DPDK 实现一个基于 L3 的路由转发器必须是可执行的-DPDK中文网

实现一个基于 L3 的路由转发器使用 DPDK（Data Plane Development Kit）需要一定的网络编程和 DPDK 的知识。下面是一个简单的示例代码，展示如何使用 DPDK 创建一个基本的 L3 路由转发器。请注意，这是一个简化的版本，实际应用中需要考虑错误处理和其他细节。

前提条件

确保您已经安装了 DPDK，并配置了相关环境变量。

示例代码

#include <stdio.h>
#include <stdint.h>
#include <rte_eal.h>
#include <rte_ethdev.h>
#include <rte_ip.h>
#include <rte_mbuf.h>

#define NUM_MBUFS 8191
#define MBUF_SIZE (sizeof(struct rte_mbuf) + RTE_PKTMBUF_HEADROOM)

static uint16_t port_id;

static void process_packet(struct rte_mbuf *mbuf) {
    struct ether_hdr *eth_hdr;
    struct ipv4_hdr *ipv4_hdr;

    // Parse Ethernet header
    eth_hdr = rte_pktmbuf_mtod(mbuf, struct ether_hdr *);
    
    // Check if the packet is an IPv4 packet
    if (eth_hdr->ether_type == rte_cpu_to_be_16(ETHER_TYPE_IPv4)) {
        ipv4_hdr = (struct ipv4_hdr *)(eth_hdr + 1);
        
        // Here you can add your routing logic based on the IP address
        // For example, forward to another interface based on destination IP
        
        printf("Received IPv4 packet: src=%u.%u.%u.%u dst=%u.%u.%u.%u\n",
               (ipv4_hdr->src_addr >> 24) & 0xFF,
               (ipv4_hdr->src_addr >> 16) & 0xFF,
               (ipv4_hdr->src_addr >> 8) & 0xFF,
               (ipv4_hdr->src_addr) & 0xFF,
               (ipv4_hdr->dst_addr >> 24) & 0xFF,
               (ipv4_hdr->dst_addr >> 16) & 0xFF,
               (ipv4_hdr->dst_addr >> 8) & 0xFF,
               (ipv4_hdr->dst_addr) & 0xFF);
        
        // Add forwarding logic here...
    }

    // Free mbuf after processing
    rte_pktmbuf_free(mbuf);
}

int main(int argc, char **argv) {
    int ret;
    uint16_t nb_rxd = 128; // Number of packets to receive

    // Initialize the Environment Abstraction Layer (EAL)
    ret = rte_eal_init(argc, argv);
    if (ret < 0) {
        fprintf(stderr, "Error with EAL initialization\n");
        return -1;
    }

    port_id = atoi(argv[1]); // Get port ID from command line argument
    
    // Configure the Ethernet device for RX/TX
    struct rte_eth_conf port_conf_default = { .rxmode = { .max_rx_pkt_len = ETHER_MAX_LEN }};
    
    ret = rte_eth_dev_configure(port_id, 1, 1, &port_conf_default);
    
   if(ret !=0){
      printf("Failed to configure device\n");
      return -1;
   }
    
   rte_eth_rx_queue_setup(port_id, queue_id, nb_rxd,
                          rte_socket_id(), NULL);

   rte_eth_tx_queue_setup(port_id, queue_id, nb_txd,
                          rte_socket_id(), NULL);

   ret = rte_eth_dev_start(port_id);

   while(1){
       struct rte_mbuf *pkts_burst[BURST_SIZE];
       uint16_t rx_count;

       rx_count = rte_eth_rx_burst(port_id, queue_id, pkts_burst,BURST_SIZE);

       for(uint16_t i=0;i<rx_count;i++){
           process_packet(pkts_burst[i]);
       }
       
   }

   return ret;
}