NS: Add support for persistent NS-VC configuration

With persistent NS-VC configuration (configured through VTY),
we can respond properly to BSS with a somewhat strange NS
implementation Such as the BSplus.  It enables us to respond
with a proper NS-RESET (including NSVCI/NSEI) when receiving
a NS-ALIVE or other PDU for a BLOCKED/DEAD NS-VC after our
end of the connection is rebooted.

openbsc/include/openbsc/gprs_ns.h

@@ -140,7 +140,8 @@ struct gprs_nsvc {
 	enum nsvc_timer_mode timer_mode;
 	int alive_retries;
 
-	int remote_end_is_sgsn;
+	unsigned int remote_end_is_sgsn:1;
+	unsigned int persistent:1;
 
 	union {
 		struct {
@@ -178,4 +179,8 @@ int nsip_listen(struct gprs_ns_inst *nsi, uint16_t udp_port);
 struct gprs_nsvc *nsip_connect(struct gprs_ns_inst *nsi,
 				struct sockaddr_in *dest, uint16_t nsei,
 				uint16_t nsvci);
+
+/* Add NS-specific VTY stuff */
+int gprs_ns_vty_init(struct gprs_ns_inst *nsi);
+
 #endif

openbsc/include/vty/command.h

@@ -109,6 +109,7 @@ enum node_type {
 	MGCP_NODE,
 	GBPROXY_NODE,
 	SGSN_NODE,
+	NS_NODE,
 };
 
 /* Node which has some commands and prompt string and configuration

openbsc/src/gprs/gb_proxy_main.c

@@ -105,11 +105,6 @@ int main(int argc, char **argv)
 	log_set_all_filter(stderr_target, 1);
 
 	telnet_init(&dummy_network, 4246);
-	rc = gbproxy_parse_config(config_file, &gbcfg);
-	if (rc < 0) {
-		LOGP(DGPRS, LOGL_FATAL, "Cannot parse config file\n");
-		exit(2);
-	}
 
 	bssgp_nsi = gprs_ns_instantiate(&proxy_ns_cb);
 	if (!bssgp_nsi) {
@@ -117,7 +112,15 @@ int main(int argc, char **argv)
 		exit(1);
 	}
 	gbcfg.nsi = bssgp_nsi;
+	gprs_ns_vty_init(bssgp_nsi);
 	register_signal_handler(SS_NS, &gbprox_signal, NULL);
+
+	rc = gbproxy_parse_config(config_file, &gbcfg);
+	if (rc < 0) {
+		LOGP(DGPRS, LOGL_FATAL, "Cannot parse config file\n");
+		exit(2);
+	}
+
 	nsip_listen(bssgp_nsi, gbcfg.nsip_listen_port);
 
 	/* 'establish' the outgoing connection to the SGSN */

openbsc/src/gprs/gb_proxy_vty.c

@@ -70,29 +70,6 @@ static int config_write_gbproxy(struct vty *vty)
 	return CMD_SUCCESS;
 }
 
-DEFUN(show_ns, show_ns_cmd, "show ns",
-      SHOW_STR "Display information about the NS protocol")
-{
-	/* FIXME: iterate over list of NS-VC's and display their state */
-	struct gprs_ns_inst *nsi = g_cfg->nsi;
-	struct gprs_nsvc *nsvc;
-
-	llist_for_each_entry(nsvc, &nsi->gprs_nsvcs, list) {
-		vty_out(vty, "NSEI %5u, NS-VC %5u, %s-mode, %s %s%s",
-			nsvc->nsei, nsvc->nsvci,
-			nsvc->remote_end_is_sgsn ? "BSS" : "SGSN",
-			nsvc->state & NSE_S_ALIVE ? "ALIVE" : "DEAD",
-			nsvc->state & NSE_S_BLOCKED ? "BLOCKED" : "UNBLOCKED",
-			VTY_NEWLINE);
-		if (nsvc->nsi->ll == GPRS_NS_LL_UDP)
-			vty_out(vty, "  remote peer %s:%u%s",
-				inet_ntoa(nsvc->ip.bts_addr.sin_addr),
-				ntohs(nsvc->ip.bts_addr.sin_port), VTY_NEWLINE);
-	}
-
-	return CMD_SUCCESS;
-}
-
 DEFUN(cfg_gbproxy,
       cfg_gbproxy_cmd,
       "gbproxy",
@@ -173,10 +150,8 @@ DEFUN(cfg_nsip_sgsn_nsvci,
 	return CMD_SUCCESS;
 }
 
-
 int gbproxy_vty_init(void)
 {
-	install_element(VIEW_NODE, &show_ns_cmd);
 	install_element(VIEW_NODE, &show_gbproxy_cmd);
 
 	install_element(CONFIG_NODE, &cfg_gbproxy_cmd);

openbsc/src/gprs/gprs_ns.c

@@ -131,6 +131,14 @@ static struct gprs_nsvc *nsvc_create(struct gprs_ns_inst *nsi, uint16_t nsvci)
 	return nsvc;
 }
 
+static void nsvc_delete(struct gprs_nsvc *nsvc)
+{
+	if (bsc_timer_pending(&nsvc->timer))
+		bsc_del_timer(&nsvc->timer);
+	llist_del(&nsvc->list);
+	talloc_free(nsvc);
+}
+
 static void ns_dispatch_signal(struct gprs_nsvc *nsvc, unsigned int signal,
 			       uint8_t cause)
 {
@@ -592,15 +600,9 @@ int gprs_ns_rcvmsg(struct gprs_ns_inst *nsi, struct msgb *msg,
 			fake_nsvc.nsi = nsi;
 			fake_nsvc.ip.bts_addr = *saddr;
 			fake_nsvc.state = NSE_S_ALIVE;
-#if 0
 			return gprs_ns_tx_status(&fake_nsvc,
 						NS_CAUSE_PDU_INCOMP_PSTATE, 0,
 						msg);
-#else
-			/* BS+ Gb implementation ignores STATUS, so we try
-			 * our luck with a RESET incompatible with the spec */
-			return gprs_ns_tx_simple(&fake_nsvc, NS_PDUT_RESET);
-#endif
 		}
 		rc = tlv_parse(&tp, &ns_att_tlvdef, nsh->data,
 						msgb_l2len(msg), 0, 0);
@@ -628,9 +630,14 @@ int gprs_ns_rcvmsg(struct gprs_ns_inst *nsi, struct msgb *msg,
 
 	switch (nsh->pdu_type) {
 	case NS_PDUT_ALIVE:
-		/* remote end inquires whether we're still alive,
+		/* If we're dead and blocked and suddenly receive a
-		 * we need to respond with ALIVE_ACK */
+		 * NS-ALIVE out of the blue, we might have been re-started
-		rc = gprs_ns_tx_alive_ack(nsvc);
+		 * and should send a NS-RESET to make sure everything recovers
+		 * fine. */
+		if (nsvc->state == NSE_S_BLOCKED)
+			rc = gprs_ns_tx_reset(nsvc, NS_CAUSE_PDU_INCOMP_PSTATE);
+		else
+			rc = gprs_ns_tx_alive_ack(nsvc);
 		break;
 	case NS_PDUT_ALIVE_ACK:
 		/* stop Tns-alive */
@@ -844,3 +851,203 @@ struct gprs_nsvc *nsip_connect(struct gprs_ns_inst *nsi,
 
 	return nsvc;
 }
+
+#include <vty/vty.h>
+#include <vty/command.h>
+
+static struct gprs_ns_inst *vty_nsi = NULL;
+
+static struct cmd_node ns_node = {
+	NS_NODE,
+	"%s(ns)#",
+	1,
+};
+
+static int config_write_ns(struct vty *vty)
+{
+	struct gprs_nsvc *nsvc;
+
+	vty_out(vty, "ns%s", VTY_NEWLINE);
+
+	llist_for_each_entry(nsvc, &vty_nsi->gprs_nsvcs, list) {
+		if (!nsvc->persistent)
+			continue;
+		vty_out(vty, " nse %u nsvci %u%s",
+			nsvc->nsei, nsvc->nsvci, VTY_NEWLINE);
+		vty_out(vty, " nse %u remote-role %s%s",
+			nsvc->nsei, nsvc->remote_end_is_sgsn ? "sgsn" : "bss",
+			VTY_NEWLINE);
+		if (nsvc->nsi->ll == GPRS_NS_LL_UDP) {
+			vty_out(vty, " nse %u remote-ip %s%s",
+				nsvc->nsei, 
+				inet_ntoa(nsvc->ip.bts_addr.sin_addr),
+				VTY_NEWLINE);
+			vty_out(vty, " nse %u remote-port %u%s",
+				nsvc->nsei, ntohs(nsvc->ip.bts_addr.sin_port),
+				VTY_NEWLINE);
+		}
+		vty_out(vty, "%s", VTY_NEWLINE);
+	}
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_ns, cfg_ns_cmd,
+      "ns",
+      "Configure the GPRS Network Service")
+{
+	vty->node = NS_NODE;
+	return CMD_SUCCESS;
+}
+
+DEFUN(show_ns, show_ns_cmd, "show ns",
+      SHOW_STR "Display information about the NS protocol")
+{
+	struct gprs_ns_inst *nsi = vty_nsi;
+	struct gprs_nsvc *nsvc;
+
+	llist_for_each_entry(nsvc, &nsi->gprs_nsvcs, list) {
+		vty_out(vty, "NSEI %5u, NS-VC %5u, Remote: %-4s, %5s %9s",
+			nsvc->nsei, nsvc->nsvci,
+			nsvc->remote_end_is_sgsn ? "SGSN" : "BSS",
+			nsvc->state & NSE_S_ALIVE ? "ALIVE" : "DEAD",
+			nsvc->state & NSE_S_BLOCKED ? "BLOCKED" : "UNBLOCKED");
+		if (nsvc->nsi->ll == GPRS_NS_LL_UDP)
+			vty_out(vty, ", %15s:%u",
+				inet_ntoa(nsvc->ip.bts_addr.sin_addr),
+				ntohs(nsvc->ip.bts_addr.sin_port));
+		vty_out(vty, "%s", VTY_NEWLINE);
+	}
+
+	return CMD_SUCCESS;
+}
+
+
+#define NSE_CMD_STR "NS Entity\n" "NS Entity ID (NSEI)\n"
+
+DEFUN(cfg_nse_nsvc, cfg_nse_nsvci_cmd,
+	"nse <0-65535> nsvci <0-65534>",
+	NSE_CMD_STR
+	"NS Virtual Connection\n"
+	"NS Virtual Connection ID (NSVCI)\n"
+	)
+{
+	uint16_t nsei = atoi(argv[0]);
+	uint16_t nsvci = atoi(argv[1]);
+	struct gprs_nsvc *nsvc;
+
+	nsvc = nsvc_by_nsei(vty_nsi, nsei);
+	if (!nsvc) {
+		nsvc = nsvc_create(vty_nsi, nsvci);
+		nsvc->nsei = nsei;
+	}
+	nsvc->nsvci = nsvci;
+	/* All NSVCs that are explicitly configured by VTY are
+	 * marked as persistent so we can write them to the config
+	 * file at some later point */
+	nsvc->persistent = 1;
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_nse_remoteip, cfg_nse_remoteip_cmd,
+	"nse <0-65535> remote-ip A.B.C.D",
+	NSE_CMD_STR
+	"Remote IP Address\n"
+	"Remote IP Address\n")
+{
+	uint16_t nsei = atoi(argv[0]);
+	struct gprs_nsvc *nsvc;
+
+	nsvc = nsvc_by_nsei(vty_nsi, nsei);
+	if (!nsvc) {
+		vty_out(vty, "No such NSE (%u)%s", nsei, VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+	inet_aton(argv[1], &nsvc->ip.bts_addr.sin_addr);
+
+	return CMD_SUCCESS;
+
+}
+
+DEFUN(cfg_nse_remoteport, cfg_nse_remoteport_cmd,
+	"nse <0-65535> remote-port <0-65535>",
+	NSE_CMD_STR
+	"Remote UDP Port\n"
+	"Remote UDP Port Number\n")
+{
+	uint16_t nsei = atoi(argv[0]);
+	uint16_t port = atoi(argv[1]);
+	struct gprs_nsvc *nsvc;
+
+	nsvc = nsvc_by_nsei(vty_nsi, nsei);
+	if (!nsvc) {
+		vty_out(vty, "No such NSE (%u)%s", nsei, VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	nsvc->ip.bts_addr.sin_port = htons(port);
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_nse_remoterole, cfg_nse_remoterole_cmd,
+	"nse <0-65535> remote-role (sgsn|bss)",
+	NSE_CMD_STR
+	"Remote NSE Role\n"
+	"Remote Peer is SGSN\n"
+	"Remote Peer is BSS\n")
+{
+	uint16_t nsei = atoi(argv[0]);
+	struct gprs_nsvc *nsvc;
+
+	nsvc = nsvc_by_nsei(vty_nsi, nsei);
+	if (!nsvc) {
+		vty_out(vty, "No such NSE (%u)%s", nsei, VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	if (!strcmp(argv[1], "sgsn"))
+		nsvc->remote_end_is_sgsn = 1;
+	else
+		nsvc->remote_end_is_sgsn = 0;
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_no_nse, cfg_no_nse_cmd,
+	"no nse <0-65535>",
+	"Delete NS Entity\n"
+	"Delete " NSE_CMD_STR)
+{
+	uint16_t nsei = atoi(argv[0]);
+	struct gprs_nsvc *nsvc;
+
+	nsvc = nsvc_by_nsei(vty_nsi, nsei);
+	if (!nsvc) {
+		vty_out(vty, "No such NSE (%u)%s", nsei, VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	nsvc_delete(nsvc);
+
+	return CMD_SUCCESS;
+}
+
+int gprs_ns_vty_init(struct gprs_ns_inst *nsi)
+{
+	vty_nsi = nsi;
+
+	install_element(VIEW_NODE, &show_ns_cmd);
+
+	install_element(CONFIG_NODE, &cfg_ns_cmd);
+	install_node(&ns_node, config_write_ns);
+	install_default(NS_NODE);
+	install_element(NS_NODE, &cfg_nse_nsvci_cmd);
+	install_element(NS_NODE, &cfg_nse_remoteip_cmd);
+	install_element(NS_NODE, &cfg_nse_remoteport_cmd);
+	install_element(NS_NODE, &cfg_nse_remoterole_cmd);
+	install_element(NS_NODE, &cfg_no_nse_cmd);
+
+	return 0;
+}

openbsc/src/gprs/osmo_gbproxy.cfg

@@ -7,7 +7,7 @@ line vty
 !
 gbproxy
   nsip bss local port 23000
-  nsip sgsn remote ip 192.168.100.239
+  nsip sgsn remote ip 127.0.0.1
-  nsip sgsn remote port 23000
+  nsip sgsn remote port 7777
-  nsip sgsn nsei 1
+  nsip sgsn nsei 101
-  nsip sgsn nsvci 11
+  nsip sgsn nsvci 101

openbsc/src/vty/command.c

@@ -2365,6 +2365,7 @@ gDEFUN(config_exit,
 	case MGCP_NODE:
 	case GBPROXY_NODE:
 	case SGSN_NODE:
+	case NS_NODE:
 		vty->node = CONFIG_NODE;
 		vty->index = NULL;
 	default: