examples/multi_process/client_server_mp/mp_server/main.c

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

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

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

#include "common.h"
#include "args.h"
#include "init.h"

/*
 * When doing reads from the NIC or the client queues,
 * use this batch size
 */
#define PACKET_READ_SIZE 32

/*
 * Local buffers to put packets in, used to send packets in bursts to the
 * clients
 */
struct client_rx_buf {
    struct rte_mbuf *buffer[PACKET_READ_SIZE];
    uint16_t count;
};

/* One buffer per client rx queue - dynamically allocate array */
static struct client_rx_buf *cl_rx_buf;

static const char *
get_printable_mac_addr(uint16_t port)
{
    static const struct rte_ether_addr null_mac; /* static defaults to 0 */
    static char err_address[32];
    static char addresses[RTE_MAX_ETHPORTS][32];
    int ret;

    if (unlikely(port >= RTE_MAX_ETHPORTS)) {
        if (err_address[0] == '\0')
            rte_ether_format_addr(err_address,
                    sizeof(err_address), &null_mac);
        return err_address;
    }
    if (unlikely(addresses[port][0]=='\0')){
        struct rte_ether_addr mac;
        ret = rte_eth_macaddr_get(port, &mac);
        if (ret != 0) {
            printf("Failed to get MAC address (port %u): %s\n",
                   port, rte_strerror(-ret));
            return err_address;
        }
        rte_ether_format_addr(addresses[port],
                sizeof(addresses[port]), &mac);
    }
    return addresses[port];
}

/*
 * This function displays the recorded statistics for each port
 * and for each client. It uses ANSI terminal codes to clear
 * screen when called. It is called from a single worker
 * thread in the server process, when the process is run with more
 * than one lcore enabled.
 */
static void
do_stats_display(void)
{
    unsigned i, j;
    const char clr[] = { 27, '[', '2', 'J', '\0' };
    const char topLeft[] = { 27, '[', '1', ';', '1', 'H','\0' };
    uint64_t port_tx[RTE_MAX_ETHPORTS], port_tx_drop[RTE_MAX_ETHPORTS];
    uint64_t client_tx[MAX_CLIENTS], client_tx_drop[MAX_CLIENTS];

    /* to get TX stats, we need to do some summing calculations */
    memset(port_tx, 0, sizeof(port_tx));
    memset(port_tx_drop, 0, sizeof(port_tx_drop));
    memset(client_tx, 0, sizeof(client_tx));
    memset(client_tx_drop, 0, sizeof(client_tx_drop));

    for (i = 0; i < num_clients; i++){
        const volatile struct tx_stats *tx = &ports->tx_stats[i];
        for (j = 0; j < ports->num_ports; j++){
            /* assign to local variables here, save re-reading volatile vars */
            const uint64_t tx_val = tx->tx[ports->id[j]];
            const uint64_t drop_val = tx->tx_drop[ports->id[j]];
            port_tx[j] += tx_val;
            port_tx_drop[j] += drop_val;
            client_tx[i] += tx_val;
            client_tx_drop[i] += drop_val;
        }
    }

    /* Clear screen and move to top left */
    printf("%s%s", clr, topLeft);

    printf("PORTS\n");
    printf("-----\n");
    for (i = 0; i < ports->num_ports; i++)
        printf("Port %u: '%s'\t", (unsigned)ports->id[i],
                get_printable_mac_addr(ports->id[i]));
    printf("\n\n");
    for (i = 0; i < ports->num_ports; i++){
        printf("Port %u - rx: %9"PRIu64"\t"
                "tx: %9"PRIu64"\n",
                (unsigned)ports->id[i], ports->rx_stats.rx[i],
                port_tx[i]);
    }

    printf("\nCLIENTS\n");
    printf("-------\n");
    for (i = 0; i < num_clients; i++){
        const unsigned long long rx = clients[i].stats.rx;
        const unsigned long long rx_drop = clients[i].stats.rx_drop;
        printf("Client %2u - rx: %9llu, rx_drop: %9llu\n"
                "            tx: %9"PRIu64", tx_drop: %9"PRIu64"\n",
                i, rx, rx_drop, client_tx[i], client_tx_drop[i]);
    }

    printf("\n");
}

/*
 * The function called from each worker lcore used by the process.
 * The test_and_set function is used to randomly pick a single lcore on which
 * the code to display the statistics will run. Otherwise, the code just
 * repeatedly sleeps.
 */
static int
sleep_lcore(__rte_unused void *dummy)
{
    /* Used to pick a display thread - static, so zero-initialised */
    static RTE_ATOMIC(uint32_t) display_stats;

    uint32_t status = 0;
    /* Only one core should display stats */
    if (rte_atomic_compare_exchange_strong_explicit(&display_stats, &status, 1,
            rte_memory_order_relaxed, rte_memory_order_relaxed)) {
        const unsigned sleeptime = 1;
        printf("Core %u displaying statistics\n", rte_lcore_id());

        /* Longer initial pause so above printf is seen */
        sleep(sleeptime * 3);

        /* Loop forever: sleep always returns 0 or <= param */
        while (sleep(sleeptime) <= sleeptime)
            do_stats_display();
    }
    return 0;
}

/*
 * Function to set all the client statistic values to zero.
 * Called at program startup.
 */
static void
clear_stats(void)
{
    unsigned i;

    for (i = 0; i < num_clients; i++)
        clients[i].stats.rx = clients[i].stats.rx_drop = 0;
}

/*
 * send a burst of traffic to a client, assuming there are packets
 * available to be sent to this client
 */
static void
flush_rx_queue(uint16_t client)
{
    uint16_t j;
    struct client *cl;

    if (cl_rx_buf[client].count == 0)
        return;

    cl = &clients[client];
    if (rte_ring_enqueue_bulk(cl->rx_q, (void **)cl_rx_buf[client].buffer,
            cl_rx_buf[client].count, NULL) == 0){
        for (j = 0; j < cl_rx_buf[client].count; j++)
            rte_pktmbuf_free(cl_rx_buf[client].buffer[j]);
        cl->stats.rx_drop += cl_rx_buf[client].count;
    }
    else
        cl->stats.rx += cl_rx_buf[client].count;

    cl_rx_buf[client].count = 0;
}

/*
 * marks a packet down to be sent to a particular client process
 */
static inline void
enqueue_rx_packet(uint8_t client, struct rte_mbuf *buf)
{
    cl_rx_buf[client].buffer[cl_rx_buf[client].count++] = buf;
}

/*
 * This function takes a group of packets and routes them
 * individually to the client process. Very simply round-robins the packets
 * without checking any of the packet contents.
 */
static void
process_packets(uint32_t port_num __rte_unused,
        struct rte_mbuf *pkts[], uint16_t rx_count)
{
    uint16_t i;
    static uint8_t client;

    for (i = 0; i < rx_count; i++) {
        enqueue_rx_packet(client, pkts[i]);

        if (++client == num_clients)
            client = 0;
    }

    for (i = 0; i < num_clients; i++)
        flush_rx_queue(i);
}

/*
 * Function called by the main lcore of the DPDK process.
 */
static void
do_packet_forwarding(void)
{
    unsigned port_num = 0; /* indexes the port[] array */

    for (;;) {
        struct rte_mbuf *buf[PACKET_READ_SIZE];
        uint16_t rx_count;

        /* read a port */
        rx_count = rte_eth_rx_burst(ports->id[port_num], 0, \
                buf, PACKET_READ_SIZE);
        ports->rx_stats.rx[port_num] += rx_count;

        /* Now process the NIC packets read */
        if (likely(rx_count > 0))
            process_packets(port_num, buf, rx_count);

        /* move to next port */
        if (++port_num == ports->num_ports)
            port_num = 0;
    }
}

static void
signal_handler(int signal)
{
    uint16_t port_id;

    if (signal == SIGINT)
        RTE_ETH_FOREACH_DEV(port_id) {
            rte_eth_dev_stop(port_id);
            rte_eth_dev_close(port_id);
        }
    exit(0);
}

int
main(int argc, char *argv[])
{
    signal(SIGINT, signal_handler);
    /* initialise the system */
    if (init(argc, argv) < 0 )
        return -1;
    RTE_LOG(INFO, APP, "Finished Process Init.\n");

    cl_rx_buf = calloc(num_clients, sizeof(cl_rx_buf[0]));

    /* clear statistics */
    clear_stats();

    /* put all other cores to sleep except main */
    rte_eal_mp_remote_launch(sleep_lcore, NULL, SKIP_MAIN);

    do_packet_forwarding();

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

    return 0;
}