481 lines
14 KiB
C
481 lines
14 KiB
C
/* (C) 2021 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
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* Author: Oliver Smith <osmith@sysmocom.de>
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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/lienses/>.
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*
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*/
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#include "config.h"
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#include <errno.h>
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#include <inttypes.h>
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#include <stdint.h>
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#include <osmocom/core/fsm.h>
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#include <osmocom/core/select.h>
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#include <osmocom/gsm/gsm0808.h>
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#include <osmocom/sigtran/osmo_ss7.h>
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#include <osmocom/sigtran/sccp_helpers.h>
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#include <osmocom/bsc_nat/bsc.h>
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#include <osmocom/bsc_nat/bsc_nat.h>
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#include <osmocom/bsc_nat/bsc_nat_fsm.h>
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#include <osmocom/bsc_nat/bssap.h>
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#include <osmocom/bsc_nat/logging.h>
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#include <osmocom/bsc_nat/msc.h>
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#include <osmocom/bsc_nat/subscr_conn.h>
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#define DEFAULT_PC_RAN "0.23.1" /* same as default for OsmoMSC */
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#define DEFAULT_PC_CN "0.23.3" /* same as default for OsmoBSC */
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#define X(s) (1 << (s))
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enum bsc_nat_fsm_states {
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BSC_NAT_FSM_ST_STOPPED,
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BSC_NAT_FSM_ST_STARTING,
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BSC_NAT_FSM_ST_STARTED,
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};
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enum bsc_nat_fsm_events {
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BSC_NAT_FSM_EV_START,
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BSC_NAT_FSM_EV_STOP,
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};
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/* For connection-oriented messages, figure out which side is not the BSCNAT,
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* either the called_addr or calling_addr. */
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static int get_peer_addr(struct bsc_nat_sccp_inst *sccp_inst, struct osmo_sccp_addr **addr,
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struct osmo_sccp_addr *called_addr, struct osmo_sccp_addr *calling_addr)
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{
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if (osmo_sccp_addr_ri_cmp(&sccp_inst->addr, called_addr) != 0) {
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*addr = called_addr;
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return 0;
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} else if (osmo_sccp_addr_ri_cmp(&sccp_inst->addr, calling_addr) != 0) {
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*addr = calling_addr;
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return 0;
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}
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char buf_called[255];
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char buf_calling[255];
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osmo_sccp_addr_to_str_buf(buf_called, sizeof(buf_called), NULL, called_addr);
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osmo_sccp_addr_to_str_buf(buf_calling, sizeof(buf_calling), NULL, calling_addr);
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LOGP(DMAIN, LOGL_ERROR, "Invalid connection oriented message, locally configured address %s"
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" is neither called address %s nor calling address %s!\n",
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osmo_sccp_inst_addr_name(NULL, &sccp_inst->addr), buf_called, buf_calling);
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return -1;
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}
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/* Handle incoming messages from CN (MSC) */
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static int sccp_sap_up_cn(struct osmo_prim_hdr *oph, void *scu)
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{
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struct bsc_nat_sccp_inst *sccp_inst = osmo_sccp_user_get_priv(scu);
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struct osmo_scu_prim *prim = (struct osmo_scu_prim *) oph;
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struct osmo_sccp_addr *addr; /* MSC's address */
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struct subscr_conn *subscr_conn;
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int rc = -1;
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LOGP(DMAIN, LOGL_DEBUG, "Rx %s from CN\n", osmo_scu_prim_name(oph));
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switch (OSMO_PRIM_HDR(oph)) {
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case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_INDICATION):
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/* indication of new inbound connection request */
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/* FIXME: MSC has sent a message without conn_id, figure out to
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* which BSC to forward this. */
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LOGP(DMAIN, LOGL_ERROR, "%s(%s) is not implemented!\n", __func__, osmo_scu_prim_name(oph));
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break;
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case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_CONFIRM):
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/* indication of connection confirm */
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if (get_peer_addr(sccp_inst, &addr, &prim->u.connect.called_addr, &prim->u.connect.calling_addr) < 0)
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goto error;
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subscr_conn = subscr_conn_get_by_id(prim->u.connect.conn_id, BSC_NAT_NET_CN);
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if (!subscr_conn) {
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LOGP(DMAIN, LOGL_ERROR, "Unknown conn_id=%" PRIu32 " from %s\n", prim->u.connect.conn_id,
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bsc_nat_print_addr_cn(addr));
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goto error;
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}
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LOGP(DMAIN, LOGL_DEBUG, "Fwd via %s\n", talloc_get_name(subscr_conn));
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msgb_pull_to_l2(oph->msg);
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osmo_sccp_tx_conn_resp(g_bsc_nat->ran.sccp_inst->scu,
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subscr_conn->ran.id,
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&subscr_conn->ran.bsc->addr,
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oph->msg->data,
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msgb_length(oph->msg));
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rc = 0;
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break;
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case OSMO_PRIM(OSMO_SCU_PRIM_N_DATA, PRIM_OP_INDICATION):
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/* connection-oriented data received */
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subscr_conn = subscr_conn_get_by_id(prim->u.data.conn_id, BSC_NAT_NET_CN);
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if (!subscr_conn) {
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LOGP(DMAIN, LOGL_ERROR, "Unknown conn_id=%" PRIu32 " from %s\n", prim->u.data.conn_id,
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bsc_nat_print_addr_cn(addr));
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goto error;
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}
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rc = bssap_handle_dt(BSC_NAT_NET_CN, subscr_conn, oph->msg, msgb_l2len(oph->msg));
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break;
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case OSMO_PRIM(OSMO_SCU_PRIM_N_DISCONNECT, PRIM_OP_INDICATION):
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/* indication of disconnect */
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subscr_conn = subscr_conn_get_by_id(prim->u.disconnect.conn_id, BSC_NAT_NET_CN);
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if (!subscr_conn) {
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LOGP(DMAIN, LOGL_ERROR, "Unknown conn_id=%" PRIu32 " from %s\n", prim->u.disconnect.conn_id,
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bsc_nat_print_addr_cn(addr));
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goto error;
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}
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LOGP(DMAIN, LOGL_DEBUG, "Fwd via %s\n", talloc_get_name(subscr_conn));
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osmo_sccp_tx_disconn(g_bsc_nat->ran.sccp_inst->scu,
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subscr_conn->ran.id,
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&g_bsc_nat->ran.sccp_inst->addr,
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prim->u.disconnect.cause);
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subscr_conn_free(subscr_conn);
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rc = 0;
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break;
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case OSMO_PRIM(OSMO_SCU_PRIM_N_UNITDATA, PRIM_OP_INDICATION):
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/* connection-less data received */
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rc = bssap_handle_udt(sccp_inst, &prim->u.unitdata.calling_addr, oph->msg, msgb_l2len(oph->msg));
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break;
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default:
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LOGP(DMAIN, LOGL_ERROR, "%s(%s) is not implemented!\n", __func__, osmo_scu_prim_name(oph));
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break;
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}
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error:
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msgb_free(oph->msg);
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return rc;
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}
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/* Handle incoming messages from RAN (BSC) */
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static int sccp_sap_up_ran(struct osmo_prim_hdr *oph, void *scu)
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{
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struct bsc_nat_sccp_inst *sccp_inst = osmo_sccp_user_get_priv(scu);
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struct osmo_scu_prim *prim = (struct osmo_scu_prim *) oph;
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struct osmo_sccp_addr *addr; /* BSC's address */
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struct subscr_conn *subscr_conn;
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struct msc *msc;
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struct bsc *bsc;
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int rc = -1;
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LOGP(DMAIN, LOGL_DEBUG, "Rx %s from RAN\n", osmo_scu_prim_name(oph));
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msc = msc_get();
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if (!msc_is_connected(msc)) {
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LOGP(DMAIN, LOGL_DEBUG, "Ignoring message from RAN, MSC is not connected yet\n");
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goto error;
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}
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switch (OSMO_PRIM_HDR(oph)) {
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case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_INDICATION):
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/* indication of new inbound connection request */
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if (get_peer_addr(sccp_inst, &addr, &prim->u.connect.called_addr, &prim->u.connect.calling_addr) < 0)
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goto error;
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bsc = bsc_get_by_pc(addr->pc);
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if (!bsc)
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bsc = bsc_alloc(addr);
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if (subscr_conn_get_by_id(prim->u.connect.conn_id, BSC_NAT_NET_RAN)) {
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LOGP(DMAIN, LOGL_ERROR, "%s attempted to create new connection with already used"
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" conn_id=%" PRIu32 ", ignoring\n", talloc_get_name(bsc), prim->u.connect.conn_id);
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goto error;
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}
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subscr_conn = subscr_conn_alloc(msc, bsc, subscr_conn_get_next_id(BSC_NAT_NET_CN), prim->u.connect.conn_id);
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LOGP(DMAIN, LOGL_DEBUG, "Fwd via %s\n", talloc_get_name(subscr_conn));
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msgb_pull_to_l2(oph->msg);
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osmo_sccp_tx_conn_req(g_bsc_nat->cn.sccp_inst->scu,
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subscr_conn->cn.id,
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&g_bsc_nat->cn.sccp_inst->addr,
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&subscr_conn->cn.msc->addr,
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oph->msg->data,
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msgb_length(oph->msg));
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rc = 0;
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break;
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case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_CONFIRM):
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/* indication of connection confirm */
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if (get_peer_addr(sccp_inst, &addr, &prim->u.connect.called_addr, &prim->u.connect.calling_addr) < 0)
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goto error;
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subscr_conn = subscr_conn_get_by_id(prim->u.connect.conn_id, BSC_NAT_NET_RAN);
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if (!subscr_conn) {
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LOGP(DMAIN, LOGL_ERROR, "Unknown conn_id=%" PRIu32 " from %s\n", prim->u.connect.conn_id,
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bsc_nat_print_addr_ran(addr));
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goto error;
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}
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LOGP(DMAIN, LOGL_DEBUG, "Fwd via %s\n", talloc_get_name(subscr_conn));
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msgb_pull_to_l2(oph->msg);
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osmo_sccp_tx_conn_resp(g_bsc_nat->cn.sccp_inst->scu,
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subscr_conn->cn.id,
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&subscr_conn->cn.msc->addr,
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oph->msg->data,
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msgb_length(oph->msg));
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rc = 0;
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break;
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case OSMO_PRIM(OSMO_SCU_PRIM_N_DATA, PRIM_OP_INDICATION):
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/* connection-oriented data received */
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subscr_conn = subscr_conn_get_by_id(prim->u.data.conn_id, BSC_NAT_NET_RAN);
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if (!subscr_conn) {
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LOGP(DMAIN, LOGL_ERROR, "Unknown conn_id=%" PRIu32 " from %s\n", prim->u.data.conn_id,
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bsc_nat_print_addr_ran(addr));
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goto error;
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}
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rc = bssap_handle_dt(BSC_NAT_NET_RAN, subscr_conn, oph->msg, msgb_l2len(oph->msg));
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break;
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case OSMO_PRIM(OSMO_SCU_PRIM_N_DISCONNECT, PRIM_OP_INDICATION):
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/* indication of disconnect */
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subscr_conn = subscr_conn_get_by_id(prim->u.disconnect.conn_id, BSC_NAT_NET_RAN);
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if (!subscr_conn) {
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LOGP(DMAIN, LOGL_ERROR, "Unknown conn_id=%" PRIu32 " from %s\n", prim->u.disconnect.conn_id,
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bsc_nat_print_addr_ran(addr));
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goto error;
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}
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LOGP(DMAIN, LOGL_DEBUG, "Fwd via %s\n", talloc_get_name(subscr_conn));
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osmo_sccp_tx_disconn(g_bsc_nat->cn.sccp_inst->scu,
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subscr_conn->cn.id,
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&g_bsc_nat->cn.sccp_inst->addr,
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prim->u.disconnect.cause);
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subscr_conn_free(subscr_conn);
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rc = 0;
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break;
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case OSMO_PRIM(OSMO_SCU_PRIM_N_UNITDATA, PRIM_OP_INDICATION):
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/* connection-less data received */
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rc = bssap_handle_udt(sccp_inst, &prim->u.unitdata.calling_addr, oph->msg, msgb_l2len(oph->msg));
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break;
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default:
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LOGP(DMAIN, LOGL_ERROR, "%s(%s) is not implemented!\n", __func__, osmo_scu_prim_name(oph));
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break;
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}
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error:
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msgb_free(oph->msg);
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return rc;
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}
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static int sccp_inst_init(struct bsc_nat_sccp_inst *sccp_inst, const char *name, const char *default_pc_str,
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osmo_prim_cb prim_cb, enum osmo_sccp_ssn ssn)
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{
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int default_pc;
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struct osmo_sccp_instance *sccp;
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default_pc = osmo_ss7_pointcode_parse(NULL, default_pc_str);
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OSMO_ASSERT(default_pc >= 0);
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sccp = osmo_sccp_simple_client_on_ss7_id(sccp_inst, sccp_inst->ss7_id, name, default_pc, OSMO_SS7_ASP_PROT_M3UA,
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0, NULL, 0, NULL);
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if (!sccp) {
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LOGP(DMAIN, LOGL_ERROR, "%s: failed to request sccp client instance for sccp user\n", name);
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return -1;
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}
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sccp_inst->ss7_inst = osmo_ss7_instance_find(sccp_inst->ss7_id);
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osmo_sccp_local_addr_by_instance(&sccp_inst->addr, sccp, ssn);
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sccp_inst->scu = osmo_sccp_user_bind(sccp, name, prim_cb, ssn);
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if (!sccp_inst->scu) {
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LOGP(DMAIN, LOGL_ERROR, "%s: failed to bind sccp user\n", name);
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return -2;
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}
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osmo_sccp_user_set_priv(sccp_inst->scu, sccp_inst);
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return 0;
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}
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static void sccp_inst_free(struct bsc_nat_sccp_inst *sccp_inst)
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{
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if (sccp_inst->scu) {
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osmo_sccp_user_unbind(sccp_inst->scu);
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sccp_inst->scu = NULL;
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}
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if (sccp_inst->ss7_inst) {
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osmo_ss7_instance_destroy(sccp_inst->ss7_inst);
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sccp_inst->ss7_inst = NULL;
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}
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talloc_free(sccp_inst);
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}
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static int mgw_init(struct mgcp_client_pool *pool)
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{
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unsigned int pool_members_initialized;
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/* Initialize MGW pool. This initalizes and connects all MGCP clients that are currently configured in
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* the pool. Adding additional MGCP clients to the pool is possible but the user has to configure and
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* (re)connect them manually from the VTY. */
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pool_members_initialized = mgcp_client_pool_connect(pool);
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if (!pool_members_initialized) {
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LOGP(DMAIN, LOGL_ERROR, "Failed to initialize any MGW pool members!\n");
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return -1;
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}
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LOGP(DMAIN, LOGL_NOTICE, "MGW pool with %u pool member(s) initialized\n", pool_members_initialized);
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return 0;
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}
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static void st_starting_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state)
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{
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struct bsc_nat *bsc_nat = (struct bsc_nat *)fi->priv;
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if (sccp_inst_init(bsc_nat->cn.sccp_inst, "OsmoBSCNAT-CN", DEFAULT_PC_CN, sccp_sap_up_cn, OSMO_SCCP_SSN_BSSAP) < 0) {
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osmo_fsm_inst_state_chg(fi, BSC_NAT_FSM_ST_STOPPED, 0, 0);
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return;
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}
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if (sccp_inst_init(bsc_nat->ran.sccp_inst, "OsmoBSCNAT-RAN", DEFAULT_PC_RAN, sccp_sap_up_ran, OSMO_SCCP_SSN_BSSAP) < 0) {
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osmo_fsm_inst_state_chg(fi, BSC_NAT_FSM_ST_STOPPED, 0, 0);
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return;
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}
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if (mgw_init(bsc_nat->mgw.pool) < 0) {
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osmo_fsm_inst_state_chg(fi, BSC_NAT_FSM_ST_STOPPED, 0, 0);
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return;
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}
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osmo_fsm_inst_state_chg(fi, BSC_NAT_FSM_ST_STARTED, 0, 0);
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}
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static void st_started(struct osmo_fsm_inst *fi, uint32_t event, void *data)
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{
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switch (event) {
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case BSC_NAT_FSM_EV_STOP:
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osmo_fsm_inst_state_chg(fi, BSC_NAT_FSM_ST_STOPPED, 0, 0);
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break;
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default:
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OSMO_ASSERT(false);
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}
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}
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static void st_stopped_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state)
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{
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struct bsc_nat *bsc_nat = (struct bsc_nat *)fi->priv;
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sccp_inst_free(bsc_nat->cn.sccp_inst);
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bsc_nat->cn.sccp_inst = NULL;
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sccp_inst_free(bsc_nat->ran.sccp_inst);
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bsc_nat->ran.sccp_inst = NULL;
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}
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static void st_stopped(struct osmo_fsm_inst *fi, uint32_t event, void *data)
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{
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switch (event) {
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case BSC_NAT_FSM_EV_START:
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osmo_fsm_inst_state_chg(fi, BSC_NAT_FSM_ST_STARTING, 0, 0);
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break;
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default:
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OSMO_ASSERT(false);
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}
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}
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static struct osmo_fsm_state bsc_nat_fsm_states[] = {
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[BSC_NAT_FSM_ST_STOPPED] = {
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.name = "STOPPED",
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.in_event_mask = 0
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| X(BSC_NAT_FSM_EV_START)
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,
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.out_state_mask = 0
|
|
| X(BSC_NAT_FSM_ST_STARTING)
|
|
,
|
|
.action = st_stopped,
|
|
.onenter = st_stopped_on_enter,
|
|
},
|
|
[BSC_NAT_FSM_ST_STARTING] = {
|
|
.name = "STARTING",
|
|
.out_state_mask = 0
|
|
| X(BSC_NAT_FSM_ST_STARTED)
|
|
| X(BSC_NAT_FSM_ST_STOPPED)
|
|
,
|
|
.onenter = st_starting_on_enter,
|
|
},
|
|
[BSC_NAT_FSM_ST_STARTED] = {
|
|
.name = "STARTED",
|
|
.in_event_mask = 0
|
|
| X(BSC_NAT_FSM_EV_STOP)
|
|
,
|
|
.out_state_mask = 0
|
|
| X(BSC_NAT_FSM_ST_STOPPED)
|
|
,
|
|
.action = st_started,
|
|
},
|
|
};
|
|
|
|
const struct value_string bsc_nat_fsm_event_names[] = {
|
|
OSMO_VALUE_STRING(BSC_NAT_FSM_EV_START),
|
|
OSMO_VALUE_STRING(BSC_NAT_FSM_EV_STOP),
|
|
{ 0, NULL }
|
|
};
|
|
|
|
struct osmo_fsm bsc_nat_fsm = {
|
|
.name = "BSC_NAT",
|
|
.states = bsc_nat_fsm_states,
|
|
.num_states = ARRAY_SIZE(bsc_nat_fsm_states),
|
|
.log_subsys = DMAIN,
|
|
.event_names = bsc_nat_fsm_event_names,
|
|
};
|
|
|
|
static __attribute__((constructor)) void bsc_nat_fsm_init(void)
|
|
{
|
|
OSMO_ASSERT(osmo_fsm_register(&bsc_nat_fsm) == 0);
|
|
}
|
|
|
|
void bsc_nat_fsm_alloc(struct bsc_nat *bsc_nat)
|
|
{
|
|
bsc_nat->fi = osmo_fsm_inst_alloc(&bsc_nat_fsm, bsc_nat, bsc_nat, LOGL_INFO, NULL);
|
|
OSMO_ASSERT(bsc_nat->fi);
|
|
}
|
|
|
|
int bsc_nat_fsm_start(struct bsc_nat *bsc_nat)
|
|
{
|
|
int rc = osmo_fsm_inst_dispatch(bsc_nat->fi, BSC_NAT_FSM_EV_START, NULL);
|
|
if (rc)
|
|
return rc;
|
|
|
|
/* st_starting_on_enter() doesn't change to STARTED if e.g. vty config
|
|
* is incomplete */
|
|
if (bsc_nat->fi->state != BSC_NAT_FSM_ST_STARTED)
|
|
return -1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
void bsc_nat_fsm_stop(struct bsc_nat *bsc_nat)
|
|
{
|
|
osmo_fsm_inst_dispatch(bsc_nat->fi, BSC_NAT_FSM_EV_STOP, NULL);
|
|
}
|