osmo-msc/include/osmocom/msc/transaction.h

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#pragma once
2009-07-23 19:25:08 +00:00
#include <osmocom/msc/gsm_data.h>
#include <osmocom/msc/gsm_subscriber.h>
#include <osmocom/core/linuxlist.h>
#include <osmocom/core/fsm.h>
#include <osmocom/msc/gsm_04_11.h>
#include <osmocom/msc/mncc.h>
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
#include <osmocom/msc/msc_a.h>
#include <osmocom/msc/debug.h>
#include <osmocom/msc/codec_filter.h>
#include <osmocom/gsm/gsm0411_smc.h>
#include <osmocom/gsm/gsm0411_smr.h>
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
struct vty;
/* Used for late TID assignment */
#define TRANS_ID_UNASSIGNED 0xff
#define LOG_TRANS_CAT_SRC(trans, subsys, file, line, level, fmt, args...) \
LOGPSRC(subsys, level, file, line, \
"trans(%s %s callref-0x%x tid-%u%s) " fmt, \
(trans) ? trans_name(trans) : "NULL", \
(trans) ? ((trans)->msc_a ? (trans)->msc_a->c.fi->id : vlr_subscr_name((trans)->vsub)) : "NULL", \
(trans) ? (trans)->callref : 0, \
(trans) ? (trans)->transaction_id : 0, \
(trans) && (trans)->paging_request ? ",PAGING" : "", \
##args)
#define LOG_TRANS_CAT(trans, subsys, level, fmt, args...) \
LOG_TRANS_CAT_SRC(trans, subsys, __FILE__, __LINE__, level, fmt, ##args)
#define LOG_TRANS(trans, level, fmt, args...) \
LOG_TRANS_CAT(trans, (trans) ? (trans)->log_subsys : DMSC, level, fmt, ##args)
enum bridge_state {
BRIDGE_STATE_NONE,
BRIDGE_STATE_LOOPBACK_PENDING,
BRIDGE_STATE_LOOPBACK_ESTABLISHED,
BRIDGE_STATE_BRIDGE_PENDING,
BRIDGE_STATE_BRIDGE_ESTABLISHED,
};
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
enum trans_type {
TRANS_CC = GSM48_PDISC_CC,
TRANS_SMS = GSM48_PDISC_SMS,
TRANS_USSD = GSM48_PDISC_NC_SS,
TRANS_SILENT_CALL,
};
extern const struct value_string trans_type_names[];
static inline const char *trans_type_name(enum trans_type val)
{ return get_value_string(trans_type_names, val); }
uint8_t trans_type_to_gsm48_proto(enum trans_type type);
/* One transaction */
struct gsm_trans {
/* Entry in list of all transactions */
struct llist_head entry;
/* Back pointer to the network struct */
struct gsm_network *net;
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
/* What kind of transaction */
enum trans_type type;
/* Which category to log on, for LOG_TRANS(). */
int log_subsys;
/* The current transaction ID */
uint8_t transaction_id;
/* The DLCI (DCCH/ACCH + SAPI) of this transaction */
uint8_t dlci;
/* To whom we belong, unique identifier of remote MM entity */
Use libvlr in libmsc (large refactoring) Original libvlr code is by Harald Welte <laforge@gnumonks.org>, polished and tweaked by Neels Hofmeyr <nhofmeyr@sysmocom.de>. This is a long series of trial-and-error development collapsed in one patch. This may be split in smaller commits if reviewers prefer that. If we can keep it as one, we have saved ourselves the additional separation work. SMS: The SQL based lookup of SMS for attached subscribers no longer works since the SQL database no longer has the subscriber data. Replace with a round-robin on the SMS recipient MSISDNs paired with a VLR subscriber RAM lookup whether the subscriber is currently attached. If there are many SMS for not-attached subscribers in the SMS database, this will become inefficient: a DB hit returns a pending SMS, the RAM lookup will reveal that the subscriber is not attached, after which the DB is hit for the next SMS. It would become more efficient e.g. by having an MSISDN based hash list for the VLR subscribers and by marking non-attached SMS recipients in the SMS database so that they can be excluded with the SQL query already. There is a sanity limit to do at most 100 db hits per attempt to find a pending SMS. So if there are more than 100 stored SMS waiting for their recipients to actually attach to the MSC, it may take more than one SMS queue trigger to deliver SMS for subscribers that are actually attached. This is not very beautiful, but is merely intended to carry us over to a time when we have a proper separate SMSC entity. Introduce gsm_subscriber_connection ref-counting in libmsc. Remove/Disable VTY and CTRL commands to create subscribers, which is now a task of the OsmoHLR. Adjust the python tests accordingly. Remove VTY cmd subscriber-keep-in-ram. Use OSMO_GSUP_PORT = 4222 instead of 2222. See I4222e21686c823985be8ff1f16b1182be8ad6175. So far use the LAC from conn->bts, will be replaced by conn->lac in Id3705236350d5f69e447046b0a764bbabc3d493c. Related: OS#1592 OS#1974 Change-Id: I639544a6cdda77a3aafc4e3446a55393f60e4050
2016-06-19 16:06:02 +00:00
struct vlr_subscr *vsub;
/* The associated connection we are using to transmit messages */
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
struct msc_a *msc_a;
/* reference from MNCC or other application */
uint32_t callref;
/* if traffic channel receive was requested */
int tch_recv;
/* is thats one paging? */
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
struct paging_request *paging_request;
/* bearer capabilities (rate and codec) */
struct gsm_mncc_bearer_cap bearer_cap;
union {
struct {
/* current call state */
int state;
/* current timer and message queue */
int Tcurrent; /* current CC timer */
int T308_second; /* used to send release again */
struct osmo_timer_list timer;
struct osmo_timer_list timer_guard;
struct gsm_mncc msg; /* stores setup/disconnect/release message */
bool mncc_initiated; /* Whether an MNCC Release is necessary on failure */
struct osmo_lcls *lcls;
/* Track codec choices from BSS and remote call leg */
struct codec_filter codecs;
} cc;
struct {
struct gsm411_smc_inst smc_inst;
struct gsm411_smr_inst smr_inst;
/* SM-RP-MR, Message Reference (see GSM TS 04.11, section 8.2.3) */
uint8_t sm_rp_mr;
/* More Messages to Send (see 3GPP TS 29.002, section 7.6.8.7) */
bool sm_rp_mmts_ind;
struct gsm_sms *sms;
} sms;
struct {
/**
* Stores a GSM 04.80 message to be sent to
* a subscriber after successful Paging Response
*/
struct msgb *msg;
/* Inactivity timer, triggers transaction release */
struct osmo_timer_list timer_guard;
} ss;
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
struct {
struct gsm0808_channel_type ct;
struct osmo_sockaddr_str rtp_cn;
struct vty *from_vty;
} silent_call;
};
struct {
struct gsm_trans *peer;
enum bridge_state state;
} bridge;
};
2009-07-23 19:25:08 +00:00
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
struct gsm_trans *trans_find_by_type(const struct msc_a *msc_a, enum trans_type type);
struct gsm_trans *trans_find_by_id(const struct msc_a *msc_a,
enum trans_type type, uint8_t trans_id);
struct gsm_trans *trans_find_by_callref(const struct gsm_network *net,
uint32_t callref);
struct gsm_trans *trans_find_by_sm_rp_mr(const struct gsm_network *net,
const struct vlr_subscr *vsub,
uint8_t sm_rp_mr);
2009-07-23 19:25:08 +00:00
struct osmo_lcls *trans_lcls_compose(const struct gsm_trans *trans, bool use_lac);
struct gsm_trans *trans_alloc(struct gsm_network *net,
Use libvlr in libmsc (large refactoring) Original libvlr code is by Harald Welte <laforge@gnumonks.org>, polished and tweaked by Neels Hofmeyr <nhofmeyr@sysmocom.de>. This is a long series of trial-and-error development collapsed in one patch. This may be split in smaller commits if reviewers prefer that. If we can keep it as one, we have saved ourselves the additional separation work. SMS: The SQL based lookup of SMS for attached subscribers no longer works since the SQL database no longer has the subscriber data. Replace with a round-robin on the SMS recipient MSISDNs paired with a VLR subscriber RAM lookup whether the subscriber is currently attached. If there are many SMS for not-attached subscribers in the SMS database, this will become inefficient: a DB hit returns a pending SMS, the RAM lookup will reveal that the subscriber is not attached, after which the DB is hit for the next SMS. It would become more efficient e.g. by having an MSISDN based hash list for the VLR subscribers and by marking non-attached SMS recipients in the SMS database so that they can be excluded with the SQL query already. There is a sanity limit to do at most 100 db hits per attempt to find a pending SMS. So if there are more than 100 stored SMS waiting for their recipients to actually attach to the MSC, it may take more than one SMS queue trigger to deliver SMS for subscribers that are actually attached. This is not very beautiful, but is merely intended to carry us over to a time when we have a proper separate SMSC entity. Introduce gsm_subscriber_connection ref-counting in libmsc. Remove/Disable VTY and CTRL commands to create subscribers, which is now a task of the OsmoHLR. Adjust the python tests accordingly. Remove VTY cmd subscriber-keep-in-ram. Use OSMO_GSUP_PORT = 4222 instead of 2222. See I4222e21686c823985be8ff1f16b1182be8ad6175. So far use the LAC from conn->bts, will be replaced by conn->lac in Id3705236350d5f69e447046b0a764bbabc3d493c. Related: OS#1592 OS#1974 Change-Id: I639544a6cdda77a3aafc4e3446a55393f60e4050
2016-06-19 16:06:02 +00:00
struct vlr_subscr *vsub,
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
enum trans_type type, uint8_t trans_id,
uint32_t callref);
2009-07-23 19:25:08 +00:00
void trans_free(struct gsm_trans *trans);
int trans_assign_trans_id(const struct gsm_network *net, const struct vlr_subscr *vsub,
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
enum trans_type type);
struct gsm_trans *trans_has_conn(const struct msc_a *msc_a);
void trans_conn_closed(const struct msc_a *msc_a);
static inline int trans_log_subsys(enum trans_type type)
{
switch (type) {
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
case TRANS_CC:
case TRANS_SILENT_CALL:
return DCC;
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
case TRANS_SMS:
return DLSMS;
case TRANS_USSD:
return DSS;
default:
break;
}
return DMSC;
}
const char *trans_name(const struct gsm_trans *trans);