From 73f83d533ba8d929a840ab76efb099da4d5b6174 Mon Sep 17 00:00:00 2001 From: Philipp Date: Fri, 2 Sep 2016 13:38:01 +0200 Subject: SNDCP: add V.42bis data compression functionality - Add compression control for V.42bis Add code to handle compression (gprs_sndcp_dcomp.c/h) - Add Adjustments in SNDCP - Add VTY commands Change-Id: I6d36cbdf2f5c5f83ca9ba57c70452f02b8582e7e --- openbsc/include/openbsc/Makefile.am | 1 + openbsc/include/openbsc/gprs_sndcp_dcomp.h | 53 ++++++++++++++++++++++++++++++ openbsc/include/openbsc/sgsn.h | 9 +++++ 3 files changed, 63 insertions(+) create mode 100644 openbsc/include/openbsc/gprs_sndcp_dcomp.h (limited to 'openbsc/include') diff --git a/openbsc/include/openbsc/Makefile.am b/openbsc/include/openbsc/Makefile.am index 3014d5fa1..c6a01499f 100644 --- a/openbsc/include/openbsc/Makefile.am +++ b/openbsc/include/openbsc/Makefile.am @@ -26,6 +26,7 @@ noinst_HEADERS = \ gprs_sgsn.h \ gprs_sndcp.h \ gprs_sndcp_comp.h \ + gprs_sndcp_dcomp.h \ gprs_sndcp_pcomp.h \ gprs_sndcp_xid.h \ gprs_utils.h \ diff --git a/openbsc/include/openbsc/gprs_sndcp_dcomp.h b/openbsc/include/openbsc/gprs_sndcp_dcomp.h new file mode 100644 index 000000000..a76b4a4b3 --- /dev/null +++ b/openbsc/include/openbsc/gprs_sndcp_dcomp.h @@ -0,0 +1,53 @@ +/* GPRS SNDCP data compression handler */ + +/* (C) 2016 by sysmocom s.f.m.c. GmbH + * All Rights Reserved + * + * Author: Philipp Maier + * + * 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 . + */ + +#pragma once + +#include +#include +#include + +/* Note: The decompressed packet may have a maximum size of: + * Return value * MAX_DATADECOMPR_FAC */ +#define MAX_DATADECOMPR_FAC 10 + +/* Note: In unacknowledged mode (SN_UNITDATA), the comression state is reset + * for every NPDU. The compressor needs a reasonably large payload to operate + * effectively (yield positive compression gain). For packets shorter than 100 + * byte, no positive compression gain can be expected so we will skip the + * compression for short packets. */ +#define MIN_COMPR_PAYLOAD 100 + +/* Initalize data compression */ +int gprs_sndcp_dcomp_init(const void *ctx, struct gprs_sndcp_comp *comp_entity, + const struct gprs_sndcp_comp_field *comp_field); + +/* Terminate data compression */ +void gprs_sndcp_dcomp_term(struct gprs_sndcp_comp *comp_entity); + +/* Expand packet */ +int gprs_sndcp_dcomp_expand(uint8_t *data, unsigned int len, uint8_t pcomp, + const struct llist_head *comp_entities); + +/* Compress packet */ +int gprs_sndcp_dcomp_compress(uint8_t *data, unsigned int len, uint8_t *pcomp, + const struct llist_head *comp_entities, + uint8_t nsapi); diff --git a/openbsc/include/openbsc/sgsn.h b/openbsc/include/openbsc/sgsn.h index 9537c0afc..786e2b240 100644 --- a/openbsc/include/openbsc/sgsn.h +++ b/openbsc/include/openbsc/sgsn.h @@ -100,6 +100,15 @@ struct sgsn_config { int passive; int s01; } pcomp_rfc1144; + + /* V.42vis data compression */ + struct { + int active; + int passive; + int p0; + int p1; + int p2; + } dcomp_v42bis; }; struct sgsn_instance { -- cgit v1.2.3