diff options
Diffstat (limited to 'openbsc/src/gprs/gprs_sndcp_pcomp.c')
| -rw-r--r-- | openbsc/src/gprs/gprs_sndcp_pcomp.c | 282 |
1 files changed, 0 insertions, 282 deletions
diff --git a/openbsc/src/gprs/gprs_sndcp_pcomp.c b/openbsc/src/gprs/gprs_sndcp_pcomp.c deleted file mode 100644 index a2236c3b1..000000000 --- a/openbsc/src/gprs/gprs_sndcp_pcomp.c +++ /dev/null @@ -1,282 +0,0 @@ -/* GPRS SNDCP header 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/slhc.h> -#include <openbsc/debug.h> -#include <openbsc/gprs_sndcp_comp.h> -#include <openbsc/gprs_sndcp_pcomp.h> - -/* Initalize header compression */ -int gprs_sndcp_pcomp_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 header compression - * entity is created by gprs_sndcp.c */ - - OSMO_ASSERT(comp_entity); - OSMO_ASSERT(comp_field); - - if (comp_entity->compclass == SNDCP_XID_PROTOCOL_COMPRESSION - && comp_entity->algo == RFC_1144) { - OSMO_ASSERT(comp_field->rfc1144_params); - comp_entity->state = - slhc_init(ctx, comp_field->rfc1144_params->s01 + 1, - comp_field->rfc1144_params->s01 + 1); - LOGP(DSNDCP, LOGL_INFO, - "RFC1144 header compression initalized.\n"); - return 0; - } - - /* Just in case someone tries to initalize an unknown or unsupported - * header compresson. Since everything is checked during the SNDCP - * negotiation process, this should never happen! */ - OSMO_ASSERT(false); -} - -/* Terminate header compression */ -void gprs_sndcp_pcomp_term(struct gprs_sndcp_comp *comp_entity) -{ - /* Note: This function is automatically called from - * gprs_sndcp_comp.c when a header compression - * entity is deleted by gprs_sndcp.c */ - - OSMO_ASSERT(comp_entity); - - if (comp_entity->compclass == SNDCP_XID_PROTOCOL_COMPRESSION - && comp_entity->algo == RFC_1144) { - if (comp_entity->state) { - slhc_free((struct slcompress *)comp_entity->state); - comp_entity->state = NULL; - } - LOGP(DSNDCP, LOGL_INFO, - "RFC1144 header 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); -} - -/* Compress a packet using Van Jacobson RFC1144 header compression */ -static int rfc1144_compress(uint8_t *pcomp_index, uint8_t *data, - unsigned int len, struct slcompress *comp) -{ - uint8_t *comp_ptr; - int compr_len; - uint8_t *data_o; - - /* Create a working copy of the incoming data */ - data_o = talloc_zero_size(comp, len); - memcpy(data_o, data, len); - - /* Run compressor */ - compr_len = slhc_compress(comp, data, len, data_o, &comp_ptr, 0); - - /* Generate pcomp_index */ - if (data_o[0] & SL_TYPE_COMPRESSED_TCP) { - *pcomp_index = 2; - data_o[0] &= ~SL_TYPE_COMPRESSED_TCP; - memcpy(data, data_o, compr_len); - } else if ((data_o[0] & SL_TYPE_UNCOMPRESSED_TCP) == - SL_TYPE_UNCOMPRESSED_TCP) { - *pcomp_index = 1; - data_o[0] &= 0x4F; - memcpy(data, data_o, compr_len); - } else - *pcomp_index = 0; - - talloc_free(data_o); - return compr_len; -} - -/* Expand a packet using Van Jacobson RFC1144 header compression */ -static int rfc1144_expand(uint8_t *data, unsigned int len, uint8_t pcomp_index, - struct slcompress *comp) -{ - int data_decompressed_len; - int type; - - /* Note: this function should never be called with pcomp_index=0, - * since this condition is already filtered - * out by gprs_sndcp_pcomp_expand() */ - - /* Determine the data type by the PCOMP index */ - switch (pcomp_index) { - case 0: - type = SL_TYPE_IP; - break; - case 1: - type = SL_TYPE_UNCOMPRESSED_TCP; - break; - case 2: - type = SL_TYPE_COMPRESSED_TCP; - break; - default: - LOGP(DSNDCP, LOGL_ERROR, - "rfc1144_expand() Invalid pcomp_index value (%d) detected, assuming no compression!\n", - pcomp_index); - type = SL_TYPE_IP; - break; - } - - /* Restore the original version nibble on - * marked uncompressed packets */ - if (type == SL_TYPE_UNCOMPRESSED_TCP) { - /* Just in case the phone tags uncompressed tcp-data - * (normally this is handled by pcomp so there is - * no need for tagging the data) */ - data[0] &= 0x4F; - data_decompressed_len = slhc_remember(comp, data, len); - return data_decompressed_len; - } - - /* Uncompress compressed packets */ - else if (type == SL_TYPE_COMPRESSED_TCP) { - data_decompressed_len = slhc_uncompress(comp, data, len); - return data_decompressed_len; - } - - /* Regular or unknown packets will not be touched */ - return len; -} - -/* Expand packet header */ -int gprs_sndcp_pcomp_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, - "Header compression entity list: comp_entities=%p\n", - comp_entities); - - LOGP(DSNDCP, LOGL_DEBUG, "Header compression mode: pcomp=%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 protocol compression entities may appear in - * protocol compression context */ - OSMO_ASSERT(comp_entity->compclass == SNDCP_XID_PROTOCOL_COMPRESSION); - - /* Note: Currently RFC1144 is the only compression method we - * support, so the only allowed algorithm is RFC1144 */ - OSMO_ASSERT(comp_entity->algo == RFC_1144); - - /* Find pcomp_index */ - pcomp_index = gprs_sndcp_comp_get_idx(comp_entity, pcomp); - - /* Run decompression algo */ - rc = rfc1144_expand(data, len, pcomp_index, comp_entity->state); - slhc_i_status(comp_entity->state); - slhc_o_status(comp_entity->state); - - LOGP(DSNDCP, LOGL_DEBUG, - "Header expansion done, old length=%d, new length=%d, entity=%p\n", - len, rc, comp_entity); - - return rc; -} - -/* Compress packet header */ -int gprs_sndcp_pcomp_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, - "Header 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 protocol compression entities may appear in - * protocol compression context */ - OSMO_ASSERT(comp_entity->compclass == SNDCP_XID_PROTOCOL_COMPRESSION); - - /* Note: Currently RFC1144 is the only compression method we - * support, so the only allowed algorithm is RFC1144 */ - OSMO_ASSERT(comp_entity->algo == RFC_1144); - - /* Run compression algo */ - rc = rfc1144_compress(&pcomp_index, data, len, comp_entity->state); - slhc_i_status(comp_entity->state); - slhc_o_status(comp_entity->state); - - /* Find pcomp value */ - *pcomp = gprs_sndcp_comp_get_comp(comp_entity, pcomp_index); - - LOGP(DSNDCP, LOGL_DEBUG, "Header compression mode: pcomp=%d\n", *pcomp); - - LOGP(DSNDCP, LOGL_DEBUG, - "Header compression done, old length=%d, new length=%d, entity=%p\n", - len, rc, comp_entity); - return rc; -} |