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_LINUXAPP
#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 = {
        .rxmode = {
                .ignore_offload_bitfield = 1,
                .offloads = DEV_RX_OFFLOAD_CRC_STRIP,
        },
        .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_LINUXAPP
/*
 * 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)
                snprintf(ifr.ifr_name, IFNAMSIZ, "%s", name);

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

        if (name)
                snprintf(name, IFNAMSIZ, "%s", ifr.ifr_name);

        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.txq_flags = ETH_TXQ_FLAGS_IGNORE;
        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;
}