diff options
Diffstat (limited to 'src/gprs/gprs_sndcp_comp.c')
| -rw-r--r-- | src/gprs/gprs_sndcp_comp.c | 323 |
1 files changed, 323 insertions, 0 deletions
diff --git a/src/gprs/gprs_sndcp_comp.c b/src/gprs/gprs_sndcp_comp.c new file mode 100644 index 000000000..a12c39aa6 --- /dev/null +++ b/src/gprs/gprs_sndcp_comp.c @@ -0,0 +1,323 @@ +/* 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/>. + */ + +#include <stdio.h> +#include <string.h> +#include <stdint.h> +#include <math.h> +#include <errno.h> +#include <stdbool.h> + +#include <osmocom/core/linuxlist.h> +#include <osmocom/core/talloc.h> +#include <osmocom/core/utils.h> + +#include <openbsc/debug.h> +#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, + const struct + gprs_sndcp_comp_field + *comp_field) +{ + struct gprs_sndcp_comp *comp_entity; + comp_entity = talloc_zero(ctx, struct gprs_sndcp_comp); + + /* Copy relevant information from the SNDCP-XID field */ + comp_entity->entity = comp_field->entity; + comp_entity->comp_len = comp_field->comp_len; + memcpy(comp_entity->comp, comp_field->comp, sizeof(comp_entity->comp)); + + if (comp_field->rfc1144_params) { + comp_entity->nsapi_len = comp_field->rfc1144_params->nsapi_len; + memcpy(comp_entity->nsapi, + comp_field->rfc1144_params->nsapi, + sizeof(comp_entity->nsapi)); + } else if (comp_field->rfc2507_params) { + comp_entity->nsapi_len = comp_field->rfc2507_params->nsapi_len; + memcpy(comp_entity->nsapi, + comp_field->rfc2507_params->nsapi, + sizeof(comp_entity->nsapi)); + } else if (comp_field->rohc_params) { + comp_entity->nsapi_len = comp_field->rohc_params->nsapi_len; + memcpy(comp_entity->nsapi, comp_field->rohc_params->nsapi, + sizeof(comp_entity->nsapi)); + } else if (comp_field->v42bis_params) { + comp_entity->nsapi_len = comp_field->v42bis_params->nsapi_len; + memcpy(comp_entity->nsapi, + comp_field->v42bis_params->nsapi, + sizeof(comp_entity->nsapi)); + } else if (comp_field->v44_params) { + comp_entity->nsapi_len = comp_field->v44_params->nsapi_len; + memcpy(comp_entity->nsapi, + comp_field->v44_params->nsapi, + sizeof(comp_entity->nsapi)); + } else { + /* The caller is expected to check carefully if the all + * data fields required for compression entity creation + * are present. Otherwise we blow an assertion here */ + OSMO_ASSERT(false); + } + comp_entity->algo = comp_field->algo; + + /* Check if an NSAPI is selected, if not, it does not make sense + * to create the compression entity, since the caller should + * have checked the presence of the NSAPI, we blow an assertion + * in case of missing NSAPIs */ + OSMO_ASSERT(comp_entity->nsapi_len > 0); + + /* Determine of which class our compression entity will be + * (Protocol or Data compresson ?) */ + comp_entity->compclass = gprs_sndcp_get_compression_class(comp_field); + + OSMO_ASSERT(comp_entity->compclass != -1); + + /* Create an algorithm specific compression context */ + if (comp_entity->compclass == SNDCP_XID_PROTOCOL_COMPRESSION) { + if (gprs_sndcp_pcomp_init(ctx, comp_entity, comp_field) != 0) { + talloc_free(comp_entity); + comp_entity = NULL; + } + } else { + if (gprs_sndcp_dcomp_init(ctx, comp_entity, comp_field) != 0) { + talloc_free(comp_entity); + comp_entity = NULL; + } + } + + /* Bail on failure */ + if (comp_entity == NULL) { + LOGP(DSNDCP, LOGL_ERROR, + "Compression entity creation failed!\n"); + return NULL; + } + + /* Display info message */ + if (comp_entity->compclass == SNDCP_XID_PROTOCOL_COMPRESSION) { + LOGP(DSNDCP, LOGL_INFO, + "New header compression entity (%d) created.\n", + comp_entity->entity); + } else { + LOGP(DSNDCP, LOGL_INFO, + "New data compression entity (%d) created.\n", + comp_entity->entity); + } + + return comp_entity; +} + +/* Allocate a compression enitiy list */ +struct llist_head *gprs_sndcp_comp_alloc(const void *ctx) +{ + struct llist_head *lh; + + lh = talloc_zero(ctx, struct llist_head); + INIT_LLIST_HEAD(lh); + + return lh; +} + +/* Free a compression entitiy list */ +void gprs_sndcp_comp_free(struct llist_head *comp_entities) +{ + struct gprs_sndcp_comp *comp_entity; + + /* We expect the caller to take care of allocating a + * compression entity list properly. Attempting to + * free a non existing list clearly points out + * a malfunction. */ + OSMO_ASSERT(comp_entities); + + llist_for_each_entry(comp_entity, comp_entities, list) { + /* Free compression entity */ + if (comp_entity->compclass == SNDCP_XID_PROTOCOL_COMPRESSION) { + LOGP(DSNDCP, LOGL_INFO, + "Deleting header compression entity %d ...\n", + comp_entity->entity); + gprs_sndcp_pcomp_term(comp_entity); + } else { + LOGP(DSNDCP, LOGL_INFO, + "Deleting data compression entity %d ...\n", + comp_entity->entity); + gprs_sndcp_dcomp_term(comp_entity); + } + } + + talloc_free(comp_entities); +} + +/* Delete a compression entity */ +void gprs_sndcp_comp_delete(struct llist_head *comp_entities, + unsigned int entity) +{ + struct gprs_sndcp_comp *comp_entity; + struct gprs_sndcp_comp *comp_entity_to_delete = NULL; + + OSMO_ASSERT(comp_entities); + + llist_for_each_entry(comp_entity, comp_entities, list) { + if (comp_entity->entity == entity) { + comp_entity_to_delete = comp_entity; + break; + } + } + + if (!comp_entity_to_delete) + return; + + if (comp_entity_to_delete->compclass == SNDCP_XID_PROTOCOL_COMPRESSION) { + LOGP(DSNDCP, LOGL_INFO, + "Deleting header compression entity %d ...\n", + comp_entity_to_delete->entity); + gprs_sndcp_pcomp_term(comp_entity_to_delete); + } else { + LOGP(DSNDCP, LOGL_INFO, + "Deleting data compression entity %d ...\n", + comp_entity_to_delete->entity); + } + + /* Delete compression entity */ + llist_del(&comp_entity_to_delete->list); + talloc_free(comp_entity_to_delete); +} + +/* 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) +{ + struct gprs_sndcp_comp *comp_entity; + + OSMO_ASSERT(comp_entities); + OSMO_ASSERT(comp_field); + + /* Just to be sure, if the entity is already in + * the list it will be deleted now */ + gprs_sndcp_comp_delete(comp_entities, comp_field->entity); + + /* Create and add a new entity to the list */ + comp_entity = gprs_sndcp_comp_create(ctx, comp_field); + + if (!comp_entity) + return NULL; + + llist_add(&comp_entity->list, comp_entities); + return comp_entity; +} + +/* 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) +{ + struct gprs_sndcp_comp *comp_entity; + int i; + + OSMO_ASSERT(comp_entities); + + llist_for_each_entry(comp_entity, comp_entities, list) { + for (i = 0; i < comp_entity->comp_len; i++) { + if (comp_entity->comp[i] == comp) + return comp_entity; + } + } + + LOGP(DSNDCP, LOGL_ERROR, + "Could not find a matching compression entity for given pcomp/dcomp value %d.\n", + comp); + return NULL; +} + +/* 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) +{ + struct gprs_sndcp_comp *comp_entity; + int i; + + OSMO_ASSERT(comp_entities); + + llist_for_each_entry(comp_entity, comp_entities, list) { + for (i = 0; i < comp_entity->nsapi_len; i++) { + if (comp_entity->nsapi[i] == nsapi) + return comp_entity; + } + } + + return NULL; +} + +/* 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) +{ + /* Note: This function returns a normalized version of the comp value, + * which matches up with the position of the comp field. Since comp=0 + * is reserved for "no compression", the index value starts counting + * at one. The return value is the PCOMPn/DCOMPn value one can find + * in the Specification (see e.g. 3GPP TS 44.065, 6.5.3.2, Table 7) */ + + int i; + OSMO_ASSERT(comp_entity); + + /* A pcomp/dcomp value of zero is reserved for "no comproession", + * So we just bail and return zero in this case */ + if (comp == 0) + return 0; + + /* Look in the pcomp/dcomp list for the index */ + for (i = 0; i < comp_entity->comp_len; i++) { + if (comp_entity->comp[i] == comp) + return i + 1; + } + + LOGP(DSNDCP, LOGL_ERROR, + "Could not find a matching comp_index for given pcomp/dcomp value %d\n", + comp); + return 0; +} + +/* 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) +{ + OSMO_ASSERT(comp_entity); + + /* A comp_index of zero translates to zero right away. */ + if (comp_index == 0) + return 0; + + if (comp_index > comp_entity->comp_len) { + LOGP(DSNDCP, LOGL_ERROR, + "Could not find a matching pcomp/dcomp value for given comp_index value %d.\n", + comp_index); + return 0; + } + + /* Look in the pcomp/dcomp list for the comp_index, see + * note in gprs_sndcp_comp_get_idx() */ + return comp_entity->comp[comp_index - 1]; +} |