The previous implementation of msc_send_ussd_release_complete() was
based on gsm0480_create_ussd_release_complete(), that doesn't
allow to specify GSM 04.07 transaction identifier.
The ability to specify particular transaction identifier
is required for handling multiple SS/USSD transactions.
Change-Id: Id2975c3383f18e83124ba38927c03980d67ddadb
Depends Change-Id: (libosmocore) Ie3ac85fcef90a5e532334ba3482804d5305c88d7
In preparation for inter-BSC and inter-MSC handover, we need to separate the
subscriber management logic from the actual RAN connections. What better time
to finally rename gsm_subscriber_connection.
* Name choice:
In 2G, this is a connection to the BSS, but even though 3GPP TS commonly talk
of "BSS-A" and "BSS-B" when explaining handover, it's not good to call it
"bss_conn": in 3G a BSS is called RNS, IIUC.
The overall term for 2G (GERAN) and 3G (UTRAN) is RAN: Radio Access Network.
* Rationale:
A subscriber in the MSC so far has only one RAN connection, but e.g. for
inter-BSC handover, a second one needs to be created to handover to. Most of
the items in the former gsm_subscriber_connection are actually related to the
RAN, with only a few MM and RTP related items. So, as a first step, just rename
it to ran_conn, to cosmetically prepare for moving the not strictly RAN related
items away later.
Also:
- Rename some functions from msc_subscr_conn_* to ran_conn_*
- Rename "Subscr_Conn" FSM instance name to "RAN_conn"
- Rename SUBSCR_CONN_* to RAN_CONN_*
Change-Id: Ic595f7a558d3553c067f77dc67543ab59659707a
Since we don't process SS/USSD requests in OsmoMSC anymore, there
are some useless GSM 04.80 functions remained from the past.
In particular, this change does the following:
- removes both gsm0480_send_{ussd_response|return_error}
functions because they are not used anymore;
- changes symbol prefix from 'gsm0480_' to 'msc_', in order to
avoid possible conflicts with the libosmogsm's GSM 04.80 API;
- cleans up useless includes;
Change-Id: I2990d8627bce0ce6afb1dcf6b11bb194292380d3
There is no need to pass a pointer to a ss_request struct when
calling the gsm0480_send_ussd_* functions, because they only
use both transaction ID and InvokeID from there, which may
be passed directly.
This change allows one to use this API without parsing the
whole GSM 04.80 message, or when parsing is failed. Moreover,
if InvokeID is not available, one can pass any incorrect,
(e.g. negative) value, so the universal NULL tag will be used.
Finally, setting a TI flag is also up to the caller.
Change-Id: I13d5abbfdcf8238ebaf0566c420f09cd9255b648
There are error and problem codes defined by GSM TS 04.80:
- Error codes are used when a message is structured correctly,
but something is wrong in context of the current operation.
Usually they are carried by 'Return Error' component.
- Problem codes are used when something is wrong with the
message structure, or with carried values. They are
carried by 'Reject' component.
There are three groups of them (see table 3.13):
- General Problem Codes (table 3.14),
- Invoke Problem Codes (table 3.15),
- Return Result Problem Codes (table 3.16),
- Return Error Problem Codes (table 3.17).
The first group is general purpose, and can be sent in
response to any kind of message, excluding 'Reject' itself.
Other ones are bound to specific component types, such as
'Invoke', 'Return Result' and 'Return Error'.
For some reason, a 'Reject' component with the general problem
code 'GSM_0480_GEN_PROB_CODE_UNRECOGNISED' was always used in
OsmoMSC. Even when the message structure is correct.
Let's properly indicate errors in the following way:
- 'Reject' with GSM_0480_GEN_PROB_CODE_UNRECOGNISED
when the gsm0480_decode_ss_request() fails to decode
a message. It can only return 0 or 1, so it's hard to
guess which exact part of message caused the error.
- 'Return Error' with GSM0480_ERR_CODE_ILLEGAL_SS_OPERATION
when the operation code is not related to USSD.
- 'Return Error' with GSM0480_ERR_CODE_UNEXPECTED_DATA_VALUE
when the requested USSD code is unhandled (not supported).
There is a TTCN-3 testcase for this:
https://gerrit.osmocom.org/9470/
Change-Id: I800e7ec98dc9d0bca2d45a8b8255d60253d63e14
This change removes a few USSD specific declarations, which are
not actually used now, and probably accidentally migrated from
legacy OpenBSC.
Change-Id: Id57a24b92790d3ce0f9c7343d060f511e2b979c7
Vadim Yanitskiy