Add hand-written encoder/decoder for RLC/MAC UL/DL data blocks
Their format is simply too complex to be used with the automatic RAW
encoder/decoder. Let's implement it by hand, using the automatic
coder whenever possible.
diff --git a/library/RLCMAC_EncDec.cc b/library/RLCMAC_EncDec.cc
new file mode 100644
index 0000000..b2f0525
--- /dev/null
+++ b/library/RLCMAC_EncDec.cc
@@ -0,0 +1,265 @@
+#include "RLCMAC_Types.hh"
+#include "GSM_Types.hh"
+/* Decoding of TS 44.060 GPRS RLC/MAC blocks, portions requiring manual functions
+ * beyond what TITAN RAW coder can handle internally.
+ *
+ * (C) 2017 by Harald Welte <laforge@gnumonks.org>
+ */
+
+namespace RLCMAC__Types {
+
+OCTETSTRING enc__RlcmacDlDataBlock(const RlcmacDlDataBlock& si)
+{
+ RlcmacDlDataBlock in = si;
+ OCTETSTRING ret_val;
+ TTCN_Buffer ttcn_buffer;
+ int i;
+
+ /* Fix 'e' bit of initial header based on following blocks */
+ if (!in.blocks().is_bound() || (in.blocks().size_of() == 1 && !in.blocks()[0].hdr().is_bound()))
+ in.mac__hdr().hdr__ext().e() = true;
+ else
+ in.mac__hdr().hdr__ext().e() = false;
+
+ /* use automatic/generated decoder for header */
+ in.mac__hdr().encode(DlMacDataHeader_descr_, ttcn_buffer, TTCN_EncDec::CT_RAW);
+
+ /* Add LI octets, if any */
+ if (in.blocks().is_bound() &&
+ (in.blocks().size_of() != 1 || in.blocks()[0].hdr().is_bound())) {
+ /* first write LI octets */
+ for (i = 0; i < in.blocks().size_of(); i++) {
+ /* fix the 'E' bit in case it is not clear */
+ if (i < in.blocks().size_of()-1)
+ in.blocks()[i].hdr().e() = false;
+ else
+ in.blocks()[i].hdr().e() = true;
+ in.blocks()[i].hdr().encode(LlcBlockHdr_descr_, ttcn_buffer, TTCN_EncDec::CT_RAW);
+ }
+ }
+ if (in.blocks().is_bound()) {
+ for (i = 0; i < in.blocks().size_of(); i++) {
+ if (!in.blocks()[i].is_bound())
+ continue;
+ ttcn_buffer.put_string(in.blocks()[i].payload());
+ }
+ }
+
+ ttcn_buffer.get_string(ret_val);
+ return ret_val;
+}
+
+RlcmacDlDataBlock dec__RlcmacDlDataBlock(const OCTETSTRING& stream)
+{
+ RlcmacDlDataBlock ret_val;
+ TTCN_Buffer ttcn_buffer(stream);
+ int num_llc_blocks = 0;
+
+ /* use automatic/generated decoder for header */
+ ret_val.mac__hdr().decode(DlMacDataHeader_descr_, ttcn_buffer, TTCN_EncDec::CT_RAW);
+
+ /* optional extension octets, containing LI+M+E of Llc blocks */
+ if (ret_val.mac__hdr().hdr__ext().e() == false) {
+ /* extension octet follows, i.e. optional Llc length octets */
+ while (1) {
+ /* decode one more extension octet with LlcBlocHdr inside */
+ LlcBlock lb;
+ lb.hdr().decode(LlcBlockHdr_descr_, ttcn_buffer, TTCN_EncDec::CT_RAW);
+ ret_val.blocks()[num_llc_blocks++] = lb;
+
+ /* if E == '1'B, we can proceed further */
+ if (lb.hdr().e() == true)
+ break;
+ }
+ }
+
+ /* RLC blocks at end */
+ if (ret_val.mac__hdr().hdr__ext().e() == true) {
+ LlcBlock lb;
+ unsigned int length = ttcn_buffer.get_read_len();
+ /* LI not present: The Upper Layer PDU that starts with the current RLC data block either
+ * fills the current RLC data block precisely or continues in the following in-sequence RLC
+ * data block */
+ lb.payload() = OCTETSTRING(length, ttcn_buffer.get_read_data());
+ ttcn_buffer.increase_pos(length);
+ ret_val.blocks()[0] = lb;
+ } else {
+ if (ret_val.blocks().is_bound()) {
+ for (int i = 0; i < ret_val.blocks().size_of(); i++) {
+ unsigned int length = ret_val.blocks()[i].hdr().length__ind();
+ if (length > ttcn_buffer.get_read_len())
+ length = ttcn_buffer.get_read_len();
+ ret_val.blocks()[i].payload() = OCTETSTRING(length, ttcn_buffer.get_read_data());
+ ttcn_buffer.increase_pos(length);
+ }
+ }
+ }
+
+ return ret_val;
+}
+
+
+OCTETSTRING enc__RlcmacUlDataBlock(const RlcmacUlDataBlock& si)
+{
+ RlcmacUlDataBlock in = si;
+ OCTETSTRING ret_val;
+ TTCN_Buffer ttcn_buffer;
+ int i;
+
+ /* Fix 'e' bit of initial header based on following blocks */
+ if (!in.blocks().is_bound() || (in.blocks().size_of() == 1 && !in.blocks()[0].hdr().is_bound()))
+ in.mac__hdr().e() = true;
+ else
+ in.mac__hdr().e() = false;
+
+ /* Fix other presence indications */
+ in.mac__hdr().tlli__ind() = in.tlli().is_bound();
+ in.mac__hdr().pfi__ind() = in.pfi().is_bound();
+
+ /* use automatic/generated decoder for header */
+ in.mac__hdr().encode(UlMacDataHeader_descr_, ttcn_buffer, TTCN_EncDec::CT_RAW);
+
+ /* Add LI octets, if any */
+ if (in.blocks().is_bound() &&
+ (in.blocks().size_of() != 1 || in.blocks()[0].hdr().is_bound())) {
+ /* first write LI octets */
+ for (i = 0; i < in.blocks().size_of(); i++) {
+ /* fix the 'E' bit in case it is not clear */
+ if (i < in.blocks().size_of()-1)
+ in.blocks()[i].hdr().e() = false;
+ else
+ in.blocks()[i].hdr().e() = true;
+ in.blocks()[i].hdr().encode(LlcBlockHdr_descr_, ttcn_buffer, TTCN_EncDec::CT_RAW);
+ }
+ }
+
+ if (in.mac__hdr().tlli__ind()) {
+ /* FIXME */
+ //in.tlli().encode(GSM__Types::GprsTlli_descr_, ttcn_buffer, TTCN_EncDec::CT_RAW);
+ INTEGER t = in.tlli();
+ unsigned int tmp = t.get_long_long_val();
+ ttcn_buffer.put_c(tmp >> 24);
+ ttcn_buffer.put_c(tmp >> 16);
+ ttcn_buffer.put_c(tmp >> 8);
+ ttcn_buffer.put_c(tmp);
+ }
+
+ if (in.mac__hdr().pfi__ind()) {
+ in.pfi().encode(RlcmacUlDataBlock_pfi_descr_, ttcn_buffer, TTCN_EncDec::CT_RAW);
+ }
+
+ if (in.blocks().is_bound()) {
+ for (i = 0; i < in.blocks().size_of(); i++) {
+ if (!in.blocks()[i].is_bound())
+ continue;
+ ttcn_buffer.put_string(in.blocks()[i].payload());
+ }
+ }
+
+ ttcn_buffer.get_string(ret_val);
+ return ret_val;
+}
+
+RlcmacUlDataBlock dec__RlcmacUlDataBlock(const OCTETSTRING& stream)
+{
+ RlcmacUlDataBlock ret_val;
+ TTCN_Buffer ttcn_buffer(stream);
+ int num_llc_blocks = 0;
+
+ TTCN_Logger::begin_event(TTCN_Logger::DEBUG_ENCDEC);
+ TTCN_Logger::log_event_str("==================================\n"
+ "dec_RlcmacUlDataBlock(): Stream before decoding: ");
+ stream.log();
+ TTCN_Logger::end_event();
+
+ /* use automatic/generated decoder for header */
+ ret_val.mac__hdr().decode(UlMacDataHeader_descr_, ttcn_buffer, TTCN_EncDec::CT_RAW);
+
+ TTCN_Logger::begin_event(TTCN_Logger::DEBUG_ENCDEC);
+ TTCN_Logger::log_event_str("dec_RlcmacUlDataBlock(): Stream after decoding hdr: ");
+ ttcn_buffer.log();
+ TTCN_Logger::end_event();
+ TTCN_Logger::begin_event(TTCN_Logger::DEBUG_ENCDEC);
+ TTCN_Logger::log_event_str("dec_RlcmacUlDataBlock(): ret_val after decoding hdr: ");
+ ret_val.log();
+ TTCN_Logger::end_event();
+
+ /* Manually decoder remainder of ttcn_buffer, containing optional header octets,
+ * optional tlli, optional pfi and LLC Blocks */
+
+ /* optional extension octets, containing LI+M+E of Llc blocks */
+ if (ret_val.mac__hdr().e() == false) {
+ /* extension octet follows, i.e. optional Llc length octets */
+ while (1) {
+ /* decode one more extension octet with LlcBlocHdr inside */
+ LlcBlock lb;
+ lb.hdr().decode(LlcBlockHdr_descr_, ttcn_buffer, TTCN_EncDec::CT_RAW);
+ ret_val.blocks()[num_llc_blocks++] = lb;
+
+ TTCN_Logger::begin_event(TTCN_Logger::DEBUG_ENCDEC);
+ TTCN_Logger::log_event_str("dec_RlcmacUlDataBlock(): Stream after decoding ExtOct: ");
+ ttcn_buffer.log();
+ TTCN_Logger::end_event();
+ TTCN_Logger::begin_event(TTCN_Logger::DEBUG_ENCDEC);
+ TTCN_Logger::log_event_str("dec_RlcmacUlDataBlock(): ret_val after decoding ExtOct: ");
+ ret_val.log();
+ TTCN_Logger::end_event();
+
+ /* if E == '1'B, we can proceed further */
+ if (lb.hdr().e() == true)
+ break;
+ }
+ }
+
+ /* parse optional TLLI */
+ if (ret_val.mac__hdr().tlli__ind()) {
+ /* FIXME: Why is this not working ?!? */
+ //ret_val.tlli().decode(GSM__Types::GprsTlli_descr_, ttcn_buffer, TTCN_EncDec::CT_RAW);
+ const unsigned char *cur = ttcn_buffer.get_read_data();
+ unsigned int tmp = cur[0] << 24 | cur[1] << 16 | cur[2] << 8 | cur[3];
+ INTEGER t;
+ t.set_long_long_val(tmp);
+ ret_val.tlli() = t;
+ ttcn_buffer.increase_pos(4);
+ }
+ /* parse optional PFI */
+ if (ret_val.mac__hdr().pfi__ind()) {
+ ret_val.pfi().decode(RlcmacUlDataBlock_pfi_descr_, ttcn_buffer, TTCN_EncDec::CT_RAW);
+ }
+
+ /* RLC blocks at end */
+ if (ret_val.mac__hdr().e() == true) {
+ LlcBlock lb;
+ unsigned int length = ttcn_buffer.get_read_len();
+ /* LI not present: The Upper Layer PDU that starts with the current RLC data block either
+ * fills the current RLC data block precisely or continues in the following in-sequence RLC
+ * data block */
+ lb.payload() = OCTETSTRING(length, ttcn_buffer.get_read_data());
+ ttcn_buffer.increase_pos(length);
+ ret_val.blocks()[0] = lb;
+ } else {
+ if (ret_val.blocks().is_bound()) {
+ for (int i = 0; i < ret_val.blocks().size_of(); i++) {
+ unsigned int length = ret_val.blocks()[i].hdr().length__ind();
+ if (length > ttcn_buffer.get_read_len())
+ length = ttcn_buffer.get_read_len();
+ ret_val.blocks()[i].payload() = OCTETSTRING(length, ttcn_buffer.get_read_data());
+ ttcn_buffer.increase_pos(length);
+ }
+ }
+ }
+
+ TTCN_Logger::begin_event(TTCN_Logger::DEBUG_ENCDEC);
+ TTCN_Logger::log_event_str("dec_RlcmacUlDataBlock(): Stream before return: ");
+ ttcn_buffer.log();
+ TTCN_Logger::end_event();
+ TTCN_Logger::begin_event(TTCN_Logger::DEBUG_ENCDEC);
+ TTCN_Logger::log_event_str("dec_RlcmacUlDataBlock(): ret_val before return: ");
+ ret_val.log();
+ TTCN_Logger::end_event();
+
+ return ret_val;
+}
+
+
+} // namespace