Attention is currently required from: laforge, pespin.
osmith has posted comments on this change by osmith. ( https://gerrit.osmocom.org/c/osmo-ggsn/+/38383?usp=email )
Change subject: gtp: allow packets with E-bit set ......................................................................
Patch Set 1:
(1 comment)
Commit Message:
https://gerrit.osmocom.org/c/osmo-ggsn/+/38383/comment/8ac75fa7_10cc00a1?usp... : PS1, Line 17: Related: OS#6223
I think this needs some spec analysis of what the expected behaviour is when packets with unknown/un […]
I've looked into it some more: 3GPP TS 29.060 § 6 towards the end explains when comprehension is required or not, it depends on bits 7 and 8 of the Extension Header Type. If comprehension is required, but the recipient doesn't understand it, it is supposed to: * send a response with cause "unknown mandatory extension header" * send a Supported Extension Headers Notification * log an error
So I guess the right thing to do would be: * accept packets with the E-bit set * iterate over all extension headers * look at the comprehension bits, and if no comprehension is required then ignore the extension header * otherwise reject the packet with the steps listed above
@laforge@gnumonks.org: do you want me to implement this, or put it in a new ticket? I'm not sure how important this is.