tree 829521b0b16a3185fee97d720498eee6cf68ae77
parent 04ee9c04f492d8d1f7800e54b92f20609293ade7
author Vadim Yanitskiy <axilirator@gmail.com> 1502278719 +0600
committer Harald Welte <laforge@gnumonks.org> 1516185939 +0000

gsm0480: fix USSD OCTET STRING length confusion

According to the GSM 04.80 (version 5.0.0) specification Annex A
"Expanded ASN.1 Module "SS-Protocol", the maximum size of a USSD
OCTET STRING is 160 bytes.

Thus according to ETSI TS 123 038 (version 10.0.0) specification
6.1.2.3 "USSD packing of 7 bit characters", in 160 octets, it's
possible to pack (160 * 8) / 7 = 182.8, that is 182 characters.
The remaining 6 bits are set to zero.

This change defines both mentioned values:

  - GSM0480_USSD_OCTET_STRING_LEN  160
  - GSM0480_USSD_7BIT_STRING_LEN   182

keeping the old MAX_LEN_USSD_STRING 'as is' due to compatibility
reasons. Now the new value is used for ss_request structure, while
old one is still used for deprecated ussd_request structure.

Change-Id: I6dead74f9ecea079752ff2400cdaf7c30187784e