Fix PS RAB Assignment operation:
- add #include "config.h"
- fix uncompilable code in ENABLE_PFCP sections.
A series of oversights made me completely break PFCP / UPF operation for
PS RAB Assignments in this commit:
'context map: introduce RUA and SCCP FSMs to fix leaks'
ed424d5be4
I6ff7e36532ff57c6f2d3e7e419dd22ef27dafd19
- In my HNBGW_Tests.ttcn, I used osmo-hnbgw-with-pfcp.cfg, but failed to
set mp_enable_pfcp_tests := true in HNBGW_Tests.cfg.
- Hence I was under the impression that I was testing PFCP via UPF when
really I wasn't. So I did not notice that:
- in the new files context_map_rua.c and context_map_sccp.c, the
ENABLE_PFCP macro was always unset because I forgot to
#include "config.h".
- Hence I did not notice that the moved PFCP RAB code was never once
compiled or run.
My bad, that was really dumb.
Related: SYS#6297
Change-Id: I5df5073f0092ecdfd73d5d08207ca4042154eab1
Silence the error log about "unknown" PCSTATE prim.
Todo / coming up: instead of ignoring, detect a Destination Unavailable
from prim->u.pcstate and disconnect all conns with that particular CN
link.
Depends: libosmo-sccp If381f537ab91af1feef7f0e51921217f27e18e6a
Change-Id: I547387a5cc14ccb506be04ac785e6807fc4e6a96
Refactor the entire RUA <-> SCCP connection-oriented message forwarding:
- conquer confusion about hnbgw_context_map release behavior, and
- eradicate SCCP connection leaks.
Finer points:
== Context map state ==
So far, we had a single context map state and some flags to keep track
of both the RUA and the SCCP connections. It was easy to miss connection
cleanup steps, especially on the SCCP side.
Instead, the two FSMs clearly define the RUA and SCCP conn states
separately, and each side takes care of its own release needs for all
possible scenarios.
- When both RUA and SCCP are released, the context map is discarded.
- A context map can stay around to wait for proper SCCP release, even if
the RUA side has lost the HNB connection.
- Completely drop the async "context mapper garbage collection", because
the FSMs clarify the release and free steps, synchronously.
- We still keep a (simplified) enum for global context map state, but
this is only used so that VTY reporting remains mostly unchanged.
== Context map cleanup confusion ==
The function context_map_hnb_released() was the general cleanup function
for a context map. Instead, add separate context_map_free().
== Free context maps separately from HNB ==
When a HNB releases, talloc_steal() the context maps out of the HNB
specific hnb_ctx, so that they are not freed along with the HNB state,
possibly leaving SCCP connections afloat.
(It is still nice to normally keep context maps as talloc children of
their respective hnb_ctx, so talloc reports show which belongs to
which.)
So far, context map handling found the global hnb_gw pointer via
map->hnb_ctx->gw. But in fact, a HNB may disappear at any point in time.
Instead, use a separate hnb_gw pointer in map->gw.
== RUA procedure codes vs. SCCP prims ==
So far, the RUA rx side composed SCCP prims to pass on:
RUA rx ---SCCP-prim--> RANAP handling ---SCCP-prim--> SCCP tx
That is a source of confusion: a RUA procedure code should not translate
1:1 to SCCP prims, especially for RUA id-Disconnect (see release charts
below).
Instead, move SCCP prim composition over to the SCCP side, using FSM
events to forward:
RUA rx --event--> RUA FSM --event--> SCCP FSM --SCCP-prim--> SCCP tx
+RANAP +RANAP +RANAP
RUA tx <--RUA---- RUA FSM <--event-- SCCP FSM <--event-- SCCP rx
+RANAP +RANAP +RANAP
Hence choose the correct prim according to the SCCP FSM state.
- in hnbgw_rua.c, use RUA procedure codes, not prim types.
- via the new FSM events' data args, pass msgb containing RANAP PDUs.
== Fix SCCP Release behavior ==
So far, the normal conn release behavior was
HNB HNBGW CN
| --id-Disconnect--> | ---SCCP-Released--> | Iu-ReleaseComplete
| | <--SCCP-RLC-------- | (no data)
Instead, the SCCP release is now in accordance with 3GPP TS 48.006 9.2
'Connection release':
The MSC sends a SCCP released message. This message shall not contain
any user data field.
i.e.:
HNB HNBGW CN
| --id-Disconnect--> | ---Data-Form-1(!)--> | Iu-ReleaseComplete
| | <--SCCP-Released---- | (no data)
| | ---SCCP-RLC--------> | (no data)
(Side note, the final SCCP Release Confirm step is taken care of
implicitly by libosmo-sigtran's sccp_scoc.c FSM.)
If the CN fails to respond with SCCP-Released, on new X31 timeout,
osmo-hnbgw will send an SCCP Released to the CN as fallback.
== Memory model for message dispatch ==
So far, an osmo_scu_prim aka "oph" was passed between RUA and SCCP
handling code, and the final dispatch freed it. Every error path had to
take care not to leak any oph.
Instead, use a much easier and much more leakage proof memory model,
inspired by fixeria:
- on rx, dispatch RANAP msgb that live in OTC_SELECT.
- no code path needs to msgb_free() -- the msgb is discarded via
OTC_SELECT when handling is done, error or no error.
- any code path may also choose to store the msgb for async dispatch,
using talloc_steal(). The user plane mapping via MGW and UPF do that.
- if any code path does msgb_free(), that would be no problem either
(but none do so now, for simplicity).
== Layer separation ==
Dispatch *all* connection-oriented RUA tx via the RUA FSM and SCCP tx
via the SCCP FSM, do not call rua_tx_dt() or osmo_sccp_user_sap_down()
directly.
== Memory model for decoded ranap_message IEs ==
Use a talloc destructor to make sure that the ranap_message IEs are
always implicitly freed upon talloc_free(), so that no code path can
possibly forget to do so.
== Implicit cleanup by talloc ==
Use talloc scoping to remove a bunch of explicit cleanup code. For
example, make a chached message a talloc child of its handler:
talloc_steal(mgw_fsm_priv, message);
mgw_fsm_priv->ranap_rab_ass_req_message = message;
and later implicitly free 'message' by only freeing the handler:
talloc_free(mgw_fsm_priv)
Related: SYS#6297
Change-Id: I6ff7e36532ff57c6f2d3e7e419dd22ef27dafd19
The SCCP CR payload length limit is now implemented in libosmo-sigtran
v1.7.0. The limit no longer needs to be enforced in osmo-hnbgw.
This reverts commit 2c91bd66a1,
except for keeping the cfg option, marked deprecated, and not doing
anything.
Fixes: OS#5906
Related: SYS#5968
Related: OS#5579
Depends: I174b2ce06a31daa5a129c8a39099fe8962092df8 (osmo-ttcn3-hacks)
Change-Id: I18dece84b33bbefce8617fbb0b2d79a7e5adb263
Clean up SCCP connections when a HNB disconnects.
When a HNB disconnects, we clean up all RUA <-> SCCP connection state
for that HNB. In that cleanup, discarding the SCCP connection is so far
missing.
Add a flag indicating true between SCCP CC and DISCONNECT. Hence we can
tell during context_map_deactivate() whether the cleanup is graceful
(DISCONNECT already sent) or non-graceful (need to DISCONNECT).
Change-Id: Icc2db9f6c0b2d0a814ff1110ffbe5e8f7f629222
For the benefit of skipping decoding of all PS RANAP and RUA messages,
introduce code dup: decode CS and PS separately.
Related: SYS#5895
Change-Id: Ifb57bad6a0d5ff263e4c6c3facc51620e110e7d2
It is reported that a third-party SGSN is rejecting SCCP CR when the
SCCP message part exceeds a certain length. The solution is to first
send an SCCP CR without payload, and send the payload in a DT later.
Add config option
hnbgw
sccp cr max-payload-len <0-999999>
If the RANAP payload surpasses the given length, osmo-hnbgw will first
send an SCCP CR without payload, cache the RANAP payload, and put that
in an SCCP DT once the SCCP CC is received.
The original idea was to limit the size of the entire SCCP part of the
message, but I'm currently not sure how to determine that without
copying much of the osmo_sccp code. I figured using a limit on the RANAP
payload is sufficient. To avoid the error with above third-party SGSN,
the easy solution is to set max-payload-len to 0, so that we always get
a separate SCCP CR without payload.
Related: SYS#5968
Related: I827e081eaacfb8e76684ed1560603e6c8f896c38 (osmo-ttcn3-hacks)
Change-Id: If0c5c0a76e5230bf22871f527dcb2dbdf34d7328
Upcoming patch adds to this function. Let me first combine those four
LOGP() to a single one, use proper osmo_sccp_addr_to_str_c(OTC_SELECT).
To be able to use OTC_SELECT, switch hnbgw.c to osmo_select_main_ctx().
Related: SYS#5968
Change-Id: I1e0ea0a883e8cf65e6cfb45ed9b6f3d8fb7c59eb
osmo-hnbgw lacks support for an co-located media gateway. This makes it
virtually impossible to isolate the HNB from the core network properly.
Lets add MGCP support to osmo-hnbgw so that it can control a co-located
media gateway to relay the RTP streams between HNB and core network.
Change-Id: Ib9b62e0145184b91c56ce5d8870760bfa49cc5a4
Related: OS#5152
Neels Hofmeyr
Neels Hofmeyr
Pau Espin
Philipp Maier