/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2021+ Vitaliy Filippov
 */

// DPDK-based ping-pong
// USAGE:
// Host 1: RECV=1 ./pingpong
// Host 2: ./pingpong

#include <stdint.h>
#include <inttypes.h>
#include <rte_eal.h>
#include <rte_ethdev.h>
#include <rte_cycles.h>
#include <rte_lcore.h>
#include <rte_mbuf.h>
#include <rte_ether.h>
#include <rte_ip.h>
#include <rte_udp.h>

#define RX_RING_SIZE 1024
#define TX_RING_SIZE 1024

#define NUM_MBUFS 8191
#define MBUF_CACHE_SIZE 250
#define BURST_SIZE 32

static const struct rte_eth_conf port_conf_default = {
	.rxmode = {
		.max_rx_pkt_len = RTE_ETHER_MAX_LEN,
	},
};

/*
 * Initializes a given port using global settings and with the RX buffers
 * coming from the mbuf_pool passed as a parameter.
 */
static inline int
port_init(uint16_t port, struct rte_mempool *mbuf_pool)
{
	struct rte_eth_conf port_conf = port_conf_default;
	const uint16_t rx_rings = 1, tx_rings = 1;
	uint16_t nb_rxd = RX_RING_SIZE;
	uint16_t nb_txd = TX_RING_SIZE;
	int retval;
	uint16_t q;
	struct rte_eth_dev_info dev_info;
	struct rte_eth_txconf txconf;

	if (!rte_eth_dev_is_valid_port(port))
		return -1;

	retval = rte_eth_dev_info_get(port, &dev_info);
	if (retval != 0) {
		printf("Error during getting device (port %u) info: %s\n",
				port, strerror(-retval));
		return retval;
	}

	if (dev_info.tx_offload_capa & DEV_TX_OFFLOAD_MBUF_FAST_FREE)
		port_conf.txmode.offloads |=
			DEV_TX_OFFLOAD_MBUF_FAST_FREE;

	/* Configure the Ethernet device. */
	retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf);
	if (retval != 0)
		return retval;

	retval = rte_eth_dev_adjust_nb_rx_tx_desc(port, &nb_rxd, &nb_txd);
	if (retval != 0)
		return retval;

	/* Allocate and set up 1 RX queue per Ethernet port. */
	for (q = 0; q < rx_rings; q++) {
		retval = rte_eth_rx_queue_setup(port, q, nb_rxd,
				rte_eth_dev_socket_id(port), NULL, mbuf_pool);
		if (retval < 0)
			return retval;
	}

	txconf = dev_info.default_txconf;
	txconf.offloads = port_conf.txmode.offloads;
	/* Allocate and set up 1 TX queue per Ethernet port. */
	for (q = 0; q < tx_rings; q++) {
		retval = rte_eth_tx_queue_setup(port, q, nb_txd,
				rte_eth_dev_socket_id(port), &txconf);
		if (retval < 0)
			return retval;
	}

	if (9000 > dev_info.max_mtu || 9000 < dev_info.min_mtu) {
		printf("Set MTU failed. MTU:%u is not in valid range, min:%u - max:%u\n",
			9000, dev_info.min_mtu, dev_info.max_mtu);
		return -1;
	}
	retval = rte_eth_dev_set_mtu(port, 9000);
	if (retval < 0) {
		printf("Set MTU failed. retval=%d\n", retval);
		return retval;
	}

	/* Start the Ethernet port. */
	retval = rte_eth_dev_start(port);
	if (retval < 0)
		return retval;

	/* Display the port MAC address. */
	struct rte_ether_addr addr;
	retval = rte_eth_macaddr_get(port, &addr);
	if (retval != 0)
		return retval;

	printf("Port %u MAC: %02" PRIx8 " %02" PRIx8 " %02" PRIx8
			   " %02" PRIx8 " %02" PRIx8 " %02" PRIx8 "\n",
			port,
			addr.addr_bytes[0], addr.addr_bytes[1],
			addr.addr_bytes[2], addr.addr_bytes[3],
			addr.addr_bytes[4], addr.addr_bytes[5]);

	/* Enable RX in promiscuous mode for the Ethernet device. */
	retval = rte_eth_promiscuous_enable(port);
	if (retval != 0)
		return retval;

	return 0;
}

/*
 * The lcore main. This is the main thread that does the work, reading from
 * an input port and writing to an output port.
 */
static __attribute__((noreturn)) void
lcore_recv_main(void)
{
	uint16_t port;

	/*
	 * Check that the port is on the same NUMA node as the polling thread
	 * for best performance.
	 */
	RTE_ETH_FOREACH_DEV(port)
		if (rte_eth_dev_socket_id(port) > 0 &&
				rte_eth_dev_socket_id(port) !=
						(int)rte_socket_id())
			printf("WARNING, port %u is on remote NUMA node to "
					"polling thread.\n\tPerformance will "
					"not be optimal.\n", port);

	printf("\nCore %u echoing packets. [Ctrl+C to quit]\n",
			rte_lcore_id());

	uint16_t buf;
	struct rte_ether_addr s_addr;

	/* Run until the application is quit or killed. */
	for (;;) {
		/*
		 * Receive packets on a port and forward them on the paired
		 * port. The mapping is 0 -> 1, 1 -> 0, 2 -> 3, 3 -> 2, etc.
		 */
		RTE_ETH_FOREACH_DEV(port) {

			/* Get burst of RX packets, from first port of pair. */
			struct rte_mbuf *bufs[BURST_SIZE];
			const uint16_t nb_rx = rte_eth_rx_burst(port, 0,
					bufs, BURST_SIZE);

			if (unlikely(nb_rx == 0))
				continue;

			for (buf = 0; buf < nb_rx; buf++) {
				struct rte_ether_hdr *eth_hdr = rte_pktmbuf_mtod(bufs[buf], struct rte_ether_hdr*);
				s_addr = eth_hdr->s_addr;
				eth_hdr->s_addr = eth_hdr->d_addr;
				eth_hdr->d_addr = s_addr;
			}

			/* Send burst of TX packets, to second port of pair. */
			const uint16_t nb_tx = rte_eth_tx_burst(port, 0,
					bufs, nb_rx);

			/* Free any unsent packets. */
			if (unlikely(nb_tx < nb_rx)) {
				for (buf = nb_tx; buf < nb_rx; buf++)
					rte_pktmbuf_free(bufs[buf]);
			}
		}
	}
}

static struct rte_mempool *mbuf_pool;
static uint64_t lat_count = 0, lat_us = 0, lat_min = 0, lat_max = 0;
static double lat_mean = 0, lat_m2 = 0;

static __attribute__((noreturn)) void
lcore_send_main(void)
{
	uint16_t port;

	/*
	 * Check that the port is on the same NUMA node as the polling thread
	 * for best performance.
	 */
	RTE_ETH_FOREACH_DEV(port)
		if (rte_eth_dev_socket_id(port) > 0 &&
				rte_eth_dev_socket_id(port) !=
						(int)rte_socket_id())
			printf("WARNING, port %u is on remote NUMA node to "
					"polling thread.\n\tPerformance will "
					"not be optimal.\n", port);

	printf("\nCore %u sending echo packets. [Ctrl+C to quit]\n",
			rte_lcore_id());

	struct rte_ether_hdr *eth_hdr;
	struct rte_ether_addr s_addr = {{0xc6,0x47,0x2c,0x07,0x8a,0x24}};
	struct rte_ether_addr d_addr = {{0xbc,0x01,0xa4,0x9b,0x03,0x98}};
	uint16_t ether_type = 0x0a00;
	uint64_t lat_this;

	/* Run until the application is quit or killed. */
	struct timespec ckpt, start, end;
	clock_gettime(CLOCK_REALTIME, &ckpt);
	for (;;) {
		RTE_ETH_FOREACH_DEV(port) {
			clock_gettime(CLOCK_REALTIME, &start);
			struct rte_mbuf *pkt[BURST_SIZE];
			int i;
			for (i = 0; i < 1; i++) {
				pkt[i] = rte_pktmbuf_alloc(mbuf_pool);
				eth_hdr = (struct rte_ether_hdr*)rte_pktmbuf_append(pkt[i], sizeof(struct rte_ether_hdr));
				eth_hdr->d_addr = d_addr;
				eth_hdr->s_addr = s_addr;
				eth_hdr->ether_type = ether_type;
				char *data = rte_pktmbuf_append(pkt[i], 4096);
				memset(data, 0xaa, 4096);
			}
			uint16_t nb_tx = 0;
			while (nb_tx == 0) {
				nb_tx = rte_eth_tx_burst(port, 0, pkt, 1);
			}
			// Receive reply
			pkt[0] = 0;
			uint16_t nb_rx = 0;
			while (nb_rx == 0) {
				nb_rx = rte_eth_rx_burst(port, 0, pkt, BURST_SIZE);
			}
			for (uint16_t buf = 0; buf < nb_rx; buf++)
				rte_pktmbuf_free(pkt[buf]);
			clock_gettime(CLOCK_REALTIME, &end);
			lat_this = (end.tv_sec-start.tv_sec)*1000000 + (end.tv_nsec-start.tv_nsec)/1000;
			lat_count++;
			lat_us += lat_this;
			if (lat_min == 0 || lat_min > lat_this)
				lat_min = lat_this;
			if (lat_max < lat_this)
				lat_max = lat_this;
			double delta = lat_this-lat_mean;
			lat_mean += delta/lat_count;
			lat_m2 += delta*(lat_this-lat_mean);
			if (end.tv_sec > ckpt.tv_sec+5) {
				printf("latency: avg %lu us, min %lu us, max %lu us, stddev %lu us (%lu packets)\n",
					lat_us/lat_count, lat_min, lat_max, (uint64_t)(lat_m2/(lat_count-1)), lat_count);
				lat_count = lat_us = lat_min = lat_max = 0;
				lat_mean = lat_m2 = 0;
				ckpt = end;
			}
		}
	}
}

/*
 * The main function, which does initialization and calls the per-lcore
 * functions.
 */
int
main(int argc, char *argv[])
{
	unsigned nb_ports;
	uint16_t portid;

	/* Initialize the Environment Abstraction Layer (EAL). */
	int ret = rte_eal_init(argc, argv);
	if (ret < 0)
		rte_exit(EXIT_FAILURE, "Error with EAL initialization\n");

	argc -= ret;
	argv += ret;

	/* Check that there is a port to send/receive on. */
	nb_ports = rte_eth_dev_count_avail();
	if (!nb_ports)
		rte_exit(EXIT_FAILURE, "Error: no ports\n");

	/* Creates a new mempool in memory to hold the mbufs. */
	mbuf_pool = rte_pktmbuf_pool_create("MBUF_POOL", NUM_MBUFS * nb_ports,
		MBUF_CACHE_SIZE, 0, 9000, rte_socket_id());

	if (mbuf_pool == NULL)
		rte_exit(EXIT_FAILURE, "Cannot create mbuf pool\n");

	// FIXME: Use only one device
	/* Initialize all ports. */
	RTE_ETH_FOREACH_DEV(portid)
		if (port_init(portid, mbuf_pool) != 0)
			rte_exit(EXIT_FAILURE, "Cannot init port %"PRIu16 "\n",
					portid);

	if (rte_lcore_count() > 1)
		printf("\nWARNING: Too many lcores enabled. Only 1 used.\n");

	/* Call lcore_main on the master core only. */
	if (getenv("RECV"))
		lcore_recv_main();
	else
		lcore_send_main();

	return 0;
}