Change in libosmo-gprs[master]: llc: import FCS (CRC24) calculation API from osmo-sgsn.git

fixeria has submitted this change. ( https://gerrit.osmocom.org/c/libosmo-gprs/+/29400 ) Change subject: llc: import FCS (CRC24) calculation API from osmo-sgsn.git ...................................................................... llc: import FCS (CRC24) calculation API from osmo-sgsn.git osmo-sgsn.git fb6cf3221ef4989441c09a650011e4a334c37d12 Changes made: * Add 'osmo_' prefix to gprs_llc_fcs(), * osmo_gprs_llc_fcs() takes size_t and returns uint32_t, * crc24_calc() takes size_t. Change-Id: Ib4465c289d9ef2a1b8ef5730c559bc799bb1f012 --- M include/osmocom/gprs/llc/llc.h M src/llc/Makefile.am A src/llc/crc24.c M src/llc/llc_pdu.c 4 files changed, 83 insertions(+), 0 deletions(-) Approvals: Jenkins Builder: Verified pespin: Looks good to me, but someone else must approve neels: Looks good to me, but someone else must approve laforge: Looks good to me, approved diff --git a/include/osmocom/gprs/llc/llc.h b/include/osmocom/gprs/llc/llc.h index 5e8860c..8c5134b 100644 --- a/include/osmocom/gprs/llc/llc.h +++ b/include/osmocom/gprs/llc/llc.h @@ -3,6 +3,7 @@ /* LLC (Logical Link Control) definitions from 3GPP TS 44.064 */ #include <stdint.h> +#include <stddef.h> /* Section 6.2.3 Service Access Point Identifier (SAPI) */ enum osmo_gprs_llc_sapi { @@ -128,3 +129,5 @@ uint16_t kD; uint16_t kU; }; + +uint32_t osmo_gprs_llc_fcs(const uint8_t *data, size_t len); diff --git a/src/llc/Makefile.am b/src/llc/Makefile.am index 5a4ad72..5dc2060 100644 --- a/src/llc/Makefile.am +++ b/src/llc/Makefile.am @@ -22,6 +22,7 @@ $(NULL) libosmo_gprs_llc_la_SOURCES = \ + crc24.c \ llc_pdu.c \ $(NULL) diff --git a/src/llc/crc24.c b/src/llc/crc24.c new file mode 100644 index 0000000..48be08a --- /dev/null +++ b/src/llc/crc24.c @@ -0,0 +1,66 @@ +/* GPRS LLC CRC-24 Implementation */ + +/* (C) 2008-2009 by Harald Welte &lt;laforge(a)gnumonks.org&gt; + * + * All Rights Reserved + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation; either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + */ + +#include <stdint.h> +#include <stddef.h> + +/* CRC24 table - FCS */ +static const uint32_t tbl_crc24[256] = { + 0x00000000, 0x00d6a776, 0x00f64557, 0x0020e221, 0x00b78115, 0x00612663, 0x0041c442, 0x00976334, + 0x00340991, 0x00e2aee7, 0x00c24cc6, 0x0014ebb0, 0x00838884, 0x00552ff2, 0x0075cdd3, 0x00a36aa5, + 0x00681322, 0x00beb454, 0x009e5675, 0x0048f103, 0x00df9237, 0x00093541, 0x0029d760, 0x00ff7016, + 0x005c1ab3, 0x008abdc5, 0x00aa5fe4, 0x007cf892, 0x00eb9ba6, 0x003d3cd0, 0x001ddef1, 0x00cb7987, + 0x00d02644, 0x00068132, 0x00266313, 0x00f0c465, 0x0067a751, 0x00b10027, 0x0091e206, 0x00474570, + 0x00e42fd5, 0x003288a3, 0x00126a82, 0x00c4cdf4, 0x0053aec0, 0x008509b6, 0x00a5eb97, 0x00734ce1, + 0x00b83566, 0x006e9210, 0x004e7031, 0x0098d747, 0x000fb473, 0x00d91305, 0x00f9f124, 0x002f5652, + 0x008c3cf7, 0x005a9b81, 0x007a79a0, 0x00acded6, 0x003bbde2, 0x00ed1a94, 0x00cdf8b5, 0x001b5fc3, + 0x00fb4733, 0x002de045, 0x000d0264, 0x00dba512, 0x004cc626, 0x009a6150, 0x00ba8371, 0x006c2407, + 0x00cf4ea2, 0x0019e9d4, 0x00390bf5, 0x00efac83, 0x0078cfb7, 0x00ae68c1, 0x008e8ae0, 0x00582d96, + 0x00935411, 0x0045f367, 0x00651146, 0x00b3b630, 0x0024d504, 0x00f27272, 0x00d29053, 0x00043725, + 0x00a75d80, 0x0071faf6, 0x005118d7, 0x0087bfa1, 0x0010dc95, 0x00c67be3, 0x00e699c2, 0x00303eb4, + 0x002b6177, 0x00fdc601, 0x00dd2420, 0x000b8356, 0x009ce062, 0x004a4714, 0x006aa535, 0x00bc0243, + 0x001f68e6, 0x00c9cf90, 0x00e92db1, 0x003f8ac7, 0x00a8e9f3, 0x007e4e85, 0x005eaca4, 0x00880bd2, + 0x00437255, 0x0095d523, 0x00b53702, 0x00639074, 0x00f4f340, 0x00225436, 0x0002b617, 0x00d41161, + 0x00777bc4, 0x00a1dcb2, 0x00813e93, 0x005799e5, 0x00c0fad1, 0x00165da7, 0x0036bf86, 0x00e018f0, + 0x00ad85dd, 0x007b22ab, 0x005bc08a, 0x008d67fc, 0x001a04c8, 0x00cca3be, 0x00ec419f, 0x003ae6e9, + 0x00998c4c, 0x004f2b3a, 0x006fc91b, 0x00b96e6d, 0x002e0d59, 0x00f8aa2f, 0x00d8480e, 0x000eef78, + 0x00c596ff, 0x00133189, 0x0033d3a8, 0x00e574de, 0x007217ea, 0x00a4b09c, 0x008452bd, 0x0052f5cb, + 0x00f19f6e, 0x00273818, 0x0007da39, 0x00d17d4f, 0x00461e7b, 0x0090b90d, 0x00b05b2c, 0x0066fc5a, + 0x007da399, 0x00ab04ef, 0x008be6ce, 0x005d41b8, 0x00ca228c, 0x001c85fa, 0x003c67db, 0x00eac0ad, + 0x0049aa08, 0x009f0d7e, 0x00bfef5f, 0x00694829, 0x00fe2b1d, 0x00288c6b, 0x00086e4a, 0x00dec93c, + 0x0015b0bb, 0x00c317cd, 0x00e3f5ec, 0x0035529a, 0x00a231ae, 0x007496d8, 0x005474f9, 0x0082d38f, + 0x0021b92a, 0x00f71e5c, 0x00d7fc7d, 0x00015b0b, 0x0096383f, 0x00409f49, 0x00607d68, 0x00b6da1e, + 0x0056c2ee, 0x00806598, 0x00a087b9, 0x007620cf, 0x00e143fb, 0x0037e48d, 0x001706ac, 0x00c1a1da, + 0x0062cb7f, 0x00b46c09, 0x00948e28, 0x0042295e, 0x00d54a6a, 0x0003ed1c, 0x00230f3d, 0x00f5a84b, + 0x003ed1cc, 0x00e876ba, 0x00c8949b, 0x001e33ed, 0x008950d9, 0x005ff7af, 0x007f158e, 0x00a9b2f8, + 0x000ad85d, 0x00dc7f2b, 0x00fc9d0a, 0x002a3a7c, 0x00bd5948, 0x006bfe3e, 0x004b1c1f, 0x009dbb69, + 0x0086e4aa, 0x005043dc, 0x0070a1fd, 0x00a6068b, 0x003165bf, 0x00e7c2c9, 0x00c720e8, 0x0011879e, + 0x00b2ed3b, 0x00644a4d, 0x0044a86c, 0x00920f1a, 0x00056c2e, 0x00d3cb58, 0x00f32979, 0x00258e0f, + 0x00eef788, 0x003850fe, 0x0018b2df, 0x00ce15a9, 0x0059769d, 0x008fd1eb, 0x00af33ca, 0x007994bc, + 0x00dafe19, 0x000c596f, 0x002cbb4e, 0x00fa1c38, 0x006d7f0c, 0x00bbd87a, 0x009b3a5b, 0x004d9d2d +}; + +uint32_t crc24_calc(uint32_t fcs, const uint8_t *data, size_t len) +{ + while (len--) + fcs = (fcs >> 8) ^ tbl_crc24[(fcs ^ *data++) & 0xff]; + return fcs; +} diff --git a/src/llc/llc_pdu.c b/src/llc/llc_pdu.c index 0a98416..0a936a8 100644 --- a/src/llc/llc_pdu.c +++ b/src/llc/llc_pdu.c @@ -51,3 +51,16 @@ { OSMO_GPRS_LLC_FUNC_RNR, "RNR" }, { 0, NULL } }; + +uint32_t crc24_calc(uint32_t fcs, const uint8_t *data, size_t len); + +uint32_t osmo_gprs_llc_fcs(const uint8_t *data, size_t len) +{ + uint32_t fcs_calc; + + fcs_calc = crc24_calc(0xffffff, data, len); + fcs_calc = ~fcs_calc; + fcs_calc &= 0xffffff; + + return fcs_calc; +} -- To view, visit https://gerrit.osmocom.org/c/libosmo-gprs/+/29400 To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: libosmo-gprs Gerrit-Branch: master Gerrit-Change-Id: Ib4465c289d9ef2a1b8ef5730c559bc799bb1f012 Gerrit-Change-Number: 29400 Gerrit-PatchSet: 2 Gerrit-Owner: fixeria &lt;vyanitskiy(a)sysmocom.de&gt; Gerrit-Reviewer: Jenkins Builder Gerrit-Reviewer: fixeria &lt;vyanitskiy(a)sysmocom.de&gt; Gerrit-Reviewer: laforge &lt;laforge(a)osmocom.org&gt; Gerrit-Reviewer: neels &lt;nhofmeyr(a)sysmocom.de&gt; Gerrit-Reviewer: pespin &lt;pespin(a)sysmocom.de&gt; Gerrit-MessageType: merged