For 3G, I need a BCD composer/parser similar to gsm48_generate_lai()/ gsm48_decode_lai(). Those functions also handle a trivial extra member (lac) which I don't need in this way for 3G.

So create new functions to take on the MCC+MNC BCD handling and call those from gsm48_generate_lai() and gsm48_decode_lai(). In this way, the 3G code in openbsc can use only the BCD functionality without code duplication. --- include/osmocom/gsm/gsm48.h | 3 +++ src/gsm/gsm48.c | 55 ++++++++++++++++++++++++++++----------------- src/gsm/libosmogsm.map | 2 ++ 3 files changed, 39 insertions(+), 21 deletions(-)

diff --git a/include/osmocom/gsm/gsm48.h b/include/osmocom/gsm/gsm48.h index 74ac52c..d6e58c2 100644 --- a/include/osmocom/gsm/gsm48.h +++ b/include/osmocom/gsm/gsm48.h @@ -39,3 +39,6 @@ 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);

int gsm48_number_of_paging_subchannels(struct gsm48_control_channel_descr *chan_desc); + +void gsm48_mcc_mnc_to_bcd(uint8_t *bcd_dst, uint16_t mcc, uint16_t mnc); +void gsm48_mcc_mnc_from_bcd(uint8_t *bcd_src, uint16_t *mcc, uint16_t *mnc); diff --git a/src/gsm/gsm48.c b/src/gsm/gsm48.c index 60937cb..d0a2286 100644 --- a/src/gsm/gsm48.c +++ b/src/gsm/gsm48.c @@ -278,25 +278,50 @@ static void to_bcd(uint8_t *bcd, uint16_t val) val = val / 10; }

-void gsm48_generate_lai(struct gsm48_loc_area_id *lai48, uint16_t mcc, - uint16_t mnc, uint16_t lac) +/* Convert given mcc and mnc to BCD and write to *bcd_dst, which must be an + * allocated buffer of (at least) 3 bytes length. */ +void gsm48_mcc_mnc_to_bcd(uint8_t *bcd_dst, uint16_t mcc, uint16_t mnc) { uint8_t bcd[3];

to_bcd(bcd, mcc); - lai48->digits[0] = bcd[0] | (bcd[1] << 4); - lai48->digits[1] = bcd[2]; + bcd_dst[0] = bcd[0] | (bcd[1] << 4); + bcd_dst[1] = bcd[2];

to_bcd(bcd, mnc); /* FIXME: do we need three-digit MNC? See Table 10.5.3 */ if (mnc > 99) { - lai48->digits[1] |= bcd[2] << 4; - lai48->digits[2] = bcd[0] | (bcd[1] << 4); + bcd_dst[1] |= bcd[2] << 4; + bcd_dst[2] = bcd[0] | (bcd[1] << 4); + } else { + bcd_dst[1] |= 0xf << 4; + bcd_dst[2] = bcd[1] | (bcd[2] << 4); + } +} + +/* Convert given 3-byte BCD buffer to integers and write results to *mcc and + * *mnc. The first three BCD digits result in the MCC and the remaining ones in + * the MNC. */ +void gsm48_mcc_mnc_from_bcd(uint8_t *bcd_src, uint16_t *mcc, uint16_t *mnc) +{ + *mcc = (bcd_src[0] & 0x0f) * 100 + + (bcd_src[0] >> 4) * 10 + + (bcd_src[1] & 0x0f); + + if ((bcd_src[1] & 0xf0) == 0xf0) { + *mnc = (bcd_src[2] & 0x0f) * 10 + + (bcd_src[2] >> 4); } else { - lai48->digits[1] |= 0xf << 4; - lai48->digits[2] = bcd[1] | (bcd[2] << 4); + *mnc = (bcd_src[2] & 0x0f) * 100 + + (bcd_src[2] >> 4) * 10 + + (bcd_src[1] >> 4); } +}

+void gsm48_generate_lai(struct gsm48_loc_area_id *lai48, uint16_t mcc, + uint16_t mnc, uint16_t lac) +{ + gsm48_mcc_mnc_to_bcd(&lai48->digits[0], mcc, mnc); lai48->lac = htons(lac); }

@@ -304,20 +329,8 @@ void gsm48_generate_lai(struct gsm48_loc_area_id *lai48, uint16_t mcc, int gsm48_decode_lai(struct gsm48_loc_area_id *lai, uint16_t *mcc, uint16_t *mnc, uint16_t *lac) { - *mcc = (lai->digits[0] & 0x0f) * 100 - + (lai->digits[0] >> 4) * 10 - + (lai->digits[1] & 0x0f); - - if ((lai->digits[1] & 0xf0) == 0xf0) { - *mnc = (lai->digits[2] & 0x0f) * 10 - + (lai->digits[2] >> 4); - } else { - *mnc = (lai->digits[2] & 0x0f) * 100 - + (lai->digits[2] >> 4) * 10 - + (lai->digits[1] >> 4); - } + gsm48_mcc_mnc_from_bcd(&lai->digits[0], mcc, mnc); *lac = ntohs(lai->lac); - return 0; }

diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map index 7eebe7f..0aeefbb 100644 --- a/src/gsm/libosmogsm.map +++ b/src/gsm/libosmogsm.map @@ -138,6 +138,8 @@ gsm48_number_of_paging_subchannels; gsm48_parse_ra; gsm48_rr_att_tlvdef; gsm48_mi_type_name; +gsm48_mcc_mnc_to_bcd; +gsm48_mcc_mnc_from_bcd;

gsm_7bit_decode; gsm_7bit_decode_ussd;