Linux系统下UDP发送和接收广播消息

发送端源码：

// 发送端  
#include <iostream>  
#include <stdio.h>  
#include <sys/socket.h>  
#include <unistd.h>  
#include <sys/types.h>  
#include <netdb.h>  
#include <netinet/in.h>  
#include <arpa/inet.h>  
#include <string.h>  
 
 
using namespace std;  
 
int main()  
{  
    setvbuf(stdout, NULL, _IONBF, 0);   
    fflush(stdout);   
 
    int sock = -1;  
    if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1)   
    {     
        cout<<"socket error"<<endl;   
        return false;  
    }     
 
    const int opt = 1;  
    //设置该套接字为广播类型，  
    int nb = 0;  
    nb = setsockopt(sock, SOL_SOCKET, SO_BROADCAST, (char *)&opt, sizeof(opt));  
    if(nb == -1)  
    {  
        cout<<"set socket error..."<<endl;  
        return false;  
    }  
 
    struct sockaddr_in addrto;  
    bzero(&addrto, sizeof(struct sockaddr_in));  
    addrto.sin_family=AF_INET;  
    addrto.sin_addr.s_addr=htonl(INADDR_BROADCAST);  
    addrto.sin_port=htons(6000);  
    int nlen=sizeof(addrto);  
 
    while(1)  
    {  
        sleep(1);  
        //从广播地址发送消息  
        char smsg[] = {"abcdef"};  
        int ret=sendto(sock, smsg, strlen(smsg), 0, (sockaddr*)&addrto, nlen);  
        if(ret<0)  
        {  
            cout<<"send error...."<<ret<<endl;  
        }  
        else  
        {         
            printf("ok ");    
        }  
    }  
 
    return 0;  
}

接收端源码：

// 接收端
 
#include <iostream>  
#include <stdio.h>  
#include <sys/socket.h>  
#include <unistd.h>  
#include <sys/types.h>  
#include <netdb.h>  
#include <netinet/in.h>  
#include <arpa/inet.h>  
#include <string.h>  
 
 
using namespace std;  
 
int main()  
{  
    setvbuf(stdout, NULL, _IONBF, 0);   
    fflush(stdout);   
 
    // 绑定地址  
    struct sockaddr_in addrto;  
    bzero(&addrto, sizeof(struct sockaddr_in));  
    addrto.sin_family = AF_INET;  
    addrto.sin_addr.s_addr = htonl(INADDR_ANY);  
    addrto.sin_port = htons(6000);  
 
    // 广播地址  
    struct sockaddr_in from;  
    bzero(&from, sizeof(struct sockaddr_in));  
    from.sin_family = AF_INET;  
    from.sin_addr.s_addr = htonl(INADDR_ANY);  
    from.sin_port = htons(6000);  
 
    int sock = -1;  
    if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1)   
    {     
        cout<<"socket error"<<endl;   
        return false;  
    }     
 
    const int opt = 1;  
    //设置该套接字为广播类型，  
    int nb = 0;  
    nb = setsockopt(sock, SOL_SOCKET, SO_BROADCAST, (char *)&opt, sizeof(opt));  
    if(nb == -1)  
    {  
        cout<<"set socket error..."<<endl;  
        return false;  
    }  
 
    if(bind(sock,(struct sockaddr *)&(addrto), sizeof(struct sockaddr_in)) == -1)   
    {     
        cout<<"bind error..."<<endl;  
        return false;  
    }  
 
    int len = sizeof(sockaddr_in);  
    char smsg[100] = {0};  
 
    while(1)  
    {  
        //从广播地址接受消息  
        int ret=recvfrom(sock, smsg, 100, 0, (struct sockaddr*)&from,(socklen_t*)&len);  
        if(ret<=0)  
        {  
            cout<<"read error...."<<sock<<endl;  
        }  
        else  
        {         
            printf("%s\t", smsg);     
        }  
 
        sleep(1);  
    }  
 
    return 0;  
}

使用g++编译，接收端与发射端要在同一局域网段内。

转载于:https://my.oschina.net/lvsin/blog/383366

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