kernel module to generate UDP & TCP traffic?

kernel module to generate UDP & TCP traffic?

[Ben Greear]

I'm considering writing a kernel module that will be used to
generate and receive copious amounts of Ethernet, UDP, and TCP
traffic.  I would prefer to tweak/use an existing tool if any
is available.  Any suggestions?

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>       <Ben_Greear AT excite.com>
President of Candela Technologies Inc      http://www.candelatech.com
ScryMUD:  http://scry.wanfear.com     http://scry.wanfear.com/~greear

Re: kernel module to generate UDP & TCP traffic?

[David S. Miller]

net/core/pg3.c

Re: kernel module to generate UDP & TCP traffic?

[Amit Kucheria]

On Mon, 15 Apr 2002, Ben Greear wrote:

> I'm considering writing a kernel module that will be used to
> generate and receive copious amounts of Ethernet, UDP, and TCP
> traffic.  I would prefer to tweak/use an existing tool if any
> is available.  Any suggestions?
> 
> Thanks,
> Ben


How about using the tun/tap devices in the 2.4. kernels which can RX/TX 
Ethernet frames from/to userspace?

http://vtun.sourceforge.net

-- 
I'm an angel!!! Honest!
The horns are just there to hold the halo up straight.
^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^
                  Amit Kucheria
          EECS Grad. Research Assistant
         University of Kansas @ Lawrence
   (R)+1-(785)-830 8521 ||| (O)+1-(785)-864 7774
____________________________________________________

Re: kernel module to generate UDP & TCP traffic?

[Ben Greear]

Amit Kucheria wrote:

> On Mon, 15 Apr 2002, Ben Greear wrote:
> 
> 
>>I'm considering writing a kernel module that will be used to
>>generate and receive copious amounts of Ethernet, UDP, and TCP
>>traffic.  I would prefer to tweak/use an existing tool if any
>>is available.  Any suggestions?
>>
>>Thanks,
>>Ben
>>
> 
> 
> How about using the tun/tap devices in the 2.4. kernels which can RX/TX 
> Ethernet frames from/to userspace?


I can already send/rcv packets with raw sockets, but the problem is that
causes coppies to/from user space, which not only decreases throughput, but
adds considerable latency.  If I can run the generation down in the kernel,
it will run much faster.


> 
> http://vtun.sourceforge.net
> 
> 


-- 
Ben Greear <greearb@candelatech.com>       <Ben_Greear AT excite.com>
President of Candela Technologies Inc      http://www.candelatech.com
ScryMUD:  http://scry.wanfear.com     http://scry.wanfear.com/~greear

Re: kernel module to generate UDP & TCP traffic?

[Ben Greear]

David S. Miller wrote:

> net/core/pg3.c


It appears to be net/core/pktgen.c, but I found it :)

After reading through it a few times, I have a few questions:

It appears I can interject spacing between packets, and it also
appears that it will basically busy-spin while waiting.  So, can
I assume it would be a pretty bad idea to configure large times
between packet transmits?  (ie does the nanosleep consume the machine?)

If I wanted this thing to send a packet that would be routed,
I would just set the MAC of the router and the IP of the eventualy
destination, correct?

It appears impossible to run traffic on two interfaces simultaneously
with this module, is that true?

Would you accept a patch that turned many of these counters into 64bit
counters?

Is there any similar module that can receive these packets on the other
side and verify a correct packet was received?

Would you accept a patch that placed timestamps and sequence counters in
the packets for latency detection and packet-drop detection?


Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>       <Ben_Greear AT excite.com>
President of Candela Technologies Inc      http://www.candelatech.com
ScryMUD:  http://scry.wanfear.com     http://scry.wanfear.com/~greear

injecting packets

[Vasu]

Hi.

I am trying to write a module that takes Ethernet packets from the user
domain, and injects it into the proper place ( which I think is the
sk_buffers ), so that to the IP, TCP layer, the packets look as if coming
from the Ethernet device. Can someone please suggest me which files to
look into, and which structs to handle, for getting this done. Also, I
want to do the reverse task, i.e. take some particular packets ( say which
come from a specific port ) from sk_buffers and send it to user space.

Please assume that this silly looking Rx/Tx has some importance :)

Regards.

Vasu.
III yr EE student.

RE: injecting packets

[Avniwb]

try dev_queue_xmit in dev.c.

or u can see chapter 13 of this...

http://www.cs.unh.edu/cnrg/gherrin/linux-net.html

ENJOY!!!
Avni :-)


-----Original Message-----
From: linux-net-owner@vger.kernel.org
[mailto:linux-net-owner@vger.kernel.org]On Behalf Of Vasu
Sent: Tuesday, 16 April 2002 12:10 PM
To: linux-net
Subject: injecting packets



Hi.

I am trying to write a module that takes Ethernet packets from the user
domain, and injects it into the proper place ( which I think is the
sk_buffers ), so that to the IP, TCP layer, the packets look as if coming
from the Ethernet device. Can someone please suggest me which files to
look into, and which structs to handle, for getting this done. Also, I
want to do the reverse task, i.e. take some particular packets ( say which
come from a specific port ) from sk_buffers and send it to user space.

Please assume that this silly looking Rx/Tx has some importance :)

Regards.

Vasu.
III yr EE student.


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Re: injecting packets

[Casey Carter]

It sounds like you want the Universal Tunnel/Tap driver, that lives in 
drivers/net/tun.c

Vasu wrote:

>Hi.
>
>I am trying to write a module that takes Ethernet packets from the user
>domain, and injects it into the proper place ( which I think is the
>sk_buffers ), so that to the IP, TCP layer, the packets look as if coming
>from the Ethernet device. Can someone please suggest me which files to
>look into, and which structs to handle, for getting this done. Also, I
>want to do the reverse task, i.e. take some particular packets ( say which
>come from a specific port ) from sk_buffers and send it to user space.
>
>Please assume that this silly looking Rx/Tx has some importance :)
>
>Regards.
>
>Vasu.
>III yr EE student.
>
>
>-
>To unsubscribe from this list: send the line "unsubscribe linux-net" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at  http://vger.kernel.org/majordomo-info.html
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