rlc: Use the rlc structure to access the data unit in the RLC message

Currently most offsets are hard-coded which makes it difficult to
access the data units and their headers when padding has to be taken
into account. These offset are already provided by the
gprs_rlc_data_info_init_ul/dl functions.

Change the encoder/decoder to use these values.

Note that some assumptions (bit alignment) are still present in the
code and checked by assertions.

Sponsored-by: On-Waves ehf
This commit is contained in:
Jacob Erlbeck 2016-02-03 18:35:27 +01:00
parent fbd82e4e9f
commit 0f5c6956dd
2 changed files with 31 additions and 21 deletions

View File

@ -348,16 +348,16 @@ int Decoding::rlc_parse_ul_data_header(struct gprs_rlc_data_info *rlc,
const struct rlc_ul_header *gprs;
unsigned int e_ti_header;
unsigned int cur_bit = 0;
unsigned int data_len = 0;
rlc->cs = cs;
data_len = cs.maxDataBlockBytes();
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;
@ -372,20 +372,23 @@ int Decoding::rlc_parse_ul_data_header(struct gprs_rlc_data_info *rlc,
rlc->block_info[0].ti = gprs->ti;
rlc->block_info[0].spb = 0;
cur_bit += 3 * 8;
rlc->data_offs_bits[0] = cur_bit;
rlc->block_info[0].data_len = data_len;
cur_bit += data_len * 8;
cur_bit += rlc->data_offs_bits[0];
/* skip data area */
cur_bit += cs.maxDataBlockBytes() * 8;
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 = (egprs3->cps_a << 0) | (egprs3->cps_b << 2);
rlc->cps = cps;
rlc->rsb = egprs3->rsb;
rlc->num_data_blocks = 1;
@ -395,17 +398,18 @@ int Decoding::rlc_parse_ul_data_header(struct gprs_rlc_data_info *rlc,
rlc->block_info[0].bsn =
(egprs3->bsn1_a << 0) | (egprs3->bsn1_b << 5);
cur_bit += 3 * 8 + 7;
cur_bit += rlc->data_offs_bits[0] - 2;
e_ti_header = (data[3] + (data[4] << 8)) >> 7;
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;
rlc->data_offs_bits[0] = cur_bit;
rlc->block_info[0].data_len = data_len;
cur_bit += data_len * 8;
/* skip data area */
cur_bit += cs.maxDataBlockBytes() * 8;
break;
case GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_1:

View File

@ -762,8 +762,10 @@ int Encoding::rlc_write_dl_data_header(const struct gprs_rlc_data_info *rlc,
/* first FBI/E header */
e_fbi_header = rlc->block_info[0].e ? 0x01 : 0;
e_fbi_header |= rlc->block_info[0].cv == 0 ? 0x02 : 0; /* FBI */
offs = rlc->data_offs_bits[0] / 8;
OSMO_ASSERT(rlc->data_offs_bits[0] % 8 == 2);
e_fbi_header <<= 0;
data[5] = (data[5] & 0b11111100) | e_fbi_header;
data[offs] = (data[offs] & 0b11111100) | e_fbi_header;
/* second FBI/E header */
e_fbi_header = rlc->block_info[1].e ? 0x01 : 0;
@ -792,8 +794,10 @@ int Encoding::rlc_write_dl_data_header(const struct gprs_rlc_data_info *rlc,
e_fbi_header = rlc->block_info[0].e ? 0x01 : 0;
e_fbi_header |= rlc->block_info[0].cv == 0 ? 0x02 : 0; /* FBI */
offs = rlc->data_offs_bits[0] / 8;
OSMO_ASSERT(rlc->data_offs_bits[0] % 8 == 6);
e_fbi_header <<= 4;
data[3] = (data[3] & 0b11001111) | e_fbi_header;
data[offs] = (data[offs] & 0b11001111) | e_fbi_header;
break;
case GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_3:
@ -816,9 +820,11 @@ int Encoding::rlc_write_dl_data_header(const struct gprs_rlc_data_info *rlc,
e_fbi_header = rlc->block_info[0].e ? 0x01 : 0;
e_fbi_header |= rlc->block_info[0].cv == 0 ? 0x02 : 0; /* FBI */
offs = rlc->data_offs_bits[0] / 8;
OSMO_ASSERT(rlc->data_offs_bits[0] % 8 == 1);
e_fbi_header <<= 7;
data[3] = (data[3] & 0b01111111) | (e_fbi_header >> 0);
data[4] = (data[4] & 0b11111110) | (e_fbi_header >> 8);
data[offs-1] = (data[offs-1] & 0b01111111) | (e_fbi_header >> 0);
data[offs] = (data[offs] & 0b11111110) | (e_fbi_header >> 8);
break;
default: