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-rw-r--r--src/osmo-bsc/bsc_api.c841
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diff --git a/src/osmo-bsc/bsc_api.c b/src/osmo-bsc/bsc_api.c
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+++ b/src/osmo-bsc/bsc_api.c
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+/* GSM 08.08 like API for OpenBSC. The bridge from MSC to BSC */
+
+/* (C) 2010-2011 by Holger Hans Peter Freyther
+ * (C) 2010-2011 by On-Waves
+ * (C) 2009,2017 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 <osmocom/bsc/bsc_api.h>
+#include <osmocom/bsc/bsc_rll.h>
+#include <osmocom/bsc/gsm_data.h>
+#include <osmocom/bsc/signal.h>
+#include <osmocom/bsc/abis_rsl.h>
+#include <osmocom/bsc/chan_alloc.h>
+#include <osmocom/bsc/handover.h>
+#include <osmocom/bsc/debug.h>
+#include <osmocom/bsc/gsm_04_08_utils.h>
+#include <osmocom/bsc/bsc_subscriber.h>
+#include <osmocom/bsc/penalty_timers.h>
+#include <osmocom/bsc/osmo_bsc_sigtran.h>
+
+#include <osmocom/gsm/protocol/gsm_08_08.h>
+#include <osmocom/gsm/gsm48.h>
+
+#include <osmocom/core/talloc.h>
+
+#define GSM0808_T10_VALUE 6, 0
+
+#define HO_DTAP_CACHE_MSGB_CB_LINK_ID 0
+#define HO_DTAP_CACHE_MSGB_CB_ALLOW_SACCH 1
+
+static void rll_ind_cb(struct gsm_lchan *, uint8_t, void *, enum bsc_rllr_ind);
+static void send_sapi_reject(struct gsm_subscriber_connection *conn, int link_id);
+static void handle_release(struct gsm_subscriber_connection *conn, struct bsc_api *bsc, struct gsm_lchan *lchan);
+static void handle_chan_ack(struct gsm_subscriber_connection *conn, struct bsc_api *bsc, struct gsm_lchan *lchan);
+static void handle_chan_nack(struct gsm_subscriber_connection *conn, struct bsc_api *bsc, struct gsm_lchan *lchan);
+
+/*! \brief Determine and apply AMR multi-rate configuration to lchan
+ * Determine which AMR multi-rate configuration to use and apply it to
+ * the lchan (so it can be communicated to BTS and MS during channel
+ * activation.
+ * \param[in] conn subscriber connection (used to resolve bsc_api)
+ * \param[out] lchan logical channel to which to apply mr config
+ * \param[in] full_rate whether to use full-rate (1) or half-rate (0) config
+ */
+static void handle_mr_config(struct gsm_subscriber_connection *conn,
+ struct gsm_lchan *lchan, int full_rate)
+{
+ struct bsc_api *api;
+ api = conn->network->bsc_api;
+ struct amr_multirate_conf *mr;
+ struct gsm48_multi_rate_conf *mr_conf;
+
+ /* BSC api override for this method, used in OsmoBSC mode with
+ * bsc_mr_config() to use MSC-specific/specified configuration */
+ if (api->mr_config)
+ return api->mr_config(conn, lchan, full_rate);
+
+ /* NITB case: use the BTS-specic multi-rate configuration from
+ * the vty/configuration file */
+ if (full_rate)
+ mr = &lchan->ts->trx->bts->mr_full;
+ else
+ mr = &lchan->ts->trx->bts->mr_half;
+
+ mr_conf = (struct gsm48_multi_rate_conf *) mr->gsm48_ie;
+ mr_conf->ver = 1;
+
+ /* default, if no AMR codec defined */
+ if (!mr->gsm48_ie[1]) {
+ mr_conf->icmi = 1;
+ mr_conf->m5_90 = 1;
+ }
+ /* store encoded MR config IE lchan for both MS (uplink) and BTS
+ * (downlink) directions */
+ gsm48_multirate_config(lchan->mr_ms_lv, mr, mr->ms_mode);
+ gsm48_multirate_config(lchan->mr_bts_lv, mr, mr->bts_mode);
+}
+
+/*
+ * Start a new assignment and make sure that it is completed within T10 either
+ * positively, negatively or by the timeout.
+ *
+ * 1.) allocate a new lchan
+ * 2.) copy the encryption key and other data from the
+ * old to the new channel.
+ * 3.) RSL Channel Activate this channel and wait
+ *
+ * -> Signal handler for the LCHAN
+ * 4.) Send GSM 04.08 assignment command to the MS
+ *
+ * -> Assignment Complete/Assignment Failure
+ * 5.) Release the SDCCH, continue signalling on the new link
+ */
+static int handle_new_assignment(struct gsm_subscriber_connection *conn, int chan_mode, int full_rate)
+{
+ struct gsm_lchan *new_lchan;
+ enum gsm_chan_t chan_type;
+
+ chan_type = full_rate ? GSM_LCHAN_TCH_F : GSM_LCHAN_TCH_H;
+
+ new_lchan = lchan_alloc(conn_get_bts(conn), chan_type, 0);
+
+ if (!new_lchan) {
+ LOGP(DMSC, LOGL_NOTICE, "%s No free channel for %s\n",
+ bsc_subscr_name(conn->bsub), gsm_lchant_name(chan_type));
+ return -1;
+ }
+
+ /* check if we are on TCH/F and requested TCH/H, but got TCH/F */
+ if (conn->lchan->type == new_lchan->type
+ && chan_type != new_lchan->type) {
+ LOGPLCHAN(conn->lchan, DHO, LOGL_NOTICE,
+ "-> %s Will not re-assign to identical channel type, %s was requested\n",
+ gsm_lchan_name(new_lchan), gsm_lchant_name(chan_type));
+ lchan_free(new_lchan);
+ return -1;
+ }
+
+ /* copy old data to the new channel */
+ memcpy(&new_lchan->encr, &conn->lchan->encr, sizeof(new_lchan->encr));
+ new_lchan->ms_power = conn->lchan->ms_power;
+ new_lchan->bs_power = conn->lchan->bs_power;
+ new_lchan->rqd_ta = conn->lchan->rqd_ta;
+
+ /* copy new data to it */
+ new_lchan->tch_mode = chan_mode;
+ new_lchan->rsl_cmode = (chan_mode == GSM48_CMODE_SIGN) ?
+ RSL_CMOD_SPD_SIGN : RSL_CMOD_SPD_SPEECH;
+
+ /* handle AMR correctly */
+ if (chan_mode == GSM48_CMODE_SPEECH_AMR)
+ handle_mr_config(conn, new_lchan, full_rate);
+
+ if (rsl_chan_activate_lchan(new_lchan, 0x1, 0) < 0) {
+ LOGPLCHAN(new_lchan, DHO, LOGL_ERROR, "could not activate channel\n");
+ lchan_free(new_lchan);
+ return -1;
+ }
+
+ /* remember that we have the channel */
+ conn->secondary_lchan = new_lchan;
+ new_lchan->conn = conn;
+ return 0;
+}
+
+static void ho_dtap_cache_add(struct gsm_subscriber_connection *conn, struct msgb *msg,
+ int link_id, bool allow_sacch)
+{
+ if (conn->ho_dtap_cache_len >= 23) {
+ LOGP(DHO, LOGL_ERROR, "%s: Cannot cache more DTAP messages,"
+ " already reached sane maximum of %u cached messages\n",
+ bsc_subscr_name(conn->bsub), conn->ho_dtap_cache_len);
+ msgb_free(msg);
+ return;
+ }
+ conn->ho_dtap_cache_len ++;
+ LOGP(DHO, LOGL_DEBUG, "%s: Caching DTAP message during ho/ass (%u)\n",
+ bsc_subscr_name(conn->bsub), conn->ho_dtap_cache_len);
+ msg->cb[HO_DTAP_CACHE_MSGB_CB_LINK_ID] = (unsigned long)link_id;
+ msg->cb[HO_DTAP_CACHE_MSGB_CB_ALLOW_SACCH] = allow_sacch ? 1 : 0;
+ msgb_enqueue(&conn->ho_dtap_cache, msg);
+}
+
+void ho_dtap_cache_flush(struct gsm_subscriber_connection *conn, int send)
+{
+ struct msgb *msg;
+ unsigned int flushed_count = 0;
+
+ if (conn->secondary_lchan || conn->ho) {
+ LOGP(DHO, LOGL_ERROR, "%s: Cannot send cached DTAP messages, handover/assignment is still ongoing\n",
+ bsc_subscr_name(conn->bsub));
+ send = 0;
+ }
+
+ while ((msg = msgb_dequeue(&conn->ho_dtap_cache))) {
+ conn->ho_dtap_cache_len --;
+ flushed_count ++;
+ if (send) {
+ int link_id = (int)msg->cb[HO_DTAP_CACHE_MSGB_CB_LINK_ID];
+ bool allow_sacch = !!msg->cb[HO_DTAP_CACHE_MSGB_CB_ALLOW_SACCH];
+ LOGP(DHO, LOGL_DEBUG, "%s: Sending cached DTAP message after handover/assignment (%u/%u)\n",
+ bsc_subscr_name(conn->bsub), flushed_count, conn->ho_dtap_cache_len);
+ gsm0808_submit_dtap(conn, msg, link_id, allow_sacch);
+ } else
+ msgb_free(msg);
+ }
+}
+
+int bsc_api_init(struct gsm_network *network, struct bsc_api *api)
+{
+ network->bsc_api = api;
+ return 0;
+}
+
+/*! \brief process incoming 08.08 DTAP from MSC (send via BTS to MS) */
+int gsm0808_submit_dtap(struct gsm_subscriber_connection *conn,
+ struct msgb *msg, int link_id, int allow_sacch)
+{
+ uint8_t sapi;
+
+
+ if (!conn->lchan) {
+ LOGP(DMSC, LOGL_ERROR,
+ "%s Called submit dtap without an lchan.\n",
+ bsc_subscr_name(conn->bsub));
+ msgb_free(msg);
+ return -1;
+ }
+
+ /* buffer message during assignment / handover */
+ if (conn->secondary_lchan || conn->ho) {
+ ho_dtap_cache_add(conn, msg, link_id, !! allow_sacch);
+ return 0;
+ }
+
+ sapi = link_id & 0x7;
+ msg->lchan = conn->lchan;
+ msg->dst = msg->lchan->ts->trx->rsl_link;
+
+ /* If we are on a TCH and need to submit a SMS (on SAPI=3) we need to use the SACH */
+ if (allow_sacch && sapi != 0) {
+ if (conn->lchan->type == GSM_LCHAN_TCH_F || conn->lchan->type == GSM_LCHAN_TCH_H)
+ link_id |= 0x40;
+ }
+
+ msg->l3h = msg->data;
+ /* is requested SAPI already up? */
+ if (conn->lchan->sapis[sapi] == LCHAN_SAPI_UNUSED) {
+ /* Establish L2 for additional SAPI */
+ OBSC_LINKID_CB(msg) = link_id;
+ if (rll_establish(msg->lchan, sapi, rll_ind_cb, msg) != 0) {
+ msgb_free(msg);
+ send_sapi_reject(conn, link_id);
+ return -1;
+ }
+ return 0;
+ } else {
+ /* Directly forward via RLL/RSL to BTS */
+ return rsl_data_request(msg, link_id);
+ }
+}
+
+/*
+ * \brief Check if the given channel is compatible with the mode/fullrate
+ */
+static int chan_compat_with_mode(struct gsm_lchan *lchan, int chan_mode, int full_rate)
+{
+ switch (chan_mode) {
+ case GSM48_CMODE_SIGN:
+ switch (lchan->type) {
+ case GSM_LCHAN_TCH_F:
+ case GSM_LCHAN_TCH_H:
+ case GSM_LCHAN_SDCCH:
+ return 1;
+ default:
+ return 0;
+ }
+ case GSM48_CMODE_SPEECH_V1:
+ case GSM48_CMODE_SPEECH_AMR:
+ case GSM48_CMODE_DATA_3k6:
+ case GSM48_CMODE_DATA_6k0:
+ /* these services can all run on TCH/H, but we may have
+ * an explicit override by the 'full_rate' argument */
+ switch (lchan->type) {
+ case GSM_LCHAN_TCH_F:
+ return full_rate ? 1 : 0;
+ case GSM_LCHAN_TCH_H:
+ return full_rate ? 0 : 1;
+ default:
+ return 0;
+ }
+ case GSM48_CMODE_DATA_12k0:
+ case GSM48_CMODE_DATA_14k5:
+ case GSM48_CMODE_SPEECH_EFR:
+ /* these services all explicitly require a TCH/F */
+ return (lchan->type == GSM_LCHAN_TCH_F) ? 1 : 0;
+ default:
+ return 0;
+ }
+}
+
+/*! Send a GSM08.08 Assignment Request. Right now this does not contain the
+ * audio codec type or the allowed rates for the config. In case the current
+ * channel does not allow the selected mode a new one will be allocated.
+ * \param[out] conn related subscriber connection
+ * \param[in] chan_mode mode of the channel (see enum gsm48_chan_mode)
+ * \param[in] full_rate select full rate or half rate channel
+ * \returns 0 on success, 1 when no operation is neccessary, -1 on failure */
+int gsm0808_assign_req(struct gsm_subscriber_connection *conn, int chan_mode, int full_rate)
+{
+ /* TODO: Add multirate configuration, make it work for more than audio. */
+
+ struct bsc_api *api;
+ api = conn->network->bsc_api;
+
+ if (!chan_compat_with_mode(conn->lchan, chan_mode, full_rate)) {
+ if (handle_new_assignment(conn, chan_mode, full_rate) != 0)
+ goto error;
+ } else {
+ /* Check if the channel is already in the requested mode, if
+ * yes, we skip unnecessary channel mode modify operations. */
+ if (conn->lchan->tch_mode == chan_mode)
+ return 1;
+
+ if (chan_mode == GSM48_CMODE_SPEECH_AMR)
+ handle_mr_config(conn, conn->lchan, full_rate);
+
+ LOGPLCHAN(conn->lchan, DMSC, LOGL_NOTICE,
+ "Sending ChanModify for speech: %s\n",
+ get_value_string(gsm48_chan_mode_names, chan_mode));
+ gsm48_lchan_modify(conn->lchan, chan_mode);
+ }
+
+ /* we expect the caller will manage T10 */
+ return 0;
+
+error:
+ api->assign_fail(conn, 0, NULL);
+ return -1;
+}
+
+int gsm0808_page(struct gsm_bts *bts, unsigned int page_group, unsigned int mi_len,
+ uint8_t *mi, int chan_type)
+{
+ return rsl_paging_cmd(bts, page_group, mi_len, mi, chan_type, false);
+}
+
+static void handle_ass_compl(struct gsm_subscriber_connection *conn,
+ struct msgb *msg)
+{
+ struct gsm48_hdr *gh = msgb_l3(msg);
+ struct bsc_api *api = conn->network->bsc_api;
+ enum gsm48_rr_cause cause;
+
+ /* Expecting gsm48_hdr + cause value */
+ if (msgb_l3len(msg) != sizeof(*gh) + 1) {
+ LOGPLCHAN(msg->lchan, DRR, LOGL_ERROR,
+ "RR Assignment Complete: length invalid: %u, expected %zu\n",
+ msgb_l3len(msg), sizeof(*gh) + 1);
+ return;
+ }
+
+ cause = gh->data[0];
+
+ LOGPLCHAN(msg->lchan, DRR, LOGL_DEBUG, "ASSIGNMENT COMPLETE cause = %s\n",
+ rr_cause_name(cause));
+
+ if (conn->ho) {
+ struct lchan_signal_data sig = {
+ .lchan = msg->lchan,
+ };
+ osmo_signal_dispatch(SS_LCHAN, S_LCHAN_ASSIGNMENT_COMPL, &sig);
+ /* FIXME: release old channel */
+
+ /* send pending messages, if any */
+ ho_dtap_cache_flush(conn, 1);
+
+ return;
+ }
+
+ if (conn->secondary_lchan != msg->lchan) {
+ LOGPLCHAN(msg->lchan, DRR, LOGL_ERROR,
+ "RR Assignment Complete does not match conn's secondary lchan.\n");
+ return;
+ }
+
+ /* swap channels */
+ osmo_timer_del(&conn->T10);
+
+ lchan_release(conn->lchan, 0, RSL_REL_LOCAL_END);
+ conn->lchan = conn->secondary_lchan;
+ conn->secondary_lchan = NULL;
+
+ /* send pending messages, if any */
+ ho_dtap_cache_flush(conn, 1);
+
+ if (is_ipaccess_bts(conn_get_bts(conn)) && conn->lchan->tch_mode != GSM48_CMODE_SIGN)
+ rsl_ipacc_crcx(conn->lchan);
+
+ api->assign_compl(conn, cause);
+}
+
+static void handle_ass_fail(struct gsm_subscriber_connection *conn,
+ struct msgb *msg)
+{
+ struct bsc_api *api = conn->network->bsc_api;
+ uint8_t *rr_failure;
+ struct gsm48_hdr *gh;
+
+ if (conn->ho) {
+ struct lchan_signal_data sig;
+ struct gsm48_hdr *gh = msgb_l3(msg);
+
+ LOGPLCHAN(msg->lchan, DRR, LOGL_DEBUG, "ASSIGNMENT FAILED cause = %s\n",
+ rr_cause_name(gh->data[0]));
+
+ sig.lchan = msg->lchan;
+ sig.mr = NULL;
+ osmo_signal_dispatch(SS_LCHAN, S_LCHAN_ASSIGNMENT_FAIL, &sig);
+ /* FIXME: release allocated new channel */
+
+ /* send pending messages, if any */
+ ho_dtap_cache_flush(conn, 1);
+
+ return;
+ }
+
+ if (conn->lchan != msg->lchan) {
+ LOGPLCHAN(msg->lchan, DMSC, LOGL_ERROR,
+ "Assignment failure should occur on primary lchan.\n");
+ return;
+ }
+
+ /* stop the timer and release it */
+ osmo_timer_del(&conn->T10);
+ if (conn->secondary_lchan) {
+ lchan_release(conn->secondary_lchan, 0, RSL_REL_LOCAL_END);
+ conn->secondary_lchan = NULL;
+ }
+
+ /* send pending messages, if any */
+ ho_dtap_cache_flush(conn, 1);
+
+ gh = msgb_l3(msg);
+ if (msgb_l3len(msg) - sizeof(*gh) != 1) {
+ LOGPLCHAN(conn->lchan, DMSC, LOGL_ERROR, "assignment failure unhandled: %zu\n",
+ msgb_l3len(msg) - sizeof(*gh));
+ rr_failure = NULL;
+ } else {
+ rr_failure = &gh->data[0];
+ }
+
+ api->assign_fail(conn,
+ GSM0808_CAUSE_RADIO_INTERFACE_MESSAGE_FAILURE,
+ rr_failure);
+}
+
+static void handle_classmark_chg(struct gsm_subscriber_connection *conn,
+ struct msgb *msg)
+{
+ struct bsc_api *api = msg->lchan->ts->trx->bts->network->bsc_api;
+ struct gsm48_hdr *gh = msgb_l3(msg);
+ unsigned int payload_len = msgb_l3len(msg) - sizeof(*gh);
+ uint8_t cm2_len, cm3_len = 0;
+ uint8_t *cm2, *cm3 = NULL;
+
+ LOGPLCHAN(msg->lchan, DRR, LOGL_DEBUG, "CLASSMARK CHANGE ");
+
+ /* classmark 2 */
+ cm2_len = gh->data[0];
+ cm2 = &gh->data[1];
+ DEBUGPC(DRR, "CM2(len=%u) ", cm2_len);
+
+ if (payload_len > cm2_len + 1) {
+ /* we must have a classmark3 */
+ if (gh->data[cm2_len+1] != 0x20) {
+ DEBUGPC(DRR, "ERR CM3 TAG\n");
+ return;
+ }
+ if (cm2_len > 3) {
+ DEBUGPC(DRR, "CM2 too long!\n");
+ return;
+ }
+
+ cm3_len = gh->data[cm2_len+2];
+ cm3 = &gh->data[cm2_len+3];
+ if (cm3_len > 14) {
+ DEBUGPC(DRR, "CM3 len %u too long!\n", cm3_len);
+ return;
+ }
+ DEBUGPC(DRR, "CM3(len=%u)\n", cm3_len);
+ }
+ api->classmark_chg(conn, cm2, cm2_len, cm3, cm3_len);
+}
+
+/* Chapter 9.1.16 Handover complete */
+static void handle_rr_ho_compl(struct msgb *msg)
+{
+ struct lchan_signal_data sig;
+ struct gsm48_hdr *gh = msgb_l3(msg);
+
+ LOGPLCHAN(msg->lchan, DRR, LOGL_DEBUG,
+ "HANDOVER COMPLETE cause = %s\n", rr_cause_name(gh->data[0]));
+
+ sig.lchan = msg->lchan;
+ sig.mr = NULL;
+ osmo_signal_dispatch(SS_LCHAN, S_LCHAN_HANDOVER_COMPL, &sig);
+ /* FIXME: release old channel */
+
+ /* send pending messages, if any */
+ ho_dtap_cache_flush(msg->lchan->conn, 1);
+}
+
+/* Chapter 9.1.17 Handover Failure */
+static void handle_rr_ho_fail(struct msgb *msg)
+{
+ struct lchan_signal_data sig;
+ struct gsm48_hdr *gh = msgb_l3(msg);
+
+ /* Log on both RR and HO categories: it is an RR message, but is still quite important when
+ * filtering on HO. */
+ LOGPLCHAN(msg->lchan, DRR, LOGL_DEBUG,
+ "HANDOVER FAILED cause = %s\n", rr_cause_name(gh->data[0]));
+ LOGPLCHAN(msg->lchan, DHO, LOGL_DEBUG,
+ "HANDOVER FAILED cause = %s\n", rr_cause_name(gh->data[0]));
+
+ sig.lchan = msg->lchan;
+ sig.mr = NULL;
+ osmo_signal_dispatch(SS_LCHAN, S_LCHAN_HANDOVER_FAIL, &sig);
+ /* FIXME: release allocated new channel */
+
+ /* send pending messages, if any */
+ ho_dtap_cache_flush(msg->lchan->conn, 1);
+}
+
+
+static void dispatch_dtap(struct gsm_subscriber_connection *conn,
+ uint8_t link_id, struct msgb *msg)
+{
+ struct bsc_api *api = msg->lchan->ts->trx->bts->network->bsc_api;
+ struct gsm48_hdr *gh;
+ uint8_t pdisc;
+ uint8_t msg_type;
+ int rc;
+
+ if (msgb_l3len(msg) < sizeof(*gh)) {
+ LOGP(DMSC, LOGL_ERROR, "(%s) Message too short for a GSM48 header.\n",
+ bsc_subscr_name(conn->bsub));
+ return;
+ }
+
+ gh = msgb_l3(msg);
+ pdisc = gsm48_hdr_pdisc(gh);
+ msg_type = gsm48_hdr_msg_type(gh);
+
+ /* the idea is to handle all RR messages here, and only hand
+ * MM/CC/SMS-CP/LCS up to the MSC. Some messages like PAGING
+ * RESPONSE or CM SERVICE REQUEST will not be covered here, as
+ * they are only possible in the first L3 message of each L2
+ * channel, i.e. 'conn' will not exist and gsm0408_rcvmsg()
+ * will call api->compl_l3() for it */
+ switch (pdisc) {
+ case GSM48_PDISC_RR:
+ switch (msg_type) {
+ case GSM48_MT_RR_GPRS_SUSP_REQ:
+ LOGPLCHAN(msg->lchan, DRR, LOGL_DEBUG,
+ "%s\n", gsm48_rr_msg_name(GSM48_MT_RR_GPRS_SUSP_REQ));
+ break;
+ case GSM48_MT_RR_STATUS:
+ LOGPLCHAN(msg->lchan, DRR, LOGL_NOTICE,
+ "%s (cause: %s)\n", gsm48_rr_msg_name(GSM48_MT_RR_STATUS),
+ rr_cause_name(gh->data[0]));
+ break;
+ case GSM48_MT_RR_MEAS_REP:
+ /* This shouldn't actually end up here, as RSL treats
+ * L3 Info of 08.58 MEASUREMENT REPORT different by calling
+ * directly into gsm48_parse_meas_rep */
+ LOGPLCHAN(msg->lchan, DMEAS, LOGL_ERROR,
+ "DIRECT GSM48 MEASUREMENT REPORT ?!?\n");
+ gsm48_tx_rr_status(conn, GSM48_RR_CAUSE_MSG_TYPE_N_COMPAT);
+ break;
+ case GSM48_MT_RR_HANDO_COMPL:
+ handle_rr_ho_compl(msg);
+ break;
+ case GSM48_MT_RR_HANDO_FAIL:
+ handle_rr_ho_fail(msg);
+ break;
+ case GSM48_MT_RR_CIPH_M_COMPL:
+ if (api->cipher_mode_compl)
+ api->cipher_mode_compl(conn, msg,
+ conn->lchan->encr.alg_id);
+ break;
+ case GSM48_MT_RR_ASS_COMPL:
+ handle_ass_compl(conn, msg);
+ break;
+ case GSM48_MT_RR_ASS_FAIL:
+ handle_ass_fail(conn, msg);
+ break;
+ case GSM48_MT_RR_CHAN_MODE_MODIF_ACK:
+ osmo_timer_del(&conn->T10);
+ rc = gsm48_rx_rr_modif_ack(msg);
+ if (rc < 0) {
+ api->assign_fail(conn,
+ GSM0808_CAUSE_NO_RADIO_RESOURCE_AVAILABLE,
+ NULL);
+ } else if (rc >= 0) {
+ api->assign_compl(conn, 0);
+ }
+ break;
+ case GSM48_MT_RR_CLSM_CHG:
+ handle_classmark_chg(conn, msg);
+ break;
+ case GSM48_MT_RR_APP_INFO:
+ /* Passing RR APP INFO to MSC, not quite
+ * according to spec */
+ if (api->dtap)
+ api->dtap(conn, link_id, msg);
+ break;
+ default:
+ /* Drop unknown RR message */
+ LOGPLCHAN(msg->lchan, DRR, LOGL_NOTICE,
+ "Dropping %s 04.08 RR message\n", gsm48_rr_msg_name(msg_type));
+ gsm48_tx_rr_status(conn, GSM48_RR_CAUSE_MSG_TYPE_N);
+ break;
+ }
+ break;
+ default:
+ if (api->dtap)
+ api->dtap(conn, link_id, msg);
+ break;
+ }
+}
+
+/*! \brief RSL has received a DATA INDICATION with L3 from MS */
+int gsm0408_rcvmsg(struct msgb *msg, uint8_t link_id)
+{
+ int rc;
+ struct bsc_api *api = msg->lchan->ts->trx->bts->network->bsc_api;
+ struct gsm_lchan *lchan;
+
+ lchan = msg->lchan;
+ if (lchan->state != LCHAN_S_ACTIVE) {
+ LOGPLCHAN(msg->lchan, DRSL, LOGL_INFO, "Got data in non active state, discarding.\n");
+ return -1;
+ }
+
+
+ if (lchan->conn) {
+ /* if we already have a connection, forward via DTAP to
+ * MSC */
+ dispatch_dtap(lchan->conn, link_id, msg);
+ } else {
+ /* allocate a new connection */
+ rc = BSC_API_CONN_POL_REJECT;
+ lchan->conn = bsc_subscr_con_allocate(msg->lchan->ts->trx->bts->network);
+ if (!lchan->conn) {
+ lchan_release(lchan, 1, RSL_REL_NORMAL);
+ return -1;
+ }
+ lchan->conn->lchan = lchan;
+
+ /* fwd via bsc_api to send COMPLETE L3 INFO to MSC */
+ rc = api->compl_l3(lchan->conn, msg, 0);
+
+ if (rc != BSC_API_CONN_POL_ACCEPT) {
+ //osmo_fsm_inst_dispatch(lchan->conn->fi, FIXME, NULL);
+ }
+ }
+
+ return 0;
+}
+
+/*! \brief We received a GSM 08.08 CIPHER MODE from the MSC */
+int gsm0808_cipher_mode(struct gsm_subscriber_connection *conn, int cipher,
+ const uint8_t *key, int len, int include_imeisv)
+{
+ if (cipher > 0 && key == NULL) {
+ LOGP(DRSL, LOGL_ERROR, "%s: Need to have an encryption key.\n",
+ bsc_subscr_name(conn->bsub));
+ return -1;
+ }
+
+ if (len > MAX_A5_KEY_LEN) {
+ LOGP(DRSL, LOGL_ERROR, "%s: The key is too long: %d\n",
+ bsc_subscr_name(conn->bsub), len);
+ return -1;
+ }
+
+ LOGP(DRSL, LOGL_DEBUG, "(subscr %s) Cipher Mode: cipher=%d key=%s include_imeisv=%d\n",
+ bsc_subscr_name(conn->bsub), cipher, osmo_hexdump_nospc(key, len), include_imeisv);
+
+ conn->lchan->encr.alg_id = RSL_ENC_ALG_A5(cipher);
+ if (key) {
+ conn->lchan->encr.key_len = len;
+ memcpy(conn->lchan->encr.key, key, len);
+ }
+
+ return gsm48_send_rr_ciph_mode(conn->lchan, include_imeisv);
+}
+
+/*
+ * Release all occupied RF Channels but stay around for more.
+ */
+int gsm0808_clear(struct gsm_subscriber_connection *conn)
+{
+ if (conn->ho)
+ bsc_clear_handover(conn, 1);
+
+ if (conn->secondary_lchan)
+ lchan_release(conn->secondary_lchan, 0, RSL_REL_LOCAL_END);
+
+ if (conn->lchan)
+ lchan_release(conn->lchan, 1, RSL_REL_NORMAL);
+
+ conn->lchan = NULL;
+ conn->secondary_lchan = NULL;
+
+ osmo_timer_del(&conn->T10);
+
+ return 0;
+}
+
+static void send_sapi_reject(struct gsm_subscriber_connection *conn, int link_id)
+{
+ struct bsc_api *api;
+
+ if (!conn)
+ return;
+
+ api = conn->network->bsc_api;
+ if (!api || !api->sapi_n_reject)
+ return;
+
+ api->sapi_n_reject(conn, link_id);
+}
+
+static void rll_ind_cb(struct gsm_lchan *lchan, uint8_t link_id, void *_data, enum bsc_rllr_ind rllr_ind)
+{
+ struct msgb *msg = _data;
+
+ /*
+ * There seems to be a small window that the RLL timer can
+ * fire after a lchan_release call and before the S_CHALLOC_FREED
+ * is called. Check if a conn is set before proceeding.
+ */
+ if (!lchan->conn)
+ return;
+
+ switch (rllr_ind) {
+ case BSC_RLLR_IND_EST_CONF:
+ rsl_data_request(msg, OBSC_LINKID_CB(msg));
+ break;
+ case BSC_RLLR_IND_REL_IND:
+ case BSC_RLLR_IND_ERR_IND:
+ case BSC_RLLR_IND_TIMEOUT:
+ send_sapi_reject(lchan->conn, OBSC_LINKID_CB(msg));
+ msgb_free(msg);
+ break;
+ }
+}
+
+static int bsc_handle_lchan_signal(unsigned int subsys, unsigned int signal,
+ void *handler_data, void *signal_data)
+{
+ struct bsc_api *bsc;
+ struct gsm_lchan *lchan;
+ struct lchan_signal_data *lchan_data;
+
+ if (subsys != SS_LCHAN)
+ return 0;
+
+
+ lchan_data = signal_data;
+ if (!lchan_data->lchan || !lchan_data->lchan->conn)
+ return 0;
+
+ lchan = lchan_data->lchan;
+ bsc = lchan->ts->trx->bts->network->bsc_api;
+ if (!bsc)
+ return 0;
+
+ switch (signal) {
+ case S_LCHAN_UNEXPECTED_RELEASE:
+ handle_release(lchan->conn, bsc, lchan);
+ break;
+ case S_LCHAN_ACTIVATE_ACK:
+ handle_chan_ack(lchan->conn, bsc, lchan);
+ break;
+ case S_LCHAN_ACTIVATE_NACK:
+ handle_chan_nack(lchan->conn, bsc, lchan);
+ break;
+ }
+
+ return 0;
+}
+
+static void handle_release(struct gsm_subscriber_connection *conn,
+ struct bsc_api *bsc, struct gsm_lchan *lchan)
+{
+ if (conn->secondary_lchan == lchan) {
+ osmo_timer_del(&conn->T10);
+ conn->secondary_lchan = NULL;
+
+ bsc->assign_fail(conn,
+ GSM0808_CAUSE_RADIO_INTERFACE_FAILURE,
+ NULL);
+ }
+
+ /* clear the connection now */
+ if (bsc->clear_request)
+ bsc->clear_request(conn, 0);
+
+ /* now give up all channels */
+ if (conn->lchan == lchan)
+ conn->lchan = NULL;
+ if (conn->ho && conn->ho->new_lchan == lchan)
+ bsc_clear_handover(conn, 0);
+ lchan->conn = NULL;
+}
+
+static void handle_chan_ack(struct gsm_subscriber_connection *conn,
+ struct bsc_api *api, struct gsm_lchan *lchan)
+{
+ if (conn->secondary_lchan != lchan)
+ return;
+
+ LOGPLCHAN(lchan, DMSC, LOGL_NOTICE, "Sending RR Assignment\n");
+ gsm48_send_rr_ass_cmd(conn->lchan, lchan, lchan->ms_power);
+}
+
+static void handle_chan_nack(struct gsm_subscriber_connection *conn,
+ struct bsc_api *api, struct gsm_lchan *lchan)
+{
+ if (conn->secondary_lchan != lchan)
+ return;
+
+ LOGPLCHAN(lchan, DMSC, LOGL_ERROR, "Channel activation failed. Waiting for timeout now\n");
+ conn->secondary_lchan->conn = NULL;
+ conn->secondary_lchan = NULL;
+}
+
+static __attribute__((constructor)) void on_dso_load_bsc(void)
+{
+ osmo_signal_register_handler(SS_LCHAN, bsc_handle_lchan_signal, NULL);
+}