Change in osmo-bsc-nat[master]: Store MSC - gerrit-log

10 Mar 2022

osmith has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-bsc-nat/+/27473 )
Change subject: Store MSC
......................................................................
Store MSC
Expect one MSC to be configured in the address book (part of the cs7
section in the config, see doc/examples/osmo-bsc-nat/osmo-bsc-nat.cfg)
and store it on start up.
Store the MSC in a list, as we may potentially support multiple MSCs in
the future. Also that makes it symmetric to the BSC list.
Prepare a FSM for MSC, as the next patch will extend this FSM to send a
RESET to the MSC on start up.
Don't use the stored MSCs in the forwarding logic just yet, a future
commit will replace the current forwarding code with proper connection
mappings.
Related: SYS#5560
Change-Id: I711df0c649728f1007857fbfda500ed5ef69287b
---
M include/osmocom/bsc_nat/Makefile.am
M include/osmocom/bsc_nat/bsc_nat.h
A include/osmocom/bsc_nat/msc_fsm.h
M src/osmo-bsc-nat/Makefile.am
M src/osmo-bsc-nat/bsc_nat.c
M src/osmo-bsc-nat/bsc_nat_fsm.c
M src/osmo-bsc-nat/bssap.c
M src/osmo-bsc-nat/main.c
A src/osmo-bsc-nat/msc_fsm.c
9 files changed, 161 insertions(+), 16 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-bsc-nat refs/changes/73/27473/1

diff --git a/include/osmocom/bsc_nat/Makefile.am b/include/osmocom/bsc_nat/Makefile.am
index 76aada0..4c2bd09 100644
--- a/include/osmocom/bsc_nat/Makefile.am
+++ b/include/osmocom/bsc_nat/Makefile.am
@@ -3,5 +3,6 @@
    bsc_nat_fsm.h \
    bssap.h \
    logging.h \
+	msc_fsm.h \
    vty.h \
    $(NULL)
diff --git a/include/osmocom/bsc_nat/bsc_nat.h b/include/osmocom/bsc_nat/bsc_nat.h
index eb48f08..0807d83 100644
--- a/include/osmocom/bsc_nat/bsc_nat.h
+++ b/include/osmocom/bsc_nat/bsc_nat.h
@@ -29,6 +29,12 @@
    struct osmo_sccp_user *scu;
 };
+struct msc {
+	struct llist_head list;
+	struct osmo_sccp_addr addr;
+	struct osmo_fsm_inst *fi;
+};
+
 struct bsc {
    struct llist_head list;
    struct osmo_sccp_addr addr;
@@ -40,12 +46,18 @@
    struct bsc_nat_sccp_inst *cn;
    struct bsc_nat_sccp_inst *ran;
+	struct llist_head mscs; /* list of struct msc */
    struct llist_head bscs; /* list of struct bsc */
 };
struct bsc_nat *bsc_nat_alloc(void *tall_ctx);
 void bsc_nat_free(struct bsc_nat *bsc_nat);
+struct msc *bsc_nat_msc_add(struct bsc_nat *bsc_nat, struct osmo_sccp_addr *addr);
+struct msc *bsc_nat_msc_add_from_addr_book(struct bsc_nat *bsc_nat);
+struct msc *bsc_nat_msc_get(struct bsc_nat *bsc_nat);
+void bsc_nat_msc_del(struct bsc_nat *bsc_nat, struct msc *msc);
+
 struct bsc *bsc_nat_bsc_add(struct bsc_nat *bsc_nat, struct osmo_sccp_addr *addr);
 struct bsc *bsc_nat_bsc_get_by_pc(struct bsc_nat *bsc_nat, uint32_t pointcode);
 void bsc_nat_bsc_del(struct bsc_nat *bsc_nat, struct bsc *bsc);
diff --git a/include/osmocom/bsc_nat/msc_fsm.h b/include/osmocom/bsc_nat/msc_fsm.h
new file mode 100644
index 0000000..0ea3024
--- /dev/null
+++ b/include/osmocom/bsc_nat/msc_fsm.h
@@ -0,0 +1,21 @@
+/* (C) 2022 by sysmocom - s.f.m.c. GmbH info@sysmocom.de
+ * Author: Oliver Smith osmith@sysmocom.de
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see http://www.gnu.org/lienses/.
+ *
+ */
+#pragma once
+
+void msc_fsm_alloc(struct msc *msc);
diff --git a/src/osmo-bsc-nat/Makefile.am b/src/osmo-bsc-nat/Makefile.am
index 445c098..2c2d9fa 100644
--- a/src/osmo-bsc-nat/Makefile.am
+++ b/src/osmo-bsc-nat/Makefile.am
@@ -30,6 +30,7 @@
    bssap.c \
    logging.c \
    main.c \
+	msc_fsm.c \
    vty.c \
    $(NULL)
diff --git a/src/osmo-bsc-nat/bsc_nat.c b/src/osmo-bsc-nat/bsc_nat.c
index 5a6e84e..b8c87dd 100644
--- a/src/osmo-bsc-nat/bsc_nat.c
+++ b/src/osmo-bsc-nat/bsc_nat.c
@@ -21,6 +21,7 @@
 #include <osmocom/bsc_nat/bsc_nat.h>
 #include <osmocom/bsc_nat/bsc_nat_fsm.h>
 #include <osmocom/bsc_nat/logging.h>
+#include <osmocom/bsc_nat/msc_fsm.h>
 #include <osmocom/core/talloc.h>
 #include <osmocom/core/utils.h>
@@ -39,6 +40,7 @@
    OSMO_ASSERT(bsc_nat->ran);
    talloc_set_name_const(bsc_nat->ran, "struct bsc_nat_sccp_inst (RAN)");
+	INIT_LLIST_HEAD(&bsc_nat->mscs);
    INIT_LLIST_HEAD(&bsc_nat->bscs);
bsc_nat_fsm_alloc(bsc_nat);
@@ -46,6 +48,56 @@
    return bsc_nat;
 }
+struct msc *bsc_nat_msc_add(struct bsc_nat *bsc_nat, struct osmo_sccp_addr *addr)
+{
+	struct msc *msc = talloc_zero(bsc_nat, struct msc);
+
+	OSMO_ASSERT(msc);
+	talloc_set_name(msc, "MSC(PC=%s)", osmo_ss7_pointcode_print(NULL, addr->pc));
+
+	LOGP(DMAIN, LOGL_DEBUG, "Add %s\n", talloc_get_name(msc));
+
+	msc->addr = *addr;
+
+	INIT_LLIST_HEAD(&msc->list);
+	llist_add(&msc->list, &bsc_nat->mscs);
+
+	msc_fsm_alloc(msc);
+
+	return msc;
+}
+
+struct msc *bsc_nat_msc_add_from_addr_book(struct bsc_nat *bsc_nat)
+{
+	struct osmo_sccp_addr addr;
+
+	/* For now only one MSC is supported */
+	if (osmo_sccp_addr_by_name_local(&addr, "msc", bsc_nat->cn->ss7_inst) < 0) {
+		LOGP(DMAIN, LOGL_ERROR, "Configuration error, MSC not found in address book\n");
+		return NULL;
+	}
+
+	return bsc_nat_msc_add(bsc_nat, &addr);
+}
+
+
+struct msc *bsc_nat_msc_get(struct bsc_nat *bsc_nat)
+{
+	/* For now only one MSC is supported */
+
+	OSMO_ASSERT(!llist_empty(&bsc_nat->mscs));
+
+	return llist_first_entry(&bsc_nat->mscs, struct msc, list);
+}
+
+void bsc_nat_msc_del(struct bsc_nat *bsc_nat, struct msc *msc)
+{
+	LOGP(DMAIN, LOGL_DEBUG, "Del %s\n", talloc_get_name(msc));
+	llist_del(&msc->list);
+	osmo_fsm_inst_free(msc->fi);
+	talloc_free(msc);
+}
+
 struct bsc *bsc_nat_bsc_add(struct bsc_nat *bsc_nat, struct osmo_sccp_addr *addr)
 {
    struct bsc *bsc = talloc_zero(bsc_nat, struct bsc);
@@ -84,6 +136,7 @@
void bsc_nat_free(struct bsc_nat *bsc_nat)
 {
+	struct msc *msc;
    struct bsc *bsc;
if (bsc_nat->fi) {
@@ -91,6 +144,10 @@
    	bsc_nat->fi = NULL;
    }
+	llist_for_each_entry(msc, &bsc_nat->mscs, list) {
+		bsc_nat_msc_del(bsc_nat, msc);
+	}
+
    llist_for_each_entry(bsc, &bsc_nat->bscs, list) {
    	bsc_nat_bsc_del(bsc_nat, bsc);
    }
diff --git a/src/osmo-bsc-nat/bsc_nat_fsm.c b/src/osmo-bsc-nat/bsc_nat_fsm.c
index 3091687..b35376d 100644
--- a/src/osmo-bsc-nat/bsc_nat_fsm.c
+++ b/src/osmo-bsc-nat/bsc_nat_fsm.c
@@ -186,22 +186,7 @@
case OSMO_PRIM(OSMO_SCU_PRIM_N_UNITDATA, PRIM_OP_INDICATION):
    	/* connection-less data received */
-		addr = &prim->u.unitdata.calling_addr;
-
-		if (sccp_sap_get_peer_addr_out(sccp_inst, addr, &peer_addr_out) < 0)
-			goto error;
-
-		LOGP(DMAIN, LOGL_DEBUG, "Fwd to %s\n", bsc_nat_print_addr(g_bsc_nat->ran, &peer_addr_out));
-
-		/* oph->msg stores oph and unitdata msg. Move oph->msg->data to
-		 * unitdata msg and send it again. */
-		msgb_pull_to_l2(oph->msg);
-		osmo_sccp_tx_unitdata(g_bsc_nat->ran->scu,
-				      &g_bsc_nat->ran->addr,
-				      &peer_addr_out,
-				      oph->msg->data,
-				      msgb_length(oph->msg));
-		rc = 0;
+		rc = bssap_handle_udt(sccp_inst, &prim->u.unitdata.calling_addr, oph->msg, msgb_l2len(oph->msg));
    	break;
default:
diff --git a/src/osmo-bsc-nat/bssap.c b/src/osmo-bsc-nat/bssap.c
index af6c8b3..ef12192 100644
--- a/src/osmo-bsc-nat/bssap.c
+++ b/src/osmo-bsc-nat/bssap.c
@@ -20,6 +20,7 @@
 #include "config.h"
 #include <osmocom/bsc_nat/bsc_nat.h>
 #include <osmocom/bsc_nat/logging.h>
+#include <osmocom/bsc_nat/msc_fsm.h>
 #include <osmocom/core/msgb.h>
 #include <osmocom/gsm/gsm0808.h>
 #include <osmocom/sigtran/sccp_helpers.h>
diff --git a/src/osmo-bsc-nat/main.c b/src/osmo-bsc-nat/main.c
index ef4b78d..86a774f 100644
--- a/src/osmo-bsc-nat/main.c
+++ b/src/osmo-bsc-nat/main.c
@@ -199,6 +199,9 @@
bsc_nat_fsm_start(g_bsc_nat);
+	if (!bsc_nat_msc_add_from_addr_book(g_bsc_nat))
+		exit(1);
+
    while (!osmo_select_shutdown_done())
    	osmo_select_main_ctx(0);
diff --git a/src/osmo-bsc-nat/msc_fsm.c b/src/osmo-bsc-nat/msc_fsm.c
new file mode 100644
index 0000000..30434f4
--- /dev/null
+++ b/src/osmo-bsc-nat/msc_fsm.c
@@ -0,0 +1,64 @@
+/* (C) 2022 by sysmocom - s.f.m.c. GmbH info@sysmocom.de
+ * Author: Oliver Smith osmith@sysmocom.de
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see http://www.gnu.org/lienses/.
+ *
+ */
+
+#include "config.h"
+#include <osmocom/bsc_nat/bsc_nat.h>
+#include <osmocom/bsc_nat/bssap.h>
+#include <osmocom/bsc_nat/logging.h>
+#include <osmocom/core/fsm.h>
+#include <osmocom/sigtran/sccp_sap.h>
+
+#define X(s) (1 << (s))
+
+enum msc_fsm_states {
+	MSC_FSM_ST_DISCONNECTED,
+};
+
+static struct osmo_fsm_state msc_fsm_states[] = {
+	[MSC_FSM_ST_DISCONNECTED] = {
+		.name = "DISCONNECTED",
+		.in_event_mask = 0
+			,
+		.out_state_mask = 0
+			,
+	},
+};
+
+const struct value_string msc_fsm_event_names[] = {
+	{ 0, NULL }
+};
+
+struct osmo_fsm msc_fsm = {
+	.name = "MSC",
+	.states = msc_fsm_states,
+	.num_states = ARRAY_SIZE(msc_fsm_states),
+	.log_subsys = DMAIN,
+	.event_names = msc_fsm_event_names,
+};
+
+static __attribute__((constructor)) void msc_fsm_init(void)
+{
+	OSMO_ASSERT(osmo_fsm_register(&msc_fsm) == 0);
+}
+
+void msc_fsm_alloc(struct msc *msc)
+{
+	msc->fi = osmo_fsm_inst_alloc(&msc_fsm, msc, msc, LOGL_INFO, NULL);
+	OSMO_ASSERT(msc->fi);
+}
-- 
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Gerrit-Project: osmo-bsc-nat
Gerrit-Branch: master
Gerrit-Change-Id: I711df0c649728f1007857fbfda500ed5ef69287b
Gerrit-Change-Number: 27473
Gerrit-PatchSet: 1
Gerrit-Owner: osmith osmith@sysmocom.de
Gerrit-MessageType: newchange



    