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
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
In testing against a particular EPC, the SGsAP-SERVICE-REQUEST
can contain a MO fallback value TLV with T 0xF1
Change-Id: Ia2460af9673818d375e28c67f1631b5f7eacdaeb
The function msgb_sgsap_name_put() assignes the return code of
osmo_apn_from_str() directly to len. Len is an uint8_t and the return
code an int. If osmo_apn_from_str() returns -1. Len would become 0xFF
causing a buffer overrun with msgb_tlv_put. Lets use the proper type to
catch the return code and check it before using it as length.
Change-Id: Ic0bc5114eee47bdcf2300a6e4b0df473d3d1903a
Fixes: CID#190405
Fixes: CID#190401
Related: OS#3615
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
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
Oliver Smith
Harald Welte
Neels Hofmeyr
Philipp Maier