[PATCH 1/2] Refactor the Uplink RLC header parsing function

Parsing the uplink data header for GPRS and EGPRS header type 3 is handled in separate functions. This patch will enhance modularity of the code. --- src/decoding.cpp | 140 ++++++++++++++++++++++++++++++------------------------- src/decoding.h | 9 +++- 2 files changed, 84 insertions(+), 65 deletions(-) diff --git a/src/decoding.cpp b/src/decoding.cpp index f2b548c..0c81b2a 100644 --- a/src/decoding.cpp +++ b/src/decoding.cpp @@ -344,74 +344,14 @@ void Decoding::extract_rbb(const struct bitvec *rbb, char *show_rbb) int Decoding::rlc_parse_ul_data_header(struct gprs_rlc_data_info *rlc, const uint8_t *data, GprsCodingScheme cs) { - const struct gprs_rlc_ul_header_egprs_3 *egprs3; - const struct rlc_ul_header *gprs; - unsigned int e_ti_header; unsigned int cur_bit = 0; - int punct, punct2, with_padding, cps; - unsigned int offs; - switch(cs.headerTypeData()) { - case GprsCodingScheme::HEADER_GPRS_DATA: - gprs = static_cast<struct rlc_ul_header *> - ((void *)data); - - gprs_rlc_data_info_init_ul(rlc, cs, false); - - rlc->r = gprs->r; - rlc->si = gprs->si; - rlc->tfi = gprs->tfi; - rlc->cps = 0; - rlc->rsb = 0; - - rlc->num_data_blocks = 1; - rlc->block_info[0].cv = gprs->cv; - rlc->block_info[0].pi = gprs->pi; - rlc->block_info[0].bsn = gprs->bsn; - rlc->block_info[0].e = gprs->e; - rlc->block_info[0].ti = gprs->ti; - rlc->block_info[0].spb = 0; - - cur_bit += rlc->data_offs_bits[0]; - - /* skip data area */ - cur_bit += cs.maxDataBlockBytes() * 8; + case GprsCodingScheme::HEADER_GPRS_DATA : + cur_bit = rlc_parse_ul_data_header_gprs(rlc, data, cs); break; - case GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_3: - egprs3 = static_cast<struct gprs_rlc_ul_header_egprs_3 *> - ((void *)data); - - cps = (egprs3->cps_a << 0) | (egprs3->cps_b << 2); - gprs_rlc_mcs_cps_decode(cps, cs, &punct, &punct2, &with_padding); - gprs_rlc_data_info_init_ul(rlc, cs, with_padding); - - rlc->r = egprs3->r; - rlc->si = egprs3->si; - rlc->tfi = (egprs3->tfi_a << 0) | (egprs3->tfi_b << 2); - rlc->cps = cps; - rlc->rsb = egprs3->rsb; - - rlc->num_data_blocks = 1; - rlc->block_info[0].cv = egprs3->cv; - rlc->block_info[0].pi = egprs3->pi; - rlc->block_info[0].spb = egprs3->spb; - rlc->block_info[0].bsn = - (egprs3->bsn1_a << 0) | (egprs3->bsn1_b << 5); - - cur_bit += rlc->data_offs_bits[0] - 2; - - offs = rlc->data_offs_bits[0] / 8; - OSMO_ASSERT(rlc->data_offs_bits[0] % 8 == 1); - - e_ti_header = (data[offs-1] + (data[offs] << 8)) >> 7; - rlc->block_info[0].e = !!(e_ti_header & 0x01); - rlc->block_info[0].ti = !!(e_ti_header & 0x02); - cur_bit += 2; - - /* skip data area */ - cur_bit += cs.maxDataBlockBytes() * 8; + case GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_3 : + cur_bit = rlc_parse_ul_data_header_egprs_type_3(rlc, data, cs); break; - case GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_1: case GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_2: /* TODO: Support both header types */ @@ -426,6 +366,78 @@ int Decoding::rlc_parse_ul_data_header(struct gprs_rlc_data_info *rlc, return cur_bit; } +int Decoding::rlc_parse_ul_data_header_egprs_type_3( + struct gprs_rlc_data_info *rlc, + const uint8_t *data, + const GprsCodingScheme &cs) +{ + int punct, punct2, with_padding, cps; + unsigned int e_ti_header, offs, cur_bit = 0; + const struct gprs_rlc_ul_header_egprs_3 *egprs3; + + egprs3 = static_cast < struct gprs_rlc_ul_header_egprs_3 * > + ((void *)data); + + cps = (egprs3->cps_a << 0) | (egprs3->cps_b << 2); + gprs_rlc_mcs_cps_decode(cps, cs, &punct, &punct2, &with_padding); + gprs_rlc_data_info_init_ul(rlc, cs, with_padding); + + rlc->r = egprs3->r; + rlc->si = egprs3->si; + rlc->tfi = (egprs3->tfi_a << 0) | (egprs3->tfi_b << 2); + rlc->cps = cps; + rlc->rsb = egprs3->rsb; + + rlc->num_data_blocks = 1; + rlc->block_info[0].cv = egprs3->cv; + rlc->block_info[0].pi = egprs3->pi; + rlc->block_info[0].spb = egprs3->spb; + rlc->block_info[0].bsn = + (egprs3->bsn1_a << 0) | (egprs3->bsn1_b << 5); + + cur_bit += rlc->data_offs_bits[0] - 2; + offs = rlc->data_offs_bits[0] / 8; + OSMO_ASSERT(rlc->data_offs_bits[0] % 8 == 1); + e_ti_header = (data[offs-1] + (data[offs] << 8)) >> 7; + rlc->block_info[0].e = !!(e_ti_header & 0x01); + rlc->block_info[0].ti = !!(e_ti_header & 0x02); + cur_bit += 2; + /* skip data area */ + cur_bit += cs.maxDataBlockBytes() * 8; + + return cur_bit; +} + +int Decoding::rlc_parse_ul_data_header_gprs(struct gprs_rlc_data_info *rlc, + const uint8_t *data, const GprsCodingScheme &cs) +{ + const struct rlc_ul_header *gprs; + unsigned int cur_bit = 0; + + gprs = static_cast < struct rlc_ul_header * > + ((void *)data); + + gprs_rlc_data_info_init_ul(rlc, cs, false); + + rlc->r = gprs->r; + rlc->si = gprs->si; + rlc->tfi = gprs->tfi; + rlc->cps = 0; + rlc->rsb = 0; + rlc->num_data_blocks = 1; + rlc->block_info[0].cv = gprs->cv; + rlc->block_info[0].pi = gprs->pi; + rlc->block_info[0].bsn = gprs->bsn; + rlc->block_info[0].e = gprs->e; + rlc->block_info[0].ti = gprs->ti; + rlc->block_info[0].spb = 0; + cur_bit += rlc->data_offs_bits[0]; + /* skip data area */ + cur_bit += cs.maxDataBlockBytes() * 8; + + return cur_bit; +} + /** * \brief Copy LSB bitstream RLC data block to byte aligned buffer. * diff --git a/src/decoding.h b/src/decoding.h index 58ecd18..1043d67 100644 --- a/src/decoding.h +++ b/src/decoding.h @@ -43,7 +43,14 @@ public: static void extract_rbb(const uint8_t *rbb, char *extracted_rbb); static void extract_rbb(const struct bitvec *rbb, char *show_rbb); - + static int rlc_parse_ul_data_header_egprs_type_3( + struct gprs_rlc_data_info *rlc, + const uint8_t *data, + const GprsCodingScheme &cs); + static int rlc_parse_ul_data_header_gprs( + struct gprs_rlc_data_info *rlc, + const uint8_t *data, + const GprsCodingScheme &cs); static int rlc_parse_ul_data_header(struct gprs_rlc_data_info *rlc, const uint8_t *data, GprsCodingScheme cs); static unsigned int rlc_copy_to_aligned_buffer( -- 2.5.0