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P1sec / pysctp

SCTP stack for Python
http://www.p1sec.com
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[Query] PPID for received message? #29

Closed ChaturGopalkrishna closed 4 years ago

ChaturGopalkrishna commented 4 years ago

Hi, Can you please let me know how to obtain the PPID of the received SCTP message? Which API to use?

Thanks!

p1-bmu commented 4 years ago

PPID, and other SCTP metadata, are available through the socket notifications mechanism. Here are some references to the corenet source code, that makes use of it:

1) notifications are available at each call to sctp_recv(): https://github.com/P1sec/pycrate/blob/61203949886aaeeb31e502fbf6ad8755a140c142/pycrate_corenet/Server.py#L481

2) What you receive inside notifications needs to be configured after the creation of the socket: https://github.com/P1sec/pycrate/blob/61203949886aaeeb31e502fbf6ad8755a140c142/pycrate_corenet/Server.py#L461

3) You can then extract SCTP metadata form the notification structure: https://github.com/P1sec/pycrate/blob/61203949886aaeeb31e502fbf6ad8755a140c142/pycrate_corenet/Server.py#L556

Take care as some of them are in network byte-order (hence require conversion with ntohl), but not all. This is the way the Linux API is actually working.

All of this is documented in details in the excellent pysctp doc strings from the original developer (Elvis Pfützenreuter):

>>> import sctp
>>> help(sctp)

Hope this helps.

ChaturGopalkrishna commented 4 years ago

Great! Thanks for the quick help :)