diff --git a/src/osmo-bsc/bsc_sccp.c b/src/osmo-bsc/bsc_sccp.c index 431e194f8..e0cce39bf 100644 --- a/src/osmo-bsc/bsc_sccp.c +++ b/src/osmo-bsc/bsc_sccp.c @@ -47,6 +47,33 @@ uint32_t bsc_sccp_inst_next_conn_id(struct osmo_sccp_instance *sccp) /* 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. */ + /* SCCP towards SMLC: */ + if (bsc_gsmnet->smlc->sccp == sccp) { + for (i = 0; i < SCCP_CONN_ID_MAX; i++) { + struct gsm_subscriber_connection *conn; + uint32_t conn_id = next_id; + bool conn_id_already_used = false; + + /* Optimized modulo operation (% SCCP_CONN_ID_MAX) using bitwise AND plus CMP: */ + next_id = (next_id + 1) & 0x00FFFFFF; + if (OSMO_UNLIKELY(next_id == 0x00FFFFFF)) + next_id = 0; + + llist_for_each_entry(conn, &bsc_gsmnet->subscr_conns, entry) { + if (conn->lcs.lb.state != SUBSCR_SCCP_ST_NONE && + conn->lcs.lb.conn_id == conn_id) { + conn_id_already_used = true; + break; + } + } + + if (!conn_id_already_used) + return conn_id; + } + return 0xFFFFFFFF; + } + + /* SCCP towards MSC: */ for (i = 0; i < SCCP_CONN_ID_MAX; i++) { struct gsm_subscriber_connection *conn; uint32_t conn_id = next_id; @@ -58,19 +85,10 @@ uint32_t bsc_sccp_inst_next_conn_id(struct osmo_sccp_instance *sccp) next_id = 0; 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->sccp.msc && conn->sccp.msc->a.sccp == sccp && + conn->sccp.conn_id == conn_id) { + conn_id_already_used = true; + break; } }