapfilter: igb0: nomatch upper
>
> ngctl mkpeer igb1: etf lower downstream
> ngctl name igb1:lower laneapfilter
> ngctl connect laneapfilter: igb1: nomatch upper
>
> ngctl connect waneapfilter laneapfilter eapout eapout
>
> ngctl msg waneapfilter: 'setfilter { matchhook=3D"eapout"
> ethertype=3D0x888e }'
> ngctl msg laneapfilter: 'setfilter { matchhook=3D"eapout"
> ethertype=3D0x888e }'
>
>
> Thanks.
>
> Sent from my iPhone
>
> On Jan 5, 2018, at 11:16 PM, John Lyon <johnllyon@gmail.com> wrote:
>
> Julian,
>
> So this didn't work when I tried to implement it on hardware in real life
> and I can't figure out why. I am sure it's really basic, but the error
> message is not very descriptive.
>
> I use the following script to create a graph that filters the EAP traffic
> and forwards directly from the first Ethernet interface to the second. I=
t
> works perfectly.
>
> kldload ng_etf
> ngctl mkpeer igb0: etf lower downstream
> ngctl name igb0:lower waneapfilter
> ngctl connect waneapfilter: igb0: nomatch upper
> ngctl connect wanfilter: igb1: waneapout lower
> ngctl msg wanfilter: 'setfilter { matchhook=3D"waneapout"
> ethertype=3D0x888e }'
>
> The end result is that EAPOL frames are forwarded directly from igb0 (WAN=
)
> to igb1 (LAN). Graphically, it looks like (arrows indicating flow of
> traffic):
>
> igb0]lower--->>downstream[ETF0]nomatch--->>upper[igb0...
> waneapout
> |
> |------>>lower[igb1....
>
> However, I also need to do the reverse and forward EAPOL frames in the op=
posite direction from igb1 (LAN) to igb0 (WAN). Graphically, I want (arrow=
s indicating flow):
>
> igb1]lower--->>downstream[ETF1]nomatch--->>upper[igb1...
> laneapout
> |
> |------>>lower[igb0....
>
> So I try a mirror image of my first script. However, when I type the fir=
st line of:
>
> ngctl mkpeer igb1: etf lower downstream
>
> I get the following error message:
>
> ngctl: send msg: File exists.
>
> My guess (based on an earlier email in this thread) is that because I've =
already connected my first NG_ETF node to the lower hook of igb1 (in order =
to forward traffic out that interface), I am getting the error that the "Fi=
le exists" when I try to connect a second ETF node to igb1 lower. If this =
is the case, how can I write traffic out the interface, while filtering inc=
oming traffic on the same interface? I tried to used two different ETF node=
s, as suggested, but get an error message when I try.
>
> Thanks for any help. I feel like I am so close. At this point, I probab=
ly should have just jumped ship and tried an alternate solution, but I just=
can't allow the machine to win. :-) I have to get this working!
>
>
> --------------------------------
> John L. Lyon
> PGP Key Available At:
> https://www.dropbox.com/s/skmedtscs0tgex7/02150BFE.asc
>
> On Fri, Dec 29, 2017 at 4:06 AM, Julian Elischer <julian@freebsd.org>
> wrote:
>
>> On 29/12/17 10:52 am, John Lyon wrote:
>>
>> It works!!! In virtual machine land at least, it works! It will be
>> interesting to see what happens when the rubber meets the road and I
>> actually test it "in the field."
>>
>> The issue was a missing single line that was not obvious from the man
>> pages:
>>
>> sudo ngctl connect eapfilter: ix1: eapout lower
>>
>> your next issue will be that you can only attach em1:lower to a single
>> peer at a time. So return packets can not DTRT.
>>
>> You will need to either put a multiplexing node in each interface, OR if
>> I wrote it correctly, use the fact that packets fed into an etf match ho=
ok
>> will feed back out the input hook.
>>
>> so you need this:
>>
>> em0]lower---downstream[ETF0]nomatch---upper[em0...
>> eapout
>> |
>> |
>> eapout
>> em1]lower---downstream[ETF1]nomatch---upper[em1...
>>
>>
>> ie. use an etf node on each interface.
>>
>>
>>
>>
>>
>>
>>
>> Apparently, I had not created an alias for the connection between the ET=
F
>> and the ether nodes. Once this connect command was issued, the connecti=
on
>> to the lower hook of the ether node was ready to be connected to the ETF=
.
>>
>> Thanks *so much* for your help.
>>
>>
>> --------------------------------
>> John L. Lyon
>> PGP Key Available At:
>> https://www.dropbox.com/s/skmedtscs0tgex7/02150BFE.asc
>>
>> On Thu, Dec 28, 2017 at 9:48 AM, Julian Elischer <julian@freebsd.org>
>> wrote:
>>
>>> On 28/12/17 9:59 pm, Julian Elischer wrote:
>>>
>>>> On 28/12/17 1:37 am, John Lyon wrote:
>>>>
>>>>> Julian,
>>>>>
>>>>> Unfortunately, this issue remains unresolved. I would like to think
>>>>> that this is just a PEBKAC issue, but I have tried every permutation =
of
>>>>> escape characters in case it's an issue with my syntax and I get the =
same
>>>>> set of errors. No matter what I do, I can't connect the no match hoo=
k of
>>>>> an ETF node to the upper hook of an ng_ether node. Do you have any
>>>>> insights into why this might be occurring?
>>>>>
>>>>> By the way, thanks for reaching out to me! I was going to email you
>>>>> directly after the holidays since your name and email address are at =
the
>>>>> bottom of the relevant Netgraph man pages. I figured that must mean =
if you
>>>>> didn't know the answer, no one does. :-)
>>>>>
>>>>
>>>> what is EAP?
>>>> what about return EAP packets? (are there any?)
>>>>
>>>
>>> oops left out a line from the cut-n-paste...
>>>
>>>>
>>>> I think this is what you want:
>>>> $ sudo ngctl list
>>>> There are 7 total nodes:
>>>> Name: igb0 Type: ether ID: 00000001 Num hooks=
:
>>>> 0
>>>> Name: igb1 Type: ether ID: 00000002 Num hooks=
:
>>>> 0
>>>> Name: ix0 Type: ether ID: 00000003 Num hooks=
:
>>>> 0
>>>> Name: ix1 Type: ether ID: 00000004 Num hooks=
:
>>>> 0
>>>> Name: tap0 Type: ether ID: 00000005 Num hooks=
:
>>>> 0
>>>> Name: bridge3 Type: ether ID: 00000006 Num hooks=
:
>>>> 0
>>>> Name: ngctl7372 Type: socket ID: 00000007 Num hooks=
:
>>>> 0
>>>> $ sudo kldload ng_etf
>>>>
>>> $ sudo ngctl mkpeer ix0: etf lower downstream
>>>
>>>> $ sudo ngctl name ix0:lower eapfilter
>>>> $ sudo ngctl connect eapfilter: ix0: nomatch upper
>>>> $ sudo ngctl connect eapfilter: ix1: eapout lower
>>>> $ sudo ngctl show eapfilter:
>>>> Name: eapfilter Type: etf ID: 00000021 Num hooks=
:
>>>> 3
>>>> Local hook Peer name Peer type Peer ID Peer hook
>>>> ---------- --------- --------- ------- ---------
>>>> eapout ix1 ether 00000004 lower
>>>> nomatch ix0 ether 00000003 upper
>>>> downstream ix0 ether 00000003 lower
>>>> $ sudo ngctl msg eapfilter: 'setfilter { matchhook=3D"eapout"
>>>> ethertype=3D0x888e }'
>>>> $
>>>>
>>>>
>>>>
>>>>> Thanks.
>>>>>
>>>>>
>>>>> --------------------------------
>>>>> John L. Lyon
>>>>> PGP Key Available At:
>>>>> https://www.dropbox.com/s/skmedtscs0tgex7/02150BFE.asc
>>>>>
>>>>> On Wed, Dec 27, 2017 at 10:32 AM, Julian Elischer <julian@freebsd.org
>>>>> <mailto:julian@freebsd.org>> wrote:
>>>>>
>>>>> John did you get a resolution to this issue?
>>>>>
>>>>>
>>>>> On 16/12/17 2:59 am, John Lyon wrote:
>>>>>
>>>>> Harry and Eugene (and others),
>>>>>
>>>>> I appreciate all of your help. It's been really
>>>>> insightful. Although I
>>>>> feel like I'm getting much closer to the solution, I don't
>>>>> think my problem
>>>>> has been diagnosed. I've outlined my thought process
>>>>> below. Can you
>>>>> please tell me if I am misunderstanding something?
>>>>> Admittedly, I am not a
>>>>> kernel developer and my C language skills have atrophied the
>>>>> last few
>>>>> years. However, I've reviewed my script and I looked in the
>>>>> code for
>>>>> ng_etf.c and I don't think I am violating any of the
>>>>> requirements for
>>>>> linking a hook for no match.
>>>>>
>>>>> As Eugene stated:
>>>>>
>>>>> 1) referenced "matchook" exists and you should not
>>>>> use "indirect name"
>>>>>
>>>>> here,
>>>>>
>>>>> only hook own name, or else you get error ENOENT (No
>>>>> such file or
>>>>>
>>>>> directory);
>>>>>
>>>>> This does not seem to be a problem as the upper and lower
>>>>> hooks for the em1
>>>>> already exist (I can confirm this).
>>>>>
>>>>> 2) referenced "matchook" is *not* downstream hook,
>>>>> or else you get error
>>>>> EINVAL (Invalid argument);
>>>>>
>>>>> I read the ng_etf.c file in the source tree and found this
>>>>> little snippet:
>>>>>
>>>>> /* and is not the downstream hook */
>>>>> if (hook =3D=3D etfp->downstream_hook.hook) {
>>>>> error =3D EINVAL;
>>>>> break;
>>>>> }
>>>>>
>>>>> This appears to be an error check to make sure you are not
>>>>> creating a cycle
>>>>> in the graph by referencing the ETF node's own downstream
>>>>> hook (i.e.
>>>>> filtering incoming traffic and circularly feeding
>>>>> non-matching frames back
>>>>> into the ETF's own filter). I'm not doing this. I am
>>>>> feeding non-matching
>>>>> packets into the *lower* hook of another ether node and not
>>>>> back into the
>>>>> *downstream* hook of the etf node I am creating. As a
>>>>> result, my netgraph
>>>>> should not be triggering this error condition.
>>>>>
>>>>> 3) it was not already configured, or else you get
>>>>> error EEXIST (File
>>>>>
>>>>> exists).
>>>>>
>>>>> I am not getting this error, so it appears not to be an
>>>>> issue in my case.
>>>>>
>>>>> What am I missing here? The man page states that "*any
>>>>> other *hook" can be
>>>>>
>>>>> used for the non-matching packets. So the man page says
>>>>> this should work,
>>>>> and there's no explicit error condition that I see (caveat,
>>>>> I have not
>>>>> written in C for at least 10 years - PEBKAC is entirely
>>>>> possible) that
>>>>> would be triggered in the ng_etf code. So what is going wron=
g?
>>>>>
>>>>> Thanks for all of your help, patience, and understanding.
>>>>>
>>>>>
>>>>> --------------------------------
>>>>> John L. Lyon
>>>>> PGP Key Available At:
>>>>> https://www.dropbox.com/s/skmedtscs0tgex7/02150BFE.asc
>>>>> <https://www.dropbox.com/s/skmedtscs0tgex7/02150BFE.asc>;
>>>>>
>>>>> On Fri, Dec 15, 2017 at 3:48 AM, Harry Schmalzbauer
>>>>> <freebsd@omnilan.de <mailto:freebsd@omnilan.de>>
>>>>> wrote:
>>>>>
>>>>> Bez=C3=BCglich Eugene Grosbein's Nachricht vom 14.12.2017
>>>>> 23:07 (localtime):
>>>>>
>>>>> 15.12.2017 4:27, John Lyon wrote:
>>>>>
>>>>> I'm a new Netgraph user, but am having
>>>>> some problems with a simple
>>>>> Netgraph
>>>>> script I have written. Unfortunately,
>>>>> the error message is cryptic
>>>>>
>>>>> and I
>>>>>
>>>>> can't tell what I am doing wrong since
>>>>> my script closely follows the
>>>>> example provided in the ng_etf man page.
>>>>>
>>>>> For some context, I'm trying to filter
>>>>> EAP traffic coming in on my LAN
>>>>> interface. Any ethernet frames that
>>>>> correspond to EAP traffic need
>>>>>
>>>>> to be
>>>>>
>>>>> immediately forwarded from the LAN
>>>>> interface to my WAN interface. All
>>>>> other ethernet frames coming in on my
>>>>> LAN interface need to be
>>>>>
>>>>> handled by
>>>>>
>>>>> the kernel's network stack. A (horrid)
>>>>> ASCII art representation of my
>>>>> desired netgraph would look like this:
>>>>>
>>>>> lower -> em0 -> downstream -> ETF -> no
>>>>> match -> upper em0
>>>>> -> match ->
>>>>> lower em1
>>>>>
>>>>> The script I have written is this:
>>>>>
>>>>> #! /bin/sh
>>>>> ngctl mkpeer em0: etf lower downstre=
am
>>>>> ngctl name em0:lower lan_filter
>>>>> ngctl connect em0: lan_filter:
>>>>> upper nomatch
>>>>> ngctl msg lan_filter: setfilter {
>>>>> matchhook=3D"em1:lower"
>>>>> ethertype=3D0x888e }
>>>>>
>>>>> Unfortunately, the last line of my
>>>>> script generates the following
>>>>>
>>>>> error
>>>>>
>>>>> message:
>>>>>
>>>>> ngctl: send msg: Invalid Argument
>>>>>
>>>>> For "setfilter" command to work, ng_etf requires that=
:
>>>>>
>>>>> 1) referenced "matchook" exists and you should not
>>>>> use "indirect name"
>>>>>
>>>>> here,
>>>>>
>>>>> only hook own name, or else you get error ENOENT (No
>>>>> such file or
>>>>>
>>>>> directory);
>>>>>
>>>>> 2) referenced "matchook" is *not* downstream hook,
>>>>> or else you get error
>>>>> EINVAL (Invalid argument);
>>>>> 3) it was not already configured, or else you get
>>>>> error EEXIST (File
>>>>>
>>>>> exists).
>>>>>
>>>>> Eugene kindly looked into the code and found that the
>>>>> error is due to
>>>>> wrong matchhook definition.
>>>>> I've never had any contact with ng_etf yet, but
>>>>> according to the man
>>>>> page, you need to set the (additional) filter hook by
>>>>> 'nghook -a
>>>>> lan_filter: mydrain' and use 'matchhook=3Dmydrain' for th=
e
>>>>> 'msg' command.
>>>>>
>>>>> Do idea about the intention, so for the rest you have to
>>>>> tweak as needed.
>>>>>
>>>>> -harry
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> freebsd-net@freebsd.org <mailto:freebsd-net@freebsd.org>
>>>>> mailing list
>>>>> https://lists.freebsd.org/mailman/listinfo/freebsd-net
>>>>> <https://lists.freebsd.org/mailman/listinfo/freebsd-net>;
>>>>> To unsubscribe, send any mail to
>>>>> "freebsd-net-unsubscribe@freebsd.org
>>>>> <mailto:freebsd-net-unsubscribe@freebsd.org>"
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>> _______________________________________________
>>>> freebsd-net@freebsd.org mailing list
>>>> https://lists.freebsd.org/mailman/listinfo/freebsd-net
>>>> To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org"
>>>>
>>>>
>>>>
>>>
>>
>>
>
>
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