Because the sender is known, one unique TEI per tunnel suffices to map the TEIs
that the peers are sending to gtphub, instead of previously 4 (SGSN<->GGSN
interaction on User and Ctrl plane, where each had an own unique TEI).
Also, previously, a tunnel's endpoints should also have been checked against
each other for TEI reuse, not only against the endpoints of other tunnels. This
simplification fixes that problem for free.
Thus simplify TEI reuse detection and improve VTY show readability and
debugging.
Adjust log and VTY output for tunnels.
Adjust tests accordingly.
Suggested-by: Holger Hans Peter Freyther <holger@moiji-mobile.com>
Sponsored-by: On-Waves ehi
If an SGSN is behind NAT, we cannot rely on the default ports. Specifically,
if a GGSN sends a message, the forwarding to the SGSN should go to whichever
port the SGSN last sent from (whether sequence nr is known or not).
Add sgsn_use_sender config and VTY command, and store the sender instead
of the GSN Address IE and default port if set.
Sponsored-by: On-Waves ehi
This is a mostly cosmetic change. Instead of separate buffer handling
functions, reduce some code duplication by using a side_idx just like the
plane_idx, with arrays.
Sponsored-by: On-Waves ehi
So far, gtphub worked perfectly by only tracking single TEIs ... for probably
most uses. But a Ctrl plane tunnel may have expired despite a still active
corresponding User plane tunnel. The User plane would continue to work
indefinitely, but if any Ctrl messages followed after more than six hours of
Ctrl silence, they would have been dropped due to an expired TEI mapping.
We want to
- combine expiry of a user TEI with its ctrl TEI. (done in this patch)
- upon delete PDP context, remove both user and ctrl TEI mappings. (future)
- when a peer indicates a restart counter bump, invalidate its tunnels.
(future)
To facilitate these, track tunnels, complete with both SGSN's and GGSN's
address, original and replaced TEIs, all for both user and ctrl plane, in a
single struct. A single expiry entry handles the entire tunnel, instead of
previously four separate expiries for each endpoint identifier.
Add the concept of a "side", being either GGSN or SGSN, to index tunnel
endpoint structs, and so on.
Track the originating side in the gtp_packet_desc.
Add header_tei_rx: set_tei() overwrites header_tei, but the originally received
header TEI is still needed to match a Create PDP Context Response up with its
Request (and for logging).
Adjust the test suite to expect tunnel listing strings instead of TEI mappings,
with a bonus of making it a lot easier to grok, and including the IP addresses.
Add regression test for refreshing tunnel expiry upon use.
Note: the current implementation is as slow as can possibly be, iterating all
the tunnels all the time. Optimizations are kept for a future commit, on
purpose.
BTW, the sequence number mapping/unmapping structures remain unchanged.
Sponsored-by: On-Waves ehi
From sgsn_vty.c, copy the cfg_grx_ggsn_cmd to add an ares server to the static
sgsn_instance.
This is sort of preliminary. As described in comments, the sgsn_ares functions
should actually be separated from the static sgsn structure. gtphub keeps such
an sgsn structure just for the sgsn_ares functions.
Sponsored-by: On-Waves ehi
First steps towards a new GTP hub. The aim is to mux GTP connections, so that
multiple SGSN <--> GGSN links can pass through a single point. Background:
allow having more than one SGSN, possibly in various remote locations.
The recent addition of OAP to GSUP is related to the same background idea.
(This is a collapsed patch of various changes that do not make sense to review
in chronological order anymore, since a lot of it has thorougly transmorphed
after it was first committed.)
Sponsored-by: On-Waves ehf
Neels Hofmeyr