Import gsm48_construct_ra() from openbsc

This commit is contained in:
Harald Welte 2010-05-01 14:25:22 +02:00
parent debf955074
commit 35a939463e
2 changed files with 26 additions and 0 deletions

View File

@ -29,5 +29,6 @@ int gsm48_mi_to_string(char *string, const int str_len,
/* Parse Routeing Area Identifier */
void gsm48_parse_ra(struct gprs_ra_id *raid, const uint8_t *buf);
int gsm48_construct_ra(uint8_t *buf, const struct gprs_ra_id *raid);
#endif

View File

@ -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;
}