examples/skeleton/basicfwd.c

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

#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>

#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 = ETHER_MAX_LEN,
                .ignore_offload_bitfield = 1,
        },
};

/* 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.
 */
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;

        rte_eth_dev_info_get(port, &dev_info);
        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.txq_flags = ETH_TXQ_FLAGS_IGNORE;
        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;
        }

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

        /* Display the port MAC address. */
        struct ether_addr addr;
        rte_eth_macaddr_get(port, &addr);
        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. */
        rte_eth_promiscuous_enable(port);

        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_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());

        /* 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;

                        /* 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]);
                        }
                }
        }
}

/*
 * 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;

        /* 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 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. */
        mbuf_pool = rte_pktmbuf_pool_create("MBUF_POOL", NUM_MBUFS * nb_ports,
                MBUF_CACHE_SIZE, 0, RTE_MBUF_DEFAULT_BUF_SIZE, rte_socket_id());

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

        /* 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. */
        lcore_main();

        return 0;
}