diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/gsm48.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/src/gsm48.c b/src/gsm48.c index 7e510664..d957aef6 100644 --- a/src/gsm48.c +++ b/src/gsm48.c @@ -326,3 +326,28 @@ void gsm48_parse_ra(struct gprs_ra_id *raid, const uint8_t *buf) raid->lac = ntohs(*(uint16_t *)(buf + 3)); raid->rac = buf[5]; } + +int gsm48_construct_ra(uint8_t *buf, const struct gprs_ra_id *raid) +{ + uint16_t mcc = raid->mcc; + uint16_t mnc = raid->mnc; + + buf[0] = ((mcc / 100) % 10) | (((mcc / 10) % 10) << 4); + buf[1] = (mcc % 10); + + /* I wonder who came up with the stupidity of encoding the MNC + * differently depending on how many digits its decimal number has! */ + if (mnc < 100) { + buf[1] |= 0xf0; + buf[2] = ((mnc / 10) % 10) | ((mnc % 10) << 4); + } else { + buf[1] |= (mnc % 10) << 4; + buf[2] = ((mnc / 100) % 10) | (((mcc / 10) % 10) << 4); + } + + *(uint16_t *)(buf+3) = htons(raid->lac); + + buf[5] = raid->rac; + + return 6; +} |