通过UDP协议实现MP3格式文件传输

#本文实现了使用UDP协议传输MP3文件

#include <arpa/inet.h>
#include <stdio.h>
#include <errno.h>
#include <netinet/ip.h>
#include <netinet/in.h>
#include <netinet/udp.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <unistd.h>
#include <sys/types.h> /* See NOTES */
#include <sys/socket.h>
#include <sys/stat.h>
#include <unistd.h>

/*******************************************************************
 *
 *	file name:	music_server.c
 *	author	 :  j_howe@163.com
 *	date	 :  2024/6/10
 *	function :  通过UDP协议从服务器中下载MP3音频文件
 * 	note	 :  使用该.c文件时应确保服务器处于运行态
 *
 *	CopyRight (c)  2023-2024   j_howe@163.com   All Right Reseverd
 *
 * *****************************************************************/


#define MP3_PATH "./leave.mp3"

int main()
{
    // 1.创建UDP套接字
    int udp_socket = socket(AF_INET, SOCK_DGRAM, 0);
    if (udp_socket == -1)
    {
        fprintf(stderr, "udp socket error,errno:%d,%s\n", errno, strerror(errno));
        exit(1);
    }
    // 2.服务器绑定本地的端口和IP地址
    struct sockaddr_in host_addr;

    host_addr.sin_family = AF_INET;            // 协议族，是固定的
    host_addr.sin_port = htons(atoi("60000")); // 目标端口，必须转换为网络字节序
    host_addr.sin_addr.s_addr = INADDR_ANY;    // 目标地址 "192.168.64.xxx"  已经转换为网络字节序  INADDR_ANY

    bind(udp_socket, (struct sockaddr *)&host_addr, sizeof(host_addr));

    struct sockaddr_in client;
    socklen_t client_len = sizeof(client);

    // 3.等待客户端发送请求
    char recvbuf[64];
    char sendbuf[512];

    while (1)
    {
        recvfrom(udp_socket, recvbuf, sizeof(recvbuf), 0, (struct sockaddr *)&client, &client_len);
        if (strstr(recvbuf, "download"))
        {
            FILE *fp = fopen(MP3_PATH, "rb");

            struct stat mp3_file;
            stat(MP3_PATH, &mp3_file);
            int mp3_size = mp3_file.st_size;

            // 判断循环次数->需要发送多少次512字节
            int num = mp3_size / 512;
            int remainder = mp3_size % 512;
            if (remainder > 0)
            {
                num++;
            }
            printf("num = %d\n", num);
            int cnt = 0;
            for (int i = 0; i < num; i++)
            {
                fread(sendbuf, 1, 512, fp);
                sendto(udp_socket, sendbuf, sizeof(sendbuf), 0, (struct sockaddr *)&client, client_len);
                usleep(2000);
                printf("cnt = %d\n", cnt++);
                bzero(sendbuf, 512);
            }
            sendto(udp_socket, "over", 5, 0, (struct sockaddr *)&client, client_len);
            printf("123456\n");
            fclose(fp);
        }
    }

    return 0;
}

/*******************************************************************
 *
 *	file name:	music_server.c
 *	author	 :  j_howe@163.com
 *	date	 :  2024/6/10
 *	function :  指定用户需要下载文件路径，提供下载资源
 * 	note	 :  本文件优先于客户端运行
 *
 *	CopyRight (c)  2023-2024   j_howe@163.com   All Right Reseverd
 *
 * *****************************************************************/

#define MP3_PATH "./leave.mp3"

int main()
{
    // 1.创建UDP套接字
    int udp_socket = socket(AF_INET, SOCK_DGRAM, 0);
    if (udp_socket == -1)
    {
        fprintf(stderr, "udp socket error,errno:%d,%s\n", errno, strerror(errno));
        exit(1);
    }
    // 2.服务器绑定本地的端口和IP地址
    struct sockaddr_in host_addr;

    host_addr.sin_family = AF_INET;            // 协议族，是固定的
    host_addr.sin_port = htons(atoi("60000")); // 目标端口，必须转换为网络字节序
    host_addr.sin_addr.s_addr = INADDR_ANY;    // 目标地址 "192.168.64.xxx"  已经转换为网络字节序  INADDR_ANY

    bind(udp_socket, (struct sockaddr *)&host_addr, sizeof(host_addr));

    struct sockaddr_in client;
    socklen_t client_len = sizeof(client);

    // 3.等待客户端发送请求
    char recvbuf[64];
    char sendbuf[512];

    while (1)
    {
        recvfrom(udp_socket, recvbuf, sizeof(recvbuf), 0, (struct sockaddr *)&client, &client_len);
        if (strstr(recvbuf, "download"))
        {
            FILE *fp = fopen(MP3_PATH, "rb");

            struct stat mp3_file;
            stat(MP3_PATH, &mp3_file);
            int mp3_size = mp3_file.st_size;

            // 判断循环次数->需要发送多少次512字节
            int num = mp3_size / 512;
            int remainder = mp3_size % 512;
            if (remainder > 0)
            {
                num++;
            }
            printf("num = %d\n", num);
            int cnt = 0;
            for (int i = 0; i < num; i++)
            {
                fread(sendbuf, 1, 512, fp);
                sendto(udp_socket, sendbuf, sizeof(sendbuf), 0, (struct sockaddr *)&client, client_len);
                usleep(2000);
                printf("cnt = %d\n", cnt++);
                bzero(sendbuf, 512);
            }
            sendto(udp_socket, "over", 5, 0, (struct sockaddr *)&client, client_len);
            printf("123456\n");
            fclose(fp);
        }
    }

    return 0;
}