/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2015 Intel Corporation
 */

#include <stdint.h>
#include <stdlib.h>
#include <inttypes.h>
#include <rte_eal.h>
#include <rte_ethdev.h>
#include <rte_cycles.h>
#include <rte_lcore.h>
#include <rte_mbuf.h>

#define RX_RING_SIZE 1024
#define TX_RING_SIZE 1024

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

/* basicfwd.c: Basic DPDK skeleton forwarding example. */

/*
 * Initializes a given port using global settings and with the RX buffers
 * coming from the mbuf_pool passed as a parameter.
 */

/* Main functional part of port initialization. 8< */
static inline int
port_init(uint16_t port, struct rte_mempool *mbuf_pool)
{
	struct rte_eth_conf port_conf;
	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;

	memset(&port_conf, 0, sizeof(struct rte_eth_conf));

	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 & RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE)
		port_conf.txmode.offloads |=
			RTE_ETH_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;
	}

	/* Starting Ethernet port. 8< */
	retval = rte_eth_dev_start(port);
	/* >8 End of starting of ethernet 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, RTE_ETHER_ADDR_BYTES(&addr));

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

	return 0;
}
/* >8 End of main functional part of port initialization. */

/*
 * The lcore main. This is the main thread that does the work, reading from
 * an input port and writing to an output port.
 */

 /* Basic forwarding application lcore. 8< */
static __rte_noreturn void
lcore_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 forwarding packets. [Ctrl+C to quit]\n",
			rte_lcore_id());

	/* Main work of application loop. 8< */
	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;

			/* Send burst of TX packets, to second port of pair. */
			const uint16_t nb_tx = rte_eth_tx_burst(port ^ 1, 0,
					bufs, nb_rx);

			/* Free any unsent packets. */
			if (unlikely(nb_tx < nb_rx)) {
				uint16_t buf;
				for (buf = nb_tx; buf < nb_rx; buf++)
					rte_pktmbuf_free(bufs[buf]);
			}
		}
	}
	/* >8 End of loop. */
}
/* >8 End Basic forwarding application lcore. */

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

	/* Initializion the Environment Abstraction Layer (EAL). 8< */
	int ret = rte_eal_init(argc, argv);
	if (ret < 0)
		rte_exit(EXIT_FAILURE, "Error with EAL initialization\n");
	/* >8 End of initialization the Environment Abstraction Layer (EAL). */

	argc -= ret;
	argv += ret;

	/* Check that there is an even number of ports to send/receive on. */
	nb_ports = rte_eth_dev_count_avail();
	if (nb_ports < 2 || (nb_ports & 1))
		rte_exit(EXIT_FAILURE, "Error: number of ports must be even\n");

	/* Creates a new mempool in memory to hold the mbufs. */

	/* Allocates mempool to hold the mbufs. 8< */
	mbuf_pool = rte_pktmbuf_pool_create("MBUF_POOL", NUM_MBUFS * nb_ports,
		MBUF_CACHE_SIZE, 0, RTE_MBUF_DEFAULT_BUF_SIZE, rte_socket_id());
	/* >8 End of allocating mempool to hold mbuf. */

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

	/* Initializing all ports. 8< */
	RTE_ETH_FOREACH_DEV(portid)
		if (port_init(portid, mbuf_pool) != 0)
			rte_exit(EXIT_FAILURE, "Cannot init port %"PRIu16 "\n",
					portid);
	/* >8 End of initializing all ports. */

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

	/* Call lcore_main on the main core only. Called on single lcore. 8< */
	lcore_main();
	/* >8 End of called on single lcore. */

	/* clean up the EAL */
	rte_eal_cleanup();

	return 0;
}