The TBF should use the IMSI to identify a block flow but all
handling is spread across the entire code. Start to clean this
up by moving relevant code into the tbf file. Afterwards one
can clean up and add more internal structure.
Do not claim that the payload is not known. Add the missing break.
Do not print:
<0002> gprs_rlcmac.cpp:1174 GPRS_RLCMAC_CONTROL_BLOCK_OPT block payload is not supported.
<0002> gprs_rlcmac.cpp:1176 Unknown RLCMAC block payload.
Introduce the concept of tests that will be ran one after the other.
This new test will send static message that will lead to the opening
of a PDP context. At this point one should use ping with a large
packet size and suspend/stop the emulator. Once the NS connection is
considered dead the SGSN will crash with a double free.
Reproduce:
0.) Add IMSI 901700000003094 to the ACL
1.) Stop/Suspend the emulation process so the NS Alive times out
2.) Use ping IP -s 2048
This will create a double free...
#4 0xb7bb2646 in talloc_abort_double_free () at talloc.c:175
#5 0xb7bbd41a in talloc_chunk_from_ptr (ptr=0x8091208) at talloc.c:190
#6 _talloc_free (ptr=0x8091208) at talloc.c:517
#7 talloc_free (ptr=ptr@entry=0x8091208) at talloc.c:990
#8 0xb7bb319b in msgb_free (m=m@entry=0x8091208) at msgb.c:72
#9 0x0804db54 in sndcp_send_ud_frag (fs=0xbfffcc6c) at gprs_sndcp.c:423
#10 sndcp_unitdata_req (msg=msg@entry=0x808eed8, lle=0x808fbc8, nsapi=5 '\005',
mmcontext=mmcontext@entry=0x80903e8) at gprs_sndcp.c:471
This will send a static message. It will trigger the GMM code
on the SGSN and might ask us for the IMEI/IMSI or send us an
accept. As we are not replying at all the SGSN needs to send new
requests and we can observe if the sequence number is increasing
like it should.
For mocking/unit-testing/emulation (and a dual trx-systems) having
global state is quite bad. Cut back on the usage of the global
struct gprs_rlcmac_bts. It also makes the complexity of certain
routines more clear.
As a last minute change I probably ran git rebase --whitespace=fix
on the patch set and broke the test result. Update the expected
file and tests should pass.
Fixes:
bitvector.cpp: In function 'int bitvec_pack(bitvec*, uint8_t*)':
bitvector.cpp:53:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
bitvector.cpp: In function 'int bitvec_unpack(bitvec*, uint8_t*)':
bitvector.cpp:63:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
bitvector.cpp: In function 'uint64_t bitvec_read_field(bitvec*, unsigned int&, unsigned int)':
bitvector.cpp:91:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
bitvector.cpp: In function 'int bitvec_write_field(bitvec*, unsigned int&, uint64_t, unsigned int)':
bitvector.cpp:108:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
femtobts.c:250:2: warning: excess elements in array initializer [enabled by default]
{ SuperFemto_ClkSrcId_NetList, "nwl" },
^
femtobts.c:250:2: warning: (near initialization for ‘femtobts_clksrc_names’) [enabled by default]
femtobts.c:251:2: warning: excess elements in array initializer [enabled by default]
{ 0, NULL }
^
femtobts.c:251:2: warning: (near initialization for ‘femtobts_clksrc_names’) [enabled by default]
This might clash with C++11 and literal values but we will
see that once the compilers enable that by default.
Fixes:
csn1.cpp: In function 'gint16 csnStreamDecoder(csnStream_t*, const CSN_DESCR*, bitvec*, unsigned int&, void*)':
csn1.cpp:864:17: warning: format '%d' expects argument of type 'int', but argument 8 has type 'guint64 {aka long unsigned int}' [-Wformat]
csn1.cpp:1144:15: warning: format '%u' expects argument of type 'unsigned int', but argument 7 has type 'uint64_t {aka long long unsigned int}' [-Wformat]
csn1.cpp:1150:15: warning: format '%u' expects argument of type 'unsigned int', but argument 7 has type 'uint64_t {aka long long unsigned int}' [-Wformat]
csn1.cpp: In function 'gint16 csnStreamEncoder(csnStream_t*, const CSN_DESCR*, bitvec*, unsigned int&, void*)':
csn1.cpp:2119:17: warning: format '%d' expects argument of type 'int', but argument 8 has type 'guint64 {aka long unsigned int}' [-Wformat]
Decrease the number of lines of a single method by splitting things up.
The fewer lines of code, branches and side-effects in a method, the easier
it will be to understand. The other benefit is that one can start creating
unit tests for the some parts of the code.
One of the issues with not properly re-setting everything is that
due the global state it is not clear which variables belong together
and how long it exists. Begin with creating a osmo_pcu and moving
things into this class.
Think of an organic cell, this commit is introducing the cell wall
around it... and defines what is inside and what is outside of it.
The PCU does not properly re-set the state when the connection to the
BTS is lost (and the SGSN potentially is re-started during that). This
results in the BSSGP BVCI > 1 remaining blocked and no data will be
accepted by the SGSN.
Add the '-e' option and exit the PCU when the BSSGP/NS are getting
destroyed.
osmo_timer_del is an idempotent operation. There is no requirement
to check if it is running. If you don't want a timer to run, delete
it. Maybe one should have called the method _unschedule, _cancel to
make this more clear.
The timing advance of any TBF is stored when it ends. Whenever a new TBF
with the same TLLI is created (downlink TBF), the stored TA is recalled.
This algorithm assumes that the mobile does not move too fast during
transfer. Also the mobile must start a connection in order to get correct
initial timing advance.
This algorithm does not implement the timing advance procedure as defined
in TS 04.60. To implement the standard timing advance procedure, the BTS
must decode RACH on certain bursts, the mobile is expected to send them.
This requires much more complexity to a transceiver like USRP/UmTRX or
Calypso BTS.
The algorithm was tested at TA >= 8 and works quite well.
I ported the Holger's scheduling patch from sysmobts to osmo-pcu.
This is usefull, if PCU uses direct access to the DSP of sysmobts.
The latency to respond to a PH-READY_TO_SEND.ind may not be higher
than 18ms. Currently we are using nice to increase our priority but
for a heavily loaded cell this is not enough. Add an option to enable
realtime scheduling and use it in the screenrc.
Linux offers two realtime scheduling classes these are SCHED_FIFO
and SCHED_RR. For SCHED_FIFO the process is running as long as possible
(potentially taking all the CPU and never yielding it), for SCHED_RR
the process can still be pre-empted at the end of the timeslice.
Using SCHED_RR appears to be the more safe option as a run-a-way
sysmobts process will not be able to take all the CPU time.
The measurements include:
- DL bandwidth usage
- DL packet loss rate
- DL measurements by mobile
- UL measurements by BTS
In order to receive DL measurements from mobile, it must be enabled via
system information message at BSC.
Since we don't know the RX and TX parameters of the BTS that might be used
with PCU, the MS should not adapt the TX power from the RX level. So the
MS should always transmits with same power.
Finding an 'alpha' and 'gamma' value that will result in a constant
RX level at the BTS is a task of deployment.