1 files changed, 82 insertions, 0 deletions
diff --git a/include/osmocom/sgsn/gprs_sndcp_comp.h b/include/osmocom/sgsn/gprs_sndcp_comp.h
new file mode 100644
index 000000000..c04f7d49a
--- /dev/null
+++ b/include/osmocom/sgsn/gprs_sndcp_comp.h
@@ -0,0 +1,82 @@
+/* GPRS SNDCP header compression entity management tools */
+
+/* (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 <osmocom/sgsn/gprs_sndcp_xid.h>
+
+/* Header / Data compression entity */
+struct gprs_sndcp_comp {
+	struct llist_head list;
+
+	/* Serves as an ID in case we want to delete this entity later */
+	unsigned int entity;	/* see also: 6.5.1.1.3 and 6.6.1.1.3 */
+
+	/* Specifies to which NSAPIs the compression entity is assigned */
+	uint8_t nsapi_len;	/* Number of applicable NSAPIs (default 0) */
+	uint8_t nsapi[MAX_NSAPI];	/* Applicable NSAPIs (default 0) */
+
+	/* Assigned pcomp values */
+	uint8_t comp_len;	/* Number of contained PCOMP / DCOMP values */
+	uint8_t comp[MAX_COMP];	/* see also: 6.5.1.1.5 and 6.6.1.1.5 */
+
+	/* Algorithm parameters */
+	int algo;		/* Algorithm type (see gprs_sndcp_xid.h) */
+	int compclass;		/* See gprs_sndcp_xid.h/c */
+	void *state;		/* Algorithm status and parameters */
+};
+
+#define MAX_COMP 16	/* Maximum number of possible pcomp/dcomp values */
+#define MAX_NSAPI 11	/* Maximum number usable NSAPIs */
+
+/* Allocate a compression enitiy list */
+struct llist_head *gprs_sndcp_comp_alloc(const void *ctx);
+
+/* Free a compression entitiy list */
+void gprs_sndcp_comp_free(struct llist_head *comp_entities);
+
+/* Delete a compression entity */
+void gprs_sndcp_comp_delete(struct llist_head *comp_entities, unsigned int entity);
+
+/* Create and Add a new compression entity
+ * (returns a pointer to the compression entity that has just been created) */
+struct gprs_sndcp_comp *gprs_sndcp_comp_add(const void *ctx,
+					    struct llist_head *comp_entities,
+					    const struct gprs_sndcp_comp_field
+					    *comp_field);
+
+/* Find which compression entity handles the specified pcomp/dcomp */
+struct gprs_sndcp_comp *gprs_sndcp_comp_by_comp(const struct llist_head
+						*comp_entities, uint8_t comp);
+
+/* Find which compression entity handles the specified nsapi */
+struct gprs_sndcp_comp *gprs_sndcp_comp_by_nsapi(const struct llist_head
+						 *comp_entities, uint8_t nsapi);
+
+/* Find a comp_index for a given pcomp/dcomp value */
+uint8_t gprs_sndcp_comp_get_idx(const struct gprs_sndcp_comp *comp_entity,
+				uint8_t comp);
+
+/* Find a pcomp/dcomp value for a given comp_index */
+uint8_t gprs_sndcp_comp_get_comp(const struct gprs_sndcp_comp *comp_entity,
+			         uint8_t comp_index);