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
diff --git a/src/decoding.cpp b/src/decoding.cpp
index f4b539b..f2b548c 100644
--- a/src/decoding.cpp
+++ b/src/decoding.cpp
@@ -348,16 +348,16 @@
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 @@
rlc->block_info[0].ti = gprs->ti;
rlc->block_info[0].spb = 0;
- cur_bit += 3 * 8;
+ cur_bit += rlc->data_offs_bits[0];
- 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_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 @@
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:
diff --git a/src/encoding.cpp b/src/encoding.cpp
index a7d7b16..6c50abe 100644
--- a/src/encoding.cpp
+++ b/src/encoding.cpp
@@ -762,8 +762,10 @@
/* 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 @@
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 @@
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: