dpdk的kni使用例子，给出详细代码并注释。-DPDK中文网

下面是一个简单的DPDK KNI使用示例，包含详细注释：

”` #include #include #include #include #include

// DPDK相关头文件 #include #include #include #include

#define RX_RING_SIZE 1024 #define TX_RING_SIZE 1024

#define NUM_MBUFS 8192 #define MBUF_CACHE_SIZE 256

#define BURST_SIZE 32

// KNI设备名字 #define KNI_DEV_NAME “vEth0”

static const struct rte_eth_conf port_conf_default = {

.rxmode = { .max_rx_pkt_len = ETHER_MAX_LEN }

};

static struct rte_mempool *mbuf_pool;

/**

程序初始化，包括DPDK环境初始化和KNI设备的创建。 */ static int init(int argc, char **argv) { int ret; unsigned nb_ports; uint16_t portid; struct rte_eth_dev_info dev_info; struct rte_kni_conf conf; struct rte_kni_ops ops;

// 初始化EAL（Environment Abstraction Layer） ret = rte_eal_init(argc, argv); if (ret < 0) {

rte_exit(EXIT_FAILURE, "Error: %s\n", strerror(errno));
return -1;

}

argc -= ret; argv += ret;

// 获取网卡数量，并检查是否有符合要求的网卡 nb_ports = rte_eth_dev_count_avail(); if (nb_ports == 0) {

rte_exit(EXIT_FAILURE, "No Ethernet ports - bye\n");
return -1;

}

// 配置KNI设备 conf.addr = NULL; conf.id = 0; snprintf(conf.name, RTE_KNI_NAMESIZE, “%s”, KNI_DEV_NAME); ops.port_id = 0;

// 创建KNI设备 if (rte_kni_init(nb_ports, &conf) < 0) {

rte_exit(EXIT_FAILURE, "Error: %s\n", strerror(errno));
return -1;

}

// 获取网卡信息，并开启网卡端口 for (portid = 0; portid < nb_ports; portid++) {

memset(&dev_info, 0, sizeof(dev_info));
rte_eth_dev_info_get(portid, &dev_info);


ret = rte_eth_dev_configure(portid, 1, 1, &port_conf_default);
if (ret != 0) {
    printf("Cannot configure device: err=%d,port=%u\n",
           ret,
           portid);
    return -1;
}


ret = rte_eth_rx_queue_setup(
          portid,
          0,
          RX_RING_SIZE,
          rte_eth_dev_socket_id(portid),
          NULL,
          mbuf_pool);
if (ret < 0) {
    printf("Cannot init RX queue: err=%d,port=%u\n",
           ret,
           portid);
    return -1;
}


ret = rte_eth_tx_queue_setup(
          portid,
          0,
          TX_RING_SIZE,
          rte_eth_dev_socket_id(portid),
          NULL);
if (ret < 0) {
    printf("Cannot init TX queue: err=%d,port=%u\n",
           ret,
           portid);
    return -1;
}


/* Start the Ethernet port */
ret = rte_eth_dev_start(portid);
if (ret < 0) {
    printf("Cannot start device: err=%d,port=%u\n",
           ret,
           portid);
    return -1;
}


/* Enable RX in promiscuous mode for the Ethernet device. */
rte_eth_promiscuous_enable(portid);


/* Display the port MAC address. */
struct ether_addr addr;
rte_eth_macaddr_get(portid, &addr);
printf("Port %u MAC: %02" PRIx8 " %02" PRIx8 " %02" PRIx8
       " %02" PRIx8 " %02" PRIx8 " %02" PRIx8 "\n",
       portid,
       addr.addr_bytes[0], addr.addr_bytes[1],
       addr.addr_bytes[2], addr.addr_bytes[3],
       addr.addr_bytes[4], addr.addr_bytes[5]);

}

return 0; }

/**

主函数，处理KNI设备和网络数据包收发。 */ int main(int argc, char **argv) { int i, nb_rx;

// 初始化DPDK环境和KNI设备 init(argc, argv);

// 获取MBUF内存池 mbuf_pool = rte_pktmbuf_pool_create(

             "MBUF_POOL", NUM_MBUFS * RTE_MAX_ETHPORTS,
             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");
return -1;

}

// 接收和发送数据包 while (1) {

struct rte_mbuf *pkts_burst[BURST_SIZE];
struct rte_mbuf *pkts_kni[BURST_SIZE];


// 接收数据包
nb_rx = rte_eth_rx_burst(0, 0, pkts_burst, BURST_SIZE);
if (nb_rx == 0) {
    continue;
}


// 处理接收到的数据包
for (i = 0; i < nb_rx; i++) {
    printf("RX Packet: port=0,len=%d\n", pkts_burst[i]->pkt_len);


    // 将数据包发送到KNI设备中
    int ret = rte_kni_tx_burst(
                  ops.port_id,
                  pkts_burst[i],
                  &pkts_kni[i],
                  1);
    if (ret > 0) {
        printf("TX Packet: len=%d\n", pkts_kni[i]->pkt_len);
    } else {
        rte_pktmbuf_free(pkts_kni[i]);
    }
}


// 发送从KNI设备中接收到的数据包
struct rte_mbuf *kni_pkts[BURST_SIZE];
nb_rx = rte_kni_rx_burst(ops.port_id<br/><br/><br/><font size=1 color=#CCCCCC>内容由零声教学AI助手提供，问题来源于学员提问</font>