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authorNeels Hofmeyr <neels@hofmeyr.de>2017-07-04 23:08:44 +0200
committerNeels Hofmeyr <neels@hofmeyr.de>2017-08-27 03:52:43 +0200
commit218e4b4aa0fc6de842ff820dec8e97d1f083268a (patch)
tree268a6e509270b1c80a36dd1a526da41a9b01a8e0 /include/openbsc/gprs_sndcp_dcomp.h
parent5ea6bfce56d6ae7be6d85e05b5e4eaebc94d1005 (diff)
move openbsc/* to repos root
This is the first step in creating this repository from the legacy openbsc.git. Like all other Osmocom repositories, keep the autoconf and automake files in the repository root. openbsc.git has been the sole exception, which ends now. Change-Id: I9c6f2a448d9cb1cc088cf1cf6918b69d7e69b4e7
Diffstat (limited to 'include/openbsc/gprs_sndcp_dcomp.h')
-rw-r--r--include/openbsc/gprs_sndcp_dcomp.h53
1 files changed, 53 insertions, 0 deletions
diff --git a/include/openbsc/gprs_sndcp_dcomp.h b/include/openbsc/gprs_sndcp_dcomp.h
new file mode 100644
index 000000000..a76b4a4b3
--- /dev/null
+++ b/include/openbsc/gprs_sndcp_dcomp.h
@@ -0,0 +1,53 @@
+/* GPRS SNDCP data compression handler */
+
+/* (C) 2016 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include <osmocom/core/linuxlist.h>
+#include <openbsc/gprs_sndcp_comp.h>
+
+/* 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);