用c语言写个简单的DHCP server-DPDK中文网

好的，下面是一个简单的DHCP服务器的C语言实现代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>

#define DHCP_SERVER_PORT 67
#define DHCP_CLIENT_PORT 68

typedef struct {
    unsigned char op;           // Message op code / message type.
    unsigned char htype;        // Hardware address type (e.g., '1' = 10mb ethernet).
    unsigned char hlen;         // Hardware address length (e.g., '6' for 10mb ethernet).
    unsigned char hops;         // Client sets to zero, optionally used by relay agents when booting via a relay agent.
    unsigned long xid;          // Transaction ID, a random number chosen by the client, used by the client and server to associate messages and responses between a client and a server.
    unsigned short secs;        // Filled in by client, seconds elapsed since client began address acquisition or renewal process.
    unsigned short flags;
    struct in_addr ciaddr;      // Client IP address: only filled in if client is in BOUND, RENEW or REBINDING state and can respond to ARP requests.
    struct in_addr yiaddr;      // 'your' (client) IP address: offer from server.
    struct in_addr siaddr;      // Next server to use in bootstrap: returned in DHCPOFFER, DHCPACK by server.
    struct in_addr giaddr;      // Relay agent IP address, used in booting via a relay agent.
    unsigned char chaddr[16];   // Client hardware address (MAC)
} dhcp_packet;

int main() {
    int sockfd;
    dhcp_packet packet;
    
    memset(&packet, 0, sizeof(packet));
    
    packet.op = 2;              // DHCP reply
    packet.htype = 1;           // Ethernet
    packet.hlen = 6;            // MAC address is 6 bytes long
    packet.xid = 0x12345678;    // Example transaction ID
    
    struct sockaddr_in server_addr, client_addr;
    
    sockfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
    if (sockfd < 0) {
        perror("socket() failed");
        exit(1);
    }
    
    memset(&server_addr, 0, sizeof(server_addr));
    
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(DHCP_SERVER_PORT);
    server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    
    if (bind(sockfd, (struct sockaddr*)&server_addr, sizeof(server_addr)) < 0) {
        perror("bind() failed");
        exit(1);
    }
    
    socklen_t len = sizeof(client_addr);
    
    while (1) {
        int n = recvfrom(sockfd, &packet, sizeof(packet), 0, (struct sockaddr*)&client_addr, &len);
        
        if (n < 0) {
            perror("recvfrom() failed");
            continue;
        }
        
        printf("Received %d bytes from %s:%d\n", n,
               inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));
        
        packet.op = 2;          // DHCP reply
        
        // TODO: Add more code to fill in the rest of the fields in the dhcp_packet structure as appropriate for your DHCP server.
        
        n = sendto(sockfd, &packet, sizeof(packet), 0,
                   (struct sockaddr*)&client_addr, len);
        
        if (n < 0) {
            perror("sendto() failed");
            continue;
        }
        
        printf("Sent %d bytes to %s:%d\n", n,
               inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));
    }
    
    return 0;
}

请注意，此代码仅为演示目的。实际的DHCP服务器需要更复杂的代码来处理客户端请求和响应。