142 lines
3.7 KiB
C
142 lines
3.7 KiB
C
/* GSM BSC Radio Link Layer API
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* 3GPP TS 08.58 version 8.6.0 Release 1999 / ETSI TS 100 596 V8.6.0 */
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/* (C) 2009 by Harald Welte <laforge@gnumonks.org>
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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 <errno.h>
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#include <openbsc/debug.h>
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#include <osmocore/talloc.h>
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#include <osmocore/timer.h>
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#include <osmocore/linuxlist.h>
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#include <openbsc/bsc_rll.h>
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#include <openbsc/gsm_data.h>
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#include <openbsc/chan_alloc.h>
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#include <openbsc/abis_rsl.h>
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#include <openbsc/signal.h>
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struct bsc_rll_req {
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struct llist_head list;
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struct timer_list timer;
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struct gsm_lchan *lchan;
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u_int8_t link_id;
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void (*cb)(struct gsm_lchan *lchan, u_int8_t link_id,
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void *data, enum bsc_rllr_ind);
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void *data;
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};
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/* we only compare C1, C2 and SAPI */
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#define LINKID_MASK 0xC7
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static LLIST_HEAD(bsc_rll_reqs);
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static void complete_rllr(struct bsc_rll_req *rllr, enum bsc_rllr_ind type)
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{
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llist_del(&rllr->list);
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rllr->cb(rllr->lchan, rllr->link_id, rllr->data, type);
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talloc_free(rllr);
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}
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static void timer_cb(void *_rllr)
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{
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struct bsc_rll_req *rllr = _rllr;
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complete_rllr(rllr, BSC_RLLR_IND_TIMEOUT);
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}
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/* establish a RLL connection with given SAPI / priority */
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int rll_establish(struct gsm_lchan *lchan, u_int8_t sapi,
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void (*cb)(struct gsm_lchan *, u_int8_t, void *,
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enum bsc_rllr_ind),
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void *data)
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{
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struct bsc_rll_req *rllr = talloc_zero(tall_bsc_ctx, struct bsc_rll_req);
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u_int8_t link_id;
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if (!rllr)
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return -ENOMEM;
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link_id = sapi;
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/* If we are a TCH and not in signalling mode, we need to
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* indicate that the new RLL connection is to be made on the SACCH */
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if ((lchan->type == GSM_LCHAN_TCH_F ||
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lchan->type == GSM_LCHAN_TCH_H) && sapi != 0)
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link_id |= 0x40;
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rllr->lchan = lchan;
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rllr->link_id = link_id;
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rllr->cb = cb;
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rllr->data = data;
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llist_add(&rllr->list, &bsc_rll_reqs);
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rllr->timer.cb = &timer_cb;
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rllr->timer.data = rllr;
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bsc_schedule_timer(&rllr->timer, 10, 0);
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/* send the RSL RLL ESTablish REQuest */
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return rsl_establish_request(rllr->lchan, rllr->link_id);
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}
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/* Called from RSL code in case we have received an indication regarding
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* any RLL link */
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void rll_indication(struct gsm_lchan *lchan, u_int8_t link_id, u_int8_t type)
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{
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struct bsc_rll_req *rllr, *rllr2;
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llist_for_each_entry_safe(rllr, rllr2, &bsc_rll_reqs, list) {
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if (rllr->lchan == lchan &&
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(rllr->link_id & LINKID_MASK) == (link_id & LINKID_MASK)) {
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bsc_del_timer(&rllr->timer);
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complete_rllr(rllr, type);
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return;
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}
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}
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}
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static int rll_lchan_signal(unsigned int subsys, unsigned int signal,
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void *handler_data, void *signal_data)
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{
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struct challoc_signal_data *challoc;
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struct bsc_rll_req *rllr, *rllr2;
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if (subsys != SS_CHALLOC || signal != S_CHALLOC_FREED)
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return 0;
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challoc = (struct challoc_signal_data *) signal_data;
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llist_for_each_entry_safe(rllr, rllr2, &bsc_rll_reqs, list) {
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if (rllr->lchan == challoc->lchan) {
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bsc_del_timer(&rllr->timer);
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complete_rllr(rllr, BSC_RLLR_IND_ERR_IND);
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}
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}
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return 0;
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}
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static __attribute__((constructor)) void on_dso_load_rll(void)
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{
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register_signal_handler(SS_CHALLOC, rll_lchan_signal, NULL);
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}
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