library/GSM_RR_Types.ttcn: refactor IaRestOctHH coding

According to 3GPP TS 44.018, section 10.5.2.16, IA Rest Octets IE
starting with 'HH' bits may contain one of the following CSN.1
encoded components:

  7 6 5 4 3 2 1 0  Bit Numbers
  H H 0 0 . . . .  Packet Uplink Assignment
  H H 0 1 . . . .  Packet Downlink Assignment
  H H 1 . . . . .  Second Part Packet Assignment

We already have (partial) support for the first two, while the
last type has not been supported so far. Let's add it.

Also, this change introduces several templates for IA Rest Octets
IE and some of its components mentioned above. This would allow
us to abstract the API users from dealing with further changes,
e.g. adding a coding attribute 'CSN.1 L/H' and missing fields.

Change-Id: Ib3a21e7c5fa1cad4466e3a09fa70540de7f6ecc5

2 files changed, 118 insertions, 62 deletions

diff --git a/library/GSM_RR_Types.ttcn b/library/GSM_RR_Types.ttcn
index b090d25e..3d2f76ae 100644
--- a/library/GSM_RR_Types.ttcn
+++ b/library/GSM_RR_Types.ttcn
@@ -445,13 +445,37 @@ module GSM_RR_Types {
 		variant (mobile_allocation) "PRESENCE(freq_par_len != 0)"
 */
 	};
+	type record SecondPartAssign {
+		BIT1		r99, /* H / L */
+		BIT1		presence optional,
+		BIT5		ext_ra optional
+	} with {
+		/* TODO: use 'CSN.1 L/H' attribute here */
+		variant (presence) "PRESENCE(r99 = '1'B)" /* H */
+		variant (ext_ra) "PRESENCE(presence = '1'B)"
+	};
+	type union PacketUlDlAssignUnion {
+		PacketUlAssign		ul,
+		PacketDlAssign		dl
+	};
+	type record PacketUlDlAssign {
+		BIT1			ass_disc,
+		PacketUlDlAssignUnion	ass
+	} with {
+		variant (ass) "CROSSTAG(dl, ass_disc = '1'B; ul, ass_disc = '0'B)"
+	};
+	type union PacketAssignUnion {
+		SecondPartAssign	spa,
+		PacketUlDlAssign	uldl
+	};
 	type record IaRestOctHH {
-		BIT2			presence,
-		PacketUlAssign		ul optional,
-		PacketDlAssign		dl optional
+		/* Packet Assignment discriminator:
+		 * Packet Uplink / Downlink Assignment (0)
+		 * Second Part Packet Assignment (1) */
+		BIT1			pa_disc,
+		PacketAssignUnion	pa
 	} with {
-		variant (ul) "PRESENCE(presence = '00'B)"
-		variant (dl) "PRESENCE(presence = '01'B)"
+		variant (pa) "CROSSTAG(spa, pa_disc = '1'B; uldl, pa_disc = '0'B)"
 	};
 	type record PacketUlAssignDyn {
 		uint5_t		tfi_assignment,
@@ -724,6 +748,88 @@ module GSM_RR_Types {
 		with { extension "prototype(convert) decode(RAW)" };
 
 
+	template PacketDlAssign tr_PacketDlAssign(template GprsTlli tlli) := {
+		tlli := tlli,
+		group1_present := ?,
+		group1 := *,
+		ta_index_present := ?,
+		ta_index := *,
+		tbf_starting_time_present := ?,
+		tbf_starting_time := *,
+		p0_present := ?,
+		p0 := *,
+		pr_mode := *
+	};
+
+	template IaRestOctets tr_IaRestOctets_DLAss(template PacketDlAssign dl_ass) := {
+		presence := '11'B, /* HH */
+		ll := omit, lh := omit, hl := omit,
+		hh := {
+			pa_disc := '0'B, /* Packet Assignment (0) */
+			pa := {
+				uldl := {
+					ass_disc := '1'B, /* Downlink Assignment (1) */
+					ass := { dl := dl_ass }
+				}
+			}
+		}
+	};
+
+	template PacketUlAssign tr_PacketUlDynAssign(template uint5_t tfi := ?,
+						     template BIT1 polling := ?,
+						     template uint3_t usf := ?,
+						     template BIT1 usf_granularity := ?,
+						     template ChCodingCommand cs := ?) := {
+		presence := '1'B, /* Dynamic Assignment */
+		dynamic := {
+			tfi_assignment := tfi,
+			polling := polling,
+			spare := '0'B, /* Dynamic Assignment (mandatory after Rel-4) */
+			usf := usf,
+			usf_granularity := usf_granularity,
+			p0_present := ?,
+			p0 := *,
+			pr_mode := *,
+			ch_coding_cmd := cs,
+			tlli_block_chan_coding := ?,
+			alpha_present := ?,
+			alpha := *,
+			gamma := ?,
+			/* TODO: add to parameters */
+			ta_index_present := ?,
+			ta_index := *,
+			tbf_starting_time_present := ?,
+			tbf_starting_time := *
+		},
+		single := omit
+	};
+
+	template PacketUlAssign tr_PacketUlSglAssign := {
+		presence := '1'B, /* Single Block Assignment */
+		dynamic := omit,
+		single := {
+			alpha_present := ?,
+			alpha := *,
+			gamma := ?,
+			padding := '01'B,
+			tbf_starting_time := ?
+		}
+	};
+
+	template IaRestOctets tr_IaRestOctets_ULAss(template PacketUlAssign ul_ass) := {
+		presence := '11'B, /* HH */
+		ll := omit, lh := omit, hl := omit,
+		hh := {
+			pa_disc := '0'B, /* Packet Assignment (0) */
+			pa := {
+				uldl := {
+					ass_disc := '0'B, /* Uplink Assignment (0) */
+					ass := { ul := ul_ass }
+				}
+			}
+		}
+	};
+
 	template (value) GsmRrMessage ts_IMM_ASS(uint8_t ra, GsmFrameNumber fn, TimingAdvance ta,
 						ChannelDescription ch_desc, MobileAllocation ma) := {
 		header := t_RrHeader(IMMEDIATE_ASSIGNMENT, 0),
@@ -802,6 +908,7 @@ module GSM_RR_Types {
 		}
 	};
 
+	/* TODO: introduce generic TBF Assignment template for DL and UL */
 	template ImmediateAssignment t_IMM_ASS_TBF_DL(template GprsTlli tlli) := {
 		ded_or_tbf := {
 			spare := ?,
@@ -822,28 +929,7 @@ module GSM_RR_Types {
 		req_ref := ?,
 		timing_advance := ?,
 		mobile_allocation := ?,
-		rest_octets := {
-			presence := '11'B,
-			ll := omit,
-			lh := omit,
-			hl := omit,
-			hh := {
-				presence := '01'B,
-				ul := omit,
-				dl := {
-					tlli := tlli,
-					group1_present := ?,
-					group1 := *,
-					ta_index_present := ?,
-					ta_index := *,
-					tbf_starting_time_present := ?,
-					tbf_starting_time := *,
-					p0_present := ?,
-					p0 := *,
-					pr_mode := *
-				}
-			}
-		}
+		rest_octets := tr_IaRestOctets_DLAss(tr_PacketDlAssign(tlli))
 	};
 
 	template GsmRrMessage t_RR_IMM_ASS_TBF_DL(template GprsTlli tlli) := {
diff --git a/library/LAPDm_RAW_PT.ttcn b/library/LAPDm_RAW_PT.ttcn
index 2ede5660..5a8d9eae 100644
--- a/library/LAPDm_RAW_PT.ttcn
+++ b/library/LAPDm_RAW_PT.ttcn
@@ -261,44 +261,13 @@ module LAPDm_RAW_PT {
 		a[idx] := tfi_usf;
 	}
 
-	/* Match an IMM.ASS for an Uplink TBF with a dynamic allocation */
+	/* Match an IMM.ASS for an Uplink TBF with a dynamic allocation
+	 * FIXME: this template has nothing to do with LAPDm, move to GSM_RR_Types.ttcn */
 	template ImmediateAssignment t_IMM_ASS_TBF_UL_DYN(uint8_t ra, GsmFrameNumber fn) modifies t_IMM_ASS := {
 		ded_or_tbf := { spare := ?, tma := ?, downlink := false, tbf := true},
 		chan_desc := omit,
 		pkt_chan_desc := ?,
-		rest_octets := {
-			presence := '11'B,
-			ll := omit,
-			lh := omit,
-			hl := omit,
-			hh := {
-				presence := '00'B,
-				ul := {
-					presence := '1'B,
-					dynamic := {
-						tfi_assignment := ?,
-						polling := ?,
-						spare := '0'B,
-						usf := ?,
-						usf_granularity := ?,
-						p0_present := ?,
-						p0 := *,
-						pr_mode := *,
-						ch_coding_cmd := ?,
-						tlli_block_chan_coding:= ?,
-						alpha_present := ?,
-						alpha := *,
-						gamma := ?,
-						ta_index_present := ?,
-						ta_index := *,
-						tbf_starting_time_present := ?,
-						tbf_starting_time := *
-					},
-					single := omit
-				},
-				dl := omit
-			}
-		}
+		rest_octets := tr_IaRestOctets_ULAss(tr_PacketUlDynAssign())
 	};
 
 	template (value) RLCMAC_ph_data_req ts_PH_DATA_ABS(uint8_t tbf_id, GprsCodingScheme cs,
@@ -332,7 +301,8 @@ module LAPDm_RAW_PT {
 			//chan_desc := imm_ass.chan_desc;
 
 			/* Important: ARFCN, TN, TSC, USF, USF_GRANULARITY, CH_CODING_CMD */
-			f_TfiUsfArrSet(tua, imm_ass.pkt_chan_desc.tn, imm_ass.rest_octets.hh.ul.dynamic.usf);
+			f_TfiUsfArrSet(tua, imm_ass.pkt_chan_desc.tn,
+				       imm_ass.rest_octets.hh.pa.uldl.ass.ul.dynamic.usf);
 			f_L1CTL_TBF_CFG(L1CTL, true, tua);
 		} else {
 			/* FIXME: single block uplink allocation */