diff options
Diffstat (limited to 'src/host/layer23/src/mobile/gsm414.c')
| -rw-r--r-- | src/host/layer23/src/mobile/gsm414.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/src/host/layer23/src/mobile/gsm414.c b/src/host/layer23/src/mobile/gsm414.c new file mode 100644 index 00000000..90fc2dfd --- /dev/null +++ b/src/host/layer23/src/mobile/gsm414.c @@ -0,0 +1,218 @@ +/* + * (C) 2020 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de> + * Author: Vadim Yanitskiy <vyanitskiy@sysmocom.de> + * + * All Rights Reserved + * + * SPDX-License-Identifier: GPL-2.0+ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 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 General Public License for more details. + * + */ + +#include <stdint.h> +#include <errno.h> + +#include <osmocom/core/logging.h> +#include <osmocom/core/utils.h> +#include <osmocom/core/msgb.h> + +#include <osmocom/gsm/gsm48.h> +#include <osmocom/gsm/rsl.h> + +#include <osmocom/gsm/protocol/gsm_04_08.h> +#include <osmocom/gsm/protocol/gsm_04_14.h> +#include <osmocom/gsm/protocol/gsm_08_58.h> + +#include <osmocom/bb/common/osmocom_data.h> +#include <osmocom/bb/common/ms.h> +#include <osmocom/bb/common/logging.h> +#include <osmocom/bb/mobile/gsm48_rr.h> + +#include <l1ctl_proto.h> + +int gsm48_rr_tx_rr_status(struct osmocom_ms *ms, uint8_t cause); +int gsm48_send_rsl(struct osmocom_ms *ms, uint8_t msg_type, + struct msgb *msg, uint8_t link_id); +struct msgb *gsm48_l3_msgb_alloc(void); + +#define loop_mode_name(mode) \ + get_value_string(loop_mode_names, mode) + +static const struct value_string loop_mode_names[] = { + { L1CTL_TCH_LOOP_OPEN, "(OPEN)" }, + { L1CTL_TCH_LOOP_A, "A" }, + { L1CTL_TCH_LOOP_B, "B" }, + { L1CTL_TCH_LOOP_C, "C" }, + { L1CTL_TCH_LOOP_D, "D" }, + { L1CTL_TCH_LOOP_E, "E" }, + { L1CTL_TCH_LOOP_F, "F" }, + { L1CTL_TCH_LOOP_I, "I" }, + { 0, NULL } +}; + +static struct msgb *alloc_gsm414_msg(uint8_t msg_type) +{ + struct gsm48_hdr *ngh; + struct msgb *nmsg; + + nmsg = gsm48_l3_msgb_alloc(); + if (nmsg == NULL) + return NULL; + + ngh = (struct gsm48_hdr *) msgb_put(nmsg, sizeof(*ngh)); + ngh->proto_discr = GSM48_PDISC_TEST; + ngh->msg_type = msg_type; + + return nmsg; +} + +static int handle_close_tch_loop(struct osmocom_ms *ms, const struct msgb *msg) +{ + struct gsm48_rrlayer *rr = &ms->rrlayer; + const struct gsm48_hdr *gh = msgb_l3(msg); + unsigned int msg_len = msgb_l3len(msg); + struct msgb *nmsg; + + /* Make sure that we have an active connection */ + if (rr->state != GSM48_RR_ST_DEDICATED) { + LOGP(DMM, LOGL_NOTICE, "TCH loop requires an active connection\n"); + gsm48_rr_tx_rr_status(ms, GSM48_RR_CAUSE_MSG_TYPE_N_COMPAT); + return -EINVAL; + } + + /* Make sure that the established channel is either TCH/F or TCH/H */ + if ((rr->cd_now.chan_nr & 0xf8) != RSL_CHAN_Bm_ACCHs + && (rr->cd_now.chan_nr & 0xf0) != RSL_CHAN_Lm_ACCHs) { + LOGP(DMM, LOGL_NOTICE, "TCH loop requires a TCH/F or TCH/H connection\n"); + gsm48_rr_tx_rr_status(ms, GSM48_RR_CAUSE_MSG_TYPE_N_COMPAT); + return -EINVAL; + } + + /* Check if a loop is already closed */ + if (rr->tch_loop_mode != L1CTL_TCH_LOOP_OPEN) { + LOGP(DMM, LOGL_NOTICE, "TCH loop has already been closed\n"); + gsm48_rr_tx_rr_status(ms, GSM48_RR_CAUSE_MSG_TYPE_N_COMPAT); + return -EINVAL; + } + + if ((msg_len - sizeof(*gh)) < 1) + return -EINVAL; + + /* Parse type of the TCH test loop, convert to L1CTL format */ + uint8_t gsm414_loop_mode = (gh->data[0] >> 1) & 0x1f; + + /* NOTE: some bits are not specified, so they can be 0 or 1 */ + if (gsm414_loop_mode == GSM414_LOOP_A) + rr->tch_loop_mode = L1CTL_TCH_LOOP_A; + else if (gsm414_loop_mode == GSM414_LOOP_B) + rr->tch_loop_mode = L1CTL_TCH_LOOP_B; + else if ((gsm414_loop_mode & 0x1e) == GSM414_LOOP_C) + rr->tch_loop_mode = L1CTL_TCH_LOOP_C; + else if ((gsm414_loop_mode & 0x1c) == GSM414_LOOP_D) + rr->tch_loop_mode = L1CTL_TCH_LOOP_D; + else if ((gsm414_loop_mode & 0x1c) == GSM414_LOOP_E) + rr->tch_loop_mode = L1CTL_TCH_LOOP_E; + else if ((gsm414_loop_mode & 0x1c) == GSM414_LOOP_F) + rr->tch_loop_mode = L1CTL_TCH_LOOP_F; + else if ((gsm414_loop_mode & 0x1c) == GSM414_LOOP_I) + rr->tch_loop_mode = L1CTL_TCH_LOOP_I; + else { + LOGP(DMM, LOGL_NOTICE, "Unhandled 3GPP TS 44.014 TCH loop " + "mode=0x%02x => rejecting\n", gsm414_loop_mode); + gsm48_rr_tx_rr_status(ms, GSM48_RR_CAUSE_MSG_TYPE_N); + return -ENOTSUP; + } + + LOGP(DMM, LOGL_NOTICE, "(%s) Closing 3GPP TS 44.014 TCH loop mode '%s'\n", + rsl_chan_nr_str(rr->cd_now.chan_nr), loop_mode_name(rr->tch_loop_mode)); + + /* Instruct the L1 to enable received TCH loopback mode + * FIXME: delay applying this mode, so we can send the ACK first */ + l1ctl_tx_tch_mode_req(ms, rr->cd_now.mode, rr->audio_mode, rr->cd_now.tch_flags, rr->tch_loop_mode); + + /* Craft and send the ACKnowledgement */ + nmsg = alloc_gsm414_msg(GSM414_MT_CLOSE_TCH_LOOP_ACK); + if (nmsg == NULL) + return -ENOMEM; + + return gsm48_send_rsl(ms, RSL_MT_DATA_REQ, nmsg, 0); +} + +static int handle_open_tch_loop(struct osmocom_ms *ms, const struct msgb *msg) +{ + struct gsm48_rrlayer *rr = &ms->rrlayer; + struct msgb *nmsg; + + /* Make sure that we have an active connection */ + if (rr->state != GSM48_RR_ST_DEDICATED) { + LOGP(DMM, LOGL_NOTICE, "TCH loop requires an active connection\n"); + gsm48_rr_tx_rr_status(ms, GSM48_RR_CAUSE_MSG_TYPE_N_COMPAT); + return -EINVAL; + } + + /* Make sure that the established channel is either TCH/F or TCH/H */ + if ((rr->cd_now.chan_nr & 0xf8) != RSL_CHAN_Bm_ACCHs + && (rr->cd_now.chan_nr & 0xf0) != RSL_CHAN_Lm_ACCHs) { + LOGP(DMM, LOGL_NOTICE, "TCH loop requires a TCH/F or TCH/H connection\n"); + gsm48_rr_tx_rr_status(ms, GSM48_RR_CAUSE_MSG_TYPE_N_COMPAT); + return -EINVAL; + } + + /* Check if a loop actually needs to be closed */ + if (rr->tch_loop_mode == L1CTL_TCH_LOOP_OPEN) { + LOGP(DMM, LOGL_NOTICE, "TCH loop has not been closed (already open)\n"); + gsm48_rr_tx_rr_status(ms, GSM48_RR_CAUSE_MSG_TYPE_N_COMPAT); + return -EINVAL; + } + + LOGP(DMM, LOGL_NOTICE, "(%s) Opening 3GPP TS 44.014 TCH loop mode '%s'\n", + rsl_chan_nr_str(rr->cd_now.chan_nr), loop_mode_name(rr->tch_loop_mode)); + + /* Instruct the L1 to disable the TCH loopback mode */ + l1ctl_tx_tch_mode_req(ms, rr->cd_now.mode, rr->audio_mode, rr->cd_now.tch_flags, L1CTL_TCH_LOOP_OPEN); + + /* Only the loop mode C needs to be ACKnowledged */ + bool needs_ack = rr->tch_loop_mode == L1CTL_TCH_LOOP_C; + rr->tch_loop_mode = L1CTL_TCH_LOOP_OPEN; + if (!needs_ack) + return 0; + + /* Craft and send the ACKnowledgement */ + nmsg = alloc_gsm414_msg(GSM414_MT_OPEN_LOOP_CMD); + if (nmsg == NULL) + return -ENOMEM; + + msgb_put_u8(nmsg, GSM414_OPEN_LOOP_ACK_IE); + + return gsm48_send_rsl(ms, RSL_MT_DATA_REQ, nmsg, 0); +} + +int gsm414_rcv_test(struct osmocom_ms *ms, const struct msgb *msg) +{ + const struct gsm48_hdr *gh = msgb_l3(msg); + + LOGP(DMM, LOGL_INFO, "Received 3GPP TS 44.014 message '%s' (0x%02x)\n", + get_value_string(gsm414_msgt_names, gh->msg_type), gh->msg_type); + + /* TODO: check if the test SIM (special EF.ADM) is inserted */ + switch (gh->msg_type) { + case GSM414_MT_CLOSE_TCH_LOOP_CMD: + return handle_close_tch_loop(ms, msg); + case GSM414_MT_OPEN_LOOP_CMD: + return handle_open_tch_loop(ms, msg); + default: + LOGP(DMM, LOGL_NOTICE, "Unhandled 3GPP TS 44.014 message '%s' (0x%02x)\n", + get_value_string(gsm414_msgt_names, gh->msg_type), gh->msg_type); + gsm48_rr_tx_rr_status(ms, GSM48_RR_CAUSE_MSG_TYPE_N); + return -ENOTSUP; + } +} |