d1ceca9d48
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 |
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| utils | ||
| .gitignore | ||
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| .mailmap | ||
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| Doxyfile.codec.in | ||
| Doxyfile.coding.in | ||
| Doxyfile.core.in | ||
| Doxyfile.ctrl.in | ||
| Doxyfile.gb.in | ||
| Doxyfile.gsm.in | ||
| Doxyfile.vty.in | ||
| Makefile.am | ||
| README.md | ||
| TODO-RELEASE | ||
| configure.ac | ||
| git-version-gen | ||
| libosmocodec.pc.in | ||
| libosmocoding.pc.in | ||
| libosmocore.pc.in | ||
| libosmoctrl.pc.in | ||
| libosmogb.pc.in | ||
| libosmogsm.pc.in | ||
| libosmosim.pc.in | ||
| libosmousb.pc.in | ||
| libosmovty.pc.in | ||
| osmo-release.mk | ||
| osmo-release.sh | ||
README.md
libosmocore - set of Osmocom core libraries
This repository contains a set of C-language libraries that form the core infrastructure of many Osmocom Open Source Mobile Communications projects.
Historically, a lot of this code was developed as part of the OpenBSC project, but which are of a more generic nature and thus useful to (at least) other programs that we develop in the sphere of Free Software / Open Source mobile communications.
There is no clear scope of it. We simply move all shared code between the various Osmocom projects in this library to avoid code duplication.
The libosmocore.git repository build multiple libraries:
- libosmocore contains some general-purpose functions like select-loop abstraction, message buffers, timers, linked lists
- libosmovty contains routines related to the interactive command-line interface called VTY
- libosmogsm contains definitions and helper code related to GSM protocols
- libosmoctrl contains a shared implementation of the Osmocom control interface
- libosmogb contains an implementation of the Gb interface with its NS/BSSGP protocols
- libosmocodec contains an implementation of GSM voice codecs
- libosmocoding contains an implementation of GSM channel coding
- libosmosim contains infrastructure to interface SIM/UICC/USIM cards
Homepage
The official homepage of the project is https://osmocom.org/projects/libosmocore/wiki/Libosmocore
GIT Repository
You can clone from the official libosmocore.git repository using
git clone git://git.osmocom.org/libosmocore.git
There is a cgit interface at http://git.osmocom.org/libosmocore/
Documentation
Doxygen-generated API documentation is generated during the build process, but also available online for each of the sub-libraries at http://ftp.osmocom.org/api/latest/libosmocore/
Mailing List
Discussions related to libosmocore are happening on the openbsc@lists.osmocom.org mailing list, please see https://lists.osmocom.org/mailman/listinfo/openbsc for subscription options and the list archive.
Please observe the Osmocom Mailing List Rules when posting.
Contributing
Our coding standards are described at https://osmocom.org/projects/cellular-infrastructure/wiki/Coding_standards
We us a gerrit based patch submission/review process for managing contributions. Please see https://osmocom.org/projects/cellular-infrastructure/wiki/Gerrit for more details
The current patch queue for libosmocore can be seen at https://gerrit.osmocom.org/#/q/project:libosmocore+status:open