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
If a GSN indicates that it has reset, tear down each known tunnel for that GSN
individually (don't send the GSNs on the other side a different restart
counter, because they represent more than just this GSN).
Sponsored-by: On-Waves ehi
During resolution of the header TEI, also return the tunnel struct that
resolved the TEI, so the Delete PDP Ctx code does not need to look it up
again.
Upon Delete PDP Ctx Request, remember the IEs and that a request was made.
Upon Delete PDP Ctx Response, find the pending delete and remove the
corresponding tunnel, iff the response indicates success.
Add a context deletion to regression tests, rename the test appropriately.
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
There's no need to keep two separate number pools when both can be fed
from the same pool. User and Ctrl plane TEIs can technically overlap without
colliding, but it doesn't hurt if they don't overlap, either.
Sponsored-by: On-Waves ehi
Force passing a restart counter, by adding such arg to gtphub_start() (test
suite is not affected by this).
In gtphub_main.c, add -r,--restart-file <path> and next_restart_count() to
maintain the counter file. While at it, tweak the cmdline help to unify the
formatting (mostly commas and a missing line break).
Send gtphub's own restart counter. So far, the sender's restart counter was
copied through, which would break as soon as more than one GSN would talk to
the same peer with differing restart counters.
Also fix the in-mem restart counter data type (one octet, not two).
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
The expiry queues are already used for resolved GGSN addresses, and will
soon enlist tunnel structs. Hence the naming should be more general.
Sponsored-by: On-Waves ehi
Clean up functionality is added for the test suite only, to be able to clean
out all allocations and test against memory leaks.
So far, it was sufficient to expire everything to free a gtphub. In preparation
for the upcoming rate counters, which will need to be freed explicitly, add
gtphub functions to clean up everything.
As added bonus, also close the sockets explicitly -- not really needed upon
program exit, neither by the test suite, but *if* we have a cleanup function,
it should clean up everything properly.
Closing the sockets is however kept separate, for the test suite.
gtphub_start() and gtphub_stop() are for normal use (published in gtphub.h),
and gtphub_init() and gtphub_free() are for the test suite, without sockets.
(gtphub_stop() will probably never be called by anyone, but its existence
completes the picture.)
In gtphub_test.c, have a function to clean up the testing gtphub struct. First,
expire everything by timeout, assert emptiness, then call the cleanup function.
Call from each test in the end.
Sponsored-by: On-Waves ehi
gtphub_ext.c's initial purpose was to wrap a specific function. The file
then turned into everything related to DNS, which fits pretty well. Rename
to gtphub_ares.c.
Tweak the header comment to reflect the new file name.
Sponsored-by: On-Waves ehi
Implement min/max bounds for nr_pool, adjust nr_pool_init() and current tests,
and create unit tests for nr_map wrapping.
Sequence numbers range from 0 to 65535, while TEIs range from 1 to 0xffffffff.
Both cause problems when the nr_pool surpasses the range: seq exit their valid
range, causing unmappings to fail, and a TEI would be mapped as zero (invalid).
Add a comment about TEI wrapping, and lose the comment about random TEIs (not
really important).
Sponsored-by: On-Waves ehi
Use unsigned int for nr_map, just large enough to fit the TEI space.
Adjust log output formats and casts accordingly.
Fixes: TEIs are uint32_t, but the nr_map so far used int. This would cause TEIs
from 0x80000000 on to be handled and printed as a negative value.
Sponsored-by: On-Waves ehi
The del_cb is now also used for ares (GGSN resolution) timeouts, and expiry is
anyway separated from nr_map, so this comment is void.
Sponsored-by: On-Waves ehi
Fit most of the code in 80 chars width. Some instances still leak past 80
characters because of long function names, inline comments or the like, "the
exception proves the rule."
Sponsored-by: On-Waves ehi
Allow logging the plane (Ctrl/User) and side (SGSN/GGSN) in functions that only
have a gtphub_bind* to work with, by adding a constant label to each bind.
Sponsored-by: On-Waves ehi
Initialize llist_heads to empty (2 were missing). Move those for struct gtphub
instances to gtphub_zero() (one moved, one added).
In from_[gs]gsns_read_cb(), use a return type that can actually reflect
negative return values.
resolved_addr.buf: no need to take the address of a byte array var
(cosmetic).
Pass the proper user data address to sgsn_ares_query(), not the address of
the pointer holding the user data address.
Initialize ggsn_lookup->expiry_entry (was missing). Publish the function for that
in gtphub.h so gtphub_ext.c can use it.
Sponsored-by: On-Waves ehi
Generalize to make the PDP ctx message definitions and "sending" of messages
from SGSN->gtphub->GGSN and back reusable in future tests.
Publish gsn_addr_from_sockaddr() in gtphub.h for use in gtphub_test.c.
Use an osmo_sockaddr for resolved_ggsn_addr, because one is needed for
comparison in probably every future test.
Add LVL2_ASSERT() to print assertion message and return instead of abort,
so that functions can be called from several tests without losing the
info of which test caused it from which line.
Use globals for struct gtphub and time_t now, to reduce nr of args that need to
be passed around when writing tests. Add a default test setup function.
Sponsored-by: On-Waves ehi
Up to now I used the Echo as a test for sequence nr mappings. But Echos
should be handled differently: they are scoped on the link and an Echo
response should be sent right back to the requester.
Sponsored-by: On-Waves ehi
For the resolving function, change the function signature to return a
gtphub_peer_port. In consequence, publish two functions concerned with
gtphub_peer_port instances for use in test and gtphub_ext.c.
Add GGSN resolution queue, callback and cache. Simple implementation: if an
SGSN asks for a GGSN, it will first get no answer, and I hope it will ask again
once the GGSN is in the cache.
Within gtphub_ext.c, have a dummy sgsn struct, as the sgsn_ares code currently
depends on it (half the functions pass an sgsn instance pointer around, but the
other half use the global one).
In the unit tests, wrap away the ares initialization so that they can work
without a DNS server around. The netcat test breaks because of this, will
remove it.
Using sgsn_ares, implement the gtphub_resolve_ggsn_addr() function, I hope:
untested.
Minor cosmetics just to see if you're paying attention... ;)
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