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