NS: Add support for GPRS NS IP Sub-Network-Service (SNS)

The NS implementation part of the Gb implementation libosmogb
so far implemented a rather classic dialect of Gb, with lots of
heritage to FR (Frame Relay) transports.  At least since Release 6
of the NS specification, there's an IP Sub-Network Service (SNS),
which
* permits for dynamic configuration of IP endpoints and their NS-VCs
* abandons the concept of a NSVCI on IP transport
* forbids the use of RESET/BLOCK/UNBLOCK procedures on IP transport

This commit introduces BSS-side IP-SNS support to libosmogb in a
minimally invasive way.  It adds a corresponding SNS FSM to each NS
instance, and implements the new SIZE/CONFIG/ADD/DELETE/CHANGE_WEIGHT
procedures very closely aligned with the spec.

In order to use the SNS flavor (rather than the classic one),
a BSS implementation should use gprs_ns_nsip_connect_sns() instead
of the existing gprs_ns_nsip_connect().

This implementation comes with a set of TTCN-3 tests in
PCU_Tests_RAW_SNS.ttcn, see Change-ID
I0fe3d4579960bab0494c294ec7ab8032feed4fb2 of osmo-ttcn3-hacks.git

Closes: OS#3372
Closes: OS#3617
Change-Id: I84786c3b43a8ae34ef3b3ba84b33c90042d234ea

1 files changed, 10 insertions, 0 deletions

diff --git a/src/gb/gprs_ns_vty.c b/src/gb/gprs_ns_vty.c
index 15247639..53c71a9a 100644
--- a/src/gb/gprs_ns_vty.c
+++ b/src/gb/gprs_ns_vty.c
@@ -46,6 +46,7 @@
 #include <osmocom/vty/misc.h>
 
 #include "common_vty.h"
+#include "gb_internal.h"
 
 static struct gprs_ns_inst *vty_nsi = NULL;
 
@@ -59,6 +60,7 @@ static const struct value_string gprs_ns_timer_strs[] = {
 	{ 4, "tns-test" },
 	{ 5, "tns-alive" },
 	{ 6, "tns-alive-retries" },
+	{ 7, "tsns-prov" },
 	{ 0, NULL }
 };
 
@@ -208,6 +210,8 @@ static void dump_ns(struct vty *vty, const struct gprs_ns_inst *nsi, bool stats,
 			continue;
 		dump_nse(vty, nsvc, stats, persistent_only);
 	}
+
+	gprs_sns_dump_vty(vty, nsi, stats);
 }
 
 DEFUN(show_ns, show_ns_cmd, "show ns",
@@ -556,6 +560,12 @@ DEFUN(nsvc_nsei, nsvc_nsei_cmd,
 		return CMD_WARNING;
 	}
 
+	if (nsvc->nsi->bss_sns_fi) {
+		vty_out(vty, "A NS Instance using the IP Sub-Network doesn't use BLOCK/UNBLOCK/RESET%s",
+			VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
 	if (!strcmp(operation, "block"))
 		gprs_ns_tx_block(nsvc, NS_CAUSE_OM_INTERVENTION);
 	else if (!strcmp(operation, "unblock"))