dpdk 建流-DPDK中文网

DPDK可以使用以下步骤建立数据流：

初始化DPDK环境
配置网卡和端口参数（例如，MAC地址、IP地址和MTU等）
创建和配置RX队列和TX队列
启动端口
接收数据包
处理数据包
发送数据包

下面是一个基本的示例代码：

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <rte_eal.h>
#include <rte_ethdev.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 }
};

int main(int argc, char *argv[])
{
    int ret;
    uint16_t nb_ports;
    uint16_t portid;
    struct rte_mempool *mbuf_pool;
    struct rte_eth_dev_info dev_info;
    struct rte_eth_txconf tx_conf;
    struct rte_eth_rxconf rx_conf;
    struct rte_eth_conf port_conf = port_conf_default;

    // 初始化EAL
    ret = rte_eal_init(argc, argv);
    if (ret < 0)
        rte_exit(EXIT_FAILURE, "Error: %s\n", rte_strerror(ret));

    // 获取端口数量
    nb_ports = rte_eth_dev_count_avail();
    if (nb_ports == 0)
        rte_exit(EXIT_FAILURE, "No Ethernet ports found.\n");

    // 配置MBUF内存池
    mbuf_pool = rte_pktmbuf_pool_create("MBUF_POOL", NUM_MBUFS,
        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");

    // 配置端口参数
    portid = 0;
    memset(&dev_info, 0, sizeof(dev_info));
    ret = rte_eth_dev_info_get(portid, &dev_info);
    if (ret != 0)
        rte_exit(EXIT_FAILURE, "Error: %s\n", rte_strerror(ret));

    tx_conf = dev_info.default_txconf;
    rx_conf = dev_info.default_rxconf;

    tx_conf.txq_flags = ETH_TXQ_FLAGS_IGNORE;
    rx_conf.rx_drop_en = 1;

    ret = rte_eth_dev_configure(portid, 1, 1, &port_conf);
    if (ret < 0)
        rte_exit(EXIT_FAILURE, "Cannot configure device: %s\n", rte_strerror(ret));

    ret = rte_eth_dev_adjust_nb_rx_tx_desc(portid, &RX_RING_SIZE, &TX_RING_SIZE);
    if (ret < 0)
        rte_exit(EXIT_FAILURE, "Cannot adjust number of descriptors: %s\n", rte_strerror(ret));

    ret = rte_eth_tx_queue_setup(portid, 0, TX_RING_SIZE, rte_eth_dev_socket_id(portid), &tx_conf);
    if (ret < 0)
        rte_exit(EXIT_FAILURE, "Cannot setup TX queue: %s\n", rte_strerror(ret));

    ret = rte_eth_rx_queue_setup(portid, 0, RX_RING_SIZE, rte_eth_dev_socket_id(portid), &rx_conf, mbuf_pool);
    if (ret < 0)
        rte_exit(EXIT_FAILURE, "Cannot setup RX queue: %s\n", rte_strerror(ret));

    // 启动端口
    ret = rte_eth_dev_start(portid);
    if (ret < 0)
        rte_exit(EXIT_FAILURE, "Cannot start device: %s\n", rte_strerror(ret));

    printf("Port %u is up.\n", portid);

    // 接收和发送数据包
    struct rte_mbuf *bufs[BURST_SIZE];
    while (1) {
        const uint16_t nb_rx = rte_eth_rx_burst(portid, 0, bufs, BURST_SIZE);
        if (nb_rx == 0)
            continue;

        for (uint16_t i = 0; i < nb_rx; i++)
            rte_pktmbuf_free(bufs[i]);

        const uint16_t nb_tx = rte_eth_tx_burst(portid, 0, bufs, nb_rx);
        if (nb_tx < nb_rx) {
            for (uint16_t i = nb_tx; i < nb_rx; i++)
                rte_pktmbuf_free(bufs[i]);
        }
    }

    return 0;
}