| /* Generic SCCP handling across all OsmoBSC users */ |
| /* |
| * (C) 2020 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de> |
| * |
| * All Rights Reserved |
| * |
| * Author: Neels Hofmeyr <neels@hofmeyr.de> |
| * |
| * 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/gsm_data.h> |
| #include <osmocom/bsc/bsc_msc_data.h> |
| #include <osmocom/bsc/lb.h> |
| |
| /* We need an unused SCCP conn_id across all SCCP users. */ |
| int bsc_sccp_inst_next_conn_id(struct osmo_sccp_instance *sccp) |
| { |
| static uint32_t next_id = 1; |
| int i; |
| |
| /* This looks really suboptimal, but in most cases the static next_id should indicate exactly the next unused |
| * conn_id, and we only iterate all conns once to make super sure that it is not already in use. */ |
| |
| for (i = 0; i < 0xFFFFFF; i++) { |
| struct gsm_subscriber_connection *conn; |
| uint32_t conn_id = next_id; |
| bool conn_id_already_used = false; |
| next_id = (next_id + 1) & 0xffffff; |
| |
| llist_for_each_entry(conn, &bsc_gsmnet->subscr_conns, entry) { |
| if (conn->sccp.msc && conn->sccp.msc->a.sccp == sccp) { |
| if (conn_id == conn->sccp.conn_id) { |
| conn_id_already_used = true; |
| break; |
| } |
| } |
| |
| if (bsc_gsmnet->smlc->sccp == sccp |
| && conn->lcs.lb.state != SUBSCR_SCCP_ST_NONE) { |
| if (conn_id == conn->lcs.lb.conn_id) { |
| conn_id_already_used = true; |
| break; |
| } |
| } |
| } |
| |
| if (!conn_id_already_used) |
| return conn_id; |
| } |
| return -1; |
| } |