/* TITAN REW encode/decode definitions for 3GPP TS 44.060 RLC/MAC Blocks */

/* (C) 2017-2018 Harald Welte <laforge@gnumonks.org>
 * All rights reserved.
 *
 * Released under the terms of GNU General Public License, Version 2 or
 * (at your option) any later version.
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

module RLCMAC_Types {
	import from General_Types all;
	import from Osmocom_Types all;
	import from GSM_Types all;
	import from RLCMAC_CSN1_Types all;

	/* TS 44.060 10.4.7 */
	type enumerated MacPayloadType {
		MAC_PT_RLC_DATA			('00'B),
		MAC_PT_RLCMAC_NO_OPT		('01'B),
		MAC_PT_RLCMAC_OPT		('10'B),
		MAC_PT_RESERVED			('11'B)
	} with { variant "FIELDLENGTH(2)" };

	/* TS 44.060 10.4.5 */
	type enumerated MacRrbp {
		RRBP_Nplus13_mod_2715648	('00'B),
		RRBP_Nplus17_or_18_mod_2715648	('01'B),
		RRBP_Nplus21_or_22_mod_2715648	('10'B),
		RRBP_Nplus26_mod_2715648	('11'B)
	} with { variant "FIELDLENGTH(2)" };

	/* Partof DL RLC data block and DL RLC/MAC ctrl block */
	type record DlMacHeader {
		MacPayloadType	payload_type,
		MacRrbp		rrbp,
		boolean		rrbp_valid,
		uint3_t		usf
	} with {
		variant (rrbp_valid) "FIELDLENGTH(1)"
	};

	/* TS 44.060 10.4.10a */
	type enumerated PowerReduction {
		PWR_RED_0_to_3dB		('00'B),
		PWR_RED_3_to_7dB		('01'B),
		PWR_RED_7_to_10dB		('10'B),
		PWR_RED_RESERVED		('11'B)
	} with { variant "FIELDLENGTH(2)" };

	/* TS 44.060 10.4.9d */
	type enumerated DirectionBit {
		DIR_UPLINK_TBF		('0'B),
		DIR_DOWNLINK_TBF	('1'B)
	} with { variant "FIELDLENGTH(1)" };

	type record TfiOctet {
		/* PR, TFI, D */
		PowerReduction	pr,
		uint5_t		tfi,
		DirectionBit	d
	} with { variant "" };

	type record RbsnExtOctet {
		uint3_t		rbsn_e,
		BIT1		fs_e,
		BIT4		spare
	} with { variant "" };

	type record DlCtrlOptOctets {
		/* RBSN, RTI, FS, AC (optional, depending on mac_hdr.payload_type) */
		BIT1		rbsn,
		uint5_t		rti,
		boolean		fs,
		boolean		tfi_octet_present,
		TfiOctet	tfi optional,
		RbsnExtOctet	rbsn_ext optional
	} with {
		variant (fs) "FIELDLENGTH(1)"
		variant (tfi_octet_present) "FIELDLENGTH(1)"
		variant (tfi) "PRESENCE(tfi_octet_present = true)"
		variant (rbsn_ext) "PRESENCE(rbsn='1'B, fs=false)"
	};

	/* TS 44.060 10.3.1 Downlink RLC/MAC control block */
	type record RlcmacDlCtrlBlock {
		DlMacHeader		mac_hdr,
		DlCtrlOptOctets		opt optional,
		RlcmacDlCtrlMsg		payload
	} with {
		variant (opt) "PRESENCE(mac_hdr.payload_type = MAC_PT_RLCMAC_OPT)"
	};

	external function enc_RlcmacDlCtrlBlock(in RlcmacDlCtrlBlock si) return octetstring
		with { extension "prototype(convert) encode(RAW)" };
	external function dec_RlcmacDlCtrlBlock(in octetstring stream) return RlcmacDlCtrlBlock
		with { extension "prototype(convert) decode(RAW)" };

	type record UlMacCtrlHeader {
		MacPayloadType		payload_type,
		BIT5			spare,
		boolean			retry
	} with { variant (retry) "FIELDLENGTH(1)" };

	/* TS 44.060 10.3.2 UplinkRLC/MAC control block */
	type record RlcmacUlCtrlBlock {
		UlMacCtrlHeader		mac_hdr,
		RlcmacUlCtrlMsg		payload
	} with { variant "" };

	external function enc_RlcmacUlCtrlBlock(in RlcmacUlCtrlBlock si) return octetstring
		with { extension "prototype(convert) encode(RAW)" };
	external function dec_RlcmacUlCtrlBlock(in octetstring stream) return RlcmacUlCtrlBlock
		with { extension "prototype(convert) decode(RAW)" };

	/* a single RLC block / LLC-segment */
	type record LlcBlockHdr {
		uint6_t		length_ind,
		/* 1 = new LLC PDU starts */
		boolean		more,
		/* 0 = another extension octet after LLC PDU, 1 = no more extension octets */
		boolean		e
	} with {
		variant (e) "FIELDLENGTH(1)"
		encode "RAW"
	};

	external function enc_LlcBlockHdr(in LlcBlockHdr si) return octetstring
		with { extension "prototype(convert) encode(RAW)" };
	external function dec_LlcBlockHdr(in octetstring stream) return LlcBlockHdr
		with { extension "prototype(convert) decode(RAW)" };

	type record LlcBlock {
		/* Header is only present if LI field was present */
		LlcBlockHdr	hdr optional,
		octetstring 	payload
	} with { variant "" };
	type record of LlcBlock LlcBlocks;

	/* TS 44.060 10.2.1 Downlink RLC data block */
	type record DlMacHdrDataExt {
		/* Octet 1 */
		PowerReduction		pr,
		BIT1			spare,
		uint4_t			tfi, /* 3 or 4? */
		boolean			fbi,
		/* Octet 2 */
		uint7_t			bsn,
		boolean			e
	} with {
		variant (e) "FIELDLENGTH(1)"
	};
	type record DlMacDataHeader {
		DlMacHeader		mac_hdr,
		DlMacHdrDataExt		hdr_ext
	} with { variant "" };
	type record RlcmacDlDataBlock {
		DlMacDataHeader		mac_hdr,
		/* Octet 3..M / N: manual C++ Decoder */
		LlcBlocks		blocks
	} with {
		variant ""
	};

	external function enc_RlcmacDlDataBlock(in RlcmacDlDataBlock si) return octetstring;
	external function dec_RlcmacDlDataBlock(in octetstring stream) return RlcmacDlDataBlock;


	/* TS 44.060 10.2.2 */
	type record UlMacDataHeader {
		/* Octet 0 */
		MacPayloadType		payload_type,
		uint4_t			countdown,
		boolean			stall_ind,
		boolean			retry,
		/* Octet 1 */
		BIT1			spare,
		boolean			pfi_ind,
		uint5_t			tfi,
		boolean			tlli_ind,
		/* Octet 2 */
		uint7_t			bsn,
		boolean			e
	} with {
		variant (stall_ind)	"FIELDLENGTH(1)"
		variant (retry)		"FIELDLENGTH(1)"
		variant (pfi_ind)	"FIELDLENGTH(1)"
		variant (tlli_ind)	"FIELDLENGTH(1)"
		variant (e)		"FIELDLENGTH(1)"
	};

	type record RlcMacUlPfi {
		uint7_t			pfi,
		boolean			m
	} with {
		variant (m) "FIELDLENGTH(1)"
	};

	/* TS 44.060 10.2.2 */
	type record RlcmacUlDataBlock {
		/* MAC header */
		UlMacDataHeader		mac_hdr,
		/* Octet 3 ... M (optional): manual C++ Decoder */
		GprsTlli		tlli optional,
		RlcMacUlPfi		pfi optional,
		LlcBlocks		blocks
	} with {
		variant (tlli) "PRESENCE(mac_hdr.tlli_ind = true)"
		variant (pfi) "PRESENCE(mac_hdr.pfi_ind = true)"
	};

	external function enc_RlcmacUlDataBlock(in RlcmacUlDataBlock si) return octetstring;
	external function dec_RlcmacUlDataBlock(in octetstring stream) return RlcmacUlDataBlock;

	type union RlcmacUlBlock {
		RlcmacUlDataBlock	data,
		RlcmacUlCtrlBlock	ctrl
	} with {
		variant "TAG(data, mac_hdr.payload_type = MAC_PT_RLC_DATA;
			     ctrl, mac_hdr.payload_type = MAC_PT_RLCMAC_NO_OPT;
			     ctrl, mac_hdr.payload_type = MAC_PT_RLCMAC_OPT)"
	};

	/* as the sub-types (RlcmacDl*Block) are not using the RAW coder, we cannot
	 * use auto-generated functions here, as they would decode those sub-types
	 * based on the RAW coder, not baed on the manual C++ functions */
	external function enc_RlcmacUlBlock(in RlcmacUlBlock si) return octetstring;
	external function dec_RlcmacUlBlock(in octetstring stream) return RlcmacUlBlock;

	type union RlcmacDlBlock {
		RlcmacDlDataBlock	data,
		RlcmacDlCtrlBlock	ctrl
	} with {
		variant "TAG(data, mac_hdr.mac_hdr.payload_type = MAC_PT_RLC_DATA;
			     ctrl, mac_hdr.payload_type = MAC_PT_RLCMAC_NO_OPT;
			     ctrl, mac_hdr.payload_type = MAC_PT_RLCMAC_OPT)"
	};

	/* as the sub-types (RlcmacDl*Block) are not using the RAW coder, we cannot
	 * use auto-generated functions here, as they would decode those sub-types
	 * based on the RAW coder, not baed on the manual C++ functions */
	external function enc_RlcmacDlBlock(in RlcmacDlBlock si) return octetstring;
	external function dec_RlcmacDlBlock(in octetstring stream) return RlcmacDlBlock;

	template (value) RlcmacUlBlock ts_RLC_UL_CTRL_ACK(RlcmacUlCtrlMsg ctrl,
							MacPayloadType pt := MAC_PT_RLCMAC_NO_OPT,
							boolean retry := false) := {
		ctrl := {
			mac_hdr := {
				payload_type := pt,
				spare := '00000'B,
				retry := retry
			},
			payload := ctrl
		}
	}

	/* Template fro uplink Data block */
	template RlcmacUlBlock t_RLCMAC_UL_DATA(template uint5_t tfi, template uint4_t cv, template uint7_t bsn,
						template LlcBlocks blocks := {}, template boolean stall := false) := {
		data := {
			mac_hdr := {
				payload_type := MAC_PT_RLC_DATA,
				countdown := cv,
				stall_ind := false,
				retry := false,
				spare := '0'B,
				pfi_ind := false,
				tfi := tfi,
				tlli_ind := false,
				bsn := bsn,
				e := false
			},
			tlli := omit,
			pfi := omit,
			blocks := blocks
		}
	}
	template RlcmacUlBlock t_RLCMAC_UL_DATA_TLLI(template uint5_t tfi, template uint4_t cv, template uint7_t bsn,
						     template LlcBlocks blocks := {}, template boolean stall := false, template GprsTlli tlli) := {
		data := {
			mac_hdr := {
				payload_type := MAC_PT_RLC_DATA,
				countdown := cv,
				stall_ind := false,
				retry := false,
				spare := '0'B,
				pfi_ind := false,
				tfi := tfi,
				tlli_ind := true,
				bsn := bsn,
				e := false
			},
			tlli := tlli,
			pfi := omit,
			blocks := blocks
		}
	}

	template DlMacHeader t_RLCMAC_DlMacH(template MacPayloadType pt, template MacRrbp rrbp, template
uint3_t usf) := {
		payload_type := pt,
		rrbp := rrbp,
		rrbp_valid := ispresent(rrbp),
		usf := usf
	}

	/* Receive Template for Downlink ACK/NACK */
	template RlcmacDlBlock tr_RLCMAC_ACK_NACK(template uint5_t ul_tfi, template GprsTlli tlli := ?) := {
		ctrl := {
			mac_hdr := {
				payload_type := (MAC_PT_RLCMAC_NO_OPT, MAC_PT_RLCMAC_OPT),
				rrbp:= ?,
				rrbp_valid := true,
				usf := ?
			},
			opt := *,
			payload := {
				msg_type := PACKET_UL_ACK_NACK,
				u := {
					ul_ack_nack := {
						page_mode := ?,
						msg_excape := ?,
						uplink_tfi := ul_tfi,
						is_egprs := '0'B,
						gprs := {
							ch_coding_cmd := ?,
							ack_nack_desc := ?,
							cont_res_tlli_present := ?,
							cont_res_tlli := tlli,
							pkt_ta_present := ?,
							pkt_ta := *,
							pwr_ctrl_present := ?,
							pwr_ctrl := *
						}
					}
				}
			}
		}
	}

	template RlcmacDlBlock tr_RLCMAC_DATA_RRBP := {
		data := {
			mac_hdr := {
				mac_hdr := {
					payload_type := MAC_PT_RLC_DATA,
					rrbp := ?,
					rrbp_valid := true,
					usf := ?
				},
				hdr_ext := ?
			},
			blocks := ?
		}
	}

	/* Template for Uplink MAC Control Header */
	template UlMacCtrlHeader t_RLCMAC_UlMacCtrlH(template MacPayloadType pt, template boolean retry := false) := {
		payload_type := pt,
		spare := '00000'B,
		retry := retry
	}

	/* Template for Uplink Conntrol ACK */
	template RlcmacUlBlock ts_RLCMAC_CTRL_ACK(GprsTlli tlli, CtrlAck ack := MS_RCVD_TWO_RLC_SAME_RTI_DIFF_RBSN) := {
		ctrl := {
			mac_hdr := t_RLCMAC_UlMacCtrlH(MAC_PT_RLCMAC_NO_OPT),
			payload := {
				msg_type := PACKET_CONTROL_ACK,
				u := {
					ctrl_ack := {
						tlli := tlli,
						ctrl_ack := ack
					}
				}
			}
		}
	}

	/* Template for a LlcBlock (part of a LLC frame inside RlcMac?lDataBlock */
	template LlcBlock t_RLCMAC_LLCBLOCK(octetstring data, boolean more := false, boolean e := true) := {
		/* let encoder figure out the header */
		hdr := omit,
		payload := data
	}


} with { encode "RAW"; variant "FIELDORDER(msb)" }