mirror of https://gerrit.osmocom.org/libosmocore
83025bf1a6
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 current osmo CNI programs, replacing the Mobile Identity coding with this new API. Deprecate the old MI API. osmo-bsc: I71c3b4c65dbfdfa51409e09d4868aea83225338a osmo-msc: Ic3f969e739654c1e8c387aedeeba5cce07fe2307 osmo-sgsn: I4cacb10bac419633ca0c14f244f9903f7f517b49 Note that some GPRS and SGs related coding is done here in libosmocore and hence currently remains using the old implementation (see previous version of this patch: Ic3f969e739654c1e8c387aedeeba5cce07fe2307). 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. As a result, applications using osmo_mobile_identity will be stricter in rejecting coding mistakes (some of which we currently have in our test suites, and which we'll need to fix). 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. This patch was first merged as Ic3f969e739654c1e8c387aedeeba5cce07fe2307 and caused test fallout, because it re-implemented old API with the new stricter decoding. In this patch version, old API remains 1:1 unchanged to avoid such fallout. Applications will soon switch to the new osmo_mobile_identity API and become stricter on MI coding when that happens, not implicitly by a new libosmocore version. Change-Id: If4f7be606e54cfa1c59084cf169785b1cbda5cf5 |
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| codec | ||
| coding | ||
| ctrl | ||
| gb | ||
| gsm | ||
| pseudotalloc | ||
| sim | ||
| usb | ||
| vty | ||
| Makefile.am | ||
| application.c | ||
| backtrace.c | ||
| bitcomp.c | ||
| bits.c | ||
| bitvec.c | ||
| context.c | ||
| conv.c | ||
| conv_acc.c | ||
| conv_acc_generic.c | ||
| conv_acc_sse.c | ||
| conv_acc_sse_avx.c | ||
| conv_acc_sse_impl.h | ||
| counter.c | ||
| crc16.c | ||
| crcXXgen.c.tpl | ||
| exec.c | ||
| fsm.c | ||
| gsmtap_util.c | ||
| isdnhdlc.c | ||
| logging.c | ||
| logging_gsmtap.c | ||
| logging_syslog.c | ||
| loggingrb.c | ||
| macaddr.c | ||
| msgb.c | ||
| msgfile.c | ||
| panic.c | ||
| plugin.c | ||
| prbs.c | ||
| prim.c | ||
| rate_ctr.c | ||
| rbtree.c | ||
| select.c | ||
| sercomm.c | ||
| serial.c | ||
| signal.c | ||
| sockaddr_str.c | ||
| socket.c | ||
| stat_item.c | ||
| stats.c | ||
| stats_statsd.c | ||
| strrb.c | ||
| tdef.c | ||
| timer.c | ||
| timer_clockgettime.c | ||
| timer_gettimeofday.c | ||
| use_count.c | ||
| utils.c | ||
| write_queue.c | ||