diff options
| -rw-r--r-- | include/osmocom/msc/Makefile.am | 1 | ||||
| -rw-r--r-- | include/osmocom/msc/msc_vgcs.h | 228 | ||||
| -rw-r--r-- | include/osmocom/msc/ran_conn.h | 10 | ||||
| -rw-r--r-- | include/osmocom/msc/transaction.h | 19 | ||||
| -rw-r--r-- | src/libmsc/Makefile.am | 1 | ||||
| -rw-r--r-- | src/libmsc/gsm_04_11_gsup.c | 1 | ||||
| -rw-r--r-- | src/libmsc/msc_vgcs.c | 2741 | ||||
| -rw-r--r-- | src/libmsc/transaction.c | 15 |
8 files changed, 3015 insertions, 1 deletions
diff --git a/include/osmocom/msc/Makefile.am b/include/osmocom/msc/Makefile.am index 3c54dee5b..9fa06eb8e 100644 --- a/include/osmocom/msc/Makefile.am +++ b/include/osmocom/msc/Makefile.am @@ -25,6 +25,7 @@ noinst_HEADERS = \ msc_a_remote.h \ msc_common.h \ msc_ho.h \ + msc_vgcs.h \ msc_i.h \ msc_i_remote.h \ msc_roles.h \ diff --git a/include/osmocom/msc/msc_vgcs.h b/include/osmocom/msc/msc_vgcs.h new file mode 100644 index 000000000..2b2f45d31 --- /dev/null +++ b/include/osmocom/msc/msc_vgcs.h @@ -0,0 +1,228 @@ +/* Handle a call via VGCS/VBCS (Voice Group/Broadcast Call Service). */ +/* + * (C) 2023 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de> + * All Rights Reserved + * + * SPDX-License-Identifier: AGPL-3.0+ + * + * Author: Andreas Eversberg + * + * 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/>. + */ +#pragma once + +#include <osmocom/msc/transaction.h> + +#define GSM44068_ALLOC_SIZE 2048 +#define GSM44068_ALLOC_HEADROOM 256 + +static inline struct msgb *gsm44068_msgb_alloc_name(const char *name) +{ + return msgb_alloc_headroom(GSM44068_ALLOC_SIZE, GSM44068_ALLOC_HEADROOM, name); +} + +/* VGCS/VBS "call control" connection to each BSS */ +struct vgcs_bss { + struct llist_head list; /* List entry */ + struct llist_head cell_list; /* List of cells */ + struct gsm_trans *trans; /* Back pointer to transaction */ + struct osmo_fsm_inst *fi; /* State machine of each BSS */ + struct ran_conn *conn; /* RAN ("SCCP") connection */ + enum trans_type trans_type; /* Transaction type */ + uint32_t callref; /* Callref */ + int pc; /* Point code for debug purpose */ +}; + +/* VGCS/VBS "resource control" connection to each cell in BSS */ +struct vgcs_bss_cell { + struct llist_head list_bss; /* List entry in vgcs_bss */ + struct llist_head list_mgw; /* List entry in MGW endpoint */ + struct vgcs_bss *bss; /* Back pointer to vgcs_bss */ + struct vgcs_mgw_ep *mgw; /* Back pointer to vgcs_mgw_ep */ + struct osmo_fsm_inst *fi; /* State machine of each cell */ + int cell_id; /* Id of cell (BTS) to use */ + struct ran_conn *conn; /* RAN ("SCCP") connection */ + enum trans_type trans_type; /* Transaction type */ + uint32_t callref; /* Callref */ + int call_id; /* Id of call (used for MGW connections) */ + int pc; /* Point code for debug purpose */ + bool assigned; /* Flags if assignment is complete */ + struct rtp_stream *rtps; /* MGW connection process */ +}; + +/* VGCS/VBS MGW endpoint for each call */ +struct vgcs_mgw_ep { + struct llist_head cell_list; /* List of cells with connections */ + struct llist_head list; /* List entry */ + struct osmo_fsm_inst *fi; /* State machine of each cell */ + struct osmo_mgcpc_ep *mgw_ep; /* MGW endpoint */ +}; + +/* Events for the GCC/BCC state machine. + * There is no primitive definition like MNGCC-* oder MNBCC-* in the standard. */ +enum vgcs_gcc_fsm_event { + /* The network sets up a call. */ + VGCS_GCC_EV_NET_SETUP, + /* The network requests termination. */ + VGCS_GCC_EV_NET_TERM, + /* The user sets up a call. */ + VGCS_GCC_EV_USER_SETUP, + /* The user requests termination. */ + VGCS_GCC_EV_USER_TERM, + /* BSS completed call establishment (all BSCs) */ + VGCS_GCC_EV_BSS_ESTABLISHED, + /* Assignment was completed. */ + VGCS_GCC_EV_BSS_ASSIGN_CPL, + /* Assignment failed. */ + VGCS_GCC_EV_BSS_ASSIGN_FAIL, + /* BSS released call establishment (all BSCs) */ + VGCS_GCC_EV_BSS_RELEASED, + /* Inactivity timeout */ + VGCS_GCC_EV_TIMEOUT, +}; + +/* 3GPP TS 44.068 6.1.2.2 States of GCC/BCC */ +enum vgcs_gcc_fsm_state { + /* No call. Initial state when instance is created. */ + VGCS_GCC_ST_N0_NULL = 0, + /* An MS wants to establish a call. */ + VGCS_GCC_ST_N1_CALL_INITIATED, + /* Call established in at least one cell. */ + VGCS_GCC_ST_N2_CALL_ACTIVE, + /* Channel activation is requested, CONNECT already sent to MS. */ + VGCS_GCC_ST_N3_CALL_EST_PROC, + /* Call termination is requested, waiting for all cells to confirm. */ + VGCS_GCC_ST_N4_TERMINATION_REQ, +}; + +const char *vgcs_bcc_gcc_state_name(struct osmo_fsm_inst *fi); + +/* Events for the VGCS/VBS "call control" state machine */ +enum vgcs_bss_fsm_event { + /* Start a VGCS/VBS call using VGCS/VBS SETUP message */ + VGCS_BSS_EV_SETUP, + /* VGCS/VBS SETUP ACK is received */ + VGCS_BSS_EV_SETUP_ACK, + /* VGCS/VBS SETUP REFUSE is received */ + VGCS_BSS_EV_SETUP_REFUSE, + /* VGCS/VBS ASSIGNMENT complete or failed */ + VGCS_BSS_EV_ACTIVE_OR_FAIL, + /* Talker request */ + VGCS_BSS_EV_UL_REQUEST, + /* Talker established uplink */ + VGCS_BSS_EV_UL_REQUEST_CNF, + /* Talker send app data */ + VGCS_BSS_EV_UL_APP_DATA, + /* Talker send signaling data */ + VGCS_BSS_EV_BSS_DTAP, + /* Talker becomes listener */ + VGCS_BSS_EV_UL_RELEASE, + /* Release channel towards BSS */ + VGCS_BSS_EV_CLEAR, + /* Channel closed from BSS */ + VGCS_BSS_EV_CLOSE, + /* Release is complete */ + VGCS_BSS_EV_RELEASED, +}; + +/* States of the VGCS/VBS "call control" state machine */ +enum vgcs_bss_fsm_state { + /* No call. Initial state when instance is created. */ + VGCS_BSS_ST_NULL = 0, + /* VGCS/VBS SETUP is sent towards BSC */ + VGCS_BSS_ST_SETUP, + /* VGCS/VBS ASSIGNMENT REQUEST is sent towards BSC */ + VGCS_BSS_ST_ASSIGNMENT, + /* VGCS/VBS is establised */ + VGCS_BSS_ST_ACTIVE, + /* CLEAR COMMAND was sent */ + VGCS_BSS_ST_RELEASE, +}; + +/* Events for the VGCS/VBS "resource control" state machine */ +enum vgcs_cell_fsm_event { + /* RTP stream gone */ + VGCS_CELL_EV_RTP_STREAM_GONE, + /* RTP stream remote addr available */ + VGCS_CELL_EV_RTP_STREAM_ADDR_AVAILABLE, + /* RTP stream established */ + VGCS_CELL_EV_RTP_STREAM_ESTABLISHED, + /* Start a VGCS/VBS channel using VGCS/VBS ASSIGNMENT message */ + VGCS_CELL_EV_ASSIGN, + /* VGCS/VBS ASSIGNMENT RESULT is received */ + VGCS_CELL_EV_ASSIGN_RES, + /* VGCS/VBS ASSIGNMENT FAILURE is received */ + VGCS_CELL_EV_ASSIGN_FAIL, + /* Release channel towards BSS */ + VGCS_CELL_EV_CLEAR, + /* Channel closed from BSS */ + VGCS_CELL_EV_CLOSE, + /* Release is complete */ + VGCS_CELL_EV_RELEASED, +}; + +/* States of the VGCS/VBS "resource control" state machine */ +enum vgcs_cell_fsm_state { + /* No call. Initial state when instance is created. */ + VGCS_CELL_ST_NULL = 0, + /* VGCS/VBS ASSIGNMENT REQUEST is sent towards BSC */ + VGCS_CELL_ST_ASSIGNMENT, + /* Channel is establised */ + VGCS_CELL_ST_ACTIVE, + /* CLEAR COMMAND was sent */ + VGCS_CELL_ST_RELEASE, +}; + +/* Events for the VGCS/VBS MGW endpoint state machine */ +enum vgcs_mgw_ep_fsm_event { + /* MGW endpoint gone */ + VGCS_MGW_EP_EV_FREE, + /* Destroy MGW endpoint */ + VGCS_MGW_EP_EV_CLEAR, +}; + +/* States of the VGCS/VBS MGW endpoint state machine */ +enum vgcs_mgw_ep_fsm_state { + VGCS_MGW_EP_ST_NULL = 0, + /* MGW endpoint allocated */ + VGCS_MGW_EP_ST_ACTIVE, +}; + +const char *gsm44068_group_id_string(uint32_t callref); + +struct gcr; + +int gsm44068_rcv_rr(struct msc_a *msc_a, struct msgb *msg); +int gsm44068_rcv_bcc_gcc(struct msc_a *msc_a, struct gsm_trans *trans, struct msgb *msg); +const char *vgcs_vty_initiate(struct gsm_network *gsmnet, struct gcr *gcr); +const char *vgcs_vty_terminate(struct gsm_network *gsmnet, struct gcr *gcr); +void gsm44068_bcc_gcc_trans_free(struct gsm_trans *trans); + +void vgcs_vbs_setup_ack(struct vgcs_bss *bss, const struct ran_msg *ran_msg); +void vgcs_vbs_setup_refuse(struct vgcs_bss *bss, const struct ran_msg *ran_msg); +void vgcs_vbs_assign_result(struct vgcs_bss_cell *cell, const struct ran_msg *ran_msg); +void vgcs_vbs_assign_fail(struct vgcs_bss_cell *cell, const struct ran_msg *ran_msg); +void vgcs_vbs_queuing_ind(struct vgcs_bss_cell *cell); +void vgcs_uplink_request(struct vgcs_bss *bss, const struct ran_msg *ran_msg); +void vgcs_uplink_request_cnf(struct vgcs_bss *bss, const struct ran_msg *ran_msg); +void vgcs_app_data(struct vgcs_bss *bss, const struct ran_msg *ran_msg); +void vgcs_bss_dtap(struct vgcs_bss *bss, const struct ran_msg *ran_msg); +void vgcs_uplink_release_ind(struct vgcs_bss *bss, const struct ran_msg *ran_msg); +void vgcs_vbs_assign_status(struct vgcs_bss_cell *cell, const struct ran_msg *ran_msg); +void vgcs_vbs_clear_req_channel(struct vgcs_bss_cell *cell, const struct ran_msg *ran_msg); +void vgcs_vbs_clear_cpl_channel(struct vgcs_bss_cell *cell, const struct ran_msg *ran_msg); +void vgcs_vbs_clear_req(struct vgcs_bss *bss, const struct ran_msg *ran_msg); +void vgcs_vbs_clear_cpl(struct vgcs_bss *bss, const struct ran_msg *ran_msg); +void vgcs_vbs_caller_assign_cpl(struct gsm_trans *trans); +void vgcs_vbs_caller_assign_fail(struct gsm_trans *trans); diff --git a/include/osmocom/msc/ran_conn.h b/include/osmocom/msc/ran_conn.h index 7aa50df07..cdaa02652 100644 --- a/include/osmocom/msc/ran_conn.h +++ b/include/osmocom/msc/ran_conn.h @@ -18,9 +18,17 @@ struct ran_conn { uint32_t sccp_conn_id; /* MSC role that this RAN connection belongs to. This will be either an msc_i (currently active - * connection) or an msc_t (transitory new connection during Handover). */ + * connection) or an msc_t (transitory new connection during Handover). + * Used for usual L3 ran_conn to a subscriber. */ struct osmo_fsm_inst *msc_role; + /* For VGCS/VBS, we have additional N connections to BSS. When receiving messages for a group call peer, + * dispatch to the VGCS management. */ + struct { + void *bss; + void *cell; + } vgcs; + bool closing; }; diff --git a/include/osmocom/msc/transaction.h b/include/osmocom/msc/transaction.h index 356bd6c8b..a5a2e84ea 100644 --- a/include/osmocom/msc/transaction.h +++ b/include/osmocom/msc/transaction.h @@ -99,6 +99,25 @@ struct gsm_trans { union { struct { + /* State machine of setup process towards BSS */ + struct osmo_fsm_inst *fi; + /* BSS list with all VGCS/VBS calls */ + struct llist_head bss_list; + /* Inactivity timeout and timer */ + int inactivity_to; + struct osmo_timer_list timer_inactivity; + /* If talker's downlink shall be muted */ + bool mute_talker; + /* Indicator, if Uplink is used in one cell */ + bool uplink_busy; + /* BSS that uses the uplink */ + struct vgcs_bss *uplink_bss; + /* Cell that uses the uplink */ + struct vgcs_bss_cell *uplink_cell; + /* If uplink is used by the originator */ + bool uplink_originator; + } gcc; + struct { /* current call state */ int state; diff --git a/src/libmsc/Makefile.am b/src/libmsc/Makefile.am index c4e134c19..2e6240284 100644 --- a/src/libmsc/Makefile.am +++ b/src/libmsc/Makefile.am @@ -55,6 +55,7 @@ libmsc_a_SOURCES = \ msc_t.c \ msc_t_remote.c \ msc_ho.c \ + msc_vgcs.c \ neighbor_ident.c \ neighbor_ident_vty.c \ paging.c \ diff --git a/src/libmsc/gsm_04_11_gsup.c b/src/libmsc/gsm_04_11_gsup.c index 7a47e9386..0f1891280 100644 --- a/src/libmsc/gsm_04_11_gsup.c +++ b/src/libmsc/gsm_04_11_gsup.c @@ -33,6 +33,7 @@ #include <osmocom/msc/vlr.h> #include <osmocom/msc/msub.h> #include <osmocom/msc/gsup_client_mux.h> +#include <osmocom/msc/msc_a.h> /* Common helper for preparing to be encoded GSUP message */ static void gsup_sm_msg_init(struct osmo_gsup_message *gsup_msg, diff --git a/src/libmsc/msc_vgcs.c b/src/libmsc/msc_vgcs.c new file mode 100644 index 000000000..1af9aaec1 --- /dev/null +++ b/src/libmsc/msc_vgcs.c @@ -0,0 +1,2741 @@ +/* Handle VGCS/VBCS calls. (Voice Group/Broadcast Call Service). */ +/* + * (C) 2023 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de> + * All Rights Reserved + * + * SPDX-License-Identifier: AGPL-3.0+ + * + * Author: Andreas Eversberg + * + * 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/>. + */ + +/* The process consists of four state machines: + * + * The call control state machine "GCC" handles the voice group/broadcast call. + * There is one instance for every call. It is mainly controlled by the calling + * subscriber. The state machine is described in 3GPP TS 44.068 / 44.069. + * One SCCP connection to the calling subscriber is associated with the state + * machine. Once the calling subscriber leaves or is assigned to the VGCS/VBS + * channel, the association to the MSC-A role is removed and the SCCP connection + * is closed. The state machine with the transaction still exists until the end + * of the call. + * + * The BSS control state machine "vgcs_bss_fsm" handles the call in each BSC. + * There are as many instances as there are BSCs where the call is placed to. + * The instances are linked to the call control in a 1:n relation. + * One SCCP connection for every BSC is associated with the state machine. + * It sets up the call in the BSC and handles the uplink control and signaling + * with the talking phone. + * + * The resource controling state machine "vgcs_cell_fsm" handles the channel for + * each BTS that has a VGCS for the call. The instances are linked to the BSS + * control in a 1:n relation. + * One SCCP connection for every cell is associated with each list entry. + * It assigns the VGCS/VBS channel and the conference bridge in the MGW. + * + * The MGW endpoint state machine "vgcs_mgw_ep_fsm" handles the endpoint + * connection for each call. It controls the clearing of the MGW connections + * in case of endpoint failure. All instances of the resource controlling state + * machine are linked to this state machine in a 1:n relation. + * + * Setup of a call: + * + * When the calling subscriber dials a group/broadcast call, the GCR is checked + * for an existing Group ID. If it exists, the call is setup towards the a given + * list of MSCs for this Group ID. Also the channels are assigned for a given + * list of cells for this Group ID. + * The call can also be initiated via VTY. + * + * Then the calling subscriber is assigned to the VGCS channel of the same cell + * where the call was initialized. Afterwards the call is connected. The calling + * subscriber may then stay on the uplink or release it. + * + * Uplink control: + * + * Any BSC may indicate a talking subscriber. If there is no talking subscriber + * yet, the uplink is granted, otherwise it is rejected. If the uplink is in + * use on one BSC, all other BSCs will be blocked. If the uplink becomes free, + * all other BSCs will be unblocked. + * + * Termination of the call: + * + * The calling subscriber accesses the uplink. The it sends a termination + * request. This request is acknowledged by a termination command towards + * the calling subscriber. The call is cleared. + * The call can also be terminated via VTY and/or a timeout. + * + */ + +#include <osmocom/core/utils.h> +#include <osmocom/core/fsm.h> +#include <osmocom/gsm/protocol/gsm_44_068.h> +#include <osmocom/sigtran/sccp_helpers.h> +#include <osmocom/mgcp_client/mgcp_client_endpoint_fsm.h> + +#include <osmocom/msc/gsm_data.h> +#include <osmocom/msc/sccp_ran.h> +#include <osmocom/msc/ran_infra.h> +#include <osmocom/msc/ran_peer.h> +#include <osmocom/msc/ran_msg_a.h> +#include <osmocom/msc/msub.h> +#include <osmocom/msc/debug.h> +#include <osmocom/msc/msc_a.h> +#include <osmocom/msc/vlr.h> +#include <osmocom/msc/rtp_stream.h> +#include <osmocom/msc/codec_mapping.h> +#include <osmocom/msc/msc_vgcs.h> +#include <osmocom/msc/asci_gcr.h> + +#define S(x) (1 << (x)) + +#define LOG_GCC(trans, level, fmt, args...) \ + LOGP((trans) ? ((trans->type == TRANS_GCC) ? DGCC : DBCC) : DASCI, level, \ + (trans) ? ((trans->type == TRANS_GCC) ? ("GCC callref %s: " fmt) : ("BCC callref %s: " fmt)) : "%s" fmt, \ + (trans) ? gsm44068_group_id_string(trans->callref) : "", ##args) +#define LOG_BSS(bss, level, fmt, args...) \ + LOGP(DASCI, level, \ + (bss->trans_type == TRANS_GCC) ? ("GCC callref %s, BSS #%s: " fmt) : ("BCC callref %s, BSS #%s: " fmt), \ + gsm44068_group_id_string(bss->callref), osmo_ss7_pointcode_print(NULL, bss->pc), ##args) +#define LOG_CELL(cell, level, fmt, args...) \ + LOGP(DASCI, level, \ + (cell->trans_type == TRANS_GCC) ? ("GCC callref %s, BSS #%s, CID %d: " fmt) \ + : ("BCC callref %s, BSS #%s, CID %d: " fmt), \ + gsm44068_group_id_string(cell->callref), osmo_ss7_pointcode_print(NULL, cell->pc), cell->cell_id, ##args) + +static struct osmo_fsm vgcs_bcc_fsm; +static struct osmo_fsm vgcs_gcc_fsm; +static struct osmo_fsm vgcs_bss_fsm; +static struct osmo_fsm vgcs_cell_fsm; +static struct osmo_fsm vgcs_mgw_ep_fsm; + +static __attribute__((constructor)) void vgcs_fsm_init(void) +{ + OSMO_ASSERT(osmo_fsm_register(&vgcs_bcc_fsm) == 0); + OSMO_ASSERT(osmo_fsm_register(&vgcs_gcc_fsm) == 0); + OSMO_ASSERT(osmo_fsm_register(&vgcs_bss_fsm) == 0); + OSMO_ASSERT(osmo_fsm_register(&vgcs_cell_fsm) == 0); + OSMO_ASSERT(osmo_fsm_register(&vgcs_mgw_ep_fsm) == 0); +} + +const char *gsm44068_group_id_string(uint32_t callref) +{ + static char string[9]; + + snprintf(string, sizeof(string), "%08u", callref); + string[sizeof(string) - 1] = '\0'; + + return string; +} + +/* Resolve ran peer from point-code */ +static struct ran_peer *ran_peer_for_pc(struct gsm_network *msc_network, int pc) +{ + struct sccp_ran_inst *sri; + struct osmo_sccp_addr addr = {}; + struct ran_peer *rp; + + sri = msc_network->a.sri; + if (!osmo_sccp_get_ss7(sri->sccp)) { + LOGP(DASCI, LOGL_ERROR, "No SS7???\n"); + return NULL; + } + osmo_sccp_make_addr_pc_ssn(&addr, pc, sri->ran->ssn); + rp = ran_peer_find_by_addr(sri, &addr); + + return rp; +} + +/* Encode message and send towards BSC. */ +int ran_encode_and_send(struct osmo_fsm_inst *fi, struct ran_msg *ran_msg, struct ran_conn *conn, bool initial) +{ + struct msgb *l3_msg; + int rc; + + l3_msg = ran_a_encode(fi, ran_msg); + if (!l3_msg) { + LOGP(DASCI, LOGL_ERROR, "ran_a_encode() failed.\n"); + return -EINVAL; + } + rc = ran_conn_down_l2_co(conn, l3_msg, initial); + msgb_free(l3_msg); + + return rc; +} + +/* Transmit DTAP message to talker + * This is used for sending group/broadcast call control messages. */ +int tx_dtap_to_talker(struct vgcs_bss *bss, struct msgb *l3_msg) +{ + struct ran_msg ran_msg; + struct gsm48_hdr *gh = msgb_l3(l3_msg) ? : l3_msg->data; + uint8_t pdisc = gsm48_hdr_pdisc(gh); + int rc; + + + LOG_BSS(bss, LOGL_DEBUG, "Sending DTAP: %s %s\n", + gsm48_pdisc_name(pdisc), gsm48_pdisc_msgtype_name(pdisc, gsm48_hdr_msg_type(gh))); + + ran_msg = (struct ran_msg){ + .msg_type = RAN_MSG_DTAP, + .dtap = l3_msg, + }; + + rc = ran_encode_and_send(bss->fi, &ran_msg, bss->conn, false); + + return rc; +} + +/* + * GCC/BCC Message transcoding + */ + +static void _add_cause_ie(struct msgb *msg, uint8_t cause, uint8_t *diag, uint8_t diag_len) +{ + uint8_t *ie = msgb_put(msg, 2 + diag_len); + + ie[0] = 1 + diag_len; + ie[1] = cause; + if (diag && diag_len) { + ie[1] |= 0x80; + memcpy(ie + 2, diag, diag_len); + } +} + +static void _add_callref_ie(struct msgb *msg, uint32_t callref, bool with_prio, uint8_t prio) +{ + uint32_t ie; + + ie = callref << 5; + if (with_prio) + ie |= 0x10 | (prio << 1); + msgb_put_u32(msg, ie); +} + +static int _msg_too_short(void) +{ + LOGP(DASCI, LOGL_ERROR, "MSG too short.\n"); + return -EINVAL; +} + +static int _ie_invalid(void) +{ + LOGP(DASCI, LOGL_ERROR, "IE invalid.\n"); + return -EINVAL; +} + +static int _rx_callref(uint8_t *ie, unsigned int remaining_len, uint32_t *callref, bool *with_prio, uint8_t *prio) +{ + uint8_t ie_len; + + ie_len = sizeof(uint32_t); + if (remaining_len < ie_len) + return _msg_too_short(); + *callref = osmo_load32be(ie) >> 5; + if (ie[3] & 0x10) { + *with_prio = true; + *prio = (ie[3] >> 1) & 0x7; + } else + *with_prio = false; + + return ie_len; +} + +/* 3GPP TS 44.068 Clause 8.1 */ +static int gsm44068_tx_connect(struct gsm_trans *trans, uint8_t pdisc, uint32_t callref, bool with_prio, uint8_t prio, + uint8_t oi, uint8_t talker_prio, bool with_sms, uint8_t sms_dc, uint8_t sms_gp) +{ + struct msgb *msg = gsm44068_msgb_alloc_name("GSM 44.068 TX CONNECT"); + struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); + uint8_t ie; + + gh->proto_discr = pdisc; + gh->msg_type = OSMO_GSM44068_MSGT_CONNECT; + _add_callref_ie(msg, callref, with_prio, prio); + ie = (talker_prio << 4) | oi; + msgb_put_u8(msg, ie); + if (with_sms) { + ie = OSMO_GSM44068_IEI_SMS_INDICATIONS | (sms_dc << 1) | sms_gp; + msgb_put_u8(msg, ie); + } + + /* Send to calling subscriber, depending on the link he is. */ + if (trans->msc_a) + return msc_a_tx_dtap_to_i(trans->msc_a, msg); + if (trans->gcc.uplink_bss) + return tx_dtap_to_talker(trans->gcc.uplink_bss, msg); + msgb_free(msg); + return -EIO; +} + +/* The Get Status procedure is not used by the current implementation. + * It is commented out, so it can be used in the future. + * The idea is to have a complete set of GCC/BCC message transcoding. + */ +#if 0 +/* 3GPP TS 44.068 Clause 8.2 */ +static int gsm44068_tx_get_status(struct gsm_trans *trans, uint8_t pdisc, struct osmo_mobile_identity *mi) +{ + struct msgb *msg = gsm44068_msgb_alloc_name("GSM 44.068 TX GET STATUS"); + struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); + + gh->proto_discr = pdisc; + gh->msg_type = OSMO_GSM44068_MSGT_GET_STATUS; + if (mi) { + uint8_t *l; + int rc; + + l = msgb_tl_put(msg, OSMO_GSM44068_IEI_MOBILE_IDENTITY); + rc = osmo_mobile_identity_encode_msgb(msg, mi, false); + if (rc < 0) { + msgb_free(msg); + return -EINVAL; + } + *l = rc; + } + + /* Send to calling subscriber, depending on the link he is. */ + if (trans->msc_a) + return msc_a_tx_dtap_to_i(trans->msc_a, msg); + if (trans->gcc.uplink_bss) + return tx_dtap_to_talker(trans->gcc.uplink_bss, msg); + msgb_free(msg); + return -EIO; +} +#endif + +/* 3GPP TS 44.068 Clause 8.3 and 8.3a */ +static int gsm44068_rx_immediate_setup(struct msgb *msg, uint8_t *talker_prio, uint8_t *key_seq, + struct gsm48_classmark2 *cm2, struct osmo_mobile_identity *mi, + uint32_t *callref, bool *with_prio, uint8_t *prio, char *user_user) +{ + struct gsm48_hdr *gh = msgb_l3(msg); + unsigned int remaining_len = msgb_l3len(msg) - sizeof(*gh); + uint8_t *ie = gh->data; + uint8_t ie_len; + uint64_t otdi; + int i; + int rc; + + /* Talker priority / Cyphering key sequence */ + if (remaining_len < 1) + return _msg_too_short(); + *talker_prio = ie[0] & 0x07; + *key_seq = (ie[0] >> 4) & 0x07; + remaining_len -= 1; + ie += 1; + + /* Mobile station classmark 2 */ + if (remaining_len < 4) + return _msg_too_short(); + ie_len = ie[0]; + if (remaining_len < ie_len + 1) + return _msg_too_short(); + if (ie_len != 3) + return _ie_invalid(); + memcpy(cm2, ie + 1, ie_len); + remaining_len -= ie_len + 1; + ie += ie_len + 1; + + /* Mobile indentity */ + if (gh->msg_type == OSMO_GSM44068_MSGT_IMMEDIATE_SETUP) { + /* IMMEDIATE SETUP uses IMSI/TMSI */ + if (remaining_len < 2) + return _msg_too_short(); + ie_len = ie[0]; + if (remaining_len < ie_len + 1) + return _msg_too_short(); + rc = osmo_mobile_identity_decode(mi, ie + 1, ie_len, false); + if (rc) { + LOGP(DMM, LOGL_ERROR, "Failure to decode Mobile Identity in GCC/BCC IMMEDDIATE SETUP" + " (rc=%d)\n", rc); + return -EINVAL; + } + remaining_len -= ie_len + 1; + ie += ie_len + 1; + } else { + /* IMMEDIATE SETUP 2 uses TMSI only */ + if (remaining_len < 4) + return _msg_too_short(); + mi->type = GSM_MI_TYPE_TMSI; + mi->tmsi = osmo_load32be(ie); + remaining_len -= 4; + ie += 4; + } + + /* Call reference */ + rc = _rx_callref(ie, remaining_len, callref, with_prio, prio); + if (rc < 0) + return rc; + remaining_len -= rc; + ie += rc; + + /* OTID */ + if (gh->msg_type == OSMO_GSM44068_MSGT_IMMEDIATE_SETUP_2 && user_user) { + ie_len = 5; + if (remaining_len < ie_len) + return _msg_too_short(); + otdi = osmo_load32be(ie + 1) | ((uint64_t)ie[0] << 32); + + for (i = 0; i < 12; i++) { + user_user[i] = (otdi % 10) + '0'; + otdi /= 10; + } + user_user[i] = '\0'; + remaining_len -= ie_len; + ie += ie_len; + } else if (user_user) + user_user[0] = '\0'; + + return 0; +} + +/* 3GPP TS 44.068 Clause 8.4 */ +static int gsm44068_tx_set_parameter(struct gsm_trans *trans, uint8_t pdisc, uint8_t da, uint8_t ua, uint8_t comm, + uint8_t oi) +{ + struct msgb *msg = gsm44068_msgb_alloc_name("GSM 44.068 TX SET PARAMETER"); + struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); + uint8_t ie; + + gh->proto_discr = pdisc; + gh->msg_type = OSMO_GSM44068_MSGT_SET_PARAMETER; + ie = (da << 3) | (ua << 2) | (comm << 1) | oi; + msgb_put_u8(msg, ie); + + /* Send to calling subscriber, depending on the link he is. */ + if (trans->msc_a) + return msc_a_tx_dtap_to_i(trans->msc_a, msg); + if (trans->gcc.uplink_bss) + return tx_dtap_to_talker(trans->gcc.uplink_bss, msg); + msgb_free(msg); + return -EIO; +} + +/* 3GPP TS 44.068 Clause 8.5 */ +static int gsm44068_rx_setup(struct msgb *msg, bool *with_talker_prio, uint8_t *talker_prio, + uint32_t *callref, bool *with_prio, uint8_t *prio, char *user_user) +{ + struct gsm48_hdr *gh = msgb_l3(msg); + unsigned int remaining_len = msgb_l3len(msg) - sizeof(*gh); + uint8_t *ie = gh->data; + struct tlv_parsed tp; + struct tlv_p_entry *tlv; + int rc; + + /* Call reference */ + rc = _rx_callref(ie, remaining_len, callref, with_prio, prio); + if (rc < 0) + return rc; + remaining_len -= rc; + ie += rc; + + rc = tlv_parse(&tp, &osmo_gsm44068_att_tlvdef, ie, remaining_len, 0, 0); + if (rc < 0) + return _ie_invalid(); + + /* User-user */ + tlv = TLVP_GET(&tp, OSMO_GSM44068_IEI_USER_USER); + if (tlv && tlv->len && tlv->len <= 1 + 12 && user_user) { + memcpy(user_user, tlv->val, tlv->len - 1); + user_user[tlv->len - 1] = '\0'; + } + + /* Talker priority */ + tlv = TLVP_GET(&tp, OSMO_GSM44068_IEI_TALKER_PRIORITY); + if (tlv && tlv->len) { + *with_talker_prio = true; + *talker_prio = tlv->val[0] & 0x07; + } else + *with_talker_prio = false; + + return 0; +} + +/* 3GPP TS 44.068 Clause 8.6 */ +static int gsm44068_rx_status(struct msgb *msg, uint8_t *cause, uint8_t *diag, uint8_t *diag_len, + bool *with_call_state, enum osmo_gsm44068_call_state *call_state, + bool *with_state_attrs, uint8_t *da, uint8_t *ua, uint8_t *comm, uint8_t *oi) +{ + struct gsm48_hdr *gh = msgb_l3(msg); + unsigned int remaining_len = msgb_l3len(msg) - sizeof(*gh); + uint8_t *ie = gh->data; + uint8_t ie_len; + struct tlv_parsed tp; + struct tlv_p_entry *tlv; + int rc; + + /* Cause */ + if (remaining_len < 2 || ie[0] < remaining_len - 2) + return _msg_too_short(); + ie_len = ie[0]; + if (remaining_len < ie_len + 1) + return _msg_too_short(); + if (ie_len < 1) + return _ie_invalid(); + *cause = ie[1] & 0x7f; + *diag_len = ie_len - 1; + if (*diag_len) + memcpy(diag, ie + 2, ie_len - 1); + remaining_len -= ie_len + 1; + ie += ie_len + 1; + + rc = tlv_parse(&tp, &osmo_gsm44068_att_tlvdef, ie, remaining_len, 0, 0); + if (rc < 0) + return _ie_invalid(); + + /* Call state */ + tlv = TLVP_GET(&tp, OSMO_GSM44068_IEI_CALL_STATE); + if (tlv) { + *with_call_state = true; + *call_state = tlv->val[0] & 0x7; + } else + *with_call_state = false; + + /* State attributes */ + tlv = TLVP_GET(&tp, OSMO_GSM44068_IEI_STATE_ATTRIBUTES); + if (tlv) { + *with_state_attrs = true; + *da = (tlv->val[0] >> 3) & 0x1; + *ua = (tlv->val[0] >> 2) & 0x1; + *comm = (tlv->val[0] >> 1) & 0x1; + *oi = tlv->val[0] & 0x1; + } else + *with_state_attrs = false; + + return 0; +} + +/* 3GPP TS 44.068 Clause 8.7 and 8.8 */ +static int gsm44068_tx_termination(struct msc_a *msc_a, struct vgcs_bss *bss, uint8_t pdisc, uint8_t msg_type, + uint8_t cause, uint8_t *diag, uint8_t diag_len) +{ + struct msgb *msg = gsm44068_msgb_alloc_name("GSM 44.068 TX TERMINATION"); + struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); + + gh->proto_discr = pdisc; + gh->msg_type = msg_type; + _add_cause_ie(msg, cause, diag, diag_len); + + /* Send to calling subscriber, depending on the link he is. */ + if (msc_a) + return msc_a_tx_dtap_to_i(msc_a, msg); + if (bss) + return tx_dtap_to_talker(bss, msg); + msgb_free(msg); + return -EIO; +} + +/* 3GPP TS 44.068 Clause 8.9 */ +static int gsm44068_rx_termination_req(struct msgb *msg, uint32_t *callref, bool *with_prio, uint8_t *prio, + bool *with_talker_prio, uint8_t *talker_prio) +{ + struct gsm48_hdr *gh = msgb_l3(msg); + unsigned int remaining_len = msgb_l3len(msg) - sizeof(*gh); + uint8_t *ie = gh->data; + struct tlv_parsed tp; + struct tlv_p_entry *tlv; + int rc; + + /* Call reference */ + rc = _rx_callref(ie, remaining_len, callref, with_prio, prio); + if (rc < 0) + return rc; + remaining_len -= rc; + ie += rc; + + rc = tlv_parse(&tp, &osmo_gsm44068_att_tlvdef, ie, remaining_len, 0, 0); + if (rc < 0) + return _ie_invalid(); + + /* Talker priority */ + tlv = TLVP_GET(&tp, OSMO_GSM44068_IEI_TALKER_PRIORITY); + if (tlv && tlv->len) { + *with_talker_prio = true; + *talker_prio = tlv->val[0] & 0x07; + } else + *with_talker_prio = false; + + return 0; +} + +/* + * GCC/BCC state machine - handles calling subscriber process + */ + +static const struct value_string vgcs_gcc_fsm_event_names[] = { + OSMO_VALUE_STRING(VGCS_GCC_EV_NET_SETUP), + OSMO_VALUE_STRING(VGCS_GCC_EV_NET_TERM), + OSMO_VALUE_STRING(VGCS_GCC_EV_USER_SETUP), + OSMO_VALUE_STRING(VGCS_GCC_EV_USER_TERM), + OSMO_VALUE_STRING(VGCS_GCC_EV_BSS_ESTABLISHED), + OSMO_VALUE_STRING(VGCS_GCC_EV_BSS_ASSIGN_CPL), + OSMO_VALUE_STRING(VGCS_GCC_EV_BSS_ASSIGN_FAIL), + OSMO_VALUE_STRING(VGCS_GCC_EV_BSS_RELEASED), + OSMO_VALUE_STRING(VGCS_GCC_EV_TIMEOUT), + { } +}; + +static int gcc_establish_bss(struct gsm_trans *trans) +{ + struct gsm_network *net = trans->net; + struct vgcs_mgw_ep *mgw = NULL; + struct mgcp_client *mgcp_client; + struct gcr *gcr; + struct gcr_bss *b; + struct gcr_cell *c; + struct vgcs_bss *bss; + struct vgcs_bss_cell *cell; + struct osmo_fsm_inst *fi; + struct ran_peer *rp; + + /* Failure should not happen, because it has been checked before. */ + gcr = gcr_by_callref(trans->net, trans->type, trans->callref); + if (!gcr) + return -EINVAL; + + /* Allocate MGW endpoint. */ + mgcp_client = mgcp_client_pool_get(trans->net->mgw.mgw_pool); + if (!mgcp_client) { + LOG_GCC(trans, LOGL_ERROR, "No MGW client, please check config.\n"); + goto err_mgw; + } + fi = osmo_fsm_inst_alloc(&vgcs_mgw_ep_fsm, net, NULL, LOGL_DEBUG, NULL); + if (!fi) { + LOG_GCC(trans, LOGL_ERROR, "No memory for VGCS MSG state machine.\n"); + goto err_mgw; + } + osmo_fsm_inst_update_id(fi, "vgcs-mgw-ep"); + osmo_fsm_inst_state_chg(fi, VGCS_MGW_EP_ST_ACTIVE, 0, 0); + mgw = talloc_zero(fi, struct vgcs_mgw_ep); + if (!mgw) { + LOG_GCC(trans, LOGL_ERROR, "No memory for MGW ep structure.\n"); + osmo_fsm_inst_free(fi); + goto err_mgw; + } + mgw->fi = fi; + fi->priv = mgw; + INIT_LLIST_HEAD(&mgw->cell_list); + mgw->mgw_ep = osmo_mgcpc_ep_alloc(mgw->fi, VGCS_MGW_EP_EV_FREE, + mgcp_client, trans->net->mgw.tdefs, mgw->fi->id, + "%s", mgcp_client_rtpbridge_wildcard(mgcp_client)); + if (!mgw->mgw_ep) { + LOG_GCC(trans, LOGL_ERROR, "No memory for MGW endpoint state machine.\n"); + goto err_mgw; + } + + /* Create BSS list structures. */ + llist_for_each_entry(b, &gcr->bss_list, list) { + LOG_GCC(trans, LOGL_DEBUG, " -> BSS with PC %s.\n", osmo_ss7_pointcode_print(NULL, b->pc)); + /* Resolve ran_peer. */ + rp = ran_peer_for_pc(trans->net, b->pc); + if (!rp) { + LOG_GCC(trans, LOGL_ERROR, "Failed to resolve point code %s, skipping BSS!\n", + osmo_ss7_pointcode_print(NULL, b->pc)); + continue; + } + /* Create state machine. */ + fi = osmo_fsm_inst_alloc(&vgcs_bss_fsm, net, NULL, LOGL_DEBUG, NULL); + if (!fi) { + LOG_GCC(trans, LOGL_ERROR, "No memory for state machine.\n"); + break; + } + /* Create call structure. */ + bss = talloc_zero(fi, struct vgcs_bss); + if (!bss) { + LOG_GCC(trans, LOGL_ERROR, "No memory for BSS call structure.\n"); + osmo_fsm_inst_free(fi); + break; + } + bss->fi = fi; + fi->priv = bss; + INIT_LLIST_HEAD(&bss->cell_list); + bss->trans = trans; + bss->trans_type = trans->type; + bss->callref = trans->callref; + bss->pc = b->pc; + /* Create ran connection. */ + bss->conn = ran_conn_create_outgoing(rp); + if (!bss->conn) { + osmo_fsm_inst_free(bss->fi); + continue; + } + bss->conn->vgcs.bss = bss; + /* Create cell list structures. */ + llist_for_each_entry(c, &b->cell_list, list) { + /* Create state machine. */ + fi = osmo_fsm_inst_alloc(&vgcs_cell_fsm, net, NULL, LOGL_DEBUG, NULL); + if (!fi) { + LOG_GCC(trans, LOGL_ERROR, "No memory for state machine.\n"); + break; + } + /* Create cell structure. */ + cell = talloc_zero(fi, struct vgcs_bss_cell); + if (!cell) { + LOG_GCC(trans, LOGL_ERROR, "No memory for BSS cell structure.\n"); + osmo_fsm_inst_free(fi); + break; + } + cell->fi = fi; + fi->priv = cell; + osmo_fsm_inst_update_id_f(cell->fi, "vgcs-cell-%d", c->cell_id); + cell->trans_type = trans->type; + cell->callref = trans->callref; + cell->pc = b->pc; + cell->cell_id = c->cell_id; + cell->call_id = trans->call_id; + /* Create ran connection. */ + cell->conn = ran_conn_create_outgoing(rp); + if (!cell->conn) { + osmo_fsm_inst_free(cell->fi); + continue; + } + cell->conn->vgcs.cell = cell; + /* Attach to cell list of BSS and MGW endpoint */ + llist_add_tail(&cell->list_bss, &bss->cell_list); + cell->bss = bss; + llist_add_tail(&cell->list_mgw, &mgw->cell_list); + cell->mgw = mgw; + } + /* No cell? */ + if (llist_empty(&bss->cell_list)) { + osmo_fsm_inst_free(bss->fi); + break; + } + /* Attach to transaction list */ + llist_add_tail(&bss->list, &trans->gcc.bss_list); + /* Trigger VGCS/VBS SETUP */ + osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_SETUP, NULL); + } + /* No BSS? */ + if (llist_empty(&trans->gcc.bss_list)) { + /* Also destroy MGW, because this list is empty too! */ + goto err_mgw; + } + return 0; + +err_mgw: + if (mgw) { + if (mgw->mgw_ep) { + /* This will also free FSM instance and vgcs_mgw_ep structure. */ + osmo_fsm_inst_dispatch(mgw->fi, VGCS_MGW_EP_EV_CLEAR, NULL); + return -EINVAL; + } + osmo_fsm_inst_free(mgw->fi); + } + return -EINVAL; +} + +/* Send Assignment Request to the calling subscriber. + * This is used to assign the subscriber from early assigned channel to the VGCS/VBS channel. */ +static int gcc_assign(struct gsm_trans *trans) +{ + struct ran_msg tx_ran_msg; + struct gsm0808_channel_type channel_type; + struct vgcs_bss *bss = NULL, *b; + + /* No assignment, because the calling subscriber is already assigned or there is no calling subscriber. */ + if (!trans->msc_a) + return 0; + + /* Check calling subscriber's MSC */ + struct ran_conn *conn = msub_ran_conn(trans->msc_a->c.msub); + if (!conn) { + LOG_GCC(trans, LOGL_ERROR, "Calling subscriber has no ran_conn????\n"); + return -EINVAL; + } + llist_for_each_entry(b, &trans->gcc.bss_list, list) { + if (osmo_sccp_addr_ri_cmp(&conn->ran_peer->peer_addr, &b->conn->ran_peer->peer_addr)) + continue; + bss = b; + break; + } + if (!bss) { + LOG_GCC(trans, LOGL_ERROR, "Calling subscriber comes from BSC that has no VGCS call.\n"); + return -EINVAL; + } + + /* For now we support GSM/FR V1 only. This shall be supported by all MS. */ + channel_type = (struct gsm0808_channel_type) { + .ch_indctr = GSM0808_CHAN_SPEECH, + .ch_rate_type = GSM0808_SPEECH_FULL_BM, + .perm_spch_len = 1, + .perm_spch[0] = GSM0808_PERM_FR1, + }; + + /* Send assignment to VGCS channel */ + tx_ran_msg = (struct ran_msg) { + .msg_type = RAN_MSG_ASSIGNMENT_COMMAND, + .assignment_command = { + .channel_type = &channel_type, + .callref_present = true, + .callref = { + .sf = (trans->type == TRANS_GCC), + }, + }, + }; + osmo_store32be_ext(trans->callref >> 3, &tx_ran_msg.assignment_command.callref.call_ref_hi, 3); + tx_ran_msg.assignment_command.callref.call_ref_lo = trans->callref & 0x7; + if (msc_a_ran_down(trans->msc_a, MSC_ROLE_I, &tx_ran_msg)) { + LOG_GCC(trans, LOGL_ERROR, "Cannot send Assignment\n"); + return -EIO; + } + + /* Assign Talker to BSS of the calling subscriber. */ + trans->gcc.uplink_bss = bss; + + return 0; +} + +/* Send CONNECT to the calling subscriber. */ +static void gcc_connect(struct gsm_trans *trans) +{ + uint8_t pdisc = (trans->type == TRANS_GCC) ? GSM48_PDISC_GROUP_CC : GSM48_PDISC_BCAST_CC; + int rc; + + /* Send CONNECT towards MS. */ + rc = gsm44068_tx_connect(trans, + pdisc | (trans->transaction_id << 4), + trans->callref, 0, 0, 1, 0, 0, 0, 0); + if (rc < 0) + LOG_GCC(trans, LOGL_ERROR, "Failed to send CONNECT towards MS. Continue anyway.\n"); +} + +/* Release dedicated (SDCCH) channel of calling subscriber after assigning to VGCS */ +static void release_msc_a(struct gsm_trans *trans) +{ + struct msc_a *msc_a = trans->msc_a; + + if (!msc_a) + return; + + trans->msc_a = NULL; + switch (trans->type) { + case TRANS_GCC: + msc_a_put(msc_a, MSC_A_USE_GCC); + break; + case TRANS_BCC: + msc_a_put(msc_a, MSC_A_USE_BCC); + break; + default: + break; + } +} + +/* Send TERMINATE to the calling/talking subscriber, then destroy transaction. */ +static void gcc_terminate_and_destroy(struct gsm_trans *trans, enum osmo_gsm44068_cause cause) +{ + uint8_t pdisc = (trans->type == TRANS_GCC) ? GSM48_PDISC_GROUP_CC : GSM48_PDISC_BCAST_CC; + int rc; + + /* Send TERMINATION towards MS. */ + rc = gsm44068_tx_termination(trans->msc_a, trans->gcc.uplink_bss, + pdisc | (trans->transaction_id << 4), + OSMO_GSM44068_MSGT_TERMINATION, + cause, NULL, 0); + if (rc < 0) + LOG_GCC(trans, LOGL_ERROR, "Failed to send TERMINATION towards MS. Continue anyway.\n"); + + /* Destroy transaction, note that also _gsm44068_gcc_trans_free() will be called by trans_free(). + * There the complete state machine is destroyed. */ + trans->callref = 0; + trans_free(trans); +} + +/* Start inactivity timer. + * This timer is used to terminate the call, if the radio connection to the caller gets lost. */ +static void start_inactivity_timer(struct gsm_trans *trans) +{ + if (trans->gcc.inactivity_to) { + LOG_GCC(trans, LOGL_DEBUG, "Set inactivity timer to %d seconds.\n", trans->gcc.inactivity_to); + osmo_timer_schedule(&trans->gcc.timer_inactivity, trans->gcc.inactivity_to, 0); + } +} + +static void stop_inactivity_timer(struct gsm_trans *trans) +{ + if (osmo_timer_pending(&trans->gcc.timer_inactivity)) { + LOG_GCC(trans, LOGL_DEBUG, "Stop pending inactivity timer.\n"); + osmo_timer_del(&trans->gcc.timer_inactivity); + } +} + +static void inactivity_timer_cb(void *data) +{ + struct gsm_trans *trans = data; + + osmo_fsm_inst_dispatch(trans->gcc.fi, VGCS_GCC_EV_TIMEOUT, NULL); +} + +/* Set the parameters of the talker. (downlink mute/unmute, uplink unmute, COMM=T, originator) */ +static int set_parameter(struct gsm_trans *trans) +{ + uint8_t pdisc = (trans->type == TRANS_GCC) ? GSM48_PDISC_GROUP_CC : GSM48_PDISC_BCAST_CC; + int rc; + + rc = gsm44068_tx_set_parameter(trans, pdisc, !trans->gcc.mute_talker, 1, 1, trans->gcc.uplink_originator); + if (rc < 0) + LOG_GCC(trans, LOGL_ERROR, "Failed to send SET PARAMETER towards MS.\n"); + return rc; +} + +/* Check in which cell the uplink is used and set "uplink_cell". */ +static int set_uplink_cell(struct vgcs_bss *bss, struct gsm0808_cell_id *cell_id_ie, uint16_t cell_id) +{ + struct vgcs_bss_cell *cell; + + if (cell_id_ie) { + /* Get cell ID to determine talker channel. */ + switch (cell_id_ie->id_discr) { + case CELL_IDENT_CI: + cell_id = cell_id_ie->id.ci; + break; + case CELL_IDENT_LAC_AND_CI: + cell_id = cell_id_ie->id.lac_and_ci.ci; + break; + default: + LOG_BSS(bss, LOGL_DEBUG, "Cannot idenitfy cell, please fix!\n"); + return -EINVAL; + } + } + + /* Search for cell ID. */ + bss->trans->gcc.uplink_cell = NULL; + llist_for_each_entry(cell, &bss->cell_list, list_bss) { + if (cell->cell_id == cell_id) { + LOG_BSS(bss, LOGL_DEBUG, "Talker is talking on cell %d.\n", cell->cell_id); + bss->trans->gcc.uplink_cell = cell; + return 0; + } + } + + LOG_BSS(bss, LOGL_DEBUG, "Cell ID %d is not in list of current BSS, please fix!\n", cell_id); + return -EINVAL; +} + +/* Set the MGW conference mode. + * All cells are listening to the conference. If there is a talker, this cell is also transmitting to the conference. */ +static int set_mgw_conference(struct gsm_trans *trans) +{ + struct vgcs_bss *bss; + struct vgcs_bss_cell *cell; + struct rtp_stream *rtps; + int rc; + + /* All cells without talker are listening */ + llist_for_each_entry(bss, &trans->gcc.bss_list, list) { + llist_for_each_entry(cell, &bss->cell_list, list_bss) { + if (!(rtps = cell->rtps)) + continue; + if (rtps->crcx_conn_mode != MGCP_CONN_SEND_ONLY) { + LOG_CELL(cell, LOGL_DEBUG, "Setting cell %d into listening mode.\n", cell->cell_id); + rtp_stream_set_mode(rtps, MGCP_CONN_SEND_ONLY); + rc = rtp_stream_commit(rtps); + if (rc < 0) + LOG_CELL(cell, LOGL_ERROR, "Failed to commit parameters to RTP stream " + "for cell %d.\n", cell->cell_id); + } + } + } + + if (trans->gcc.uplink_cell && trans->gcc.uplink_cell->rtps) { + cell = trans->gcc.uplink_cell; + rtps = cell->rtps; + LOG_CELL(cell, LOGL_DEBUG, "Setting cell %d into listening mode.\n", cell->cell_id); + rtp_stream_set_mode(rtps, MGCP_CONN_CONFECHO); + rc = rtp_stream_commit(rtps); + if (rc < 0) + LOG_CELL(cell, LOGL_ERROR, "Failed to commit parameters to RTP stream " + "for cell %d.\n", cell->cell_id); + } + + return 0; +} + +static void _assign_complete(struct gsm_trans *trans, bool send_connect) +{ + uint16_t cell_id; + + /* Change state. */ + osmo_fsm_inst_state_chg(trans->gcc.fi, VGCS_GCC_ST_N2_CALL_ACTIVE, 0, 0); + /* Get cell ID. */ + if (trans->msc_a) + cell_id = trans->msc_a->via_cell.cell_identity; + else + LOG_GCC(trans, LOGL_ERROR, "Missing msc_a, please fix!\n"); + /* Releasing dedicated channel. */ + release_msc_a(trans); + /* Send CONNECT to the calling subscriber. */ + if (send_connect) + gcc_connect(trans); + /* Set parameter. */ + set_parameter(trans); + /* Start inactivity timer, if uplink is free. */ + if (!trans->gcc.uplink_busy) + start_inactivity_timer(trans); + /* Set cell of current talker. */ + set_uplink_cell(trans->gcc.uplink_bss, NULL, cell_id); + /* Set MGW conference. */ + set_mgw_conference(trans); +} + +#define CONNECT_OPTION false + +static void vgcs_gcc_fsm_n0_null(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct gsm_trans *trans = fi->priv; + int rc; + + switch (event) { + case VGCS_GCC_EV_NET_SETUP: + /* Establish call towards all BSSs. */ + LOG_GCC(trans, LOGL_DEBUG, "Setup by network, trying to establish cells.\n"); + rc = gcc_establish_bss(trans); + if (rc < 0) { + LOG_GCC(trans, LOGL_NOTICE, "Failed to setup call to any cell.\n"); + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); + break; + } + /* Keep state until established or released. */ + break; + case VGCS_GCC_EV_NET_TERM: + LOG_GCC(trans, LOGL_DEBUG, "Termination by network, destroying call.\n"); + /* Destroy group call in all cells. */ + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NORMAL_CALL_CLEARING); + break; + case VGCS_GCC_EV_USER_SETUP: + LOG_GCC(trans, LOGL_DEBUG, "Setup by MS, trying to establish cells.\n"); + /* Change state. */ + osmo_fsm_inst_state_chg(fi, VGCS_GCC_ST_N1_CALL_INITIATED, 0, 0); + /* Establish call towards all BSSs. */ + rc = gcc_establish_bss(trans); + if (rc < 0) { + LOG_GCC(trans, LOGL_NOTICE, "Failed to setup call to any cell.\n"); + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); + break; + } + if (CONNECT_OPTION) { + /* Send CONNECT to the calling subscriber. */ + gcc_connect(trans); + /* Change state. */ + osmo_fsm_inst_state_chg(fi, VGCS_GCC_ST_N3_CALL_EST_PROC, 0, 0); + } + break; + case VGCS_GCC_EV_BSS_ESTABLISHED: + LOG_GCC(trans, LOGL_DEBUG, "All cells establised, for a group call, sending CONNECT to caller.\n"); + /* Change state. */ + osmo_fsm_inst_state_chg(fi, VGCS_GCC_ST_N2_CALL_ACTIVE, 0, 0); + /* Start inactivity timer, if uplink is free. */ + if (!trans->gcc.uplink_busy) + start_inactivity_timer(trans); + break; + case VGCS_GCC_EV_BSS_RELEASED: + LOG_GCC(trans, LOGL_DEBUG, "All group call in all cells failed, destroying call.\n"); + /* Send TERMINATE to the calling subscriber. */ + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); + break; + default: + OSMO_ASSERT(false); + } +} + +static void vgcs_gcc_fsm_n1_call_initiated(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct gsm_trans *trans = fi->priv; + int rc; + + switch (event) { + case VGCS_GCC_EV_NET_TERM: + LOG_GCC(trans, LOGL_DEBUG, "Termination by network, destroying call.\n"); + /* Destroy group call in all cells. */ + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NORMAL_CALL_CLEARING); + break; + case VGCS_GCC_EV_USER_TERM: + LOG_GCC(trans, LOGL_DEBUG, "Termination by user, destroying call.\n"); + /* Send TERMINATE to the calling subscriber and destroy group call in all cells. */ + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NORMAL_CALL_CLEARING); + break; + case VGCS_GCC_EV_BSS_ESTABLISHED: + LOG_GCC(trans, LOGL_DEBUG, "All cells establised, for a group call, assign caller to VGCS.\n"); + /* Send assignment to the calling subscriber. */ + rc = gcc_assign(trans); + if (rc < 0) { + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); + break; + } + break; + case VGCS_GCC_EV_BSS_ASSIGN_CPL: + LOG_GCC(trans, LOGL_DEBUG, "Assignment complete, sending CONNECT to caller, releasing channel.\n"); + /* Handle assignment complete */ + _assign_complete(trans, true); + break; + case VGCS_GCC_EV_BSS_ASSIGN_FAIL: + LOG_GCC(trans, LOGL_DEBUG, "Assignment failed, releasing call.\n"); + /* Send TERMINATE to the calling subscriber. */ + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); + break; + case VGCS_GCC_EV_BSS_RELEASED: + LOG_GCC(trans, LOGL_DEBUG, "All group call in all cells failed, destroying call.\n"); + /* Send TERMINATE to the calling subscriber. */ + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); + break; + default: + OSMO_ASSERT(false); + } +} + +static void vgcs_gcc_fsm_n2_call_active(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct gsm_trans *trans = fi->priv; + + switch (event) { + case VGCS_GCC_EV_NET_TERM: + LOG_GCC(trans, LOGL_DEBUG, "Termination by network, destroying call.\n"); + /* Destroy group call in all cells. */ + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NORMAL_CALL_CLEARING); + break; + case VGCS_GCC_EV_USER_TERM: + LOG_GCC(trans, LOGL_DEBUG, "Termination by user, destroying call.\n"); + /* Send TERMINATE to the calling subscriber and destroy group call in all cells. */ + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NORMAL_CALL_CLEARING); + break; + case VGCS_GCC_EV_BSS_RELEASED: + LOG_GCC(trans, LOGL_DEBUG, "All group call in all cells failed, destroying call.\n"); + /* Send TERMINATE to the calling subscriber. */ + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); + break; + case VGCS_GCC_EV_TIMEOUT: + LOG_GCC(trans, LOGL_DEBUG, "Termination by inactivity timer, destroying call.\n"); + /* Destroy group call in all cells. */ + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NORMAL_CALL_CLEARING); + break; + default: + OSMO_ASSERT(false); + } +} + +static void vgcs_gcc_fsm_n3_call_est_proc(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct gsm_trans *trans = fi->priv; + int rc; + + switch (event) { + case VGCS_GCC_EV_NET_TERM: + LOG_GCC(trans, LOGL_DEBUG, "Termination by network, destroying call.\n"); + /* Destroy group call in all cells. */ + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NORMAL_CALL_CLEARING); + break; + case VGCS_GCC_EV_USER_TERM: + LOG_GCC(trans, LOGL_DEBUG, "Termination by user, destroying call.\n"); + /* Send TERMINATE to the calling subscriber and destroy group call in all cells. */ + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NORMAL_CALL_CLEARING); + break; + case VGCS_GCC_EV_BSS_ESTABLISHED: + LOG_GCC(trans, LOGL_DEBUG, "All cells establised, for a group call, assign caller to VGCS.\n"); + /* Send assignment to the calling subscriber. */ + rc = gcc_assign(trans); + if (rc < 0) { + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); + break; + } + break; + case VGCS_GCC_EV_BSS_ASSIGN_CPL: + LOG_GCC(trans, LOGL_DEBUG, "Assignment complete, sending CONNECT to caller, releasing channel.\n"); + /* Handle assignment complete */ + _assign_complete(trans, false); + break; + case VGCS_GCC_EV_BSS_ASSIGN_FAIL: + LOG_GCC(trans, LOGL_DEBUG, "Assignment failed, releasing call.\n"); + /* Send TERMINATE to the calling subscriber. */ + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); + break; + case VGCS_GCC_EV_BSS_RELEASED: + LOG_GCC(trans, LOGL_DEBUG, "All group call in all cells failed, destroying call.\n"); + /* Send TERMINATE to the calling subscriber. */ + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); + break; + default: + OSMO_ASSERT(false); + } +} + +static const struct osmo_fsm_state vgcs_gcc_fsm_states[] = { + [VGCS_GCC_ST_N0_NULL] = { + .name = "NULL (N0)", + .in_event_mask = S(VGCS_GCC_EV_NET_SETUP) | + S(VGCS_GCC_EV_NET_TERM) | + S(VGCS_GCC_EV_USER_SETUP) | + S(VGCS_GCC_EV_BSS_ESTABLISHED) | + S(VGCS_GCC_EV_BSS_RELEASED), + .out_state_mask = S(VGCS_GCC_ST_N1_CALL_INITIATED) | + S(VGCS_GCC_ST_N2_CALL_ACTIVE), + .action = vgcs_gcc_fsm_n0_null, + }, + [VGCS_GCC_ST_N1_CALL_INITIATED] = { + .name = "CALL INITATED (N1)", + .in_event_mask = S(VGCS_GCC_EV_NET_TERM) | + S(VGCS_GCC_EV_USER_TERM) | + S(VGCS_GCC_EV_BSS_ESTABLISHED) | + S(VGCS_GCC_EV_BSS_ASSIGN_CPL) | + S(VGCS_GCC_EV_BSS_ASSIGN_FAIL) | + S(VGCS_GCC_EV_BSS_RELEASED), + .out_state_mask = S(VGCS_GCC_ST_N0_NULL) | + S(VGCS_GCC_ST_N2_CALL_ACTIVE) | + S(VGCS_GCC_ST_N3_CALL_EST_PROC), + .action = vgcs_gcc_fsm_n1_call_initiated, + }, + [VGCS_GCC_ST_N2_CALL_ACTIVE] = { + .name = "CALL ACTIVE (N2)", + .in_event_mask = S(VGCS_GCC_EV_NET_TERM) | + S(VGCS_GCC_EV_USER_TERM) | + S(VGCS_GCC_EV_BSS_RELEASED) | + S(VGCS_GCC_EV_TIMEOUT), + .out_state_mask = S(VGCS_GCC_ST_N0_NULL), + .action = vgcs_gcc_fsm_n2_call_active, + }, + [VGCS_GCC_ST_N3_CALL_EST_PROC] = { + .name = "CALL EST PROCEEDING (N3)", + .in_event_mask = S(VGCS_GCC_EV_NET_TERM) | + S(VGCS_GCC_EV_USER_TERM) | + S(VGCS_GCC_EV_BSS_ESTABLISHED) | + S(VGCS_GCC_EV_BSS_ASSIGN_CPL) | + S(VGCS_GCC_EV_BSS_ASSIGN_FAIL) | + S(VGCS_GCC_EV_BSS_RELEASED), + .out_state_mask = S(VGCS_GCC_ST_N2_CALL_ACTIVE) | + S(VGCS_GCC_ST_N0_NULL), + .action = vgcs_gcc_fsm_n3_call_est_proc, + }, + // We don't need a state to wait for the group call to be terminated in all cells +}; + +static struct osmo_fsm vgcs_bcc_fsm = { + .name = "bcc", + .states = vgcs_gcc_fsm_states, + .num_states = ARRAY_SIZE(vgcs_gcc_fsm_states), + .log_subsys = DBCC, + .event_names = vgcs_gcc_fsm_event_names, +}; + +static struct osmo_fsm vgcs_gcc_fsm = { + .name = "gcc", + .states = vgcs_gcc_fsm_states, + .num_states = ARRAY_SIZE(vgcs_gcc_fsm_states), + .log_subsys = DGCC, + .event_names = vgcs_gcc_fsm_event_names, +}; + +const char *vgcs_bcc_gcc_state_name(struct osmo_fsm_inst *fi) +{ + return vgcs_gcc_fsm_states[fi->state].name; +} + +static int update_uplink_state(struct vgcs_bss *bss, bool uplink_busy); + +/* Receive RR messages from calling subscriber, prior assignment to VGCS/VBS. */ +int gsm44068_rcv_rr(struct msc_a *msc_a, struct msgb *msg) +{ + struct gsm_trans *trans = NULL; + struct gsm48_hdr *gh; + uint8_t msg_type; + + gh = msgb_l3(msg); + msg_type = gsm48_hdr_msg_type(gh); + + /* Find transaction. */ + trans = trans_find_by_type(msc_a, TRANS_GCC); + if (!trans) + trans = trans_find_by_type(msc_a, TRANS_BCC); + + if (!trans) { + LOG_GCC(trans, LOGL_ERROR, "No VGCS/VBS transaction.\n"); + return -EINVAL; + } + + /* In case the phone releases uplink prior being assigned to a VGCS */ + if (msg_type == GSM48_MT_RR_UPLINK_RELEASE) { + struct vgcs_bss *bss; + + LOG_GCC(trans, LOGL_INFO, "Received UPLINK RELEASE on initial channel.\n"); + /* Clear the busy flag and unblock all cells. */ + trans->gcc.uplink_bss = NULL; + trans->gcc.uplink_cell = NULL; + trans->gcc.uplink_busy = false; + llist_for_each_entry(bss, &trans->gcc.bss_list, list) { + /* Update uplink state. */ + update_uplink_state(bss, trans->gcc.uplink_busy); + } + /* Start inactivity timer. */ + start_inactivity_timer(bss->trans); + /* Next, the MS will switch to the VGCS as listener. Nothing else to do here. */ + } + + return 0; +} + +/* Allocation of transaction for group call */ +static struct gsm_trans *trans_alloc_vgcs(struct gsm_network *net, + struct vlr_subscr *vsub, + enum trans_type trans_type, uint8_t transaction_id, + uint32_t callref, + struct gcr *gcr, + bool uplink_busy) +{ + struct gsm_trans *trans; + + trans = trans_alloc(net, vsub, trans_type, transaction_id, callref); + if (!trans) { + LOG_GCC(trans, LOGL_ERROR, "No memory for trans.\n"); + return NULL; + } + /* The uplink is busy when the call is started until the calling subscriber releases. */ + trans->gcc.uplink_busy = uplink_busy; + trans->gcc.uplink_originator = true; + INIT_LLIST_HEAD(&trans->gcc.bss_list); + trans->gcc.inactivity_to = gcr->timeout; + trans->gcc.mute_talker = gcr->mute_talker; + trans->gcc.timer_inactivity.data = trans; + trans->gcc.timer_inactivity.cb = inactivity_timer_cb; + trans->gcc.fi = osmo_fsm_inst_alloc((trans_type == TRANS_GCC) ? &vgcs_gcc_fsm : &vgcs_bcc_fsm, + trans, trans, LOGL_DEBUG, NULL); + if (!trans->gcc.fi) { + LOG_GCC(trans, LOGL_ERROR, "No memory for state machine.\n"); + trans_free(trans); + return NULL; + } + + return trans; +} + +/* Create transaction from incoming voice group/broadcast call. */ +static struct gsm_trans *trans_create_bcc_gcc(struct msc_a *msc_a, enum trans_type trans_type, uint8_t transaction_id, + uint8_t pdisc, uint8_t msg_type, uint32_t callref) +{ + struct gsm_network *net = msc_a_net(msc_a); + struct vlr_subscr *vsub = msc_a_vsub(msc_a); + struct gsm_trans *trans = NULL; + struct gcr *gcr; + int rc; + + if (!msc_a) { + LOG_GCC(trans, LOGL_ERROR, "Invalid conn: no msc_a\n"); + return NULL; + } + if (!vsub) { + LOG_GCC(trans, LOGL_ERROR, "Invalid conn: no subscriber\n"); + return NULL; + } + + /* An earlier CM Service Request for this CC message now has concluded */ + if (!osmo_use_count_by(&msc_a->use_count, + (trans_type == TRANS_GCC) ? MSC_A_USE_CM_SERVICE_GCC : MSC_A_USE_CM_SERVICE_BCC)) + LOG_MSC_A(msc_a, LOGL_ERROR, + "Creating new %s transaction without prior CM Service Request.\n", + get_value_string(trans_type_names, trans_type)); + else + msc_a_put(msc_a, + (trans_type == TRANS_GCC) ? MSC_A_USE_CM_SERVICE_GCC : MSC_A_USE_CM_SERVICE_BCC); + + /* A transaction must be created with a SETUP message. */ + if (msg_type != OSMO_GSM44068_MSGT_IMMEDIATE_SETUP + && msg_type != OSMO_GSM44068_MSGT_SETUP + && msg_type != OSMO_GSM44068_MSGT_IMMEDIATE_SETUP_2) { + LOG_GCC(trans, LOGL_ERROR, "No transaction and message is not a SETUP.\n"); + return NULL; + } + + /* Check if callref already exists. */ + trans = trans_find_by_callref(net, trans_type, callref); + if (trans) { + LOG_GCC(trans, LOGL_INFO, "Call to existing %s with callref %s, rejecting!\n", + trans_type_name(trans_type), gsm44068_group_id_string(callref)); + rc = gsm44068_tx_termination(msc_a, NULL, + pdisc | (transaction_id << 4), + OSMO_GSM44068_MSGT_TERMINATION, + OSMO_GSM44068_CAUSE_BUSY, NULL, 0); + if (rc < 0) + LOG_GCC(trans, LOGL_ERROR, "Failed to send TERMINATION towards MS.\n"); + return 0; + } + + /* Check GCR for Group ID. */ + gcr = gcr_by_callref(net, trans_type, callref); + if (!gcr) { + LOG_GCC(trans, LOGL_INFO, "No Group configured for %s callref %s, rejecting!\n", + trans_type_name(trans_type), gsm44068_group_id_string(callref)); + // FIXME: Better cause value for a group that does not exist ? + rc = gsm44068_tx_termination(msc_a, NULL, + pdisc | (transaction_id << 4), + OSMO_GSM44068_MSGT_TERMINATION, + OSMO_GSM44068_CAUSE_REQUESTED_SERVICE_NOT_SUB, NULL, 0); + if (rc < 0) + LOG_GCC(trans, LOGL_ERROR, "Failed to send TERMINATION towards MS.\n"); + return 0; + } + + /* Create transaction, uplink is busy. */ + trans = trans_alloc_vgcs(net, vsub, trans_type, transaction_id, callref, gcr, true); + if (!trans) { + rc = gsm44068_tx_termination(msc_a, NULL, + pdisc | (transaction_id << 4), + OSMO_GSM44068_MSGT_TERMINATION, + OSMO_GSM44068_CAUSE_NETWORK_FAILURE, NULL, 0); + if (rc < 0) + LOG_GCC(trans, LOGL_ERROR, "Failed to send TERMINATION towards MS.\n"); + return NULL; + } + + if (osmo_fsm_inst_dispatch(msc_a->c.fi, MSC_A_EV_TRANSACTION_ACCEPTED, trans)) { + LOG_MSC_A(msc_a, LOGL_ERROR, "Not allowed to accept %s transaction.\n", + get_value_string(trans_type_names, trans_type)); + gcc_terminate_and_destroy(trans, OSMO_GSM44068_CAUSE_NETWORK_FAILURE); + return NULL; + } + + /* Assign transaction */ + msc_a_get(msc_a, (trans_type == TRANS_GCC) ? MSC_A_USE_GCC : MSC_A_USE_BCC); + trans->msc_a = msc_a; + trans->dlci = 0; /* main DCCH */ + + return trans; +} + +/* Receive GCC/BCC messages from calling subscriber, depending on the PDISC used. */ +int gsm44068_rcv_bcc_gcc(struct msc_a *msc_a, struct gsm_trans *trans, struct msgb *msg) +{ + struct gsm48_hdr *gh = msgb_l3(msg); + uint8_t msg_type = gsm48_hdr_msg_type(gh); + uint8_t pdisc = gsm48_hdr_pdisc(gh); + uint8_t transaction_id = gsm48_hdr_trans_id_flip_ti(gh); + enum trans_type trans_type = (pdisc == GSM48_PDISC_GROUP_CC) ? TRANS_GCC : TRANS_BCC; + + uint8_t key_seq; + bool talker_prio_requested; + bool with_talker_prio; + uint8_t talker_prio; + struct gsm48_classmark2 cm2; + struct osmo_mobile_identity mi; + uint32_t callref; + bool with_prio; + uint8_t prio; + char user_user[64] = ""; + uint8_t cause; + uint8_t diag[256]; + uint8_t diag_len; + bool with_call_state; + enum osmo_gsm44068_call_state call_state; + bool with_state_attrs; + uint8_t da, ua, comm, oi; + int rc = 0; + + /* Remove sequence number (bit 7) from message type. */ + msg_type &= 0xbf; + + /* Parse messages. */ + switch (msg_type) { + case OSMO_GSM44068_MSGT_SETUP: + rc = gsm44068_rx_setup(msg, &talker_prio_requested, &talker_prio, &callref, &with_prio, &prio, + user_user); + break; + case OSMO_GSM44068_MSGT_IMMEDIATE_SETUP: + case OSMO_GSM44068_MSGT_IMMEDIATE_SETUP_2: + rc = gsm44068_rx_immediate_setup(msg, &talker_prio, &key_seq, &cm2, &mi, &callref, &with_prio, &prio, + user_user); + break; + case OSMO_GSM44068_MSGT_STATUS: + rc = gsm44068_rx_status(msg, &cause, diag, &diag_len, &with_call_state, &call_state, + &with_state_attrs, &da, &ua, &comm, &oi); + break; + case OSMO_GSM44068_MSGT_TERMINATION_REQUEST: + rc = gsm44068_rx_termination_req(msg, &callref, &with_prio, &prio, &with_talker_prio, &talker_prio); + break; + default: + LOG_GCC(trans, LOGL_ERROR, "Invalid message type: 0x%02x\n", msg_type); + return -EINVAL; + } + if (rc < 0) + return rc; + + /* Find transaction, if called from msc_a. */ + if (!trans) + trans = trans_find_by_id(msc_a, trans_type, transaction_id); + + /* Create transaction for SETUP message. */ + if (!trans) { + trans = trans_create_bcc_gcc(msc_a, trans_type, transaction_id, pdisc, msg_type, callref); + if (!trans) + return -EINVAL; + } else { + /* A phone may not call while a VGCS is already active */ + if (msg_type == OSMO_GSM44068_MSGT_IMMEDIATE_SETUP + || msg_type == OSMO_GSM44068_MSGT_SETUP + || msg_type == OSMO_GSM44068_MSGT_IMMEDIATE_SETUP_2) { + LOG_GCC(trans, LOGL_ERROR, "Received SETUP while call is already set up, rejecting.\n"); + rc = gsm44068_tx_termination(msc_a, NULL, + pdisc | (transaction_id << 4), + OSMO_GSM44068_MSGT_TERMINATION, + OSMO_GSM44068_CAUSE_NETWORK_FAILURE, NULL, 0); + if (rc < 0) + LOG_GCC(trans, LOGL_ERROR, "Failed to send TERMINATION towards MS.\n"); + return -EINVAL; + } + } + + /* Handle received GCC messages (trigger state machine). */ + switch (msg_type) { + case OSMO_GSM44068_MSGT_IMMEDIATE_SETUP: + case OSMO_GSM44068_MSGT_SETUP: + case OSMO_GSM44068_MSGT_IMMEDIATE_SETUP_2: + LOG_GCC(trans, LOGL_INFO, "Received SETUP.\n"); + osmo_fsm_inst_dispatch(trans->gcc.fi, VGCS_GCC_EV_USER_SETUP, NULL); + break; + case OSMO_GSM44068_MSGT_STATUS: + LOG_GCC(trans, LOGL_NOTICE, "Received STATUS with cause %d (%s).\n", cause, + get_value_string(osmo_gsm44068_cause_names, cause)); + if (diag_len) + LOG_GCC(trans, LOGL_NOTICE, " -> diagnostics: %s\n", osmo_hexdump(diag, diag_len)); + if (with_call_state) + LOG_GCC(trans, LOGL_NOTICE, " -> call state %s\n", + get_value_string(osmo_gsm44068_call_state_names, call_state)); + break; + case OSMO_GSM44068_MSGT_TERMINATION_REQUEST: + LOG_GCC(trans, LOGL_INFO, "Received TERMINATRION REQUEST.\n"); + if (callref != trans->callref) { + LOG_GCC(trans, LOGL_NOTICE, "Received callref 0x%x does not match!\n", callref); + break; + } + osmo_fsm_inst_dispatch(trans->gcc.fi, VGCS_GCC_EV_USER_TERM, NULL); + break; + } + + return 0; +} + +static void bss_clear(struct vgcs_bss *bss, uint8_t cause, bool notify_trans); + +/* Call Control Specific transaction release. + * gets called by trans_free, DO NOT CALL YOURSELF! */ +void gsm44068_bcc_gcc_trans_free(struct gsm_trans *trans) +{ + struct vgcs_bss *bss, *bss2; + + /* Change state. */ + osmo_fsm_inst_state_chg(trans->gcc.fi, VGCS_GCC_ST_N0_NULL, 0, 0); + + /* Free FSM. */ + if (trans->gcc.fi) + osmo_fsm_inst_term(trans->gcc.fi, OSMO_FSM_TERM_REGULAR, NULL); + + /* Remove relations to cells. + * We must loop safe, because bss_clear() will detach every call control instance from list. */ + llist_for_each_entry_safe(bss, bss2, &trans->gcc.bss_list, list) + osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_CLEAR, NULL); + + /* Stop inactivity timer. */ + stop_inactivity_timer(trans); +} + +/* Create a new call from VTY command. */ +const char *vgcs_vty_initiate(struct gsm_network *gsmnet, struct gcr *gcr) +{ + enum trans_type trans_type; + uint32_t callref; + struct gsm_trans *trans; + + /* Get callref from stored suffix. Caller cannot choose a prefix. */ + trans_type = gcr->trans_type; + callref = atoi(gcr->group_id); + + /* Check if callref already exists. */ + trans = trans_find_by_callref(gsmnet, trans_type, callref); + if (trans) { + LOG_GCC(trans, LOGL_INFO, "Call to existing %s with callref %s, rejecting!\n", + trans_type_name(trans_type), gsm44068_group_id_string(callref)); + return "Call already exists."; + } + + /* Create transaction, uplink is free. */ + trans = trans_alloc_vgcs(gsmnet, NULL, trans_type, 0, callref, gcr, false); + if (!trans) { + LOG_GCC(trans, LOGL_ERROR, "No memory for trans.\n"); + return "Failed to create call."; + } + + LOG_GCC(trans, LOGL_INFO, "VTY initiates call.\n"); + osmo_fsm_inst_dispatch(trans->gcc.fi, VGCS_GCC_EV_NET_SETUP, NULL); + + return NULL; +} + +/* Destroy a call from VTY command. */ +const char *vgcs_vty_terminate(struct gsm_network *gsmnet, struct gcr *gcr) +{ + enum trans_type trans_type; + uint32_t callref; + struct gsm_trans *trans; + + /* Get callref from stored suffix. Caller cannot choose a prefix. */ + trans_type = gcr->trans_type; + callref = atoi(gcr->group_id); + + /* Check if callref exists. */ + trans = trans_find_by_callref(gsmnet, trans_type, callref); + if (!trans) + return "Call does not exist."; + + LOG_GCC(trans, LOGL_INFO, "VTY terminates call.\n"); + osmo_fsm_inst_dispatch(trans->gcc.fi, VGCS_GCC_EV_NET_TERM, NULL); + + return NULL; +} + +/* + * BSS state machine - handles all BSS "call control" instances + */ + +static const struct value_string vgcs_bss_fsm_event_names[] = { + OSMO_VALUE_STRING(VGCS_BSS_EV_SETUP), + OSMO_VALUE_STRING(VGCS_BSS_EV_SETUP_ACK), + OSMO_VALUE_STRING(VGCS_BSS_EV_SETUP_REFUSE), + OSMO_VALUE_STRING(VGCS_BSS_EV_ACTIVE_OR_FAIL), + OSMO_VALUE_STRING(VGCS_BSS_EV_UL_REQUEST), + OSMO_VALUE_STRING(VGCS_BSS_EV_UL_REQUEST_CNF), + OSMO_VALUE_STRING(VGCS_BSS_EV_UL_APP_DATA), + OSMO_VALUE_STRING(VGCS_BSS_EV_BSS_DTAP), + OSMO_VALUE_STRING(VGCS_BSS_EV_UL_RELEASE), + OSMO_VALUE_STRING(VGCS_BSS_EV_CLEAR), + OSMO_VALUE_STRING(VGCS_BSS_EV_CLOSE), + OSMO_VALUE_STRING(VGCS_BSS_EV_RELEASED), + { } +}; + +/* Blocks or unblocks uplinks of a BSS. */ +static int update_uplink_state(struct vgcs_bss *bss, bool uplink_busy) +{ + struct ran_msg ran_msg; + int rc; + + if (uplink_busy) { + /* Send UPLINK SEIZED COMMAND to BSS. */ + LOG_BSS(bss, LOGL_DEBUG, "Sending (VGCS) UPLINK SEIZED COMMAND towards BSS.\n"); + ran_msg = (struct ran_msg){ + .msg_type = RAN_MSG_UPLINK_SEIZED_CMD, + .uplink_seized_cmd = { + .cause = GSM0808_CAUSE_CALL_CONTROL, + }, + }; + } else { + /* Send UPLINK RELEASE COMMAND to BSS. */ + LOG_BSS(bss, LOGL_DEBUG, "Sending (VGCS) UPLINK RELEASE COMMAND towards BSS.\n"); + ran_msg = (struct ran_msg){ + .msg_type = RAN_MSG_UPLINK_RELEASE_CMD, + .uplink_release_cmd = { + .cause = GSM0808_CAUSE_CALL_CONTROL, + }, + }; + } + + rc = ran_encode_and_send(bss->fi, &ran_msg, bss->conn, false); + + return rc; +} + +/* Clear the connection towards BSS. + * The instance is removed soon, so it is detached from transaction and cells. */ +static void bss_clear(struct vgcs_bss *bss, uint8_t cause, bool notify_trans) +{ + struct ran_msg ran_msg; + struct gsm_trans *trans = bss->trans; + struct vgcs_bss_cell *cell, *cell2; + + /* Must detach us from transaction. */ + if (bss->trans) { + /* Remove pointer to talking BSS and cell. */ + if (bss == bss->trans->gcc.uplink_bss) { + bss->trans->gcc.uplink_bss = NULL; + bss->trans->gcc.uplink_cell = NULL; + } + llist_del(&bss->list); + bss->trans = NULL; + } + + /* Change state. */ + osmo_fsm_inst_state_chg(bss->fi, VGCS_BSS_ST_RELEASE, 0, 0); + + /* Send Clear Command to BSS. */ + ran_msg = (struct ran_msg){ + .msg_type = RAN_MSG_CLEAR_COMMAND, + .clear_command = { + .gsm0808_cause = cause, + }, + }; + if (bss->conn) { + LOG_BSS(bss, LOGL_DEBUG, "Sending CLEAR COMMAND for call controling channel.\n"); + ran_encode_and_send(bss->fi, &ran_msg, bss->conn, false); + } + + /* Trigger clear of all cells. Be safe, because the process will remove cells from list. */ + llist_for_each_entry_safe(cell, cell2, &bss->cell_list, list_bss) + osmo_fsm_inst_dispatch(cell->fi, VGCS_CELL_EV_CLEAR, NULL); + + /* Detach us from all BSS, if still linked */ + llist_for_each_entry_safe(cell, cell2, &bss->cell_list, list_bss) { + llist_del(&cell->list_bss); + cell->bss = NULL; + } + + /* If all BS are gone, notify calling subscriber process. */ + if (notify_trans && trans && llist_empty(&trans->gcc.bss_list)) { + LOG_BSS(bss, LOGL_DEBUG, "Notify calling user process, that all BSSs are cleared.\n"); + osmo_fsm_inst_dispatch(trans->gcc.fi, VGCS_GCC_EV_BSS_RELEASED, NULL); + } +} + +/* When finally the BSS connection is released. (CLEAR COMPLETE response) + * The instance is removed, so it is detached from transaction and cells, if not already. */ +static void bss_destroy(struct vgcs_bss *bss) +{ + struct vgcs_bss_cell *cell, *cell2; + + LOG_BSS(bss, LOGL_DEBUG, "Removing BSS call controling instance.\n"); + + /* Must detach us from transaction, if not already. */ + if (bss->trans) { + /* Remove pointer to talking BSS and cell. */ + if (bss == bss->trans->gcc.uplink_bss) { + bss->trans->gcc.uplink_bss = NULL; + bss->trans->gcc.uplink_cell = NULL; + } + llist_del(&bss->list); + bss->trans = NULL; + } + + /* Detach us from RAN connection. */ + if (bss->conn) { + if (bss->conn->vgcs.bss == bss) + bss->conn->vgcs.bss = NULL; + if (bss->conn->vgcs.cell == bss) + bss->conn->vgcs.cell = NULL; + ran_conn_close(bss->conn); + bss->conn = NULL; + } + + /* Detach us from all BSS, if still linked */ + llist_for_each_entry_safe(cell, cell2, &bss->cell_list, list_bss) { + llist_del(&cell->list_bss); + cell->bss = NULL; + } + + /* Free FSM. (should be allocated) */ + osmo_fsm_inst_state_chg(bss->fi, VGCS_BSS_ST_NULL, 0, 0); + osmo_fsm_inst_term(bss->fi, OSMO_FSM_TERM_REGULAR, NULL); +} + +/* Get identity of talker. + * This is required to detect if the talker is the calling subscriber. */ +static int talker_identity(struct vgcs_bss *bss, uint8_t *l3, int l3_len) +{ + struct osmo_mobile_identity mi; + int rc; + + puts(osmo_hexdump(l3, l3_len)); + rc = osmo_mobile_identity_decode_from_l3_buf(&mi, l3, l3_len, false); + if (rc < 0) { + LOG_BSS(bss, LOGL_DEBUG, "Talker's Identity cannot be decoded.\n"); + return rc; + } + + switch (mi.type) { + case GSM_MI_TYPE_IMSI: + if (!bss->trans->vsub) + break; + LOG_BSS(bss, LOGL_DEBUG, "Talker's sends IMSI %s, originator has IMSI %s.\n", + mi.imsi, bss->trans->vsub->imsi); + if (!strcmp(mi.imsi, bss->trans->vsub->imsi)) + return 1; + break; + case GSM_MI_TYPE_TMSI: + if (!bss->trans->vsub) + break; + LOG_BSS(bss, LOGL_DEBUG, "Talker's sends TMSI 0x%08x, originator has TMSI 0x%08x.\n", + mi.tmsi, bss->trans->vsub->tmsi); + if (mi.tmsi == bss->trans->vsub->tmsi) + return 1; + break; + default: + LOG_BSS(bss, LOGL_DEBUG, "Talker's Identity is not IMSI nor TMSI.\n"); + return -EINVAL; + } + + return 0; +} + +static void vgcs_bss_fsm_null(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct vgcs_bss *bss = fi->priv; + struct ran_msg ran_msg; + + switch (event) { + case VGCS_BSS_EV_SETUP: + /* Change state. */ + osmo_fsm_inst_state_chg(fi, VGCS_BSS_ST_SETUP, 0, 0); + /* Send VGCS/VBS SETUP to BSS. */ + LOG_BSS(bss, LOGL_DEBUG, "Sending VGCS/VBS SETUP towards BSS.\n"); + ran_msg = (struct ran_msg){ + .msg_type = RAN_MSG_VGCS_VBS_SETUP, + .vgcs_vbs_setup = { + .callref = { + .sf = (bss->trans->type == TRANS_GCC), + }, + .vgcs_feature_flags_present = true, + }, + }; + osmo_store32be_ext(bss->callref >> 3, &ran_msg.vgcs_vbs_setup.callref.call_ref_hi, 3); + ran_msg.vgcs_vbs_setup.callref.call_ref_lo = bss->callref & 0x7; + /* First message, so we must set "initial" to "true". */ + ran_encode_and_send(fi, &ran_msg, bss->conn, true); + break; + case VGCS_BSS_EV_CLEAR: + /* The calling user process requested clearing of VGCS/VBS call. */ + LOG_BSS(bss, LOGL_DEBUG, "Received clearing from calling user process.\n"); + bss_clear(bss, GSM0808_CAUSE_CALL_CONTROL, false); + break; + default: + OSMO_ASSERT(false); + } +} + +static void vgcs_bss_fsm_setup(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct vgcs_bss *bss = fi->priv; + struct vgcs_bss_cell *cell, *cell2; + + switch (event) { + case VGCS_BSS_EV_SETUP_ACK: + /* Receive VGCS/VBS SETUP ACK from BSS. */ + LOG_BSS(bss, LOGL_DEBUG, "Received VGCS/VBS SETUP ACK from BSS.\n"); + /* Send current uplink state to this BSS. */ + if (bss->trans) + update_uplink_state(bss, bss->trans->gcc.uplink_busy); + /* Change state. */ + osmo_fsm_inst_state_chg(fi, VGCS_BSS_ST_ASSIGNMENT, 0, 0); + /* Trigger VGCS/VBS ASSIGNMENT */ + llist_for_each_entry_safe(cell, cell2, &bss->cell_list, list_bss) + osmo_fsm_inst_dispatch(cell->fi, VGCS_CELL_EV_ASSIGN, NULL); + /* If all failed, clear call. */ + if (llist_empty(&bss->cell_list)) { + LOG_BSS(bss, LOGL_NOTICE, "All VGCS/VBS assignments failed.\n"); + bss_clear(bss, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC, true); + break; + } + break; + case VGCS_BSS_EV_SETUP_REFUSE: + /* Received VGCS/VBS SETUP REFUSE from BSS. */ + LOG_BSS(bss, LOGL_NOTICE, "Received VGCS/VBS SETUP REFUSE from BSS.\n"); + bss_clear(bss, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC, true); + break; + case VGCS_BSS_EV_CLEAR: + /* The calling user process requested clearing of VGCS/VBS call. */ + LOG_BSS(bss, LOGL_DEBUG, "Received clearing from calling user process.\n"); + bss_clear(bss, GSM0808_CAUSE_CALL_CONTROL, false); + break; + case VGCS_BSS_EV_CLOSE: + /* The SCCP connection from the MSC has been closed. */ + LOG_BSS(bss, LOGL_NOTICE, "Received SCCP connecting closing from MSC.\n"); + if (bss->conn) { + bss->conn->vgcs.bss = NULL; + bss->conn = NULL; + } + bss_clear(bss, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC, true); + break; + default: + OSMO_ASSERT(false); + } +} + +static void vgcs_bss_fsm_assignment(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct vgcs_bss *bss = fi->priv; + struct vgcs_bss_cell *c; + bool assigned; + + switch (event) { + case VGCS_BSS_EV_ACTIVE_OR_FAIL: + /* If all gone, clear call. */ + if (llist_empty(&bss->cell_list)) { + LOG_BSS(bss, LOGL_NOTICE, "All VGCS/VBS assignments failed.\n"); + bss_clear(bss, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC, true); + break; + } + /* Is there a response for all cells? + * This means that all the channels have a positive response + * There is no channel with negative response, because a + * negative response will remove the channel. */ + assigned = true; + llist_for_each_entry(c, &bss->cell_list, list_bss) { + if (!c->assigned) + assigned = false; + } + if (!assigned) + break; + LOG_BSS(bss, LOGL_DEBUG, "All VGCS/VBS assignments have responded.\n"); + /* Change state. */ + osmo_fsm_inst_state_chg(fi, VGCS_BSS_ST_ACTIVE, 0, 0); + /* Notify calling subscriber process. */ + LOG_BSS(bss, LOGL_DEBUG, "Notify calling user process, that all BSSs are connected.\n"); + if (bss->trans) + osmo_fsm_inst_dispatch(bss->trans->gcc.fi, VGCS_GCC_EV_BSS_ESTABLISHED, NULL); + break; + case VGCS_BSS_EV_CLEAR: + /* The calling user process requested clearing of VGCS/VBS call. */ + LOG_BSS(bss, LOGL_DEBUG, "Received clearing from calling user process.\n"); + bss_clear(bss, GSM0808_CAUSE_CALL_CONTROL, false); + break; + case VGCS_BSS_EV_CLOSE: + /* The SCCP connection from the MSC has been closed. */ + LOG_BSS(bss, LOGL_NOTICE, "Received SCCP connecting closing from MSC.\n"); + if (bss->conn) { + bss->conn->vgcs.bss = NULL; + bss->conn = NULL; + } + bss_clear(bss, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC, true); + break; + default: + OSMO_ASSERT(false); + } +} + +static void vgcs_bss_fsm_active(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct vgcs_bss *bss = fi->priv, *other; + struct ran_msg *rx_ran_msg = data; + struct ran_msg tx_ran_msg; + int rc; + + switch (event) { + case VGCS_BSS_EV_UL_REQUEST: + LOG_BSS(bss, LOGL_DEBUG, "Listener changed to talker.\n"); + if (!bss->trans) + break; + /* Someone is talking. Check if there is no other uplink already busy. + * This should not happen, since all other cells are blocked (SEIZED) as soon as the uplink was + * requested. This may happen due to a race condition, where the uplink was requested before the + * UPLINK SEIZED COMMAND has been received by BSS. */ + if (bss->trans->gcc.uplink_busy) { + /* Send UPLINK REJECT COMMAND to BSS. */ + LOG_BSS(bss, LOGL_DEBUG, "Sending (VGCS) UPLINK REJECT COMMAND towards BSS.\n"); + tx_ran_msg = (struct ran_msg){ + .msg_type = RAN_MSG_UPLINK_REJECT_CMD, + .uplink_reject_cmd = { + .cause = GSM0808_CAUSE_CALL_CONTROL, + }, + }; + ran_encode_and_send(fi, &tx_ran_msg, bss->conn, false); + break; + } + /* Send UPLINK REQUEST ACKNOWLEDGE to BSS. */ + LOG_BSS(bss, LOGL_DEBUG, "Sending (VGCS) UPLINK REQUEST ACKNOWLEDGE towards BSS.\n"); + tx_ran_msg = (struct ran_msg){ + .msg_type = RAN_MSG_UPLINK_REQUEST_ACK, + }; + ran_encode_and_send(fi, &tx_ran_msg, bss->conn, false); + /* Set the busy flag and block all other cells. */ + bss->trans->gcc.uplink_bss = bss; + bss->trans->gcc.uplink_busy = true; + bss->trans->gcc.uplink_originator = false; + llist_for_each_entry(other, &bss->trans->gcc.bss_list, list) { + if (other == bss) + continue; + /* Update uplink state. */ + update_uplink_state(bss, bss->trans->gcc.uplink_busy); + } + /* Stop inactivity timer. */ + stop_inactivity_timer(bss->trans); + break; + case VGCS_BSS_EV_UL_REQUEST_CNF: + LOG_BSS(bss, LOGL_DEBUG, "Talker established uplink.\n"); + if (!bss->trans) + break; + if (!bss->trans->gcc.uplink_busy || bss->trans->gcc.uplink_bss != bss) { + LOG_BSS(bss, LOGL_ERROR, "Got UL REQUEST CNF, but we did not granted uplink.\n"); + break; + } + /* Determine if talker is the originator of the call. */ + rc = talker_identity(bss, rx_ran_msg->uplink_request_cnf.l3.l3, + rx_ran_msg->uplink_request_cnf.l3.l3_len); + if (rc > 0) { + bss->trans->gcc.uplink_originator = true; + LOG_BSS(bss, LOGL_DEBUG, "Talker is the originator of the call.\n"); + } + /* Set parameter. */ + set_parameter(bss->trans); + /* Set cell of current talker. */ + set_uplink_cell(bss, &rx_ran_msg->uplink_request_cnf.cell_identifier, 0); + /* Set MGW conference. */ + set_mgw_conference(bss->trans); + break; + case VGCS_BSS_EV_UL_APP_DATA: + LOG_BSS(bss, LOGL_DEBUG, "Talker sends application data on uplink.\n"); + if (!bss->trans) + break; + if (!bss->trans->gcc.uplink_busy || bss->trans->gcc.uplink_bss != bss) { + LOG_BSS(bss, LOGL_ERROR, "Got UP APP DATA, but we did not granted uplink.\n"); + break; + } + // FIXME: Use L3 info and feed to app. + break; + case VGCS_BSS_EV_BSS_DTAP: + LOG_BSS(bss, LOGL_DEBUG, "Talker sends DTAP message.\n"); + if (!bss->trans) + break; + if (!bss->trans->gcc.uplink_busy || bss->trans->gcc.uplink_bss != bss) { + LOG_BSS(bss, LOGL_ERROR, "Got DTAP from BSS, but we did not granted uplink.\n"); + break; + } + gsm44068_rcv_bcc_gcc(NULL, bss->trans, rx_ran_msg->dtap); + break; + case VGCS_BSS_EV_UL_RELEASE: + LOG_BSS(bss, LOGL_DEBUG, "Talker released uplink.\n"); + if (!bss->trans) + break; + if (bss->trans->type == TRANS_BCC) { + LOG_BSS(bss, LOGL_DEBUG, "This is a broadcast call, terminating call.\n"); + gcc_terminate_and_destroy(bss->trans, OSMO_GSM44068_CAUSE_NORMAL_CALL_CLEARING); + break; + } + if (!bss->trans->gcc.uplink_busy) { + LOG_BSS(bss, LOGL_NOTICE, "Got uplink release, but no uplink busy.\n"); + break; + } + /* Talker release the uplink. Ignore, if not from the current talking cell. */ + if (bss->trans->gcc.uplink_bss != bss) { + LOG_BSS(bss, LOGL_NOTICE, "Got uplink release, but uplink busy in other cell.\n"); + break; + } + /* Clear the busy flag and unblock all other cells. */ + bss->trans->gcc.uplink_bss = NULL; + bss->trans->gcc.uplink_cell = NULL; + bss->trans->gcc.uplink_busy = false; + llist_for_each_entry(other, &bss->trans->gcc.bss_list, list) { + if (other == bss) + continue; + /* Update uplink state. */ + if (bss->trans) + update_uplink_state(bss, bss->trans->gcc.uplink_busy); + } + /* Set MGW conference. */ + set_mgw_conference(bss->trans); + /* Start inactivity timer. */ + start_inactivity_timer(bss->trans); + break; + case VGCS_BSS_EV_CLEAR: + /* The calling user process requested clearing of VGCS/VBS call. */ + LOG_BSS(bss, LOGL_DEBUG, "Received clearing from calling user process.\n"); + bss_clear(bss, GSM0808_CAUSE_CALL_CONTROL, false); + break; + case VGCS_BSS_EV_CLOSE: + /* The SCCP connection from the MSC has been closed. */ + LOG_BSS(bss, LOGL_NOTICE, "Received SCCP connecting closing from MSC.\n"); + if (bss->conn) { + bss->conn->vgcs.bss = NULL; + bss->conn = NULL; + } + bss_clear(bss, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC, true); + break; + default: + OSMO_ASSERT(false); + } +} + +static void vgcs_bss_fsm_release(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct vgcs_bss *bss = fi->priv; + + switch (event) { + case VGCS_BSS_EV_CLOSE: + /* The SCCP connection from the MSC has been closed while waitring fro CLEAR COMPLETE. */ + LOG_BSS(bss, LOGL_NOTICE, "Received SCCP closing collision.\n"); + bss_destroy(bss); + break; + case VGCS_BSS_EV_RELEASED: + LOG_BSS(bss, LOGL_DEBUG, "Received CLEAR COMPLETE from BSS, we are done!\n"); + bss_destroy(bss); + break; + default: + OSMO_ASSERT(false); + } +} + +static const struct osmo_fsm_state vgcs_bss_fsm_states[] = { + [VGCS_BSS_ST_NULL] = { + .name = "NULL", + .in_event_mask = S(VGCS_BSS_EV_SETUP) | + S(VGCS_BSS_EV_CLEAR), + .out_state_mask = S(VGCS_BSS_ST_SETUP), + .action = vgcs_bss_fsm_null, + }, + [VGCS_BSS_ST_SETUP] = { + .name = "SETUP sent", + .in_event_mask = S(VGCS_BSS_EV_SETUP_ACK) | + S(VGCS_BSS_EV_SETUP_REFUSE) | + S(VGCS_BSS_EV_CLEAR) | + S(VGCS_BSS_EV_CLOSE), + .out_state_mask = S(VGCS_BSS_ST_ASSIGNMENT) | + S(VGCS_BSS_ST_RELEASE), + .action = vgcs_bss_fsm_setup, + }, + [VGCS_BSS_ST_ASSIGNMENT] = { + .name = "ASSIGNMENT Sent", + .in_event_mask = S(VGCS_BSS_EV_ACTIVE_OR_FAIL) | + S(VGCS_BSS_EV_CLEAR) | + S(VGCS_BSS_EV_CLOSE), + .out_state_mask = S(VGCS_BSS_ST_ACTIVE) | + S(VGCS_BSS_ST_RELEASE), + .action = vgcs_bss_fsm_assignment, + }, + [VGCS_BSS_ST_ACTIVE] = { + .name = "VGCS/VBS Active", + .in_event_mask = S(VGCS_BSS_EV_UL_REQUEST) | + S(VGCS_BSS_EV_UL_REQUEST_CNF) | + S(VGCS_BSS_EV_UL_APP_DATA) | + S(VGCS_BSS_EV_BSS_DTAP) | + S(VGCS_BSS_EV_UL_RELEASE) | + S(VGCS_BSS_EV_CLEAR) | + S(VGCS_BSS_EV_CLOSE), + .out_state_mask = S(VGCS_BSS_ST_RELEASE), + .action = vgcs_bss_fsm_active, + }, + [VGCS_BSS_ST_RELEASE] = { + .name = "Releasing VGCS/VBS control", + .in_event_mask = S(VGCS_BSS_EV_CLEAR) | + S(VGCS_BSS_EV_RELEASED), + .out_state_mask = S(VGCS_BSS_ST_NULL), + .action = vgcs_bss_fsm_release, + }, +}; + +static struct osmo_fsm vgcs_bss_fsm = { + .name = "vgcs_bss", + .states = vgcs_bss_fsm_states, + .num_states = ARRAY_SIZE(vgcs_bss_fsm_states), + .log_subsys = DASCI, + .event_names = vgcs_bss_fsm_event_names, +}; + +/* The BSS accepts VGCS/VBS and sends us supported features. */ +void vgcs_vbs_setup_ack(struct vgcs_bss *bss, const struct ran_msg *ran_msg) +{ + if (!bss->trans) + return; + osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_SETUP_ACK, (void *)ran_msg); +} + +/* The BSS refuses VGCS/VBS. */ +void vgcs_vbs_setup_refuse(struct vgcs_bss *bss, const struct ran_msg *ran_msg) +{ + if (!bss->trans) + return; + osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_SETUP_REFUSE, (void *)ran_msg); +} + +/* The BSS needs more time for VGCS/VBS channel assignment. */ +void vgcs_vbs_queuing_ind(struct vgcs_bss_cell *cell) +{ + if (!cell->bss) + return; +} + +/* A mobile station requests the uplink on a VGCS channel. */ +void vgcs_uplink_request(struct vgcs_bss *bss, const struct ran_msg *ran_msg) +{ + if (!bss->trans) + return; + osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_UL_REQUEST, (void *)ran_msg); +} + +/* The uplink on a VGCS channel has been established. */ +void vgcs_uplink_request_cnf(struct vgcs_bss *bss, const struct ran_msg *ran_msg) +{ + if (!bss->trans) + return; + osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_UL_REQUEST_CNF, (void *)ran_msg); +} + +/* Application data received on the uplink of a VGCS channel. */ +void vgcs_app_data(struct vgcs_bss *bss, const struct ran_msg *ran_msg) +{ + if (!bss->trans) + return; + osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_UL_APP_DATA, (void *)ran_msg); +} + +/* Application data received on the uplink of a VGCS channel. */ +void vgcs_bss_dtap(struct vgcs_bss *bss, const struct ran_msg *ran_msg) +{ + if (!bss->trans) + return; + osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_BSS_DTAP, (void *)ran_msg); +} + +/* A mobile station releases the uplink on a VGCS channel. */ +void vgcs_uplink_release_ind(struct vgcs_bss *bss, const struct ran_msg *ran_msg) +{ + if (!bss->trans) + return; + osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_UL_RELEASE, (void *)ran_msg); +} + +/* The BSS gives cell status about VGCS/VBS channel. */ +void vgcs_vbs_assign_status(struct vgcs_bss_cell *cell, const struct ran_msg *ran_msg) +{ + if (!cell->bss) + return; +} + +void vgcs_vbs_caller_assign_cpl(struct gsm_trans *trans) +{ + osmo_fsm_inst_dispatch(trans->gcc.fi, VGCS_GCC_EV_BSS_ASSIGN_CPL, NULL); +} + +void vgcs_vbs_caller_assign_fail(struct gsm_trans *trans) +{ + osmo_fsm_inst_dispatch(trans->gcc.fi, VGCS_GCC_EV_BSS_ASSIGN_FAIL, NULL); +} + +/* BSS indicated that the channel has been released. */ +void vgcs_vbs_clear_req(struct vgcs_bss *bss, const struct ran_msg *ran_msg) +{ + osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_CLOSE, (void *)ran_msg); +} + +/* BSS indicated that the channel has been released. */ +void vgcs_vbs_clear_cpl(struct vgcs_bss *bss, const struct ran_msg *ran_msg) +{ + osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_RELEASED, (void *)ran_msg); +} + +/* + * Cell resource state machine - handles all "resource control" instances + */ + +static const struct value_string vgcs_cell_fsm_event_names[] = { + OSMO_VALUE_STRING(VGCS_CELL_EV_RTP_STREAM_GONE), + OSMO_VALUE_STRING(VGCS_CELL_EV_RTP_STREAM_ADDR_AVAILABLE), + OSMO_VALUE_STRING(VGCS_CELL_EV_RTP_STREAM_ESTABLISHED), + OSMO_VALUE_STRING(VGCS_CELL_EV_ASSIGN), + OSMO_VALUE_STRING(VGCS_CELL_EV_ASSIGN_RES), + OSMO_VALUE_STRING(VGCS_CELL_EV_ASSIGN_FAIL), + OSMO_VALUE_STRING(VGCS_CELL_EV_CLEAR), + OSMO_VALUE_STRING(VGCS_CELL_EV_CLOSE), + OSMO_VALUE_STRING(VGCS_CELL_EV_RELEASED), + { } +}; + +static void cell_destroy(struct vgcs_bss_cell *cell); + +/* Clear the connection towards BSS. + * Relations to the BSS and transaction is removed. */ +static void cell_clear(struct vgcs_bss_cell *cell, uint8_t cause) +{ + struct ran_msg ran_msg; + + /* Must detach us from BSS. */ + if (cell->bss) { + /* Remove pointer to talking channel. */ + if (cell->bss->trans && cell->bss->trans->gcc.uplink_cell == cell) + cell->bss->trans->gcc.uplink_cell = NULL; + llist_del(&cell->list_bss); + cell->bss = NULL; + } + + /* Change state. */ + if (cell->fi->state != VGCS_CELL_ST_RELEASE) + osmo_fsm_inst_state_chg(cell->fi, VGCS_CELL_ST_RELEASE, 0, 0); + + /* If there is no event to wait for, we can just destroy. */ + if (!cell->conn && !cell->rtps) { + cell_destroy(cell); + return; + } + + /* Send Clear Command to BSS. */ + if (cell->conn) { + ran_msg = (struct ran_msg){ + .msg_type = RAN_MSG_CLEAR_COMMAND, + .clear_command = { + .gsm0808_cause = cause, + }, + }; + LOG_CELL(cell, LOGL_DEBUG, "Sending CLEAR COMMAND for call controling channel.\n"); + ran_encode_and_send(cell->fi, &ran_msg, cell->conn, false); + } + + /* Clear RTP stream. This may trigger VGCS_CELL_EV_RTP_STREAM_GONE within this release function. */ + if (cell->rtps) + rtp_stream_release(cell->rtps); +} + +/* When finally the BSS connection is released. (CLEAR COMPLETE response) + * Relations to the BSS and transaction is removed, if not already. */ +static void cell_destroy(struct vgcs_bss_cell *cell) +{ + struct vgcs_mgw_ep *mgw; + + /* close RAN conn */ + if (cell->conn) { + cell->conn->vgcs.cell = NULL; + ran_conn_close(cell->conn); + cell->conn = NULL; + } + + /* Detach from BSS now. Check, to prevent race condition. */ + if (cell->bss) { + /* Remove pointer to talking channel. */ + if (cell->bss->trans && cell->bss->trans->gcc.uplink_cell == cell) + cell->bss->trans->gcc.uplink_cell = NULL; + llist_del(&cell->list_bss); + cell->bss = NULL; + } + + /* Detach from MGW now. Check, to prevent race condition. */ + if (cell->mgw) { + mgw = cell->mgw; + llist_del(&cell->list_mgw); + cell->mgw = NULL; + /* Destroy MGW endpoint, if list is empty. */ + if (llist_empty(&mgw->cell_list)) + osmo_fsm_inst_dispatch(mgw->fi, VGCS_MGW_EP_EV_CLEAR, NULL); + } + + LOG_CELL(cell, LOGL_DEBUG, "Detroy connection to cell.\n"); + + /* Free FSM. (should be allocated) */ + osmo_fsm_inst_state_chg(cell->fi, VGCS_CELL_ST_NULL, 0, 0); + osmo_fsm_inst_term(cell->fi, OSMO_FSM_TERM_REGULAR, NULL); +} + +static void vgcs_cell_fsm_null(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct vgcs_bss_cell *cell = fi->priv; + const struct codec_mapping *cm; + int rc; + + switch (event) { + case VGCS_CELL_EV_ASSIGN: + LOG_CELL(cell, LOGL_DEBUG, "Received assignment from BSS controling process.\n"); + /* Allocate rtps stream. */ + cell->rtps = rtp_stream_alloc(cell->fi, VGCS_CELL_EV_RTP_STREAM_GONE, + VGCS_CELL_EV_RTP_STREAM_ADDR_AVAILABLE, + VGCS_CELL_EV_RTP_STREAM_ESTABLISHED, RTP_TO_RAN, cell->call_id, + NULL); + if (!cell->rtps) { + LOG_CELL(cell, LOGL_DEBUG, "Failed to allocate RTP stream, cannot continue.\n"); + cell_destroy(cell); + break; + } + /* Hard coded codec: GSM V1 */ + cm = codec_mapping_by_gsm0808_speech_codec_type(GSM0808_SCT_FR1); + rtp_stream_set_one_codec(cell->rtps, &cm->sdp); + /* Set initial mode. */ + rtp_stream_set_mode(cell->rtps, MGCP_CONN_RECV_ONLY); + /* Commit RTP stream. */ + if (!cell->bss && !cell->bss->trans) { + LOG_CELL(cell, LOGL_DEBUG, "No transaction, cannot continue.\n"); + cell_clear(cell, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC); + break; + } + if (!cell->mgw && !cell->mgw->mgw_ep) { + LOG_CELL(cell, LOGL_DEBUG, "No MGW endpoint, cannot continue.\n"); + cell_clear(cell, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC); + break; + } + rc = rtp_stream_ensure_ci(cell->rtps, cell->mgw->mgw_ep); + if (rc < 0) { + LOG_CELL(cell, LOGL_DEBUG, "Failed to trigger RTP stream CI.\n"); + cell_clear(cell, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC); + break; + } + /* Change state. */ + osmo_fsm_inst_state_chg(fi, VGCS_CELL_ST_ASSIGNMENT, 0, 0); + break; + case VGCS_CELL_EV_CLEAR: + /* The calling user process requested clearing of VGCS/VBS call. */ + LOG_CELL(cell, LOGL_DEBUG, "Received clearing from BSS controling process.\n"); + cell_clear(cell, GSM0808_CAUSE_CALL_CONTROL); + break; + default: + OSMO_ASSERT(false); + } +} + +static void vgcs_cell_fsm_assignment(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct vgcs_bss_cell *cell = fi->priv; + struct ran_msg *rx_ran_msg = data; + struct ran_msg tx_ran_msg; + struct osmo_sockaddr_str ss; + const struct codec_mapping *cm; + struct vgcs_bss *bss; + int rc; + + switch (event) { + case VGCS_CELL_EV_RTP_STREAM_GONE: + /* The RTP stream failed. */ + LOG_CELL(cell, LOGL_ERROR, "RTP stream of MGW failed.\n"); + cell->rtps = NULL; + goto channel_fail; + break; + case VGCS_CELL_EV_RTP_STREAM_ADDR_AVAILABLE: + /* The RTP stream sends its peer. */ + if (!osmo_sockaddr_str_is_nonzero(&cell->rtps->local)) { + LOG_CELL(cell, LOGL_ERROR, "Invalid RTP address received from MGW: " OSMO_SOCKADDR_STR_FMT "\n", + OSMO_SOCKADDR_STR_FMT_ARGS(&cell->rtps->local)); + goto channel_fail; + } + LOG_CELL(cell, LOGL_DEBUG, + "MGW endpoint's RTP address available for the CI %s: " OSMO_SOCKADDR_STR_FMT " (osmux=%s:%d)\n", + rtp_direction_name(cell->rtps->dir), OSMO_SOCKADDR_STR_FMT_ARGS(&cell->rtps->local), + cell->rtps->use_osmux ? "yes" : "no", cell->rtps->local_osmux_cid); + /* Send VGCS/VBS ASSIGNMENT REQUEST to BSS */ + LOG_CELL(cell, LOGL_DEBUG, "Sending VGCS/VBS ASSIGNMENT REQUEST towards BSS.\n"); + tx_ran_msg = (struct ran_msg) { + .msg_type = RAN_MSG_VGCS_VBS_ASSIGN_REQ, + .vgcs_vbs_assign_req = { + /* For now we support GSM/FR V1 only. This shall be supported by all MS. */ + .channel_type = { + .ch_indctr = GSM0808_CHAN_SPEECH, + .ch_rate_type = GSM0808_SPEECH_FULL_BM, + .perm_spch_len = 1, + .perm_spch[0] = GSM0808_PERM_FR1, + }, + /* For now we want a channel without any delay. */ + .ass_req = GSM0808_ASRQ_IMMEDIATE, + .callref = { + .sf = (cell->trans_type == TRANS_GCC), + }, + /* We need to identify the cell only. */ + .cell_identifier = { + .id_discr = CELL_IDENT_CI, + .id.ci = cell->cell_id, + }, + .aoip_transport_layer_present = true, + .call_id_present = true, + .call_id = cell->call_id, + .codec_list_present = true, + .codec_list_msc_preferred = { + .len = 1, + .codec[0] = { + .fi = 1, + .type = GSM0808_SCT_FR1, + .cfg = 0, + }, + }, + }, + }; + osmo_store32be_ext(cell->callref >> 3, &tx_ran_msg.vgcs_vbs_assign_req.callref.call_ref_hi, 3); + tx_ran_msg.vgcs_vbs_assign_req.callref.call_ref_lo = cell->callref & 0x7; + osmo_sockaddr_str_to_sockaddr(&cell->rtps->local, &tx_ran_msg.vgcs_vbs_assign_req.aoip_transport_layer); + /* First message, so we must set "initial" to "true". */ + ran_encode_and_send(fi, &tx_ran_msg, cell->conn, true); + break; + case VGCS_CELL_EV_RTP_STREAM_ESTABLISHED: + /* The RTP stream established. */ + LOG_CELL(cell, LOGL_DEBUG, "RTP stream is established.\n"); + break; + case VGCS_CELL_EV_ASSIGN_RES: + /* Receive VGCS/VBS ASSIGNMENT RESULT from BSS. */ + LOG_CELL(cell, LOGL_DEBUG, "Received VGCS/VBS ASSIGNMENT RESULT from BSS.\n"); + cell->assigned = true; + if (!rx_ran_msg->vgcs_vbs_assign_res.aoip_transport_layer_present + && !rx_ran_msg->vgcs_vbs_assign_res.codec_present + && !rx_ran_msg->vgcs_vbs_assign_res.call_id_present) { + LOG_CELL(cell, LOGL_ERROR, "Mandatory IEs missing.\n"); + goto channel_fail; + } + /* Send remote peer to RTP stream. */ + if (osmo_sockaddr_str_from_sockaddr(&ss, &rx_ran_msg->vgcs_vbs_assign_res.aoip_transport_layer)) { + LOG_CELL(cell, LOGL_ERROR, "Cannot RTP-CONNECT, invalid RTP IP:port in incoming MNCC " + "message\n"); + goto channel_fail; + } + rtp_stream_set_remote_addr(cell->rtps, &ss); + /* Send remote codec to RTP stream. */ + cm = codec_mapping_by_gsm0808_speech_codec_type(rx_ran_msg->vgcs_vbs_assign_res.codec_msc_chosen.type); + if (!cm) { + LOG_CELL(cell, LOGL_ERROR, "Chosen codec by BSC is not supported by MSC.\n"); + goto channel_fail; + } + rtp_stream_set_one_codec(cell->rtps, &cm->sdp); + /* Set listening mode. */ + rtp_stream_set_mode(cell->rtps, MGCP_CONN_SEND_ONLY); + /* Commit RTP stream. */ + rc = rtp_stream_commit(cell->rtps); + if (rc < 0) { + LOG_CELL(cell, LOGL_ERROR, "Failed to commit parameters to RTP stream.\n"); + goto channel_fail; + } + /* Change state. */ + osmo_fsm_inst_state_chg(fi, VGCS_CELL_ST_ACTIVE, 0, 0); + /* Notify BSS FSM about channel activation. */ + if (cell->bss) + osmo_fsm_inst_dispatch(cell->bss->fi, VGCS_BSS_EV_ACTIVE_OR_FAIL, NULL); + break; + case VGCS_CELL_EV_ASSIGN_FAIL: + /* Received VGCS/VBS ASSIGNMENT FAILURE from BSS. */ + LOG_CELL(cell, LOGL_NOTICE, "Received VGCS/VBS ASSIGNMENT FAILURE from BSS.\n"); +channel_fail: + bss = cell->bss; + /* Remove cell. */ + tx_ran_msg = (struct ran_msg){ + .msg_type = RAN_MSG_CLEAR_COMMAND, + .clear_command = { + .gsm0808_cause = GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC, + }, + }; + ran_encode_and_send(bss->fi, &tx_ran_msg, cell->conn, false); + cell_clear(cell, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC); + /* Notify BSS FSM about channel failure. */ + if (bss) + osmo_fsm_inst_dispatch(bss->fi, VGCS_BSS_EV_ACTIVE_OR_FAIL, NULL); + break; + case VGCS_CELL_EV_CLEAR: + /* The calling user process requested clearing of VGCS/VBS call. */ + LOG_CELL(cell, LOGL_DEBUG, "Received clearing from BSS controling process.\n"); + cell_clear(cell, GSM0808_CAUSE_CALL_CONTROL); + break; + case VGCS_CELL_EV_CLOSE: + /* The SCCP connection from the MSC has been closed. */ + LOG_CELL(cell, LOGL_NOTICE, "Received SCCP connecting closing from MSC.\n"); + if (cell->conn) { + cell->conn->vgcs.bss = NULL; + cell->conn = NULL; + } + cell_clear(cell, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC); + break; + default: + OSMO_ASSERT(false); + } +} + +static void vgcs_cell_fsm_active(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct vgcs_bss_cell *cell = fi->priv; + + switch (event) { + case VGCS_CELL_EV_RTP_STREAM_GONE: + /* The RTP stream failed. */ + LOG_CELL(cell, LOGL_ERROR, "RTP stream of MGW failed.\n"); + cell->rtps = NULL; + cell_clear(cell, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC); + break; + case VGCS_CELL_EV_RTP_STREAM_ESTABLISHED: + /* The RTP stream established. */ + LOG_CELL(cell, LOGL_DEBUG, "RTP stream is established.\n"); + break; + case VGCS_CELL_EV_CLEAR: + /* The calling user process requested clearing of VGCS/VBS call. */ + LOG_CELL(cell, LOGL_DEBUG, "Received clearing from BSS controling process.\n"); + cell_clear(cell, GSM0808_CAUSE_CALL_CONTROL); + break; + case VGCS_CELL_EV_CLOSE: + /* The SCCP connection from the MSC has been closed. */ + LOG_CELL(cell, LOGL_NOTICE, "Received SCCP connecting closing from MSC.\n"); + if (cell->conn) { + cell->conn->vgcs.bss = NULL; + cell->conn = NULL; + } + cell_clear(cell, GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC); + break; + default: + OSMO_ASSERT(false); + } +} + +static void vgcs_cell_fsm_release(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct vgcs_bss_cell *cell = fi->priv; + + switch (event) { + case VGCS_CELL_EV_RTP_STREAM_GONE: + /* The RTP stream gone. */ + LOG_CELL(cell, LOGL_ERROR, "RTP stream gone.\n"); + cell->rtps = NULL; + /* Wait for RAN conn. */ + if (cell->conn) + break; + cell_destroy(cell); + break; + case VGCS_CELL_EV_CLEAR: + case VGCS_CELL_EV_RELEASED: + if (event == VGCS_CELL_EV_CLEAR) { + /* The SCCP connection from the MSC has been closed while waiting for CLEAR COMPLETE. */ + LOG_CELL(cell, LOGL_NOTICE, "Received SCCP closing collision.\n"); + } else + LOG_CELL(cell, LOGL_DEBUG, "Received CLEAR COMPLETE from BSS, we are done!\n"); + /* Wait for RTP stream. */ + if (cell->rtps) { + /* close RAN conn */ + if (cell->conn) { + cell->conn->vgcs.cell = NULL; + ran_conn_close(cell->conn); + cell->conn = NULL; + } + break; + } + cell_destroy(cell); + break; + default: + OSMO_ASSERT(false); + } +} + +static const struct osmo_fsm_state vgcs_cell_fsm_states[] = { + [VGCS_CELL_ST_NULL] = { + .name = "NULL", + .in_event_mask = S(VGCS_CELL_EV_ASSIGN) | + S(VGCS_CELL_EV_CLEAR), + .out_state_mask = S(VGCS_CELL_ST_ASSIGNMENT), + .action = vgcs_cell_fsm_null, + }, + [VGCS_CELL_ST_ASSIGNMENT] = { + .name = "ASSIGNMENT Sent", + .in_event_mask = S(VGCS_CELL_EV_RTP_STREAM_GONE) | + S(VGCS_CELL_EV_RTP_STREAM_ADDR_AVAILABLE) | + S(VGCS_CELL_EV_RTP_STREAM_ESTABLISHED) | + S(VGCS_CELL_EV_ASSIGN_RES) | + S(VGCS_CELL_EV_ASSIGN_FAIL) | + S(VGCS_CELL_EV_CLEAR) | + S(VGCS_CELL_EV_CLOSE), + .out_state_mask = S(VGCS_CELL_ST_ACTIVE) | + S(VGCS_CELL_ST_RELEASE), + .action = vgcs_cell_fsm_assignment, + }, + [VGCS_CELL_ST_ACTIVE] = { + .name = "VGCS/VBS channel active", + .in_event_mask = S(VGCS_CELL_EV_RTP_STREAM_GONE) | + S(VGCS_CELL_EV_RTP_STREAM_ESTABLISHED) | + S(VGCS_CELL_EV_CLEAR) | + S(VGCS_CELL_EV_CLOSE), + .out_state_mask = S(VGCS_CELL_ST_RELEASE), + .action = vgcs_cell_fsm_active, + }, + [VGCS_CELL_ST_RELEASE] = { + .name = "Releasing VGCS/VBS channel", + .in_event_mask = S(VGCS_CELL_EV_RTP_STREAM_GONE) | + S(VGCS_CELL_EV_CLEAR) | + S(VGCS_CELL_EV_RELEASED), + .out_state_mask = S(VGCS_CELL_ST_NULL), + .action = vgcs_cell_fsm_release, + }, +}; + +static struct osmo_fsm vgcs_cell_fsm = { + .name = "vgcs_cell", + .states = vgcs_cell_fsm_states, + .num_states = ARRAY_SIZE(vgcs_cell_fsm_states), + .log_subsys = DASCI, + .event_names = vgcs_cell_fsm_event_names, +}; + +/* The BSS accepts VGCS/VBS channel assignment. */ +void vgcs_vbs_assign_result(struct vgcs_bss_cell *cell, const struct ran_msg *ran_msg) +{ + osmo_fsm_inst_dispatch(cell->fi, VGCS_CELL_EV_ASSIGN_RES, (void *)ran_msg); +} + +/* The BSS refuses VGCS/VBS channel assignment. */ +void vgcs_vbs_assign_fail(struct vgcs_bss_cell *cell, const struct ran_msg *ran_msg) +{ + osmo_fsm_inst_dispatch(cell->fi, VGCS_CELL_EV_ASSIGN_FAIL, (void *)ran_msg); +} + +/* BSS indicated that the channel has been released. */ +void vgcs_vbs_clear_req_channel(struct vgcs_bss_cell *cell, const struct ran_msg *ran_msg) +{ + LOG_CELL(cell, LOGL_DEBUG, "Received CLEAR REQUEST for resource controling channel from BSS.\n"); + osmo_fsm_inst_dispatch(cell->fi, VGCS_CELL_EV_CLOSE, (void *)ran_msg); +} + +/* BSS confirms the release of channel. */ +void vgcs_vbs_clear_cpl_channel(struct vgcs_bss_cell *cell, const struct ran_msg *ran_msg) +{ + LOG_CELL(cell, LOGL_DEBUG, "Received CLEAR COMPLETE for resource controling channel from BSS.\n"); + osmo_fsm_inst_dispatch(cell->fi, VGCS_CELL_EV_RELEASED, (void *)ran_msg); +} + +/* + * MGW endpoint FSM + */ + +static const struct value_string vgcs_mgw_ep_fsm_event_names[] = { + OSMO_VALUE_STRING(VGCS_MGW_EP_EV_FREE), + OSMO_VALUE_STRING(VGCS_MGW_EP_EV_CLEAR), + { } +}; + +static void vgcs_mgw_ep_fsm_active(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct vgcs_mgw_ep *mgw = fi->priv; + struct vgcs_bss_cell *cell, *cell2; + struct mgcp_client *mgcp_client; + + switch (event) { + case VGCS_MGW_EP_EV_FREE: + LOGP(DASCI, LOGL_DEBUG, "MGW connection closed, removing all cell instances.\n"); + llist_for_each_entry_safe(cell, cell2, &mgw->cell_list, list_mgw) { + if (cell->rtps) + cell->rtps->ci = NULL; + llist_del(&cell->list_mgw); + cell->mgw = NULL; + } + /* Put MGCP client back into MGW pool. */ + mgcp_client = osmo_mgcpc_ep_client(mgw->mgw_ep); + mgcp_client_pool_put(mgcp_client); + /* Destroy this instance. */ + osmo_fsm_inst_term_children(fi, OSMO_FSM_TERM_PARENT, NULL); + osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, NULL); + break; + case VGCS_MGW_EP_EV_CLEAR: + if (!llist_empty(&mgw->cell_list)) + break; + LOGP(DASCI, LOGL_DEBUG, "Cell list of MGW instance is now empty, dropping.\n"); + /* Destroy this instance. */ + osmo_fsm_inst_term_children(fi, OSMO_FSM_TERM_PARENT, NULL); + osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, NULL); + break; + default: + OSMO_ASSERT(false); + } +} + +static const struct osmo_fsm_state vgcs_mgw_ep_fsm_states[] = { + [VGCS_MGW_EP_ST_NULL] = { + .name = "NULL", + .out_state_mask = S(VGCS_MGW_EP_ST_ACTIVE), + }, + [VGCS_MGW_EP_ST_ACTIVE] = { + .name = "MGW endpoint allocated", + .in_event_mask = S(VGCS_MGW_EP_EV_FREE) | + S(VGCS_MGW_EP_EV_CLEAR), + .out_state_mask = S(VGCS_MGW_EP_ST_NULL), + .action = vgcs_mgw_ep_fsm_active, + }, +}; + +static struct osmo_fsm vgcs_mgw_ep_fsm = { + .name = "vgcs_mgw_ep", + .states = vgcs_mgw_ep_fsm_states, + .num_states = ARRAY_SIZE(vgcs_mgw_ep_fsm_states), + .log_subsys = DASCI, + .event_names = vgcs_mgw_ep_fsm_event_names, +}; diff --git a/src/libmsc/transaction.c b/src/libmsc/transaction.c index a3a9ef1b8..89f77e56f 100644 --- a/src/libmsc/transaction.c +++ b/src/libmsc/transaction.c @@ -29,6 +29,7 @@ #include <osmocom/msc/msub.h> #include <osmocom/msc/paging.h> #include <osmocom/msc/silent_call.h> +#include <osmocom/msc/msc_vgcs.h> void *tall_trans_ctx; @@ -241,6 +242,14 @@ void trans_free(struct gsm_trans *trans) LOG_TRANS(trans, LOGL_DEBUG, "Freeing transaction\n"); switch (trans->type) { + case TRANS_GCC: + gsm44068_bcc_gcc_trans_free(trans); + usage_token = MSC_A_USE_GCC; + break; + case TRANS_BCC: + gsm44068_bcc_gcc_trans_free(trans); + usage_token = MSC_A_USE_BCC; + break; case TRANS_CC: _gsm48_cc_trans_free(trans); usage_token = MSC_A_USE_CC; @@ -392,6 +401,12 @@ const char *trans_name(const struct gsm_trans *trans) trans_type_name(trans->type), gsm48_cc_state_name(trans->cc.state)); return namebuf; + case TRANS_GCC: + case TRANS_BCC: + snprintf(namebuf, sizeof(namebuf), "%s:%s", + trans_type_name(trans->type), gsm44068_group_id_string(trans->callref)); + return namebuf; + default: return trans_type_name(trans->type); } |