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Diffstat (limited to 'src/libbsc/bsc_api.c')
| -rw-r--r-- | src/libbsc/bsc_api.c | 894 |
1 files changed, 894 insertions, 0 deletions
diff --git a/src/libbsc/bsc_api.c b/src/libbsc/bsc_api.c new file mode 100644 index 000000000..7613cac90 --- /dev/null +++ b/src/libbsc/bsc_api.c @@ -0,0 +1,894 @@ +/* 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 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 <openbsc/bsc_api.h> +#include <openbsc/bsc_rll.h> +#include <openbsc/gsm_data.h> +#include <openbsc/gsm_subscriber.h> +#include <openbsc/signal.h> +#include <openbsc/abis_rsl.h> +#include <openbsc/chan_alloc.h> +#include <openbsc/handover.h> +#include <openbsc/debug.h> +#include <openbsc/gsm_04_08.h> +#include <openbsc/trau_mux.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 + + +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); + +/* GSM 08.08 3.2.2.33 */ +static uint8_t lchan_to_chosen_channel(struct gsm_lchan *lchan) +{ + uint8_t channel_mode = 0, channel = 0; + + switch (lchan->tch_mode) { + case GSM48_CMODE_SPEECH_V1: + case GSM48_CMODE_SPEECH_EFR: + case GSM48_CMODE_SPEECH_AMR: + channel_mode = 0x9; + break; + case GSM48_CMODE_SIGN: + channel_mode = 0x8; + break; + case GSM48_CMODE_DATA_14k5: + channel_mode = 0xe; + break; + case GSM48_CMODE_DATA_12k0: + channel_mode = 0xb; + break; + case GSM48_CMODE_DATA_6k0: + channel_mode = 0xc; + break; + case GSM48_CMODE_DATA_3k6: + channel_mode = 0xd; + break; + } + + switch (lchan->type) { + case GSM_LCHAN_NONE: + channel = 0x0; + break; + case GSM_LCHAN_SDCCH: + channel = 0x1; + break; + case GSM_LCHAN_TCH_F: + channel = 0x8; + break; + case GSM_LCHAN_TCH_H: + channel = 0x9; + break; + case GSM_LCHAN_UNKNOWN: + default: + LOGP(DMSC, LOGL_ERROR, "Unknown lchan type: %p\n", lchan); + break; + } + + return channel_mode << 4 | channel; +} + +static uint8_t chan_mode_to_speech(struct gsm_lchan *lchan) +{ + int mode = 0; + + switch (lchan->tch_mode) { + case GSM48_CMODE_SPEECH_V1: + mode = 1; + break; + case GSM48_CMODE_SPEECH_EFR: + mode = 0x11; + break; + case GSM48_CMODE_SPEECH_AMR: + mode = 0x21; + break; + case GSM48_CMODE_SIGN: + case GSM48_CMODE_DATA_14k5: + case GSM48_CMODE_DATA_12k0: + case GSM48_CMODE_DATA_6k0: + case GSM48_CMODE_DATA_3k6: + default: + LOGP(DMSC, LOGL_ERROR, "Using non speech mode: %d\n", mode); + return 0; + break; + } + + /* assume to always do AMR HR on any TCH type */ + if (lchan->type == GSM_LCHAN_TCH_H || + lchan->tch_mode == GSM48_CMODE_SPEECH_AMR) + mode |= 0x4; + + return mode; +} + +static void assignment_t10_timeout(void *_conn) +{ + struct bsc_api *api; + struct gsm_subscriber_connection *conn = + (struct gsm_subscriber_connection *) _conn; + + LOGP(DMSC, LOGL_ERROR, "Assignment T10 timeout on %p\n", conn); + + /* + * normal release on the secondary channel but only if the + * secondary_channel has not been released by the handle_chan_nack. + */ + if (conn->secondary_lchan) + lchan_release(conn->secondary_lchan, 0, RSL_REL_LOCAL_END); + conn->secondary_lchan = NULL; + + /* inform them about the failure */ + api = conn->network->bsc_api; + api->assign_fail(conn, GSM0808_CAUSE_NO_RADIO_RESOURCE_AVAILABLE, NULL); +} + +/*! \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; + int chan_type; + + chan_type = full_rate ? GSM_LCHAN_TCH_F : GSM_LCHAN_TCH_H; + + new_lchan = lchan_alloc(conn->bts, chan_type, 0); + + if (!new_lchan) { + LOGP(DMSC, LOGL_NOTICE, "No free channel.\n"); + 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 = 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) { + LOGP(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; + + rsl_lchan_set_state(new_lchan, LCHAN_S_ACT_REQ); + return 0; +} + +struct gsm_subscriber_connection *bsc_subscr_con_allocate(struct gsm_lchan *lchan) +{ + struct gsm_subscriber_connection *conn; + struct gsm_network *net = lchan->ts->trx->bts->network; + + conn = talloc_zero(net, struct gsm_subscriber_connection); + if (!conn) + return NULL; + + conn->network = net; + conn->lchan = lchan; + conn->bts = lchan->ts->trx->bts; + conn->via_ran = RAN_GERAN_A; + lchan->conn = conn; + llist_add_tail(&conn->entry, &net->subscr_conns); + return conn; +} + +void bsc_subscr_con_free(struct gsm_subscriber_connection *conn) +{ + if (!conn) + return; + + + if (conn->subscr) { + subscr_put(conn->subscr); + conn->subscr = NULL; + } + + + if (conn->ho_lchan) { + LOGP(DNM, LOGL_ERROR, "The ho_lchan should have been cleared.\n"); + conn->ho_lchan->conn = NULL; + } + + if (conn->lchan) { + LOGP(DNM, LOGL_ERROR, "The lchan should have been cleared.\n"); + conn->lchan->conn = NULL; + } + + if (conn->secondary_lchan) { + LOGP(DNM, LOGL_ERROR, "The secondary_lchan should have been cleared.\n"); + conn->secondary_lchan->conn = NULL; + } + + llist_del(&conn->entry); + talloc_free(conn); +} + +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, + "Called submit dtap without an lchan.\n"); + msgb_free(msg); + return -1; + } + + 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: + /* signalling is always possible */ + return 1; + 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 1; + case GSM_LCHAN_TCH_H: + if (full_rate) + return 0; + else + return 1; + break; + default: + return 0; + } + break; + case GSM48_CMODE_DATA_12k0: + case GSM48_CMODE_DATA_14k5: + case GSM48_CMODE_SPEECH_EFR: + /* these services all explicitly require a TCH/F */ + if (lchan->type == GSM_LCHAN_TCH_F) + return 1; + else + return 0; + break; + } + + 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. It is assumed that + * this is for audio handling only. In case the current channel does not allow + * the selected mode a new one will be allocated. + * + * TODO: Add multirate configuration, make it work for more than audio. + */ +int gsm0808_assign_req(struct gsm_subscriber_connection *conn, int chan_mode, int full_rate) +{ + 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 { + if (chan_mode == GSM48_CMODE_SPEECH_AMR) + handle_mr_config(conn, conn->lchan, full_rate); + + LOGP(DMSC, LOGL_NOTICE, + "Sending %s ChanModify for speech: %s on channel %s\n", + gsm_lchan_name(conn->lchan), + get_value_string(gsm48_chan_mode_names, chan_mode), + get_value_string(gsm_chan_t_names, conn->lchan->type)); + gsm48_lchan_modify(conn->lchan, chan_mode); + } + + /* we will now start the timer to complete the assignment */ + osmo_timer_setup(&conn->T10, assignment_t10_timeout, conn); + osmo_timer_schedule(&conn->T10, GSM0808_T10_VALUE); + 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; + struct bsc_api *api = conn->network->bsc_api; + + if (conn->secondary_lchan != msg->lchan) { + LOGP(DMSC, LOGL_ERROR, "Assignment Compl should occur on second lchan.\n"); + return; + } + + gh = msgb_l3(msg); + if (msgb_l3len(msg) - sizeof(*gh) != 1) { + LOGP(DMSC, LOGL_ERROR, "Assignment Compl invalid: %zu\n", + msgb_l3len(msg) - sizeof(*gh)); + return; + } + + /* switch TRAU muxer for E1 based BTS from one channel to another */ + if (is_e1_bts(conn->bts)) + switch_trau_mux(conn->lchan, conn->secondary_lchan); + + /* 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; + + if (is_ipaccess_bts(conn->bts) && conn->lchan->tch_mode != GSM48_CMODE_SIGN) + rsl_ipacc_crcx(conn->lchan); + + api->assign_compl(conn, gh->data[0], + lchan_to_chosen_channel(conn->lchan), + conn->lchan->encr.alg_id, + chan_mode_to_speech(conn->lchan)); +} + +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->lchan != msg->lchan) { + LOGP(DMSC, LOGL_ERROR, "Assignment failure should occur on primary lchan.\n"); + return; + } + + /* stop the timer and release it */ + osmo_timer_del(&conn->T10); + lchan_release(conn->secondary_lchan, 0, RSL_REL_LOCAL_END); + conn->secondary_lchan = NULL; + + gh = msgb_l3(msg); + if (msgb_l3len(msg) - sizeof(*gh) != 1) { + LOGP(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; + + DEBUGP(DRR, "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); + + DEBUGP(DRR, "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 */ +} + +/* 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); + + DEBUGP(DRR, "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 */ +} + + +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, "Message too short for a GSM48 header.\n"); + 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: + DEBUGP(DRR, "%s\n", + gsm48_rr_msg_name(GSM48_MT_RR_GPRS_SUSP_REQ)); + break; + case GSM48_MT_RR_STATUS: + LOGP(DRR, LOGL_NOTICE, "%s (cause: %s)\n", + gsm48_rr_msg_name(GSM48_MT_RR_GPRS_SUSP_REQ), + 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 */ + LOGP(DMEAS, LOGL_ERROR, "DIRECT GSM48 MEASUREMENT REPORT ?!? "); + 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, + lchan_to_chosen_channel(conn->lchan), + conn->lchan->encr.alg_id, + chan_mode_to_speech(conn->lchan)); + } + 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: + /* Normally, a MSC should never receive RR + * messages, but we'd rather forward what we + * don't know than drop it... */ + LOGP(DRR, LOGL_NOTICE, + "BSC: Passing %s 04.08 RR message to MSC\n", + gsm48_rr_msg_name(msg_type)); + if (api->dtap) + api->dtap(conn, link_id, msg); + } + 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) { + LOGP(DRSL, LOGL_INFO, "Got data in non active state(%s), " + "discarding.\n", gsm_lchans_name(lchan->state)); + 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); + if (!lchan->conn) { + lchan_release(lchan, 1, RSL_REL_NORMAL); + return -1; + } + + /* 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) { + lchan->conn->lchan = NULL; + bsc_subscr_con_free(lchan->conn); + lchan_release(lchan, 1, RSL_REL_NORMAL); + } + } + + 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, "Need to have an encrytpion key.\n"); + return -1; + } + + if (len > MAX_A5_KEY_LEN) { + LOGP(DRSL, LOGL_ERROR, "The key is too long: %d\n", len); + return -1; + } + + 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_lchan) + 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; + conn->ho_lchan = NULL; + conn->bts = 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) +{ + int destruct = 1; + + 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) + destruct = bsc->clear_request(conn, 0); + + /* now give up all channels */ + if (conn->lchan == lchan) + conn->lchan = NULL; + if (conn->ho_lchan == lchan) { + bsc_clear_handover(conn, 0); + conn->ho_lchan = NULL; + } + lchan->conn = NULL; + + gsm0808_clear(conn); + + if (destruct) + bsc_subscr_con_free(conn); +} + +static void handle_chan_ack(struct gsm_subscriber_connection *conn, + struct bsc_api *api, struct gsm_lchan *lchan) +{ + if (conn->secondary_lchan != lchan) + return; + + LOGP(DMSC, LOGL_NOTICE, "Sending assignment on chan: %p\n", lchan); + 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; + + LOGP(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); +} + |