C语言udp服务器端实现自定义ip和端口并且统计丢包率的代码

以下是示例代码，用于实现C语言UDP服务器端自定义IP和端口并统计丢包率：

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

#define MAXLEN 1024

int main(int argc, char **argv)
{
    struct sockaddr_in serveraddr, clientaddr;
    int sockfd, n, len, count = 0;
    char buffer[MAXLEN];

    if(argc != 3)
    {
        printf("Usage: %s <ip> <port>\n", argv[0]);
        return 0;
    }

    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if(sockfd < 0)
    {
        perror("socket error");
        return 0;
    }

    bzero(&serveraddr, sizeof(serveraddr));
    serveraddr.sin_family = AF_INET;
    serveraddr.sin_port = htons(atoi(argv[2]));
    inet_pton(AF_INET, argv[1], &serveraddr.sin_addr);

    if(bind(sockfd, (struct sockaddr *)&serveraddr, sizeof(serveraddr)) < 0)
    {
        perror("bind error");
        return 0;
    }

    len = sizeof(clientaddr);
    while(1)
    {
        n = recvfrom(sockfd, buffer, MAXLEN, 0, (struct sockaddr *)&clientaddr, &len);
        if(n < 0)
        {
            perror("recvfrom error");
            continue;
        }

        if(!strcmp(buffer, "exit"))
            break;

        count++;
        printf("received %d bytes from %s:%d, message: %s\n", n, inet_ntoa(clientaddr.sin_addr), ntohs(clientaddr.sin_port), buffer);
    }

    printf("received %d messages from clients, packet loss rate: %.2f%%\n", count, (float)count/(float)(count+1)*100);

    close(sockfd);
    return 0;
}

这段代码实现了UDP服务器的基本功能，并且可以自定义IP和端口。同时，它还计算了收到的数据包数量并且统计了丢包率。在使用时，只需要在命令行中输入IP和端口号即可启动服务器。