examples/exception_path/main.c

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2014 Intel Corporation
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <inttypes.h>
#include <string.h>
#include <sys/queue.h>
#include <stdarg.h>
#include <errno.h>
#include <getopt.h>

#include <netinet/in.h>
#include <net/if.h>
#ifdef RTE_EXEC_ENV_LINUX
#include <linux/if_tun.h>
#endif
#include <fcntl.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <signal.h>

#include <rte_common.h>
#include <rte_log.h>
#include <rte_memory.h>
#include <rte_memcpy.h>
#include <rte_eal.h>
#include <rte_per_lcore.h>
#include <rte_launch.h>
#include <rte_atomic.h>
#include <rte_lcore.h>
#include <rte_branch_prediction.h>
#include <rte_interrupts.h>
#include <rte_debug.h>
#include <rte_ether.h>
#include <rte_ethdev.h>
#include <rte_mempool.h>
#include <rte_mbuf.h>
#include <rte_string_fns.h>
#include <rte_cycles.h>

#ifndef APP_MAX_LCORE
#if (RTE_MAX_LCORE > 64)
#define APP_MAX_LCORE 64
#else
#define APP_MAX_LCORE RTE_MAX_LCORE
#endif
#endif

/* Macros for printing using RTE_LOG */
#define RTE_LOGTYPE_APP RTE_LOGTYPE_USER1
#define FATAL_ERROR(fmt, args...)       rte_exit(EXIT_FAILURE, fmt "\n", ##args)
#define PRINT_INFO(fmt, args...)        RTE_LOG(INFO, APP, fmt "\n", ##args)

/* Max ports than can be used (each port is associated with two lcores) */
#define MAX_PORTS               (APP_MAX_LCORE / 2)

/* Max size of a single packet */
#define MAX_PACKET_SZ (2048)

/* Size of the data buffer in each mbuf */
#define MBUF_DATA_SZ (MAX_PACKET_SZ + RTE_PKTMBUF_HEADROOM)

/* Number of mbufs in mempool that is created */
#define NB_MBUF                 8192

/* How many packets to attempt to read from NIC in one go */
#define PKT_BURST_SZ            32

/* How many objects (mbufs) to keep in per-lcore mempool cache */
#define MEMPOOL_CACHE_SZ        PKT_BURST_SZ

/* Number of RX ring descriptors */
#define NB_RXD                  1024

/* Number of TX ring descriptors */
#define NB_TXD                  1024

/*
 * RX and TX Prefetch, Host, and Write-back threshold values should be
 * carefully set for optimal performance. Consult the network
 * controller's datasheet and supporting DPDK documentation for guidance
 * on how these parameters should be set.
 */

/* Options for configuring ethernet port */
static struct rte_eth_conf port_conf = {
    .txmode = {
        .mq_mode = ETH_MQ_TX_NONE,
    },
};

/* Mempool for mbufs */
static struct rte_mempool * pktmbuf_pool = NULL;

/* Mask of enabled ports */
static uint32_t ports_mask = 0;

/* Mask of cores that read from NIC and write to tap */
static uint64_t input_cores_mask = 0;

/* Mask of cores that read from tap and write to NIC */
static uint64_t output_cores_mask = 0;

/* Array storing port_id that is associated with each lcore */
static uint16_t port_ids[APP_MAX_LCORE];

/* Structure type for recording lcore-specific stats */
struct stats {
    uint64_t rx;
    uint64_t tx;
    uint64_t dropped;
} __rte_cache_aligned;

/* Array of lcore-specific stats */
static struct stats lcore_stats[APP_MAX_LCORE];

/* Print out statistics on packets handled */
static void
print_stats(void)
{
    unsigned i;

    printf("\n**Exception-Path example application statistics**\n"
           "=======  ======  ============  ============  ===============\n"
           " Lcore    Port            RX            TX    Dropped on TX\n"
           "-------  ------  ------------  ------------  ---------------\n");
    RTE_LCORE_FOREACH(i) {
        /* limit ourselves to application supported cores only */
        if (i >= APP_MAX_LCORE)
            break;
        printf("%6u %7u %13"PRIu64" %13"PRIu64" %16"PRIu64"\n",
               i, (unsigned)port_ids[i],
               lcore_stats[i].rx, lcore_stats[i].tx,
               lcore_stats[i].dropped);
    }
    printf("=======  ======  ============  ============  ===============\n");
}

/* Custom handling of signals to handle stats */
static void
signal_handler(int signum)
{
    /* When we receive a USR1 signal, print stats */
    if (signum == SIGUSR1) {
        print_stats();
    }

    /* When we receive a USR2 signal, reset stats */
    if (signum == SIGUSR2) {
        memset(&lcore_stats, 0, sizeof(lcore_stats));
        printf("\n**Statistics have been reset**\n");
        return;
    }
}

#ifdef RTE_EXEC_ENV_LINUX
/*
 * Create a tap network interface, or use existing one with same name.
 * If name[0]='\0' then a name is automatically assigned and returned in name.
 */
static int tap_create(char *name)
{
    struct ifreq ifr;
    int fd, ret;

    fd = open("/dev/net/tun", O_RDWR);
    if (fd < 0)
        return fd;

    memset(&ifr, 0, sizeof(ifr));

    /* TAP device without packet information */
    ifr.ifr_flags = IFF_TAP | IFF_NO_PI;

    if (name && *name)
        strlcpy(ifr.ifr_name, name, IFNAMSIZ);

    ret = ioctl(fd, TUNSETIFF, (void *) &ifr);
    if (ret < 0) {
        close(fd);
        return ret;
    }

    if (name)
        strlcpy(name, ifr.ifr_name, IFNAMSIZ);

    return fd;
}
#else
/*
 * Find a free tap network interface, or create a new one.
 * The name is automatically assigned and returned in name.
 */
static int tap_create(char *name)
{
    int i, fd = -1;
    char devname[PATH_MAX];

    for (i = 0; i < 255; i++) {
        snprintf(devname, sizeof(devname), "/dev/tap%d", i);
        fd = open(devname, O_RDWR);
        if (fd >= 0 || errno != EBUSY)
            break;
    }

    if (name)
        snprintf(name, IFNAMSIZ, "tap%d", i);

    return fd;
}
#endif

/* Main processing loop */
static int
main_loop(__attribute__((unused)) void *arg)
{
    const unsigned lcore_id = rte_lcore_id();
    char tap_name[IFNAMSIZ];
    int tap_fd;

    if ((1ULL << lcore_id) & input_cores_mask) {
        /* Create new tap interface */
        snprintf(tap_name, IFNAMSIZ, "tap_dpdk_%.2u", lcore_id);
        tap_fd = tap_create(tap_name);
        if (tap_fd < 0)
            FATAL_ERROR("Could not create tap interface \"%s\" (%d)",
                    tap_name, tap_fd);

        PRINT_INFO("Lcore %u is reading from port %u and writing to %s",
                   lcore_id, (unsigned)port_ids[lcore_id], tap_name);
        fflush(stdout);
        /* Loop forever reading from NIC and writing to tap */
        for (;;) {
            struct rte_mbuf *pkts_burst[PKT_BURST_SZ];
            unsigned i;
            const unsigned nb_rx =
                    rte_eth_rx_burst(port_ids[lcore_id], 0,
                        pkts_burst, PKT_BURST_SZ);
            lcore_stats[lcore_id].rx += nb_rx;
            for (i = 0; likely(i < nb_rx); i++) {
                struct rte_mbuf *m = pkts_burst[i];
                /* Ignore return val from write() */
                int ret = write(tap_fd,
                                rte_pktmbuf_mtod(m, void*),
                                rte_pktmbuf_data_len(m));
                rte_pktmbuf_free(m);
                if (unlikely(ret < 0))
                    lcore_stats[lcore_id].dropped++;
                else
                    lcore_stats[lcore_id].tx++;
            }
        }
    }
    else if ((1ULL << lcore_id) & output_cores_mask) {
        /* Create new tap interface */
        snprintf(tap_name, IFNAMSIZ, "tap_dpdk_%.2u", lcore_id);
        tap_fd = tap_create(tap_name);
        if (tap_fd < 0)
            FATAL_ERROR("Could not create tap interface \"%s\" (%d)",
                    tap_name, tap_fd);

        PRINT_INFO("Lcore %u is reading from %s and writing to port %u",
                   lcore_id, tap_name, (unsigned)port_ids[lcore_id]);
        fflush(stdout);
        /* Loop forever reading from tap and writing to NIC */
        for (;;) {
            int ret;
            struct rte_mbuf *m = rte_pktmbuf_alloc(pktmbuf_pool);
            if (m == NULL)
                continue;

            ret = read(tap_fd, rte_pktmbuf_mtod(m, void *),
                MAX_PACKET_SZ);
            lcore_stats[lcore_id].rx++;
            if (unlikely(ret < 0)) {
                FATAL_ERROR("Reading from %s interface failed",
                            tap_name);
            }
            m->nb_segs = 1;
            m->next = NULL;
            m->pkt_len = (uint16_t)ret;
            m->data_len = (uint16_t)ret;
            ret = rte_eth_tx_burst(port_ids[lcore_id], 0, &m, 1);
            if (unlikely(ret < 1)) {
                rte_pktmbuf_free(m);
                lcore_stats[lcore_id].dropped++;
            }
            else {
                lcore_stats[lcore_id].tx++;
            }
        }
    }
    else {
        PRINT_INFO("Lcore %u has nothing to do", lcore_id);
        return 0;
    }
    /*
     * Tap file is closed automatically when program exits. Putting close()
     * here will cause the compiler to give an error about unreachable code.
     */
}

/* Display usage instructions */
static void
print_usage(const char *prgname)
{
    PRINT_INFO("\nUsage: %s [EAL options] -- -p PORTMASK -i IN_CORES -o OUT_CORES\n"
               "    -p PORTMASK: hex bitmask of ports to use\n"
               "    -i IN_CORES: hex bitmask of cores which read from NIC\n"
               "    -o OUT_CORES: hex bitmask of cores which write to NIC",
               prgname);
}

/* Convert string to unsigned number. 0 is returned if error occurs */
static uint64_t
parse_unsigned(const char *portmask)
{
    char *end = NULL;
    uint64_t num;

    num = strtoull(portmask, &end, 16);
    if ((portmask[0] == '\0') || (end == NULL) || (*end != '\0'))
        return 0;

    return (uint64_t)num;
}

/* Record affinities between ports and lcores in global port_ids[] array */
static void
setup_port_lcore_affinities(void)
{
    unsigned long i;
    uint16_t tx_port = 0;
    uint16_t rx_port = 0;

    /* Setup port_ids[] array, and check masks were ok */
    for (i = 0; i < APP_MAX_LCORE; i++) {
        if (!rte_lcore_is_enabled(i))
            continue;
        if (input_cores_mask & (1ULL << i)) {
            /* Skip ports that are not enabled */
            while ((ports_mask & (1 << rx_port)) == 0) {
                rx_port++;
                if (rx_port > (sizeof(ports_mask) * 8))
                    goto fail; /* not enough ports */
            }

            port_ids[i] = rx_port++;
        } else if (output_cores_mask & (1ULL << (i & 0x3f))) {
            /* Skip ports that are not enabled */
            while ((ports_mask & (1 << tx_port)) == 0) {
                tx_port++;
                if (tx_port > (sizeof(ports_mask) * 8))
                    goto fail; /* not enough ports */
            }

            port_ids[i] = tx_port++;
        }
    }

    if (rx_port != tx_port)
        goto fail; /* uneven number of cores in masks */

    if (ports_mask & (~((1 << rx_port) - 1)))
        goto fail; /* unused ports */

    return;
fail:
    FATAL_ERROR("Invalid core/port masks specified on command line");
}

/* Parse the arguments given in the command line of the application */
static void
parse_args(int argc, char **argv)
{
    int opt;
    const char *prgname = argv[0];

    /* Disable printing messages within getopt() */
    opterr = 0;

    /* Parse command line */
    while ((opt = getopt(argc, argv, "i:o:p:")) != EOF) {
        switch (opt) {
        case 'i':
            input_cores_mask = parse_unsigned(optarg);
            break;
        case 'o':
            output_cores_mask = parse_unsigned(optarg);
            break;
        case 'p':
            ports_mask = parse_unsigned(optarg);
            break;
        default:
            print_usage(prgname);
            FATAL_ERROR("Invalid option specified");
        }
    }

    /* Check that options were parsed ok */
    if (input_cores_mask == 0) {
        print_usage(prgname);
        FATAL_ERROR("IN_CORES not specified correctly");
    }
    if (output_cores_mask == 0) {
        print_usage(prgname);
        FATAL_ERROR("OUT_CORES not specified correctly");
    }
    if (ports_mask == 0) {
        print_usage(prgname);
        FATAL_ERROR("PORTMASK not specified correctly");
    }

    setup_port_lcore_affinities();
}

/* Initialise a single port on an Ethernet device */
static void
init_port(uint16_t port)
{
    int ret;
    uint16_t nb_rxd = NB_RXD;
    uint16_t nb_txd = NB_TXD;
    struct rte_eth_dev_info dev_info;
    struct rte_eth_rxconf rxq_conf;
    struct rte_eth_txconf txq_conf;
    struct rte_eth_conf local_port_conf = port_conf;

    /* Initialise device and RX/TX queues */
    PRINT_INFO("Initialising port %u ...", port);
    fflush(stdout);
    rte_eth_dev_info_get(port, &dev_info);
    if (dev_info.tx_offload_capa & DEV_TX_OFFLOAD_MBUF_FAST_FREE)
        local_port_conf.txmode.offloads |=
            DEV_TX_OFFLOAD_MBUF_FAST_FREE;
    ret = rte_eth_dev_configure(port, 1, 1, &local_port_conf);
    if (ret < 0)
        FATAL_ERROR("Could not configure port%u (%d)", port, ret);

    ret = rte_eth_dev_adjust_nb_rx_tx_desc(port, &nb_rxd, &nb_txd);
    if (ret < 0)
        FATAL_ERROR("Could not adjust number of descriptors for port%u (%d)",
                port, ret);

    rxq_conf = dev_info.default_rxconf;
    rxq_conf.offloads = local_port_conf.rxmode.offloads;
    ret = rte_eth_rx_queue_setup(port, 0, nb_rxd,
                rte_eth_dev_socket_id(port),
                &rxq_conf,
                pktmbuf_pool);
    if (ret < 0)
        FATAL_ERROR("Could not setup up RX queue for port%u (%d)",
                port, ret);

    txq_conf = dev_info.default_txconf;
    txq_conf.offloads = local_port_conf.txmode.offloads;
    ret = rte_eth_tx_queue_setup(port, 0, nb_txd,
                rte_eth_dev_socket_id(port),
                &txq_conf);
    if (ret < 0)
        FATAL_ERROR("Could not setup up TX queue for port%u (%d)",
                port, ret);

    ret = rte_eth_dev_start(port);
    if (ret < 0)
        FATAL_ERROR("Could not start port%u (%d)", port, ret);

    rte_eth_promiscuous_enable(port);
}

/* Check the link status of all ports in up to 9s, and print them finally */
static void
check_all_ports_link_status(uint32_t port_mask)
{
#define CHECK_INTERVAL 100 /* 100ms */
#define MAX_CHECK_TIME 90 /* 9s (90 * 100ms) in total */
    uint16_t portid;
    uint8_t count, all_ports_up, print_flag = 0;
    struct rte_eth_link link;

    printf("\nChecking link status");
    fflush(stdout);
    for (count = 0; count <= MAX_CHECK_TIME; count++) {
        all_ports_up = 1;
        RTE_ETH_FOREACH_DEV(portid) {
            if ((port_mask & (1 << portid)) == 0)
                continue;
            memset(&link, 0, sizeof(link));
            rte_eth_link_get_nowait(portid, &link);
            /* print link status if flag set */
            if (print_flag == 1) {
                if (link.link_status)
                    printf(
                    "Port%d Link Up. Speed %u Mbps - %s\n",
                        portid, link.link_speed,
                (link.link_duplex == ETH_LINK_FULL_DUPLEX) ?
                    ("full-duplex") : ("half-duplex\n"));
                else
                    printf("Port %d Link Down\n", portid);
                continue;
            }
            /* clear all_ports_up flag if any link down */
            if (link.link_status == ETH_LINK_DOWN) {
                all_ports_up = 0;
                break;
            }
        }
        /* after finally printing all link status, get out */
        if (print_flag == 1)
            break;

        if (all_ports_up == 0) {
            printf(".");
            fflush(stdout);
            rte_delay_ms(CHECK_INTERVAL);
        }

        /* set the print_flag if all ports up or timeout */
        if (all_ports_up == 1 || count == (MAX_CHECK_TIME - 1)) {
            print_flag = 1;
            printf("done\n");
        }
    }
}

/* Initialise ports/queues etc. and start main loop on each core */
int
main(int argc, char** argv)
{
    int ret;
    unsigned i,high_port;
    uint16_t nb_sys_ports, port;

    /* Associate signal_hanlder function with USR signals */
    signal(SIGUSR1, signal_handler);
    signal(SIGUSR2, signal_handler);

    /* Initialise EAL */
    ret = rte_eal_init(argc, argv);
    if (ret < 0)
        FATAL_ERROR("Could not initialise EAL (%d)", ret);
    argc -= ret;
    argv += ret;

    /* Parse application arguments (after the EAL ones) */
    parse_args(argc, argv);

    /* Create the mbuf pool */
    pktmbuf_pool = rte_pktmbuf_pool_create("mbuf_pool", NB_MBUF,
            MEMPOOL_CACHE_SZ, 0, MBUF_DATA_SZ, rte_socket_id());
    if (pktmbuf_pool == NULL) {
        FATAL_ERROR("Could not initialise mbuf pool");
        return -1;
    }

    /* Get number of ports found in scan */
    nb_sys_ports = rte_eth_dev_count_avail();
    if (nb_sys_ports == 0)
        FATAL_ERROR("No supported Ethernet device found");
    /* Find highest port set in portmask */
    for (high_port = (sizeof(ports_mask) * 8) - 1;
            (high_port != 0) && !(ports_mask & (1 << high_port));
            high_port--)
        ; /* empty body */
    if (high_port > nb_sys_ports)
        FATAL_ERROR("Port mask requires more ports than available");

    /* Initialise each port */
    RTE_ETH_FOREACH_DEV(port) {
        /* Skip ports that are not enabled */
        if ((ports_mask & (1 << port)) == 0) {
            continue;
        }
        init_port(port);
    }
    check_all_ports_link_status(ports_mask);

    /* Launch per-lcore function on every lcore */
    rte_eal_mp_remote_launch(main_loop, NULL, CALL_MASTER);
    RTE_LCORE_FOREACH_SLAVE(i) {
        if (rte_eal_wait_lcore(i) < 0)
            return -1;
    }

    return 0;
}