This was reported by Kevin when he was testing handover. The problem
is the order of the signal handlers for S_ABISIP_CRCX_ACK. Right now
the handover signal handler is called before the one inside the libmsc
gsm_04_08.c. This means S_HANDOVER_ACK is signalled _before_ there is a
rtp socket created for the channel. The result is that the MDCX will
never be sent and the called will not be properly switched _after_ the
handover detection.
I do not want to play with the order of signal handlers, remove the
CRCX ack handling from the handover_logic.c and force the NITB (and
later the BSC) to check if the lchan is involved with a handover and
do the switching in there. This means right now we do what two signal
handlers did in one.
Reproduced and tested with the FakeBTS Handover test.
Log message:
<0004> abis_rsl.c:1954 (bts=1,trx=0,ts=3,ss=0) IPAC_CRCX_ACK ...
<000c> gsm_04_08.c:1400 no RTP socket for new_lchan
<001a> rtp_proxy.c:533 rtp_socket_create(): success
<001a> rtp_proxy.c:615 rtp_socket_bind(rs=0x48703c8, IP=0.0.0.0): ...
If subscriber A is calling B and has sent a CC Setup message we will
allocate the MO and MT transaction and link them together. When the
BTS or the lchan is failing the BSC API will send a clear request,
as part of the clear request all pending transactions will be released.
As part of taking down the transaction, the remote leg will be informed
and will send a MNCC_REL_REQ. This results in a call to trans_free. The
llist_for_each_entry_safe does not handle removing other elements from
the list and we would segfault.
One way to fix this is to move the transaction list into the subscriber
connection. This might require to create the subscriber connection for
MT handling earlier. Otherwise one could have one transaction list inside
the subscriber connection and a global list for MT- transactions.
This has been reported and analyzed by Tobias Engel. The IMSI Detach
is dispatched as part of the complete layer3 message. I had patched
the code to release the anchor and call msc_release_connection to
release the connection as fast as possible (otherwise the anchor would
trigger in a couple of seconds).
With commit 70ae5d3000 I made this more
generic to release the connection immediately if there are no operations,
no transaction and no silent call. This leads to the subscriber connection
being released twice and eventually causing a segfault. Remove the
msc_release_connection invocation from the IMSI Detach code as the connection
will be taken down by the BSC API.
This has been tested using the FakeBTS and an IMSI Detach message. The
channel is released immediately and the nitb does not crash.
abis_nm.c: In function ‘abis_nm_get_attr’:
abis_nm.c:1380:11: warning: unused variable ‘cur’ [-Wunused-variable]
abis_nm.c: In function ‘ipac_parse_bcch_info’:
abis_nm.c:2588:11: warning: variable ‘len’ set but not used [-Wunused-but-set-variable]
bts_nokia_site.c:1310:6: warning: variable ‘constructed’ set but not used [-Wunused-but-set-variable]
bts_nokia_site.c: At top level:
bts_nokia_site.c:1364:12: warning: ‘dump_elements’ defined but not used [-Wunused-function]
gsm_04_08.c: In function ‘mm_rx_loc_upd_req’:
gsm_04_08.c:521:6: warning: variable ‘rc’ set but not used [-Wunused-but-set-variable]
osmo_msc.c: In function ‘msc_ciph_m_compl’:
osmo_msc.c:122:7: warning: variable ‘rc’ set but not used [-Wunused-but-set-variable]
bts_hsl_femtocell.c: In function ‘hslfemto_bootstrap_om’:
bts_hsl_femtocell.c:101:11: warning: variable ‘cur’ set but not used [-Wunused-but-set-variable]
bts_hsl_femtocell.c: In function ‘hsl_drop_oml’:
bts_hsl_femtocell.c:232:21: warning: variable ‘line’ set but not used [-Wunused-but-set-variable]
handover_logic.c: In function ‘ho_chan_activ_ack’:
handover_logic.c:197:6: warning: variable ‘rc’ set but not used [-Wunused-but-set-variable]
The Nokia E71 sends a "IMSI Detach" this msc code does not immediately
send the "RR Channel Release", the E71 is impatient and sends a DISC,
the "RELEASE INDICATION" is handled by starting the channel release
procedure. OpenBSC sends a "RR Channel Release" which will never be
answered, during the early release there is no timer and the lchan will
be in "RELEASE REQUESTED" forever.
This commit removes the anchor operation and checks if the channel can
be released immediately. Regarding the channel release handling there
is already a branch that needs to be tested.
so far, osmo-bts/sysmobts used to be entered as "sysmobts" type in the
configuration file. However, there are some differences in the
protocol/behaviour and we should reflect that by a new BTS plugin (with
lots of code reuse from the nanobts driver).
RR Messages like STATUS, GPRS SUSPEND, HANDOVER COMPLETE/FAIL, ...
should be processed on the BSC side of things, not on the MSC side.
This is among other things required in preparation of intra-BSC
hand-over support in osmo-bsc.
The UTC offset from the operating system will be used by default to
calculate the NITZ in MM INFO. However, a "timezone" vty command is
added at the BTS level, allowing BTS-specific overrides, e.g. in case
BTSs are distributed accross multiple timezones.
In order to have the MNCC application reliably decide on the codec type,
it needs to know if we are running on a TCH/F or TCH/H. Thus, we pass
lchan_mode as a new parameter to the 'struct gsm_mncc'
This is a big patch that ports openBSC over libosmo-abis.
Sorry, the changes that are included here are all dependent
of libosmo-abis, splitting them into smaller pieces would
leave the repository in some intermediate state, which is
not desired.
The main changes are:
- The directory libabis/ has been removed as it now lives in
libosmo-abis.
- new configuration file format for nanoBTS and HSL femto, we
need to define the virtual e1_line and attach it to the OML
link.
- all the existing BTS drivers (nanoBTS, hsl femto, Nokia site,
BS11 and rbs2000) now use the new libosmo-abis framework.
- use r232 input driver available in libosmo-abis for bs11_config.
- use ipa_msg_recv instead of old ipaccess_read_msg function.
- delete definition of gsm_e1_subslot and input_signal_data.
These structures now lives in libosmo-abis.
Most of this patch are deletions of libabis/ which has been
moved to libosmo-abis.
This patch also modifies openBSC to use all the new definitions
available in libosmocore and libosmo-abis. In order to do that,
we have replaced the following:
- DINP, DMI, DMIB and DMUX by their respective DL* correspondences.
- SS_GLOBAL by SS_L_GLOBAL
- SS_INPUT by SS_L_INPUT
- S_GLOBAL_SHUTDOWN by S_L_GLOBAL_SHUTDOWN
- SS_INPUT by SS_L_INPUT
- S_INP_* by S_L_INP_* sub-signals
- E1INP_NODE by L_E1INP_NODE vty node
This patch has been tested with:
- one nanoBTS
- the HSL femto with the examples available under libosmo-abis
- BS11 with both dahdi and misdn drivers.
This patch modifies openBSC code to use msg->dst which stores the
pointer to the signalling link structure instead of the pointer to
the transceiver structure.
This patch prepares the introduction of libosmo-abis.
libosmogsm is a new library that is distributed in the libosmocore.
Now, openbsc depends on it. This patch gets openbsc with this
change.
This patch also rewrites all include path to the new
osmocom/[gsm|core]
Signed-off-by: Pablo Neira Ayuso <pablo@gnumonks.org>
Holger Hans Peter Freyther
Harald Welte
Dieter Spaar