Separate the a_reset FSM implementation from BSSMAP and MSC specifics, so that
it can be re-used on the Lb interface.
Move the FSM implementation to bssmap_reset.c and tweak, to match common practices we
have generally established in our osmo_fsm implementations.
Keep a_reset.h and a_reset.c and redirect to bssmap_reset.c.
A difficulty is setting a proper logging category: the FSM definition allows
only one fixed logging category for FSM state transitions and events. Ideally,
the BSSMAP reset fsm would log on DMSC, and the BSSMAP-LE reset fsm would log
on DLCS. Since that is not possible, introduce a separate DRESET logging
category. This in fact matches an item on my wishlist, because if a given MSC
is configured but currently not connected, the previous RESET FSM would
continuously "spam" log LOGL_NOTICE messages indicating that it is resending
RESET, and I often want to silence those messages without silencing the entire
DMSC category. This is now easily possible by setting DRESET logging to
LOGL_ERROR. There is additional "link up" / "link lost" logging on DMSC, so all
interesting info is still visible on DMSC.
Change-Id: Ib3c3a163186c40a93be0dea666230431172136df
The tx TRAP callback is triggered through a signal which is never sent in
osmo-bsc code, and never was as far as I can tell going quite far in the
logs.
In the meanwhile, the msc_connection_status was left in favour of
multi-msc msc.X.connection_status CTRL variable, so let's prepre the cb
function to work for that onei too, dropping global variables which may lead
to wrong output in multi-msc environments, and simply use msc->nr==0 for
the old variable "msc_connection_status".
The signal is now triggered in a_reset when the A conn becomes connected
or disconnected. As a result, a user waiting for the disconnect event
may notice that the status may be changed with a noticeable delay, since
the A conn may be reset only due to high layer timeouts after several
repeated failures (T4, BAD_CONNECTION_THRESOLD).
Related: OS#2623
Related: OS#4701
Related: SYS#5046
Change-Id: I645d198e8e1acd0aba09d05cb3ae90443946acf8
We're sending multiple RESET messages to establish a conection with
an MSC and MSC can (and often will) respond with multiple RESET ACK
messages. We should not treat this as an ERROR as it used to be
in the original code.
Change-Id: I109d638d5167e24f0357e3541415b9e7269aa5d1
Explanation from Harald:
There are plenty of things that can happen above the bare SCTP/M3UA
connection which can happen, such as SCCP or MTP level routing
problems.
The fact that a MSC responds to a BSSMAP reset tells us that all of
the underlying SS7 transport network is operational and the MSC
responds to us.
Go draw an IP analogy: Saying "SIGTAN connection up" here is like
saying "Ethernet link up" when you get an ICMP response.
Change-Id: If9d37c94f2f2b6cffef97f445774766993f538db
This way we can avoid the runtime overhead of checking whether or not
it is initialized over and over again. It also brings this code more
in line with other users of osmo_fsm_register().
Change-Id: I3c7220491cf6ffb1361e7259c0344df64a013a0a
Function fsm_reset_ack_timeout_cb() could be called directly from within
a_reset_alloc(), but it's still desirable to deferr the BSSMAP RESET to
be sent asynchronously by the timer upon next main loop step as soon as
possible, so whole process is already configured properly.
1ms needs to be set instead of 0 (immediate asynchronous) because value
0 actually disables the timer.
As a result, moving the state_chg() after the msc->a.reset_fsm
assignment is not really needed, but still makes it more clear that the
pointer will be set upon call of the timer callback.
Related: OS#4188
Change-Id: I68d76a4050d4dec7d53b0031d67e0dd35ddd8764
The API of a_reset.c is currently called with a pointer to struct
reset_ctx. This puts the responsibility of checking the presence of
msc->a.reset_fsm to the caller. It would be much more effective if the
caller would check if msc->a.reset_fsm before dereferencing it.
This also fixes at least one segfault that ocurrs when gscon_timer_cb()
is called but no sccp connection is present yet. Therefore the pointer
to bsc_msc_data would not be populated. This is now detected by
a_reset.c itsself.
- minor code cleanups
- call a_reset.c functions with msc (struct bsc_msc_data)
Change-Id: I0802aaadf0af4e58e41c98999e8c6823838adb61
Related: OS#3447
Move all of libbsc/ into osmo-bsc/, and separate/move some implementations to
allow linking from utils/* and ipaccess/* without pulling in unccessary
dependencies.
Some utilities use gsm_network and gsm_bts structs, which already include data
structures for fairly advanced uses. Move initialization that only osmo-bsc
needs into new bsc_network_init() and bsc_bts_alloc_register() functions, so
that the leaner tools can use the old gsm_* versions without the need to link
everything (e.g. handover and lchan alloc code).
In some instances, there need to be stubs if to cut off linking "just before
the RSL level" and prevent dependencies from creeping in.
- abis_rsl_rcvmsg(): the only program currently interpreting RSL messages is
osmo-bsc, the utils are merely concerned with OML, if at all.
- paging_flush_bts(): ip.access nanobts models call this when the RSL link is
dropped. Only osmo-bsc actually needs to do anything there.
- on_gsm_ts_init(): the mechanism to trigger timeslot initialization is related
to OML, while this action to take on init would pull in RSL dependencies.
utils/ and ipaccess/ each have a stubs.c file to implement these stubs. Tests
implement stubs inline where required.
From src/utils/, src/ipaccess/ and tests/*/, link in .o files from osmo-bsc/.
In order for this to work, the osmo-bsc subdir must be built before the other
source trees. (An alternative would be to include the .c files as sources, but
that would re-compile them in every source tree. Not a large burden really, but
unless linking .o files gives problems, let's have the quicker build.)
Minor obvious cleanups creep in with this patch, I will not bother to name them
individually now unless code review asks me to.
Rationale:
1) libbsc has been separate to use it for osmo-nitb and osmo-bsc in the old
openbsc.git. This is no longer required, and spreading over libbsc and osmo-bsc
is distracting.
2) Recently, ridiculous linking requirements have made adding new functions
cumbersome, because libbsc has started depending on osmo-bsc/*.c
implementations: on gscon FSM and bssap functions. For example, neither
bs11_config nor ipaccess-config nor bts_test need handover_cfg or BSSMAP
message composition. It makes no sense to link the entire osmo-bsc to it, nor
do we want to keep adding stubs to each linking realm.
Change-Id: I36a586726f5818121abe54d25654819fc451d3bf
Pau Espin
Neels Hofmeyr
Harald Welte
Martin Hauke
Philipp Maier