Provide the definitions from 3GPP TS 28.062, Table 7.11.3.1.3-2 as
generally usable API.
Likely users:
- upcoming patch to improve conversion between S0-S15 and MultiRate
config, I900fda192742fa8f6dd54e9131ef1704b14cc41a
- osmo-msc to figure out conversion between SDP AMR mode-set and 3GPP TS
48.008 Permitted Speech S0-S15.
- osmo-bsc to choose AMR modes for channel activation from cfg /
permitted speech from MSC.
Related: SYS#5066
Change-Id: Icef7dd626d3d4641c66b8dd87e2047fc0ab547d1
The motivation behind adding and using the new API is explained in
the preceeding change [1]. Whenever any of the encoding functions
fails to encode either a Speech Codec or a Codec List IE, free()
the msgb and return NULL.
Change-Id: I28219b61b9347f0652f9fd0c717f6cdf3c63e8f9
Related: [1] I199ffa0ba4a64813238519178155dfc767aa3975
Related: SYS#6229
Unfortunately "-std=c99" is not sufficient to make gcc ignore code that
uses constructs of earlier C standards, which were abandoned in C99.
See https://lwn.net/ml/fedora-devel/Y1kvF35WozzGBpc8@redhat.com/ for
some related discussion.
Change-Id: I84fd99442d0cc400fa562fa33623c142649230e2
gsm0808_create_lcls_conn_ctrl() was adding the LCLS-Configuration IE twice.
Correct is LCLS-Configuration followed by LCLS-Connection-Status-Control
(TS 48.008 3.2.1.91)
Change-Id: I455ac7695ad33ef9073bea7d1711508717732607
Remove the paragraph about writing to the Free Software Foundation's
mailing address. The FSF has changed addresses in the past, and may do
so again. In 2021 this is not useful, let's rather have a bit less
boilerplate at the start of source files.
Change-Id: I5050285e75cf120407a1d883e99b3c4bcae8ffd7
Prepare for A5/4 support in osmo-msc.
Add new function gsm0808_create_cipher2() which takes a struct as
argument instead of individual fields. This is akin to e.g.
gsm0808_create_handover_request() below in the file, and allows
backwards compatibly extending the argument list without needing a new
function signature every time.
Add struct gsm0808_cipher_mode_command, as argument list for
gsm0808_create_cipher2(), with kc128 included.
Encode the Kc128 IE in gsm0808_create_cipher2().
Implement gsm0808_create_cipher() by calling gsm0808_create_cipher2().
Change-Id: Ib3906085e0c6e5a496a9f755f0f786238a86ca34
According to 3GPP TS 48.008, section 3.2.2.44, the Chosen Encryption
Algorithm IE, which may be included in the following messages:
- 3.2.1.2 ASSIGNMENT COMPLETE
- 3.2.1.8 HANDOVER REQUEST
- 3.2.1.10 HANDOVER REQUEST ACKNOWLEDGE
- 3.2.1.12 HANDOVER COMPLETE
- 3.2.1.25 HANDOVER PERFORMED
- 3.2.1.31 CIPHER MODE COMPLETE
is coded as follows:
0000 0001 No encryption used
0000 0010 GSM A5/1
0000 0011 GSM A5/2
0000 0100 GSM A5/3
0000 0101 GSM A5/4
0000 0110 GSM A5/5
0000 0111 GSM A5/6
0000 1000 GSM A5/7
basically A5/X => X + 1. All other values are Reserved for future
international use. As can be seen, value 0x00 is RFU. Passing
this value to some encoding functions would result in a PDU with
this IE omitted. Although, some functions would still encode
Chosen Encryption Algorithm IE with this RFU value.
Let's ensure that all functions behave consistently.
Change-Id: If10e433a8174eabe6aa6d2c2937bf9cf5d14d7c9
This is basically a successor of gsm0808_create_sapi_reject(), but
instead of hard-coding GSM0808_CAUSE_BSS_NOT_EQUIPPED, it allows
the caller to specify a cause value to be used. The old function
is now deprecated and should not be used.
Change-Id: Iefe5484d0fa02d5722b628b1dc237d51d3fb1a9b
Related: OS#4728
Follows patch I353adc1aa72377f7d4b3336d2ff47791fb73d62c that was merged too
soon. Applying my code review in form of this fixup patch.
Change-Id: I979bca0c6aaa8fe4feddda922bd2e6c1cb49585b
This reverts commit d1ceca9d48, as it
introduces regressions in both osmo-msc and osmo-nitb which have been
causing failing builds for several days now.
Change-Id: I4bd958d0cd2ab4b0c4725e6d114f4404d725fcf7
Implement better API around 3GPP TS 24.008 Mobile Identity coding.
struct osmo_mobile_identity is a decoded representation of the raw Mobile
Identity, with a string representation as well as dedicated raw uint32_t TMSI.
The aim is to remove all uncertainty about decoded buffer sizes / data types.
I have patches ready for all osmo programs, completely replacing the Mobile
Identity coding with this new API. Hence deprecate the old MI API.
New API functions provide properly size-checking implementations of:
- decoding a raw MI from a bunch of MI octets;
- locating and decoding MI from a full 3GPP TS 24.008 Complete Layer 3 msgb;
- encoding to a buffer;
- encoding to the end of a msgb.
Other than the old gsm48_generate_mid(), omit a TLV tag and length from
encoding. Many callers manually stripped the tag and value after calling
gsm48_generate_mid(). The aim is to leave writing a TL to the caller entirely,
especially since some callers need to use a TvL, i.e. support a variable-size
length of 8 or 16 bit.
New validity checks so far not implemented anywhere else:
- stricter validation of number of digits of IMSI, IMEI, IMEI-SV MI.
- stricter on filler nibbles to be 0xf.
Rationale:
While implementing osmo-bsc's MSC pooling feature in osmo-bsc, this API will be
used to reduce the number of times a Mobile Identity is extracted from a raw
RSL message.
Extracting the Mobile Identity from messages has numerous duplicate
implementations across our code with various levels of specialization.
https://xkcd.com/927/
To name a few:
- libosmocore: gsm48_mi_to_string(), osmo_mi_name_buf()
- osmo-bsc: extract_sub()
- osmo-msc: mm_rx_loc_upd_req(), cm_serv_reuse_conn(), gsm48_rx_mm_serv_req(),
vlr_proc_acc_req()
We have existing functions to produce a human readable string from a Mobile
Identity, more or less awkward:
- gsm48_mi_to_string() decodes a TMSI as a decimal number. These days we use
hexadecimal TMSI everywhere.
- osmo_mi_name_buf() decodes the BCD digits from a raw MI every time, so we'd
need to pass around the raw message bytes. Also, osmo_mi_name_buf() has the
wrong signature, it should return a length like snprintf().
- osmo-bsc's extract_sub() first uses gsm48_mi_to_string() which encodes the
raw uint32_t TMSI to a string, and then calls strtoul() via
tmsi_from_string() to code those back to a raw uint32_t.
Each of the above implementations employ their own size overflow checks, each
invoke osmo_bcd2str() and implement their own TMSI osmo_load32be() handling.
Too much code dup, let's hope that each and every one is correct.
In osmo-bsc, I am now implementing MSC pooling, and need to extract NRI bits
from a TMSI Mobile Identity. Since none of the above functions are general
enough to be re-used, I found myself again copy-pasting Mobile Identity code:
locating the MI in a 24.008 message with proper size checks, decoding MI
octets.
This time I would like it to become a generally re-usable API.
Change-Id: Ic3f969e739654c1e8c387aedeeba5cce07fe2307
The call identifier in the ASSIGNMENT COMMAND is encoded in the wrong
endieness. 3GPP TS 48.008, section 3.2.2.105 specifies that the least
significant byte should be transmitted first, which means that the
endieness here is little endian. Lets make sure that the endieness is
correctly transmitted, regardless of the host byte order.
Change-Id: I6468e502f552f99ab54aec9d4b1c169fdc0adfb8
Related: OS#4582
Function gsm0808_get_cipher_reject_cause() was previously available
in private gsm0808_utils.h. In practice, the exact same code is useful
to extract Cause IE value from any of the many other BSSMAP messages
which use it.
So let's rename it to gsm0808_get_cause() and make it avilable
to everyone to use.
Change-Id: Idf2b99e9ef014eba26e3d4f0f38c2714d3a0520a
See TS 08.08 section 3.2.1.34 SAPI "n" REJECT:
1) DLCI is a TV element, not V.
2) Cause is a TLV element and we have a special function to encode it.
Change-Id: I033afe556c06427d06ac55c4f78854a45e41aae6
IE GSM0808_IE_OSMO_OSMUX_SUPPORT (T, 1 byte) is sent in AoIP appended to
BSSMAP RESET in order to announce the peer that its MGW supports handling
Osmux streams upon call set up.
IE GSM0808_IE_OSMO_OSMUX_CID (TV, T 1 byte & V 1 byte) is sent in AoIP
during call set up:
* MSC->BSC Assignment Request
* BSC->MSC Assignemnt Complete
The 1 byte value contains the local Osmux CID, aka the recvCID aka CID where the
peer sending the Assign Req/Compl will look for Osmux frames on that
call. Hence, the peer receiving this CID value must use it to send Osmux
frames for that call.
As a result, a given call leg BSC<->MSC can have one different Osmux CID
per direction. For example:
* MS => MGW_BSC ==CID 0==> MGW_MSC
* MS <= MGW_BSC <=CID 1=== MGW_MSC
This allows for setups with 256 call legs per BSC on scenarios where NAT
is not a problem, where MSC can have a pool of 256 CID per MGW_BSC (or
remote peer).
Related: OS#2551
Change-Id: I28f83e2e32b9533c99e65ccc1562900ac2aec74e
osmo-bsc so far omits the AoIP Transport Layer Address from its Handover
Request Acknowledge message, which breaks inter-BSC Handover for AoIP.
Allow fixing that.
One quirk I really don't like about this: I would prefer to directly use struct
sockaddr_storage as a member of the struct gsm0808_handover_request_ack. Even
though struct sockaddr_storage appears in various function signatures, the
gsm0808.c actually also gets built on embedded systems that lack arpa/inet.h
(for me indicated by the ARM build job on jenkins). Compiling gsm0808.c works
only because the actual coding of struct sockaddr_storage is implemented in
gsm0808_util.c, which (apparently) does not get built on embedded and hence,
even though there are undefined references to e.g.
gsm0808_enc_aoip_trasp_addr() it works.
Related: I4a5acdb2d4a0b947cc0c62067a67be88a3d467ff (osmo-bsc)
Change-Id: Ia71542ea37d4fd2c9fb9b40357db7aeb111ec576
Change two instances of Speech Version values to enum gsm0808_permitted_speech.
It is often not trivial to find the right values for a uint8_t member, giving
the enum name makes it a lot easier/safer to use.
In gsm0808_create_handover_required(), use msgb_tv_put() so that the enum's
storage size doesn't matter. (Already used for handover_performed)
Fix typo in doc of gsm0808_create_handover_required().
Change-Id: I6387836bab76e1fa42daa0f42ab94fc14b70b112
This single function has a quite different behavior than the other
gsm0808_ functions in terms of how the resulting msgb l3h
pointers are set. Let's document that to avoid more confusion.
Change-Id: I0367760a588fc968c5a2dea46001ef1ee7965c8c
In Change-Id Id8a75e1da2d5f520064666e4ee413d1c91da6ae3 we recently
introduced adding the "CSFB INDICATOR" IE to the CLEAR COMMAND,
but we did so with a wrong length value.
Change-Id: I4d07d25fb03ca0f89fd7b94226c54309c77a010a
Closes: OS#3805
Related: OS#2778
When a call that was established in a CSFB context ends the CLEAR
COMMAND that is send from the BSC to the MSC should contain a CSFB
indication IE, which consists of just the IE byte itsslef. This
additional IE tells the BSC to include other CSFB related IEs into the
RR Release message.
Change-Id: Id8a75e1da2d5f520064666e4ee413d1c91da6ae3
Related: OS#3778
* add gsm0808_create_ass_compl2() with additional gsm0808_lcls_status
parameter and make gsm0808_create_ass_compl() into trivial wrapper
around it
* update tests accordingly
Change-Id: I547c6b8707123aa8c1ef636db88908df112d90a4
Related: OS#2487
Previously it could encode both incorrect values as well as incorrect
message. Let's fix this by explicitly checking for invalid values and
ensuring that at least one of the parameters is valid.
This function have no external or internal users so it's better to fix
type signature as well to match the rest of gsm0808_create_lcls_*().
Change-Id: I7b33a771acbd391c5f9a494d6450edb18511433f
In 3GPP TS 48.008 the Global Call Reference IE is only used in HANDOVER
REQUEST (§3.2.1.8) and ASSIGNMENT REQUEST (§3.2.1.1) messages which
also include LCLS Config and CSC parameters. Hence, there's no point in
using GCR encode/decode functions alone.
Introduce gsm0808_dec_lcls() and gsm0808_enc_lcls() as trivial wrappers
on top of GCR enc/dec routines which are made static. Adjust tests
accordingly. Test output intentionally left unchanged.
Change-Id: Icfbb2404e1a1d500243e2071173299b557369335
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
We currently have no generator function that can generate BSSMAP
HANDOVER PERFORMED messages. Lets add function for this.
Change-Id: I825106858bd89afc9837811b8fed2e8accc82441
Related: OS#3645
* add spec reference
* remove LCLS note: CI parameter is optional but have nothing to do with
LCLS
It's pretty hard to decipher from the spec what CI is useful for and we
have not used it anyway so let's just keep it as "Optional" for now.
Change-Id: I5552732afcec48047d993ae6ffb73a3e5d7c9202
* 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
Add values indicating that LCLS control/config/status value has not been
received yet.
Change-Id: I52dc6a52f5ee043ed2c1625ffecfd495e3c746b1
Related: OS#2487
* 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
* add note about (yet) unsupported standard feature
* use enum constant instead of hex value
Change-Id: I5cc5fc1ae8d5474dbc8d3385a493adf6420a3c98
Related: OS#3187
The function that generates the clear command takes a parameter
"reason", which is the cause code. Lets give it the name "cause" to have
a coherent naming scheme that matches the other functions and the 3gpp
specs.
Change-Id: I7b6c15e8fa8db13deef5041095944ca1c58fb99f
The api documentation names a parametery by a different name than it is
listed in the parameter list of the function. Lets make the apidoc
coherent.
Change-Id: Id21ed1e920fb64522a734f206efbe2871ec05b06
Andreas Eversberg
Neels Hofmeyr
Vadim Yanitskiy
Harald Welte
Keith Whyte
Pau Espin
Oliver Smith
Philipp Maier