[PATCH v6 2/2] Add l2reflect measurement application

[Felix Moessbauer <felix.moessbauer@siemens.com>]

The l2reflect application implements a ping-pong benchmark to
measure the latency between two instances. For communication,
we use raw ethernet and send one packet at a time. The timing data
is collected locally and min/max/avg values are displayed in a TUI.
Finally, a histogram of the latencies is printed which can be
further processed with the jitterdebugger visualization scripts.
To debug latency spikes, a max threshold can be defined.
If it is hit, a trace point is created on both instances.

Signed-off-by: Felix Moessbauer <felix.moessbauer@siemens.com>
Signed-off-by: Henning Schild <henning.schild@siemens.com>
---
 app/l2reflect/colors.c    |   34 ++
 app/l2reflect/colors.h    |   19 +
 app/l2reflect/l2reflect.h |   53 ++
 app/l2reflect/main.c      | 1007 +++++++++++++++++++++++++++++++++++++
 app/l2reflect/meson.build |   21 +
 app/l2reflect/payload.h   |   26 +
 app/l2reflect/stats.c     |  225 +++++++++
 app/l2reflect/stats.h     |   67 +++
 app/l2reflect/utils.c     |   67 +++
 app/l2reflect/utils.h     |   20 +
 app/meson.build           |    1 +
 11 files changed, 1540 insertions(+)
 create mode 100644 app/l2reflect/colors.c
 create mode 100644 app/l2reflect/colors.h
 create mode 100644 app/l2reflect/l2reflect.h
 create mode 100644 app/l2reflect/main.c
 create mode 100644 app/l2reflect/meson.build
 create mode 100644 app/l2reflect/payload.h
 create mode 100644 app/l2reflect/stats.c
 create mode 100644 app/l2reflect/stats.h
 create mode 100644 app/l2reflect/utils.c
 create mode 100644 app/l2reflect/utils.h

diff --git a/app/l2reflect/colors.c b/app/l2reflect/colors.c
new file mode 100644
index 0000000000..af881d8788
--- /dev/null
+++ b/app/l2reflect/colors.c
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2020 Siemens AG
+ */
+
+#include "colors.h"
+
+const struct color_palette *colors;
+
+static const struct color_palette color_palette_default = {
+	.red = "\x1b[01;31m",
+	.green = "\x1b[01;32m",
+	.yellow = "\x1b[01;33m",
+	.blue = "\x1b[01;34m",
+	.magenta = "\x1b[01;35m",
+	.cyan = "\x1b[01;36m",
+	.reset = "\x1b[0m"
+};
+
+static const struct color_palette color_palette_bw = { .red = "",
+						       .green = "",
+						       .yellow = "",
+						       .blue = "",
+						       .magenta = "",
+						       .cyan = "",
+						       .reset = "" };
+
+void
+enable_colors(int enable)
+{
+	if (enable)
+		colors = &color_palette_default;
+	else
+		colors = &color_palette_bw;
+}
diff --git a/app/l2reflect/colors.h b/app/l2reflect/colors.h
new file mode 100644
index 0000000000..346547138b
--- /dev/null
+++ b/app/l2reflect/colors.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2020 Siemens AG
+ */
+#ifndef _L2REFLECT_COLORS_H_
+#define _L2REFLECT_COLORS_H_
+
+/* posix terminal colors */
+struct color_palette {
+	const char *red, *green, *yellow, *blue, *magenta, *cyan, *reset;
+};
+
+/* ptr to the current tui color palette */
+extern const struct color_palette *colors;
+
+/* disable colored output */
+void
+enable_colors(int enable);
+
+#endif /* _L2REFLECT_COLORS_H_ */
diff --git a/app/l2reflect/l2reflect.h b/app/l2reflect/l2reflect.h
new file mode 100644
index 0000000000..922bd7c281
--- /dev/null
+++ b/app/l2reflect/l2reflect.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2020 Siemens AG
+ */
+
+#include <stdatomic.h>
+
+#ifndef _L2REFLECT_L2REFLECT_H_
+#define _L2REFLECT_L2REFLECT_H_
+
+#define RTE_LOGTYPE_L2REFLECT RTE_LOGTYPE_USER1
+
+/* max size that common 1G NICs support */
+#define MAX_JUMBO_PKT_LEN 9600
+
+/* Used to compare MAC addresses. */
+#define MAC_ADDR_CMP 0xFFFFFFFFFFFFull
+
+#define MAX(x, y) (((x) > (y)) ? (x) : (y))
+#define MIN(x, y) (((x) < (y)) ? (x) : (y))
+
+enum {
+	TRACE_TYPE_DATA,
+	TRACE_TYPE_HELO,
+	TRACE_TYPE_EHLO,
+	TRACE_TYPE_RSET,
+	TRACE_TYPE_QUIT,
+};
+
+enum STATE {
+	/* elect the initial sender */
+	S_ELECT_LEADER = 1,
+	/* reset the counters */
+	S_RESET_TRX = 2,
+	/* measurement S_RUNNING */
+	S_RUNNING = 4,
+	/* terminated by local event */
+	S_LOCAL_TERM = 8,
+	/* terminated by remote event */
+	S_REMOTE_TERM = 16
+};
+
+extern int l2reflect_hist;
+extern unsigned int l2reflect_hist_buckets;
+extern atomic_int l2reflect_output_hist;
+extern int l2reflect_interrupt;
+extern uint64_t l2reflect_sleep_msec;
+extern uint64_t l2reflect_pkt_bytes;
+extern uint16_t l2reflect_port_number;
+extern atomic_int l2reflect_state;
+extern struct rte_ether_addr l2reflect_port_eth_addr;
+extern struct rte_ether_addr l2reflect_remote_eth_addr;
+
+#endif /* _L2REFLECT_L2REFLECT_H_ */
diff --git a/app/l2reflect/main.c b/app/l2reflect/main.c
new file mode 100644
index 0000000000..33a87e8fad
--- /dev/null
+++ b/app/l2reflect/main.c
@@ -0,0 +1,1007 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2020 Siemens AG
+ *
+ * The l2reflect application implements a ping-pong benchmark to
+ * measure the latency between two instances. For communication,
+ * we use raw ethernet and send one packet at a time. The timing data
+ * is collected locally and min/max/avg values are displayed in a TUI.
+ * Finally, a histogram of the latencies is printed which can be
+ * further processed with the jitterdebugger visualization scripts.
+ * To debug latency spikes, a max threshold can be defined.
+ * If it is hit, a trace point is created on both instances.
+ *
+ * Examples:
+ *   launch (non-rt kernel): l2reflect --lcores 0@0,1@6 -n 1
+ *   launch (rt kernel): l2reflect --lcores 0@0,1@6 -n 1 -- -P 50 -r -l
+ *
+ * For histogram data, launch with -H <usec> -F <output file>, e.g.
+ * -H 10 -F histogram.json for a histogram with 10 usec buckets which
+ * is written to a histogram.json file. This file can then be visualized
+ * using the jitterdebugger plotting scripts:
+ *   jitterplot hist histogram.json
+ *
+ * While the application is running, it can be controlled by sending
+ * signals to one of the processes:
+ * - SIGUSR1: reset the min/max/avg on both instances
+ * - SIGUSR2: output / write the current histogram
+ * - SIGHUP/SIGINT: gracefully terminate both instances
+ *
+ * Note on wiring:
+ * The l2reflect application sends the packets via a physical ethernet
+ * interface. When running both instances on a single system, at least
+ * two dedicated physical ports and a (physical) loopback between them
+ * is required.
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+#include <time.h>
+#include <inttypes.h>
+#include <getopt.h>
+#include <sys/signal.h>
+#include <assert.h>
+#include <unistd.h>
+#ifdef HAS_SYS_IO
+#include <sys/io.h>
+#endif
+#include <sched.h>
+#include <sys/mman.h>
+#include <stdatomic.h>
+
+#include <rte_common.h>
+#include <rte_errno.h>
+#include <rte_log.h>
+#include <rte_memory.h>
+#include <rte_memcpy.h>
+#include <rte_memzone.h>
+#include <rte_eal.h>
+#include <rte_eal_trace.h>
+#include <rte_per_lcore.h>
+#include <rte_launch.h>
+#include <rte_atomic.h>
+#include <rte_cycles.h>
+#include <rte_prefetch.h>
+#include <rte_lcore.h>
+#include <rte_per_lcore.h>
+#include <rte_branch_prediction.h>
+#include <rte_interrupts.h>
+#include <rte_random.h>
+#include <rte_debug.h>
+#include <rte_ether.h>
+#include <rte_ethdev.h>
+#include <rte_ring.h>
+#include <rte_mempool.h>
+#include <rte_mbuf.h>
+
+#include "l2reflect.h"
+#include "payload.h"
+#include "utils.h"
+#include "colors.h"
+#include "stats.h"
+
+#define NSEC_PER_SEC 1000000000
+
+#define NB_MBUF 2047
+
+#define MAX_PKT_BURST 32
+/* warmup a few round before starting the measurement */
+#define WARMUP_ROUNDS 42
+
+/* break after one second */
+#define DEFAULT_BREAKVAL_USEC 1000000ull
+/* break if no rx for more than this rounds */
+#define RX_TIMEOUT_MASK ~0xFFFFFull
+
+/* delay between two election packets */
+#define DELAY_ELECTION_MS 500
+
+int l2reflect_hist;
+unsigned int l2reflect_hist_buckets = HIST_NUM_BUCKETS_DEFAULT;
+atomic_int l2reflect_output_hist;
+int l2reflect_fake_mac;
+int l2reflect_interrupt;
+uint64_t l2reflect_sleep_msec;
+uint64_t l2reflect_pkt_bytes = 64;
+uint16_t l2reflect_port_number;
+atomic_int l2reflect_state;
+struct rte_ether_addr l2reflect_port_eth_addr;
+struct rte_ether_addr l2reflect_remote_eth_addr;
+
+static struct timespec last_sent, last_recv;
+static int quiet, disable_int, priority, policy, l2reflect_mlock;
+
+static atomic_int sleep_start;
+static uint64_t rounds;
+
+/* Configurable number of RX/TX ring descriptors */
+#define RTE_TEST_RX_DESC_DEFAULT 128
+#define RTE_TEST_TX_DESC_DEFAULT 128
+static uint16_t nb_rxd = RTE_TEST_RX_DESC_DEFAULT;
+static uint16_t nb_txd = RTE_TEST_TX_DESC_DEFAULT;
+
+static struct rte_eth_conf port_conf = {
+	.rxmode = {
+		.split_hdr_size = 0,
+	},
+	.txmode = {
+		.mq_mode = RTE_ETH_MQ_TX_NONE,
+	},
+};
+
+static uint32_t l2reflect_q;
+static uint64_t l2reflect_break_usec = DEFAULT_BREAKVAL_USEC;
+
+static struct rte_ether_addr ether_bcast_addr = {
+	.addr_bytes = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }
+};
+
+struct rte_mempool *l2reflect_pktmbuf_pool;
+
+static void
+l2reflect_usage(const char *prgname)
+{
+	printf("%s [EAL options] -- [-p PORT] -P [PRIO] [-b USEC] [-n SIZE] [-r] [-f] [-l]"
+	       "[-q] [-d] [-H USEC] [-B NUM] [-F FILE] [-S] [-i MSEC] [-m] [-c] [-h]\n"
+	       "  -p PORT: port to configure\n"
+	       "  -P PRIO: scheduling priority to use\n"
+	       "  -b USEC: break when latency > USEC\n"
+	       "  -n SIZE: size of packet in bytes [%i,%i]\n"
+	       "           (when using jumbo frames, sender and receiver values have to match)\n"
+	       "  -r: scheduling policy SCHED_RR\n"
+	       "  -f: scheduling policy SCHED_FIFO\n"
+	       "  -l: lock memory (mlockall)\n"
+	       "  -q: quiet, do not print stats\n"
+#ifdef HAS_SYS_IO
+	       "  -d: ignore maskable interrupts\n"
+#endif
+	       "  -H USEC: create histogram of latencies with USEC time slices\n"
+	       "  -B NUM: number of histogram buckets\n"
+	       "  -F FILE: write histogram to file\n"
+	       "  -S: start processing threads in sleep, wake with SIGCONT\n"
+	       "  -i MSEC: use interrupts instead of polling (cont. on interrupt or after MSEC)\n"
+	       "  -m: fake the source mac addr by adding 1 to the last tuple\n"
+	       "  -c: disable colored output\n"
+	       "  -h: display help message\n",
+	       prgname, RTE_ETHER_MIN_LEN, MAX_JUMBO_PKT_LEN);
+}
+
+static int
+check_opts_for_help(int argc, char **argv, void(*display_help)(const char *))
+{
+	if (argc > 2 && !strncmp(argv[1], "--", 3)) {
+		if (!strncmp(argv[2], "-h", 3) || !strncmp(argv[2], "--help", 7)) {
+			display_help(argv[0]);
+			return 1;
+		}
+	}
+	return 0;
+}
+
+/* Parse the argument given in the command line of the application */
+static int
+l2reflect_parse_args(int argc, char **argv)
+{
+	int opt, ret;
+	char **argvopt;
+	int option_index;
+	int opt_colors = 1;
+	char *prgname = argv[0];
+	static struct option lgopts[] = { { NULL, 0, 0, 0 } };
+
+	argvopt = argv;
+	policy = SCHED_OTHER;
+	hist_filename = NULL;
+	l2reflect_output_hist = 0;
+
+	while ((opt = getopt_long(argc, argvopt, "p:P:b:H:B:F:i:n:qdrflScm", lgopts,
+				  &option_index)) != EOF) {
+		switch (opt) {
+		/* port */
+		case 'p':
+			l2reflect_port_number =
+				(uint16_t)strtoul(optarg, NULL, 10);
+			break;
+		case 'P':
+			priority = strtoul(optarg, NULL, 10);
+			if (priority > 0) {
+				if (policy == SCHED_OTHER)
+					policy = SCHED_RR;
+				l2reflect_mlock = 1;
+			}
+			break;
+		case 'b':
+			l2reflect_break_usec = strtoul(optarg, NULL, 10);
+			break;
+		case 'S':
+			sleep_start = 1;
+			break;
+		case 'q':
+			quiet = 1;
+			break;
+		case 'd':
+			disable_int = 1;
+			break;
+		case 'r':
+			policy = SCHED_RR;
+			break;
+		case 'f':
+			policy = SCHED_FIFO;
+			break;
+		case 'l':
+			l2reflect_mlock = 1;
+			break;
+		case 'H':
+			l2reflect_hist = 1;
+			hist_bucket_usec = strtoul(optarg, NULL, 10);
+#ifndef RTE_HAS_JANSSON
+			printf("not compiled with cjson support\n");
+			return -1;
+#endif
+			break;
+		case 'B':
+			l2reflect_hist_buckets = strtoul(optarg, NULL, 10);
+			break;
+		case 'F':
+			hist_filename = strndup(optarg, 128);
+			break;
+		case 'i':
+			l2reflect_interrupt = 1;
+			l2reflect_sleep_msec = strtoul(optarg, NULL, 10);
+			break;
+		case 'n':
+			l2reflect_pkt_bytes = strtoull(optarg, NULL, 10);
+			if (l2reflect_pkt_bytes < RTE_ETHER_MIN_LEN ||
+			   l2reflect_pkt_bytes > MAX_JUMBO_PKT_LEN) {
+				printf("packet size %" PRIu64 " not valid\n", l2reflect_pkt_bytes);
+				return -1;
+			}
+			if (l2reflect_pkt_bytes > RTE_MBUF_DEFAULT_DATAROOM) {
+				printf("NOT IMPLEMENTED. Packet size %" PRIu64 " requires segmented buffers.\n",
+					l2reflect_pkt_bytes);
+				return -1;
+			}
+			break;
+		case 'c':
+			opt_colors = 0;
+			break;
+		case 'm':
+			l2reflect_fake_mac = 1;
+			break;
+		default:
+			l2reflect_usage(prgname);
+			return -1;
+		}
+	}
+
+	if (optind >= 0)
+		argv[optind - 1] = prgname;
+
+	if (hist_filename && !l2reflect_hist) {
+		printf("-F switch requires -H switch as well\n");
+		return -1;
+	}
+
+	/* output is redirected, disable coloring */
+	if (!isatty(fileno(stdout)))
+		opt_colors = 0;
+
+	enable_colors(opt_colors);
+
+	ret = optind - 1;
+	optind = 0; /* reset getopt lib */
+	return ret;
+}
+
+/* Send a burst of one packet */
+static inline int
+l2reflect_send_packet(struct rte_mbuf **m, uint16_t port)
+{
+	unsigned int ret;
+	struct rte_ether_hdr *eth;
+	struct my_magic_packet *pkt;
+	uint16_t type;
+
+	eth = rte_pktmbuf_mtod(*m, struct rte_ether_hdr *);
+	pkt = (struct my_magic_packet *)eth;
+	type = pkt->type;
+
+	if (likely(type == TRACE_TYPE_DATA))
+		clock_gettime(CLOCK_MONOTONIC, &last_sent);
+	ret = rte_eth_tx_burst(port, l2reflect_q, m, 1);
+	if (unlikely(ret < 1))
+		rte_pktmbuf_free(*m);
+	return 0;
+}
+
+static inline void
+l2reflect_simple_forward(struct rte_mbuf *m)
+{
+	struct rte_ether_hdr *eth;
+	struct my_magic_packet *pkt;
+
+	eth = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
+	pkt = (struct my_magic_packet *)eth;
+
+	/* dst addr */
+	rte_ether_addr_copy(&eth->src_addr, &eth->dst_addr);
+	/* src addr */
+	rte_ether_addr_copy(&l2reflect_port_eth_addr, &eth->src_addr);
+
+	if (unlikely(pkt->magic == MAGIC_TRACE_PAYLOAD))
+		rte_eal_trace_generic_str("sending traced packet");
+
+	l2reflect_send_packet(&m, l2reflect_port_number);
+}
+
+static struct rte_mbuf *
+l2reflect_new_pkt(unsigned int type)
+{
+	struct rte_mbuf *m;
+	struct rte_ether_hdr *eth;
+	struct my_magic_packet *pkt;
+	uint64_t frame_bytes = RTE_ETHER_MIN_LEN;
+
+	m = rte_pktmbuf_alloc(l2reflect_pktmbuf_pool);
+	if (m == NULL)
+		rte_exit(EXIT_FAILURE, "rte_pktmbuf_alloc failed\n");
+
+	eth = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
+
+	if (type == TRACE_TYPE_DATA)
+		frame_bytes = l2reflect_pkt_bytes;
+
+	/* zero out packet to make dumps better readable */
+	memset(eth, 0, frame_bytes - RTE_ETHER_CRC_LEN);
+
+	if (type == TRACE_TYPE_HELO)
+		rte_ether_addr_copy(&ether_bcast_addr, &eth->dst_addr);
+	else
+		rte_ether_addr_copy(&l2reflect_remote_eth_addr, &eth->dst_addr);
+
+	/* src addr */
+	rte_ether_addr_copy(&l2reflect_port_eth_addr, &eth->src_addr);
+	eth->ether_type = rte_cpu_to_be_16(ETHER_TYPE_L2REFLECT);
+
+	m->data_len = frame_bytes - RTE_ETHER_CRC_LEN;
+	m->pkt_len = frame_bytes - RTE_ETHER_CRC_LEN;
+
+	pkt = (struct my_magic_packet *)eth;
+	pkt->type = type;
+	pkt->breakval = l2reflect_break_usec;
+	pkt->req_pkt_bytes = l2reflect_pkt_bytes;
+
+	return m;
+}
+
+static void
+l2reflect_send_reset(void)
+{
+	struct rte_mbuf *m;
+	m = l2reflect_new_pkt(TRACE_TYPE_RSET);
+	l2reflect_send_packet(&m, l2reflect_port_number);
+}
+
+static void
+l2reflect_send_quit(void)
+{
+	struct rte_mbuf *m;
+	m = l2reflect_new_pkt(TRACE_TYPE_QUIT);
+	l2reflect_send_packet(&m, l2reflect_port_number);
+}
+
+static void
+l2reflect_new_ball(void)
+{
+	struct rte_mbuf *pnewball;
+	struct rte_ether_hdr *eth;
+	struct my_magic_packet *pkt;
+	char mac_src_str[RTE_ETHER_ADDR_FMT_SIZE];
+	char mac_dst_str[RTE_ETHER_ADDR_FMT_SIZE];
+
+	RTE_LOG(INFO, L2REFLECT, "Should create a packet to play with ...\n");
+	pnewball = l2reflect_new_pkt(TRACE_TYPE_DATA);
+
+	eth = rte_pktmbuf_mtod(pnewball, struct rte_ether_hdr *);
+
+	rte_ether_format_addr(mac_src_str, sizeof(mac_src_str), &l2reflect_port_eth_addr);
+	rte_ether_format_addr(mac_dst_str, sizeof(mac_dst_str), &l2reflect_remote_eth_addr);
+	RTE_LOG(INFO, L2REFLECT, "from MAC address: %s to %s\n\n", mac_src_str, mac_dst_str);
+
+	pkt = (struct my_magic_packet *)eth;
+
+	/* we are tracing lets tell the others */
+	if (l2reflect_break_usec)
+		pkt->magic = MAGIC_TRACE_PAYLOAD;
+
+	l2reflect_send_packet(&pnewball, l2reflect_port_number);
+}
+
+static inline int64_t
+calcdiff_ns(struct timespec t1, struct timespec t2)
+{
+	int64_t diff;
+	diff = NSEC_PER_SEC * (int64_t)((int)t1.tv_sec - (int)t2.tv_sec);
+	diff += ((int)t1.tv_nsec - (int)t2.tv_nsec);
+	return diff;
+}
+
+/* filter the received packets for actual l2reflect messages */
+static inline unsigned int
+l2reflect_rx_filter(
+	struct rte_mbuf *buf)
+{
+	struct rte_ether_hdr *eth;
+	eth = rte_pktmbuf_mtod(buf, struct rte_ether_hdr *);
+
+	if (unlikely(buf->nb_segs > 1))
+		RTE_LOG(WARNING, L2REFLECT, "Segmented packet: data-len: %i, pkt-len: %i, #seg: %i\n",
+			buf->data_len, buf->pkt_len, buf->nb_segs);
+
+	/* check for the l2reflect ether type */
+	if (unlikely(eth->ether_type != rte_cpu_to_be_16(ETHER_TYPE_L2REFLECT)))
+		return 0;
+
+	/*
+	 * if the packet is not from our partner
+	 * (and we already have a partner), drop it
+	 */
+	if (unlikely(l2reflect_state != S_ELECT_LEADER &&
+		!rte_is_same_ether_addr(&eth->src_addr, &l2reflect_remote_eth_addr)))
+		return 0;
+
+	/* filter bounce-back packets */
+	if (unlikely(rte_is_same_ether_addr(&eth->src_addr, &l2reflect_port_eth_addr)))
+		return 0;
+
+	return 1;
+}
+
+/*
+ * automatically elect the leader of the benchmark by
+ * sending out HELO packets and waiting for responses.
+ * On response, the mac addresses are compared and the
+ * numerically larger one becomes the leader.
+ */
+static int
+elect_leader(uint16_t portid)
+{
+	struct rte_mbuf *pkts_burst[MAX_PKT_BURST];
+	struct rte_mbuf *m;
+	struct rte_ether_hdr *eth;
+	struct rte_ether_addr *src_addr;
+	struct rte_eth_dev_info dev_info;
+	struct my_magic_packet *pkt;
+	unsigned int i, nb_rx;
+	int ehlo_send = 0;
+	int i_win;
+
+	while (l2reflect_state == S_ELECT_LEADER) {
+		/* send a packet to make sure the MAC addr of this interface is publicly known */
+		m = l2reflect_new_pkt(TRACE_TYPE_HELO);
+		RTE_LOG(INFO, L2REFLECT, "looking for player HELO\n");
+		l2reflect_send_packet(&m, l2reflect_port_number);
+		rte_delay_ms(DELAY_ELECTION_MS);
+
+		/* receive election packets */
+		nb_rx = rte_eth_rx_burst(portid, l2reflect_q, pkts_burst,
+					 MAX_PKT_BURST);
+
+		/* note: do not short-circuit as otherwise the mbufs are not freed */
+		for (i = 0; i < nb_rx; i++) {
+			m = pkts_burst[i];
+			eth = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
+			src_addr = &eth->src_addr;
+			pkt = (struct my_magic_packet *)eth;
+
+			if (!l2reflect_rx_filter(m)) {
+				rte_pktmbuf_free(m);
+				continue;
+			}
+
+			if (pkt->type == TRACE_TYPE_EHLO && l2reflect_state == S_ELECT_LEADER) {
+				/* check if both modes are equal */
+				if (((l2reflect_pkt_bytes <= RTE_ETHER_MTU)
+				   != (pkt->req_pkt_bytes <= RTE_ETHER_MTU))) {
+					l2reflect_state = S_LOCAL_TERM;
+					m = l2reflect_new_pkt(TRACE_TYPE_QUIT);
+					l2reflect_send_packet(&m, l2reflect_port_number);
+					rte_exit(EXIT_FAILURE,
+						"remote and local jumbo config does not match "
+						"(%" PRIu64 " vs %" PRIu64 ")\n",
+						l2reflect_pkt_bytes, pkt->req_pkt_bytes);
+				}
+				if (l2reflect_pkt_bytes != pkt->req_pkt_bytes) {
+					l2reflect_pkt_bytes = MAX(l2reflect_pkt_bytes,
+								  pkt->req_pkt_bytes);
+					rte_eth_dev_info_get(l2reflect_port_number, &dev_info);
+					const uint32_t overhead_len = eth_dev_get_overhead_len(
+									dev_info.max_rx_pktlen,
+									dev_info.max_mtu);
+					const uint16_t mtu = MAX(l2reflect_pkt_bytes - overhead_len,
+								 dev_info.min_mtu);
+					RTE_LOG(INFO, L2REFLECT,
+						"update frame sizes: frame: %" PRIu64 ", MTU %d\n",
+						l2reflect_pkt_bytes, mtu);
+					const int ret = rte_eth_dev_set_mtu(
+								l2reflect_port_number,
+								mtu);
+					if (ret < 0)
+						rte_exit(EXIT_FAILURE, "failed to update MTU: %s\n",
+								 strerror(-ret));
+				}
+
+				if (ehlo_send) {
+					l2reflect_state = S_RUNNING;
+					RTE_LOG(INFO, L2REFLECT, "Enter running state\n");
+				}
+			}
+			/* we got a HELO packet, respond with EHLO */
+			if (pkt->type == TRACE_TYPE_HELO) {
+				char mac_str_other[RTE_ETHER_ADDR_FMT_SIZE];
+				rte_ether_addr_copy(src_addr, &l2reflect_remote_eth_addr);
+				m = l2reflect_new_pkt(TRACE_TYPE_EHLO);
+				rte_ether_format_addr(
+				  mac_str_other, sizeof(mac_str_other), &l2reflect_remote_eth_addr);
+				RTE_LOG(INFO, L2REFLECT, "found one HELO from %s\n", mac_str_other);
+				l2reflect_send_packet(&m, l2reflect_port_number);
+				ehlo_send = 1;
+			}
+			rte_pktmbuf_free(m);
+		}
+	}
+
+	if (rte_is_same_ether_addr(&l2reflect_port_eth_addr, &l2reflect_remote_eth_addr))
+		rte_exit(EXIT_FAILURE, "talking to myself ... confused\n");
+
+	/* the one with the bigger MAC is the leader */
+	i_win = ((*((uint64_t *)&l2reflect_port_eth_addr)   & MAC_ADDR_CMP) >
+			 (*((uint64_t *)&l2reflect_remote_eth_addr) & MAC_ADDR_CMP));
+
+	RTE_LOG(INFO, L2REFLECT, "i am the \"%s\"\n", i_win ? "rick" : "morty");
+
+	return i_win;
+}
+
+/*
+ * add the measured time diff to the statistics.
+ * return false if threshold is hit
+ */
+static inline int
+add_to_record(const uint64_t diff)
+{
+	record.rounds++;
+	/* do not count the first rounds, diff would be too high */
+	if (record.rounds < WARMUP_ROUNDS)
+		return 1;
+
+	if (l2reflect_hist) {
+		const uint64_t bucket =
+			MIN(diff / (hist_bucket_usec * 1000), l2reflect_hist_buckets-1);
+		record.hist[bucket]++;
+	}
+
+	record.avg_round_ns += (double)diff;
+	if (diff < record.min_round_ns)
+		record.min_round_ns = diff;
+	if (diff > record.max_round_ns) {
+		record.max_round_ns = diff;
+		if (l2reflect_break_usec &&
+		   (record.max_round_ns > (l2reflect_break_usec * 1000)))
+			return 0;
+	}
+	return 1;
+}
+
+/*
+ * process a single packet.
+ * return false if latency threshold is hit
+ */
+static inline int
+process_packet(
+	struct my_magic_packet *pkt,
+	struct timespec *rx_time,
+	uint64_t *diff)
+{
+	if (pkt->type == TRACE_TYPE_DATA) {
+		rte_memcpy(&last_recv, rx_time, sizeof(*rx_time));
+		*diff = calcdiff_ns(last_recv, last_sent);
+		if (!unlikely(add_to_record(*diff))) {
+			/* TODO: improve tracing */
+			rte_eal_trace_generic_u64(record.max_round_ns / 1000);
+			return 0;
+		}
+	}
+	if (pkt->magic == MAGIC_TRACE_PAYLOAD)
+		rte_eal_trace_generic_str("received traced packet");
+
+	return 1;
+}
+
+/*
+ * free all packet buffers in the range [begin, end[.
+ */
+static void
+free_pktbufs(
+		struct rte_mbuf **bufs,
+		int begin,
+		int end)
+{
+	int i = begin;
+	for (; i < end; i++)
+		rte_pktmbuf_free(bufs[0]);
+}
+
+/*
+ * return 1 in case the ball was lost (cheap check)
+ */
+static inline void
+check_ball_lost(const uint64_t dp_idle) {
+	/* only check if we are in running state and have a breakval */
+	if (unlikely(dp_idle & RX_TIMEOUT_MASK) &&
+	   l2reflect_state == S_RUNNING &&
+	   l2reflect_break_usec &&
+	   record.rounds > WARMUP_ROUNDS) {
+		RTE_LOG(INFO, L2REFLECT, "lost ball after %" PRIu64 " rounds\n", record.rounds);
+		l2reflect_state = S_LOCAL_TERM;
+	}
+}
+
+/* main processing loop */
+static void
+l2reflect_main_loop(void)
+{
+	struct rte_mbuf *pkts_burst[MAX_PKT_BURST];
+	struct rte_mbuf *m;
+	unsigned int lcore_id;
+	unsigned int j, nb_rx, nb_evt;
+	uint16_t portid;
+	/* number of consequent idle passes */
+	uint64_t dp_idle = 0;
+	uint64_t diff = 0;
+	int sender;
+	struct my_magic_packet *pkt;
+	struct rte_ether_hdr *eth;
+	struct rte_epoll_event event;
+
+	lcore_id = rte_lcore_id();
+
+	RTE_LOG(INFO, L2REFLECT, "entering main loop on lcore %u\n", lcore_id);
+
+	portid = l2reflect_port_number;
+	RTE_LOG(INFO, L2REFLECT, " -- lcoreid=%u portid=%u\n", lcore_id,
+		portid);
+	assert_link_status(portid);
+
+restart:
+	init_record();
+	rte_eth_stats_reset(portid);
+	l2reflect_state = S_ELECT_LEADER;
+	sender = elect_leader(portid);
+
+	if (l2reflect_break_usec)
+		rte_eal_trace_generic_str("hit breakval");
+
+	/* the leader election implements a latch (half-barrier).
+	 * To ensure that the other party is in running state, we
+	 * have to wait at least a full election period
+	 */
+	rte_delay_ms(DELAY_ELECTION_MS * 2);
+
+	/* we are the sender so we bring one ball into the game */
+	if (sender)
+		l2reflect_new_ball();
+
+	/* reset the record */
+	init_record();
+	while (l2reflect_state == S_RUNNING) {
+		struct timespec rx_time;
+
+		if (l2reflect_interrupt) {
+			rte_eth_dev_rx_intr_enable(portid, l2reflect_q);
+			/* wait for interrupt or timeout */
+			nb_evt = rte_epoll_wait(RTE_EPOLL_PER_THREAD, &event, 1,
+						l2reflect_sleep_msec);
+			rte_eth_dev_rx_intr_disable(portid, l2reflect_q);
+			if (nb_evt == 0 && rounds > WARMUP_ROUNDS)
+				++record.timeouts;
+		}
+
+		nb_rx = rte_eth_rx_burst(portid, l2reflect_q, pkts_burst,
+					 MAX_PKT_BURST);
+
+		if (nb_rx) {
+			clock_gettime(CLOCK_MONOTONIC, &rx_time);
+			dp_idle = 0;
+		} else
+			++dp_idle;
+
+		for (j = 0; j < nb_rx; j++) {
+			m = pkts_burst[j];
+			eth = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
+			pkt = (struct my_magic_packet *)eth;
+
+			rte_prefetch0(eth);
+
+			if (unlikely(!l2reflect_rx_filter(m))) {
+				rte_pktmbuf_free(m);
+				continue;
+			}
+
+			/* remote is telling us to reset or stop */
+			if (unlikely(pkt->type == TRACE_TYPE_RSET)) {
+				free_pktbufs(pkts_burst, j, nb_rx);
+				goto restart;
+			}
+			if (unlikely(pkt->type == TRACE_TYPE_QUIT)) {
+				l2reflect_state = S_REMOTE_TERM;
+				free_pktbufs(pkts_burst, j, nb_rx);
+				break;
+			}
+
+			if (likely(l2reflect_state == S_RUNNING)) {
+				if (unlikely(!process_packet(pkt, &rx_time, &diff))) {
+					l2reflect_state = S_LOCAL_TERM;
+					free_pktbufs(pkts_burst, j, nb_rx);
+					break;
+				}
+				l2reflect_simple_forward(m);
+			}
+		}
+		check_ball_lost(dp_idle);
+	}
+
+	const int state_cpy = l2reflect_state;
+	switch (state_cpy) {
+	case S_RESET_TRX:
+		l2reflect_send_reset();
+		l2reflect_state = S_ELECT_LEADER;
+		/* fallthrough */
+	case S_ELECT_LEADER:
+		goto restart;
+	}
+
+	if (state_cpy == S_LOCAL_TERM) {
+		rte_eal_trace_generic_str("local termination");
+		l2reflect_send_quit();
+	} else if (state_cpy == S_REMOTE_TERM) {
+		RTE_LOG(INFO, L2REFLECT, "received message that remote hit threshold (or is cancelled)\n");
+	}
+}
+
+static int
+l2reflect_launch_one_lcore(__rte_unused void *dummy)
+{
+	struct sched_param param;
+	int err;
+
+	if (sleep_start) {
+		RTE_LOG(INFO, L2REFLECT, "Sleeping and waiting for SIGCONT\n");
+		while (sleep_start) {
+			rte_delay_ms(10);
+			if (l2reflect_state == S_LOCAL_TERM)
+				rte_exit(EXIT_SUCCESS, "Quit\n");
+		}
+		RTE_LOG(INFO, L2REFLECT, "Got SIGCONT, continuing");
+	}
+	if (l2reflect_mlock) {
+		err = mlockall(MCL_CURRENT | MCL_FUTURE);
+		if (err)
+			rte_exit(EXIT_FAILURE, "mlockall failed: %s\n",
+				 strerror(errno));
+	}
+	if (priority > 0 || policy != SCHED_OTHER) {
+		memset(&param, 0, sizeof(param));
+		param.sched_priority = priority;
+		err = sched_setscheduler(0, policy, &param);
+		if (err)
+			rte_exit(EXIT_FAILURE,
+				 "sched_setscheduler failed: %s\n",
+				 strerror(errno));
+	}
+	if (l2reflect_interrupt) {
+		err = rte_eth_dev_rx_intr_ctl_q(l2reflect_port_number,
+						l2reflect_q,
+						RTE_EPOLL_PER_THREAD,
+						RTE_INTR_EVENT_ADD, NULL);
+		if (err)
+			rte_exit(EXIT_FAILURE,
+				 "could not register I/O interrupt\n");
+	}
+	l2reflect_main_loop();
+	return 0;
+}
+
+static void
+sig_handler(int signum)
+{
+	switch (signum) {
+	case SIGUSR1:
+		if (l2reflect_state == S_RUNNING)
+			l2reflect_state = S_RESET_TRX;
+		break;
+	case SIGUSR2:
+		l2reflect_output_hist = 1;
+		break;
+	case SIGCONT:
+		sleep_start = 0;
+		break;
+	case SIGHUP:
+	case SIGINT:
+		l2reflect_state = S_LOCAL_TERM;
+		break;
+	}
+}
+
+int
+main(int argc, char **argv)
+{
+	struct rte_eth_dev_info dev_info;
+	struct rte_eth_txconf txconf;
+	int ret;
+	uint32_t i;
+	uint16_t nb_ports;
+	unsigned int lcore_id;
+	struct sigaction action;
+	bzero(&action, sizeof(action));
+	char mempool_name[128];
+	char mac_str[RTE_ETHER_ADDR_FMT_SIZE];
+
+	action.sa_handler = sig_handler;
+	if (sigaction(SIGHUP, &action, NULL) < 0 ||
+	    sigaction(SIGUSR1, &action, NULL) < 0 ||
+	    sigaction(SIGUSR2, &action, NULL) < 0 ||
+	    sigaction(SIGCONT, &action, NULL) < 0 ||
+	    sigaction(SIGINT, &action, NULL) < 0) {
+		rte_exit(EXIT_FAILURE, "Could not register signal handler\n");
+	}
+
+	lcore_id = rte_lcore_id();
+
+	if (check_opts_for_help(argc, argv, l2reflect_usage))
+		return 0;
+
+	/* init EAL */
+	ret = rte_eal_init(argc, argv);
+	if (ret < 0)
+		rte_exit(EXIT_FAILURE, "Invalid EAL arguments\n");
+	argc -= ret;
+	argv += ret;
+
+	/* parse application arguments (after the EAL ones) */
+	ret = l2reflect_parse_args(argc, argv);
+	if (ret < 0)
+		rte_exit(EXIT_FAILURE, "Invalid L2REFLECT arguments\n");
+
+	snprintf(mempool_name, sizeof(mempool_name), "mbuf_pool_%d", getpid());
+	RTE_LOG(DEBUG, L2REFLECT, "About to create mempool \"%s\"\n", mempool_name);
+	/* create the mbuf pool */
+	l2reflect_pktmbuf_pool =
+		rte_pktmbuf_pool_create(mempool_name, NB_MBUF,
+			MAX_PKT_BURST, 0, RTE_MBUF_DEFAULT_BUF_SIZE,
+			rte_socket_id());
+
+	if (l2reflect_pktmbuf_pool == NULL)
+		rte_exit(EXIT_FAILURE,
+			 "Cannot init/find mbuf pool name %s\nError: %d %s\n",
+			 mempool_name, rte_errno, rte_strerror(rte_errno));
+
+	nb_ports = rte_eth_dev_count_avail();
+	if (nb_ports == 0)
+		rte_exit(EXIT_FAILURE, "No Ethernet ports - bye\n");
+	if (l2reflect_port_number + 1 > nb_ports)
+		rte_exit(EXIT_FAILURE, "Chosen port %d does not exist - bye\n",
+			 l2reflect_port_number);
+	RTE_LOG(INFO, L2REFLECT, "We have %d ports and will use port %d\n", nb_ports,
+	       l2reflect_port_number);
+
+	rte_eth_dev_info_get(l2reflect_port_number, &dev_info);
+	RTE_LOG(INFO, L2REFLECT, "Initializing port %u ...\n", l2reflect_port_number);
+	fflush(stdout);
+
+	if (l2reflect_interrupt)
+		port_conf.intr_conf.rxq = 1;
+
+	ret = config_port_max_pkt_len(&port_conf, &dev_info);
+	if (ret < 0)
+		rte_exit(EXIT_FAILURE,
+			"Invalid max packet length: %u (port %u)\n",
+			l2reflect_port_number, l2reflect_port_number);
+
+	ret = rte_eth_dev_configure(l2reflect_port_number, 1, 1, &port_conf);
+	if (ret < 0)
+		rte_exit(EXIT_FAILURE,
+			"Cannot configure device: err=%s, port=%u\n",
+			strerror(-ret), l2reflect_port_number);
+
+	ret = rte_eth_dev_adjust_nb_rx_tx_desc(l2reflect_port_number, &nb_rxd, &nb_txd);
+	if (ret != 0)
+		rte_exit(EXIT_FAILURE,
+			 "Cannot adjust # of Rx/Tx descriptors to HW limits: err=%s, port=%u\n",
+			 strerror(-ret), l2reflect_port_number);
+
+	/* init RX queues */
+	for (i = 0; i <= l2reflect_q; i++) {
+		ret = rte_eth_rx_queue_setup(
+			l2reflect_port_number, i, nb_rxd,
+			rte_eth_dev_socket_id(l2reflect_port_number), NULL,
+			l2reflect_pktmbuf_pool);
+		if (ret < 0)
+			rte_exit(
+				EXIT_FAILURE,
+				"rte_eth_rx_queue_setup:err=%s, port=%u q=%u\n",
+				strerror(-ret), l2reflect_port_number, i);
+	}
+
+	/* init one TX queue on each port */
+	txconf = dev_info.default_txconf;
+	txconf.offloads = port_conf.txmode.offloads;
+	ret = rte_eth_tx_queue_setup(
+		l2reflect_port_number, 0, nb_txd,
+		rte_eth_dev_socket_id(l2reflect_port_number), &txconf);
+	if (ret < 0)
+		rte_exit(EXIT_FAILURE,
+			 "rte_eth_tx_queue_setup:err=%s, port=%u\n",
+			 strerror(-ret), (unsigned int)l2reflect_port_number);
+
+	/* Start device */
+	ret = rte_eth_dev_start(l2reflect_port_number);
+	if (ret < 0)
+		rte_exit(EXIT_FAILURE, "rte_eth_dev_start:err=%s, port=%u\n",
+			 strerror(-ret), (unsigned int)l2reflect_port_number);
+
+	rte_eth_macaddr_get(l2reflect_port_number, &l2reflect_port_eth_addr);
+
+	/*
+	 * When running on a Tap device, we might want to use a foreign
+	 * mac address to make sure that the application and the Tap device
+	 * do not share the same MAC addr. By that, we enforce that the
+	 * bridge learns this address and correctly forwards unicast packets.
+	 */
+	if (l2reflect_fake_mac)
+		l2reflect_port_eth_addr.addr_bytes[5] += 1;
+
+	rte_ether_format_addr(mac_str, sizeof(mac_str),
+			      &l2reflect_port_eth_addr);
+	RTE_LOG(INFO, L2REFLECT, "Port %u, MAC address: %s\n\n",
+	       (unsigned int)l2reflect_port_number, mac_str);
+
+	/*
+	 * in quiet mode the primary executes the main packet loop
+	 * otherwise the one worker does it and the primary prints stats
+	 */
+	if (quiet) {
+		assert(rte_lcore_count() == 1);
+#ifdef HAS_SYS_IO
+		if (disable_int) {
+			iopl(3);
+			asm("cli");
+		}
+#endif
+		RTE_LOG(INFO, L2REFLECT, "PID %i, Parent %i\n", getpid(), getppid());
+		l2reflect_launch_one_lcore(NULL);
+	} else {
+		assert(rte_lcore_count() == 2);
+		/* the worker reflects the packets */
+		RTE_LCORE_FOREACH_WORKER(lcore_id)
+		{
+			rte_eal_remote_launch(l2reflect_launch_one_lcore, NULL,
+					      lcore_id);
+		}
+
+		/* the primary prints the stats */
+		init_record();
+		l2reflect_stats_loop();
+		rte_eal_mp_wait_lcore();
+	}
+	rte_eal_cleanup();
+
+	if (l2reflect_hist)
+		output_histogram_snapshot();
+
+	cleanup_record();
+
+	return 0;
+}
diff --git a/app/l2reflect/meson.build b/app/l2reflect/meson.build
new file mode 100644
index 0000000000..14b154ef06
--- /dev/null
+++ b/app/l2reflect/meson.build
@@ -0,0 +1,21 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2022 Siemens AG
+
+cc = meson.get_compiler('c')
+
+jansson = dependency('libjansson', required: false)
+
+if not jansson.found()
+    jansson = cc.find_library('jansson', required: false)
+endif
+
+if cc.has_header('sys/io.h')
+    cflags += '-DHAS_SYS_IO'
+endif
+
+sources = files('main.c', 'utils.c', 'stats.c', 'colors.c')
+deps += ['ethdev']
+if jansson.found()
+    ext_deps += jansson
+    cflags += '-DRTE_HAS_JANSSON'
+endif
diff --git a/app/l2reflect/payload.h b/app/l2reflect/payload.h
new file mode 100644
index 0000000000..c1fae5d5e4
--- /dev/null
+++ b/app/l2reflect/payload.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2022 Siemens AG
+ */
+#include <rte_ether.h>
+
+#ifndef _L2REFLECT_PAYLOAD_H_
+#define _L2REFLECT_PAYLOAD_H_
+
+#define MAGIC_TRACE_PAYLOAD 0xd00faffeaffed00full
+/* IEEE Std 802 - Local Experimental Ethertype */
+#define ETHER_TYPE_L2REFLECT 0x88B5
+
+struct my_magic_packet {
+	/* l2 packet header */
+	struct rte_ether_hdr eth;
+	/* type of the l2reflect packet */
+	uint8_t type;
+	/* magic easy-to-spot pattern for tracing */
+	uint64_t magic;
+	/* break if latency is larger than this */
+	uint64_t breakval;
+	/* intended size of the packet */
+	uint64_t req_pkt_bytes;
+};
+
+#endif /* _L2REFLECT_PAYLOAD_H_ */
diff --git a/app/l2reflect/stats.c b/app/l2reflect/stats.c
new file mode 100644
index 0000000000..6bcbb7a2bf
--- /dev/null
+++ b/app/l2reflect/stats.c
@@ -0,0 +1,225 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2020 Siemens AG
+ */
+#include <stdio.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <time.h>
+#include <string.h>
+#ifdef RTE_HAS_JANSSON
+#include <jansson.h>
+#endif
+#include "colors.h"
+#include "stats.h"
+
+unsigned int hist_bucket_usec;
+struct stats record;
+char *hist_filename;
+
+void
+init_record(void)
+{
+	record.max_round_ns = 0;
+	record.min_round_ns = MIN_INITIAL;
+	record.rounds = 0;
+	record.timeouts = 0;
+	record.avg_round_ns = 0;
+	if (l2reflect_hist) {
+		if (!record.hist_size) {
+			record.hist =
+				calloc(l2reflect_hist_buckets, sizeof(uint64_t));
+			record.hist_size = l2reflect_hist_buckets;
+		} else {
+			memset(record.hist, 0,
+			       record.hist_size * sizeof(uint64_t));
+		}
+	}
+	clock_gettime(CLOCK_MONOTONIC, &record.time_start);
+}
+
+void
+cleanup_record(void)
+{
+	if (l2reflect_hist) {
+		free(record.hist);
+		record.hist = NULL;
+		record.hist_size = 0;
+	}
+}
+
+void
+output_histogram_snapshot(void)
+{
+	char *json = serialize_histogram(&record);
+	FILE *fd = stderr;
+	if (hist_filename)
+		fd = fopen(hist_filename, "w");
+	fputs(json, fd);
+	fputs("\n", fd);
+	free(json);
+	if (hist_filename)
+		fclose(fd);
+}
+
+void
+print_stats(void)
+{
+	const char clr[] = { 27, '[', '2', 'J', '\0' };
+	const char topLeft[] = { 27, '[', '1', ';', '1', 'H', '\0' };
+	const uint64_t bytes_in_gib = 0x40000000;
+	struct rte_eth_stats stats;
+	char mac_str_me[RTE_ETHER_ADDR_FMT_SIZE];
+	char mac_str_remote[RTE_ETHER_ADDR_FMT_SIZE];
+	char timeout_bound_str[32];
+	const char *str_jumbo = l2reflect_pkt_bytes > RTE_ETHER_MTU ?
+		"jumbo" : "no-jumbo";
+	struct timespec time_now;
+
+	if (l2reflect_interrupt == 0)
+		snprintf(timeout_bound_str, sizeof(timeout_bound_str), "     polling");
+	else if (l2reflect_sleep_msec == -1u)
+		snprintf(timeout_bound_str, sizeof(timeout_bound_str), ">=  infinite");
+	else
+		snprintf(timeout_bound_str, sizeof(timeout_bound_str), ">%9" PRIu64 "ms",
+			l2reflect_sleep_msec);
+
+	rte_eth_stats_get(l2reflect_port_number, &stats);
+	rte_ether_format_addr(mac_str_me, sizeof(mac_str_me),
+			      &l2reflect_port_eth_addr);
+	rte_ether_format_addr(mac_str_remote, sizeof(mac_str_remote),
+			      &l2reflect_remote_eth_addr);
+
+	clock_gettime(CLOCK_MONOTONIC, &time_now);
+	const uint64_t time_since_start = time_now.tv_sec - record.time_start.tv_sec;
+
+	/* Clear screen and move to top left */
+	printf("%s%s", clr, topLeft);
+
+	printf("%sNetworking Roundtrip Test%s\n", colors->green, colors->reset);
+	printf("\n%sPort statistics ====================================%s",
+	       colors->magenta, colors->reset);
+
+	printf("\nMe: %s <--> Remote: %s", mac_str_me, mac_str_remote);
+	printf("\nStatistics for port %d PID %d on lcore %d ---------"
+			"\nState: %-16s %10" PRIu64 " s"
+			"\nPackets tx: %22" PRIu64 "\nPackets rx: %22" PRIu64
+			"\nBytes tx: %24" PRIu64 "    (%8.2f GiB)"
+			"\nBytes rx: %24" PRIu64 "    (%8.2f GiB)"
+			"\nErrors tx: %23" PRIu64 "\nErrors rx: %23" PRIu64
+			"\nTimeouts rx: %21" PRIu64 "    (%s)"
+			"\nPacketsize [Byte]: %15" PRIu64 "    (%12s)",
+			l2reflect_port_number, getpid(), rte_lcore_id(),
+			runstate_tostring(l2reflect_state),
+			time_since_start,
+			stats.opackets, stats.ipackets, stats.obytes,
+			(double)stats.obytes / bytes_in_gib, stats.ibytes,
+			(double)stats.ibytes / bytes_in_gib, stats.oerrors,
+			stats.ierrors, record.timeouts,
+			timeout_bound_str, l2reflect_pkt_bytes, str_jumbo);
+	printf("\n%sPort timing statistics =============================%s",
+	       colors->magenta, colors->reset);
+	if (l2reflect_state == S_ELECT_LEADER ||
+		record.min_round_ns == MIN_INITIAL) {
+		printf("\n\nBenchmark not started yet...\n");
+	} else {
+		printf("\n%sMax%s roundtrip: %19" PRIu64 " us", colors->red,
+		       colors->reset, record.max_round_ns / 1000);
+		printf("\n%sAvg%s roundtrip: %19" PRIu64 " us", colors->yellow,
+		       colors->reset,
+		       record.rounds ? (uint64_t)(record.avg_round_ns /
+						  record.rounds / 1000) :
+				       0);
+		printf("\n%sMin%s roundtrip: %19" PRIu64 " us", colors->green,
+		       colors->reset, record.min_round_ns / 1000);
+	}
+	printf("\n%s====================================================%s\n",
+	       colors->magenta, colors->reset);
+}
+
+void
+l2reflect_stats_loop(void)
+{
+	while (!(l2reflect_state & (S_LOCAL_TERM | S_REMOTE_TERM))) {
+		print_stats();
+		if (l2reflect_hist && l2reflect_output_hist) {
+			output_histogram_snapshot();
+			l2reflect_output_hist = 0;
+		}
+		rte_delay_us_sleep(1000000);
+	}
+}
+
+char *
+serialize_histogram(__rte_unused const struct stats *record)
+{
+#ifndef RTE_HAS_JANSSON
+	return strdup("to print histogram, build with jansson support");
+#else
+	char *str = NULL;
+	char key[8];
+	unsigned int i;
+	json_t *hist0, *cpu0, *all_cpus, *output;
+
+	output = json_object();
+	/* version: 1 */
+	json_object_set_new(output, "version", json_integer(1));
+
+	/* cpu 0 histogram */
+	hist0 = json_object();
+	for (i = 0; i < record->hist_size; ++i) {
+		/* only log positive numbers to meet jitterplot format */
+		if (record->hist[i] != 0) {
+			snprintf(key, 8, "%u", i * hist_bucket_usec);
+			json_object_set(hist0, key,
+					json_integer(record->hist[i]));
+		}
+	}
+
+	/* in case of empty histogram, set these values to zero */
+	const json_int_t min_round_us =
+		record->rounds ? record->min_round_ns / 1000 : 0;
+	const json_int_t avg_round_us =
+		record->rounds ? record->avg_round_ns / record->rounds / 1000 : 0;
+	const json_int_t max_round_us =
+		record->rounds ? record->max_round_ns / 1000 : 0;
+
+	/* cpu 0 stats */
+	cpu0 = json_object();
+	json_object_set_new(cpu0, "histogram", hist0);
+	json_object_set_new(cpu0, "count", json_integer(record->rounds));
+	json_object_set_new(cpu0, "min", json_integer(min_round_us));
+	json_object_set_new(cpu0, "max", json_integer(max_round_us));
+	json_object_set_new(cpu0, "avg", json_integer(avg_round_us));
+
+	/* combine objects */
+	all_cpus = json_object();
+	json_object_set_new(all_cpus, "0", cpu0);
+	json_object_set_new(output, "cpu", all_cpus);
+
+	str = json_dumps(output, JSON_ENSURE_ASCII | JSON_INDENT(2));
+
+	/* cleanup */
+	json_decref(output);
+
+	return str;
+#endif
+}
+
+const char *
+runstate_tostring(int s)
+{
+	switch (s) {
+	case S_ELECT_LEADER:
+		return "Electing";
+	case S_RESET_TRX:
+		return "Resetting";
+	case S_RUNNING:
+		return "Running";
+	case S_LOCAL_TERM:
+		return "Term. local";
+	case S_REMOTE_TERM:
+		return "Term. remote";
+	default:
+		return "Preparing";
+	}
+}
diff --git a/app/l2reflect/stats.h b/app/l2reflect/stats.h
new file mode 100644
index 0000000000..7f3dd9fffb
--- /dev/null
+++ b/app/l2reflect/stats.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2020 Siemens AG
+ */
+#ifndef _L2REFLECT_STATS_H_
+#define _L2REFLECT_STATS_H_
+#include <stdint.h>
+#include <stdatomic.h>
+#include <limits.h>
+
+#include <rte_ethdev.h>
+
+#include "l2reflect.h"
+
+#define MIN_INITIAL ULONG_MAX
+#define HIST_NUM_BUCKETS_DEFAULT 128
+
+/* runtime statistics */
+struct stats {
+	uint64_t max_round_ns;
+	uint64_t min_round_ns;
+	uint64_t rounds;
+	uint64_t timeouts;
+	double avg_round_ns;
+	unsigned int hist_size;
+	/* each slot is 10us */
+	uint64_t *hist;
+	struct timespec time_start;
+};
+
+/* size of each histogram bucket in usec */
+extern unsigned int hist_bucket_usec;
+extern struct stats record;
+extern char *hist_filename;
+
+void
+init_record(void);
+void
+cleanup_record(void);
+
+void
+l2reflect_stats_loop(void);
+
+/*
+ * Write the histogram to file / stdio without any locking.
+ * When called during the measurement, values are approximations
+ * (racy reads).
+ */
+void
+output_histogram_snapshot(void);
+
+/* Print out statistics on packets dropped */
+void
+print_stats(void);
+
+/*
+ * get a JSON representation of the record
+ */
+char *
+serialize_histogram(const struct stats *record);
+
+/*
+ * get a string representation of the current runstate
+ */
+const char *
+runstate_tostring(int s);
+
+#endif /* _L2REFLECT_STATS_H_ */
diff --git a/app/l2reflect/utils.c b/app/l2reflect/utils.c
new file mode 100644
index 0000000000..4116b986d2
--- /dev/null
+++ b/app/l2reflect/utils.c
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2021 Siemens AG
+ */
+
+#include <rte_ethdev.h>
+#include <rte_log.h>
+#include <rte_ethdev.h>
+
+#include "utils.h"
+#include "l2reflect.h"
+
+void
+assert_link_status(int port_id)
+{
+	struct rte_eth_link link;
+	uint8_t rep_cnt = MAX_REPEAT_TIMES;
+	int link_get_err = -EINVAL;
+
+	memset(&link, 0, sizeof(link));
+	do {
+		link_get_err = rte_eth_link_get_nowait(port_id, &link);
+		if (link_get_err == 0 && link.link_status == RTE_ETH_LINK_UP)
+			break;
+		rte_delay_ms(CHECK_INTERVAL);
+		RTE_LOG(INFO, L2REFLECT, "Link not ready yet, try again...\n");
+	} while (--rep_cnt && (l2reflect_state != S_LOCAL_TERM));
+
+	if (link_get_err < 0)
+		rte_exit(EXIT_FAILURE, "error: link get is failing: %s\n",
+			 rte_strerror(-link_get_err));
+	if (link.link_status == RTE_ETH_LINK_DOWN)
+		rte_exit(EXIT_FAILURE, "error: link is still down\n");
+
+	const char *linkspeed_str = rte_eth_link_speed_to_str(link.link_speed);
+	RTE_LOG(INFO, L2REFLECT,
+		"Link status on port %d: speed: %s, duplex: %s\n",
+		port_id, linkspeed_str,
+		link.link_duplex == RTE_ETH_LINK_FULL_DUPLEX ? "full" : "half");
+}
+
+uint32_t
+eth_dev_get_overhead_len(uint32_t max_rx_pktlen, uint16_t max_mtu)
+{
+	uint32_t overhead_len;
+	if (max_mtu != UINT16_MAX && max_rx_pktlen > max_mtu)
+		overhead_len = max_rx_pktlen - max_mtu;
+	else
+		overhead_len = RTE_ETHER_HDR_LEN + RTE_ETHER_CRC_LEN;
+	return overhead_len;
+}
+
+int
+config_port_max_pkt_len(struct rte_eth_conf *conf,
+						struct rte_eth_dev_info *dev_info)
+{
+	uint32_t overhead_len;
+	if (l2reflect_pkt_bytes < RTE_ETHER_MIN_LEN ||
+		l2reflect_pkt_bytes > MAX_JUMBO_PKT_LEN)
+		return -1;
+	overhead_len = eth_dev_get_overhead_len(dev_info->max_rx_pktlen,
+		dev_info->max_mtu);
+	conf->rxmode.mtu = MAX(l2reflect_pkt_bytes - overhead_len,
+			       dev_info->min_mtu);
+	if (conf->rxmode.mtu > RTE_ETHER_MTU)
+		conf->txmode.offloads |= RTE_ETH_TX_OFFLOAD_MULTI_SEGS;
+	return 0;
+}
diff --git a/app/l2reflect/utils.h b/app/l2reflect/utils.h
new file mode 100644
index 0000000000..177ad8cda6
--- /dev/null
+++ b/app/l2reflect/utils.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2021 Siemens AG
+ */
+
+#ifndef _L2REFLECT_UTILS_H_
+#define _L2REFLECT_UTILS_H_
+
+#define MAX_REPEAT_TIMES 30
+#define CHECK_INTERVAL 2000
+
+void assert_link_status(int port_id);
+
+uint32_t
+eth_dev_get_overhead_len(uint32_t max_rx_pktlen, uint16_t max_mtu);
+
+int
+config_port_max_pkt_len(struct rte_eth_conf *conf,
+			struct rte_eth_dev_info *dev_info);
+
+#endif /* _L2REFLECT_UTILS_H_ */
diff --git a/app/meson.build b/app/meson.build
index 0ea04cadeb..3593322ab2 100644
--- a/app/meson.build
+++ b/app/meson.build
@@ -3,6 +3,7 @@
 
 apps = [
         'dumpcap',
+        'l2reflect',
         'pdump',
         'proc-info',
         'test-acl',
-- 
2.30.2