/* Encoding/Decoding routines for GSM System Information messages * according to 3GPP TS 44.018 Version 12.3.0 Release 12 * * (C) 2017-2018 Harald Welte * 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 GSM_Types { import from General_Types all; import from Osmocom_Types all; import from Misc_Helpers all; type integer GsmArfcn (0..1023); type integer UmtsArfcn (0..16383); type integer UmtsScramblingCode (0..511); const integer GsmMaxFrameNumber := 26*51*2048; type integer GsmFrameNumber (0..GsmMaxFrameNumber); type integer GsmRxLev (0..63); type integer GsmTsc (0..7) with { variant "FIELDLENGTH(8)" }; type uint32_t GsmTmsi; type OCT4 GprsTlli; type hexstring GsmMcc length(3); type hexstring GsmMnc length(2 .. 3); type uint16_t GsmLac; type uint16_t GsmCellId; type octetstring GroupCallRef length(1 .. 5); /* ARFCN with explicit band discrimination */ type record GsmBandArfcn { boolean pcs, boolean uplink, BIT4 spare, GsmArfcn arfcn } with { variant (arfcn) "BYTEORDER(last)" variant (arfcn) "FIELDLENGTH(10)" }; template (value) GsmBandArfcn ts_GsmBandArfcn(template (value) GsmArfcn arfcn, template (value) boolean pcs := false, template (value) boolean uplink := false) := { pcs := pcs, uplink := uplink, spare := '0000'B, arfcn := arfcn }; template GsmBandArfcn tr_GsmBandArfcn(template (present) GsmArfcn arfcn, template (present) boolean pcs := ?, template (present) boolean uplink := ?) := { pcs := pcs, uplink := uplink, spare := ?, arfcn := arfcn }; /* see enum 'gsm_phys_chan_config' in libosmocore */ type enumerated PchanConfig { GSM_PCHAN_NONE, GSM_PCHAN_CCCH, GSM_PCHAN_CCCH_SDCCH4, GSM_PCHAN_CCCH_SDCCH4_CBCH, GSM_PCHAN_SDCCH8, GSM_PCHAN_SDCCH8_CBCH, GSM_PCHAN_TCHF, GSM_PCHAN_TCHH, GSM_PCHAN_PDCH, /* IPA style dynamic TCH/F+PDCH */ GSM_PCHAN_TCHF_PDCH, /* Osmocom style dynamic TCH/H+TCH/F+PDCH */ GSM_PCHAN_TCHH_TCHF_PDCH }; type enumerated GprsCodingScheme { CS1, CS2, CS3, CS4 }; function f_gprs_blocksize(GprsCodingScheme cs) return integer { select (cs) { case (CS1) { return 22 } case (CS2) { return 32 } case (CS3) { return 38 } case (CS3) { return 52 } } Misc_Helpers.f_shutdown(__BFILE__, __LINE__, fail, log2str("Invalid GPRS CS ", cs)); return 0; } const GprsTlli TLLI_UNUSED := 'FFFFFFFF'O; function f_gen_tlli() return GprsTlli { var GprsTlli tlli := f_rnd_octstring(4); if (tlli == TLLI_UNUSED) { tlli := 'EEEEEEEE'O; } return tlli; } /* 10.5.2.8 */ type enumerated ChannelNeeded { CHAN_NEED_ANY (0), CHAN_NEED_SDCCH (1), CHAN_NEED_TCH_F (2), CHAN_NEED_TCH_H (3) } with { variant "FIELDLENGTH(2)" }; type record ChannelNeeded12 { ChannelNeeded second, ChannelNeeded first } with { variant "" }; /* TS 48.058 9.3.1 Channel Number IE */ type enumerated RslChanNr0 { RSL_CHAN_NR_INVALID ('00000'B), RSL_CHAN_NR_Bm_ACCH ('00001'B), RSL_CHAN_NR_BCCH ('10000'B), RSL_CHAN_NR_RACH ('10001'B), RSL_CHAN_NR_PCH_AGCH ('10010'B), RSL_CHAN_NR_OSMO_PDCH ('11000'B), RSL_CHAN_NR_OSMO_CBCH4 ('11001'B), RSL_CHAN_NR_OSMO_CBCH8 ('11010'B), RSL_CHAN_NR_OSMO_VAMOS_Bm_ACCH ('11101'B) } with { variant "FIELDLENGTH(5)" variant "FIELDORDER(msb)" }; type record RslChanNr2 { BIT4 tag ('0001'B, '1111'B), uint1_t sub_chan } with { variant "FIELDLENGTH(5)" variant "FIELDORDER(msb)" }; type record RslChanNr4 { BIT3 tag ('001'B), uint2_t sub_chan } with { variant "FIELDLENGTH(5)" variant "FIELDORDER(msb)" }; type record RslChanNr8 { BIT2 tag ('01'B), uint3_t sub_chan } with { variant "FIELDLENGTH(5)" variant "FIELDORDER(msb)" }; type union RslChanNrU { RslChanNr0 ch0, RslChanNr2 lm, RslChanNr4 sdcch4, RslChanNr8 sdcch8 } with { variant "TAG(lm, tag = '0001'B; lm, tag = '1111'B; sdcch4, tag = '001'B; sdcch8, tag = '01'B; ch0, OTHERWISE)" variant "FIELDLENGTH(5)" variant "FIELDORDER(msb)" }; type record RslChannelNr { RslChanNrU u, uint3_t tn } with { variant "FIELDLENGTH(8)" variant "FIELDORDER(msb)" }; template RslChannelNr t_RslChanNr0(template uint3_t tn, template RslChanNr0 cht) := { u := { ch0 := cht }, tn := tn } template RslChannelNr t_RslChanNr_RACH(template uint3_t tn) := t_RslChanNr0(tn, RSL_CHAN_NR_RACH); template RslChannelNr t_RslChanNr_BCCH(template uint3_t tn) := t_RslChanNr0(tn, RSL_CHAN_NR_BCCH); template RslChannelNr t_RslChanNr_PCH_AGCH(template uint3_t tn) := t_RslChanNr0(tn, RSL_CHAN_NR_PCH_AGCH); template RslChannelNr t_RslChanNr_Bm(template uint3_t tn) := t_RslChanNr0(tn, RSL_CHAN_NR_Bm_ACCH); template RslChannelNr t_RslChanNr_PDCH(template uint3_t tn) := t_RslChanNr0(tn, RSL_CHAN_NR_OSMO_PDCH); template RslChannelNr t_RslChanNr_CBCH4(template uint3_t tn) := t_RslChanNr0(tn, RSL_CHAN_NR_OSMO_CBCH4); template RslChannelNr t_RslChanNr_CBCH8(template uint3_t tn) := t_RslChanNr0(tn, RSL_CHAN_NR_OSMO_CBCH8); template RslChannelNr t_RslChanNr_Lm(template uint3_t tn, template uint1_t sub_slot) := { u := { lm := { tag := '0001'B, sub_chan := sub_slot } }, tn := tn } template RslChannelNr t_RslChanNr_SDCCH4(template uint3_t tn, template uint2_t sub_slot) := { u := { sdcch4 := { tag := '001'B, sub_chan := sub_slot } }, tn := tn } template RslChannelNr t_RslChanNr_SDCCH8(template uint3_t tn, template uint3_t sub_slot) := { u := { sdcch8 := { tag := '01'B, sub_chan := sub_slot } }, tn := tn } template RslChannelNr t_RslChanNr_Osmo_VAMOS_Bm(template uint3_t tn) := { u := { ch0 := RSL_CHAN_NR_OSMO_VAMOS_Bm_ACCH }, tn := tn } template RslChannelNr t_RslChanNr_Osmo_VAMOS_Lm(template uint3_t tn, template uint1_t sub_slot) := { u := { lm := { tag := '1111'B, sub_chan := sub_slot } }, tn := tn } template (value) RslChannelNr ts_RslChanNr0(uint3_t tn, RslChanNr0 cht) := { u := { ch0 := cht }, tn := tn } template (value) RslChannelNr ts_RslChanNr_RACH(uint3_t tn) := ts_RslChanNr0(tn, RSL_CHAN_NR_RACH); template (value) RslChannelNr ts_RslChanNr_BCCH(uint3_t tn) := ts_RslChanNr0(tn, RSL_CHAN_NR_BCCH); template (value) RslChannelNr ts_RslChanNr_PCH_AGCH(uint3_t tn) := ts_RslChanNr0(tn, RSL_CHAN_NR_PCH_AGCH); template (value) RslChannelNr ts_RslChanNr_Bm(uint3_t tn) := ts_RslChanNr0(tn, RSL_CHAN_NR_Bm_ACCH); template (value) RslChannelNr ts_RslChanNr_PDCH(uint3_t tn) := ts_RslChanNr0(tn, RSL_CHAN_NR_OSMO_PDCH); template (value) RslChannelNr ts_RslChanNr_CBCH4(uint3_t tn) := ts_RslChanNr0(tn, RSL_CHAN_NR_OSMO_CBCH4); template (value) RslChannelNr ts_RslChanNr_CBCH8(uint3_t tn) := ts_RslChanNr0(tn, RSL_CHAN_NR_OSMO_CBCH8); template (value) RslChannelNr ts_RslChanNr_Lm(uint3_t tn, uint1_t sub_slot) := { u := { lm := { tag := '0001'B, sub_chan := sub_slot } }, tn := tn } template (value) RslChannelNr ts_RslChanNr_SDCCH4(uint3_t tn, uint2_t sub_slot) := { u := { sdcch4 := { tag := '001'B, sub_chan := sub_slot } }, tn := tn } template (value) RslChannelNr ts_RslChanNr_SDCCH8(uint3_t tn, uint3_t sub_slot) := { u := { sdcch8 := { tag := '01'B, sub_chan := sub_slot } }, tn := tn } template (value) RslChannelNr ts_RslChanNr_Osmo_VAMOS_Bm(uint3_t tn) := { u := { ch0 := RSL_CHAN_NR_OSMO_VAMOS_Bm_ACCH }, tn := tn } template (value) RslChannelNr ts_RslChanNr_Osmo_VAMOS_Lm(uint3_t tn, uint1_t sub_slot) := { u := { lm := { tag := '1111'B, sub_chan := sub_slot } }, tn := tn } /* TS 48.058 9.3.2 Link ID */ type enumerated RslLinkIdC { FACCH_SDCCH (0), SACCH (1), OSMO_PTCCH (2) /* Osmocom (trxcon) specific extension */ } with { variant "FIELDLENGTH(2)" }; type enumerated RslSapi0Prio { SAPI0_PRIO_NORMAL (0), SAPI0_PRIO_HIGH (1), SAPI0_PRIO_LOW (2) } with { variant "FIELDLENGTH(2)" }; type uint3_t GsmSapi; type record RslLinkId { RslLinkIdC c, boolean na, RslSapi0Prio prio, GsmSapi sapi } with { variant "" }; template RslLinkId tr_RslLinkId := { c := ?, na := ?, prio := ?, sapi := ? }; template RslLinkId tr_RslLinkID_DCCH(template GsmSapi sapi) modifies tr_RslLinkId := { c := FACCH_SDCCH, na := false, sapi := sapi }; template RslLinkId tr_RslLinkID_SACCH(template GsmSapi sapi) modifies tr_RslLinkId := { c := SACCH, na := false, sapi := sapi }; template RslLinkId tr_RslLinkID_OSMO_PTCCH(template GsmSapi sapi) modifies tr_RslLinkId := { c := OSMO_PTCCH, na := false, sapi := sapi }; template (value) RslLinkId ts_RslLinkID_DCCH(GsmSapi sapi) := { c := FACCH_SDCCH, na := false, prio := SAPI0_PRIO_NORMAL, sapi := sapi }; template (value) RslLinkId ts_RslLinkID_SACCH(GsmSapi sapi) := { c := SACCH, na := false, prio := SAPI0_PRIO_NORMAL, sapi := sapi }; template (value) RslLinkId ts_RslLinkID_OSMO_PTCCH(GsmSapi sapi) := { c := OSMO_PTCCH, na := false, prio := SAPI0_PRIO_NORMAL, sapi := sapi }; function f_hex_is_odd_length(hexstring digits) return bitstring { if (lengthof(digits) rem 2 == 1) { return '1'B; } else { return '0'B; } } /* TS 04.12 Section 3.3.1 Block type */ type record CBCH_BlockType { BIT1 spare, BIT2 lpd, boolean last_block, uint4_t seq_nr }; template (value) CBCH_BlockType ts_CBCH_BlockType(template (value) uint4_t seq_nr, template (value) boolean last_block) := { spare := '0'B, lpd := '01'B, last_block := last_block, seq_nr := seq_nr }; template CBCH_BlockType tr_CBCH_BlockType(template uint4_t seq_nr := ?, template boolean last_block := ?) := { spare := '0'B, lpd := '01'B, last_block := last_block, seq_nr := seq_nr }; /* TS 04.12 Section 3.3 */ type record CBCH_Block { CBCH_BlockType block_type, OCT22 payload }; template (value) CBCH_Block ts_CBCH_Block(template (value) uint4_t seq_nr, template (value) boolean last_block, template (value) OCT22 payload) := { block_type := ts_CBCH_BlockType(seq_nr, last_block), payload := payload }; template CBCH_Block tr_CBCH_Block(template uint4_t seq_nr := ?, template boolean last_block := ?, template OCT22 payload := ?) := { block_type := tr_CBCH_BlockType(seq_nr, last_block), payload := payload }; external function enc_CBCH_Block(in CBCH_Block msg) return octetstring with { extension "prototype(convert) encode(RAW)" }; external function dec_CBCH_Block(in octetstring stream) return CBCH_Block with { extension "prototype(convert) decode(RAW)" }; /* Convert RF signal level in dBm to RxLev (TS 45.008 Chapter 8.1.4) */ function dbm2rxlev(integer dbm) return uint6_t { var integer rxlev := dbm + 110; if (rxlev > 63) { rxlev := 63; } else if (rxlev < 0) { rxlev := 0; } return rxlev; } function rxlev2dbm(uint6_t rxlev) return integer { return -110 + rxlev; } /* convert BER to RxQual value (TS 45.008 Chapter 8.2.4 */ function ber2rxqual(float ber) return uint3_t { if (ber < 0.2) { return 0; } else if (ber < 0.4) { return 1; } else if (ber < 0.8) { return 2; } else if (ber < 1.6) { return 3; } else if (ber < 3.2) { return 4; } else if (ber < 6.4) { return 5; } else if (ber < 12.8) { return 6; } else { return 7; } } /* convert RxQual to BER (TS 45.008 Chapter 8.2.4 */ function rxqual2ber(uint3_t rxqual) return float { select (rxqual) { case (0) { return 0.14 } case (1) { return 0.28 } case (2) { return 0.57 } case (3) { return 1.13 } case (4) { return 2.26 } case (5) { return 4.53 } case (6) { return 9.05 } case (7) { return 18.10 } case else { return 1000.0 } } } const float GSM_FRAME_DURATION := 0.12/26.0; /* 4.615 ms */ const float GSM51_MFRAME_DURATION := 51.0 * GSM_FRAME_DURATION; /* 235.365 ms */ const float GSM51_MFRAMES_PER_SEC := 1.0 / GSM51_MFRAME_DURATION; /* 4.248 */ /* number of downlink CCCH blocks per second */ function f_ccch_blocks_per_mframe(boolean combined_ccch) return integer { if (not combined_ccch) { /* 9 blocks per 51 multiframe */ return 9; } else { /* 3 blocks per 51 multiframe */ return 3; } } /* this ignores any possible paging combining! */ function f_pch_block_rate_est(boolean combined_ccch, integer bs_ag_blks_res) return float { var integer ccch_per_mframe := f_ccch_blocks_per_mframe(combined_ccch); var integer pch_per_mframe := ccch_per_mframe - bs_ag_blks_res; return GSM51_MFRAMES_PER_SEC * int2float(pch_per_mframe); } /* this ignores any possible imm.ass combining! */ function f_agch_block_rate_est(boolean combined_ccch, integer bs_ag_blks_res) return float { var integer ccch_per_mframe := f_ccch_blocks_per_mframe(combined_ccch); return GSM51_MFRAMES_PER_SEC * int2float(bs_ag_blks_res); } /* compute TC as per 45.002 6.3.1.3 */ function f_gsm_compute_tc(integer fn) return integer { return (fn / 51) mod 8; } type hexstring GsmBcdString with { variant "HEXORDER(low)" }; type GsmBcdString BcdMccMnc with { variant "FIELDLENGTH(6)" }; /* hex2oct()/oct2hex() do not respect the HEXORDER/FIELDLENGTH attributes, * so better use the functions, employing TITAN's RAW codec, dclared below. */ external function enc_BcdMccMnc(in BcdMccMnc str) return octetstring with { extension "prototype(convert) encode(RAW)" }; external function dec_BcdMccMnc(in octetstring str) return BcdMccMnc with { extension "prototype(convert) decode(RAW)" }; /* Compute BcdMccMnc from a pair of GsmMcc/GsmMnc values */ function f_build_BcdMccMnc(GsmMcc mcc, GsmMnc mnc) return BcdMccMnc { if (lengthof(mnc) == 2) { mnc := mnc[0] & mnc[1] & 'F'H; } /* 3GPP TS 24.008, Figure 10.5.13 * | MCC digit 2 | MCC digit 1 | octet 1 * | MNC digit 3 | MCC digit 3 | octet 2 * | MNC digit 2 | MNC digit 1 | octet 3 * * NOTE: TITAN takes care of swapping the nibbles in octets, * so we use the normal (low-to-high) ordering here. */ return mcc[0] & mcc[1] & mcc[2] & mnc[2] & mnc[0] & mnc[1]; } /* Compute BcdMccMnc from integer values */ function f_build_BcdMccMnc_int(uint16_t mcc, uint16_t mnc, boolean mnc_3_digits) return BcdMccMnc { var hexstring mcc_str := str2hex(int2str(mcc)); var hexstring mnc_str := str2hex(int2str(mnc)); if (mnc_3_digits == true) { return f_build_BcdMccMnc(mcc_str[0] & mcc_str[1] & mcc_str[2], mnc_str[0] & mnc_str[1] & mnc_str[2]); } else { return f_build_BcdMccMnc(mcc_str[0] & mcc_str[1] & mcc_str[2], mnc_str[0] & mnc_str[1]); } } testcase TC_selftest_BcdMccMnc() runs on Dummy_CT { if (not match('62F224'O, decmatch BcdMccMnc:'262F42'H)) { setverdict(fail); } if (not match('21F354'O, decmatch BcdMccMnc:'123F45'H)) { setverdict(fail); } if (not match('216354'O, decmatch BcdMccMnc:'123645'H)) { setverdict(fail); } if (not match(enc_BcdMccMnc('262F42'H), '62F224'O)) { setverdict(fail); } if (not match(enc_BcdMccMnc('123F45'H), '21F354'O)) { setverdict(fail); } if (not match(enc_BcdMccMnc('123645'H), '216354'O)) { setverdict(fail); } if (not match(f_build_BcdMccMnc('262'H, '42'H), BcdMccMnc:'262F42'H)) { setverdict(fail); } if (not match(f_build_BcdMccMnc('123'H, '45'H), BcdMccMnc:'123F45'H)) { setverdict(fail); } if (not match(f_build_BcdMccMnc('123'H, '456'H), BcdMccMnc:'123645'H)) { setverdict(fail); } if (not match(f_build_BcdMccMnc_int(262, 42, false), BcdMccMnc:'262F42'H)) { setverdict(fail); } if (not match(f_build_BcdMccMnc_int(123, 45, false), BcdMccMnc:'123F45'H)) { setverdict(fail); } if (not match(f_build_BcdMccMnc_int(123, 456, true), BcdMccMnc:'123645'H)) { setverdict(fail); } setverdict(pass); } /* 24.008 10.5.1.3 */ type record LocationAreaIdentification { BcdMccMnc mcc_mnc, uint16_t lac } with { variant "" }; template (value) LocationAreaIdentification ts_LAI(BcdMccMnc mcc_mnc, uint16_t lac) := { mcc_mnc := mcc_mnc, lac := lac }; /* 24.008 10.5.5.15 */ type record RoutingAreaIdentification { LocationAreaIdentification lai, uint8_t rac } with { variant "" }; template (value) RoutingAreaIdentification ts_RAI(template (value) LocationAreaIdentification lai, uint8_t rac) := { lai := lai, rac := rac }; external function enc_RoutingAreaIdentification(RoutingAreaIdentification rai) return octetstring with { extension "prototype(convert)" extension "encode(RAW)" } /* TS 24.008 10.5.1.1 */ type uint16_t CellIdentity; } with { encode "RAW"; variant "FIELDORDER(msb)" }