143 lines
4.3 KiB
C
143 lines
4.3 KiB
C
/* GPRS LLC as per 3GPP TS 44.064 7.2.4 */
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/*
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* (C) 2022 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
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*
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* All Rights Reserved
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License as published by
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* the Free Software Foundation; either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Affero General Public License for more details.
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*
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* You should have received a copy of the GNU Affero General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include <stdint.h>
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#include <errno.h>
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#include <osmocom/core/msgb.h>
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#include <osmocom/core/utils.h>
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#include <osmocom/core/logging.h>
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#include <osmocom/crypt/gprs_cipher.h>
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#include <osmocom/gsm/gsm_utils.h>
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#include <osmocom/gprs/llc/llc.h>
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#include <osmocom/gprs/llc/llc_prim.h>
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#include <osmocom/gprs/llc/llc_private.h>
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const struct value_string osmo_gprs_llc_bssgp_prim_type_names[] = {
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{ OSMO_GPRS_LLC_BSSGP_DL_UNITDATA, "DL-UNITDATA" },
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{ OSMO_GPRS_LLC_BSSGP_UL_UNITDATA, "UL-UNITDATA" },
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{ 0, NULL }
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};
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/********************************
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* Primitive allocation:
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********************************/
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static inline struct osmo_gprs_llc_prim *llc_prim_bssgp_alloc(enum osmo_gprs_llc_bssgp_prim_type type,
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enum osmo_prim_operation operation,
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unsigned int l3_len)
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{
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return gprs_llc_prim_alloc(OSMO_GPRS_LLC_SAP_BSSGP, type, operation, l3_len);
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}
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/* 7.2.4.1 BSSGP-UL-UNITDATA.ind (SGSN):*/
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struct osmo_gprs_llc_prim *osmo_gprs_llc_prim_alloc_bssgp_ul_unitdata_ind(
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uint32_t tlli, uint8_t *ll_pdu,
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size_t ll_pdu_len)
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{
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struct osmo_gprs_llc_prim *llc_prim;
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llc_prim = llc_prim_bssgp_alloc(OSMO_GPRS_LLC_BSSGP_UL_UNITDATA, PRIM_OP_INDICATION, ll_pdu_len);
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llc_prim->bssgp.tlli = tlli;
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llc_prim->bssgp.ll_pdu = ll_pdu;
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llc_prim->bssgp.ll_pdu_len = ll_pdu_len;
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return llc_prim;
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}
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/* 7.2.4.2 BSSGP-UL-UNITDATA.ind (SGSN):*/
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struct osmo_gprs_llc_prim *gprs_llc_prim_alloc_bssgp_dl_unitdata_req(
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uint32_t tlli, uint8_t *ll_pdu, size_t ll_pdu_len)
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{
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struct osmo_gprs_llc_prim *llc_prim;
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llc_prim = llc_prim_bssgp_alloc(OSMO_GPRS_LLC_BSSGP_DL_UNITDATA, PRIM_OP_REQUEST, ll_pdu_len);
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llc_prim->bssgp.tlli = tlli;
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llc_prim->bssgp.ll_pdu = ll_pdu;
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llc_prim->bssgp.ll_pdu_len = ll_pdu_len;
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return llc_prim;
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}
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/********************************
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* Handling from lower layers:
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********************************/
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static int gprs_llc_prim_handle_bssgp_ul_unitdata_ind(struct osmo_gprs_llc_prim *llc_prim)
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{
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int rc;
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struct gprs_llc_pdu_decoded pdu_dec = {0};
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const char *llc_pdu_name = NULL;
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struct gprs_llc_lle *lle = NULL;
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rc = gprs_llc_pdu_decode(&pdu_dec, llc_prim->bssgp.ll_pdu, llc_prim->bssgp.ll_pdu_len);
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if (rc < 0) {
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LOGLLC(LOGL_ERROR, "%s: Error parsing LLC header\n", osmo_gprs_llc_prim_name(llc_prim));
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return rc;
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}
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llc_pdu_name = gprs_llc_pdu_hdr_dump(&pdu_dec);
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LOGLLC(LOGL_DEBUG, "Rx %s: %s\n", osmo_gprs_llc_prim_name(llc_prim), llc_pdu_name);
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switch (gprs_tlli_type(llc_prim->bssgp.tlli)) {
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case TLLI_LOCAL:
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case TLLI_FOREIGN:
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case TLLI_RANDOM:
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case TLLI_AUXILIARY:
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break;
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default:
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LOGLLC(LOGL_ERROR, "%s: Discarding frame with strange TLLI type\n", llc_pdu_name);
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return -EINVAL;
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}
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lle = gprs_llc_lle_for_rx_by_tlli_sapi(llc_prim->bssgp.tlli, pdu_dec.sapi, pdu_dec.func);
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if (!lle) {
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switch (pdu_dec.sapi) {
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case OSMO_GPRS_LLC_SAPI_SNDCP3:
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case OSMO_GPRS_LLC_SAPI_SNDCP5:
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case OSMO_GPRS_LLC_SAPI_SNDCP9:
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case OSMO_GPRS_LLC_SAPI_SNDCP11:
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#if 0
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/* TODO: probaby send some primitive to the upper layers (GMM) */
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/* Ask an upper layer for help. */
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return gsm0408_gprs_force_reattach_oldmsg(msg, NULL);
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#endif
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default:
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break;
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}
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return 0;
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}
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rc = gprs_llc_lle_rx_unitdata_ind(lle, llc_prim->bssgp.ll_pdu, llc_prim->bssgp.ll_pdu_len, &pdu_dec);
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return rc;
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}
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int gprs_llc_prim_lower_up_bssgp(struct osmo_gprs_llc_prim *llc_prim)
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{
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int rc;
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switch (OSMO_PRIM_HDR(&llc_prim->oph)) {
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case OSMO_PRIM(OSMO_GPRS_LLC_BSSGP_UL_UNITDATA, PRIM_OP_INDICATION):
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rc = gprs_llc_prim_handle_bssgp_ul_unitdata_ind(llc_prim);
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break;
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default:
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rc = -ENOTSUP;
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}
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return rc;
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}
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