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-rw-r--r--openbsc/include/openbsc/Makefile.am1
-rw-r--r--openbsc/include/openbsc/gprs_sndcp_dcomp.h53
-rw-r--r--openbsc/include/openbsc/sgsn.h9
-rw-r--r--openbsc/src/gprs/Makefile.am1
-rw-r--r--openbsc/src/gprs/gprs_sndcp.c87
-rw-r--r--openbsc/src/gprs/gprs_sndcp_comp.c12
-rw-r--r--openbsc/src/gprs/gprs_sndcp_dcomp.c357
-rw-r--r--openbsc/src/gprs/sgsn_main.c5
-rw-r--r--openbsc/src/gprs/sgsn_vty.c77
-rw-r--r--openbsc/tests/sgsn/Makefile.am1
10 files changed, 585 insertions, 18 deletions
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 <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);
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 {
diff --git a/openbsc/src/gprs/Makefile.am b/openbsc/src/gprs/Makefile.am
index 3970ba6dd..d228b397a 100644
--- a/openbsc/src/gprs/Makefile.am
+++ b/openbsc/src/gprs/Makefile.am
@@ -72,6 +72,7 @@ osmo_sgsn_SOURCES = \
gprs_sgsn.c \
gprs_sndcp.c \
gprs_sndcp_comp.c \
+ gprs_sndcp_dcomp.c \
gprs_sndcp_pcomp.c \
gprs_sndcp_vty.c \
gprs_sndcp_xid.c \
diff --git a/openbsc/src/gprs/gprs_sndcp.c b/openbsc/src/gprs/gprs_sndcp.c
index c006d9bcf..0b18f816e 100644
--- a/openbsc/src/gprs/gprs_sndcp.c
+++ b/openbsc/src/gprs/gprs_sndcp.c
@@ -38,6 +38,7 @@
#include <openbsc/gprs_llc_xid.h>
#include <openbsc/gprs_sndcp_xid.h>
#include <openbsc/gprs_sndcp_pcomp.h>
+#include <openbsc/gprs_sndcp_dcomp.h>
#include <openbsc/gprs_sndcp_comp.h>
#define DEBUG_IP_PACKETS 0 /* 0=Disabled, 1=Enabled */
@@ -204,7 +205,8 @@ LLIST_HEAD(gprs_sndcp_entities);
/* Check if any compression parameters are set in the sgsn configuration */
static inline int any_pcomp_or_dcomp_active(struct sgsn_instance *sgsn) {
- if (sgsn->cfg.pcomp_rfc1144.active || sgsn->cfg.pcomp_rfc1144.passive)
+ if (sgsn->cfg.pcomp_rfc1144.active || sgsn->cfg.pcomp_rfc1144.passive ||
+ sgsn->cfg.dcomp_v42bis.active || sgsn->cfg.dcomp_v42bis.passive)
return true;
else
return false;
@@ -324,11 +326,22 @@ static int defrag_segments(struct gprs_sndcp_entity *sne)
#endif
if (any_pcomp_or_dcomp_active(sgsn)) {
- expnd = talloc_zero_size(msg, npdu_len + MAX_HDRDECOMPR_INCR);
+ expnd = talloc_zero_size(msg, npdu_len * MAX_DATADECOMPR_FAC +
+ MAX_HDRDECOMPR_INCR);
memcpy(expnd, npdu, npdu_len);
+ /* Apply data decompression */
+ rc = gprs_sndcp_dcomp_expand(expnd, npdu_len, sne->defrag.dcomp,
+ sne->defrag.data);
+ if (rc < 0) {
+ LOGP(DSNDCP, LOGL_ERROR,
+ "Data decompression failed!\n");
+ talloc_free(expnd);
+ return -EIO;
+ }
+
/* Apply header decompression */
- rc = gprs_sndcp_pcomp_expand(expnd, npdu_len, sne->defrag.pcomp,
+ rc = gprs_sndcp_pcomp_expand(expnd, rc, sne->defrag.pcomp,
sne->defrag.proto);
if (rc < 0) {
LOGP(DSNDCP, LOGL_ERROR,
@@ -653,6 +666,19 @@ int sndcp_unitdata_req(struct msgb *msg, struct gprs_llc_lle *lle, uint8_t nsapi
* the new, compressed buffer size */
msgb_get(msg, msg->len);
msgb_put(msg, rc);
+
+ /* Apply data compression */
+ rc = gprs_sndcp_dcomp_compress(msg->data, msg->len, &dcomp,
+ lle->llme->comp.data, nsapi);
+ if (rc < 0) {
+ LOGP(DSNDCP, LOGL_ERROR, "Data compression failed!\n");
+ return -EIO;
+ }
+
+ /* Fixup pointer locations and sizes in message buffer to match
+ * the new, compressed buffer size */
+ msgb_get(msg, msg->len);
+ msgb_put(msg, rc);
}
#if DEBUG_IP_PACKETS == 1
DEBUGP(DSNDCP, "===================================================\n");
@@ -784,11 +810,22 @@ int sndcp_llunitdata_ind(struct msgb *msg, struct gprs_llc_lle *lle,
#endif
if (any_pcomp_or_dcomp_active(sgsn)) {
- expnd = talloc_zero_size(msg, npdu_len + MAX_HDRDECOMPR_INCR);
+ expnd = talloc_zero_size(msg, npdu_len * MAX_DATADECOMPR_FAC +
+ MAX_HDRDECOMPR_INCR);
memcpy(expnd, npdu, npdu_len);
+ /* Apply data decompression */
+ rc = gprs_sndcp_dcomp_expand(expnd, npdu_len, sne->defrag.dcomp,
+ sne->defrag.data);
+ if (rc < 0) {
+ LOGP(DSNDCP, LOGL_ERROR,
+ "Data decompression failed!\n");
+ talloc_free(expnd);
+ return -EIO;
+ }
+
/* Apply header decompression */
- rc = gprs_sndcp_pcomp_expand(expnd, npdu_len, sne->defrag.pcomp,
+ rc = gprs_sndcp_pcomp_expand(expnd, rc, sne->defrag.pcomp,
sne->defrag.proto);
if (rc < 0) {
LOGP(DSNDCP, LOGL_ERROR,
@@ -884,8 +921,11 @@ static int gprs_llc_gen_sndcp_xid(uint8_t *bytes, int bytes_len, uint8_t nsapi)
LLIST_HEAD(comp_fields);
struct gprs_sndcp_pcomp_rfc1144_params rfc1144_params;
struct gprs_sndcp_comp_field rfc1144_comp_field;
+ struct gprs_sndcp_dcomp_v42bis_params v42bis_params;
+ struct gprs_sndcp_comp_field v42bis_comp_field;
memset(&rfc1144_comp_field, 0, sizeof(struct gprs_sndcp_comp_field));
+ memset(&v42bis_comp_field, 0, sizeof(struct gprs_sndcp_comp_field));
/* Setup rfc1144 */
if (sgsn->cfg.pcomp_rfc1144.active) {
@@ -903,6 +943,23 @@ static int gprs_llc_gen_sndcp_xid(uint8_t *bytes, int bytes_len, uint8_t nsapi)
llist_add(&rfc1144_comp_field.list, &comp_fields);
}
+ /* Setup V.42bis */
+ if (sgsn->cfg.dcomp_v42bis.active) {
+ v42bis_params.nsapi[0] = nsapi;
+ v42bis_params.nsapi_len = 1;
+ v42bis_params.p0 = sgsn->cfg.dcomp_v42bis.p0;
+ v42bis_params.p1 = sgsn->cfg.dcomp_v42bis.p1;
+ v42bis_params.p2 = sgsn->cfg.dcomp_v42bis.p2;
+ v42bis_comp_field.p = 1;
+ v42bis_comp_field.entity = entity;
+ v42bis_comp_field.algo = V42BIS;
+ v42bis_comp_field.comp[V42BIS_DCOMP1] = 1;
+ v42bis_comp_field.comp_len = V42BIS_DCOMP_NUM;
+ v42bis_comp_field.v42bis_params = &v42bis_params;
+ entity++;
+ llist_add(&v42bis_comp_field.list, &comp_fields);
+ }
+
/* Compile bytestream */
return gprs_sndcp_compile_xid(bytes, bytes_len, &comp_fields);
}
@@ -1008,13 +1065,19 @@ static int handle_dcomp_entities(struct gprs_sndcp_comp_field *comp_field,
/* Process proposed parameters */
switch (comp_field->algo) {
case V42BIS:
- /* V42BIS is not yet supported,
- * so we set applicable nsapis to zero */
- LOGP(DSNDCP, LOGL_DEBUG,
- "Rejecting V.42bis data compression...\n");
- comp_field->v42bis_params->nsapi_len = 0;
- gprs_sndcp_comp_delete(lle->llme->comp.data,
- comp_field->entity);
+ if (sgsn->cfg.dcomp_v42bis.passive &&
+ comp_field->v42bis_params->nsapi_len > 0) {
+ DEBUGP(DSNDCP,
+ "Accepting V.42bis data compression...\n");
+ gprs_sndcp_comp_add(lle->llme, lle->llme->comp.data,
+ comp_field);
+ } else {
+ LOGP(DSNDCP, LOGL_DEBUG,
+ "Rejecting V.42bis data compression...\n");
+ gprs_sndcp_comp_delete(lle->llme->comp.data,
+ comp_field->entity);
+ comp_field->v42bis_params->nsapi_len = 0;
+ }
break;
case V44:
/* V44 is not yet supported,
diff --git a/openbsc/src/gprs/gprs_sndcp_comp.c b/openbsc/src/gprs/gprs_sndcp_comp.c
index 1a9d030bc..b13cb8b23 100644
--- a/openbsc/src/gprs/gprs_sndcp_comp.c
+++ b/openbsc/src/gprs/gprs_sndcp_comp.c
@@ -34,6 +34,7 @@
#include <openbsc/gprs_sndcp_xid.h>
#include <openbsc/gprs_sndcp_comp.h>
#include <openbsc/gprs_sndcp_pcomp.h>
+#include <openbsc/gprs_sndcp_dcomp.h>
/* Create a new compression entity from a XID-Field */
static struct gprs_sndcp_comp *gprs_sndcp_comp_create(const void *ctx,
@@ -100,16 +101,16 @@ static struct gprs_sndcp_comp *gprs_sndcp_comp_create(const void *ctx,
comp_entity = NULL;
}
} else {
- LOGP(DSNDCP, LOGL_ERROR,
- "We don't support data compression yet!\n");
- talloc_free(comp_entity);
- return NULL;
+ if (gprs_sndcp_dcomp_init(ctx, comp_entity, comp_field) != 0) {
+ talloc_free(comp_entity);
+ comp_entity = NULL;
+ }
}
/* Display info message */
if (comp_entity == NULL) {
LOGP(DSNDCP, LOGL_ERROR,
- "Header compression entity (%d) creation failed!\n",
+ "Compression entity (%d) creation failed!\n",
comp_entity->entity);
return NULL;
}
@@ -159,6 +160,7 @@ void gprs_sndcp_comp_free(struct llist_head *comp_entities)
LOGP(DSNDCP, LOGL_INFO,
"Deleting data compression entity %d ...\n",
comp_entity->entity);
+ gprs_sndcp_dcomp_term(comp_entity);
}
}
diff --git a/openbsc/src/gprs/gprs_sndcp_dcomp.c b/openbsc/src/gprs/gprs_sndcp_dcomp.c
new file mode 100644
index 000000000..489106b47
--- /dev/null
+++ b/openbsc/src/gprs/gprs_sndcp_dcomp.c
@@ -0,0 +1,357 @@
+/* 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 <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+#include <math.h>
+#include <errno.h>
+#include <stdbool.h>
+
+#include <osmocom/core/utils.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/gsm/tlv.h>
+
+#include <openbsc/gprs_llc.h>
+#include <openbsc/sgsn.h>
+#include <openbsc/gprs_sndcp_xid.h>
+#include <openbsc/v42bis.h>
+#include <openbsc/v42bis_private.h>
+#include <openbsc/debug.h>
+#include <openbsc/gprs_sndcp_comp.h>
+#include <openbsc/gprs_sndcp_dcomp.h>
+
+/* A struct to capture the output data of compressor and decompressor */
+struct v42bis_output_buffer {
+ uint8_t *buf;
+ uint8_t *buf_pointer;
+ int len;
+};
+
+/* Handler to capture the output data from the compressor */
+void tx_v42bis_frame_handler(void *user_data, const uint8_t *pkt, int len)
+{
+ struct v42bis_output_buffer *output_buffer =
+ (struct v42bis_output_buffer *)user_data;
+ memcpy(output_buffer->buf_pointer, pkt, len);
+ output_buffer->buf_pointer += len;
+ output_buffer->len += len;
+ return;
+}
+
+/* Handler to capture the output data from the decompressor */
+void rx_v42bis_data_handler(void *user_data, const uint8_t *buf, int len)
+{
+ struct v42bis_output_buffer *output_buffer =
+ (struct v42bis_output_buffer *)user_data;
+ memcpy(output_buffer->buf_pointer, buf, len);
+ output_buffer->buf_pointer += len;
+ output_buffer->len += len;
+ return;
+}
+
+/* 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)
+{
+ /* Note: This function is automatically called from
+ * gprs_sndcp_comp.c when a new data compression
+ * entity is created by gprs_sndcp.c */
+
+ OSMO_ASSERT(comp_entity);
+ OSMO_ASSERT(comp_field);
+
+ if (comp_entity->compclass == SNDCP_XID_DATA_COMPRESSION
+ && comp_entity->algo == V42BIS) {
+ comp_entity->state =
+ v42bis_init(ctx, NULL, comp_field->v42bis_params->p0,
+ comp_field->v42bis_params->p1,
+ comp_field->v42bis_params->p2,
+ &tx_v42bis_frame_handler, NULL,
+ V42BIS_MAX_OUTPUT_LENGTH,
+ &rx_v42bis_data_handler, NULL,
+ V42BIS_MAX_OUTPUT_LENGTH);
+ LOGP(DSNDCP, LOGL_INFO,
+ "V.42bis data compression initalized.\n");
+ return 0;
+ }
+
+ /* Just in case someone tries to initalize an unknown or unsupported
+ * data compresson. Since everything is checked during the SNDCP
+ * negotiation process, this should never happen! */
+ OSMO_ASSERT(false);
+}
+
+/* Terminate data compression */
+void gprs_sndcp_dcomp_term(struct gprs_sndcp_comp *comp_entity)
+{
+ /* Note: This function is automatically called from
+ * gprs_sndcp_comp.c when a data compression
+ * entity is deleted by gprs_sndcp.c */
+
+ OSMO_ASSERT(comp_entity);
+
+ if (comp_entity->compclass == SNDCP_XID_DATA_COMPRESSION
+ && comp_entity->algo == V42BIS) {
+ if (comp_entity->state) {
+ v42bis_free((v42bis_state_t *) comp_entity->state);
+ comp_entity->state = NULL;
+ }
+ LOGP(DSNDCP, LOGL_INFO,
+ "V.42bis data compression terminated.\n");
+ return;
+ }
+
+ /* Just in case someone tries to terminate an unknown or unsupported
+ * data compresson. Since everything is checked during the SNDCP
+ * negotiation process, this should never happen! */
+ OSMO_ASSERT(false);
+}
+
+/* Perform a full reset of the V.42bis compression state */
+static void v42bis_reset(v42bis_state_t *comp)
+{
+ /* This function performs a complete reset of the V.42bis compression
+ * state by reinitalizing the state withe the previously negotiated
+ * parameters. */
+
+ int p0, p1, p2;
+ p0 = comp->decompress.v42bis_parm_p0 | comp->compress.v42bis_parm_p0;
+ p1 = comp->decompress.v42bis_parm_n2;
+ p2 = comp->decompress.v42bis_parm_n7;
+
+ DEBUGP(DSNDCP, "Resetting compression state: %p, p0=%d, p1=%d, p2=%d\n",
+ comp, p0, p1, p2);
+
+ v42bis_init(NULL, comp, p0, p1, p2, &tx_v42bis_frame_handler, NULL,
+ V42BIS_MAX_OUTPUT_LENGTH, &rx_v42bis_data_handler, NULL,
+ V42BIS_MAX_OUTPUT_LENGTH);
+}
+
+/* Compress a packet using V.42bis data compression */
+static int v42bis_compress_unitdata(uint8_t *pcomp_index, uint8_t *data,
+ unsigned int len, v42bis_state_t *comp)
+{
+ /* Note: This implementation may only be used to compress SN_UNITDATA
+ * packets, since it resets the compression state for each NPDU. */
+
+ uint8_t *data_o;
+ int rc;
+ int skip = 0;
+ struct v42bis_output_buffer compressed_data;
+
+ /* Don't bother with short packets */
+ if (len < MIN_COMPR_PAYLOAD)
+ skip = 1;
+
+ /* Skip if compression is not enabled for TX direction */
+ if (!comp->compress.v42bis_parm_p0)
+ skip = 1;
+
+ /* Skip compression */
+ if (skip) {
+ *pcomp_index = 0;
+ return len;
+ }
+
+ /* Reset V.42bis compression state */
+ v42bis_reset(comp);
+
+ /* Run compressor */
+ data_o = talloc_zero_size(comp, len * MAX_DATADECOMPR_FAC);
+ compressed_data.buf = data_o;
+ compressed_data.buf_pointer = data_o;
+ compressed_data.len = 0;
+ comp->compress.user_data = (&compressed_data);
+ rc = v42bis_compress(comp, data, len);
+ if (rc < 0) {
+ LOGP(DSNDCP, LOGL_ERROR,
+ "Data compression failed, skipping...\n");
+ skip = 1;
+ }
+ rc = v42bis_compress_flush(comp);
+ if (rc < 0) {
+ LOGP(DSNDCP, LOGL_ERROR,
+ "Data compression failed, skipping...\n");
+ skip = 1;
+ }
+
+ /* The compressor might yield negative compression gain, in
+ * this case, we just decide to send the packat as normal,
+ * uncompressed payload => skip compresssion */
+ if (compressed_data.len >= len) {
+ LOGP(DSNDCP, LOGL_ERROR,
+ "Data compression ineffective, skipping...\n");
+ skip = 1;
+ }
+
+ /* Skip compression */
+ if (skip) {
+ *pcomp_index = 0;
+ talloc_free(data_o);
+ return len;
+ }
+
+ *pcomp_index = 1;
+ memcpy(data, data_o, compressed_data.len);
+ talloc_free(data_o);
+
+ return compressed_data.len;
+}
+
+/* Expand a packet using V.42bis data compression */
+static int v42bis_expand_unitdata(uint8_t *data, unsigned int len,
+ uint8_t pcomp_index, v42bis_state_t *comp)
+{
+ /* Note: This implementation may only be used to compress SN_UNITDATA
+ * packets, since it resets the compression state for each NPDU. */
+
+ int rc;
+ struct v42bis_output_buffer uncompressed_data;
+ uint8_t *data_i;
+
+ /* Skip when the packet is marked as uncompressed */
+ if (pcomp_index == 0) {
+ return len;
+ }
+
+ /* Reset V.42bis compression state */
+ v42bis_reset(comp);
+
+ /* Decompress packet */
+ data_i = talloc_zero_size(comp, len);
+ memcpy(data_i, data, len);
+ uncompressed_data.buf = data;
+ uncompressed_data.buf_pointer = data;
+ uncompressed_data.len = 0;
+ comp->decompress.user_data = (&uncompressed_data);
+ rc = v42bis_decompress(comp, data_i, len);
+ talloc_free(data_i);
+ if (rc < 0)
+ return -EINVAL;
+ rc = v42bis_decompress_flush(comp);
+ if (rc < 0)
+ return -EINVAL;
+
+ return uncompressed_data.len;
+}
+
+/* Expand packet */
+int gprs_sndcp_dcomp_expand(uint8_t *data, unsigned int len, uint8_t pcomp,
+ const struct llist_head *comp_entities)
+{
+ int rc;
+ uint8_t pcomp_index = 0;
+ struct gprs_sndcp_comp *comp_entity;
+
+ OSMO_ASSERT(data);
+ OSMO_ASSERT(comp_entities);
+
+ LOGP(DSNDCP, LOGL_DEBUG,
+ "Data compression entity list: comp_entities=%p\n", comp_entities);
+
+ LOGP(DSNDCP, LOGL_DEBUG, "Data compression mode: dcomp=%d\n", pcomp);
+
+ /* Skip on pcomp=0 */
+ if (pcomp == 0) {
+ return len;
+ }
+
+ /* Find out which compression entity handles the data */
+ comp_entity = gprs_sndcp_comp_by_comp(comp_entities, pcomp);
+
+ /* Skip compression if no suitable compression entity can be found */
+ if (!comp_entity) {
+ return len;
+ }
+
+ /* Note: Only data compression entities may appear in
+ * data compression context */
+ OSMO_ASSERT(comp_entity->compclass == SNDCP_XID_DATA_COMPRESSION);
+
+ /* Note: Currently V42BIS is the only compression method we
+ * support, so the only allowed algorithm is V42BIS */
+ OSMO_ASSERT(comp_entity->algo == V42BIS);
+
+ /* Find pcomp_index */
+ pcomp_index = gprs_sndcp_comp_get_idx(comp_entity, pcomp);
+
+ /* Run decompression algo */
+ rc = v42bis_expand_unitdata(data, len, pcomp_index, comp_entity->state);
+
+ LOGP(DSNDCP, LOGL_DEBUG,
+ "Data expansion done, old length=%d, new length=%d, entity=%p\n",
+ len, rc, comp_entity);
+
+ return rc;
+}
+
+/* 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)
+{
+ int rc;
+ uint8_t pcomp_index = 0;
+ struct gprs_sndcp_comp *comp_entity;
+
+ OSMO_ASSERT(data);
+ OSMO_ASSERT(pcomp);
+ OSMO_ASSERT(comp_entities);
+
+ LOGP(DSNDCP, LOGL_DEBUG,
+ "Data compression entity list: comp_entities=%p\n", comp_entities);
+
+ /* Find out which compression entity handles the data */
+ comp_entity = gprs_sndcp_comp_by_nsapi(comp_entities, nsapi);
+
+ /* Skip compression if no suitable compression entity can be found */
+ if (!comp_entity) {
+ *pcomp = 0;
+ return len;
+ }
+
+ /* Note: Only data compression entities may appear in
+ * data compression context */
+ OSMO_ASSERT(comp_entity->compclass == SNDCP_XID_DATA_COMPRESSION);
+
+ /* Note: Currently V42BIS is the only compression method we
+ * support, so the only allowed algorithm is V42BIS */
+ OSMO_ASSERT(comp_entity->algo == V42BIS);
+
+ /* Run compression algo */
+ rc = v42bis_compress_unitdata(&pcomp_index, data, len,
+ comp_entity->state);
+
+ /* Find pcomp value */
+ *pcomp = gprs_sndcp_comp_get_comp(comp_entity, pcomp_index);
+
+ LOGP(DSNDCP, LOGL_DEBUG, "Data compression mode: dcomp=%d\n", *pcomp);
+
+ LOGP(DSNDCP, LOGL_DEBUG,
+ "Data compression done, old length=%d, new length=%d, entity=%p\n",
+ len, rc, comp_entity);
+
+ return rc;
+}
diff --git a/openbsc/src/gprs/sgsn_main.c b/openbsc/src/gprs/sgsn_main.c
index 9f3260d55..fb5b6d585 100644
--- a/openbsc/src/gprs/sgsn_main.c
+++ b/openbsc/src/gprs/sgsn_main.c
@@ -299,6 +299,11 @@ static struct log_info_cat gprs_categories[] = {
.description = "RFC1144 TCP/IP Header compression (SLHC)",
.enabled = 1, .loglevel = LOGL_DEBUG,
},
+ [DV42BIS] = {
+ .name = "DV42BIS",
+ .description = "V.42bis data compression (SNDCP)",
+ .enabled = 1, .loglevel = LOGL_DEBUG,
+ }
};
static const struct log_info gprs_log_info = {
diff --git a/openbsc/src/gprs/sgsn_vty.c b/openbsc/src/gprs/sgsn_vty.c
index 0eea35029..1b477e524 100644
--- a/openbsc/src/gprs/sgsn_vty.c
+++ b/openbsc/src/gprs/sgsn_vty.c
@@ -277,6 +277,26 @@ static int config_write_sgsn(struct vty *vty)
} else
vty_out(vty, " no compression rfc1144%s", VTY_NEWLINE);
+ if (g_cfg->dcomp_v42bis.active && g_cfg->dcomp_v42bis.p0 == 1) {
+ vty_out(vty,
+ " compression v42bis active direction sgsn codewords %d strlen %d%s",
+ g_cfg->dcomp_v42bis.p1, g_cfg->dcomp_v42bis.p2,
+ VTY_NEWLINE);
+ } else if (g_cfg->dcomp_v42bis.active && g_cfg->dcomp_v42bis.p0 == 2) {
+ vty_out(vty,
+ " compression v42bis active direction ms codewords %d strlen %d%s",
+ g_cfg->dcomp_v42bis.p1, g_cfg->dcomp_v42bis.p2,
+ VTY_NEWLINE);
+ } else if (g_cfg->dcomp_v42bis.active && g_cfg->dcomp_v42bis.p0 == 3) {
+ vty_out(vty,
+ " compression v42bis active direction both codewords %d strlen %d%s",
+ g_cfg->dcomp_v42bis.p1, g_cfg->dcomp_v42bis.p2,
+ VTY_NEWLINE);
+ } else if (g_cfg->dcomp_v42bis.passive) {
+ vty_out(vty, " compression v42bis passive%s", VTY_NEWLINE);
+ } else
+ vty_out(vty, " no compression v42bis%s", VTY_NEWLINE);
+
return CMD_SUCCESS;
}
@@ -1117,6 +1137,59 @@ DEFUN(cfg_comp_rfc1144p, cfg_comp_rfc1144p_cmd,
return CMD_SUCCESS;
}
+DEFUN(cfg_no_comp_v42bis, cfg_no_comp_v42bis_cmd,
+ "no compression v42bis",
+ NO_STR COMPRESSION_STR "disable V.42bis data compression\n")
+{
+ g_cfg->dcomp_v42bis.active = 0;
+ g_cfg->dcomp_v42bis.passive = 0;
+ return CMD_SUCCESS;
+}
+
+DEFUN(cfg_comp_v42bis, cfg_comp_v42bis_cmd,
+ "compression v42bis active direction (ms|sgsn|both) codewords <512-65535> strlen <6-250>",
+ COMPRESSION_STR
+ "V.42bis data compresion scheme\n"
+ "Compression is actively proposed\n"
+ "Direction in which the compression shall be active (p0)\n"
+ "Compress ms->sgsn direction only\n"
+ "Compress sgsn->ms direction only\n"
+ "Both directions\n"
+ "Number of codewords (p1)\n"
+ "Number of codewords\n"
+ "Maximum string length (p2)\n" "Maximum string length\n")
+{
+ g_cfg->dcomp_v42bis.active = 1;
+ g_cfg->dcomp_v42bis.passive = 1;
+
+ switch (argv[0][0]) {
+ case 'm':
+ g_cfg->dcomp_v42bis.p0 = 1;
+ break;
+ case 's':
+ g_cfg->dcomp_v42bis.p0 = 2;
+ break;
+ case 'b':
+ g_cfg->dcomp_v42bis.p0 = 3;
+ break;
+ }
+
+ g_cfg->dcomp_v42bis.p1 = atoi(argv[1]);
+ g_cfg->dcomp_v42bis.p2 = atoi(argv[2]);
+ return CMD_SUCCESS;
+}
+
+DEFUN(cfg_comp_v42bisp, cfg_comp_v42bisp_cmd,
+ "compression v42bis passive",
+ COMPRESSION_STR
+ "V.42bis data compresion scheme\n"
+ "Compression is available on request\n")
+{
+ g_cfg->dcomp_v42bis.active = 0;
+ g_cfg->dcomp_v42bis.passive = 1;
+ return CMD_SUCCESS;
+}
+
int sgsn_vty_init(void)
{
install_element_ve(&show_sgsn_cmd);
@@ -1174,7 +1247,9 @@ int sgsn_vty_init(void)
install_element(SGSN_NODE, &cfg_no_comp_rfc1144_cmd);
install_element(SGSN_NODE, &cfg_comp_rfc1144_cmd);
install_element(SGSN_NODE, &cfg_comp_rfc1144p_cmd);
-
+ install_element(SGSN_NODE, &cfg_no_comp_v42bis_cmd);
+ install_element(SGSN_NODE, &cfg_comp_v42bis_cmd);
+ install_element(SGSN_NODE, &cfg_comp_v42bisp_cmd);
return 0;
}
diff --git a/openbsc/tests/sgsn/Makefile.am b/openbsc/tests/sgsn/Makefile.am
index 92506323c..9ee5455e7 100644
--- a/openbsc/tests/sgsn/Makefile.am
+++ b/openbsc/tests/sgsn/Makefile.am
@@ -62,6 +62,7 @@ sgsn_test_LDADD = \
$(top_builddir)/src/gprs/gprs_sndcp_comp.o \
$(top_builddir)/src/gprs/gprs_sndcp_pcomp.o \
$(top_builddir)/src/gprs/v42bis.o \
+ $(top_builddir)/src/gprs/gprs_sndcp_dcomp.o \
$(top_builddir)/src/libcommon/libcommon.a \
$(LIBOSMOABIS_LIBS) \
$(LIBOSMOCORE_LIBS) \
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-23 23:06:35 +0000