osmo-ns-dummy: Add simple NS traffic generator

This adds a simple NS traffic generator that can be used to perform
load testing on NS links, particularly those with limited bandwidth
such as frame-relay E1 lines.

Related: OS#4995
Change-Id: Iad3b694c85962dbbc6b4a27a0ed5bc841add464f

3 files changed, 312 insertions, 1 deletions

diff --git a/utils/Makefile.am b/utils/Makefile.am
index 4fac477d..4e54a78b 100644
--- a/utils/Makefile.am
+++ b/utils/Makefile.am
@@ -29,7 +29,7 @@ endif
 if ENABLE_EXT_TESTS
 if ENABLE_GB
 noinst_PROGRAMS += osmo-ns-dummy
-osmo_ns_dummy_SOURCES = osmo-ns-dummy.c
+osmo_ns_dummy_SOURCES = osmo-ns-dummy.c osmo-ns-dummy-vty.c
 osmo_ns_dummy_LDADD = $(LDADD) $(TALLOC_LIBS) \
 			$(top_builddir)/src/gb/libosmogb.la \
 			$(top_builddir)/src/vty/libosmovty.la \
diff --git a/utils/osmo-ns-dummy-vty.c b/utils/osmo-ns-dummy-vty.c
new file mode 100644
index 00000000..1b7ce1c7
--- /dev/null
+++ b/utils/osmo-ns-dummy-vty.c
@@ -0,0 +1,309 @@
+/* VTY for osmo-ns-dummy */
+
+/* (C) 2021 Harald Welte <laforge@gnumonks.org>
+ *
+ * All Rights Reserved
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <talloc.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <inttypes.h>
+
+
+#include <osmocom/core/select.h>
+#include <osmocom/core/application.h>
+#include <osmocom/core/stats.h>
+#include <osmocom/core/utils.h>
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/logging.h>
+
+#include <osmocom/gsm/prim.h>
+#include <osmocom/gprs/gprs_ns2.h>
+
+#include <osmocom/vty/vty.h>
+#include <osmocom/vty/command.h>
+#include <osmocom/vty/logging.h>
+#include <osmocom/vty/stats.h>
+#include <osmocom/vty/misc.h>
+
+static struct gprs_ns2_inst *g_nsi;
+static struct llist_head g_ns_traf_gens = LLIST_HEAD_INIT(g_ns_traf_gens);
+
+/* one NS traffic generator instance.  You can have as many of these as you want,
+ * just as long as they have unique names */
+struct ns_traf_gen {
+	struct llist_head list;
+	const char *name;
+	struct {
+		uint16_t nsei;
+		uint16_t bvci;
+		/* size of each packet */
+		uint16_t pkt_size;
+		/* interval between packets in us */
+		uint32_t interval_us;
+		/* fixed (false) or random (true) LSP */
+		bool lsp_randomize;
+		/* (fixeD) Link Selector Parameter */
+		uint32_t lsp;
+	} cfg;
+	struct osmo_fd timerfd;
+	bool running;
+};
+
+#define LOGNTG(ntg, lvl, fmt, args ...) \
+	LOGP(DLGLOBAL, lvl, "traf-gen(%s): " fmt, (ntg)->name, ## args)
+
+/* allocate and transmit one NS message */
+static int ntg_tx_one(struct ns_traf_gen *ntg)
+{
+	struct osmo_gprs_ns2_prim nsp = {};
+	struct msgb *msg = msgb_alloc_headroom(3072, 20, "NS traffic gen");
+
+	if (!msg)
+		return -ENOMEM;
+	msgb_put(msg, ntg->cfg.pkt_size);
+	nsp.bvci = ntg->cfg.bvci;
+	nsp.nsei = ntg->cfg.nsei;
+	if (ntg->cfg.lsp_randomize)
+		nsp.u.unitdata.link_selector = rand();
+	else
+		nsp.u.unitdata.link_selector = ntg->cfg.lsp;
+	osmo_prim_init(&nsp.oph, SAP_NS, GPRS_NS2_PRIM_UNIT_DATA, PRIM_OP_REQUEST, msg);
+	return gprs_ns2_recv_prim(g_nsi, &nsp.oph);
+}
+
+/* call-back from transmit timer-fd */
+static int ntg_timerfd_cb(struct osmo_fd *ofd, unsigned int what)
+{
+	uint64_t expire_count;
+	struct ns_traf_gen *ntg = ofd->data;
+	unsigned int i;
+	int rc;
+
+	OSMO_ASSERT(what & OSMO_FD_READ);
+
+	rc = read(ofd->fd, (void *) &expire_count, sizeof(expire_count));
+	if (rc < 0 && errno == EAGAIN)
+		return 0;
+	OSMO_ASSERT(rc == sizeof(expire_count));
+
+	for (i = 0; i < expire_count; i++)
+		ntg_tx_one(ntg);
+
+	return 0;
+}
+
+static struct ns_traf_gen *ns_traf_gen_find(const char *name)
+{
+	struct ns_traf_gen *ntg;
+
+	llist_for_each_entry(ntg, &g_ns_traf_gens, list) {
+		if (!strcmp(ntg->name, name))
+			return ntg;
+	}
+	return NULL;
+}
+
+static struct ns_traf_gen *ns_traf_gen_find_or_alloc(const char *name)
+{
+	struct ns_traf_gen *ntg;
+	int rc;
+
+	ntg = ns_traf_gen_find(name);
+	if (ntg)
+		return ntg;
+
+	ntg = talloc_zero(g_nsi, struct ns_traf_gen);
+	OSMO_ASSERT(ntg);
+	ntg->name = talloc_strdup(ntg, name);
+	ntg->timerfd.fd = -1;
+	rc = osmo_timerfd_setup(&ntg->timerfd, ntg_timerfd_cb, ntg);
+	OSMO_ASSERT(rc >= 0);
+	llist_add_tail(&ntg->list, &g_ns_traf_gens);
+
+	return ntg;
+}
+
+enum nodes {
+	NTG_NODE = _LAST_OSMOVTY_NODE + 1,
+};
+
+static struct cmd_node ntg_node = {
+	NTG_NODE,
+	"%s(config-ns-traf-gen)# ",
+	1,
+};
+
+static int config_write_ntg(struct vty *vty)
+{
+	struct ns_traf_gen *ntg;
+
+	llist_for_each_entry(ntg, &g_ns_traf_gens, list) {
+		vty_out(vty, "ns-traffic-generator %s%s", ntg->name, VTY_NEWLINE);
+		vty_out(vty, " nsei %u%s", ntg->cfg.nsei, VTY_NEWLINE);
+		vty_out(vty, " bvci %u%s", ntg->cfg.bvci, VTY_NEWLINE);
+		vty_out(vty, " packet-size %u%s", ntg->cfg.pkt_size, VTY_NEWLINE);
+		vty_out(vty, " interval-us %u%s", ntg->cfg.interval_us, VTY_NEWLINE);
+		vty_out(vty, " lsp %u%s", ntg->cfg.lsp, VTY_NEWLINE);
+		vty_out(vty, " lsp-mode %s%s", ntg->cfg.lsp_randomize ? "randomized" : "fixed", VTY_NEWLINE);
+	}
+
+	return 0;
+}
+
+DEFUN(ntg_start, ntg_start_stop_cmd,
+	"ns-traffic-generator (start|stop) NAME",
+	"Control named NS traffic generator\n"
+	"Start generating traffic in this traffic generator\n"
+	"Stop generating traffic in this traffic generator\n"
+	"Name of NS traffic generator to start\n")
+{
+	struct ns_traf_gen *ntg = ns_traf_gen_find(argv[1]);
+	if (!ntg) {
+		vty_out(vty, "NS Traffic generator '%s' doesn't exist%s", argv[1], VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	if (!strcmp(argv[0], "start")) {
+		struct timespec interval;
+		if (ntg->running) {
+			vty_out(vty, "NS Traffic generator was already started%s", VTY_NEWLINE);
+			return CMD_WARNING;
+		}
+		interval.tv_sec = ntg->cfg.interval_us / 1000000;
+		interval.tv_nsec = (ntg->cfg.interval_us % 1000000) * 1000;
+		osmo_timerfd_schedule(&ntg->timerfd, NULL, &interval);
+		ntg->running = true;
+	} else {
+		if (!ntg->running) {
+			vty_out(vty, "NS Traffic generator was already stopped%s", VTY_NEWLINE);
+			return CMD_WARNING;
+		}
+		osmo_timerfd_disable(&ntg->timerfd);
+		ntg->running = false;
+	}
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(ntg_nsei, ntg_nsei_cmd,
+	"nsei <0-65535>",
+	"NSEI to use when generating traffic\n"
+	"NSEI to use when generating traffic\n")
+{
+	struct ns_traf_gen *ntg = vty->index;
+	ntg->cfg.nsei = atoi(argv[0]);
+	return CMD_SUCCESS;
+}
+
+DEFUN(ntg_bvci, ntg_bvci_cmd,
+	"bvci <0-65535>",
+	"BVCI to use when generating traffic\n"
+	"BVCI to use when generating traffic\n")
+{
+	struct ns_traf_gen *ntg = vty->index;
+	ntg->cfg.bvci = atoi(argv[0]);
+	return CMD_SUCCESS;
+}
+
+DEFUN(ntg_pkt_size, ntg_pkt_size_cmd,
+	"packet-size <0-2048>",
+	"Packet size for generated NS-UNITDATA payload\n"
+	"Packet size for generated NS-UNITDATA payload\n")
+{
+	struct ns_traf_gen *ntg = vty->index;
+	ntg->cfg.pkt_size = atoi(argv[0]);
+	return CMD_SUCCESS;
+}
+
+DEFUN(ntg_pkt_intv_us, ntg_pkt_intv_us_cmd,
+	"interval-us <0-1000000>",
+	"Interval between packets in microseconds\n"
+	"Interval between packets in microseconds\n")
+{
+	struct ns_traf_gen *ntg = vty->index;
+	ntg->cfg.interval_us = atoi(argv[0]);
+	if (ntg->running) {
+		/* TODO: update timer */
+	}
+	return CMD_SUCCESS;
+}
+
+DEFUN(ntg_lsp, ntg_lsp_cmd,
+	"lsp <0-4294967295>",
+	"Link Selector Parameter (only used in fixed mode)\n"
+	"Link Selector Parameter (only used in fixed mode)\n")
+{
+	struct ns_traf_gen *ntg = vty->index;
+	ntg->cfg.lsp = strtoul(argv[0], NULL, 10);
+	return CMD_SUCCESS;
+}
+
+DEFUN(ntg_lsp_mode, ntg_lsp_mode_cmd,
+	"lsp-mode (fixed|randomized)",
+	"Link Selector Parameter Mode\n"
+	"Fixed / Staic LSP\n"
+	"Randomized LSP\n")
+{
+	struct ns_traf_gen *ntg = vty->index;
+	if (!strcmp(argv[0], "randomized"))
+		ntg->cfg.lsp_randomize = true;
+	else
+		ntg->cfg.lsp_randomize = false;
+	return CMD_SUCCESS;
+}
+
+DEFUN(gen_traffic, gen_traffic_cmd,
+	"ns-traffic-generator NAME",
+	"Configure a given NS traffic generator\n" "Name of NS traffic generator\n")
+{
+	struct ns_traf_gen *ntg = ns_traf_gen_find_or_alloc(argv[0]);
+
+	if (!ntg)
+		return CMD_WARNING;
+
+	vty->index = ntg;
+	vty->node = NTG_NODE;
+
+	return CMD_SUCCESS;
+}
+
+int nsdummy_vty_init(struct gprs_ns2_inst *nsi)
+{
+	g_nsi = nsi;
+
+	/* configuration of traffic generators via CONFIG / NTG node */
+	install_element(CONFIG_NODE, &gen_traffic_cmd);
+	install_node(&ntg_node, config_write_ntg);
+	install_element(NTG_NODE, &ntg_nsei_cmd);
+	install_element(NTG_NODE, &ntg_bvci_cmd);
+	install_element(NTG_NODE, &ntg_pkt_size_cmd);
+	install_element(NTG_NODE, &ntg_pkt_intv_us_cmd);
+	install_element(NTG_NODE, &ntg_lsp_cmd);
+	install_element(NTG_NODE, &ntg_lsp_mode_cmd);
+
+	/* starting/stopping the traffic generators is in 'enable' mode, not 'config' */
+	install_element(ENABLE_NODE, &ntg_start_stop_cmd);
+
+	return 0;
+}
diff --git a/utils/osmo-ns-dummy.c b/utils/osmo-ns-dummy.c
index 5625f759..4b937884 100644
--- a/utils/osmo-ns-dummy.c
+++ b/utils/osmo-ns-dummy.c
@@ -199,6 +199,7 @@ int bssgp_prim_cb(struct osmo_prim_hdr *oph, void *ctx)
 	return 0;
 }
 
+extern int nsdummy_vty_init(struct gprs_ns2_inst *nsi);
 
 int main (int argc, char *argv[])
 {
@@ -230,6 +231,7 @@ int main (int argc, char *argv[])
 	}
 
 	gprs_ns2_vty_init(nsi);
+	nsdummy_vty_init(nsi);
 	rc = vty_read_config_file(config_file, NULL);
 	if (rc < 0 && config_given) {
 		fprintf(stderr, "Failed to parse the config file: '%s'\n",