gsm23003: add osmo_imei_str_valid()
Verify 14 digit and 15 digit IMEI strings. OsmoHLR will use the 14
digit version to check IMEIs before writing them to the DB.
Place the Luhn checksum code in a dedicated osmo_luhn() function, so
it can be used elsewhere.
Related: OS#2541
Change-Id: Id2d2a3a93b033bafc74c62e15297034bf4aafe61
diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map
index a903787..331c3f0 100644
--- a/src/gsm/libosmogsm.map
+++ b/src/gsm/libosmogsm.map
@@ -551,6 +551,7 @@
osmo_imsi_str_valid;
osmo_msisdn_str_valid;
+osmo_imei_str_valid;
osmo_mncc_stringify;
osmo_mncc_names;