290 lines
7.7 KiB
C
290 lines
7.7 KiB
C
/* Interaction with the SCCP subsystem */
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/*
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* (C) 2009-2010 by Holger Hans Peter Freyther <zecke@selfish.org>
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* (C) 2009-2010 by On-Waves
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* All Rights Reserved
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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 Affero General Public License as published by
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* the Free Software Foundation; either version 3 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 Affero General Public License for more details.
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*
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* You should have received a copy of the GNU Affero General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include <openbsc/gsm_data.h>
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#include <openbsc/osmo_bsc.h>
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#include <openbsc/osmo_bsc_grace.h>
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#include <openbsc/osmo_msc_data.h>
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#include <openbsc/debug.h>
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#include <openbsc/ipaccess.h>
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#include <openbsc/signal.h>
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#include <osmocom/core/talloc.h>
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#include <osmocom/gsm/gsm0808.h>
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#include <osmocom/gsm/protocol/gsm_08_08.h>
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#include <osmocom/sccp/sccp.h>
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/* SCCP helper */
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#define SCCP_IT_TIMER 60
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static LLIST_HEAD(active_connections);
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static void free_queued(struct osmo_bsc_sccp_con *conn)
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{
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struct msgb *msg;
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while (!llist_empty(&conn->sccp_queue)) {
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/* this is not allowed to fail */
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msg = msgb_dequeue(&conn->sccp_queue);
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msgb_free(msg);
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}
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conn->sccp_queue_size = 0;
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}
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static void send_queued(struct osmo_bsc_sccp_con *conn)
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{
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struct msgb *msg;
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while (!llist_empty(&conn->sccp_queue)) {
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/* this is not allowed to fail */
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msg = msgb_dequeue(&conn->sccp_queue);
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sccp_connection_write(conn->sccp, msg);
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msgb_free(msg);
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conn->sccp_queue_size -= 1;
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}
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}
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static void msc_outgoing_sccp_data(struct sccp_connection *conn,
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struct msgb *msg, unsigned int len)
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{
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struct osmo_bsc_sccp_con *bsc_con =
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(struct osmo_bsc_sccp_con *) conn->data_ctx;
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bsc_handle_dt1(bsc_con, msg, len);
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}
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static void msc_outgoing_sccp_state(struct sccp_connection *conn, int old_state)
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{
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struct osmo_bsc_sccp_con *con_data;
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if (conn->connection_state >= SCCP_CONNECTION_STATE_RELEASE_COMPLETE) {
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con_data = (struct osmo_bsc_sccp_con *) conn->data_ctx;
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if(con_data->conn) {
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LOGP(DMSC, LOGL_ERROR,
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"ERROR: The lchan is still associated.\n");
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gsm0808_clear(con_data->conn);
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subscr_con_free(con_data->conn);
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con_data->conn = NULL;
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}
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con_data->sccp = NULL;
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free_queued(con_data);
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sccp_connection_free(conn);
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bsc_delete_connection(con_data);
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} else if (conn->connection_state == SCCP_CONNECTION_STATE_ESTABLISHED) {
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LOGP(DMSC, LOGL_DEBUG, "Connection established: %p\n", conn);
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con_data = (struct osmo_bsc_sccp_con *) conn->data_ctx;
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osmo_timer_del(&con_data->sccp_cc_timeout);
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osmo_timer_schedule(&con_data->sccp_it_timeout, SCCP_IT_TIMER, 0);
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send_queued(con_data);
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}
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}
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static void bsc_sccp_force_free(struct osmo_bsc_sccp_con *data)
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{
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if (data->conn) {
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gsm0808_clear(data->conn);
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subscr_con_free(data->conn);
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data->conn = NULL;
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}
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free_queued(data);
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sccp_connection_force_free(data->sccp);
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data->sccp = NULL;
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bsc_delete_connection(data);
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}
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static void sccp_it_timeout(void *_data)
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{
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struct osmo_bsc_sccp_con *data =
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(struct osmo_bsc_sccp_con *) _data;
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sccp_connection_send_it(data->sccp);
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osmo_timer_schedule(&data->sccp_it_timeout, SCCP_IT_TIMER, 0);
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}
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static void sccp_cc_timeout(void *_data)
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{
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struct osmo_bsc_sccp_con *data =
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(struct osmo_bsc_sccp_con *) _data;
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if (data->sccp->connection_state >= SCCP_CONNECTION_STATE_ESTABLISHED)
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return;
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LOGP(DMSC, LOGL_ERROR, "The connection was never established.\n");
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bsc_sccp_force_free(data);
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}
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static void msc_sccp_write_ipa(struct sccp_connection *conn, struct msgb *msg,
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void *global_ctx, void *ctx)
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{
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struct gsm_network *net = (struct gsm_network *) global_ctx;
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msc_queue_write(net->msc_data->msc_con, msg, IPAC_PROTO_SCCP);
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}
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static int msc_sccp_accept(struct sccp_connection *connection, void *data)
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{
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LOGP(DMSC, LOGL_DEBUG, "Rejecting incoming SCCP connection.\n");
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return -1;
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}
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static int msc_sccp_read(struct msgb *msgb, unsigned int length, void *data)
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{
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struct gsm_network *net = (struct gsm_network *) data;
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return bsc_handle_udt(net, net->msc_data->msc_con, msgb, length);
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}
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int bsc_queue_for_msc(struct osmo_bsc_sccp_con *conn, struct msgb *msg)
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{
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struct sccp_connection *sccp = conn->sccp;
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if (sccp->connection_state > SCCP_CONNECTION_STATE_ESTABLISHED) {
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LOGP(DMSC, LOGL_ERROR, "Connection closing, dropping packet on: %p\n", sccp);
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msgb_free(msg);
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} else if (sccp->connection_state == SCCP_CONNECTION_STATE_ESTABLISHED
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&& conn->sccp_queue_size == 0) {
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sccp_connection_write(sccp, msg);
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msgb_free(msg);
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} else if (conn->sccp_queue_size > 10) {
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LOGP(DMSC, LOGL_ERROR, "Connection closing, dropping packet on: %p\n", sccp);
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msgb_free(msg);
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} else {
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LOGP(DMSC, LOGL_DEBUG, "Queueing packet on %p. Queue size: %d\n", sccp, conn->sccp_queue_size);
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conn->sccp_queue_size += 1;
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msgb_enqueue(&conn->sccp_queue, msg);
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}
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return 0;
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}
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int bsc_create_new_connection(struct gsm_subscriber_connection *conn)
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{
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struct gsm_network *net;
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struct osmo_bsc_sccp_con *bsc_con;
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struct sccp_connection *sccp;
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net = conn->bts->network;
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if (!net->msc_data->msc_con->is_authenticated) {
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LOGP(DMSC, LOGL_ERROR, "Not connected to a MSC. Not forwarding data.\n");
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return -1;
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}
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if (!bsc_grace_allow_new_connection(net)) {
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LOGP(DMSC, LOGL_NOTICE, "BSC in grace period. No new connections.\n");
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return -1;
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}
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sccp = sccp_connection_socket();
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if (!sccp) {
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LOGP(DMSC, LOGL_ERROR, "Failed to allocate memory.\n");
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return -ENOMEM;
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}
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bsc_con = talloc_zero(conn->bts, struct osmo_bsc_sccp_con);
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if (!bsc_con) {
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LOGP(DMSC, LOGL_ERROR, "Failed to allocate.\n");
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sccp_connection_free(sccp);
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return -1;
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}
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/* callbacks */
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sccp->state_cb = msc_outgoing_sccp_state;
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sccp->data_cb = msc_outgoing_sccp_data;
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sccp->data_ctx = bsc_con;
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/* prepare the timers */
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bsc_con->sccp_it_timeout.cb = sccp_it_timeout;
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bsc_con->sccp_it_timeout.data = bsc_con;
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bsc_con->sccp_cc_timeout.cb = sccp_cc_timeout;
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bsc_con->sccp_cc_timeout.data = bsc_con;
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INIT_LLIST_HEAD(&bsc_con->sccp_queue);
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bsc_con->sccp = sccp;
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bsc_con->msc_con = net->msc_data->msc_con;
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bsc_con->conn = conn;
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llist_add_tail(&bsc_con->entry, &active_connections);
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conn->sccp_con = bsc_con;
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return 0;
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}
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int bsc_open_connection(struct osmo_bsc_sccp_con *conn, struct msgb *msg)
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{
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osmo_timer_schedule(&conn->sccp_cc_timeout, 10, 0);
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sccp_connection_connect(conn->sccp, &sccp_ssn_bssap, msg);
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msgb_free(msg);
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return 0;
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}
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int bsc_delete_connection(struct osmo_bsc_sccp_con *sccp)
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{
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if (!sccp)
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return 0;
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if (sccp->conn)
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LOGP(DMSC, LOGL_ERROR, "Should have been cleared.\n");
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llist_del(&sccp->entry);
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osmo_timer_del(&sccp->sccp_it_timeout);
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osmo_timer_del(&sccp->sccp_cc_timeout);
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talloc_free(sccp);
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return 0;
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}
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static void bsc_close_connections(struct bsc_msc_connection *msc_con)
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{
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struct osmo_bsc_sccp_con *con, *tmp;
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llist_for_each_entry_safe(con, tmp, &active_connections, entry)
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bsc_sccp_force_free(con);
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}
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static int handle_msc_signal(unsigned int subsys, unsigned int signal,
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void *handler_data, void *signal_data)
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{
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struct msc_signal_data *msc;
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if (subsys != SS_MSC)
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return 0;
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msc = signal_data;
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if (signal == S_MSC_LOST)
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bsc_close_connections(msc->data->msc_con);
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return 0;
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}
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int osmo_bsc_sccp_init(struct gsm_network *gsmnet)
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{
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sccp_set_log_area(DSCCP);
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sccp_system_init(msc_sccp_write_ipa, gsmnet);
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sccp_connection_set_incoming(&sccp_ssn_bssap, msc_sccp_accept, NULL);
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sccp_set_read(&sccp_ssn_bssap, msc_sccp_read, gsmnet);
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osmo_signal_register_handler(SS_MSC, handle_msc_signal, gsmnet);
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return 0;
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}
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