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-rw-r--r--src/libbsc/bsc_rll.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/src/libbsc/bsc_rll.c b/src/libbsc/bsc_rll.c
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+++ b/src/libbsc/bsc_rll.c
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+/* GSM BSC Radio Link Layer API
+ * 3GPP TS 08.58 version 8.6.0 Release 1999 / ETSI TS 100 596 V8.6.0 */
+
+/* (C) 2009 by Harald Welte <laforge@gnumonks.org>
+ *
+ * All Rights Reserved
+ *
+ * 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 <errno.h>
+
+#include <openbsc/debug.h>
+#include <osmocore/talloc.h>
+#include <osmocore/timer.h>
+#include <osmocore/linuxlist.h>
+#include <openbsc/bsc_rll.h>
+#include <openbsc/gsm_data.h>
+#include <openbsc/chan_alloc.h>
+#include <openbsc/abis_rsl.h>
+#include <openbsc/signal.h>
+
+struct bsc_rll_req {
+ struct llist_head list;
+ struct timer_list timer;
+
+ struct gsm_lchan *lchan;
+ u_int8_t link_id;
+
+ void (*cb)(struct gsm_lchan *lchan, u_int8_t link_id,
+ void *data, enum bsc_rllr_ind);
+ void *data;
+};
+
+/* we only compare C1, C2 and SAPI */
+#define LINKID_MASK 0xC7
+
+static LLIST_HEAD(bsc_rll_reqs);
+
+static void complete_rllr(struct bsc_rll_req *rllr, enum bsc_rllr_ind type)
+{
+ llist_del(&rllr->list);
+ rllr->cb(rllr->lchan, rllr->link_id, rllr->data, type);
+ talloc_free(rllr);
+}
+
+static void timer_cb(void *_rllr)
+{
+ struct bsc_rll_req *rllr = _rllr;
+
+ complete_rllr(rllr, BSC_RLLR_IND_TIMEOUT);
+}
+
+/* establish a RLL connection with given SAPI / priority */
+int rll_establish(struct gsm_lchan *lchan, u_int8_t sapi,
+ void (*cb)(struct gsm_lchan *, u_int8_t, void *,
+ enum bsc_rllr_ind),
+ void *data)
+{
+ struct bsc_rll_req *rllr = talloc_zero(tall_bsc_ctx, struct bsc_rll_req);
+ u_int8_t link_id;
+ if (!rllr)
+ return -ENOMEM;
+
+ link_id = sapi;
+
+ /* If we are a TCH and not in signalling mode, we need to
+ * indicate that the new RLL connection is to be made on the SACCH */
+ if ((lchan->type == GSM_LCHAN_TCH_F ||
+ lchan->type == GSM_LCHAN_TCH_H) && sapi != 0)
+ link_id |= 0x40;
+
+ rllr->lchan = lchan;
+ rllr->link_id = link_id;
+ rllr->cb = cb;
+ rllr->data = data;
+
+ llist_add(&rllr->list, &bsc_rll_reqs);
+
+ rllr->timer.cb = &timer_cb;
+ rllr->timer.data = rllr;
+
+ bsc_schedule_timer(&rllr->timer, 10, 0);
+
+ /* send the RSL RLL ESTablish REQuest */
+ return rsl_establish_request(rllr->lchan, rllr->link_id);
+}
+
+/* Called from RSL code in case we have received an indication regarding
+ * any RLL link */
+void rll_indication(struct gsm_lchan *lchan, u_int8_t link_id, u_int8_t type)
+{
+ struct bsc_rll_req *rllr, *rllr2;
+
+ llist_for_each_entry_safe(rllr, rllr2, &bsc_rll_reqs, list) {
+ if (rllr->lchan == lchan &&
+ (rllr->link_id & LINKID_MASK) == (link_id & LINKID_MASK)) {
+ bsc_del_timer(&rllr->timer);
+ complete_rllr(rllr, type);
+ return;
+ }
+ }
+}
+
+static int rll_lchan_signal(unsigned int subsys, unsigned int signal,
+ void *handler_data, void *signal_data)
+{
+ struct challoc_signal_data *challoc;
+ struct bsc_rll_req *rllr, *rllr2;
+
+ if (subsys != SS_CHALLOC || signal != S_CHALLOC_FREED)
+ return 0;
+
+ challoc = (struct challoc_signal_data *) signal_data;
+
+ llist_for_each_entry_safe(rllr, rllr2, &bsc_rll_reqs, list) {
+ if (rllr->lchan == challoc->lchan) {
+ bsc_del_timer(&rllr->timer);
+ complete_rllr(rllr, BSC_RLLR_IND_ERR_IND);
+ }
+ }
+
+ return 0;
+}
+
+static __attribute__((constructor)) void on_dso_load_rll(void)
+{
+ register_signal_handler(SS_CHALLOC, rll_lchan_signal, NULL);
+}