mscsplit: various preparations to separate MSC from BSC
Disable large parts of the code that depend on BSC presence. The code sections
disabled by #if BEFORE_MSCSPLIT shall be modified or dropped in the course of
adding the A-interface.
Don't set msg->lchan nor msg->dst.
Don't use lchan in libmsc.
Decouple lac from bts.
Prepare entry/exit point for MSC -> BSC and MSC -> RNC communication:
Add msc_ifaces.[hc], a_iface.c, with a general msc_tx_dtap() to redirect to
different interfaces depending on the actual subscriber connection.
While iu_tx() is going to be functional fairly soon, the a_tx() is going to be
just a dummy for some time (see comment).
Add Iu specific fields in gsm_subscriber_connection: the UE connection pointer
and an indicator for the Integrity Protection status on Iu (to be fully
implemented in later commits).
Add lac member to gsm_subscriber_connection, to allow decoupling from
bts->location_area_code. The conn->lac will actually be set in iu.c in an
upcoming commit ("add iucs.[hc]").
move to libcommon-cs: gsm48_extract_mi(), gsm48_paging_extract_mi().
libmsc: duplicate gsm0808 / gsm48 functions (towards BSC).
In osmo-nitb, libmsc would directly call the functions on the BSC level, not
always via the bsc_api. When separating libmsc from libbsc, some functions are
missing from the linkage.
Hence duplicate these functions to libmsc, add an msc_ prefix for clarity, also
add a _tx to gsm0808_cipher_mode():
* add msc_gsm0808_tx_cipher_mode() (dummy/stub)
* add msc_gsm48_tx_mm_serv_ack()
* add msc_gsm48_tx_mm_serv_rej()
Call these from libmsc instead of
* gsm0808_cipher_mode()
* gsm48_tx_mm_serv_ack()
* gsm48_tx_mm_serv_rej()
Also add a comment related to msc_gsm0808_tx_cipher_mode() in two places.
Remove internal RTP streaming code; OsmoNITB supported that, but for OsmoMSC,
this will be done with an external MGCP gateway.
Remove LCHAN_MODIFY from internal MNCC state machine.
Temporarily disable all paging to be able to link libmsc without libbsc.
Skip the paging part of channel_test because the paging is now disabled.
Employ fake paging shims in order for msc_vlr_tests to still work.
msc_compl_l3(): publish in .h, tweak return value. Use new libmsc enum values
for return val, to avoid dependency on libbsc headers. Make callable from
other scopes: publish in osmo_msc.h and remove 'static' in osmo_msc.c
add gsm_encr to subscr_conn
move subscr_request to gsm_subscriber.h
subscr_request_channel() -> subscr_request_conn()
move to libmsc: osmo_stats_vty_add_cmds()
gsm_04_08: remove apply_codec_restrictions()
gsm0408_test: use NULL for root ctx
move to libbsc: gsm_bts_neighbor()
move to libbsc: lchan_next_meas_rep()
move vty config for t3212 to network level (periodic lu)
remove unneccessary linking from some tests
remove handle_abisip_signal()
abis_rsl.c: don't use libvlr from libbsc
gsm_subscriber_connection: put the LAC here, so that it is available without
accessing conn->bts. In bsc_api.c, place this lac in conn for the sake of
transition: Iu and A will use this new field to pass the LAC around, but in a
completely separate OsmoBSC this is not actually needed. It can be removed
again from osmo-bsc.git when the time has come.
Siemens MRPCI: completely drop sending the MRPCI messages for now, they shall
be added in osmo-bsc once the A-Interface code has settled. See OS#2389.
Related: OS#1845 OS#2257 OS#2389
Change-Id: Id3705236350d5f69e447046b0a764bbabc3d493c
diff --git a/include/openbsc/Makefile.am b/include/openbsc/Makefile.am
index 456a4a2..1dfe6c3 100644
--- a/include/openbsc/Makefile.am
+++ b/include/openbsc/Makefile.am
@@ -54,6 +54,7 @@
misdn.h \
mncc.h \
mncc_int.h \
+ msc_ifaces.h \
nat_rewrite_trie.h \
network_listen.h \
oap_client.h \
diff --git a/include/openbsc/gsm_04_08.h b/include/openbsc/gsm_04_08.h
index c40d96d..6d6ead1 100644
--- a/include/openbsc/gsm_04_08.h
+++ b/include/openbsc/gsm_04_08.h
@@ -65,8 +65,6 @@
int send_siemens_mrpci(struct gsm_lchan *lchan, uint8_t *classmark2_lv);
int gsm48_extract_mi(uint8_t *classmark2, int length, char *mi_string, uint8_t *mi_type);
int gsm48_paging_extract_mi(struct gsm48_pag_resp *pag, int length, char *mi_string, uint8_t *mi_type);
-int gsm48_handle_paging_resp(struct gsm_subscriber_connection *conn,
- struct msgb *msg, struct bsc_subscr *bsub);
int gsm48_lchan_modify(struct gsm_lchan *lchan, uint8_t lchan_mode);
int gsm48_rx_rr_modif_ack(struct msgb *msg);
diff --git a/include/openbsc/gsm_data.h b/include/openbsc/gsm_data.h
index fa2fed7..17b3d71 100644
--- a/include/openbsc/gsm_data.h
+++ b/include/openbsc/gsm_data.h
@@ -26,6 +26,7 @@
struct bsc_subscr;
struct vlr_instance;
struct vlr_subscr;
+struct ue_conn_ctx;
#define OBSC_LINKID_CB(__msgb) (__msgb)->cb[3]
@@ -117,6 +118,12 @@
uint8_t classmark3[14]; /* if cm3 gets extended by spec, it will be truncated */
};
+enum integrity_protection_state {
+ INTEGRITY_PROTECTION_NONE = 0,
+ INTEGRITY_PROTECTION_IK = 1,
+ INTEGRITY_PROTECTION_IK_CK = 2,
+};
+
/* active radio connection of a mobile subscriber */
struct gsm_subscriber_connection {
/* global linked list of subscriber_connections */
@@ -176,6 +183,15 @@
enum ran_type via_ran;
struct gsm_classmark classmark;
+
+ uint16_t lac;
+ struct gsm_encr encr;
+
+ /* which Iu-CS connection, if any. */
+ struct {
+ struct ue_conn_ctx *ue_ctx;
+ int integrity_protection;
+ } iu;
};
@@ -311,6 +327,12 @@
};
struct gsm_network {
+ /* TODO MSCSPLIT the gsm_network struct is basically a kitchen sink for
+ * global settings and variables, "madly" mixing BSC and MSC stuff. Split
+ * this in e.g. struct osmo_bsc and struct osmo_msc, with the things
+ * these have in common, like country and network code, put in yet
+ * separate structs and placed as members in osmo_bsc and osmo_msc. */
+
/* global parameters */
uint16_t country_code;
uint16_t network_code;
@@ -416,6 +438,9 @@
uint16_t gsup_server_port;
struct vlr_instance *vlr;
+
+ /* Periodic location update default value */
+ uint8_t t3212;
};
struct osmo_esme;
@@ -471,10 +496,6 @@
int gsm_set_bts_type(struct gsm_bts *bts, enum gsm_bts_type type);
-/* Get reference to a neighbor cell on a given BCCH ARFCN */
-struct gsm_bts *gsm_bts_neighbor(const struct gsm_bts *bts,
- uint16_t arfcn, uint8_t bsic);
-
enum gsm_bts_type parse_btstype(const char *arg);
const char *btstype2str(enum gsm_bts_type type);
struct gsm_bts *gsm_bts_by_lac(struct gsm_network *net, unsigned int lac,
@@ -557,7 +578,6 @@
int gsm48_ra_id_by_bts(uint8_t *buf, struct gsm_bts *bts);
void gprs_ra_id_by_bts(struct gprs_ra_id *raid, struct gsm_bts *bts);
-struct gsm_meas_rep *lchan_next_meas_rep(struct gsm_lchan *lchan);
int gsm_btsmodel_set_feature(struct gsm_bts_model *model, enum gsm_bts_features feat);
int gsm_bts_model_register(struct gsm_bts_model *model);
diff --git a/include/openbsc/gsm_subscriber.h b/include/openbsc/gsm_subscriber.h
index c65b8a3..60eb0cd 100644
--- a/include/openbsc/gsm_subscriber.h
+++ b/include/openbsc/gsm_subscriber.h
@@ -19,8 +19,6 @@
#define GSM_SUBSCRIBER_NO_EXPIRATION 0x0
-struct subscr_request;
-
enum gsm_subscriber_field {
GSM_SUBSCRIBER_IMSI,
GSM_SUBSCRIBER_TMSI,
@@ -34,17 +32,35 @@
GSM_SUBSCRIBER_UPDATE_EQUIPMENT,
};
-int subscr_update(struct vlr_subscr *vsub, struct gsm_bts *bts, int reason);
+/*
+ * Struct for pending channel requests. This is managed in the
+ * llist_head requests of each subscriber. The reference counting
+ * should work in such a way that a subscriber with a pending request
+ * remains in memory.
+ */
+struct subscr_request {
+ struct llist_head entry;
+
+ /* the callback data */
+ gsm_cbfn *cbfn;
+ void *param;
+};
+
+int subscr_update(struct vlr_subscr *vsub, int reason);
/*
* Paging handling with authentication
*/
-struct subscr_request *subscr_request_channel(struct vlr_subscr *vsub,
- int channel_type,
- gsm_cbfn *cbfn, void *param);
+struct subscr_request *subscr_request_conn(struct vlr_subscr *vsub,
+ int channel_type,
+ gsm_cbfn *cbfn, void *param);
+
void subscr_remove_request(struct subscr_request *req);
int subscr_paging_dispatch(unsigned int hooknum, unsigned int event,
struct msgb *msg, void *data, void *param);
+int msc_fake_paging_request(struct vlr_subscr *vsub);
+void msc_fake_paging_request_stop(struct vlr_subscr *vsub);
+
#endif /* _GSM_SUBSCR_H */
diff --git a/include/openbsc/mncc.h b/include/openbsc/mncc.h
index 49f0c8b..881e041 100644
--- a/include/openbsc/mncc.h
+++ b/include/openbsc/mncc.h
@@ -155,9 +155,6 @@
int notify; /* 0..127 */
int emergency;
char imsi[16];
-
- unsigned char lchan_type;
- unsigned char lchan_mode;
};
struct gsm_data_frame {
@@ -179,7 +176,6 @@
uint32_t called_offset;
uint32_t signal_offset;
uint32_t emergency_offset;
- uint32_t lchan_type_offset;
};
struct gsm_mncc_rtp {
diff --git a/include/openbsc/msc_ifaces.h b/include/openbsc/msc_ifaces.h
new file mode 100644
index 0000000..83aad92
--- /dev/null
+++ b/include/openbsc/msc_ifaces.h
@@ -0,0 +1,47 @@
+#pragma once
+
+#include <osmocom/core/msgb.h>
+#include <openbsc/gsm_data.h>
+
+/* These are the interfaces of the MSC layer towards (from?) the BSC and RNC,
+ * i.e. in the direction towards the mobile device (MS aka UE).
+ *
+ * 2G will use the A-interface,
+ * 3G aka UMTS will use the Iu-interface (for the MSC, it's IuCS).
+ *
+ * To allow linking parts of the MSC code without having to include entire
+ * infrastructures of external libraries, the core transmitting and receiving
+ * functions are left unimplemented. For example, a unit test does not need to
+ * link against external ASN1 libraries if it is never going to encode actual
+ * outgoing messages. It is up to each building scope to implement real world
+ * functions or to plug mere dummy implementations.
+ *
+ * For example, msc_tx_dtap(conn, msg), depending on conn->via_iface, will call
+ * either iu_tx() or a_tx() [note: at time of writing, the A-interface is not
+ * yet implemented]. When you try to link against libmsc, you will find that
+ * the compiler complains about an undefined reference to iu_tx(). If you,
+ * however, link against libiu as well as the osmo-iuh libs (etc.), iu_tx() is
+ * available. A unit test may instead simply implement a dummy iu_tx() function
+ * and not link against osmo-iuh.
+ */
+
+/* Each main linkage must implement this function (see comment above). */
+extern int iu_tx(struct msgb *msg, uint8_t sapi);
+
+/* So far this is a dummy implemented in libmsc/a_iface.c. When A-interface
+ * gets implemented, it should be in a separate lib (like libiu), this function
+ * should move there, and the following comment should remain here: "
+ * Each main linkage must implement this function (see comment above).
+ * " */
+extern int a_tx(struct msgb *msg);
+
+int msc_tx_dtap(struct gsm_subscriber_connection *conn,
+ struct msgb *msg);
+
+int msc_gsm48_tx_mm_serv_ack(struct gsm_subscriber_connection *conn);
+int msc_gsm48_tx_mm_serv_rej(struct gsm_subscriber_connection *conn,
+ enum gsm48_reject_value value);
+
+/* TODO: specific to A interface, move this away */
+int msc_gsm0808_tx_cipher_mode(struct gsm_subscriber_connection *conn, int cipher,
+ const uint8_t *key, int len, int include_imeisv);
diff --git a/include/openbsc/osmo_msc.h b/include/openbsc/osmo_msc.h
index 0642c91..5a26b60 100644
--- a/include/openbsc/osmo_msc.h
+++ b/include/openbsc/osmo_msc.h
@@ -51,6 +51,11 @@
return get_value_string(subscr_conn_from_names, val);
}
+enum msc_compl_l3_rc {
+ MSC_CONN_ACCEPT = 0,
+ MSC_CONN_REJECT = 1,
+};
+
struct bsc_api *msc_bsc_api();