[2/2] Add l2reflect measurement application

diff --git a/app/l2reflect/colors.c b/app/l2reflect/colors.c
new file mode 100644
index 000000000..af881d878
--- /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 000000000..82d33a8b8
--- /dev/null
+++ b/app/l2reflect/colors.h
@@ -0,0 +1,19 @@ 
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2020 Siemens AG
+ */
+#ifndef _COLORS_H_
+#define _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 /* _COLORS_H_ */
diff --git a/app/l2reflect/l2reflect.h b/app/l2reflect/l2reflect.h
new file mode 100644
index 000000000..e7b19d537
--- /dev/null
+++ b/app/l2reflect/l2reflect.h
@@ -0,0 +1,48 @@ 
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2020 Siemens AG
+ */
+#ifndef _L2REFLECT_H_
+#define _L2REFLECT_H_
+#define MAGIC_TRACE_PAYLOAD 0xd00faffeaffed00full
+/* IEEE Std 802 - Local Experimental Ethertype */
+#define ETHER_TYPE_L2REFLECT 0x88B5
+/* Used to compare MAC addresses. */
+#define MAC_ADDR_CMP 0xFFFFFFFFFFFFull
+
+enum {
+	TRACE_TYPE_DATA,
+	TRACE_TYPE_HELO,
+	TRACE_TYPE_EHLO,
+	TRACE_TYPE_RSET,
+	TRACE_TYPE_QUIT,
+};
+
+struct my_magic_packet {
+	struct rte_ether_hdr eth;
+	uint8_t type;
+	uint64_t magic;
+	uint64_t breakval;
+};
+
+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 atomic_int l2reflect_output_hist;
+extern uint64_t l2reflect_sleep_msec;
+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_H_ */
diff --git a/app/l2reflect/main.c b/app/l2reflect/main.c
new file mode 100644
index 000000000..23ace81a5
--- /dev/null
+++ b/app/l2reflect/main.c
@@ -0,0 +1,907 @@ 
+/* 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
+ * - SIGHUB/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 <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 <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.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_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 "colors.h"
+#include "stats.h"
+
+#define RTE_LOGTYPE_L2REFLECT RTE_LOGTYPE_USER1
+
+#define NSEC_PER_SEC 1000000000
+
+#define MBUF_SIZE (2048 + sizeof(struct rte_mbuf) + RTE_PKTMBUF_HEADROOM)
+#define NB_MBUF 2047
+
+#define MAX_PKT_BURST 32
+/* warmup a few round before starting the measurement */
+#define WARMUP_ROUNDS 42
+
+#define MAX(x, y) (((x) > (y)) ? (x) : (y))
+#define MIN(x, y) (((x) < (y)) ? (x) : (y))
+
+int l2reflect_hist;
+atomic_int l2reflect_output_hist;
+uint64_t l2reflect_sleep_msec;
+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,
+	l2reflect_interrupt, trace_fd;
+
+static atomic_int sleep_start;
+
+static uint64_t rounds;
+static int quiet, disable_int, priority, policy, l2reflect_mlock,
+	l2reflect_interrupt, trace_fd;
+
+/* Configurable number of RX/TX ring descriptors */
+#define RTE_TEST_RX_DESC_DEFAULT 128
+#define RTE_TEST_TX_DESC_DEFAULT 512
+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 = ETH_MQ_TX_NONE,
+	},
+};
+
+static uint32_t l2reflect_q;
+static uint64_t l2reflect_break_usec = UINT64_MAX;
+static uint64_t l2reflect_break_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] [-r] [-f] [-l]"
+	       "[-s] [-q] [-d] [-S] [-i MSEC] [-c]\n"
+	       "  -p PORT: port to configure\n"
+	       "  -P PRIO: scheduling priority to use\n"
+	       "  -b USEC: break when latency > USEC\n"
+	       "  -r: scheduling policy SCHED_RR\n"
+	       "  -f: scheduling policy SCHED_FIFO\n"
+	       "  -l: lock memory (mlockall)\n"
+	       "  -s: send one packet on startup\n"
+	       "  -q: quiet, do not print stats\n"
+#ifdef HAS_SYS_IO
+	       "  -d: die die die cli\n"
+#endif
+	       "  -H USEC: create histogram of latencies with USEC time slices\n"
+	       "  -F FILE: write histogram to file\n"
+	       "  -S: start processing threads in sleep, wake with SIGUSR2\n"
+	       "  -i MSEC: use interrupts instead of polling (cont. on interrupt or after MSEC)\n"
+	       "  -c: disable colored output\n",
+	       prgname);
+}
+
+/* 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:F:i:sqdrflSc", 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 'F':
+			hist_filename = strndup(optarg, 128);
+			break;
+		case 'i':
+			l2reflect_interrupt = 1;
+			l2reflect_sleep_msec = strtoul(optarg, NULL, 10);
+			break;
+		case 'c':
+			opt_colors = 0;
+			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;
+}
+
+__rte_format_printf(1, 0)
+static void
+trace_write(const char *fmt, ...)
+{
+	va_list ap;
+	char buf[256];
+	int n, err;
+
+	if (trace_fd == 0)
+		trace_fd = open("/sys/kernel/debug/tracing/trace_marker",
+				O_WRONLY);
+	if (trace_fd < 0)
+		return;
+
+	va_start(ap, fmt);
+	n = vsnprintf(buf, 256, fmt, ap);
+	va_end(ap);
+
+	err = write(trace_fd, buf, n);
+	assert(err >= 1);
+}
+
+/* Send a burst of one packet */
+static 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;
+
+	ret = rte_eth_tx_burst(port, l2reflect_q, m, 1);
+	if (unlikely(ret < 1)) {
+		rte_pktmbuf_free(*m);
+	} else {
+		if (type == TRACE_TYPE_DATA) {
+			clock_gettime(CLOCK_MONOTONIC, &last_sent);
+			l2reflect_state = S_RUNNING;
+		}
+	}
+	return 0;
+}
+
+static 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->s_addr, &eth->d_addr);
+	/* src addr */
+	rte_ether_addr_copy(&l2reflect_port_eth_addr, &eth->s_addr);
+
+	if ((eth->ether_type == rte_cpu_to_be_16(ETHER_TYPE_L2REFLECT)) &&
+	    (pkt->magic == MAGIC_TRACE_PAYLOAD)) {
+		/* and the native one */
+		trace_write("sending traced packet\n");
+	}
+
+	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;
+
+	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 (l2reflect_state != S_ELECT_LEADER)
+		rte_ether_addr_copy(&l2reflect_remote_eth_addr, &eth->d_addr);
+	else
+		rte_ether_addr_copy(&ether_bcast_addr, &eth->d_addr);
+
+	/* src addr */
+	rte_ether_addr_copy(&l2reflect_port_eth_addr, &eth->s_addr);
+	eth->ether_type = rte_cpu_to_be_16(ETHER_TYPE_L2REFLECT);
+
+	m->data_len = 64;
+	m->nb_segs = 1;
+	m->pkt_len = 64;
+	m->l2_len = sizeof(struct rte_ether_hdr);
+
+	pkt = (struct my_magic_packet *)eth;
+	pkt->type = type;
+	pkt->breakval = l2reflect_break_usec;
+
+	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[32];
+	char mac_dst_str[32];
+
+	printf("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), &eth->s_addr);
+	rte_ether_format_addr(mac_dst_str, sizeof(mac_dst_str), &eth->d_addr);
+	printf("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 **bufs,
+	unsigned int nb_rx,
+	unsigned int data_only)
+{
+	struct rte_ether_hdr *eth;
+	struct my_magic_packet *pkt;
+	unsigned int i, ret;
+
+	ret = 0;
+	for (i = 0; i < nb_rx; i++) {
+		eth = rte_pktmbuf_mtod(bufs[i], struct rte_ether_hdr *);
+		/*
+		 * if the packet is not from our partner
+		 * (and we already have a partner), drop it
+		 */
+		if (l2reflect_state != S_ELECT_LEADER &&
+		    !rte_is_same_ether_addr(&eth->s_addr,
+					    &l2reflect_remote_eth_addr))
+			goto drop;
+
+		/* check for the l2reflect ether type */
+		if (eth->ether_type != rte_cpu_to_be_16(ETHER_TYPE_L2REFLECT))
+			goto drop;
+
+		/* check if the message is a control message */
+		pkt = (struct my_magic_packet *)eth;
+		if (data_only && (pkt->type != TRACE_TYPE_DATA &&
+				  pkt->type != TRACE_TYPE_RSET &&
+				  pkt->type != TRACE_TYPE_QUIT))
+			goto drop;
+
+		bufs[ret++] = bufs[i];
+		continue;
+drop:
+		rte_pktmbuf_free(bufs[i]);
+	}
+
+	return ret;
+}
+
+/*
+ * 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 my_magic_packet *pkt;
+	uint64_t my_mac, other_mac, breakval;
+	unsigned int i, nb_rx;
+	int i_win;
+	int searching = 1;
+
+	other_mac = 0ULL;
+	my_mac = 0ULL;
+	breakval = 0;
+
+	while (l2reflect_state == S_ELECT_LEADER) {
+		nb_rx = rte_eth_rx_burst(portid, l2reflect_q, pkts_burst,
+					 MAX_PKT_BURST);
+		nb_rx = l2reflect_rx_filter(pkts_burst, nb_rx, 0);
+		for (i = 0; i < nb_rx && searching; i++) {
+			eth = rte_pktmbuf_mtod(pkts_burst[i],
+					       struct rte_ether_hdr *);
+			pkt = (struct my_magic_packet *)eth;
+			if (pkt->type == TRACE_TYPE_HELO ||
+			    pkt->type == TRACE_TYPE_EHLO) {
+				l2reflect_state = S_RUNNING;
+				rte_ether_addr_copy(&eth->s_addr,
+						    &l2reflect_remote_eth_addr);
+				rte_ether_addr_copy(
+					&eth->s_addr,
+					(struct rte_ether_addr *)&other_mac);
+				rte_ether_addr_copy(
+					&l2reflect_port_eth_addr,
+					(struct rte_ether_addr *)&my_mac);
+				breakval = pkt->breakval;
+				/* break, but cleanup */
+				searching = 0;
+			}
+			/* we got a HELO packet, respond with EHLO */
+			if (pkt->type == TRACE_TYPE_HELO) {
+				m = l2reflect_new_pkt(TRACE_TYPE_EHLO);
+				RTE_LOG(INFO, L2REFLECT, "found one EHLO\n");
+				l2reflect_send_packet(&m,
+						      l2reflect_port_number);
+			}
+			rte_pktmbuf_free(pkts_burst[i]);
+		}
+		m = l2reflect_new_pkt(TRACE_TYPE_HELO);
+		RTE_LOG(INFO, L2REFLECT, "looking for player HELO\n");
+		l2reflect_send_packet(&m, l2reflect_port_number);
+		usleep(500000);
+	}
+	/* leave election logic */
+	if (l2reflect_state != S_RUNNING)
+		return 0;
+
+	if (my_mac == other_mac)
+		rte_exit(EXIT_FAILURE, "talking to myself ... confused\n");
+
+	/* the one with the bigger MAC is the leader */
+	i_win = (my_mac > other_mac);
+
+	RTE_LOG(INFO, L2REFLECT, "i am the \"%s\"\n", i_win ? "rick" : "morty");
+
+	/* looser takes tracing break value from winner */
+	if (!i_win)
+		l2reflect_break_usec = breakval;
+
+	return i_win;
+}
+
+/*
+ * add the measured time diff to the statistics.
+ * return false if threshold is hit
+ */
+static inline bool
+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) {
+		if (l2reflect_hist) {
+			const uint64_t bucket =
+				MIN(diff / (hist_bucket_usec * 1000),
+				    HIST_CAP_BUCKET);
+			record.hist[bucket]++;
+		}
+
+		record.avg_round += (double)diff;
+		if (diff < record.min_round)
+			record.min_round = diff;
+		if (diff > record.max_round) {
+			record.max_round = diff;
+			if (l2reflect_break_usec &&
+				(record.max_round >
+					l2reflect_break_usec *
+						1000))
+				return false;
+		}
+	}
+	return true;
+}
+
+/*
+ * process a single packet.
+ * return false if latency threshold is hit
+ */
+static inline bool
+process_packet(
+	struct my_magic_packet *pkt,
+	uint64_t *diff)
+{
+	if (pkt->type == TRACE_TYPE_DATA) {
+		clock_gettime(CLOCK_MONOTONIC, &last_recv);
+		*diff = calcdiff_ns(last_recv, last_sent);
+		if (!add_to_record(*diff))
+			return false;
+	}
+	if (pkt->magic == MAGIC_TRACE_PAYLOAD) {
+		/* and the native one */
+		trace_write("received traced packet\n");
+	}
+	return true;
+}
+
+/* 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;
+	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);
+
+restart:
+	init_record();
+	l2reflect_state = S_ELECT_LEADER;
+	sender = elect_leader(portid);
+
+	/* we are the sender so we bring one ball into the game */
+	if (sender)
+		l2reflect_new_ball();
+
+	while (l2reflect_state == S_RUNNING) {
+		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);
+
+		/* TODO use drivers/hw to filter mac */
+		nb_rx = l2reflect_rx_filter(pkts_burst, nb_rx, 1);
+
+		/* remote is telling us to reset or stop */
+		if (nb_rx) {
+			eth = rte_pktmbuf_mtod(pkts_burst[0],
+					       struct rte_ether_hdr *);
+			pkt = (struct my_magic_packet *)eth;
+			if (eth->ether_type ==
+				rte_cpu_to_be_16(ETHER_TYPE_L2REFLECT)) {
+				if (pkt->type == TRACE_TYPE_RSET) {
+					rte_pktmbuf_free(pkts_burst[0]);
+					goto restart;
+				}
+				if (pkt->type == TRACE_TYPE_QUIT) {
+					l2reflect_state = S_REMOTE_TERM;
+					break;
+				}
+			}
+		}
+
+		if (l2reflect_state == S_RUNNING && nb_rx) {
+			eth = rte_pktmbuf_mtod(pkts_burst[0],
+					struct rte_ether_hdr *);
+			pkt = (struct my_magic_packet *)eth;
+			if (eth->ether_type ==
+				rte_cpu_to_be_16(ETHER_TYPE_L2REFLECT)) {
+				if (!process_packet(pkt, &diff))
+					break;
+			}
+		}
+		for (j = 0; j < nb_rx; j++) {
+			m = pkts_burst[j];
+			rte_prefetch0(rte_pktmbuf_mtod(m, void *));
+			l2reflect_simple_forward(m);
+		}
+	}
+	const int state_cpy = l2reflect_state;
+	switch (state_cpy) {
+	case S_RESET_TRX:
+		l2reflect_send_reset();
+		l2reflect_state = S_ELECT_LEADER;
+	case S_ELECT_LEADER:
+		goto restart;
+	}
+
+	if (state_cpy == S_LOCAL_TERM) {
+		l2reflect_send_quit();
+		if (record.max_round > l2reflect_break_usec) {
+			printf("hit latency threshold (%" PRIu64
+			       ".%03u > %" PRIu64 ")\n",
+			       diff / 1000, (unsigned int)(diff % 1000),
+			       l2reflect_break_usec);
+		}
+	} else if (state_cpy == S_REMOTE_TERM) {
+		printf("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) {
+		printf("Sleeping and waiting for SIGCONT\n");
+		while (sleep_start)
+			usleep(10000);
+
+		printf("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;
+	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[32];
+
+	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();
+	/* 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());
+	printf("About to create mempool \"%s\"\n", mempool_name);
+	/* create the mbuf pool */
+	l2reflect_pktmbuf_pool =
+		rte_mempool_create(mempool_name, NB_MBUF, MBUF_SIZE,
+			MAX_PKT_BURST, sizeof(struct rte_pktmbuf_pool_private),
+			rte_pktmbuf_pool_init, NULL,
+			rte_pktmbuf_init, NULL, rte_socket_id(), 0);
+
+	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);
+	printf("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);
+	printf("Initializing port %u... ", l2reflect_port_number);
+	fflush(stdout);
+
+	if (l2reflect_interrupt)
+		port_conf.intr_conf.rxq = 1;
+	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);
+
+	rte_eth_macaddr_get(l2reflect_port_number, &l2reflect_port_eth_addr);
+
+	/* init RX queues */
+	fflush(stdout);
+	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 */
+	fflush(stdout);
+	ret = rte_eth_tx_queue_setup(
+		l2reflect_port_number, 0, nb_txd,
+		rte_eth_dev_socket_id(l2reflect_port_number), NULL);
+	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_promiscuous_enable(l2reflect_port_number);
+
+	rte_ether_format_addr(mac_str, sizeof(mac_str),
+			      &l2reflect_port_eth_addr);
+	printf("Port %u, MAC address: %s\n\n",
+	       (unsigned int)l2reflect_port_number, mac_str);
+
+	/*
+	 * in quiet mode the master executes the main packet loop
+	 * otherwise the one slave does it and the master prints stats
+	 */
+	if (quiet) {
+		assert(rte_lcore_count() == 1);
+#ifdef HAS_SYS_IO
+		if (disable_int) {
+			iopl(3);
+			asm("cli");
+		}
+#endif
+		l2reflect_launch_one_lcore(NULL);
+	} else {
+		assert(rte_lcore_count() == 2);
+		/* the slave reflects the packets */
+		RTE_LCORE_FOREACH_SLAVE(lcore_id)
+		{
+			rte_eal_remote_launch(l2reflect_launch_one_lcore, NULL,
+					      lcore_id);
+		}
+
+		/* the master prints the stats */
+		init_record();
+		l2reflect_stats_loop();
+		rte_eal_mp_wait_lcore();
+	}
+	rte_eal_cleanup();
+
+	if (l2reflect_hist)
+		output_histogram_snapshot();
+
+	cleanup_record();
+
+	if (trace_fd)
+		close(trace_fd);
+
+	return 0;
+}
diff --git a/app/l2reflect/meson.build b/app/l2reflect/meson.build
new file mode 100644
index 000000000..d5cfa906f
--- /dev/null
+++ b/app/l2reflect/meson.build
@@ -0,0 +1,25 @@ 
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2020 Siemens AG
+
+# meson file, for building this example as part of a main DPDK build.
+cc = meson.get_compiler('c')
+
+jansson = dependency('libjansson', required: false)
+
+if not jansson.found()
+    jansson = cc.find_library('jansson', required: false)
+endif
+
+if not is_linux
+        build = false
+endif
+if cc.has_header('sys/io.h')
+    cflags += '-DHAS_SYS_IO'
+endif
+
+sources = files('main.c', 'stats.c', 'colors.c')
+deps += ['ethdev']
+if jansson.found()
+    ext_deps += jansson
+    cflags += '-DRTE_HAS_JANSSON'
+endif
diff --git a/app/l2reflect/stats.c b/app/l2reflect/stats.c
new file mode 100644
index 000000000..3f2ef9b1e
--- /dev/null
+++ b/app/l2reflect/stats.c
@@ -0,0 +1,178 @@ 
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2020 Siemens AG
+ */
+#include <stdio.h>
+#include <sys/types.h>
+#include <unistd.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 = 0;
+	record.min_round = MIN_INITIAL;
+	record.rounds = 0;
+	record.timeouts = 0;
+	record.avg_round = 0;
+	if (l2reflect_hist) {
+		if (!record.hist_size) {
+			record.hist =
+				calloc(HIST_NUM_BUCKETS, sizeof(uint64_t));
+			record.hist_size = HIST_NUM_BUCKETS;
+		} else {
+			memset(record.hist, 0,
+			       record.hist_size * sizeof(uint64_t));
+		}
+	}
+}
+
+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[32];
+	char mac_str_remote[32];
+
+	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);
+
+	/* 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 ---------"
+			"\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 "    (>%9" PRIu64 "ms)",
+			l2reflect_port_number, getpid(), rte_lcore_id(),
+			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, l2reflect_sleep_msec);
+	printf("\n%sPort timing statistics =============================%s",
+	       colors->magenta, colors->reset);
+	if (l2reflect_state == S_ELECT_LEADER ||
+		record.min_round == 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 / 1000);
+		printf("\n%sAvg%s roundtrip: %19" PRIu64 " us", colors->yellow,
+		       colors->reset,
+		       record.rounds ? (uint64_t)(record.avg_round /
+						  record.rounds / 1000) :
+				       0);
+		printf("\n%sMin%s roundtrip: %19" PRIu64 " us", colors->green,
+		       colors->reset, record.min_round / 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;
+		}
+		sleep(1);
+	}
+}
+
+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]));
+		}
+	}
+
+	/* 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(record->min_round));
+	json_object_set_new(cpu0, "max", json_integer(record->max_round));
+	json_object_set_new(
+		cpu0, "avg",
+		json_integer((record->avg_round / record->rounds / 1000)));
+
+	/* 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
+}
diff --git a/app/l2reflect/stats.h b/app/l2reflect/stats.h
new file mode 100644
index 000000000..d13f81a54
--- /dev/null
+++ b/app/l2reflect/stats.h
@@ -0,0 +1,61 @@ 
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2020 Siemens AG
+ */
+#ifndef _STATS_H_
+#define _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 128
+#define HIST_CAP_BUCKET (HIST_NUM_BUCKETS - 1)
+
+/* runtime statistics */
+struct stats {
+	uint64_t max_round;
+	uint64_t min_round;
+	uint64_t rounds;
+	uint64_t timeouts;
+	double avg_round;
+	unsigned int hist_size;
+	/* each slot is 10us */
+	uint64_t *hist;
+};
+
+/* 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);
+
+#endif /* _STATS_H_ */
diff --git a/app/meson.build b/app/meson.build
index ab43a8403..52d119f7d 100644
--- a/app/meson.build
+++ b/app/meson.build
@@ -6,6 +6,7 @@  if is_windows
 endif
 
 apps = [
+	'l2reflect',
 	'pdump',
 	'proc-info',
 	'test-acl',