Reading network data going into a VM from netback.c

Reading network data going into a VM from netback.c

[#PATHANGI JANARDHANAN JATINSHRAVAN#]

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Hi all,
Recently, I’ve been trying to modify netback.c to print network data that is going into the VM. For example, I’m doing an SSL handshake with the VM as the server, and I send the following hexadecimal string from the client to the VM:


160302002f0100002b03026161616161616161616161616161616161616161616161616161616161616161000002000501000000


Now,  to read this ingoing data to the VM from netback.c, I’ve been trying to get the sk_buff from the function xenvif_rx_action() and extract the TCP header from it using the tcp_hdr(skb) function.


I then try to get the data from the TCP header using the line: (unsigned char *)((unsigned char *)tcph + (tcph->doff * 4))


But I am not able to parse the hexadecimal string as shown above.


Can anyone point me in the right direction regarding this?


Thanks

Jatin

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Reading network data going into a VM from netback.c

[#PATHANGI JANARDHANAN JATINSHRAVAN#]

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Hi all,
Recently, I’ve been trying to modify netback.c to print network data that is going into the VM. For example, I’m doing an SSL handshake with the VM as the server, and I send the following hexadecimal string from the client to the VM:


160302002f0100002b03026161616161616161616161616161616161616161616161616161616161616161000002000501000000


Now,  to read this ingoing data to the VM from netback.c, I’ve been trying to get the sk_buff from the function xenvif_rx_action() and extract the TCP header from it using the tcp_hdr(skb) function.


I then try to get the data from the TCP header using the line: (unsigned char *)((unsigned char *)tcph + (tcph->doff * 4))


But I am not able to parse the hexadecimal string as shown above.


Can anyone point me in the right direction regarding this?


Thanks

Jatin

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Reading network data going into a VM from netback.c

[Pathangi]

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Hi all, 
Recently, I’ve been trying to modify netback.c to print network data that is going into the VM. For example, I’m doing an SSL handshake with the VM as the server, and I send the following hexadecimal string from the client to the VM:

160302002f0100002b03026161616161616161616161616161616161616161616161616161616161616161000002000501000000



Now,  to read this ingoing data to the VM from netback.c, I’ve been trying to get the sk_buff from the function xenvif_rx_action() and extract the TCP header from it using the tcp_hdr(skb) function. 



I then try to get the data from the TCP header using the line: (unsigned char *)((unsigned char *)tcph + (tcph->doff * 4))



But I am not able to parse the hexadecimal string as shown above. 



Can anyone point me in the right direction regarding this?



Thanks

Jatin



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Reading network data going into a VM from netback.c

[#PATHANGI JANARDHANAN JATINSHRAVAN#]

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Hi all,
Recently, I’ve been trying to modify netback.c to print network data that is going into the VM. For example, I’m doing an SSL handshake with the VM as the server, and I send the following hexadecimal string from the client to the VM:


160302002f0100002b03026161616161616161616161616161616161616161616161616161616161616161000002000501000000


Now,  to read this ingoing data to the VM from netback.c, I’ve been trying to get the sk_buff from the function xenvif_rx_action() and extract the TCP header from it using the tcp_hdr(skb) function.


I then try to get the data from the TCP header using the line: (unsigned char *)((unsigned char *)tcph + (tcph->doff * 4))


But I am not able to parse the hexadecimal string as shown above.


Can anyone point me in the right direction regarding this?


Thanks

Jatin

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Re: Reading network data going into a VM from netback.c

[Dario Faggioli]

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On Tue, 2017-01-17 at 06:02 +0000, #PATHANGI JANARDHANAN JATINSHRAVAN#
wrote:
> But I am not able to parse the hexadecimal string as shown above. 
> 
> Can anyone point me in the right direction regarding this?
> 
I'm afraid I can't.

At the same time, I'm quite sure that by sending the same exact HTML
email 3 times, within a couple of hours, you're makes it very unlikely
that you'd receive any useful help.

Perhaps (re)read
https://wiki.xenproject.org/wiki/Asking_Developer_Questions

Regards,
Dario
-- 
<<This happens because I choose it to happen!>> (Raistlin Majere)
-----------------------------------------------------------------
Dario Faggioli, Ph.D, http://about.me/dario.faggioli
Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)

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