mirror of https://gerrit.osmocom.org/libosmocore
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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| .. | ||
| milenage | ||
| Makefile.am | ||
| a5.c | ||
| abis_nm.c | ||
| apn.c | ||
| auth_comp128v1.c | ||
| auth_comp128v23.c | ||
| auth_core.c | ||
| auth_milenage.c | ||
| auth_xor.c | ||
| bts_features.c | ||
| cbsp.c | ||
| comp128.c | ||
| comp128v23.c | ||
| gan.c | ||
| gea.c | ||
| gprs_cipher_core.c | ||
| gprs_gea.c | ||
| gprs_rlc.c | ||
| gsm48.c | ||
| gsm48_arfcn_range_encode.c | ||
| gsm48_ie.c | ||
| gsm48_rest_octets.c | ||
| gsm0341.c | ||
| gsm0411_smc.c | ||
| gsm0411_smr.c | ||
| gsm0411_utils.c | ||
| gsm0414.c | ||
| gsm0480.c | ||
| gsm0502.c | ||
| gsm0808.c | ||
| gsm0808_utils.c | ||
| gsm23003.c | ||
| gsm23236.c | ||
| gsm29118.c | ||
| gsm29205.c | ||
| gsm48049.c | ||
| gsm_04_08_gprs.c | ||
| gsm_utils.c | ||
| gsup.c | ||
| gsup_sms.c | ||
| i460_mux.c | ||
| ipa.c | ||
| kasumi.c | ||
| lapd_core.c | ||
| lapdm.c | ||
| libosmogsm.map | ||
| mncc.c | ||
| oap.c | ||
| oap_client.c | ||
| rsl.c | ||
| rxlev_stat.c | ||
| sysinfo.c | ||
| tlv_parser.c | ||