网络编程day3作业-优快云博客

本文链接：https://blog.youkuaiyun.com/qfsdfsd/article/details/130069390

该代码示例展示了如何使用C语言实现UDP协议的广播和组播功能。程序创建了socket，设置IP地址和端口，进行数据发送和接收。广播中，数据发送到特定的IP（如192.168.43.255），而组播则使用多播地址（如224.224.255.255）并加入组播成员。

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1.广播

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define ERR_MSG(msg)                          \
    do                                        \
    {                                         \
        fprintf(stderr, "line:%d", __LINE__); \
        perror(msg);                          \
    } while (0)
#define GRP_IP "224.224.255.255"
#define PORT 6666
int main(int argc, const char *argv[])
{
    int sfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sfd < 0)
    {
        ERR_MSG("socket");
        return -1;
    }
    printf("socket success __%d__\n", __LINE__);
    struct sockaddr_in sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(PORT);
    sin.sin_addr.s_addr = inet_addr(GRP_IP);
    struct sockaddr_in rcvaddr;
    socklen_t addrlen = sizeof(rcvaddr);
    char buf[128] = "";
    ssize_t res = 0;
    while (1)
    {
        bzero(buf, sizeof(buf));
        printf("please puts>>>");
        fgets(buf, sizeof(buf), stdin);
        buf[strlen(buf) - 1] = 0;
        if (sendto(sfd, buf, sizeof(buf), 0, (struct sockaddr *)&sin, sizeof(sin)) < 0)
        {
            perror("sento");
            return -1;
        }
        printf("send succes\n");

       
    }
    return 0;
}

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define ERR_MSG(msg)                          \
    do                                        \
    {                                         \
        fprintf(stderr, "line:%d", __LINE__); \
        perror(msg);                          \
    } while (0)
#define IP "192.168.43.255"
#define PORT 6666
int main(int argc, const char *argv[])
{
    int sfd=socket(AF_INET,SOCK_DGRAM,0);
    if(sfd<0)
    {
        ERR_MSG("socket");
        return -1;
    }
    printf("socket success __%d__\n",__LINE__);
    struct sockaddr_in sin;
    sin.sin_family =AF_INET;
    sin.sin_port=htons(PORT);
    sin.sin_addr.s_addr=inet_addr(IP);
    if (bind(sfd, (struct sockaddr *)&sin, sizeof(sin)) < 0)
    {
        ERR_MSG("bind");
        return -1;
    }
    printf("bind success __%d__\n",__LINE__);
    struct sockaddr_in cin;
    socklen_t addrlen=sizeof(cin);
    char buf[128]="";
    ssize_t res =0;
    while(1)
    {
        bzero(buf,sizeof(buf));
        res =recvfrom(sfd,buf,sizeof(buf),0,(struct sockaddr*)&cin,&addrlen);
        if(res<0)
        {
            perror("recvfrom");
            return -1;
        }
        printf("[%s : %d] sfd=%d %s __%d__\n",inet_ntoa(cin.sin_addr),ntohs(cin.sin_port),sfd,buf,__LINE__);
        strcat(buf,"*_*");
    }
    return 0;
}

2.组播

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define ERR_MSG(msg)                          \
    do                                        \
    {                                         \
        fprintf(stderr, "line:%d", __LINE__); \
        perror(msg);                          \
    } while (0)
#define GRP_IP "224.224.255.255"
#define PORT 6666
int main(int argc, const char *argv[])
{
    int sfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sfd < 0)
    {
        ERR_MSG("socket");
        return -1;
    }
    printf("socket success __%d__\n", __LINE__);
    struct sockaddr_in sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(PORT);
    sin.sin_addr.s_addr = inet_addr(GRP_IP);
    struct sockaddr_in rcvaddr;
    socklen_t addrlen = sizeof(rcvaddr);
    char buf[128] = "";
    ssize_t res = 0;
    while (1)
    {
        bzero(buf, sizeof(buf));
        printf("please puts>>>");
        fgets(buf, sizeof(buf), stdin);
        buf[strlen(buf) - 1] = 0;
        if (sendto(sfd, buf, sizeof(buf), 0, (struct sockaddr *)&sin, sizeof(sin)) < 0)
        {
            perror("sento");
            return -1;
        }
        printf("send succes\n");
        bzero(buf, sizeof(buf));

    }
    return 0;
}

include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define ERR_MSG(msg)                          \
    do                                        \
    {                                         \
        fprintf(stderr, "line:%d", __LINE__); \
        perror(msg);                          \
    } while (0)
#define IP "192.168.43.255"
#define GRP_IP "224.224.255.255"
#define PORT 6666
int main(int argc, const char *argv[])
{
    int sfd=socket(AF_INET,SOCK_DGRAM,0);
    if(sfd<0)
    {
        ERR_MSG("socket");
        return -1;
    }
    struct ip_mreqn mq;
    mq.imr_multiaddr.s_addr=inet_addr(GRP_IP);
    mq.imr_address.s_addr=inet_addr(IP);
    mq.imr_ifindex=2;
    	if(setsockopt(sfd,IPPROTO_IP,IP_ADD_MEMBERSHIP,&mq,sizeof(mq))<0)
	{
		perror("setsockopt");
		return -1;
	}
    printf("socket success __%d__\n",__LINE__);
    struct sockaddr_in sin;
    sin.sin_family =AF_INET;
    sin.sin_port=htons(PORT);
    sin.sin_addr.s_addr=inet_addr(IP);
    if (bind(sfd, (struct sockaddr *)&sin, sizeof(sin)) < 0)
    {
        ERR_MSG("bind");
        return -1;
    }
    printf("bind success __%d__\n",__LINE__);
    struct sockaddr_in cin;
    socklen_t addrlen=sizeof(cin);
    char buf[128]="";
    ssize_t res =0;
    while(1)
    {
        bzero(buf,sizeof(buf));
        res =recvfrom(sfd,buf,sizeof(buf),0,(struct sockaddr*)&cin,&addrlen);
        if(res<0)
        {
            perror("recvfrom");
            return -1;
        }
        printf("[%s : %d] sfd=%d %s __%d__\n",inet_ntoa(cin.sin_addr),ntohs(cin.sin_port),sfd,buf,__LINE__);
        strcat(buf,"*_*");

    }
    return 0;
}