Commit Graph

147 Commits

Author SHA1 Message Date
Max 7918f84aeb LCLS, TS 29.205: add GCR routines
Add functions to encode and decode Global Call Reference as per
3GPP TS 29.205 Table B 2.1.9.1 add corresponding tests.

Change-Id: Iee95aa4e5c056645b6cb5667e4a067097d52dfbf
Related: OS#2487
2018-12-14 13:15:39 +00:00
Philipp Maier 4f4905fac5 gsm0808: add encoder for cause codes and use it
At the moment the all gsm0808 cause codes are encoded directly using the
tlv API directly to put a one byte TLV field. This works ok for most
situations where the cause code consists of a single byte. However,
gsm0808 specifies a two byte cause code model where cause codes may be
extended up to two bytes. Instead of implementing the encoding over and
over and again, let's rather have an encoder function we can call.

- Add an encoder function that can generate single byte and extended
  cause codeds and makes the length decision automatically.

- Use only this function to append cause codes

Change-Id: I71d58fad89502a43532f60717ca022c15c73f8bb
2018-12-08 19:29:34 +00:00
Philipp Maier e190e032d9 gsm29118: add generator functions for GSM29118 messages
We already have some GSM29118 related definitions and functions in
libosmocore. Lets also add some functions to generate GSM29118 messages
(similar to those we have for GSM0808).

Change-Id: Ic87f8a771b87b52215d0a7451b67794557b80b8a
Related: OS#3615
2018-12-07 18:35:10 +01:00
Philipp Maier 225bdf4779 gsm0808: add message generator for BSSMAP HANDOVER PERFORMED
We currently have no generator function that can generate BSSMAP
HANDOVER PERFORMED messages. Lets add function for this.

Change-Id: I825106858bd89afc9837811b8fed2e8accc82441
Related: OS#3645
2018-12-03 13:54:31 +00:00
Pau Espin c8772517d9 gsm: Deprecate buggy gsm_arfcn2band API and introduce gsm_arfcn2band_rc
ARFCNs are values in well defined ranges. Until this patch, ARFCNs not
belonging to any band were blindly assigned to DCS1800 by
gsm_arfcn2band, causing unnoticed bugs and misconfigurations in
osmo-bsc.

Previous API gsm_arfcn2band cannot accomodate this kind of check easily,
so let's deprecate it to tell people to use a new API gsm_arfcn2band_rc
which performs this kind of checks and allows callers to log failures,
misconfigurations, etc.
At the same time, modify implementation of gsm_arfcn2band to abort if an
invalid ARFCN is passed, this way users of this API can notice they are
passing wrong data to it that most probably will produce unexpected
results.

Related: OS#3063
Change-Id: I780d452dcebce385469e32ef2fd844df6033393a
2018-11-20 16:56:28 +00:00
Max ed651d2485 Support cipher mode reject with extended cause
* add function to generate cipher mode reject with extended (2-byte)
  Cause IE
* add function to get (extended) Cause value
* add corresponding (extended cause) test
* update existing (non-extended cause) test
* use enum as a parameter for existing non-extended version to make
  interface more unified

Change-Id: Id5509b94a18180a44f45300caaa02b843c166fa3
Related: OS#3187
2018-11-19 05:52:28 +00:00
Max aa93463053 Update 3GPP TS 08.08 Cause handling
* add Class definitions
* add helper to check for extended bit
* add helper to get Cause's Class
* use enum in gsm0808_cause_name() and gsm0808_create_cipher_reject() to
  avoid confusion between class and cause
* update gsm0808_create_cipher_reject() comments

Change-Id: I31b31dfc22eb4b6b07089e1255246ac458125340
Related: OS#3187
2018-11-18 20:14:06 +00:00
Philipp Maier 086b345414 gsm29118: add value strings for SGSAP IEI
The value strings for the SGSAP IEI are missing, lets add a set of value
strings and a function to retrieve them.

Change-Id: I2787303174f74ffba86675bce2c12f680d8ea708
Related: OS#3615
2018-11-16 17:42:38 +01:00
Harald Welte de1da35d51 gsm23003: Add MME domain name related helper functions
osmo_gen_mme_group_domain(), osmo_gen_mme_group_domain() and
osmo_gen_home_network_domain()

Change-Id: Ia882d9db05ec0037e593aeebea21bc31adb680bb
2018-10-28 14:16:18 +01:00
Harald Welte 6721144c80 SGsAP protocol definitions (header + C file)
Change-Id: Idddfc9b851eb4c2fa7dd661a9ce1b03a04883109
2018-10-21 12:35:34 +00:00
Philipp Maier 8515d035ae gsm0808: add function to convert AMR S15-S0 to gsm0408 settings
Add a function to convert S0-S15 bits to struct gsm48_multi_rate_conf,
which hold the codec settings for AMR.

Change-Id: I973736273c236eee84decf15868190e339c3fed4
Related: OS#3548
2018-09-25 15:32:29 +00:00
Philipp Maier 5f2eb15074 gsm0808: add function to convert amr gsm0408 setings to gsm0808
Add a function to convert struct gsm48_multi_rate_conf, which holds the
codec settings for AMR, to S0-S15 bit representation as defined in
3GPP TS 48.008 3.2.2.49

This resurrects change-id I4e656731b16621736c7a2f4e64d9ce63b1064e98
which was reverted in I9e0d405e303ed86d23703ca6362e958dddb2f861
due to gsm0808_test failing.

The test failure is fixed by properly clearing the struct
gsm48_multirate_cfg prior to running tests (add memset(0)).

Change-Id: Ia782e21c206c15e840226d79b4209d13658ee916
Related: OS#3548
2018-09-19 14:01:10 +00:00
Neels Hofmeyr dd8c73cc6d Revert "gsm0808: add function to convert amr gsm0408 setings to gsm0808"
This reverts commit 2fd4fe6aa1.

As shown in https://jenkins.osmocom.org/jenkins/view/master/job/master-libosmocore/475/a2=default,a3=default,arch=amd64,label=osmocom-master-debian9/console

This commit breaks gsm0808_test with:

stderr:
--- expout	2018-09-16 22:37:31.382280438 +0200
+++ /n/s/dev/make/libosmocore/tests/testsuite.dir/at-groups/21/stdout	2018-09-16 22:37:31.426281372 +0200
@@ -78,9 +78,9 @@
 Input:
  m4_75= 0   smod=  0
  m5_15= 0   spare= 0
- m5_90= 0   icmi=  0
+ m5_90= 0   icmi=  1
  m6_70= 0   nscb=  0
- m7_40= 0   ver=   0
+ m7_40= 0   ver=   6
  m7_95= 0
  m10_2= 0
  m12_2= 0
@@ -92,9 +92,9 @@
 Input:
  m4_75= 1   smod=  0
  m5_15= 0   spare= 0
- m5_90= 0   icmi=  0
+ m5_90= 0   icmi=  1
  m6_70= 0   nscb=  0
- m7_40= 0   ver=   0
+ m7_40= 0   ver=   6
  m7_95= 0
  m10_2= 0
  m12_2= 0
@@ -106,9 +106,9 @@
 Input:
  m4_75= 0   smod=  0
  m5_15= 1   spare= 0
- m5_90= 0   icmi=  0
+ m5_90= 0   icmi=  1
[...]

Change-Id: I9e0d405e303ed86d23703ca6362e958dddb2f861
2018-09-16 21:02:25 +00:00
Philipp Maier 2fd4fe6aa1 gsm0808: add function to convert amr gsm0408 setings to gsm0808
Add a function to convert struct gsm48_multi_rate_conf, which holds the
codec settings for AMR, to S0-S15 bit representation as defined in
3GPP TS 48.008 3.2.2.49

Change-Id: I4e656731b16621736c7a2f4e64d9ce63b1064e98
Related: OS#3548
2018-09-14 16:24:10 +02:00
Neels Hofmeyr 2c79d55934 gsm0808: implement BSSMAP Classmark Request
Related: OS#3043
Change-Id: I4a2e1d3923e33912579c4180aa1ff8e8f5abb7e7
2018-09-13 14:27:26 +00:00
Keith Whyte 3cdaa8d525 Add CC_CAUSE value_string array
Adds a value_string array for GSM 04.08 Call Control
cause values

Change-Id: I296f208581ce2550805f9d96e20f7319e1199023
2018-09-02 12:33:54 +02:00
Vadim Yanitskiy 30cfeeb4a0 libosmogsm: (re)introduce gsm48_push_l3hdr()
There was gsm0480_l3hdr_push() declared in a header file, but
not exposed in 'libosmogsm.map'. Furthermore, for some reason
it was a part of GSM 04.80 API, what is not actually correct.

Let's rename this symbol, and properly expose it as a part of
the GSM 04.08 API. Also, let's introduce an auxiliary wrapper
for messages, where the transaction identifier is required
(see GSM 04.07, section 11.2.3.1.2).

Change-Id: I8a045efe8335d83fcbe8d43eb180972e3b1d9dda
2018-08-05 23:21:43 +07:00
Harald Welte 5a7740d1db re-introduce ipa_ccm_idtag_parse_off()
In the previous commit we deprecated ipa_ccm_idtag_parse() but
also removed ipa_ccm_idtag_parse_off(), for which I couldn't find
any users.  However, legacy openbsc.git still uses this function,
so let's re-introiduce it in its original form.

Change-Id: Ibfe53b04340eb355c8bfb8453a2af1522a4b6baf
2018-08-01 17:42:06 +02:00
Harald Welte 7869baf843 Deprecate ipa_ccm_idtag_parse() with ipa_ccm_id_{get,resp}_parse()
In the past, the function ipa_ccm_idtag_parse() was used to parse
the payload of IPA CCM ID RESP packets.  However, the function was
based on a possible misunderstanding of the message encoding, and
callers actually counted the first (upper) length nibble as part
of the header and passed a pointer to the second
(lower) length nibble of the first TLV into this function.  As such,
it was unfixable, and had to be replaced with a new function called
ipa_ccm_id_resp_parse().  At the same time, we also add
ipa_ccm_id_get_parse() to parse the slightly different format of
the IPA CCM ID GET payload.

We can never be 100% sure what is "correct", as our understanding
of the protocol is entirely based on protocol analysis, without any
official documentation available.

This patch also introduces unit test coverage for both of the new
functions.

Revert "ipa: Add libosmogsm.map entry for ipa_ccm_idtag_parse_off"
This reverts commit 7f31c90b80.

Revert "ipa: Properly parse LV stream of a ID_GET request"
This reverts commit f558ed4bb9.

It introduced a function/behavior that was not originally intended:
The parse of IPA CCM ID GET (8bit length followed by 1 byte tag
and variable-length payload) instead of the IPA CCM ID RESP (16bit
length followed by 1 byte tag and variable-length payload).

Change-Id: I1834d90fbcdbfcb05f5b8cfe39bfe9543737ef8f
2018-08-01 13:38:17 +02:00
Harald Welte 9b04c17c7a oap_client: Rename symbols with osmo_ prefix
As we're moving this to a common/shared library now, we need to use
the osmo_ namespace prefix for symbol names, struct/type names and
constants.

Change-Id: Ie36729996abd30b84d1c30a09f62ebc6a9794950
2018-07-30 12:50:51 +02:00
Harald Welte fdd366ed1b import oap_client into libosmogsm
This imports the code from osmo-msc 6afef893e17bce67e4d4119acd34d480ed03ba77
with minimal changes to make it compile.  Symbol renaming to osmo_
prefix is done separately in a follow-up patch to have a as-clean-as-possible
import first.

Change-Id: I9bc38102318da02d1fe46ef516df3cfd6bf8e3da
2018-07-30 12:16:11 +02:00
Harald Welte 7ecc4a3171 04.80: New gsm0480_gen_{reject,return_error}() functions
Add functions to generate TS 04.80 (supplementary services)
Reject and ReturnError components.

Change-Id: I6e5ee39c3d03364f7833ec717593d5ddb0a4c5f9
2018-07-29 14:39:36 +00:00
Harald Welte b0d9594081 USSD: Introduce gsm0480_gen_ussd_resp_7bit()
Contrary to the existing gsm0480_create_ussd_resp(), the new function
only generates the value part of the FACILITY IE, and not the IE
Tag/Length or the 04.08 L3 header.  This is needed in the context of
GSUP-encapsulated USSD, as here we don't work with L3 messages, but
only pass on the FACILITY IE value.

Change-Id: Ide240279240322f643e142229eb7829f538c6314
2018-07-29 14:39:36 +00:00
Harald Welte 88fa5a3e1e gsm0480: Factor out msgb allocation helper function
Change-Id: If25b467481023eadaaf3f78157eceff4b81d24d2
2018-07-29 14:39:36 +00:00
Pau Espin f2cda621c0 gsm0808: Add value_string for encryption algorithms
Change-Id: Iadf6460c438d02c53c2eaa9e42d51844ad28859a
2018-07-12 20:58:23 +02:00
Philipp Maier cdd05816da gsm_08_08: gsm0808_permitted_speech does not have value strings
enum gsm0808_permitted_speech does not have any value strings. Lets
add value strings to make debugging easier.

Change-Id: I5b5612a5df2758b0137a34c17f7c8c2b3f07c806
2018-07-12 18:18:39 +00:00
Neels Hofmeyr 60f3153125 add and tweak inter-BSC HO API
Add:
gsm0808_create_handover_detect()
gsm0808_create_handover_complete()
gsm0808_create_handover_failure()

To existing structs gsm0808_old_bss_to_new_bss_info and
gsm0808_handover_required, add a final 'more_items' flag that makes future
extensions API and ABI compatible.

Fix the msgb string for Handover Request Ack.

Extend some API doc comments.

Related: OS#2283 (inter-BSC Handover, BSC side, MT)
Change-Id: I03ee7ce840ecfa0b6a33358e7385528aabd4873f
2018-06-18 17:32:58 +00:00
Harald Welte b1a35d63b9 gsm 04.80: Add value_string for component type and op code
Change-Id: I2615a88db5224d65f37c7cc505e183ec8b196e8a
2018-06-16 18:39:59 +02:00
Harald Welte 6a6a609309 gsup: Add value_string for Session State IE
In Change-Id I1cee271fed0284a134ffed103c0d4bebbcfde2a8 we added support
for a new session state IE, but we didn't add any value_string array
for string conversion of it.  Let's fix this.

Change-Id: I3d9f087786dc37c42498fa9a2be07483ec93ba7b
2018-06-16 11:11:08 +02:00
Harald Welte 520ebc17d9 gsup: Add osmo_gsup_get_err_msg_type() function
This function can be used to resolve the error message type for
a given message type.  Can be used by generic error handlers that
work for any incoming message type.

Change-Id: Ic637bec53dd7fe3ec83da99b49b4eae34d5602b2
2018-06-11 20:28:18 +02:00
Vadim Yanitskiy 5a09f75c1e gsm/gsm0480: refactor and expose gsm0480_parse_facility_ie()
This function can be used when there is only a part of GSM 04.80
message available - Facility IE, e.g. when a message is carried
over GSUP/MAP. Let's expose it.

Refactoring includes the following:

  - adding the 'gsm0480_' prefix;
  - correcting inverted return value;
  - cosmetic code style changes.

Change-Id: I623c39ffbe6cdee65eade8435a2faa04d0da193e
2018-06-11 23:50:00 +07:00
Vadim Yanitskiy 52e44121db gsm/gsm0480.c: introduce gsm0480_extract_ie_by_tag()
In some cases, there is no need to parse the whole message,
e.g. during the conversion from DTAP to GSUP/MAP. This
function can be used to extract given IE from a message.

Change-Id: I3989d061903352473305f80712f1a1560d05df3d
2018-06-11 23:45:48 +07:00
Harald Welte ebd362dbd2 gsm0808: Add value_string for LCLS related IEs
Change-Id: I18d7a29496929c761aeaba9c0aee847befc13108
2018-06-02 14:44:09 +02:00
Harald Welte 64e807c4bc gsm0808: Add encoding functions for LCLS BSSMAP messages
Change-Id: Ib83143e467df068b7d462a8e51d94b9d961ce18f
2018-05-30 01:36:04 +02:00
Neels Hofmeyr b662b36da0 add gsm0808_create_handover_request_ack()
Related: OS#2283 (inter-BSC Handover, BSC side, MT)
Change-Id: I692292a06c7d66004404560dc4ed933ca9107f9b
2018-05-27 22:04:17 +02:00
Neels Hofmeyr 70aba3ffe2 add support for gsm0808 HANDOVER REQUIRED message
Related: OS#2283 (inter-BSC Handover, BSC side, MO)
Change-Id: Idb6dc3eab0282158a17091d97ed77c1e2e3eb3c2
2018-05-27 22:04:17 +02:00
Neels Hofmeyr 38e58416b1 add gsm0808_cell_id_to_list()
The idea is to be able to add a gsm0808_cell_id to a gsm0808_cell_id_list2:
first convert it to a list, then re-use gsm0808_cell_id_list_add(). It will be
used by osmo-bsc to manage neighbor-BSS cell identifiers from VTY.

Change-Id: Ibf746ac60b1b1e920baf494b396658a5ceabd788
2018-05-27 21:54:12 +02:00
Harald Welte dfd85137cf mncc: properly export osmo_mncc_name()
For some strange reason, the osmo_mncc_name() inline function
was not in the mncc.h header, but in the mncc.c file. Let's fix that.

Change-Id: I2c3666510c981dffa4ba25bed517fd7ebd1250f5
2018-05-24 12:19:45 +02:00
Neels Hofmeyr afacc2be9f add gsm0808 channel enum to IE val conversion functions
Add:
- gsm0808_current_channel_type_1()
- gsm0808_permitted_speech()
- gsm0808_chosen_channel()
- gsm0808_channel_type_name()

gsm0808_permitted_speech() is moved from osmo-bsc's bssap_speech_from_lchan();
gsm0808_chosen_channel() is moved from osmo-bsc's lchan_to_chosen_channel();

Rationale: will be re-used by inter-BSC handover, makes sense to keep with the
other gsm0808 utils.

Related: OS#2283 (inter-BSC handover, BSC side)
Change-Id: I8a3cc5d4548e9a78d945d54c69ccced251edcec9
2018-05-08 20:32:56 +00:00
Neels Hofmeyr a4399c8891 add gsm0808_cell_{id,id_list}_name() and friends
Provide comprehensive API to obtain string representations of Cell Identifiers
and -Lists.

Change gsm0808_test.c to use the new functions (which simplifies the output a
bit), so that we don't duplicate printing code in gsm0808_test.c, and so that
the not-so-trivial printing code is also tested.

In gsm0808_test, also test gsm0808_cell_id_list_name_buf()'s return value and
truncation behavior.

The rationale for gsm0808_cell_id_list_name(), i.e. printing an entire list of
cell identifiers, is that even though the maximum is 127 elements, a list of
more than a few elements is hardly ever expected in practice (even more than
one element isn't actually expected: either "entire BSS" or a single LAC). It
is thus useful to log the entire list when it shows up in Paging and Handover.

Change-Id: I9b2106805422f96c5cc96ebb9178451355582df3
2018-04-18 02:38:37 +02:00
Neels Hofmeyr 250e7f7d30 add gsm0808_{enc,dec}_cell_id
Clarify semantics and micro-optimise for the case of single Cell Identifer IEs.
Test in gsm0808_test.c

So far we have gsm0808_enc_cell_id_list2(), but there also exist instances of
single Cell Identifiers (3GPP TS 48.008 3.2.2.17).

It is possible to decode the same using the cell identifier list API, but this
forces the caller to also keep a full struct gsm0808_cell_id_list2 with all its
127 entries around.

E.g. for handover, there are two Cell Identifiers (Serving and Target); I'd
need two full cell id lists for each, and these would be dynamically allocated
for each handover operation, whether it uses them or not.

Related: OS#2283 (inter-BSC HO, BSC side)
Change-Id: I9f9c528965775698ab62ac386af0516192c4b0cc
2018-04-13 05:38:47 +02:00
Neels Hofmeyr a78b22ba20 add tlv_parse2(), capable of multiple instances of the same IE
Allow passing multiple struct tlv_parsed in an array, to allow parsing as many
repeated IEs as are expected by the caller.

From tlv_parse(), call tlv_parse2() with dec_multiple = 1 to yield the previous
behavior. tlv_parse() remains valid API.

An example of multiple IEs is the BSSMAP Handover Request, containing Cell
Identifier (Serving) and Cell Identifier (Target), both defined by 3GPP TS
48.008 3.2.2.17 with identical IE tags; both are mandatory.

Related: OS#2283 (inter-BSC HO, BSC side)
Change-Id: Id04008eaf0a1cafdbdc11b7efc556e3035b1c84d
2018-04-13 05:28:09 +02:00
Neels Hofmeyr 74663d97c6 add gsm0808_cell_id_list_add() to combine two cell identifier lists
This will be used by the upcoming neighbor_ident API in osmo-bsc, where the vty
interface allows composing neihbor BSS cell identifier lists, and we want to
allow adding individual items from individual user commands.

It will also be useful to accumulate cell identifiers in case a subscriber sees
multiple alternative cells from a neighboring BSS, and we want to pass these on
to the MSC in a Handover Required.

Related: OS#2283 (inter-BSC HO, BSC side)
Change-Id: I5781f5fa5339c92ab2e2620489b002829d206925
2018-04-13 05:28:09 +02:00
Neels Hofmeyr 43496206c1 add osmo_cgi_name()
This will be used by cell idenitifier list code, like upcoming neighbor_ident
VTY in osmo-bsc and regression tests.

Change-Id: Iebc5cdf61b697b1603900993fc265af3eca0cedf
2018-04-13 05:27:02 +02:00
Neels Hofmeyr aead241df0 add gsm48_reject_value_names
There seems to be quite some confusion / overlap between enum
gsm48_reject_value, gsm48_gsm_cause and gsm48_gmm_cause. I tried to go with
gsm48_gsm_cause_names[], but e.g. GSM48_REJECT_CONGESTION is not represented.

Instead of attempting to mix/merge those enums, provide a separate value string
array for enum gsm48_reject_value.

This will be used by osmo-msc's libvlr (refactoring of FSM result handling),
I27bf8d68737ff1f8dc6d11fb1eac3d391aab0cb1.

Change-Id: I6661f139e68a498fb1bef10c266c2f064b72774a
2018-04-09 17:57:15 +02:00
Philipp Maier dbb7659208 gsm0808: Add value strings for BSSMAP cause codes
libosmocore has no value strings for BSSMAP cause codes yet.

- Add value strings for BSSMAP cause codes and a function
  to retrieve them

Change-Id: I313dd8d7b06374e1e35ddc18b7a42562d9e25d45
Related: OS#1609
2018-03-29 15:00:41 +02:00
Harald Welte d86055b431 abis_nm: Introduce abis_nm_dump_foh()
This is a more modern way of printing the Abis OML Formatted Object
Header, without assuming that it would be used in a log statement
or prescribing the log level to be used.

Change-Id: I9b2c2afec28882b817d104d5b062651ade7aadd8
2018-03-17 11:28:31 +00:00
Stefan Sperling 11a4d9dd91 support for more cell ID list types in libosmocore
Introduce gsm0808_dec_cell_id_list2() with supports additional types of
cell identifier lists. The new parsing routines are based on similar
routines used by the paging code in osmo-bsc's osmo_bsc_bssap.c.

Likewise, introduce gsm0808_enc_cell_id_list2() with support for the
same additional types of cell identifier lists.

The old API using struct gsm0808_cell_id_list is deprecated.
The previous definition was insufficient because it assumed that all
decoded cell ID types could be represented with a single uint16_t.
It was declared in a GSM protocol header (gsm/protocol/gsm_08_08.h)
despite being a host-side representation of data in an IE.
The only user I am aware of is in osmo-msc, where this struct is used
for one local variable. osmo-msc releases >= 1.1.0 make use of this API.

While here, fix a small bug in a test:
test_gsm0808_enc_dec_cell_id_list_bss() set the cell ID type to 'LAC'
but obviously wants to use type 'BSS'.

Change-Id: Ib7e754f538df0c83298a3c958b4e15a32fcb8abb
Related: OS#2847
2018-03-13 14:28:15 +01:00
Philipp Maier 680acae725 features: move bts feature related functionality to libosmocore
osmo-bsc and osmo-bts share enums and value strings to describe
feature data that is exchanged via OML (manufacturer id) on startup.
Also the functions to set and get the respecitive bits in the feature
bitvectors are in osmo-bsc and osmo-bts. This is a code duplication
and should be resolved.

- add enum osmo_bts_features (replaces enum gsm_bts_features)
- add osmo_bts_features_descs (replaces gsm_bts_features_descs)
- add osmo_bts_set_feature (replaces gsm_btsmodel_set_feature)
- add osmo_bts_has_feature (replaces gsm_btsmodel_has_feature)

Change-Id: Id0c35aef11aa49aa40abe7deef1f9dbd12210776
2018-03-02 16:54:16 +01:00
Neels Hofmeyr 721aa6ded9 gsm: add osmo_mnc_from_str(), osmo_mnc_cmp(), osmo_plmn_cmp() for 3-digit MNC
osmo_mnc_from_str() preserves leading zeros in the string and is useful for
VTY config parsing (osmo-bsc, osmo-msc, osmo-sgsn, osmo-pcu).

osmo_{plmn,mnc}_cmp() takes care of the slight intricacy of ignoring the 3-digit flag
if the MNC is anyway >99. Will be used by osmo-sgsn.git and osmo-bsc.git.  (All
current users just care about identical MNC, but a proper cmp doesn't hurt.)

Change-Id: Ib7176b1d65a03b76f41f94bc9d3293a8a07d24c6
2018-02-28 19:26:43 +01:00