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osmo-msc/src/libmsc/msc_mgcp.c

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/* (C) 2017 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
* All Rights Reserved
*
* Author: Philipp Maier
*
* 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 <arpa/inet.h>
#include <osmocom/mgcp_client/mgcp_client.h>
#include <osmocom/core/logging.h>
#include <osmocom/core/utils.h>
#include <osmocom/core/timer.h>
#include <osmocom/core/fsm.h>
#include <osmocom/core/byteswap.h>
#include <osmocom/msc/msc_mgcp.h>
#include <osmocom/msc/debug.h>
#include <osmocom/msc/transaction.h>
#include <osmocom/msc/a_iface.h>
#include <osmocom/msc/msc_ifaces.h>
#include <osmocom/msc/gsm_04_08.h>
#include <osmocom/msc/iucs.h>
#include <osmocom/msc/vlr.h>
#include "../../bscconfig.h"
#define S(x) (1 << (x))
#define CONN_ID_RAN 1
#define CONN_ID_CN 2
#define MGCP_MGW_TIMEOUT 4 /* in seconds */
#define MGCP_MGW_TIMEOUT_TIMER_NR 1
#define MGCP_RAN_TIMEOUT 120 /* in seconds */
#define MGCP_RAN_TIMEOUT_TIMER_NR 2
#define MGCP_REL_TIMEOUT 60 /* in seconds */
#define MGCP_REL_TIMEOUT_TIMER_NR 3
#define MGCP_ASS_TIMEOUT 10 /* in seconds */
#define MGCP_ASS_TIMEOUT_TIMER_NR 4
/* Some internal cause codes to indicate fault condition inside the FSM */
enum msc_mgcp_cause_code {
MGCP_ERR_MGW_FAIL,
MGCP_ERR_MGW_INVAL_RESP,
MGCP_ERR_MGW_TX_FAIL,
MGCP_ERR_MGW_TIMEOUT,
MGCP_ERR_UNEXP_TEARDOWN,
MGCP_ERR_UNSUPP_ADDR_FMT,
MGCP_ERR_RAN_TIMEOUT,
MGCP_ERR_ASS_TIMEOUT,
MGCP_ERR_TOOLONG,
MGCP_ERR_ASSGMNT_FAIL
};
/* Human readable respresentation of the faul codes, will be displayed by
* handle_error() */
static const struct value_string msc_mgcp_cause_codes_names[] = {
{MGCP_ERR_MGW_FAIL, "operation failed on MGW"},
{MGCP_ERR_MGW_INVAL_RESP, "invalid / unparseable response from MGW"},
{MGCP_ERR_MGW_TX_FAIL, "failed to transmit MGCP message to MGW"},
{MGCP_ERR_MGW_TIMEOUT, "request to MGW timed out"},
{MGCP_ERR_UNEXP_TEARDOWN, "unexpected connection teardown"},
{MGCP_ERR_UNSUPP_ADDR_FMT, "unsupported network address format used (RAN)"},
{MGCP_ERR_RAN_TIMEOUT, "call could not be completed in time (RAN)"},
{MGCP_ERR_ASS_TIMEOUT, "assignment could not be completed in time (RAN)"},
{MGCP_ERR_TOOLONG, "string value too long"},
{MGCP_ERR_ASSGMNT_FAIL, "assignment failure (RAN)"},
{0, NULL}
};
enum fsm_msc_mgcp_states {
ST_CRCX_RAN,
ST_CRCX_CN,
ST_CRCX_COMPL,
ST_MDCX_CN,
ST_MDCX_CN_COMPL,
ST_MDCX_RAN,
ST_MDCX_RAN_COMPL,
ST_CALL,
ST_HALT,
};
enum msc_mgcp_fsm_evt {
/* Initial event: start off the state machine */
EV_INIT,
/* External event: Notify that the Assignment is complete and we
* may now forward IP/Port of the remote call leg to the MGW */
EV_ASSIGN,
/* External event: Notify that the Call is complete and that the
* two half open connections on the MGW should now be connected */
EV_CONNECT,
/* External event: Notify that the call is over and the connections
* on the mgw shall be removed */
EV_TEARDOWN,
/* Internal event: An error occurred that requires a controlled
* teardown of the RTP connections */
EV_TEARDOWN_ERROR,
/* Internal event: The mgcp_gw has sent its CRCX response for
* the RAN side */
EV_CRCX_RAN_RESP,
/* Internal event: The mgcp_gw has sent its CRCX response for
* the CN side */
EV_CRCX_CN_RESP,
/* Internal event: The mgcp_gw has sent its MDCX response for
* the RAN side */
EV_MDCX_RAN_RESP,
/* Internal event: The mgcp_gw has sent its MDCX response for
* the CN side */
EV_MDCX_CN_RESP,
/* Internal event: The mgcp_gw has sent its DLCX response for
* the RAN and CN side */
EV_DLCX_ALL_RESP,
};
static const struct value_string msc_mgcp_fsm_evt_names[] = {
OSMO_VALUE_STRING(EV_INIT),
OSMO_VALUE_STRING(EV_ASSIGN),
OSMO_VALUE_STRING(EV_CONNECT),
OSMO_VALUE_STRING(EV_TEARDOWN),
OSMO_VALUE_STRING(EV_TEARDOWN_ERROR),
OSMO_VALUE_STRING(EV_CRCX_RAN_RESP),
OSMO_VALUE_STRING(EV_CRCX_CN_RESP),
OSMO_VALUE_STRING(EV_MDCX_RAN_RESP),
OSMO_VALUE_STRING(EV_MDCX_CN_RESP),
OSMO_VALUE_STRING(EV_DLCX_ALL_RESP),
{0, NULL}
};
/* A general error handler function. On error we still have an interest to
* remove a half open connection (if possible). This function will execute
* a controlled jump to the DLCX phase. From there, the FSM will then just
* continue like the call were ended normally */
#define handle_error(mgcp_ctx, cause, dlcx) _handle_error(mgcp_ctx, cause, dlcx, __FILE__, __LINE__)
static void _handle_error(struct mgcp_ctx *mgcp_ctx, enum msc_mgcp_cause_code cause, bool dlcx, const char *file,
int line)
{
bool dlcx_possible = true;
struct osmo_fsm_inst *fi;
struct gsm_mncc mncc;
OSMO_ASSERT(mgcp_ctx);
fi = mgcp_ctx->fsm;
OSMO_ASSERT(fi);
/* Check if the endpoint identifier is a specific endpoint identifier,
* since in order to perform a DLCX we must know the specific
* identifier of the endpoint we want to release. If we do not have
* this information because of errornous communication we can not
* perform a DLCX. */
if (strstr(mgcp_ctx->rtp_endpoint, "*"))
dlcx_possible = false;
LOGPFSMLSRC(mgcp_ctx->fsm, LOGL_ERROR, file, line, "%s -- graceful shutdown...\n",
get_value_string(msc_mgcp_cause_codes_names, cause));
/* Request the higher layers (gsm_04_08.c) to release the call. If the
* problem occured after msc_mgcp_call_release() was calls, remain
* silent because we already got informed and the higher layers might
* already freed their context information (trans). */
if (!mgcp_ctx->free_ctx) {
mncc = (struct gsm_mncc) {
.msg_type = MNCC_REL_REQ,
.callref = mgcp_ctx->trans->callref,
.cause = {
.location = GSM48_CAUSE_LOC_PRN_S_LU,
.coding = 0, /* FIXME */
.value = GSM48_CC_CAUSE_RESOURCE_UNAVAIL
}
};
mncc_set_cause(&mncc, GSM48_CAUSE_LOC_TRANS_NET,
GSM48_CC_CAUSE_RESOURCE_UNAVAIL);
mncc_tx_to_cc(mgcp_ctx->trans->net, MNCC_REL_REQ, &mncc);
}
/* For the shutdown we have two options. Whenever it makes sense to
* send a DLCX to the MGW in order to be sure that the connection is
* properly cleaned up, the dlcx flag should be set. In other cases
* where a DLCX does not make sense (e.g. the MGW times out), halting
* directly is the better options. In those cases, the dlcx flag
* should not be set */
if (dlcx && dlcx_possible) {
/* Fast-forward the FSM into call state. In this state the FSM
* expects either an EV_TEARDOWN or an EV_TEARDOWN_ERROR. When
* one of the two events is received a DLCX will be send to
* the MGW. After that. The FSM automatically halts but will
* still expect a call msc_mgcp_call_release() to be freed
* completely */
osmo_fsm_inst_state_chg(fi, ST_CALL, 0, 0);
osmo_fsm_inst_dispatch(mgcp_ctx->fsm, EV_TEARDOWN_ERROR, mgcp_ctx);
} else {
/* Halt the state machine immediately. The FSM will not be
* freed yet, we stil require the higher layers to call
* msc_mgcp_call_release() */
osmo_fsm_inst_state_chg(fi, ST_HALT, 0, 0);
osmo_fsm_inst_dispatch(fi, EV_TEARDOWN_ERROR, mgcp_ctx);
}
}
/* Timer callback to shut down in case of connectivity problems */
static int fsm_timeout_cb(struct osmo_fsm_inst *fi)
{
struct mgcp_ctx *mgcp_ctx = fi->priv;
struct mgcp_client *mgcp;
OSMO_ASSERT(mgcp_ctx);
mgcp = mgcp_ctx->mgcp;
OSMO_ASSERT(mgcp);
if (fi->T == MGCP_MGW_TIMEOUT_TIMER_NR) {
/* We were unable to communicate with the MGW, unfortunately
* there is no meaningful action we can take now other than
* giving up. */
/* Cancel the transaction that timed out */
mgcp_client_cancel(mgcp, mgcp_ctx->mgw_pending_trans);
/* halt of the FSM */
handle_error(mgcp_ctx, MGCP_ERR_MGW_TIMEOUT, false);
} else if (fi->T == MGCP_RAN_TIMEOUT_TIMER_NR) {
/* If the logic that controls the RAN is unable to negotiate a
* connection, we presumably still have a working connection to
* the MGW, we will try to shut down gracefully. */
handle_error(mgcp_ctx, MGCP_ERR_RAN_TIMEOUT, true);
} else if (fi->T == MGCP_REL_TIMEOUT_TIMER_NR) {
/* Under normal conditions, the MSC logic should always command
* to release the call at some point. However, the release may
* be missing due to errors in the MSC logic and we may have
* reached ST_HALT because of cascading errors and timeouts. In
* this and only in this case we will allow ST_HALT to free all
* context information on its own authority. */
mgcp_ctx->free_ctx = true;
/* Initiate self destruction of the FSM */
osmo_fsm_inst_state_chg(fi, ST_HALT, 0, 0);
osmo_fsm_inst_dispatch(fi, EV_TEARDOWN, mgcp_ctx);
} else if (fi->T == MGCP_ASS_TIMEOUT_TIMER_NR) {
/* There may be rare cases in which the MSC is unable to
* complete the call assignment */
handle_error(mgcp_ctx, MGCP_ERR_ASS_TIMEOUT, true);
} else {
/* Ther must not be any unsolicited timers in this FSM. If so,
* we have serious problem. */
OSMO_ASSERT(false);
}
return 0;
}
static void mgw_crcx_ran_resp_cb(struct mgcp_response *r, void *priv);
/* Callback for ST_CRCX_RAN: Send CRCX for RAN side to MGW */
static void fsm_crcx_ran_cb(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct mgcp_ctx *mgcp_ctx = data;
struct mgcp_client *mgcp;
struct mgcp_msg mgcp_msg;
struct msgb *msg;
int rc;
struct gsm_trans *trans;
struct ran_conn *conn;
OSMO_ASSERT(mgcp_ctx);
mgcp = mgcp_ctx->mgcp;
OSMO_ASSERT(mgcp);
trans = mgcp_ctx->trans;
OSMO_ASSERT(trans);
conn = trans->conn;
OSMO_ASSERT(conn);
/* NOTE: In case of error, we will not be able to perform any DLCX
* operation because until this point we do not have requested any
* endpoint yet. */
LOGPFSML(fi, LOGL_DEBUG,
"CRCX/RAN: creating connection for the RAN side on MGW endpoint:%s...\n", mgcp_ctx->rtp_endpoint);
/* Generate MGCP message string */
mgcp_msg = (struct mgcp_msg) {
.verb = MGCP_VERB_CRCX,
.presence = (MGCP_MSG_PRESENCE_ENDPOINT | MGCP_MSG_PRESENCE_CALL_ID | MGCP_MSG_PRESENCE_CONN_MODE),
.call_id = mgcp_ctx->call_id,
.conn_mode = MGCP_CONN_RECV_ONLY
};
if (osmo_strlcpy(mgcp_msg.endpoint, mgcp_client_rtpbridge_wildcard(mgcp), sizeof(mgcp_msg.endpoint)) >=
MGCP_ENDPOINT_MAXLEN) {
handle_error(mgcp_ctx, MGCP_ERR_TOOLONG, false);
return;
}
/* HACK: We put the connection in loopback mode at the beginnig to
* trick the hNodeB into doing the IuUP negotiation with itself.
* This is a hack we need because osmo-mgw does not support IuUP yet, see OS#2459. */
#ifdef BUILD_IU
if (conn->via_ran == OSMO_RAT_UTRAN_IU)
mgcp_msg.conn_mode = MGCP_CONN_LOOPBACK;
#endif
msg = mgcp_msg_gen(mgcp, &mgcp_msg);
OSMO_ASSERT(msg);
/* Transmit MGCP message to MGW */
mgcp_ctx->mgw_pending_trans = mgcp_msg_trans_id(msg);
rc = mgcp_client_tx(mgcp, msg, mgw_crcx_ran_resp_cb, mgcp_ctx);
if (rc < 0) {
handle_error(mgcp_ctx, MGCP_ERR_MGW_TX_FAIL, false);
return;
}
osmo_fsm_inst_state_chg(fi, ST_CRCX_CN, MGCP_MGW_TIMEOUT, MGCP_MGW_TIMEOUT_TIMER_NR);
}
/* Callback for MGCP-Client: handle response for RAN associated CRCX */
static void mgw_crcx_ran_resp_cb(struct mgcp_response *r, void *priv)
{
struct mgcp_ctx *mgcp_ctx = priv;
int rc;
struct gsm_trans *trans;
struct ran_conn *conn;
/* NOTE: In case of error, we will not be able to perform any DLCX
* operation because until we either get a parseable message that
* contains an error code (no endpoint is seized in those cases)
* or we get an unparseable message. In this case we can not be
* sure, but we also can not draw any assumptions from unparseable
* messages. */
OSMO_ASSERT(mgcp_ctx);
trans = mgcp_ctx->trans;
OSMO_ASSERT(trans);
conn = trans->conn;
OSMO_ASSERT(conn);
if (r->head.response_code != 200) {
LOGPFSML(mgcp_ctx->fsm, LOGL_ERROR,
"CRCX/RAN: response yields error: %d %s\n", r->head.response_code, r->head.comment);
handle_error(mgcp_ctx, MGCP_ERR_MGW_FAIL, false);
return;
}
/* memorize connection identifier and specific endpoint id */
osmo_strlcpy(mgcp_ctx->conn_id_ran, r->head.conn_id, sizeof(mgcp_ctx->conn_id_ran));
LOGPFSML(mgcp_ctx->fsm, LOGL_DEBUG, "CRCX/RAN: MGW responded with CI: %s\n", mgcp_ctx->conn_id_ran);
osmo_strlcpy(mgcp_ctx->rtp_endpoint, r->head.endpoint, sizeof(mgcp_ctx->rtp_endpoint));
LOGPFSML(mgcp_ctx->fsm, LOGL_DEBUG, "CRCX/RAN: MGW assigned endpoint: %s\n", mgcp_ctx->rtp_endpoint);
rc = mgcp_response_parse_params(r);
if (rc) {
LOGPFSML(mgcp_ctx->fsm, LOGL_ERROR, "CRCX/RAN: Cannot parse response\n");
handle_error(mgcp_ctx, MGCP_ERR_MGW_INVAL_RESP, false);
return;
}
LOGPFSML(mgcp_ctx->fsm, LOGL_DEBUG, "CRCX/RAN: MGW responded with address %s:%u\n", r->audio_ip, r->audio_port);
conn->rtp.local_port_ran = r->audio_port;
osmo_strlcpy(conn->rtp.local_addr_ran, r->audio_ip, sizeof(conn->rtp.local_addr_ran));
/* Notify the FSM that we got the response. */
osmo_fsm_inst_dispatch(mgcp_ctx->fsm, EV_CRCX_RAN_RESP, mgcp_ctx);
}
static void mgw_crcx_cn_resp_cb(struct mgcp_response *r, void *priv);
/* Callback for ST_CRCX_CN: check MGW response and send CRCX for CN side to MGW */
static void fsm_crcx_cn_cb(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct mgcp_ctx *mgcp_ctx = data;
struct mgcp_client *mgcp;
struct mgcp_msg mgcp_msg;
struct msgb *msg;
int rc;
struct gsm_trans *trans;
struct ran_conn *conn;
OSMO_ASSERT(mgcp_ctx);
mgcp = mgcp_ctx->mgcp;
OSMO_ASSERT(mgcp);
trans = mgcp_ctx->trans;
OSMO_ASSERT(trans);
conn = trans->conn;
OSMO_ASSERT(conn);
switch (event) {
case EV_CRCX_RAN_RESP:
break;
default:
handle_error(mgcp_ctx, MGCP_ERR_UNEXP_TEARDOWN, true);
return;
}
LOGPFSML(fi, LOGL_DEBUG,
"CRCX/CN creating connection for the CN side on MGW endpoint:%s...\n", mgcp_ctx->rtp_endpoint);
/* Generate MGCP message string */
mgcp_msg = (struct mgcp_msg) {
.verb = MGCP_VERB_CRCX,
.presence = (MGCP_MSG_PRESENCE_ENDPOINT | MGCP_MSG_PRESENCE_CALL_ID | MGCP_MSG_PRESENCE_CONN_MODE),
.call_id = mgcp_ctx->call_id,
.conn_mode = MGCP_CONN_RECV_ONLY
};
if (osmo_strlcpy(mgcp_msg.endpoint, mgcp_ctx->rtp_endpoint, sizeof(mgcp_msg.endpoint)) >=
MGCP_ENDPOINT_MAXLEN) {
handle_error(mgcp_ctx, MGCP_ERR_TOOLONG, true);
return;
}
msg = mgcp_msg_gen(mgcp, &mgcp_msg);
OSMO_ASSERT(msg);
/* Transmit MGCP message to MGW */
mgcp_ctx->mgw_pending_trans = mgcp_msg_trans_id(msg);
rc = mgcp_client_tx(mgcp, msg, mgw_crcx_cn_resp_cb, mgcp_ctx);
if (rc < 0) {
handle_error(mgcp_ctx, MGCP_ERR_MGW_TX_FAIL, true);
return;
}
osmo_fsm_inst_state_chg(fi, ST_CRCX_COMPL, MGCP_MGW_TIMEOUT, MGCP_MGW_TIMEOUT_TIMER_NR);
}
/* Callback for MGCP-Client: handle response for CN associated CRCX */
static void mgw_crcx_cn_resp_cb(struct mgcp_response *r, void *priv)
{
struct mgcp_ctx *mgcp_ctx = priv;
int rc;
struct gsm_trans *trans;
struct ran_conn *conn;
OSMO_ASSERT(mgcp_ctx);
trans = mgcp_ctx->trans;
OSMO_ASSERT(trans);
conn = trans->conn;
OSMO_ASSERT(conn);
if (r->head.response_code != 200) {
LOGPFSML(mgcp_ctx->fsm, LOGL_ERROR,
"CRCX/CN: response yields error: %d %s\n", r->head.response_code, r->head.comment);
handle_error(mgcp_ctx, MGCP_ERR_MGW_FAIL, true);
return;
}
/* memorize connection identifier */
osmo_strlcpy(mgcp_ctx->conn_id_cn, r->head.conn_id, sizeof(mgcp_ctx->conn_id_cn));
LOGPFSML(mgcp_ctx->fsm, LOGL_DEBUG, "CRCX/CN: MGW responded with CI: %s\n", mgcp_ctx->conn_id_cn);
rc = mgcp_response_parse_params(r);
if (rc) {
LOGPFSML(mgcp_ctx->fsm, LOGL_ERROR, "CRCX/CN: Cannot parse response\n");
handle_error(mgcp_ctx, MGCP_ERR_MGW_INVAL_RESP, true);
return;
}
LOGPFSML(mgcp_ctx->fsm, LOGL_DEBUG, "CRCX/CN: MGW responded with address %s:%u\n", r->audio_ip, r->audio_port);
conn->rtp.local_port_cn = r->audio_port;
osmo_strlcpy(conn->rtp.local_addr_cn, r->audio_ip, sizeof(conn->rtp.local_addr_cn));
/* Notify the FSM that we got the response. */
osmo_fsm_inst_dispatch(mgcp_ctx->fsm, EV_CRCX_CN_RESP, mgcp_ctx);
}
/* Callback for ST_CRCX_COMPL: check MGW response, start assignment */
static void fsm_crcx_compl(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct mgcp_ctx *mgcp_ctx = data;
struct gsm_trans *trans;
struct ran_conn *conn;
OSMO_ASSERT(mgcp_ctx);
trans = mgcp_ctx->trans;
OSMO_ASSERT(trans);
conn = trans->conn;
OSMO_ASSERT(conn);
switch (event) {
case EV_CRCX_CN_RESP:
break;
default:
handle_error(mgcp_ctx, MGCP_ERR_UNEXP_TEARDOWN, true);
return;
}
/* Forward assignment request to A/RANAP */
if (conn->via_ran == OSMO_RAT_UTRAN_IU) {
#ifdef BUILD_IU
/* Assign a voice channel via RANAP on 3G */
if (iu_rab_act_cs(trans))
goto error;
#else
LOGPFSML(fi, LOGL_ERROR, "Cannot send Iu RAB Assignment: built without Iu support\n");
goto error;
#endif
} else if (conn->via_ran == OSMO_RAT_GERAN_A) {
/* Assign a voice channel via A on 2G */
if (a_iface_tx_assignment(trans))
goto error;
} else {
/* Unset or unimplemented new RAN type */
LOGPFSML(fi, LOGL_ERROR, "Unknown RAN type: %d\n", conn->via_ran);
return;
}
/* Respond back to MNCC (if requested) */
if (trans->tch_rtp_create) {
if (gsm48_tch_rtp_create(trans))
goto error;
}
/* Note: When we reach this point then the situation is basically that
* we have two sides connected, both are in loopback. The local ports
* of the side pointing towards the BSS should be already communicated
* and we are waiting now the other end to pick up. */
osmo_fsm_inst_state_chg(fi, ST_MDCX_CN, MGCP_RAN_TIMEOUT, MGCP_RAN_TIMEOUT_TIMER_NR);
return;
error:
handle_error(mgcp_ctx, MGCP_ERR_ASSGMNT_FAIL, true);
}
static void mgw_mdcx_cn_resp_cb(struct mgcp_response *r, void *priv);
/* Callback for ST_MDCX_CN: send MDCX for RAN side to MGW */
static void fsm_mdcx_cn_cb(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct mgcp_ctx *mgcp_ctx = data;
struct mgcp_client *mgcp;
struct gsm_trans *trans;
struct ran_conn *conn;
struct mgcp_msg mgcp_msg;
struct msgb *msg;
int rc;
OSMO_ASSERT(mgcp_ctx);
mgcp = mgcp_ctx->mgcp;
OSMO_ASSERT(mgcp);
trans = mgcp_ctx->trans;
OSMO_ASSERT(trans);
conn = trans->conn;
OSMO_ASSERT(conn);
switch (event) {
case EV_CONNECT:
break;
default:
handle_error(mgcp_ctx, MGCP_ERR_UNEXP_TEARDOWN, true);
return;
}
LOGPFSML(fi, LOGL_DEBUG,
"MDCX/CN: completing connection for the CN side on MGW endpoint:%p, remote leg expects RTP input on address %s:%u\n",
mgcp_ctx->rtp_endpoint, conn->rtp.remote_addr_cn, conn->rtp.remote_port_cn);
/* Generate MGCP message string */
mgcp_msg = (struct mgcp_msg) {
.verb = MGCP_VERB_MDCX,
.presence = (MGCP_MSG_PRESENCE_ENDPOINT | MGCP_MSG_PRESENCE_CALL_ID | MGCP_MSG_PRESENCE_CONN_ID |
MGCP_MSG_PRESENCE_CONN_MODE | MGCP_MSG_PRESENCE_AUDIO_IP |
MGCP_MSG_PRESENCE_AUDIO_PORT),
.call_id = mgcp_ctx->call_id,
.conn_id = mgcp_ctx->conn_id_cn,
.conn_mode = MGCP_CONN_RECV_SEND,
.audio_ip = conn->rtp.remote_addr_cn,
.audio_port = conn->rtp.remote_port_cn,
.codecs[0] = conn->rtp.codec_cn,
.codecs_len = 1
};
if (osmo_strlcpy(mgcp_msg.endpoint, mgcp_ctx->rtp_endpoint, sizeof(mgcp_msg.endpoint)) >=
MGCP_ENDPOINT_MAXLEN) {
handle_error(mgcp_ctx, MGCP_ERR_TOOLONG, true);
return;
}
msg = mgcp_msg_gen(mgcp, &mgcp_msg);
OSMO_ASSERT(msg);
/* Transmit MGCP message to MGW */
mgcp_ctx->mgw_pending_trans = mgcp_msg_trans_id(msg);
rc = mgcp_client_tx(mgcp, msg, mgw_mdcx_cn_resp_cb, mgcp_ctx);
if (rc < 0) {
handle_error(mgcp_ctx, MGCP_ERR_MGW_TX_FAIL, true);
return;
}
osmo_fsm_inst_state_chg(fi, ST_MDCX_CN_COMPL, MGCP_MGW_TIMEOUT, MGCP_MGW_TIMEOUT_TIMER_NR);
}
/* Callback for MGCP-Client: handle response for CN associated CRCX */
static void mgw_mdcx_cn_resp_cb(struct mgcp_response *r, void *priv)
{
struct mgcp_ctx *mgcp_ctx = priv;
OSMO_ASSERT(mgcp_ctx);
if (r->head.response_code != 200) {
LOGPFSML(mgcp_ctx->fsm, LOGL_ERROR,
"MDCX/CN: response yields error: %d %s\n", r->head.response_code, r->head.comment);
handle_error(mgcp_ctx, MGCP_ERR_MGW_FAIL, true);
return;
}
/* Notify the FSM that we got the response. */
osmo_fsm_inst_dispatch(mgcp_ctx->fsm, EV_MDCX_CN_RESP, mgcp_ctx);
}
/* Callback for ST_MDCX_CN_COMPL: wait for mgw response, move on with the MDCX
* for the RAN side if we already have valid IP/Port data for the RAN sided
* RTP stream. */
static void fsm_mdcx_cn_compl_cb(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct mgcp_ctx *mgcp_ctx = data;
struct ran_conn *conn;
struct gsm_trans *trans;
OSMO_ASSERT(mgcp_ctx);
trans = mgcp_ctx->trans;
OSMO_ASSERT(trans);
conn = trans->conn;
OSMO_ASSERT(conn);
switch (event) {
case EV_MDCX_CN_RESP:
break;
default:
handle_error(mgcp_ctx, MGCP_ERR_UNEXP_TEARDOWN, true);
return;
}
/* Enter MDCX phase, but we must be sure that the Assigmnet on the A or
* IuCS interface is complete (IP-Address and Port are valid) */
osmo_fsm_inst_state_chg(fi, ST_MDCX_RAN, MGCP_ASS_TIMEOUT, MGCP_ASS_TIMEOUT_TIMER_NR);
/* If we already have a valid remote port and IP-Address from the RAN side
* call leg, the assignment has been completed before we got here, so we
* may move on immediately */
if (conn->rtp.remote_port_ran != 0 || strlen(conn->rtp.remote_addr_ran) > 0)
osmo_fsm_inst_dispatch(mgcp_ctx->fsm, EV_ASSIGN, mgcp_ctx);
}
static void mgw_mdcx_ran_resp_cb(struct mgcp_response *r, void *priv);
/* Callback for ST_MDCX_RAN: wait for assignment completion, send MDCX for CN side to MGW */
static void fsm_mdcx_ran_cb(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct mgcp_ctx *mgcp_ctx = data;
struct mgcp_client *mgcp;
struct gsm_trans *trans;
struct ran_conn *conn;
struct mgcp_msg mgcp_msg;
struct msgb *msg;
int rc;
OSMO_ASSERT(mgcp_ctx);
mgcp = mgcp_ctx->mgcp;
OSMO_ASSERT(mgcp);
trans = mgcp_ctx->trans;
OSMO_ASSERT(trans);
conn = trans->conn;
OSMO_ASSERT(conn);
switch (event) {
case EV_ASSIGN:
break;
default:
handle_error(mgcp_ctx, MGCP_ERR_UNEXP_TEARDOWN, true);
return;
}
LOGPFSML(fi, LOGL_DEBUG,
"MDCX/RAN: completing connection for the CN side on MGW endpoint:%p, RAN expects RTP input on address %s:%u\n",
mgcp_ctx->rtp_endpoint, conn->rtp.remote_addr_ran, conn->rtp.remote_port_ran);
/* Generate MGCP message string */
mgcp_msg = (struct mgcp_msg) {
.verb = MGCP_VERB_MDCX,
.presence = (MGCP_MSG_PRESENCE_ENDPOINT | MGCP_MSG_PRESENCE_CALL_ID | MGCP_MSG_PRESENCE_CONN_ID |
MGCP_MSG_PRESENCE_CONN_MODE | MGCP_MSG_PRESENCE_AUDIO_IP |
MGCP_MSG_PRESENCE_AUDIO_PORT),
.call_id = mgcp_ctx->call_id,
.conn_id = mgcp_ctx->conn_id_ran,
.conn_mode = MGCP_CONN_RECV_SEND,
.audio_ip = conn->rtp.remote_addr_ran,
.audio_port = conn->rtp.remote_port_ran,
.codecs[0] = conn->rtp.codec_ran,
.codecs_len = 1
};
if (osmo_strlcpy(mgcp_msg.endpoint, mgcp_ctx->rtp_endpoint, sizeof(mgcp_msg.endpoint)) >=
MGCP_ENDPOINT_MAXLEN) {
handle_error(mgcp_ctx, MGCP_ERR_TOOLONG, true);
return;
}
msg = mgcp_msg_gen(mgcp, &mgcp_msg);
OSMO_ASSERT(msg);
/* Transmit MGCP message to MGW */
mgcp_ctx->mgw_pending_trans = mgcp_msg_trans_id(msg);
rc = mgcp_client_tx(mgcp, msg, mgw_mdcx_ran_resp_cb, mgcp_ctx);
if (rc < 0) {
handle_error(mgcp_ctx, MGCP_ERR_MGW_TX_FAIL, true);
return;
}
osmo_fsm_inst_state_chg(fi, ST_MDCX_RAN_COMPL, MGCP_MGW_TIMEOUT, MGCP_MGW_TIMEOUT_TIMER_NR);
}
/* Callback for MGCP-Client: handle response for CN associated CRCX */
static void mgw_mdcx_ran_resp_cb(struct mgcp_response *r, void *priv)
{
struct mgcp_ctx *mgcp_ctx = priv;
OSMO_ASSERT(mgcp_ctx);
if (r->head.response_code != 200) {
LOGPFSML(mgcp_ctx->fsm, LOGL_ERROR,
"MDCX/RAN: response yields error: %d %s\n", r->head.response_code, r->head.comment);
handle_error(mgcp_ctx, MGCP_ERR_MGW_FAIL, true);
return;
}
/* Notify the FSM that we got the response. */
osmo_fsm_inst_dispatch(mgcp_ctx->fsm, EV_MDCX_RAN_RESP, mgcp_ctx);
}
/* Callback for ST_MDCX_RAN_COMPL: check MGW response */
static void fsm_mdcx_ran_compl_cb(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct mgcp_ctx *mgcp_ctx = data;
OSMO_ASSERT(mgcp_ctx);
switch (event) {
case EV_MDCX_RAN_RESP:
break;
default:
handle_error(mgcp_ctx, MGCP_ERR_UNEXP_TEARDOWN, true);
return;
}
LOGPFSML(fi, LOGL_DEBUG, "call active, waiting for teardown...\n");
osmo_fsm_inst_state_chg(fi, ST_CALL, 0, 0);
}
static void mgw_dlcx_all_resp_cb(struct mgcp_response *r, void *priv);
/* Callback for ST_CALL: call is active, send DLCX for both sides on teardown */
static void fsm_call_cb(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct mgcp_ctx *mgcp_ctx = (struct mgcp_ctx *)data;
struct mgcp_client *mgcp;
struct mgcp_msg mgcp_msg;
struct msgb *msg;
int rc;
OSMO_ASSERT(mgcp_ctx);
mgcp = mgcp_ctx->mgcp;
OSMO_ASSERT(mgcp);
LOGPFSML(fi, LOGL_DEBUG,
"DLCX: removing connection for the RAN and CN side on MGW endpoint:%s...\n", mgcp_ctx->rtp_endpoint);
/* Generate MGCP message string */
mgcp_msg = (struct mgcp_msg) {
.verb = MGCP_VERB_DLCX,
.presence = (MGCP_MSG_PRESENCE_ENDPOINT | MGCP_MSG_PRESENCE_CALL_ID),
.call_id = mgcp_ctx->call_id
};
if (osmo_strlcpy(mgcp_msg.endpoint, mgcp_ctx->rtp_endpoint, sizeof(mgcp_msg.endpoint)) >=
MGCP_ENDPOINT_MAXLEN) {
handle_error(mgcp_ctx, MGCP_ERR_TOOLONG, true);
return;
}
msg = mgcp_msg_gen(mgcp, &mgcp_msg);
OSMO_ASSERT(msg);
/* Transmit MGCP message to MGW */
mgcp_ctx->mgw_pending_trans = mgcp_msg_trans_id(msg);
rc = mgcp_client_tx(mgcp, msg, mgw_dlcx_all_resp_cb, mgcp_ctx);
if (rc < 0) {
handle_error(mgcp_ctx, MGCP_ERR_MGW_TX_FAIL, true);
return;
}
osmo_fsm_inst_state_chg(fi, ST_HALT, MGCP_MGW_TIMEOUT, MGCP_MGW_TIMEOUT_TIMER_NR);
}
/* Callback for MGCP-Client: handle response for CN associated CRCX */
static void mgw_dlcx_all_resp_cb(struct mgcp_response *r, void *priv)
{
struct mgcp_ctx *mgcp_ctx = priv;
OSMO_ASSERT(mgcp_ctx);
/* DLCX is the only command where 250 is permitted as positive result */
if (r->head.response_code != 200 && r->head.response_code != 250) {
LOGPFSML(mgcp_ctx->fsm, LOGL_ERROR,
"DLCX: response yields error: %d %s\n", r->head.response_code, r->head.comment);
handle_error(mgcp_ctx, MGCP_ERR_MGW_FAIL, true);
return;
}
/* Notify the FSM that we got the response. */
osmo_fsm_inst_dispatch(mgcp_ctx->fsm, EV_DLCX_ALL_RESP, mgcp_ctx);
}
/* Callback for ST_HALT: Terminate the state machine */
static void fsm_halt_cb(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct mgcp_ctx *mgcp_ctx = data;
struct mgcp_client *mgcp;
OSMO_ASSERT(mgcp_ctx);
mgcp = mgcp_ctx->mgcp;
OSMO_ASSERT(mgcp);
/* NOTE: We must not free the context information now, we have to
* wait until msc_mgcp_call_release() is called. Then we are sure
* that the logic controlling us is fully aware that the context
* information is freed. If we would free early now the controlling
* logic might mistakenly think that the context info is still alive,
* so lets keep the context info until we are explicitly asked for
* throwing it away. */
if (mgcp_ctx->free_ctx) {
/* Be sure that there is no pending MGW transaction */
mgcp_client_cancel(mgcp, mgcp_ctx->mgw_pending_trans);
/* Free FSM and its context information */
osmo_fsm_inst_free(mgcp_ctx->fsm);
talloc_free(mgcp_ctx);
return;
}
osmo_fsm_inst_state_chg(fi, ST_HALT, MGCP_REL_TIMEOUT, MGCP_REL_TIMEOUT_TIMER_NR);
}
static struct osmo_fsm_state fsm_msc_mgcp_states[] = {
/* Startup state machine, send CRCX for RAN side. */
[ST_CRCX_RAN] = {
.in_event_mask = S(EV_INIT),
.out_state_mask = S(ST_HALT) | S(ST_CALL) | S(ST_CRCX_CN),
.name = OSMO_STRINGIFY(ST_CRCX_RAN),
.action = fsm_crcx_ran_cb,
},
/* When the response to the RAN CRCX is received, then proceed with
sending the CRCX for CN side */
[ST_CRCX_CN] = {
.in_event_mask = S(EV_TEARDOWN) | S(EV_TEARDOWN_ERROR) | S(EV_CRCX_RAN_RESP),
.out_state_mask = S(ST_HALT) | S(ST_CALL) | S(ST_CRCX_COMPL),
.name = OSMO_STRINGIFY(ST_CRCX_CN),
.action = fsm_crcx_cn_cb,
},
/* Complete the CRCX phase by starting the assignment. Depending on the
* RAT (Radio Access Technology), this will either trigger an
* Assignment Request on the A-Interface or an RAB-Assignment on the
* IU-interface */
[ST_CRCX_COMPL] = {
.in_event_mask = S(EV_TEARDOWN) | S(EV_TEARDOWN_ERROR) | S(EV_CRCX_CN_RESP),
.out_state_mask = S(ST_HALT) | S(ST_CALL) | S(ST_MDCX_CN),
.name = OSMO_STRINGIFY(ST_CRCX_COMPL),
.action = fsm_crcx_compl,
},
/* Wait for MSC to complete the assignment request, when complete, we
* will enter the MDCX phase by sending an MDCX for the CN side to the
* MGW */
[ST_MDCX_CN] = {
.in_event_mask = S(EV_TEARDOWN) | S(EV_TEARDOWN_ERROR) | S(EV_CONNECT),
.out_state_mask = S(ST_HALT) | S(ST_CALL) | S(ST_MDCX_CN_COMPL),
.name = OSMO_STRINGIFY(ST_MDCX_CN),
.action = fsm_mdcx_cn_cb,
},
/* We arrive in this state when the MDCX phase for the CN side has
* completed we will check the IP/Port of the RAN connection. If this
* data is valid we may continue with the MDCX phase for the RAN side.
* If not we wait until the assinment completes on the A or on the IuCS
* interface. The completion of the assignment will fill in the port and
* IP-Address of the RAN side and way may continue then. */
[ST_MDCX_CN_COMPL] = {
.in_event_mask = S(EV_TEARDOWN) | S(EV_MDCX_CN_RESP),
.out_state_mask = S(ST_HALT) | S(ST_CALL) | S(ST_MDCX_RAN),
.name = OSMO_STRINGIFY(ST_MDCX_CN_COMPL),
.action = fsm_mdcx_cn_compl_cb,
},
/* When the response for the CN MDCX is received, send the MDCX for the
* RAN side to the MGW */
[ST_MDCX_RAN] = {
.in_event_mask = S(EV_TEARDOWN) | S(EV_TEARDOWN_ERROR) | S(EV_ASSIGN),
.out_state_mask = S(ST_HALT) | S(ST_CALL) | S(ST_MDCX_RAN_COMPL),
.name = OSMO_STRINGIFY(ST_MDCX_RAN),
.action = fsm_mdcx_ran_cb,
},
/* The RAN side MDCX phase is complete when the response is received
* from the MGW. The call is then active, we change to ST_CALL and wait
* there until the call ends. */
[ST_MDCX_RAN_COMPL] = {
.in_event_mask = S(EV_TEARDOWN) | S(EV_TEARDOWN_ERROR) | S(EV_MDCX_RAN_RESP),
.out_state_mask = S(ST_HALT) | S(ST_CALL),
.name = OSMO_STRINGIFY(ST_MDCX_RAN_COMPL),
.action = fsm_mdcx_ran_compl_cb,
},
/* We are now in the active call phase, wait until the call is done
* and send a DLCX then to remove all connections from the MGW */
[ST_CALL] = {
.in_event_mask = S(EV_TEARDOWN) | S(EV_TEARDOWN_ERROR),
.out_state_mask = S(ST_HALT),
.name = OSMO_STRINGIFY(ST_CALL),
.action = fsm_call_cb,
},
/* When the MGW confirms that the connections are terminated, then halt
* the state machine. */
[ST_HALT] = {
.in_event_mask = S(EV_TEARDOWN) | S(EV_TEARDOWN_ERROR) | S(EV_DLCX_ALL_RESP),
.out_state_mask = S(ST_HALT),
.name = OSMO_STRINGIFY(ST_HALT),
.action = fsm_halt_cb,
},
};
/* State machine definition */
static struct osmo_fsm fsm_msc_mgcp = {
.name = "msc-mgcp",
.states = fsm_msc_mgcp_states,
.num_states = ARRAY_SIZE(fsm_msc_mgcp_states),
.log_subsys = DMGCP,
.timer_cb = fsm_timeout_cb,
.event_names = msc_mgcp_fsm_evt_names,
};
/* Try to invoke call assignment and set trans->cc.assignment_started flag if invoked.
* This is relevant for already ongoing calls -- scenario:
* - subscriber is in an active voice call,
* - another call is coming in.
* For the second call coming in, we must wait to establish RTP and assignment until the first call is CC-Disconnected.
*/
int msc_mgcp_try_call_assignment(struct gsm_trans *trans)
{
struct ran_conn *conn = trans->conn;
if (trans->cc.assignment_started)
return 0;
if (conn->rtp.mgcp_ctx) {
LOGPFSMSL(conn->fi, DMGCP, LOGL_INFO, "Another call is already ongoing, not assigning yet\n");
return 0;
}
LOGPFSMSL(conn->fi, DMGCP, LOGL_INFO, "Starting call assignment\n");
trans->cc.assignment_started = true;
return msc_mgcp_call_assignment(trans);
}
/* Notify that a new call begins. This will create a connection for the
* RAN and the CN on the MGW.
* Parameter:
* trans: transaction context.
* Returns -EINVAL on error, 0 on success. */
int msc_mgcp_call_assignment(struct gsm_trans *trans)
{
struct mgcp_ctx *mgcp_ctx;
static bool fsm_registered = false;
struct ran_conn *conn;
struct mgcp_client *mgcp;
OSMO_ASSERT(trans);
if (!trans->conn) {
LOGP(DMGCP, LOGL_ERROR, "(subscriber:%s) invalid conn, call assignment failed\n",
vlr_subscr_name(trans->vsub));
return -EINVAL;
}
conn = trans->conn;
mgcp = conn->network->mgw.client;
OSMO_ASSERT(mgcp);
if (conn->rtp.mgcp_ctx) {
LOGP(DMGCP, LOGL_ERROR, "(subscriber:%s) double assignment detected, dropping...\n",
vlr_subscr_name(trans->vsub));
return -EINVAL;
}
#ifdef BUILD_IU
/* FIXME: HACK. where to scope the RAB Id? At the conn / subscriber / ranap_ue_conn_ctx? */
static uint8_t next_iu_rab_id = 1;
if (conn->via_ran == OSMO_RAT_UTRAN_IU)
conn->iu.rab_id = next_iu_rab_id++;
#endif
/* Register the fsm description (if not already done) */
if (fsm_registered == false) {
osmo_fsm_register(&fsm_msc_mgcp);
fsm_registered = true;
}
/* Allocate and configure a new fsm instance */
mgcp_ctx = talloc_zero(NULL, struct mgcp_ctx);
OSMO_ASSERT(mgcp_ctx);
if (osmo_strlcpy(mgcp_ctx->rtp_endpoint, mgcp_client_rtpbridge_wildcard(mgcp), sizeof(mgcp_ctx->rtp_endpoint))
>= sizeof(mgcp_ctx->rtp_endpoint)) {
talloc_free(mgcp_ctx);
LOGP(DMGCP, LOGL_ERROR, "(subscriber:%s) endpoint identifier exceeds maximum length: %s\n",
vlr_subscr_name(trans->vsub), osmo_quote_str(mgcp_client_rtpbridge_wildcard(mgcp), -1));
return -EINVAL;
}
mgcp_ctx->fsm = osmo_fsm_inst_alloc(&fsm_msc_mgcp, NULL, NULL, LOGL_DEBUG, NULL);
OSMO_ASSERT(mgcp_ctx->fsm);
osmo_fsm_inst_update_id_f(mgcp_ctx->fsm, "%s_%s_trans%d",
vlr_subscr_name(trans->vsub), ran_conn_get_conn_id(conn), trans->transaction_id);
mgcp_ctx->fsm->priv = mgcp_ctx;
mgcp_ctx->mgcp = mgcp;
mgcp_ctx->trans = trans;
mgcp_ctx->call_id = trans->callref;
/* start state machine */
OSMO_ASSERT(mgcp_ctx->fsm->state == ST_CRCX_RAN);
osmo_fsm_inst_dispatch(mgcp_ctx->fsm, EV_INIT, mgcp_ctx);
conn->rtp.mgcp_ctx = mgcp_ctx;
LOGP(DMGCP, LOGL_DEBUG, "(subscriber:%s) call assignment initiated\n",
vlr_subscr_name(conn->vsub));
return 0;
}
/* Inform the FSM that the assignment (RAN connection) is now complete.
* Parameter:
* conn: RAN connection context.
* port: port number of the remote leg.
* addr: IP-address of the remote leg.
* Returns -EINVAL on error, 0 on success. */
int msc_mgcp_ass_complete(struct ran_conn *conn, uint16_t port, char *addr)
{
struct mgcp_ctx *mgcp_ctx;
OSMO_ASSERT(conn);
if (port == 0) {
LOGP(DMGCP, LOGL_ERROR, "(subscriber:%s) invalid remote call leg port, assignment completion failed\n",
vlr_subscr_name(conn->vsub));
return -EINVAL;
}
if (!addr || strlen(addr) <= 0) {
LOGP(DMGCP, LOGL_ERROR, "(subscriber:%s) missing remote call leg address, assignment completion failed\n",
vlr_subscr_name(conn->vsub));
return -EINVAL;
}
mgcp_ctx = conn->rtp.mgcp_ctx;
if (!mgcp_ctx) {
LOGP(DMGCP, LOGL_ERROR, "(subscriber:%s) invalid mgcp context, assignment completion failed.\n",
vlr_subscr_name(conn->vsub));
return -EINVAL;
}
/* Memorize port and IP-Address of the remote RAN call leg. We need this
* information at latest when we enter the MDCX phase for the RAN side. */
conn->rtp.remote_port_ran = port;
osmo_strlcpy(conn->rtp.remote_addr_ran, addr, sizeof(conn->rtp.remote_addr_ran));
LOGP(DMGCP, LOGL_DEBUG, "(subscriber:%s) assignment completed, rtp %s:%d.\n",
vlr_subscr_name(conn->vsub), conn->rtp.remote_addr_ran, port);
/* Note: We only dispatch the event if we are really waiting for the
* assignment, if we are not yet waiting, there is no need to loudly
* broadcast an event that the all other states do not understand anyway */
if (mgcp_ctx->fsm->state == ST_MDCX_RAN)
osmo_fsm_inst_dispatch(mgcp_ctx->fsm, EV_ASSIGN, mgcp_ctx);
return 0;
}
/* Notify the MGCP context that Assignment failed.
* This will end the "ringing" on the other call leg, and will usually result in L3 and conn release (i.e. when no other
* transactions are still pending, which is usually the case). */
int msc_mgcp_ass_fail(struct ran_conn *conn)
{
struct mgcp_ctx *mgcp_ctx;
OSMO_ASSERT(conn);
mgcp_ctx = conn->rtp.mgcp_ctx;
if (!mgcp_ctx)
return -EINVAL;
LOGPFSMSL(conn->fi, DMGCP, LOGL_ERROR, "Assignment failed\n");
osmo_fsm_inst_dispatch(mgcp_ctx->fsm, EV_TEARDOWN_ERROR, mgcp_ctx);
return 0;
}
/* Make the connection of a previously assigned call complete
* Parameter:
* trans: transaction context.
* port: port number of the remote leg.
* addr: IP-address of the remote leg.
* Returns -EINVAL on error, 0 on success. */
int msc_mgcp_call_complete(struct gsm_trans *trans, uint16_t port, char *addr)
{
struct mgcp_ctx *mgcp_ctx;
struct ran_conn *conn;
OSMO_ASSERT(trans);
OSMO_ASSERT(addr);
if (port == 0) {
LOGP(DMGCP, LOGL_ERROR, "(subscriber:%s) invalid remote call leg port, call completion failed\n",
vlr_subscr_name(trans->vsub));
return -EINVAL;
}
if (!addr || strlen(addr) <= 0) {
LOGP(DMGCP, LOGL_ERROR, "(subscriber:%s) missing remote call leg address, call completion failed\n",
vlr_subscr_name(trans->vsub));
return -EINVAL;
}
if (!trans->conn) {
LOGP(DMGCP, LOGL_ERROR, "(subscriber:%s) invalid conn, call completion failed\n",
vlr_subscr_name(trans->vsub));
return -EINVAL;
}
if (!trans->conn->rtp.mgcp_ctx) {
LOGP(DMGCP, LOGL_ERROR, "(subscriber:%s) invalid mgcp context, call completion failed.\n",
vlr_subscr_name(trans->vsub));
return -EINVAL;
}
if (!trans->conn->rtp.mgcp_ctx->fsm) {
LOGP(DMGCP, LOGL_ERROR, "(subscriber:%s) no FSM, call completion failed\n",
vlr_subscr_name(trans->vsub));
return -EINVAL;
}
mgcp_ctx = trans->conn->rtp.mgcp_ctx;
/* The FSM should already have passed all CRCX phases and be ready to move
* on with the MDCX phases. */
if (mgcp_ctx->fsm->state != ST_MDCX_CN) {
LOGP(DMGCP, LOGL_ERROR, "(subscriber:%s) invalid call state, call completion failed\n",
vlr_subscr_name(trans->vsub));
return -EINVAL;
}
conn = trans->conn;
osmo_strlcpy(conn->rtp.remote_addr_cn, addr, sizeof(conn->rtp.remote_addr_cn));
conn->rtp.remote_port_cn = port;
osmo_fsm_inst_dispatch(mgcp_ctx->fsm, EV_CONNECT, mgcp_ctx);
LOGP(DMGCP, LOGL_DEBUG, "(subscriber:%s) call completion initiated\n",
vlr_subscr_name(conn->vsub));
return 0;
}
static struct gsm_trans *find_waiting_call(struct ran_conn *conn)
{
struct gsm_trans *trans;
struct gsm_network *net = conn->network;
llist_for_each_entry(trans, &net->trans_list, entry) {
if (trans->conn != conn)
continue;
if (trans->protocol != GSM48_PDISC_CC)
continue;
if (trans->cc.assignment_started)
continue;
return trans;
}
return NULL;
}
/* Release ongoing call.
* Parameter:
* trans: connection context.
* Returns -EINVAL on error, 0 on success. */
int msc_mgcp_call_release(struct gsm_trans *trans)
{
struct mgcp_ctx *mgcp_ctx;
struct ran_conn *conn = trans->conn;
struct gsm_trans *waiting_trans;
OSMO_ASSERT(trans);
if (!conn) {
LOGP(DMGCP, LOGL_ERROR, "(subscriber:%s) invalid conn, call release failed\n",
vlr_subscr_name(trans->vsub));
return -EINVAL;
}
mgcp_ctx = conn->rtp.mgcp_ctx;
if (!mgcp_ctx) {
LOGP(DMGCP, LOGL_ERROR, "(subscriber:%s) invalid mgcp context, call release failed.\n",
vlr_subscr_name(trans->vsub));
return -EINVAL;
}
if (!mgcp_ctx->fsm) {
LOGP(DMGCP, LOGL_ERROR, "(subscriber:%s) no FSM, call release failed\n",
vlr_subscr_name(trans->vsub));
return -EINVAL;
}
if (mgcp_ctx->trans != trans) {
LOGP(DMGCP, LOGL_DEBUG, "(ti %02x %s) call release for background CC transaction\n",
trans->transaction_id, vlr_subscr_name(trans->vsub));
return 0;
}
LOGP(DMGCP, LOGL_DEBUG, "(ti %02x %s) Call release: tearing down MGW endpoint\n",
trans->transaction_id, vlr_subscr_name(trans->vsub));
/* Inform the FSM that as soon as it reaches ST_HALT it may free
* all context information immediately */
mgcp_ctx->free_ctx = true;
/* Initaite teardown, regardless of which state we are currently
* in */
osmo_fsm_inst_dispatch(mgcp_ctx->fsm, EV_TEARDOWN, mgcp_ctx);
/* Prevent any further operation that is triggered from outside by
* overwriting the context pointer with NULL. The FSM will now
* take care for a graceful shutdown and when done it will free
* all related context information */
conn->rtp.mgcp_ctx = NULL;
/* If there is another call still waiting to be activated, this is the time when the mgcp_ctx is available again
* and the other call can start assigning. */
waiting_trans = find_waiting_call(conn);
if (waiting_trans) {
LOGP(DMGCP, LOGL_DEBUG, "(ti %02x %s) Call waiting: starting Assignment\n",
waiting_trans->transaction_id, vlr_subscr_name(trans->vsub));
msc_mgcp_try_call_assignment(waiting_trans);
}
return 0;
}
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