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/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: