osmo-iuh[master]: ensure unique CellIDs in HNB-GW

This is merely a historical archive of years 2008-2021, before the migration to mailman3.

A maintained and still updated list archive can be found at https://lists.osmocom.org/hyperkitty/list/gerrit-log@lists.osmocom.org/.

Stefan Sperling gerrit-no-reply at lists.osmocom.org
Thu Feb 22 16:05:39 UTC 2018


Patch Set 1:

I have now written three proof-of-concept patches for several possible solutions proposed by me, Harald, and Neels. All patches affect libnetif and osmo-iuh. I don't see a way to implement a solution for this problem without making any changes to libnetif.

Our current options are:

1) Make libnetif provide a txflush_cb callback which allows the hnbgw code to safely close the connection after HNB-REGISTER-REJECT has been put on the Tx queue and the Tx queue has been drained. This approach should work fine but changes the libnetif API to a larger extent than options 2 and 3 do.
 
2) Set a flag in msgb->cb[0] which causes libnetif to destroy the connection after sending the message buffer. The hnbgw code can now destroy hnb context state in the close_cb() callback of the connection. Care must be taken to ensure that hnb_context_release does not call osmo_stream_srv_destroy() recursively. We also need to verify that msg->cb[0] is not already used for other purposes in libnetif (this seems to be the case).

3) This works just like approach 2, except that instead of setting a flag in the msgb control buffer we pass a message buffer of zero length to libnetif after passing the HNB-REGISTER-REJECT message. There is the unlikely possibility that queuing the HNB-REGISTER-REJECT message succeeds but queuing the zero-length message fails. My proof-of-concept patch logs a warning if this happens and relies on the other end to close the connection.

-- 
To view, visit https://gerrit.osmocom.org/6602
To unsubscribe, visit https://gerrit.osmocom.org/settings

Gerrit-MessageType: comment
Gerrit-Change-Id: Iffd441eb2b6b75dfbe001b49b01bea015ca6e11c
Gerrit-PatchSet: 1
Gerrit-Project: osmo-iuh
Gerrit-Branch: master
Gerrit-Owner: Stefan Sperling <ssperling at sysmocom.de>
Gerrit-Reviewer: Harald Welte <laforge at gnumonks.org>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: Neels Hofmeyr <nhofmeyr at sysmocom.de>
Gerrit-Reviewer: Stefan Sperling <ssperling at sysmocom.de>
Gerrit-HasComments: No



More information about the gerrit-log mailing list