This patch refactors SGSN NSEI handling to support a secondary SGSN.
It adds the following VTY commands:
- secondary-sgsn nsei <0-65534>
- no secondary-sgsn
Sending messages to the secondary SGSN is not yet implemented, but
received messages from such a SGSN would be forwarded to the BSS
peers.
Sponsored-by: On-Waves ehf
This should have been part of the 'Implement IMSI acquisition'
commit, where a similar change has been made for BSS originated PTP
messages.
Sponsored-by: On-Waves ehf
We want to reduce the background traffic and might set the ping
interval to be in the range of minutes. But this means that if
the TCP connection is frozen several "SCCP CR CM Service Requests"
will be stuck in the send queue without ever being answered. I
could have used the logic of not receiving the "SCCP CC" to close
the connection but instead I am introducing an overload to schedule
the ping as part of the normal SCCP connection establishment.
The VTY write case has been manually verified, I have also looked
at a single trace to see that the SCCP CR and the IPA PING is
transfered in the same ethernet frame.
Jacob ran the tests with ASAN and noticed that the state is
dead. This is on purpose as we have forced a change in the
transcoding. Re-load the state and verify that it has not
changed in the other cases.
To modify or route messages based on the IMSI the latter must be known
when the action shall take place.
This patch modifies the gbproxy to optionally retain and enqueue
messages from the MS while initiating an identification procedure.
Further message processing of the LLC PTP link towards the SGSN will
be done, when the identity of the MS has been acquired.
Note that the N(U) of the LLC GMM SAPI are not adjusted, so it is
possible that adjacent messages of a single LLC link arriving either
at the BSS or the SGSN have the same N(U) and might get discarded,
leading to retransmissions and additional delay.
Note also that retransmissions and packet loss are not yet handled
explicitely. If for instance the generated IDENT REQ gets lost, the
gbproxy will not act on its own. In this case, the MS will time out
and eventually resend the Attach Request on which the gbproxy will
act exactly like before (thus having two Attach Req messages in its
queue, which will both be sent after the Ident Resp arrives).
This has been tested successfully with an E71, needing one
retransmission by the SGSN due to an N(U) collision.
Ticket: OW#1261
Sponsored-by: On-Waves ehf
This patch copies test_gbproxy_ptmsi_patching to
test_gbproxy_imsi_acquisition as a base for a later test for IMSI
acquisition (which is not yet implemented). The idea behind this is
to make the different behaviour visible in the ok file without
compromising the P-TMSI test.
Sponsored-by: On-Waves ehf
Currently when patching is enabled and an error happens when
receiving a message from the SGSN, the patched message is sent back
with the PDU_IN_ERROR IE.
This patch modifies gbprox_rx_sig_from_sgsn() to copy the message
before it is patched, so that the original message can be used with
the STATUS message. gbprox_rx_ptp_from_sgsn() does all checks before
the message is patched, so copying is not necessary.
Since gbprox_rx_sig_from_sgsn() is not called for BSSGP UNITDATA
messages and the msgb is already been copied in the gbprox_relay2peer
function, the relative performance impact is expected to be low.
Note that the PDU IE of STATUS messages received from an MS and
forwarded to the SGSN will not be patched. STATUS messages from the
SGSN are only logged and not forwarded to the MS.
Sponsored-by: On-Waves ehf
Currently messages like these with a TLLI IE (BSSGP) are not
tested (properly) with TLLI patching.
This patch extends the send_bssgp_suspend* functions to accept a
TLLI as argument and adds the send_bssgp_llc_discarded function.
These are then used in test_gbproxy_ptmsi_patching() with a valid
TLLI.
Note that the TLLI IE patching doesn't work currently.
Sponsored-by: On-Waves ehf
This patch adds gbprox_rx_data_from_sgsn() and
gbprox_rx_ptp_from_bss() which contain the PTP message processing
of gbprox_rcvmsg(). The calls to gbprox_process_bssgp_ul() are moved
from gbprox_relay2sgsn() to gbprox_rx_ptp_from_bss() and
gbprox_rx_sig_from_bss().
The goal is, to do all patching (and calls to gbprox_process_bssgp_*)
from within the gbprox_rx_* functions. Doing the patching from within
gbprox_relay2sgsn has the drawback, that the patching code cannot
call gbprox_relay2sgsn() which is needed if a single message shall
trigger a sequence of messages.
Sponsored-by: On-Waves ehf
The compiler also uses this attribute for code elimination. If the
nonnull attribute has been given erroneously for an parameter, that
is later been checked against NULL, this check is removed silently
by the gcc if optimization is enabled. This can lead to hard-to-find
segmentation violation faults.
To be on the safe side, this patch removes all uses of the nonnull
attribute in openbsc.
Compiler:
- gcc 4.8.2 (Ubuntu 4.8.2-19ubuntu1): no warning, segfault
- clang 3.4 (3.4-1ubuntu3): no warning, no segfault, asm ok
Example:
/* foo.c */
int f(int* p) __attribute((nonnull));
int f(int *p) {
if (!p)
return 0;
return *p;
}
/* main.c */
int f(int* p) __attribute((nonnull));
int g () {
return f(arg);
}
int main() {
return g(NULL);
}
When these files are compiled into an executable, no warnungs are
issued but it will fail with a segfault when -O2 is used (unless LTO
is active).
Compiler output (gcc -O2):
int f(int *p) {
0: 8b 44 24 04 mov 0x4(%esp),%eax
4: 8b 00 mov (%eax),%eax
6: c3 ret
}
Sponsored-by: On-Waves ehf
In case we get offered G729 and G711 we might have selected
G729 as the audio codec. The first packet we receive might be
G711 though. In that case we will need to change. But only if
we have a matching alternate codec payload_type. E.g. in the
case of comfort noise we will receive the PT=11 and we don't
want to change.
In case of some RTP proxy from time to time we are offered both
G729 and G711 but only one of them will work. I intend to adjust
the codec at runtime in case we receive the wrong codec.
We might be offered multiple codecs by the remote and need to
switch between them once we receive data. Do this by moving it
to a struct so we can separate between proposed and current
codec. In SDP we can have multiple codecs but a global ptime.
The current code doesn't separate that clearly instead we write
it to the main codec.
Use the rtp_hdr structure. The basic alignment issue remains
and I need to merge/cherry-pick Jacob's getters for the ts,
sequence number and other attributes.
./configure --help indicates:
--enable-external-tests Include the VTY/CTRL tests in make check
[default=no]
but
./configure ... --enable-external-tests
configure: WARNING: unrecognized options: --enable-external-tests
the name of the option seems to be --enable-ext-tests.
The library allows to indicate zero as batch size if you want to use
the default size, however openbsc saves 'osmux batch-size 0' which is
not good as input.
Use OSMUX_BATCH_DEFAULT_MAX to explicitly initialize the batch size
from mgcp_parse_config().
The talloc_free on the nat lead to the freeing of the bsc_config
which lead to freeing of the rate_ctr_group. The rate_ctr_group
remained in a global list and the next creation of a bsc_config
would access dead memory. Fix it.
The free routine is only meant to be used by the test, for the
real nat we would need to make sure that all connections and
other state that refers to the cfg is removed/closed first.
Fix various memleaks in the test while we are at it. There are
still some to fix.
==7195== Invalid write of size 4
==7195== at 0x4043171: rate_ctr_group_alloc (linuxlist.h:65)
==7195== by 0x804D893: bsc_config_alloc (bsc_nat_utils.c:174)
==7195== by 0x804B5D2: main (bsc_nat_test.c:954)
==7195== Address 0x4311cbc is 52 bytes inside a block of size 208 free'd
==7195== at 0x4029D28: free (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==7195== by 0x4048D98: _talloc_free (talloc.c:609)
==7195== by 0x4052806: talloc_free (talloc.c:578)
==7195== by 0x804B58A: main (bsc_nat_test.c:940)
bsc_nat_ctrl.c: In function ‘set_net_cfg_cmd’:
bsc_nat_ctrl.c:360:3: warning: implicit declaration of function ‘bsc_replace_string’ [-Wimplicit-function-declaration]
bsc_replace_string(bsc_cfg, &bsc_cfg->acc_lst_name, cmd->value);
^
gbproxy_patch_bssgp: Move a check for tlli_info in front of the first
conditional that depends on it, and return immediately if it is NULL.
gbproxy_register_tlli: Initialize tlli_already_known to 0.
Fixes: Coverity CID 1232691
Fixes: Coverity CID 1232692
Sponsored-by: On-Waves ehf
Remove redundant information log message:
<000b> bsc_mgcp_utils.c:647 BSC doesn't want to use Osmux, failing back to RTP
<000b> bsc_mgcp_utils.c:669 bsc didn't accept to use Osmux (cid=0)
One single log message is just fine. The error path already indicates
the precise reason not to accept the request to use Osmux.
This patch includes several osmux fixes that are interdependent:
1) This adds Osmux circuit ID, this is allocated from the bsc-nat. This
announces the circuit ID in the CRCX MGCP message. This aims to resolve
the lack of uniqueness due to the use of endp->ci, which is local to
the bsc. This ID is notified via X-Osmux: NUM where NUM is the osmux
circuit ID.
2) The dummy load routines are now used to setup osmux both in bsc and
bsc-nat to resolve source port NAT issues as suggested by Holger. The
source port that is used from the bsc is not known until the first
voice message is sent to the bsc-nat, therefore enabling osmux from
the MGCP plane breaks when a different source port is used.
3) Add refcnt to struct osmux_handle, several endpoints can be using the
same input RTP osmux handle to perform the batching. Remove it from the
osmux handle list once nobody is using it anymore to clean it up.
4) Add a simple Osmux state-machine with three states. The initial state
is disabled, then if the bsc-nat requests Osmux, both sides enters
activating. The final enabled state is reached once the bsc-nat sees
the dummy load message that tells what source port is used by the bsc.
5) The osmux input handle (which transforms RTP messages to one Osmux batch)
is now permanently attached to the endpoint when Osmux is set up from the
dummy load path, so we skip a lookup for each message. This simplifies
osmux_xfrm_to_osmux().
After this patch, the workflow to setup Osmux is the following:
bsc bsc-nat
| |
|<------ CRCX ----------|
| X-Osmux: 3 | (where 3 is the Osmux circuit ID
| | that the bsc-nat has allocated)
|------- resp --------->|
| X-Osmux: 3 | (the bsc confirm that it can
| | use Osmux).
. .
| |
setup osmux |----- dummy load ----->| setup osmux
| Osmux CID: 3 |
In two steps:
1st) Allocate the Osmux Circuit ID (CID): The bsc-nat allocates an unique
Osmux CID that is notified to the bsc through the 'X-Osmux:' extension.
The bsc-nat annotates this circuit ID in the endpoint object. The bsc
replies back with the 'X-Osmux:' to confirm that it agrees to use Osmux.
If the bsc doesn't want to use Osmux, it doesn't include the extension
so the bsc-nat knows that it has to use to RTP.
2nd) The dummy load is used to convey the Osmux CID. This needs to happen
at this stage since the bsc-nat needs to know what source port the bsc
uses to get this working since the bsc may use a different source
port due to NAT. Unfortunately, this can't be done from the MGCP signal
plane since the real source port is not known that the bsc uses is not
known.
This patch also reverts the MDCX handling until it is clear that we need
this special handling for this case.
In the bsc-nat side, the osmux socket initialization can be done from
the vty. This ensure that the osmux socket is available by the time the
bsc-nt receives the dummy load that confirms that the osmux flow has
been set up.
This change is required by the follow up patch. This change ensures that
the Osmux socket in the bsc-nat is already in place by the time this
receives the dummy load.
Back in March 2013, some structures and defines related to decoded
measurement reports have been moved from openbsc to libosmocore
(libosmocore e128f4663104ed64e33e362cff2566f36d65e658) so that they can
be used also from osmo-bts. This finally makes gsm_lchan follow suit
for osmo-bts.
Jacob Erlbeck
Harald Welte