ask for sample ping source code without IP protocal stack

Hi,
   I am testing an ethernet device on a development board, I programmed
a ping echo program based on the ethernet driver, not using any IP
protocol stack, but I have a hard time using the program to echo the
ping from my Windows 2000 PC. From some network traffic tool I can see
the ethernet frame coming to the PC and I believe the ethernet header
and ICMP header are correct, but Windows ping can not receive my echo.
   I suspect I miss some tricks, so I am wondering if there are ping
source code for Windows to reference. From web searching, I see someone
mentioned Windows SDK has a sample ICMP application, but I do not have
access of that and I think that application should be based on socket
programming, while I am looking for no protocol stack source file.
    Could you help here?

Thanks.

On Fri, 05 Mar 2004 16:26:22 -0700, John Black wrote:

>   I am testing an ethernet device on a development board, I programmed
>a ping echo program based on the ethernet driver, not using any IP
>protocol stack

Start with straight Ethernet. Understand the difference between DIX
and IEEE formats, and how to cope with both.

Now implement ARP.

Once you have ARP, try simple IP datagrams.

Once you can send/receive IP, try ICMP echo.

Now write the tricky bits  :o)


Don't even *think* of trying to get this working without an Ethernet
packet sniffer, btw.

-- 
  Max

John Black wrote:
>    I am testing an ethernet device on a development
> board, I programmed a ping echo program [...]

You are trying to run before you can crawl.  First do ping, then ARP,
then ping replies.

ICMP Echo Replies need to match the signature of the Echo or they will
be ignored by the pinging station, so you cannot hard-code an Echo Reply
string.  Also, you need to implement ARP or install static entries in
the PC side (sounds like you must have done this already) so the ping
will reach you at all.  And, you need to calculate the IP checksums
on-the-fly for replies, since the content varies.  None of these
obstacles exist if your device is the one pinging instead of replying.

1) Goto http://www.ethereal.com and get their packet sniffer.  It's
free, and it's invaluable.

2) Sniff PC A sending an ICMP ping to PC B on the same subnet.

3) Copy the packet hex *exactly* into your program.  Don't change the
MAC addresses or any values in the packet.

4) Run your program to send pings.  On PC B, run Ethereal and see the
incoming pings and outgoing replies.  Yes, the replies will go to PC A's
MAC address instead of back to your device, but you've succeeded in
transmitting a working IP packet.

5) Then, work on varying the source MAC and IP, while updating the IP
checksums.

6) Implement an ARP responder on your device so it can be pinged

7) Listen for incoming pings and generate replies with the right payload
and checksum.

Then you'd be at the point you're trying to start from.


>    I suspect I miss some tricks, so I am wondering
> if there are ping source code for Windows to
> reference. From web searching, I see someone
> mentioned Windows SDK has a sample ICMP
> application [...]

You're wasting your time with this search.  Most sample ICMP programs
are going to make calls into an IP stack, which will actually format the
packet and handle transmission.


If you don't have 2 PCs, use PC A and a DSL router, or any other device
that will answer a ping.  Run the Ethereal on PC A instead; if you use a
hub, it'll see all the traffic anyway.

Good luck,
Richard

John Black <black@eed.com> wrote in message news:<40490C9E.74D5732A@eed.com>...
> Hi,
>    I am testing an ethernet device on a development board, I programmed
> a ping echo program based on the ethernet driver, not using any IP
> protocol stack, but I have a hard time using the program to echo the
> ping from my Windows 2000 PC. From some network traffic tool I can see
> the ethernet frame coming to the PC and I believe the ethernet header
> and ICMP header are correct, but Windows ping can not receive my echo.
>    I suspect I miss some tricks, so I am wondering if there are ping
> source code for Windows to reference. From web searching, I see someone
> mentioned Windows SDK has a sample ICMP application, but I do not have
> access of that and I think that application should be based on socket
> programming, while I am looking for no protocol stack source file.
>     Could you help here?


There's not really much to question here: ICMP echo-request/reply are
pretty solidly spec'd in the RFCs.  Can you post the network monitor
trace of the echo request from the Windows box and the reply from your
device?  Be sure to include everything out to the MAC frame.  Also,
let us know what the MAC and IP addresses are for the two boxes, and
be sure to include any ARP traffic.

My suspicion is that you are either not putting the correct MAC or IP
address into the reply, or you're not copying over the identifier and
sequence number fields from the request.

John,
you can find a lot of ideas and hands on information in Jeremy Bentham's
book:
"TCP/IP lean".
It helps a lot to understand the different protocols of TCP/IP.
ICMP is one of them.

grtnx
/jan


John Black <black@eed.com> schrieb in im Newsbeitrag:
40490C9E.74D5732A@eed.com...
> Hi,
>    I am testing an ethernet device on a development board, I programmed
> a ping echo program based on the ethernet driver, not using any IP
> protocol stack, but I have a hard time using the program to echo the
> ping from my Windows 2000 PC. From some network traffic tool I can see
> the ethernet frame coming to the PC and I believe the ethernet header
> and ICMP header are correct, but Windows ping can not receive my echo.
>    I suspect I miss some tricks, so I am wondering if there are ping
> source code for Windows to reference. From web searching, I see someone
> mentioned Windows SDK has a sample ICMP application, but I do not have
> access of that and I think that application should be based on socket
> programming, while I am looking for no protocol stack source file.
>     Could you help here?
>
> Thanks.
>

John Black wrote:
> Hi,
>    I am testing an ethernet device on a development board, I programmed
> a ping echo program based on the ethernet driver, not using any IP
> protocol stack, but I have a hard time using the program to echo the
> ping from my Windows 2000 PC. From some network traffic tool I can see
> the ethernet frame coming to the PC and I believe the ethernet header
> and ICMP header are correct, but Windows ping can not receive my echo.
>    I suspect I miss some tricks, so I am wondering if there are ping
> source code for Windows to reference. From web searching, I see someone
> mentioned Windows SDK has a sample ICMP application, but I do not have
> access of that and I think that application should be based on socket
> programming, while I am looking for no protocol stack source file.
>     Could you help here?
> 

There is no such thing. Ping (as used on PC's and other Internet
devices) is a part of the ICMP (Internet Control Message Protocol).

ICMP runs using the IP (Internet Protocol) to transfer the packets.

For Ethernet, IP needs also ARP (Address Resolution Protocol) to
translate from IP addresses to Ethernet addresses.

So, for a working ping, you'll need at least in stripped form
the protocol handlers for ICMP, IP and ARP in addition to the
Ethernet packet driver.

Been there - done that.

Tauno Voipio
tauno voipio @ iki fi

On Sat, 6 Mar 2004 09:29:38 +0100, Jan Homuth wrote:

>you can find a lot of ideas and hands on information in Jeremy Bentham's
>book:
>"TCP/IP lean".
>It helps a lot to understand the different protocols of TCP/IP.
>ICMP is one of them.

There are quite a lot of errors in the published code though (at least
in the 1st edition). It's very patchy in it's pacing, as well. I
wouldn't recommend it to someone inexperienced in networking.

I'd suggest the "TCP/IP Illustrated" series by Richard Stevens,
published by Addison-Wesley.

-- 
  Max

Max wrote:
> I'd suggest the "TCP/IP Illustrated" series by Richard Stevens,
> published by Addison-Wesley.

I'd agree.  Volume I is an excellent book for IP packet reference.  It's
a little dated (a couple newer ICMP codes and IPsec aren't covered,
IIRC), but it's the best one available.  Hopefully someone will pick up
the torch from the late author and release a new edition.

However, I don't recommend trying to craft a packet from scratch using
specs from the book, since there are a couple different Ethernet frame
types to deal with.  (Been there, done that.)  Better to start with a
known-working packet from a Sniffer trace, then modify it using the book
as reference.

Cheers,
Richard

On Fri, 05 Mar 2004 21:08:40 -0700, Richard wrote:

>If you don't have 2 PCs, use PC A and a DSL router, or any other device
>that will answer a ping.  Run the Ethereal on PC A instead; if you use a
>hub, it'll see all the traffic anyway.

Good post, and I agree with most of it, but that's not quite true
nowadays. Most devices sold as "hubs" are actually store&forward
switches, which only retransmit frames on the output port with the
addressed MAC device attached.

-- 
  Max

Max wrote:
> Good post, and I agree with most of it, but that's
> not quite true nowadays. Most devices sold as "hubs"
> are actually store&forward switches

Yes, I should have left my draft wording of "if you use a hub (not a
switch)", since fewer people know the difference these days.

These days you can still buy a 10Mb hub (or even 100 or 10/100 hubs),
and many products like DSL routers have them integrated - but equally,
the cost of switches has dropped to nearly completely displace hubs. 
Especially since switches are technically superior for all but this kind
of application.

Vendors are still fairly explicit in hub vs. switch labelling for
marketing value, but one must know to look for it.